Using Stress Ultrasonography to Understand the Risk of UCL Injury Among Professional Baseball Pitchers Based on Ligament Morphology and Dynamic Abnormalities.

BACKGROUND: Ulnar collateral ligament (UCL) injury of the elbow is a common and debilitating problem seen frequently among elite baseball pitchers. Ultrasound is a useful diagnostic tool in evaluating UCL injuries. HYPOTHESIS: Evaluation with stress ultrasound of the elbow to measure the morphology of the UCL and the ulnohumeral joint space gapping is indicative of higher risk of UCL injury among professional baseball pitchers. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: Ultrasound imaging was used to assess the medial joint laxity of the elbow of 70 asymptomatic professional baseball pitchers during spring training. Medial joint laxity and UCL morphology were assessed with OsiriX imaging software under 2 conditions-gravity valgus load and 5.5 lb of valgus load per a handheld dynamometer-with the shoulder in the maximal cocking position and the elbow in 90° of flexion. Two trials of resting position, elbow gapping, and UCL thickness were collected, measured, and averaged for data analysis. Intra- and interrater reliabilities were established and maintained, with intraclass correlation coefficients in the acceptable range for all measures (0.84-0.99). One-way analysis of variance was used to compare dominant variables between those pitchers who sustained a subsequent UCL injury and those who did not. A receiver operating curve was used to identify pitchers who, based on elbow gapping measures (by cut score), were at high risk versus low risk for UCL injury. RESULTS: Players who went on to injure the UCL (n = 7) displayed a significantly wider opening under 5.5 lb of applied stress (6.5 ± 1.2 vs 5.3 ± 1.2 mm, P = .01) when compared with pitchers without UCL injury history (n = 63); they also presented a trend toward wider dominant arm resting joint opening (4.9 ± 1.2 vs 4.0 ± 1.1 mm, P = .07). Professional pitchers with valgus stress ulnohumeral joint gapping ≥5.6 mm (area underneath the curve, 0.77; P = .02) of the dominant arm were at a 6-times greater risk of sustaining a UCL tear requiring reconstruction within a season. CONCLUSION: Our data suggest that ultrasound evaluation of UCL morphology may be indicative of pitchers who are at risk of sustaining UCL injury and that it may improve player assessment.

Osteonecrosis of the femoral head in childhood malignancy.

PURPOSE: Children undergoing chemotherapeutic treatment of malignancies have up to a 9 % incidence of osteonecrosis. The purpose of this article is to determine the time from initiation of chemotherapy to the onset of symptoms and the diagnosis of osteonecrosis of the femoral head in this patient population. METHODS: A retrospective review of the records of 18 patients (29 hips) under 21 years of age with both a diagnosis of osteonecrosis of the femoral head and childhood onset malignancy was undertaken to determine the time from initiation of chemotherapy to the onset of symptoms and diagnosis of osteonecrosis of the femoral head. RESULTS: Mean time from initiation of chemotherapy to the onset of pain was 18.8 months (8.0-49.1). The mean time from development of pain to diagnosis of osteonecrosis was 3.9 months (-13.1 to 25). The mean overall time from initiation of chemotherapy to diagnosis of osteonecrosis was 22.7 months (9.0-54.1). 11/18 patients had bilateral disease. 16/18 patients (21/29 hips) had already progressed to stage 4 osteonecrosis at the time of diagnosis. CONCLUSIONS: There was a high incidence of stage 4 or greater osteonecrosis at the time of diagnosis. Providers caring for these patients should be aware of the potential for osteonecrosis, and the need for prompt diagnosis and referral to an orthopedic surgeon. Screening with advanced imaging studies may be warranted for children undergoing chemotherapeutic regimens for childhood malignancy to prevent delay in the diagnosis and management of this process so that joint preservation therapies remain an option.