Lack of efficacy of intra-articular opioids for analgesia after day-case arthroscopy.

A randomised double-blind placebo-controlled trial was undertaken to assess the analgesic efficacy of intra-articular opioids following arthroscopy of the knee. At the completion of surgery, patients received an intra-articular injection of: morphine 1 mg, buprenorphine 30 micrograms or 0.9% saline. There were no differences in pain scores among groups for the first 24 h postoperatively. We have found no clinical evidence for a peripherally-mediated opioid analgesic effect.