EARLY FAILURE MODALITIES IN HIP RESURFACING

Abstract

Between January 1996 and July 2002, 60 patients (65 hips) were treated in our unit by 5 consultant surgeons using the Corin Cobalt-Chrome metal-on-metal hip resurfacing. 41 procedures were performed on male patients and 24 female.

All 65 cases used the Cormet Hip resurfacing (Corin, UK). Of these, 12 cases (18.5%) have required revision for mechanical failure. 5 of these patients were male and 7 female. The time to failure was defined as the interval between the date of primary and the date of revision surgery. The mean time to failure was 10.2 months (range 48 hours to 53 months). 8 out of 12 patients required revision within 6 months of the primary procedure. The mean age at the time of revision was 56 years (range 22–71 years).

The commonest mechanism of failure in our series is fractured neck of femur and 4 out of the 6 fractured neck of femur occurred in females over the age of 60. Only 12 of our primary hip resurfacings were women over 60 with the result that 33% of this group were complicated by fractured neck of femur.

In 4 cases, the indication for revision was acetabular loosening. One patient underwent revision surgery for chronic pain of unknown aetiology and one developed progressive avascular necrosis of the femoral head.

Our early results suggest that the procedure is operator-dependent and associated with a steep learning curve. The procedure would appear to be contraindicated in women over 60 and others at risk of osteoporosis.