Medial malleolar osteotomy for the correction of varus deformity during total ankle arthroplasty: results in 15 ankles.

BACKGROUND Preoperative deformity in the frontal plane in the arthritic ankle is a risk factor for failure after total ankle arthroplasty. Medial malleolar lengthening osteotomy was developed to correct varus malalignment. MATERIALS AND METHODS From 1998 to 2005 total ankle arthroplasty combined with medial malleolar lengthening osteotomy was done in 15 ankles (13 patients) with a mean preoperative varus deformity of 14.9 (SD, 7.8) degrees. Diagnosis was arthritis with instability in 11 ankles (9 patients) and inflammatory joint disease in 4 ankles. Two mobile-bearing designs were used. Osteosynthesis of the osteotomy was done in 2 ankles; for the remaining 13 osteotomies, no fixation was used. RESULTS Followup was 5 (range 2 to 8) years. Neutral alignment was obtained in all ankles. In 3 patients residual hindfoot varus remained, for which a second-stage hindfoot correction was done. Two rheumatoid ankles developed a symptom-free nonunion of the medial malleolus, all other malleolar osteotomies united. One tibial component, implanted with too much anterior slope, developed early aseptic loosening and was revised. Debridement for talar-malleolar arthritis was done in two ankles. Of the 14 ankles in followup, 12 were rated as excellent or good, one as fair. One ankle with subsidence of the talar component was rated as unsatisfactory. AOFAS score increased from 30.8 preoperative to 81.0 at followup (p < 0.01). CONCLUSION Medial malleolar lengthening osteotomy is an easy technique for the realignment of the varus ankle at the time of total ankle arthroplasty, and served as an alternative to medial ligament release or lateral ligament reconstruction.