Femoral head deformity and severity of acetabular dysplasia of the hip

K. Okano, K. Yamaguchi, Y. Ninomiya, S. Matsubayashi, M. Osaki, K. Takahashi


Patients with acetabular dysplasia commonly undergo peri-acetabular osteotomy after skeletal maturity to reduce the risk of the late development of osteoarthritis. Several studies have suggested that deformity of the femoral head influences the long-term outcome. We radiologically examined 224 hips in 112 patients with acetabular dysplasia and early-stage osteoarthritis. There were 103 women and nine men with a mean age of 37.6 years (18 to 49). A total of 201 hips were placed in the acetabular dysplasia group and 23 in a normal group. The centre–edge angle and acetabular head index were significantly smaller (both p < 0.001), and the acetabular angle, acetabular roof angle and roundness index were significantly greater in the acetabular dysplasia group than those in the normal group (all p < 0.001). There were significant correlations between the roundness index and other parameters. Femoral head shape may be influenced by the severity of the acetabular dysplasia.

Cite this article: Bone Joint J 2013;95-B:1192–6.


  • The authors would like to thank Dr K. Mihara for advice on writing English articles, and Dr K. Aoyagi for advice on the statistical analysis.

    No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article.

    This article was primary edited by D. Rowley and first-proof edited by G. Scott.

  • Received December 20, 2012.
  • Accepted April 15, 2013.
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