Radiological and Functional Outcome of Medial Tibial Reduction Osteotomy for Severe Varus Deformity in patients undergoing Total Knee Arthroplasty- A Prospective Cohort Study

Abstract

Introduction: The deformity and imbalance in an osteoarthritic knee undergoing Total Knee Arthroplasty (TKA) are the result of a combination of bony and soft tissue changes locally. Proper and ideal balancing of ligaments is considered essential to the success of a TKA. There are numerous techniques to achieve soft tissue balance in varus knee. More recently, Medial Tibial Reduction Osteotomy (MTRO) has been described as an adjuvant to soft tissue release. Limited data exists on the outcomes of patients requiring a MTRO. There are not many Indian studies available regarding the radiographic and clinical outcomes of medial reduction osteotomy in severe varus deformity in TKA. Aim: To find out the radiological and functional outcome of MTRO for severe varus deformity in patients undergoing TKA. Materials and Methods: This study was Prospective Cohort study conducted at the Department of Orthopaedics, Rajagiri Hospital, Chunangamveli, Aluva, Kerala from December 2018 to November 2019. Twenty patients 15 females and 5 males (30 knees), in the age group 55-80 years with osteoarthritis of knee with severe varus deformity, were enrolled in the study. Preoperative and postoperative standing leg Antero-posterior radiographs were taken for all patients and hip- knee- ankle angle was measured and amount of deformity correction was calculated. Postoperatively, radiographs were taken on the 5th day and 3rd month. Knee society scores were also recorded preoperatively and on the 5th postoperative day, postoperative visits on 6 weeks, 3 months and clinical outcome was assessed. The statistical analysis was performed by SPSS version 25 using Analysis of Variance(ANOVA) and Wilcoxon Signed Rank test. Results: The median knee score improved from 47±9 to 93±3 postoperatively. Similarly, median function score improved from 50±5 to 80±0. The improvement in function score and knee score were statistically significant (p-value 0.001). The correction of varus between preoperative, postoperative (p-value 0.001) day 5 & 3 months postoperatively was statistically significant. No patient required a release of the superficial Medial Collateral Ligament (MCL). The MTRO was associated with statistically significantly improved Knee Society scores and varus deformity correction. Conclusion: In patients with fixed varus deformity of the knee, the MTRO is found to be safe and adequate to achieve coronal alignment.

Keywords

• knee society score
• ligament balancing
• medial tibial osteophytes
• medial collateral ligament