Organizational risk profiling and education associated with reduction in professional pitching arm injuries: a natural experiment.

Background: Risk profiling and education are strategies implemented to help reduce injury risk; however, currently. there is little evidence on the effect of these interventions on injury incidence. The purpose of this study was to evaluate the influence of risk profiling and education on upper extremity injury incidence in minor league (MiLB) pitchers and to stratify by injury severity. Methods: A prospective natural experiment study was conducted from 2013 to 2019 on MiLB pitchers. Beginning in the 2015 season, pitchers were examined and risk profiled for upper extremity injury. Shoulder external, internal, total range of motion, horizontal adduction, and humeral torsion were measured. Organizational risk profiling and education was implemented starting in 2015, based on preseason assessments. Chi-squared test was performed to investigate potential differences between shoulder range of motion risk categories between 2013-2014 (pre) and 2015-2019 (post) seasons. Interrupted time series analyses were performed to assess the association between organizational risk profiling and education on arm injury in MiLB pitchers and were repeated for 7-27 and 28+ day injury severity. Results: 297 pitchers were included (pre: 119, post: 178). Upper extremity injury incidence was 1.5 injuries per 1000 athletic exposures. Pitchers in the 2015-2019 seasons demonstrated increased preseason shoulder injury risk for internal (P = .003) and external (P = .007), while the 2013-2014 seasons demonstrated greater horizontal adduction risk (P = .04). There were no differences between seasons for total range of motion risk (P =.76). Risk profiling and education resulted in an adjusted time loss upper extremity injury reduction for the 2015-2019 seasons (0.68 (95% CI: 0.47, 0.99)), which impacted 7-27 days (0.62 (95% CI: 0.42, 0.93)) but not for 28+ days (0.71 (95% CI: 0.47, 1.06)) time loss. There was no reduction in combined trunk and lower extremity injuries for the 2015-2019 seasons (1.55 (95% CI: 0.79, 3.01)). Conclusions: Organizational risk profiling and education appear to reduce professional pitching overall and 7-27-day upper extremity injury risk by 33%-38%. There was no difference in trunk and lower extremity injuries over the period, strengthening the reduction in upper extremity injury risk results. This suggests that while injury risk increased over time, organizational risk profiling mitigated the expected increase in upper extremity injury rates. Risk profiling and education can be used as a clinical screening and intervention tool to help decrease upper extremity injuries in professional baseball populations.

Improving Clinical Utility of Real-World Prediction Models: Updating Through Recalibration.

ABSTRACT: Bullock, GS, Shanley, E, Thigpen, CA, Arden, NK, Noonan, TK, Kissenberth, MJ, Wyland, DJ, and Collins, GS. Improving clinical utility of real-world prediction models: updating through recalibration. J Strength Cond Res 37(5): 1057-1063, 2023-Prediction models can aid clinicians in identifying at-risk athletes. However, sport and clinical practice patterns continue to change, causing predictive drift and potential suboptimal prediction model performance. Thus, there is a need to temporally recalibrate previously developed baseball arm injury models. The purpose of this study was to perform temporal recalibration on a previously developed injury prediction model and assess model performance in professional baseball pitchers. An arm injury prediction model was developed on data from a prospective cohort from 2009 to 2019 on minor league pitchers. Data for the 2015-2019 seasons were used for temporal recalibration and model performance assessment. Temporal recalibration constituted intercept-only and full model redevelopment. Model performance was investigated by assessing Nagelkerke's R-square, calibration in the large, calibration, and discrimination. Decision curves compared the original model, temporal recalibrated model, and current best evidence-based practice. One hundred seventy-eight pitchers participated in the 2015-2019 seasons with 1.63 arm injuries per 1,000 athlete exposures. The temporal recalibrated intercept model demonstrated the best discrimination (0.81 [95% confidence interval [CI]: 0.73, 0.88]) and R-square (0.32) compared with original model (0.74 [95% CI: 0.69, 0.80]; R-square: 0.32) and the redeveloped model (0.80 [95% CI: 0.73, 0.87]; R-square: 0.30). The temporal recalibrated intercept model demonstrated an improved net benefit of 0.34 compared with current best evidence-based practice. The temporal recalibrated intercept model demonstrated the best model performance and clinical utility. Updating prediction models can account for changes in sport training over time and improve professional baseball arm injury outcomes.

Shoulder Stabilization Versus Immobilization for First-Time Anterior Shoulder Dislocation: A Systematic Review and Meta-analysis of Level 1 Randomized Controlled Trials.

BACKGROUND: Multiple studies have compared redislocation rates after stabilization and immobilization for patients experiencing a traumatic, first-time anterior shoulder dislocation (ASD). PURPOSE: To systematically review the literature to compare rates of recurrent instability and subsequent instability surgery in patients undergoing treatment for a first-time ASD with surgical stabilization versus shoulder immobilization. STUDY DESIGN: Systematic review and meta-analysis; Level of evidence, 1. METHODS: A systematic review was performed by searching PubMed, the Cochrane Library, and Embase to identify level 1 randomized studies that compared outcomes of surgical stabilization versus immobilization for treatment of primary ASD. The following search phrase was used: (glenohumeral OR anterior shoulder) AND (conservative OR nonoperative OR nonsurgical OR physiotherapy) AND (Bankart OR repair OR stabilization OR surgical OR surgery OR arthroscopic OR arthroscopy) AND (instability OR dislocation). Patients with soft tissue disruption alone as well as those with additional minor bony lesions (Hill-Sachs, Bankart) were included. Recurrent instability and subsequent instability surgery rates, the Western Ontario Shoulder Instability Index (WOSI), and range of motion were evaluated. RESULTS: A total of 5 studies met inclusion criteria, including 126 patients undergoing surgical stabilization (mean age, 23.6 years; range, 15.0-39.0 years) and 133 patients undergoing treatment with sling immobilization only (mean age, 23.1 years; range, 15.0-31.0 years). Mean follow-up was 59.7 months. Overall, 6.3% of operative patients experienced recurrent instability at latest follow-up compared with 46.6% of nonoperative patients (P < .00001). Similarly, 4.0% of operative patients underwent a subsequent instability surgery compared with 30.8% of nonoperative patients (P < .00001). These same trends were demonstrated when data were isolated to nonoperative patients immobilized in internal rotation. When comparing the operative and nonoperative groups at latest follow-up, 1 study found significantly improved WOSI scores among operative patients (P = .035) and 1 study found significantly improved abducted external rotation in nonoperative patients (P = .02). CONCLUSION: Patients, particularly active men in their 20s and 30s, undergoing treatment for a first-time ASD with a surgical stabilization procedure can be expected to experience significantly lower rates of recurrent instability and a significantly decreased need for a future stabilization procedure when compared with patients treated nonoperatively.

Development of an Injury Burden Prediction Model in Professional Baseball Pitchers.

Background: Baseball injuries are a significant problem and have increased in incidence over the last decade. Reporting injury incidence only gives context to rate but not in relation to severity or injury time loss. Hypothesis/Purpose: The purpose of this study was to 1) incorporate both modifiable and non-modifiable factors to develop an arm injury burden prediction model in Minor League Baseball (MiLB) pitchers; and 2) understand how the model performs separately on elbow and shoulder injury burden. Study Design: Prospective longitudinal study. Methods: The study was conducted from 2013 to 2019 on MiLB pitchers. Pitchers were evaluated in spring training arm for shoulder range of motion and injuries were followed throughout the season. A model to predict arm injury burden was produced using zero inflated negative binomial regression. Internal validation was performed using ten-fold cross validation. Subgroup analyses were performed for elbow and shoulder separately. Model performance was assessed with root mean square error (RMSE), model fit (R2), and calibration with 95% confidence intervals (95% CI). Results: Two-hundred, ninety-seven pitchers (94 injuries) were included with an injury incidence of 1.15 arm injuries per 1000 athletic exposures. Median days lost to an arm injury was 58 (11, 106). The final model demonstrated good prediction ability (RMSE: 11.9 days, R2: 0.80) and a calibration slope of 0.98 (95% CI: 0.92, 1.04). A separate elbow model demonstrated weaker predictive performance (RMSE: 21.3; R2: 0.42; calibration: 1.25 [1.16, 1.34]), as did a separate shoulder model (RMSE: 17.9; R2: 0.57; calibration: 1.01 [0.92, 1.10]). Conclusions: The injury burden prediction model demonstrated excellent performance. Caution should be advised with predictions between one to 14 days lost to arm injury. Separate elbow and shoulder prediction models demonstrated decreased performance. The inclusion of both modifiable and non-modifiable factors into a comprehensive injury burden model provides the most accurate prediction of days lost in professional pitchers. Level of Evidence: 2.

Including Modifiable and Nonmodifiable Factors Improves Injury Risk Assessment in Professional Baseball Pitchers.

OBJECTIVES: To (1) evaluate an injury risk model that included modifiable and nonmodifiable factors into an arm injury risk prediction model in Minor League Baseball (MiLB) pitchers and (2) compare model performance separately for predicting the incidence of elbow and shoulder injuries. DESIGN: Prospective cohort. METHODS: A 10-year MiLB injury risk study was conducted. Pitchers were evaluated during preseason, and pitches and arm injuries were documented prospectively. Nonmodifiable variables included arm injury history, professional experience, arm dominance, year, and humeral torsion. Modifiable variables included BMI, pitch count, total range of motion, and horizontal adduction. We compared modifiable, nonmodifiable, and combined model performance by R2, calibration (best = 1.00), and discrimination (area under the curve [AUC]; higher number is better). Sensitivity analysis included only arm injuries sustained in the first 90 days. RESULTS: In this study, 407 MiLB pitchers (141 arm injuries) were included. Arm injury incidence was 0.27 injuries per 1000 pitches. The arm injury model (calibration 1.05 [0.81-1.30]; AUC: 0.74 [0.69-0.80]) had improved performance compared to only using modifiable predictors (calibration: 0.91 [0.68-1.14]; AUC: 0.67 [0.62-0.73]) and only shoulder range of motion (calibration: 0.52 [0.29, 0.75]; AUC: 0.52 [0.46, 58]). Elbow injury model demonstrated improved performance (calibration: 1.03 [0.76-1.33]; AUC: 0.76 [0.69-0.83]) compared to the shoulder injury model (calibration: 0.46 [0.22-0.69]; AUC: 0.62 [95% CI: 0.55, 0.69]). The sensitivity analysis demonstrated improved model performance compared to the arm injury model. CONCLUSION: Arm injury risk is influenced by modifiable and nonmodifiable risk factors. The most accurate way to identify professional pitchers who are at risk for arm injury is to use a model that includes modifiable and nonmodifiable risk factors. J Orthop Sports Phys Ther 2022;52(9):630-640. Epub: 9 July 2022. doi:10.2519/jospt.2022.11072.

Initial kinematic chain injuries increase hazard of subsequent arm injuries in professional baseball pitchers.

BACKGROUND: Currently, there are few studies that have evaluated the relationship between a lower extremity or trunk injury (kinematic chain) and subsequent arm injury. The purpose of this study was (1) to investigate the relationship between initial kinematic chain (lower extremity or trunk) injury and subsequent arm injury; and (2) to investigate the relationship between initial shoulder or elbow injury and subsequent arm injury. METHODS: A 7-year prospective injury risk study was conducted with Minor League Baseball pitchers. Pitches, pitching appearances, athlete exposures (AEs), and arm injuries (≥1-day time loss) were documented throughout the season. Cox survival analyses with 95% confidence intervals (95% CIs) were performed. Confounders controlled for included age, body mass index, arm dominance, pitching role, previous arm injury, number of pitching appearances, and seasonal pitch load. RESULTS: A total of 297 pitchers participated (total player days = 85,270). Arm injury incidence was 11.4 arm injuries/10,000 AEs, and kinematic chain incidence was 5.2 injuries/10,000 AEs. Pitchers who sustained a kinematic chain injury demonstrated a greater hazard (2.6 [95% CI: 1.2, 5.6], P = .019) of sustaining an arm injury. Pitchers who sustained an initial shoulder injury demonstrated a greater hazard (9.3 [95% CI: 1.1, 83], P = .047) of sustaining a subsequent shoulder or elbow injury compared with pitchers who sustained an initial elbow injury. CONCLUSIONS: Pitchers who sustained an initial lower extremity or trunk injury demonstrated an increased subsequent arm injury hazard compared with pitchers who did not. Pitchers who sustained an initial shoulder injury demonstrated a greater hazard of sustaining a subsequent arm injury compared with pitchers who sustained an initial elbow injury. However, this secondary analysis should be interpreted with caution. Clinicians should monitor risk with workload accumulation, which may be related to pitching compensatory strategies in a fatigued state. Pitchers who sustain a shoulder injury should be evaluated and perform both shoulder and elbow rehabilitation strategies before return to sport.

Machine Learning Does Not Improve Humeral Torsion Prediction Compared to Regression in Baseball Pitchers.

Background: Humeral torsion is an important osseous adaptation in throwing athletes that can contribute to arm injuries. Currently there are no cheap and easy to use clinical tools to measure humeral torsion, inhibiting clinical assessment. Models with low error and "good" calibration slope may be helpful for prediction. Hypothesis/Purpose: To develop prediction models using a range of machine learning methods to predict humeral torsion in professional baseball pitchers and compare these models to a previously developed regression-based prediction model. Study Design: Prospective cohort. Methods: An eleven-year professional baseball cohort was recruited from 2009-2019. Age, arm dominance, injury history, and continent of origin were collected as well as preseason shoulder external and internal rotation, horizontal adduction passive range of motion, and humeral torsion were collected each season. Regression and machine learning models were developed to predict humeral torsion followed by internal validation with 10-fold cross validation. Root mean square error (RMSE), which is reported in degrees (°) and calibration slope (agreement of predicted and actual outcome; best = 1.00) were assessed. Results: Four hundred and seven pitchers (Age: 23.2 +/-2.4 years, body mass index: 25.1 +/-2.3 km/m2, Left-Handed: 17%) participated. Regression model RMSE was 12° and calibration was 1.00 (95% CI: 0.94, 1.06). Random Forest RMSE was 9° and calibration was 1.33 (95% CI: 1.29, 1.37). Gradient boosting machine RMSE was 9° and calibration was 1.09 (95% CI: 1.04, 1.14). Support vector machine RMSE was 10° and calibration was 1.13 (95% CI: 1.08, 1.18). Artificial neural network RMSE was 15° and calibration was 1.03 (95% CI: 0.97, 1.09). Conclusion: This is the first study to show that machine learning models do not improve baseball humeral torsion prediction compared to a traditional regression model. While machine learning models demonstrated improved RMSE compared to the regression, the machine learning models displayed poorer calibration compared to regression. Based on these results it is recommended to use a simple equation from a statistical model which can be quickly and efficiently integrated within a clinical setting. Levels of Evidence: 2.

Hazard of Arm Injury in Professional Starting and Relief Pitchers.

CONTEXT: How different pitching roles affect the risk of arm injury in professional pitchers is currently unclear. OBJECTIVES: To investigate differences between professional baseball starting and relief pitchers in the hazard of (1) arm injury and (2) elbow and shoulder injury. DESIGN: Prospective cohort study. SETTING: Minor League Baseball (MiLB) from 2013 to 2019. PATIENTS OR OTHER PARTICIPANTS: Pitchers in MiLB. MAIN OUTCOME MEASURE(S): Pitchers were followed for the entire MiLB season, and athlete-exposures and injuries were recorded. Risk ratios and risk difference were calculated between starting and relieving MiLB pitchers. A Cox survival analysis was then performed in relation to time to arm injury between starting and relieving MiLB pitchers. Subgroup analyses were conducted for elbow and shoulder injuries. RESULTS: A total of 297 pitchers were included, with 85 270 player-days recorded. The incidence of arm injuries was 11.4 per 10 000 athlete-exposures. Starting pitchers demonstrated a greater risk ratio (1.2 [95% CI = 1.1, 1.3]), risk difference (13.6 [95% CI = 5.6, 21.6]), and hazard of arm injury (2.4 [95% CI = 1.5, 4.0]) than relief pitchers. No differences were observed for the hazard of elbow injury between starting and relief pitchers (1.9; 95% CI = 0.8, 4.2). Starting pitchers had a greater hazard of shoulder injury than relief pitchers (3.8 [95% CI = 2.0, 7.1]). CONCLUSIONS: Starting pitchers displayed a 2.4 times greater hazard of arm injury than relief pitchers. Subgroup analyses indicated that starters exhibited a greater hazard of shoulder injury than relievers, but no differences occurred for the hazard of elbow injury. However, due to the wide CIs, these subgroup analyses should be interpreted with caution. Clinicians may need to consider cumulative exposure and fatigue and how these factors relate to different pitching roles when assessing the risk of pitching arm injury.

Usability of smart infusion pumps: A heuristic evaluation.

Although smart infusion pumps were built to eliminate medication errors, new types of usability errors have arisen. The purposes of this study were to determine potential risks when using smart pumps during secondary medication administration and to identify opportunities for design improvements. We observed and analyzed nurses when they interacted with smart pumps and heuristically evaluated the smart pump to identify usability problems. Forty-three usability problems were identified with the smart pump. The usability problems have the potential to create high cognitive burden on nurses and to increase the likelihood of mistakes. We discuss design and process improvement recommendations for each major finding from this study.

Professional Pitchers Display Differences in UCL Morphology and Elbow Gapping During Moving Valgus Stress Testing After UCL Reconstruction.

BACKGROUND: Ulnar collateral ligament (UCL) reconstruction (UCLR) of the elbow has received much attention given the rise in incidence among baseball pitchers. Stress ultrasonography has been demonstrated to be a critical evaluation tool of the UCL. No study has dynamically evaluated the ability of UCLR to restore normal kinematics. PURPOSE/HYPOTHESIS: The purpose of this study was to compare ulnohumeral gapping during a moving valgus stress test as well as UCL thickness between professional pitchers with and without UCLR. We hypothesized that the ulnohumeral joint will display greater gapping and the UCL graft will be thicker in pitchers after UCLR compared with uninjured pitchers. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: Ultrasonography was used to measure the medial ulnohumeral joint distance and the UCL thickness of 70 asymptomatic professional baseball pitchers; 6 of the participants had a history of UCLR. Images were captured of the dominant (D) and nondominant (ND) elbows at the maximal cocking position under 2 loaded conditions within the moving valgus stress test arc: (1) gravity stress and (2) 2.5 kg (5.5 lb) of valgus force using a dynamometer. Intra- and interrater reliability of the measurements was established with intraclass correlation coefficients (ICCs). Separate mixed-model analyses of variance (D side × UCL) were used to compare the D and ND elbow variables between pitchers with and without a history of UCLR. RESULTS: All measurements displayed good reliability according to ICCs. Pitchers with a history of UCLR demonstrated less gapping (5.6 ± 2.9 vs 4.2 ± 1.2 mm; P = .002) and greater UCL graft thickness (0.17 ± 0.07 vs 0.11 ± 0.08 mm; P = .03) compared with the native ligament in pitchers without prior UCL injury. CONCLUSION: Our data demonstrated that the UCLR results in a thicker, stiffer construct with less medial elbow gapping than the anatomical UCL. Using ultrasound to evaluate the UCL was a reliable, efficient, and clinically feasible method to assess UCL thickness and joint gapping in players with a history of UCLR. Future studies may consider this approach to evaluate surgical techniques and graft types for UCLR.

Development and internal validation of a humeral torsion prediction model in professional baseball pitchers.

BACKGROUND: Humeral torsion (HT) has been linked to pitching arm injury risk after controlling for shoulder range of motion. Currently measuring HT uses expensive equipment, which inhibits clinical assessment. Developing an HT predictive model can aid clinical baseball arm injury risk examination. Therefore, the purpose of this study was to develop and internally validate an HT prediction model using standard clinical tests and measures in professional baseball pitchers. METHODS: An 11-year (2009-2019) prospective professional baseball cohort was used for this study. Participants were included if they were able to participate in all practices and competitions and were under a Minor League Baseball contract. Preseason shoulder range of motion (external rotation [ER], internal rotation [IR], horizontal adduction [HA]) and HT were collected each season. Player age, arm dominance, arm injury history, and continent of origin were also collected. Examiners were blinded to arm dominance. An a priori power analysis determined that 244 players were needed for accurate prediction models. Missing data was low (<3%); thus, a complete case analysis was performed. Model development followed the transparent reporting of a multivariable prediction model for individual prognosis or diagnosis (TRIPOD) recommendations. Regression models with restricted cubic splines were performed. Following primary model development, bootstrapping with 2000 iterations were performed to reduce overfitting and assess optimism shrinkage. Prediction model performance was assessed through root mean square error (RMSE), R2, and calibration slope with 95% confidence intervals (CIs). Sensitivity analyses included dominant and nondominant HT. RESULTS: A total of 407 professional pitchers (age: 23.2 [standard deviation 2.4] years, left-handed: 17%; arm history prevalence: 21%) participated. Predictors with the highest influence within the model include IR (0.4, 95% CI 0.3, 0.5; P < .001), ER (-0.3, 95% CI -0.4, -0.2; P < .001), HA (0.3, 95% CI 0.2, 0.4; P < .001), and arm dominance (right-handed: -1.9, 95% CI -3.6, -0.1; P = .034). Final model RMSE was 12, R2 was 0.41, and calibration was 1.00 (95% CI 0.94, 1.06). Sensitivity analyses demonstrated similar model performance. CONCLUSIONS: Every 3° of IR explained 1° of HT. Every 3° of ER explained 1° less of HT, and every 7° of HA explained 1° of HT. Right-handers had 2° less HT. Models demonstrated good predictive performance. This predictive model can be used by clinicians to infer HT using standard clinical test and measures. These data can be used to enhance professional baseball arm injury examination.

Return-to-Play Outcomes in Professional Baseball Players After Nonoperative Treatment of Incomplete Medial Ulnar Collateral Ligament Injuries: A Long-Term Follow-up Study.

BACKGROUND: Medial ulnar collateral ligament (UCL) injuries are common among baseball players. There is sparse literature on long-term results after nonoperative treatment of UCL injuries in professional baseball players. PURPOSE: The primary purpose was to assess long-term follow-up on reinjury rates, performance metrics, rate of return to the same level of play or higher (RTP), and ability to advance to the next level of play in professional baseball players after nonoperative treatment of incomplete UCL injuries. The secondary aim was to perform a matched-pair comparison between pitchers treated nonoperatively and a control group without a history of UCL injuries. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Twenty-eight professional baseball players (18 pitchers, 10 position players) treated nonoperatively were identified from a previous retrospective review of a single professional baseball organization between 2006 and 2011. UCL reinjury rates and player performance metrics were evaluated at long-term (minimum, 9 years) follow-up. Rates of RTP were calculated. A matched-pair comparison was made between the pitchers treated nonoperatively and pitchers without a history of UCL injuries. RESULTS: Overall, 27 players (17 pitchers, 10 position players) were available for long-term follow-up at a mean follow-up of 12 years (SD, 2 years). The overall rate of RTP was 85% (23/27), with the rate of RTP being 82% (14/17) in pitchers and 90% (9/10) in position players. Of the 23 players who did RTP, 18 (78%) reached a higher level of play and 5 (21.7%) stayed at the same level. Of the 9 position players who did RTP, the median number of seasons played after injury was 4.5 (interquartile range, 3.3). Of the 14 pitchers who did RTP, the mean number of seasons played after injury was 5.8 (SD, 3.8). In the matched-pair analysis, no significant differences were observed in any performance metrics (P > .05). The overall reinjury rate was 11.1% (3/27), with no players requiring UCL reconstruction. CONCLUSION: There was a high rate of RTP for professional baseball players treated nonoperatively for incomplete UCL injuries. Compared with a matched cohort with no history of UCL injury, professional baseball pitchers treated nonoperatively had similar performance metrics. Reinjury rates were low, and no player had reinjury requiring UCL reconstruction. Nonoperative treatment of incomplete UCL injuries in professional baseball players, specifically pitchers, is a viable treatment option in the long term.

Distal Triceps Tendon Injuries.

Distal triceps ruptures are uncommon, usually caused by a fall on an outstretched hand or a direct blow. Factors linked to injury include eccentric loading of a contracting triceps, anabolic steroid use, weightlifting, and traumatic laceration. Risk factors include local steroid injection, hyperparathyroidism, and olecranon bursitis. Initial diagnosis can be complicated by pain and swelling, and a palpable defect is not always present. Plain radiographs can be helpful. MRI confirms the diagnosis and directs treatment. Incomplete tears can be treated nonsurgically; complete tears are best managed surgically. Good to excellent restoration of function has been shown with surgical repair.

Using Stress Ultrasonography to Understand the Risk of UCL Injury Among Professional Baseball Pitchers Based on Ligament Morphology and Dynamic Abnormalities.

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.

Melt Electrospinning Writing of Highly Ordered Large Volume Scaffold Architectures.

The additive manufacturing of highly ordered, micrometer-scale scaffolds is at the forefront of tissue engineering and regenerative medicine research. The fabrication of scaffolds for the regeneration of larger tissue volumes, in particular, remains a major challenge. A technology at the convergence of additive manufacturing and electrospinning-melt electrospinning writing (MEW)-is also limited in thickness/volume due to the accumulation of excess charge from the deposited material repelling and hence, distorting scaffold architectures. The underlying physical principles are studied that constrain MEW of thick, large volume scaffolds. Through computational modeling, numerical values variable working distances are established respectively, which maintain the electrostatic force at a constant level during the printing process. Based on the computational simulations, three voltage profiles are applied to determine the maximum height (exceeding 7 mm) of a highly ordered large volume scaffold. These thick MEW scaffolds have fully interconnected pores and allow cells to migrate and proliferate. To the best of the authors knowledge, this is the first study to report that z-axis adjustment and increasing the voltage during the MEW process allows for the fabrication of high-volume scaffolds with uniform morphologies and fiber diameters.

Glenohumeral internal rotation deficit in throwing athletes: current perspectives.

Glenohumeral internal rotation deficit (GIRD) is an adaptive process in which the throwing shoulder experiences a loss of internal rotation (IR). GIRD has most commonly been defined by a loss of >20° of IR compared to the contralateral shoulder. Total rotational motion of the shoulder is the sum of internal and external rotation and may be more important than the absolute value of IR loss. Pathologic GIRD has been defined as a loss of IR combined with a loss of total rotational motion. The leading pathologic process in GIRD is posterior capsular and rotator-cuff tightness, due to the repetitive cocking that occurs with the overhead throwing motion. GIRD has been associated with numerous pathologic conditions, including posterior superior labral tears, partial articular-sided rotator-cuff tears, and superior labral anterior-to-posterior tears. The mainstay of treatment for patients with GIRD is posterior capsular stretching and strengthening to improve scapular mechanics. In patients who fail nonoperative therapy, shoulder arthroscopy can be performed. Arthroscopic surgery in the high-level throwing athlete should be to restore them to their functional baseline with the minimum amount of intervention possible.

Multimodality imaging in the diagnosis of a large accessory papillary muscle.

An accessory papillary muscle is an uncommon congenital anomaly usually found incidentally on routine cardiac imaging. While frequently asymptomatic, it is occasionally associated with mitral regurgitation, left ventricular dynamic outflow obstruction and hypertrophic cardiomyopathy1 and it is important to differentiate it from other pathological processes including papillary fibroelastoma, left ventricle thrombus, hemangioma, a single papillary muscle with a parachute mitral valve and a left ventricle false tendon. The clinical implication of these findings varies according to the degree of left ventricular out flow obstruction, location and pathology. We report a case that underscores the importance of multimodality imaging in the diagnosis and differentiation of an accessory papillary muscle from other intracardiac masses. [Full article available at http://rimed.org/rimedicaljournal-2017-09.asp].

Humeral Torsion as a Risk Factor for Shoulder and Elbow Injury in Professional Baseball Pitchers.

BACKGROUND: Numerous studies have demonstrated that humeral retrotorsion is increased in the dominant arms of throwing athletes. No study has clearly defined the relationship between humeral retrotorsion and shoulder and elbow injury. HYPOTHESIS: Uninjured professional pitchers will display more dominant humeral torsion (HT) than professional pitchers who sustain shoulder injuries but less than pitchers who sustain elbow injuries. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: Pitchers from the Colorado Rockies professional baseball organization were recruited for participation for this prospective injury study from 2009 to 2013. HT was assessed using indirect ultrasonographic techniques and was measured prospectively in 255 pitchers before each spring training (average of 2 trials). From the beginning of the preseason to the end of the postseason, overuse upper extremity injuries (shoulder or elbow) were tracked for each participating athlete. All athletes who reported pain or injury to their coach were referred to the organization's athletic trainer for evaluation and classification of each injury. The difference in HT was calculated by subtracting measurement of the dominant arm from the nondominant arm, and 3 separate mixed-model analyses of variance (side × injury group) were used to compare the dominant and nondominant HT between all pitchers who developed an arm injury (shoulder and elbow combined), as well as comparing pitchers who developed a shoulder or elbow injury to those who did not miss games due to shoulder or elbow injury (α = .05). RESULTS: During the course of the study, 60 arm (30 shoulder; 30 elbow) injuries were observed; 195 pitchers did not suffer an injury. There were no differences when HT was compared between all injured (shoulder and elbow injuries combined) and uninjured pitchers (P = .13; effect size 0.14). There was a significant interaction effect showing that pitchers who suffered a shoulder injury displayed 4° less dominant humeral retrotorsion compared with pitchers without injury (P = .04) and that pitchers with elbow injury displayed 5° greater humeral retrotorsion (P = .04). In addition, those who suffered an ulnar collateral ligament injury requiring reconstruction (n = 17) also displayed 4(o) greater dominant retrotorsion and 5° less nondominant humeral retrotorsion compared with pitchers who did not suffer an injury (n = 195; P = .05). There was not a significant difference between nondominant HT among pitchers who sustained shoulder and elbow injuries and pitchers without injury. CONCLUSION: The results of this study show a contrast in dominant humeral retrotorsion between pitchers who suffered shoulder and elbow injuries compared with those without an injury. Pitchers who sustained shoulder injuries had less dominant humeral retrotorsion compared with noninjured pitchers. In contrast, pitchers who sustained time-loss elbow injuries displayed increased humeral retrotorsion compared with noninjured pitchers. Together, these results suggest that increased adaptive humeral retrotorsion is protective against shoulder injuries but a harmful contributor for elbow injuries in professional pitchers. This is the first study to show differing injury risk profiles for shoulder and elbow injury.

Thromboembolic Events After Arthroscopic Knee Surgery: Increased Risk at High Elevation.

PURPOSE: To evaluate the incidence of thromboembolic events in patients undergoing arthroscopic surgery of the knee in centers located at elevations near sea level and compare those rates with the patients undergoing the same operations in centers at high elevation. METHODS: A retrospective review was conducted using a database of a major health care system with surgery centers located throughout the United States. More than 115 centers located in 15 different states were analyzed for any reported thromboembolic events including deep vein thromboses and pulmonary embolism (PE) in patients who had undergone knee arthroscopy over a 2-year period. The centers located at elevations lower than 1,000 ft were considered sea level centers. Centers located at elevations above 4,000 ft were considered high-elevation centers. Centers located between 1,000 ft and 4,000 ft elevation were excluded. RESULTS: A total of 35,877 patients underwent a knee arthroscopy at a low-elevation center and 10,181 patients underwent a knee arthroscopy at a high-elevation center between 2011 and 2012. During that same time period, 45 total venous thromboembolic events (VTEs) including 12 PEs occurred at centers considered low elevation, whereas 50 VTEs including 4 PEs occurred at centers considered high elevation. The incidence of VTE at low-elevation centers was 0.13%. The incidence of VTE at high-elevation centers was 0.49%. The difference was statistically significant, P < .0001. The relative risk of developing a VTE was 3.8 times higher at high elevation. There was no difference in PE incidence between high- and low-elevation centers (0.04% vs 0.03%, respectively; P = .78). CONCLUSIONS: Patients undergoing arthroscopic procedures of the knee in centers at high elevation are at 3.8 times higher risk of developing a VTE than those undergoing the same procedures in centers at low elevations. There was no observed increased risk of PE. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Return-to-Play Outcomes in Professional Baseball Players After Medial Ulnar Collateral Ligament Injuries: Comparison of Operative Versus Nonoperative Treatment Based on Magnetic Resonance Imaging Findings.

BACKGROUND: The medial ulnar collateral ligament (UCL) is the primary static stabilizer to valgus stress of the elbow. Injuries to the UCL are common in baseball pitchers. In the 1970s, reconstructive surgery was developed. Return-to-play (RTP) rates of 67% to 95% after reconstruction have been reported. There is a paucity of published studies among professional baseball players reporting RTP with nonoperative treatment. PURPOSE: To identify professional baseball players' ability to RTP after the nonoperative treatment of UCL injuries based on the magnetic resonance imaging (MRI) grade. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A review of elbow injuries among a professional baseball organization from 2006 to 2011 was performed. MRI was performed on all players. Forty-three UCL injuries were diagnosed. Treatment included rehabilitation, surgery, or both. Rates of RTP and return to the same level of play or higher (RTSP) were calculated and correlated with the MRI grade, location of injury, and player position. MRI grading was as follows: I, intact ligament with or without edema; IIA, partial tear; IIB, chronic healed injury; and III, complete tear. RESULTS: Forty-three UCL injuries in 43 players were diagnosed. Eight had complete tears (grade III), were treated operatively with UCL reconstruction, and had an RTP rate of 75% and RTSP rate of 63% (5/8 returned to the same level and 1 to a lower level). All 8 were pitchers. The remaining 35 players had incomplete injuries (4 grade I, 8 grade IIA, and 23 grade IIB), consisting of 24 pitchers and 11 positional players. Of these 35 players, 1 underwent surgery without attempted rehabilitation, 3 initiated rehabilitation until MRI was performed and then underwent surgery, and 3 underwent surgery after failed rehabilitation. The 7 players who underwent UCL reconstruction surgery had an RTP rate of 100% and RTSP rate of 86% (6/7 returned to the same level and 1 to a lower level). The remaining 28 with nonoperative treatment had both RTP and RTSP rates of 93% (26/28 returned to the same level and 0 to a lower level). Of these, 10 were positional players with an RTSP rate of 90%, and 18 were pitchers with an RTSP rate of 94%. Of all players with incomplete UCL injuries who completed nonoperative rehabilitative treatment (n = 31), 26 had a successful RTSP (84%). CONCLUSION: Incomplete UCL injuries in professional baseball players can be successfully treated nonoperatively in the majority of cases. Pitchers are more likely to have complete tears leading to surgery. MRI grading of UCL injuries can help predict RTP and the need for surgery.