Kissenberth, Michael J.

BACKGROUND Despite increased awareness of factors related to athletic performance and injury prevention, youth and adolescent baseball players continue to report injuries at alarming rates. Upper extremity muscle strength is an integral part of physical assessment and injury prevention in baseball players, however minimal data exists in youth populations. Changes in anthropometric measures, inherent in physically developing athletes, have been shown to impact strength measures, however normalization methodology is rarely reported. PURPOSE The purposes of this study were to 1) compare the measurement properties of five potential methods for normalizing isometric shoulder strength in a cohort of 9-12 year old male baseball players and 2) examine the relationship between normalized isometric shoulder strength and ball velocity in a cohort of 9-12 year old male baseball players. STUDY DESIGN Prospective cohort study (n=159) METHODS Baseline and follow up height, weight and bilateral ulnar length measurements were assessed followed by isometric strength in both the dominant and non-dominant shoulders. Strength measures included scapular plane abduction (scaption), external rotation (ER) at 0°, ER and internal rotation (IR) at 90°. Ball velocity was assessed as a measure of throwing performance. Intraclass correlation coefficients (ICC2,1), standard errors of measurement (SEM) and minimal detectable change (MDC95) were calculated for all strength measures. Repeated measures ANOVA were conducted comparing changes in normalized strength using five separate anthropometric measures: weight, height, body mass index, ulnar length and % of non-dominant shoulder strength. Linear regression models were used to examine the relationships between normalized isometric shoulder strength and ball velocity. Statistical significance was set a priori at α=0.05. RESULTS Shoulder strength normalized using ulnar length was the only method that demonstrated excellent reliability (ICC2,1 0.98-0.99) and detected significant changes between strength in each of the four measures tested (SEM 0.39-0.69 Nm). Modest but significant correlations were observed between scaption and ball velocity (r2 = 0.27, p < 0.001) and ER at 0° and ball velocity (r2 = 0.23, p < 0.001). CONCLUSION Ulnar length was the most stable and reliable normalization method for assessing isometric shoulder strength in youth baseball players. In addition, normalized scaption strength was the most significant predictor of ball velocity, followed by ER at 0° strength in this population. LEVEL OF EVIDENCE Level 2b (etiology)

This biomechanical study evaluates the performance of a solid titanium-alloy intra-medullary ( IM) clavicular screw in torsion and cantilever bending in cadaveric clavicle specimens with simulated simple oblique and butterfly wedge midshaft fractures. Thirty-two fresh-frozen male clavicles were sorted into six experimental groups: Torsion Control, Torsion Simple Oblique Fracture, Torsion Butterfly Wedge Fracture, Bending Control, Bending Simple Oblique Fracture, and Bending Butterfly Wedge Fracture. The experimental groups were controlled for density, length, diameter, and laterality. All other samples were osteotomy-induced and implanted with a single 90 mm × 3 mm clavicle screw. All groups were tested to physiologically relevant cutoff points in torsion or bending. There were no statistically significant differences in the performance of the oblique and butterfly wedge fracture models for any torsion or bend testing measures, including maximum torsional resistance ( p = 0.66), torsional stiffness ( p = 0.51), maximum bending moment ( p = 0.43), or bending stiffness ( p = 0.73). Torsional testing of samples in the direction of thread tightening tended to be stronger than samples tested in loosening, with all groups either approaching or achieving statistical significance. There were no significant differences between the simple oblique or the butterfly-wedge fracture groups for any of the tested parameters, suggesting that there is no difference in the gross biomechanical properties of the bone-implant construct when the IM clavicle screw is used in either a simple midshaft fracture pattern or a more complex butterfly wedge fracture pattern.

Background: Functional bracing is often used as an adjunct to nonoperative treatment of anterior shoulder instability, but no study has evaluated the effectiveness of in-season bracing. The purpose of this study was to examine successful return to play in a nonoperative cohort of adolescent athletes with in-season shoulder instability and compare those athletes treated with bracing to those who were not. Hypothesis: The use of functional bracing will improve success rates in a cohort of athletes treated nonoperatively for in-season shoulder instability. Study Design: Cohort study. Level of Evidence: Level 3. Methods: A total of 97 athletes with anterior shoulder instability were followed for a minimum of 1 year. The mean age was 15.8 ± 1.4 years (range, 12.0-18.0 years). All athletes were treated with initial nonoperative management. Twenty athletes (21%) were also treated with bracing while 77 (79%) were not. The athlete completing the current season and 1 subsequent season without surgery or time lost from shoulder injury was defined as a successful outcome. Results: There was no statistical difference in nonoperative success rates between the braced and nonbraced athletes ( P = 0.33). Braced athletes (n = 20) returned to play 80% of the time, while nonbraced athletes (n = 77) returned at a rate of 88%. Of the braced athletes, 85% were football players (n = 17). A football-only comparison demonstrated no difference between braced failures (26%) and nonbraced failures (16%) ( P = 0.47). Conclusion: This is the first study to evaluate the utility of functional bracing in returning an athlete to sport and completing a full subsequent season without surgery or time loss due to injury of the shoulder. In adolescent athletes with shoulder instability treated nonoperatively, functional bracing did not result in increased success rates when compared with no bracing. Clinical Relevance: The data from this study indicate that functional bracing may not improve success rates for athletes with shoulder instability.

ContextSport specialization is thought to be a primary contributor to the throwing-related injury risk in youth baseball players.ObjectiveTo (1) establish arm-injury incidence in a cohort of male youth (9–12 years old) baseball players and (2) examine sport specialization and the frequency of arm injuries in the same cohort.DesignCohort study.SettingGreenville, South Carolina, youth baseball programs and tournaments.Patients or Other ParticipantsA total of 159 asymptomatic youth baseball players (age = 11.1 ± 1.1 years) were physically assessed and then were prospectively followed for 6.7 ± 1.5 months.Main Outcome Measure(s)Athlete demographics and playing and injury histories were initially recorded. Athlete-exposures and presence of arm injury were prospectively tracked. All injuries were physically confirmed by a licensed physical therapist.ResultsYouth players demonstrated an arm-injury incidence rate of 2.22 per 1000 athlete-exposures. Parents and players underestimated sport-specialization status based on the standard research definition (self versus research based: 31% versus 83%, respectively; P = .001). The frequency of arm injuries was higher in specialized players (100%) than in nonspecialized players (80%, P = .03) but did not differ between pitchers and position players (13.2% each, P = 1.00).ConclusionsSport specialization was associated with throwing-related arm injuries in a small cohort of youth baseball players. It is concerning that 57.9% of parents and specialized players were unaware of the athletes' status. Larger studies with longer follow-up periods are needed to further evaluate injury-risk profiles in physically developing youth populations.

Background: Young age and contact sports have been postulated as risk factors for anterior shoulder instability. Management after shoulder instability is controversial, with studies suggesting that nonoperative management increases the risk of recurrence. Several studies examined return to play after an in-season instability episode, and few followed these patients to determine if they were able to successfully compete in a subsequent season. No study has evaluated this question in a high school athlete population. Purpose: To compare the likelihood of return to scholastic sport and complete the next full season without an additional time-loss injury among athletes with anterior shoulder instability in terms of treatment, instability type, and sport classification. Study Design: Cohort study; Level of evidence, 2 Methods: Athletes were included in this study as identified by a scholastic athletic trainer as experiencing a traumatic time-loss anterior shoulder instability injury related to school-sponsored participation. The cohort was predominantly male (n = 108, 84%) and consisted mostly of contact athletes (n = 101, 78%). All athletes had dislocation or subluxation diagnosed by a board-certified physician who determined the athlete’s course of care (nonoperative vs operative). Successful treatment was defined as completion of care and return to the athlete’s index sport, with full participation for the following season. Chi-square and relative risk analyses were completed to compare success of treatment (nonoperative vs operative care) and instability type. Separate logistic regressions were used to compare the effect of sex and sport classification on the athletes’ ability to return to sport. Statistical significance was set a priori as α = .05. Results: Scholastic athletes (N = 129) received nonoperative (n = 97) or operative (n = 32) care. Nonoperatively treated (85%) and operatively treated (72%) athletes successfully returned to the same sport without injury for at least 1 full season ( P = .11). Players sustaining a dislocation were significantly more likely to fail to return when compared with those sustaining a subluxation (26% vs 89%, P = .013). Sex ( P = .85) and sport classification ( P = .74) did not influence the athlete’s ability to return to sport, regardless of treatment type. Conclusion: A high percentage of athletes with shoulder instability achieved successful return to sport without missing any additional time for shoulder injury. Those with subluxations were at almost 3 times the odds of a successful return compared with those sustaining a dislocation.

Background: Movement toward a value-based health-care system necessitates the development of performance measures to compare physicians, hospitals, and health-care systems. Patient-reported outcomes (PROs) are a potential metric. However, valid use of PROs hinges on the ability to risk-adjust for baseline patient differences across a surgeon’s panel of patients. The purpose of this study was to propose an approach for baseline risk adjustment and evaluate the importance of risk adjustment when comparing surgeons’ performance of rotator cuff repair. Methods: Patients (n = 995) treated with arthroscopic rotator cuff repair by 34 surgeons from 2010 to 2017 were identified from a large sports medicine clinical data registry. A linear regression model was used to adjust for baseline PROs, patient demographics, and clinical characteristics to predict American Shoulder and Elbow Surgeons (ASES) change scores for each surgeon. A risk-adjusted performance measure was calculated as the difference between the average unadjusted ASES change scores and the risk-adjusted predicted ASES change scores across all patients treated by a surgeon. Results: The differences between unadjusted and risk-adjusted performance scores varied widely across surgeons (range, −13.8 to 10.3 ASES points). Use of the risk-adjusted performance scores resulted in a dramatic change in the relative ranking of surgeons, compared with the ranking based on the observed ASES change scores, with 31 of the 34 surgeons’ rank changing following risk adjustment. On average, the observed ASES scores improved from 49.5 ± 17.5 at baseline to 78.0 ± 22.5 at 6 months across all surgeons. In the risk-adjustment model (R 2 = 0.44), male sex, Workers’ Compensation status, higher scores on the Veterans RAND 12-item Health Survey (VR-12), lower baseline ASES scores, fair and poor tendon quality, and night pain all had a significant effect on the predicted ASES change scores (p < 0.05). Conclusions: Our results show wide variation of nearly 25 points in the risk-adjusted 6-month ASES performance difference from the highest to the lowest-performing surgeons. Additionally, 91% of surgeons’ rank changed following risk adjustment. This suggests that performance measurement that does not account for baseline patient characteristics would likely result in incorrect conclusions about a surgeon’s relative performance based on PROs. Level of Evidence: Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

Background: There is an ever-increasing demand for widespread implementation of patient-reported outcomes. However, adoption is slow owing to limitations in clinical infrastructure and resources within busy orthopaedic practices. Prior studies showed the single alpha-numeric evaluation (SANE) score to correlate at a single point in time with the American Shoulder and Elbow Surgeons (ASES) score. However, no study has validated the SANE in terms of test-retest reliability, responsiveness, or clinical utility. Purpose: To validate SANE with the ASES across a sample of patients with common orthopaedic shoulder diagnoses. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: Patients undergoing rotator cuff repair (n = 77), total shoulder replacement (n = 55), or physical therapy (n = 80) for signs and symptoms of subacromial impingement syndrome (n = 61) or adhesive capsulitis (n = 19) were administered the SANE and ASES at baseline and again at their 3-month follow-up from initial care or surgery (N = 212, mean ± SD age = 52.6 ± 1.2 years, n = 145 women). Interclass correlation coefficient (ICC 2,1 ) and standard error of the measurement (SEm) were used to evaluate the test-retest reliability of the SANE and the validity between the SANE and ASES scores. Analysis of variance (treatment group × time) was used to evaluate the responsiveness to treatment, and a receiver operating characteristic curve was used to establish the minimal clinically important difference (MCID) for the SANE as compared with the ASES (α = .05). Floor and ceiling effects were evaluated as the percentage of patients who scored the highest or lowest score on each tool. Results: The SANE demonstrated good pretreatment reliability (ICC 2,1 = 0.84, SEM = 3.8), similar to the ASES (ICC 2,1 = 0.82, SEM = 3.4). The SANE also showed good agreement with the ASES before and after treatment across all treatment groups (rotator cuff repair, ICC 2,1 = 0.85, SEM = 3.4; total shoulder replacement, ICC 2,1 = 0.72, SEM = 5.2; physical therapy: ICC 2,1 = 0.82, SEM = 2.9). The SANE and ASES displayed similar responsiveness after treatment, with similar mean change and SD within each treatment group. The receiver operating characteristic curve revealed an area under the curve of 0.79 (SE, 0.62; P < .001) and a cutoff of 15% on the SANE, with a sensitivity of 85% to establish the MCID. Acceptable and similar floor and ceiling effects were observed for the ASES (4%) and SANE (9%). Conclusion: The study demonstrates that the SANE is valid for a range of common shoulder diagnoses to assess patient outcomes across operative and nonoperative treatment for shoulder complaints. The MCID of 15% is similar to that of the ASES (11%), suggesting that the SANE is a simple and efficient tool to assess treatment effects for shoulder disorders. Future studies are warranted to confirm these results and compare across other body parts and diagnoses.

Background: Ulnar collateral ligament (UCL) injury of the elbow is a common and debilitating problem seen frequently among elite baseball pitchers. Ultrasound is a useful diagnostic tool in evaluating UCL injuries. Hypothesis: Evaluation with stress ultrasound of the elbow to measure the morphology of the UCL and the ulnohumeral joint space gapping is indicative of higher risk of UCL injury among professional baseball pitchers. Study Design: Cohort study; Level of evidence, 2. Methods: Ultrasound imaging was used to assess the medial joint laxity of the elbow of 70 asymptomatic professional baseball pitchers during spring training. Medial joint laxity and UCL morphology were assessed with OsiriX imaging software under 2 conditions—gravity valgus load and 5.5 lb of valgus load per a handheld dynamometer—with the shoulder in the maximal cocking position and the elbow in 90° of flexion. Two trials of resting position, elbow gapping, and UCL thickness were collected, measured, and averaged for data analysis. Intra- and interrater reliabilities were established and maintained, with intraclass correlation coefficients in the acceptable range for all measures (0.84-0.99). One-way analysis of variance was used to compare dominant variables between those pitchers who sustained a subsequent UCL injury and those who did not. A receiver operating curve was used to identify pitchers who, based on elbow gapping measures (by cut score), were at high risk versus low risk for UCL injury. Results: Players who went on to injure the UCL (n = 7) displayed a significantly wider opening under 5.5 lb of applied stress (6.5 ± 1.2 vs 5.3 ± 1.2 mm, P = .01) when compared with pitchers without UCL injury history (n = 63); they also presented a trend toward wider dominant arm resting joint opening (4.9 ± 1.2 vs 4.0 ± 1.1 mm, P = .07). Professional pitchers with valgus stress ulnohumeral joint gapping ≥5.6 mm (area underneath the curve, 0.77; P = .02) of the dominant arm were at a 6-times greater risk of sustaining a UCL tear requiring reconstruction within a season. Conclusion: Our data suggest that ultrasound evaluation of UCL morphology may be indicative of pitchers who are at risk of sustaining UCL injury and that it may improve player assessment.

Objectives: Early results following arthroscopic superior capsular reconstruction(SCR) in patients with massive, irreparable rotator cuff tears are promising. However, no studies have compared patient reported outcomes between SCR or reverse total shoulder(rTSA) and rotator cuff debridement for these patients. Therefore, the purpose of this study was to compare 1-year outcomes between patients with massive irreparable rotator cuff tears who underwent a SCR, rTSA, or rotator cuff debridement with a concurrent biceps tenotomy or tenodesis. Methods: Patients(n=63) who underwent either SCR(n=21), rTSA(21), or cuff debridement(n=21) and biceps tenotomy or tenodesis for a massive, irreparable rotator cuff tear treated with a minimum 1-year follow up were retrospectively reviewed. Age, sex, BMI, smoking status, Charlson Index, Hamada classification, and ASES scores were recorded and compared using a multivariate ANOVA were used to compare between surgical approaches. A Chi Square analyses were used to compare sex distribution and the Charlson Deyo Index between groups (α=0.05). Results: Overall, patients across the 3 groups were not statistically different in age or follow up ASES score at minimum 14 month follow up ( P> 0.05). There was a significant interaction effect between surgery group and sex (P=0.02) on ASES score but not age ( P=0.08). Univariate F tests revealed that male patients who received an SCR displayed a 10-14% better outcome at follow up compared to other groups (Table 1) which exceeds the reported ASES score MCID. Conclusion: Our results show comparable results across surgical options for massive irreparable cuff tears with good patient reported outcomes. Male patients displayed clinically important greater ASES scores at 1 year follow up. Future studies should evaluate these preliminary results to assess if these preliminary results hold up at longer follow up times.

Background: Controversy exists as to whether the subscapularis should be repaired after reverse shoulder arthroplasty. The purpose of the present study was to evaluate the utility of repairing the subscapularis after reverse shoulder arthroplasty with regard to complications, objective findings, and patient-reported outcome measures. Methods: We retrospectively reviewed the records for 99 patients who had undergone a lateralized reverse shoulder arthroplasty with (n = 58) or without (n = 41) subscapularis repair. Outcomes were compared with the Single Assessment Numeric Evaluation (SANE), Penn shoulder score (PSS), Veterans RAND (VR)-12, and American Shoulder and Elbow Surgeons (ASES) score at a minimum of 2 years of follow-up. Demographics, range of motion, and complications were also compared. A 1-way analysis of variance was performed to determine differences in performance and outcome scores, and a chi-square analysis was performed to compare the frequency of complications between groups. Results: There were no significant differences between the repair and no-repair groups in terms of SANE, PSS, ASES, or VR-12 scores. There also were no significant differences between the 2 groups in terms of postoperative ranges of forward elevation (128° versus 123°; p = 0.44) and external rotation (33° versus 29°; p = 0.29), the dislocation rate (5% versus 2%; p = 0.49), or the overall complication rate (9% versus 5%; p = 0.47). Conclusions: The results of the present study suggest that repair of the subscapularis tendon after lateralized reverse shoulder arthroplasty may not be necessary. Level of Evidence: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.