Dr. Abrams specializes in Sports Medicine and arthroscopy, upper extremity joint replacement, as well as ligament reconstructive surgery of the shoulder, knee, and elbow. He is Board Certified in Orthopedic Surgery, with a subspecialty certificate in Sports Medicine, and is a member of the American Academy of Orthopedic Surgeons (AAOS), American Orthopedic Society for Sports Medicine (AOSSM), and the Arthroscopy Association of North America (AANA), among others. He is actively involved in tendon disease research, focusing on the role of microRNA and tendon-derived stem cells in the pathogenesis of the disease. Dr. Abrams received his undergraduate degree from Stanford University and his Doctor of Medicine from the University of California - San Diego. He completed his residency in Orthopedic Surgery at Stanford University and went on to a Fellowship in Orthopedic Sports Medicine and Shoulder Surgery at Rush University Medical Center in Chicago, Illinois. He currently serves as Director of Sports Medicine for the Lacob Family Sports Medicine Center, which cares for Stanford varsity athletes, as well as assistant team physician for the Golden State Warriors and San Francisco 49ers. Dr. Abrams has authored or co-authored over 60 peer-reviewed scientific articles, over 20 book chapters, has presented original research at numerous national and international scientific meetings, and serves as a reviewer for numerous Sports Medicine scientific journals.

Clinical Focus

  • Orthopaedic Surgery
  • Sports Medicine

Academic Appointments

Boards, Advisory Committees, Professional Organizations

  • Member, American Academy of Orthopedic Surgeons (2009 - Present)
  • Member, American Orthopedic Society for Sports Medicine (2013 - Present)
  • Member, California Orthopedic Association (2013 - Present)
  • Member, Arthroscopy Association of North America (2013 - Present)
  • Member, Western Orthopedic Association (2013 - Present)

Professional Education

  • Board Certification: Sports Medicine (2016)N/A
  • Board Certification: Orthopaedic Surgery, American Board of Orthopaedic Surgery (2015)
  • Fellowship:Rush University Medical Center (2013) IL
  • Residency:Stanford University School of Medicine (2012) CA
  • Internship:Stanford University School of Medicine (2008) CA
  • Medical Education:UCSD (2007) CA

Research & Scholarship

Current Research and Scholarly Interests

Dr. Abrams' research is focused on the role that joint synovial tissue and inflammatory mediators have on rotator cuff pathology as well as cartilage lesions in the shoulder, knee, and hip.


2017-18 Courses


All Publications

  • Decreased Synovial Inflammation in Atraumatic Hip Microinstability Compared With Femoroacetabular Impingement. Arthroscopy Abrams, G. D., Luria, A., Sampson, J., Madding, R. A., Robinson, W. H., Safran, M. R., Sokolove, J. 2017; 33 (3): 553-558


    To compare the inflammatory profile of hip synovial tissue in those with atraumatic microinstability to patients with femoroacetabular impingement (FAI).Patients with cam and mixed-type FAI (FAI group) and patients with hip instability underwent sampling of the anterolateral synovium. Demographic data, intraoperative measurements, and functional outcome scores (International Hip Outcomes Tool and Short Form-12) were recorded. Cryosections were stained and examined under light microscopy as well as confocal fluorescent microscopy for anti-CD45 (common leukocyte antigen), anti-CD31 (endothelial), and anti-CD68 (macrophage) cell surface markers. A grading system was used to quantify synovitis under light microscopy whereas digital image analysis was used to quantify immunofluorescence staining area. Comparison were made with Student t test, Mann-Whitney U, χ(2), and regression analysis.There were 12 patients in the FAI group and 5 in the instability group. Mean age was not significantly different (P > .05), but there was a significantly greater proportion of females in the instability group versus the FAI group (P < .001). There was a significant correlation (r = 0.653; P = .005) between number of turns needed for 10 mm of distraction and increased synovitis. Synovitis scores also were increased significantly in patients with cam morphology and articular cartilage damage (P = .024) versus those without. Immunohistochemistry did not reveal differences (P > .082) between the instability and FAI groups, but CD68 staining was significantly greater in those with cam morphology and cartilage damage (P < .045). CD45+/CD68- cells were noted in the perivascular area while CD45+/CD68+ cells were noted within the synovial lining in both groups.Increased synovial inflammation was associated with an increased number of turns to achieve joint distraction. Both instability and FAI groups demonstrated baseline levels of synovial inflammation. Synovitis scores also were increased in patients with cartilage damage.An understanding of the molecular and cellular mechanisms behind both hip instability and FAI may lead to novel therapeutic anti-inflammatory therapy, which may serve as an adjunct to treatment of mechanical abnormalities in this conditions.

    View details for DOI 10.1016/j.arthro.2016.09.007

    View details for PubMedID 27939067

  • Complication Rates for Hip Arthroscopy Are Underestimated: A Population-Based Study. Arthroscopy Truntzer, J. N., Hoppe, D. J., Shapiro, L. M., Abrams, G. D., Safran, M. 2017


    To identify major and minor complication rates associated with hip arthroscopy from a payer-based national database and compare with the rates reported in the existing literature.Patients who underwent hip arthroscopy between 2007 and 2014 were identified using PearlDiver, a publicly available database. Rates of major and minor complications, as well as conversion to total hip arthroscopy (THA), were determined by using Current Procedural Terminology (CPT) and International Classification of Diseases, Ninth Revision (ICD-9), codes. Incidence rates of select major complications across the entire database were used as a comparison group. Statistical significance was set at P < .05.Of 18 million patients screened from 2007 to 2014, a total of 2,581 hip arthroscopies were identified. The rates of major and minor complications within a 1-year postoperative period were 1.74% and 4.22%, respectively. Complications included heterotopic ossification (2.85%), bursitis (1.23%), proximal femur fracture (1.08%), deep vein thrombosis (0.79%), and hip dislocation (0.58%). The rate of conversion to THA within 1 year was 2.85%. When compared to rates in the general population, the relative risks [RRs] of requiring a THA (age <50 years, RR = 57.66, P < .001; age >50 years, RR = 22.05, P < .001), sustaining a proximal femur fracture (age <50 years, RR = 18.02, P < .001; age >50 years, RR = 2.23, P < .001), or experiencing a hip dislocation (RR 19.60, P < .001) at 1 year after hip arthroscopy were significantly higher in all age groups.Higher major complication rates after hip arthroscopy were observed using a national payer-based database than previously reported in the literature, especially in regard to hip dislocations and proximal femur fractures. Rates of total hip arthroplasty were similar to prior studies, whereas the rates of revision hip arthroscopy were higher.Level IV, case series.

    View details for DOI 10.1016/j.arthro.2017.01.021

    View details for PubMedID 28259588

  • Cytokines as a predictor of clinical response following hip arthroscopy: minimum 2-year follow-up. Journal of hip preservation surgery Shapiro, L. M., Safran, M. R., Maloney, W. J., Goodman, S. B., Huddleston, J. I., Bellino, M. J., Scuderi, G. J., Abrams, G. D. 2016; 3 (3): 229-235


    Hip arthroscopy in patients with osteoarthritis has been shown to have suboptimal outcomes. Elevated cytokine concentrations in hip synovial fluid have previously been shown to be associated with cartilage pathology. The purpose of this study was to determine whether a relationship exists between hip synovial fluid cytokine concentration and clinical outcomes at a minimum of 2 years following hip arthroscopy. Seventeen patients without radiographic evidence of osteoarthritis had synovial fluid aspirated at time of portal establishment during hip arthroscopy. Analytes included fibronectin-aggrecan complex as well as a multiplex cytokine array. Patients completed the modified Harris Hip Score, Western Ontario and McMaster Universities Arthritis Index and the International Hip Outcomes Tool pre-operatively and at a minimum of 2 years following surgery. Pre and post-operative scores were compared with a paired t-test, and the association between cytokine values and clinical outcome scores was performed with Pearson's correlation coefficient with an alpha value of 0.05 set as significant. Sixteen of seventeen patients completed 2-year follow-up questionnaires (94%). There was a significant increase in pre-operative to post-operative score for each clinical outcome measure. No statistically significant correlation was seen between any of the intra-operative cytokine values and either the 2-year follow-up scores or the change from pre-operative to final follow-up outcome values. No statistically significant associations were seen between hip synovial fluid cytokine concentrations and 2-year follow-up clinical outcome assessment scores for those undergoing hip arthroscopy.

    View details for DOI 10.1093/jhps/hnw013

    View details for PubMedID 27583163

  • Association of synovial inflammation and inflammatory mediators with glenohumeral rotator cuff pathology JOURNAL OF SHOULDER AND ELBOW SURGERY Abrams, G. D., Luria, A., Carr, R. A., Rhodes, C., Robinson, W. H., Sokolove, J. 2016; 25 (6): 989-997


    We hypothesized that patients with full-thickness rotator cuff tears would have greater synovial inflammation compared with those without rotator cuff tear pathology, with gene expression relating to histologic findings.Synovial sampling was performed in 19 patients with full-thickness rotator cuff tears (RTC group) and in 11 patients without rotator cuff pathology (control group). Cryosections were stained and examined under light microscopy and confocal fluorescent microscopy for anti-cluster CD45 (common leukocyte antigen), anti-CD31 (endothelial), and anti-CD68 (macrophage) cell surface markers. A grading system was used to quantitate synovitis under light microscopy, and digital image analysis was used to quantify the immunofluorescence staining area. Quantitative polymerase chain reaction was performed for validated inflammatory markers. Data were analyzed with analysis of covariance, Mann-Whitney U, and Spearman rank order testing, with significance set at α = .05.The synovitis score was significantly increased in the RTC group compared with controls. Immunofluorescence demonstrated significantly increased staining for CD31, CD45, and CD68 in the RTC vs control group. CD45+/68- cells were found perivascularly, with CD45+/68+ cells toward the joint lining edge of the synovium. Levels of matrix metalloproteinase-3 (MMP-3) and interleukin-6 were significantly increased in the RTC group, with a positive correlation between the synovitis score and MMP-3 expression.Patients with full-thickness rotator cuff tears have greater levels of synovial inflammation, angiogenesis, and MMP-3 upregulation compared with controls. Gene expression of MMP-3 correlates with the degree of synovitis.

    View details for DOI 10.1016/j.jse.2015.10.011

    View details for Web of Science ID 000376178500022

    View details for PubMedID 26775747

  • Rotator cuff tears after total shoulder arthroplasty in primary osteoarthritis: A systematic review INTERNATIONAL JOURNAL OF SHOULDER SURGERY Levy, D. M., Abrams, G. D., Harris, J. D., Bach, B. R., Nicholson, G. P., Romeo, A. A. 2016; 10 (2): 78-84


    Rotator cuff tears have been reported to be uncommon following total shoulder arthroplasty (TSA). Postoperative rotator cuff tears can lead to pain, proximal humeral migration, and glenoid component loosening. The purpose of this paper was to evaluate the incidence of post-TSA rotator cuff tears or dysfunction in osteoarthritic patients. A systematic review of multiple databases was performed using preferred reporting items for systematic reviews and meta-analyses guidelines. Levels I-IV evidence clinical studies of patients with primary osteoarthritis with a minimum 2-year follow-up were included. Fifteen studies with 1259 patients (1338 shoulders) were selected. Student's t-tests were used with a significant alpha value of 0.05. All patients demonstrated significant improvements in motion and validated clinical outcome scores (P < 0.001). Radiographic humeral head migration was the most commonly reported data point for extrapolation of rotator cuff integrity. After 6.6 ± 3.1 years, 29.9 ± 20.7% of shoulders demonstrated superior humeral head migration and 17.9 ± 14.3% migrated a distance more than 25% of the head. This was associated with an 11.3 ± 7.9% incidence of postoperative superior cuff tears. The incidence of radiographic anterior humeral head migration was 11.9 ± 15.9%, corresponding to a 3.0 ± 13.6% rate of subscapularis tears. We found an overall 1.2 ± 4.5% rate of reoperation for cuff injury. Nearly all studies reported indirect markers of rotator cuff dysfunction, such as radiographic humeral head migration and clinical exam findings. This systematic review suggests that rotator cuff dysfunction following TSA may be more common than previously reported. IV, systematic review of Levels I-IV studies.

    View details for DOI 10.4103/0973-6042.180720

    View details for Web of Science ID 000375090300005

    View details for PubMedID 27186060

    View details for PubMedCentralID PMC4857535

  • Posterior Glenoid Wear in Total Shoulder Arthroplasty: Eccentric Anterior Reaming Is Superior to Posterior Augment CLINICAL ORTHOPAEDICS AND RELATED RESEARCH Wang, T., Abrams, G. D., Behn, A. W., Lindsey, D., Giori, N., Cheung, E. V. 2015; 473 (12): 3928-3936

    View details for DOI 10.1007/s11999-015-4482-8

    View details for Web of Science ID 000364146300041

    View details for PubMedID 26242283

  • Arthroscopic Reduction and Internal Fixation of an Inferior Glenoid Fracture With Scapular Extension (Ideberg V). Arthroscopy techniques Tuman, J. M., Bishop, J. A., Abrams, G. D. 2015; 4 (6): e869-72


    Arthroscopic reduction and internal fixation of glenoid fractures have been well described, especially for glenoid rim (Bankart) fractures, as well as for scapular body fractures with extensions into the articular surface. This approach has the advantage of decreasing comorbidities associated with a standard open approach, but it can be technically challenging and may not be amenable to all fracture patterns. Arthroscopic fixation of scapular fractures incorporating a transverse pattern along the inferior aspect of the glenoid is particularly challenging because of difficulty in accessing this space. We detail the use of a posteroinferior arthroscopic portal for fracture reduction and hardware placement in a scapular fracture with inferior glenoid involvement.

    View details for DOI 10.1016/j.eats.2015.08.012

    View details for PubMedID 27284526

    View details for PubMedCentralID PMC4886700

  • Extra-Articular Impingement: lschiofemoral Impingement and Trochanteric-Pelvic OPERATIVE TECHNIQUES IN SPORTS MEDICINE Beckmann, J. T., Safran, M. R., Abrams, G. D. 2015; 23 (3): 184-189
  • Anterolateral Versus Medial Plating of Distal Extra-articular Tibia Fractures: A Biomechanical Model ORTHOPEDICS Pirolo, J. M., Behn, A. W., Abrams, G. D., Bishop, J. A. 2015; 38 (9): E760-E765

    View details for DOI 10.3928/01477447-20150902-52

    View details for Web of Science ID 000365393600003

    View details for PubMedID 26375532

  • Biomechanical Evaluation of Capsulotomy, Capsulectomy, and Capsular Repair on Hip Rotation. Arthroscopy Abrams, G. D., Hart, M. A., Takami, K., Bayne, C. O., Kelly, B. T., Espinoza Orías, A. A., Nho, S. J. 2015; 31 (8): 1511-1517


    To determine the effect of different types of capsulotomies on hip rotational biomechanical characteristics.Seven fresh-frozen cadaveric hip specimens were thawed and dissected, leaving the hip capsule and labrum intact. The femur was transected and potted, and each specimen was placed in a custom loading apparatus that allowed for adjustment of flexion, extension, and axial rotation of the femur. Six reflective infrared markers were attached to the specimens to track the motion of the femoral head with respect to the acetabulum in real time, and external rotation was produced by applying a torque of 10 Nm to the hip specimens. Data analysis was performed using the 3-dimensional position of the markers in space. The specimens were tested in neutral flexion and 40° of flexion in the following capsular states: intact, interportal capsulotomy, T-capsulotomy, repaired capsulotomy, and capsulectomy. Paired t tests and analysis of variance were used with an α value of .05 set as significant.With the hip in neutral flexion, there was increased external rotation with a T-capsulotomy (91.1° ± 20.3°, P = .029) and capsulectomy (91.9° ± 19.6°, P = .015) compared with the intact hip (83.2° ± 20.5°). After complete repair of the T-capsulotomy (87.4° ± 20.6°), there was no significant difference in external rotation compared with the intact hip. No significant differences were seen between groups at 40° of hip flexion.A T-capsulotomy showed significantly increased external rotation versus the intact and interportal capsulotomy states. The repaired T-capsulotomy restored the rotational profile back to the native state.Many methods of capsular treatment during hip arthroscopy exist. Capsulotomy and capsulectomy do not restore the external rotation restraint of the hip back to its native state.

    View details for DOI 10.1016/j.arthro.2015.02.031

    View details for PubMedID 25882176

  • Biomechanical Evaluation of Capsulotomy, Capsulectomy, and Capsular Repair on Hip Rotation ARTHROSCOPY-THE JOURNAL OF ARTHROSCOPIC AND RELATED SURGERY Abrams, G. D., Hart, M. A., Takami, K., Bayne, C. O., Kelly, B. T., Orias, A. A., Nho, S. J. 2015; 31 (8): 1511-1517
  • Fibronectin-aggrecan complex as a marker for cartilage degradation in non-arthritic hips. Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA Abrams, G. D., Safran, M. R., Shapiro, L. M., Maloney, W. J., Goodman, S. B., Huddleston, J. I., Bellino, M. J., Scuderi, G. J. 2014; 22 (4): 768-773


    To report hip synovial fluid cytokine concentrations in hips with and without radiographic arthritis.Patients with no arthritis (Tonnis grade 0) and patients with Tonnis grade 2 or greater hip osteoarthritis (OA) were identified from patients undergoing either hip arthroscopy or arthroplasty. Synovial fluid was collected at the time of portal establishment for those undergoing hip arthroscopy and prior to arthrotomy for the arthroplasty group. Analytes included fibronectin-aggrecan complex (FAC) as well as a standard 12 cytokine array. Variables recorded were Tonnis grade, centre-edge angle of Wiberg, as well as labrum and cartilage pathology for the hip arthroscopy cohort. A priori power analysis was conducted, and a Mann-Whitney U test and regression analyses were used with an alpha value of 0.05 set as significant.Thirty-four patients were included (17 arthroplasty, 17 arthroscopy). FAC was the only analyte to show a significant difference between those with and without OA (p < 0.001). FAC had significantly higher concentration in those without radiographic evidence of OA undergoing microfracture versus those not receiving microfracture (p < 0.05).There was a significantly higher FAC concentration in patients without radiographic OA. Additionally, those undergoing microfracture had increased levels of FAC. As FAC is a cartilage breakdown product, no significant amounts may be present in those with OA. In contrast, those undergoing microfracture have focal area(s) of cartilage breakdown. These data suggest that FAC may be useful in predicting cartilage pathology in those patients with hip pain but without radiographic evidence of arthritis.Diagnostic, Level III.

    View details for DOI 10.1007/s00167-014-2863-2

    View details for PubMedID 24477496

  • What's New in Femoroacetabular Impingement Surgery: Will We Be Better in 2023? Sports health Gupta, A. K., Abrams, G. D., Nho, S. J. 2014; 6 (2): 162-170


    Femoroacetabular impingement (FAI) has been described as a common cause of hip pain in young adults. This leads to abnormal hip joint mechanics and contact pressures. The associated pathomechanics can lead to the development of early osteoarthritis. Better understanding of the anatomy and pathophysiology, biomechanics, and diagnostic and therapeutic advances has led to improved clinical outcomes. A growing body of evidence has set the foundation for future progress in the treatment of this commonly encountered condition.The PubMed database was searched for English-language articles pertaining to FAI over the past 15 years (1998-2013).Retrospective literature review.Level 4.The authors evaluated and discussed the current evidence regarding the anatomy, physiology, biomechanics, imaging, and clinical outcomes of surgical intervention for FAI. Based on this information, future directions for improving the diagnosis and management of FAI are proposed.There remains a diverse approach to the diagnosis and management of cam- and/or pincer-type FAI. Recent advances in clinical diagnosis, imaging, indications, and arthroscopic techniques have led to improved outcomes and have set the foundation for future progress in the management of this condition.B.

    View details for DOI 10.1177/1941738113513006

    View details for PubMedID 24587868

  • Rate of return to pitching and performance after tommy john surgery in major league baseball pitchers. American journal of sports medicine Erickson, B. J., Gupta, A. K., Harris, J. D., Bush-Joseph, C., Bach, B. R., Abrams, G. D., San Juan, A. M., Cole, B. J., Romeo, A. A. 2014; 42 (3): 536-543


    Medial ulnar collateral ligament (UCL) reconstruction is a common procedure performed on Major League Baseball (MLB) pitchers in the United States.To determine (1) the rate of return to pitching (RTP) in the MLB after UCL reconstruction, (2) the RTP rate in either the MLB and minor league combined, (3) performance after RTP, and (4) the difference in the RTP rate and performance between pitchers who underwent UCL reconstruction and matched controls without UCL injuries.Cohort study; Level of evidence, 3.Major League Baseball pitchers with symptomatic medial UCL deficiency who underwent UCL reconstruction were evaluated. All player, elbow, and surgical demographic data were analyzed. Controls matched by age, body mass index, position, handedness, and MLB experience and performance were selected from the MLB during the same years as those undergoing UCL reconstruction. An "index year" was designated for controls, analogous to the UCL reconstruction year in cases. Return to pitching and performance measures in the MLB were compared between cases and controls. Student t tests were performed for analysis of within-group and between-group variables, respectively.A total of 179 pitchers with UCL tears who underwent reconstruction met the inclusion criteria and were analyzed. Of these, 148 pitchers (83%) were able to RTP in the MLB, and 174 pitchers were able to RTP in the MLB and minor league combined (97.2%), while only 5 pitchers (2.8%) were never able to RTP in either the MLB or minor league. Pitchers returned to the MLB at a mean 20.5 ± 9.72 months after UCL reconstruction. The length of career in the MLB after UCL reconstruction was 3.9 ± 2.84 years, although 56 of these patients were still currently actively pitching in the MLB at the start of the 2013 season. The revision rate was 3.9%. In the year before UCL reconstruction, pitching performance declined significantly in the cases versus controls in the number of innings pitched, games played, and wins and the winning percentage (P < .05). After surgery, pitchers showed significantly improved performance versus before surgery (fewer losses, a lower losing percentage, lower earned run average [ERA], threw fewer walks, and allowed fewer hits, runs, and home runs) (P < .05). Comparisons between cases and controls for the time frame after UCL reconstruction (cases) or the index year (controls) demonstrated that cases had significantly (P < .05) fewer losses per season and a lower losing percentage. In addition, cases had a significantly lower ERA and allowed fewer walks and hits per inning pitched.There is a high rate of RTP in professional baseball after UCL reconstruction. Performance declined before surgery and improved after surgery. When compared with demographic-matched controls, patients who underwent UCL reconstruction had better results in multiple performance measures. Reconstruction of the UCL allows for a predictable and successful return to the MLB.

    View details for DOI 10.1177/0363546513510890

    View details for PubMedID 24352622

  • Trends in the Surgical Treatment of Articular Cartilage Lesions in the United States: An Analysis of a Large Private-Payer Database Over a Period of 8 Years ARTHROSCOPY-THE JOURNAL OF ARTHROSCOPIC AND RELATED SURGERY McCormick, F., Harris, J. D., Abrams, G. D., Frank, R., Gupta, A., Hussey, K., Wilson, H., Bach, B., Cole, B. 2014; 30 (2): 222-226


    The purpose of this study was to quantify the current trends in knee cartilage surgical techniques performed in the United States from 2004 through 2011 using a large private-payer database. A secondary objective was to identify salient demographic factors associated with these procedures.We performed a retrospective database review using a large private-payer medical record database within the PearlDiver database. The PearlDiver database is a publicly available, Health Insurance Portability and Accountability Act-compliant national database compiled from a collection of private insurer records. A search was performed for surgical techniques in cartilage palliation (chondroplasty), repair (microfracture/drilling), and restoration (arthroscopic osteochondral autograft, arthroscopic osteochondral allograft, autologous chondrocyte implantation, open osteochondral allograft, and open osteochondral autograft). The incidence, growth, and demographic factors associated with the surgical procedures were assessed.From 2004 through 2011, 198,876,000 patients were analyzed. A surgical procedure addressing a cartilage defect was performed in 1,959,007 patients, for a mean annual incidence of 90 surgeries per 10,000 patients. Across all cartilage procedures, there was a 5.0% annual incidence growth (palliative, 3.7%; repair, 0%; and restorative, 3.1%) (P = .027). Palliative techniques (chondroplasty) were more common (>2:1 ratio for repair [marrow-stimulation techniques] and 50:1 ratio for restoration [autologous chondrocyte implantation and osteochondral autograft and allograft]). Palliative surgical approaches were the most common technique, regardless of age, sex, or region.Articular cartilage surgical procedures in the knee are common in the United States, with an annual incidence growth of 5%. Surgical techniques aimed at palliation are more common than cartilage repair and restoration techniques regardless of age, sex, or region.Level IV, retrospective database analysis.

    View details for DOI 10.1016/j.arthro.2013.11.001

    View details for Web of Science ID 000330571400015

    View details for PubMedID 24485115

  • Biomechanical analysis of three tennis serve types using a markerless system BRITISH JOURNAL OF SPORTS MEDICINE Abrams, G. D., Harris, A. H., Andriacchi, T. P., Safran, M. R. 2014; 48 (4)

    View details for DOI 10.1136/bjsports-2012-091371

    View details for Web of Science ID 000331185400013

    View details for PubMedID 22936411

  • Biomechanical analysis of three tennis serve types using a markerless system. British journal of sports medicine Abrams, G. D., Harris, A. H., Andriacchi, T. P., Safran, M. R. 2014; 48 (4): 339-342


    PURPOSE: The tennis serve is commonly associated with musculoskeletal injury. Advanced players are able to hit multiple serve types with different types of spin. No investigation has characterised the kinematics of all three serve types for the upper extremity and back. METHODS: Seven NCAA Division I male tennis players performed three successful flat, kick and slice serves. Serves were recorded using an eight camera markerless motion capture system. Laser scanning was utilised to accurately collect body dimensions and data were computed using inverse kinematic methods. RESULTS: There was no significant difference in maximum back extension angle for the flat, kick or slice serves. The kick serve had a higher force magnitude at the back than the flat and slice as well as larger posteriorly directed shoulder forces. The flat serve had significantly greater maximum shoulder internal rotation velocity versus the slice serve. Force and torque magnitudes at the elbow and wrist were not significantly different between the serves. CONCLUSIONS: The kick serve places higher physical demands on the back and shoulder while the slice serve demonstrated lower overall kinetic forces. This information may have injury prevention and rehabilitation implications.

    View details for DOI 10.1136/bjsports-2012-091371

    View details for PubMedID 22936411

  • Arthroscopic Repair of Full-Thickness Rotator Cuff Tears With and Without Acromioplasty: Randomized Prospective Trial With 2-Year Follow-up. The American journal of sports medicine Abrams, G. D., Gupta, A. K., Hussey, K. E., Tetteh, E. S., Karas, V., Bach, B. R., Cole, B. J., Romeo, A. A., Verma, N. N. 2014


    BACKGROUND:Acromioplasty is commonly performed during arthroscopic rotator cuff repair, but its effect on short-term outcomes is debated. PURPOSE:To report the short-term clinical outcomes of patients undergoing arthroscopic repair of full-thickness rotator cuff tears with and without acromioplasty. STUDY DESIGN:Randomized controlled trial; Level of evidence, 2. METHODS:Patients undergoing arthroscopic repair of full-thickness rotator cuff tears were randomized into acromioplasty or nonacromioplasty groups. The Simple Shoulder Test (SST), American Shoulder and Elbow Surgeons (ASES) score, Constant score, University of California-Los Angeles (UCLA) score, and Short Form-12 (SF-12) health assessment were collected along with physical examination including range of motion and dynamometer strength testing. Intraoperative data including tear size, repair configuration, and concomitant procedures were recorded. Follow-up examination was performed at regular intervals up to 2 years. Preoperative imaging was reviewed to classify the acromial morphologic type, acromial angle, and lateral acromial angulation. RESULTS:A total of 114 patients were initially enrolled in the study, and 95 (83%; 43 nonacromioplasty, 52 acromioplasty) were available for a minimum 2-year follow-up. There were no significant differences in baseline characteristics, including number of tendons torn, repair configuration, concomitant procedures, and acromion type and angles. Within groups, there was a significant (P < .001) improvement in all functional outcome scores from preoperatively to all follow-up time points, including 2 years, for the nonacromioplasty and acromioplasty groups (ASES score: 55.1-91.5, 48.8-89.0; Constant score: 48.3-75.0, 51.9-78.7, respectively). There were no significant differences in functional outcomes between nonacromioplasty and acromioplasty groups or between subjects with different acromial features at any time point. CONCLUSION:The results of this study demonstrate no difference in clinical outcomes after rotator cuff repair with or without acromioplasty at 2 years postoperatively.

    View details for DOI 10.1177/0363546514529091

    View details for PubMedID 24733157

  • Return to sport after ACL reconstruction. Orthopedics Harris, J. D., Abrams, G. D., Bach, B. R., Williams, D., Heidloff, D., Bush-Joseph, C. A., Verma, N. N., Forsythe, B., Cole, B. J. 2014; 37 (2): e103–8


    Objective guidelines permitting safe return to sport following anterior cruciate ligament (ACL) reconstruction are infrequently used. The purpose of this study was to determine the published return to sport guidelines following ACL reconstruction in Level I randomized controlled trials. A systematic review was performed using Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. Level I randomized controlled trials were included if they reported a minimum 2-year follow-up after ACL reconstruction and return to sport criteria. Outcomes analyzed were the timing of initiation of return to sport, follow-up duration, and use of quantitative/qualitative criteria to determine return to sport. Forty-nine studies were included (N=4178; 68% male; mean patient age, 27.5±3.2 years; mean follow-up, 3.0±1.9 years; mean time from injury to reconstruction, 379±321 days). Ninety-six percent of reconstructions used autograft and 87% were single-bundle reconstructions. Lysholm score, single-leg hop, isokinetic strength, and KT-1000 or KT-2000 arthrometer (MEDmetric, San Diego, California) testing were performed in 67%, 31%, 31%, and 82% of studies, respectively. Only 5 studies reported whether patients were able to successfully return to sport. Ninety percent and 65% of studies failed to use objective criteria or any criteria, respectively, to permit return to sport. Description of permission/allowance to return to sport was highly variable and poor. Twenty-four percent of studies failed to report when patients were allowed return to sport without restrictions. Overall, 39%, 45%, and 51% of studies permitted running at 3 months, return to cutting/pivoting sports at 6 months, and return to sport without restrictions at 6 months, respectively. Further research into validated return to sport guidelines is necessary to fill the existing void in contemporary literature and to guide clinical practice.

    View details for DOI 10.3928/01477447-20140124-10

    View details for PubMedID 24679194

  • Reverse total shoulder arthroplasty in patients of varying body mass index JOURNAL OF SHOULDER AND ELBOW SURGERY Gupta, A. K., Chalmers, P. N., Rahman, Z., Bruce, B., Harris, J. D., McCormick, F., Abrams, G. D., Nicholson, G. P. 2014; 23 (1): 35-42


    Body mass index (BMI) is an independent predictor of complications after hip and knee arthroplasty. Whether similar trends apply to patients undergoing reverse total shoulder arthroplasty (RTSA) is unknown.A retrospective review of primary RTSAs with a minimum 90-day follow-up were included. Complications were classified as major or minor and medical or surgical. Patients were classified into 3 groups: normal BMI (BMI <25 kg/m(2)), overweight or mildly obese (BMI 25-35 kg/m(2)), and moderately or severely obese (BMI >35 kg/m(2)).Of the 119 patients met our inclusion criteria, 30 (25%) had a BMI of less than 25 kg/m(2); 65 (55%) had a BMI of 25 to 35 kg/m(2), and 24 (20%) had BMI exceeding 35 kg/m(2). Complications occurred in 30 patients (25%), comprising major in 11 (9%), minor in 19 (16%), surgical in 21 (18%), and medical in 14 (12%). The most common surgical complications were acute blood loss anemia requiring transfusion (8.4%) and dislocation (4.2%). The most common medical complications were atelectasis (2.5%) and acute renal insufficiency (2.5%). Patients with a BMI exceeding 35 kg/m(2) had a significantly higher overall complication rate (P < .05) and intraoperative blood loss (P = .05) than the other groups. Patients with BMI of less than 25 kg/m(2) had a greater overall complication rate than those with a BMI of 25 to 35 kg/m(2) (P < .05). Multivariate regression analysis demonstrated BMI was the only significant determinant of overall complication rates and medical complication rates (P < .05).Patients with a BMI exceeding 35 kg/m(2) (severely obese) or a BMI of less than 25 kg/m(2) have higher rates of complication after RTSA.

    View details for DOI 10.1016/j.jse.2013.07.043

    View details for Web of Science ID 000328684200009

    View details for PubMedID 24090984

  • Current status of evidence-based sports medicine. Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association Harris, J. D., Cvetanovich, G., Erickson, B. J., Abrams, G. D., Chahal, J., Gupta, A. K., McCormick, F. M., Bach, B. R. 2014; 30 (3): 362–71


    The purpose of this investigation is to determine the proportion of sports medicine studies that are labeled as Level I Evidence in 5 journals and compare the quality of surgical and nonsurgical studies using simple quality assessment tools (Consolidated Standards of Reporting Trials [CONSORT] and Jadad).By use of PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines over the prior 2 years in the top 5 (citation and impact factor based) sports medicine journals, only Level I Evidence studies were eligible for inclusion and were analyzed. All study types (therapeutic, prognostic, diagnostic, and economic) were analyzed. Study quality was assessed with the level of evidence, Jadad score, and CONSORT 2010 guidelines. Study demographic data were compared among journals and between surgical and nonsurgical studies by use of χ(2), 1-way analysis of variance, and 2-sample Z tests.We analyzed 190 Level I Evidence studies (10% of eligible studies) (119 randomized controlled trials [RCTs]). Therapeutic, nonsurgical, single-center studies from the United States were the most common studies published. Sixty-two percent of studies reported a financial conflict of interest. The knee was the most common body part studied, and track-and-field/endurance sports were the most common sports analyzed. Significant differences (P < .05) were shown in Jadad and CONSORT scores among the journals reviewed. Overall, the Jadad and CONSORT scores were 2.71 and 77%, respectively. No differences (P > .05) were shown among journals based on the proportion of Level I studies or appropriate randomization. Significant strengths and limitations of RCTs were identified.This study showed that Level I Evidence and RCTs comprise 10% and 6% of contemporary sports medicine literature, respectively. Therapeutic, nonsurgical, single-center studies are the most common publications with Level I Evidence. Significant differences across sports medicine journals were found in study quality. Surgical studies appropriately described randomization, blinding, and patient enrollment significantly more than nonsurgical studies.Level I, systematic review of Level I studies.

    View details for DOI 10.1016/j.arthro.2013.11.015

    View details for PubMedID 24581261

  • Evidence of capsular defect following hip arthroscopy. Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA McCormick, F., Slikker, W., Harris, J. D., Gupta, A. K., Abrams, G. D., Frank, J., Bach, B. R., Nho, S. J. 2014; 22 (4): 902–5


    The purpose of this study is to identify the incidence of capsular defects in patients undergoing revision hip arthroscopy.A radiographic and anatomical analysis of MR arthrograms of patients undergoing revision arthroscopy was performed to assess for the presence of capsular defect. Intra-operative images and findings were reviewed. Patients with persistent cam and pincer lesions were excluded.From October 2011 to October 2012, 25 patients underwent revision hip arthroscopy surgery, and 9 patients met our inclusion criteria. Within this series, all patients had post-surgical capsular irregularities and seven patients (78 %) had radiographic evidence of capsule and iliofemoral defects on MR arthrogram. Gross capsular defects were confirmed at revision surgery in two patients.The findings of this study demonstrate post-surgical radiographic and anatomical evidence of capsular defects in a select group of patients following hip arthroscopy.IV.

    View details for DOI 10.1007/s00167-013-2591-z

    View details for PubMedID 23851921

  • Survival and Reoperation Rates After Meniscal Allograft Transplantation: Analysis of Failures for 172 Consecutive Transplants at a Minimum 2-Year Follow-up. The American journal of sports medicine McCormick, F., Harris, J. D., Abrams, G. D., Hussey, K. E., Wilson, H., Frank, R., Gupta, A. K., Bach, B. R., Cole, B. J. 2014; 42 (4): 892–97


    Meniscal allograft transplantation (MAT) is a treatment option for knee pain in young patients with meniscal deficiency in the setting of intact articular surfaces, ligamentous stability, and normal alignment. It is being performed with increasing frequency, and the need for reoperations is not uncommon. A mean survival rate of allografts and indications for reoperations would be helpful information when counseling patients regarding the procedure. Purpose/The purpose of this study was to quantify survival for MAT and report findings at reoperation. The hypothesis was that the reoperation rate would be frequent and that the most common secondary surgery would be arthroscopic debridement.Case series; Level of evidence, 4.A retrospective review of a prospectively collected database of patients who underwent MAT from 2003 to 2011 was conducted; all surgeries were performed by a single surgeon. The reoperation rate, timing of reoperation, procedure performed at reoperation, and findings at surgery, including the status of the meniscal and articular cartilage, were reviewed. Survival was defined as a lack of revision MAT or knee arthroplasty. Descriptive statistics, log-rank testing, cross-tabulation, and χ(2) testing were analyzed, with an α value of .05 set as significant.Of 200 patients who underwent MAT during the study period, 172 patients (86%; mean age, 34.3 ± 10.3 years) were evaluated at a mean of 59 months (range, 24-118 months) with a minimum 2-year follow-up. Forty-one percent of MATs were isolated, while 60% were performed with concomitant procedures. Sixty-four patients (32%) returned to the operating room after their index procedure. Arthroscopic debridement was performed in 59% (38/64) of these patients. The mean time to subsequent surgery was 21 months (range, 2-107 months), with 73% occurring within 2 years. Eight of 172 patients (4.7%) went on to require revision MAT or total knee replacement. Patients requiring secondary surgery within 2 years had an odds ratio of 8.4 (95% CI, 1.6-43.4) for future arthroplasty or MAT revision (P = .007).In this series, there was a 32% reoperation rate for MAT, with simple arthroscopic debridement being the most common surgical treatment (59%), and a 95% allograft survival rate at a mean of 5 years. Those requiring additional surgery still benefited, having an 88% allograft survival rate, but were at an increased risk of failure. Patients requiring secondary surgery within 2 years had an odds ratio of 8.4 for future arthroplasty or MAT revision.

    View details for DOI 10.1177/0363546513520115

    View details for PubMedID 24532597

  • Platelet-rich Plasma for Articular Cartilage Repair SPORTS MEDICINE AND ARTHROSCOPY REVIEW Abrams, G. D., Frank, R. M., Fortier, L. A., Cole, B. J. 2013; 21 (4): 213-219


    Platelet concentrates have been gaining popularity for a number of applications in orthopedic surgery as a way to enhance both healing of various tissues and reduce pain. One major area of focus has been the effect of platelet-rich plasma (PRP) on stem cells and chondrocytes and the potential for PRP to enhance cartilage regeneration as well as reduce catabolic factors that lead to cartilage degradation. This article provides an up-to-date review of the current literature regarding the effect of PRP on articular cartilage and its use in the treatment of osteoarthritis. Basic science, animal, and human clinical investigations are presented. In general, PRP has been shown to promote chondrogenic differentiation in vitro and lead to enhanced cartilage repair during animal investigations. Human trials, mostly conducted in the form of injection into knees with osteoarthritis, have shown promise in a number of investigations for achieving symptomatic relief of pain and improving function.

    View details for DOI 10.1097/JSA.0b013e3182999740

    View details for Web of Science ID 000326985200007

    View details for PubMedID 24212369

  • Return-to-Sport and Performance After Anterior Cruciate Ligament Reconstruction in National Basketball Association Players. Sports health Harris, J. D., Erickson, B. J., Bach, B. R., Abrams, G. D., Cvetanovich, G. L., Forsythe, B., McCormick, F. M., Gupta, A. K., Cole, B. J. 2013; 5 (6): 562-568


    Anterior cruciate ligament (ACL) rupture is a significant injury in National Basketball Association (NBA) players.NBA players undergoing ACL reconstruction (ACLR) have high rates of return to sport (RTS), with RTS the season following surgery, no difference in performance between pre- and postsurgery, and no difference in RTS rate or performance between cases (ACLR) and controls (no ACL tear).Case-control.NBA players undergoing ACLR were evaluated. Matched controls for age, body mass index (BMI), position, and NBA experience were selected during the same years as those undergoing ACLR. RTS and performance were compared between cases and controls. Paired-sample Student t tests, chi-square, and linear regression analyses were performed for comparison of within- and between-group variables.Fifty-eight NBA players underwent ACLR while in the NBA. Mean player age was 25.7 ± 3.5 years. Forty percent of ACL tears occurred in the fourth quarter. Fifty players (86%) RTS in the NBA, and 7 players (12%) RTS in the International Basketball Federation (FIBA) or D-league. Ninety-eight percent of players RTS in the NBA the season following ACLR (11.6 ± 4.1 months from injury). Two players (3.1%) required revision ACLR. Career length following ACLR was 4.3 ± 3.4 years. Performance upon RTS following surgery declined significantly (P < 0.05) regarding games per season; minutes, points, and rebounds per game; and field goal percentage. However, following the index year, controls' performances declined significantly in games per season; points, rebounds, assists, blocks, and steals per game; and field goal and free throw percentage. Other than games per season, there was no significant difference between cases and controls.There is a high RTS rate in the NBA following ACLR. Nearly all players RTS the season following surgery. Performance significantly declined from preinjury level; however, this was not significantly different from controls. ACL re-tear rate was low.There is a high RTS rate in the NBA after ACLR, with no difference in performance upon RTS compared with controls.

    View details for DOI 10.1177/1941738113495788

    View details for PubMedID 24427434

  • Trends in Meniscus Repair and Meniscectomy in the United States, 2005-2011 AMERICAN JOURNAL OF SPORTS MEDICINE Abrams, G. D., Frank, R. M., Gupta, A. K., Harris, J. D., McCormick, F. M., Cole, B. J. 2013; 41 (10): 2333-2339


    Meniscus deficiency may lead to degenerative arthritis in the knee. There is a significant emphasis on meniscus preservation, particularly in the young patient, to reduce the risk of arthritis.To report on the incidence of meniscus repair and meniscectomy, with and without concomitant anterior cruciate ligament (ACL) reconstruction, in the United States (US) over the past 7 years.Descriptive epidemiology study.Patients who underwent arthroscopic meniscectomy (Current Procedural Terminology [CPT] codes 29880 and 29881), meniscus repair (CPT codes 29882 and 29883), and ACL reconstruction (CPT code 29888) for the years 2005 through 2011 were identified using the PearlDiver Patient Record Database. Age group and sex were collected for each patient. Patient groups included meniscectomy alone, meniscus repair alone, meniscus repair followed by meniscectomy, ACL reconstruction with concomitant meniscus repair, and ACL reconstruction with concomitant meniscus repair followed by meniscectomy. Linear regression and Student t tests were utilized for comparisons, with an α value of .05 set as significant.The database represented approximately 9% of the US population under 65 years of age. There was no significant change in the number of patients in the covered population during the study time frame (P = .138). From 2005 to 2011, there were a total of 387,833 meniscectomies, 23,640 meniscus repairs, and 84,927 ACL reconstructions. There was a significant increase in the total number of isolated meniscus repairs performed (P = .001) and a doubling of the incidence of repairs from 2005 to 2011. There was no significant increase in the total number of meniscectomies performed (P = .712), while the incidence of meniscectomies increased only 14% from 2005 to 2011. There was no significant change in the number of meniscus repairs performed at the same time as ACL reconstruction during the study time frame. The total number and incidence of meniscectomies after repair with and without ACL reconstruction significantly decreased.There has been an increased number of isolated meniscus repairs being performed in the US over the past 7 years without a concomitant increase in meniscectomies over the same time frame. These data suggest that meniscus repairs are preferentially being performed over meniscectomies.

    View details for DOI 10.1177/0363546513495641

    View details for Web of Science ID 000325096300016

    View details for PubMedID 23863849

  • Authors' reply. Arthroscopy Harris, J. D., Gupta, A. K., Mall, N. A., Abrams, G. D., McCormick, F. M., Cole, B. J., Bach, B. R., Romeo, A. A., Verma, N. N. 2013; 29 (10): 1602-1603

    View details for DOI 10.1016/j.arthro.2013.08.007

    View details for PubMedID 24075610

  • An assessment of the quality of rotator cuff randomized controlled trials: utilizing the Jadad score and CONSORT criteria JOURNAL OF SHOULDER AND ELBOW SURGERY McCormick, F., Cvetanovich, G. L., Kim, J. M., Harris, J. D., Gupta, A. K., Abrams, G. D., Romeo, A. A., Provencher, C. D. 2013; 22 (9): 1180-1185


    The AAOS's Clinical Practice Guideline on "Optimizing Care of Rotator Cuff Problems" suggested a lack of high-quality data. Our purpose is to quantify the quality of randomized controlled trials of rotator cuff disorders via the Jadad score, and to apply the 2010 Consolidated Standards of Reporting Trials CONSORT Criteria to determine factors associated with high Jadad scores and areas for improvement.A systematic review using PRISMA guidelines was performed. Utilizing an iterative search strategy of the top 6 impact factor orthopaedic journals from 2001 to 2011, all randomized controlled studies involving rotator cuff disorders were identified and scored in a systematic, blinded fashion. Each study received a Jadad score. Adherence to CONSORT criteria was quantified and linked to the Jadad score via linear regression. Common deficiencies were described.A total of 129 manuscripts were identified; 54 met inclusion criteria: total patients n = 4099; mean patients per article = 76; range, 16-660. The mean Jadad score was 3.0. Sixty-six percent (35/53) of studies were high quality (high quality: >3). Among these, the majority (63%, 22/35) were nonoperative trials. Adherence to CONSORT Criteria was associated with higher Jadad scores (R(2) = 0.3). The most common deficient CONSORT Criteria were: trial design descriptions (66%; 36/54 studies), descriptions of randomization type (65%; 35/54), and power analysis (46%; 25/54).The majority of randomized controlled trials of rotator cuff pathology are high-quality studies based on the Jadad score. Adherence to CONSORT criteria is linked to high-quality scores. Future studies should use full CONSORT Criteria.

    View details for DOI 10.1016/j.jse.2013.01.017

    View details for Web of Science ID 000324647100011

    View details for PubMedID 23510746

  • Spontaneous Hip Labrum Regrowth After Initial Surgical D,bridement CLINICAL ORTHOPAEDICS AND RELATED RESEARCH Abrams, G. D., Safran, M. R., Sadri, H. 2013; 471 (8): 2504-2508


    BACKGROUND: Anecdotal evidence from second-look hip arthroscopies and animal studies has suggested spontaneous labral regrowth may occur after débridement. However, these observations have not been systematically confirmed. QUESTIONS/PURPOSES: We (1) determined whether labral regrowth occurs after débridement in human hips; (2) if so, described the characteristics of the reconstituted labrum; and (3) determined the association, if any, of age with the presence and quality of labral regrowth. METHODS: We retrospectively reviewed all 24 patients who previously had open hip surgical dislocation with labral débridement for treatment of femoroacetabular impingement (FAI) and concomitant hip arthroscopy 2 years after index procedure in association with planned removal of trochanteric hardware between January and December 1999. Data recorded included amount of labral resection at the index procedure using the clockface method, presence and quality of any labral regrowth, presence of any labral scarring or inflammation, and WOMAC(®) scores. Minimum clinical followup was 11 years (average, 12 years; range, 11-12 years). RESULTS: All patients demonstrated labral regrowth at arthroscopy at 2 years. Homogeneous regrowth of labral height was seen in 21 of 24 patients, with labral scarring noted in four of 24. Average WOMAC(®) score was 98 points (range, 90-100 points) at the time of hardware removal. Increasing patient age was independently associated with decreased WOMAC(®) score and inhomogeneous regrowth of the labrum. CONCLUSIONS: Labral regrowth after resection was seen in all patients at 2 years from index operation. Increasing age, however, was associated with poorer quality of the reconstituted labrum. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

    View details for DOI 10.1007/s11999-013-2914-x

    View details for Web of Science ID 000321549600017

    View details for PubMedID 23483380

  • Topographic Analysis of the Glenoid and Proximal Medial Tibial Articular Surfaces A Search for the Ideal Match for Glenoid Resurfacing AMERICAN JOURNAL OF SPORTS MEDICINE Gupta, A. K., Forsythe, B., Lee, A. S., Harris, J. D., McCormick, F., Abrams, G. D., Verma, N. N., Romeo, A. A., Inoue, N., Cole, B. J. 2013; 41 (8): 1893-1899


    Current knowledge is lacking concerning the appropriate site of osteochondral allograft harvest to match glenoid shape for the purposes of glenoid resurfacing. This has led to difficulty with adequate restoration of the geometry of the glenoid with currently available techniques.The medial tibial plateau will provide a suitable osteochondral harvest site because of its concavity and anatomic similarity to the glenoid.Descriptive laboratory study.Computed tomography (CT) was performed on 4 cadaveric proximal tibias and 4 scapulae, allowing for 16 glenoid-tibial comparative combinations. Three-dimensional CT models were created and exported into point-cloud models. A local coordinate map of the glenoid and medial tibial plateau articular surfaces was created. Two zones of the medial tibial articular surface (anterior and posterior) were quantified. The glenoid articular surface was defined as a best-fit circle of the glenoid articular surface maintaining a 2-mm bony rim. This surface was virtually placed on a point on the tibial articular surface in 3D space. The tibial surface was segmented, and its 3D surface orientation was determined with respect to its surface. The 3D orientation of the glenoid surface was reoriented so that the direction of the glenoid surface matched that of the tibial surface. The least distances between the point-clouds on the glenoid and tibial surfaces were calculated. The glenoid surface was rotated 360° in 1° increments, and the mean least distance was determined at each rotating angle.When the centroid of the glenoid surface was placed on the medial tibial articular surface, it covered approximately two-thirds of the anterior or posterior tibial surfaces. Overall, the mean least distance difference in articular congruity of all 16 glenoid-medial tibial surface combinations was 0.74 mm (standard deviation, ±0.13 mm). The mean least distance difference of the anterior and posterior two-thirds of the medial tibial articular surface was 0.72 mm (±0.13 mm) and 0.76 mm (±0.16 mm), respectively. There was no significant difference between the anterior and posterior two-thirds of the tibia with regard to topographic match of the glenoid (P = .187).The findings suggest that the medial tibial articular surface provides an appropriate anatomic match to the glenoid articular surface. Both the anterior and posterior two-thirds of the medial tibial articular surface are potential sites for osteochondral graft harvest.This method can be applied to future studies evaluating the ideal sites of graft harvest to treat zonal glenoid bone wear and/or loss.

    View details for DOI 10.1177/0363546513484126

    View details for Web of Science ID 000325708000025

    View details for PubMedID 23857887

  • Biomechanical evaluation of a coracoclavicular and acromioclacicular ligament reconstruction technique utilizing a single continuous intramedullary free tendon graft. Journal of shoulder and elbow surgery Abrams, G. D., McGarry, M. H., Jain, N. S., Freehill, M. T., Shin, S., Cheung, E. V., Lee, T. Q., Safran, M. R. 2013; 22 (7): 979-985


    Reconstruction of only the coracoclavicular (CC) ligaments may restore superior-inferior (S-I) but not anterior-posterior (A-P) stability of the acromioclavicular (AC) joint. Concomitant reconstruction of both the AC and CC ligaments may more reliably restore intact biomechanical characteristics of the AC joint.Ten matched pairs of shoulders were utilized. Five specimens underwent CC ligament reconstruction while an equal number underwent combined AC and CC ligament reconstruction utilizing an intramedullary tendon graft. Each of the reconstructions was compared with the intact contralateral control. Translational and load to failure characteristics were compared between groups.No difference was found in S-I translation between intact specimens and CC-only reconstructions (P = .20) nor between intact specimens and AC/CC reconstructions (P = .33) at 10 Newton (N) loads. Significant differences were noted in A-P translation between intact specimens and CC-only reconstructions (P < .001) but no difference in A-P translation between intact specimens and AC/CC reconstructions (P = .34).The A-P and S-I translational biomechanical characteristics of the AC joint were restored using the new technique described. Reconstruction of the CC ligaments only (versus AC/CC combined) led to significantly increased translational motion in the A-P plane as compared to intact control specimens.

    View details for DOI 10.1016/j.jse.2012.09.013

    View details for PubMedID 23313367

  • Response to letter to editor regarding "Risk factors for development of heterotopic ossification of the elbow after fracture fixation". Journal of shoulder and elbow surgery Abrams, G. D., Bellino, M. J., Cheung, E. V. 2013; 22 (7)

    View details for DOI 10.1016/j.jse.2013.03.011

    View details for PubMedID 23623207

  • Methodologic Quality of Knee Articular Cartilage Studies ARTHROSCOPY-THE JOURNAL OF ARTHROSCOPIC AND RELATED SURGERY Harris, J. D., Erickson, B. J., Abrams, G. D., Cvetanovich, G. L., McCormick, F. M., Gupta, A. K., Bach, B. R., Cole, B. J. 2013; 29 (7): 1243-U184


    (1) To evaluate the quality of knee articular cartilage surgery literature using established methodologic quality instruments, and (2) to assess whether study quality has improved with time.A systematic review was performed using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Studies of autologous chondrocyte implantation (ACI), osteochondral autograft and allograft transplant, and microfracture were analyzed. Study methodologic quality was assessed by the level of evidence and 9 different methodologic quality questionnaires. Comparisons were made between different surgical technique groups by use of Student's t tests. Assessment of study quality improvement with time was performed by comparison of the Coleman Methodology Score (CMS) from the included studies (2004 to present) and CMS from a prior study assessing quality of articular cartilage studies (1985 to 2004). Furthermore, assessment of study quality improvement with time was performed over the period of the included studies (2004 to present).We included 194 studies (11,787 subjects). Most evidence was Level IV (76%) and nonrandomized (91%). ACI was the most commonly reported technique (62% of studies). Only 34% of studies denied the presence of a financial conflict of interest. The mean subject age was 33.5 ± 8.2 years, and the mean length of follow-up was 3.7 ± 2.3 years. By use of study quality questionnaires, the methodologic quality of articular cartilage studies was poor. However, study quality (after 2004) was significantly improved versus that reported from a prior study (before 2004) using the CMS (P < .01). The mean level of evidence, CMS, CONSORT (Consolidated Standards of Reporting Trials) score, and Jadad score showed no significant improvement over the period of the included studies (P > .05). The quality of randomized controlled trials (RCTs) was significantly higher than that of non-RCTs (P < .05). The most common study weaknesses included blinding, subject selection process, study type, sample size calculation, and outcome measures and assessment.The methodologic quality of knee articular cartilage surgery studies was poor overall and also for individual techniques (ACI, osteochondral autograft transplant, osteochondral allograft transplant, and microfracture). However, the overall quality of the investigations in this review (after June 2004) has significantly improved in comparison to those published before 2004. The quality of RCTs was significantly higher than that of non-RCTs. Level of evidence, CMS, CONSORT score, and Jadad score did not significantly improve with later publication date within the period of the studies analyzed. Methodologic quality deficiencies identified in this investigation may be used to guide future articular cartilage studies' design, conduct, and reporting.Level IV, systematic review of studies with Levels of Evidence I-IV.

    View details for DOI 10.1016/j.arthro.2013.02.023

    View details for Web of Science ID 000321105200020

    View details for PubMedID 23623292

  • Return to sport following shoulder surgery in the elite pitcher: a systematic review. Sports health Harris, J. D., Frank, J. M., Jordan, M. A., Bush-Joseph, C. A., Romeo, A. A., Gupta, A. K., Abrams, G. D., McCormick, F. M., Bach, B. R. 2013; 5 (4): 367-376


    The ability to return to elite pitching, performance, and clinical outcomes of shoulder surgery in elite baseball pitchers are not definitively established.To determine (1) the rate of return to sport (RTS) in elite pitchers following shoulder surgery, (2) postoperative clinical outcomes upon RTS, and (3) performance upon RTS and to compare RTS rates in different types of shoulder surgery.Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and checklist, Medline, SciVerse Scopus, SportDiscus, and Cochrane Central Register of Controlled Trials were searched.Levels I-IV evidence were eligible for inclusion if performance-based (eg, RTS) and/or clinical outcome-based reporting of outcomes were reported following surgical treatment of shoulder pathology in elite pitchers (major or minor league or collegiate).Subject, shoulder, and pre- and postoperative performance-based variables of interest were extracted. All shoulder surgery types were potentially inclusive (eg, open, arthroscopic, rotator cuff, labrum, biceps, acromioclavicular joint, fracture). Study methodological quality was analyzed using the Modified Coleman Methodology Score (MCMS).Six studies were analyzed (287 elite male pitchers [mean age, 27 years] who underwent shoulder surgery, with 99% on the dominant, throwing shoulder). MCMS was 38 (poor). Most pitchers were professional, with a mean career length of 6.58 years and postoperative clinical follow-up of 3.62 years. In 5 of 6 studies, multiple diagnoses were addressed concomitantly at surgery. Rate of RTS was 68% at mean 12 months following surgery. Twenty-two percent of Major League Baseball (MLB) pitchers never RTS in MLB. Overall performance did improve following surgery; however, this did not improve to pre-injury levels.In this systematic review, the rate of return to elite baseball pitching following surgery was established. Performance tended to decrease prior to surgery and gradually improve postoperatively, though not reaching pre-injury levels of pitching.IV (systematic review of studies level I-IV evidence), therapeutic.

    View details for DOI 10.1177/1941738113482673

    View details for PubMedID 24459557

  • Hyaluronic acid and platelet-rich plasma, intra-articular infiltration in the treatment of gonarthrosis: letter to the editor. American journal of sports medicine Abrams, G. D., Cole, B. J., Cerza, F., Carcangiu, A. 2013; 41 (5): NP27-?

    View details for DOI 10.1177/0363546513485064

    View details for PubMedID 23636557

  • Long-Term Outcomes After Bankart Shoulder Stabilization ARTHROSCOPY-THE JOURNAL OF ARTHROSCOPIC AND RELATED SURGERY Harris, J. D., Gupta, A. K., Mall, N. A., Abrams, G. D., McCormick, F. M., Cole, B. J., Bach, B. R., Romeo, A. A., Verma, N. N. 2013; 29 (5): 920-933


    The purposes of this study were (1) to analyze long-term outcomes in patients who have undergone open or arthroscopic Bankart repair and (2) to evaluate study methodologic quality through validated tools.We performed a systematic review of Level I to IV Evidence using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Clinical outcome studies after open or arthroscopic Bankart repair with a minimum of 5 years' follow-up were analyzed. Clinical and radiographic outcomes were extracted and reported. Study methodologic quality was evaluated with Modified Coleman Methodology Scores and Quality Appraisal Tool scores.We analyzed 26 studies (1,781 patients). All but 2 studies were Level III or IV Evidence with low Modified Coleman Methodology Scores and Quality Appraisal Tool scores. Patients analyzed were young (mean age, 28 years) male patients (81%) with unilateral dominant shoulder (61%), post-traumatic recurrent (mean of 11 dislocations before surgery) anterior shoulder instability without significant glenoid bone loss. The mean length of clinical follow-up was 11 years. There was no significant difference in recurrence of instability with arthroscopic (11%) versus open (8%) techniques (P = .06). There was no significant difference in instability recurrence with arthroscopic suture anchor versus open Bankart repair (8.5% v 8%, P = .82). There was a significant difference in rate of return to sport between open (89%) and arthroscopic (74%) techniques (P < .01), whereas no significant difference was observed between arthroscopic suture anchor (87%) and open repair (89%) (P = .43). There was no significant difference in the rate of postoperative osteoarthritis between arthroscopic suture anchor and open Bankart repair (26% and 33%, respectively; P = .059). There was no significant difference in Rowe or Constant scores between groups (P > .05).Surgical treatment of anterior shoulder instability using arthroscopic suture anchor and open Bankart techniques yields similar long-term clinical outcomes, with no significant difference in the rate of recurrent instability, clinical outcome scores, or rate of return to sport. No significant difference was shown in the incidence of postoperative osteoarthritis with open versus arthroscopic suture anchor repair. Study methodologic quality was poor, with most studies having Level III or IV Evidence.Level IV, systematic review of studies with Level I through IV Evidence.

    View details for DOI 10.1016/j.arthro.2012.11.010

    View details for Web of Science ID 000319038900018

    View details for PubMedID 23395467

  • Complications and Reoperations During and After Hip Arthroscopy: A Systematic Review of 92 Studies and More Than 6,000 Patients ARTHROSCOPY-THE JOURNAL OF ARTHROSCOPIC AND RELATED SURGERY Harris, J. D., McCormick, F. M., Abrams, G. D., Gupta, A. K., Ellis, T. J., Bach, B. R., Bush-Joseph, C. A., Nho, S. J. 2013; 29 (3): 589-595


    To determine the prevalence of complications and reoperations during and after hip arthroscopy.A systematic review of multiple medical databases was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and checklist. All clinical outcome studies that reported the presence or absence of complications and/or reoperations were eligible for inclusion. Length of follow-up was not an exclusion criterion. Complication and reoperation rates were extracted from each study. Duplicate patient populations within separate distinct publications were analyzed and reported only once.Ninety-two studies (6,134 participants) were included. Most were Level IV evidence studies (88%) with short-term follow-up (mean 2.0 years). Labral tears and femoroacetabular impingement (FAI) were the 2 most common diagnoses treated, and labral treatment and acetabuloplasty/femoral osteochondroplasty were the 2 most common surgical techniques reported. Overall, major and minor complication rates were 0.58% and 7.5%, respectively. Iatrogenic chondrolabral injury and temporary neuropraxia were the 2 most common minor complications. The overall reoperation rate was 6.3%, occurring at a mean of 16 months. Total hip arthroplasty (THA) was the most common reoperation. The conversion rate to THA was 2.9%.The rate of major complications was 0.58% after hip arthroscopy. The reoperation rate was 6.3%, and the most common reason for reoperation was conversion to THA. Minor complications and the reoperation rate are directly related to the learning curve of hip arthroscopy. As surgical indications evolve, patient selection should limit the number of cases that would have been converted to THA. Similarly, the number of minor complications is directly related to technical aspects of the procedure and therefore will decrease with surgeon experience and improvement in instrumentation.Level IV, a systematic review of Level I to IV studies.

    View details for DOI 10.1016/j.arthro.2012.11.003

    View details for Web of Science ID 000315584200029

    View details for PubMedID 23544691

  • Arthroscopic bony bankart fixation using a modified sugaya technique. Arthroscopy techniques Gupta, A. K., McCormick, F. M., Abrams, G. D., Harris, J. D., Bach, B. R., Romeo, A. A., Verma, N. N. 2013; 2 (3): e251-5


    Arthroscopic fixation of bony Bankart lesions in the setting of anterior shoulder instability has had successful long-term results. Key factors such as patient positioning, portal placement, visualization, mobilization of bony/soft tissues, and anatomic reduction and fixation are crucial to yield such results. We present a modified Sugaya technique that is reproducible and based on such key principles. This technique facilitates ease of anchor and suture placement to allow for anatomic reduction and fixation.

    View details for DOI 10.1016/j.eats.2013.02.018

    View details for PubMedID 24265994

  • Treatment of a lateral tibial plateau osteochondritis dissecans lesion with subchondral injection of calcium phosphate. Arthroscopy techniques Abrams, G. D., Alentorn-Geli, E., Harris, J. D., Cole, B. J. 2013; 2 (3): e271-4


    Osteochondritis dissecans lesions occur frequently in children and adolescents. Treatment can be challenging and depends on the status of the articular cartilage and subchondral bone. Injection of calcium phosphate bone substitute into the area of subchondral bone edema (Subchondroplasty; Knee Creations, West Chester, PA) may be an option. We present a case of a lateral tibial plateau osteochondritis dissecans lesion treated with subchondral injection of nanocrystalline calcium phosphate. Preoperative magnetic resonance imaging is used to determine the area of subchondral edema, and intraoperative fluoroscopy is used to localize this area with the injection cannula. Calcium phosphate is injected by use of a series of syringes until the appropriate fill is obtained. Treatment of concomitant cartilage defects may also be carried out at this time.

    View details for DOI 10.1016/j.eats.2013.03.001

    View details for PubMedID 24265997

  • The posterolateral portal: optimizing anchor placement and labral repair at the inferior glenoid. Arthroscopy techniques Cvetanovich, G. L., McCormick, F., Erickson, B. J., Gupta, A. K., Abrams, G. D., Harris, J. D., Romeo, A. A., Bach, B. R., Provencher, M. T. 2013; 2 (3): e201-4


    The Bankart lesion is considered the critical lesion in anterior shoulder instability, in which the anteroinferior glenoid labrum separates from the glenoid rim. Technical advances in arthroscopy have ushered in a shift from open to arthroscopic Bankart repair. When one is performing an arthroscopic Bankart repair, proper portal placement is critical for success in labral preparation and anchor placement. Frequently, standard anterior portals are insufficient for inferior glenoid anchor placement and suture shuttling. The posterolateral portal-located 4 cm lateral to the posterolateral corner of the acromion-simplifies and improves anchor placement, trajectory, and anatomic capsulolabral repair of the inferior glenoid. We present our preferred technique for capsulolabral repair of the inferior glenoid.

    View details for DOI 10.1016/j.eats.2013.02.011

    View details for PubMedID 24265983

  • Risk factors for development of heterotopic ossification of the elbow after fracture fixation JOURNAL OF SHOULDER AND ELBOW SURGERY Abrams, G. D., Bellino, M. J., Cheung, E. V. 2012; 21 (11): 1550-1554


    Postoperative heterotopic ossification (HO) about the elbow may occur after surgical fixation of fractures and can contribute to dysfunction. Factors associated with HO formation after surgical fixation of elbow trauma are not well understood.All patients who underwent surgery for elbow trauma at our institution from October 2001 through August 2010 were retrospectively reviewed. Patients with prior injury or deformity to the involved elbow were excluded. Demographic data; fracture type; surgical treatment; and presence, location, and size of HO were recorded. The Fisher exact test, χ(2) test, and multivariate logistic regression were used with an α value of .05 used for significance.A total of 159 patients were identified, with 89 (37 men and 52 women) meeting inclusion and exclusion criteria. The mean age was 54.4 years (range, 18-90 years), and the mean follow-up time was 180 days. Age, male gender, lateral collateral ligament repair, and dual-incision approach were not associated with increased ectopic bone formation. Distal humeral fractures were a significant predictor of heterotopic bone. In patients in whom HO ultimately developed, it was visible on radiographs obtained 2 weeks postoperatively in 86% of cases.This investigation found predictors for the development of HO after surgical fixation of intra-articular elbow fractures. Furthermore, HO went on to develop at the time of final follow-up in only 14% of patients without HO on radiographs obtained 2 weeks postoperatively. This may suggest that absence of HO on radiographs obtained 2 weeks postoperatively may predict a more favorable outcome.

    View details for DOI 10.1016/j.jse.2012.05.040

    View details for Web of Science ID 000312000600021

    View details for PubMedID 22947234

  • 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

  • Epidemiology of musculoskeletal injury in the tennis player BRITISH JOURNAL OF SPORTS MEDICINE Abrams, G. D., Renstrom, P. A., Safran, M. R. 2012; 46 (7): 492-498


    Tennis is a popular sport with tens of millions of players participating worldwide. This popularity was one factor leading to the reappearance of tennis as a medal sport at the 1988 Summer Olympics in Seoul, South Korea. The volume of play, combined with the physical demands of the sports, can lead to injuries of the musculoskeletal system. Overall, injury incidence and prevalence in tennis has been reported in a number of investigations. The sport creates specific demands on the musculoskeletal system, with acute injuries, such as ankle sprains, being more frequent in the lower extremity while chronic overuse injuries, such as lateral epicondylitis, are more common in the upper extremity in the recreational player and shoulder pain more common in the high-level player. This review discusses the epidemiology of injuries frequently experienced in tennis players and examines some of these injuries' correlation with the development of osteoarthritis. In addition, player-specific factors, such as age, sex, volume of play, skill level, racquet properties and grip positions as well as the effect of playing surface on the incidence and prevalence of injury is reported. Finally, recommendations on standardisation of future epidemiological studies on tennis injuries are made in order to be able to more easily compare results of future investigations.

    View details for DOI 10.1136/bjsports-2012-091164

    View details for Web of Science ID 000305280500010

    View details for PubMedID 22554841

  • Surgical Technique: Methods for Removing a Compress (R) Compliant Prestress Implant CLINICAL ORTHOPAEDICS AND RELATED RESEARCH Abrams, G. D., Gajendran, V. K., Mohler, D. G., Avedian, R. S. 2012; 470 (4): 1204-1212


    The Compress® device uses a unique design using compressive forces to achieve bone ingrowth on the prosthesis. Because of its design, removal of this device may require special techniques to preserve host bone. DESCRIPTION OF TECHNIQUES: Techniques needed include removal of a small amount of bone to relieve compressive forces, use of a pin extractor and/or Kirschner wires for removal of transfixation pins, and creation of a cortical window in the diaphysis to gain access to bone preventing removal of the anchor plug.We retrospectively reviewed the records of 63 patients receiving a Compress® device from 1996 to 2011 and identified 11 patients who underwent subsequent prosthesis removal. The minimum followup was 1 month (average, 20 months; range, 1-80 months). The most common reason for removal was infection (eight patients) and the most common underlying diagnosis was osteosarcoma (five patients). Three patients underwent above-knee amputation, whereas the others (eight patients) had further limb salvage procedures at the time of prosthesis removal.Five patients had additional unplanned surgeries after explantation. Irrigation and débridement of the surgical wound was the most common unplanned procedure followed by latissimus free flap and hip prosthesis dislocation. At the time of followup, all patients were ambulating on either salvaged extremities or prostheses.Although removal of the Compress® device presents unique challenges, we describe techniques to address those challenges.

    View details for DOI 10.1007/s11999-011-2128-z

    View details for Web of Science ID 000301442800032

    View details for PubMedID 22002827

  • MRI and arthroscopy correlations of the elbow: a case-based approach. Instructional course lectures Abrams, G. D., Stoller, D. W., Safran, M. R. 2012; 61: 235-249


    The number of elbow arthroscopies and indications for the procedure have increased significantly since the advent of modern elbow arthroscopy in the 1980s. In addition to the patient history, physical examination, and plain radiography, MRI is an important tool for the clinician in diagnosing several pathologies within and around the elbow. Understanding the pathophysiology and clinical presentation and being familiar with the MRI characteristics of a variety of elbow conditions will assist the physician in making an accurate diagnosis and help guide appropriate treatment.

    View details for PubMedID 22301236

  • Kinematics Differences Between the Flat, Kick, and Slice Serves Measured Using a Markerless Motion Capture Method ANNALS OF BIOMEDICAL ENGINEERING Sheets, A. L., Abrams, G. D., Corazza, S., Safran, M. R., Andriacchi, T. P. 2011; 39 (12): 3011-3020


    Tennis injuries have been associated with serving mechanics, but quantitative kinematic measurements in realistic environments are limited by current motion capture technologies. This study tested for kinematic differences at the lower back, shoulder, elbow, wrist, and racquet between the flat, kick, and slice serves using a markerless motion capture (MMC) system. Seven male NCAA Division 1 players were tested on an outdoor court in daylight conditions. Peak racquet and joint center speeds occurred sequentially and increased from proximal (back) to distal (racquet). Racquet speeds at ball impact were not significantly different between serve types. However, there were significant differences in the direction of the racquet velocity vector between serves: the kick serve had the largest lateral and smallest forward racquet velocity components, while the flat serve had the smallest vertical component (p < 0.01). The slice serve had lateral velocity, like the kick, and large forward velocity, like the flat. Additionally, the racquet in the kick serve was positioned 8.7 cm more posterior and 21.1 cm more medial than the shoulder compared with the flat, which could suggest an increased risk of shoulder and back injury associated with the kick serve. This study demonstrated the potential for MMC for testing sports performance under natural conditions.

    View details for DOI 10.1007/s10439-011-0418-y

    View details for Web of Science ID 000296507000014

    View details for PubMedID 21984513

  • Musculoskeletal injuries in the tennis player MINERVA ORTOPEDICA E TRAUMATOLOGICA Abrams, G. D., Safran, M. R. 2011; 62 (4): 311-329
  • Review of tennis serve motion analysis and the biomechanics of three serve types with implications for injury SPORTS BIOMECHANICS Abrams, G. D., Sheets, A. L., Andriacchi, T. P., Safran, M. R. 2011; 10 (4): 378-390


    The tennis serve has the potential for musculoskeletal injury as it is an overhead motion and is performed repetitively during play. Early studies evaluating the biomechanics and injury potential of the tennis serve utilized skin-based marker technologies; however, markerless motion measurement systems have recently become available and have obviated some of the problems associated with the marker-based technology. The late cocking and early acceleration phases of the kinetic chain of the service motion produce the highest internal forces and pose the greatest risk of injury during the service motion. Previous biomechanical data on the tennis serve have primarily focused on the flat serve, with some data on the kick serve, and very little published data elucidating the biomechanics of the slice serve. This review discusses the injury potential of the tennis serve with respect to the four phases of the service motion, the history, and early findings of service motion evaluation, as well as biomechanical data detailing the differences between the three types of serves and how this may relate to injury prevention, rehabilitation, and return to play.

    View details for DOI 10.1080/14763141.2011.629302

    View details for Web of Science ID 000299832400010

    View details for PubMedID 22303788

  • Diagnosis and management of superior labrum anterior posterior lesions in overhead athletes BRITISH JOURNAL OF SPORTS MEDICINE Abrams, G. D., Safran, M. R. 2010; 44 (5): 311-318


    Shoulder pain is a common complaint in overhead athletes, and superior labrum anterior posterior (SLAP) lesions are a common cause of this pain. The pathological cascade which results in the SLAP lesion consists of a combination of posterior inferior capsular tightness and scapular dyskinesis, resulting in a 'peel back' phenomenon at the biceps anchor and leading to the SLAP tear. Physical exam tests vary in their sensitivity and specificity in detecting SLAP lesions, so MRI is helpful in demonstrating the anatomical alteration. Treatment can be conservative, with posterior inferior capsular stretching and scapular open and closed chain exercises. Many SLAP lesions in overhead athletes require surgical treatment that involves repair of the labrum back to the glenoid. Treatment of concomitant injuries such as rotator cuff tears and Bankart lesions in conjunction with the SLAP repair may be necessary.

    View details for DOI 10.1136/bjsm.2009.070458

    View details for Web of Science ID 000276368100005

    View details for PubMedID 20371556

  • Muscle geometry affects accuracy of forearm volume determination by magnetic resonance imaging (MRI) JOURNAL OF BIOMECHANICS Eng, C. M., Abrams, G. D., Smallwood, L. R., Lieber, R. L., Ward, S. R. 2007; 40 (14): 3261-3266


    Upper extremity musculoskeletal modeling is becoming increasingly sophisticated, creating a growing need for subject-specific muscle size parameters. One method for determining subject-specific muscle volume is magnetic resonance imaging (MRI). The purpose of this study was to determine the validity of MRI-derived muscle volumes in the human forearm across a variety of muscle sizes and shapes. Seventeen cadaveric forearms were scanned using a fast-spoiled gradient echo pulse sequence with high isotropic spatial resolution (1mm(3) voxels) on a 3T MR system. Pronator teres (PT), extensor carpi radialis brevis (ECRB), extensor pollicis longus (EPL), flexor carpi ulnaris (FCU), and brachioradialis (BR) muscles were manually segmented allowing volume to be calculated. Forearms were then dissected, muscles isolated, and muscle masses obtained, which allowed computation of muscle volume. Intraclass correlation coefficients (ICC(2,1)) and absolute volume differences were used to compare measurement methods. There was excellent agreement between the anatomical and MRI-derived muscle volumes (ICC = 0.97, relative error = 12.8%) when all 43 muscles were considered together. When individual muscles were considered, there was excellent agreement between measurement methods for PT (ICC = 0.97, relative error = 8.4%), ECRB (ICC = 0.93, relative error = 7.7%), and FCU (ICC = 0.91, relative error = 9.8%), and fair agreement for EPL (ICC = 0.68, relative error = 21.6%) and BR (ICC = 0.93, relative error = 17.2%). Thus, while MRI-based measurements of muscle volume produce relatively small errors in some muscles, muscles with high surface area-to-volume ratios may predispose them to segmentation error, and, therefore, the accuracy of these measurements may be unacceptable.

    View details for DOI 10.1016/j.jbiomech.2007.04.005

    View details for Web of Science ID 000250848000026

    View details for PubMedID 17521657

  • Pronator teres is an appropriate donor muscle for restoration of wrist and thumb extension. journal of hand surgery Abrams, G. D., Ward, S. R., Fridén, J., Lieber, R. L. 2005; 30 (5): 1068-1073


    To compare the detailed architectural properties of the pronator teres (PT), extensor carpi radialis brevis (ECRB), and extensor pollicis longus (EPL) muscles to evaluate the suitability of PT-to-ECRB and PT-to-EPL surgical procedures.Muscle physiologic cross-sectional areas and region-specific muscle fiber lengths were measured in cadaveric PT, ECRB, and EPL muscles (n = 10 muscles of each type). One-way repeated-analyses of variance measures and post hoc t tests with Bonferroni corrections were used for statistical comparisons.The ulnar head of the PT was present in 8 of 10 specimens. The average PT fiber length was similar to that of the ECRB (7.02 +/- 0.49 cm vs 6.17 +/- 0.27 cm) but was significantly longer than that of the EPL (5.44 +/- 0.25 mm). Fiber length in the humeral head of the PT was longer compared with the ulnar head (7.19 +/- 0.52 cm vs 4.14 +/- 0.25 cm). The average physiologic cross-sectional area of the PT was similar to that of the ECRB (3.5 +/- 0.4 cm2 vs 3.3 +/- 0.3 cm2) but was significantly larger than that of the EPL (3.5 +/- 0.4 cm2 vs 1.1 +/- 0.1 cm2).From an architectural point of view the PT is an excellent donor choice for transfer to the ECRB for restoration of wrist extension or to the EPL for restoration of thumb extension. Because there is fiber length heterogeneity within the PT, however, when the ulnar head is present it may limit the total excursion of the donor muscle. These data suggest that releasing the ulnar head of the PT before transfer may result in larger excursions of this important motor in tendon transfer surgery.

    View details for PubMedID 16182069