The cruciate ligaments of the knee joint. Anatomical, functional and experimental analysis.

The anatomical and functional details of the cruciate ligamants of the knee were studied on 20 cadaver knees and 24 fresh knees. Each anterior cruciate ligament was found to consist of 2 parts: a distinct anteromedial band (AMB) and a main posterolateral part. The exact geometry of the ligaments and their relationship to bony landmarks were recorded in detail. The state of the cruciate ligaments, i.e. tightness or looseness was recorded in the various positions of the knee as the basis for classification of the function of the various anatomical components. Selective cutting of the anterior cruciate ligament resulted in an increase of anterior drawer flexion and extension. External and internal rotation were increased in both flexion and extionsion. Hyperextension also was increased. It is suggested that the AMB of the anterior cruciate is responsible for the in anteroposterior drawer with flexion. The selective cutting of the posterior cruciate ligament demonstrated that it is important in the flexed knee and produces an.increased posterior drawer sign. Rotational stability was unchanged in extension, but altered in flexion after cutting the posterior cruciate.