Julius Bishop, MD

All Publications

• The Effects of Limb Elevation on Muscle Oxygen Saturation: A Near-Infrared Spectroscopy Study in Humans PM&R Palanca, A. A., Yang, A., Bishop, J. A. 2016; 8 (3): 221-224

  View details for DOI 10.1016/j.pmrj.2015.07.015

  View details for Web of Science ID 000372434900004

• The Effects of Limb Elevation on Muscle Oxygen Saturation: A Near-Infrared Spectroscopy Study in Humans. PM & R : the journal of injury, function, and rehabilitation Palanca, A. A., Yang, A., Bishop, J. A. 2016; 8 (3): 221-224

  Abstract

  Orthopaedic and rehabilitation physicians often instruct patients to elevate a traumatized or postoperative lower extremity. Elevation is thought to improve patient comfort, as well as decrease swelling, wound complications, and the risk of compartment syndrome. Elevating a limb with increased compartment pressures, however, has been shown to reduce perfusion pressure and contribute to tissue ischemia. This investigation aims to advance our understanding of the tissue effects of limb elevation using a healthy patient model.To quantify the effects of elevation, experimentally induced ischemia, and immobilization on muscle oxygen saturation in the human leg using near-infrared spectroscopy (NIRS).Experimental crossover study.Orthopaedic Surgery research laboratory, Stanford Hospitals & Clinics.Twenty-six healthy volunteers.Using transcutaneous sensors, we measured muscle oxygen saturation of the anterior compartment of the left (control) leg at 0, 15, and 30 cm of elevation relative to the heart using NIRS. A standardized short leg splint and a thigh tourniquet inflated to 50 mmHg were then applied to the right (experimental) leg to simulate a traumatized state. NIRS measurements were then repeated, again at 0, 15, and 30 cm of elevation. Muscle oxygen saturation values at various degrees of elevation of the control and experimental limb were then compared and analyzed by the use of a crossover study design and mixed-effects regression.Muscle oxygen saturation at varying levels of elevation in both the (1) control leg and (2) experimental leg in a simulated traumatic state.Male (18) males and female (8) patients between 22 and 62 years of age (mean 29.8 years) were enrolled. Mean regional muscle oxygen saturation (rSO2) of the control limbs at 0, 15 and, 30 cm of elevation were 74.2%, 72.5%, and 70.6%, respectively, whereas mean rSO2 of the experimental limbs were 66.3%, 65.0%, and 63.3%. A statistically significant decrease of rSO2 was observed (mean 7.65%) in the experimental limbs compared with the control limbs. As elevation increased, there was a statistically significant decrease in rSO2 of 0.12% per centimeter of elevation. Elevation did not decrease the rSO2 in the experimental limb to a greater degree than in the control limb.Increasing levels of elevation in a human limb results in progressively compromised muscle oxygen saturation as measured by NIR.

  View details for DOI 10.1016/j.pmrj.2015.07.015

  View details for PubMedID 26261022

• Operative Versus Nonoperative Treatment of Jones Fractures: A Decision Analysis Model. American journal of orthopedics (Belle Mead, N.J.) Bishop, J. A., Braun, H. J., Hunt, K. J. 2016; 45 (3): E69-76

  Abstract

  Optimal management of metadiaphyseal fifth metatarsal fractures (Jones fractures) remains controversial. Decision analysis can optimize clinical decision-making based on available evidence and patient preferences. We conducted a study to establish the determinants of decision-making and to determine the optimal treatment strategy for Jones fractures using a decision analysis model. Probabilities for potential outcomes of operative and nonoperative treatment of Jones fractures were determined from a review of the literature. Patient preferences for outcomes were obtained by questionnaire completed by 32 healthy adults with no history of foot fracture. Derived values were used in the model as a measure of utility. A decision tree was constructed, and fold-back and sensitivity analyses were performed to determine optimal treatment. Nonoperative treatment was associated with a value of 7.74, and operative treatment with an intramedullary screw was associated with a value of 7.88 given the outcome probabilities and utilities studied, making operative treatment the optimal strategy. When parameters were varied, nonoperative treatment was favored when the likelihood of healing with nonoperative treatment rose above 82% and when the probability of healing after surgery fell below 92%. In this decision analysis model, operative fixation is the preferred management strategy for Jones fractures.

  View details for PubMedID 26991586

• Conventional versus virtual radiographs of the injured pelvis and acetabulum SKELETAL RADIOLOGY Bishop, J. A., Rao, A. J., Pouliot, M. A., Beaulieu, C., Bellino, M. 2015; 44 (9): 1303-1308

  Abstract

  Evaluation of the fractured pelvis or acetabulum requires both standard radiographic evaluation as well as computed tomography (CT) imaging. The standard anterior-posterior (AP), Judet, and inlet and outlet views can now be simulated using data acquired during CT, decreasing patient discomfort, radiation exposure, and cost to the healthcare system. The purpose of this study is to compare the image quality of conventional radiographic views of the traumatized pelvis to virtual radiographs created from pelvic CT scans.Five patients with acetabular fractures and ten patients with pelvic ring injuries were identified using the orthopedic trauma database at our institution. These fractures were evaluated with both conventional radiographs as well as virtual radiographs generated from a CT scan. A web-based survey was created to query overall image quality and visibility of relevant anatomic structures. This survey was then administered to members of the Orthopaedic Trauma Association (OTA).Ninety-seven surgeons completed the acetabular fracture survey and 87 completed the pelvic fracture survey. Overall image quality was judged to be statistically superior for the virtual as compared to conventional images for acetabular fractures (3.15 vs. 2.98, p = 0.02), as well as pelvic ring injuries (2.21 vs. 1.45, p = 0.0001). Visibility ratings for each anatomic landmark were statistically superior with virtual images as well.Virtual radiographs of pelvic and acetabular fractures offer superior image quality, improved comfort, decreased radiation exposure, and a more cost-effective alternative to conventional radiographs.

  View details for DOI 10.1007/s00256-015-2171-z

  View details for Web of Science ID 000358329600008

• The Inadequacy of Pediatric Fracture Care Information in Emergency Medicine and Pediatric Literature and Online Resources. Journal of pediatric orthopedics Tileston, K., Bishop, J. A. 2015; 35 (7): 769-773

  Abstract

  Emergency medicine and pediatric physicians often provide initial pediatric fracture care. Therefore, basic knowledge of the various treatment options is essential. The purpose of this study was to determine the accuracy of information commonly available to these physicians in textbooks and online regarding the management of pediatric supracondylar humerus and femoral shaft fractures.The American Academy of Orthopaedic Surgeons Clinical Practice Guidelines for pediatric supracondylar humerus and femoral shaft fractures were used to assess the content of top selling emergency medicine and pediatric textbooks as well as the top returned Web sites after a Google search. Only guidelines that addressed initial patient management were included. Information provided in the texts was graded as consistent, inconsistent, or omitted.Five emergency medicine textbooks, 4 pediatric textbooks, and 5 Web sites were assessed. Overall, these resources contained a mean 31.6% (SD=32.5) complete and correct information, whereas 3.6 % of the information was incorrect or inconsistent, and 64.8% was omitted. Emergency medicine textbooks had a mean of 34.3% (SD=28.3) correct and complete recommendations, 5.7% incorrect or incomplete recommendations, and 60% omissions. Pediatric textbooks were poor in addressing any of the American Academy of Orthopaedic Surgeons guidelines with an overall mean of 7.14% (SD=18.9) complete and correct recommendations, a single incorrect/incomplete recommendation, and 91.1% omissions. Online resources had a mean of 48.6% (SD=33.1) complete and correct recommendations, 5.72% incomplete or incorrect recommendations, and 45.7% omissions.This study highlights important deficiencies in resources available to pediatric and emergency medicine physicians seeking information on pediatric fracture management. Information in emergency medicine and pediatric textbooks as well as online is variable, with both inaccuracies and omissions being common. This lack of high-quality information could compromise patient care. Resources should be committed to ensuring accurate and complete information is readily available to all physicians providing pediatric fracture care. In addition, orthopaedic surgeons should take an active role to ensure that nonorthopaedic textbooks and online resources contain complete and accurate information.Level IV.

  View details for DOI 10.1097/BPO.0000000000000357

  View details for PubMedID 25393570

• The Prevalence of Sacroiliac Joint Degeneration in Asymptomatic Adults JOURNAL OF BONE AND JOINT SURGERY-AMERICAN VOLUME Eno, J. T., Boone, C. R., Bellino, M. J., Bishop, J. A. 2015; 97A (11): 932-936

  Abstract

  Degenerative changes of the sacroiliac joint have been implicated as a cause of lower back pain in adults. The purpose of this study was to determine the prevalence of sacroiliac joint degeneration in asymptomatic patients.Five hundred consecutive pelvic computed tomography (CT) scans, made at a tertiary-care medical center, of patients with no history of pain in the lower back or pelvic girdle were retrospectively reviewed and analyzed for degenerative changes of the sacroiliac joint. After exclusion criteria were applied, 373 CT scans (746 sacroiliac joints) were evaluated for degenerative changes. Regression analysis was used to determine the association between age and the degree of sacroiliac joint degeneration.The prevalence of sacroiliac joint degeneration was 65.1%, with substantial degeneration occurring in 30.5% of asymptomatic subjects. The prevalence steadily increased with age, with 91% of subjects in the ninth decade of life displaying degenerative changes.Radiographic evidence of sacroiliac joint degeneration is highly prevalent in the asymptomatic population and is associated with age. Caution must be exercised when attributing lower back or pelvic girdle pain to sacroiliac joint degeneration seen on imaging.Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

  View details for DOI 10.2106/JBJS.N.01101

  View details for Web of Science ID 000363418100010

• CORR Insights ®: A dedicated research program increases the quantity and quality of orthopaedic resident publications. Clinical orthopaedics and related research Bishop, J. A. 2015; 473 (4): 1522-1523

  View details for DOI 10.1007/s11999-014-4111-y

  View details for PubMedID 25516003

• Terrible Triad Elbow Fracture-Dislocation With Triceps and Flexor-Pronator Mass Avulsion ORTHOPEDICS Gajendran, V. K., Bishop, J. A. 2015; 38 (2): E143-E146

  Abstract

  Terrible triad elbow injuries, consisting of fractures of the radial head and coronoid with ulnohumeral dislocation, are challenging to treat. They require a comprehensive understanding of the complex anatomy of the elbow to effectively treat all of the pathology and create a stable, congruent joint. The authors present a case of a terrible triad injury with avulsion of the triceps and flexor-pronator mass after a low-energy fall in a young patient. Although most terrible triad fracture-dislocations can be successfully treated with coronoid fixation, radial head fixation or replacement, and repair of the lateral collateral ligament complex, this case involved a completely circumferential injury to the elbow. The coronoid and anterior capsule were disrupted anteriorly, the radial head and lateral collateral ligament complex were disrupted laterally, the triceps was disrupted posteriorly, and the flexor-pronator mass was disrupted medially. Although the authors prefer to address most terrible triad injuries through a lateral approach, they suspected a circumferential injury preoperatively and elected to use a single posterior incision to address all of the pathology conveniently. This injury required treatment of all disrupted structures, because the elbow remained unstable until the triceps and flexor-pronator mass avulsions were ultimately repaired. With any elbow fracture-dislocation, surgeons should look for evidence of additional injuries that do not fit the commonly described patterns, because they may necessitate modifications to the treatment plan. Given the relatively common complications of stiffness and instability despite modern surgical techniques, additional injuries may further compromise functional outcomes unless they are addressed properly.

  View details for DOI 10.3928/01477447-20150204-91

  View details for Web of Science ID 000352076100012

  View details for PubMedID 25665121

• Open Reduction and Internal Fixation Versus Total Elbow Arthroplasty for the Treatment of Geriatric Distal Humerus Fractures: A Systematic Review and Meta-Analysis JOURNAL OF ORTHOPAEDIC TRAUMA Githens, M., Yao, J., Sox, A. H., Bishop, J. 2014; 28 (8): 481-488

  View details for Web of Science ID 000340149400019

• Fabrication, vascularization and osteogenic properties of a novel synthetic biomimetic induced membrane for the treatment of large bone defects BONE Ren, L., Kang, Y., Browne, C., Bishop, J., Yang, Y. 2014; 64: 173-182

  View details for DOI 10.1016/j.bone.2014.04.011

  View details for Web of Science ID 000337011500024

• Fabrication, vascularization and osteogenic properties of a novel synthetic biomimetic induced membrane for the treatment of large bone defects. Bone Ren, L., Kang, Y., Browne, C., Bishop, J., Yang, Y. 2014; 64: 173-182

  Abstract

  The induced membrane has been widely used in the treatment of large bone defects but continues to be limited by a relatively lengthy healing process and a requisite two stage surgical procedure. Here we report the development and characterization of a synthetic biomimetic induced membrane (BIM) consisting of an inner highly pre-vascularized cell sheet and an outer osteogenic layer using cell sheet engineering. The pre-vascularized inner layer was formed by seeding human umbilical vein endothelial cells (HUVECs) on a cell sheet comprised of a layer of undifferentiated human bone marrow-derived mesenchymal stem cells (hMSCs). The outer osteogenic layer was formed by inducing osteogenic differentiation of hMSCs. In vitro results indicated that the undifferentiated hMSC cell sheet facilitated the alignment of HUVECs and significantly promoted the formation of vascular-like networks. Furthermore, seeded HUVECs rearranged the extracellular matrix produced by hMSC sheet. After subcutaneous implantation, the composite constructs showed rapid vascularization and anastomosis with the host vascular system, forming functional blood vessels in vivo. Osteogenic potential of the BIM was evidenced by immunohistochemistry staining of osteocalcin, tartrate-resistant acid phosphatase (TRAP) staining, and alizarin red staining. In summary, the synthetic BIM showed rapid vascularization, significant anastomoses, and osteogenic potential in vivo. This synthetic BIM has the potential for treatment of large bone defects in the absence of infection.

  View details for DOI 10.1016/j.bone.2014.04.011

  View details for PubMedID 24747351

• Delayed union and nonunions: Epidemiology, clinical issues, and financial aspects INJURY-INTERNATIONAL JOURNAL OF THE CARE OF THE INJURED Hak, D. J., Fitzpatrick, D., Bishop, J. A., Marsh, J. L., Tilp, S., Schnettler, R., Simpson, H., Alt, V. 2014; 45: S3-S7

  Abstract

  Fracture healing is a critically important clinical event for fracture patients and for clinicians who take care of them. The clinical evaluation of fracture healing is based on both radiographic findings and clinical findings. Risk factors for delayed union and nonunion include patient dependent factors such as advanced age, medical comorbidities, smoking, non-steroidal anti-inflammatory use, various genetic disorders, metabolic disease and nutritional deficiency. Patient independent factors include fracture pattern, location, and displacement, severity of soft tissue injury, degree of bone loss, quality of surgical treatment and presence of infection. Established nonunions can be characterised in terms of biologic capacity, deformity, presence or absence of infection, and host status. Hypertrophic, oligotrophic and atrophic radiographic appearances allow the clinician to make inferences about the degree of fracture stability and the biologic viability of the fracture fragments while developing a treatment plan. Non-unions are difficult to treat and have a high financial impact. Indirect costs, such as productivity losses, are the key driver for the overall costs in fracture and non-union patients. Therefore, all strategies that help to reduce healing time with faster resumption of work and activities not only improve medical outcome for the patient, they also help reduce the financial burden in fracture and non-union patients.

  View details for DOI 10.1016/j.injury.2014.04.002

  View details for Web of Science ID 000343236400002

  View details for PubMedID 24857025

• Lack of Proficiency in Musculoskeletal Medicine Among Emergency Medicine Physicians JOURNAL OF ORTHOPAEDIC TRAUMA Comer, G. C., Liang, E., Bishop, J. A. 2014; 28 (4): E85-E87

  Abstract

  Emergency medicine (EM) physicians are frequently responsible for evaluating and treating patients with urgent or emergent musculoskeletal conditions, so it is critical that they achieve a basic level of proficiency in musculoskeletal medicine. However, inadequacies in musculoskeletal education have previously been documented among medical students, residents, and attending physicians in a number of specialties. The goal of this study was to assess the proficiency with musculoskeletal medicine among EM physicians in particular.A validated musculoskeletal medicine competency examination was administered to the EM residents and faculty at a university-affiliated level 1 trauma center. Demographic data and satisfaction with musculoskeletal education were also surveyed.Twenty-three EM residents and 21 attending physicians completed the survey. Thirty-five percent of residents and 43% of attending physicians failed to demonstrate proficiency on the examination. Pass rates were not significantly different among junior residents, senior residents, or attending physicians. Twenty-three percent of respondents indicated that they were dissatisfied with their musculoskeletal education.Significant deficiencies in musculoskeletal education exist among EM physicians in training and attending staff. Given the frequency with which these physicians evaluate and treat acute musculoskeletal conditions, additional resources should be committed to their training.

  View details for DOI 10.1097/BOT.0b013e3182a66829

  View details for Web of Science ID 000333153200004

  View details for PubMedID 23899765

• The Biomechanical Significance of Washer Use With Screw Fixation JOURNAL OF ORTHOPAEDIC TRAUMA Bishop, J. A., Behn, A. W., Castillo, T. N. 2014; 28 (2): 114-117

  Abstract

  OBJECTIVES:: Washers can be used with lag screws during fracture fixation to optimize compression and minimize the risk of unintentional intrusion of the screw head through cortical bone during screw insertion. The concept of using washers to optimize screw fixation is particularly applicable to iliosacral screw fixation as well as screw fixation of the femoral neck, distal femur, proximal and distal tibia. However, there is a paucity of literature on this topic. The purpose of this study was to detail the biomechanical consequences of washer use and screw intrusion. METHODS:: Partially threaded 7.0 mm cannulated screws with and without washers were placed through synthetic bone blocks fabricated to simulate cortical and cancellous bone. A load cell was used to measure the compressive force before and after screw intrusion. Screws were tested with a washer (N=8), without a washer (N=8), and with a washer after initially being intruded (N=8). RESULTS:: Screws inserted with washers generated significantly more compressive force than screws inserted without washers before screw intrusion. After intrusion, compressive force decreased significantly under all conditions, but screws inserted with washers maintained greater compressive force than screws inserted without washers. Screws with washers reinserted after intrusion without a washer, produced almost as much compressive force as screws inserted with washers primarily. CONCLUSIONS:: Screw intrusion during fracture fixation results in a loss of compressive force that may compromise fixation quality. Washers are advantageous in that they allow for more compression to be generated before intrusion occurs and can be used to salvage compressive force of intruded screws.

  View details for Web of Science ID 000331197000014

  View details for PubMedID 23782961

• Survey Finds Few Orthopedic Surgeons Know The Costs Of The Devices They Implant HEALTH AFFAIRS Okike, K., O'Toole, R. V., Pollak, A. N., Bishop, J. A., McAndrew, C. M., Mehta, S., Cross, W. W., Garrigues, G. E., Harris, M. B., Lebrun, C. T. 2014; 33 (1): 103-109

  Abstract

  Orthopedic procedures represent a large expense to the Medicare program, and costs of implantable medical devices account for a large proportion of those procedures' costs. Physicians have been encouraged to consider cost in the selection of devices, but several factors make acquiring cost information difficult. To assess physicians' levels of knowledge about costs, we asked orthopedic attending physicians and residents at seven academic medical centers to estimate the costs of thirteen commonly used orthopedic devices between December 2012 and March 2013. The actual cost of each device was determined at each institution; estimates within 20 percent of the actual cost were considered correct. Among the 503 physicians who completed our survey, attending physicians correctly estimated the cost of the device 21 percent of the time, and residents did so 17 percent of the time. Thirty-six percent of physicians and 75 percent of residents rated their knowledge of device costs "below average" or "poor." However, more than 80 percent of all respondents indicated that cost should be "moderately," "very," or "extremely" important in the device selection process. Surgeons need increased access to information on the relative prices of devices and should be incentivized to participate in cost containment efforts.

  View details for DOI 10.1377/hlthaff.2013.0453

  View details for Web of Science ID 000330289300014

  View details for PubMedID 24395941

• The posterior approach to pelvic ring injuries: A technique for minimizing soft tissue complications INJURY-INTERNATIONAL JOURNAL OF THE CARE OF THE INJURED Fowler, T. T., Bishop, J. A., Bellino, M. J. 2013; 44 (12): 1780-1786

  Abstract

  Surgical techniques and fixation strategies for the treatment of unstable posterior pelvic ring injuries continue to evolve. The safety of the posterior surgical approach in particular has been questioned due to historically high rates of wound related complications. More contemporary studies have shown lower infection rates, however concern still persists. These concerns for infection and wound necrosis have led, in part, to increased interest in closed reduction and percutaneous fixation for treatment of these injuries but an open posterior approach remains the optimal strategy in some injury patterns. We describe herein a modified posterior approach to the pelvis designed to minimize wound related complications and present our clinical results demonstrating wound complication rates consistent with contemporary publications.

  View details for DOI 10.1016/j.injury.2013.08.005

  View details for Web of Science ID 000326376500016

  View details for PubMedID 24011422

• Surgical Versus Nonsurgical Treatment of Femur Fractures in People With Spinal Cord Injury: An Administrative Analysis of Risks ARCHIVES OF PHYSICAL MEDICINE AND REHABILITATION Bishop, J. A., Suarez, P., DiPonio, L., Ota, D., Curtin, C. M. 2013; 94 (12): 2357-2364

  Abstract

  To assess the risks associated with surgical and nonsurgical care of femur fractures in people with spinal cord injury (SCI).Retrospective cohort study; an analysis of Veterans Affairs (VA) data from the National Patient Care Database.Administrative data from database.The cohort was identified by searching the administrative data from fiscal years 2001 to 2006 for veterans with a femur fracture diagnosis using the International Classification of Diseases, 9th Revision, Clinical Modification codes. This group was subdivided into those with (n=396) and without (n=13,350) SCI and those treated with and without surgical intervention.Not applicable.Rates of mortality and adverse events.The SCI group was younger with more distal fractures than the non-SCI group. In the non-SCI population, 78% of patients had associated surgical codes compared with 37% in the SCI population. There was higher mortality in the non-SCI group treated nonoperatively. In the SCI population, there was no difference in mortality between patients treated nonoperatively and operatively. Overall adverse events were similar between groups except for pressure sores in the SCI population, of which the nonoperative group had 20% and the operative had 7%. Rates of surgical interventions for those with SCI varied greatly among VA institutions.We found lower rates of surgical intervention in the SCI population. Those with SCI who had surgery did not have increased mortality or adverse events. Surgical treatment minimizes the risks of immobilization and should be considered in appropriate SCI patients.

  View details for DOI 10.1016/j.apmr.2013.07.024

  View details for Web of Science ID 000327905600006

• Synthesis and characterization of novel elastomeric poly(D,L-lactide urethane) maleate composites for bone tissue engineering EUROPEAN POLYMER JOURNAL Mercado-Pagan, A. E., Kang, Y., Ker, D. F., Park, S., Yao, J., Bishop, J., Yang, Y. P. 2013; 49 (10): 3337-3349

  View details for DOI 10.1016/j.eurpolymj.2013.07.004

  View details for Web of Science ID 000325233800049

• Provisional mini-fragment plate fixation in clavicle shaft fractures. American journal of orthopedics (Belle Mead, N.J.) Bishop, J. A., Castillo, T. N. 2013; 42 (10): 470-472

  Abstract

  Plate fixation has an increasingly prominent role in the management of select clavicle fractures. However, many fracture patterns are not easily reduced and provisionally stabilized with conventional clamp application and lag-screw placement, and maintaining an appropriate reduction can be a challenge. In this article, we present a technique in which a mini-fragment plate is used to provisionally maintain fracture reduction while the definitive plate is applied.

  View details for PubMedID 24278907

• Antegrade Femoral Nailing in Acetabular Fractures Requiring a Kocher-Langenbeck Approach ORTHOPEDICS Bishop, J. A., Cross, W. W., Krieg, J. C., Routt, M. L. 2013; 36 (9): E1159-E1164

  View details for DOI 10.3928/01477447-20130821-18

  View details for Web of Science ID 000325553500009

• The effect of rhBMP-2 and PRP delivery by biodegradable beta-tricalcium phosphate scaffolds on new bone formation in a non-through rabbit cranial defect model JOURNAL OF MATERIALS SCIENCE-MATERIALS IN MEDICINE Lim, H., Mercado-Pagan, A. E., Yun, K., Kang, S., Choi, T., Bishop, J., Koh, J., Maloney, W., Lee, K., Yang, Y. P., Park, S. 2013; 24 (8): 1895-1903

  Abstract

  This study evaluated whether the combination of biodegradable β-tricalcium phosphate (β-TCP) scaffolds with recombinant human bone morphogenetic protein-2 (rhBMP-2) or platelet-rich plasma (PRP) could accelerate bone formation and increase bone height using a rabbit non-through cranial bone defect model. Four non-through cylindrical bone defects with a diameter of 8-mm were surgically created on the cranium of rabbits. β-TCP scaffolds in the presence and absence of impregnated rhBMP-2 or PRP were placed into the defects. At 8 and 16 weeks after implantation, samples were dissected and fixed for analysis by microcomputed tomography and histology. Only defects with rhBMP-2 impregnated β-TCP scaffolds showed significantly enhanced bone formation compared to non-impregnated β-TCP scaffolds (P < 0.05). Although new bone was higher than adjacent bone at 8 weeks after implantation, vertical bone augmentation was not observed at 16 weeks after implantation, probably due to scaffold resorption occurring concurrently with new bone formation.

  View details for DOI 10.1007/s10856-013-4939-9

  View details for Web of Science ID 000321915300008

  View details for PubMedID 23779152

• Cost-Effectiveness Analysis of Primary Arthroscopic Stabilization Versus Nonoperative Treatment for First-Time Anterior Glenohumeral Dislocations ARTHROSCOPY-THE JOURNAL OF ARTHROSCOPIC AND RELATED SURGERY Crall, T. S., Bishop, J. A., Guttman, D., Kocher, M., Bozic, K., Lubowitz, J. H. 2012; 28 (12): 1755-1765

  Abstract

  The purpose of this study was to compare the cost-effectiveness of initial observation versus surgery for first-time anterior shoulder dislocation.The clinical scenario of first-time anterior glenohumeral dislocation was simulated using a Markov model (where variables change over time depending on previous states). Nonoperative outcomes include success (no recurrence) and recurrence; surgical outcomes include success, recurrence, and complications of infection or stiffness. Probabilities for outcomes were determined from published literature. Costs were tabulated from Medicare Current Procedural Terminology data, as well as hospital and office billing records. We performed microsimulation and probabilistic sensitivity analysis running 6 models for 1,000 patients over a period of 15 years. The 6 models tested were male versus female patients aged 15 years versus 25 years versus 35 years.Primary surgery was less costly and more effective for 15-year-old boys, 15-year-old girls, and 25-year-old men. For the remaining scenarios (25-year-old women and 35-year-old men and women), primary surgery was also more effective but was more costly. However, for these scenarios, primary surgery was still very cost-effective (cost per quality-adjusted life-year, <$25,000). After 1 recurrence, surgery was less costly and more effective for all scenarios.Primary arthroscopic stabilization is a clinically effective and cost-effective treatment for first-time anterior shoulder dislocations in the cohorts studied. By use of a willingness-to-pay threshold of $25,000 per quality-adjusted life-year, surgery was more cost-effective than nonoperative treatment for the majority of patients studied in the model.Level II, economic and decision analysis.

  View details for DOI 10.1016/j.arthro.2012.05.885

  View details for Web of Science ID 000311751500008

  View details for PubMedID 23040837

• Open Reduction and Intramedullary Nail Fixation of Closed Tibial Fractures ORTHOPEDICS Bishop, J. A., Dikos, G. D., Mickelson, D., Barei, D. P. 2012; 35 (11): E1631-E1634

  Abstract

  Some tibial shaft fractures cannot be accurately reduced using closed or percutaneous techniques during an intramedullary nailing procedure. Under these circumstances, a formal open reduction can be performed. Direct exposure of the fracture facilitates accurate reduction but does violate the soft tissue envelope. The purpose of this study was to evaluate the safety and efficacy of open reduction prior to intramedullary nailing. Using the trauma database at a Level I trauma center, 11 uncomplicated closed displaced tibia fractures treated with formal open reduction prior to intramedullary nailing were identified and matched with a cohort of 21 fractures treated with closed reduction and nailing. The authors attempted to match 2 controls to each patient to improve the power of the study. Clinical and radiographic outcomes were compared. All fractures ultimately healed within 5° of anatomic alignment. No infections or non-unions occurred in the open reduction group, and 1 deep infection and 1 nonunion occurred in the closed reduction group. No significant differences existed between the study groups. Although closed reduction and intramedullary nailing remains the treatment of choice for most significantly displaced tibial shaft fractures, open reduction with respectful handling of the soft tissue envelope can be safe and effective and should be considered when less invasive techniques are unsuccessful.

  View details for DOI 10.3928/01477447-20121023-21

  View details for Web of Science ID 000311031900010

  View details for PubMedID 23127455

• Predictive Factors for Knee Stiffness After Periarticular Fracture A Case-Control Study JOURNAL OF BONE AND JOINT SURGERY-AMERICAN VOLUME Bishop, J., Agel, J., Dunbar, R. 2012; 94A (20): 1833-1838

  Abstract

  Knee stiffness is an important complication after periarticular fracture, but a systematic evaluation of risk factors for this complication and outcomes of treatment has not been undertaken, to our knowledge. The aims of this study were to evaluate risk factors for knee stiffness requiring manipulation after periarticular fracture and to document the clinical outcomes of the manipulation.This study was designed as a case-control study in which patients requiring manipulation under anesthesia after periarticular fracture were compared with those who did not require manipulation. Using billing data from a regional level-I trauma center, we identified twenty-four knees requiring manipulation for refractory stiffness over a six-year period. These were matched, on the basis of the AO/OTA classification, with forty-three control knees that did not develop stiffness requiring manipulation. Descriptive statistics were used for frequency and mean analysis.Univariate analysis revealed that extensor mechanism disruption (chi square = 0.05), fasciotomy (chi square = 0.020), wounds requiring ongoing management and precluding knee motion (p = 0.001), and the need for more than two surgical procedures to achieve definitive fracture fixation and soft-tissue coverage (p = 0.003) all placed patients at increased risk for knee stiffness requiring manipulation. The mean improvement in knee motion following all procedures targeting knee stiffness was 62°. Mean final flexion was significantly less in the case group (107°) compared with the control group (124°; p=0.01).To our knowledge, this is the first study to systematically evaluate the risk factors for knee stiffness after periarticular fracture and document the outcomes of manipulation under anesthesia. It demonstrates that injury characteristics that delay or prevent postoperative knee motion place patients at increased risk for refractory knee stiffness. Although knee motion remains compromised, late surgery aimed at improving knee motion leads to improvements in flexion

  View details for DOI 10.2106/JBJS.K.00659

  View details for Web of Science ID 000310416700002

• The osteogenic differentiation of human bone marrow MSCs on HUVEC-derived ECM and beta-TCP scaffold BIOMATERIALS Kang, Y., Kim, S., Bishop, J., Khademhosseini, A., Yang, Y. 2012; 33 (29): 6998-7007

  Abstract

  Extracellular matrix (ECM) serves a key role in cell migration, attachment, and cell development. Here we report that ECM derived from human umbilical vein endothelial cells (HUVEC) promoted osteogenic differentiation of human bone marrow mesenchymal stem cells (hMSC). We first produced an HUVEC-derived ECM on a three-dimensional (3D) beta-tricalcium phosphate (?-TCP) scaffold by HUVEC seeding, incubation, and decellularization. The HUVEC-derived ECM was then characterized by SEM, FTIR, XPS, and immunofluorescence staining. The effect of HUVEC-derived ECM-containing ?-TCP scaffold on hMSC osteogenic differentiation was subsequently examined. SEM images indicate a dense matrix layer deposited on the surface of struts and pore walls. FTIR and XPS measurements show the presence of new functional groups (amide and hydroxyl groups) and elements (C and N) in the ECM/?-TCP scaffold when compared to the ?-TCP scaffold alone. Immunofluorescence images indicate that high levels of fibronectin and collagen IV and low level of laminin were present on the scaffold. ECM-containing ?-TCP scaffolds significantly increased alkaline phosphatase (ALP) specific activity and up-regulated expression of osteogenesis-related genes such as runx2, alkaline phosphatase, osteopontin and osteocalcin in hMSC, compared to ?-TCP scaffolds alone. This increased effect was due to the activation of MAPK/ERK signaling pathway since disruption of this pathway using an ERK inhibitor PD98059 results in down-regulation of these osteogenic genes. Cell-derived ECM-containing calcium phosphate scaffolds is a promising osteogenic-promoting bone void filler in bone tissue regeneration.

  View details for DOI 10.1016/j.biomaterials.2012.06.061

  View details for Web of Science ID 000308269600010

  View details for PubMedID 22795852

• Use of an Inflatable Pressure Bag Bump for Medial and Lateral Operative Approaches to the Lower Leg FOOT & ANKLE INTERNATIONAL Abrams, G. D., Bishop, J. A. 2012; 33 (9): 795-797

  View details for DOI 10.3113/FAI.2012.0795

  View details for Web of Science ID 000308273000019

  View details for PubMedID 22995270

• Osseous fixation pathways in pelvic and acetabular fracture surgery: Osteology, radiology, and clinical applications JOURNAL OF TRAUMA AND ACUTE CARE SURGERY Bishop, J. A., Routt, M. L. 2012; 72 (6): 1502-1509

  View details for DOI 10.1097/TA.0b013e318246efe5

  View details for Web of Science ID 000305422900012

  View details for PubMedID 22695413

• Assessment of Compromised Fracture Healing JOURNAL OF THE AMERICAN ACADEMY OF ORTHOPAEDIC SURGEONS Bishop, J. A., Palanca, A. A., Bellino, M. J., Lowenberg, D. W. 2012; 20 (5): 273-282

  Abstract

  No standard criteria exist for diagnosing fracture nonunion, and studies suggest that assessment of fracture healing varies among orthopaedic surgeons. This variability can be problematic in both clinical and orthopaedic trauma research settings. An understanding of risk factors for nonunion and of diagnostic tests used to assess fracture healing can facilitate a systematic approach to evaluation and management. Risk factors for nonunion include medical comorbidities, age, and the characteristics of the injury. The method of fracture management also influences healing. Comprehensive evaluation includes an assessment of the patient's symptoms, signs, and immune and endocrine status as well as the biologic capacity of the fracture, presence of infection, and quality of reduction and fixation. Diagnostic tests include plain radiography, CT, ultrasonography, fluoroscopy, bone scan, MRI, and several laboratory tests, including assays for bone turnover markers in the peripheral circulation. A systematic approach to evaluating fracture union can help surgeons determine the timing and nature of interventions.

  View details for DOI 10.5435/JAAOS-20-05-273

  View details for Web of Science ID 000303366800003

  View details for PubMedID 22553099

• Operative versus nonoperative treatment after primary traumatic anterior glenohumeral dislocation: expected-value decision analysis JOURNAL OF SHOULDER AND ELBOW SURGERY Bishop, J. A., Crall, T. S., Kocher, M. S. 2011; 20 (7): 1087-1094

  Abstract

  The optimal management strategy for primary traumatic anterior glenohumeral dislocation remains controversial. Patients have traditionally been managed nonoperatively, but high recurrence rates in certain populations have led to increased interest in early operative stabilization. The purpose of this study was to use expected-value decision analysis to determine the optimal management strategy--nonoperative treatment or arthroscopic stabilization--for a first-time traumatic anterior shoulder dislocation.Probabilities for the occurrences of the potential outcomes after nonoperative and arthroscopic treatment of a first-time traumatic anterior glenohumeral dislocation were determined from a systematic review of the literature. Utilities for these outcomes were obtained from a questionnaire on patient preferences completed by 42 subjects without a history of shoulder injury. A decision tree was constructed, fold-back analysis was performed to determine optimal management, and sensitivity analyses were used to determine the effect on decision making of varying outcome probabilities and utilities.Nonoperative treatment was associated with a utility value of 5.9 and early arthroscopic surgery with a value of 7.6. On sensitivity analysis, it was found that when the rate of recurrence after nonoperative treatment falls below 32% or when the utility value for successful arthroscopic stabilization falls below 6.6, nonoperative treatment is the preferred management strategy.Arthroscopic stabilization was the preferred strategy after a primary anterior glenohumeral dislocation. In clinical settings where the likelihood of recurrent instability is low after nonoperative care or when an informed patient has an aversion to surgery, nonoperative treatment may be the preferred treatment strategy.

  View details for DOI 10.1016/j.jse.2011.01.031

  View details for Web of Science ID 000296386600015

  View details for PubMedID 21530321

• Closed Intramedullary Nailing of the Femur in the Lateral Decubitus Position JOURNAL OF TRAUMA-INJURY INFECTION AND CRITICAL CARE Bishop, J. A., Rodriguez, E. K. 2010; 68 (1): 231-235

  Abstract

  Closed intramedullary nailing is the standard of care for femoral shaft fractures and the technique now has broader applications with the proliferation of cephalomedullary instrumentation for the treatment of intertrochanteric and subtrochanteric femur fractures. Nailing in the lateral decubitus position has several advantages, but we are unaware of a detailed, contemporary description of the surgical technique published in the English language literature.A retrospective review of 158 patients treated with intramedullary nailing in the lateral position by a single surgeon over a 3-year period was performed. Clinical and radiographic outcomes were evaluated. In a group of 58 diaphyseal femur fractures, there were three rotational malreductions and one limb length discrepancy that required operative intervention. All but one were recognized and corrected intraoperatively on placing the patient supine. In a group of 100 primarily geriatric intertrochanteric, subtrochanteric, or peritrochatneric fractures managed with a cephalomedullary device, there were two lag screw cutouts, one nonunion, and one hardware failure. All of these required revision surgery. There were no rotational or length malreductions that required correction. There were no injuries to the perineum or contralateral leg, nerve palsies, or traction-related complications. Lateral positioning obviates the need for a fracture table, makes it easier to establish a starting point for an intramedullary device, and facilitates conversion to an open procedure without repositioning should this become necessary. This study demonstrates that the technique is safe and effective with an incidence of complications comparable with fracture table and supine positioning.

  View details for DOI 10.1097/TA.0b013e3181c488d8

  View details for Web of Science ID 000273585800045

  View details for PubMedID 20065779

• Management of radial nerve palsy associated with humeral shaft fracture: a decision analysis model. journal of hand surgery Bishop, J., Ring, D. 2009; 34 (6): 991-6 e1

  Abstract

  When managing radial nerve palsy associated with a humerus fracture, both surgeon and patient must balance the risks and benefits of performing an invasive surgical procedure to address a functional deficit that is likely, but not certain, to recover with nonsurgical management. The purpose of this study was to better understand the determinants of optimal management strategy using expected-value decision analysis.Probabilities for the occurrences of the potential outcomes after initial observation or early surgery were determined from a systematic review of the literature. Scores for these outcomes were obtained from a questionnaire on patient preferences completed by 82 subjects without a history of humerus fracture and radial nerve palsy and used in the model as a measure of utility. A decision tree was constructed, fold-back analysis was performed to determine optimal treatment, and sensitivity analyses were used to determine the effect on decision making of varying outcome probabilities and utilities.Observation was associated with a value of 8.4 and early surgery a value of 6.7 given the outcome probabilities and utilities studied in this model, making observation the optimal management strategy. When parameters were varied in sensitivity analysis, it was noted that when the rate of recovery after initial observation falls below 40% or when the utility value for successful early surgery rises above 9.4, early surgery is the preferred management strategy.Initial observation was the preferred strategy. In clinical settings in which the likelihood of spontaneous recovery of nerve function is low or when an informed patient has a strong preference for surgery, early surgery may optimize outcome.Economic and Decision Analysis II.

  View details for DOI 10.1016/j.jhsa.2008.12.029

  View details for PubMedID 19361935

• Locking plate fixation for pediatric femur fractures JOURNAL OF PEDIATRIC ORTHOPAEDICS Hedequist, D., Bishop, J., Hresko, T. 2008; 28 (1): 6-9

  Abstract

  The use of locking plates for pediatric femur fractures has not been studied. Locking plate applications for fractures associated with comminution, osteopenia, or minimal bone available for purchase have been well studied in the adult trauma population.We conducted a retrospective review of children at our institution treated with a locking plate for a femur fracture. We identified 32 patients treated at an average age of 11 years (6-15 years of age). Locking plates were chosen for comminution in 13 patients, nonmalignant pathologic fracture in 9 patients, fracture location in 7 patients, and osteopenia in 3 patients. All patients were treated with a locking plate and followed up until definitive radiologic union.There were no intraoperative complications related to this technology. All patients were healed with near-anatomic alignment with the exception of 1 patient who had valgus malalignment of 12 degrees, which was of no clinical concern and required no intervention. Seven patients had the plates removed with no noted complications.Locking plates are a safe and effective treatment for children and adolescents with femur fractures that may not be amenable to other current means of stabilization.

  View details for Web of Science ID 000255766600002

  View details for PubMedID 18157038

• Prophylactic pinning of the contralateral hip after unilateral slipped capital femoral epiphysis JOURNAL OF BONE AND JOINT SURGERY-AMERICAN VOLUME Kocher, M. S., Bishop, J. A., Hresko, M. T., Millis, M. B., Kim, Y. J., Kasser, J. R. 2004; 86A (12): 2658-2665

  Abstract

  The management of the contralateral hip after unilateral slipped capital femoral epiphysis is controversial. The purpose of this study was to determine, with use of expected-value decision analysis, the optimal management strategy-prophylactic in situ pinning versus observation-for the contralateral hip.Outcome probabilities were determined from a systematic review of the literature. Utility values were obtained from a questionnaire on patient preferences completed with use of a visual analog scale by twenty-five adolescent male patients without slipped capital femoral epiphysis. A decision tree was constructed, fold-back analysis was performed to determine the optimal treatment, and one and two-way sensitivity analyses were performed to determine the effect on decision-making of varying outcome probabilities and utilities.Observation was the optimal management strategy for the contralateral hip given the outcome probabilities and utilities that we studied (the expected value was 9.5 for observation and 9.2 for prophylactic in situ pinning, with a marginal value of 0.3). Increased rates of a late second slip favored prophylactic in situ pinning (the threshold probability was 27%). Risk-taking patients with a high utility for uncomplicated prophylactic in situ pinning favored prophylaxis (the threshold utility was 9.8).The iatrogenic risks of treating a healthy patient or an uninvolved body part rarely outweigh the potential benefits unless the probability of the adverse event is likely and the consequences of the adverse event are very severe. In this decision analysis, the optimal decision was observation. In cases where the probability of contralateral slipped capital femoral epiphysis exceeds 27% or in cases where reliable follow-up is not feasible, pinning of the contralateral hip is favored. For a given individual patient, the optimal strategy depends not only on probabilities of the various outcomes but also on personal preference. Thus, we advocate a model of doctor-patient shared decision-making in which both the outcome probabilities and the patient preferences are considered in order to optimize the decision-making process.Economic and decision analysis, Level III-1 (limited alternatives and costs; poor estimates). See Instructions to Authors for a complete description of levels of evidence.

  View details for Web of Science ID 000225719700011

  View details for PubMedID 15590850

• Delay in diagnosis of slipped capital femoral epiphysis PEDIATRICS Kocher, M. S., Bishop, J. A., Weed, B., Hresko, M. T., Millis, M. B., Kim, Y. J., Kasser, J. R. 2004; 113 (4): E322-E325

  Abstract

  Delay in diagnosis of slipped capital femoral epiphysis (SCFE) has important implications in terms of slip severity and long-term hip outcome. The purpose of this study was to identify predictors of delay in the diagnosis of SCFE.A review of 196 patients with SCFE was performed. The primary outcome measure was delay from onset of symptoms to diagnosis. Covariates included age, gender, side, weight, pain location, insurance status, family income, slip severity, and slip stability. Delay in diagnosis was not normal in distribution; therefore, nonparametric univariate and multivariate analyses were performed.The median delay in diagnosis was 8.0 weeks. There was a significant relationship between delay in diagnosis and slip severity (<30 degrees : 10.0 weeks; 30 degrees to 50 degrees : 14.4 weeks; >50 degrees : 20.6 weeks). There were no significant associations between delay in diagnosis and covariates of age, gender, side, and weight. There were significant associations between longer delay in diagnosis and covariates of knee/distal-thigh pain versus hip/proximal-thigh pain (6.0 vs 15.0 weeks), Medicaid coverage versus private insurance (12.0 vs 7.5 weeks), lower family income, and stable slips versus unstable slips (8.0 vs 6.5 weeks). Controlling for the other covariates, knee/distal-thigh pain, Medicaid insurance, and stable slips remained significant independent multivariate predictors of delay in diagnosis.Patients who present with primarily knee or distal-thigh pain, patients with Medicaid coverage, and patients with stable slips have longer delays in diagnosis of SCFE. Focused intervention programs to reduce the delay in diagnosis of SCFE should emphasize patients with knee/thigh pain and patients with Medicaid coverage.

  View details for Web of Science ID 000220585100048

  View details for PubMedID 15060261

• Images in clinical medicine. Something fishy going on in the heart. New England journal of medicine de la Torre, J., Bishop, J. 2002; 347 (22): 1769-?

  View details for PubMedID 12456853

• Operative versus nonoperative management of acute Achilles tendon rupture - Expected-value decision analysis AMERICAN JOURNAL OF SPORTS MEDICINE Kocher, M. S., Bishop, J., Marshall, R., Briggs, K. K., Hawkins, R. J. 2002; 30 (6): 783-790

  Abstract

  The optimal management strategy for acute Achilles tendon rupture is controversial.To determine the optimal management by using expected-value decision analysis.Cross-sectional study.Outcome probabilities were determined from a systematic literature review, and patient-derived utility values were obtained from a visual analog scale questionnaire. A decision tree was constructed, and fold-back analysis was used to determine optimal treatment. Sensitivity analyses were used to determine the effect of varying outcome probabilities and utilities on decision-making.Outcome probabilities (expressed as operative; nonoperative) were as follows: well (0.762; 0.846), rerupture (0.022; 0.121), major complication (0.030; 0.025), moderate complication (0.075; 0.003), and mild complication (0.111; 0.005). Outcome utility values were well operative (7.9), well nonoperative (7.0), rerupture (2.6), major complication (1.0), moderate complication (3.5), and mild complication (4.7). Fold-back analysis revealed operative treatment as the optimal management strategy (6.89 versus 6.30). Threshold values were determined for the probability of a moderate complication from operative treatment (0.21) and the utility of rerupture (6.8).Operative management was the optimal strategy, given the outcome probabilities and patient utilities we studied. Nonoperative management was favored by increasing rates of operative complications; operative, by decreasing utility of rerupture. We advocate a model of doctor-patient shared decision-making in which both outcome probabilities and patient preferences are considered.

  View details for Web of Science ID 000179364300004

  View details for PubMedID 12435641