Ivan Cheng, MD

All Publications

• Does ACDF Utilization and Reimbursement Change Based on Certificate of Need Status? Clinical spine surgery Ziino, C., Bala, A., Cheng, I. 2019

  Abstract

  INTRODUCTION: Anterior cervical discectomy and fusion (ACDF) remain an effective treatment option for multiple pathologies of the cervical spine. As the health care economic climate has changed, so have reimbursements with a concomitant push toward outpatient procedures. Certificate of Need (CON) programs were established in response to burgeoning health care costs which require states to demonstrate need before expansion of medical facilities. The impact of this program on spine surgery is largely unknown. The purpose of this study was to examine the impact of CON status on reimbursement and utilization trends of ACDF in both inpatient and outpatient settings.MATERIALS AND METHODS: We queried a combined private payer and Medicare database from 2007 to 2015. All single-level ACDFs were identified. We then split each procedure into those performed in CON versus non-CON states. We then further split each group into the inpatient and outpatient settings. Compound annual growth rate (CAGR) was used to compare utilization and reimbursement trends. Reimbursement was adjusted for inflation using the United States Bureau of Labor Statistics consumer price index.RESULTS: A total of 32,727 single-level ACDFs were identified, of which 28,441 were performed in the inpatient setting, and 4286 were performed in the outpatient setting. Reimbursement decreased across all settings, with the most pronounced decrease in the non-CON outpatient setting with an adjusted CAGR of -11.0%. Utilization increased across all groups, although the fastest growth was seen in the outpatient CON setting with a CAGR of 47.7%, and the slowest growth seen in the inpatient non-CON setting at a CAGR of 12.9%.CONCLUSIONS: ACDF utilization increased most rapidly in the outpatient setting, and CON status did not appear to hinder growth. Reimbursement decreased across all settings, with the outpatient setting in non-CON states most affected. Surgeons should be aware of these trends in the changing health care environment.

  View details for DOI 10.1097/BSD.0000000000000914

  View details for PubMedID 31693517

• Single-Level In Vitro Kinematic Comparison of Novel Inline Cervical Interbody Devices With Intervertebral Screw, Anchor, or Blade. Global spine journal Arnold, P. M., Cheng, I., Harris, J. A., Hussain, M. M., Zhang, C., Karamian, B., Bucklen, B. S. 2019; 9 (7): 697?707

  Abstract

  Study Design: In vitro cadaveric biomechanical study.Objective: To compare the biomechanics of integrated anchor and blade versus traditional screw fixation techniques for interbody fusion.Methods: Fifteen cadaveric cervical spines were divided into 3 equal groups (n = 5). Each spine was tested: intact, after discectomy (simulating an injury model), interbody spacer alone (S), integrated interbody spacer (iSA), and integrated spacer with lateral mass screw and rod fixation (LMS+iS). Each treatment group included integrated spacers with either screw, anchor, or blade integrated spacers. Constructs were tested in flexion-extension (FE), lateral bending (LB), and axial rotation (AR) under pure moments (±1.5 Nm).Results: Across all 3 planes, the following range of motion trend was observed: Injured > Intact > S > iSA > LMS+iS. In FE and LB, integrated anchor and blade significantly decreased motion compared with intact and injured conditions, before and after supplemental posterior fixation (P < .05). Comparing tested devices revealed biomechanical equivalence between screw, anchor, and blade fixation methods in all loading modes (P > .05).Conclusion: All integrated interbody devices reduced intact and injured motion; lateral mass screws and rods further stabilized the single motion segment. Comparing screw, anchor, or bladed integrated anterior cervical discectomy and fusion spacers revealed no significant differences.

  View details for DOI 10.1177/2192568219833055

  View details for PubMedID 31552149

• Short-Term Outcomes of Staged Versus Same-Day Surgery for Adult Spinal Deformity Correction. Spine deformity Arzeno, A. H., Koltsov, J., Alamin, T. F., Cheng, I., Wood, K. B., Hu, S. S. 2019; 7 (5): 796

  Abstract

  STUDY DESIGN: Retrospective cohort study.OBJECTIVES: Assess differences between staged (?3 days) and same-day surgery in perioperative factors, radiographic measures, and complications.SUMMARY OF BACKGROUND DATA: Surgical adult spinal deformity correction may require combined anterior and posterior approaches. To modulate risk, some surgeons perform surgery that is expected to be longer and/or more complex in two stages. Prior studies comparing staged (?7 days) and same-day surgery demonstrated mixed results and none have examined results with shorter staging intervals.METHODS: Retrospective review of adults undergoing combined anterior/posterior approaches for spinal deformity over a 3-year period at a single institution (n=92). Univariate differences between staged and same-day surgery were assessed with chi-squared, Fisher exact, and Mann-Whitney U tests. Generalized estimating equations assessed whether differences in perioperative outcomes between groups remained after adjusting for differences in demographic and surgical characteristics.RESULTS: In univariate analyses, staged surgery was associated with a length of stay (LOS) 3 days longer than same-day surgery (9.2 vs. 6.3 days, p < .001), and greater operative time, blood loss, transfusion requirement, and days in intensive care unit (p < .001 for each). Staged surgery had a higher rate of thrombotic events (p = .011) but did not differ in readmission rates or other complications. Radiographically, improvements in Cobb angle (average 13° vs. 17°, p = .028), lumbar lordosis (average 14° vs. 23°, p = .019), and PI-LL mismatch (average 10° vs. 2° p = .018) were greater for staged surgery, likely related to more extensive use of osteotomies in the staged group. After risk adjustment, taking into account the procedural specifics including longer fusion constructs and greater number of osteotomies, LOS no longer differed between staged and same-day surgery; however, the total operative time was 98 minutes longer for staged surgery (p < .001). Differences in blood loss between groups was accounted for by differences in operative time and patient and surgical characteristics.CONCLUSIONS: Although univariate analysis of our results were in accordance with previously published works, multivariate analysis allowing individual case risk adjustment revealed that LOS was not significantly increased in the staged group as reported in previous studies. There was no difference in infection rates as previously described but an increase in thrombotic events was observed.LEVEL OF EVIDENCE: Level III.

  View details for DOI 10.1016/j.jspd.2018.12.008

  View details for PubMedID 31495481

• Grade II Spondylolisthesis: Reverse Bohlman Procedure with Trans-Discal S1-L5 and S2Ai Screws Placed with Robotic Guidance. World neurosurgery Ho, A. L., Varshneya, K., Medress, Z. A., Pendharkar, A. V., Sussman, E. S., Cheng, I., Veeravagu, A. 2019

  Abstract

  STUDY DESIGN: Technical Report with two illustrative cases.OBJECTIVE: Grade II spondylolisthesis remains a complex surgical pathology for which there is no consensus regarding optimal surgical strategies. Surgical strategies vary regarding extent of reduction, utilization of instrumentation/interbody support, and anterior versus posterior approaches with or without decompression. The objective of this study is to provide the first report on the efficacy of robotic spinal surgery systems in supporting the treatment of grade II spondylolisthesis.METHODS: Utilizing two illustrative cases, we provide a technical report of how a robotic spinal surgery platform can be utilized to treatment grade II spondylolisthesis with a novel instrumentation strategy.RESULTS: We describe how utilization of the "Reverse Bohlman" technique to achieve a large anterior fusion construct spanning the pathologic level and buttressed by the adjacent level above, coupled with a novel, high fidelity posterior fixation scheme with transdiscal S1-L5 and S2Ai screws placed in a minimally invasive fashion with robot guidance allows for the best chance of fusion in situ.CONCLUSIONS: The "Reverse Bohlman" technique coupled with transdiscal S1-L5 and S2Ai screw fixation accomplishes the surgical goals of creating a solid fusion construct, avoiding neurologic injury with aggressive reduction, and halting the progression of anterolisthesis. Utilization of robot guidance allows for efficient placement of these difficult screw trajectories in a minimally invasive fashion.

  View details for DOI 10.1016/j.wneu.2019.07.229

  View details for PubMedID 31398524

• Reliability of radiological measurements of type 2 odontoid fracture SPINE JOURNAL Karamian, B. A., Liu, N., Ajiboye, R. M., Cheng, I., Hu, S. S., Wood, K. B. 2019; 19 (8): 1324?30

  View details for DOI 10.1016/j.spinee.2019.04.020

  View details for Web of Science ID 000476725600004

• Analysis of single-position for revision surgery using lateral interbody fusion and pedicle screw fixation: feasibility and perioperative results. Journal of spine surgery (Hong Kong) Ziino, C., Arzeno, A., Cheng, I. 2019; 5 (2): 201?6

  Abstract

  Background: To analyze perioperative and radiographic outcomes following revision surgery using lateral lumbar interbody fusion (LLIF) performed entirely in the lateral position. Traditionally, patients undergoing interbody fusion in the lateral decubitus position are placed prone for pedicle screw fixation. However prone positioning carries known risks and may increase surgical time due to the need to re-drape and reposition. Little is published regarding revision surgery in a single position.Methods: Sixteen patients over the age of 18 with degenerative lumbar pathology who underwent a revision of previous lumbar fusion using interbody fusion via lateral access and revision of posterior instrumentation from a single surgeon met inclusion criteria. Patients who underwent combined procedures requiring repositioning or had inadequate preoperative imaging were excluded. Patients remained in the lateral decubitus position for the entirety of the procedure including interbody placement, revision of prior instrumentation, and pedicle screw fixation. Demographics, surgical details, and perioperative outcomes were reported.Results: The mean operative time was 211 minutes for all cases, 161 minutes for single-level procedures and 296 minutes for two-level procedures. Mean estimated blood loss was 206 cc. The mean patient age was 66, 70% of which were male. The mean body mass index (BMI) was 27.4 and Charleson Comorbidity Index (CCI) was 3. All cases were performed on the lumbar spine (T12/L1-L4/L5), with the majority of procedures performed at the L2/3 level (44%). The mean pelvic incidence (PI) was 60 degrees (range, 41-71 degrees) with mean preoperative PI/lumbar lordosis (LL) mismatch of 23.9 degrees. Mean postoperative PI/LL mismatch was 12 degrees.Conclusions: Revision surgery in the lateral position is feasible with complication rates comparable to published literature. The need to reposition is eliminated and single position surgery reduces operative time.

  View details for DOI 10.21037/jss.2019.05.09

  View details for PubMedID 31380473

• Decreased estimated blood loss in lateral trans-psoas versus anterior approach to lumbar interbody fusion for degenerative spondylolisthesis. Journal of spine surgery (Hong Kong) Goodnough, L. H., Koltsov, J., Wang, T., Xiong, G., Nathan, K., Cheng, I. 2019; 5 (2): 185?93

  Abstract

  Background: The goal of the current study was to compare the perioperative and post-operative outcomes of eXtreme lateral trans-psoas approach (XLIF) versus anterior lumbar interbody fusion (ALIF) for single level degenerative spondylolisthesis. The ideal approach for degenerative spondylolisthesis remains controversial.Methods: Consecutive patients undergoing single level XLIF (n=21) or ALIF (n=54) for L4-5 degenerative spondylolisthesis between 2008-2012 from a single academic center were retrospectively reviewed. Groups were compared for peri-operative data (estimated blood loss, operative time, adjunct procedures or additional implants), radiographic measurements (L1-S1 cobb angle, disc height, fusion grade, subsidence), 30-day complications (infection, DVT/PE, weakness/paresthesia, etc.), and patient reported outcomes (leg and back Numerical Rating Scale, and Oswestry Disability Index).Results: Estimated blood loss was significantly lower for XLIF [median 100; interquartile range (IQR), 50-100 mL] than for ALIF (median 250; IQR, 150-400 mL; P<0.001), including after adjusting for significantly higher rates of posterior decompression in the ALIF group. There were no significant differences in rates of complications within 30 days, radiographic outcomes, or in re-operation rates. Both groups experienced significant pain relief post-operatively.Conclusions: The lateral trans-psoas approach is associated with diminished blood loss compared to the anterior approach in the treatment of degenerative spondylolisthesis. We were unable to detect differences in radiographic outcomes, complication rates, or patient reported outcomes. Continued efforts to directly compare approaches for specific indications will minimize complications and improve outcomes. Further studies will continue to define indications for lateral versus anterior approach to lumbar spine for degenerative spondylolisthesis.

  View details for DOI 10.21037/jss.2019.05.08

  View details for PubMedID 31380471

• Reliability of Radiological Measurements of Type-2 Odontoid Fracture. The spine journal : official journal of the North American Spine Society Karamian, B. A., Liu, N., Ajiboye, R. M., Cheng, I., Hu, S. S., Wood, K. B. 2019

  Abstract

  It is recognized that radiological parameters of type 2 dens fractures, including displacement and angulation, are predictive of treatment outcomes and are used to guide surgical decision-making. The reproducibility of such measurements, therefore, is of critical importance. Past literature has shown poor inter-observer reliability for both displacement and angulation measurements of type 2 dens fractures. Since such studies however, various advancements of radiological review systems and measurement tools have evolved to potentially improve such measurements.To re-examine the interrater reliability of measuring displacement and angulation of type 2 dens fractures utilizing modern radiologic review systems. Besides quantitative measurements, the reliability of raters in identifying diagnostic classifications based on translational and angulational displacement was also examined.Radiographic measurement reliability and agreement study.Thirty-seven patients seen at a single institution between 2002 and 2017 with primary diagnosis of acute type II dens fracture with complete CT imaging.Radiological measurements included displacement and angulation. Diagnostic classifications based on consensus-based clinical cut-off points were also recorded.Measurements were performed by five surgeons with varying years of experience in spine surgery using the hospital's electronic medical record radiological measuring tools. The radiological measurements included displacement and angulation. Diagnostic classifications based on consensus-based clinical cut-off points were also recorded. Each rater received a graphic demonstration of the measurement methods, but had the autonomy to select a best cut from the sagittal CT to measure. All raters were blinded to patient information.Measurements for displacement and angulation among the five raters demonstrated "excellent" reliability. Intra-rater reliability was also "excellent" in measuring displacement and angulation. The reliability of diagnostic classification of displacement (above vs. below 5mm), was found to be "very good" among the raters. The reliability of diagnostic classification of angulation (above vs. below 11°) demonstrated "good" reliability.Advancement of radiological review systems, including review tools and embedded image processing software, has facilitated more reliable measurements for type-2 odontoid fractures.

  View details for PubMedID 31078698

• Patient Preferences for Shared Decision Making: Not All Decisions Should Be Shared. The Journal of the American Academy of Orthopaedic Surgeons E Lindsay, S., Alokozai, A., Eppler, S. L., Fox, P., Curtin, C., Gardner, M., Avedian, R., Palanca, A., Abrams, G. D., Cheng, I., Kamal, R. N. 2019

  Abstract

  To assess bounds of shared decision making in orthopaedic surgery, we conducted an exploratory study to examine the extent to which patients want to be involved in decision making in the management of a musculoskeletal condition.One hundred fifteen patients at an orthopaedic surgery clinic were asked to rate preferred level of involvement in 25 common theoretical clinical decisions (passive [0], semipassive [1 to 4], equally shared involvement between patient and surgeon [5], semiactive [6 to 9], active [10]).Patients preferred semipassive roles in 92% of decisions assessed. Patients wanted to be most involved in scheduling surgical treatments (4.75 ± 2.65) and least involved in determining incision sizes (1.13 ± 1.98). No difference exists in desired decision-making responsibility between patients who had undergone orthopaedic surgery previously and those who had not. Younger and educated patients preferred more decision-making responsibility. Those with Medicare desired more passive roles.Despite the importance of shared decision making on delivering patient-centered care, our results suggest that patients do not prefer to share all decisions.

  View details for DOI 10.5435/JAAOS-D-19-00146

  View details for PubMedID 31567900

• The Relationship Between Lumbar Lateral Listhesis and Radiculopathy in Adult Scoliosis. Spine Kleimeyer, J. P., Liu, N., Hu, S. S., Cheng, I., Alamin, T., Grottkau, B. E., Kukreja, S., Wood, K. B. 2019; 44 (14): 1003?9

  Abstract

  Retrospective review and prospective validation study.To develop a classification system of lumbar lateral listhesis that suggests different likelihoods of having radiculopathy in adult scoliosis.The association of lumbar lateral listhesis with radiculopathy remains uncertain.A retrospective cohort of patients with adult scoliosis enrolled from 2011 to 2015 was studied to develop a classification system of lateral listhesis that can stratify the likelihood of having radiculopathy. Four radiological aspects of lateral listhesis, including Nash and Moe vertebral rotation, L4-L5 lateral listhesis, the number of consecutive listheses, and the presence of a contralateral lateral listhesis at the thoracolumbar junction above a caudal listhesis, were evaluated on radiographs. Their associations with the presence of radicular leg pain were evaluated using multivariable logistic regression. The classification system of lateral listhesis was thus developed using the most influential radiological factors and then validated in a prospective cohort from 2016 to 2017.The retrospective cohort included 189 patients. Vertebral rotation is more than or equal to grade 2 (odds ratio [OR]?=?9.45, 95% confidence interval [CI]: 4.07-25.14) and L4-5 listhesis (OR?=?4.56, 95%CI: 1.85-12.35) were the two most influential listhesis factors associated with radiculopathy. The classification system of lateral listhesis was thus built based on the combinations of their respective presence: Type 0, 1, 2, 3 were defined as not having listhesis at all, none of the two factors present, one of the two presents, and both present, respectively. This classification significantly stratified the probability of radiculopathy, in both the retrospective cohort (0%, 6.4%, 33.8%, and 68.4% in Type 0, 1, 2, and 3, respectively; P?

  View details for DOI 10.1097/BRS.0000000000002986

  View details for PubMedID 30664100

• The Effects of Varenicline on Lumbar Spinal Fusion in a Rat Model. The spine journal : official journal of the North American Spine Society Kang, J., Glaeser, J. D., Karamian, B., Kanim, L., NaPier, Z., Koltsov, J., Thio, T., Salehi, K., Bae, H. W., Cheng, I. 2019

  Abstract

  Smoking is detrimental to obtaining a solid spinal fusion mass with previous studies demonstrating its association with pseudoarthrosis in patients undergoing spinal fusion. Varenicline is a pharmacologic adjunct used in smoking cessation which acts as a partial agonist of the same nicotinic receptors activated during tobacco use. However, no clinical or basic science studies to date have characterized if varenicline has negative effects on spinal fusion and bone healing by itself.Our study aim was to elucidate whether varenicline affects the frequency or quality of posterolateral spinal fusion in a rodent model at an endpoint of 12 weeks.Randomized control trial PATIENT SAMPLE: 14 male Lewis rats randomly separated into two experimental groups OUTCOME MEASURES: Manual palpation of fusion segment, radiography, ?CT imaging, 4-point bend.Fourteen male Lewis rats were randomly separated into two experimental groups undergoing L4-5 posterior spinal fusion procedure followed by daily subcutaneous injections of human dose varenicline or saline (control) for 12 weeks post-surgery. Spine samples were explanted, and fusion was determined via manual palpation of segments by two independent observers. High-resolution radiographs were obtained to evaluate bridging fusion mass. ?CT imaging was performed to characterize fusion mass and consolidation. Lumbar spinal fusion units were tested in 4-point bending to evaluate stiffness and peak load. Study funding sources include $5000 OREF Grant. There were no applicable financial relationships or conflicts of interest.At three months post-surgery, 12 out of 14 rats demonstrated lumbar spine fusion (86% fused) with no difference in fusion frequency between the varenicline and control groups as detected by manual palpation. High resolution radiography revealed six out of seven rats (86%) having complete fusion in both groups. ?CT showed no significant difference in bone mineral density or bone fraction volume between groups in the region of interest. Biomechanical testing demonstrated no significant different in the average stiffness or peak loads at the fusion site of the varenicline and control groups.Based on the results of our rat study, there is no indication that varenicline itself has a detrimental effect on the frequency and quality of spinal fusion.

  View details for DOI 10.1016/j.spinee.2019.07.015

  View details for PubMedID 31377475

• Single position versus lateral-then-prone positioning for lateral interbody fusion and pedicle screw fixation. Journal of spine surgery (Hong Kong) Ziino, C., Konopka, J. A., Ajiboye, R. M., Ledesma, J. B., Koltsov, J. C., Cheng, I. 2018; 4 (4): 717?24

  Abstract

  Background: To compare perioperative and radiographic outcomes following lateral lumbar interbody fusions in two cohorts of patients who either underwent single position or dual position surgery.Methods: Patients over the age of 18 with degenerative lumbar pathology who underwent a lumbar interbody fusion via lateral access from 2012-2015 from a single surgeon met inclusion criteria. Patients who underwent combined procedures, had a history of retroperitoneal surgery, or had inadequate preoperative imaging were excluded. Patients who remained in the lateral decubitus position for pedicle screw fixation [single-position (SP)] were compared to those turned prone [dual-position (DP)]. Demographics, surgical details, and perioperative outcomes were compared between groups.Results: A total of 42 SP and 24 DP patients were analyzed. The DP group had a 44.4-minute longer operating room time compared to the SP group (P<0.001) after adjusting for the number of levels operated (P<0.001) and unilateral versus bilateral screw placement (P=0.048). Otherwise, no differences were observed in peri-operative outcomes. Lordosis was not different between groups pre-operatively (P>0.999) or post-operatively (P=0.479), and neither was the pre- to post-operative change (P=0.283).Conclusions: Lateral pedicle screw fixation following lateral interbody fusion decreases operating room time without compromising post-operative lordosis, complication rates, or perioperative outcomes.

  View details for PubMedID 30714003

• Selective Anterior Lumbar Interbody Fusion for Low Back Pain Associated With Degenerative Disc Disease Versus Nonsurgical Management SPINE Kleimeyer, J. P., Cheng, I., Alamin, T. F., Hu, S. S., Cha, T., Yanamadala, V., Wood, K. B. 2018; 43 (19): 1372?80

  Abstract

  This is a retrospective cohort study.To evaluate the long-term outcomes of selective one- to two-level anterior lumbar interbody fusions (ALIFs) in the lower lumbar spine versus continued nonsurgical management.Low back pain associated with lumbar intervertebral disc degeneration is common with substantial economic impact, yet treatment remains controversial. Surgical fusion has previously provided mixed results with limited durable improvement of pain and function.Seventy-five patients with one or two levels of symptomatic Pfirrmann grades 3 to 5 disc degeneration from L3-S1 were identified. All patients had failed at least 6 months of nonsurgical treatment. Forty-two patients underwent one- or two-level ALIFs; 33 continued multimodal nonsurgical care. Patients were evaluated radiographically and the visual analog pain scale (VAS), Oswestry Disability Index (ODI), EuroQol five dimensions (EQ-5D), and Patient-Reported Outcomes Measurement Information System scores for pain interference, pain intensity, and anxiety. As-treated analysis was performed to evaluate outcomes at a mean follow-up of 7.4 years (range: 2.5-12).There were no differences in pretreatment demographics or nonsurgical therapy utilization between study arms. At final follow-up, the surgical arm demonstrated lower VAS, ODI, EQ-5D, and Patient-Reported Outcomes Measurement Information System pain intensity scores versus the nonsurgical arm. VAS and ODI scores improved 52.3% and 51.1% in the surgical arm, respectively, versus 15.8% and -0.8% in the nonsurgical arm. Single-level fusions demonstrated improved outcomes versus two-level fusions. The pseudarthrosis rate was 6.5%, with one patient undergoing reoperation. Asymptomatic adjacent segment degeneration was identified in 11.9% of patients.Selective ALIF limited to one or two levels in the lower lumbar spine provided improved pain and function when compared with continued nonsurgical care. ALIF may be a safe and effective treatment for low back pain associated with disc degeneration in select patients who fail nonsurgical management.3.

  View details for PubMedID 29529003

• Lumbar Epidural Steroid Injections for Herniation and Stenosis: Incidence and Risk Factors of Subsequent Surgery. The spine journal : official journal of the North American Spine Society Koltsov, J. C., Smuck, M. W., Zagel, A., Alamin, T. F., Wood, K. B., Cheng, I., Hu, S. S. 2018

  Abstract

  BACKGROUND CONTEXT: Lumbosacral ESIs have increased dramatically despite a narrowing of the clinical indications for use. One potential indication is to avoid or delay surgery, yet little information exists regarding surgery rates after ESI.PURPOSE: The purpose of this research was to determine the proportion of patients having surgery after lumbar epidural steroid injection (ESI) for disc herniation or stenosis and to identify the timing and factors associated with this progression STUDY DESIGN/SETTING: This study was a retrospective review of nationally-representative administrative claims data from the Truven Health MarketScan databases from 2007 - 2014.PATIENT SAMPLE: The study cohort was comprised of 179,025 patients (54±15 years, 48% female) having lumbar epidural steroid injections (ESIs) for diagnoses of stenosis and/or herniation.OUTCOME MEASURES: The primary outcome measure was the time from ESI to surgery.METHODS: Inclusion criteria were ESI for stenosis and/or herniation, age ?18 years, and health plan enrollment for 1 year prior to ESI to screen for exclusions. Patients were followed longitudinally until they progressed to surgery or had a lapse in enrollment, at which time they were censored. Rates of surgery were assessed with the Kaplan-Meier survival curves. Demographic and treatment factors associated with surgery were assessed with multivariable Cox proportional hazard models. No external funding was procured for this research and the authors' conflicts of interest are not pertinent to the present work.RESULTS: Within 6 months, 12.5% of ESI patients underwent lumbar surgery. By 1 year, 16.9% had surgery, and by 5 years, 26.1% had surgery. Patients with herniation had surgery at rates of up to 5 to 7 fold higher, with the highest rates of surgery in younger patients and those with both herniation and stenosis. Other concomitant spine diagnoses, male sex, previous tobacco use, and residence a rural areas or regions other than the Northeastern United States were associated with higher surgery rates. Medical comorbidities (previous treatment for drug use, CHF, obesity, COPD, hypercholesterolemia, and other cardiac complications) were associated with lower surgery rates.CONCLUSIONS: In the long-term, more than 1 out of every 4 patients undergoing ESI for lumbar herniation or stenosis subsequently had surgery, and nearly 1 of 6 had surgery within the first year. After adjusting for other patient demographics and comorbidities, patients with herniation were more likely have surgery than those with stenosis. The improved understanding of the progression from lumbar ESI to surgery will help to better inform discussions regarding the value of ESI and aid in the shared decision making process.

  View details for PubMedID 29959098

• Frequency and Acceptability of Adverse Events After Anterior Cervical Discectomy and Fusion A Survey Study From the Cervical Spine Research Society CLINICAL SPINE SURGERY Wilson, J. R., Radcliff, K., Schroeder, G., Booth, M., Lucasti, C., Fehlings, M., Ahmad, N., Vaccaro, A., Arnold, P., Sciubba, D., Ching, A., Smith, J., Shaffrey, C., Singh, K., Darden, B., Daffner, S., Cheng, I., Ghogawala, Z., Ludwig, S., Buchowski, J., Brodke, D., Wang, J., Lehman, R. A., Hilibrand, A., Yoon, T., Grauer, J., Dailey, A., Steinmetz, M., Harrop, J. S. 2018; 31 (5): E270?E277

  Abstract

  Anterior cervical discectomy and fusion has a low but well-established profile of adverse events. The goal of this study was to gauge surgeon opinion regarding the frequency and acceptability of these events.A 2-page survey was distributed to attendees at the 2015 Cervical Spine Research Society (CSRS) meeting. Respondents were asked to categorize 18 anterior cervical discectomy and fusion-related adverse events as either: "common and acceptable," "uncommon and acceptable," "uncommon and sometimes acceptable," or "uncommon and unacceptable." Results were compiled to generate the relative frequency of these responses for each complication. Responses for each complication event were also compared between respondents based on practice location (US vs. non-US), primary specialty (orthopedics vs. neurosurgery) and years in practice.Of 150 surveys distributed, 115 responses were received (76.7% response rate), with the majority of respondents found to be US-based (71.3%) orthopedic surgeons (82.6%). Wrong level surgery, esophageal injury, retained drain, and spinal cord injury were considered by most to be unacceptable and uncommon complications. Dysphagia and adjacent segment disease occurred most often, but were deemed acceptable complications. Although surgeon experience and primary specialty had little impact on responses, practice location was found to significantly influence responses for 12 of 18 complications, with non-US surgeons found to categorize events more toward the uncommon and unacceptable end of the spectrum as compared with US surgeons.These results serve to aid communication and transparency within the field of spine surgery, and will help to inform future quality improvement and best practice initiatives.

  View details for PubMedID 29708891

• Neurologic adverse event avoidance in lateral lumbar interbody fusion: technical considerations using muscle relaxants. Journal of spine surgery (Hong Kong) Fogel, G. R., Rosen, L., Koltsov, J. C., Cheng, I. 2018; 4 (2): 247?53

  Abstract

  The retroperitoneal trans-psoas extreme lateral interbody fusion (XLIF) technique has improved over the last decade with increased efficiency and an emphasis on complication avoidance. After all known procedural safeguards are enacted, the most common failure of neuro-monitoring precision may be the use of non-depolarizing muscle relaxants (MR) for induction that is standard of care for anesthesia. Even when non-depolarizing MRs are minimized there is often a small dose given to decrease risk of vocal cord injury with intubation. The most common neurological adverse events (AE) attendant to the lateral approach are thigh dysesthetic pain and hip flexor weakness. The purpose of this study is to present a consecutive series of L3-4 and L4-5 XLIF patients treated by a single surgeon using all procedural safeguards with and without the use of a low dose of non-depolarizing MRs prior to intubation.A retrospective review of 74 consecutive patients treated at 150 levels with XLIF and no muscle relaxants (NMR) were compared to a group of 124 consecutive XLIF patients treated at 238 levels with MR. The surgeon upon discovering a small dose of rocuronium was used for intubation, questioned the effect on the neuromonitoring and NMR group was begun. All procedural technique details remained the same. All patients had XLIF at L3-4, L4-5, or both levels. Perioperative variables were collected, including evoked and free-run EMG readings and postoperative neural and muscular side effects. Hospital records including progress notes describing postoperative symptoms and anesthesia records describing the drugs, dosages, and timing were studied. Clinical records were reviewed at 1, 3 and 6 months for complaints of neurologic AE.NMR patients had a perfect twitch test (>99%) immediately. MR patients had slower arrival of the twitch and often settled at a lower level (80-92%). No surgery was attempted until the twitch test was at least 80%. NMR had 8/74 (10.8%) and MR 36/125 (28.8%) thigh AE (thigh dysthetic pain) at 1 month (P<0.005). No lower extremity weaknesses (femoral nerve injury) were observed in the NMR group and three in the MR group. All NMR thigh AEs resolved by the third month postoperative visit compared with 17/125 at 3 months (P=0.001) and 6/125 at 6 months (P=0.176) with persistent thigh AEs in the MR group.Eliminating MRs altogether appears to have allowed the evoked and free running EMG to be more reliable and accurate in predicting the proximity of the neurologic structures. Thigh AEs related to neural and muscular integrity in NMR patients were limited and eliminated by the 3rd month. The MR group was significantly more likely to have a thigh AE at 1 month and persistent at 3 months. Neurologic AEs may be limited or eliminated when MRs are avoided in lateral lumbar fusion surgery.

  View details for PubMedID 30069514

  View details for PubMedCentralID PMC6046327

• Does timing of transplantation of neural stem cells following spinal cord injury affect outcomes in an animal model? Journal of spine surgery (Hong Kong) Cheng, I., Park, D. Y., Mayle, R. E., Githens, M., Smith, R. L., Park, H. Y., Hu, S. S., Alamin, T. F., Wood, K. B., Kharazi, A. I. 2017; 3 (4): 567?71

  Abstract

  Background: We previously reported that functional recovery of rats with spinal cord contusions can occur after acute transplantation of neural stem cells distal to the site of injury. To investigate the effects of timing of administration of human neural stem cell (hNSC) distal to the site of spinal cord injury on functional outcomes in an animal model.Methods: Thirty-six adult female Long-Evans hooded rats were randomized into three experimental and three control groups with six animals in each group. The T10 level was exposed via posterior laminectomy, and a moderate spinal cord contusion was induced by the Multicenter Animal Spinal Cord Injury Study Impactor (MASCIS, W.M. Keck Center for Collaborative Neuroscience, Piscataway, NJ, USA). The animals received either an intrathecal injection of hNSCs or control media through a separate distal laminotomy immediately, one week or four weeks after the induced spinal cord injury. Observers were blinded to the interventions. Functional assessment was measured immediately after injury and weekly using the Basso, Beattie, Bresnahan (BBB) locomotor rating score.Results: A statistically significant functional improvement was seen in all three time groups when compared to their controls (acute, mean 9.2 vs. 4.5, P=0.016; subacute, mean 11.1 vs. 6.8, P=0.042; chronic, mean 11.3 vs. 5.8, P=0.035). Although there was no significant difference in the final BBB scores comparing the groups that received hNSCs, the group which achieved the greatest improvement from the time of cell injection was the subacute group (+10.3) and was significantly greater than the chronic group (+5.1, P=0.02).Conclusions: The distal intrathecal transplantation of hNSCs into the contused spinal cord of a rat led to significant functional recovery of the spinal cord when injected in the acute, subacute and chronic phases of spinal cord injury (SCI), although the greatest gains appeared to be in the subacute timing group.

  View details for PubMedID 29354733

• Ribosomal PCR assay of excised intervertebral discs from patients undergoing single-level primary lumbar microdiscectomy. European spine journal Alamin, T. F., Munoz, M., Zagel, A., Ith, A., Carragee, E., Cheng, I., Scuderi, G., Budvytiene, I., Banei, N. 2017

  Abstract

  To determine the presence of infectious microorganisms in the herniated discs of immunocompetent patients, using methodology that we hoped would be of higher sensitivity and specificity than has been reported in the past. Recent studies have demonstrated a significant rate of positive cultures for low virulent organisms in excised HNP samples (range 19-53%). These studies have served as the theoretical basis for a pilot trial, and then, a well done prospective randomized trial that demonstrated that systemic treatment with antibiotics may yield lasting improvements in a subset of patients with axial back pain. Whether the reported positive cultures in discectomy specimens represent true positives is as yet not proven, and critically important if underlying the basis of therapeutic approaches for chronic low back pain.This consecutive case series from a single academic center included 44 patients with radiculopathy and MRI findings of lumbar HNP. Patients elected for lumbar microdiscectomy after failure of conservative management. All patients received primary surgery at a single spinal level in the absence of immune compromise. Excised disc material was analyzed with a real-time PCR assay targeting the 16S ribosomal RNA gene followed by amplicon sequencing. No concurrent cultures were performed. Inclusion criteria were as follows: sensory or motor symptoms in a single lumbar nerve distribution; positive physical examination findings including positive straight leg raise test, distributional weakness, and/or a diminished deep tendon reflexes; and magnetic resonance imaging of the lumbar spine positive for HNP in a distribution correlating with the radicular complaint.The PCR assay for the 16S rRNA sequence was negative in all 44 patients (100%). 95% CI 0-8%.Based on the data presented here, there does not appear to be a significant underlying rate of bacterial disc infection in immunocompetent patients presenting with radiculopathy from disc herniation.

  View details for DOI 10.1007/s00586-017-5141-4

  View details for PubMedID 28567591

• Predicting complication risk in spine surgery: a prospective analysis of a novel risk assessment tool. Journal of neurosurgery. Spine Veeravagu, A., Li, A., Swinney, C., Tian, L., Moraff, A., Azad, T. D., Cheng, I., Alamin, T., Hu, S. S., Anderson, R. L., Shuer, L., Desai, A., Park, J., Olshen, R. A., Ratliff, J. K. 2017: 1-11

  Abstract

  OBJECTIVE The ability to assess the risk of adverse events based on known patient factors and comorbidities would provide more effective preoperative risk stratification. Present risk assessment in spine surgery is limited. An adverse event prediction tool was developed to predict the risk of complications after spine surgery and tested on a prospective patient cohort. METHODS The spinal Risk Assessment Tool (RAT), a novel instrument for the assessment of risk for patients undergoing spine surgery that was developed based on an administrative claims database, was prospectively applied to 246 patients undergoing 257 spinal procedures over a 3-month period. Prospectively collected data were used to compare the RAT to the Charlson Comorbidity Index (CCI) and the American College of Surgeons National Surgery Quality Improvement Program (ACS NSQIP) Surgical Risk Calculator. Study end point was occurrence and type of complication after spine surgery. RESULTS The authors identified 69 patients (73 procedures) who experienced a complication over the prospective study period. Cardiac complications were most common (10.2%). Receiver operating characteristic (ROC) curves were calculated to compare complication outcomes using the different assessment tools. Area under the curve (AUC) analysis showed comparable predictive accuracy between the RAT and the ACS NSQIP calculator (0.670 [95% CI 0.60-0.74] in RAT, 0.669 [95% CI 0.60-0.74] in NSQIP). The CCI was not accurate in predicting complication occurrence (0.55 [95% CI 0.48-0.62]). The RAT produced mean probabilities of 34.6% for patients who had a complication and 24% for patients who did not (p = 0.0003). The generated predicted values were stratified into low, medium, and high rates. For the RAT, the predicted complication rate was 10.1% in the low-risk group (observed rate 12.8%), 21.9% in the medium-risk group (observed 31.8%), and 49.7% in the high-risk group (observed 41.2%). The ACS NSQIP calculator consistently produced complication predictions that underestimated complication occurrence: 3.4% in the low-risk group (observed 12.6%), 5.9% in the medium-risk group (observed 34.5%), and 12.5% in the high-risk group (observed 38.8%). The RAT was more accurate than the ACS NSQIP calculator (p = 0.0018). CONCLUSIONS While the RAT and ACS NSQIP calculator were both able to identify patients more likely to experience complications following spine surgery, both have substantial room for improvement. Risk stratification is feasible in spine surgery procedures; currently used measures have low accuracy.

  View details for DOI 10.3171/2016.12.SPINE16969

  View details for PubMedID 28430052

• Intervertebral disc/bone marrow cross-talk with Modic changes. European spine journal Dudli, S., Sing, D. C., Hu, S. S., Berven, S. H., Burch, S., Deviren, V., Cheng, I., Tay, B. K., Alamin, T. F., Ith, M. A., Pietras, E. M., Lotz, J. C. 2017

  Abstract

  Cross-sectional cohort analysis of patients with Modic Changes (MC).Our goal was to characterize the molecular and cellular features of MC bone marrow and adjacent discs. We hypothesized that MC associate with biologic cross-talk between discs and bone marrow, the presence of which may have both diagnostic and therapeutic implications.MC are vertebral bone marrow lesions that can be a diagnostic indicator for discogenic low back pain. Yet, the pathobiology of MC is largely unknown.Patients with Modic type 1 or 2 changes (MC1, MC2) undergoing at least 2-level lumbar interbody fusion with one surgical level having MC and one without MC (control level). Two discs (MC, control) and two bone marrow aspirates (MC, control) were collected per patient. Marrow cellularity was analyzed using flow cytometry. Myelopoietic differentiation potential of bone marrow cells was quantified to gauge marrow function, as was the relative gene expression profiles of the marrow and disc cells. Disc/bone marrow cross-talk was assessed by comparing MC disc/bone marrow features relative to unaffected levels.Thirteen MC1 and eleven MC2 patients were included. We observed pro-osteoclastic changes in MC2 discs, an inflammatory dysmyelopoiesis with fibrogenic changes in MC1 and MC2 marrow, and up-regulation of neurotrophic receptors in MC1 and MC2 bone marrow and discs.Our data reveal a fibrogenic and pro-inflammatory cross-talk between MC bone marrow and adjacent discs. This provides insight into the pain generator at MC levels and informs novel therapeutic targets for treatment of MC-associated LBP.

  View details for DOI 10.1007/s00586-017-4955-4

  View details for PubMedID 28138783

  View details for PubMedCentralID PMC5409869

• 18F-FDG PET/MRI in Chronic Sciatica: Early Results Revealing Spinal and Non-spinal Abnormalities. Journal of nuclear medicine : official publication, Society of Nuclear Medicine Cipriano, P., Yoon, D., Gandhi, H., Holley, D., Thakur, D., Ith, M., Hargreaves, B., Kennedy, D., Smuck, M., Cheng, I., Biswal, S. 2017

  Abstract

  Chronic sciatica is a major cause of disability worldwide, but accurate diagnosis of the offending pathology remains challenging. In this report, the feasibility of a fluorodeoxyglucose (18F-FDG) positron emission tomography/magnetic resonance imaging (PET/MRI) approach for improved diagnosis of chronic sciatica is presented. Methods:18F-FDG PET/MRI was performed on 9 chronic sciatica patients and 5 healthy volunteers. Region-of-interest analysis using maximum standardized uptake values (SUVmax) was performed, and 18F-FDG uptake in lesions was compared with the corresponding areas in healthy controls. Results: Significantly increased 18F-FDG uptake was observed in detected lesions of all patients, which was correlated with pain symptoms. 18F-FDG-avid lesions were not only found in impinged spinal nerves, but were also associated with non-spinal causes, such as a facet joint degeneration, pars defect, or a presumed scar neuroma. Conclusion: The feasibility of 18F-FDG PET/MRI for diagnosing pain generators in chronic sciatica has been demonstrated, revealing various possible etiologies.

  View details for PubMedID 29097408

• A Biomechanical Comparison of Shape Design and Positioning of Transforaminal Lumbar Interbody Fusion Cages. Global spine journal Comer, G. C., Behn, A., Ravi, S., Cheng, I. 2016; 6 (5): 432-438

  Abstract

  Cadaveric biomechanical analysis.The aim of this study was to compare three interbody cage shapes and their position within the interbody space with regards to construct stability for transforaminal lumbar interbody fusion.Twenty L2-L3 and L4-L5 lumbar motion segments from fresh cadavers were potted in polymethyl methacrylate and subjected to testing with a materials testing machine before and after unilateral facetectomy, diskectomy, and interbody cage insertion. The three cage types were kidney-shaped, articulated, and straight bullet-shaped. Each cage type was placed in a common anatomic area within the interbody space before testing: kidney, center; kidney, anterior; articulated, center; articulated, anterior; bullet, center; bullet, lateral. Load-deformation curves were generated for axial compression, flexion, extension, right bending, left bending, right torsion, and left torsion. Finally, load to failure was tested.For all applied loads, there was a statistically significant decrease in the slope of the load-displacement curves for instrumented specimens compared with the intact state (p?

  View details for DOI 10.1055/s-0035-1564568

  View details for PubMedID 27433426

  View details for PubMedCentralID PMC4947403

• Local versus distal transplantation of human neural stem cells following chronic spinal cord injury SPINE JOURNAL Cheng, I., Githens, M., Smith, R. L., Johnston, T. R., Park, D. Y., Stauff, M. P., Salari, N., Tileston, K. R., Kharazi, A. I. 2016; 16 (6): 764-769

  Abstract

  Previous studies have demonstrated functional recovery of rats with spinal cord contusions after transplantation of neural stem cells adjacent to the site of acute injury.The purpose of the study was to determine if the local or distal injection of neural stem cells can cause functional difference in recovery after chronic spinal cord injury.Twenty-four adult female Long-Evans hooded rats were randomized into four groups, with six animals in each group: two experimental and two control groups. Functional assessment was measured after injury and then weekly for 6 weeks using the Basso, Beattie, and Bresnahan locomotor rating score. Data were analyzed using two-sample t test and linear mixed-effects model analysis.Posterior exposure and laminectomy at the T10 level was used. Moderate spinal cord contusion was induced by the Multicenter Animal Spinal Cord Injury Study Impactor with 10-g weight dropped from a height of 25?mm. Experimental subjects received either a subdural injection of human neural stem cells (hNSCs) locally at the injury site or intrathecal injection of hNSCs through a separate distal laminotomy 4 weeks after injury. Controls received control media injection either locally or distally.A statistically significant functional improvement in subjects that received hNSCs injected distally to the site of injury was observed when compared with the control (p=.042). The difference between subjects that received hNSCs locally and the control did not reach statistical significance (p=.085).The transplantation of hNSCs into the contused spinal cord of a rat led to significant functional recovery of the spinal cord when injected distally but not locally to the site of chronic spinal cord injury.

  View details for DOI 10.1016/j.spinee.2015.12.007

  View details for Web of Science ID 000378201100035

  View details for PubMedID 26698654

• Predicting Occurrence of Spine Surgery Complications Using "Big Data" Modeling of an Administrative Claims Database JOURNAL OF BONE AND JOINT SURGERY-AMERICAN VOLUME Ratliff, J. K., Balise, R., Veeravagu, A., Cole, T. S., Cheng, I., Olshen, R. A., Tian, L. 2016; 98 (10): 824-834

  Abstract

  Postoperative metrics are increasingly important in determining standards of quality for physicians and hospitals. Although complications following spinal surgery have been described, procedural and patient variables have yet to be incorporated into a predictive model of adverse-event occurrence. We sought to develop a predictive model of complication occurrence after spine surgery.We used longitudinal prospective data from a national claims database and developed a predictive model incorporating complication type and frequency of occurrence following spine surgery procedures. We structured our model to assess the impact of features such as preoperative diagnosis, patient comorbidities, location in the spine, anterior versus posterior approach, whether fusion had been performed, whether instrumentation had been used, number of levels, and use of bone morphogenetic protein (BMP). We assessed a variety of adverse events. Prediction models were built using logistic regression with additive main effects and logistic regression with main effects as well as all 2 and 3-factor interactions. Least absolute shrinkage and selection operator (LASSO) regularization was used to select features. Competing approaches included boosted additive trees and the classification and regression trees (CART) algorithm. The final prediction performance was evaluated by estimating the area under a receiver operating characteristic curve (AUC) as predictions were applied to independent validation data and compared with the Charlson comorbidity score.The model was developed from 279,135 records of patients with a minimum duration of follow-up of 30 days. Preliminary assessment showed an adverse-event rate of 13.95%, well within norms reported in the literature. We used the first 80% of the records for training (to predict adverse events) and the remaining 20% of the records for validation. There was remarkable similarity among methods, with an AUC of 0.70 for predicting the occurrence of adverse events. The AUC using the Charlson comorbidity score was 0.61. The described model was more accurate than Charlson scoring (p < 0.01).We present a modeling effort based on administrative claims data that predicts the occurrence of complications after spine surgery.We believe that the development of a predictive modeling tool illustrating the risk of complication occurrence after spine surgery will aid in patient counseling and improve the accuracy of risk modeling strategies.

  View details for DOI 10.2106/JBJS.15.00301

  View details for Web of Science ID 000378644500009

  View details for PubMedID 27194492

• Point-Counterpoint: The Use of Neuromonitoring in Lateral Transpsoas Surgery SPINE Cheng, I., Acosta, F., Chang, K., Pham, M. 2016; 41 (8): S145-S151

  Abstract

  Expert opinion.The objective of this study is to debate the requirement for intraoperative neuromonitoring in 90° lateral transpsoas spine surgery (lateral lumbar interbody fusion [LLIF]) in a point-counterpoint style with an argument made for each side followed by a brief rebuttal of each. Dr. Ivan Cheng will argue in favor of the use of neuromonitoring in LLIF, and Dr. Frank Acosta will argue against the requirement for the use of neuromonitoring in LLIF.The lateral approach to the lumbar spine has been used since at least the 1990s and requires passage near or adjacent to the lumbar plexus. The mini-open lateral transpsoas approach was introduced in the literature in 2006 and uses evoked electromyography integrated into the approach and procedural instrumentation that stimulates in directional orientations and provides discrete threshold responses to avoid the nerves of the lumbar plexus. More recently, lateral transpsoas approaches to the lumbar spine have been developed that do not require or advocate for the use of neuromonitoring, instead relying on direct visualization and avoidance of nerves (shallow-docking).Two experienced lateral approach surgeons who regularly perform lateral transpsoas approaches with integrated neuromonitoring (IC) and without neuromonitoring (FA) present arguments for and against the requirement for neuromonitoring.Advocating for the use of neuromonitoring, points made include the broader literature validation of the lateral transpsoas approach with the use of advanced neuromonitoring and the relatively low rate of neural complications in neuromonitored transpsoas lateral approaches compared to those rates in shallow-docking literature. Advocating against the requirement for neuromonitoring in lateral transpsoas, points made include the potentially higher reliability of nerve avoidance with direct visualization as well as the favorable early results in the literature with respect to both new postoperative motor and sensory deficits.There are arguments to be made on both sides of this debate. There is substantially more literature describing the use of neuromonitoring in lateral transpsoas surgery though shallow-docking reports continue to emerge.5.

  View details for DOI 10.1097/BRS.0000000000001461

  View details for PubMedID 26796711

• Breaking Through the "Glass Ceiling" of Minimally Invasive Spine Surgery. Spine Phillips, F. M., Cheng, I., Rampersaud, Y. R., Akbarnia, B. A., Pimenta, L., Rodgers, W. B., Uribe, J. S., Khanna, N., Smith, W. D., Youssef, J. A., Sulaiman, W. A., Tohmeh, A., Cannestra, A., Wohns, R. N., Okonkwo, D. O., Acosta, F., Rodgers, E. J., Andersson, G. 2016; 41: S39-43

  View details for DOI 10.1097/BRS.0000000000001482

  View details for PubMedID 26839987

• Response to letter to the editor regarding: "Local versus distal transplantation of human neural stem cells following chronic spinal cord injury" by Cheng et al. The spine journal : official journal of the North American Spine Society Park, D. Y., Cheng, I. 2016; 16 (6): 793?94

  View details for PubMedID 27342710

• Biomechanical Determination of Distal Level for Fusions across the Cervicothoracic Junction. Global spine journal Cheng, I., Sundberg, E. B., Iezza, A., Lindsey, D. P., Riew, K. D. 2015; 5 (4): 282-286

  Abstract

  Study Design?In vitro testing. Objective?To determine whether long cervical and cervicothoracic fusions increase the intradiscal pressure at the adjacent caudal disk and to determine which thoracic end vertebra causes the least increase in the adjacent-level intradiscal pressure. Methods?A bending moment was applied to six cadaveric cervicothoracic spine specimens with intact rib cages. Intradiscal pressures were recorded from C7-T1 to T9-10 before and after simulated fusion by anterior cervical plating and posterior thoracic pedicle screw constructs. The changes in the intradiscal pressure from baseline were calculated and compared. Results?No significant differences where found when the changes of the juxtafusion intradiscal pressure at each level were compared for the flexion, extension, and left and right bending simulations. However, combining the pressures for all directions of bending at each level demonstrated a decrease in the pressures at the T2-T3 level. Exploratory analysis comparing changes in the pressure at T2-T3 to other levels showed a significant decrease in the pressures at this level (p?=?0.005). Conclusions?Based on the combined intradiscal pressures alone it may be advantageous to end long constructs spanning the cervicothoracic junction at the T2 level if there are no other mitigating factors.

  View details for DOI 10.1055/s-0035-1546418

  View details for PubMedID 26225276

  View details for PubMedCentralID PMC4516757

• Outcomes of Two Different Techniques Using the Lateral Approach for Lumbar Interbody Arthrodesis. Global spine journal Cheng, I., Briseño, M. R., Arrigo, R. T., Bains, N., Ravi, S., Tran, A. 2015; 5 (4): 308-314

  Abstract

  Study Design?Retrospective cohort study. Objective?To determine the short-term outcomes of two different lateral approaches to the lumbar spine. Methods?This was a retrospective review performed with four fellowship-trained spine surgeons from a single institution. Two different approach techniques were identified. (1) Traditional transpsoas (TP) approach: dissection was performed through the psoas performed using neuromonitored sequential dilation. (2) Direct visualization (DV) approach: retractors are placed superficial to the psoas followed by directly visualized dissection through psoas. Outcome measures included radiographic fusion and adverse event (AE) rate. Results?In all, 120 patients were identified, 79 women and 41 men. Average age was 64.2 years (22 to 86). When looking at all medical and surgical AEs, 31 patients (25.8%) had one or more AEs; 22 patients (18.3%) had a total of 24 neurologically related AEs; 15 patients (12.5%) had anterior/lateral thigh dysesthesias; 6 patients (5.0%) had radiculopathic pain; and 3 patients (2.5%) had postoperative weakness. Specifically, for neurologic AEs, the DV group had a rate of 28.0% and the TP group had a rate of 14.2% (p?

  View details for DOI 10.1055/s-0035-1546816

  View details for PubMedID 26225280

  View details for PubMedCentralID PMC4516734

• Posterior vertebral column resection and intraoperative manual traction to correct severe post-tubercular rigid spinal deformities incurred during childhood: minimum 2-year follow-up EUROPEAN SPINE JOURNAL Lu, G., Wang, B., Li, Y., Li, L., Zhang, H., Cheng, I. 2015; 24 (3): 586-593

  Abstract

  To evaluate the clinical and radiographic outcomes of posterior vertebral column resection (PVCR) and intraoperative manual traction to correct severe post-tubercular spinal deformity incurred during childhood.A retrospective review of 11 patients' (4 males and 7 females) charts was performed. Clinical outcome assessment was performed using Oswestry Disability Index and Visual Analog Scale for back pain. Imaging measurements and fusion status were assessed using plain radiography and computed tomography. Intraoperative and postoperative complications were recorded.No perioperative mortality occurred among the patients. The average follow-up was 42.8 ± 13.1 months (range 25-60 months). Kyphosis improved from a preoperative average of 93.4° ± 10.1° to a postoperative average of 18.7° ± 6.3° for a correction of 80.1 %. The Cobb angle in the coronal plane improved from an average of 48.1° ± 18.9° to 10.3° ± 3.0° postoperatively for a correction of 76.3 %. At the last follow-up, two patients improved neurologically from ASIA grade C to grade D, and one patient improved from grade C to grade E. Only one patient with ASIA grade D deficits did not improve. Perioperative complications occurred in 4 of the 11 cases. One patient had a dural tear. Three patients had temporary degradation of intraoperative neuromonitoring, and one experienced transient paralysis of the left lower extremity postoperatively.PVCR and intraoperative manual traction are effective alternatives to manage severe post-tubercular spinal deformity although the procedure can be highly challenging with possible neurologic complications.

  View details for DOI 10.1007/s00586-015-3760-1

  View details for Web of Science ID 000351514600022

  View details for PubMedID 25597040

• Electrodiagnostic testing before surgery for spinal stenosis. PM & R : the journal of injury, function, and rehabilitation Cheng, I., Ho, S., Kennedy, D. J. 2014; 6 (10): 945?50

  View details for PubMedID 25441719

• Does the presence of the fibronectin-aggrecan complex predict outcomes from lumbar discectomy for disc herniation? The spine journal : official journal of the North American Spine Society Smith, M. W., Ith, A., Carragee, E. J., Cheng, I., Alamin, T. F., Golish, S. R., Mitsunaga, K., Scuderi, G. J., Smuck, M. 2013

  Abstract

  Protein biomarkers associated with lumbar disc disease have been studied as diagnostic indicators and therapeutic targets. Recently, a cartilage degradation product, the fibronectin-aggrecan complex (FAC) identified in the epidural space, has been shown to predict response to lumbar epidural steroid injection in patients with radiculopathy from herniated nucleus pulposus (HNP).Determine the ability of FAC to predict response to microdiscectomy for patients with radiculopathy due to lumbar disc herniation STUDY DESIGN/SETTING: Single-center prospective consecutive cohort study.Patients with radiculopathy from HNP with concordant symptoms to MRI who underwent microdiscectomy.Oswestry disability index (ODI) and visual analog scores (VAS) were noted at baseline and at 3-month follow-up. Primary outcome of clinical improvement was defined as patients with both a decrease in VAS of at least 3 points and ODI >20 points.Intraoperative sampling was done via lavage of the excised fragment by ELISA for presence of FAC. Funding for the ELISA was provided by Cytonics, Inc.Seventy-five patients had full complement of data and were included in this analysis. At 3-month follow-up, 57 (76%) patents were "better." There was a statistically significant association of the presence of FAC and clinical improvement (p=.017) with an 85% positive predictive value. Receiver-operating-characteristic (ROC) curve plotting association of FAC and clinical improvement demonstrates an area under the curve (AUC) of 0.66±0.08 (p=.037). Subset analysis of those with weakness on physical examination (n=48) plotting the association of FAC and improvement shows AUC on ROC of 0.81±0.067 (p=.002).Patients who are "FAC+" are more likely to demonstrate clinical improvement following microdiscectomy. The data suggest that the inflammatory milieu plays a significant role regarding improvement in patients undergoing discectomy for radiculopathy in lumbar HNP, even in those with preoperative weakness. The FAC represents a potential target for treatment in HNP.

  View details for DOI 10.1016/j.spinee.2013.06.064

  View details for PubMedID 24239034

• Complications: a critical component of patient outcome. spine journal Stauff, M. P., Cheng, I. 2013; 13 (6): 625-627

  Abstract

  COMMENTARY ON: Mannion AF, Fekete TF, O'Riordan D, et al. The assessment of complications after spine surgery: time for a paradigm shift? Spine J 2013;13:615-24 (in this issue).

  View details for DOI 10.1016/j.spinee.2013.03.008

  View details for PubMedID 23578984

• Combined Transplantation of Human Neuronal and Mesenchymal Stem Cells following Spinal Cord Injury. Global spine journal Park, D. Y., Mayle, R. E., Smith, R. L., Corcoran-Schwartz, I., Kharazi, A. I., Cheng, I. 2013; 3 (1): 1-6

  Abstract

  Transplantation of human fetal neural stem cells (hNSCs) previously demonstrated significant functional recovery after spinal cord contusion in rats. Other studies indicated that human mesenchymal stem cells (hMSCs) can home to areas of damage and cross the blood-brain barrier. The purpose of this article is to determine if combined administration of mesenchymal stem cells and neuronal stem cells improves functional outcomes in rats. The study design was a randomized controlled animal trial. Female adult Long-Evans hooded rats underwent laminectomy at T10 level. Moderate spinal cord contusion at T10 level was induced by the MASCIS Impactor. Four groups were identified. The MSC?+?NSC group received hMSCs intravenously (IV) immediately after spinal cord injury (acute) and returned 1?week later (subacute) for injection of hNSC directly at site of injury. The MSC-only group received hMSC IV acutely and cell media subacutely. The NSC-only group received cell media IV acutely and hNSC subacutely. The control group received cell media IV acutely and subacutely. Subjects were assessed for 6 weeks using Basso, Beattie, Bresnahan Locomotor Rating Score. Twenty-four subjects were utilized, six subjects in each group. Statistically significant functional improvement was seen in the MSC?+?NSC group and the NSC-only group versus controls (p?=?0.027, 0.042, respectively). The MSC-only group did not demonstrate a significant improvement over control (p?=?0.145). Comparing the MSC?+?NSC group and the NSC-only group, there was no significant difference (p?=?0.357). Subacute transplantation of hNSCs into contused spinal cord of rats led to significant functional recovery when injected either with or without acute IV administration of hMSCs. Neither hMSCs nor addition of hMSC to hNSC resulted in significant improvement.

  View details for DOI 10.1055/s-0033-1337118

  View details for PubMedID 24436845

  View details for PubMedCentralID PMC3854610

• Thoracolumbar fracture dislocation sustained during childbirth in a patient with ankylosing spondylitis SPINE JOURNAL Mayle, R. E., Cheng, I., Carragee, E. J. 2012; 12 (11): E5-E8

  Abstract

  Ankylosing spondylitis (AS) is a major subtype of the spondyloarthropathies. Uncoupling of bone formation and resorption along with ectopic ossification of paraspinal soft-tissue structures alters the biomechanics of the spine and leads to an increased susceptibility to fracture.To report on a thoracolumbar fracture dislocation sustained in a 33-year-old Gravida 2/Para 2 woman, which occurred during labor. Although there are several reports in the literature of thoracolumbar fracture dislocations sustained in patients with AS, none have been reported during childbirth.Case report.An elevated suspicion for injury should be maintained when patients with AS present with back or neck pain even without a history of significant trauma.

  View details for DOI 10.1016/j.spinee.2012.10.012

  View details for Web of Science ID 000311807300002

  View details for PubMedID 23199410

• Postoperative spinal deformity after treatment of intracanal spine lesions SPINE JOURNAL Joaquim, A. F., Cheng, I., Patel, A. A. 2012; 12 (11): 1067-1074

  Abstract

  Surgical treatment of intracanal (both intramedullary and extramedullary) spine lesions requires posterior decompressive techniques in nearly all instances. Postoperative spinal deformities, most notably sagittal and coronal decompensation, are of significant concern for both the patient and the spinal surgeon.To review and define principles and features of spinal deformities after posterior spinal decompression for intracanal spinal lesions, and to define patients who may benefit from the concomitant spinal fusion.A systematic review of MEDLINE was conducted, including articles published between 1980 and 2011. Articles related to spinal deformities after posterior decompression for the treatment of intracanal spine lesions were identified.Ten articles met all inclusion and exclusion criteria. All were case series with limited evidence (Level IV). Many risk factors to deformity were implied but with limited evidence. Young age was the most commonly identified risk in these articles.Spinal deformity after posterior decompression is a common complication, most notably in children and young adults, after the removal of intramedullary tumors. Many risk factors have been implied to increase the postoperative development of spinal deformity, including young age, laminectomy extension, preoperative deformity, and extensive facet resection, among others. However, there is a lack of high-quality evidence to propose an algorithm for treatment or preventive measures. New studies with larger series of patients and standardized clinical outcomes are necessary to establish optimal treatment protocols.

  View details for DOI 10.1016/j.spinee.2012.09.054

  View details for Web of Science ID 000311807300017

  View details for PubMedID 23116818

• Functional assessment of the acute local and distal transplantation of human neural stem cells after spinal cord injury SPINE JOURNAL Cheng, I., Mayle, R. E., Cox, C. A., Park, D. Y., Smith, R. L., Corcoran-Schwartz, I., Ponnusamy, K. E., Oshtory, R., Smuck, M. W., Mitra, R., Kharazi, A. I., Carragee, E. J. 2012; 12 (11): 1040-1044

  Abstract

  Spinal cord injury can lead to severe functional impairments secondary to axonal damage, neuronal loss, and demyelination. The injured spinal cord has limited regrowth of damaged axons. Treatment remains controversial, given inconsistent functional improvement. Previous studies demonstrated functional recovery of rats with spinal cord contusion after transplantation of rat fetal neural stem cells.We hypothesized that acute transplantation of human fetal neural stem cells (hNSCs) both locally at the injury site as well as distally via intrathecal injection would lead to improved functional recovery compared with controls.Twenty-four adult female Long-Evans hooded rats were randomized into four groups with six animals in each group: two experimental and two control. Functional assessment was measured after injury and then weekly for 6 weeks using the Basso, Beattie, and Bresnahan Locomotor Rating Score. Data were analyzed using two-sample t test and linear mixed-effects model analysis.Posterior exposure and laminectomy at T10 level was used. Moderate spinal cord contusion was induced by the Multicenter Animal Spinal Cord Injury Study Impactor with 10-g weight dropped from a height of 25 mm. Experimental subjects received either a subdural injection of hNSCs locally at the injury site or intrathecal injection of hNSCs through a separate distal laminotomy. Controls received control media injection either locally or distally.Statistically significant functional improvement was observed in local or distal hNSCs subjects versus controls (p=.034 and 0.016, respectively). No significant difference was seen between local or distal hNSC subjects (p=.66).Acute local and distal transplantation of hNSCs into the contused spinal cord led to significant functional recovery in the rat model. No statistical difference was found between the two techniques.

  View details for DOI 10.1016/j.spinee.2012.09.005

  View details for Web of Science ID 000311807300013

  View details for PubMedID 23063425

• Full-endoscopic interlaminar approach for the surgical treatment of lumbar disc herniation: the causes and prophylaxis of conversion to open ARCHIVES OF ORTHOPAEDIC AND TRAUMA SURGERY Wang, B., Lu, G., Liu, W., Cheng, I., Patel, A. A. 2012; 132 (11): 1531-1538

  Abstract

  Retrospective case series.To analyze the causes of conversion to open for the surgical treatment of lumbar disc herniation with use of full endoscopic (FE) technique, and prophylaxis of conversion to open also proposed.50 patients with lumbar disc herniation underwent discectomy using unilateral portal FE interlaminar approach collected from August 2008 to August 2010. All FE operations were performed under general anesthesia and endotracheal intubation. According to the level incision of the ligament flavum, the starting point of nerve root at the dura under endoscopic view was classified as: Type I (starting point of the nerve root was higher than the incision) and Type II (the starting point of nerve root was lower than the incision). The causes and effective prophylactic measurements for cases of conversion to open were analyzed.There were 47 cases classified as Type I for a rate of 94 %, and Type II in 3 cases for a rate of 6 %. Five cases were converted to open surgery, and the conversion rate was 10 %. There were three males and two females with a mean age of 36.2 (29-44) years, the average duration of symptoms was 58.4 (35-105) days. The level was L5-S1 in four cases and L4-5 in one, lateral extrusion in three cases, paracentral extrusion in one, and sequestration in one. Leg pain resolved in three cases and improved in two after open surgery. Of five cases of conversion to open, misplacement of the working portal occurred in one case (Type I). Difficult dissection of nerve root and hemostasis resulting in open conversion occurred in one case (Type II); this patient sustained a dural injury. The nerve root could not be exposed in three cases (Type II), the FE changed to open finally. During the open procedure with Type II, we found that the location of origin of the nerve root was caudal to the inferior laminar edge. Therefore, partial removal of bony structures along lateral recess was necessary in order to visualize the nerve root.Misplacement of working portal during the exposure of the ligament flavum and difficulty in indentifying anatomy are potential causes for conversion to open in the initial adoption of FE technique. However, uncommon conditions such as variation of the nerve root origin can also result in conversion to open in experienced hands. Endoscopic experience, proper patient selection and specific radiographic examination are needed to obtain optimal outcomes using a full endoscopic technique for microdiscectomies.

  View details for DOI 10.1007/s00402-012-1581-9

  View details for Web of Science ID 000310086700002

  View details for PubMedID 22763864

• A biologic without guidelines: the YODA project and the future of bone morphogenetic protein-2 research SPINE JOURNAL Carragee, E. J., Baker, R. M., Benzel, E. C., Bigos, S. J., Cheng, I., Corbin, T. P., Deyo, R. A., Hurwitz, E. L., Jarvik, J. G., Kang, J. D., Lurie, J. D., Mroz, T. E., Oener, F. C., Peul, W. C., Rainville, J., Ratliff, J. K., Rihn, J. A., Rothman, D. J., Schoene, M. L., Spengler, D. M., Weiner, B. K. 2012; 12 (10): 877-880

  View details for DOI 10.1016/j.spinee.2012.11.002

  View details for Web of Science ID 000311684600004

  View details for PubMedID 23199819

• Arachnoid ossificans containing metaplastic hematopoietic marrow resulting in diffuse thoracic intrathecal cysts and severe myelopathy. European spine journal Abrams, J., Li, G., Mindea, S. A., Haynes, C. M., Cheng, I. 2012; 21: S436-40

  Abstract

  To present a rare case of multiple compressive thoracic intradural cysts with pathologic arachnoid ossification, review the literature and present the surgical options. Few reports have identified the existence of arachnoid calcifications and intrathecal cysts causing progressive myelopathy. The literature regarding each of these pathologies is limited to case reports. Their clinical significance is not well studied, although known to cause neurologic sequelae.An 81-year-old female clinically presents with rapidly progressive myelopathy. Pre-operative magnetic resonance imaging identified multiple compressive thoracic intrathecal cysts. Surgical exploration and decompression of these cysts identified calcified plaques within the arachnoid. Histopathologic examination revealed fibrocalcific tissue undergoing ossification with bone marrow elements.Due to progressive myelopathy, the thoracic cysts were decompressed and calcified plaques were excised, once identified intra-operatively.On last examination, the patient's neurologic status had not improved, but had stabilized. The rate of neurologic improvement from excision and decompression is variable, but it may still be warranted in the face of progressive neurologic deficits.

  View details for DOI 10.1007/s00586-011-2005-1

  View details for PubMedID 21892775

• Foot and Ankle Questions on the Orthopaedic In-Training Examination: Analysis of Content, Reference, and Performance ORTHOPEDICS Barr, C. R., Cheng, I., Chou, L. B., Hunt, K. J. 2012; 35 (6): E880-E888

  Abstract

  The purpose of this study was to provide a comprehensive analysis of the Orthopaedic In-Training Examination's (OITE's) questions, question sources, and resident performance over the course of residency training.The authors analyzed all OITE questions pertaining to foot and ankle surgery between 2006 and 2010. Recorded data included the topic and area tested, imaging modality used, tested treatment method, taxonomic classification, cited references, and resident performance scores. Foot- and ankle-related questions made up 13.9% (186/1341) of the OITE questions. Thirteen general topic areas were identified, with the most common being foot and ankle trauma, the pediatric foot, and foot and ankle deformity. Imaging modalities were tested in approximately half of the questions. Knowledge of treatment modalities was required in 58.1% (108/186) of the questions. Recall-type questions were the most common. Trends existed in the recommended references, with 2 journals and 1 textbook being commonly and consistently cited: Foot and Ankle International, The Journal of Bone and Joint Surgery American Volume, and Surgery of the Foot and Ankle, respectively. Resident performance scores increased with each successive level of training.An understanding of the topics and resources used for OITE foot and ankle questions is an important aid in creating or improving residency programs' foot and ankle education curricula. With knowledge of question content, source, and resident performance, education can be optimized toward efficient learning and improved scores on this section of the examination.

  View details for DOI 10.3928/01477447-20120525-28

  View details for PubMedID 22691661

• Morbidity and Mortality of C2 Fractures in the Elderly: Surgery and Conservative Treatment NEUROSURGERY Chen, Y., Boakye, M., Arrigo, R. T., Kalanithi, P. S., Cheng, I., Alamin, T., Carragee, E. J., Mindea, S. A., Park, J. 2012; 70 (5): 1055-1059

  Abstract

  Closed C2 fractures commonly occur after falls or other trauma in the elderly and are associated with significant morbidity and mortality. Controversy exists as to best treatment practices for these patients.To compare outcomes for elderly patients with closed C2 fractures by treatment modality.We retrospectively reviewed 28 surgically and 28 nonsurgically treated cases of closed C2 fractures without spinal cord injury in patients aged 65 years of age or older treated at Stanford Hospital between January 2000 and July 2010. Comorbidities, fracture characteristics, and treatment details were recorded; primary outcomes were 30-day mortality and complication rates; secondary outcomes were length of hospital stay and long-term survival.Surgically treated patients tended to have more severe fractures with larger displacement. Charlson comorbidity scores were similar in both groups. Thirty-day mortality was 3.6% in the surgical group and 7.1% in the nonsurgical group, and the 30-day complication rates were 17.9% and 25.0%, respectively; these differences were not statistically significant. Surgical patients had significantly longer lengths of hospital stay than nonsurgical patients (11.8 days vs 4.4 days). Long-term median survival was not significantly different between groups.The 30-day mortality and complication rates in surgically and nonsurgically treated patients were comparable. Elderly patients faced relatively high morbidity and mortality regardless of treatment modality; thus, age alone does not appear to be a contraindication to surgical fixation of C2 fractures.

  View details for DOI 10.1227/NEU.0b013e3182446742

  View details for Web of Science ID 000303390400013

  View details for PubMedID 22157549

• Commentary: Spinopelvic parameters-how far have we come? SPINE JOURNAL Cheng, I. 2012; 12 (5): 447-448

  Abstract

  COMMENTARY ON: Vrtovec T, Janssen MMA, Likar B. A review of methods for evaluating the quantitative parameters of sagittal pelvic alignment. Spine J 2012;12:433-46 (in this issue).

  View details for DOI 10.1016/j.spinee.2012.03.007

  View details for Web of Science ID 000305298300013

  View details for PubMedID 22698152

• Anterior debridement and reconstruction via thoracoscopy-assisted mini-open approach for the treatment of thoracic spinal tuberculosis: minimum 5-year follow-up EUROPEAN SPINE JOURNAL Lu, G., Wang, B., Li, J., Liu, W., Cheng, I. 2012; 21 (3): 463-469

  Abstract

  Video-assisted thoracoscopic surgery (VATS) has been developed for surgical treatment of thoracic spinal tuberculosis to overcome the problems associated with a formal thoracotomy. VATS, however, is technically demanding with a difficult learning curve.We conducted a retrospective long-term follow-up study of anterior debridement and reconstruction via a thoracoscopy-assisted mini-open approach for the surgical treatment of thoracic spinal tuberculosis. There were 50 patients collected with mean age 38.3 years with thoracic spinal tuberculosis.The average operative time was 210 min (range 170-300 min), the average blood loss during operation was 550 ml (range 300-1,000 ml), and the mean chest drainage duration was 3.5 days (3-5 days). Complications occurred in 17 patients (34%). The mean follow-up was 6.5 years. There was statistically difference in VAS 3 months after surgery compared to preoperatively (P<0.001), as well as final follow-up compared to 3 months post-op (P<0.001). In patients with minor pulmonary impairment as measured by pulmonary function testing, 15 improved to normal and 5 had no change. In patients with moderate pulmonary impairment, 6 improved to normal and 2 improved to minor impairment at final follow-up. Neurological improvement of one to three grades had occurred in 26 patients by final follow-up. There was statistically difference in kyphotic angle 3 months after surgery compared to preoperatively (P<0.05), as well as final follow-up compared to 3 months post-op (P<0.001). The average correction rate of kyphotic angle was 38.7% and the loss of correction rate was 1.3% at final follow-up. No recurrent tuberculosis was found.Thoracoscopy-assisted mini-open approach can provide a simple, safe, and practical treatment option with minimal invasiveness in cases of thoracic spinal tuberculosis. Successful clinical and radiographic outcomes can be achieved via anterior debridement and reconstruction at long-term follow-up.

  View details for DOI 10.1007/s00586-011-2038-5

  View details for Web of Science ID 000301441100013

  View details for PubMedID 21997276

  View details for PubMedCentralID PMC3296839

• The American Orthopaedic Association-Japanese Orthopaedic Association 2010 traveling fellowship. journal of bone and joint surgery. American volume Patel, A. A., Cheng, I., Yao, J., Huffman, G. R. 2011; 93 (24)

  Abstract

  We started this journey excited by the prospects of visiting Japan, a country with a proud and historic past. We ended the fellowship accomplishing those goals, and we left with a great deal of admiration for our orthopaedic colleagues halfway around the world for their excellence in education, clinical care, and research. Their hospitality and attention to the details of our visit were exemplary and a lesson to us as we host visiting fellows in the future. Japan reflects its past, but it also offers a preview into our own nation's future: an aging population, a shrinking workforce, a stagnant economy, nationalized health care, and a mushrooming national debt. Of all of these factors, it is the aging population that we, as orthopaedic surgeons, will be most acutely aware of and involved with. The degenerative disorders that affect elderly patients dominate the landscape of surgical care in Japan. Osteoporosis and osteopenia permeate many aspects of care across orthopaedic subspecialties. The surgeons in Japan are developing innovative and cost-effective means of treating the large volume of older patients within the fiscal constraints of a nationalized health-care system. We learned, and will continue to learn more, from Japan about the management of this growing patient population with its unique pathologies and challenges. With the recent natural disaster and ongoing safety concerns in Japan, the character and will of the people of Japan have been on display. Their courage and resolve combined with order and compassion are a testament to the nation's cultural identity. The seeds of the Traveling Fellowship were planted shortly after Japan's last wide-scale reconstruction, and the ties that have bound the JOA and the AOA together are strengthened through this trying time. We strongly urge our colleagues in the U.S. to help support the people, the physicians, and the health-care system of Japan through its most recent tribulations and offer them the same care and hospitality that we were shown during our fellowship. Japan is an open and friendly nation, and we encourage anyone interested to seek out opportunities to visit or work with our orthopaedic colleagues there. We are grateful to our hosts at each institution as well as to the JOA and AOA organizations for continuing this wonderful tradition. This exchange is now entering its twentieth year. It remains a ?trip of a lifetime? for those fortunate enough to be selected. For us, as for many who have participated before us, it will shape our careers in the years to come.

  View details for DOI 10.2106/JBJS.K.00472

  View details for PubMedID 22258785

• Anterior Radical Debridement and Reconstruction Using Titanium Mesh Cage for the Surgical Treatment of Thoracic and Thoracolumbar Spinal Tuberculosis: Minimium Five-Year Follow-Up TURKISH NEUROSURGERY Wang, B., Li, G., Liu, W., Cheng, I. 2011; 21 (4): 575-581

  View details for DOI 10.5137/1019-5149.JTN.4639-11.1

  View details for Web of Science ID 000297229200022

• Charlson Score is a Robust Predictor of 30-Day Complications Following Spinal Metastasis Surgery SPINE Arrigo, R. T., Kalanithi, P., Cheng, I., Alamin, T., Carragee, E. J., Mindea, S. A., Boakye, M., Park, J. 2011; 36 (19): E1274-E1280

  Abstract

  Retrospective chart review.To identify predictors of 30-day complications after the surgical treatment of spinal metastasis.Surgical treatment of spinal metastasis is considered palliative with the aim of reducing or delaying neurologic deficit. Postoperative complication rates as high as 39% have been reported in the literature. Complications may impact patient quality of life and increase costs; therefore, an understanding of which preoperative variables best predict 30-day complications will help risk-stratify patients and guide therapeutic decision making and informed consent.We retrospectively reviewed 200 cases of spinal metastasis surgically treated at Stanford Hospital between 1999 and 2009. Multiple logistic regression was performed to determine which preoperative variables were independent predictors of 30-day complications.Sixty-eight patients (34%) experienced one or more complications within 30 days of surgery. The most common complications were respiratory failure, venous thromboembolism, and pneumonia. On multivariate analysis, Charlson Comorbidity Index score was the most significant predictor of 30-day complications. Patients with a Charlson score of two or greater had over five times the odds of a 30-day complication as patients with a score of zero or one.After adjusting for demographic, oncologic, neurologic, operative, and health factors, Charlson score was the most robust predictor of 30-day complications. A Charlson score of two or greater should be considered a surgical risk factor for 30-day complications, and should be used to risk-stratify surgical candidates. If complications are anticipated, medical staff can prepare in advance, for instance, scheduling aggressive ICU care to monitor for and treat complications. Finally, Charlson score should be controlled for in future spinal metastasis outcomes studies and compared to other comorbidity assessment tools.

  View details for DOI 10.1097/BRS.0b013e318206cda3

  View details for Web of Science ID 000294207500005

  View details for PubMedID 21358481

• Anterior endoscopically assisted transcervical reconstruction of the upper cervical spine EUROPEAN SPINE JOURNAL Wang, B., Lu, G., Deng, Y., Liu, W., Li, J., Cheng, I. 2011; 20 (9): 1526-1532

  Abstract

  Anterior decompression and/or reconstruction can be an effective method for the surgical treatment of ventral spinal cord compression in the upper cervical spine. Options for traditional surgical approaches include transoral, transnasal, and extraoral. The risk and complex anatomy with the aforementioned approaches induces surgeons to use the transcervical route to expose the upper cervical spine. A traditional transcervical approach, however, carries the disadvantages of a deep operative field and steep trajectory. We performed a new endoscopically assisted method of anterior reconstruction for the treatment of ventral lesions in upper cervical spine. Six patients were treated from January 2005 to December 2007. Among those six patients, three patients were diagnosed with fixed atlantoaxial dislocations, two with plasmacytomas, and one with a giant cell tumor. All patients were treated by combined endoscopically assisted anterior reconstruction and posterior fusion. One patient with a fixed atlantoaxial dislocation sustained a cerebrospinal fluid leak in the immediate postoperative period, which spontaneously resolved 7 days after surgery. None of the patients had any neurologic deterioration following surgery, nor did any require admission to the intensive care unit for any reason. At the final follow-up, all patients were found to have evidence of a successful clinical outcomes and radiographic fusion. There were no implant failures or radiographic signs of implant migration or loosening. In conclusion, this study demonstrates that an anterior transcervical decompression using endoscopic visualization combined with a posterior arthodesis can achieve good clinical and radiographic outcomes.

  View details for DOI 10.1007/s00586-011-1770-1

  View details for Web of Science ID 000294706700016

  View details for PubMedID 21416277

  View details for PubMedCentralID PMC3175909

• Comparison of perioperative parameters and complications observed in the anterior exposure of the lumbar spine by a spine surgeon with and without the assistance of an access surgeon SPINE JOURNAL Smith, M. W., Rahn, K. A., Shugart, R. M., Belschner, C. D., Stout, K. S., Cheng, I. 2011; 11 (5): 389-394

  Abstract

  The anterior approach to the spine is becoming an increasingly important avenue to treat spine conditions. Most of the literature reporting on the exposure uses an access surgeon assisting the spine surgeon to expose and prepare the spine for implant.To compare perioperative parameters and complications in anterior lumbar spine surgery with the exposure performed either by a spine surgeon or a general surgeon.A retrospective cohort study comparing perioperative parameters and complications of anterior lumbar spine surgery.A retrospective review was completed on 96 consecutive patients who underwent anterior spine surgery between Levels L3 and S1 from 1995 to 2008. Patient and surgery characteristics including demographics, comorbidities, perioperative parameters, and complications were logged. In the first 56 consecutive patients, a general surgeon completed the exposure, with an additional patient who later had the exposure performed by a general surgeon because of extensive prior abdominal surgeries. In the next 39 patients, the orthopedic surgeon completed the exposure.When the operation was performed solely by a spine surgeon, the estimated blood loss, operative time, and hospital stay was 204 mL, 2.80 hours, and 3.5 days, respectively. In the procedures completed with the aid of a general surgeon, it was found that the same parameters were 420 mL, 3.93 hours, and 4.7 days, respectively, and statistically significantly less in the group without the assistance of the general surgeon (p=.0007, p=.0003, and p=.0006, respectively). Fewer complications also were observed in that group (p<.00001). The most common complication was an ileus. Major complications including retrograde ejaculation, iliac vein bleeding, peritoneal rent requiring repair, dyspareunia, or scrotal/penile swelling were only observed in the group with the assistance of the general surgeon.This study indicated that a spine surgeon can successfully and safely carry out the anterior exposure to the spine without the aid of an access surgeon.

  View details for DOI 10.1016/j.spinee.2011.03.014

  View details for Web of Science ID 000290396800006

  View details for PubMedID 21498131

• Predictors of Survival After Surgical Treatment of Spinal Metastasis NEUROSURGERY Arrigo, R. T., Kalanithi, P., Cheng, I., Alamin, T., Carragee, E. J., Mindea, S. A., Park, J., Boakye, M. 2011; 68 (3): 674-681

  Abstract

  Surgery for spinal metastasis is a palliative treatment aimed at improving patient quality of life by alleviating pain and reversing or delaying neurologic dysfunction, but with a mean survival time of less than 1 year and significant complication rates, appropriate patient selection is crucial.To identify the most significant prognostic variables of survival after surgery for spinal metastasis.Chart review was performed on 200 surgically treated spinal metastasis patients at Stanford Hospital between 1999 and 2009. Survival analysis was performed and variables entered into a Cox proportional hazards model to determine their significance.Median overall survival was 8.0 months, with a 30-day mortality rate of 3.0% and a 30-day complication rate of 34.0%. A Cox proportional hazards model showed radiosensitivity of the tumor (hazard ratio: 2.557, P<.001), preoperative ambulatory status (hazard ratio: 2.355, P=.0001), and Charlson Comorbidity Index (hazard ratio: 2.955, P<.01) to be significant predictors of survival. Breast cancer had the best prognosis (median survival, 27.1 months), whereas gastrointestinal tumors had the worst (median survival, 2.66 months).We identified the Charlson Comorbidity Index score as one of the strongest predictors of survival after surgery for spinal metastasis. We confirmed previous findings that radiosensitivity of the tumor and ambulatory status are significant predictors of survival.

  View details for DOI 10.1227/NEU.0b013e318207780c

  View details for Web of Science ID 000287242300036

  View details for PubMedID 21311295

• Pregabalin as a Neuroprotector after Spinal Cord Injury in Rats: Biochemical Analysis and Effect on Glial Cells JOURNAL OF KOREAN MEDICAL SCIENCE Ha, K., Carragee, E., Cheng, I., Kwon, S., Kim, Y. 2011; 26 (3): 404-411

  Abstract

  As one of trials on neuroprotection after spinal cord injury, we used pregabalin. After spinal cord injury (SCI) in rats using contusion model, we observed the effect of pregabalin compared to that of the control and the methylprednisolone treated rats. We observed locomotor improvement of paralyzed hindlimb and body weight changes for clinical evaluation and caspase-3, bcl-2, and p38 MAPK expressions using western blotting. On histopathological analysis, we also evaluated reactive proliferation of glial cells. We were able to observe pregabalin's effectiveness as a neuroprotector after SCI in terms of the clinical indicators and the laboratory findings. The caspase-3 and phosphorylated p38 MAPK expressions of the pregabalin group were lower than those of the control group (statistically significant with caspase-3). Bcl-2 showed no significant difference between the control group and the treated groups. On the histopathological analysis, pregabalin treatment demonstrated less proliferation of the microglia and astrocytes. With this animal study, we were able to demonstrate reproducible results of pregabalin's neuroprotection effect. Diminished production of caspase-3 and phosphorylated p38 MAPK and as well as decreased proliferation of astrocytes were seen with the administration of pregabalin. This influence on spinal cord injury might be a possible approach for achieving neuroprotection following central nervous system trauma including spinal cord injury.

  View details for DOI 10.3346/jkms.2011.26.3.404

  View details for Web of Science ID 000288838400014

  View details for PubMedID 21394310

  View details for PubMedCentralID PMC3051089

• Kyphectomy in the treatment of patients with myelomeningocele SPINE JOURNAL Samagh, S. P., Cheng, I., Elzik, M., Kondrashov, D. G., Rinsky, L. A. 2011; 11 (3): E5-E11

  Abstract

  Myelomeningocele kyphosis is a complex disorder that usually requires surgical intervention. Many complications can occur as a result of this disorder and its treatment, but only surgical correction offers the possibility of restoring spinal alignment.The purpose of this retrospective study was to summarize the surgical results, complications, and short-term and midterm outcomes for surgical correction of severe kyphosis using a consistent surgical technique.This was a retrospective review of our database of pediatric patients with myelomeningocele and lumbar kyphosis who underwent kyphectomy with the use of the Warner and Fackler technique.Eleven pediatric kyphectomy cases performed by a single surgeon from 1984 to 2009 were reviewed.Outcome measures include imaging, kyphotic angle measurement, and physical examination.Patients underwent the Warner and Fackler technique of posterior-only kyphectomy and bayonet-shaped anterior sacral fixation.The mean extent of kyphosis was 115.6° (range, 77-176°) preoperatively with a correction to 13.0° (range, 0-32°) postoperatively, and a reduction with an average of 102.6° (range, 65-160°), for an 88.7% correction. On an average, 2.0 (range, 1-6) vertebrae were resected. Immediately postoperatively and at follow-up, with an average of 67.2 months (range, 8-222 months), the average kyphosis angle was 13.0° (range, 0-32°). All patients undergoing the procedure were unable to lie supine preoperatively. All patients postoperatively could lie in the supine position. The functional outcome in patients and caretakers was rated very favorably because all patients and caretakers who provided feedback (9 of 11) reported that they were satisfied with the procedure and would undergo the procedure again if given the choice.This technique has become the most effective surgical reconstruction in myelomeningocele kyphosis. Although significant complications can occur during and after the procedure, most patients had satisfactory postoperative outcomes and restoration of sagittal balance with high patient and parent satisfaction.

  View details for DOI 10.1016/j.spinee.2011.01.020

  View details for Web of Science ID 000288013200002

  View details for PubMedID 21377598

• An evaluation of the learning curve for a complex surgical technique: the full endoscopic interlaminar approach for lumbar disc herniations SPINE JOURNAL Wang, B., Lue, G., Patel, A. A., Ren, P., Cheng, I. 2011; 11 (2): 122-130

  View details for DOI 10.1016/j.spinee.2010.12.006

  View details for Web of Science ID 000286980400013

• An evaluation of the learning curve for a complex surgical technique: the full endoscopic interlaminar approach for lumbar disc herniations. The spine journal : official journal of the North American Spine Society Wang, B., Lü, G., Patel, A. A., Ren, P., Cheng, I. 2011; 11 (2): 122-130

  Abstract

  Compared with conventional microsurgical technique, the full endoscopic (FE) interlaminar approach is a more minimally invasive technique for the surgical treatment of lumbar disc herniations. Its efficacy and safety have been confirmed by numerous studies. However, a steep learning curve with the use of such a complex technique is a major concern for the initial adoption of this technique.To evaluate the learning curve of using an FE interlaminar technique for the surgical treatment of lumbar disc herniation.A prospective study of patients with lumbar disc herniation who underwent discectomy via interlaminar approach assisted by FE instruments.Thirty patients with lumbar disc herniation underwent discectomy using an interlaminar endoscopic-only approach between 2008 and 2009.The patients were divided into three groups of 10 sequential cases each. Group A consisted of the first 10 cases, Group B the subsequent 10 cases, and Group C the last 10 cases. The clinical evaluation data included operative time, length of hospital stay, visual analog scale (VAS) leg and back pain scores, complications, and rate of conversion to an open.All patients were observed prospectively for 1.61 ± 0.22 years (range, 1.2-2.0 years). There was no measurable intraoperative bleeding and postoperative infections in the three groups. Compared with Group A, the operative time in Group B was significantly decreased (p < .001). The patients in Group C had much less operative time than in Group B (p = .002). There was no significant difference with length of hospital stay in the three groups (p = .897). The improvement of VAS leg and back pain scores in each group was similar: there was a significant improvement (p < .01) at 3 months after surgery when compared with preoperative scores, but there was no statistical difference (p > .05) in the VAS leg and back pain scores between 3 months after surgery and final follow-up. The complication rate was 12.5% for Group A, 10% for Group B, and 0% for Group C. The need for conversion to an open procedure for Group A was 20% compared with zero cases in both Groups B and C. There were no symptomatic recurrences in our study.Excellent clinical and minimally invasive outcomes can be obtained in the surgical treatment of lumbar disc herniation via the interlaminar approach assisted by FE technique. However, attention must be paid to the steep learning curve by using this complex technique. Imprecise anatomic orientation and manipulation inside the spinal canal are key factors in the steep learning curve. Obtaining microsurgical experience, attending workshops, and suitable patient selection can help shorten the learning curve and decrease the complications.

  View details for DOI 10.1016/j.spinee.2010.12.006

  View details for PubMedID 21296295

• Anterior radical debridement and reconstruction using titanium mesh cage for the surgical treatment of thoracic and thoracolumbar spinal tuberculosis: minimium five-year follow-up. Turkish neurosurgery Wang, B., Lv, G., Liu, W., Cheng, I. 2011; 21 (4): 575-581

  Abstract

  To evaluate the long-term outcomes for the surgical treatment of thoracic and thoracolumbar spinal tuberculosis with anterior radical debridement and reconstruction with titanium mesh cages (TMCs).69 patients with thoracic and thoracolumbar spinal tuberculosis were retrospectively analyzed. Outcomes data included VAS back pain, subjective clinical results, and radiographic data.All patients had resolution of their infections, obtained solid bony fusions without failure of fixation, experienced improvement of neurological function, and improved in their VAS back pain scores at final long-term follow-up. In the thoracic spine group, 92.3% of patients had good or excellent subjective clinical results. The loss of kyphotic angle correction and intervertebral height was 9.6% and 3.8%, respectively. In the thoracolumbar spine group, 93.3% of patients had good or excellent subjective clinical results. The loss of kyphotic angle correction and intervertebral height was 12.8% and 4.2%, respectively.Anterior radical debridement and reconstruction using TMCs for the treatment of thoracic and thoracolumbar spinal tuberculosis is an acceptable treatment option. Solid bony fusion, good clinical outcomes as well as improvement of neurological function can be achieved although TMCs subsidence can occur.

  View details for DOI 10.5137/1019-5149.JTN .4639-11.1

  View details for PubMedID 22194119

• Massive spontaneous epidural hematoma in a high-level swimmer: a case report. journal of bone and joint surgery. American volume Fleager, K., Lee, A., Cheng, I., Hou, L., Ryu, S., Boakye, M. 2010; 92 (17): 2843-2846

  View details for DOI 10.2106/JBJS.I.01604

  View details for PubMedID 21123615

• Massive Spontaneous Epidural Hematoma in a High-Level Swimmer A Case Report JOURNAL OF BONE AND JOINT SURGERY-AMERICAN VOLUME Fleager, K., Lee, A., Cheng, I., Hou, L., Ryu, S., Boakye, M. 2010; 92A (17): 2843-2846

  View details for DOI 10.2106/JBJS.I.01604

  View details for Web of Science ID 000285118500010

• Biomechanical Analysis of Derotation of the Thoracic Spine Using Pedicle Screws SPINE Cheng, I., Hay, D., Iezza, A., Lindsey, D., Lenke, L. G. 2010; 35 (10): 1039-1043

  Abstract

  Biomechanical analysis of derotational load-to-failure of pedicle screw (PS) instrumentation in cadaveric thoracic spinal segments.To investigate the derotational torque that can be applied to the thoracic spine through different linked constructs and evaluate the modes of failure.Thoracic derotation with PSs has been shown to provide better 3 plane correction than other methods but the effects of linked PS constructs has not been studied.Four groups of thoracic segments with different PS constructs were loaded to failure with a rotational torque applied to the construct to simulate the left to right derotational force applied to a typical idiopathic dextrorotary thoracic scoliosis curve. Single screw T4 segments instrumented on the medial (group 1M) and lateral (group 1L) sides, bilaterally-linked T5 segments (group 2), unilaterally-linked T6-T9 segments on the medial (group 3M) and lateral (group 3L) sides, and quadrangularly-linked T6-T9 segments (group 4) were loaded with MTS machine in a simulated thoracic derotation model.Single T4 PSs on the medial and lateral sides failed at 4.0 +/- 1.4 Nm (group 1M) and 6.1 +/- 2.5 Nm (group 1L), respectively. Bilaterally-linked T5 screws failed at 11.9 +/- 3.1 Nm (group 2). Unilaterally linked T6-T9 PS constructs on the medial and lateral sides failed at 21.2 +/- 7.5 Nm (group 3M) and 17.9 +/- 11.1 Nm (group 3L), respectively. Quadrangularly-linked PSs failed at 42.5 +/- 14.5 Nm (group 4). CONCLUSION.: A near linear increase in relative torque applied before failure was found with each additional PS linked. Linked constructs allow for significantly greater torque with less risk of PS breach of the spinal canal.

  View details for DOI 10.1097/BRS.0b013e3181d85ec8

  View details for Web of Science ID 000277224800005

  View details for PubMedID 20393385

• Minimum acceptable outcomes after lumbar spinal fusion SPINE JOURNAL Carragee, E. J., Cheng, I. 2010; 10 (4): 313-320

  Abstract

  Defining success after spinal surgery remains problematic. The minimal clinically important difference (MCID) in pain or functional outcomes is a common metric often calculated independent of perceived risk and morbidity, which is an important consideration in large procedures such as spinal fusion and instrumentation.The purpose of this study was to describe a method of assessing treatment success based on prospective, patient-reported "minimum acceptable" outcome for which they would undergo a procedure. These goals can then be compared at follow-up to gauge how frequently patient goals are met and determine correlation with patient satisfaction.This is a clinical descriptive study of the patient-reported minimum acceptable outcomes for spinal fusion surgery.Minimum acceptable outcomes were determined by patients on preoperatively administered standard questionnaires regarding ultimate pain intensity, functional outcome (Oswestry Disability Index [ODI]), medication usage, and work status. Satisfaction with outcomes was assessed at 2-year follow-up.One hundred sixty-five consecutive patients undergoing lumbar fusion for either isthmic spondylolisthesis or disc degeneration were asked to preoperatively define on standard questionnaires their minimum acceptable outcomes after surgery. Two-year outcomes and satisfaction were subsequently reported and compared with the preoperatively determined minimum acceptable outcomes.Both the spondylolisthesis and the degenerative disc disease (DDD) groups reported that a high degree of improvement was the minimum acceptable threshold for considering spinal fusion. A large majority indicated that the minimum acceptable outcomes included at least a decrease in pain intensity to 3/10 or less, an improvement in ODI of 20 or more, discontinuing opioid medications, and return to some occupational activity. Achieving the minimum acceptable outcome was strongly associated with satisfaction at 2 years after surgery. Patients with compensation claims, psychological distress, and other psychosocial stressors were more likely to report satisfaction in the absence of achieving their minimum acceptable outcome.Patients with spondylolisthesis and DDD both have relatively high minimum acceptable outcomes for spinal fusion. In these cohorts, few subjects considered more commonly proposed MCIDs for pain and function as an acceptable outcome and report that they would not have surgery if they did not expect to achieve more than those marginal improvements. Although there was good concordance between achieving the minimum acceptable outcomes and ultimate satisfaction, patients with significant psychosocial factors (compensation claims, psychological distress, and others) are less likely to associate satisfaction with outcomes with actually achieving these improvements.

  View details for DOI 10.1016/j.spinee.2010.02.001

  View details for Web of Science ID 000276971600006

  View details for PubMedID 20362247

• Facet Pain in Thoracic Compression Fractures PAIN MEDICINE Mitra, R., Do, H., Alamin, T., Cheng, I. 2010; 11 (11): 1674-1677

  Abstract

  To determine if thoracic facet joints may be a significant secondary pain generator in patients with compression fractures. Traditionally, pain from vertebral compression fractures has been attributed to vertebral body itself. Compression fractures have been shown to increase thoracic kyphosis and thereby increase the thoracic flexion moment; these changes eventually increase the shear stress on the posterior elements.We present a small case series of patients with thoracic compression fractures managed with intra-articular facet injections.Tertiary care academic medical center.Two patients with thoracic compression fractures.The subjects received fluoroscopically guided thoracic facet steroid injections for pain management.Change in verbal analog pain score.Patients with thoracic compression fractures received significant long-lasting relief after receiving fluoroscopically guided intra-articular injections.Facet joints may be abnormally stressed due to the increasing thoracic flexion moment in anterior compression fractures, which may serve as a secondary pain generator; intra-articular facet blocks may be an alternative to vertebroplasty.

  View details for Web of Science ID 000283989800011

  View details for PubMedID 21029349

• Point of view: spinopelvic parameters in postfusion flatback deformity patients SPINE JOURNAL Cheng, I. 2009; 9 (8): 672-673

  View details for DOI 10.1016/j.spinee.2009.05.011

  View details for Web of Science ID 000268786300009

  View details for PubMedID 19560404

• TREATMENT OF NECK PAIN Injections and Surgical Interventions: Results of the Bone and Joint Decade 2000-2010 Task Force on Neck Pain and Its Associated Disorders (Reprinted from Spine, vol 33, pg S153-S169, 2008) JOURNAL OF MANIPULATIVE AND PHYSIOLOGICAL THERAPEUTICS Carragee, E. J., Hurwitz, E. L., Cheng, I., Carroll, L. J., Nordin, M., Guzman, J., Peloso, P., Holm, L. W., Cote, P., Hogg-Johnson, S., van der Velde, G., Cassidy, J. D., Haldeman, S. 2009; 32 (2): S176-S193

  Abstract

  Best evidence synthesis.To identify, critically appraise, and synthesize literature from 1980 through 2006 on surgical interventions for neck pain alone or with radicular pain in the absence of serious pathologic disease.There have been no comprehensive systematic literature or evidence-based reviews published on this topic.We systematically searched Medline for literature published from 1980 to 2006 on percutaneous and open surgical interventions for neck pain. Publications on the topic were also solicited from experts in the field. Consensus decisions were made about the scientific merit of each article; those judged to have adequate internal validity were included in our Best Evidence Synthesis.Of the 31,878 articles screened, 1203 studies were relevant to the Neck Pain Task Force mandate and of these, 31 regarding treatment by surgery or injections were accepted as scientifically admissible. Radiofrequency neurotomy, cervical facet injections, cervical fusion and cervical arthroplasty for neck pain without radiculopathy are not supported by current evidence. We found there is support for short-term symptomatic improvement of radicular symptoms with epidural corticosteroids. It is not clear from the evidence that long-term outcomes are improved with the surgical treatment of cervical radiculopathy compared to nonoperative measures. However, relatively rapid and substantial symptomatic relief after surgical treatment seems to be reliably achieved. It is not evident that one open surgical technique is clearly superior to others for radiculopathy. Cervical foramenal or epidural injections are associated with relatively frequent minor adverse events (5%-20%); however, serious adverse events are very uncommon (<1%). After open surgical procedures on the cervical spine, potentially serious acute complications are seen in approximately 4% of patients.Surgical treatment and limited injection procedures for cervical radicular symptoms may be reasonably considered in patients with severe impairments. Percutaneous and open surgical treatment for neck pain alone, without radicular symptoms or clear serious pathology, seems to lack scientific support.

  View details for DOI 10.1016/j.jmpt.2008.11.018

  View details for Web of Science ID 000264208500018

  View details for PubMedID 19251063

• Retroperitoneal lymphocele after anterior spinal surgery SPINE Patel, A. A., Spiker, W. R., Daubs, M. D., Brodke, D. S., Cheng, I., Glasgow, R. E. 2008; 33 (18): E648-E652

  Abstract

  Case report; Review of Literature.To present an uncommon complication after anterior lumbar surgery as well as a treatment option and a review of the literature.A number of complications have been reported after anterior lumbar surgery. Common complications include vascular, ureteral, and neurologic injuries. The development of a retroperitoneal lymphocele has been previously been described, but details regarding evaluation, diagnosis, and treatment options are lacking in the literature.The case of a single patient with a postoperative retroperitoneal lymphocele was identified and retrospectively reviewed. Permission was obtained from the patient to review and publish this information. A review of literature on lymphoceles and anterior lumbar complications was also performed using PubMed and Ovid databases.A 76-year-old woman underwent anterior interbody fusion from L2-L3-L4-L5, followed by posterior T11-L5 fusion for degenerative scoliosis and spinal stenosis. Six weeks after surgery, she presented with severe abdominal pain, nausea, and emesis. Examination revealed a retroperitoneal lymphocele, which was confirmed after aspiration. The patient was treated with a laparoscopic marsupialization procedure without recurrence. At 12 months, the patient had no further abdominal symptoms, noted improvements in back and leg pain scores, and had stable radiographic findings.Retroperitoneal lymphocele is a rare complication after anterior lumbar interbody fusion. The different diagnosis should include infectious abscess, ureteral injury with urinoma, pancreatic injury with pseudocyst formation, and spinal fluid leak with pseudomeningocele. Diagnosis can be guided by serum and cyst fluid analysis. Although treatment options exist, surgical treatment may provide the most reliable results.

  View details for Web of Science ID 000258592800022

  View details for PubMedID 18708917

• Chymopapain: a shot from the past. Pain practice Mitra, R., Wedemeyer, M., Cheng, I. 2008; 8 (4): 331-332

  View details for DOI 10.1111/j.1533-2500.2008.00217.x

  View details for PubMedID 18727771

• Treatment of neck pain - Injections and surgical interventions: Results of the bone and joint decade 2000-2010 task force on neck pain and its associated disorders EUROPEAN SPINE JOURNAL Carragee, E. J., Hurwitz, E. L., Cheng, I., Carroll, L. J., Nordin, M., Guzman, J., Peloso, P., Holm, L. W., Cote, P., Hogg-Johnson, S., van der Velde, G., Cassidy, J. D., Haldeman, S. 2008; 17: S153-S169

  View details for DOI 10.1007/s00586-008-0632-y

  View details for Web of Science ID 000255167500017

• Treatment of neck pain - Injections and surgical interventions: Results of the bone and joint decade 2000-2010 task force on neck pain and its associated disorders SPINE Carragee, E. J., Hurwitz, E. L., Cheng, I., Carroll, L. J., Nordin, M., Guzman, J., Peloso, P., Holm, L. W., Cote, P., Hogg-Johnson, S., van der Velde, G., Cassidy, J. D., Haldeman, S. 2008; 33 (4): S153-S169

  Abstract

  Best evidence synthesis.To identify, critically appraise, and synthesize literature from 1980 through 2006 on surgical interventions for neck pain alone or with radicular pain in the absence of serious pathologic disease.There have been no comprehensive systematic literature or evidence-based reviews published on this topic.We systematically searched Medline for literature published from 1980 to 2006 on percutaneous and open surgical interventions for neck pain. Publications on the topic were also solicited from experts in the field. Consensus decisions were made about the scientific merit of each article; those judged to have adequate internal validity were included in our Best Evidence Synthesis.Of the 31,878 articles screened, 1203 studies were relevant to the Neck Pain Task Force mandate and of these, 31 regarding treatment by surgery or injections were accepted as scientifically admissible. Radiofrequency neurotomy, cervical facet injections, cervical fusion and cervical arthroplasty for neck pain without radiculopathy are not supported by current evidence. We found there is support for short-term symptomatic improvement of radicular symptoms with epidural corticosteroids. It is not clear from the evidence that long-term outcomes are improved with the surgical treatment of cervical radiculopathy compared to nonoperative measures. However, relatively rapid and substantial symptomatic relief after surgical treatment seems to be reliably achieved. It is not evident that one open surgical technique is clearly superior to others for radiculopathy. Cervical foramenal or epidural injections are associated with relatively frequent minor adverse events (5%-20%); however, serious adverse events are very uncommon (<1%). After open surgical procedures on the cervical spine, potentially serious acute complications are seen in approximately 4% of patients.Surgical treatment and limited injection procedures for cervical radicular symptoms may be reasonably considered in patients with severe impairments. Percutaneous and open surgical treatment for neck pain alone, without radicular symptoms or clear serious pathology, seems to lack scientific support.

  View details for Web of Science ID 000253739500017

  View details for PubMedID 18204388

• Interspinous ligament steroid injections for the management of Baastrup's disease: A case report ARCHIVES OF PHYSICAL MEDICINE AND REHABILITATION Mitra, R., Ghazi, U., Kirpalani, D., Cheng, I. 2007; 88 (10): 1353-1356

  Abstract

  Mitra R, Ghazi U, Kirpalani D, Cheng I. Interspinous ligament steroid injections for the management of Baastrup's disease: a case report. Baastrup's disease has been identified as a source of axial low back pain. There has been debate as to the etiology of pain in patients with Baastrup's disease. It has been theorized that the pain may originate from degenerative disk disease and spinal stenosis associated with the disease, whereas some have identified the neoarthrosis between joints and accompanying reactive eburnation as the source of pain. We present a simple case report of an 89-year-old woman with symptomatic Baastrup's disease. The patient underwent a fluoroscopically guided interspinous process injection of 20mg of triamcinolone acetate with local anesthetic. The patient remained pain free for 3 months. The neoarthrosis in Baastrup's disease may be the primary pain generator in cases of Baastrup's disease without significant central canal stenosis.

  View details for DOI 10.1016/j.apmr.2007.05.033

  View details for Web of Science ID 000250161500021

  View details for PubMedID 17908582

• The role of osteobiologics in spinal deformity NEUROSURGERY CLINICS OF NORTH AMERICA Cheng, I., Oshtory, R., Wildstein, M. S. 2007; 18 (2): 393-?

  Abstract

  Spinal deformity surgery represents one of the most challenging environments in which to achieve bone fusion. High rates of pseudarthroses, limited quantities of available autograft bone, and the potential morbidity of iliac crest harvest have driven a search for bone graft extenders and substitutes. With expanding knowledge of bone biology, the authors review options in spinal fusion with a particular focus on deformity surgery, including the use of autograft, allograft, demineralized bone matrix, ceramics, and bone morphogenetic proteins.

  View details for DOI 10.1016/j.nec.2007.01.002

  View details for Web of Science ID 000247680600025

  View details for PubMedID 17556142

• Posterior cervical spine surgery for radiculopathy NEUROSURGERY Riew, K. D., Cheng, I., Pimenta, L., Taylor, B. 2007; 60 (1): 57-63

  View details for DOI 10.1227/01.NEU.0000215409.64026.E2

  View details for Web of Science ID 000243421600015

• Posterior cervical spine surgery for radiculopathy. Neurosurgery Riew, K. D., Cheng, I., Pimenta, L., Taylor, B. 2007; 60 (1): S57-63

  Abstract

  It is now common knowledge that cervical radiculopathy, frequently caused by disc herniation and/or degeneration, will often improve without surgical intervention. Only a small percentage of patients with the severity of symptoms necessitate surgical treatment. Surgery for radiculopathy is indicated for motor weakness, progressive neurological deficits, and progressive symptoms that do not improve with nonoperative treatment. Advantages and disadvantages exist for both ventral and dorsal approaches in the surgical treatment of cervical radiculopathy. Indications and results for dorsal nerve root decompression are discussed, and a review of our preferred techniques, including use of minimally invasive technology, is presented.

  View details for PubMedID 17204887

• Does minor trauma cause serious low back illness? SPINE Carragee, E., Alamin, T., Cheng, I., Franklin, T., Hurwitz, E. 2006; 31 (25): 2942-2949

  Abstract

  Prospective, 5-year, cohort study of working subjects.To assess whether the occurrence of common minor trauma events affects the risk of developing serious low back pain (LBP) and LBP disability in subjects with and without degenerative changes to the lumbar spine.Although some theories suggest that minor traumatic events in combination with preexisting degenerative changes commonly cause significant structural injury to spinal segments and serious LBP illness, no prospective data exist on the relationship of minor trauma, detailed structural changes, and outcome measures of serious LBP episodes and occupational disability.Two hundred subjects without clinical LBP problems were recruited, and underwent baseline clinical and imaging studies. Every 6 months, subjects completed a scripted, algorithm-based interview assessing interval back pain episodes, severity, medical treatment, occupational disability, and the subject's perceived relation of this LBP episode to any preceding event. If a serious LBP episode clinically required a new magnetic resonance examination, the follow-up imaging was obtained and compared to baseline for interval changes.There was no association of minor trauma to adverse LBP events. For each 6-month study interval, the risk of developing a serious LBP episode was 2.1% unassociated with minor trauma and 2.4% following minor trauma (P = 0.59). Neither the frequency of minor trauma events nor the reported severity of the event correlated with adverse outcomes. Subjects with advanced structural findings were not more likely to become symptomatic with minor trauma events than with spontaneously evolving LBP episodes. Follow-up magnetic resonance imaging evaluating new serious LBP illness rarely revealed new clinically significant findings. Age and sex-adjusted prediction models, including abnormal psychometric testing, smoking, and compensation issues, accurately identified 80% of serious LBP events and 93% of LBP disability events.In this study cohort, minor trauma does not appear to increase the risk of serious LBP episodes or disability. The vast majority of incident-adverse LBP events may be predicted not by structural findings or minor trauma but by a small set of demographic and behavioral variables.

  View details for Web of Science ID 000242576200009

  View details for PubMedID 17139225

• Are first-time episodes of serious LBP associated with new MRI findings? spine journal Carragee, E., Alamin, T., Cheng, I., Franklin, T., van den Haak, E., Hurwitz, E. 2006; 6 (6): 624-635

  Abstract

  Magnetic resonance (MR) imaging is frequently used to evaluate first-time episodes of serious low back pain (LBP). Common degenerative findings are often interpreted as recent developments and the probable anatomic cause of the new symptoms. To date no prospective study has established a baseline MR status of the lumbar spine in subjects without significant LBP problems and prospectively surveyed these subjects for acute changes shortly after new and serious LBP episodes. This method can identify new versus old MR findings possibly associated with the acute symptomatic episode.To determine if new and serious episodes of LBP are associated with new and relevant findings on MRI.Prospective observational study with baseline and post-LBP MRI monitoring of 200 subjects over 5 years.Clinical outcomes: LBP intensity (visual analogue scale), Oswestry Disability Index, and work loss. MRI outcomes: disc degeneration, herniation, annular fissures, end plate changes, facet arthrosis, canal stenosis, spondylolisthesis, and root impingement.200 subjects with a lifetime history of no significant LBP problems, and a high risk for new LBP episodes were studied at baseline with physical examination, plain radiographs, and MR imaging. Subjects were followed every 6 months for 5 years with a detailed telephone interview. Subjects with a new severe LBP episode (LBP>or=6/10,>1 week) were assessed for new diagnostic tests. New MR imaging, taken within 6 to 12 weeks of the start of a new LBP episode, was compared with baseline (asymptomatic) images. Two independent and blinded readers evaluated each baseline and follow-up study.During the 5-year observation period of 200 subjects, 51 (25%) subjects were evaluated with a lumbar MRI for clinically serious LBP episodes, and 3/51 (6%) had a primary radicular complaint. These 51 subjects had 67 MR scans. Of 51 subjects, 43 (84%) had either unchanged MR or showed regression of baseline changes. The most common progressive findings were disc signal loss (10%), progressive facet arthrosis (10%), or increased end plate changes (4%). Only two subjects, both with primary radicular complaints, had new findings of probable clinical significance (4%). Subjects having another MR were more likely to have had chronic pain at baseline (odds ratio [OR]=3.19; 95% confidence interval [CI] 1.61-6.32), to smoke (OR=5.81; 95% CI 1.99-16.45), have baseline psychological distress (OR 2.27; 95% CI 1.15-4.49), and have previous disputed compensation claims (OR=2.35; 95% CI 0.97-5.69). Subjects involved in current compensation claims were also more likely to have an MR scan to evaluate the LBP episode (risk ratio=4.75, p<.001), but were unlikely to have significant new findings. New findings were not more frequent in subjects with LBP episodes developing after minor trauma than when LBP developed spontaneously.Findings on MR imaging within 12 weeks of serious LBP inception are highly unlikely to represent any new structural change. Most new changes (loss of disc signal, facet arthrosis, and end plate signal changes) represent progressive age changes not associated with acute events. Primary radicular syndromes may have new root compression findings associated with root irritation.

  View details for PubMedID 17088193

• Surgical treatment for unstable low-grade isthmic spondylolisthesis in adults: a prospective controlled study of posterior instrumented fusion compared with combined anterior-posterior fusion. spine journal Swan, J., Hurwitz, E., Malek, F., van den Haak, E., Cheng, I., Alamin, T., Carragee, E. 2006; 6 (6): 606-614

  Abstract

  The surgical treatment for low-grade isthmic spondylolisthesis in adults with intractable lumbar pain is usually spinal fusion. It has been postulated that anterior column reconstruction may be relatively advantageous in those patients with unstable slips.To compare the early and medium term treatment efficacy of two common fusion techniques in isthmic spondylolisthesis.Prospective controlled trial comparing single-level posterior-lateral instrumented fusion with combined anterior and posterior-lateral instrumented fusion in sequential matched cohorts of patients with radiographically unstable isthmic spondylolisthesis.Primary outcome measure of success was an Oswestry Disability Index (ODI)

  View details for PubMedID 17088191

• Prospective radiographic and clinical outcomes of dual-rod instrumented anterior spinal fusion in adolescent idiopathic scoliosis: Comparison with single-rod constructs SPINE Hurford, R. K., Lenke, L. G., Lee, S. S., Cheng, I., Sides, B., Bridwell, K. H. 2006; 31 (20): 2322-2328

  Abstract

  Anterior single or dual-rod instrumentation may be performed for the treatment of main thoracic, thoracolumbar, or lumbar adolescent idiopathic scoliosis (AIS) curves.To compare the results of anterior dual-rod instrumentation in single-major AIS curves with our previous experience using single-rod constructs.Several reports have described the use of anterior single-rod instrumentation for the treatment of AIS curves with acceptable correction rates but with pseudarthroses/implant failures of up to 31%.A total of 60 consecutive patients with AIS (12 males and 48 females; average age 15.3 years) with major thoracic (n = 18) or thoracolumbar/lumbar (n = 42) curves were treated with dual-rod instrumented anterior spinal fusion. Follow-up was 2-5 years. Patients were evaluated prospectively with Scoliosis Research Society (SRS) questionnaires.Major thoracic curves were corrected from a mean of 55 degrees to 27 degrees (51% correction), while major thoracolumbar/lumbar curves were corrected from an average of 51 degrees to 17 degrees at latest follow-up (67% correction). No pseudarthroses were identified. With the use of single-rod constructs, a similar amount of coronal correction was obtained for both thoracic (47%) and thoracolumbar/lumbar curves (70%). However, the pseudarthrosis rate for single-rod constructs was 5.5%. The obvious trend toward a lower pseudarthrosis rate in dual-rod (0/60) versus single-rod (5/90) constructs was not statistically significant (P = 0.07). Follow-up SRS questionnaire data for patients with dual-rod instrumentation showed 95% satisfaction, and 93% would choose the same treatment with similar results in the single-rod instrumentation study, 88% patient satisfaction, and 89% choosing the same treatment. Overall SRS scores improved after treatment (P < 0.01). SRS domain scores improved at a significant level for pain (P = 0.05), self-image (P < 0.01), and function (P = 0.01).In this largest, to our knowledge, single-center report of dual-rod constructs for patients with AIS, a similar amount of radiographic deformity correction was obtained when compared to single-rod implants. However, the absence of any pseudarthroses in the 60 patients with dual-rod is a distinct advantage.

  View details for Web of Science ID 000240696400011

  View details for PubMedID 16985460

• Apical sublaminar wires versus pedicle screws - Which provides better results for surgical correction of adolescent idiopathic scoliosis? SPINE Cheng, I., Kim, Y., Gupta, M. C., Bridwell, K. H., Hurford, R. K., Lee, S. S., Theerajunyaporn, T., Lenke, L. G. 2005; 30 (18): 2104-2112

  Abstract

  The results of correction for adolescent idiopathic scoliosis (AIS) were compared using apical sublaminar wires versus pedicle screws.To compare comprehensively the 2-year minimum postoperative results of posterior correction and spinal fusion using translational correction through either hybrid hook/sublaminar wire/pedicle screw constructs versus in situ rod-contouring correction with pedicle screw constructs in the treatment of AIS at 2 institutions.Despite the reports of satisfactory correction of scoliotic curves by both apical (sublaminar wire) instrumentation and apical pedicle screw instrumentation, to our knowledge, no reports on the comprehensive comparison of hybrid (hook/sublaminar wire/pedicle screw) instrumentation versus segmental pedicle screw instrumentation exist.A total of 50 patients with AIS at 2 institutions who underwent posterior spinal fusion with sublaminar wire (25 patients) or pedicle screw (25) constructs were sorted and matched according to 4 criteria: (1) similar age at surgery (14.2 years in the sublaminar wire and 14.4 in the pedicle screw group, P = 0.72); (2) similar number of fused vertebrae (11.4 in the sublaminar wire and 11.8 in the pedicle screw group, P = 0.36); (3) similar operative methods; and (4) identical Lenke curve types and similar preoperative major curve measurements (63.5 degrees in the sublaminar wire and 59.5 degrees in the pedicle screw group, P = 0.42). Patients were evaluated preoperatively, immediately postoperatively, and at 2-year follow-up according to radiographic changes in curve correction, operating time, intraoperative blood loss, implant costs, and the Scoliosis Research Society patient questionnaire (SRS-24) scores.After surgery, average major curve correction was 67.4% in the sublaminar wire and 68.1% in the pedicle screw group (P = 0.56). At 2-year follow-up, loss of the major curve correction was 4.6% in the sublaminar wire compared to 5.1% in the pedicle screw group (P = 0.79). Postoperative global coronal and sagittal balance were similar in both groups. No significant difference was found in the average number of levels fused from the distal end vertebra (1.48 in the sublaminar wire and 0.64 in the pedicle screw group, P = 0.21). Operating time averaged 350 minutes in the sublaminar wire and 357 in the pedicle screw group (P = 0.86). Intraoperative blood loss was significantly different in both groups (1791 +/- 816 mL in the sublaminar wire and 824 +/- 440 mL in the pedicle screw group) (P = 0.0003). Average implant cost in the sublaminar wire group (16.0 fixation points; 8,341 US dollars) was significantly lower than that of the pedicle screw group (17.1 fixation points; 13,462 US dollars) (P < 0.0001). Postoperative 2-year SRS-24 scores were similar in both groups (sublaminar wire = 107.3, pedicle screw = 103.5, P = 0.19). There were no neurologic or visceral complications related to sublaminar wire or pedicle screw instrumentation and no reoperations at a minimum 2-year follow-up.Apical sublaminar wire and pedicle screw instrumentation both offer similar major curve correction with similar fusion lengths without neurologic problems in the operative treatment of AIS. Although more expensive, pedicle screw constructs had significantly less blood loss and slightly shorter fusion lengths than the sublaminar wire constructs.

  View details for Web of Science ID 000231885900018

  View details for PubMedID 16166903

• Use of bone morphogenetic protein-2 for adult spinal deformity SPINE Luhmann, S. J., Bridwell, K. H., Cheng, I., Imamura, T., Lenke, L. G., Schootman, M. 2005; 30 (17): S110-S117

  Abstract

  Prospective, single-center, nonblinded clinical and radiographic analysis of consecutive adult deformity patients treated with recombinant human bone morphogenetic protein-2 (rhBMP-2) without iliac or rib bone graft supplementation.To determine the ability of rhBMP-2 to achieve both anterior and posterior spinal fusion in patients undergoing multilevel fusions for adult spinal deformity.The literature concerning one-level anterior fusions, and potentially one-level posterior fusions, using rhBMP-2 has demonstrated clinical efficacy. No published data exist on the use of rhBMP-2 in multilevel spine fusions.Prospective analysis of patients treated with rhBMP-2 in multilevel anterior and posterior fusions with a minimum 1-year follow-up. There were a total of 95 patient samples (70 total patients; 25 patients had rhBMP-2 used circumferentially): 46 anterior fusions (Group 1), 41 posterior fusions (Group 2), and 8 patients were "compassionate use" fusions (Group 3). In the anterior fusion group (n = 46), mean rhBMP-2/level was 10.8 mg in titanium mesh cages without any bone graft or other substance. The posterior fusion group had only local bone graft, no harvested rib or iliac bone graft (n = 41). The mean rhBMP-2/level was 13.7 mg. The "compassionate use" group (n = 8 patients) consisted of patients who had prior surgeries, prior iliac harvesting, and substantial comorbidities and therefore a higher concentration and different carrier was used. No local bone graft, no harvested bone was used. The mean rhBMP-2/level was 28.6 mg. The median dose was 40 mg for Group 3.For the anterior fusion group (n = 46), operative levels were deemed fused in 89 of the 93 (96%) levels. For the posterior fusion group (n = 41), a solid fusion was assessed in 110 of the 118 (93%) operative levels. For the "compassionate-use" patients, the overall fusion rate was 100% (52 of 52 operative levels).With the use of rhBMP-2, a high rate of apparent fusion was observed for anterior (96%) and posterior (93%) fusions in adult spinal deformity patients. Use of rhBMP-2 results in a promising early fusion rate without the graft harvest site morbidity.

  View details for Web of Science ID 000231770500018

  View details for PubMedID 16138058

• Use of Bone Morphogenetic Protein-2 for Adult Spinal Deformity Spine Luhmann SJ, Bridwell KH, Cheng I, Imamura T, Lenke LG, Schootman M. 2005; accepted
• Expression of an extracellular calcium-sensing receptor in rat stomach Digestive Diseases Week 97 Meeting Cheng, I., Qureshi, I., Chattopadhyay, N., Qureshi, A., Butters, R. R., Hall, A. E., Cima, R. R., Rogers, K. V., Hebert, S. C., Geibel, J. P., Brown, E. M., Soybel, D. I. W B SAUNDERS CO-ELSEVIER INC. 1999: 118?26

  Abstract

  Circulating levels of Ca2+ can influence secretory functions and myoelectrical properties of the stomach. A Ca2+-sensing receptor (CaR) has recently been identified in tissues that regulate systemic Ca2+ homeostasis. The aim of this study was to evaluate expression of CaR in the stomach of the rat.In forestomach and glandular stomach, reverse-transcription polymerase chain reaction was used to amplify a 380-base pair product, which is 99% homologous with transcripts obtained in parathyroid and kidney.Northern analysis of gastric mucosal polyA+ RNA revealed 7. 5- and 4.1-kilobase transcripts, similar to those obtained in rat parathyroid and kidney. Immunohistochemistry revealed CaR expression in regions of the submucosal plexus and myenteric neurons. In sections of intact tissue, preparations of primary culture surface cells and surgically dissected gastric glands, staining was observed consistently in epithelial cells of the gastric glands and in gastric surface cells. In parietal cells in isolated gastric glands, intracellular levels of Ca2+ responded to conditions that are known to activate CaR.These are the first reported observations that CaR is expressed in different epithelial cells of mammalian gastric mucosa and its enteric nerve regions. The effects of extracellular Ca2+ on gastric function may be attributable to activation of CaR.

  View details for Web of Science ID 000077785500022

  View details for PubMedID 9869609

• Identification and localization of the extracellular calcium-sensing receptor in human breast JOURNAL OF CLINICAL ENDOCRINOLOGY & METABOLISM Cheng, I., Klingensmith, M. E., Chattopadhyay, N., Kifor, O., Butters, R. R., Soybel, D. I., Brown, E. M. 1998; 83 (2): 703-707

  Abstract

  The extracellular calcium (Ca2+o)-sensing receptor (CaR) plays a critical role in maintaining Ca2+o homeostasis in mammals by virtue of its presence in parathyroid gland and kidney. The breast is well recognized as a Ca(2+)-handling organ, and the effects of altering Ca2+o on the proliferation of breast epithelial cells are well documented. To date there are no data regarding the expression and localization of CaR in breast tissue. In the present study, we assessed the distribution of CaR messenger ribonucleic acid (mRNA) and protein in normal and fibrocystic human breast tissue as well as in ductal carcinoma of the breast using RT-PCR, Northern analysis, and immunohistochemistry with CaR-specific antisera. In all tissues, RT-PCR performed using sense and antisense primers based on the sequence of the human parathyroid CaR complementary DNA amplified a product of the size expected (425 bp) for genuine CaR transcripts. Nucleotide sequencing of RT-PCR products confirmed more than 99% homology with human parathyroid CaR complementary DNA. Although insufficient quantities of mRNA were isolated from normal and fibrocystic tissue for Northern analysis, a single 5.2-kb CaR transcript was expressed in malignant breast tissue similar to the major CaR transcript in human parathyroid. Localization of CaR protein by immunohistochemistry showed specific CaR staining of the ductal epithelial cells of the breast in all three tissue types. These findings indicate the presence of CaR mRNA and protein in the breast, providing indirect evidence that the CaR may have some role(s) in the control of Ca2+ transport, epithelial cell proliferation, and/or other processes in normal and abnormal breast tissue.

  View details for Web of Science ID 000071823900067

  View details for PubMedID 9467597

• Identification and localization of extracellular calcium sensing receptor in the rat intesting Am J Phys Chattopadhyay N, Cheng I, Rogers K, Riccardi D, Hall A, Diaz R, Hebert SC, Soybel DI, Brown EM. 1998; 274 (1): G122-30
• Identification and functional assay of an extracellular calcium-sensing receptor in Necturus gastric mucosa Digestive Diseases Week 97 Meeting Cima, R. R., Cheng, I., Klingensmith, M. E., Chattopadhyay, N., Kifor, O., Hebert, S. C., Brown, E. M., Soybel, D. I. AMER PHYSIOLOGICAL SOC. 1997: G1051?G1060

  Abstract

  In mammals and amphibians, increases in extracellular Ca2+ can activate bicarbonate secretion and other protective functions of gastric mucosa. We hypothesized that the recently cloned extracellular Ca(2+)-sensing receptor (CaR) is functioning in the gastric mucosa. In Necturus maculosus gastric mucosa, reverse transcription-polymerase chain reaction using primers based on previously cloned CaR sequences amplified a 326-bp DNA fragment that had 84% nucleotide sequence identity with the rat kidney CaR. Immunohistochemical localization of the CaR using specific anti-CaR antiserum revealed its presence on the basal aspect of gastric epithelial cells. In microelectrode studies of Necturus antral mucosa, exposure to elevated Ca2+ (4.8 mM) and the CaR agonists NPS-467 and neomycin sulfate resulted in significant hyperpolarizations of basal membrane electrical potentials and increases in apical-to-basal membrane resistance ratios. Circuit analysis revealed that these changes reflected specific decreases in basolateral membrane resistance. Inhibition of prostaglandin synthesis using indomethacin significantly attenuated these effects. We conclude that the CaR is present and functioning in Necturus gastric antrum.

  View details for Web of Science ID A1997YF88400011

  View details for PubMedID 9374702