Sidhu Sahil Prabhnoor, Lanting Brent, Kelly Paul, Vasarhelyi Edward, Willing Ryan
Western University, Department of Orthopaedic Surgery, London, Ontario, N6A 5A5, Canada.
Orthop Res Rev. 2021 Jun 28;13:81-88. doi: 10.2147/ORR.S309995. eCollection 2021.
Trialling is a key step in total knee arthroplasty (TKA) and helps the surgeon assess for adequate balancing, range of motion, and stability. Despite this, there are no studies investigating knee kinematics when using trial versus final polyethylene tibial inserts.
Fourteen fresh frozen cadaveric specimens were cycled in a VIVO joint motion simulator. Using both simple compression and simulated muscle loads, joints were tested after TKA with a trial insert or a final tibial poly insert. Anterior/posterior (AP), internal/external (IE), and varus/valgus (VV) kinematics and laxities were analyzed.
Knees with trial poly inserts had significantly greater AP hysteresis (difference between flexion and extension motion) than those with final poly inserts (p=0.001). There was no significant difference in IE (p=0.563) or VV (p=0.580) hysteresis. There was no difference in AP, IE, or VV motion or laxities when considering the flexion path alone. Prosthetic joints followed different paths in flexion versus extension.
While trial tibial inserts impart valuable information, they may not accurately reproduce the same joint kinematics as final inserts. Balancing of the knee at specific degrees of flexion may depend on the path taken to get there.
试验是全膝关节置换术（TKA）的关键步骤，有助于外科医生评估平衡是否合适、活动范围和稳定性。尽管如此，尚无研究调查使用试验性与最终聚乙烯胫骨假体时的膝关节运动学。
14个新鲜冷冻尸体标本在VIVO关节运动模拟器中进行循环测试。使用简单压缩和模拟肌肉负荷，在TKA术后分别使用试验性假体或最终胫骨聚乙烯假体对关节进行测试。分析前后（AP）、内外（IE）和内翻/外翻（VV）的运动学和松弛度。
使用试验性聚乙烯假体的膝关节比使用最终聚乙烯假体的膝关节具有显著更大的AP滞后（屈伸运动之间的差异）（p = 0.001）。IE（p = 0.563）或VV（p = 0.580）滞后无显著差异。仅考虑屈曲路径时，AP、IE或VV运动及松弛度无差异。假体关节在屈伸过程中遵循不同路径。
虽然试验性胫骨假体可提供有价值的信息，但它们可能无法准确再现与最终假体相同的关节运动学。膝关节在特定屈曲角度的平衡可能取决于达到该角度所采取的路径。
