Varus Gonarthrosis Predisposes to Varus Malalignment in TKA

Abstract

Postoperative alignment is a predictor for longterm survival of total knee arthroplasty (TKA). The purpose of this study was to evaluate whether or not preoperative deformities predispose to intraoperative malposition of TKA components. A retrospective radiographic analysis of 53 primary TKA cases was performed. Preoperative AP hip to ankle and lateral knee radiographs were compared with postoperative views to evaluate component positioning. The following angles were measured: the hip-knee-ankle (HKA) angle expressing the mechanical axis of the leg, the mechanical lateral distal femur angle (mLDFA), the medial proximal tibia angle (MPTA), the posterior distal femur angle (PDFA), and the posterior proximal tibia angle (PPTA). Postoperative measurement of the HKA revealed 34.0% of the cases had a deviation of >±3°from neutral alignment. Sixteen knees (30.2%) were in varus and, with one exception, all presented with severe varus gonarthrosis prior to surgery with a mean tibiofemoral angle of 12.4°c ompared with 1.0°of valgus in the optimally aligned group. Patients (93.3%) with preoperative valgus malalignment showed optimal postoperative HKA. Odds ratios for malalignment of TKA for varus knees in comparison with valgus knees were 7

Component alignment in simultaneous bilateral or unilateral total knee arthroplasty

“…Varus component malposition may be encountered in varus knees [10]. Similarity in varus angles of the knees recruited for the study was important.…”

“…The surgeon can get tired and make mistakes in these long surgical sessions [9]. Component malalignment is one of the common errors in TKA [10][11][12]. Therefore, there is a need to search for a difference in component alignment between simultaneous bilateral TKA and unilateral TKA cases.…”

Femoral Lateral Bowing and Varus Condylar Orientation Are Prevalent and Affect Axial Alignment of TKA in Koreans

“…A knee with severe varus inclination of the tibia plateau requires modification of surgical techniques such as more aggressive medial release or greater external rotation of the femoral component to create rectangular gaps [20]. Furthermore, it is conceivable the presence of these anatomical features is associated with the occurrence of outliers in the coronal alignment and that knees with such outliers have inferior function and durability to properly aligned knees [9,10,20,21,33].…”

Pre-operative frontal plane malalignment predicts the extension gap asymmetry in knee osteoarthritis

“…Stress radiographs under varus and valgus conditions enable a better determination of the stability of the knee joint [12], but involve additional radiation exposure and greater costs and are therefore reserved for special questions [13]. In contrast to this, the pre-operative long standing X-ray is standard in most hospitals, as it is necessary for planning the tibial and femoral resection planes in relation to the mechanical axis [14][15][16]. Up to now, it has been unclear to what extent the axis deviation shown in this radiograph allows conclusions to be drawn about the ligamentous situation of the knee joint, since not just soft-tissue tension but also cartilage/bone defects and extra-articular deviations of the femur or tibia determine the leg axis.…”