Endoscopic treatment of gluteus medius tendon tear

Tears in the gluteus medius and minimus tendons are a common cause of greater trochanter pain syndrome (GTPS). Given the non-specific clinical signs and imaging findings, they are often misdiagnosed, with delayed treatment. The lesions can show several aspects: trochanteric bursitis, simple tendinopathy, partial or full-thickness tear, tendon retraction, or fatty degeneration. Non-surgical treatment associates physical rehabilitation and activity modification, oral analgesics, anti-inflammatories and peri-trochanteric injections (corticosteroids, PRP). In the event of symptoms recalcitrant to medical treatment, surgery may be indicated. A 5-stage classification according to intraoperative observations and elements provided by MRI is used to guide technique: isolated bursectomy with microperforation, single or double row tendon repair, or palliative surgery such as muscle transfer (gluteus maximus with or without fascia lata). The development of conservative hip surgery now makes it possible to perform all of these surgical techniques endoscopically, with significant improvement in functional scores and pain in the short and medium term and a lower rate of complications than with an open technique. However, tendon retraction and fatty degeneration have been reported to be factors of poor prognosis for functional results and tendon healing and palliative tendon transfer gives mixed results for recovery of tendon strength. It is therefore preferable not to wait for the onset of Trendelenburg gait to propose endoscopic repair of the gluteus medius tendon in case of pain with a tear visible on MRI and failure of more than 6 months' medical treatment. Based on expert opinion, this article provides an update on the diagnosis of gluteus medius lesions, treatment, and in particular the place of endoscopy, indications and current results. LEVEL OF EVIDENCE: V.