Radiographic and Clinical Outcomes of Adolescents With Acetabular Retroversion Treated Arthroscopically.

Background: Retroversion of the acetabulum is a cause of pincer impingement. Symptomatic retroversion has traditionally been treated with anteverting periacetabular osteotomy (PAO). However, arthroscopic rim trimming can also treat pincer impingement associated with acetabular retroversion. The purpose of this study was to report the outcomes and radiographic findings in a series of adolescent patients with symptomatic acetabular retroversion treated arthroscopically.

Methods: Data were prospectively gathered at a single institution using an established hip preservation registry. Patients below 18 years with a retroverted acetabulum that underwent primary hip arthroscopy with 2-year follow-up were included. Acetabular retroversion was defined by 3 radiographic criteria: the presence of crossover, ischial spine sign, and posterior wall sign. Radiographic measurements of the lateral center-edge angle, anterior center-edge angle, alpha angle, and crossover percentage were reported preoperatively and postoperatively. Patient-reported outcome (PROs) measures included the modified Harris Hip Score, the non-Arthritic Hip Score, Hip Outcome Score Sports Subscale, visual analog scale, and patient satisfaction, recorded at 3 months, 1 year, and 2 years, postoperatively. In addition, International Hip Outcome Tool scores were gathered at 2 years.

Results: Between April 2008 and July 2014, there were 43 patients (48 hips) treated with hip arthroscopy who met the inclusion criteria. The average age was 16.1 years (range, 13.9 to 17.9 y) and there were 38 females and 10 males. The average follow-up was 50.4 months, with a minimum of 2 years. Statistically significant improvements in all PROs were found at 2 years postoperatively. There were 9 hips with lateral center-edge angle ≤25 degrees; the PROs of this group was not different than patients with normal coverage. Three patients underwent arthroscopic revision. No patient subsequently underwent anteverting PAO during the study period. There were no reported complications.

Conclusions: Femoroacetabular impingement caused by acetabular retroversion treated with hip arthroscopy demonstrates good outcomes at 2 years with a low complication rate. Symptomatic adolescents may be safely and successfully treated arthroscopically, potentially avoiding anteverting PAO.

Study Design: Level of evidence 4-case series.