Proprioceptive defects after an anterior cruciate ligament rupture - the relation to associated anatomical lesions and subjective knee function

A disturbed proprioception has been described in patients with an anterior cruciate ligament (ACL) deficient knee. The relation to demographic data an d to different commonly associated anatomical lesions, as well as to subjec tive knee function, was prospectively studied in 16 consecutive patients af ter an acute knee ligament injury. Ail patients had a complete rupture of t he ACL, but variable associated anatomical lesions. The threshold to detect a passive motion, as a measure of their proprioceptive ability, was regist ered repeatedly during the first year after injury. Four of the patients ha d consistently severe and persistent deficits at 1, 2, and 8 months. These four individuals had more chondral lesions and a lower subjective rating of their knee function than the remaining patients. In the whole group there were significant correlations between the recorded thresholds and associate d chondral lesions, meniscal lesions and the subjective rating of knee func tion. We found no significant relation between age, gender, activity level, grade of mechanical laxity increase or a medial collateral ligament ruptur e, and the proprioceptive recordings. Thus, morphological lesions other tha n a rupture of the ACL seem to contribute to the proprioceptive deficits af ter a knee ligament injury, and the patients' ability to detect a passive m otion showed a relation to subjective knee function from the time of injury onwards.