Anterior Inferior Iliac Spine Deformity as an Extra-Articular
Source for Hip Impingement: A Series of 10 Patients Treated
With Arthroscopic Decompression
Iftach Hetsroni, M.D., Christopher M. Larson, M.D., Katrina Dela Torre, R.N., M.S.N.,
Robert M. Zbeda, B.A., Erin Magennis, M.Sc., and Bryan T. Kelly, M.D.
Purpose: To 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. Methods: We 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. Results: The 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). Conclusions: Arthroscopic
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 decom-
pressing 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 Evidence: Level IV,
therapeutic case series.
T
he anterior inferior iliac spine (AIIS) apophysis
arises just above the level of the anterior-supe-
rior acetabular rim. Though located outside the hip
capsule, deformities of the AIIS, such as those
resulting from excessive bone formation after avul-
sion injuries of the rectus femoris, can result in hip
dysfunction and may benefit from surgical decom-
pression.
1-4
In the past, resection of a symptomatic
prominent AIIS has been described with an open
surgical approach (i.e., the Smith-Petersen ap-
proach),
2,3
but recently, the concept of AIIS im-
pingement that can benefit from arthroscopic de-
compression has been introduced in a case report.
4
In this study we present a consecutive series of 10
patients who underwent arthroscopic decompression
of AIIS deformities, which were presumed to be due
From the Department of Orthopedic Surgery, Meir General Hospital, Sapir Medical Center (I.H.), Kfar Saba, Israel; Sackler Faculty of
Medicine, Tel Aviv University (I.H.), Tel Aviv, Israel; Minnesota Orthopaedic Sports Medicine Institute (C.M.L.), Edina, Minnesota; and
Hospital for Special Surgery, Weill Cornell Medical College University (K.D.T., R.M.Z., E.M., B.T.K.), New York, New York, U.S.A.
The authors report that they have no conflicts of interest in the authorship and publication of this article.
Received October 13, 2011; accepted May 8, 2012.
Address correspondence to Bryan T. Kelly, M.D., Department of Orthopedic Surgery, Hospital for Special Surgery, Weill Medical College
of Cornell University, 535 E 70th St, New York, NY 10021, U.S.A. E-mail: KellyB@hss.edu.
© 2012 by the Arthroscopy Association of North America
0749-8063/11665/$36.00
http://dx.doi.org/10.1016/j.arthro.2012.05.882
Original Article With Video Illustration
1644 Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 28, No 11 (November), 2012: pp 1644-1653