Biplanar Open Wedge High Tibial Osteotomy in the Medial Compartment Osteoarthritis of the Knee Joint: Comparison between the Aescula and TomoFix Plate

BACKGROUND The purpose of this study was to compare the results of Aescula and TomoFix plates used for biplanar open wedge high tibial osteotomy in medial osteoarthritis of the knee joint with varus deformity. METHODS A consecutive series of 50 cases of biplanar open wedge high tibial osteotomy were evaluated retrospectively. Group A contained 25 cases treated by using the Aescula plate, and group T contained 25 cases treated by using the TomoFix plate. Full weight-bearing was permitted at 6 weeks after surgery in group A and at 2 weeks in group T. Clinical evaluations were performed at the final follow-up by using postoperative knee scores and functional scores. Radiographic analysis included postoperative mechanical femur-tibia angle, change in posterior tibial slope angle, and complications related to implants. The mean follow-up periods were 30 months in group A and 26 months in group T. RESULTS The knee and functional scores were improved at the final follow-up in both groups (p < 0.05), but no differences were observed between the two groups (p > 0.05). An acceptable correction angle was obtained in 52% of group A and in 84% of group T (p = 0.015). Change in posterior tibial slope angle was larger in group A than in group T (p < 0.001), showing better maintenance of posterior tibial slope in group T. In group A, there were 3 cases of screw loosening and 4 cases of delayed union. In addition, there were residual varus deformities in 7 cases (6 in group A and 1 in group T). CONCLUSIONS This study shows that firm fixation using a TomoFix plate for open wedge high tibial osteotomy produces better radiologic results and a low complication rate than those of the Aescula spacer plate.