Reconstruction of the anterior cruciate ligament: comparison of analgesia using intrathecal morphine, intra-articular morphine and intra-articular levobupivacaine☆

OBJECTIVE To compare the analgesic effect of intra-articular administration of morphine and levobupivacaine (separately or in combination) with intrathecal administration of morphine in patients undergoing anterior cruciate ligament (ACL) reconstruction using autologous grafts from the patellar tendon. METHODS This was a retrospective analysis on data gathered from the medical files of 60 patients aged 20 to 50 years who underwent knee video arthroscopy for ACL reconstruction. The patients were divided into four groups of 15 individuals (A, B, C and D) according to the agent administered into the joint and around the incision: 20 mL of saline solution with 5 mg of morphine in A; 20 mL of 0.5% levobupivacaine solution in B; 10 mL of solution with 2.5 mg of morphine plus 10 mL of 0.5% levobupivacaine solution in C; and morphine administered intrathecally in D. RESULTS All the groups presented low pain scores during the first 12 h after the surgery. Groups B and C presented significantly greater pain scores than shown by group D (control), 24 h after the surgery. There was no statistical difference in pain scores between group A and group D. CONCLUSION The patients in group A presented analgesia comparable to that of the patients in group D, whereas the procedure of group C was no capable of reproducing the analgesic effect observed in group D, as observed 24 h after the surgery. Further studies are needed in order to show the exact mechanism of action, along with the ideal dose and concentration for applying opioids to joints.