THE USE OF ENDOPROSTHETIC REPLACEMENTS FOR NON-TUMOUR LIMB SALVAGE SURGERY

Abstract

Introduction: Limb salvage reconstruction evolved from the treatment of primary bone tumours. Endoprosthetic replacements (EPR) were originally designed for this purpose, but the versatility of these implants has resulted in an extension in the indications for their use. Severe bone loss, failed revision surgery and persistent deep infection present similar challenges and when a salvage procedure is required, EPR are occasionally used. The aim of our study was to assess the medium term survival and functional outcome of EPR.

Materials and Methods: 38 patients (23 females and 15 males), who underwent EPR for non-neoplastic conditions were identified from a prospectively kept database of all patient seen at the Royal Orthopaedic Hospital Oncology Service. The indications for replacement included failed joint replacement, fracture non-union, failed internal fixation and periprosthetic fractures.

The 38 procedures were identified from September 1995 to June 2007 and included 17 distal femoral replacements, 12 proximal femoral replacements, 4 proximal humeral replacements, 2 distal humeral replacements, 2 hemi-pelvic replacements and 1 total femoral replacement. EPR survivorship was calculated using a Kaplan-Meier survival curve. The quality of patients’ mobility and performance of activities of daily living was used to assess functional outcome.

Results: Patients had a mean age of 60 years (range 15–85 years) at surgery and had between 0 and 4 previous operations prior to EPR. Seven out of 38 patients had recorded deep infection prior to surgery (18%). The Kaplan-Meier implant survival was 91.3% at 5 years, 68.5% at 10 years and 45.7% at 20 years. The limb salvage survival for all reconstructions was 75% at 10 years.

87.4% of patients who underwent a lower limb EPR achieved a satisfactory or very satisfactory functional outcome. 100% of patients achieved a satisfactory or very satisfactory functional outcome in the upper limb EPR group.

3 implants failed, 2 as a result of infection and required staged revisions, 1 eventually requiring amputation, and 1 failed as a result of aseptic loosening. 2 patients dislocated their proximal femoral replacements, both were treated successfully by closed reduction. Despite the salvage surgery subsequent amputation was only required in one patient.

Conclusion: EPR appears to be effective and the medium term survival is encouraging. The aim of a pain free functional limb is achievable with this technique. The complication rates are acceptable considering the salvage nature of these patients. We recommend referral of complex cases to a tertiary centre with expertise in this type of surgery.