Distal femoral replacement in periprosthetic fracture around total knee arthroplasty.

INTRODUCTION: Total knee arthroplasty is a common orthopaedic procedure in the UK; consequently, revision surgery and periprosthetic fractures are increasing in incidence. Strategies for management of these cases include non-operative strategies, internal plate fixation and revision of the distal femoral component. One under-reported practice is to perform distal femoral replacement in cases with poor distal femoral bone stock.

MATERIALS AND METHODS: The department's electronic database was searched for all patients undergoing revision of total knee arthroplasty. From these, all patients having distal femoral replacement for periprosthetic fracture around the distal femoral component using the Stryker Global Modular Replacement System (GMRS) implant were filtered. A retrospective analysis of the patient notes was performed to examine the patient demographics, surgical factors and postoperative complications. Postoperative scores were performed for these patients.

RESULTS: From 2005 onwards, 11 patients (mean age 81 years, range 61-90 years) had their implants revised with a distal femoral replacement for periprosthetic fracture with associated poor bone stock. Follow up was for a mean of 33 months (range 4-72 months). One of these patients died of causes unrelated to their operation. Of the rest, all implants survived without the need of re-operation. The mean postoperative Oxford Knee Score for these patients was 22.5 (range 5-34).

CONCLUSIONS: Distal femoral replacement for patients with fracture around a total knee arthroplasty has been performed in our department with few complications and acceptable functional outcomes. It is a technically challenging operation and it should be a salvage procedure reserved for patients with poor bone stock and low demands where other methods of fixation are not suitable.

LEVEL OF EVIDENCE: IV.