Improving total knee arthroplasty perioperative pain management using a periarticular injection with bupivacaine liposomal suspension

Patients undergoing total knee arthroplasty (TKA) report low satisfaction with postoperative pain control. The purpose of this study is to examine if there is a difference in post-operative pain for TKA patients without femoral nerve block receiving an intra-operative pericapsular injection of bupivacaine liposome suspension (EXPAREL; Pacira Pharmaceuticals, Inc., San Diego, California) versus a concentrated multi drug cocktail. Seventy TKA patients were randomly assigned to either the bupivacaine liposome or the multi-drug cocktail. Post-operative pain scores, morphine sulfate equivalence consumption values, adverse events, and overall pain control satisfaction scores were collected. Patients reported significantly higher pain level for the cocktail group on post-op day 1 (p < .05) and post-op day 2 (p < .01) versus the bupivacaine liposome group. This same trend was found for morphine sulfate equivalence consumption in the PACU (p < .01) and post-op day 2 (p < .01). Higher satisfaction in pain control (p < .001) and overall experience (p < .01) was also found in the bupivacaine liposome group. Finally, significantly more adverse events were found in the multi-drug group versus the bupivacaine liposome group (p < .05). The study findings demonstrated a non-inferior difference, albeit not a clinically significant difference, in patient-perceived pain scores, morphine sulfate equivalence consumption, adverse events, and overall satisfaction.