Does periarticular injection have additional pain relieving effects during contemporary multimodal pain control protocols for TKA?: A randomised, controlled study.

Although the analgesic effects of periarticular multimodal drug injection (PMDI) after TKA have been well documented, there is little information about additional pain relieving effects of PMDI incorporated to contemporary multimodal pain control protocols which have been proved to provide excellent analgesia. We performed a parallel-group, randomised, controlled study to determine whether PMDI provides additional clinical benefits on contemporary multimodal analgesic protocols including preemptive analgesics, continuous femoral nerve block, and IV-PCA. Eighty-seven patients were randomized to a PMDI group (n=45) or to a No-PMDI group (n=42). Pain level and opioid consumption were compared as primary outcomes. The incidences of narcotic and ropivacaine related side effects and complications, functional recovery, and satisfaction were also compared. The PMDI group experienced less pain during the operation night and the 1st postoperative day and showed lower opioid consumption over 24h after surgery. However, the PMDI group had a higher VAS pain score on the 1st postoperative day than during the operation night. No group differences in side-effects and complication incidences, functional recovery, and satisfaction were found. This study demonstrates that PMDI provides additional pain relief and reduces opioid consumption only during the early postoperative period in patients managed by the contemporary pain management protocol following TKA.