Comparison of local infiltration anesthesia and continuous femoral block anesthesia with respect to postoperative opioid consumption, clinical outcomes and safety profiles in Chinese arthritic patients undergoing total knee arthroplasty

Purpose: To compare postoperative opioid consumption, clinical outcomes and safety profile of local infiltration anesthesia versus continuous femoral block in Chinese arthritis patients undergoing total knee arthroplasty (TKA). Method: Chinese patients diagnosed with osteoarthritis (OA) of the knee undergoing TKA were given either local infiltration anesthesia (ropivacaine 0.2 % + adrenaline 0.5 mg) or continuous femoral block (ropivacaine 0.2 % bolus dose followed by maintenance dose) in a ratio of 1:1. The following efficacy variables were assessed: (1) post-operative pain score was measured on numerical rating scale (NRS); 2) post-operative consumption; 3) functional outcome assessed using walking capacity tests. Also, the degree of physical movement using CHAMPS survey questionnaire, health-related quality of life (QoL) of patients using SF-12 questionnaire, and clinical outcomes of knee function assessed using WOMAC score. Results: Data for 220 subjects were analyzed. Compared to local infiltration anesthesia, reduction in NRS score was significantly greater in patients who received continuous femoral block (p < 0.05). Continuous femoral block techniques demonstrated significantly greater reduction in postoperative pain on walking, including out of bed time for sitting and walking, and during knee movement when compared to local infiltration anesthesia on days 1 and 2 (p < 0.05). Functional outcome including QoL was significantly favored toward the continuous femoral block techniques when compared to local infiltration anesthesia Conclusion: Femoral block demonstrates significantly greater reduction in post-operative pain with decrease in postoperative opioid consumption relative to local infiltration anesthesia. Also, femoral block significantly improves QoL and functional recovery when compared to infiltration anesthesia.