Barroso Rosa Sergio, Ismailidis Petros, Doma Kenji, Grant Andrea, McEwen Peter, Wilkinson Matthew, Parkinson Benjamin
Orthopaedic Research Institute of Queensland, Townsville, Australia; Department of Clinical and Surgical Sciences, University of Las Palmas de Gran Canaria, Canary Islands, Spain.
Orthopaedic Research Institute of Queensland, Townsville, Australia; Department of Orthopaedics and Traumatology, University Hospital, Basel, Switzerland; Department of Clinical Research, University of Basel, Basel, Switzerland.
J Arthroplasty. 2025 Jun 5. doi: 10.1016/j.arth.2025.05.128.
Over the last decade alternative alignment techniques in primary total knee arthroplasty (TKA) have been developed in the hope to allow knee prostheses to better replicate normal knee kinematics and improve clinical outcomes. The purpose of this study was to quantify prosthesis soft-tissue balance and pivot patterns based on a restricted kinematic alignment (KA) or mechanical alignment (MA) surgical technique.
A total of 109 primary cruciate retaining TKAs were randomized to either a mechanical or KA technique. Medial and lateral compartmental pressures and contact point patterns were quantified at 10, 45, and 90 degrees of flexion using an insert pressure sensor.
A significantly greater proportion of KA knees were balanced through a full range of motion (ROM) after the initial bone resections (61 KA versus 12% MA, P < 0.001) and the differences were significant at all positions of ROM. For the unbalanced prostheses, the MA knees required significantly more soft-tissue releases (P = 0.008) and bone alignment adjustments (P < 0.001). The initial and final rollback pivot patterns were not significantly different between techniques (initial P = 0.29, final P = 0.29). The primary driving factor for the pivot patterns was not alignment, but instead the differential pressure between the medial and lateral compartments at 45 and 90 degrees flexion (45° P < 0.001, 90° P < 0.001), with the knee pivoting on the tighter compartment in flexion.
In primary cruciate retaining TKA a restricted KA technique achieves a balanced prosthesis with significantly fewer soft-tissue releases or bone recuts. The knee's natural medial pivot pattern can be replicated with a prosthesis by controlling the soft tissue balance to achieve a non-symmetrical flexion gap: equal balance in extension, with medial ligament tension maintained through ROM while allowing increased lateral soft-tissue laxity in flexion. The trial and protocol were registered with the Australian New Zealand Clinical Trials Registry (ACTRN12616001705471).
在过去十年中，全膝关节置换术（TKA）中开发了替代对线技术，希望能使膝关节假体更好地复制正常膝关节运动学并改善临床结果。本研究的目的是基于受限运动学对线（KA）或机械对线（MA）手术技术，对假体软组织平衡和旋转模式进行量化。
总共109例初次保留交叉韧带的TKA被随机分为机械对线或KA技术组。使用插入式压力传感器在屈膝10°、45°和90°时对内侧和外侧间室压力及接触点模式进行量化。
在初次骨切除后，KA膝关节在整个运动范围（ROM）内实现平衡的比例显著更高（61%的KA膝关节与12%的MA膝关节，P < 0.001），并且在ROM的所有位置差异均显著。对于不平衡的假体，MA膝关节需要显著更多的软组织松解（P = 0.008）和骨对线调整（P < 0.001）。两种技术之间初始和最终的后滚旋转模式没有显著差异（初始P = 0.29，最终P = 0.29）。旋转模式的主要驱动因素不是对线，而是屈膝45°和90°时内侧和外侧间室之间的压差（45°P < 0.001，90°P < 0.001），膝关节在屈膝时向较紧的间室旋转。
在初次保留交叉韧带的TKA中，受限KA技术能以显著更少的软组织松解或骨重新截骨实现假体平衡。通过控制软组织平衡以实现非对称屈曲间隙，可使假体复制膝关节自然的内侧旋转模式：伸直时平衡相等，在ROM过程中保持内侧韧带张力，同时在屈膝时允许外侧软组织松弛增加。该试验和方案已在澳大利亚新西兰临床试验注册中心注册（ACTRN12616001705471）。
