Relative individual workload changes may be a risk factor for rerupture of ulnar collateral ligament reconstruction

Performance-Based Outcomes after Revision Ulnar Collateral Ligament Surgery in Professional Pitchers

OBJECTIVE

To compare performance in baseball pitchers before and after revision ulnar collateral ligament (UCL) surgery using performance metrics.

DESIGN

Case series.

SETTING

Public online database.

PATIENTS OR PARTICIPANTS

Players who underwent revision UCL surgery between 2015 and 2021 were identified. Players were included if they were Minor League (MiLB) or Major League (Major League baseball [MLB]) pitchers. Players were excluded if they were not pitchers, if they underwent their revision surgery as an amateur, or if there is no record of their primary reconstruction surgery.

INTERVENTIONS

Revision UCL surgery (repair or reconstruction).

MAIN OUTCOME MEASURES

Return to sport (RTS) rate, RTS time, pitch velocity, and pitch spin rate.

RESULTS

Sixty-five pitchers underwent revision UCL surgery. MiLB pitchers had a shorter RTS time after their primary surgery (15.62 vs 20.77 months, P < 0.01) compared with MLB pitchers but similar RTS times after their revision reconstruction (19.64 vs 18.48 months, P = 0.44). There was also no difference in return to play (RTP) rate overall after primary versus revision reconstruction ( P = 1.00). Major League baseball pitchers also had decreased RTS time after primary compared with revision reconstruction (15.62 vs 19.64 months, P < 0.01) but similar RTP rates ( P = 0.28). Finally, MLB pitchers had similar pitch breakdowns, velocities, and spin rates before and after their primary and revision repair or reconstruction.

CONCLUSIONS

Both revision UCL repair and reconstruction can return pitchers to preinjury performance levels. Pitchers and teams should be properly counseled on realistic RTP times and postsurgery performance when discussing revision UCL surgeries.

Variable Return to Play and Sport Performance After Elbow Ulnar Collateral Ligament Reconstruction in Baseball Players: A Systematic Review

PURPOSE

To evaluate return to play (RTP) and return to same level of play (RTSP) rates as well as preoperative and postoperative in-game performance metrics in baseball pitchers who underwent ulnar collateral ligament reconstruction (UCLR). Secondarily, this review sought to assess outcomes based on primary versus revision UCLR as well as level of competition.

METHODS

This review was performed using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. PubMed/MEDLINE, Embase, Web of Science, and Cochrane Database of Systematic Reviews were queried to identify articles evaluating UCLR in baseball players between January 2002 and October 2022. Data included RTP, RTSP, and performance metrics including earned run average, innings pitched, walks and hits per inning pitched, batting average against, strikeouts per 9 innings, walks per 9 innings, percentage of fastballs thrown, and average fastball velocity. The Methodological Index for Non-randomized Studies criteria were used for quality assessment.

RESULTS

Analysis included 25 articles reporting on 2,100 elbows. After primary UCLR, RTP ranged from 336 to 615 days (57% to 100% achieved) and RTSP ranged from 330 to 513 days (61% to 95%). After revision UCLR, RTP ranged from 381 to 631 days (67% to 98%) and RTSP ranged from 518 to 575 days (42% to 78%). When stratifying primary UCLR outcomes by competitive level, RTP and RTSP ranged respectively from 417 to 615 days (75% to 100%) and 513 days (73% to 87%) for Major League Baseball only, 409 to 615 days (57% to 100%) and 470 to 513 days (61% to 95%) for Major League Baseball plus Minor League Baseball, and 336 to 516 days (73% to 85%) and 330 days (55% to 74%) for college plus high school. Heterogeneity was seen in postoperative sports performance metrics.

CONCLUSIONS

Although more than half of baseball players appear able to RTP after primary and revision UCLR, RTSP rates after revision UCLR were as low as 42% in the literature. Preoperative and postoperative performance metrics varied.

LEVEL OF EVIDENCE

Level IV, systematic review of Level II-IV studies.

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.

Injuries in the emerging sport of roundnet (Spikeball): a cross-sectional study of 166 players

Objectives

To describe injury frequency and characteristics in roundnet athletes and compare injury characteristics between elite and non-elite athletes.

Methods

This cross-sectional study was performed by convenience sampling recreational and competitive roundnet athletes via a REDCap survey distributed through social media platforms. The custom survey evaluated athlete demographics, past sport participation, training workload and roundnet-related injuries throughout their whole playing career. Injury characteristics were reported for the full study cohort and compared between elite and non-elite athletes.

Results

166 athletes participated in the study, with 33.7% playing at the elite level. 279 injuries were reported, with 86.1% (n=143) of athletes reporting at least one injury throughout their playing career. Injuries most frequently involved the shoulder (20%), ankle (18%), knee (14%) and elbow (14%). 47% of reported injuries occurred due to overuse, and 67% resulted in missed competition time averaging 2.0 months. There were 10 injuries (3.6%) that required surgery. No differences were found in regards to injury frequency (1.9±1.5 vs 1.6±1.1 injuries per athlete, p=0.159) or any injury characteristics between elite and non-elite athletes.

Conclusion

Roundnet athletes experienced a mean of 1.7±1.2 injuries while playing roundnet. Injuries most frequently involved the shoulder and ankle and often resulted in missed competition time. The level of competition does not significantly impact injury frequency or characteristics. Roundnet athletes may benefit from injury prevention programmes that include shoulder strengthening, maintaining shoulder range of motion and ankle stability.

Characteristics Associated With Noncompliance of Current Pitch Smart Guidelines in High School Baseball Pitchers Throughout the United States

Background

Although pitch count and rest guidelines have been promoted for youth and adolescent baseball players for nearly 2 decades, compliance with guidelines remains poorly understood.

Purpose/Hypothesis

The purpose of this study was to determine the frequency of compliance with Major League Baseball (MLB) Pitch Smart guidelines as well as the association between compliance and range of motion (ROM), strength, velocity, injury, and pitcher utilization. It was hypothesized that pitchers in violation of current recommendations would have increased strength, velocity, and injury.

Study Design

Case-control study; Level of evidence, 3.

Methods

This was a prospective, multicenter study of 115 high school pitchers throughout the United States. Pitchers were surveyed about their compliance with current off-season, rest-related guidelines, and history of injury. During the preseason, pitchers underwent standardized physical examinations, and pitch velocity was measured. Pitch counts were collected during the baseball season that followed. Dynamometer strength testing of shoulder forward flexion, and external rotation as well as grip strength was recorded. We compared pitchers who were compliant with recommendations with those who were noncompliant using Student t and Mann-Whitney U tests.

Results

Based on preseason data, 84% of pitchers had violated current Pitch Smart guidelines. During the season, 14% had at least 1 violation of the Pitch Smart guidelines. Across both the preseason survey and in-season pitch counts, 89% of players had at least 1 violation of the Pitch Smart guidelines. While there were no significant differences in ROM or strength, the noncompliant group had higher maximum pitch velocity than the compliant group (74 ± 8 vs 69 ± 5 mph [119 ± 13 vs 111 ± 8 kph], respectively; P = .009). Players' self-reported velocity differed significantly from the direct measurement, for both peak velocity (80 ± 6 vs 73 ± 8 mph [129 ± 9 vs 117 ± 13 kph], respectively; P < .001) and mean velocity (73 ± 8 vs 53 ± 27 mph [117 ± 13 vs 85 ± 43 kph], respectively; P < .001).

Conclusion

Most high school pitchers were not fully compliant with current Pitch Smart guidelines, and they tended to overestimate their peak velocity by 7 mph (11 kph). Pitchers who threw with greater velocity were at higher risk for violating Pitch Smart recommendations.

Hidden Pitches in Major League Baseball: What Are the Injury Implications of These Often Overlooked Pitches?

Background

Pitch counts are tightly monitored in Major League Baseball (MLB). Hidden pitches-including warm-up pitches before and between innings and pitches before the starting/relieving pitcher's appearance in a game-are not as closely monitored.

Purpose/Hypothesis

To report the number of hidden pitches thrown per game and over the course of a season for a single organization. We hypothesized that players who threw more hidden pitches would be at an increased risk of injury compared with those who threw fewer hidden pitches.

Study Design

Case-control study; Level of evidence, 3.

Methods

All pitchers who played for a single MLB organization in the 2021 season were included. Hidden pitches, in-game pitches, and total pitches thrown during all games in the season were recorded. Injuries to these pitchers were also recorded. Players were defined as having an injury if they spent any time on the injured list.

Results

Overall, 137 pitchers were included, 66 (48%) of whom sustained an injury and were placed on the IL during the 2021 season (mean time on IL, 53.6 ± 45.6 days). Of the 66 players who sustained an injury, 18 (27.3%) sustained an elbow injury, while 12 (18.2%) sustained a shoulder injury. Only 1 player sustained an ulnar collateral ligament tear. When comparing hidden pitches, in-game pitches, and total pitches between pitchers who sustained an injury and those who did not, there were no significant differences between groups (P = .150; P = .830; and P = .377, respectively). On average, hidden pitches made up 45.4% of the total number of pitches thrown during the course of the season. When evaluating the number of hidden pitches as a percentage of the total number of pitches thrown in a season, there was no significant difference between pitchers who sustained an injury and those who did not (P = .654).

Conclusion

MLB pitchers who sustained an injury did not throw more hidden pitches than those who did not sustain an injury. Larger scale studies are needed to confirm the results of this single-team study.

Upper-Extremity Injuries Have the Poorest Return to Play and Most Time Lost in Professional Baseball: A Systematic Review of Injuries in Major League Baseball

PURPOSE

To summarize the incidence of injuries occurring in professional baseball and compare player outcomes reported in the literature.

METHODS

We conducted a systematic review using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines across 3 databases (PubMed, MEDLINE, Embase). Inclusion criteria were studies of injury incidences and/or injury outcomes on active Major League Baseball (MLB) athletes and studies published in the English language. Exclusion criteria were non-MLB players, case series and case report studies with a cohort of ≤3 players, and/or review articles.

RESULTS

A total of 477 articles were identified from the initial search of 3 databases, with 105 studies meeting inclusion criteria. Among these articles, the most common injuries studied were elbow (38%), shoulder (14%), hip/groin (11%), hand/wrist (7%), head/face (7%), knee (7%), spine (5%), and foot/ankle (3%). Injuries with the greatest incidence included hand/wrist (150.3 per year), hamstring (7.8-73.5 per year), ulnar collateral ligament (UCL) tears (0.23-26.8 per year), gastrocnemius strains (24.2 per year), and concussions (3.6-20.5 per year). Lowest rates of return to play were seen following shoulder labral tears (40%-72.5%), rotator cuff tears (33.3%-87%), and UCL tears (51%-87.9%). The injuries leading to most time away from sport included elbow UCL tears (average 90.3 days treated nonoperatively to 622.8 days following revision reconstruction), shoulder labral tears (average 315-492 days), and anterior cruciate ligament (ACL) tears (average 156.2-417.5 days). Following ACL tears, rotator cuff tears, shoulder labral tears, and hip femoroacetabular impingement requiring arthroscopy, athletes had a significantly lower workloads compared with before injury upon return to play.

CONCLUSIONS

Most published investigations focus on elbow injuries of the UCL, with variable return to play and mixed performance following surgery. UCL tears, shoulder labral tears, and ACL tears result in the most missed time. Upper-extremity injury such as shoulder labral tears, rotator cuff tears, and UCL tears had the poorest return to play rates. Workload was most affected following ACL reconstruction, rotator cuff repair, shoulder labral repair, and hip arthroscopy for femoroacetabular impingement.

LEVEL OF EVIDENCE

IV, systematic review of level II-IV studies.

Biomechanical comparison of novel ulnar collateral ligament reconstruction with internal brace augmentation vs. modified docking technique

BACKGROUND

Ulnar collateral ligament (UCL) reconstruction (UCLR) is a common surgery among baseball pitchers. UCL repair combined with augmentation using high-strength tape, referred to as an internal brace, was developed as an alternative to UCLR in select patients with the benefit of allowing these athletes to return to sport (RTS) faster. A combined UCLR with an internal brace may allow players indicated for a UCLR to RTS more expeditiously.

METHODS

Twenty-four cadaveric elbows were divided into 3 groups: 12 specimens into the modified docking (MD) group, 6 into the double-docking (DD) group, and 6 into the double docking with internal brace augmentation (DDA) group. This allowed a 1:1 comparison of the MD to the DD and the MD to the DDA. Valgus cyclic testing of native and reconstructed specimens was executed at 90° elbow flexion. After preconditioning, all specimens were cycled between 2 and 10 Nm for 250 cycles. Reconstructed specimens continued to a torque test to catastrophic failure step. Outcome data included intracyclic stiffness, maximum cyclic rotational displacement, gap formation, and failure torque.

RESULTS

Cyclic stiffness of the constructs remained constant throughout the entirety of the torque-controlled cycling phase. The DDA group resulted in a 38% increase in cyclic stiffness from native testing (not statistically significant) and a statistically significant 54% increase from the MD (P = .002). The DDA mean cyclic stiffness was significantly greater than the Native (P < .001), DD (P = .025), and MD (P < .001) groups. Between reconstruction groups, mean gap formation was greatest among the MD group (2.51° ± 1.59°) and least for the DDA group (1.01° ± 0.57°) but did not reach statistical significance.

CONCLUSION

Tape augmentation to the modified UCLR (DDA group) improved cyclic stiffness and reduced gap formation compared with the MD group.

Using Advanced Data to Analyze the Impact of Injury on Performance of Major League Baseball Pitchers: A Narrative Review

Major league baseball (MLB) pitchers are at risk of numerous injuries during play, and there is an increasing focus on evaluating their performance in the context of injury. Historically, performance after return to play (RTP) from injury has focused on general descriptive statistics, such as innings or games played, or rate statistics with inherent variability (eg, earned run average, walks and hits per inning pitched, strikeouts per 9 innings, or walks per 9 innings). However, in recent years, MLB has incorporated advanced technology and tracking systems in every stadium, allowing for more in-depth analysis of pitcher-specific data that are captured with every pitch of every game. This technology allows for the ability to delve into the pitching performance on a basis that is more specific to each pitcher and allows for more in-depth analysis of different aspects of pitching performance. The purpose of this narrative review was to illustrate the current state of injury recording for professional baseball pitchers, highlight recent technological advances in MLB, and describe the advanced data available for analysis. We used advanced data in the literature to review the current state of performance analysis after RTP in MLB pitchers after injury. Finally, we strived to provide a framework for future studies to more meticulously assess RTP performance given the current available resources for analysis.

Is workload associated with latissimus dorsi and teres major tears in professional baseball pitchers? An analysis of days of rest, innings pitched, and batters faced

BACKGROUND

Latissimus dorsi (LD) and teres major (TM) tears have become increasingly recognized injuries in professional baseball pitchers. The purpose of this study was to determine whether workload, as measured by the number of days of rest between outings, number of innings pitched, number of batters faced, and being a starting pitcher, is associated with an increased risk of sustaining an LD-TM tear in professional baseball pitchers.

METHODS

All professional baseball pitchers who sustained an LD-TM tear between 2011 and 2017 were identified using the Major League Baseball Health and Injury Tracking System. A separate player-usage data set was used to determine workload. We then compared workload variables between pitcher-games 2, 6, 12, and >12 weeks prior to a documented LD-TM tear and pitcher-games from a non-LD-TM tear control group. In a paired analysis, we compared the acute workload (2, 6, and 12 weeks) prior to injury and the injured pitchers' non-acute workload >12 weeks prior to injury.

RESULTS

A total of 224 unique LD-TM tears were documented in the Major League Baseball Health and Injury Tracking System database. In most periods, player-games with more innings pitched and more batters faced were associated with a higher incidence of subsequent LD-TM tears. The number of days of rest was not a significant predictor of an LD-TM tear in the acute workload setting, but pitchers who sustained an LD-TM injury averaged fewer days of rest over the previous ≥12 weeks than controls (P < .001). Pitchers who faced >30 batters per game showed a 1.57-fold increase in the percentage of pitchers with a subsequent LD-TM tear as compared with pitchers who faced ≤5 batters per game. Significantly more starting pitchers were in the case group that sustained LD-TM tears over multiple time points than in the control group.

CONCLUSION

Having a greater pitcher workload and being a starting pitcher were associated with an increased risk of sustaining LD-TM tears in professional baseball players. The average number of days of rest was only a risk factor for LD-TM tears over a 3-month or longer period.

Effect of Weather and Game Factors on Injury Rates in Professional Baseball Players

BACKGROUND

Injury rates in baseball players of all ages are increasing. Identifying modifiable risk factors is paramount to implementing injury prevention programs.

PURPOSE/HYPOTHESIS

The purpose was to evaluate the influence of weather (temperature, humidity, atmospheric pressure, and heat index) and game factors (start time, duration, single vs doubleheader) on injury rates in professional baseball players. We hypothesized that colder temperatures would be associated with significantly more injuries per game.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

This was a retrospective database study. Two data sets were combined: 1 containing all injuries in Major and Minor League Baseball between 2011 and 2017 and 1 containing all games played in Major and Minor League Baseball during the same period to determine the number of injuries per game. Temperature, humidity, atmospheric pressure, and heat index were determined for each game using the data from the US Environmental Protection Agency. Additional game variables included the level of play, the turf type (natural vs artificial grass), the stadium type (open vs dome vs retractable), the game start time, the game duration, and whether the game was a doubleheader. Then, a multivariate analysis was conducted to determine which factors were associated with the number of injuries per game.

RESULTS

In total, our analysis included 33,587 injuries and 76,747 games. A total of 25,776 (33.6%) games contained an injury, and 41% of injuries occurred as multiples per game, with up to 9 injuries per game. The multivariate analysis identified significant associations between game duration and injuries per game (P < .001; effect size, 0.013) and the level of play and injuries per game (P < .001; effect size, 0.011). There were significant associations between the venue type (P < .001), the game start time (P < .001), humidity (P < .001), the turf type (P = .016), and barometric pressure (P = .031); however, the effect size for each was <0.001, suggesting that these factors are clinically unimportant. Our overall model produced an R² of 0.04, indicating that these variables only predicted 4% of the variance in injury risk.

CONCLUSION

In professional baseball, the weather is not associated with injury risk; however, game duration may contribute to injury risk.

Seasonal and monthly trends in elbow ulnar collateral ligament injuries and surgeries: a national epidemiological study

Background

Monthly incidence of elbow ulnar collateral ligament (UCL) injuries and surgeries is relatively unknown. Defining seasonal peaks of UCL injuries and surgeries may identify opportunities for injury-prevention strategies. The purpose of this study is to analyze seasonal and monthly variations in UCL injuries and surgeries across the United States with emphasis on the timing of baseball season.

Methods

The Truven Health MarketScan database (2013-2015) was queried for patients younger than 40 years with a diagnosis code of elbow UCL sprain and a procedural code for UCL repair or reconstruction. Differences in patient characteristics were evaluated using chi-square and Mann-Whitney U-tests. Negative binomial regression models were calculated for UCL injuries and surgeries to assess monthly trends.

Results

UCL injuries were sustained by 13,894 patients, with 1404 (10.1%) patients having undergone surgery. The median age at first diagnosis was 17 years, and the median age of patients requiring surgery decreased from 20 to 18 years from 2013 to 2015 (P = .75). Most UCL injuries (n = 3785) and surgeries (n = 438) occurred during the spring season (March 21-June 20), and spring injuries were most likely to result in surgical management (11.6%). During the baseball season (March to September), the number of UCL injuries peaked in April/May, then declined, except for a second peak in September/October (incidence rate ratio 0.97; confidence interval 0.95, 0.99; P = .01). The number of UCL surgeries steadily increased from March (n = 116) to June (n = 152), followed by a gradual decline (incidence rate ratio 1.00; confidence interval 0.96, 1.04; P = .99).

Conclusion

Athletes frequently experienced UCL injuries and surgeries in the early months (April-June) of the baseball season. More emphasis should be paid to rehabilitative strategies at the beginning of a baseball season to help mitigate injury risk.

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.

Game Utilization and Performance Following RTP From ACL Reconstruction Does not Influence a Subsequent Second ACL Injury in National Football League Players

Purpose

The purpose of this study is to evaluate differences in game utilization or performance following primary anterior cruciate ligament (ACL) reconstruction between National Football League (NFL) players with and without a second ACL injury.

Methods

NFL players who underwent ACL reconstruction between 2013 and 2017 were identified. Players were classified as having one injury (“tear”) or having later sustained a subsequent second (reinjury or contralateral) ACL injury (“retear”). Players were excluded if they tore their ACL prior to the NFL, did not return to play (RTP), did not play the season before injury, or had concomitant injuries. Demographic characteristics, game utilization statistics, and season approximate value (SAV) performance metrics were recorded. Statistical analysis compared data after RTP from primary ACL reconstruction (seasons +1, +2, and +3) relative to the season before injury (season −1) between cohorts using mean differences and relative percentages.

Results

Analysis included a total of 45 players, 32 in the “tear” group and 13 in the “retear” group. Demographics, level of play, and time to RTP after primary ACL reconstruction did not differ between the groups (P > .05). Tear and retear groups demonstrated similar utilization and performance metrics the season prior to injury (−1) and the 3 seasons following RTP (season of injury is “0”). Both groups had a similar decrease (relative percentage) in games played and started, snap counts, and SAV during the 3 seasons following RTP compared to baseline (P > .05). The draft pick position was correlated with the relative percentage of games started the first season after RTP (r = .6, P = .02).

Conclusions

Game utilization and performance metrics following ACL reconstruction were not associated with a subsequent second ACL injury. Players with a higher draft pick position were more likely to return to the starting lineup following primary ACL reconstruction. Ultimately, player game utilization and performance following primary ACL reconstruction is not predictive of a subsequent second ACL injury.

Level of Evidence

Level III, retrospective case-control study

Do Injury Rates in Position Players Who Convert to Pitchers in Professional Baseball Differ From Players Who Have Always Been Pitchers?

Background:

There are some professional baseball players who begin their career as a position player and later convert to a pitcher; injury rates in these players are unknown.

Purpose:

To compare injury rates of professional baseball players who started their career as position players and converted to pitchers with a control group of pitchers who have been only pitchers throughout their professional career.

Hypothesis:

Injury rates would be lower in the conversion players.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

All players who began their professional baseball career as position players and converted to pitchers between 2011 and 2018 were included. All injuries that occurred after they converted to pitchers were included. The conversion players were matched 1 to 1 with a control group of pitchers who entered professional baseball as pitchers and never changed position. Injury rates were compared between groups. The performance between groups was also compared.

Results:

Overall, 221 players were identified who converted from position players to pitchers. There were significantly more injuries per year in the control pitcher group (0.8 ± 0.9) than in the conversion pitcher group (0.7 ± 0.9; P = .015). Injuries in the control group resulted in 61 ± 112 days missed per injury, while injuries in the conversion player group resulted in 54 ± 102 days missed per injury (P = .894). Injury characteristics differed between groups. However, in both groups, most of the injuries were related to pitching or throwing, were noncontact or gradual overuse injuries, and involved the upper extremity. Converted pitchers had lower pitcher usage, with fewer games and innings pitched (P < .001), with significantly worse statistics for walks plus hits per inning pitched (P = .018).

Conclusion:

Professional baseball players who convert from position players to pitchers are injured at lower rates than control pitchers. Conversion pitchers have lower pitcher usage, which may contribute to their reduced injury rates.

Anterior Cruciate Ligament Reconstruction Does Not Impact Career Earnings After Return to Play in National Basketball Association Athletes

Purpose

To quantify the financial impact of an anterior cruciate ligament (ACL) injury on the remaining career earnings of National Basketball Association (NBA) players.

Methods

We performed a retrospective review of all NBA players who had an ACL rupture between 2000 and 2019. Players were matched to healthy controls by age, position, body mass index, and player efficiency rating at the time of injury (index year). Player information collected included demographic information, position, team role, draft pick, date of injury, contract length, and earnings during the 3 years before and 7 years after the index year, as well as new contract length and earnings after injury.

Results

A total of 12 players (22%) did not return to play (RTP). No statistically significant difference in annual earnings was present at any time point between cohorts. When we examined the mean difference in earnings between the first 3 post-index seasons and the 3 pre-index seasons, both the ACL and control cohorts showed increased salaries as players’ careers progressed, without a significant difference in earnings. When comparing cohorts, we found no significant difference in the length and earnings of contracts during the index year. Furthermore, there was no significant difference in the length or earnings of the first new contract signed after the index year between cohorts. Additionally, NBA players who were able to RTP after ACL reconstruction were more likely to experience increased earnings if they had greater experience and performance prior to their injury (P < .01).

Conclusions

Our study found that NBA players did not experience diminished earnings after RTP from an ACL reconstruction when compared with matched controls. Furthermore, no differences were seen in lengths of new contracts or in contract earnings between cohorts. Players with greater experience and performance prior to injury were more likely to have increased earnings after ACL reconstruction.

Level of Evidence

Level III, retrospective case-control study.

High Return to Play Rate and Reduced Career Longevity Following Surgical Management of Athletic Pubalgia in National Basketball Association Players

Purpose

To assess the effects of surgical treatment of athletic pubalgia (AP) on game use and performance metrics in National Basketball Association (NBA) players.

Methods

A retrospective review of all NBA players who underwent surgical management for AP from 1996 to 2018 was performed. A matched control group was created for comparison. The index period was defined as the entire NBA season in which surgery occurred, including the corresponding offseason. Player demographics, use (games played, games started, and minutes per game) and performance (player efficiency rating) metrics were collected for all players. Statistical analysis was performed to compare data before and after return to play.

Results

Thirty players with a history of surgical management for AP were included in the final analysis. Following surgery for AP, NBA players were found to have a return to play (RTP) rate of 90.91% (30/33). The average RTP following surgery was 4.73 ± 2.62 months. Compared with control athletes, athletes in the AP group played significantly fewer seasons postinjury (4.17 ± 2.70 vs 5.49 ± 3.04 seasons, respectively; P = .02). During the first year following RTP, NBA players experienced significant reductions in game use and performance, both when compared with the year prior and matched control athletes (P < .05). At 3-year follow-up, players continued to demonstrate significant reductions in game use (minutes per game, P < .05) but not performance.

Conclusions

Following surgical treatment of AP, NBA players demonstrated a high RTP rate, but shortened career. A short-term reduction in game use and performance metrics was found the year of return following surgery. However, 3-year follow-up performance metrics normalized when compared with healthy controls.

Study Design

Level III; retrospective case-control study.

Increased Upper Arm Length and Loading Rate Identified as Potential Risk Factors for Injury in Youth Baseball Pitchers

BACKGROUND

In the throwing elbow, increased elbow torque has been correlated with increased injury risk. Additional insight into the relationships between anthropometric factors and elbow joint loading is warranted.

PURPOSE

To investigate the relationship among physical limb length characteristics, elbow kinetics, and elbow kinematics in youth baseball pitchers and to examine the relationship between elbow varus loading rate and elbow kinetics.

DESIGN

Descriptive laboratory study.

METHODS

A total of 27 male youth baseball pitchers participated (mean ± SD: age, 15.8 ± 2.7 years; height, 176.3 ± 13.0 cm; weight, 71.7 ± 16.4 kg). Upper arm (UA) and forearm (FA) lengths were measured using a moveable sensor to digitize bony landmarks. Kinematic data were collected at 240 Hz using an electromagnetic tracking system. Participants threw 3 fastballs to a catcher at a regulation distance (60 ft 6 in), and the fastest velocity trial was used for analysis. Linear regression was used to determine the relationship among limb length characteristics, elbow kinetics, and elbow kinematics after accounting for the effects of body weight and height.

RESULTS

Pitchers with longer UA length experienced increased maximum elbow varus torque (P = .005) and maximum net elbow force (P = .001). Pitchers with an increased forearm to UA ratio had decreased elbow compression force (P < .001) and exhibited a more flexed elbow at foot contact (P = .001). Pitchers with greater maximum loading rates experienced greater elbow varus torque (P = .002).

CONCLUSION

In youth baseball pitchers, longer UA length and greater loading rate increase varus torque about the elbow during a fastball pitch.

CLINICAL RELEVANCE

Longer UA length and greater loading rate may place pitchers at risk of injury because of their relationship with kinetic values.

Effect of Achilles Tendon Rupture on Player Performance and Longevity in Women's National Basketball Association Players

Background

Women's National Basketball Association (WNBA) players have a greater incidence of lower extremity injury compared with male players, yet no data exist on functional outcomes after Achilles tendon rupture (ATR).

Purpose

To evaluate the effect of Achilles tendon repair on game utilization, player performance, and career longevity in WNBA athletes.

Study Design

Cohort study; Level of evidence, 3.

Methods

WNBA players from 1997 to 2019 with a history of ATR (n = 12) were matched 1:2 to a healthy control group. Player characteristics, game utilization, and in-game performance data were collected for each athlete, from which the player efficiency rating (PER) was calculated. Statistical analysis was performed comparing postinjury data to preinjury baseline as well as cumulative career data. Changes at each time point relative to the preinjury baseline were also compared between groups.

Results

Of the 12 players with ATR, 10 (83.3%) returned to play at the WNBA level at a mean (±SD) of 12.5 ± 3.3 months. Four players participated in only 1 WNBA season after injury. There were no differences in characteristics between the 10 players who returned to play after injury and the control group. After return to play, the WNBA players demonstrated a significant decrease in game utilization compared with preinjury, playing in 6.0 ± 6.9 fewer games, starting in 12.7 ± 15.4 fewer games, and playing 10.2 ± 9.1 fewer minutes per game (P < .05 for all). After the index date of injury, the players with Achilles repair played 2.1 ± 1.2 more years in the WNBA, while control players played 5.35 ± 3.2 years (P < .01) Additionally, the players with Achilles repair had a significant decrease in PER in the year after injury compared with preinjury (7.1 ± 5.3 vs 11.0 ± 4.4; P = .02). The reduction in game utilization and decrease in PER in these players was maintained when compared with the matched controls (P < .05 for both).

Conclusion

The majority of WNBA players who sustained ATR were able to return to sport after their injury; however, their career longevity was shorter than that of healthy controls. There was a significant decrease in game utilization and performance in the year after return to play compared with healthy controls.

Return-to-Play and Competitive Outcomes After Ulnar Collateral Ligament Reconstruction Among Baseball Players: A Systematic Review

Background:

Ulnar collateral ligament (UCL) reconstruction (UCLR) is very common in baseball. However, no review has compared the return-to-play (RTP) and in-game performance statistics of pitchers after primary and revision UCLR as well as of position players after UCLR.

Purpose:

To review, synthesize, and evaluate the published literature on outcomes after UCLR in baseball players to determine RTP and competitive outcomes among various populations of baseball players.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

A literature search including studies between 1980 and November 4, 2019, was conducted for articles that included the following terms: ulnar collateral ligament, elbow, medial collateral ligament, Tommy John surgery, throwing athletes, baseball pitchers, biomechanics, and performance. To be included, studies must have evaluated baseball players at any level who underwent UCLR (primary or revision) and assessed RTP and/or competitive outcomes.

Results:

A total of 29 studies with relatively high methodological quality met the inclusion criteria. After primary UCLR, Major League Baseball (MLB) pitchers returned to play in 80% to 97% of cases in approximately 12 months; however, return to the same level of play (RTSP) was less frequent and took longer, with 67% to 87% of MLB pitchers returning in about 15 months. RTP rates for MLB pitchers after revision UCLR were slightly lower, ranging from 77% to 85%, while RTSP rates ranged from 55% to 78%. RTP rates for catchers (59%-80%) were generally lower than RTP rates for infielders (76%) and outfielders (89%). All studies found a decrease in pitching workloads after UCLR. Fastball usage may also decrease after UCLR. Changes in earned run average and walks plus hits per inning pitched were inconclusive.

Conclusion:

Pitchers returned to play after UCLR in approximately 12 months and generally took longer to return to their same level of play. Pitchers also returned to play less frequently after revision UCLR. After both primary and revision UCLR, professional pitchers experienced decreased workloads and potentially decreased fastball usage as well. Catchers may RTP after UCLR less frequently than pitchers, infielders, and outfielders possibly because of the frequency of throwing in the position. These results will help guide clinical decision making and patient education when treating UCL tears in baseball players.

Effect of Achilles Tendon Rupture on Player Performance and Longevity in National Basketball Association Players

Background:

National Basketball Association (NBA) players who return to sport (RTS) after Achilles tendon rupture have been reported to have poor outcomes.

Purpose:

To evaluate the effect of Achilles tendon ruptures on player performance and career longevity in NBA athletes.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

NBA players who sustained Achilles tendon ruptures between 1970 and 2019 were identified using publicly available resources and were matched 1:1 to a healthy control group by age, position, height, and body mass index. Demographic characteristics, player utilization (games and minutes), and performance efficiency rating (PER) were documented for all athletes. The season of Achilles tendon rupture was set as the index year, and statistical analysis compared postindex versus preindex data both acutely and in the long term. Percentages relative to preoperative values were calculated to compare the injured and control groups in a standardized fashion.

Results:

Of 47 players, 34 (72.3%) with Achilles tendon ruptures returned to play at the NBA level after surgical intervention. A total of 7 players were excluded from the study. No differences were found in demographic characteristics or PER (2 years before injury) between the remaining 27 players and matched controls. The injured players had significantly shorter careers compared with control players (3.1 ± 2.3 vs 5.8 ± 3.5 seasons, respectively; P < .05). Injured players demonstrated significant declines in games per season (GPS), minutes per game (MPG), and PER at 1 year and 3 years after RTS compared with preindex baseline (P < .05). Injured players, compared with control players, had reduced relative percentages of games started (GS) (50% vs 125%, respectively), MPG (83% vs 103%), and PER (80% vs 96%) at 1 year after return (P < .05), but reductions at extended 3-year follow-up were seen only in GPS (71% vs 91%) and GS (39% vs 99%) (P < .05).

Conclusion:

Our study found that 72.3% of NBA players returned to play after Achilles tendon repair, but they had shorter careers compared with uninjured controls. Players returning from Achilles tendon repairs had decreased game utilization and performance at all time points relative to their individual preindex baseline. However, for the injured players when compared with controls, game utilization but not performance was found to be decreased at 3-year follow-up.

Effect of Workload After ACL Reconstruction on Rerupture Rates in NBA Players

Background:

Rupture of the anterior cruciate ligament (ACL) is a common and potentially career-altering injury sustained by players in the National Basketball Association (NBA). Strategies have been employed by the league to prevent reinjury of players after ACL reconstruction (ACLR), including minute restrictions and rest games; however, it remains unknown whether workload metrics after ACLR influence the risk for reinjury and revision surgery.

Purpose:

To evaluate whether workload changes after return to play (RTP) from primary ACLR influences the risk of rerupture in NBA players.

Study Design:

Case-control study; Level of evidence, 3.

Methods:

We identified NBA players from 1975 to 2018 who underwent primary ACLR as well as those who required revision ACLR. Primary outcomes included workload measures such as games played, games started, and minutes per game. Secondary outcomes included in-game performance statistics. Statistical analysis was used to compare relative workload and performance 3 years before and 3 years after undergoing primary ACLR. Workload was also compared between the control group of NBA players who underwent primary ACLR and those who required revision ACLR.

Results:

A total of 68 players who underwent primary ACLR were included, 8 of whom subsequently required revision ACLR. In their first season upon RTP, control players (primary ACLR) demonstrated a significant reduction in all workload metrics relative to the season before injury (P < .001), while the revision group demonstrated an unchanged to increased workload. In a comparison between the primary and revision groups during the first season after RTP, the primary group demonstrated significantly fewer games started (mean ± SD, 22.2 ± 3.0 vs 35.8 ± 8.3; P = .039) and minutes per game (20.5 ± 1.1 vs 27.0 ± 3.1; P = .048) than revision players. The primary ACLR group demonstrated reduced cumulative workload trends for the first 3 years after RTP relative to 3 years before injury, which was not demonstrated in the revision ACLR group, albeit statistically insignificant.

Conclusion:

Our study found that after ACLR, a reduction in workload parameters relative to preinjury baseline was associated with players who did not sustain rerupture. Further study is required to determine if workload measures following RTP from primary ACLR should be individualized relative to preinjury baseline.

Timing of Return to Batting Milestones After Ulnar Collateral Ligament Reconstruction in Professional Baseball Players

BACKGROUND

Ulnar collateral ligament reconstruction (UCLR) is a common procedure in professional baseball position players. Timing of return to hitting after UCLR is unknown.

PURPOSE/HYPOTHESIS

The purpose was to determine the time to return to batting milestones after UCLR as well as the effect of UCLR upon batting performance in professional baseball players. The hypothesis was that position players would return to batting in an in-season game before fielding in an in-season game, and hitting performance would remain unchanged after UCLR.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

All professional position players who underwent UCLR between 2010 and 2018 were included. Time to batting milestones after UCLR was analyzed. Batting performance before and after UCLR was compared and analyzed.

RESULTS

Overall, 141 UCLRs (96% performed on the dominant arm) in 137 position players were included (86% Minor League players). Four players underwent revision, all within 1 year of the primary UCLR. With regard to position, catchers and shortstops were overrepresented. With regard to batting side, 57% batted from the right and 12% batted as switch-hitters. Of the surgeries, 76% were on the trail/back arm. While 91% of players returned to some form of throwing, there was a progressive gradual decline as the rehabilitation process progressed, as only 77% were able to return to hitting in a real game and 75% were able to return to fielding in a real game. The first dry swing occurred at 150 ± 49 days after surgery, the first batting practice occurred at 195 ± 58 days after surgery, the first hitting in a real game occurred at 323 ± 92 days after surgery, and the first fielding in a real game occurred at 343 ± 98 days after surgery. However, players generally saw a decrease in their utilization, with fewer at bats (P < .001) translating into fewer hits (P < .001) and runs (P < .001).

CONCLUSION

Professional position players begin swinging at 150 days (approximately 5 months) after UCLR, while they do not hit in batting practice until 195 days (approximately 6.5 months) and do not hit in a real game until 323 days (approximately 10.7 months) after UCLR. Players see a decrease in hitting utilization after UCLR. On average, players hit in a real game 20 days before fielding in a real game.

Revision Medial Ulnar Collateral Ligament Reconstruction in Baseball Pitchers: Review of Epidemiology, Surgical Techniques, and Outcomes

PURPOSE OF REVIEW

The purposes of this review are to describe the epidemiology, treatment options, and clinical outcomes of revision medial ulnar collateral ligament reconstruction in baseball pitchers.

RECENT FINDINGS

Rates of revision UCL range from 1 to 15% and have slowly increased over the past several years. Revision UCL procedures are associated with higher complication rates, likely due to the distortion of innate anatomy after primary reconstruction. Techniques for reconstruction are largely influenced by the index surgery and integrity of the ulnar and humeral bone tunnels/sockets. Current literature reporting on the outcomes following revision UCL reconstruction is limited to case series and database studies. Mean time between primary reconstruction and revision surgery is approximately 5 years and return to play rates range from 47 to 85%. Outcomes following revision UCL reconstruction are relatively guarded compared with those of primary UCL reconstruction with the most studies reporting lower return to play rates, decreased workloads compared with pre-injury levels of play, and shorter career longevity following revision surgery. Future research regarding optimal reconstruction techniques and post-operative rehabilitation are needed as the incidence and demand for this procedure is expected to increase.

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.

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.

Elbow Injuries in National Collegiate Athletic Association Athletes: A 5-Season Epidemiological Study

Background:

Little research has focused on the rates and patterns of elbow injuries in National Collegiate Athletic Association (NCAA) student-athletes.

Purpose:

To describe the epidemiological patterns of elbow injuries in NCAA athletes during 5 seasons over the academic years 2009 through 2014 using the NCAA Injury Surveillance Program (NCAA-ISP) database.

Study Design:

Descriptive epidemiology study.

Methods:

A voluntary convenience sample of NCAA varsity teams from 11 sports was examined to determine the rates and patterns of elbow injuries. Rates and distributions of elbow injuries were identified within the context of sport, event type, time in season, mechanism, time lost from sport, surgical treatment, and injury type. Rates of injury were calculated as the number of injuries divided by the total number of athlete-exposures (AEs). An AE was defined as any student participation in 1 NCAA-sanctioned practice or competition with an inherent risk of exposure to potential injury. Injury rate ratios (IRRs) and injury proportion ratios (IPRs) were then calculated to compare the rates within and between sports by event type, season, sex, mechanism, surgical treatment, and time lost from sport. Comparisons between sexes were made using only sports data that had both male and female samples.

Results:

Overall, 373 elbow injuries were reported in the NCAA-ISP data set during the 2009-2010 through 2013-2014 academic years among 11 varsity sports. The overall rate of injury was 1.76 per 10,000 AEs. The rate of elbow injuries in men was 0.74 per 10,000 AEs, while women experienced injuries at a rate of 0.63 per 10,000 AEs. In sex-comparable sports, men were 1.17 times more likely to experience an elbow injury compared with women. Men’s wrestling (6.00/10,000 AEs) and women’s tennis (1.86/10,000 AEs) were the sports with the highest rates of elbow injuries by sex, respectively. The top 3 highest injury rates overall occurred in men’s wrestling, baseball, and tennis. Elbow injuries were 3.5 times more likely to occur during competition compared with practice. Athletes were 0.76 times less likely to sustain an elbow injury during the preseason compared with in-season. Contact events were the most common mechanism of injury (67%). For sex-comparable sports, men were 2.41 times more likely than women to have contact as their injury mechanism (95% CI, 0.78-7.38). The majority of athletes missed less than 24 hours of participation time (67%), and only a minority (3%) of patients with elbow injuries went on to have surgical intervention. Elbow ulnar collateral ligament injuries were most common (26% of total injuries).

Conclusion:

Analysis of the study data demonstrated a significant rate of elbow injuries, 1.76 injuries per 10,000 AEs in NCAA collegiate athletes. Higher injury rates can be expected in males within sex-comparable sports. Elbow injuries are most common in the setting of competitions and most commonly occur secondary to contact-type mechanisms. Injuries were more likely to occur during in-season play. The majority of injuries required less than 24 hours of time away from sport and did not require surgical intervention.

Return to Play and In-Game Performance Statistics Among Pitchers After Ulnar Collateral Ligament Reconstruction of the Elbow: A Systematic Review

BACKGROUND

Injury to the ulnar collateral ligament of the elbow is relatively common among baseball pitchers. Ulnar collateral ligament reconstruction (UCLR) has revolutionized the management of this injury, allowing a greater proportion of pitchers to return to play.

PURPOSE

To assess the return to play and in-game performance specific to baseball pitchers who have undergone primary UCLR.

STUDY DESIGN

Systematic review.

METHODS

This review was conducted according to the PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-Analyses). The electronic databases MEDLINE, EMBASE, and PubMed were searched for relevant studies, and pertinent data were abstracted. Only studies reporting in-game performance statistics (earned run average [ERA], pitching velocity, innings pitched per season, etc) of pitchers after UCLR were included. The methodological index for nonrandomized studies (MINORS) was used to assess study quality.

RESULTS

A total of 14 studies and 1520 pitchers were included in this systematic review. All studies were of level 3 or 4 evidence, and the mean ± SD MINORS score was 14.4 ± 3.0, which indicates fair quality of evidence for nonrandomized studies. The rates of return to any level of pitching after UCLR ranged from 79% to 100%. Subgroup analysis revealed that 79% to 87% of Major League Baseball (MLB) pitchers returned to preinjury levels of pitching. The mean time to return to play was 19.8 ± 13.5 months, and the mean time to return to competition for MLB pitchers was 17.3 ± 2.4 months. Of the 5 studies reporting ERA, 2 cited a significant increase after UCLR, and 1 indicated a significant decrease. Of the 4 studies reporting fastball velocity, 3 cited decreased pitching velocities after UCLR. All studies found that pitchers pitched, on average, fewer innings per game or season after UCLR.

CONCLUSION

There was a high rate of return to pitching after UCLR. However, most studies showed that UCLR was associated with a prolonged recovery and significant decline in pitching performance as objectively measured by in-game statistics. The strength of these conclusions is limited by the quality of the available literature and inconsistencies in the reporting of outcomes.

Fastball Velocity and Elbow-Varus Torque in Professional Baseball Pitchers

CONTEXT

High loads in the elbow during baseball pitching can lead to serious injuries, including injuries to the ulnar collateral ligament. These injuries have substantial implications for individual pitchers and their teams, especially at the professional level of competition. With a trend toward increased ball velocity in professional baseball, controversy still exists regarding the strength of the relationship between ball velocity and elbow-varus torque.

OBJECTIVE

To examine the relationship between fastball velocity and elbow-varus torque in professional pitchers using between- and within-subjects statistical analyses.

DESIGN

Cross-sectional study.

SETTING

Motion-analysis laboratory.

PATIENTS OR OTHER PARTICIPANTS

Using the previously collected biomechanical data of 452 professional baseball pitchers, we performed a retrospective analysis of the 64 pitchers (52 right-hand dominant, 12 left-hand dominant; age = 21.8 ± 2.0 years, height = 1.90 ± 0.05 m, mass = 94.6 ± 7.8 kg) with fastball velocity distributions that enabled between- and within-subjects statistical analyses.

MAIN OUTCOME MEASURE(S)

We measured ball velocity using a radar gun and 3-dimensional motion data using a 12-camera automated motion-capture system sampling at 240 Hz. We calculated elbow-varus torque using inverse-dynamics techniques and then analyzed the relationship between ball velocity and elbow torque using both a simple linear regression model and a mixed linear model with random intercepts.

RESULTS

The between-subjects analyses displayed a weak positive association between ball velocity and elbow-varus torque (R² = 0.076, P = .03). The within-subjects analyses showed a considerably stronger positive association (R² = 0.957, P < .001).

CONCLUSIONS

When comparing 2 professional baseball pitchers, higher velocity may not necessarily indicate higher elbow-varus torque due to the confounding effects of pitcher-specific differences (eg, detailed anthropometrics and pitching mechanics). However, within an individual pitcher, higher ball velocity was strongly associated with higher elbow-varus torque.

Medial Elbow Pain During the Return-to-Throwing Period After Ulnar Collateral Ligament Reconstruction in Pitchers

Background:

Ulnar collateral ligament reconstruction (UCLR) is common in the sport of baseball, particularly among pitchers. Postoperative return-to-sport protocols have many players beginning to throw at 4 to 5 months and returning to full competition between 12 and 16 months after surgery. Medial elbow pain during the return-to-throwing period often occurs and can be difficult to manage.

Purpose:

To evaluate the incidence of medial elbow pain and associations with outcomes and revision surgery during the return-to-throwing period after UCLR.

Study Design:

Case-control study; Level of evidence, 3.

Methods:

Between the years of 2002 and 2014, all pitchers who underwent UCLR at a single institution were identified. Charts were reviewed for incidence of medial elbow pain during return to throwing, return to sport, and subsequent operative interventions, including revision ulnar collateral ligament surgery.

Results:

Of a total of 616 pitchers who underwent UCLR during the study period, 317 were included in this study. Medial elbow pain was experienced by 45.1% (143 of 317), with a mean time of complaint of 9.75 months after surgery. The groups with and without pain did not differ statistically with regard to age (pain, 20.6 years; no pain, 20.9 years) or level of competition. Of those who experienced medial elbow pain, 10.5% did not return to sport; 5.6% underwent revision UCLR; and 19.6% underwent other operative procedures at the elbow. Among those who did not experience medial elbow pain when returning to throw, 8.7% did not return to sport, with only 1.7% undergoing revision UCLR and 6.9% undergoing other operative elbow procedures.

Conclusion:

Of the pitchers evaluated in the study, approximately half reported pain during the return-to-throwing phase after UCLR. Those who experienced medial elbow pain had a higher rate of subsequent surgical intervention.

Increased pitch velocity and workload are common risk factors for ulnar collateral ligament injury in baseball players: a systematic review

Importance

Ulnar collateral ligament (UCL) injuries commonly occur in baseball players. Strategies for injury prevention have long been accepted without clinical data informing which risk factors lead to serious injury.

Objective

The objective of this study was to systematically review the impact of various pitching-related risk factors for UCL injury in baseball players from all levels of play.

Evidence review

The electronic databases MEDLINE, EMBASE and PubMed were systematically searched until 4 March 2018, and pertinent data were abstracted by two independent reviewers. Search terms included ‘ulnar collateral ligament’, ‘medial ulnar collateral ligament’, ‘Tommy John’, ‘risk’ and ‘association’. Inclusion criteria were English-language studies, level of evidence I–IV and studies reporting risk factors for UCL injury of the elbow in baseball players. Study quality was assessed using the methodological index for non-randomised studies (MINORS) criteria. The results are presented in a narrative summary.

Findings

Pitching practices (workload and pitch characteristics) were reported in 9/15 studies. Specifically, three of four studies (n=1810) reported increased pitch workload as a risk factor for native UCL injury (p<0.001 to 0.02). The most common pitch characteristic reported was pitch velocity with four of five studies showing increased velocity being significantly associated with native UCL injury (p<0.01 to 0.02). Biomechanical risk factors reported were increased humeral retrotorsion (two studies; n=324), poor lower extremity and trunk balance (one study; n=42) and loss of total arc of shoulder motion (two studies; n=118), all significantly associated with UCL injury (p<0.0001 to 0.05). One of three studies assessing pitch workload as a risk factor for re-rupture of UCL reconstruction found a significant association (p<0.01).

Conclusions and relevance

Pitching practices, reflected by increased pitch workload and velocity, were most commonly associated with UCL injury; however, the definition of workload (number of pitches per game, inning or season) was inconsistently reported. Biomechanical risk factors were less commonly reported and lack sufficient evidence to recommend preventative strategies. More quality data is needed to refine the current recommendations for injury prevention in baseball players.

Level of evidence

III.

Relationship Between Pitching a Complete Game and Spending Time on the Disabled List for Major League Baseball Pitchers

Background:

Injury rates among Major League Baseball pitchers have been increasing over the past several years. It is currently unknown whether pitching a complete game (CG) is a risk factor for spending time on the disabled list (DL).

Purpose/Hypothesis:

The purpose of this study was to determine the relationship between pitching a CG and time on the DL. We hypothesized that pitchers who threw a CG (1) would be at increased risk for spending time on the DL, which would be earlier in the season and for a longer period, than those who did not and (2) would be at further increased risk for spending time on the DL during subsequent seasons than matched controls.

Study Design:

Descriptive epidemiology study.

Methods:

Pitchers who threw a CG between 2010 and 2016 at the major league level and were placed on the DL during the same season were included. Timing and length of period on the DL were determined, as well as placement on the DL during subsequent seasons. Matched controls who did not throw a CG were assessed for time spent on the DL during that season and subsequent seasons.

Results:

Overall, 246 individual pitchers (501 pitcher-seasons) threw at least 1 CG between 2010 and 2016. Of the pitcher-seasons, 370 (73.9%) included a period on the DL, as compared with only 20% of controls. There were no differences in length of time on the DL (P = .928) or days from season start to time on the DL (P = .861) between pitchers who threw a CG and controls. Pitchers who threw a CG were significantly more likely than controls to spend subsequent seasons on the DL (1.9 ± 1.1 vs 0.5 ± 0.9, P < .001).

Conclusion:

Overall, 74% of pitchers who threw a CG spent time on the DL, as compared with 20% of controls. Pitchers who threw a CG during the study period spent more time in subsequent seasons on the DL than did matched controls who did not throw a CG.

Return to Throwing after Shoulder or Elbow Injury

PURPOSE OF REVIEW

Throwing places high demands on the human body, and specific characteristics are developed over time unique to these athletes. When returning to throw after injury, it is important to follow a criterion-based progression that allows the body to be prepared appropriately for the stresses that throwing will require. There is currently a void in the literature for criteria-based progression that helps these athletes return to the highest level of play.

RECENT FINDINGS

As injury rates continue to rise in baseball, there is increased evidence showing contributions of the core and lower extremity to the baseball pitch. There is also additional data showing pitcher specific characteristics such as range of motion and scapular position in this unique population. The rehab professional should take into account every phase of the pitch starting from balance through ball release when designing a comprehensive return-to-throwing program. Returning an athlete back to a throwing sport can be an overwhelming task. The rehabilitation specialist must have a sound understanding of the throwing motion as well as any biomechanical implications on the body, contributions throughout the kinetic chain, range of motion, and strength characteristics specific to the thrower as well as proper tissue loading principles. It is important that these athletes are not progressed too quickly through their programs and that a criteria-based progression is followed. They should have normalized range of motion, strength, and scapular mechanics, followed by a sound plyometric progression. Once this is achieved, they are advanced to an interval throwing program with increasing distance, effort, and volume which should be tracked for workload, making sure they do not throw more than their body is prepared for.

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.