Factors Associated With Failure of Hip Arthroscopy in Patients With Hip Dysplasia

The purpose of this study was to compare a group of dysplastic hips treated successfully with hip arthroscopy with a group of dysplastic hips treated unsuccessfully with hip arthroscopy to determine (1) preoperative patient characteristics and radiographic parameters and (2) intraoperative findings and treatment associated with outcome. The authors retrospectively reviewed a prospective database of 20 adult patients (17 female, 3 male) with hip dysplasia who underwent primary hip arthroscopy between January 2009 and February 2013. Modified Beck scores to quantify cartilage damage as well as preoperative and postoperative radiographic measurements (including alpha, Tonnis, and lateral center edge angles [LCEAs]) were compared between patients who failed hip arthroscopy (11 patients) and those who did not (9 patients). Failure after hip arthroscopy was defined as a modified Harris hip score of less than 80 or the need for subsequent hip arthroscopy, arthroplasty, or periacetabular osteotomy. The mean follow-up for the successful patients was 58 months (range, 37-82 months), with an average modified Harris hip score of 93 at most recent follow-up. Preoperative radiographs showed a lower mean LCEA (18.0 degrees vs 21.3 degrees; P=. 02) in the failure group, and all successes occurred with a LCEA of 17 degrees or greater. The failure group was more likely to have rim resection of greater than 3 mm performed (hazard ratio, 3.53; P=. 04). Among the hips with dysplasia undergoing arthroscopic treatment, patients with a poor outcome were more likely to have an LCEA of less than 17 degrees and intraoperative rim resection of greater than 3 mm. Furthermore, the labral repair group did substantially better than the labral debridement group.