FEMORAL HEAD LENGTHENING COMBINED WITH HIP RESURFACING IN YOUNG PATIENTS WITH SEVERE HIP DEFORMITY

Abstract

INTRODUCTION Metal-on-metal hip resurfacing (MOMHR) has recently been reintroduced as a viable treatment option for young active patients. A short femoral neck and insufficient head are common deformities following CDH, Perthes disease and SFCE. Therefore, severity of these deformities is a contraindication for MOMHR, as contact between the femoral resurfacing component and the femoral head would be inadequate and off-set insufficient.

METHODS 32 patients with severe deformity of the hip were treated with Birmingham hip resurfacing and head lengthening. We used a standard acetabular component in 18 patients and a CDH acetabular component and supplementary screw fixation in 14. Bone chips produced while reaming the acetabulum were impacted on the femoral head to achieve the desired length, as evaluated on pre-op x-rays. Rehabilitation included no weight-bearing for 1 month and partial weight-bearing for another month.

RESULTS Median patient age was 44 years. Median head lengthening was 1.2 cm. Minimum follow-up was 3.1 years, maximum 5.2. Mean Harris Hip Score was 98. At follow-up 82% of the patients were involved in heavy or moderately heavy work. 34% of the patients practiced sports. Co and Cr serum concentrations at 25 months were respectively ng/ml 1.76, and 0.75. DXA analysis of the proximal femur showed complete recovery of BMD in Gruen zone 1 and increased in zone 7 (p= 0.05). There were no major complications.

DISCUSSION AND CONCLUSIONS The absence of major complications and the quality of our results support this technique in young active patients with severe deformity of the hip.