Outcome of distal femoral osteotomy for the correction of varus deformities originating in the distal femur: a prospective study

Abstract

Background: The authors hypothesized that implication of distal femur osteotomy (DFO) in patients with varus deformities that originated in the distal femur will reduce the rate of joint-line obliquity, thereby improving the radiographic, clinical, and functional outcomes of the patients. Here, the authors aimed to evaluate the outcome of DFO in the correction of varus deformities that originated in the distal femur. Methods: In a prospective study, 27 patients (31 knees) with varus deformities located in the distal femur who underwent a lateral biplane closed wedge DFO were included. Radiographic evaluations included the joint-line obliquity, medial proximal tibial angle (MPTA), lateral distal femoral angle (LDFA), and joint-line convergence angle (JLCA). Lysholm-Tegner score and Knee Injury and Osteoarthritis Outcome Score (KOOS) were used for the evaluation of functional outcome. The union of the osteotomy site was assessed radiographically. Results: At the final evaluation session, the mean preoperative varus angle significantly improved from 12.7±3.4 degrees to 1.6±1.6 degrees (P<0.001). The mean preoperative LDFA significantly improved from 96±2.1 degrees to 87.9±1.1 degrees (P<0.001). The mean preoperative JLCA significantly improved from 3.1±0.4 degrees to 2±0.3 degrees (P<0.001). The mean preoperative Lysholm-Tegner scores also improved considerably from 66.4±2 degrees to 88.9±2.6 degrees (P<0.001). The mean KOOS of the patients improved from 63.9±4.1 degrees to 86.1±4.6 degrees. Only one patient (3.2%) was observed to have joint-line obliquity (greater than±4 degrees). Bone union was seen in all patients at an average period of 9±1.9 wk. Conclusions: DFO results in small rate of joint-line obliquity, as well as acceptable radiographic, clinical, and functional outcomes in patients with varus deformities located in the distal femur. Level of Evidence: Level III.