Analgesic efficacy of a single-dose, intraoperative, intra-articular morphine application in ACL reconstruction

Background: Anterior cruciate ligament (ACL) reconstruction is the mainstay treatment for the symptomatic anterior cruciate ligament insufficiency. Postoperative rehabilitation is the key main factor in successful surgical outcome but, the postoperative pain is a major obstacle to achieve good postoperative rehabilitation. The purpose of this study is to compare the effects of intra-articular morphine (IAMO) with normal saline [control group (C)] for postoperative pain control in the ACL reconstruction knees. Methods: Patients who underwent ACL reconstruction during 2017-2019 were included, prospectively, from Khon Kaen hospital and randomized into 2 groups: IAMO group and the control group (C). After surgery, all patients received the same rehabilitation protocols. The results were assessed using the visual analogue scale (VAS), following the spinal block anesthesia at 6, 12,18 and 24 hours. Time to first analgesic request, range of motion and adverse effects were recorded. Results: Forty patients were included and twenty were designated to the IAMO group. The mean age was 25.3 +/- 7.6 years and 80 percent of the patients were males. The IAMO group had lower VAS scores at the 12 and 24 hour postoperative periods [greatest variance at 12 hours (4.7 +/- 1.7 vs 5.8 +/- 1.6)]. In the IAMO group, time to first analgesic request was longer and morphine consumption was less, but these were not statistically significant. No complications were observed in both groups. Conclusions: The trend of VAS in the IAMO group was lower than in the control group, especially at 12 hours after surgery with no statistically significant differences. From this study and with the advantages of IAMO after ACL reconstruction, IAMO is useful in ACL reconstruction patients without complications. (C) 2020 Asia Pacific Knee, Arthroscopy and Sports Medicine Society. Published by Elsevier (Singapore) Pte Ltd.