Asymmetrical tibial polyethylene geometry-cruciate retaining total knee arthroplasty does not fully restore in-vivo articular contact kinematics during strenuous activities

Abstract

Purpose A new CR TKA design with concave medial and convex lateral tibial polyethylene bearing components was introduced recently to improve functional outcomes. This study aimed to investigate in-vivo articular contact kinematics in unilateral asymmetrical tibial polyethylene geometry CR TKA patients during strenuous knee lexion activities. Methods Fifteen unilateral CR TKA patients (68.4 ± 5.8 years; 6 male/9 female) were evaluated for both knees during sitto-stand, single-leg deep lunges and step-ups using validated combined computer tomography and dual luoroscopic imaging system. Medial and lateral condylar contact positions were quantiied during weight-bearing lexion activities. The Wilcoxon signed-rank test was performed to determine if there is a signiicant diference in articular contact kinematics during strenuous lexion activities between CR TKA and the non-operated knees. Results Contact excursions of the lateral condyle in CR TKAs were signiicantly more anteriorly located than the contralateral non-operated knee during sit-to-stand (3.7 ± 4.8 mm vs − 7.8 ± 4.3 mm) and step-ups (− 1.5 ± 3.2 mm vs − 6.3 ± 5.8 mm). Contact excursions of the lateral condyle in CR TKAs were signiicantly less laterally located than the contralateral non-operated knee during sit-to-stand (21.4 ± 2.8 mm vs 24.5 ± 4.7 mm) and single-leg deep lunges (22.6 ± 4.4 mm vs 26.2 ± 5.7 mm, p < 0.05). Lateral condyle posterior rollback was not fully restored in CR TKA patients during sit-to-stand (9.8 ± 6.7 mm vs 12.9 ± 8.3 mm) and step-ups (8.1 ± 4.8 mm vs 12.2 ± 6.4 mm). Lateral pivoting patterns were observed in 80%, 73% and 69% of patients during sit-to-stand, step-ups and single-leg deep lunges respectively. Conclusion Although lateral femoral rollback and lateral pivoting patterns were observed during strenuous functional daily activities, asymmetric contact kinematics still persisted in unilateral CR TKA patients. This suggests the speciic investigated contemporary asymmetrical tibial polyethylene geometry CR TKA design evaluated in this study does not fully replicate healthy knee contact kinematics during strenuous functional daily activities. Level of evidence III.

The higher patient-reported outcome measure group had smaller external rotation of the femur in bicruciate-stabilized total knee arthroplasty

“…Recently, BCS‐TKA yielded better outcomes than did the PS version [6]. In addition, a new cruciate‐retaining TKA (CR‐TKA) version, asymmetrical tibial polyethylene geometry CR‐TKA, does not fully replicate healthy knee contact kinematics during strenuous functional daily activities [11]. To further improve clinical outcomes, the elimination of kinematic conflict is important.…”

Higher rates of fully preserved posterior cruciate ligament in total knee arthroplasty using a double tibial cut: a prospective randomized controlled trial

“…Several investigations have analyzed femoral rollback in patients undergoing TKA using fluoroscopic imaging [ 35 – 37 ]. However, most of previous studies included a limited number of patients in whom different types of TKA were compared [ 35 – 37 ]. Kim et al, analysed the femoral rollback using intraoperative sensors in patients who had a CR and PS TKA [ 38 ].…”