Adductor Canal Block With Bupivacaine Liposome Versus Ropivacaine Pain Ball for Pain Control in Total Knee Arthroplasty: A Retrospective Cohort Study.

Background: Appropriate postoperative pain control following total knee arthroplasty is important in patient recovery. Adductor canal block (ACB) is a novel method to deliver anesthesia. There are currently no studies using bupivacaine liposome with ACB while also taking into account cost.

Objective: To compare the efficacy and cost of using bupivacaine liposome to ropivacaine pain ball (RPB) for postsurgical pain control in total knee replacement surgery. The primary efficacy endpoint is mean pain score. Secondary endpoints include opioid and nonopioid pain medication consumption and cost per patient case.

Methods: This was a retrospective, matched cohort study with data collected from electronic medical records from February 2013 to June 2014. Mean pain score was measured by the 11-point Visual Analogue Scale over a 72-hour period. Cost analysis was also done looking at medication, direct, indirect, and total cost per patient case.

Results: Mean pain score over the 72 hours was 3.24 in the bupivacaine liposome group compared with 3.83 in the RPB group (P < 0.001). Lower mean pain scores were found in the bupivacaine liposome group during the first 36-hour interval postsurgery (3.1 vs 4.0, respectively, P < 0.001). Mean total cost was $20,919.53 with bupivacaine liposome versus $22,574.17 with RPB (P = 0.03).

Conclusion: Liposomal bupivacaine demonstrated statistically significant impact in pain control in the first 36 hours, but by the end of the 72-hour interval, it was comparable to RPB in postoperative pain management. Using bupivacaine liposome did provide direct and total cost savings compared with RPB.