Current Reviews in Musculoskeletal Medicine

, Volume 12, Issue 3, pp 253–259 | Cite as

Etiology and Pathomechanics of Femoroacetabular Impingement

  • W. Jeffrey Grantham
  • Marc J. PhilipponEmail author
Femoroacetabular Impingement/Labral Tears (A Zhang, Section Editor)
Part of the following topical collections:
  1. Topical Collection on Femoroacetabular Impingement/Labral Tears


Purpose of review

Femoroacetabular impingement is a common cause of hip pain in young patients and has been shown to progress to osteoarthritis. The purpose of this review is to better understand the development of femoroacetabular impingement.

Recent findings

Recent literature shows little genetic transmission of FAI. However, molecular studies show strong similarities with the cartilage in osteoarthritis. The development of cam lesions has a strong association with sports participation, particularly at the time of physeal closure suggesting abnormal development. Lumbar, pelvis, and femoral biomechanics may also play an important role in dynamic impingement.


In summary, femoroacetabular impingement is a dynamic process with many influences. Further research is needed to clarify the pathophysiology of FAI development in hopes of finding preventative options to reduce symptoms and progression to osteoarthritis.


Femoroacetabular impingement FAI etiology FAI pathomechanics FAI pathophysiology Cam development Pincer development 


Compliance with ethical standards

Conflict of interest

W. Jeffrey Grantham declares that he has no conflict of interest. Marc J. Philippon reports royalties from Smith & Nephew, Arthrosurface, Arthrex, Bledsoe, ConMed Linvatec, DonJoy, SLACK Inc., and Elsevier, consultancy fees from Smith & Nephew and MIS, and research support from Smith & Nephew, Ossur, Arthrex, and Siemens.

Human and animal rights and informed consent

This article does not contain any studies with human or animal subjects performed by any of the authors.


Papers of particular interest, published recently, have been highlighted as: • Of importance

  1. 1.
    Murray RO. The aetiology of primary osteoarthritis of the hip. Br J Radiol. 1965;38(455):810–24.CrossRefPubMedGoogle Scholar
  2. 2.
    Harris WH. Etiology of osteoarthritis of the hip. Clin Orthop Relat Res. 1986;213:20–33.Google Scholar
  3. 3.
    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(7):1012–8.CrossRefPubMedGoogle Scholar
  4. 4.
    Ganz R, Leunig M, Leunig-Ganz K, Harris WH. The etiology of osteoarthritis of the hip: an integrated mechanical concept. Clin Orthop Relat Res. 2008;466(2):264–72.CrossRefPubMedPubMedCentralGoogle Scholar
  5. 5.
    Ganz R, Parvizi J, Beck M, Leunig M, Notzli H, Siebenrock KA. Femoroacetabular impingement: a cause for osteoarthritis of the hip. Clin Orthop Relat Res. 2003;417:112–20.Google Scholar
  6. 6.
    Agricola R, Heijboer MP, Bierma-Zeinstra SM, Verhaar JA, Weinans H, Waarsing JH. Cam impingement causes osteoarthritis of the hip: a nationwide prospective cohort study (CHECK). Ann Rheum Dis. 2013;72(6):918–23.CrossRefPubMedGoogle Scholar
  7. 7.
    Maradit Kremers H, Larson DR, Crowson CS, Kremers WK, Washington RE, Steiner CA, et al. Prevalence of total hip and knee replacement in the United States. The Journal of bone and joint surgery American. 2015;97(17):1386–97.CrossRefGoogle Scholar
  8. 8.
    • Dickenson E, Wall PD, Robinson B, Fernandez M, Parsons H, Buchbinder R, et al. Prevalence of cam hip shape morphology: a systematic review. Osteoarthr Cartil. 2016;24(6):949–61. The systematic review of thirty studies looks at the prevalence of radiographic measures of femoroacetabular impingement noting a wide range in prevalance and significant biases in these studies. Google Scholar
  9. 9.
    • Raveendran R, Stiller JL, Alvarez C, Renner JB, Schwartz TA, Arden NK, et al. Population-based prevalence of multiple radiographically-defined hip morphologies: the Johnston County Osteoarthritis Project. Osteoarthr Cartil. 2018;26(1):54–61. The study is the first large population-based prospective study of radiographic hip morphology prevalence. Cam morphology on AP radiographs was present in 25% of men and 10% of women while pincer morphology was present in 4.4% of men and 5.5% of women. Google Scholar
  10. 10.
    Roling MA, Mathijssen NM, Bloem RM. Incidence of symptomatic femoroacetabular impingement in the general population: a prospective registration study. J Hip Preserv Surg. 2016;3(3):203–7.CrossRefPubMedPubMedCentralGoogle Scholar
  11. 11.
    Kopec JA, Cibere J, Li LC, Zhang C, Barber M, Qian H, et al. Relationship between physical activity and hip pain in persons with and without cam or pincer morphology: a population-based case-control study. Osteoarthr Cartil. 2017;25(7):1055–61.CrossRefPubMedGoogle Scholar
  12. 12.
    Clohisy JC, Baca G, Beaule PE, Kim YJ, Larson CM, Millis MB, et al. Descriptive epidemiology of femoroacetabular impingement: a North American cohort of patients undergoing surgery. Am J Sports Med. 2013;41(6):1348–56.CrossRefPubMedGoogle Scholar
  13. 13.
    Pollard TC, Villar RN, Norton MR, Fern ED, Williams MR, Murray DW, et al. Genetic influences in the aetiology of femoroacetabular impingement: a sibling study. J Bone Joint Surg Br. 2010;92(2):209–16.CrossRefPubMedGoogle Scholar
  14. 14.
    Hogervorst T, Eilander W, Fikkers JT, Meulenbelt I. Hip ontogenesis: how evolution, genes, and load history shape hip morphotype and cartilotype. Clin Orthop Relat Res. 2012;470(12):3284–96.CrossRefPubMedPubMedCentralGoogle Scholar
  15. 15.
    Safran MH, Smith LS. Paper 31: Is there a genetic link to FAI: A DNA pilot study of GDF5 and frizzle single nucleotide polymorphisms. Arthroscopy: the journal of arthroscopic & related surgery: official publication of the Arthroscopy Association of North America and the International Arthroscopy Association. 2011;27:e18.CrossRefGoogle Scholar
  16. 16.
    Sekimoto T, Kurogi S, Funamoto T, Ota T, Watanabe S, Sakamoto T, et al. Possible association of single nucleotide polymorphisms in the 3’ untranslated region of HOXB9 with acetabular overcoverage. Bone Joint Res. 2015;4(4):50–5.CrossRefPubMedPubMedCentralGoogle Scholar
  17. 17.
    Speirs AD, Beaule PE, Huang A, Frei H. Properties of the cartilage layer from the cam-type hip impingement deformity. J Biomech. 2017;55:78–84.CrossRefPubMedGoogle Scholar
  18. 18.
    Hashimoto S, Rai MF, Gill CS, Zhang Z, Sandell LJ, Clohisy JC. Molecular characterization of articular cartilage from young adults with femoroacetabular impingement. J Bone Joint Surg Am. 2013;95(16):1457–64.CrossRefPubMedPubMedCentralGoogle Scholar
  19. 19.
    • Chinzei N, Hashimoto S, Fujishiro T, Hayashi S, Kanzaki N, Uchida S, et al. Inflammation and degeneration in cartilage samples from patients with femoroacetabular impingement. J Bone Joint Surg Am. 2016;98(2):135–41. Gene expression from tissue samples of hips undergoing arthroscopy for FAI was compared to those undergoing total hip arthroplasty for osteoarthritis. There was elevated mRNA expression of inflammatory cytokines and catabolic genes in the cartilage of patients with FAI. Google Scholar
  20. 20.
    Sutter R, Dietrich TJ, Zingg PO, Pfirrmann CW. Femoral antetorsion: comparing asymptomatic volunteers and patients with femoroacetabular impingement. Radiology. 2012;263(2):475–83.CrossRefPubMedGoogle Scholar
  21. 21.
    Kraeutler MJ, Chadayammuri V, Garabekyan T, Mei-Dan O. Femoral version abnormalities significantly outweigh effect of cam impingement on hip internal rotation. J Bone Joint Surg Am. 2018;100(3):205–10.CrossRefPubMedGoogle Scholar
  22. 22.
    Lerch TD, Todorski IAS, Steppacher SD, Schmaranzer F, Werlen SF, Siebenrock KA, et al. Prevalence of femoral and acetabular version abnormalities in patients with symptomatic hip disease: a controlled study of 538 hips. Am J Sports Med. 2018;46(1):122–34.CrossRefGoogle Scholar
  23. 23.
    Ejnisman L, Philippon MJ, Lertwanich P, Pennock AT, Herzog MM, Briggs KK, et al. Relationship between femoral anteversion and findings in hips with femoroacetabular impingement. Orthopedics. 2013;36(3):e293–300.CrossRefPubMedGoogle Scholar
  24. 24.
    Fader RR, Tao MA, Gaudiani MA, Turk R, Nwachukwu BU, Esposito CI, et al. The role of lumbar lordosis and pelvic sagittal balance in femoroacetabular impingement. Bone Joint J. 2018;100-B(10):1275–9.CrossRefPubMedGoogle Scholar
  25. 25.
    Pierannunzii L. Pelvic posture and kinematics in femoroacetabular impingement: a systematic review. J Orthop Traumatol: official journal of the Italian Society of Orthopaedics and Traumatology. 2017;18(3):187–96.CrossRefGoogle Scholar
  26. 26.
    Gebhart JJ, Streit JJ, Bedi A, Bush-Joseph CA, Nho SJ, Salata MJ. Correlation of pelvic incidence with cam and pincer lesions. Am J Sports Med. 2014;42(11):2649–53.CrossRefPubMedGoogle Scholar
  27. 27.
    Weinberg DS, Gebhart JJ, Liu RW, Salata MJ. Radiographic signs of femoroacetabular impingement are associated with decreased pelvic incidence. Arthroscopy: the journal of arthroscopic & related surgery: official publication of the Arthroscopy Association of North America and the International Arthroscopy Association. 2016;32(5):806–13.CrossRefGoogle Scholar
  28. 28.
    Hellman MD, Haughom BD, Brown NM, Fillingham YA, Philippon MJ, Nho SJ. Femoroacetabular impingement and pelvic incidence: radiographic comparison to an asymptomatic control. Arthroscopy: the journal of arthroscopic & related surgery: official publication of the Arthroscopy Association of North America and the International Arthroscopy Association. 2017;33(3):545–50.CrossRefGoogle Scholar
  29. 29.
    Kennedy MJ, Lamontagne M, Beaule PE. Femoroacetabular impingement alters hip and pelvic biomechanics during gait walking biomechanics of FAI. Gait Posture. 2009;30(1):41–4.CrossRefPubMedGoogle Scholar
  30. 30.
    Lamontagne M, Kennedy MJ, Beaule PE. The effect of cam FAI on hip and pelvic motion during maximum squat. Clin Orthop Relat Res. 2009;467(3):645–50.CrossRefPubMedGoogle Scholar
  31. 31.
    Ponseti IV. Growth and development of the acetabulum in the normal child Anatomical, histological, and roentgenographic studies. J Bone Joint Surg Am. 1978;60(5):575–85.CrossRefPubMedGoogle Scholar
  32. 32.
    Monazzam S, Bomar JD, Dwek JR, Hosalkar HS, Pennock AT. Development and prevalence of femoroacetabular impingement-associated morphology in a paediatric and adolescent population: a CT study of 225 patients. Bone Joint J. 2013;95-B(5):598–604.CrossRefPubMedGoogle Scholar
  33. 33.
    • Albers CE, Schwarz A, Hanke MS, Kienle KP, Werlen S, Siebenrock KA. Acetabular version increases after closure of the triradiate cartilage complex. Clin Orthop Relat Res. 2017;475(4):983–94. The acetabulums of healthy children were evaluated for the state of the triradiate cartilage and acetabular version. There was significant increase in acetabular version on MRI between the time of open and closing of the physes. Google Scholar
  34. 34.
    Hingsammer AM, Bixby S, Zurakowski D, Yen YM, Kim YJ. How do acetabular version and femoral head coverage change with skeletal maturity? Clin Orthop Relat Res. 2015;473(4):1224–33.CrossRefPubMedGoogle Scholar
  35. 35.
    Siebenrock KA, Wahab KH, Werlen S, Kalhor M, Leunig M, Ganz R. Abnormal extension of the femoral head epiphysis as a cause of cam impingement. Clin Orthop Relat Res. 2004;418:54–60.CrossRefGoogle Scholar
  36. 36.
    Jonasson PS, Ekstrom L, Hansson HA, Sansone M, Karlsson J, Sward L, et al. Cyclical loading causes injury in and around the porcine proximal femoral physeal plate: proposed cause of the development of cam deformity in young athletes. J Exp Orthop. 2015;2(1):6.CrossRefPubMedPubMedCentralGoogle Scholar
  37. 37.
    Vo A, Beaule PE, Sampaio ML, Rotaru C, Rakhra KS. The femoral head-neck contour varies as a function of physeal development. Bone Joint Res. 2015;4(2):17–22.CrossRefPubMedPubMedCentralGoogle Scholar
  38. 38.
    Murray RO, Duncan C. Athletic activity in adolescence as an etiological factor in degenerative hip disease. J Bone Joint Surg Br. 1971;53(3):406–19.CrossRefPubMedGoogle Scholar
  39. 39.
    Oka M, Hatanpaa S. Degenerative hip disease in adolescent athletes. Med Sci Sports. 1976 Summer;8(2):77–80.PubMedGoogle Scholar
  40. 40.
    Gerhardt MB, Romero AA, Silvers HJ, Harris DJ, Watanabe D, Mandelbaum BR. The prevalence of radiographic hip abnormalities in elite soccer players. Am J Sports Med. 2012;40(3):584–8.CrossRefPubMedGoogle Scholar
  41. 41.
    Kapron AL, Anderson AE, Aoki SK, Phillips LG, Petron DJ, Toth R, et al. Radiographic prevalence of femoroacetabular impingement in collegiate football players: AAOS Exhibit Selection. J Bone Joint Surg Am. 2011;93(19):e111(1–10).CrossRefGoogle Scholar
  42. 42.
    Ayeni OR, Banga K, Bhandari M, Maizlin Z, de Sa D, Golev D, et al. Femoroacetabular impingement in elite ice hockey players. Knee Surg Sports Traumatol Arthroscopy: official journal of the ESSKA. 2014;22(4):920–5.CrossRefGoogle Scholar
  43. 43.
    Siebenrock KA, Ferner F, Noble PC, Santore RF, Werlen S, Mamisch TC. The cam-type deformity of the proximal femur arises in childhood in response to vigorous sporting activity. Clin Orthop Relat Res. 2011;469(11):3229–40.CrossRefPubMedPubMedCentralGoogle Scholar
  44. 44.
    Siebenrock KA, Behning A, Mamisch TC, Schwab JM. Growth plate alteration precedes cam-type deformity in elite basketball players. Clin Orthop Relat Res. 2013;471(4):1084–91.CrossRefPubMedGoogle Scholar
  45. 45.
    Siebenrock KA, Kaschka I, Frauchiger L, Werlen S, Schwab JM. Prevalence of cam-type deformity and hip pain in elite ice hockey players before and after the end of growth. Am J Sports Med. 2013;41(10):2308–13.CrossRefPubMedGoogle Scholar
  46. 46.
    Philippon MJ, Ho CP, Briggs KK, Stull J, LaPrade RF. Prevalence of increased alpha angles as a measure of cam-type femoroacetabular impingement in youth ice hockey players. Am J Sports Med. 2013;41(6):1357–62.CrossRefPubMedGoogle Scholar
  47. 47.
    Stull JD, Philippon MJ, LaPrade RF. “At-risk” positioning and hip biomechanics of the Peewee ice hockey sprint start. Am J Sports Med. 2011;39(Suppl):29S–35S.CrossRefPubMedGoogle Scholar
  48. 48.
    Agricola R, Bessems JH, Ginai AZ, Heijboer MP, van der Heijden RA, Verhaar JA, et al. The development of Cam-type deformity in adolescent and young male soccer players. Am J Sports Med. 2012;40(5):1099–106.CrossRefPubMedGoogle Scholar
  49. 49.
    Johnson AC, Shaman MA, Ryan TG. Femoroacetabular impingement in former high-level youth soccer players. Am J Sports Med. 2012;40(6):1342–6.CrossRefPubMedGoogle Scholar
  50. 50.
    Monckeberg J, Amenabar T, Rafols C, Garcia N, Yanez R. Prevalence of FAI radiographic hip abnormalities in elite soccer players: are there differences related to skeletal maturity? BMJ Open Sport Exerc Med. 2016;2(1):e000162.CrossRefPubMedGoogle Scholar
  51. 51.
    Palmer A, Fernquest S, Gimpel M, Birchall R, Judge A, Broomfield J, et al. Physical activity during adolescence and the development of cam morphology: a cross-sectional cohort study of 210 individuals. Br J Sports Med. 2018;52(9):601–10.CrossRefPubMedGoogle Scholar
  52. 52.
    • Nepple JJ, Vigdorchik JM, Clohisy JC. What is the association between sports participation and the development of proximal femoral cam deformity? A systematic review and meta-analysis. Am J Sports Med. 2015;43(11):2833–40. The systematic review evaluates nine studies showing evidence that high impact sports participation increases the risk of developing cam deformity at skeletal maturity. Google Scholar
  53. 53.
    Mayer SW, Abdo JC, Hill MK, Kestel LA, Pan Z, Novais EN. Femoroacetabular impingement is associated with sports-related posterior hip instability in adolescents: a matched-cohort study. Am J Sports Med. 2016;44(9):2299–303.CrossRefPubMedGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2019

Authors and Affiliations

  1. 1.The Steadman ClinicVailUSA
  2. 2.Steadman Philippon Research InstituteVailUSA

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