THE RESULTS OF THREE-PHASE REVISION FOR INFECTION OF MASSIVE DISTAL FEMORAL ENDOPROSTHETIC REPLACEMENT

Abstract

Introduction: Deep infection following distal femoral endoprosthetic replacement remains an uncommon, (< 7%), but serious complication; we present the results all three-phase revisions performed at our unit.

Method: Using the endoprosthesis-survivorship database we identified and analysed 15 consecutive cases, (including MSTS functional assessment of all available patients), performed between 1993 and 2002. The primary replacement had been performed for trauma and fourteen for limb reconstruction following excision of tumour. All cases underwent a three-phase revision. The first stage involved debridement and exchange of prosthesis for a custom-made antibiotic-impregnated spacer. Following at least six weeks of intravenous antibiotics, a further endoprosthesis was inserted.

Results: Eight patients had complete clinical, radiological & biochemical resolution of infection, (mean follow-up 60 months). Mean MSTS score for this group was 83% (range 60–97%). The remaining seven had recurrence of infection, all within 18 months. Of this group, two underwent a successful second revision procedure with conversion to a total femoral replacement. Two cases are satisfactorily managed with antibiotic suppression therapy and three have required amputation. Two of these cases underwent above-knee amputation following a failed second revision, whilst the third was given a femoral stump endoprosthesis to avoid disarticulation. Revision was generally more successful in younger patients. Neither the original pathology nor the timing of revision surgery appeared to affect outcome. Negative tissue cultures from the first stage were associated with a successful result. Very high levels of inflammatory markers were associated with failure of revision

Conclusion: We recommend two-stage revision of distal femoral replacement as an effective treatment for infection, allowing limb salvage with excellent functional outcome in the majority of patients. The antibiotic phase may need to exceed six weeks in certain cases, and levels of inflammatory markers appear to be critical. If this revision fails, conversion to a total femoral replacement should be considered.