Analgesic effect of intraarticular morphine, bupivacaine, and morphine/bupivacaine after arthroscopic knee surgery.

In a double-blind randomized fashion, 38 patients were divided into four groups according to the intraarticular injection received after arthroscopic surgery. Patients in group I (n = 7) received saline, group II (n = 10) morphine, group III bupivacaine, and group IV (n = 11) morphine and bupivacaine. Before surgery and at 0.5, 1, 1.5, 2, 6, and 24 h postoperatively, pain levels were recorded. In addition, postoperative supplemental i.v. morphine requested by the patient was tabulated. Results showed that the mean consumption of supplemental analgesia was lowest in the morphine/bupivacaine group. Although there was a statistically significant difference in pain scores between the saline group and the other three groups during the early postoperative period, there was no significant difference in pain scores between the morphine, bupivacaine, and morphine/bupivacaine groups. We conclude that postoperative, intraarticular injection of analgesics is beneficial in reducing pain levels. The combination of morphine/bupivacaine appears to be the most beneficial analgesic due to its low supplemental analgesic requirements postoperatively.