HIGH TIBIA OSTEOTOMY WITH KOSHINO TECHNIQUE FOR MEDIAL PATELLOFEMORAL OSTEOARTHRITIS OF THE KNEE

From March 1988 to March 1992, a total of 40 high tibial osteotomies(HTO) were performed according to Koshino technique in 35 patients, suffering fromosteoarthritis of knee joints. There were 9 male and 26 female patients. The right kneeand left knee were involved in 15 cases each and both knees involved in 5 cases. The ageof the patients ranged from 33 to 75 years with an average of 58. 6 years. Allosteoarthritis of knee joint were primary except 4 patients with secondary disease due toupper tibiai fracture in the past. According to the classification of knee osteoarthritis ofthe Yokohama City University in Japan, all our patients suffered from medialpatellofemoral type of knee osteoarthritis. On the basis of the pre-operative evaluation ofknee function with the Yokohama City University criteria, the patients had from 40 pointsto 65 points with an average of 53 points. The femoro-tibial angles (FTA) before opera-tion wcre from 178°to 192°with an average of 185.1°±4.7°. The size of bone wedgeto be removed was accurately calculated so as to produce a femoro-tibial angle of 170°after operation, giving 10°of valgus. In severe cases the exposed bone and cartilage ero-sion were found during the operation. In knees with deformity adequately corrected,marked relief of pain was obtained and walking resumed by 4-6 months after operation.The post-operative follow-up ranged from 6 months to 2 years and 3 months with an av-erage of 14.2 months. Out of the 40 patients 17 had their implant removed over a year.Early complications, such as wound infection, hematoma, joint adhesion, deep-veinthrombosis or non-union of bone, did not occur. The post-operative FTA ranged from166°to 177°with an average of 170.3°±3.7°. Post-operative evaluating showed kneefunction from 75 points to 95 points with an average of 88 points, implying good func-tional results. We consider that the Koshino technique of high tibial osteotomy has manyadvantages. It is suited to medial and medial patello-femoral osteoarthritis of the kneejoint.