Bioengineering Laboratory, Department of Orthopaedic Surgery, Massachusetts General Hospital/Harvard Medical School, Boston, MA, USA.
Med Sci Sports Exerc. 2009 Jun;41(6):1198-205. doi: 10.1249/MSS.0b013e3181981eb5.
To investigate the effect of posterior cruciate ligament (PCL) deficiency on the kinematics and the cartilage contact characteristics of the patellofemoral joint during an in vivo single-leg lunge.
Ten patients with an isolated PCL injury in one knee and the contralateral side intact participated in the study. Magnetic resonance and dual fluoroscopic imaging techniques were used to analyze the patellofemoral kinematics and cartilage contact of the intact and the PCL-deficient knee during a quasi-static single-leg lunge from 0 degrees to 120 degrees of flexion.
PCL deficiency significantly changed the patellofemoral kinematics between 90 degrees and 120 degrees of knee flexion (P < 0.007): an increased patellar flexion angle by 10.7 degrees on average and a decreased lateral shift (on average -1.9 mm), patellar tilt (approximately -2.7 degrees ), and valgus rotation (approximately -1.8 degrees ) were observed in the PCL-deficient knee compared with the intact contralateral joint. The changes in patellofemoral kinematics resulted in significant changes in patellofemoral cartilage contact (P < 0.007). PCL deficiency caused a distal (approximately -3.3 mm) and medial (approximately + 2.7 mm) shift of cartilage contact from 75 degrees to 120 degrees of flexion.
The altered tibiofemoral kinematics that were previously described in PCL deficiency resulted in changes in patellofemoral joint function at flexion angles greater than 75 degrees. This abnormal loading of the patellofemoral joint might predispose the patellofemoral cartilage to degenerative changes. Because we did not detect differences in the patellofemoral joint behavior of the intact and the PCL-deficient knee between 0 degrees and 60 degrees of flexion, rehabilitation exercises might be safely performed in this range of flexion. On the other hand, repetitive deep knee squats should be avoided in PCL-deficient patients, so as not to excessively disturb the patellofemoral cartilage contact kinematics.
研究在活体单腿下蹲过程中，后交叉韧带（PCL）缺失对髌股关节运动学和软骨接触特征的影响。
本研究纳入了 10 名单侧膝关节 PCL 损伤患者及其健侧作为对照。采用磁共振和双荧光透视成像技术，分析了 0 度至 120 度膝关节屈曲时，完整膝和 PCL 缺失膝在准静态单腿下蹲过程中的髌股运动学和软骨接触情况。
PCL 缺失在 90 度至 120 度膝关节屈曲时显著改变了髌股运动学（P < 0.007）：与健侧相比，PCL 缺失膝的髌骨屈曲角度平均增加了 10.7 度，外侧位移（平均-1.9 毫米）、髌骨倾斜（约-2.7 度）和外翻旋转（约-1.8 度）减小。髌股运动学的变化导致髌股软骨接触发生显著变化（P < 0.007）。PCL 缺失导致从 75 度到 120 度屈曲时，软骨接触向远端（约-3.3 毫米）和内侧（约+2.7 毫米）移位。
先前描述的 PCL 缺失导致的胫股关节运动学改变，导致了膝关节屈曲角度大于 75 度时髌股关节功能的改变。髌股关节的这种异常负荷可能使髌股软骨易发生退行性改变。由于我们没有检测到在 0 度至 60 度膝关节屈曲时，完整膝和 PCL 缺失膝髌股关节行为的差异，因此在这个屈曲范围内进行康复锻炼可能是安全的。另一方面，应避免 PCL 缺失患者进行反复的深度膝关节下蹲，以免过度干扰髌股软骨接触的运动学。
