Total ankle replacement outcome in low volume centers: short-term followup

The indication for total ankle replacement (TAR) as an alternative to ankle fusion continues to be a much-debated topic. The reported survival of TAR at midterm followup is approximately 90%. The aim of this study was to compare functional outcome and survival of TAR in low volume centers versus high volume centers.

A retrospective cohort study was carried out in four low volume centers. Sixty-four Salto TARs were performed between 2003 and 2007 in 60 patients. Fifty-five (59 TAR) patients were eligible for followup with 28 men. Standardized American Orthopaedic Foot and Ankle Society (AOFAS) scores, patient satisfaction, and range of motion (ROM) were measured. Standardized and dynamic radiographs were used for evaluation of radiolucencies, ROM and component alignment.

Seven of the 59 ankle prostheses had to be revised: five for loosening and two for deep infection. Three of the five revised for loosening went on to fusion, and in two a revision of one of the components was performed. Both infected ankles were fused. Five patients declined to participate this study, among these two were TAR failures. Survival with revision as the endpoint was 86% at final followup. The average AOFAS score was 75 (SD ± 15). On dynamic radiographs the ROM was 22 degrees (SD ± 8) in the tibiotalar joint.

This study demonstrated that functional results of total ankle replacement in low volume centers were comparable to most high volume centers but survival was lower especially when we consider our shorter followup than most comparable series.