Department of Mechanical and Aerospace Engineering, The Ohio State University, E 305 Scott Laboratory, W. 19th Ave, Columbus, Ohio.
Department of Orthopedic Surgery, Northwestern University, Evanston, Illinois.
J Orthop Res. 2019 Feb;37(2):335-349. doi: 10.1002/jor.24181. Epub 2018 Dec 27.
Instability after total knee arthroplasty (TKA) can lead to suboptimal outcomes and revision surgery. Medially-stabilized implants aim to more closely replicate normal knee motion than other implants following TKA, but no study has investigated knee laxity (motion under applied loads) and balance (i.e., difference in varus/valgus motion under load) following medially-stabilized TKA. The primary purposes of this study were to investigate how medially-stabilized implants change knee laxity in non-arthritic, cadaveric knees, and if it produces a balanced knee after TKA. Force-displacement data were collected on 18 non-arthritic cadaveric knees before and after arthroplasty using medially-stabilized implants. Varus-valgus and anterior-posterior laxity and varus-valgus balance were compared between native and medially-stabilized knees at 0°, 20°, 60°, and 90° under three different loading conditions. Varus-valgus and anterior-posterior laxities were not different between native and medially-stabilized knees under most testing conditions (p ≥ 0.068), but differences of approximately 2° less varus-valgus laxity at 20° of flexion and 4 mm more anterior-posterior laxity at 90° were present from native laxities (p < 0.017) Medially-stabilized implant balance had ≤1.5° varus bias at all flexion angles. Future studies should confirm if the consistent laxity afforded by the medially-stabilized implant is associated with better and more predictable postoperative outcomes. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:335-349, 2019.
全膝关节置换术后不稳定可导致手术效果不佳和翻修手术。与其他膝关节假体相比，内侧稳定型假体在 TKA 后更接近正常膝关节运动，但尚无研究调查内侧稳定型 TKA 后的膝关节松弛度（施加负荷下的运动）和平衡度（即负荷下的内翻/外翻运动差异）。本研究的主要目的是研究内侧稳定型植入物如何改变非关节炎、尸体膝关节的膝关节松弛度，以及它是否在 TKA 后产生平衡的膝关节。在使用内侧稳定型植入物进行 TKA 前后，使用 18 个非关节炎尸体膝关节收集力-位移数据。在三种不同的加载条件下，在 0°、20°、60°和 90°下，比较了自然膝关节和内侧稳定膝关节的内翻/外翻松弛度和前/后松弛度以及内翻/外翻平衡度。在大多数测试条件下（p≥0.068），自然膝关节和内侧稳定膝关节的内翻/外翻松弛度没有差异，但在 20°屈曲时的内翻/外翻松弛度减少约 2°，在 90°时的前/后松弛度增加 4mm，与自然松弛度相比存在差异（p<0.017）。内侧稳定型植入物的平衡在所有屈曲角度下均有≤1.5°的内翻偏差。未来的研究应证实内侧稳定型植入物提供的一致性松弛度是否与更好、更可预测的术后结果相关。©2018 骨科研究协会。 Wiley Periodicals, Inc. 出版 J 骨科研究 37:335-349, 2019。
