Comparison of intra-articular morphine and bupivacaine following knee arthroscopy.

A prospective study was conducted to investigate and compare the analgesic effect of morphine and bupivacaine injected intra-articularly following elective knee arthroscopy performed under general anesthesia without the use of a tourniquet. Cost-effectiveness of these agents was also evaluated. Patients in Group 1 (n = 41) received 30 cc of 0.25% bupivacaine with 1:200,000 epinephrine; while Group 2 (n = 40) received 2 mg morphine (1 mg/cc) in 28 cc normal saline (total volume 30 cc). Postoperative pain scores and the amount of supplemental analgesic agents used in a 24-hour period were recorded. Results showed that patients in Group 2 reported significantly less pain overall (P < .006) and significantly lower analgesic requirements (P < .0004) at a lower average patient cost than Group 1. We conclude that intra-articular morphine reduces postoperative pain and analgesic requirements more effectively and at a lower average patient cost than bupivacaine.