Proprioceptive sensitivity and performance in anterior cruciate ligament-deficient knee joints

We studied the performance and proprioception of the knee joint in a group of non-reconstructed anterior cruciate ligament (ACL)-deficient (n = 20) pa tients and compared them with a group of ACE-reconstructed patients (n = 18 ) and a group of healthy controls (n = 20), Each patient was scored accordi ng to Lysholm and Tegner and was then asked to subjectively evaluate the pe rformance of the injured knee and the degree of retropatellar discomfort. T he knee joint laxity was measured, The performance was assessed based on th e performance in a triple jump test and a one-leg one-step leap test. The p roprioception in the knee was measured as the threshold when passive moveme nt was detected and as the ability to reproduce a flexion angle from a star t position of 60 degrees of flexion or from full extension of the knee, All tests were performed on both legs, The scoring systems and the subjective evaluation showed significant differences between the reconstructed and the non-reconstructed patients. No significant difference in knee joint laxity was found between the two groups, In the triple jump test and the one-step leap test, both groups performed significantly worse on the leg with the i njured knee joint than on the non-injured leg. The proprioceptive tests sho wed decreased ability to recognize and reproduce a prior angle from a start position of 60 degrees, The threshold to detection of passive movement wit h the injured knee was significantly increased in both groups of patients. No difference was found between the dominant and non-dominant knee in the c ontrol group, When reproduction of the same angles started from full extens ion, the groups did not differ. These data show that decreased performance and changes in the proprioception of the knee joint accompany ACL rupture.