Revision arthroplasty with an isoelastic uncemented femoral stem.

Abstract

We carried out 102 hip revision arthroplasties using an uncemented isoelastic femoral stem on 92 patients between 1985 and 1989. The proximal femoral bone stock had deteriorated in 45%. Eleven patients died during the mean follow up of 5.7 years. The femoral component has been revised again for loosening in 13, for infection in 5 and for dislocation in 3. Radiographs of 70 hips showed incipient migration at 3 months in 20, and at the time of review 27 hips had migrated 5 mm or more. Nine stems had migrated more than 8 mm and were judged to be loose. There were 11 fractures before operation and 15 during operation; they all healed. Slight cortical hypertrophy of not more than 2 mm was present in most cases. Three patients (4 hips) were excluded because of severe systemic illness. Of the remaining 66 hips, the clinical outcome was excellent in 18%, good in 50%, fair in 26% and poor in 6%. The isoelastic stem is associated with poor primary fixation which is indicated by early subsidence. The results, with a total failure rate of 33%, are unsatisfactory and the isoelastic femoral stem used in this series cannot be recommended for revision operations.