Intraarticular analgesia following knee arthroscopy

A randomized, double-blind, controlled study was conducted in patients undergoing elective knee arthroscopy to assess the analgesic effect of intraarticular morphine and bupivacaine, alone and in combination. Patients in group 1 (n = 10) received 5 mg of morphine in 25 mL of saline; patients in group 2 (n = 10) received 25 mL of 0.25% bupivacaine (62.5 mg); patients in group 3 (n = 10) received a combination of 5 mg of morphine and 62.5 mg of bupivacaine in 25 mL dilution; and patients in group 4 (n = 10) received 25 mL of saline. All the drugs were injected intraarticularly. Postoperative pain was assessed using the visual analogue scale at 1, 2, 4, 8, and 24 h after the intraarticular injection. The need for supplemental analgesia was recorded. Results showed that there was no significant difference in the pain scores or analgesic requirements between groups 1 and 3. Patients in groups 1 and 3 had significantly lower pain scores than those in groups 2 and 4. These low pain scores were associated with lower requirements of supplementary analgesics. The patients in group 4 showed the highest pain scores and analgesic requirements. We conclude that intraarticular morphine significantly reduces postoperative pain following knee arthroscopy and that there is no advantage of combining bupivacaine with morphine.