Effect of component mal‐rotation on knee loading in total knee arthroplasty using multi‐body dynamics modeling under a simulated walking gait

Abstract

Mal-rotation of the components in total knee arthorplasty (TKA) is a major cause of postoperative complications, with an increased propensity for implant loosening or wear leading to revision. A musculoskeletal multi-body dynamics model was used to perform a parametric study of the effects of the rotational mal-alignments in TKA on the knee loading under a simulated walking gait. The knee contact forces were found to be more sensitive to variations in the varus-valgus rotation of both the tibial and the femoral components and the internal-external rotation of the femoral component in TKA. The varus-valgus mal-rotation of the tibial or femoral component and the internal-external mal-rotation of the femoral component with a 5˚variation were found to affect the peak medial contact force by 17.8-53.1%, the peak lateral contact force by 35.0-88.4% and the peak total contact force by 5.2-18.7%. Our findings support the clinical observations that a greater than 3˚internal mal-rotation of the femoral component may lead to unsatisfactory pain levels and a greater than 3˚varus mal-rotation of the tibial component may lead to medial bone collapse. These findings determined the quantitative effects of the mal-rotation of the components in TKA on the contact load. The effect of such malrotation of the components of TKA on the kinematics would be further addressed in future studies. Keywords: total knee arthroplasty; mal-rotation; multi-body dynamics; musculoskeletal model; contact forceThe fundamental objectives of total knee arthroplasty (TKA) are to restore normal knee joint function and to relieve pain. However, the failure in TKA resulting from clinical error and mal-alignment of the components limits the long-term survivorship of such prostheses. Dalury et al. 1 retrospectively identified 820 consecutive revision TKAs and found that malposition/mal-alignment was the seventh highest reason for revision. However, mal-position/mal-alignment also affects joint loading, component loosening and wear so that it may have a much larger effect on revision. For example, mal-rotation of the components in TKA may result in overload in the medial or lateral condyle, bone damage and bone cement crack initiation, severe wear of the polyethylene component, component loosening, and ultimately revision surgery. 2,3 In contrast, good alignment measured against the neutral position (referenced to the mechanical axis to within 2˚) after TKA leads to faster rehabilitation and better function. 4 In previous clinical studies, 5 the issue of malrotation was the most frequently discussed complication in TKA. Mal-rotation of a measurable degree has been found in approximately 10-30% of patients with TKA, depending on the surgical technique and the anatomical landmarks used. 5 Even in the hands of experienced surgeons, overall coronal mal-alignment (> AE 3˚from neutral) existed in approximately 28% of the patients. 6 Despite the improvements in surgical instruments and techniques as well as implant designs, a large percentage of the cause...

The Influence of Component Alignment and Ligament Properties on Tibiofemoral Contact Forces in Total Knee Replacement

“…In agreement with previous modeling studies [23,68,69], the coronal alignment of the femoral and tibial components affected the predicted knee contact loading patterns. While total contact force magnitudes were insensitive to alignment (Fig.…”

Influence of Component Rotation in Total Knee Arthroplasty on Tibiofemoral Kinematics—A Cadaveric Investigation

“…These facts support the theorem of aiming to reconstruct natural tibial internal rotation during TKA. In contrast, increased intrinsic motion is associated with accelerated wear [44]. Therefore, tibial internal rotation, causing increased intrinsic motion and wear, consecutively might be prevented.…”

Measuring the effect of femoral malrotation on knee joint biomechanics for total knee arthroplasty using computational simulation

“…The majority of previous studies have investigated the dynamic effects of such variability on joint loading during squats, but there has been no studies that have considered both gait and squat loading conditions. 11,14,16,18-22 Furthermore, to our knowledge, analysis of the contact stress on a PE insert and patellar button, as well as the ligament forces on the knee joint with respect to malrotation during gait and squat loading conditions, has not been reported in previous studies. The level of femoral malrotation reflects the maximum reasonable amount of rotational uncertainty encountered during surgery.…”

“…Malrotation of the components in TKA has been attributed to several clinical complications. 19 Despite the reported high variability in malrotation of the femoral components in TKA, the biomechanical effects of this variability for functional tasks remain unknown. 16 Recently, malrotation was shown to lead to an elevation in the PF joint stress, PE insert wear, and ligament instability.…”

“…17-19 Moreover, Kuriyama et al reported that malrotation of the tibial component increased medial collateral ligament (MCL) tension in TKA. 20 Thompson et al 16 demonstrated that femoral rotation had a greater effect on the quadriceps forces, collateral ligament forces, and varus/valgus kinematics in the deep knee bend position.…”