13 randomized controlled trials were included in this systematic review and meta-analysis to determine the safety and efficacy of a single intra-articular injection of morphine + bupivacaine compared to morphine alone in managing pain after knee arthroscopy. Pooled analysis found combined treatment to significantly lower pain in the immediate postoperative period (0-2 hours) and significantly increase the time to first request for rescue analgesia compared to morphine alone. No significant differences in pain intensity from 2-48 hours or in the number of patients requiring rescue analgesia was observed between groups. Qualitative analysis found adverse events to be similar between treatment groups.