DIAGNOSIS OF FEMOROACETABULAR IMPINGEMENT SYNDROME
Abstract
Femoroacetabular impingement (FAI) syndrome is a frequent source of hip and groin pain in young and active populations. It arises from abnormal contact between the femoral head–neck junction and the acetabular rim, often due to cam, pincer, or mixed morphologies. Over time, this mechanical conflict can cause labral and cartilage damage, potentially leading to early osteoarthritis. Diagnosis requires a combination of patient history, physical examination, and imaging. While clinical impingement tests offer initial insights, they lack specificity and must be interpreted alongside radiographs and, when necessary, MRI. Parameters such as the alpha angle and acetabular coverage are key radiographic markers, but thresholds remain debated. Intra-articular anesthetic injections can help differentiate joint-related symptoms from other sources. Treatment options include conservative physiotherapy—focused on education, targeted exercise, and activity modification—as well as arthroscopic surgery, which aims to correct bony abnormalities and repair damaged tissue. Although surgical outcomes often show greater symptom improvement in the short and medium term, non-surgical care remains effective for many and avoids procedural risks.
References
Griffin DR, Dickenson EJ, O’Donnell J, et al. The Warwick Agreement on femoroacetabular impingement syndrome (FAI syndrome): An international consensus statement. British Journal of Sports Medicine. 2016;50(19):1169-1176. doi:10.1136/BJSPORTS-2016-096743,
Ganz R, Parvizi J, Beck M, Leunig M, Nötzli H, Siebenrock KA. Femoroacetabular Impingement: A Cause for Osteoarthritis of the Hip. Clinical Orthopaedics and Related Research. 2003;417(417):112-120. doi:10.1097/01.BLO.0000096804.78689.C2,
Agricola R, Heijboer MP, Bierma-Zeinstra SMA, Verhaar JAN, Weinans H, Waarsing JH. Cam impingement causes osteoarthritis of the hip: A nationwide prospective cohort study (CHECK). Annals of the Rheumatic Diseases. 2013;72(6):918-923. doi:10.1136/ANNRHEUMDIS-2012-201643,
Pun S, Kumar D, Lane NE. Femoroacetabular Impingement. Arthritis & rheumatology (Hoboken, NJ). 2015;67(1):17. doi:10.1002/ART.38887,
Trigg SD, Schroeder JD, Hulsopple C. Femoroacetabular Impingement Syndrome. Current Sports Medicine Reports. 2020;19(9):360-366. doi:10.1249/JSR.0000000000000748,
Mascarenhas V v., Castro MO, Rego PA, et al. The Lisbon Agreement on Femoroacetabular Impingement Imaging—part 1: overview. European Radiology. 2020;30(10):5281-5297. doi:10.1007/S00330-020-06822-9,
Hunter DJ, Eyles J, Murphy NJ, et al. Multi-centre randomised controlled trial comparing arthroscopic hip surgery to physiotherapist-led care for femoroacetabular impingement (FAI) syndrome on hip cartilage metabolism: the Australian FASHIoN trial. BMC Musculoskeletal Disorders. 2021;22(1). doi:10.1186/S12891-021-04576-Z,
Griffin DR, Dickenson EJ, Achana F, et al. Arthroscopic hip surgery compared with personalised hip therapy in people over 16 years old with femoroacetabular impingement syndrome: UK FASHIoN RCT. Health Technology Assessment. 2022;26(16). doi:10.3310/FXII0508,
Palmer A, Fernquest S, Rombach I, et al. Medium-term results of arthroscopic hip surgery compared with physiotherapy and activity modification for the treatment of femoroacetabular impingement syndrome: a multi-centre randomised controlled trial. British journal of sports medicine. 2025;59(2):109-117. doi:10.1136/BJSPORTS-2023-107712,
Rankin AT, Bleakley CM, Cullen M. Hip joint pathology as a leading cause of groin pain in the sporting population: A 6-year review of 894 cases. American Journal of Sports Medicine. 2015;43(7):1698-1703. doi:10.1177/0363546515582031,
Clohisy JC, Baca G, Beaulé PE, et al. Descriptive epidemiology of femoroacetabular impingement: A North American Cohort of patients undergoing surgery. American Journal of Sports Medicine. 2013;41(6):1348-1356. doi:10.1177/0363546513488861,
Frank JM, Harris JD, Erickson BJ, et al. Prevalence of femoroacetabular impingement imaging findings in asymptomatic volunteers: A systematic review. Arthroscopy - Journal of Arthroscopic and Related Surgery. 2015;31(6):1199-1204. doi:10.1016/j.arthro.2014.11.042,
Gosvig KK, Jacobsen S, Sonne-Holm S, Palm H, Troelsen A. Prevalence of malformations of the hip joint and their relationship to sex, groin pain, and risk of osteoarthritis: A population-based survey. Journal of Bone and Joint Surgery. 2010;92(5):1162-1169. doi:10.2106/JBJS.H.01674,
Clohisy JC, Knaus ER, Hunt DM, Lesher JM, Harris-Hayes M, Prather H. Clinical Presentation of Patients with Symptomatic Anterior Hip Impingement. Clinical Orthopaedics and Related Research. 2009;467(3):638. doi:10.1007/S11999-008-0680-Y,
Pazzinatto MF, Rio EK, Crossley KM, et al. The relationship between kinesiophobia and self-reported outcomes and physical function differs between women and men with femoroacetabular impingement syndrome. Brazilian Journal of Physical Therapy. 2022;26(2). doi:10.1016/J.BJPT.2022.100396,
Mohtadi NGH, Griffin DR, Pedersen ME, et al. The development and validation of a self-administered quality-of-life outcome measure for young, active patients with symptomatic hip disease: The International Hip Outcome Tool (iHOT-33). Arthroscopy - Journal of Arthroscopic and Related Surgery. 2012;28(5):595-610.e1. doi:10.1016/J.ARTHRO.2012.03.013,
Thorborg K, Hölmich P, Christensen R, Petersen J, Roos EM. The Copenhagen Hip and Groin Outcome Score (HAGOS): development and validation according to the COSMIN checklist. British Journal of Sports Medicine. 2011;45(6):478-491. doi:10.1136/BJSM.2010.080937,
Wong SE, Cogan CJ, Zhang AL. Physical Examination of the Hip: Assessment of Femoroacetabular Impingement, Labral Pathology, and Microinstability. Current Reviews in Musculoskeletal Medicine. 2022;15(2):38. doi:10.1007/S12178-022-09745-8,
Pålsson A, Kostogiannis I, Ageberg E. Combining results from hip impingement and range of motion tests can increase diagnostic accuracy in patients with FAI syndrome. Knee Surgery, Sports Traumatology, Arthroscopy. 2020;28(10):3382. doi:10.1007/S00167-020-06005-5,
Wichman D, Rasio JP, Looney A, Nho SJ. Physical Examination of the Hip. Sports Health. 2020;13(2):149. doi:10.1177/1941738120953418,
Castro MO, Mascarenhas V v., Afonso PD, et al. The Lisbon Agreement on Femoroacetabular Impingement Imaging—part 3: imaging techniques. European Radiology. 2021;31(7):4652-4668. doi:10.1007/S00330-020-07501-5,
Mascarenhas V v., Castro MO, Afonso PD, et al. The Lisbon Agreement on femoroacetabular impingement imaging—part 2: general issues, parameters, and reporting. European Radiology. 2021;31(7):4634-4651. doi:10.1007/S00330-020-07432-1,
Ekhtiari S, Fairhurst O, Mainwaring L, Khanduja V. The Alpha Angle. The Journal of Bone and Joint Surgery American Volume. 2024;106(20):1910. doi:10.2106/JBJS.23.01089,
Sutter R, Dietrich TJ, Zingg PO, Pfirrmann CWA. How useful is the alpha angle for discriminating between symptomatic patients with cam-type femoroacetabular impingement and asymptomatic volunteers? Radiology. 2012;264(2):514-521. doi:10.1148/RADIOL.12112479,
Lerch S, Kasperczyk A, Berndt T, Rühmann O. Ultrasound is as reliable as plain radiographs in the diagnosis of cam-type femoroacetabular impingement. Archives of Orthopaedic and Trauma Surgery. 2016;136(10):1437-1443. doi:10.1007/S00402-016-2509-6,
Tannast M, Siebenrock KA, Anderson SE. Femoroacetabular impingement: Radiographic diagnosis - What the radiologist should know. American Journal of Roentgenology. 2007;188(6):1540-1552. doi:10.2214/AJR.06.0921,
Reynolds D, Lucas J, Klaue K. Retroversion of the acetabulum. The Journal of Bone and Joint Surgery British volume. 1999;81-B(2):281-288. doi:10.1302/0301-620X.81B2.0810281,
Bardakos N v., Villar RN. Predictors of progression of osteoarthritis in femoroacetabular impingement: A radiological study with a minimum of ten years follow-up. Journal of Bone and Joint Surgery - Series B. 2009;91(2):162-169. doi:10.1302/0301-620X.91B2.21137,
El-Hajj G, Abdel-Nour H, Ayoubi R, et al. The Ischial Spine in Developmental Hip Dysplasia: Unraveling the Role of Acetabular Retroversion in Periacetabular Osteotomy. Advances in Orthopedics. 2020;2020:1826952. doi:10.1155/2020/1826952,
Kakaty DK, Fischer AF, Hosalkar HS, Siebenrock KA, Tannast M. The Ischial Spine Sign: Does Pelvic Tilt and Rotation Matter? Clinical Orthopaedics and Related Research. 2009;468(3):769. doi:10.1007/S11999-009-1021-5,
Hanson JA, Kapron AL, Swenson KM, Maak TG, Peters CL, Aoki SK. Discrepancies in measuring acetabular coverage: revisiting the anterior and lateral center edge angles. Journal of Hip Preservation Surgery. 2015;2(3):280. doi:10.1093/JHPS/HNV041,
Welton KL, Jesse MK, Kraeutler MJ, Garabekyan T, Mei-Dan O. The anteroposterior pelvic radiograph: Acetabular and femoral measurements and relation to hip pathologies. Journal of Bone and Joint Surgery - American Volume. 2018;100(1):76-85. doi:10.2106/JBJS.17.00500,
Clohisy JC, Carlisle JC, Beaulé PE, et al. A Systematic Approach to the Plain Radiographic Evaluation of the Young Adult Hip. The Journal of Bone and Joint Surgery American volume. 2008;90(Suppl 4):47. doi:10.2106/JBJS.H.00756,
Kivlan BR, Martin RL, Sekiya JK. Response to diagnostic injection in patients with femoroacetabular impingement, labral tears, chondral lesions, and extra-articular pathology. Arthroscopy - Journal of Arthroscopic and Related Surgery. 2011;27(5):619-627. doi:10.1016/j.arthro.2010.12.009,
Byrd JWT, Jones KS. Diagnostic Accuracy of Clinical Assessment, Magnetic Resonance Imaging, Magnetic Resonance Arthrography, and Intra-Articular Injection in Hip Arthroscopy Patients. The American Journal of Sports Medicine. 2004;32(7):1668-1674. doi:10.1177/0363546504266480,
Bray EDR, Sherafati M, Cutts CL, Stafford GH. The young adult hip: extra-articular causes of hip pain and how to pick the winners. Journal of Hip Preservation Surgery. 2015;2(1):51-55. doi:10.1093/JHPS/HNV012
Views:
83
Downloads:
57
Copyright (c) 2025 Michał Ciołkosz, Tomasz Antczak, Monika Gajda-Bathelt, Monika Dąbek, Katarzyna Jania, Zuzanna Perlicka, Karolina Smolińska, Paulina Sadkowska, Julia Kulczycka, Weronika Popow
This work is licensed under a Creative Commons Attribution 4.0 International License.
All articles are published in open-access and licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0). Hence, authors retain copyright to the content of the articles.
CC BY 4.0 License allows content to be copied, adapted, displayed, distributed, re-published or otherwise re-used for any purpose including for adaptation and commercial use provided the content is attributed.
