変形性膝関節症に対するけい骨粗面下骨切り術の治療経験

Abstract

High tibial osteotomies, both the wedge or dome type, are common in the treatment of osteoarthritis of the knee joint. However there is still some controversy remaining over whether the proximal fragment is too small to achieve a stable union using this technique.We performed proximal low tibial osteotomy (PLTO) to resolve the above. This technique offers the following advantages:(1) By using an equilateral triangular wedge osteotomy, the lateral cortical line is also adapted, and therefore a stable shape is maintained.(2) Using the May plate, rigid fixation is obtained.(3) Early rehabilitation is able to be carried out.We report on nine cases (11 knees), 2 male and 7 female, whose ages ranged from 52 to 72 years (mean 63.5) who were operated on using the PLTO technique from April 1990 to October 1992. The follow-up interval was from 6 to 32 months (mean 63.5). The JOA score was used for the clinical evaluation, and for the radiological evaluation, mechanical axis (MA), femorotibial angle (FTA) and condylar plateau angle (CPA) were measured.Good clinical and radiological results were obtained. On average the JOA score improved from 60 to 85 points, MA improved from 108.6% to 45%, FTA from 185° to 169° and CPA from 6.3° to 2.3°.We concluded that proximal low tibial osteotomy (PLTO) was a useful technique especially for treating the moderate osteoarthritic knee joint in which the mechanical axis passes within the medial joint surface.