Isolated Posterior Cruciate Ligament Insufficiency Induces Morphological Changes of Anterior Cruciate Ligament Collagen Fibrils

Summary: We studied the ultrastructural changes of the human anterior cruciate ligament (ACL) with transmission electron micrograph cross-sections following isolated posterior cruciate ligament (PCL) injury. Biopsy specimens were obtained from the proximal third and anteromedial aspect of the ACL. Fourteen patients with PCL-deficient knees at a mean of 22.1 months from injury to surgery and 5 normal knees amputated secondary to malignant tumors or traumatic injuries were used as controls. A significant difference was found in the number of collagen fibrils per l @mm^2 between the PCL-deficient knee group and the control group. There was a significant difference found in the collagen fibril diameter between the PCL-deficient knee group and the control group. The collagen packing density (the percentage of sampled area occupied by collagen fibrils) was also significantly different between the PCL-deficient knee and the control group. The current study shows that an isolated PCL insufficiency can induce morphological changes in ACL collagen fibrils, suggesting that a PCL insufficiency can have adverse effects on other ligamentous structures in the knee joint. Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 15, No 3 (April), 1999: pp 292-296