Ultrasound Definitions and Findings in Greater Trochanteric Pain Syndrome: A Systematic Review.

Ultrasound (US) assists in the determination of the pathology underlying greater trochanteric pain syndrome (GTPS); however, there exists no consensus regarding the US criteria used to define these pathologies. We aim to explore these US definitions and their associated prevalence. "Trochanteric bursitis" was defined in 10 studies (13 included studies) and was heterogeneously described. "Tendinopathy" was defined in 4 studies, while 7 studies defined "tendinosis." "Tendon tears" were defined in 8 studies, 6 of which distinguished between "partial- and full-thickness tears." Tendon pathology was most frequent in 5 studies (prevalence: 7%-93%), and bursitis in 2 studies (prevalence: 10%-75%); 3 studies had equal distribution. Methodological quality was limited in the descriptions of GTPS and US approaches. Together, we document the lack of standardized US definitions of the pathologies underlying GTPS. This may explain the heterogenous prevalence of US findings. Standardized definitions are needed to improve the reliability of future GTPS studies.