Customised hinged knee replacements as a salvage procedure for failed total knee arthroplasty

Failure of knee arthroplasty can lead to significant pain and functional disability. In a small number of patients with fracture, sepsis or massive bone loss they are considered for arthrodesis or above knee amputation. The purpose of this study was to investigate the results and complications of using customised hinged knee replacements in their place.

Since 1993, 30 of the 280 (10.7%) revision knee replacements in the Avon Orthopaedic Centre, Bristol have used Endo customised hinged knee prostheses (21 rotating, nine fixed) for salvage of limb threatening situations in elderly patients. Surgical indications were 22 low periprosthetic fractures (with or without aseptic loosening), five massive aseptic osteolyses, and three deep infections.

The mean length of post-operative hospital stay was just 14.6 days and all patients were discharged walking with aids. At follow up (mean 3.0 years, range 0.5-9.3 years) nine patients had died with their prostheses in situ and functioning. Six patients developed deep sepsis, two of which underwent above knee amputation, and two had received further surgery for septic problems. Two patients required further surgery for prosthetic disarticulation and one patient had successful on table vascular repair. Twenty-five patients had mid- or long- term follow up. Their mean American Knee scores (AKS) were 69.8 for knee and 35.6 for function (maximum 100), with mean total knee flexion 83 degrees. Mean Oxford knee scores (OKS) and WOMAC scores (both scored between 12 and 60 with low score indicating less difficulties) were 34.0 and 30.5, respectively.

Customised hinge revision knee replacements gave rapid rehabilitation and hospital discharge. Complications were high but at mid- and long-term review, no prostheses had failed from an aseptic cause and most of the knees of this challenging group were providing both stability and flexion.