The aim of this review is to evaluate the current available literature evidencing on peri-articular hip endoscopy (the third compartment). A comprehensive approach has been set on reports dealing with endoscopic surgery for recalcitrant trochanteric bursitis, snapping hip (or coxa-saltans; external and internal), gluteus medius and minimus tears and endoscopy (or arthroscopy) after total hip arthroplasty. This information can be used to trigger further research, innovation and education in extra-articular hip endoscopy.

Unexplained pain after hip arthroplasty is frustrating for patients and surgeons. The purpose of this study was 1. to describe the use of hip arthroscopy in management of the painful hip arthroplasty, 2. to critically evaluate the outcomes these patients, and 3. to help define indications for hip arthroscopy in this setting. We retrospectively reviewed 14 patients (16 hips) who underwent hip arthroscopy after joint replacement. One patient had suspected septic arthritis despite negative aspiration and one had known septic arthritis but was not a candidate for open arthrotomy; two had intra-articular migration of hardware. The remaining 10 patients (11 hips) had persistent pain despite negative diagnostic studies. The two patients (two hips) with infection were successfully treated with arthroscopic lavage and debridement plus intravenous antibiotics. Intra-articular metal fragments and a loose acetabular screw were successfully removed in two patients (three hips). Findings in remaining the 11 hips included a loose acetabular component (one); corrosion at the head-neck junction of a metal-on-metal articulation (one); soft tissue-scar impingement at the head cup interface (four); synovitis with associated scar tissue (four); and capsular scarring with adhesions (one). Arthroscopy represented a successful treatment or directly led to a successful treatment in 12 of 16 hips. We observed no complications as a result of the arthroscopy. Arthroscopy may be of value in selected patients