Comparison of the analgesic effect of intra-articular and extra-articular injection of morphine and ketamine compound in arthrotomy lower limb surgery under spinal anesthesia

Objective: One of the critical components in the postoperative care is pain. Given that little research has been done regarding the analgesic effects of intra-articular injection of ketamine, this study was aimed to compare the analgesic effect of intra-articular and extra-articular injection of morphine and ketamine compound in arthrotomy surgery under spinal anesthesia. Methods: A total of 50 patients were candidate for arthrotomy surgery, aged 18-60 years were divided randomly into two groups. At the end of surgery, the first group was treated with combination of intraarticular morphine and ketamine compound and the second group was treated with combination of extraarticular morphine and ketamine compound. The amount of postoperative pain was recorded in the hours of 2,4,6,12,24 respectively. Also 24 hours consumption of rescue analgesic was recorded. Results: The pain severity (VAS) in the hours of 2, 4, 6, 12 and 24 after surgery in the intra-articular injection group was significantly lower than the extra-articular injection group (P 0.05). Postoperative morphine consumption in intra-articular injection group (3.2±3.78) was significantly less than the extraarticular injection group (6.36±5.22) (p = 0.018). Conclusion: Postoperative pain severity of intra-articular injection of ketamine and morphine in knee surgery is less than extra-articular injection.