FEMORAL IMPACTION GRAFTING IN REVISION HIP REPLACEMENT: ARE THERE FACTORS THAT PREDICT OUTCOME?

Abstract

39 consecutive patients (40 hips) undergoing femoral impaction grafting were retrospectively reviewed to assess our mid-term results and analyse them for any factors that could influence outcome. 36 revisions were for aseptic loosening, 3 for infection and 1 following a periprosthetic fracture. Those hips revised for infection were revised in 2 stages. In 37 cases, the Exeter X-Change bone impaction technique was used, implanting an Exeter stem with Simplex cement through a posterior approach. A Charnley stem was implanted in the 3 others.

Each surviving patient was assessed using the Harris hip score, AP pelvis and lateral hip radiographs. Potential prognostic factors were analysed using the Spearman’s rank correlation test.

The patients were reviewed after a mean follow-up of 5 years. 1 patient didn’t wish to attend review but was asymptomatic. Complications included 4 intraoperative femoral fractures during cement removal, 2 postoperative femoral fractures, 2 dislocations, 1 femoral component fracture and 1 deep infection. There were 3 re-revisions and 1 Girdlestones procedure.

The median Harris hip score of those implants still in-situ was 78.5. Those patients who had previously undergone a revision had a significantly worse Harris hip score (p< 0.05). The patients age, reason for revision, preoperative bone loss, surgeon, simultaneous acetabular revision, simultaneous bone grafting to acetabulum, loose acetabular component on radiographs, femoral subsidence, presence of trabeculae in the graft, any radiolucency, a complete cement mantle and ectopic bone formation had no significant correlation to the Harris hip score.

In this series, previous revision was found to be the only significant risk factor for a poor Harris hip score after femoral impaction grafting. Postoperative radiographic changes in this group correlated poorly with function and could not predict outcome. Further study is required to assess other factors such as bone graft and soft tissue quality that may also predict outcome.