Advertisement

Clinical Orthopaedics and Related Research®

, Volume 468, Issue 3, pp 769–774 | Cite as

The Ischial Spine Sign: Does Pelvic Tilt and Rotation Matter?

  • Diganta K. Kakaty
  • Andreas F. Fischer
  • Harish S. Hosalkar
  • Klaus A. Siebenrock
  • Moritz TannastEmail author
Clinical Research

Abstract

Although the ischial spine sign (ISS) has been advocated to detect acetabular retroversion, it is unknown whether the sign is valid on anteroposterior (AP) pelvic radiographs with tilted or rotated pelves. We therefore evaluated reliability of the ISS as a tool for diagnosing acetabular retroversion in the presence of considerable pelvic tilt and/or malrotation. We obtained radiographs of 20 cadaver pelves in 19 different malorientations resulting in 380 pelvis images (760 hips) for evaluation. In addition, 129 clinical radiographs of patients’ hips that had varying pelvis orientations were reviewed. We found an overall sensitivity of 81% (90%), specificity of 70% (71%), positive predictive value of 77% (80.7%), and negative predictive value of 75% (85%) in the cadaver (patient) hips. Our data suggest the ISS is a valid tool for diagnosing acetabular retroversion on plain radiographs taken using a standardized technique regardless of the degree of pelvic tilt and rotation.

Keywords

Pelvic Tilt Femoroacetabular Impingement Ischial Spine Receiver Operate Characteristic Curve Curve Acetabular Retroversion 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

References

  1. 1.
    Clohisy JC, Carlisle JC, Trousdale R, Kim YJ, Beaule PE, Morgan P, Steger-May K, Schoenecker PL, Millis M. Radiographic evaluation of the hip has limited reliability. Clin Orthop Relat Res. 2009;467:666–675.CrossRefPubMedGoogle Scholar
  2. 2.
    Drenckhahn D, Eckstein F. Lower extremity. In: Drenckhahn D, ed. Benninghoff Anatomy [in German]. München, Germany: Urban & Fischer; 2003:342–350.Google Scholar
  3. 3.
    Ganz R, Parvizi J, Beck M, Leunig M, Nötzli H, Siebenrock KA. Femoroacetabular impingement: a cause for osteoarthritis of the hip. Clin Orthop Relat Res. 2003;417:112–120.PubMedGoogle Scholar
  4. 4.
    Georgen TG, Resnik D. Evaluation of acetabular anteversion following total hip arthroplasty: necessity of proper centring. Br J Radiol. 1975;48:259–260.CrossRefGoogle Scholar
  5. 5.
    Giori NJ, Trousdale RT. Acetabular retroversion is associated with osteoarthritis of the hip. Clin Orthop Relat Res. 2003;417:263–269.PubMedGoogle Scholar
  6. 6.
    Jamali AA, Mladenov K, Meyer DC, Martinez A, Beck M, Ganz R, Leunig M. Anteroposterior pelvic radiographs to assess acetabular retroversion: high validity of the ‘cross-over’ sign. J Orthop Res. 2007;25:758–765.CrossRefPubMedGoogle Scholar
  7. 7.
    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.CrossRefPubMedGoogle Scholar
  8. 8.
    Köhnlein W, Ganz R, Impellizeri FM, Leunig M. Acetabular morphology: implications for joint-preserving surgery. Clin Orthop Relat Res. 2009;467:682–691.CrossRefPubMedGoogle Scholar
  9. 9.
    Reynolds D, Lucas J, Klaue K. Retroversion of the acetabulum: a cause of hip pain. J Bone Joint Surg Br. 1999;81:281–288.CrossRefPubMedGoogle Scholar
  10. 10.
    Siebenrock KA, Kalbermatten DF, Ganz R. Effect of pelvic tilt on acetabular retroversion: a study on cadavers. Clin Orthop Relat Res. 2003;407:241–248.CrossRefPubMedGoogle Scholar
  11. 11.
    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.CrossRefPubMedGoogle Scholar
  12. 12.
    Tannast M, Siebenrock KA, Anderson SE. Femoroacetabular impingement: radiographic diagnosis–what the radiologist should know. AJR Am J Roentgenol. 2007;188:1540–1552.CrossRefPubMedGoogle Scholar
  13. 13.
    Tannast M, Zheng G, Anderegg C, Burckhard 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.CrossRefPubMedGoogle Scholar
  14. 14.
    Williams PL. The skeleton of the lower limb. In: Williams PL, Warkick R, Dyson M, Bannister LH, eds. Gray’s Anatomy. Edinburgh, Scotland: Churchill Livingstone; 1989:422–446.Google Scholar

Copyright information

© The Association of Bone and Joint Surgeons® 2009

Authors and Affiliations

  • Diganta K. Kakaty
    • 1
  • Andreas F. Fischer
    • 1
  • Harish S. Hosalkar
    • 2
  • Klaus A. Siebenrock
    • 1
  • Moritz Tannast
    • 1
    Email author
  1. 1.Department of Orthopaedic Surgery, InselspitalUniversity of BernBernSwitzerland
  2. 2.Department of Orthopaedic SurgeryHospital of the University of PennsylvaniaPhiladelphiaUSA

Personalised recommendations