Department of Orthopedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
J Orthop Res. 2024 Nov;42(11):2514-2524. doi: 10.1002/jor.25926. Epub 2024 Jul 2.
Total knee arthroplasty (TKA) and unicompartmental knee arthroplasty (UKA) are effective surgeries to treat end-stage knee osteoarthritis. Clinicians assume that TKA alters knee kinematics while UKA preserves native knee kinematics; however, few studies of in vivo kinematics have evaluated this assumption. This study used biplane radiography to compare side-to-side tibiofemoral kinematics during chair rise, stair ascent, and walking in 16 patients who received either TKA or UKA. We hypothesized that TKA knees would have significant kinematic changes and increased asymmetry with the contralateral knee, while UKA knee kinematics would not change after surgery and preoperative knee symmetry would be maintained. Native bone and implant motion were tracked using a volumetric model-based tracking technique. Six degrees of freedom kinematics were calculated throughout each motion. Kinematics were compared between the operated and contralateral knees pre- and post-surgery using a linear mixed-effects model. TKA knees became less varus with the tibia more medial, posterior, and distal relative to the femur. UKA knees became less varus with the tibia less lateral on average. Postoperative TKA knees were in less varus than UKA knees on average and at low flexion angles, with an internally rotated tibia during chair rise and stair ascent. At high flexion angles, the tibia was more medial and posterior after TKA than UKA. Side-to-side kinematic symmetry worsened after TKA but was maintained or improved after UKA. Greater understanding of kinematic differences between operated and contralateral knees after surgery may help surgeons understand why some patients remain unsatisfied with their new knees.
全膝关节置换术(TKA)和单髁膝关节置换术(UKA)是治疗终末期膝骨关节炎的有效手术。临床医生认为 TKA 改变膝关节运动学,而 UKA 保留了膝关节的自然运动学;然而,很少有关于体内运动学的研究评估了这一假设。本研究使用双平面 X 线摄影比较了 16 例接受 TKA 或 UKA 治疗的患者在坐起、上楼梯和行走时双侧胫骨股骨运动学。我们假设 TKA 膝关节会有明显的运动学变化,并与对侧膝关节相比增加不对称性,而 UKA 膝关节手术后运动学不会改变,术前膝关节的对称性将得到维持。使用基于容积模型的跟踪技术跟踪原生骨和植入物的运动。在每个运动过程中计算六个自由度的运动学。使用线性混合效应模型比较手术侧和对侧膝关节术前和术后的运动学。TKA 膝关节的胫骨相对于股骨更内侧、更后和更远端,从而减少了内翻。UKA 膝关节的胫骨平均更外侧。术后 TKA 膝关节的内翻角度小于 UKA 膝关节,在低屈曲角度下,在坐起和上楼梯时胫骨内旋。在高屈曲角度下,TKA 膝关节的胫骨比 UKA 膝关节更内侧和更后方。TKA 膝关节的侧方运动学对称性在术后恶化,但在 UKA 膝关节中得到维持或改善。更好地了解术后手术侧和对侧膝关节的运动学差异可能有助于外科医生了解为什么有些患者对他们的新膝关节仍然不满意。