Rehabilitation protocols to treat joint
contracture and
muscle atrophy following anterior cruciate ligament (ACL) reconstruction have not been established. In this study, we examined the combined effects of
exercise therapy and
steroid administration on joint
contracture and
muscle atrophy following ACL reconstruction. Rats received ACL transection and reconstructive surgery in one knee. After surgery, they were divided into four groups: no intervention, treadmill exercise (started from day three post-surgery, 12 m/min, 60 min/d, 6 d/week), treatment with the steroidal
drug dexamethasone (250 μg/kg on days 0-5, 7, and 9 post-surgery), and
dexamethasone treatment plus treadmill exercise. Age-matched untreated rats were used as controls. At day 10 or 30 post-surgery, we assessed ACL-reconstruction-induced joint
contracture, joint capsule
fibrosis,
osteophyte formation, and
muscle atrophy of the rectus femoris and gastrocnemius. Treadmill exercise after ACL reconstruction improved several indicators of
muscle atrophy in both muscles, but it did not have positive effects on joint
contracture.
Dexamethasone treatment after ACL reconstruction improved joint
contracture and joint capsule
fibrosis at both timepoints and partially attenuated
osteophyte formation at day 10 post-surgery, but delayed recovery from
atrophy of the rectus femoris at day 30 post-surgery. The two treatments combined improved both joint
contracture and
atrophy of the rectus femoris and gastrocnemius.
Exercise therapy combined with
steroid administration may therefore be a novel therapeutic strategy for joint
contracture and
muscle atrophy following ACL reconstruction.