Medial Ulnar Collateral Ligament Reconstruction With Allograft Provides Excellent Clinical Outcomes, High Rates of Return to Play, and a Low Incidence of Postoperative Complications: A Systematic Review.

PURPOSE: To perform a systematic review evaluating clinical outcomes in patients undergoing medial ulnar collateral ligament reconstruction (MUCLR) with soft-tissue allograft. METHODS: A systematic review of the literature was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The primary outcomes evaluated were patient-reported outcome scores, return to play (RTP) rates, incidence of postoperative complications, and rates of graft rupture or mechanical failure. RESULTS: The literature search identified 395 articles, and 5 studies met final inclusion criteria after full-text review. A total of 274 patients were analyzed in the included studies and follow-up ranged from 3.0 to 7.6 years. Two studies (number of patients = 141) reported outcomes exclusively of MUCLR with allograft, whereas 3 studies (number of patients = 133) reported outcomes in patients undergoing MUCLR with either allograft or autograft. Allograft sources included gracilis, semitendinosus, plantaris, peroneus longus, and palmaris longus. Level of patient athletic competition ranged from recreational athletes to the professional level; however, nonathletes in the setting of trauma were also included. The RTP rate after MUCLR with soft-tissue allograft was 95.3%, and 89.3% of patients returned to a similar or greater level of play postoperatively. The Timmerman-Andrews score was reported in 2 studies, and the means postoperatively ranged from 94.55 to 97. Postoperative complication rates were low (range, 0% to 20%), and there were no reported incidences of allograft rupture or mechanical failure. CONCLUSIONS: Based on the available data, soft-tissue allograft for MUCLR in athletic patient populations provides excellent clinical outcomes, high rates of RTP, and low rates of postoperative complications and graft failure at short-term follow-up. There remains a lack of high-quality evidence directly comparing autograft versus allograft outcomes in elite overhead-throwing athletes to support allograft as an acceptable alternative for MUCLR in this patient population. LEVEL OF EVIDENCE: Level IV, systematic review of Level III-IV studies.

Postoperative Radiographic Outcomes Following Primary Open Coracoid Transfer (Bristow-Latarjet) Vary in Definition, Classification, and Imaging Modality: A Systematic Review.

PURPOSE: To analyze radiographic outcomes by conventional radiography, computed tomography (CT), or both and complication rates of open coracoid transfer at a minimum of 12-months follow-up. METHODS: A literature search was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, using PubMed, Medline (Ovid), and EMBASE library databases. Inclusion criteria were clinical studies reporting on open Latarjet as the primary surgical procedure(revision coracoid transfer after failed prior stabilization excluded) with postoperative radiographic outcomes at a minimum mean 1-year follow-up. Patient demographics, type of postoperative imaging modality, and radiographic outcomes and complications including graft union, osteoarthritis, and osteolysis were systematically reviewed. Data were summarized as ranges of reported values for each outcome metric. Each radiographic outcome was graphically represented in a Forest plot with point estimates of the incidence of radiographic outcomes with corresponding 95% confidence intervals and I2. RESULTS: Thirty-three studies met inclusion criteria, with a total of 1,456 shoulders. The most common postoperative imaging modality was plain radiography only (n = 848 [58.2%]), both CT and radiography (n = 287 [19.7%]), and CT only (n = 321 [22.1%]). Overall, the reported graft union rate ranged from 75% to 100%, of which 79.8% (n = 395) were detected on plain radiography. The most common reported postoperative radiographic complications after the open coracoid transfer were osteoarthritis (range, 0%-100%, pooled mean 28%), graft osteolysis (range, 0%-100%, pooled mean 30%), nonunion (range, 0%-32%, pooled mean 5.1%), malpositioned graft (range, 0%-75%, pooled mean 14.75%), hardware issues (range, 0%-9.1%, pooled mean 5%), and bone block fracture (range, 0%-8%, pooled mean 2.1%). Graft healing was achieved in a majority of cases (range, 75%-100%). CONCLUSION: Postoperative radiographic outcomes after open coracoid transfer vary greatly in definition, classification, and imaging modality of choice. Greater consistency in postoperative radiographic outcomes is essential to evaluate graft healing, osteolysis, and nonunion. LEVEL OF EVIDENCE: Level IV, systematic review of Level III-IV studies.

Impact of the COVID-19 Pandemic on Sports Medicine Patient Care.

The COVID-19 pandemic has necessitated new practices in sports medicine patient care. Telehealth has been validated as a reliable tool for consultations and physical examinations and increases access to care in a cost-efficient manner. Social distancing and avoiding team members who have tested positive are the most effective ways to reduce spread. For screening, daily self-reported symptom checklists and fever monitoring help identify potentially infected athletes who should be instructed to isolate and seek care. Polymerase chain-reaction (PCR) testing for the virus via nasopharyngeal swab is not recommended for screening and should be reserved for symptomatic individuals with fever, cough, or shortness of breath. Face masks and personal protective equipment (PPE) may be beneficial in high-risk settings, but there is little evidence to support use in athletic populations. Median return to play after COVID-19 in elite athletes has been reported as 18 days (range: 12 to 30), with 27% not fully available at 28 days. Chest pain at diagnosis was the only symptom associated with time loss longer than 28 days. Finally, canceled competitions or time loss results in grief, stress, and frustration for athletes, as well as loss of a social support network and routine training regimens. Mental health support services may be indicated.

Improved Accuracy of Coronal Alignment Can Be Attained Using 3D-Printed Patient-Specific Instrumentation for Knee Osteotomies: A Systematic Review of Level III and IV Studies.

PURPOSE: To evaluate the accuracy and precision of postoperative coronal plane alignment using 3D-printed patient-specific instrumentation (PSI) in the setting of proximal tibial or distal femoral osteotomies. METHODS: A systematic review evaluating the accuracy of 3D-printed PSI for coronal plane alignment correcting knee osteotomies was performed. The primary outcomes were accuracy of coronal plane limb alignment correction and number of correction outliers. Secondary variables were duration of surgery, number of intraoperative fluoroscopic images, complications, cost, and clinical outcomes (as applicable). RESULTS: Ninety-three studies were identified, and 14 were included in the final analysis. Overall, mean postoperative deviation from target correction ranged from 0.3° to 1° for all studies using hip-knee angle measurements and 2.3% to 4.9% for all studies using weight-bearing line measurements. The incidence of correction outliers was assessed in 8 total studies and ranged from 0 to 25% (total n = 10 knees) of patients corrected with 3D-printed PSI. Osteotomies performed with 3D-printed cutting guides or wedges demonstrated significantly shorter operative times (P < .05) and fewer intraoperative fluoroscopic images (P < .05) than control groups in four case control studies. CONCLUSION: Patients undergoing distal femoral osteotomy or proximal tibial osteotomy procedures with 3D-printed patient-specific cutting guides and wedges had highly accurate coronal plane alignment with a low rate of outliers. Patients treated with 3D printed PSI also demonstrated significantly shorter operative times and decreased intraoperative fluoroscopy when compared to conventional techniques. LEVEL OF EVIDENCE: Level IV, systematic review of Level III-IV studies.

Accuracy and Reliability of Imaging Modalities for the Diagnosis and Quantification of Hill-Sachs Lesions: A Systematic Review.

PURPOSE: To determine the reliability and accuracy of different imaging modalities in assessing Hill-Sachs lesions within the setting of anterior shoulder instability. METHODS: A systematic review was performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines using the PubMed, Scopus, Embase, and Cochrane Library databases. The inclusion criteria were clinical trials or cadaveric studies that assessed the accuracy of humeral head bone loss imaging or reliability and English-language articles. The exclusion criteria were animal studies; imaging studies without measures of accuracy, reliability, or clinical predictive power; studies of shoulder injuries without humeral head bone loss; editorials; abstracts; reviews; case reports; and surveys. The search terms included "imaging" OR "radiographic" OR "CT" OR "MRI" AND "Hill-Sachs" OR "humeral head bone loss." Assessment of the methodologic quality of the included studies was performed using the original Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool. RESULTS: Forty studies (2,560 shoulders) met the inclusion criteria and were assessed. For diagnosing the presence of Hill-Sachs lesions, computed tomography (CT) arthrography had the highest reported accuracy (median, 91%; range, 66%-100%). For the same assessment, CT arthrography also had the greatest reported sensitivity (median, 94%; range, 50%-100%). For the quantification of Hill-Sachs lesion parameters, reported intraobserver reliabilities were highest for 3-dimensional (3D) CT (intraclass correlation coefficient [ICC] range, 0.916-0.999), followed by 2-dimensional CT (ICC range, 0.858-0.861) and magnetic resonance imaging (MRI) (ICC range, 0.28-0.97). For the same quantification parameters, interobserver reliabilities were also reported for 3D CT (ICC range, 0.772-0.996), 2-dimensional CT (ICC range, 0.721-0.879), and MRI (κ range, 0.444-0.700). Intraobserver reliabilities for determining glenoid tracking were only reported for 3D CT (κ range, 0.730-1.00; ICC range, 0.803-0.901) and MRI (ICC range, 0.770-0.790). CONCLUSIONS: This study shows that the current literature supports a variety of different imaging modalities that provide clinically acceptable accuracy in diagnosing and quantifying Hill-Sachs lesions, as well as determining whether they will cause persistent anterior shoulder instability. Furthermore, this systematic review justifies that further research is needed to help develop a treatment algorithm on the proper imaging modalities needed to help treat patients with anterior shoulder instability that is both reliable and financially acceptable. LEVEL OF EVIDENCE: Level IV, systematic review of Level I through IV studies.

Limited Predictive Value of the Instability Severity Index Score: Evaluation of 217 Consecutive Cases of Recurrent Anterior Shoulder Instability.

PURPOSE: To review the existing variables and their ability to predict recurrence of shoulder instability as it relates to the Instability Severity Index Score (ISIS), as well as evaluate any other pertinent imaging and patient history variables that may impact risk of recurrent anterior instability after arthroscopic Bankart repair. METHODS: All consecutive patients with recurrent anterior shoulder instability and who had arthroscopic instability repair were identified. Exclusion criteria were prior surgery on the shoulder, posterior or multidirectional instability, instability caused by seizure disorder, or a rotator cuff tear. All ISIS variables were recorded (age <20 years, sport type and level, hyperlaxity, Hill-Sachs on anteroposterior external rotation radiograph, loss of glenoid contour on anteroposterior radiograph), as well as additional variables: (1) number of instability events; (2) total time of instability; (3) glenoid bone loss (GBL) percent; and (4) Hill-Sachs measures (H/L/W/D/Volume). Postoperative outcomes were assessed based on the Western Ontario Shoulder Instability Index (WOSI), Single Assessment Numeric Evaluation (SANE) scores, and American Shoulder and Elbow Surgeons (ASES) scores, and recurrent anterior instability. Regression analysis was used to determine preoperative variables that predicted outcomes and failures. RESULTS: There were 217 consecutive patients (209 male patients [96.5%], 8 female patients [3.5%]) who met the inclusion criteria and were all treated with a primary arthroscopic shoulder stabilization during a 3.5-year period (2007-2011), with a mean follow-up time of 42 months (range, 26-58). The mean age at first instability event was 23.9 years (range, 16-48 years) and the mean cumulative ISIS score for the overall group was 3.6 (range, 1-6). Outcomes were improved from mean preoperative (WOSI = 1,050/2,100; ASES = 61.0; SANE = 52.5) to postoperative (WOSI = 305/2,100; ASES = 93.5; SANE = 95.5). A total of 11.5% (25/217) of patients had evidence of recurrent instability (subluxation or dislocation). Additionally, all 25 patients who failed postoperatively also had consistently inferior ASES, SANE, and WOSI outcome scores when compared with successfully treated patients. Factors associated with failure were GBL greater than 14.5% (P < .001), total time of instability symptoms greater than 3 months (P = .03), Hill-Sachs volume greater than 1.3 cm3 (P = .02), contact sports participation (P = .05), and age 20 years or younger (P < .01). There was no correlation in outcomes with Hill-Sachs on presence of glenoid contour loss on radiograph (P = .07), participation sports, or ISIS (mean = 3.4 success vs 3.9 failure, P > .05). CONCLUSIONS: At a mean follow-up of 42 months was an 11.5% failure rate after arthroscopic Bankart stabilization surgery. This study shows no correlation between treatment outcome and the ISIS measure, given a mean score of 3.4 for the overall cohort with little difference identified in those who failed. However, several important parameters previously unidentified were detected including, GBL greater than 14.5%, Hill-Sachs volume greater than 1.3 cm3, and duration of instability symptoms (>3 months). The ISIS may need to be redesigned to incorporate variables that more accurately portray the actual risk of failure after arthroscopic stabilization, including quantification of both glenoid and humeral head bone loss. LEVEL OF EVIDENCE: III (Retrospective Case Series).

Pullout Strength of All-Suture and Metallic Anchors in Repair of Lateral Collateral Ligament Injuries of the Elbow.

PURPOSE: To compare the biomechanical properties of metallic anchor (MA) and all-suture anchor (ASA) constructs in the anatomic reattachment of the lateral ulnar collateral ligament complex to its humeral insertion. METHODS: Twenty paired male human cadaveric elbows with a mean age of 46.3 years (range: 33-58 years) were used in this study. Each pair was randomly allocated across 2 groups of either MA or ASA. A single 3.5-mm MA or 2.6-mm ASA was then inserted flush into the lateral epicondyle. A dynamic tensile testing machine was used to perform cyclic loading followed by a load to failure test. During the cyclic loading phase, the anchors were sinusoidally tensioned from 10 N to 100 N for 1,000 cycles at a frequency of 0.5 Hz. In the load to failure test, the anchors were pulled at a rate of 3 mm/s. Load at 1-mm and 2-mm displacement, as well as load to ultimate failure were assessed. Clinical failure was defined as displacement of more than 2 mm. Normality of data was assessed with the Shapiro-Wilk test. Continuous data are presented as medians and compared with the Mann-Whitney U test and categorical data was compared with the χ2 test or Fisher exact test. RESULTS: Displacement was significantly greater for the ASA group during cyclic loading starting from the tenth cycle (P < .05). Displacement of more than 5 mm within the first 100 cycles was observed in 2 anchors in the ASA group. No difference was observed in loads required to displace 1 mm (MA: 146 N [6-169] vs ASA: 144 N [2-153]; P = .53) and 2 mm (MA: 171 N [13-202] vs ASA: 161 N [9-191]; P = .97), but there was a statistically significant difference between ultimate loads in favor of ASA in the load to failure test (MA: 297 N [84-343] vs 463 N [176-620]; P < .01). CONCLUSIONS: In the cyclic test, no difference in clinical failure defined as pull-out of more than 2 mm was observed between 3.5 mm MAs and 2.6 mm ASAs. In the ultimate load to failure analysis, no difference was observed between groups in force causing 1 and 2 mm of displacement, but there was a significant difference in favor of ASA in the pull to ultimate failure test. CLINICAL RELEVANCE: Potential benefits of all-suture anchors include preservation of bone stock, reduced radiographic artifacts, and easier revisions. Although their use has been investigated thoroughly in the shoulder, there remains a paucity of literature regarding displacement and pull-out strength in the elbow.

Postoperative Stiffness and Pain After Arthroscopic Labral Stabilization: Consider Anchor Arthropathy.

PURPOSE: To describe the key clinical, imaging, and arthroscopic characteristics of anchor arthropathy after arthroscopic shoulder stabilization procedures and, secondarily, to define risk factors for the development of anchor-induced arthropathy. METHODS: A total of 23 patients who underwent revision arthroscopic shoulder surgery and were diagnosed with glenohumeral arthropathy were retrospectively identified from prospectively collected data registries between January 2000 and May 2018. Data included initial diagnosis and index procedure performed, presenting arthropathy symptoms including duration, and examination findings before revision surgery. Pre-revision imaging was used to assess presence of glenohumeral osteoarthritis and chondromalacia, anchors/sutures, loose bodies, and labral pathology. The same parameters were recorded intraoperatively during revision surgery. Descriptive statistics were performed for demographic data and means with standard deviations were calculated for continuous data. A McNemar-Bowker test was used to analyze marginal homogeneity between preoperative imaging and intraoperative findings. RESULTS: Mean age at presentation was 33.4 ± 11.7 years (range 16-59, 17 male patients; 6 female patients). More than one half (13/23) developed symptoms within 10 months after index arthroscopic procedure (mean 32.2 ± 59.9 months, range <1 to 165.2 months) with 87% presenting with pain and 100% presenting with loss of motion on examination. Plain radiographs demonstrated humeral osteoarthritis in 57% (13/23) of patients, magnetic resonance imaging (MRI) revealed recurrent labral pathology in 19 of 23 (83%) patients, potential proud implants in 12 of 23 (52%), and loose bodies in 12 of 23 (52%). Intraoperatively, all had evidence of osteoarthritis; 22 of 23 (96%) had prominent implants. Humeral head chondromalacia was present in 21 of 23 patients (91%), the majority of which was linear stripe wear, and 6 of 23 (26%) had severe global glenohumeral osteoarthritis. Statistical analysis revealed a 54.5% (95% confidence interval 0.327-0.749) sensitivity of MRI identification of proud implants with a specificity of 100% (95% confidence interval 0.055-1). The ability of MRI to accurately assess chondromalacia of the humeral head (P = .342) or glenoid (P = .685) was not statistically significant. CONCLUSIONS: Anchor arthropathy is characterized by symptoms of pain and stiffness on examination and in many cases develops early after stabilization surgery (<10 months). Implants were implicated in the majority of cases of humeral head chondromalacia. MRI scans may produce false-negative identification of proud implants and can be a poor predictor of the severity of chondromalacia and intra-articular pathology; thus, a high index of clinical suspicion is necessary in patients with motion loss and pain postoperatively. LEVEL OF EVIDENCE: Level IV, case series.

Anchor Arthropathy of the Shoulder Joint After Instability Repair: Outcomes Improve With Revision Surgery.

PURPOSE: To report clinical and patient-reported outcome measures (PROMs) in patients undergoing revision surgery after diagnosis of anchor-induced arthropathy. METHODS: Patients who underwent revision arthroscopic shoulder surgery and were diagnosed with post-instability glenohumeral arthropathy performed from January 2006 to May 2018 were included in the current study. Patients were excluded if they underwent prior open shoulder procedures, if glenoid bone loss was present, or if prerevision imaging and records were incomplete or not available. Data included initial diagnosis and index procedure performed, presenting arthropathy symptoms including duration, exam findings before revision surgery, and surgical intervention. PROMs were prospectively collected before surgery and at minimum 2-year follow-up. RESULTS: Fourteen patients were included with a mean (± standard deviation) age at presentation of 35.2 ± 12.1 years (range 16 to 59). The follow-up rate was 86%, with a mean follow-up of 3.8 years (range 1.1 to 10.6). Mean time to development of arthropathy symptoms was 48.2 months (range <1 month to 13.8 years), all presenting with pain and decreased range of motion on exam. At time of revision surgery, all patients underwent either open or arthroscopic removal of previous implants, including anchors and suture material. Six patients underwent additional revision stabilization procedures, 1 underwent total shoulder arthroplasty, and 7 underwent arthroscopic intraarticular debridement, capsular release, and chondroplasty with or without microfracture. Pain significantly improved in 79% of patients (P = .05). Significant improvements in all PROMs were observed, including 12-item Short Form (43.8 to 54.8, P < .01); Disabilities of the Arm, Shoulder, and Hand, shortened version (31.8 to 8.4, P < .01); Single Assessment Numeric Evaluation (47.0 to 84.5, P < .05); and American Shoulder and Elbow Surgeons (61.6 to 92.1, P < .01). Average external rotation significantly improved, from 31° ± 22° to 52° ± 24° (P = .02). CONCLUSION: Rapid intervention after diagnosis, through either revision arthroscopic or open debridement and stabilization, can lead to significant improvement in range of motion, pain, and overall patient function and satisfaction. LEVEL OF EVIDENCE: IV, retrospective case series.

Biomechanical significance of the collateral ligaments in transolecranon fracture-dislocations.

BACKGROUND: It is widely accepted that transolecranon fracture-dislocations are not associated with collateral ligament disruption. The aim of the present study was to investigate the significance of the collateral ligaments in transolecranon fractures. METHODS: Twenty cadaveric elbows with a mean age of 46.3 years were used. All soft tissue was dissected to the level of the capsule, leaving the anterior band of the medial collateral ligament (MCL) and lateral collateral ligament (LCL) intact. A standardized, oblique osteotomy starting from the distal margin of the cartilage bare area of the ulna was made. The elbows were loaded with an inferiorly directed force of 5 and 10 N in the intact, MCL cut, LCL cut, and both ligaments cut states. All measurements were recorded on lateral calibrated radiographs. RESULTS: The mean inferior translation with intact ligaments (n = 20) when the humerus was loaded with 5 and 10 N was 1.52 mm (95% confidence interval [CI], 1.02-2.02) and 2.23 mm (95% CI, 1.61-2.85), respectively. When the LCL was cut first (n = 10), the inferior translation with 5 and 10 N load was 4.11 mm (95% CI, 0.95-7.26) and 4.82 mm (95% CI, 1.91-7.72), respectively. When the MCL was cut first (n = 10), the inferior translation when loaded with 5 and 10 N was 3.94 mm (95% CI, 0.796-7.08) and 5.68 mm (95% CI, 3.03-8.33), respectively. The inferior translation when loaded with 5 and 10 N and both ligaments cut was 15.65 mm (95% CI, 12.59-18.79) and 17.50 mm (95% CI, 14.86-20.13), respectively. There was a statistical difference between the intact and MCL cut first at 10 N and when both ligaments were cut at 5 and 10 N. CONCLUSIONS: The findings suggest that collateral ligament disruption is a prerequisite for a transolecranon fracture-dislocation. An inferior translation of more than 3 mm suggests that at least one of the collateral ligaments is disrupted, and more than 7.5 mm indicates that both collateral ligaments are disrupted.

Anterior Shoulder Instability Management: Indications, Techniques, and Outcomes.

Anterior shoulder instability is common in young athletes. Male individuals younger than 20 years who are involved in contact sports are at particular risk of injury and recurrence. Essential imaging includes radiography and magnetic resonance imaging in all patients, with 3-dimensional computed tomography being helpful to evaluate glenoid bone loss and Hill-Sachs lesions. Evaluation of the glenoid track is essential to help determine appropriate treatment because off-track scenarios in which the Hill-Sachs width is greater than the glenoid width impart a risk of failure with isolated arthroscopic treatment. Associated injuries also must be evaluated, including bone loss, Hill-Sachs lesions, humeral avulsion of the glenohumeral ligament (HAGL), glenolabral articular disruption (GLAD), anterior labroligamentous periosteal sleeve avulsion (ALPSA), rotator cuff injury, other fractures, and axillary nerve injury. Optimal treatment continues to be debated. Conservative management with physical therapy for rotator cuff and periscapular strengthening can be attempted, with the addition of bracing if continued play is desired until the season's conclusion. Surgical intervention is considered in patients with recurrent dislocations, glenoid bone loss, or large Hill-Sachs lesions or in young athletes involved in contact or high-risk sports. Treatment options include arthroscopic capsulolabral repair with at least 4 anchors if good tissue quality and no bone loss exist. Remplissage has been recommended by some surgeons if a large Hill-Sachs exists. Open repair is suggested in patients with a high number of recurrent dislocations without bone loss or in those who participate in high-risk sports. Coracoid transfer or the Latarjet procedure is suggested in patients with bone loss greater than 20%. Bone grafting for glenoid bone loss using autograft or allograft, such as distal tibial allograft, is recommended in patients with a failed Latarjet procedure or those with significant bone loss. Hill-Sachs lesion grafting may also be beneficial in those with large lesions that engage.

Editorial Commentary: Methodology of Measuring Bone Loss in Recurrent Shoulder Instability Surgery: Traditional Computed Tomography Scan and Magnetic Resonance Imaging Do Not Tell the Full Story.

When measuring bone loss in recurrent shoulder instability, both computed tomography (CT) scan and magnetic resonance imaging (MRI) are accurate using the circle method. However, measurement of on- versus off-track lesions can be inconsistent, and measuring Hill-Sachs lesions on MRI relative to an extrapolated rotator cuff attachment is difficult. In the end, determination of on- versus off-track treatment is quite difficult, and for this determination, differences between CT scan and MRI may be clinically imperceptible. Thus, for now, we, and we believe, other surgeons will continue to stick with the circle technique when determining individual patient treatment for recurrent shoulder instability.

A Systematic Review and Meta-analysis of Biceps Tenodesis Fixation Strengths: Fixation Type and Location Are Biomechanically Equivalent.

PURPOSE: The purpose of this meta-analysis and systematic review was to critically evaluate the biomechanical outcomes of different fixation constructs for a variety of biceps tenodesis techniques in cadaveric models based on both type of fixation and location. METHODS: A PROSPERO-registered systematic review (CCRD42018109243) of the current literature was conducted with the terms "long head of biceps" AND "tenodesis" AND "biomechanics" and numerous variations thereof in the PubMed, Embase, and Cochrane databases, yielding 1,460 abstracts. After screening by eligibility criteria, 18 full-text articles were included. The individual biomechanical factors evaluated included ultimate load to failure (in newtons), stiffness (in newtons per millimeter), and cyclic displacement (in millimeters). After reviewing the included literature, we performed a quality analysis of the studies (Quality Appraisal for Cadaveric Studies scale score) and a meta-analysis comparing raw mean differences in data between the suprapectoral and subpectoral fixation location groups, as well as between the fixation construct groups. RESULTS: Among the 18 included studies, 347 cadaveric specimens were evaluated for ultimate load to failure, stiffness, and cyclic displacement when comparing both location (suprapectoral vs subpectoral) and tenodesis fixation type (interference screw vs cortical button, suture anchor, or all-soft-tissue techniques). Interference screw fixation showed significantly greater mean stiffness by 8.0 N/mm (P = .013) compared with the other grouped techniques but did not show significant differences when evaluated for ultimate load to failure and cyclic displacement (P = .28 and P = .18, respectively). Additionally, no difference in construct strength was seen when comparing the fixation strength of suprapectoral versus subpectoral techniques for stiffness, ultimate load to failure, and cyclic loading (P = .47, P = .053, and P = .13, respectively). CONCLUSIONS: In this meta-analysis, no significant biomechanical differences were found when the results were stratified by specific surgical technique (interference screw vs other tenodesis techniques) and location (suprapectoral vs subpectoral biceps tenodesis). CLINICAL RELEVANCE: As a result of this study, when biomechanically evaluating specific tenodesis constructs, the individual clinician has the liberty of choosing the fixation technique based on his or her preference and knowledge of shortcomings of each type of fixation construct.

Glenoid Track Instability Management Score: Radiographic Modification of the Instability Severity Index Score.

PURPOSE: The purpose of this study is (1) to test the proposed treatment algorithm, the Glenoid Track Instability Management Score (GTIMS), which incorporates the glenoid track concept into the instability severity index score (ISIS), and (2) to compare treatment decision-making using either GTIMS versus ISIS in 2 cohorts of patients with operatively treated anterior instability. METHODS: A multicenter, retrospective review of two consecutive groups consisting of 72 and 189 patients treated according to ISIS and GTIMS, respectively, was conducted. Inclusion criteria for all patients were ≥2 confirmed traumatic anterior shoulder instability events and a physical examination demonstrating a positive anterior apprehension and relocation test. The GTIMS was graded for all 189 patients in the cohort, which uses 3-dimensional computed tomography as the sole radiographic parameter to assess on-track (0 points) versus off-track (4 points) Hill-Sachs lesions. This method differs from ISIS, which uses multiple plain radiographs for the 4-point imaging portion of the score. Outcomes scores were compared within the GTIMS and ISIS groups, as well as between them for overall comparisons based on the Western Ontario Shoulder Instability Index (WOSI), the Single Assessment Numerical Evaluation (SANE) score, and the mean rates of recurrent instability. RESULTS: A total of 261 consecutive patients from 2009 to 2014 who presented with recurrent anterior shoulder instability were treated according to either ISIS (n = 72/261, 27.6%) or GTIMS (n = 189/261, 72.4%). At a mean follow-up time of 33.2 months (range 24-49 months), the overall cohort mean ISIS of 2.9 ± 2.2 (range 0-9) was significantly higher than the mean GTIMS of 1.9 ± 1.9 (range = 0-9, P < .001). Of the 72 ISIS treated patients, 50 (69.4%) had an ISIS score of ≥ 4 and underwent a Latarjet, and the 22 patients (30.6%) with an ISIS score of < 4 underwent an arthroscopic Bankart repair. Based on GTIMS in the 189-patient cohort, using the same cutoff of 4 to indicate the need for a Latarjet, 162 patients were treated with arthroscopic Bankart repair (85.7%) and 27 with Latarjet (14.3%). The overall outcomes improved for patients treated with a Latarjet in both groups (GTIMS WOSI from 1099 [47.7% normal] to 395 [81.3% normal]; GTIMS SANE from 48 to 81; ISIS WOSI from 1050 [50% normal] to 345 [83.4% normal]; ISIS SANE from 50 to 84; P < .01). Similar positive outcomes were seen in patients treated with arthroscopic Bankart repair (GTIMS WOSI from 1062 [49.2% normal] to 402 [80.6% normal]; GTIMS SANE from 49 to 82; ISIS WOSI from 1080 [51.8% normal] to 490 [76.7% normal]; ISIS SANE from 48 to 77; P < .01). Of note, the patients with arthroscopically indicated ISIS had significantly worse outcomes scores than those treated arthroscopically according to GTIMS (P < .01). Of the 189 patients graded with GTIMS, there would have been 33 more Latarjet procedures recommended based on ISIS score. Thus the distribution of procedures based on ISIS versus GTIMS was significantly different (χ2 = 45.950; P < .001), indicating a higher rate of recommending Latarjets when using ISIS versus GTIMS. CONCLUSIONS: When ISIS scoring and plain radiograph parameters only are used, this predicted a 2-fold increase in recommending a Latarjet versus GTIMS scoring criteria, which uses advanced imaging and the on- and off-track principle to more conservatively delineate anterior instability treatment with promising postoperative patient outcomes. Overall, there were minimal differences in outcomes between GTIMS and ISIS Latarjet patients; however, better outcomes were seen in patients indicated for arthroscopic Bankart repair according to GTIMS and on-off track computed tomography scanning indications. LEVEL OF EVIDENCE: II, Prospective Cohort Study.

Conversion of Failed Proximal Long Head of the Biceps Tenodesis to Distal Subpectoral Tenodesis: Outcomes in an Active Population.

PURPOSE: To assess failure rates and patient reported outcomes following revision of failed proximal long head of the biceps (LHB) tenodesis. METHODS: Patients from an active-military population who underwent revision proximal (suprapectoral) to distal (subpectoral) LHB tenodesis were prospectively enrolled. Patients were included if they were between the ages of 16 and 60 years presenting after a previous biceps tenodesis with mechanical failure and clinical failure, defined as Single Assessment Numeric Evaluation (SANE) or American Shoulder and Elbow Surgeons (ASES) <70. Exclusion criteria were concomitant rotator cuff repair or debridement, full-thickness rotator cuff tear, extensive labral tears, or any evidence of glenohumeral arthritis. Pre- and postoperative SANE and ASES were documented and analyzed. RESULTS: From 2004 to 2010, a total of 12 patients (all male) with a mean age of 39.9 years (range, 30-54 years) were assessed at a mean follow-up time of 29 months (range, 24-38 months). Nine patients presented with a failed tenodesis construct located at the top of the bicipital groove and 9 patients had LHB tendons originally affixed with an interference screw. Diagnostic arthroscopy revealed that the majority of patients (10/12) had excessive scarring at the site of previous fixation. Mean preoperative assessments of SANE (70.4) and ASES (59.9) improved postoperatively to SANE (90.3; P < .01) and ASES (89.8; P < .01). No patients were lost due to follow-up, and there were no reported complications or failures. All patients returned to full active duty and were able to perform all required physical tests before returning to their vocation. CONCLUSIONS: Patients presenting with symptoms following a proximal LHB tenodesis can be successfully converted to a distal (subpectoral) LHB tenodesis with favorable outcomes. Although in a small sample, there was excessive scarring and synovitis in a majority, which improved significantly when treated with a revision subpectoral tenodesis with minimal complication risk and no reported failures. LEVEL OF EVIDENCE: IV (Therapeutic case series).

Characterization of Posterior Glenoid Bone Loss Morphology in Patients With Posterior Shoulder Instability.

PURPOSE: To systemically describe posterior bone defects in the setting of posterior shoulder instability based on several parameters, including surface area, slope and version, defect height from the base of the glenoid, and extent of bone loss at equal intervals along the long axis of the fossa. METHODS: A total of 40 young, active individuals with recurrent posterior shoulder instability and a bony injury confirmed on either computed tomography (n = 18; mean age, 26.3 ± 4.0 years) or magnetic resonance imaging (n = 22; mean age, 20.0 ± 4.9 years) were identified. The posterior glenoid bone defect was characterized using the following measures: (1) percentage of bone loss, (2) glenoid vault version, (3) slope of the posterior defect relative to the glenoid surface, (4) superior-inferior length of the defect, and (5) anterior-posterior width of the defect at 5 intervals along the glenoid fossa. RESULTS: The mean age of the 40 patients was 22.9 ± 5.5 years (range, 14.9-35.5 years). The mean surface area of glenoid bone loss was 9.7% ± 4.7%. Glenoid version measured at 5 equal intervals along the inferior two-thirds of the glenoid was 12.8° ± 4.9°, 11.9° ± 5.0°, 10.1° ± 6.3°, 10.5° ± 6.5°, and 8.7° ± 7.2° from superior to inferior. The mean slope of the posterior defect relative to the glenoid fossa was 26.8° ± 11.5°. The mean superior-inferior height of the bony defect was 21.9 ± 0.4 mm. The anterior-posterior sloped width of the defect at 5 equal intervals along the glenoid fossa was 0.9 ± 1.5 mm, 2.8 ± 2.4 mm, 4.0 ± 1.7 mm, 4.0 ± 2.1 mm, and 2.9 ± 2.6 mm from superior to inferior. Low-grade (<10%) bone loss was diagnosed in most shoulders (23 of 40 evaluated), whereas 15 had moderate bone loss (10% to <20%) and 2 had high-grade bone loss (≥20%). CONCLUSIONS: Posterior glenoid bone loss is characterized by a loss of posterior bony concavity, increased slope from anterior to posterior, and increased posterior version. The most anterior-posterior sloped width was quantified at the third and fourth intervals of 5 equal intervals from superior to inferior. This study highlights that patients with posterior instability have bone loss that is sloped relative to the glenoid fossa and suggests that management must be appropriately tailored given the distinctiveness of posterior bone loss. LEVEL OF EVIDENCE: Level IV, case series.

Outcomes of Primary Biceps Subpectoral Tenodesis in an Active Population: A Prospective Evaluation of 101 Patients.

PURPOSE: To evaluate the surgical outcomes of a primary subpectoral biceps tenodesis for long head of the biceps tendon (LHBT) pathology in a large cohort of prospectively, serially collected, patients in a young active population that has known high physical demands and requirements of their shoulder to perform their vocation. METHODS: A retrospective review of prospectively collected data from an active military personnel with a diagnosis of a Type II SLAP tear or biceps tenosynovitis was performed. Outcomes were evaluated at a minimum follow-up time of 18 months based on preoperative and postoperative assessments of the Single Assessment Numeric Evaluation, Western Ontario Rotator Cuff index, biceps position, and return to active duty. Inclusion criteria were (1) SLAP tears on magnetic resonance arthrogram (classified into SLAP group), and (2) no SLAP tear but examination findings of biceps tendonitis (placed in the LHBT tendonitis group). Patients were excluded for full-thickness rotator cuff tears, high-grade partial thickness tears requiring repair, acromioclavicular joint pathology, and labral pathology outside of the SLAP lesion. Patients from both groups subsequently were treated with open, subpectoral tenodesis. RESULTS: Over a 6-year period at a mean follow-up of 2.75 years (range 1.5-5.7 years), 125 active-duty military personnel with mean age of 42.6 years (range 26.3-56.5) were enrolled. A total of 101 of 125 patients (81%) completed study requirements at a mean of 2.75 years (range 1.5-5.7 years). In total, 40 patients were diagnosed with type II SLAP tears (39.6%) and 61 with biceps tendonitis without SLAP tear (60.4%). Following open, subpectoral tenodesis, there was a significant improvement in patient outcomes (Western Ontario Rotator Cuff = 54% preoperative vs 89% postoperative, Single Assessment Numeric Evaluation = 58 preoperative vs 89.5 postoperative, P < .01). In total, 82% of patients returned to full activity at a mean of 4.1 months. The biceps muscle measured relative to the antecubital fossa of operative (mean 3.20 cm) versus nonoperative (3.11 cm) was not clinically different (P = .57). There was an 8% complication rate, including 3 requiring revision, 2 superficial infections, and 3 transient neurapraxias. CONCLUSIONS: Primary subpectoral open biceps tenodesis for SLAP tears or pathology of the LHBT provides significant improvement in shoulder outcomes with a reliable return to activity level with low risk for complications. LEVEL OF EVIDENCE: Level IV (Case series).

Quantum Chemical and Statistical Rate Theory Studies of the Vinyl Hydroperoxides Formed in trans-2-Butene and 2,3-Dimethyl-2-butene Ozonolysis.

The vinyl hydroperoxide (VHP), the major isomerization product of the syn-alkyl Criegee intermediate (CI) formed in alkene ozonolysis, is a direct precursor of hydroxyl radical (OH), the most important oxidant in the troposphere. While simulations of CI reactivity have usually assumed the VHP to be a prompt and quantitative source of OH, recent quantum chemical studies have revealed subtleties in VHP reactivity such as a barrier to peroxy bond homolysis and a possible rearrangement to a hydroxycarbonyl. In this work, we use M06-L, Weizmann-1 Brueckner Doubles, and equation-of-motion spin-flip coupled-cluster theories to calculate a comprehensive reaction mechanism for the syn and anti conformers of the parent VHP formed in trans-2-butene ozonolysis and the 1-methyl VHP formed in 2,3-dimethyl-2-butene ozonolysis. We predict that for the parent VHP the anti homolysis transition structure (TS) is 3 kcal mol-1 lower in energy than the syn TS, but for the 1-methyl system, the syn TS is 2 kcal mol-1 lower in energy. Statistical rate theory simulations based on the quantum chemical data predict that the parent VHP preferentially decomposes to vinoxy and OH radicals under all tropospheric conditions, while the 1-methyl VHP preferentially decomposes to 1-methylvinoxy and OH radicals only close to 298 K; at 200 K, the 1-methyl VHP preferentially rearranges to hydroxyacetone. Lower temperatures and higher pressures favor the temporary accumulation of both the parent and the 1-methyl VHP.

Editorial Commentary: Rotator Interval Closure of the Shoulder Continues to Be a Challenge in Consensus on Treatment.

In discussions of repair or plication of rotator interval capsular tissue and the respective surgical techniques, there is great variability in the procedures used to accomplish this, as well as a lack of consensus in defining rotator interval closure and the complex associated anatomy. The concept of rotator interval closure and how it is performed has shown wide variation and numerous definitions. In the future, it is recommended that one truly define what type of closure is performed, what tissues are imbricated, and where these tissues are imbricated, because both medial and lateral imbrications around the joint can have significant differences in terms of rotation, stability, and overall efficacy. Through this work, we can improve diagnostic capabilities, as well as examination capabilities, and better delineate the overall rotator interval closure procedure based on diagnostic and clinical findings. In this manner, we will be better able to define when rotator interval closure is necessary and most beneficial to patients. In our opinion, clinical indications for rotator interval closure are as follows: (1) multidirectional instability with increased capsular volume, (2) anterior instability-and especially a failed arthroscopic instability repair-that could benefit from imbrication of the coracohumeral ligament, (3) a sulcus that persists in external rotation in the setting of symptomatic instability, and (4) posterior instability with a multidirectional component.