Medial epicondyle osteotomy: a method of choice in severe varus knee arthroplasty

Abstract

The purpose of this study was to evaluate the results of total knee arthroplasty (TKA) after using medial epicondyle osteotomy (MEO) as a balancing method for severe varus deformity and also to compare these results with those of TKA after using additional resection of the tibial medial plateau to correct this deformity. A total of 60 knees with severe varus deformity underwent TKA between 2006 and 2010. In 30 cases, we used MEO as a balancing method, and in other 30, additional medial tibial plateau resection was performed. The clinical outcomes were measured with the Knee Society score (KSS), the range of the motion and frontal laxity of the knee. The radiological outcomes were measured by anteroposterior simple radiographs to assess: the union state of the osteotomy site, the amount of resected tibial medial plateau bone and the femorotibial angle. The findings of the study show that in the MEO group the KSS improved from 21.13 ± 13.6 to 92.1 ± 7.6 points (P < 0.001). Moreover, the range of motion increased from 70.3° ± 25.3° to 109.3° ± 12.7° (P < 0.001). The femorotibial angle was corrected from a 22.6° ± 5.71° varus to a 4.0° ± 1.38° valgus (P < 0.001) and frontal laxity decreased from 10.83° ± 3.9° to 0.33° ± 1.2° (P < 0.001). No statistically significant differences were found between groups regarding the postoperative outcomes of KSS, range of motion, femorotibial angle and frontal laxity. The amount of resected tibial medial plateau bone was statistically significantly smaller in the MEO group (1.63 ± 0.96 mm in the MEO group and 4.73 ± 2.7 mm in the other group; P < 0.001). In the MEO group, the mean thickness of the polyethylene insert was 12.66 ± 1.21 mm, while in the second group, it was 13.73 ± 1.59 mm, with statistically significant P = 0.005. Fibrous union occurred in all knees in the MEO group. Using medial epicondyle osteotomy for varus knee when performing total knee arthroplasty could be a useful ligament-balancing technique to achieve medial stability of the knee. In addition, it could have considerable advantages towards the additional resection of the tibial medial plateau.