The Orthopaedic Research Institute of Queensland, Townsville, Australia.
Mater Hospital, Townsville, Qld Australia.
Bone Joint J. 2019 Mar;101-B(3):331-339. doi: 10.1302/0301-620X.101B3.BJJ-2018-0544.R1.
The results of kinematic total knee arthroplasty (KTKA) have been reported in terms of limb and component alignment parameters but not in terms of gap laxities and differentials. In kinematic alignment (KA), balance should reflect the asymmetrical balance of the normal knee, not the classic rectangular flexion and extension gaps sought with gap-balanced mechanical axis total knee arthroplasty (MATKA). This paper aims to address the following questions: 1) what factors determine coronal joint congruence as measured on standing radiographs?; 2) is flexion gap asymmetry produced with KA?; 3) does lateral flexion gap laxity affect outcomes?; 4) is lateral flexion gap laxity associated with lateral extension gap laxity?; and 5) can consistent ligament balance be produced without releases?
A total of 192 KTKAs completed by a single surgeon using a computer-assisted technique were followed for a mean of 3.5 years (2 to 5). There were 116 male patients (60%) and 76 female patients (40%) with a mean age of 65 years (48 to 88). Outcome measures included intraoperative gap laxity measurements and component positions, as well as joint angles from postoperative three-foot standing radiographs. Patient-reported outcome measures (PROMs) were analyzed in terms of alignment and balance: EuroQol (EQ)-5D visual analogue scale (VAS), Knee Injury and Osteoarthritis Outcome Score (KOOS), KOOS Joint Replacement (JR), and Oxford Knee Score (OKS).
Postoperative limb alignment did not affect outcomes. The standing hip-knee-ankle (HKA) angle was the sole positive predictor of the joint line convergence angle (JLCA) (p < 0.001). Increasing lateral flexion gap laxity was consistently associated with better outcomes. Lateral flexion gap laxity did not correlate with HKA angle, the JLCA, or lateral extension gap laxity. Minor releases were required in one third of cases.
The standing HKA angle is the primary determinant of the JLCA in KTKA. A rectangular flexion gap is produced in only 11% of cases. Lateral flexion gap laxity is consistently associated with better outcomes and does not affect balance in extension. Minor releases are sometimes required as well, particularly in limbs with larger preoperative deformities. Cite this article: Bone Joint J 2019;101-B:331-339.
全膝关节置换术（TKA）的运动学结果已通过肢体和组件对线参数进行了报道，但尚未通过间隙松弛度和差异来报道。在运动学对线（KA）中，平衡应反映正常膝关节的不对称平衡，而不是通过间隙平衡机械轴 TKA（MATKA）所寻求的经典矩形屈伸间隙。本文旨在解决以下问题：1）哪些因素决定站立位 X 线片上的冠状关节吻合度？2）KA 会产生屈曲间隙不对称吗？3）外侧间隙松弛度会影响结果吗？4）外侧间隙松弛度与外侧伸展间隙松弛度有关吗？5）是否可以在不进行松解的情况下产生一致的韧带平衡？
共对 192 例由同一位外科医生采用计算机辅助技术完成的 TKA 进行了随访，平均随访时间为 3.5 年（2 至 5 年）。116 例男性患者（60％）和 76 例女性患者（40％），平均年龄为 65 岁（48 至 88 岁）。评估指标包括术中间隙松弛度测量值和组件位置，以及术后三英尺站立位 X 线片上的关节角度。患者报告的结果测量（PROM）从对线和平衡方面进行了分析：EuroQol（EQ）-5D 视觉模拟量表（VAS）、膝关节损伤和骨关节炎结果评分（KOOS）、KOOS 关节置换（JR）和牛津膝关节评分（OKS）。
术后肢体对线不影响结果。站立位髋膝踝角（HKA）是关节线会聚角（JLCA）的唯一正预测因子（p <0.001）。外侧间隙松弛度增加与更好的结果始终相关。外侧间隙松弛度与 HKA 角、JLCA 或外侧伸展间隙松弛度无相关性。三分之一的病例需要进行小松解。
站立位 HKA 角是 TKA 中 JLCA 的主要决定因素。只有 11％的病例产生矩形屈曲间隙。外侧间隙松弛度与更好的结果始终相关，并且不会影响伸展时的平衡。有时也需要进行小松解，尤其是在术前畸形较大的肢体中。
Bone Joint J 2019;101-B:331-339.
