Department of Orthopaedic Surgery, Azienda Ospedaliero-Universitaria Policlinico di Modena, University of Modena and Reggio-Emilia, Via del Pozzo, 71, 41124, Modena, Italy,
Int Orthop. 2014 Feb;38(2):227-33. doi: 10.1007/s00264-013-2245-2. Epub 2014 Jan 14.
Posterior stabilised (PS) total knee arthroplasty (TKA) design development that focused on restoring normal knee kinematics was followed by the introduction of reason-guided motion designs. Although all PS fixed-bearing knee designs were thought to have similar kinematics, reports show they have differing incidences and magnitudes of posterior femoral rollback and axial rotation. In this retrospective comparative study between two guided-motion total knee systems, we hypothesised that kinematic pattern has an influence on clinical and functional outcomes.
This study represents the continuation of a previously reported clinical and kinematics analysis. We retrospectively reviewed 347 patients treated with two different TKA designs: Scorpio NRG (Stryker Orthopedics) and Journey Bi-Cruciate Stabilised (BCS) knee system (Smith & Nephew). Two hundred and eighty-one patients were assessed clinically. Patients were divided into groups according to implanted TKA. Clinical evaluation with the Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire was performed. Fifteen Scorpio NRG and 16 Journey BCS patients underwent video fluoroscopy during stair climbing, chair rising/sitting and step up/down at six months of follow-up.
At an average 29 months of clinical follow-up, patients with Journey BCS TKAs reported better clinical results. Stiffness was more frequently reported in the Journey group (5.2 % vs 1.2 %), whereas anterior knee pain was observed in the Scorpio NRG group (1.9 %) only. Both prosthetic models reported different posterior translation of the medial and lateral contact points (CP) in all analysed motor tasks during knee flexion (BCS 10-18 mm; NRG Scorpio 2-3 mm). Both designs produced progressive external rotation of the femoral component relative to the tibia during flexion.
Journey BCS showed statistically significant better KOOS results. The higher posterior femoral rollback observed in the kinematic assessment of this design, associated with a better patellofemoral design, may be the reason for better clinical outcome. The reported cases of stiffness and anterolateral joint pain could be attributed to excessive medial and lateral tibiofemoral posterior translation. The NRG group demonstrated good axial rotation, but this was not coupled with physiological kinematic patterns. Patellofemoral pain can be explained by a less friendly femoral-groove design. TKA clinical-functional outcome and complications were highly influenced by the bearing geometry and kinematic pattern of prosthetic designs.
最初的研究方向是开发关注于恢复正常膝关节运动学的后稳定（PS）全膝关节置换（TKA）设计，之后出现了基于理由的运动设计。尽管所有 PS 固定轴承膝关节设计都被认为具有相似的运动学特性，但报告显示它们在股骨后滚和轴向旋转的发生率和幅度上存在差异。在这项对两种导向运动全膝关节系统的回顾性比较研究中，我们假设运动学模式会对临床和功能结果产生影响。
这项研究是之前报道的临床和运动学分析的延续。我们回顾性地评估了 347 例接受两种不同 TKA 设计治疗的患者：Scorpio NRG（Stryker Orthopedics）和 Journey Bi-Cruciate Stabilised（BCS）膝关节系统（Smith & Nephew）。281 例患者进行了临床评估。根据植入的 TKA 将患者分为两组。使用膝关节损伤和骨关节炎结果评分（KOOS）问卷进行临床评估。在 6 个月的随访中，15 例 Scorpio NRG 和 16 例 Journey BCS 患者在爬楼梯、坐起/坐下和上下台阶时进行了视频透视检查。
在平均 29 个月的临床随访中，接受 Journey BCS TKA 的患者报告了更好的临床结果。Journey 组更频繁地报告有僵硬（5.2%比 1.2%），而 Scorpio NRG 组仅报告有前膝疼痛（1.9%）。在所有分析的运动任务中，两种假体模型在膝关节屈曲时都报告了内侧和外侧接触点（CP）不同的后向平移（BCS 10-18mm；NRG Scorpio 2-3mm）。在膝关节屈曲过程中，两种设计都导致股骨相对于胫骨产生渐进性外旋。
Journey BCS 显示出统计学上显著更好的 KOOS 结果。在该设计的运动学评估中观察到的较高的股骨后滚，以及更好的髌股关节设计，可能是临床结果更好的原因。所报道的僵硬和前外侧关节疼痛的病例可能归因于内侧和外侧胫骨股骨后向平移过多。NRG 组表现出良好的轴向旋转，但这与生理运动模式不匹配。髌股关节疼痛可以用不太友好的股骨槽设计来解释。TKA 的临床-功能结果和并发症受到假体设计的轴承几何形状和运动模式的高度影响。
