Ultrasound and shear-wave elastography of the lateral and medial epicondylar entheses in racket-sport players: a cross-sectional comparative study

Introduction Inflammatory and mechanical enthesopathies may share ultrasonographic features, particularly in non -weight-bearing entheses such as the elbow epicondyles, where adaptive changes and disease-related alterations can overlap. This study aimed to characterise the effect of biomechanical stress on elbow entheses in racket-sport players, focusing on ultrasound findings relevant for distinguishing physiological adaptation from inflammatory enthesopathy. Methods We conducted a cross-sectional comparative study including 45 racket-sport players and 45 matched non-racket-sport controls. Bilateral elbow entheses (lateral and medial epicondyle) were assessed using B-mode ultrasound, power Doppler, and shear-wave elastography. The ultrasound assessment included thickness, stiffness, echotexture, enthesophytes, and hyperemia. Correlations between cumulative practice time and ultrasonographic parameters were analysed. Results Racket players showed significantly greater enthesis thickness and stiffness in the dominant elbow compared with controls ( p < 0.001 for all comparisons). Thickness strongly correlated with cumulative practice time in the dominant lateral and medial epicondyle ( r = 0.899 and r = 0.928, respectively). Enthesophytes were more frequent among players (24.4% vs. 6.6%; OR 4.52 p = 0.04). Among racket-sport players, all enthesophytes occurred in the dominant elbow. In controls, enthesophytes were also observed in non-dominant elbows. Clinically significant Power Doppler signal was absent in controls but present in one player. Discussion These findings indicate that chronic biomechanical stress may induce structural and elastographic changes in non-weight-bearing entheses. Recognising these adaptive patterns may help refine ultrasound scoring systems and improve discrimination between physiological adaptation and inflammatory enthesopathy in spondyloarthritis.