Department of Orthopedic Surgery, Chugoku Rousai Hospital, 1-5-1 Hirotagaya, Kure, Hiroshima, 737-0193, Japan,
Knee Surg Sports Traumatol Arthrosc. 2013 Dec;21(12):2704-12. doi: 10.1007/s00167-012-2059-6. Epub 2012 May 30.
The intra-operative femorotibial joint gap and ligament balance, the predictors affecting these gaps and their balances, as well as the postoperative knee flexion, were examined. These factors were assessed radiographically after a posterior cruciate-retaining total knee arthroplasty (TKA). The posterior condylar offset and posterior tibial slope have been reported as the most important intra-operative factors affecting cruciate-retaining-type TKAs. The joint gap and balance have not been investigated in assessments of the posterior condylar offset and the posterior tibial slope.
The femorotibial gap and medial/lateral ligament balance were measured with an offset-type tensor. The femorotibial gaps were measured at 0°, 45°, 90° and 135° of knee flexion, and various gap changes were calculated at 0°-90° and 0°-135°. Cruciate-retaining-type arthroplasties were performed in 98 knees with varus osteoarthritis.
The 0°-90° femorotibial gap change was strongly affected by the posterior condylar offset value (postoperative posterior condylar offset subtracted by the preoperative posterior condylar offset). The 0°-135° femorotibial gap change was significantly correlated with the posterior tibial slope and the 135° medial/lateral ligament balance. The postoperative flexion angle was positively correlated with the preoperative flexion angle, γ angle and the posterior tibial slope. Multiple-regression analysis demonstrated that the preoperative flexion angle, γ angle, posterior tibial slope and 90° medial/lateral ligament balance were significant independent factors for the postoperative knee flexion angle. The flexion angle change (postoperative flexion angle subtracted by the preoperative flexion angle) was also strongly correlated with the preoperative flexion angle, posterior tibial slope and 90° medial/lateral ligament balance.
The postoperative flexion angle is affected by multiple factors, especially in cruciate-retaining-type TKAs. However, it is important to pay attention not only to the posterior tibial slope, but also to the flexion medial/lateral ligament balance during surgery. A cruciate-retaining-type TKA has the potential to achieve both stability and a wide range of motion and to improve the patients' activities of daily living.
研究了保留后交叉韧带的全膝关节置换术（TKA）术中的股骨-胫骨关节间隙和韧带平衡、影响这些间隙和平衡的预测因素，以及术后膝关节屈曲度。通过对保留后交叉韧带的 TKA 术后进行的放射学评估来检测这些因素。后髁偏心距和胫骨后倾角已被报道为影响保留交叉韧带型 TKA 的最重要的术中因素。在评估后髁偏心距和胫骨后倾角时，关节间隙和平衡并未被纳入考量。
采用偏移式张力计测量股骨-胫骨间隙和内外侧韧带平衡。在膝关节 0°、45°、90°和 135°时测量股骨-胫骨间隙，并计算 0°-90°和 0°-135°时的各种间隙变化。对 98 例膝内翻骨关节炎患者进行了保留后交叉韧带的 TKA。
0°-90°股骨-胫骨间隙变化主要受后髁偏心距值（术后后髁偏心距减去术前后髁偏心距）影响。0°-135°股骨-胫骨间隙变化与胫骨后倾角和 135°内外侧韧带平衡显著相关。术后膝关节屈曲角度与术前膝关节屈曲角度、γ角和胫骨后倾角呈正相关。多元回归分析表明，术前膝关节屈曲角度、γ角、胫骨后倾角和 90°内外侧韧带平衡是术后膝关节屈曲角度的重要独立影响因素。（术后膝关节屈曲角度减去术前膝关节屈曲角度）的变化也与术前膝关节屈曲角度、胫骨后倾角和 90°内外侧韧带平衡密切相关。
术后膝关节屈曲角度受多种因素影响，尤其是在保留后交叉韧带的 TKA 中。然而，手术过程中不仅要注意胫骨后倾角，还要注意屈伸侧韧带平衡。保留后交叉韧带的 TKA 具有实现稳定性和大范围运动以及提高患者日常生活活动能力的潜力。
