[Hemarthrosis and cruciate ligaments - biomechanical studies. 1]

Experimental studies on animals were conducted in order to investigate the influence exerted by a posttraumatic hemarthrosis upon the cruciate ligaments. The cruciate ligaments used in this experimentation had partly been exposed only to a posttraumatic hemarthrosis, the other part showed an additional lesion of the synovial sheath. Further investigations were carried out in order to find out if the effect of the hemarthrosis is modified by a plaster immobilization of the concerned extremity. In a comparative study, cruciate ligaments which had been exposed to hemarthrosis for different periods of time and normal cruciate ligaments were submitted to mechanical tension which was exerted until rupture. By means of extensive pre-experiments it was possible to define the practical execution, the storage of the removed cruciate ligament preparations, and the general mechanical behavior of cruciate ligaments in rabbits. The study showed that all cruciate ligaments exposed to hemarthrosis presented at least a temporary significant reduction of their mechanical loading capacity. This reduction was even more significant in case of an additional lesion of the synovial sheath. In the first case, a restitution of the normal loading capacity was observed after 8 to 12 weeks, in the second case (additional lesion of the synovial sheath) after 12 to 16 weeks. These results were not improved by a plaster immobilization of the concerned extremity; on the contrary this caused rather a negative tendency.