Effects of injury and reconstruction of the posterior cruciate ligament on proprioception and neuromuscular control

Proprioceptive deficits have been demonstrated following anterior cruciate ligament (ACL) disruption, but little research exists evaluating proprioception in the posterior cruciate ligament (PCL)-deficient and/or - reconstructed knee. We have studied proprioception in PCL-deficient and PCL- reconstructed knees. The following summarizes our protocol and results of proprioceptive testing of kinesthesia and joint position sense in participants with isolated PCL injuries and those who underwent PCL reconstruction. We studied 18 participants with isolated ruptures of the PCL and 10 participants who underwent PCL reconstruction. Proprioception was evaluated by two tests: the threshold to detect passive motion (TTDPM) and the ability to passively reproduce passive positioning (RPP). These assess kinesthesia and joint position sense, respectively. We have shown that isolated PCL deficiency in the human knee does result in reduced kinesthesia and enhanced joint position sense. Thus, the proprioceptive mechanoreceptors in the PCL do appear to have some function. We further found that PCL reconstruction significantly improved kinesthesia at 45°of knee flexion, while 110°was not significantly different between the involved and uninvolved knee in both studies.