Effect of Ulnar Collateral Ligament Reconstruction on Pitch Accuracy, Velocity, and Movement in Major League Baseball Pitchers

Rehabilitation Protocols in Elbow Medial Ulnar Collateral Ligament Injuries: A Systematic Review of Articles Published in the Last 20 Years

CONTEXT

Elbow medial ulnar collateral ligament (UCL) injuries have become increasingly common in athletes. Despite this, rehabilitation protocols appear to vary drastically, which may explain the clinical equipoise regarding optimal management.

OBJECTIVE

This systematic review reports rehabilitation characteristics reported after UCL injuries and compares reported outcomes based on early versus delayed rehabilitation.

DATA SOURCES

Our search utilized PubMed/MEDLINE, Embase, Web of Science, and Cochrane to identify all articles on UCL rehabilitation published between January 1, 2002 and October 1, 2022.

STUDY SELECTION

Studies in English with ≥5 patients that reported rehabilitation protocols for UCL injuries were evaluated.

STUDY DESIGN

Systematic review.

LEVEL OF EVIDENCE

Level 4.

DATA EXTRACTION

Data included sample characteristics, time to achieve physical therapy milestones, outcome scores, and return-to-play (RTP) rate and timing.

RESULTS

Our review included 105 articles with a total of 15,928 elbows (98% male; weighted mean age, 23 years; follow-up, 47 months), with 15,077 treated operatively and 851 treated nonoperatively. The weighted mean time patients spent adhering to nonweightbearing status was 42 days. The mean time until patients were given clearance for active range of motion (ROM) 15 days, full ROM 40 days, and elbow strengthening exercises 32 days. The mean time until all restrictions were lifted was 309 days. The mean time to begin a throwing program was 120 days. Across all rehabilitation characteristics, protocols for patients undergoing nonoperative management started patients on rehabilitation earlier. After UCL reconstruction, earlier active ROM (≤14 days), elbow strengthening (≤30 days), no restrictions (≤180 days), and throwing (≤120 days) postoperatively led to earlier RTP without a negative effect on functional outcome scores.

CONCLUSION

Current literature provides a spectrum of protocols for elbow UCL rehabilitation, regardless of management. Nonoperative patients began ROM activities, strengthening, and throwing programs sooner than operative patients, and earlier milestones led to earlier RTP.

Effect of Ulnar Collateral Ligament Reconstruction on Performance in Major League Baseball Pitchers: A 2-Year Analysis of Advanced Pitching Statistics, Velocity, and Spin Rate

BACKGROUND

Ulnar collateral ligament reconstruction (UCLR) is a common procedure for Major League Baseball (MLB) pitchers, with a rising incidence and significant financial and performance implications. However, the effect of UCLR on postinjury pitching performance remains controversial, particularly regarding advanced metrics such as spin rate and velocity.

PURPOSE

To evaluate changes in pitching performance after UCLR and the association between pitch velocity, spin rate, and performance.

STUDY DESIGN

Case-control study; Level of evidence, 4.

METHODS

A total of 43 MLB pitchers who underwent UCLR between 2017 and 2021 were compared with 86 uninjured age-matched controls. Pitching metrics, including fielding independent pitching, skill-interactive earned run average, and walks plus hits per inning pitched, as well as pitch-specific velocity and spin rate were analyzed for 2 seasons before and at least 1 season after UCLR. Principal component analysis was used to assess overall performance.

RESULTS

Pitchers showed a significant decline in overall performance during the first season after UCLR (P = .032) but returned to preinjury levels by the second season (P = .287). There was a significant decrease in the off-speed pitch spin rate observed in the first season (P = .041), but all other pitches demonstrated no significant change throughout the study period. Increases in fastball velocity (P = .046), fastball spin rate (P = .019), and off-speed pitch velocity (P = .016) were associated with superior overall performance.

CONCLUSION

The current study demonstrated that while pitchers experienced a significant decline in performance during the first season after UCLR, most of those who returned for a second season returned to their baseline preinjury performance. Additionally, increased velocity and spin rate were associated with improved performance in both injured and healthy pitchers, highlighting the value of these metrics in evaluating overall pitching performance.

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.

Changes in Pitch Velocity and Selection in Major League Baseball Pitchers Following the Ulnar Collateral Ligament Reconstruction

BACKGROUND

The ulnar collateral ligament (UCL) is a soft-tissue stabilizer of the elbow, that is commonly injured among baseball pitchers due to excess valgus stress in overhead throwing motions. The location of a UCL tear typically ranges from the central aspect of the ligament to an avulsion-type injury at its proximal insertion site on the medial epicondyle of the humerus, or its distal insertion site on the ulna. The effect of UCL reconstruction on pitching performance has become a well-studied topic in medical literature. In our study, we aimed to identify general performance patterns amongst those having undergone UCL reconstruction surgery.

METHODS

Data for patients with UCL reconstruction performed between 2010 and 2020 were extracted from publicly available databases. Pitching data was extracted from Brooks Baseball, a publicly available database for Major League Baseball (MLB) player statistics. We identified patients who played at least one full season after surgery and rehabilitation. Patient characteristics were evaluated for intergroup differences.

RESULTS

Of 109 patients with UCL reconstruction, 87 were included in the final analysis. Compared to the preoperative group, the average postoperative fastball usage rate was less despite there being an increase in the off-speed usage rate. Velocity analysis demonstrated shifts of less than 1% for all three pitch groups compared to preoperative velocity average values (all P-values <0.05). Earned Run Average (ERA)+ demonstrates a decrease in the postoperative group; this finding was not significant (P=0.61).

CONCLUSIONS

 Patients treated surgically demonstrated a throwing tendency for their secondary and tertiary pitches and a decreased usage of fastballs. Further studies are needed to explore the factors contributing to the change in pitching performance.

Dynamic Stress Ultrasound Assessment of Professional Baseball Players' Elbows After Ulnar Collateral Ligament Reconstruction

BACKGROUND

There is a paucity of data analyzing dynamic stress ultrasound (SUS) findings in elite pitchers who have undergone ulnar collateral ligament (UCL) reconstruction (UCLR) and returned to sport.

PURPOSE

To identify longitudinal, perioperative changes in the elbows of professional baseball pitchers who have undergone UCLR and to compare these findings with a matched cohort of healthy pitchers.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

This study used prospectively collected data from dynamic elbow SUS analyses of professional baseball pitchers within a single Major League Baseball organization. Pitchers were divided into 2 cohorts: a UCLR cohort and healthy cohort. The UCLR cohort eligibility included availability of (1) SUS from preseason of injury/UCLR and (2) SUS from ≥2 years after surgery. These players were 1:1 matched to players with no history of upper extremity injury to form the healthy cohort. Ligament thickness and ulnohumeral joint space at rest and under stress were directly measured. Joint laxity was calculated by subtracting joint space at rest from joint space under stress. The term "relative" was used to describe calculated differences where nondominant measurements were subtracted from dominant-side measurements.

RESULTS

Eight pitchers were included in the UCLR group and matched to 8 healthy pitchers (mean age at initial SUS examination, 19.6 years). At a minimum follow-up of 2 years, there were no significant differences between groups in terms of relative or dominant arm rest space, stress space, or laxity. Longitudinally (final measurements - baseline measurements), the mean relative ulnohumeral rest space decreased in the UCLR group and increased in the healthy group (-0.36 mm vs +0.50 mm; P = .032). The finding of increased UCL thickness in the UCLR group was expected, as UCL grafts are typically thicker than native ligaments.

CONCLUSION

Ulnhohumeral joint stability was achieved after UCLR as indicated by similar rest space, stress space, and joint laxity in dominant arms compared with a matched healthy cohort. A significant decrease in relative rest space after UCLR may represent the achievement of stability in surgery patients. Alternatively, the increase in ulnohumeral rest space seen in the healthy cohort may represent adaptive changes from pitching at a professional level.

Ulnar Collateral Ligament Reconstruction Does Not Decrease Spin Rate or Performance in Major League Pitchers

BACKGROUND

Ulnar collateral ligament reconstruction (UCLR) is commonly performed in Major League Baseball (MLB) pitchers, with variable reported effects on velocity and traditional rate statistics. Currently, no studies have evaluated spin rate in the context of return to play (RTP) after injury. Greater spin rate has become increasingly sought after in the baseball community, as it is believed to be a vital aspect of pitch effectiveness.

PURPOSE/HYPOTHESIS

The purpose was to evaluate the effect of primary UCLR on fastballs (FB) and sliders (SL) of MLB pitchers in terms of spin rate, velocity, hard-hit rate, and whiff rate. It hypothesized that the post-UCLR FB and SL spin rates, velocity, and whiff rate would be significantly decreased versus their pre-UCLR levels, while the FB and SL hard-hit rates would be higher in comparison with pre-UCLR levels.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

In total, 42 pitchers who underwent UCLR and returned to MLB play were identified from public records from 2016 to 2019. The Statcast system was used to collect spin rate, velocity, hard-hit rate, and whiff rate for 4-seam FB (4FB), 2-seam FB (2FB), and SL for pitchers in the preinjury year as well as the 2 years after return from UCLR. Data were analyzed using the appropriate statistical tests.

RESULTS

A total of 36 pitchers met the inclusion criteria, and 31 of the eligible 36 players (86.1%) were able to return to MLB pitching (RTP). There were no significant decreases for 4FB, 2FB, or SL in spin rate, measured in revolutions per minute (rpm), when comparing preinjury levels with the first and second seasons after return. There was a significant decrease in velocity for the 2FB in the first season (92.9 vs 93.7 miles per hour [mph]; P = .045) but not the second season (93 mph; P = .629) after RTP in comparison with pre-UCLR levels. For the 2FB, there was a significant increase in spin rate between preinjury and RTP season 2 (2173.5 vs 2253 rpm; P = .022). For the SL, there was a significant increase in spin rate between preinjury and RTP season 2 (2245.1 vs 2406 rpm; P = .016).

CONCLUSION

A cohort of MLB pitchers who underwent UCLR and returned to the MLB level demonstrated no significant decreases in the spin rate, velocity, whiff rate, or hard-hit rate of 4FB, 2FB, or SL at 2 years after UCLR.

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.