Paper 12: Revision Ulnar Collateral Ligament Reconstruction in Major League Baseball Pitchers: Effect on Fastball Velocity and Usage

Abstract

Objectives:

Ulnar collateral ligament (UCL) tears are prevalent in Major League Baseball (MLB) pitchers and cause significant loss of time with varying reports of impact on performance. Revision UCL reconstruction (UCLR) is increasingly common, with little known about the effects on both fastball (FB) velocity and usage (%) in this setting. The purpose of this study was to evaluate the effect of revision UCLR on MLB pitchers with respect to post-operative FB % and velocity at one and two years after return-to-play. The hypothesis was that post-operative FB usage (FB%) and velocity would significantly decrease versus pre-injury levels in the revision UCLR group, and that revision UCLRs would result in significantly decreased FB % and velocity in comparison to a matched group of MLB pitchers after primary UCLRs.

Methods:

Public records were used to identify MLB pitchers from 2008 to 2020 who underwent a revision UCLR. The PITCHf/x system, which was installed in 2007 and is a standardized recording of all pitches thrown in MLB stadiums, collected FB velocity for four-seam (4FB) and two-seam (2FB) fastballs and total FB % for pitchers in the pre-injury year as well as the first two years after return. A matched control group of pitchers who underwent primary UCLR was used for comparison.

Results:

Nineteen pitchers fit the study criteria. There were no significant differences in the revision UCLR group in FB velocity between pre-injury levels (4FB 92.87 mph, 2FB 91.43 mph) and years one (4FB 92.55 mph, p=.375) (2FB 91.2 mph, p=0.448) and two (4FB 93.38 mph, p=.695) (2FB 91.59 mph, p=0.806) after return (Table 1). There were also no significant differences in FB % usage between the pre-injury season (60.4) and first (56.5, p=.095) or second years (52.5, p=.053) after return (Table 1). In terms of walks and hits per innings pitched (WHIP), strikeouts per 9 innings (K/9), and walks per 9 innings (BB/9), the only significant difference between pre-injury and post-injury outcomes was a significant higher K/9 in the first season after return (p=0.031) (Table 1).

There were no significant differences between FB velocity or % usage between the revision and primary UCLR groups at any time point (Tables 2-4). There were also no significant differences in the revision and primary UCLR groups between WHIP, K/9, or BB/9 with the exception of lower WHIP (p=0.015) and K/9 (p=0.001) in the pre-injury season (Tables 2-4).

Conclusions:

In pitchers that return to the MLB level, there were no significant differences in FB velocity versus their pre-injury levels or in comparison to pitchers after primary UCLR. While not statistically significant, a trend was demonstrated that there was a clinically relevant decrease in FB % usage, potentially suggesting less confidence in their FB.

Table 1.

Comparison of major league baseball (MLB) revision ulnar collateral ligament reconstruction (UCLR) between pre-injury and post-operative performance. The pre-injury performance was collected for the year prior to injury while the post-operative performance was collected for the first and second years after return-to-play. Statistical comparisons were made between pre-injury performance versus the performance at 1 and 2 years after return to the MLB. Fastball (FB) velocity reported as a mean in miles-per-hour (mph). WHIP- walks and hits per inning pitched, BB/9-walks per 9 inning, K/9- strikeouts per 9 innings, *-statistically significant

Table 2.

Comparison of major league baseball (MLB) pitchers with revision ulnar collateral ligament reconstruction (UCLR) versus a group of primary UCLR (controls) in their pre-injury season prior to their respective surgical intervention. Fastball (FB) velocity reported as a mean in miles-per-hour (mph).. WHIP- walks and hits per inning pitched, BB/9-walks per 9 inning, K/9- strikeouts per 9 innings, *-statistically significant

Table 3.

Comparison of major league baseball (MLB) pitchers with revision ulnar collateral ligament reconstruction (UCLR) versus a group of primary UCLR (controls) in their first season after return to play. Fastball (FB) velocity reported as a mean in miles-per-hour (mph). WHIP- walks and hits per inning pitched, BB/9-walks per 9 inning, K/9- strikeouts per 9 innings, *-statistically significant

Table 4.

Comparison of major league baseball (MLB) pitchers with revision ulnar collateral ligament reconstruction (UCLR) versus a group of primary UCLR (controls) in their second season after return to play. Fastball (FB) velocity reported as a mean in miles-per-hour (mph). WHIP- walks and hits per inning pitched, BB/9-walks per 9 inning, K/9- strikeouts per 9 innings, *-statistically significant