Collagen ultrastructure in ruptured cruciate ligaments. An electron microscopic investigation
Neurath, M.F.; Stofft, E.
Acta Orthopaedica Scandinavica 63(5): 507-510
1992
ISSN/ISBN: 0001-6470 PMID: 1441944 Document Number: 402813
The ultrastructure of collagen fibrils was investigated in normal (n 39) and ruptured (n 23) human anterior cruciate ligaments. The normal ligament had a complex three-dimensional structure. Collagen fibrils predominantly had a unidirectional course with parallel arrangement and a mean diameter of 75 (20-185) nm. Four days after anterior cruciate ligament rupture, the mean fibril diameter was increased; it later decreased, probably due to synthesis of young, thin 30-40 nm fibrils. Interfibrillar dysplastic collagen fibrils were detected in the extracellular matrix of ruptured ligaments. They were more frequently found later than 3 days after rupture and were seen also at a distance of 2-3 cm from the rupture zone. The presence of dysplastic fibrils may explain the functional insufficiency of the repair tissue in ruptured cruciate ligaments.