The High Variability of Tibial Rotational Alignment in Total Knee Arthroplasty

Abstract

Although various techniques are advocated to establish tibial rotational alignment during total knee arthroplasty, it is unknown which is most repeatable. We evaluated the precision and accuracy of five tibial rotational alignment techniques to determine whether computer-assisted navigation systems can reduce variability of tibial component rotational alignment when compared to traditional instrumentation. Eleven orthopaedic surgeons used four computer-assisted techniques that required identification of anatomical landmarks and one that used traditional extramedullary instrumentation to establish tibial rotational alignment axes on 10 cadaver legs. Two computer-assisted techniques (axes between the most medial and lateral border of the tibial plateau, and between the posterior cruciate ligament [PCL] and the anterior tibial crest) and the traditional technique were least variable, with standard deviations of 9.9 degrees, 10.8 degrees, and 12.1 degrees, respectively. Computer-assisted techniques referencing the tibial tubercle (axes between the PCL and the medial border or medial 1/3 of the tubercle) were most variable, with standard deviations of 27.4 degrees and 28.1 degrees. The axis between the medial border of the tibial tubercle and the PCL was internally rotated compared to the other techniques. None of the techniques consistently established tibial rotational alignment, and navigation systems that establish rotational alignment by identifying anatomic landmarks were not more reliable than traditional instrumentation.

Biomechanical effects of total knee arthroplasty component malrotation: A computational simulation

“…Identical default positions with a 08 cut on the tibial plateau were used for CR and PS designs. Based on our previous studies, 11,14 femoral rotational alignment was varied between 158 external rotation and 158 internal rotation in 58 increments, and tibial rotational alignment for the CR implant was varied between 208 external rotation and 208 internal rotation in 58 increments. Due to its more highly constrained design, the simulation failed for the PS implant at the more extreme tibial rotational alignments.…”

“…[9][10][11] Siston et al 11 found rotational alignment errors ranging from 138 internal rotation to 168 external rotation. Errors can often occur in tibial component rotational alignment in the transverse plane, [12][13][14] ranging from 448 internal rotation to 468 external rotation. 14 The large variability may be due to the fact that small linear errors in identifying anatomic landmarks translate into large rotational errors.…”

“…Errors can often occur in tibial component rotational alignment in the transverse plane, [12][13][14] ranging from 448 internal rotation to 468 external rotation. 14 The large variability may be due to the fact that small linear errors in identifying anatomic landmarks translate into large rotational errors. 15 Variability in femoral and tibial component rotational alignment can lead to improper joint kinematics and pain.…”

Reliability of frames of reference used for tibial component rotation in total knee arthroplasty

“…In total knee arthroplasty (TKA) the rotational alignment of the tibial component remains an unresolved problem [1]. The tibial component has been shown to have a wider range of rotation than the femoral one [2].…”

“…The tibial component has been shown to have a wider range of rotation than the femoral one [2]. Various techniques are used to ensure optimal alignment, but there is a lack of reliability and repeatability [1]. In a study of 109 TKAs, 50% were found to have tibial malrotation of more than 5 [3], which is sufficient to result in knee pain, a poor range of motion and instability [4,5].…”