Comparison of Dynamic Sonography to Stress Radiography for Assessing Glenohumeral Laxity in Asymptomatic Shoulders

Abstract

Background Stress radiography has been the established imaging method for quantifying glenohumeral joint laxity. Dynamic ultrasound is an alternative imaging method that may be used to measure glenohumeral laxity; however, validity and repeatability have not been examined. Objective To determine criterion-related validity and repeatability of a sonographic imaging method for measuring glenohumeral laxity in asymptomatic shoulders. Study Design Controlled laboratory study. Methods In experiment 1, 20 subjects were assessed for glenohumeral laxity using stress radiography and dynamic ultrasound. In the second experiment, 13 subjects were assessed for laxity in 2 separate test sessions using the dynamic ultrasound technique. Results Correlational analysis between the sonographic and radiographic measures revealed an r = 0.79 (r2 = 0.62), indicating excellent criterion-related validity for the sonographic imaging method. Test-retest repeatability was 0.72 and 0.85 for anterior and posterior translation, respectively, and interrater repeatability was 0.96 and 0.99 for anterior and posterior translation, respectively. Conclusions Dynamic ultrasound appears to be a valid and repeatable method for assessing glenohumeral laxity in a clinical setting. Clinical Relevance Based on the results of this study, dynamic ultrasound is a repeatable and valid method for measuring glenohumeral laxity and therefore may be used as a viable replacement for stress radiography during assessments of glenohumeral laxity.