Functional outcome of arthrodesis for failed total knee arthroplasty.

To establish the ability of a salvage procedure to restore an independent lifestyle, the SF-36 functional outcome instrument and the pain, mobility, and physical activity subscales of the Arthritis Impact Measurement Scale (AIMS) was used to assess patient function. Nine patients (10 knees) who had undergone arthrodesis for failed total knee arthroplasty were compared with a control group of successful primary total knee arthroplasty patients. Average clinical follow-up was 42 months (minimum: 24 months). For six of the eight SF-36 categories, the average scores for the arthrodesis and arthroplasty groups were similar. The average global scores for the two groups were nearly identical. The arthroplasty patients scored better on the AIMS physical activity and mobility subscales than the arthrodesis group, although the latter group fared better on the pain subscale. Overall, global scores favored the arthroplasty patients. The only subscales to show a statistically significant difference between the arthrodesis and arthroplasty groups were the SF-36 physical functioning and the AIMS physical activity subscales. This pilot study demonstrated the ability of a salvage procedure to allow for an independent lifestyle with minimal complications. Furthermore, despite its popularity, the SF-36 does not appear as sensitive as the AIMS to differences in functional status or health outcomes between total knee arthroplasty and arthrodesis patients.