Quantification of the Effect of Vertical Bone Resection of the Medial Proximal Tibia for Achieving Soft Tissue Balancing in Total Knee Arthroplasty

Total knee arthroplasty (TKA) has been performed mainly for treatment of elderly patients who have severe degenerative arthritis with varus deformity. The varus knee is the most common deformity in patients presenting for TKA. A knee joint with severe varus deformity is followed by progressive contracture of the medial soft tissues and attenuation of the lateral soft tissues.1) The goal of TKA is to obtain a balanced and well-functioning knee. To achieve this result, release of contracted tissues and removal of peripheral osteophytes are necessary to correct the deformity. For successful TKA, postoperative mediolateral (ML) soft tissue balancing is essential.2) A widely-used technique for the correction of varus deformity relies on the progressive release of the medial soft tissue until its length equals that of the lateral ligamentous structures.3) Although in the majority of varus knees, medial release can be accomplished with a standard approach, a small percentage of primary knee arthroplasties will require additional sequential release of the medial soft tissues. In severe varus deformity, the release of superficial medial collateral ligament (MCL), semimembranosus tendon, posteromedial (PM) capsule, and pes tendons is required, leaving the medial side barren.4,5) This extensive direct medial soft tissue release increases the likelihood of overcorrection and may necessitate more extensive releases and the possible need for a constrained implant.6,7) To overcome these shortcomings, the method of bone resection of the medial proximal tibia (MPT) with minimal medial soft tissue release can be considered as an alternative to avoid iatrogenic medial soft tissue injury.8) This bone resection technique may reduce the incidence of excessive soft tissue release required to balance the knee for coronal stability, minimizing the risk of medial overrelease. The authors hypothesized that bone resection of the MPT for soft tissue balancing would be an effective and safe method to obtain a well-balanced knee in TKA. The purpose of this study was to investigate the effect of this present technique for ML balancing and the quantification of method of bone resection of the MPT as an alternative technique for achieving soft tissue balancing in TKA.