Shear wave elastography of the ulnar collateral ligament in Division IA pitchers across a competitive collegiate season

ABSTRACT BACKGROUND The ulnar collateral ligament (UCL) is a commonly injured elbow stabilizer during throwing. Shear wave elastography (SWE) is a technique that may reveal structural changes in the UCL that are indicative of ligament health and injury risk. The purpose of this study was to assess pre- and in-season shear wave velocity (SWV) in the UCL of collegiate pitchers and to asses repeatability of this measurement technique in healthy volunteers. METHODS 17 collegiate baseball pitchers and 11 sex-matched volunteers were recruited. 2D-SWE of the UCL was performed by a single radiologist. In pitchers, SWV was measured at the proximal, midsubstance and distal UCL for dominant and non-dominant elbows pre-, mid- and postseason, and Kerlan-Jobe Orthopaedic Clinic (KJOC) Shoulder and Elbow questionnaire scores were recorded. In volunteers, SWV was measured at UCL midsubstance in dominant elbows at 3 separate occasions over one week. An independent samples t-test was used to compare preseason midsubstance measures between pitchers and the healthy volunteers. A mixed-model ANCOVA (covaried on preseason measures) was used to compare SWV measures at the pre-, mid-, and postseason timepoints. A similar generalized linear model for non-parametric data was used to compare KJOC scores. Type-I error was set at p