Cement technique changes improved hip resurfacing longevity - implant retrieval findings.

Background: Most designs of metal-on-metal hip resurfacing utilize cement for femoral fixation, but the amount, application, and distribution of cement varies considerably according to implant design and surgeon preference. In one type of hip resurfacing system (Conserve Plus), the objective was to achieve a 1-mm cement mantle and several millimeters of penetration. In early cases of the senior investigator's (HCA) series, cement fixation failures were noted, and this prompted changes in femoral head preparation and cement application techniques. Survivorship improved following implementation of these changes. The aim of the current study was to examine revised femoral components for the cement distribution, especially in cases where the improved techniques were subsequently applied.

Method: Fifteen resurfacing femoral components were sectioned and the slices were radiographed and photographed, and the amount and distribution of cement were examined and measured. Cases representative of the evolving cementing techniques were examined in detail.

Results: There was considerable variation observed in the amount and distribution of cement, partly as a consequence of variable bone quality in this "all-comers" included series. The cement analyses showed that the newer cementing techniques helped to reduce over-penetration while providing better cement interdigitation. The use of extra fixation holes and cementing the stem in cases with poor bone quality were associated with improved cement-to-bone contact area.

Conclusion: Meticulous femoral head preparation was helpful in providing durable cement fixation and is essential in cases with poor bone quality.