Effects of injury and reconstruction of the posterior cruciate ligament onproprioception and neuromuscular control

Proprioceptive deficits have been demonstrated following anterior cruciate ligament (ACL) disruption, bur little research exists evaluating propriocep tion in the posterior cruciate ligament (PCL)-deficient and/or -reconstruct ed knee. We have studied proprioception in PCL-deficient and PCL-reconstruc ted knees. The following summarizes our protocol and results of propriocept ive testing of kinesthesia and joint position sense in participants with is olated PCL injuries and those who underwent PCL reconstruction. We studied 18 participants with isolated ruptures of the PCL and 10 participants who u nderwent PCL reconstruction. Proprioception was evaluated by two tests: the threshold to detect passive motion (TTDPM) and the ability to passively re produce passive positioning (RPP). These assess kinesthesia and joint posit ion sense, respectively. We have shown that isolated PCL deficiency in the human knee does result in reduced kinesthesia and enhanced joint position s ense. Thus, the proprioceptive mechanoreceptors in the PCL do appear to hav e some function. We further found that PCL reconstruction significantly imp roved kinesthesia at 45 degrees of knee flexion, while 110 degrees was not significantly different between the involved and uninvolved knee in both st udies.