Stress Sonography of the Ulnar Collateral Ligament of the Elbow in Professional Baseball Pitchers

Abstract

Background An injury to the ulnar collateral ligament (UCL) of the elbow is potentially career threatening for elite baseball pitchers. Stress ultrasound (US) of the elbow allows for evaluation of both the UCL and the ulnohumeral joint space at rest and with stress. Hypothesis Stress US can identify morphological and functional UCL changes and may predict the risk of a UCL injury in elite pitchers. Study Design Cross-sectional study; Level of evidence, 3. Methods A total of 368 asymptomatic professional baseball pitchers underwent preseason stress US of their dominant and non-dominant elbows over a 10-year period (2002-2012). Stress US examinations were performed in 30° of flexion at rest and with 150 N of valgus stress by a single musculoskeletal radiologist. Ligament thickness, ulnohumeral joint space width, and ligament abnormalities (hypoechoic foci and calcifications) were documented. Results There were 736 stress US studies. The mean UCL thickness in the dominant elbow (6.15 mm) was significantly greater than that in the nondominant elbow (4.82 mm) (P < .0001). The mean stressed ulnohumeral joint space width in the dominant elbow (4.56 mm) was significantly greater than that in the nondominant elbow (3.72 mm) (P < .02). In the dominant arm, hypoechoic foci and calcifications were both significantly more prevalent (28.0% vs 3.5% and 24.9% vs 1.6%, respectively; P < .001). In the 12 players who incurred a UCL injury, there were nonsignificant (P > .05) increases in baseline ligament thickness, ulnohumeral joint space gapping with stress, and incidence of hypoechoic foci and calcifications. More than 1 stress US examination was performed in 131 players, with a mean increase of 0.78 mm in joint space gapping with subsequent evaluations. Conclusion Stress US indicates that the UCL in the dominant elbow of elite pitchers is thicker, is more likely to have hypoechoic foci and/or calcifications, and has increased laxity with valgus stress over time.

Reliability and Precision of Stress Sonography of the Ulnar Collateral Ligament

“…The ulnohumeral joint space widths reported were different from our measurements; however, the differences with stress application were almost identical. Ciccotti et al 16 demonstrated an ulnohumeral joint space width difference, from rest to stress application, of 1.24 mm in the dominant arm, compared to our gapping measurement of 1.3 mm, and 0.78 mm in the nondominant arm, compared to our gapping measurement of 0.6 mm. Collectively, similar gapping measurements within the literature and this study lend support to the validity of our gapping measurements using stress sonography.…”

“…Lee et al 15 reported the medial elbow gapping in the loaded condition was 1.4 mm in the dominant arm, which was nearly identical to our measurements. A more recent study by Ciccotti et al 16 measured the joint space width and thickness of the UCL under stress sonography in asymptomatic professional baseball pitchers. That study used a standardized valgus load application device with 150 N of valgus force applied.…”

Outcomes for ulnar collateral ligament reconstruction: a retrospective review using the KJOC assessment score with two-year follow-up in an overhead throwing population

“…When MRI studies were inconclusive for a tear of the UCL, stress ultrasound was performed to evaluate for functional instability. 7,22 Patients with a partial UCL injury by MRI were initially treated nonoperatively. Conservative treatment included a period of throwing cessation, physical therapy, anti-inflammatory medications, and an interval throwing program when symptoms resolved.…”

Medial elbow pain in the overhead athlete

“…Ciccotti et al 12 utilized stress sonography to characterize the UCL in asymptomatic professional baseball pitchers. Ciccotti et al 12 utilized stress sonography to characterize the UCL in asymptomatic professional baseball pitchers.…”