Department of Orthopaedic Surgery, Osaka City University Graduate School of Medicine, Abeno-ku, Osaka, Japan.
Department of Orthopaedic Surgery, Osaka Rosai Hospital, Sakai, Osaka, Japan.
J Arthroplasty. 2018 Mar;33(3):735-739. doi: 10.1016/j.arth.2017.10.030. Epub 2017 Nov 11.
Postoperative knee flexion angle is one of the most important outcomes of total knee arthroplasty (TKA). Intraoperative ligament balancing may affect the postoperative range of motion of the knee. However, the relationship between intraoperative ligament balancing and postoperative flexion angle was still controversial. The purpose of this study was to determine whether intraoperative joint gap affects postoperative knee flexion angle or not.
Prospective multicenter study of 246 knees with varus osteoarthritis undergoing a posterior-stabilized, mobile-bearing TKA was performed. The joint gap before implantation and after implantation was measured. The joint gap after implantation was measured using a specially designed tensor device with the same shape of a total knee prosthesis at 0°, 30°, 60°, 90°, 120°, and 145° of flexion with the reduction of the patellofemoral joint. Stepwise multiple regression analysis was conducted to determine the predictors of the flexion angle of the knee after the operation.
Predictors were identified in the following 3 categories: (1) preoperative flexion angle, (2) intraoperative flexion angle, and (3) joint gap looseness at 120° of flexion (joint gap after implantation at 120° of flexion - joint gap after implantation at 0° of flexion) (R = 0.472, P < .01).
Flexion angle after TKA was not affected by the flexion joint gap looseness before implantation and the joint gap looseness after implantation from 30° to 90° of flexion. Surgeons should notice that joint gap looseness in mid-flexion range did not increase the postoperative knee flexion angle.
术后膝关节弯曲角度是全膝关节置换术（TKA）最重要的结果之一。术中韧带平衡可能会影响膝关节的术后活动范围。然而，术中韧带平衡与术后膝关节弯曲角度之间的关系仍存在争议。本研究旨在确定术中关节间隙是否会影响术后膝关节弯曲角度。
对 246 例患有内侧骨关节炎的患者进行前瞻性多中心研究，这些患者接受了后稳定、活动衬垫 TKA。测量植入前和植入后的关节间隙。使用专门设计的张量装置，在髌股关节复位的情况下，在 0°、30°、60°、90°、120°和 145°的膝关节弯曲时测量植入后的关节间隙，该装置具有与全膝关节假体相同的形状。采用逐步多元回归分析确定术后膝关节弯曲角度的预测因素。
确定了以下 3 类预测因素：（1）术前膝关节弯曲角度，（2）术中膝关节弯曲角度，和（3）120°弯曲时的关节间隙松弛度（120°弯曲时的植入后关节间隙-0°弯曲时的植入后关节间隙）（R=0.472，P<0.01）。
TKA 后膝关节弯曲角度不受植入前关节弯曲间隙松弛度和植入后从 30°到 90°的关节间隙松弛度的影响。外科医生应该注意到，在膝关节中度弯曲范围内的关节间隙松弛度不会增加术后膝关节弯曲角度。
