Open wedge tibial osteotomy by hemicallotasis for medial compartment osteoarthritis

Early clinical results were evaluated for 22 adult patients who had undergone an open wedge tibial osteotomy by hemicallotasis (HCO) due to medial compartment osteoarthritis. The mean age at the time of the index operation was 56 (range 33-66) years. The mean duration of follow up was 16 (range 9-23) months. The median hip-knee-ankle angle (HKA) was 169 (range 162-186) deg preoperatively and 182 (range 175-191) deg at follow up. We did not observe any early collapse of the new bone wedge. The median time to fixation was 79 (range 63-125) days. Complications included two pintract infections, and two hematomas were revised. Two patients felt pain during the phase of distraction, but the procedure could be continued after a short break. We evaluated the clinical results on the HSS, Lysholm, and Tegner activity scores. At the latest follow up examination, all of the scores had improved. Our findings demonstrate that HCO requires an exact correction, is a simple technique, and appears to reduce the chance of nerve and vascular damage.