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

Abstract

The purpose of our study was to examine the survival and functional outcome of endoprosthetic replacements for non-oncology limb salvage purposes. Although initially designed for bone tumours, such is the versatility of these implants they can be used to salvage failed joint replacements, peri-prosthetic fractures, failed internal fixation and non-union.

Thirty eight procedures were identified from September 1995 to June 2007 from a prospectively kept database, including 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. The quality of patients’ mobility was used to assess functional outcome and the survival of the prosthesis was calculated using a Kaplan-Meier survival curve.

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.

The best survival was as follows pelvic (n=0/2) and total femoral prostheses where there was no failure in either group (n=0/1). Distal femoral replacements survival was 91% at 5 years, a single humeral prosthesis failed at 11 years post surgery, and proximal femoral replacements had a survival at 87.5% at 5 years. Three implants failed, two as a result of infection and required staged revisions and 1 failed as a result of aseptic loosening. Two patients dislocated their proximal femoral replacements, both were treated successfully by closed reduction.

Endoprosthetic replacement 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.