Hemicallotasis for medial gonarthrosis: a short-term follow-up of 21 patients

Abstract.

We have prospectively evaluated 21 patients (22 knees; 15 men and 6 women) who underwent hemicallotasis osteotomy (HO), using an external fixator, of the proximal tibia due to medial gonarthrosis. Their median age at the time of operation was 52 (range 39–62) years. The follow- up period was 12–28 months. The Hospital for Special Surgery score (HSS) increased from median 71 preoperatively to 83 points at the follow-up (p<0.001). The median hip-knee-ankle angle (HKA) was 187° preoperatively, 177° after distraction, and 180° at the time of follow-up (p<0.001). In 5 knees, valgus angulation was not achieved during the distraction phase, and in two-thirds of the knees, there was no valgus at follow-up. The total time in external fixation was median 13 (range 8–16) weeks. Pin tract problems occurred in 12 cases. There was one deep vein thrombosis, and 2 patients had to undergo re-operations due to technical errors. One patient acquired a bacterial arthritis 6 months after the operation. The clinical short-term results with HO seem to be comparable to those reported earlier for closing-wedge osteotomy. However, HO is a trying procedure for the patient as well as for the surgeon, due to frequent minor complications requiring frequent follow-ups.