Anterior Inferior Iliac Spine Deformity as an Extra-Articular Source for Hip Impingement: A Series of 10 Patients Treated With Arthroscopic Decompression

PurposeTo describe an arthroscopic technique for decompression of a prominent anterior inferior iliac spine (AIIS) leading to extra-articular hip impingement and to provide short-term outcome after this procedure.MethodsWe retrospectively reviewed office charts, imaging studies, operative reports, arthroscopic images, preoperative and postoperative hip flexion range of motion, and preoperative and postoperative modified Harris Hip Scores in a consecutive series of 10 male patients who had arthroscopic decompression of symptomatic AIIS deformities leading to extra-articular hip impingement. The procedure was performed through standard anterolateral and mid-anterior hip arthroscopy portals that were also used to explore the joint and address concomitant intra-articular pathologies.ResultsThe mean age was 24.9 years, with 8 of 10 patients aged younger than 30 years. In 9 patients, an anterior cam lesion was identified and decompressed before the AIIS decompression. The mean follow-up time was 14.7 months (range, 6 to 26 months). Hip flexion range of motion improved from 99° ± 7° before surgery to 117° ± 8° after surgery (P < .001). The modified Harris Hip Score improved from 64 ± 18 before surgery to 98 ± 2 at latest follow-up after surgery (P < .001).ConclusionsArthroscopic decompression of a symptomatic AIIS deformity is a reproducible procedure that can provide excellent outcomes at short-term follow-up. As opposed to using an open approach for decompressing a prominent AIIS, an arthroscopic approach may be of particular value in patients with mixed intra- and extra-articular sources of hip dysfunction, because it enables the surgeon to address all pathologies with a single arthroscopic procedure.Level of EvidenceLevel IV, therapeutic case series.