Medial Tibial Reduction Osteotomy is Associated with Excellent Outcomes and Improved Coronal Alignment

Abstract

Background: The medial tibial reduction osteotomy (MTRO) was introduced to achieve coronal ligamentous balance in total knee arthroplasty (TKA) patients with substantial preoperative varus deformity. Limited data exists on the outcomes of patients requiring an MTRO. This study compares outcomes of a matched cohort of patients that either required or did not require an MTRO during TKA. Methods: A retrospective review was performed on 67 patients that underwent an MTRO during primary TKA to achieve coronal balance. This patient population was matched 1:1 to another cohort of TKA patients by age, gender, and BMI that did not require an MTRO. A clinical and radiographic evaluation was utilized to compare the two cohorts. Results: Preoperatively, the tibiofemoral angle was 3.42° valgus versus 6.12° varus in the control and MTRO cohorts respectively (p=0.01). Mean postoperative tibiofemoral angles were 3.40° versus 2.43° valgus respectively. Postoperative Knee Society Scores were superior in the MTRO cohort (183.84 versus 174.58; p=0.04). Intraoperatively, no superficial MCL releases were required to achieve coronal balance in either cohort. Complications were similar and limited in both groups.  Medial tibial bone resorption was observed in 64% of MTRO subjects averaging 2.02mm versus only 0.3mm in the control cohort ( p=0.01). Conclusion: Patients requiring an MTRO achieved similar alignment and superior knee scores compared to a control cohort with less varus deformity. This procedure eliminated the need for release of the superficial MCL.  Resorption of medial tibial bone was commonly observed, possibly secondary to saw-induced thermal necrosis associated with performing an MTRO.