Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences (NDORMS) Nuffield Orthopaedic Centre (NOC), University of Oxford, Headington, Oxford, UK.
Knee Surg Sports Traumatol Arthrosc. 2013 Dec;21(12):2800-9. doi: 10.1007/s00167-012-2233-x. Epub 2012 Oct 11.
This study tests the hypothesis that the design changes incorporated in the newer generation Triathlon posterior-stabilised TKA design result in kinematics that more closely reproduce the kinematics observed in healthy knees than those achieved by the older generation Scorpio posterior-stabilised TKA design.
Eleven patients with Triathlon posterior-stabilised TKA, twelve patients with Scorpio posterior-stabilised TKA, and 22 subjects with normal asymptomatic knees underwent fluoroscopic assessment of the knee during a step-up exercise and a weight-bearing deep knee bend. Two-dimensional and three-dimensional knee kinematics were assessed including the maximum flexion, the patella tendon angle (PTA), the patella flexion angle (PFA), the minimum distance between cam and post, and the tibio-femoral contact positions.
The average maximum flexion achieved was 114° (SD 3°), 91° (SD 10°), and 143° (SD 14°) for the Triathlon, Scorpio, and Normal groups. The average cam/post mechanism engagement was at 63° (SD 24°) and 82° (SD 16°) for the Triathlon and Scorpio groups. The condylar contact points showed a paradoxical anterior slide for the Scorpio group which was not present in the Triathlon group. The PTA and PFA values of both implants showed significant differences from normal.
Overall, the Triathlon implant design, as compared to Scorpio TKA, produced kinematics closer to that of normal knees as proposed by the hypothesis. However, despite being closer to normal, the kinematics exhibited by the Triathlon group were still different from normal. A comparison of kinematic performance, taking into account altered design parameters, will contribute to improved understanding and future design considerations.
本研究旨在验证假设，即新一代 Triathlon 后稳定型 TKA 设计中包含的设计改变，可使膝关节运动学更接近健康膝关节的运动学，而不是旧一代 Scorpio 后稳定型 TKA 设计所实现的运动学。
11 例 Triathlon 后稳定型 TKA 患者、12 例 Scorpio 后稳定型 TKA 患者和 22 例无症状正常膝关节患者接受了荧光透视评估，在台阶式运动和负重深度膝关节弯曲时评估膝关节。评估二维和三维膝关节运动学，包括最大屈曲度、髌腱角（PTA）、髌骨屈曲角（PFA）、凸轮和后稳定器之间的最小距离以及胫股接触位置。
Triathlon、Scorpio 和正常组的平均最大屈曲度分别为 114°（SD 3°）、91°（SD 10°）和 143°（SD 14°）。Triathlon 和 Scorpio 组的凸轮/后稳定器机构的平均接合角度分别为 63°（SD 24°）和 82°（SD 16°）。Scorpio 组的髁间接触点显示出反常的前滑动，而在 Triathlon 组中则没有这种情况。两种植入物的 PTA 和 PFA 值均与正常值有显著差异。
总体而言，与 Scorpio TKA 相比，Triathlon 植入物设计产生的运动学更接近假设中正常膝关节的运动学。然而，尽管与正常更接近，但 Triathlon 组的运动学仍与正常不同。考虑到设计参数的改变，对运动学性能进行比较将有助于更好地理解和考虑未来的设计。
