Intraarticular Pain Catheter Is Not a Necessary Modality for Postoperative Pain Control After Total Knee Arthroplasty

Effective pain control balanced with maintaining physical function and minimizing medication side effects is essential to accelerated recovery after total knee arthroplasty (TKA). Multimodal pain management regimens combining oral medications as well as local analgesia have shown promise in facilitating these goals. Some regimens use anesthetics delivered via a local infiltration catheter while others use periarticular injections (PAIs). However, it is uncertain if an infiltration catheter provides additional pain relief or decreases opioid consumption when compared with conventional PAI alone.

Fifty patients undergoing TKA at one institution were randomized equally into 2 groups for a prospective trial. Group I received an intraarticular catheter (On-Q∗) in combination with injection of 30 ml of 0.5% bupivacaine the day after surgery before removal. Group II received no pain catheter. Both groups received a conventional intraoperative PAI and postoperative oral pain medication. Pain scores were measured with visual analog scale and opioid medication consumption in morphine milligram equivalents (mgs).

There were no differences in pain scores or opioid consumption in the first 48-hours postoperatively (P = .05). Reported maximum pain scores were low in both groups; 3.33 in group I and 2.97 in group II. Although not statistically significant in this cohort, there was increased opioid consumption in the catheter group: 14.78 mg vs 12.76 mg.

An intraarticular pain catheter in conjunction with a multimodal approach with intraoperative PAI after TKA does not improve 48-hour pain scores or opioid consumption compared with PAI alone in this randomized controlled trial. Overall pain scores were very low.