Femoral Nerve Block Versus Long-Acting Wound Infiltration in Total Knee Arthroplasty

Multimodal wound infiltration analgesic techniques have attracted growing interest for applications in total knee arthroplasty (TKA). A benefit of using wound infiltration instead of femoral nerve block (FNB) in a multimodal pain control regimen is the limitation of muscle strength impairment to the surgical area, which will focus the pain control effort and may provide the opportunity for easier rehabilitation and earlier discharge from the hospital. The current study directly compares patients undergoing TKA who are given a continuous FNB with those who were administered an injection of liposomal bupivacaine infiltration. The study cohort included 36 patients with osteoarthritis who were treated with a continuous FNB (OnQ pump; I-Flow, Lake Forest, California), and 36 patients who were administered an injection for liposome bupivacaine infiltration (EXPAREL; Pacira Pharmaceuticals, Inc, Parsippany, New Jersey) for postoperative pain analgesia. The average number of narcotic doses and the total number of narcotics consumed was greater in the FNB group (P<.001). Average visual analog scale pain scores trended higher for patients in the FNB group (2.29 vs 1.93) overall and for each day postoperatively up to day 5, although the overall difference was not significant in this study sample (P=.115). The results of the current study support the conclusion that long-acting liposome bupivacaine infiltration gives comparable postoperative analgesia compared with a continuous FNB, but with significantly less narcotic medication. [Orthopedics. 2016; 39(3):e449-e455.].