Department of Mechanical Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea.
Joint Reconstruction Center, Department of Orthopaedic Surgery, Yonsei Sarang Hospital, 10 Hyoryeong-ro, Seocho-gu, Seoul 06698, Republic of Korea.
Biomed Res Int. 2017;2017:4908639. doi: 10.1155/2017/4908639. Epub 2017 Nov 19.
This study aimed to determine the biomechanical effect of the posterior condylar offset (PCO) and posterior tibial slope (PTS) in posterior-stabilized (PS) fixed-bearing total knee arthroplasty (TKA). We developed ±1, ±2, and ±3 mm PCO models in the posterior direction and -3°, 0°, 3°, and 6° PTS models using a previously validated FE model. The influence of changes in the PCO and PTS on the biomechanical effects under deep-knee-bend loading was investigated. The contact stress on the PE insert increased by 14% and decreased by 7% on average as the PCO increased and decreased, respectively, compared to the neutral position. In addition, the contact stress on post in PE insert increased by 18% on average as PTS increased from -3° to 6°. However, the contact stress on the patellar button decreased by 11% on average as PTS increased from -3° to 6° in all different PCO cases. The quadriceps force decreased by 14% as PTS increased from -3° to 6° in all PCO models. The same trend was found in patellar tendon force. Changes in PCO had adverse biomechanical effects whereas PTS increase had positive biomechanical effects. However, excessive PTS should be avoided to prevent knee instability and subsequent failure.
本研究旨在确定后稳定（PS）固定平台全膝关节置换术中后髁偏心距（PCO）和后胫骨倾斜角（PTS）的生物力学效应。我们使用先前验证的有限元模型，在后方开发了±1、±2 和±3mm 的 PCO 模型和-3°、0°、3°和 6°的 PTS 模型。研究了 PCO 和 PTS 变化对深屈膝负荷下生物力学效应的影响。与中立位相比，当 PCO 增加和减少时，PE 衬垫上的接触应力分别平均增加了 14%和减少了 7%。此外，随着 PTS 从-3°增加到 6°，PE 衬垫上的后柱接触应力平均增加了 18%。然而，在所有不同的 PCO 情况下，随着 PTS 从-3°增加到 6°，髌骨按钮上的接触应力平均减少了 11%。在所有 PCO 模型中，随着 PTS 从-3°增加到 6°，股四头肌力量平均减少了 14%。髌腱力也呈现出相同的趋势。PCO 的变化具有不良的生物力学效应，而 PTS 的增加具有积极的生物力学效应。然而，为了防止膝关节不稳定和随后的失败，应避免过度增加 PTS。
