Summary

In this initial study, a topical anesthetic option appears to have lower cost, faster application, and similar or superior pain management effects compared to a long-lasting bupivacaine injection.

Abstract

Introduction

The benefits of peri-articular injections for initial pain management after primary TKA are reflected by its nearly universal use. However, the many different cocktails currently available illustrates that there is no single solution to local pain management. In addition, peri-articular injections are limited by cost, consistent efficacy, and required specific technique in delivery. A novel needle-free topical dual-acting local anesthetic consisting of bupivacaine and meloxicam may provide an alternative option to the traditional limitations of peri-articular injections.

Methods

Two-hundred consecutive primary TKA patients were evaluated prospectively with application of this dual-acting local topical anesthetic, and compared to the previous 200 patients where a long-lasting periarticular injection was used. Patients were evaluated for pain scores, opioid use, therapy goals, and need for rescue medication for 72 hours after surgery.

Results

There were no intraoperative events with anesthestic application in either group. Application of the needle-free
anesthetic was faster, compared to the periarticular injection group (1 vs 4 min, p< 0.03). Pain scores between groups were similar upon entrance to the PACU after surgery. Patients receiving the topical anesthetic had less pain at discharge (p< 0.05), 17% reduction in opioid use during the hospital admission (p< 0.05), and fewer refill requests after discharge. Fewer patients had severe pain, and patients tolerated more PT after surgery compared to the control group. Incidence of adverse events were similar for the two groups.

Discussion

This extended-release dual-acting local anesthetic showed improved analgesia for the first 72 hours after primary TKA compared to a peri-articular injection protocol. This reduction in pain led to a lower requirement of opioids in this same period. In this initial study, this topical anesthetic option appears to have lower cost, faster application time, and similar or superior pain management effects compared to a long-lasting bupivacaine peri-articular injection.