Open-wedge osteotomy by hemicallotasis or the closed-wedge technique for osteoarthritis of the knee - A randomised study of 50 operations

We describe the results of 50 operations carried out on 46 patients with me dial osteoarthritis of the knee of Ahlback grade 1 to 3. Patients were rand omised either to a closed-wedge high tibial osteotomy (HTO) or an open-wedg e procedure based on the hemicallotasis technique (HCO), Their median age w as 55 years (38 to 68), The preoperative median hip-knee-ankle (NKA) angle was 171 degrees (164 to 176) in the HTO group and 173 degrees (165 to 179) in the HCO group. After six weeks, the median HKA angle was 185 degrees (17 6 to 194) in the HTO group and 184 degrees (181 to 188) in the HCO group, I n the HTO group, seven patients were within the range of 182 degrees to 186 degrees compared with 21 in the HCO group (p < 0.001). One year later, ten HTO patients mere within this range while the NKA angulation in the HCO gr oup was unchanged, At two years the numbers were 11 and 18, respectively. We evaluated the clinical results on the Hospital for Special Surgery, Lysh olm and Wallgren-Tegner activity scores, and patients completed part of the Nottingham Health Profile questionnaire. An impartial observer at the two- year follow-up concluded that all scores had improved, but found no clinica l differences between the groups.