Resurfacing arthroplasty of the hip for avascular necrosis of the femoral head

A MINIMUM FOLLOW-UP OF FOUR YEARS

V. C. Bose, MS, MCh, FRCS(Trauma & Orth), Senior Consultant Orthopaedic Surgeon¹; and B. D. Baruah, D. Ortho, DNB(Ortho), Consultant Orthopaedic Surgeon¹

¹ Department of Orthopaedic, Surgery, Apollo Speciality Hospital 320, Padma Complex, Chennai 600 035, Tamil Nadu, India.

We performed 96 Birmingham resurfacing arthroplasties of the hip in 71 consecutive patients with avascular necrosis of the femoral head. A modified neck-capsule-preserving approach was used which is described in detail. The University of California, Los Angeles outcome score, the radiological parameters and survival rates were assessed. The mean follow-up was for 5.4 years (4.0 to 8.1). All the patients remained active with a mean University of California, Los Angeles activity score of 6.86 (6 to 9). 

Three hips failed, giving a cumulative survival rate of 95.4%. With failure of the femoral component as the endpoint, the cumulative survival rate was 98.0%. We also describe the combined abduction-valgus angle of the bearing couple, which is the sum of the inclination angle of the acetabular component and the stem-shaft angle, as an index of the optimum positioning of the components in the coronal plane.

Using a modified surgical technique, it is possible to preserve the femoral head in avascular necrosis by performing hip resurfacing in patients with good results.