Randomized Prospective Trial Comparing the Use of Intravenous versus Oral Acetaminophen in Total Joint Arthroplasty

Multimodal pain management has had a significant effect on improving total joint arthroplasty recovery and patient satisfaction. There is literature supporting that intravenous (IV) acetaminophen reduces postoperative pain and narcotic use in the total joint population. However, there are no studies comparing the effectiveness of IV vs oral (PO) acetaminophen as part of a standard multimodal perioperative pain regimen.

One hundred twenty patients undergoing hip and knee arthroplasty surgeries performed by one joint arthroplasty surgeon were prospectively randomized into 2 groups. Group 1 (63 patients) received IV and group 2 (57 patients) received PO acetaminophen in addition to a standard multimodal perioperative pain regimen. Each group received 1 gram of acetaminophen preoperatively and then every 6 hours for 24 hours. Total narcotic use and visual analog scale (VAS) scores were collected every 4 hours postoperatively.

The 24-hour average hydromorphone equivalents given were not different between groups (3.71 vs 3.48) at 24 hours (P = .76), or at any of the individual 4-hour intervals. The 24-hour average visual analog scale scores in group 1 (IV) was 3.00 and in group 2 (PO) was 3.40 (P = .06). None of the 4-hour intervals were significantly different except the first interval (0-4 hour postoperatively), which favored the IV group (P = .03).

The use of IV acetaminophen may have a role when given intraoperatively to reduce the immediate pain after surgery. Following that, it does not provide a significant benefit in reducing pain or narcotic use when compared with the much less expensive PO form.