The "Wave Sign" as Evidence of a "GUCCI" (Gluteal Undersurface Concealed Crescent Injury) Lesion: A Case Report

A 63-year-old female presented with left lateral hip pain consistent with greater trochanteric pain syndrome (GTPS) and magnetic resonance imaging (MRI) findings of high-grade gluteal tendinosis and partial tearing. She failed conservative management and was thus indicated for endoscopic greater trochanteric bursectomy and gluteal tendon repair. Intraoperatively, the superficial gluteus medius tendon fibers were intact, but a "wave sign" was present on dynamic examination. Subsequent investigation revealed a proposed GUCCI (gluteal undersurface concealed crescent injury) lesion, which underwent endoscopic repair. This case highlights the importance of dynamic endoscopic examination of the gluteal tendons, as identification of a trochanteric "wave sign" may reveal clinically significant pathology concealed beneath intact bursal-sided fibers.