Total ankle replacement for rheumatoid arthritis

The purpose of the study was to assess whether alignment of the entire hindfoot in connection with total ankle replacement in rheumatoid arthritis (RA) was a lasting treatment. During the period 1981 - 2003 fifty-six cases of RA were treated with total ankle replacement. There were 45 patients (11 bilateral cases), 37 women and 8 men. The patients mean age at the operation was 57 years (range 30 - 83). Preoperatively loading of the hindfoot showed valgus (>7degrees) in 41 cases, and varus (>3degrees) in 6 cases. Nine cases were within normal hindfoot alignment. The preoperative Kofoed score was mean 24.5 points (range 6-44). All patients attended follow-ups with radiographs taken under image intensification. The scoring at the latest follow-up of surviving prostheses was median 84 (range 34 - 98). Six cases were re-operated upon. Two were revised and 4 were changed into arthrodesis. The consistency of alignment was noticed and compared to the clinical end result. Preoperatively, valgus of the hindfoot was mean 15.5degrees +/- 8.1 S.E. in 41 cases. At the latest follow-up the hindfoot valgus was mean 4.9degrees +/- 6.6 S.E., p < 0.0001. Preopartively, six cases showed hindfoot varus of mean 13.3degrees +/- 7.9 S.E. At the latest follow-up the hindfoot varus was mean 1.3degrees +/- 3.5 S.E., p < 0.0001. Forty-four of the 50 cases with the original prosthesis in situ showed normal alignment at the latest follow-up. Cases with normal hindfoot alignment scored mean 86 points (69-98). Cases with abnormal hindfoot alignment scored mean 77 points (34-90), p < 0.02. From this study with long-term follow-up it was concluded that entire hindfoot alignment is mandatory.