Total knee arthroplasty in the valgus knee

Abstract

Valgus knee deformity is a challenge in total knee arthroplasty (TKA) and it is observed in nearly 10 % of patients undergoing TKA. The valgus deformity is sustained by anatomical variations divided into bone remodelling and soft tissue contraction/elongation. Bone tissue variations consist of lateral cartilage erosion, lateral condylar hypoplasia and metaphyseal femur and tibial plateau remodelling. Soft tissue variations are represented by tightening of lateral structures: lateral collateral ligament, posterolateral capsule, popliteus tendon, hamstring tendons, the lateral head of the gastrocnemius and iliotibial band. Complete pre-operative planning and clinical examination are mandatory to manage bone deformities and soft tissue contractions/elongations and to decide if a higher constrained prosthesis is necessary. Two different approaches have been described to perform TKA in a valgus knee: the anteromedial approach and the anterolateral one. In valgus knee deformity bone cuts can be performed differently in order to correct low-grade deformities and reduce great deformities. There is still debate in the literature on the sequence of lateral soft tissue release to achieve the best alignment without any instability. The aim of this article is to review the anatomical variations underlying a valgus knee, to assess the best pre-operative planning and to evaluate how to choose the grade of constraint of the implant. We will also review the main approaches and surgical techniques both for bone cuts and soft tissue management. Finally, we will report on our experience and technique.

Primary modular total knee replacement in severe and unstable osteoarthritis. Predictive factors for failure

“…In severe valgus deformity, the medial collateral ligament may be so weak that it may not be possible to tension it and obtain a stable balanced arthroplasty [8]. It also may not be possible to balance knees with severe preoperative fixed varus deformity or fixed flexion contracture even after ligament releases.…”

Biomechanics and Biomaterials

“…Femur internal rotasyonda, tibia eksternal rotasyonda izlenir. [11] Tipik olarak lateral femoral kondil defektiftir. Anteroposterior keside hafif 3-4 derece eksternal rotasyon verilmelidir.…”

Knee arthroplasty today

“…Bone remodelling and ligament contraction and elongation, require different surgical approaches and corrections, planning in advance the amount of constraint of the implant [7], tricks and tips from experienced surgeons on all these aspects are therefore always welcome in order to achieve long lasting results in these demanding procedures.…”