Is Tommy John Surgery Performed More Frequently in Major League Baseball Pitchers From Warm Weather Areas?

Is Workload Associated With Oblique Injuries in Professional Baseball Players?

Background

Oblique strains have become a common injury among professional baseball players. The influence of player workload on oblique strains remains unknown.

Purpose/Hypothesis

To determine whether workload is a risk factor for oblique strains in professional baseball players. We hypothesized that fewer days of rest, more innings pitched/fielded per game, and more batters faced/plate appearances per game would significantly increase a player's risk of sustaining an oblique strain.

Study Design

Case-control study; Level of evidence, 3.

Methods

All professional baseball players who sustained an oblique strain between 2011 and 2017 were identified using the Major League Baseball Health and Injury Tracking System. A separate dataset of player usage-days of rest per game, innings pitched or fielded per game, and batters faced or plate appearances per game-was used to determine the workload. We compared these usage variables between player games ≤2, ≤6, ≤12, and >12 weeks before a documented oblique strain with player games from a control group of players with no oblique strains. In a paired analysis, we compared acute (player games ≤2, ≤6, and ≤12 weeks preinjury) versus chronic (player games >12 weeks preinjury) workloads.

Results

There were 311 oblique strains in pitchers and 392 oblique strains in position players during the study period. In pitchers, more innings pitched and more batters faced were associated with a subsequent oblique strain (P < .001 for all). In position players, fewer days of rest, more innings fielded, and more plate appearances were associated with a subsequent oblique strain (P < .001 for all). Pitchers who pitched ≥7 innings per game had a 2.4-fold (95% CI, 1.4-4.9) increased risk of subsequent oblique strain compared with those who pitched 1 inning per game. The percentage of position players with a subsequent oblique strain increased by 2.1-fold (95% CI, 1.3-3.5) with >4 plate appearances compared with 1 plate appearance per game.

Conclusion

Our analysis demonstrated that workload was associated with an increased risk of sustaining an oblique injury in professional baseball players. High workload over time was more predictive of oblique strains compared to acute increases over chronic baseline workload.

The influence of a single 30-pitch session on elbow laxity in adolescent and collegiate baseball pitchers

BACKGROUND

Ulnar collateral ligament (UCL) injuries are a source of significant injury among baseball players, and are increasingly evaluated under ultrasound. The purpose of this study is to determine the effect of a single session of pitching upon UCL thickness and laxity via a cross sectional, controlled ultrasonographic study. We hypothesize that a single session of pitching will cause the ulnar collateral ligament to thicken and become more lax.

METHODS

This was a cross sectional comparative study of collegiate and high school pitchers. Pitchers underwent an ultrasonographic assessment of the UCL before and after a thirty-pitch bullpen warm-up. Laxity was measured as the change in the distance between the ulna and the trochlea with and without a 5-pound weight held in hand with the elbow at 30° of flexion. Pre- and post-throwing UCL thickness and medial laxity were statistically compared with paired tests.

RESULTS

Our study included 15 pitchers, 8 collegiate and 7 high school level athletes. All played baseball at least 6 days a week, and nearly all played for at least 10 months a year. Pitchers reported a peak velocity of 89 ± 6 (77 to 98) miles per hour. In the prior season, these pitchers pitched 56 ± 33 (10 to 120) games, throwing 62 ± 34 (25-140) pitches per game on average. After throwing, there was significantly less UCL laxity (P = .013). Post-throwing laxity was significantly positively correlated with both peak pitch velocity (P = .009) and an average number of pitches thrown per game (P = .10).

CONCLUSION

Throwing 30 pitches significantly decreases medial elbow laxity with stress, possibly due to flexor-pronator activation. Post-throwing medial laxity is correlated with both peak pitch velocity and average number of pitches thrown per game. Future studies should be conducted to determine the number of throws at which laxity begins to increase, as this may provide a workload management guideline for injury prevention.

Impact of Climate on Stress Ultrasound Findings of the Elbow Ulnar Collateral Ligament in Professional Baseball Pitchers: An 18-Year Study

Background

The ulnar collateral ligament (UCL) is the primary soft tissue stabilizer to valgus stress in the elbow and is placed under this valgus stress during the throwing motion. Although there are known risk factors for UCL injury, it is unknown whether the UCL undergoes adaptive changes in athletes from different climates.

Purpose

To compare elbow stress ultrasound (SUS) findings between professional baseball pitchers from warm climates versus cold climates and assess significant differences in adaptive and morphologic changes in the UCL.

Study Design

Cross-sectional study; Level of evidence, 3.

Methods

Dynamic SUS evaluations were performed over 18 years on the dominant and nondominant arms of 643 professional pitchers from warm and cold climates as determined by the player's country/state of origin. Studies were compared with respect to relative UCL thickness (dominant arm vs nondominant arm), relative glenohumeral joint laxity (joint space distance under stress vs joint space distance at rest), and the presence of morphologic changes such as tears or calcifications. In addition, a subgroup analysis was performed to compare the progression of SUS findings over 3 years in players with sequential yearly data.

Results

Players from warmer climates had significantly greater relative UCL thicknesses than players from colder climates (1.75 vs 1.50 mm, respectively; P = .047). There were no differences between these 2 groups in terms of relative ulnohumeral joint laxity (P = .201), presence of morphologic changes (P = .433), 3-year progression of relative UCL thickness (P = .748), or relative joint laxity (P = .904).

Conclusion

Professional pitchers from warm climates had a greater side-to-side difference in UCL thickness between the dominant and nondominant arms. This may be due to the potential for year-round throwing among baseball players from warm climates. There was no difference in laxity, thickness progression, laxity progression, or the presence of additional morphologic changes.

The 50 most impactful articles on the medial ulnar collateral ligament: An altmetric analysis of online media

The purpose of this study was to use the Altmetric Attention Score to determine the 50 most impactful medial ulnar collateral ligament articles in online media and compare their characteristics to the most-cited medial ulnar collateral ligament articles in the scientific literature. The Altmetric database was queried to identify all published articles about the medial ulnar collateral ligament, and this list was stratified by the Altmetric Attention Score to identify the 50 highest scoring articles. Several data elements were extracted, including article topic, article type, journal name, and the number of online mentions on Facebook, Twitter, news, and other platforms. Each article's geographic origin was determined based on the institutional affiliation of the first author. Our index search yielded 1283 articles published between 1987 and 2020, from which the 50 articles with the highest Altmetric Attention Scores were included for analysis. Altmetric Attention Scores of the top 50 medial ulnar collateral ligament articles ranged from 20 to 482 (median: 32, interquartile range: 20-62). The most common article type was original research (72%), and the most common topic was epidemiology/risk factors (26%). A majority of studies were Level 3 (36%) or Level 4 evidence (36%). Of the top 50 medial ulnar collateral ligament articles, 94% originated from the United States. A few articles had a high Altmetric Attention Score, suggesting that medial ulnar collateral ligament research does not generate consistently high online attention. The lack of Level 1 studies suggests the need for high-level studies on the medial ulnar collateral ligament. Most studies originated in the United States and were published in the American Orthopaedic Society for Sports Medicine-affiliated journals. The medial ulnar collateral ligament articles included in this study differed substantially from a previous report of the most-cited medial ulnar collateral ligament articles in the literature, suggesting that alternative metrics add a unique dimension to understanding the overall impact of published research on the medial ulnar collateral ligament.

How does the All-Star break affect injury rates in professional baseball?

Background

Injury rates in professional baseball players are increasing. It is unclear if the time of rest from the All-Star break affects injury risk.

Methods

Every professional baseball game (A-, A+, AA, AAA, and Major League Baseball) played between 2011 and 2017 was included. Each game was then classified as control game (games played in April, May, June, and September) or game within one month after the All-Star break. Incidence of injuries in games within one month of the All-Star break was compared with the control games.

Results

Our analysis included 66,642 games: 46,630 control games and 20,012 games played within one month after the All-Star break. On univariate analysis, there was a mean ± standard deviation of 0.45 ± 0.72 injuries per game in control games and 0.41 ± 0.68 injuries per game in games played within one month after the All-Star break (P<.001). On multivariate analysis, there was a significant association between games played within one month after the All-Star break and number of injuries per game (P<.001) after adjusting for the level of play and game duration. However, the effect size was 0.001, suggesting this effect is clinically insignificant.

Conclusion

There does not appear to be a clinically significant difference in injury rates per game in professional baseball players between games played in the month after the All-Star break and all other games played during the season. Although the All-Star break provides most players with a chance to rest, it does not appear to have an effect on injury rates.

Trends in Medial Ulnar Collateral Ligament Repair and Reconstruction From 2007 to 2016: A Population-Based Study of a Large Private Insurance Database

Background: Ulnar collateral ligament (UCL) reconstruction and UCL repair of the elbow are commonly performed procedures, resulting in high return-to-play rates. Whether the incidence rate of UCL reconstruction vs UCL repair has changed over time is not currently known. Purpose/Questions: We sought to assess temporal trends in the incidence rates of UCL repair and UCL reconstruction and to identify factors associated with UCL reconstruction. We hypothesized that UCL repair would demonstrate an increased incidence overall in recent years with an associated decline in UCL reconstruction rates. Methods: Using the PearlDiver Research Program to query the Humana administrative claims database, we identified patients who had undergone UCL repair and/or reconstruction from 2007 to 2016. Patients were stratified by age (15-19; 20-29; 30-49 years), sex, and year (2007-2011 vs 2012-2016). Poisson regression analysis (continuous variables) was used to calculate the incidence risk ratio (IRR); chi-square tests were performed for categorical variables, and odds ratios were calculated with 95% confidence intervals (CI). Results: The incidence rate of UCL repair was greater in 2012-2016 than in 2007-2011 (IRR: 1.86, 95% CI: 1.16-2.96). The incidence rate of UCL reconstruction vs UCL repair was greater for patients aged 15 to 19 years (IRR: 3.37, 95% CI: 1.97-5.77) but not patients aged 20 to 29 years (IRR: 0.89, 95% CI: 0.49-1.59) as compared with patients aged 30 to 49. Males aged 19 years were more likely than females to undergo UCL reconstruction (IRR: 10.09, 95% CI: 1.37-3.45). Conclusion: While UCL procedures are becoming more popular, our retrospective analysis showed that young males are preferentially treated with UCL reconstruction, warranting further investigation into these trends.

Effect of COVID-19 on Ulnar Collateral Ligament Reconstruction in Major League Baseball Pitchers

Background:

The coronavirus disease of 2019 (COVID-19) pandemic led to the suspension and shortening of the 2020 Major League Baseball (MLB) season from 162 to 60 regular season games. The effect of this disruption on injury rates, specifically injury to the ulnar collateral ligament (UCL), has not been quantified.

Purpose/Hypothesis:

The purpose of this study was to compare the rate of UCL reconstruction (UCLR), surgery timing, and pitching workload in MLB pitchers from before and after the COVID-19 pandemic lockdown. We hypothesized that UCLR rates relative to games played would be increased and pitching workload would be decreased in 2020 compared with previous seasons.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

An extensive online search using publicly available data was conducted to identify all MLB pitchers who underwent UCLR between January 1, 2017, and December 31, 2020. Only pitchers who were competing at the MLB level when undergoing reconstruction were included. Player characteristics and surgery date, as well as career and season of surgery pitching workload, were collected for all included pitchers. All data were compared as a pooled sample (2017-2019 vs 2020).

Results:

A similar number of pitchers underwent UCLR during or after the 2020 regular season (n = 18) compared with the 2017-2019 seasons (n = 16, 20, and 16, respectively). However, after accounting for the decrease in games played during the 2020 regular season, an MLB pitcher was 2.9 times more likely to undergo surgery per game after the COVID-19 lockdown compared with the previous years (P < .001). MLB pitchers who underwent surgery in 2020 threw fewer preseason innings than did pitchers who underwent surgery between 2017 and 2019 (5.98 vs 9.39; P = .001).

Conclusion:

MLB pitchers were almost 3 times more likely to undergo UCLR per game after the COVID-19 lockdown. A decreased preseason pitching workload because of the COVID-19 lockdown may have had an effect on per game UCLR rates.

Short-Term Trends in Elbow Ulnar Collateral Ligament Surgery in Collegiate Baseball Players: An Analysis of 25,587 Player-Years

Background

Trends over time in the incidence of ulnar collateral ligament (UCL) surgeries in National Collegiate Athletic Association Division I baseball players are currently unknown.

Purpose/Hypothesis

The purpose of this study was to evaluate the trends in UCL surgeries over 3 years in Division I baseball programs. We hypothesized that surgical injuries would be consistently high over the course of the study.

Study Design

Descriptive epidemiology study.

Methods

Athletic trainers from Division I baseball programs were invited to participate in an electronic survey over 3 seasons. A total of 155 baseball programs agreed to participate in 2017, 294 programs participated in 2018, and 296 programs participated in 2019. After each of the 3 collegiate baseball seasons, the athletic trainer from each program entered anonymous, detailed descriptive data and surgical information on injured players into a secured database.

Results

During the 3 years of this study, 100% of the enrolled programs successfully completed the survey (155/155 in year 1, 294/294 in year 2, and 296/296 in year 3). This registry of 745 completed surveys over 3 years represented 25,587 player-years from Division I collegiate baseball. The percentage of programs with at least 1 UCL surgery during this time was 57% in 2017, 51% in 2018, and 49% in 2019. The majority of these players were pitchers (84% overall from the 3 years). Seniors underwent a significantly lower percentage of the UCL surgeries (8% in 2017, 10% in 2018, and 13% in 2019) than did underclassmen. Surgeries were performed most often in-season and least often during the preseason. A slight majority of players undergoing surgery originated from warm-weather states, but the number of these players was never significantly higher than was the number of players from cold-weather states. Most surgeries performed each year were UCL reconstruction, but the percentage of UCL repair with ligament augmentation increased each year (10% UCL repairs in 2017, 20% in 2018, and 25% in 2019).

Conclusion

UCL injuries requiring surgery were found to be a major source of morbidity in Division I collegiate baseball, supporting our hypothesis. This study can serve as a baseline for tracking long-term trends in UCL surgeries in collegiate baseball.

Increase in Use of Medial Ulnar Collateral Ligament Repair of the Elbow: A Large Database Analysis

Purpose

To assess the current national rate of medial ulnar collateral ligament (MUCL) repair of the elbow and delineate the patient demographics of those undergoing repair.

Methods

A retrospective review and analysis of a national private insurance database was conducted covering 2007-2017 using Pearl Diver technologies. All patients diagnosed with a MUCL injury and those who underwent repair were included using Clinical Modification and Current Procedural Terminology code 24345, referencing repair of the ulnar collateral ligament of the elbow with local tissue. The extracted data included patient age at time of procedure, sex, race, region, year of surgery, insurance type, hospital setting, and any associated diagnoses with 90 days of the repair procedure. Standard descriptive methods characterized our study sample to calculate frequency counts and percentages. Means with respective standard deviations and/or standard errors, and 95% confidence intervals were calculated and reported for continuous variables, whereas frequencies and percentages were reported for categorical variables. Pearson χ² tests were used to determine differences between group proportion categorical variables. Significance was considered at a P ≤ .05.

Results

From 2007 to 2014, MUCL injuries showed an upward trend in incidence per 100,000 from 4.59 to 7.19 (56% increase) within the database population. Accordingly, the incidence of MUCL repair rose from 0.016 to 0.49 (2962%). However, from 2015-2017 there was a drop in both categories, as injury incidence fell from 7.19 to 1.48 whereas repair rates dropped from 0.49 to 0.012. The ages undergoing repair show a significant peak in 15-24-year-olds. The incidence of MUCL repair was greatest in the West and South (P < .01). Male patients had a greater incidence of MUCL injury, and a greater incidence of MUCL repair per 100,000 persons compared to females (P < .01).

Conclusions

MUCL repair has emerged as a viable alternative to reconstruction in select indications. The impetus for this change may be to provide a quicker return to sport and fewer complications, largely due to recent improvements in surgical technique for MUCL repair. As anticipated, the incidence of MUCL repair had steadily increased in the United States from 2007 to 2014, with a subsequent relatively inexplicable decrease primarily in 2017, according to the database utilized in this study. The 15-24 year-old age group encompassing young athletes has the greatest incidence of repair by a significant margin.

Level of Evidence

IV, Therapeutic Case Series.

Limiting the Pitch Count in Youth Baseball Pitchers Decreases Elbow Pain

Background

Reducing the number of pitches thrown is regarded as the most effective way to prevent throwing injuries in youth baseball pitchers. However, few studies have compared the effectiveness of limiting the pitch count versus the limiting the number of innings pitched in terms of elbow injuries.

Hypothesis

We hypothesized that, compared with inning limits, pitch count limits would lead to greater decreases in elbow pain, range of motion deficits, positive moving valgus stress test results, and the risk of capitellar osteochondritis dissecans (OCD).

Study Design

Cohort study; Level of evidence, 3.

Methods

This study retrospectively reviewed baseball pitchers aged 8 to 12 years in 2017 and 2018. Inning and pitch count limits in games were set to a daily maximum of 7 innings in 2017 and 70 pitches in 2018. Elbow pain, range of motion, and moving valgus stress test results were evaluated. The presence of capitellar OCD was assessed on ultrasonographic and radiographic images.

Results

A total of 352 pitchers in 2017 and 367 pitchers in 2018 participated. The mean pitch count per game was lower in the pitch count limit (CL) group (52.5 ± 16.0) than in the inning limit (IL) group (98.2 ± 19.5) (P < .001). Compared with the IL group, the CL group had significantly lower rates of elbow pain (40.9% vs 31.9%, respectively; P = .01) and reduced flexion (19.0% vs 10.6%, respectively; P = .001). Multivariate analysis revealed a significant association between elbow pain and age in both the IL and the CL groups (P < .0001 and P = .02, respectively) and between OCD and elbow pain in the CL group (P = .04).

Conclusion

A pitch count limit of ≤70 pitches per day for baseball pitchers ≤12 years could be more protective against elbow pain and reduced flexion than a limit of ≤7 innings per day, but it may not be effective for reducing the risk of capitellar OCD.

Grip strength is not related to increased medial elbow joint-space gapping induced by repetitive pitching

BACKGROUND

Pitching induces elbow valgus stress, which can lead to an increase in medial elbow joint-space gapping when repeated. Previous basic research on the medial elbow joint shows that the contraction associated with gripping reduces medial elbow joint-space gapping. However, no studies have investigated the relationship between grip strength and increased medial elbow joint-space gapping during repetitive pitching. The purpose of this study was to investigate whether grip strength is related to medial elbow joint-space gapping during repetitive pitching. Our hypothesis was that increased grip strength would correlate with a reduction in medial elbow joint-space gapping.

METHODS

A total of 25 high school baseball players participated in this study. Each subject pitched 100 times. The medial elbow joint-space gapping and grip strength were measured before and after pitching. Correlation analysis was used to identify the relationship between medial elbow joint-space gapping and grip strength.

RESULTS

Medial elbow joint-space gapping (mm) increased by 25.5% ± 8.0% after 100 pitches (gapping before, 5.0 ± 0.9; gapping after, 6.2 ± 1.1; P < .001). Grip strength (kg) after 100 pitches decreased by 2.8% ± 7.4% to that before pitching (before, 40.4 ± 5.5; after 39.2 ± 5.6; P < .05). There was no significant correlation between the change rate of medial elbow joint gapping and grip strength at any time (grip strength: before pitching, P = .74; after pitching, P = .40; change rate from before to after pitching, P = .24).

CONCLUSIONS

Grip strength is not related to increased medial elbow joint-space gapping induced by repetitive pitching. This indicates that physical ability expressed by grip strength is not associated with preventing increases in medial elbow joint-space gapping during repetitive pitching. Further studies are required to investigate the stabilization mechanism of the medial elbow joint during pitching.

Incidence and risk factors for musculoskeletal disorders of the elbow in baseball pitchers: a systematic review of the literature

OBJECTIVE

To determine the incidence and risk factors of musculoskeletal disorders of the elbow in baseball pitchers.

DESIGN

Systematic review.

DATA SOURCES

Medline, CINAHL, Cochrane, PubMed and SportDiscus from onset to July 7, 2018.

ELIGIBILITY CRITERIA

Eligible studies included randomized controlled trials, cohort studies and case-control studies. Independent pairs of reviewers screened titles and abstracts for eligibility. Relevant articles were critically appraised for internal validity using the SIGN criteria. We included low risk of bias studies in our best evidence synthesis.

RESULTS

We retrieved 4502 articles, 39 were critically appraised and nine had a low risk of bias. These were included in the evidence synthesis. The incidence of musculoskeletal disorders of the elbow ranges from 2.3% in adolescent pitchers to 40.6% in youth pitchers. Evidence suggests that pitch characteristics, inadequate rest, biomechanical and anthropometric factors may be risk factors of UCL tears.

SUMMARY/CONCLUSION

Baseball pitchers develop musculoskeletal disorders of the elbow. There is little high-quality evidence to understand the etiology. Preliminary evidence suggests the risk factors are multifactorial.PROSPERO Trial Registration Number: CRD42018092081.

Sport specialization is associated with upper-extremity overuse injury in high school baseball players

BACKGROUND AND HYPOTHESIS

Sport specialization is increasingly common in youth sports and is a risk factor for lower-extremity overuse injuries. However, limited data exist on whether specialization is associated with upper-extremity (UE) overuse injuries, specifically in youth baseball players. We hypothesized that specialization in baseball and being a pitcher would be associated with poorer arm health and UE overuse injury history in the previous year.

METHODS

During the 2019 spring baseball season, 551 high school baseball athletes (aged 15.9 ± 1.3 years) from 3 states (Alabama, n = 200; California, n = 188; and Michigan, n = 163) completed an anonymous questionnaire. Athletes were recruited from 5 high schools in each state, with schools matched based on factors that influence specialization rates. The questionnaire consisted of (1) demographic characteristics, (2) baseball participation information (including sport specialization status), and (3) throwing-arm health and UE injury history in the previous 12 months. Throwing-arm health was assessed using the Youth Throwing Score (YTS), a validated and reliable outcome measure for youth baseball players. Multivariate regression analyses were used to examine the association between variables of interest and the YTS or UE overuse injury history, adjusting for covariates.

RESULTS

After adjustment for covariates, highly specialized athletes were more likely to report a UE overuse injury in the previous year compared with low-specialization athletes (odds ratio [OR], 3.77; 95% confidence interval [CI], 1.39-10.2, P = .009). Both athletes who reported playing baseball for more than 8 months per year (OR, 2.03; 95% CI, 1.12-3.65; P = .019) and athletes who reported being a pitcher (OR, 2.11; 95% CI, 1.20-3.72; P = .010) were more likely to report a history of UE overuse injury. Highly specialized players reported lower (worse) YTS values compared with low-specialization players (least-squares mean estimate ± standard error, 56.5 ± 1.1 vs. 53.3 ± 0.7; P = .034). Players who reported pitching as one of their positions scored worse on the YTS than non-pitchers (least-squares mean estimate ± standard error, 51.6 ± 0.8 vs. 57.2 ± 0.6; P < .001).

CONCLUSION

Although baseball recommendations that discourage sport specialization are widely available for parents, athletes, and coaches, high rates of sport specialization were reported in our sample. We found that being highly specialized in baseball was associated with UE overuse injury history and worse throwing-arm health in high school baseball athletes. Continued education for baseball parents, athletes, and coaches is necessary to raise awareness of the risks associated with high specialization.

Youth Single-Sport Specialization in Professional Baseball Players

Background:

An increasing number of youth baseball athletes are specializing in playing baseball at younger ages.

Purpose:

The purpose of our study was to describe the age and prevalence of single-sport specialization in a cohort of current professional baseball athletes. In addition, we sought to understand the trends surrounding single-sport specialization in professional baseball players raised within and outside the United States (US).

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

A survey was distributed to male professional baseball athletes via individual team athletic trainers. Athletes were asked if and at what age they had chosen to specialize in playing baseball at the exclusion of other sports, and data were then collected pertaining to this decision. We analyzed the rate and age of specialization, the reasons for specialization, and the athlete’s perception of injuries related to specialization.

Results:

A total of 1673 professional baseball athletes completed the survey, representing 26 of the 30 Major League Baseball (MLB) organizations. Less than half (44.5%) of professional athletes specialized in playing a single sport during their childhood/adolescence. Those who reported specializing in their youth did so at a mean age of 14.09 ± 2.79 years. MLB players who grew up outside the US specialized at a significantly earlier age than MLB players native to the US (12.30 ± 3.07 vs 14.89 ± 2.24 years, respectively; P < .001). Additionally, MLB players raised in the US recalled a significantly higher incidence of sustaining an injury attributed to specializing in baseball than MLB athletes raised outside the US (27.7% vs 20.6%, respectively; P = .05).

Conclusion:

This study challenges the current trends toward early youth sport specialization, finding that the majority of professional baseball athletes studied did not specialize as youth and that those who did specialize did so at a mean age of 14 years. With the potential cumulative effects of pitching and overhead throwing on an athlete’s arm, the trend identified in this study toward earlier specialization within baseball is concerning.

Pitch count adherence and injury assessment of youth baseball in South Carolina

Introduction

Overuse injury in youth overhead athletes remains a concern. The introduction of pitch count guidelines was designed to limit the number of pitches per game. South Carolina is considered a warm weather climate which has been proven to expose overhead athletes to higher risk for injury. The purpose of this study was to detect baseline rates of arm pain and sequelae (injury, surgery, impact on participation) among southern youth baseball/softball players to better counsel players, parents, coaches and league administration on the prevention of arm injury.

Methods

A survey was distributed to 14 pediatric practices within the South Carolina Pediatric Practice Research Network. The 2-page survey included 28 closed-ended and descriptive questions that investigated physical and psychosocial responses during and after play. Additional questions were conducted on adherence and understanding of USA Baseball guidelines and pitch counting behavior.

Results

Two hundred and seventy three surveys were completed by parents of baseball/softball players. The players' average age was 11.6 years, who played on an average of 1.78 teams/leagues for 5.2 months each year. Only 26% of baseball players answered "Sometimes", "Often" or "Always" to their arm hurting. Arm fatigue, older age, parent/coach frustration with play, and months played were statistically significantly associated with arm pain. The survey revealed 58.9% of families were familiar with pitch count guidelines.

Discussion

Arm pain is relatively prevalent among the South Carolina youth baseball community and worse in older players and experience fatigue. This survey found lower percentage of youth overhead athletes experiencing arm discomfort when compared to prior studies. It is important for warm weather climate athletes to abide by guidelines, as they are more susceptible to arm injury. Increased recognition, education and compliance with pitch count guidelines will help protect these youth athletes from overuse injury.

Level of evidence

IV, Descriptive Epidemiology Study.

Progressive Elbow Magnetic Resonance Imaging Abnormalities in Little League Baseball Players Are Common: A 3-Year Longitudinal Evaluation

BACKGROUND

Prior studies have revealed magnetic resonance imaging (MRI) evidence of elbow pathology in single-season evaluation of competitive youth baseball players. The natural history of these findings and risk factors for progression have not been reported.

PURPOSE

To characterize the natural history of bilateral elbow MRI findings in a 3-year longitudinal study and to correlate abnormalities with prior MRI findings, throwing history, playing status, and physical examination.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

A prospective study of Little League players aged 12 to 15 years was performed. All players had preseason and postseason bilateral elbow MRI performed 3 years before this study. Players underwent repeat bilateral elbow MRI, physical examination, and detailed assessment of throwing history, playing status, and arm pain. Imaging was read by a blinded musculoskeletal radiologist and compared with prior MR images to assess for progression or resolution of previously identified pathology.

RESULTS

All 26 players who participated in the previous single-season study returned for a 3-year assessment. At the completion of the study, 15 players (58%) had dominant arm MRI pathology. Eighty percent (12/15 players) of MRI findings were new or progressive lesions. Players with postseason MRI pathology at the beginning of the study were more likely to have MRI pathology at the 3-year follow-up than players with previously normal postseason MRI (P < .05), although 6 of the 14 players (43%) with previously normal MRI developed new pathology. Year-round play was a significant predictor of tenderness to elbow palpation (P = .027) and positive MRI findings at 3 years (P = .047). At the 3-year follow-up, 7 players (27%) reported having throwing elbow pain and 3 had required casting. Additionally, differences were noted in the dominant arm's internal and external rotation in those that continued to play baseball (P < .05).

CONCLUSION

Dominant elbow MRI abnormalities are common in competitive Little League Baseball players. Year-round play imparts significant risk for progression of MRI pathology and physical examination abnormalities.

Management of Ulnar Collateral Ligament Injuries in Overhead Athletes

Ulnar collateral ligament injuries of the elbow are frequent among overhead athletes. The incidence of ulnar collateral ligament reconstructions (UCLRs) in high-level players has increased dramatically over the past decade, but the optimal technique of UCLR is controversial. Surgeons need to manage the patients’ expectations appropriately when considering the mode of treatment. This article reviews current studies on the management of ulnar collateral ligament injuries, particularly in overhead athletes.

UCL Injury in the Non-throwing Athlete

PURPOSE OF REVIEW

Primarily reported in the overhead throwing athlete, ulnar collateral ligament (UCL) injuries have been extensively studied since Dr. Frank Jobe first described his technique for ulnar collateral ligament reconstruction on professional baseball pitcher Tommy John. While the framework for our understanding of UCL injury was initially established studying the repetitive valgus loading of the throwers' elbow, other sport-related activities in non-throwing athletes can impart similar valgus stress on the medial elbow placing the UCL at risk for injury. The purpose of this review is to evaluate the current literature on UCL injury specifically in the non-throwing athlete.

RECENT FINDINGS

In the four decades since Dr. Jobe's seminal description of UCL reconstruction, an abundance of literature has been published on UCL injury in the throwing athlete. The evidence evaluating the UCL specifically in the non-throwing athlete, however, is quite scarce. Several small retrospective studies have demonstrated good results with high rates of return to play with focused rehabilitation and non-operative management in non-throwing athletes. Recent evidence has also demonstrated that surgical repair and/or reconstruction of the UCL in this population can produce good outcomes. The level of evidence of these published studies is low and consists primarily of case series without control groups. Further investigation is warranted to determine the optimal treatment algorithm for UCL injury in the non-throwing athlete.

Advanced Baseball Metrics Indicate Significant Decline in MLB Pitcher Value After Tommy John Surgery

There are conflicting reports regarding the efficacy of Major League Baseball (MLB) pitchers following medial ulnar collateral ligament reconstruction (UCLR). As advanced baseball metrics have revolutionized the way general managers define pitchers' value, the authors believe that these should be used to measure clinical outcomes after UCLR. All MLB pitchers who underwent UCLR from April 1, 1991, through July 1, 2016, were compiled (N=253). Pitcher demographics and statistics were collected for up to 3 full seasons preceding and following surgery. Data for pitching controls (all MLB [AMLB] pitchers) were also collected (N=14,756). Prior to surgery, pitchers with UCLR were significantly better than the AMLB pitchers in nearly all advanced value-based statistics: higher wins above replacement (WAR; 0.93 vs 0.78; 95% confidence interval [CI], 0.80-1.06), lower fielding independent pitching (FIP; 4.23 vs 4.51; 95% CI, 4.12-4.34), lower expected fielding independent pitching (xFIP; 4.17 vs 4.38; 95% CI, 4.06-4.28), higher win probability added (WPA; 0.21 vs 0.05; 95% CI, 0.1-0.32), and higher leverage index (pLI; 1.03 vs 0.96; 95% CI, 0.99-1.06). Pitchers who returned to play after UCLR demonstrated significantly lower value with worse WAR, FIP, WPA, and pLI (P<.05). Conversely, after excluding pitchers who failed to achieve a sustained return to play of greater than 1 year, there were no significant decreases in value after surgery. The authors conclude that, prior to injury, pitchers who have UCLR are more valuable than average MLB pitchers. However, UCLR pitchers perform worse when compared with their presurgical values. This may be affected by players not being able to continue their careers for more than 1 year. [Orthopedics. 2019; 42(6):349-354.].

Do Professional Baseball Players With a Higher Valgus Carrying Angle Have an Increased Risk of Shoulder and Elbow Injuries?

Background:

There are many risk factors for shoulder and elbow injuries in professional baseball pitchers. The elbow carrying angle has not been studied as a potential risk factor.

Purpose/Hypothesis:

The aim of this study was to determine whether elbow carrying angle is a risk factor for shoulder or elbow injuries in professional baseball pitchers. We hypothesized that pitchers with a higher elbow carrying angle would be less likely to sustain an injury during the season than pitchers with a lower elbow carrying angle.

Study Design:

Cohort study; Level of evidence, 2.

Methods:

All professional pitchers for a single baseball club during the 2018 season had the carrying angle of both elbows measured at spring training by a single examiner. The pitchers were followed prospectively throughout the season. Shoulder and elbow injuries were recorded prospectively.

Results:

A total of 52 pitchers (21 [40%] Major League Baseball and 31 [60%] Minor League Baseball) were included. During the season, 23 (44%) pitchers became injured. The mean carrying angle in the throwing arm was 12.5° ± 4.2° versus 9.9° ± 2.8° in the nonthrowing arm (P < .001). Comparing the injured and noninjured groups, there were no differences in level of play (P = .870), throwing hand dominance (P = .683), batting hand dominance (P = .554), throwing-side carrying angle (P = .373), nonthrowing-side carrying angle (P = .773), or side-to-side difference in carrying angle (P = .481).

Conclusion:

The elbow carrying angle was not associated with an injury risk during a single season in professional baseball pitchers.

Professional and Amateur Pitchers' Perspective on the Ulnar Collateral Ligament Injury Risk

Background

Medial ulnar collateral ligament (UCL) injury is increasingly prevalent in professional baseball pitchers, and significant research has been devoted to understanding the risk factors and prevention strategies associated with it. To date, no study has investigated what the players themselves believe causes and prevents the injury.

Purpose

To evaluate the opinions of UCL injuries among pitchers, including professional athletes.

Study Design

Cross-sectional study.

Methods

A total of 214 baseball pitchers (45 high school/college, 169 Major League Baseball [MLB]/Minor League Baseball) completed a 52-item questionnaire designed to evaluate their opinions on the cause of UCL injuries, injury prevention, and Tommy John surgery. Overall, 51 of the 214 pitchers had previously experienced a UCL injury. The frequency of the selection of each answer option was measured. Additionally, chi-square tests were used to compare (1) responses between professional and nonprofessional pitchers and (2) responses between pitchers with and without a previous UCL injury.

Results

Only 45% of pitchers thought that UCL injuries are avoidable in MLB. Additionally, 55% of pitchers with a UCL injury had a history of elbow injuries as an adolescent/child, compared with 18% in the uninjured group (P < .0001). Also, 72% of all surveyed pitchers agreed that fatigue over the course of a season increases the risk of UCL injuries, and the majority of pitchers agreed that inadequate rest from throwing both during the off-season (61%) and the season (59%) increases the risk of UCL injuries. Moreover, 59% of pitchers believed that a 6-man starting rotation would decrease the incidence of UCL injuries. Professional and nonprofessional pitchers significantly differed (P = .005) in the type of pitch most prone to causing UCL injuries.

Conclusion

Pitchers with a previous childhood elbow injury had a significantly higher incidence of UCL injuries during their adult career, suggesting possible predisposition to UCL injury and warranting further research. Fatigue and inadequate rest were of greatest concern among all pitchers for an increased risk of UCL injuries. Understanding and acknowledging the opinions that players have regarding UCL injuries are important to improve UCL education, prevention, and treatment.

Epidemiology of Shoulder Surgery Among Professional Baseball Players

BACKGROUND

Injuries remain a significant problem for professional baseball players. There is little information regarding the incidence and outcomes of shoulder surgical procedures among these athletes.

PURPOSE/HYPOTHESIS

To report the incidence, pathology, procedure type, demographics, and return-to-sport (RTS) rate of shoulder surgery among Major League Baseball (MLB) players. Most shoulder procedures would be performed on pitchers with a history of injury; the labrum would be the most commonly involved; and that the RTS rate would be >50%.

STUDY DESIGN

Descriptive epidemiology study.

METHODS

All MLB players who underwent surgery between 2012 and 2016 were identified from a database prospectively maintained by MLB. Demographic information and details regarding the procedure were recorded and RTS rates determined. Only those players with a minimum 2-year follow-up were included.

RESULTS

There were 581 shoulder procedures performed (542 players; pitchers, 60%; incidence, 1.48%). Overall, 19% of surgical procedures were performed on major league players and 81% on minor league players. Most players were between 20 and 25 years old. The majority of procedures were performed on the posterior and anterior labrum. Of these, 67% involved labral repair. Within rotator cuff surgery, 84% involved debridement; most tears were articular sided (87%); and 75% involved the supraspinatus. Overall, 11% of players had prior shoulder surgery, and 76% spent time on the disabled list before surgery. The overall rate of RTS was 63%. Of those who returned, 86% returned to at least the same level of play or higher as before surgery. Of those who returned to their prior level of play, 73% later ascended to a higher level of play or could not ascend to a higher level because they were already in the majors.

CONCLUSION

Shoulder surgery is uncommon among professional baseball players. Of those players who require surgery, the majority are pitchers and minor league players. Most procedures involve the labrum. Rotator cuff tears are mostly articular-sided supraspinatus tears. The overall RTS rate is 63%. Of those who return, 86% are able to return to the same or higher level of play as before surgery.

The First Decade of Web-Based Sports Injury Surveillance: Descriptive Epidemiology of Injuries in US High School Boys' Baseball (2005-2006 Through 2013-2014) and National Collegiate Athletic Association Men's Baseball (2004-2005 Through 2013-2014)

CONTEXT

The advent of Web-based sports injury surveillance via programs such as the High School Reporting Information Online system and the National Collegiate Athletic Association Injury Surveillance Program has aided the acquisition of boys' and men's baseball injury data.

OBJECTIVE

To describe the epidemiology of injuries sustained in high school boys' baseball in the 2005-2006 through 2013-2014 academic years and collegiate men's baseball in the 2004-2005 through 2013-2014 academic years using Web-based sports injury surveillance.

DESIGN

Descriptive epidemiology study.

SETTING

Online injury surveillance from baseball teams in high school boys (annual average = 100) and collegiate men (annual average = 34).

PATIENTS OR OTHER PARTICIPANTS

Boys' or men's baseball players who participated in practices and competitions during the 2005-2006 through 2013-2014 academic years in high school or the 2004-2005 through 2013-2014 academic years in college, respectively.

MAIN OUTCOME MEASURE(S)

Athletic trainers collected time-loss injury and exposure data. Injury rates per 1000 athlete-exposures (AEs) were calculated. Injury rate ratios (IRRs) with 95% confidence intervals (CIs) compared injury rates by school size or division, time in season, event type, and competition level.

RESULTS

The High School Reporting Information Online system documented 1537 time-loss injuries during 1 573 257 AEs; the National Collegiate Athletic Association Injury Surveillance Program documented 2574 time-loss injuries during 804 737 AEs. The injury rate was higher in college than in high school (3.20 versus 0.98/1000 AEs; IRR = 3.27; 95% CI = 3.07, 3.49). The competition injury rate was higher than the practice injury rate in high school (IRR = 2.27; 95% CI = 2.05, 2.51) and college (IRR = 2.32; 95% CI = 2.15, 2.51). Baseball players at the high school and collegiate levels sustained a variety of injuries across the body, with the most common injuries reported to the upper extremity. Many injuries also occurred while fielding or pitching.

CONCLUSIONS

Injury rates were greater in collegiate versus high school baseball and in competition versus practice. These findings highlight the need for injury-prevention interventions focused on reducing the incidence of upper extremity injuries and protecting batters from pitches and fielders from batted balls.

Risk factors for ulnar collateral ligament injury in professional and amateur baseball players: a systematic review with meta-analysis

BACKGROUND

Risk factors for ulnar collateral ligament injury (UCLI) are unclear despite increasing injury rates. We sought to summarize UCLI risk factors in baseball players.

METHODS

A computer-assisted search of 4 databases was performed using keywords related to UCLI risk factors. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were used for study methodology. Odds ratios and 95% confidence intervals were calculated for dichotomous outcomes, and mean differences and 95% confidence intervals were calculated for continuous outcomes using a random-effects model.

RESULTS

Thirteen studies qualified for inclusion. A greater nondominant (ND) shoulder internal rotation (IR) range of motion (ROM) at 90° abduction arm demonstrated strong evidence as a significant risk factor for UCLI (P < .001) compared with a control group. Mean overall velocity (P < .001), fastball velocity (P < .001), changeup velocity (P = .03), and curveball velocity (P = .01), as well as fewer years of player experience (P < .001), less humeral retrotorsion in the ND arm (P < .001), and greater absolute side-to-side differences in retrotorsion (P = .006) were all moderate-evidence risk factors compared with control groups. Strong evidence suggests total ROM arc at 90° abduction in the dominant arm was not a risk factor for UCLI (P = .81).

CONCLUSIONS

Greater ND shoulder IR ROM and less humeral retrotorsion (in professional and amateur players) as well as pitching velocity (in professional players) demonstrated strong to moderate evidence as risk factors for UCLI. Dominant arm total arc of motion, external, or IR ROM were not risk factors for UCLI. Standardized collection and reporting of risk factors is recommended to more clearly elucidate definitive risk factors for UCLI.

Effect of Predraft Ulnar Collateral Ligament Reconstruction on Future Performance in Professional Baseball: A Matched Cohort Comparison

BACKGROUND

In recent years, there has been a dramatic rise in the annual number of ulnar collateral ligament (UCL) reconstructions performed in amateur baseball pitchers. Accordingly, increasing numbers of players are entering professional baseball having already undergone the procedure; however, the effect of prior UCL reconstruction on future success remains unknown.

PURPOSE

(1) To provide an epidemiologic report on baseball players who undergo UCL reconstruction before being selected in the Major League Baseball (MLB) Draft, (2) to define the outcomes in terms of statistical performance, and (3) to compare these results with those of matched controls (ie, non-UCL reconstruction).

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

The MLB Amateur Draft Database was queried to identify all drafted pitchers who underwent UCL reconstruction before being drafted. For each pitcher drafted from 2005 to 2014 with prior UCL reconstruction, 3 healthy controls with no history of elbow surgery were randomly identified for matched analysis. A number of demographic and performance comparisons were made between these groups.

RESULTS

A total of 345 pitchers met inclusion criteria. The annual number of pitchers undergoing predraft UCL reconstructions rose steadily from 2005 to 2016 ( P < .001). For matched control analysis, 252 pitchers with a UCL reconstruction and a minimum 2-year follow-up (drafted between 2005 and 2014) were matched to 756 controls (non-UCL reconstruction). As compared with the non-UCL reconstruction group, pitchers who underwent predraft UCL reconstruction reached the MLB level with greater frequency (20% vs 12%, P = .003), and their MLB statistical performances were similar for all measures. Compared with all other pitchers drafted during that period, players who had a predraft UCL reconstruction demonstrated an increased likelihood of reaching progressive levels of play (Full Season A, AA, and MLB) within a given time frame ( P < .05 for all).

CONCLUSION

The number of UCL reconstructions performed in amateur baseball players before the draft increased year over year for the entire study period. Professional pitchers who underwent UCL reconstruction as amateurs appear to perform at least as well as, if not better than, matched controls without elbow surgery.

Incidence of Elbow Ulnar Collateral Ligament Surgery in Collegiate Baseball Players

Background:

Recent reports have highlighted the progressive increase in the incidence of ulnar collateral ligament (UCL) injuries to the elbow in baseball players of all levels. However, knowledge of the incidence and other epidemiological factors regarding UCL injuries, specifically in college baseball players, is currently lacking.

Purpose:

To evaluate, over a period of 1 year, the incidence of UCL injuries requiring surgery in National Collegiate Athletic Association (NCAA) Division I baseball programs.

Study Design:

Descriptive epidemiology study.

Methods:

A total of 155 Division I collegiate baseball programs agreed to participate in the study. Demographics (position, year, background [location of high school]) for all players on these rosters were obtained from public websites. At the conclusion of the 2017 collegiate baseball season, the athletic trainer for each program entered anonymous, detailed information on injured players through an electronic survey into a secured database.

Results:

All 155 teams enrolled in the study completed the electronic survey. Of the 5295 collegiate baseball players on these rosters, 134 underwent surgery for an injured UCL (2.5% of all eligible athletes), resulting in a team surgery rate of 0.86 per program for 1 year. These 134 players came from 88 teams, thus 56.8% of the study teams underwent at least 1 surgery during the year. The surgery rate was 2.5 per 100 player-seasons for all players and was significantly higher among pitchers (4.4/100 player-seasons) than nonpitchers (0.7/100 player-seasons). The surgery rate was also significantly higher in underclassmen (3.1/100 player-seasons among freshmen and sophomores) than upperclassmen (1.9/100 player-seasons among juniors and seniors) (incidence rate ratio, 1.7; 95% CI, 1.1-2.4). Players from traditionally warm-weather states did not undergo UCL surgery at a significantly different rate from players from traditionally cold-weather states (2.7/100 player-seasons vs 2.1/100 player-seasons, respectively). Nearly half of surgeries (48.5%) were performed during the baseball season.

Conclusion:

The incidence of UCL surgeries in NCAA Division I collegiate baseball players represents substantial morbidity to this young athletic population. Risk factors for injuries requiring surgery include being a pitcher and an underclassman. Awareness of these factors should be considered in injury prevention programs. Furthermore, this initial study can serve as a foundation for tracking these surgical injuries in future years and then identifying trends over time.

Reasons for Retirement Following Ulnar Collateral Ligament Reconstruction Among Major League Baseball Pitchers

Background:

Ulnar collateral ligament reconstruction (UCLR) has become an increasingly common procedure among Major League Baseball (MLB) pitchers. The long-term effects of this procedure on the career of an MLB pitcher are largely unknown.

Purpose/Hypothesis:

The purpose of this study was to determine why and when MLB pitchers who underwent UCLR during their careers retired from baseball as compared with controls. We hypothesized that pitchers who underwent UCLR are no more likely than control pitchers to retire from elbow or shoulder problems.

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

All MLB pitchers who underwent UCLR were identified through publicly available data. A cohort of pitchers who did not undergo UCLR were matched to pitchers with a history of UCLR, based on sex, age, draft year, and draft round. Of those who were no longer pitching in the MLB, the reason for retirement was determined. Reason for retirement and length of career following UCLR (surgical group) and index year (control group) were determined and compared through prior studies via the MLB HITS database, MLB team websites, and publicly available internet-based injury reports.

Results:

Overall, 153 MLB pitchers who underwent UCLR between 1974 and 2015 are currently retired. Mean ± SD time to retirement was 4.4 ± 4.7 years (range, 0-26 years) after the index year in the control group and 4.4 ± 3.5 years (range, 0-15 years) after surgery in the UCLR group (P = .388). Patients who were status post-UCLR were significantly more likely to be released during the season (34 of 144, 23.6%) than were players who were not status post-UCLR (14 of 144, 9.7%) (P = .002). Shoulder injury as a reason for retirement was more common in the control group than the UCLR group (P = .011). Elbow injury as a reason for retirement was not more common in either group (P = .379). Leg injury as a reason for retirement was more common in the control group (P = .013). Performance as a reason for retirement was more common in the UCLR group than the control group (P < .001).

Conclusion:

MLB pitchers who have undergone UCLR are no more likely to retire from shoulder or elbow injuries than are those who have not undergone UCLR. MLB career length was similar between pitchers with and without a history of UCLR.

Trends in Sports-Related Elbow Ulnar Collateral Ligament Injuries

BACKGROUND

Elbow ulnar collateral ligament (UCL) injuries are common, particularly in adolescent athletes playing overhead sports. While the incidence and outcomes of surgical UCL injuries are well documented, the nonsurgical UCL injury patterns and injury management in this population are not yet known.

PURPOSE/HYPOTHESIS

The purpose of this study was to retrospectively assess the injury severity and subsequent management of UCL injuries among competitive athletes aged 11 to 22 years. We hypothesized that nonsurgical UCL injuries would occur more frequently in younger athletes compared with older athletes.

STUDY DESIGN

Descriptive epidemiological study.

METHODS

Electronic medical records (using International Classification of Diseases, 9th Revision and 10th Revision and Current Procedural Terminology codes) and keyword searches were used to identify all patients with sports-related UCL injuries between January 2000 and April 2016. A total of 136 records were included. Patients were stratified into 3 age brackets (age 11-13 years, n = 17; age 14-16 years, n = 49; age 17-22 years, n = 70). There were no prior elbow surgical interventions. The main outcome measures included the frequency and severity of UCL injuries and injury management (surgical, nonsurgical). Independent variables included age, UCL injuries per year, and sport classification.

RESULTS

There were 53 surgical and 83 nonsurgical UCL injuries. The number of nonsurgical cases increased 9-fold from 2000-2008 to 2009-2016. The UCL injuries were distributed as follows: 60 sprains, 39 partial tears, 36 ruptures, and 1 rerupture. Moreover, 7% of sprains, 51% of partial tears, and 78% of ruptures underwent UCL reconstruction. Nonsurgical management was most common in the youngest athletes (age 11-13 years, 100.0% of total injuries; age 14-16 years, 71.4% of total injuries; and age 17-22 years, 44.3% of total injuries) (P = .007). UCL injury volume was most commonly associated with javelin (odds ratio, 6.69; 95% CI, 0.72-61.62; P = .07) and baseball (odds ratio, 1.55; 95% CI, 0.69-3.51; P = .32).

CONCLUSION

Younger athletes sustained less severe UCL injuries more often than older athletes. Participation in javelin and baseball was associated with a greater likelihood of UCL injuries based on our dataset. This is the first study to provide data on the volume of nonsurgical UCL injuries among athletes in various sports.

Magnetic Resonance Imaging Predictors of Failure in the Nonoperative Management of Ulnar Collateral Ligament Injuries in Professional Baseball Pitchers

BACKGROUND

A medial ulnar collateral ligament (UCL) injury of the elbow is an increasingly common injury in professional baseball pitchers. Predictors of success and failure are not well defined for the nonoperative management of these injuries.

PURPOSE

To evaluate the efficacy of objective measures to predict failure of the nonoperative management of UCL injuries.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Thirty-two professional pitchers (82%) met inclusion criteria and underwent an initial trial of nonoperative treatment for UCL tears based on clinical and radiological findings. Age, preseason physical examination results, magnetic resonance imaging (MRI) characteristics, and performance metrics were analyzed for these pitchers. Successful nonoperative management was defined as a return to the same level of play or higher for >1 year. Failure was defined as recurrent pain or weakness requiring a surgical intervention after a minimum of 3 months' rest when attempting a return to a throwing rehabilitation program.

RESULTS

Thirty-two pitchers (mean age, 22.3 years) who underwent initial nonoperative treatment of UCL injuries were evaluated. Thirty-four percent (11/32) failed and required subsequent ligament reconstruction. Sixty-six percent (21/32) successfully returned to the same level of play for 1 year without a surgical intervention. There was no significant difference seen in physical examination findings or performance metrics between these patients. When comparing MRI findings between the groups, 82% (9/11) ( P < .001) who failed nonoperative management had distal tears, and 81% (17/21) who did not fail had proximal tears ( P < .001). When adjusting for age, location, and evidence of chronic changes on MRI, the likelihood of failing nonoperative management was 12.40 times greater ( P = .020) with a distal tear. No other variable alone or in combination reached significance. When combining the parameters of a high-grade tear and distal location, 88% (7/8) failed nonoperative management.

CONCLUSION

In professional pitchers, distal UCL tears showed significantly higher odds of failure with nonoperative management compared with proximal tears. Thus, tear location should be considered when deciding between operative and nonoperative management.

Exceeding Pitch Count Recommendations in Little League Baseball Increases the Chance of Requiring Tommy John Surgery as a Professional Baseball Pitcher

Background:

Empirical evidence has suggested a connection between youth pitch counts and subsequent elbow injury. For players within the Little League World Series (LLWS), detailed historical player data are available. Some of these players progress to both professional play and require an ulnar collateral ligament reconstruction (UCLR).

Purpose:

To determine the percentage of LLWS pitchers who proceed to play professional (major or minor league) baseball, the rate of UCLR in former LLWS pitchers who played professional baseball, and the risk to those who exceeded current pitch count recommendations while playing in the LLWS.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

All LLWS pitchers from 2001 through 2009 from all teams and countries were identified, and all performance data were extracted. A professional (major and minor league) baseball database was then searched to determine whether each former LLWS pitcher played professional baseball. These professional players were then searched for using publicly available databases to determine whether they underwent UCLR.

Results:

Overall, 638 adolescents pitched in the LLWS between 2001 and 2009; 62 (10%) progressed to professional play. Of the 56 minor league players, 25 (45%) pitched. Of the 6 Major League Baseball players, 3 (50%) pitched. Three former LLWS pitchers (5%) who played professionally underwent UCLR. In former LLWS pitchers who exceeded pitch counts and played professionally, 50% (2/4) required UCLR, while only 1.7% (1/58) of those who did not exceed pitch count recommendations required UCLR (P = .009). Similarly, among former LLWS pitchers who subsequently played professionally, 23.1% of those who played as a pitcher required UCLR while 0% of those who also played other positions required UCLR (P = .008).

Conclusion:

Progression from LLWS pitching to professional baseball is uncommon. Among youth players, both diversification (playing other positions besides pitcher) as well as following current pitch limit regulations may protect against UCLR.

Treatment of Ulnar Collateral Ligament Tears of the Elbow: Is Repair a Viable Option?

BACKGROUND

Ulnar collateral ligament (UCL) tears have become common, and UCL reconstruction (UCLR) is currently the preferred surgical treatment method for treating UCL tears.

PURPOSE/HYPOTHESIS

The purpose of this study was to review the literature surrounding UCL repair and determine the viability of new repair techniques for treatment of UCL tears. We hypothesized that UCL repair techniques will provide comparable results to UCLR for treatment of UCL tears.

STUDY DESIGN

Systematic review and meta-analysis; Level of evidence, 4.

METHODS

A systematic review was registered with PROSPERO and performed with PRISMA guidelines using 3 publicly available free databases. Biomechanical and clinical outcome investigations reporting on UCL repair with levels of evidence 1 through 4 were eligible for inclusion. Descriptive statistics were calculated for each study and parameter/variable analyzed.

RESULTS

Of the 46 studies eligible, 4 studies (3 clinical and 1 biomechanical) were included. There were 92 patients (n = 92 elbows; 61 males [62.3%]; mean age, 21.9 ± 4.7 years) included in the clinical studies, with a mean follow-up of 49 ± 14.4 months. Eighty-six percent of repairs performed were on the dominant elbow, and 38% were in college athletes. Most UCL repairs (66.3%) were performed via suture anchors. After UCL repair, 87.0% of patients were able to return to sport. Overall, 94.9% of patients scored excellent/good on the Andrews-Carson score. Patients who were able to return to sport after UCL repair did so within 6 months after surgery. Biomechanically, when UCL repair was compared with the modified Jobe technique, the repair group showed significantly less gap formation than the reconstruction group.

CONCLUSION

In patients for whom repair is properly indicated, UCL repair provides similar return-to-sport rates and clinical outcomes with shorter return-to-sport timing after repair compared with UCL reconstruction. Future outcome studies evaluating UCL repair with internal bracing are necessary before recommending this technique.

Should We Limit Innings Pitched After Ulnar Collateral Ligament Reconstruction in Major League Baseball Pitchers?

BACKGROUND

Ulnar collateral ligament reconstruction (UCLR) has become a common procedure among Major League Baseball (MLB) pitchers. It is unclear if a limit on innings pitched after UCLR should be instituted to prevent revision UCLR.

HYPOTHESIS

Number of innings pitched and number of pitches thrown after UCLR will not affect whether a pitcher requires a revision UCLR.

STUDY DESIGN

Descriptive laboratory study.

METHODS

All MLB pitchers between 1974 and 2015 who pitched at least 1 full season after UCLR were included in this study. Pitch counts and innings pitched for the first full season after UCLR as well as total pitch count and total innings pitched were recorded. Pitch counts and innings pitched were compared among players who required revision UCLR and those who did not.

RESULTS

Overall, 154 pitchers were included. Of these, 135 pitchers did not require revision UCLR while 19 underwent revision UCLR. No significant difference existed between pitchers who underwent revision UCLR and those who did not when comparing number of innings pitched in the season after UCLR (79.4 ± 46.7 vs 90.1 ± 58.6; P = .9016), number of pitches thrown in the season after UCLR (1233.2 ± 710.4 vs 1449.2 ± 904.1; P = .7337), number of innings pitched in the pitcher's career after UCLR (357.4 ± 312.0 vs 399.3 ± 446.4; P = .6945), and number of pitches thrown in the pitcher's career after UCLR (5632.7 ± 4583.9 vs 5674.7 ± 5755.4; P = .4789), respectively. Furthermore, no difference existed in revision rate between pitchers who pitched more or less than 180 innings in the first full season after UCLR (P = .6678).

CONCLUSION

The number of innings pitched and number of pitches thrown in the first full season as well as over a player's career after UCLR are not associated with an increased risk of a pitcher requiring revision UCLR.

Predictors of Ulnar Collateral Ligament Reconstruction in Major League Baseball Pitchers

BACKGROUND

Ulnar collateral ligament (UCL) reconstruction surgeries in Major League Baseball (MLB) have increased significantly in recent decades. Although several risk factors have been proposed, a scientific consensus is yet to be reached, providing challenges to those tasked with preventing UCL injuries.

PURPOSE

To identify significant predictors of UCL reconstruction in MLB pitchers.

STUDY DESIGN

Case control study; Level of evidence, 3.

METHODS

Demographic and pitching performance data were sourced from public databases for 104 MLB pitchers who underwent UCL reconstruction surgery and 104 age- and position-matched controls. These variables were compared between groups and inserted into a binary logistic regression to identify significant predictors of UCL reconstruction. Two machine learning models (naïve Bayes and support vector machine) were also employed to predict UCL reconstruction in this cohort.

RESULTS

The binary linear regression model was statistically significant (χ(2)(12) = 33.592; P = .001), explained 19.9% of the variance in UCL reconstruction surgery, and correctly classified 66.8% of cases. According to this model, (1) fewer days between consecutive games, (2) a smaller repertoire of pitches, (3) a less pronounced horizontal release location, (4) a smaller stature, (5) greater mean pitch speed, and (6) greater mean pitch counts per game were all significant predictors of UCL reconstruction. More specifically, an increase in mean days between consecutive games (odds ratio [OR], 0.685; 95% CI, 0.542-0.865) or number of unique pitch types thrown (OR, 0.672; 95% CI, 0.492-0.917) was associated with a significantly smaller likelihood of UCL reconstruction. In contrast, an increase in mean pitch speed (OR, 1.381; 95% CI, 1.103-1.729) or mean pitches per game (OR, 1.020; 95% CI, 1.007-1.033) was associated with significantly higher odds of UCL reconstruction surgery. The naïve Bayes classifier predicted UCL reconstruction with an accuracy of 72% and the support vector machine classifier with an accuracy of 75%.

CONCLUSION

This study identified 6 key performance factors that may present significant risk factors for UCL reconstruction in MLB pitchers. These findings could help to enhance the prevention of UCL reconstruction surgery in MLB pitchers and shape the direction of future research in this domain.

Fastball Pitch Velocity Helps Predict Ulnar Collateral Ligament Reconstruction in Major League Baseball Pitchers

BACKGROUND

Ulnar collateral ligament injury and its subsequent surgical reconstruction are some of the most common issues among Major League Baseball (MLB) players.

PURPOSE/HYPOTHESIS

The purpose of this study was to determine factors predictive of ulnar collateral ligament reconstruction (UCLR) among MLB pitchers. The hypothesis was that pitchers who underwent UCLR would have higher preinjury peak fastball pitch velocity.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Data on pitch velocity, number, and type (fastball, curveball, etc) for every pitcher and game within MLB from April 2, 2007 to April 14, 2015 were gathered from the publically available PitchFx database. Pitcher demographic information was also recorded. Data from after 2012 were excluded to avoid lead-time bias. Using publically available information, the names and approximate dates of surgery for every MLB pitcher who ever underwent UCLR, including those before 2007 and after 2012, were collected. Each pitcher-game was then classified as "control," "preinjury," or "postoperative." Control and preinjury pitchers were then compared to determine risk factors for UCLR.

RESULTS

Overall, 1327 pitchers were included, of whom 309 (26.8%) had undergone UCLR. Of these, 145 had preinjury velocity data. Peak pitch velocity was significantly higher among preinjury pitchers than control pitchers (mean [95% CI], 93.3 mph [92.8-93.8] vs 92.1 mph [91.9-92.3]; P < .001), as was mean pitch velocity (87.8 mph [87.3-88.3] vs 86.9 mph [86.7-87.1]; P = .001). Both demonstrated a dose-response relationship. Although height did not differ (P = .934), weight was significantly higher for preinjury pitchers than controls (P = .005). Pitch counts per year were significantly lower for preinjury pitchers compared with control pitchers, although preinjury pitchers threw more breaking pitches (P = .003). On multivariate regression, peak pitch velocity was the primary independent predictor of whether a pitcher underwent UCLR (P < .001), with mean velocity (P = .013), body mass index (P = .010), and age (P = .006) being secondary predictors. However, a model constructed with these variables only explained 7% of the variance in UCLR rates. Pitch counts were not significant predictors.

CONCLUSION

Higher pitch velocity is the most predictive factor of UCLR in MLB pitchers, with higher weight and younger age being secondary predictors, although these factors only explained 7% of the variance in UCLR rates.

Medial ulnar collateral ligament reconstruction of the elbow in major league baseball players: Where do we stand?

The ulnar collateral ligament (UCL) is a vital structure to the overhead athlete, especially the baseball pitcher. For reasons not completely understood, UCL injuries have become increasingly more common in major league baseball (MLB) pitchers over the past 10 years. UCL reconstruction (UCLR) is the current gold standard of treatment for these injuries in MLB pitchers who wish to return to sport (RTS) at a high level and who have failed a course of non-operative treatment. Results following UCLR in MLB pitchers have been encouraging, with multiple RTS rates now cited at greater than 80%. Unfortunately, with the rising number of UCLR, there has also been a spike in the number of revision UCLR in MLB pitchers. Similar to primary UCLR, the etiology of the increase in revision UCLR, aside from an increase in the number of pitchers who have undergone a primary UCLR, remains elusive. The current literature has attempted to address several questions including those surrounding surgical technique (method of exposure, graft choice, management of the ulnar nerve, concomitant elbow arthroscopy, etc.), post-operative rehabilitation strategies, and timing of RTS following UCLR. While some questions have been answered, many remain unknown. The literature surrounding UCLR in MLB pitchers will be reviewed, and future directions regarding this injury in these high level athletes will be discussed.

The Impact of Fatigue on Baseball Pitching Mechanics in Adolescent Male Pitchers

PURPOSE

To determine if shoulder and elbow kinematics, pitching velocity and accuracy, and pain change during a simulated baseball game in adolescent pitchers.

METHODS

Adolescent male pitchers aged 13 to 16 years were included. Pitchers were excluded if they had undergone previous shoulder or elbow surgery, currently had a known shoulder or elbow injury, or were unable to complete the simulated game for any reason. Shoulder range of motion was assessed before and after the game. Velocity and accuracy were measured for every pitch, and every 15th pitch was videotaped from 2 orthogonal views in high definition at 240 Hz. Quantitative and qualitative mechanics were measured from these videos. Perceived fatigue and pain were assessed after each inning using a visual analog scale. Data were statistically analyzed using a repeated-measures analysis of variance.

RESULTS

Twenty-eight elite adolescent pitchers were included. These pitchers, on average, were aged 14.6 ± 0.9 years (mean ± standard deviation), had been pitching for 6.3 ± 1.7 years, and threw 94 ± 58 pitches per week. Our experimental model functioned as expected in that pitchers became progressively more fatigued (0.3 ± 0.6 to 3.5 ± 2.1), had more pain (0.1 ± 0.4 to 1.6 ± 2.2), and pitched with a lower velocity (73 ± 5 mph to 71 ± 6 mph) as pitch number increased (P < .001, P = .001, and P < .001, respectively). Knee flexion at ball release progressively increased (49° ± 15° to 53° ± 15°) with pitch number (P = .008). Hip-to-shoulder separation significantly decreased as pitch number increased, from 90% ± 40% at pitch 15 to 40% ± 50% at pitch 90 (P < .001). Upper extremity kinematics remained unchanged (P > .271 in all cases, 91% power for elbow flexion at ball release). External rotation and total range of motion in the pitching shoulder significantly increased after pitching (P = .007 and P = .047, respectively).

CONCLUSIONS

As pitchers progress through a simulated game, they throw lower-velocity pitches, become fatigued, and have more pain. Core and leg musculature becomes fatigued before upper extremity kinematics changes.

CLINICAL RELEVANCE

On the basis of these results, there is the potential that core strengthening and leg strengthening may be valuable adjuncts to prevent upper extremity injury. Further studies specifically looking at this must be conducted.

Ulnar Collateral Ligament Reconstruction: The Rush Experience

BACKGROUND

Ulnar collateral ligament reconstruction (UCLR) is a common surgery performed in professional, collegiate, and high school athletes.

PURPOSE

To report patient demographics, surgical techniques, and outcomes of all UCLRs performed at a single institution from 2004 to 2014.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

All patients who underwent UCLR from January 1, 2004, through December 31, 2014, at a single institution were identified. Charts were reviewed to determine patient age, sex, date of surgery, sport played, athletic level, surgical technique, graft type, and complications. Data were collected prospectively, and patients were contacted via phone calls to obtain the return-to-sport rate, Conway-Jobe score, Andrews-Timmerman score, and Kerlan-Jobe Orthopaedic Clinic (KJOC) Shoulder and Elbow score. Continuous variable data were reported as weighted means, and categorical variable data were reported as frequencies with percentages.

RESULTS

A total of 187 patients (188 elbows) underwent UCLR during the study period (92% male; mean age, 19.6 ± 4.7 years; 78.2% right elbows). There were 165 baseball players (87.8% of all patients), 155 of whom were pitchers (82.5% of all patients). Ninety-seven (51.6%) were college athletes, 68 (36.2%) high school athletes, and 7 (3.7%) professional athletes at the time of surgery. The docking technique was used in 110 (58.5%) patients while the double-docking technique was used in 78 (41.5%). An ipsilateral palmaris longus graft was used in 110 (58.5%) patients while a hamstring autograft was used in 48 (25.5%) patients. The ulnar nerve was subcutaneously transposed in 79 (42%) patients. Clinical follow-up data were available on 85 patients. Mean follow-up was 60 ± 30.8 months. Overall, 94.1% of patients were able to return to sport and had a Conway-Jobe score of good/excellent while 4.3% had a score of fair. The mean KJOC score was 90.4 ± 6.7 and mean Andrews-Timmerman score was 92.5 ± 7.1. Subsequent surgeries were performed in 5.3% of patients.

CONCLUSION

UCLR was performed most commonly on collegiate athletes using an ipsilateral palmaris longus graft. Overall, 94.1% of patients who underwent UCLR were able to return to sport with a mean KJOC score of 90.4 and Andrews-Timmerman Score of 92.5.

Ulnar Collateral Ligament Reconstruction of the Elbow: A Systematic Review of the Literature

Background:

Ulnar collateral ligament reconstruction (UCLR) is a common procedure in both professional and high-level athletes.

Purpose:

To determine the effect of technique and level of play with UCLR on return to sport (RTS).

Hypothesis:

When comparing different surgical techniques or preoperative level of sports participation, there is no difference in rate of RTS after UCLR.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

A systematic review was registered with PROSPERO and performed following PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) guidelines using 3 publicly available free databases. Therapeutic clinical outcome investigations reporting UCLR outcomes with level of evidence 1 through 4 were eligible for inclusion. All study, subject, and surgical technique demographics were analyzed and compared between continents and countries. Descriptive statistics were calculated, and 2-proportion 2-sample z-test calculators with α = .05 were used to compare RTS between level of play and technique.

Results:

Twenty studies (2019 patients/elbows; mean age, 22.13 ± 4 years; 97% male; mean follow-up, 39.9 ± 16.2 months) were included. The majority of patients were baseball players (94.5%), specifically pitchers (80%). The most common level of play was collegiate (44.6%). Palmaris longus (71.2%) and the American Sports Medicine Institute (ASMI) technique (65.6%) were the most common graft choice and surgical technique, respectively. There was a pooled 86.2% RTS rate, and 90% of players scored excellent/good on the Conway-Jobe scale. RTS rates were higher among collegiate athletes (95.5%) than either high school (89.4%, P = .023) or professional athletes (86.4%, P < .0001). RTS rates were higher for the docking technique (97.0%, P = .001) and the ASMI technique (93.3%, P = .0034) than the Jobe technique (66.7%).

Conclusion:

UCLR is performed most commonly in collegiate athletes. Collegiate athletes have the highest RTS rate after UCLR of all levels of competition. The docking and ASMI techniques had higher RTS rates than the Jobe technique.

Does Geographic Location Matter on the Prevalence of Ulnar Collateral Ligament Reconstruction in Collegiate Baseball Pitchers?

Background:

There has been a significant amount of research in the prevention of throwing injuries. However, one area of research that is lacking is geographic location of play. Warm climates may permit year-round play and increased exposure to throwing arm injury risk.

Hypotheses:

(1) Pitchers from southern institutions would have greater rates of ulnar collateral ligament reconstruction (UCL-R) compared with pitchers from northern institutions. (2) Pitchers originating from high school teams in warm weather states would have a greater risk of undergoing UCL-R while in college.

Study Design:

Descriptive epidemiological study.

Methods:

This study was completed by reviewing publicly obtained records of male collegiate baseball players during the 2008 through 2014 seasons. Data were accessed through online search engines, online baseball media guides, and school websites.

Results:

A total of 5315 player-years and 2575 pitcher-years were identified. Fifty-eight UCL-R cases were found in collegiate pitchers, 40 of which occurred in the Southeastern Conference (SEC) and 18 in the Big Ten. More injuries (36/58) occurred in pitchers who participated in high school baseball in southern states as compared with northern states (22/58), regardless of location of collegiate participation (χ² = 28.8, P < .05). The injury rate for pitchers who participated in high school baseball in southern states was 25.3 per 1000 player-years versus 19.1 per 1000 player-years in northern states, with a risk ratio of 1.32 (χ² = 0.89, P = .35). The injury rate for the SEC versus Big Ten pitchers was 13.3 per 1000 player-years versus 7.8 per 1000 player-years, with a risk ratio of 1.71 (χ² = 1.45, P = .23).

Conclusion:

There is a greater likelihood of undergoing UCL-R in the SEC compared with the Big Ten. There is also an increased risk for UCL-R for pitchers who played high school baseball in southern states versus northern states, irrespective of collegiate play location.

Clinical Relevance:

Pitchers originating from high schools in a warm weather climate may be more likely to undergo UCL-R.

Trends in Medial Ulnar Collateral Ligament Reconstruction in the United States: A Retrospective Review of a Large Private-Payer Database From 2007 to 2011

BACKGROUND

Overuse injuries to the elbow in the throwing athlete are common. Ulnar collateral ligament reconstruction (UCLR), commonly known as Tommy John surgery, is performed on both recreational and high-level athletes. There is no current literature regarding the incidence and demographic distribution of this surgical procedure in relation to patient age, location within the Unites States, and sex.

PURPOSE

To determine the current demographic distribution of UCLR within the US population included in the PearlDiver database.

STUDY DESIGN

Descriptive epidemiology study.

METHODS

A retrospective analysis of the PearlDiver supercomputer database, a private-payer database, was performed to identify UCLR procedures performed between 2007 and 2011. The Current Procedural Terminology (CPT) code 24346 (reconstruction of the ulnar collateral ligament of the elbow with the use of a tendinous graft) was used.

RESULTS

Between 2007 and 2011, a total of 790 patients underwent UCLR. The average (±SD) annual incidence was 3.96 ± 0.38 per 100,000 patients for the overall population but was 22 ± 3.4 for patients aged 15 to 19 years. The overall average annual growth was 4.2%. There were 695 males and 95 females. The 15- to 19-year-old patients accounted for significantly more procedures than any other age group (56.8%; P < .001), followed by 20- to 24-year-olds (22.2%). The incidence of UCLR in the 15- to 19-year-old group increased at an average rate of 9.12% per year (P = .009). Significantly more UCLR procedures were performed in the southern United States than in any other region (P < .001). The number of procedures significantly increased over time (P = .039).

CONCLUSION

According to this database of a privately insured population, UCLR was performed significantly more in patients aged 15 to 19 than any other age group. The average annual incidence of UCLR per 100,000 people for patients aged 15 to 19 was 22 ± 3.4. Further, this database showed that the number of UCLR procedures is increasing over time. Further work should address risk reduction efforts in this at-risk population.