Clinical Orthopaedics and Related Research®

, Volume 471, Issue 6, pp 1937–1943

Femoroacetabular Impingement Predisposes to Traumatic Posterior Hip Dislocation

  • Simon D. Steppacher
  • Christoph E. Albers
  • Klaus A. Siebenrock
  • Moritz Tannast
  • Reinhold Ganz
Clinical Research



Traumatic posterior hip dislocation in adults is generally understood to be the result of a high-energy trauma. Aside from reduced femoral antetorsion, morphologic risk factors for dislocation are unknown. We previously noticed that some hips with traumatic posterior dislocations had evidence of morphologic features of femoroacetabular impingement (FAI), therefore, we sought to evaluate that possibility more formally.


We asked whether hips with a traumatic posterior hip dislocation present with (1) a cam-type deformity and/or (2) a retroverted acetabulum.


We retrospectively compared the morphologic features of 53 consecutive hips (53 patients) after traumatic posterior hip dislocation with 85 normal hips (44 patients) based on AP pelvic and crosstable axial radiographs. We measured the axial and the lateral alpha angle for detection of a cam deformity and the crossover sign, ischial spine sign, posterior wall sign, retroversion index, and ratio of anterior to posterior acetabular coverage to describe the acetabular orientation.


Hips with traumatic posterior traumatic dislocation were more likely to have cam deformities than were normal hips, in that the hips with dislocation had increased axial and lateral alpha angles. Hips with posterior dislocation also were more likely to be retroverted; dislocated hips had a higher prevalence of a positive crossover sign, ischial spine sign, and posterior wall sign, and they had a higher retroversion index and increased ratio of anterior to posterior acetabular coverage.


Hips with posterior traumatic dislocation typically present with morphologic features of anterior FAI, including a cam-type deformity and retroverted acetabulum. An explanation for these findings could be that the early interaction between the aspherical femoral head and the prominent acetabular rim acts as a fulcrum, perhaps making these hips more susceptible to traumatic dislocation.

Level of Evidence

Level III, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.


  1. 1.
    Amstutz HC, Lodwig RM, Schurman DJ, Hodgson AG. Range of motion studies for total hip replacements: a comparative study with a new experimental apparatus. Clin Orthop Relat Res. 1975;111:124–130.PubMedCrossRefGoogle Scholar
  2. 2.
    Clegg TE, Roberts CS, Greene JW, Prather BA. Hip dislocations: epidemiology, treatment, and outcomes. Injury. 2010;41:329–334.PubMedCrossRefGoogle Scholar
  3. 3.
    Dreinhofer KE, Schwarzkopf SR, Haas NP, Tscherne H. Isolated traumatic dislocation of the hip: long-term results in 50 patients. J Bone Joint Surg Br. 1994;76:6–12.PubMedGoogle Scholar
  4. 4.
    Dudda M, Albers C, Mamisch TC, Werlen S, Beck M. Do normal radiographs exclude asphericity of the femoral head-neck junction? Clin Orthop Relat Res. 2009;467:651–659.PubMedCrossRefGoogle 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;417:112–120.PubMedGoogle Scholar
  6. 6.
    Kalberer F, Sierra RJ, Madan SS, Ganz R, Leunig M. Ischial spine projection into the pelvis: a new sign for acetabular retroversion. Clin Orthop Relat Res. 2008;466:677–683.PubMedCrossRefGoogle Scholar
  7. 7.
    Kakaty DK, Fischer AF, Hosalkar HS, Siebenrock KA, Tannast M. The ischial spine sign: does tilt and rotation matter? Clin Orthop Relat Res. 2010 Mar;468(3):769–774.PubMedCrossRefGoogle Scholar
  8. 8.
    Kim YH, Choi Y, Kim JS. Influence of patient-, design-, and surgery-related factors on rate of dislocation after primary cementless total hip arthroplasty. J Arthroplasty. 2009;24:1258–1263.PubMedCrossRefGoogle Scholar
  9. 9.
    Lewinnek GE, Lewis JL, Tarr R, Compere CL, Zimmerman JR. Dislocations after total hip-replacement arthroplasties. J Bone Joint Surg Am. 1978;60:217–220.PubMedGoogle Scholar
  10. 10.
    Marchetti E, Krantz N, Berton C, Bocquet D, Fouilleron N, Migaud H, Girard J. Component impingement in total hip arthroplasty: frequency and risk factors. A continuous retrieval analysis series of 416 cup. Orthop Traumatol Surg Res. 2011;97:127–133.PubMedCrossRefGoogle Scholar
  11. 11.
    Murphy SB, Simon SR, Kijewski PK, Wilkinson RH, Griscom NT. Femoral anteversion. J Bone Joint Surg Am. 1987;69:1169–1176.PubMedGoogle Scholar
  12. 12.
    Notzli HP, Wyss TF, Stoecklin CH, Schmid MR, Treiber K, Hodler J. The contour of the femoral head-neck junction as a predictor for the risk of anterior impingement. J Bone Joint Surg Br. 2002;84:556–560.PubMedCrossRefGoogle Scholar
  13. 13.
    Philippon MJ, Kuppersmith DA, Wolff AB, Briggs KK. Arthroscopic findings following traumatic hip dislocation in 14 professional athletes. Arthroscopy. 2009;25:169–174.PubMedCrossRefGoogle Scholar
  14. 14.
    Rakhra KS, Sheikh AM, Allen D, Beaule PE. Comparison of MRI alpha angle measurement planes in femoroacetabular impingement. Clin Orthop Relat Res. 2009;467:660–665.PubMedCrossRefGoogle Scholar
  15. 15.
    Reynolds D, Lucas J, Klaue K. Retroversion of the acetabulum: a cause of hip pain. J Bone Joint Surg Br. 1999;81:281–288.PubMedCrossRefGoogle Scholar
  16. 16.
    Siebenrock K, Ganz R. The impingement problem in total hip arthroplasty. In: Rieker C, Oberholzer ST, Wyss U, eds. World Tribology Forum in Arthroplasty. Bern, Switzerland: Hans Huber; 2001:47–52.Google Scholar
  17. 17.
    Siebenrock KA, Kalbermatten DF, Ganz R. Effect of pelvic tilt on acetabular retroversion: a study of pelves from cadavers. Clin Orthop Relat Res. 2003;407:241–248.PubMedCrossRefGoogle Scholar
  18. 18.
    Steppacher SD, Tannast M, Werlen S, Siebenrock KA. Femoral morphology differs between deficient and excessive acetabular coverage. Clin Orthop Relat Res. 2008;466:782–790.PubMedCrossRefGoogle Scholar
  19. 19.
    Tannast M, Kubiak-Langer M, Langlotz F, Puls M, Murphy SB, Siebenrock KA. Noninvasive three-dimensional assessment of femoroacetabular impingement. J Orthop Res. 2007;25:122–131.PubMedCrossRefGoogle Scholar
  20. 20.
    Tannast M, Mistry S, Steppacher SD, Reichenbach S, Langlotz F, Siebenrock KA, Zheng G. Radiographic analysis of femoroacetabular impingement with Hip2Norm: reliable and validated. J Orthop Res. 2008;26:1199–1205.PubMedCrossRefGoogle Scholar
  21. 21.
    Tannast M, Pfannebecker P, Schwab JM, Albers CE, Siebenrock KA, Büchler L. Pelvic morphology differs in rotation and obliquity between developmental dysplasia of the hip and retroversion. Clin Orthop Relat Res. 2012;470:3297–3305.PubMedCrossRefGoogle Scholar
  22. 22.
    Tannast M, Siebenrock KA. [Open therapy of femoroacetabular impingement] [in German]. Oper Orthop Traumatol. 2010;22:3–16.PubMedCrossRefGoogle Scholar
  23. 23.
    Tannast M, Siebenrock KA, Anderson SE. Femoroacetabular impingement: radiographic diagnosis—what the radiologist should know. AJR Am J Roentgenol. 2007;188:1540–1552.PubMedCrossRefGoogle Scholar
  24. 24.
    Tannast M, Zheng G, Anderegg C, Burckhardt K, Langlotz F, Ganz R, Siebenrock KA. Tilt and rotation correction of acetabular version on pelvic radiographs. Clin Orthop Relat Res. 2005;438:182–190.PubMedCrossRefGoogle Scholar
  25. 25.
    Thompson VP, Epstein HC. Traumatic dislocation of the hip; a survey of two hundred and four cases covering a period of twenty-one years. J Bone Joint Surg Am. 1951;33:746–778; passim.Google Scholar
  26. 26.
    Trojan E. [Case of traumatic hip dislocation in bilateral hip dysplasia (coxa valga luxans)] [in German]. Z Orthop Ihre Grenzgeb. 1953;83:469–471.PubMedGoogle Scholar
  27. 27.
    Upadhyay SS, Moulton A, Burwell RG. Biological factors predisposing to traumatic posterior dislocation of the hip: a selection process in the mechanism of injury. J Bone Joint Surg Br. 1985;67:232–236.PubMedGoogle Scholar
  28. 28.
    Widmer KH, Majewski M. The impact of the CCD-angle on range of motion and cup positioning in total hip arthroplasty. Clin Biomech (Bristol, Avon). 2005;20:723–728.Google Scholar
  29. 29.
    Wissing H, Buddenbrock B. [Determining rotational errors of the femur by axial computerized tomography in comparison with clinical and conventional radiologic determination] [in German]. Unfallchirurgie. 1993;19:145–157.PubMedCrossRefGoogle Scholar
  30. 30.
    Zheng G, Tannast M, Anderegg C, Siebenrock KA, Langlotz F. Hip2Norm: an object-oriented cross-platform program for 3D analysis of hip joint morphology using 2D pelvic radiographs. Comput Methods Programs Biomed. 2007;87:36–45.PubMedCrossRefGoogle Scholar

Copyright information

© The Association of Bone and Joint Surgeons® 2013

Authors and Affiliations

  • Simon D. Steppacher
    • 1
  • Christoph E. Albers
    • 1
  • Klaus A. Siebenrock
    • 1
  • Moritz Tannast
    • 1
  • Reinhold Ganz
    • 2
  1. 1.Department of Orthopaedic Surgery, InselspitalUniversity of BernBernSwitzerland
  2. 2.Faculty of Medicine, University of BernGuemligenSwitzerland

Personalised recommendations