Clinical and radiological outcome of medial proximal tibial vertical (reduction) osteotomy in primary total knee arthroplasty for severe varus deformity of the knee

Abstract

: To obtain balanced knee with severe varus deformity, release of contracted tissues and removal of osteophytes is necessary. MCL release is essential step towards achievement of ligament balancing during total knee arthroplasty (TKA) with varus deformity. This led to over-release of the superficial MCL, hematoma formation, knee joint line elevation and instability. To overcome these, method of bone resection of medial proximal tibia (MPT) with minimal medial soft tissue release called reduction osteotomy (RO). Our study aims to evaluate clinical, radiological benefits of RO over progressive medial soft tissue release during a primary TKA with severe varus deformity, and quantification of method of bone resection of MPT for achieving soft tissue balancing in TKA. This study was conducted at Apollo Hospitals, Navi Mumbai included 24 patients having osteoarthritis with varus deformities more than 10 degrees. All necessary blood investigations with X-ray knee AP(standing), lateral view, scanogram were done and clinically, OKS(Oxford Knee Score) and KSS (Knee Society Score) were assessed pre-operatively & post-operatively. Patients were followed up at 3 months.: There was significant improvement in OKS and KSS at 3 months. For each unit of medial gap deficit, there was corresponding 2.14 units of Proximal tibia vertical osteotomy thickness. For each unit change of Pre-op varus angle, there was a corresponding 0.38 units of Proximal tibia vertical osteotomy thickness.: This prospective RCT on TKA indicated that in patients with severe varus deformity, addition of MPT Vertical Reduction Osteotomy step was better than conventional technique, as it could decrease intraoperative time, by bypassing the step of progressive release of medial soft tissue structures and repeated assessment of medial versus lateral gap balance to achieve a rectangular extension gap. Morbidity and complications due to risk of excessive soft tissue release and need for thicker insert or constraint implant was avoided.