THE ADVERSE-EFFECTS OF SECTIONING THE POSTERIOR CRUCIATE LIGAMENT IN RABBITS - CHANGES IN THE STRUCTURAL AND MORPHOLOGICAL PROPERTIES OF THE FEMUR-ANTERIOR CRUCIATE LIGAMENT-TIBIA COMPLEX

This study examined the changes in the structural properties of the fe mur-anterior cruciate ligament - tibia complex (FATC) and the histolog ic changes of the anterior cruciate ligament (ACL) following sectionin g of the posterior cruciate ligament (PCL) of 20 rabbits. The PCL in t he right knee was sectioned through an arthrotomy. The left knee under went arthrotomy only and was used as a control. The animals were kille d 3 and 6 months postoperatively. The tensile properties of the FATCs were tested, and the ACLs were histologically examined using polarized light microscopy and transmission electron microscopy. There were sig nificant decreases in the ultimate load following sectioning of the PC L, although there were no significant changes in the stiffness. There were no significant differences in either the crimp period or the crim p amplitude of the ACL following sectioning of the PCL. There were sig nificant increases in the number of collagen Fibrils per square microm eter, and significant decreases in the collagen fibril diameter and pr oportion of total collagen fibril area per square micrometer following sectioning of the PCL. These findings suggest that isolated PCL injur y may cause pathological changes in the ACL and its insertion sites.