Anterior border of the tibia as a landmark for extramedullary alignment guide in total knee arthroplasty for varus knees

Abstract

A disadvantage to using extramedullary alignment guides of the tibia for total knee arthroplasty (TKA) is difficulty in correctly identifying the ankle center. The anterior border of the tibia is easily palpable, as it is not covered by muscles and its shape is convex anteriorly. We hypothesized that appropriate points exist along the anterior border that can be used as landmarks for extramedullary guides. Prior to TKA, computed tomographic images of the entire tibia were obtained from 101 osteoarthritic knees with varus deformities. The relationship between the lines connecting two points on the anterior border and the mechanical axis was evaluated using 3D imaging software. The mean angles between each of 10 determined axes and the mechanical axis varied from 3.28 varus to 2.18 valgus in the coronal plane. In the sagittal plane, all axes referencing the anterior border of the tibia showed anterior inclination to the mechanical axis. The line connecting the medial one-third of the patellar tendon attachment and the distal one-fourth of the anterior border, however, was highly consistent and parallel to the mechanical axis in the coronal plane. This axis can be effectively used as a landmark for extramedullary guides during TKA. ß

Accuracy of Proximal Tibial Bone Cut Using Anterior Border of Tibia as Bony Landmark in Total Knee Arthroplasty

“…For two knees, we were able to perform a computer simulation based on preoperative CT data to evaluate the relationship between a line connecting the proximal and distal one-third of the anterior border and the mechanical axis of the tibia. The discrepancy of one knee relative to the target angle was 0.4°varus, while that of the other knee was 0.4°valgus, results that were similar to those of our previous computer simulation study [21]. …”

“…Tibial components with a varus alignment over 3°have a higher incidence of failure because of the increased stress on cancellous bone [8,29] and increased proximal tibial strain, above the threshold for fatigue damage [30]. We previously performed a three-dimensional computer simulation to identify a reliable reference point for setting the guide [21]. In that study, we found that a line connecting the proximal and distal one-third of the anterior border was similarly parallel to the mechanical axis in the coronal plane.…”

“…It would be ideal to identify a stable landmark so as to allow surgeons to most accurately realize the tibial mechanical axis. We previously performed a three-dimensional computer simulation to evaluate the efficacy of the anterior border of the tibia as a reference for setting extramedullary alignment in TKA [21]. Our computer simulation showed that (1) the line connecting the proximal and distal one-third of the anterior border, and (2) the line connecting the medial one-third of the patellar tendon attachment and the distal one-fourth of the anterior border were similarly parallel to the mechanical axis in the coronal plane.…”

Estimation of frontal alignment error of the extramedullary tibial guide on the bi-malleolar technique: A simulation study with magnetic resonance imaging

“…To avoid determining the ankle center, some surgeons have used the anterior border of the tibial shaft for the extramedullary guide. Recently, it has been reported that a line connecting the medial one-third of the patellar tendon attachment and the distal one-fourth of the anterior border of the tibia is highly consistent and parallel to the mechanical axis in the frontal plane [9]. However, the anterior border of the tibia is not always easily palpable in patients with high levels of dermal fat.…”

Proximal tibial resection in varus-deformed tibiae during total knee arthroplasty: an in vitro study using sawbone model

“…However, some authors emphasise the usefulness of bony landmarks of extramedullary reference for tibial cutting. Fukagawa et al [21] suggested that the medial one third of the patellar tendon attachment and the distal one fourth of the anterior border of the tibia was consistently parallel to the mechanical axis in the coronal plane. Tsukeoka et al [22] mentioned that the anterior tibial crest in the coronal and sagittal planes could be a useful EM guideline in performing TKAs.…”