Tsukada Sachiyuki, Kurosaka Kenji, Nishino Masahiro, Ogawa Hiroyuki, Hirasawa Naoyuki
Department of Orthopaedic Surgery, Hokusuikai Kinen Hospital, 3-2-1 Higashihara, Mito, Ibaraki, 310-0035, Japan.
Eur J Orthop Surg Traumatol. 2020 Jan;30(1):147-151. doi: 10.1007/s00590-019-02538-9. Epub 2019 Aug 27.
Although soft tissue tension during total knee arthroplasty (TKA) has been targeted to achieve equal flexion and extension gaps, such a perfect gap is not always obtained. This study was performed to investigate the impact of difference between flexion and extension gaps on postoperative knee flexion angle.
We reviewed 107 consecutive TKAs using a J-curve design posterior-stabilized prosthesis. Soft tissue tension was measured intraoperatively using an offset-type tensor under 30 lb force of joint distraction with the patella reduced. All TKAs were performed in a uniform manner including the subvastus approach and without use of a pneumatic tourniquet. We assessed the association between knee flexion angle 1 year after TKA and the difference between flexion and extension gaps using Pearson's product-moment correlation and multiple regression analysis with age, sex, body mass index, diagnosis, history of diabetes mellitus, preoperative flexion angle, and gap difference as explanatory variables.
The difference between flexion and extension gaps showed a slight negative correlation with postoperative knee flexion angle in univariate analysis (r = - 0.20, 95% CI, - 0.38 to - 0.01, p = 0.04). Multiple regression analysis showed that the gap difference was an independent factor associated with postoperative knee flexion angle (β = - 0.89, 95% CI, - 1.60 to - 0.18, p = 0.01).
The difference between flexion and extension gaps was negatively correlated with postoperative knee flexion angle. Looser flexion gap compared with extension gap should be avoided in J-curve design posterior-stabilized TKA.
尽管全膝关节置换术（TKA）期间的软组织张力旨在实现屈伸间隙相等，但这种完美的间隙并非总能实现。本研究旨在探讨屈伸间隙差异对术后膝关节屈曲角度的影响。
我们回顾了107例连续使用J形曲线设计的后稳定型假体进行的TKA手术。术中在髌骨复位且关节牵开力为30磅的情况下，使用偏置式张力器测量软组织张力。所有TKA手术均采用统一方式进行，包括股直肌下入路，且未使用气动止血带。我们使用Pearson积矩相关分析以及以年龄、性别、体重指数、诊断、糖尿病史、术前屈曲角度和间隙差异为解释变量的多元回归分析，评估TKA术后1年膝关节屈曲角度与屈伸间隙差异之间的关联。
在单因素分析中，屈伸间隙差异与术后膝关节屈曲角度呈轻微负相关（r = -0.20，95% CI，-0.38至-0.01，p = 0.04）。多元回归分析表明，间隙差异是与术后膝关节屈曲角度相关的独立因素（β = -0.89，95% CI，-1.60至-0.18，p = 0.01）。
屈伸间隙差异与术后膝关节屈曲角度呈负相关。在J形曲线设计的后稳定型TKA中，应避免屈曲间隙比伸直间隙更宽松的情况。
