Prevalence of bilateral ulnar nerve subluxation among professional baseball pitchers.

BACKGROUND: Radiographic and physical examination findings of ulnar nerve instability have been recognized in overhead throwing athletes, despite the fact that some of these abnormalities may be asymptomatic and represent adaptive changes. While recommendations for screening and early detection have been made that can adversely impact an athletes' career, the presence of bilateral ulnar nerve subluxation and its relationship with medial elbow symptoms has not been characterized in professional overhead throwing athletes. PURPOSE: To characterize the prevalence of bilateral ulnar nerve subluxation among professional baseball pitchers. METHODS: A cross-sectional observational analysis was conducted utilizing standardized ultrasonographic examinations of bilateral elbows in 91 consecutive professional baseball pitchers (median age, 22 years; range, 17-30 years). The relationship between ulnar nerve subluxation and ulnar nerve signs, symptoms, and provocative physical examination maneuvers was also investigated. RESULTS: The prevalence of bilateral ulnar nerve subluxation was 26.4% (95% CI, 17.7%-36.7%; 24 of the 91 athletes). Thirty-five athletes (38.5%; 95% CI, 28.4%-49.2%) had subluxation in at least 1 elbow. No athletes with subluxation had positive ulnar nerve signs, symptoms, or provocative tests. CONCLUSION: Ulnar nerve subluxation is common among professional pitchers, and is more often than not bilateral. In this population of athletes, ulnar nerve subluxation does not appear to be associated with pathological findings.