Pectoralis muscle injuries in Major and Minor League Baseball.

BACKGROUND AND HYPOTHESIS: Although shoulder and elbow injuries in professional baseball players have been thoroughly studied, little is known about the frequency and impact of pectoralis muscle injuries in this population. The purpose of this study was to use the official league injury surveillance system to describe pectoralis muscle injuries in professional baseball players in Major League Baseball (MLB) and Minor League Baseball (MiLB). Specifically, (1) player demographic characteristics, (2) return to play (RTP), (3) injury mechanism, (4) throwing- and batting-side dominance, and (5) injury rate per athlete exposure (AE) were characterized to guide future injury prevention strategies. METHODS: The MLB Health and Injury Tracking System database was used to compile all pectoralis muscle injuries in MLB and MiLB athletes in the 2011-2017 seasons. Injury-related data including diagnosis (tear or rupture vs. strain), player demographic characteristics, injury timing, need for surgical intervention, RTP, and mechanism of injury were recorded. Subanalyses of throwing- and batting-side dominance, as well as MLB vs. MiLB injury frequency, were performed. RESULTS: A total of 138 pectoralis muscle injuries (32 MLB and 106 MiLB injuries) were reported in the study period (5 tears or ruptures and 133 strains), with 5 of these being recurrent injuries. Operative intervention was performed in 4 athletes (2.9%). Of the 138 injuries, 116 (84.1%) resulted in missed days of play, with a mean time to RTP of 19.5 days. Starting pitchers sustained the greatest proportion of pectoralis injuries (48.1%), with pitching being the most common activity at the time of injury (45.9%). A majority of injuries (86.5%) were sustained during non-contact play. Overall, 87.5% of injuries occurred on the player's dominant throwing side and 81.3% occurred on the player's dominant batting side. There was no significant difference in the rate of pectoralis injuries in the MLB regular season (0.584 per 10,000 AEs) vs. the MiLB regular season (0.425 per 10,000 AEs) (P = .1018). CONCLUSION: Pectoralis muscle injuries are most frequently non-contact injuries, most commonly sustained by pitchers. An understanding of these injuries can guide athletic trainers and management in expectation management and decision making, in addition to directing future efforts at injury prevention.

Prognostic utility of an magnetic resonance imaging-based classification for operative versus nonoperative management of ulnar collateral ligament tears: one-year follow-up.

BACKGROUND: A recently introduced classification of medial ulnar collateral ligament (UCL) tears has demonstrated high interobserver and intraobserver reliability, but little is known about its prognostic utility. The purpose of this study was to assess the relationship of the magnetic resonance imaging (MRI)-based classification system and nonoperative vs. operative management. Secondary objectives included subanalysis of baseball players. METHODS: Eighty-five consecutive patients with UCL tears after a standardized treatment paradigm were categorized as operative vs. nonoperative. UCL tears of patients with a minimum of 1-year follow-up were retrospectively classified using the MRI-based classification system. Subanalyses for baseball players included return-to-play and return-to-prior performance. RESULTS: A total of 80 patients (62 baseball players, 54 pitchers) met inclusion criteria. A total of 51 patients underwent surgery, and 29 patients completed nonoperative management. In baseball players, 59% of the proximal tears were treated nonoperatively and 97% of the distal tears were treated operatively; 100% of the proximal partial-thickness tears and 100% of the distal complete tears were treated nonoperatively and operatively, respectively. Patients with distal (odds ratio: 48.4, P < .0001) and complete (odds ratio: 5.0, P = .004) tears were more likely to undergo surgery. Baseball players, regardless of position, were determinants of operative management, and there was no difference in return-to-play clearance and return-to-prior performance between the operative and nonoperative groups. CONCLUSION: A reliable 6-stage MRI-based classification addressing UCL tear grade and location may confer decision making between operative and nonoperative management. Complete and distal tears carry a markedly increased risk of failing nonoperative care compared with proximal, partial tears.

Validity and efficiency of a smartphone-based electronic data collection tool for operative data in rotator cuff repair.

BACKGROUND: This study tested validity and efficiency of Orthopaedic Minimal Data Set (OrthoMiDaS) Episode of Care (OME). METHODS: We analyzed 100 isolated rotator cuff repair cases in the OME database. Surgeons completed a traditional operative note and OME report. A blinded reviewer extracted data from operative notes and implant logs in electronic medical records by manual chart review. OME and electronic medical record data were compared with data counts and agreement between 40 variables of rotator cuff disease and repair procedures. Data counts were assessed using raw percentages and McNemar test (with continuity correction). Agreement of categorical variables was analyzed using Cohen κ (unweighted) and of numerical variables using the concordance correlation coefficient (CCC). Efficiency was assessed by median time to complete. RESULTS: OME database had significantly higher data counts for 25% (10/40) of variables. A high level of proportional and statistical agreement was demonstrated between the data. Among 35 categorical variables, proportional agreement was perfect for 17%, almost perfect (0.81 ≤ κ ≤ 1.00) for 37%, substantial (0.61 ≤ κ ≤ 0.80) for 20%, moderate (0.41 ≤ κ ≤ 0.60) for 14%, fair (0.21 ≤ κ ≤ 0.40) for 6%, and slight (0.0 ≤ κ ≤ 0.20) for 6%. Of 5 numerical variables, agreement was almost perfect (CCC > 0.99) for 20% and poor (CCC < 0.90) for 80%. Median OME completion time was 161.5 seconds (interquartile range, 116-224.5). CONCLUSION: OME is an efficient, valid tool for collecting comprehensive, standardized data on rotator cuff repair.

Social Media in Shoulder & Elbow Surgery: An Analysis of Twitter and Instagram.

Social media provide a unique method of analyzing outcomes and quality in medicine. The purpose of this observational study was to investigate the nature of social media content related to shoulder and elbow (S&E) surgery posted by patients, surgeons, and hospitals. A public search of Instagram for a two-year period yielded 1,177 patient-related posts. A categorical system assessed the perspective, timing, tone, and content of each post. Twitter accounts of 77 S&E specialists from the top five ranked U.S. News & World Report institutions were analyzed for activity and content. 5,246 Twitter and Instagram posts for the institutions were analyzed for frequency and content. Most patient-related posts were by patients (68%), postoperative (82%), positive (87%), and centered on return-to-play for Tommy John (34%), surgical site for shoulder arthroplasty (52%), and activities of daily living for rotator cuff repair (22%). 37% of surgeons had active accounts averaging 46 posts, 87% of which were practice advertisements. Hospitals averaged 273 posts over the 2-year period, focusing on education (38%) and community (18%). S&E patients share outcomes on social media in a positive tone with procedure-dependent emphases. Surgeons on social media use sites for practice augmentation. Hospitals often focused posts towards educating the community.

Biomechanical analysis of elbow medial ulnar collateral ligament tear location and its effect on rotational stability.

BACKGROUND: Recent anatomic and clinical studies have shown that the location of the injury to the elbow ulnar collateral ligament (UCL) is an important variable in deciding on surgical intervention; however, no studies have evaluated these findings biomechanically. METHODS: This study tested 16 intact elbow specimens. Valgus torques of 2.5 and 5 Nm were applied to the elbow at various flexion angles, and the resulting valgus angles were measured. The valgus angles were applied to the elbows in their intact states and again after partial and complete cuts were made on the proximal and distal insertions of the UCL. Resulting valgus torques were measured, and stiffness was calculated for each elbow flexion angle. Unpaired t tests were used to evaluate the effects of cut location and flexion angle on joint rotational stability and stiffness. RESULTS: The posterior-distal insertion contributed the most to stability. At valgus angles generated from 2.5 Nm intact torques, the posterior-distal insertions contributed to 51% ± 26% (P < .03) intact rotational stability, and at valgus angles generated from 5 Nm intact torques, the posterior-distal insertions contributed to 41% ± 17% (P < .02) intact rotational stability. For overall stiffness, the posterior-distal insertions contributed to 31% ± 12% (P < .045) intact stiffness. CONCLUSION: Overall, the posterior distal insertion of the UCL contributed most to rotational stability and stiffness of the medial elbow when subjected to valgus stress at 90° and 120° of elbow flexion. At higher elbow flexion angles, the posterior insertions contributed more to stability, whereas the anterior insertions had a greater effect at lower flexion angles.

Mobile technology and telemedicine for shoulder range of motion: validation of a motion-based machine-learning software development kit.

BACKGROUND: Mobile technology offers the prospect of delivering high-value care with increased patient access and reduced costs. Advances in mobile health (mHealth) and telemedicine have been inhibited by the lack of interconnectivity between devices and software and inability to process consumer sensor data. The objective of this study was to preliminarily validate a motion-based machine learning software development kit (SDK) for the shoulder compared with a goniometer for 4 arcs of motion: (1) abduction, (2) forward flexion, (3) internal rotation, and (4) external rotation. METHODS: A mobile application for the SDK was developed and "taught" 4 arcs of shoulder motion. Ten subjects without shoulder pain or prior shoulder surgery performed the arcs of motion for 5 repetitions. Each motion was measured by the SDK and compared with a physician-measured manual goniometer measurement. Angular differences between SDK and goniometer measurements were compared with univariate and power analyses. RESULTS: The comparison between the SDK and goniometer measurement detected a mean difference of less than 5° for all arcs of motion (P > .05), with a 94% chance of detecting a large effect size from a priori power analysis. Mean differences for the arcs of motion were: abduction, -3.7° ± 3.2°; forward flexion, -4.9° ± 2.5°; internal rotation, -2.4° ± 3.7°; and external rotation -2.6° ± 3.4°. DISCUSSION: The SDK has the potential to remotely substitute for a shoulder range of motion examination within 5° of goniometer measurements. An open-source motion-based SDK that can learn complex movements, including clinical shoulder range of motion, from consumer sensors offers promise for the future of mHealth, particularly in telemonitoring before and after orthopedic surgery.

Throwing-related injuries of the subscapularis in professional baseball players.

OBJECTIVE: To describe the MR appearance of a series of throwing-related injuries to the subscapularis muscle-tendon complex among baseball players. MATERIALS AND METHODS: A retrospective review of MR scans of the shoulder in players from 1 professional baseball organization over the course of 5 years was performed to identify cases with findings suggestive of subscapularis injury. These findings were graded and the medical record was reviewed to assess clinical findings, treatment, and follow-up. Preinjury baseline measurements of arm external rotation at 90° of abduction were compared to measurements from a noninjured cohort to evaluate whether this measure is a risk factor for injury. RESULTS: A total of 133 MR scans of the shoulder were evaluated. Eleven of the scans demonstrated signal changes suggesting subscapularis injury; 10 of these 11 patients had clinical findings supporting a diagnosis of throwing-related subscapularis strain. There were four grade 1, four grade 2, and two grade 3 injuries. All injuries occurred in the inferior half of the subscapularis at the myotendinous junction. Risk of subscapularis injury increased with lower levels of dominant arm external rotation (odds ratio, 1.12; 95% CI, 1.07-1.21; p < 0.001). A threshold of dominant arm external rotation of <106° demonstrated sensitivity of 0.700 (95% CI, 0.392-0.897) and specificity of 0.951 (95% CI, 0.888-0.982) for subscapularis injury. CONCLUSION: Throwing-related subscapularis injuries occur in the inferior half of the muscle at the myotendinous junction. Our data suggest that there is an increased risk of these injuries with lower levels of dominant arm external rotation.

Medial epicondylitis: evaluation and management.

Medial epicondylitis, often referred to as "golfer's elbow," is a common pathology. Flexor-pronator tendon degeneration occurs with repetitive forced wrist extension and forearm supination during activities involving wrist flexion and forearm pronation. A staged process of pathologic change in the tendon can result in structural breakdown and irreparable fibrosis or calcification. Patients typically report persistent medial-sided elbow pain that is exacerbated by daily activities. Athletes may be particularly symptomatic during the late cocking or early acceleration phases of the throwing motion. Nonsurgical supportive care includes activity modification, NSAIDs, and corticosteroid injections. Once the acute symptomology is alleviated, focus is turned to flexor-pronator mass rehabilitation and injury prevention. Surgical treatment via open techniques is typically reserved for patients with persistent symptoms.

Sonographic assessment of the medial ulnar collateral ligament distal ulnar attachment.

OBJECTIVES: The purpose of this study was to determine whether the long distal attachment of the medial ulnar collateral ligament (MUCL) can be delineated on sonography. METHODS: We used 12 fresh-frozen cadaveric elbows for this study. We performed sonography of the elbow using a coronal-equivalent long-axis view of the MUCL. All sonographic examinations and measurements were performed by a board-certified, fellowship-trained musculoskeletal radiologist. Measurements were performed from the anteroinferior aspect of the medial epicondyle to the sublime tubercle and then from the sublime tubercle to the terminal fibers of the MUCL long ulnar attachment. We then measured the length of the MUCL from its attachment at the medial epicondyle of the humerus to the sublime tubercle and then from the sublime tubercle to the distal extent of its terminal fibers at the ulnar attachment with digital calipers. RESULTS: On sonography, the average length of the MUCL from its humeral attachment to the sublime tubercle (transarticular) was 19.6 mm. The average length of the ulnar attachment was 27.9 mm. The MUCL was thickest (mediolateral dimension) at its humeral attachment and tapered as it coursed distally along the ulnar attachment. The MUCL was clearly identified on sonography and in all anatomic specimens. On gross measurement, the average lengths of the transarticular portion of the MUCL and its ulnar footprint were 21.5 and 30.2 mm, respectively. CONCLUSIONS: We have successfully shown that the distal ulnar attachment of the MUCL can be visualized on high-resolution sonography. This preliminary work provides a framework for developing protocols for diagnosis of injuries to the distal ulnar collateral ligament.

Batter's Shoulder: Diagnosis, Management, and Outcomes.

Batter's shoulder is characterized by posterior shoulder instability in the lead (front) shoulder of a batting athlete. This most commonly occurs as a discrete event, particularly a swing and miss at an outside pitch, which leads to an episode of shoulder subluxation. A thorough history and physical examination is key to diagnosis, with patients feeling pain and instability of the lead shoulder when attempting the baseball swing or during pushing-type activities, as well as positive posterior labral signs in tests such as the Kim, jerk, and modified dynamic labral shear tests. Magnetic resonance imaging can confirm the diagnosis of posterior labral tear and may show concomitant pathologies such as a reverse Hill-Sachs lesion. Nonsurgical treatment is directed at rotator cuff and scapular strengthening; however, arthroscopic posterior labral repair is often required for definitive stabilization. Overall, this is a relatively rare diagnosis, but outcomes of surgical repair are favorable with high satisfaction and rates of return to competition.

Operative management of capitellar fractures: a systematic review.

PURPOSE: This study was conducted to evaluate reports of clinical outcomes of isolated capitellar fractures. MATERIALS AND METHODS: We conducted a systematic review of medical databases reporting clinical outcomes of patients undergoing nonoperative and operative management of isolated capitellar fractures. RESULTS: We identified 28 studies for inclusion comprising 174 patients. All included studies were level IV evidence. Capitellar fractures were more common among women than men and were more likely to involve the nondominant arm. Type I fractures (84%) were more common than type II (14%) and III fractures (2%). Operative and nonoperative management both led to satisfactory clinical outcomes. No significant difference in outcomes was observed in those undergoing operative management compared with those undergoing closed reduction and immobilization. CONCLUSIONS: Nonoperative and operative management of isolated capitellar fractures leads to satisfactory clinical outcomes as determined by postoperative range of motion, improvement in pain, and a return to previous levels of function. No statistical difference in outcomes was observed between those undergoing operative management compared with those treated with closed reduction and immobilization.

Lack of race/ethnic minority representation in ulnar collateral ligament reconstruction in baseball athletes: a systematic review.

OBJECTIVES: To assess the reporting and representation of ethnic and racial minorities in comparative studies of ulnar collateral ligament (UCL) injuries and treatment in baseball athletes. METHODS: A systematic review of the literature was conducted using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) reporting guidelines. The literature search was conducted by two independent reviewers using the PubMed, Scopus, and Cochrane Library databases. Studies were included if they were UCL of the elbow clinical comparative studies, including randomized clinical trials, cohort studies, case series, and epidemiological studies. Studies were excluded if they were related to ulnar collateral ligament of the thumb, lateral ulnar collateral ligament of the elbow, biomechanical studies, non-surgical studies, non-baseball studies, and systematic reviews and meta-analyses. The Methodological Index for Non-Randomized Studies (MINORS) criterion was used to assess quality of studies included. RESULTS: A total of 108 studies were included for analysis, of which only one reported race and ethnicity in their demographics. Additionally, of the 108 studies included, only four reported Country of Origin, a subset of Race and Ethnicity, in their demographics. CONCLUSION: Race and Ethnicity demographics are scarcely reported in comparative studies evaluating ulnar collateral ligament reconstruction. Future studies evaluating similar populations should strongly consider reporting racial and ethnic demographics as this may provide clarity on any potential effect these might have on post-surgical outcomes, particularly in high-level pitchers.

Differences in Glenohumeral Range of Motion and Humeral Torsion Between Right-Handed and Left-Handed Professional Baseball Pitchers.

BACKGROUND: Elite pitchers have demonstrated significant differences in glenohumeral range of motion and humeral torsion compared with the nonthrowing population. Furthermore, abnormal shoulder range of motion measurements have been associated with different injury risks and challenges in assessing rehabilitation progress. Variations in range of motion and torsion due to handedness in the asymptomatic professional population have yet to be investigated in the literature. HYPOTHESIS: No significant differences in glenohumeral range of motion and humeral torsion would exist between asymptomatic right- and left-handed professional pitchers. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: 217 Major League Baseball pitchers from a single organization were evaluated over a 7-year period between 2013 and 2020. Range of motion was measured with a standard goniometer. Ultrasound scanning was used to determine neutral position of the shoulder, and the degree of humeral torsion was measured with a goniometer. RESULTS: Right-handed pitchers demonstrated significantly greater values of glenohumeral external rotation (118.5° vs 112.7°; P < .001) in their throwing arms compared with their left-handed counterparts. Right-handed pitchers also showed greater values of glenohumeral internal rotation deficit (13.9° vs 4.8°; P < .001) and side-to-side differences in humeral retrotorsion (-23.1° vs -2.2°; P < .001). Left-handed pitchers demonstrated significantly greater flexion deficits in the throwing arm compared with their right-handed counterparts (7.5° vs 0.0°; P < .001). CONCLUSION: In the throwing arm, right-handed pitchers demonstrated significantly greater measures of external rotation, glenohumeral internal rotation deficit, and humeral retrotorsion compared with left-handed counterparts. Furthermore, right-handed pitchers demonstrated a significant side-to-side difference in retrotorsion, whereas left-handed pitchers did not. However, left-handed pitchers demonstrated a side-to-side shoulder flexion deficit that was not present in the cohort of right-handed pitchers. The correlation between humeral retrotorsion and increased external rotation indicates that osseous adaptations may play a role in range of motion differences associated with handedness. Additionally, these findings may explain observed differences in several throwing metrics between right- and left-handed pitchers. Knowledge of these differences can inform rehabilitation programs and shoulder maintenance regimens.

Agreement between intraoperative and magnetic resonance imaging assessments of rotator cuff pathology and 2 magnetic resonance imaging-based assessments of supraspinatus muscle atrophy.

Background: Magnetic resonance imaging (MRI)-based rotator cuff assessment is often qualitative and subjective; few studies have tried to validate such preoperative assessments. This study investigates relationships of preoperative MRI assessments made by conventional approaches to intraoperative findings of tear type, location, and size or MRI-assessed muscle occupation ratio. Methods: Intraoperatively, surgeons assessed tear type, location, anterior-posterior (AP) width, and medial-lateral length in 102 rotator cuff repair patients. Two musculoskeletal radiologists independently assessed the preoperative MRI scans for these same parameters and supraspinatus muscle atrophy by both Warner classification and quantitative occupation ratio. Exact agreement proportions, kappa statistics, and correlation coefficients were used to quantify agreement relationships. Results: Agreement between MRI readers' and surgeons' observations of tear status averaged 93% with κ = 0.38, and that of tear location averaged 77% with κ = 0.50. Concordance correlations of MRI and intraoperative measures of anterior-posterior and medial-lateral tear length averaged 0.59 and 0.56 across readers, respectively. Despite excellent interrater agreement on Warner classification (exact agreement proportion 0.91) and occupation ratio (concordance correlation 0.93) separately, correlations between these 2 measures were -0.54 and -0.64 for the 2 readers, respectively. Patients with Warner grade 0 had occupation ratios ranging from 0.5 to 1.5. Conclusion: Correlations of preoperative MRI tear dimensions and muscle atrophy assessed by conventional approaches with intraoperatively measured tear dimensions and quantitative occupation ratio, respectively, were only fair. Since tear size and muscle atrophy are known strong predictors of outcomes following rotator cuff repair that may influence treatment decisions, surgeons need to be aware of the limitations of MRI methods. Continued development and validation of quantitative preoperative imaging methods to accurately assess these parameters are needed to improve surgical planning and prognosis.

Diagnosis and Management of Subcoracoid Impingement.

Impingement of the subcoracoid space is a poorly understood pathologic cause of anterior shoulder pain. Because of its relative rarity in isolation and nonspecific presentation, diagnosis and management are often challenging for orthopaedic surgeons and their patients. Stenosis of the subcoracoid space between the lesser tuberosity and the coracoid process <6 mm can lead to anterior shoulder pain and associated rotator cuff and biceps pathology. Multiple imaging modalities are available to assess narrowing of the coracohumeral interval, each with its strengths and limitations. If the patient can be accurately diagnosed with subcoracoid impingement, both conservative and surgical management options are available. Despite earlier case series demonstrating promising results with arthroscopic treatment, comparative studies have yet to support these initial claims.

Shoulder MRI: what do we miss?

OBJECTIVE: Our aim is to review several shoulder abnormalities that are difficult to detect accurately on shoulder MRI, describe the technical reasons that limit their detection, and suggest imaging protocol modifications that may improve radiologists' accuracy. CONCLUSION: Although MRI is an excellent tool for detecting some abormalities, there are a number of subtler abnormalities of clinical significance that give radiologists greater difficulty. By understanding the reasons for limited detection and modifying protocols accordingly, radiologists may be able to improve identification, allowing more accurate clinical decision making.

Three-dimensional volume-rendering computed tomography for measuring humeral version.

HYPOTHESIS: Humeral version is highly variable in human beings. Accurate assessment of humeral version may allow for more anatomic reconstruction at shoulder arthroplasty. Two-dimensional (2D) computed tomography (CT) has been used to measure humeral version but has limitations of poor interobserver reproducibility and strict dependence on arm positioning during image acquisition. This study evaluated a new technique, 3-dimensional (3D) volume rendering, for measuring humeral version. MATERIALS AND METHODS: Eight dried human humerus specimens were included in the study. Gold standard measurements of humeral version were obtained by use of metallic beads and fluoroscopy. The specimens were then scanned at CT in 2 different positions, 1 neutral to the table and 1 angled at 20 degrees . The image data sets were used to measure humeral version in each bone with both the standard 2D technique and the new 3D technique. Measurements were performed by 3 readers at 2 different time points. Readers were blinded to the gold standard results and each others' measurements. RESULTS: For all readers, 3D measurements averaged within 4.3 degrees of the gold standard. For 2 of the 3 readers, 3D measurements were more accurate than 2D measurements. For all 3 readers, intraobserver variability was better with the 3D technique. For all reader pairs, interobserver variability was better with the 3D technique. CONCLUSIONS: This study shows a 3D volume-rendering CT technique to measure humeral version accurately and consistently that is independent of patient positioning.

Conditions and Injuries Affecting the Nerves Around the Elbow.

Sports-related peripheral neuropathies account for 6% of all peripheral neuropathies and most commonly involve the upper extremity. The routes of the median, radial, and ulnar nerves are positioned in arrangements of pulleys and sheaths to glide smoothly around the elbow. However, this anatomic relationship exposes each nerve to risk of compression. The underlying mechanisms of the athletic nerve injury are compression, ischemia, traction, and friction. Chronic athletic nerve compression may cause damage with moderate or low pressure for long or intermittent periods of time.

Machine Learning Outperforms Logistic Regression Analysis to Predict Next-Season NHL Player Injury: An Analysis of 2322 Players From 2007 to 2017.

BACKGROUND: The opportunity to quantitatively predict next-season injury risk in the National Hockey League (NHL) has become a reality with the advent of advanced computational processors and machine learning (ML) architecture. Unlike static regression analyses that provide a momentary prediction, ML algorithms are dynamic in that they are readily capable of imbibing historical data to build a framework that improves with additive data. PURPOSE: To (1) characterize the epidemiology of publicly reported NHL injuries from 2007 to 2017, (2) determine the validity of a machine learning model in predicting next-season injury risk for both goalies and position players, and (3) compare the performance of modern ML algorithms versus logistic regression (LR) analyses. STUDY DESIGN: Descriptive epidemiology study. METHODS: Professional NHL player data were compiled for the years 2007 to 2017 from 2 publicly reported databases in the absence of an official NHL-approved database. Attributes acquired from each NHL player from each professional year included age, 85 performance metrics, and injury history. A total of 5 ML algorithms were created for both position player and goalie data: random forest, K Nearest Neighbors, Naïve Bayes, XGBoost, and Top 3 Ensemble. LR was also performed for both position player and goalie data. Area under the receiver operating characteristic curve (AUC) primarily determined validation. RESULTS: Player data were generated from 2109 position players and 213 goalies. For models predicting next-season injury risk for position players, XGBoost performed the best with an AUC of 0.948, compared with an AUC of 0.937 for LR (P < .0001). For models predicting next-season injury risk for goalies, XGBoost had the highest AUC with 0.956, compared with an AUC of 0.947 for LR (P < .0001). CONCLUSION: Advanced ML models such as XGBoost outperformed LR and demonstrated good to excellent capability of predicting whether a publicly reportable injury is likely to occur the next season.

Epidemiology, Treatment, and Performance-Based Outcomes in American Professional Baseball Players With Symptomatic Spondylolysis and Isthmic Spondylolisthesis.

BACKGROUND: Repetitive lumbar hyperextension and rotation during athletic activity affect the structural integrity of the lumbar spine. While many sports have been associated with an increased risk of developing a pars defect, few previous studies have systematically investigated spondylolysis and spondylolisthesis in professional baseball players. PURPOSE: To characterize the epidemiology and treatment of symptomatic lumbar spondylolysis and isthmic spondylolisthesis in American professional baseball players. We also sought to report the return-to-play (RTP) and performance-based outcomes associated with the diagnosis of a pars defect in this elite athlete population. STUDY DESIGN: Descriptive epidemiology study. METHODS: A retrospective cohort study was conducted among all Major and Minor League Baseball (MLB and MiLB, respectively) players who had low back pain and underwent lumbar spine imaging between 2011 and 2016. Players with radiological evidence of a pars defect (with or without listhesis) were included. Analyses were conducted to assess the association between player-specific characteristics and RTP time. Baseball performance metrics were also compared before and after the injury episode to determine whether there was an association between the diagnosis of a pars defect and diminished player performance. RESULTS: During the study period of 6 MLB seasons, 272 professional baseball players had low back pain and underwent lumbar spine imaging. Overall, 75 of these athletes (27.6%) received a diagnosis of pars defect. All affected athletes except one (98.7%) successfully returned to professional baseball, with a median RTP time of 51 days. Players with spondylolisthesis returned to play faster than those with spondylolysis, MLB athletes returned faster than MiLB athletes, and position players returned faster than pitchers. Athletes with a diagnosed pars defect did not show a significant decline in performance after returning to competition after their injury episode. CONCLUSION: Lumbar pars defects were a common cause of low back pain in American professional baseball players. The vast majority of affected athletes were able to return to competition without demonstrating a significant decline in baseball performance.