Poster 209: Physical Examination vs Ultrasonography for Detection of Ulnar Nerve Subluxation in Professional Baseball Pitchers

OBJECTIVES: Despite the importance of accurately detecting the presence of ulnar nerve subluxation in vulnerable athletes, minimal research has compared the performance of physical examination and ultrasound in professional baseball pitchers. Therefore, the purpose of this study was to characterize the diagnostic validity of physical examination in the detection of ulnar nerve subluxation at the cubital tunnel of the elbow compared with ultrasound. METHODS: Physical and sonographic examinations for ulnar nerve subluxation were performed on 186 elbows of 95 consecutive male professional baseball pitchers (ages 17 to 30 years) as a routine part of Spring Training assessments. Provocative maneuvers consisting of Tinel’s test and the elbow flexion compression test were evaluated over the cubital tunnel. The validity of physical examination for detecting ulnar nerve subluxation at the elbow was determined using ultrasound as the gold standard for comparison. RESULTS: Ulnar nerve subluxation was detected by physical examination in 58 (31.2%) elbows and by ultrasonography in 61 (32.8%) elbows. Of the 58 elbows with positive physical examination, 47 were positive on ultrasound. The accuracy of physical examination was 86.6%, with 77.0% sensitivity and 91.2% specificity. The positive and negative predictive value of physical examination were 81.0% and 89.1%, respectively. There was no relationship between nerve instability and positive provocative tests overall, in dominant vs nondominant arms, or in right vs left arms (all P > .05). CONCLUSIONS: Physical examination has moderate sensitivity and high specificity for detecting ulnar nerve subluxation at the cubital tunnel of the elbow when compared with ultrasound. These findings suggest that when detecting the presence of a subluxating ulnar nerve is most important, it may be advisable to obtain an ultrasound evaluation instead of relying on physical examination; however, physical examination alone may be appropriate for ruling out subluxation.