Takase Ryota, Hashimoto Shogo, Ohsawa Takashi, Kakiage Hibiki, Honda Akira, Chikuda Hirotaka
Department of Orthopaedic Surgery Gunma University Graduate School of Medicine Maebashi Gunma Japan.
J Exp Orthop. 2025 Sep 9;12(3):e70435. doi: 10.1002/jeo2.70435. eCollection 2025 Jul.
Postoperative range of motion (ROM) of the knee is an important factor for improving clinical scores and symptoms in total knee arthroplasty (TKA). This study aimed to investigate the relationship between intraoperative factors, including anteroposterior translation of the femur, and extension and flexion gaps, observed during posterior-stabilized TKA (PSTKA) using a navigation system, and preoperative and postoperative parameters.
Twenty-one knees with osteoarthritis that were treated by PSTKA were included. ROM and clinical outcomes, including the Hospital for Special Surgery Knee Score (HSS score), were measured before and one year after surgery, and intraoperative kinematic factors were measured using an image-less navigation system. We further divided the subjects into two groups based on the presence or absence of postoperative flexion contracture (defined as an extension angle ≤ -5°at one year after surgery). The no contracture group comprised 12 knees, and the contracture group comprised 9 knees.
The postoperative extension angle correlated with the starting angle of the anteroposterior translation of the femur ( = -0.60; < 0.01) and the postoperative HSS score ( = 0.46; = 0.04). The postoperative flexion angle correlated with the lateral-to-medial anteroposterior translation ratio ( = 0.47; = 0.03), indicating a medial pivot pattern. In comparison to the contracture group, the no contracture group had a significantly smaller starting angle of the anteroposterior translation of the femur in comparison to the contracture group (no contracture, 30.6° ± 17.0°; contracture, 48.4° ± 16.7°; = 0.02) and a significantly higher postoperative HSS score (no contracture, 90.8 ± 7.0; contracture, 81.1 ± 11.8; < 0.05).
This study revealed that knee joints with flexion contracture after PSTKA had a significantly larger starting angle of anteroposterior translation during surgery and that an intraoperative medial pivot pattern was beneficial for postoperative flexion angles.
Level III.
膝关节置换术后的活动范围（ROM）是改善全膝关节置换术（TKA）临床评分和症状的重要因素。本研究旨在探讨术中因素，包括股骨前后平移，以及在使用导航系统的后稳定型TKA（PSTKA）过程中观察到的伸直和屈曲间隙，与术前和术后参数之间的关系。
纳入21例行PSTKA治疗的骨关节炎膝关节。在手术前和术后1年测量ROM和临床结局，包括特种外科医院膝关节评分（HSS评分），并使用无图像导航系统测量术中运动学因素。我们根据术后是否存在屈曲挛缩（定义为术后1年伸直角度≤-5°）将受试者进一步分为两组。无挛缩组包括12个膝关节，挛缩组包括9个膝关节。
术后伸直角度与股骨前后平移的起始角度相关（r=-0.60；P<0.01）以及术后HSS评分相关（r=0.46；P=0.04）。术后屈曲角度与内外侧前后平移比率相关（r=0.47；P=0.03），表明为内侧旋转模式。与挛缩组相比，无挛缩组股骨前后平移的起始角度明显更小（无挛缩组，30.6°±17.0°；挛缩组，48.4°±16.7°；P=0.02），术后HSS评分明显更高（无挛缩组，90.8±7.0；挛缩组，81.1±11.8；P<0.05）。
本研究表明，PSTKA术后出现屈曲挛缩的膝关节在手术期间前后平移的起始角度明显更大，并且术中内侧旋转模式有利于术后屈曲角度。
III级。
