Performance Metrics in Professional Baseball Pitchers before and after Surgical Treatment for Neurogenic Thoracic Outlet Syndrome.

Background: High-performance throwing athletes may be susceptible to the development of neurogenic thoracic outlet syndrome (NTOS). This condition can be career-threatening but the outcomes of treatment for NTOS in elite athletes have not been well characterized. The purpose of this study was to utilize objective performance metrics to evaluate the impact of surgical treatment for NTOS in Major League Baseball (MLB) pitchers.

Methods: Thirteen established MLB pitchers underwent operations for NTOS between July 2001 and July 2014. For those returning to MLB, traditional and advanced (PitchF/x) MLB performance metrics were acquired from public databases for various time-period scenarios before and after surgery, with comparisons made using paired t-tests, Wilcoxon matched-pair signed-rank tests, and Kruskal-Wallis analysis of variance.

Results: Ten of 13 pitchers (77%) achieved a sustained return to MLB, with a mean age of 30.2 ± 1.4 years at the time of surgery and 10.8 ± 1.5 months of postoperative rehabilitation before the return to MLB. Pre- and postoperative career data revealed no significant differences for 15 traditional pitching metrics, including earned run average (ERA), fielding independent pitching, walks plus hits per inning pitched (WHIP), walks per 9 innings, and strikeouts to walk ratio (SO/BB). There were also no significant differences between the 3 years before and the 3 years after surgical treatment. Using PitchF/x data for 72 advanced metrics and 25 different time-period scenarios, the highest number of significant relationships (n = 18) was observed for the 8 weeks before/12 weeks after scenario. In this analysis, 54 (75%) measures were unchanged (including ERA, WHIP, and SO/BB) and 14 (19%) were significantly improved, while only 4 (6%) were significantly decreased (including hard pitch maximal velocity 93.1 ± 1.0 vs. 92.5 ± 0.9 miles/hr, P = 0.047). Six pitchers remained active in MLB during the study period, while the other 4 had retired due to factors or injuries unrelated to NTOS.

Conclusions: Objective performance metrics demonstrate that pitchers returning to MLB after surgery for NTOS have had capabilities equivalent to or better than before treatment. Thoracic outlet decompression coupled with an ample period of postoperative rehabilitation can provide effective treatment for professional baseball pitchers with career-threatening NTOS.