title: [Ex vivo studies of ACL and MCL injury of rats under mechanical stretch].
abstract: This study sought to detect the pathological changes of anterior cruciate ligament (ACL) and medial collateral ligament (MCL) under injury stretch. Bone-ACL-Bone (B-ACL-B) and B-MCL-B complexes were isolated from 20 male Wister rats, and were immersed in phosphate buffered saline. The complexes were stretched with 10% or 20% strain for 10 min or 30 min. After being stretched, the specimens were fixed in 10% buffered formalin, then mounted in paraffin. Sections were stained with Alcian blue-PAS and HE. The following results were found: In the control group, the matrix in ACL contained much more GAGs, as compared with that in MCL. When stretched with 10%, most of the fibroblasts in ACL were elongated like spindles in shape, and some pyknotic nuclei were found increased with stretching time. With 20% strain, ACL showed disruption in parts of collagen fibrils and lysis. But MCL was often torn at its tibia end. The injury can be detected in pathological slices under microscope, even this injury can not be found with naked eye. This injury first starts with the disturbance of the nucleus in the ligament, but following further stretching, it will extend to the rupture of collagen fibrils, and the serious injury of the fibroblasts is especially bad to the repair of the ligament.
authors.affiliation: Department of Bioengineering, Beihang University, Beijing 100083, China.
authors.forename: Kaiying
authors.initials: K
authors.lastname: Yang
authors.forename: Jiangi
authors.initials: J
authors.lastname: Li
authors.forename: Tailing
authors.initials: T
authors.lastname: Wang
authors.forename: Qingjun
authors.initials: Q
authors.lastname: Ma
authors.forename: K- L Paul
authors.initials: K
authors.lastname: Sung
authors.forename: Fengyuan
authors.initials: F
authors.lastname: Zhuang
mesh_terms: D000818:Animals; D016118:Anterior Cruciate Ligament / Q000473:pathology*; D000070598:Anterior Cruciate Ligament Injuries; D008297:Male; D017888:Medial Collateral Ligament, Knee / Q000293:injuries* / Q000473:pathology*; D051381:Rats; D017208:Rats, Wistar; D013314:Stress, Mechanical