Arthroscopic Subspine Decompression Is Commonly Reported in a Heterogenous Patient Population With Concomitant Procedures: A Systematic Review

Published:February 11, 2022DOI:


      To systematically review the evaluation, management, and surgical outcomes of arthroscopic subspine decompression in conjunction with other intra-articular hip preservation procedures.


      Two databases (PubMed and Embase) were searched from 2010 to 2021, in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, for articles investigating arthroscopic subspine decompression using the key words: “subspine impingement”, “AIIS impingement”, and “extra-articular impingement.” Exclusion criteria included diagnostic studies, failure to report postoperative outcomes, and case series of less than 10 hips. Studies were assessed for patient demographics, diagnostic criteria, clinical findings, concomitant procedures, outcomes, and postoperative complications. The quality of the studies was analyzed by 2 independent reviewers (A.J.C. and A.E.J.) using the Methodological Index for Non-randomized Studies (MINORS).


      Ten studies consisting of 438 patients (460 hips, 48.6% female) met the inclusion criteria, with average ages and follow-up ranging from 24.9 to 34.7 years and 6.0 to 44.4 months, respectively. There was 1 Level II study, 3 Level III studies, and 6 Level IV studies. The MINORS criteria yielded an average quality assessment of 13.0 (range: 7-22), with 3 methodological domains demonstrating mean scores of less than 1: unbiased assessment of the study endpoint (.25), loss of follow up less than 5% (.25), and prospective calculation of the study size (.7). The most common exam maneuver used was the subspine impingement test (9 studies). Most subspine decompressions were performed in addition to traditional femoroacetabular impingement syndrome (FAIS) procedures, with only one study (33 hips) reporting solely on isolated subspine osteoplasty. Average preoperative and postoperative modified Harris Hip Score (mHHS) values ranged from 44.93 to 75.7 and 79.5 to 98.0, respectively. Three studies noted improved hip flexion in the postoperative period. Five surgical complications were reported.


      Arthroscopic subspine decompression is commonly reported in a heterogenous patient population with intra-articular hip pathology. A combination of the subspine impingement test and anterior inferior iliac spine (AIIS) morphology on imaging is frequently used for diagnosis. While improved patient-reported outcomes (PROs) are consistently observed following arthroscopic decompression, conclusions are limited by study methodology and concurrent procedures performed at the time of surgery.

      Level of Evidence

      IV, systematic review of Level II through Level IV studies.

      Key Words

      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to Arthroscopy
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Beck M.
        • Kalhor M.
        • Leunig M.
        • Ganz R.
        Hip morphology influences the pattern of damage to the acetabular cartilage: Femoroacetabular impingement as a cause of early osteoarthritis of the hip.
        J Bone Joint Surg Br. 2005; 87: 1012-1018
        • Ganz R.
        • Parvizi J.
        • Beck M.
        • Leunig M.
        • Nötzli H.
        • Siebenrock K.A.
        Femoroacetabular impingement: A cause for osteoarthritis of the hip.
        Clin Orthop. 2003; 417: 112-120
        • Pan H.
        • Kawanabe K.
        • Akiyama H.
        • Goto K.
        • Onishi E.
        • Nakamura T.
        Operative treatment of hip impingement caused by hypertrophy of the anterior inferior iliac spine.
        J Bone Joint Surg Br. 2008; 90: 677-679
        • Larson C.M.
        • Kelly B.T.
        • Stone R.M.
        Making a case for anterior inferior iliac spine/subspine hip impingement: Three representative case reports and proposed concept.
        Arthroscopy. 2011; 27: 1732-1737
        • Macnicol M.F.
        • Makris D.
        Distal transfer of the greater trochanter.
        J Bone Joint Surg Br. 1991; 73: 838-841
        • Stafford G.H.
        • Villar R.N.
        Ischiofemoral impingement.
        J Bone Joint Surg Br. 2011; 93: 1300-1302
        • Taneja A.K.
        • Bredella M.A.
        • Torriani M.
        Ischiofemoral impingement.
        Magn Reson Imag Clin N Am. 2013; 21: 65-73
        • Hetsroni I.
        • Poultsides L.
        • Bedi A.
        • Larson C.M.
        • Kelly B.T.
        Anterior inferior iliac spine morphology correlates with hip range of motion: A classification system and dynamic model.
        Clin Orthop. 2013; 471: 2497-2503
        • Balazs G.C.
        • Williams B.C.
        • Knaus C.M.
        • et al.
        Morphological distribution of the anterior inferior iliac spine in patients with and without hip impingement: Reliability, validity, and relationship to the intraoperative assessment.
        Am J Sports Med. 2017; 45: 1117-1123
        • Karns M.R.
        • Adeyemi T.F.
        • Stephens A.R.
        • et al.
        Revisiting the anteroinferior iliac spine: Is the subspine pathologic? A clinical and radiographic evaluation.
        Clin Orthop. 2018; 476: 1494-1502
        • Moher D.
        • Liberati A.
        • Tetzlaff J.
        • Altman D.G.
        Preferred reporting items for systematic reviews and meta-analyses: The PRISMA statement.
        PLoS Med. 2009; 6e1000097
        • Slim K.
        • Nini E.
        • Forestier D.
        • Kwiatkowski F.
        • Panis Y.
        • Chipponi J.
        Methodological index for non-randomized studies (MINORS): Development and validation of a new instrument: Methodological index for non-randomized studies.
        ANZ J Surg. 2003; 73: 712-716
        • Shapira J.
        • Yelton M.J.
        • Glein R.M.
        • et al.
        Intraoperative findings and clinical outcomes associated with arthroscopic management of subspine impingement: A propensity-matched, controlled study.
        Arthroscopy. 2021; 37: 3090-3101
        • Roos B.D.
        • Roos M.V.
        • Camisa Júnior A.
        • Lima E.M.U.
        • Fontana M.F.
        • Okamoto R.P.
        Subspine hip impingement: Clinical and radiographic results of its arthroscopic treatment.
        Rev Bras Ortop. 2020; 55: 722-727
        • Aguilera-Bohórquez B.
        • Ramirez S.
        • Cantor E.
        Functional results of arthroscopic treatment in patients with femoroacetabular and subspine impingement diagnosed with a 3-dimensional dynamic study.
        Arthrosc Sports Med Rehabil. 2020; 2: e39-e45
        • Nwachukwu B.U.
        • Chang B.
        • Fields K.
        • et al.
        Outcomes for arthroscopic treatment of anterior inferior iliac spine (subspine) hip impingement.
        Orthop J Sports Med. 2017; 5 (2325967117723109)
        • Feghhi D.
        • Shearin J.
        • Bharam S.
        Arthroscopic management of subspinous impingement in borderline hip dysplasia and outcomes compared with a matched cohort with nondysplastic femoroacetabular impingement.
        Am J Sports Med. 2020; 48: 2919-2926
        • Michal F.
        • Amar E.
        • Atzmon R.
        • et al.
        Subspinal impingement: Clinical outcomes of arthroscopic decompression with one year minimum follow up.
        Knee Surg Sports Traumatol Arthrosc. 2020; 28: 2756-2762
        • Flores S.E.
        • Chambers C.C.
        • Borak K.R.
        • Zhang A.L.
        Arthroscopic treatment of acetabular retroversion with acetabuloplasty and subspine decompression: A matched comparison with patients undergoing arthroscopic treatment for focal pincer-type femoroacetabular impingement.
        Orthop J Sports Med. 2018; 6 (2325967118783741)
        • Tateishi S.
        • Onishi Y.
        • Suzuki H.
        • et al.
        Arthroscopic anterior inferior iliac spine decompression does not alter postoperative muscle strength.
        Knee Surg Sports Traumatol Arthrosc. 2020; 28: 2763-2771
        • Hetsroni I.
        • Larson C.M.
        • Dela Torre K.
        • Zbeda R.M.
        • Magennis E.
        • Kelly B.T.
        Anterior inferior iliac spine deformity as an extra-articular source for hip impingement: a series of 10 patients treated with arthroscopic decompression.
        Arthroscopy. 2012; 28: 1644-1653
        • Hapa O.
        • Bedi A.
        • Gursan O.
        • et al.
        Anatomic footprint of the direct head of the rectus femoris origin: Cadaveric study and clinical series of hips after arthroscopic anterior inferior iliac spine/subspine decompression.
        Arthroscopy. 2013; 29: 1932-1940
        • Poultsides L.A.
        • Bedi A.
        • Kelly B.T.
        An algorithmic approach to mechanical hip pain.
        HSS J. 2012; 8: 213-224
        • Aguilera-Bohorquez B.
        • Brugiatti M.
        • Coaquira R.
        • Cantor E.
        Frequency of subspine impingement in patients with femoroacetabular impingement evaluated with a 3-dimensional dynamic study.
        Arthroscopy. 2019; 35: 91-96
        • Lerch T.D.
        • Boschung A.
        • Todorski I.A.S.
        • et al.
        Femoroacetabular impingement patients with decreased femoral version have different impingement locations and intra- and extraarticular anterior subspine FAI on 3D-CT-based impingement simulation: Implications for hip arthroscopy.
        Am J Sports Med. 2019; 47: 3120-3132
        • Lerch T.D.
        • Siegfried M.
        • Schmaranzer F.
        • et al.
        Location of intra- and extra-articular hip impingement is different in patients with pincer-type and mixed-type femoroacetabular impingement due to acetabular retroversion or protrusio acetabuli on 3D CT-based impingement simulation.
        Am J Sports Med. 2020; 48: 661-672