Formation process of joint contracture after anterior cruciate ligament reconstruction in rats.
Knee joint contracture is often induced by anterior cruciate ligament reconstruction (ACLR). However, the temporal and spatial arthrofibrotic changes following inflammatory events, which occur in parallel with the formation of joint contractures after ACLR, are unknown. This study aimed to reveal: (a) time-dependent changes in myogenic and arthrogenic contractures; and (b) the process of arthrofibrosis development after ACLR. ACLR was performed on knees of rats unilaterally. Passive ranges of motions (ROMs) before and after myotomy, as well as inflammatory and fibrotic reactions, were examined before and after the surgery at various periods up to 56 days. Both ROMs before and after myotomy exhibited their lowest value on day 7 and increased thereafter in a time-dependent manner; nevertheless, significant restrictions remained by day 56. Myotomy partially increased ROMs at all time points, indicating contribution of the myogenic component to ACLR-induced contracture. Inflammatory and fibrotic reactions peaked on day 7. Arthrofibrosis, characterized by the thickening of the joint capsule and the shortening of the synovial length, was established by day 7 and was not completely resolved by day 56. Our results indicate that: (a) both myogenic and arthrogenic contractures generated through ACLR develop maximally by day 7 after surgery and subside thereafter, but persist at least until day 56; and (b) arthrofibrosis is established by day 7 after surgery and is not completely resolved by day 56. These findings suggest that treatment and intervention for preventing joint contracture after ACLR should be performed within the first 7 days after surgery.
['Kaneguchi|Akinori|A|0000-0002-3394-7458', 'Ozawa|Junya|J|', 'Minamimoto|Kengo|K|', 'Yamaoka|Kaoru|K|']
D000818:Animals D059549:Anterior Cruciate Ligament Reconstruction D003286:Contracture D016207:Cytokines D005355:Fibrosis D017746:Joint Capsule D007719:Knee Joint D008297:Male D016059:Range of Motion, Articular D051381:Rats D017208:Rats, Wistar D013997:Time Factors
joint contracture anterior cruciate ligament reconstruction arthrofibrosis anterior cruciate ligament injury inflammation