Objective: To investigate the effects of Hyaluronic acid (HA) on early rehabilitation of patients with isolated anterior cruciate ligament (ACL) reconstruction.
Design: Randomized, controlled clinical trial.
Setting: A total 120 patients with isolated ACL injury who had received patellar tendon autograft reconstruction were randomly assigned to four groups (groups I-IV), with 30 subjects in each group.
Interventions: All patients received 16 weeks of a regular rehabilitation program and an intra-articular injection of HA or saline weekly for 3 weeks. Additionally, patients in group I received the HA commencing at 4 weeks after surgery, patients in group II at 8 weeks, and patients in group III at 12 weeks. Patients in group IV did not receive HA but did receive the same volume of normal saline as control subjects at 4 weeks after surgery. The rehabilitation program started at the same time after surgery for all groups.
Main outcome measurements: Outcomes were measured at 4, 8, 12, and 16 weeks after reconstruction, and at follow-up 1 year later. These included the changes in Lysholm knee scoring scale, knee range of motion, ambulation speed (AS), and muscle peak torque (MPT) of knee flexion and extension.
Results: There were improvements in groups I-III shortly after receiving the HA, but not in the saline group (group IV). Patients in groups II and III showed more improvement in AS and MPT after rehabilitation program and at follow-up. Besides, the best results 1 year later occurred in the group receiving HA at 8 weeks after surgery (group II).
Conclusion: HA therapy results in more functional and MPT improvement in ACL rehabilitation, and the intervention at 8 weeks after surgery results in the best outcome.