A randomized trial found that the use of perioperative IV dexamethasone significantly decreased persistent pain after total knee arthroplasty (TKA) compared to placebo. Findings from this study will be presented today by Nitchanant Kitcharanant, MD.

Dr. Kitcharanant is a faculty member in the Department of Orthopaedics at Chiang Mai University in Thailand.

“There is a growing body of evidence on how the immune system is involved in the development of chronic pain. Inflammation that activates pain pathways is a response due to the body’s innate immune cells after injury and, if left untreated, can contribute to chronic pathologic pain via central sensitization,” Dr. Kitcharanant told AAOS Now Daily Edition. He said the study is the first double-blind, randomized, placebo-controlled study looking at the effects of steroids on severity of chronic pain after TKA.

Forty-eight patients undergoing unilateral TKA were enrolled in the trial. Patients received either IV dexamethasone 10 mg or saline immediately before surgery, followed by a second and third dose of the assigned treatment at 24 and 48 hours postoperatively. All patients received spinal anesthesia immediately following study treatment and prior to surgery along with a standardized, multimodal analgesic regimen.

The study’s primary endpoint was the modified Thai version of the Western Ontario and McMaster Osteoarthritis Index (WOMAC) at 12 weeks postoperatively. Secondary outcomes included pain during a 5-meter walk, pain during 45-degree active knee flexion, maximal pain at rest, visual analog scales for nausea, and rescue opioid and anti-emetic medicine consumption.

According to the authors, severe acute postoperative pain is a major risk factor for persistent pain after surgery. In this analysis, patients who received dexamethasone had improvements in their acute pain scores during the immediate postoperative period.

For the primary endpoint, dexamethasone treatment was associated with lower WOMAC scores for pain compared to the control group (P = 0.021); this improvement was evident at the two-week assessment and persisted at 12 weeks (Table 1). No acute periprosthetic joint infections occurred in the first 12 weeks postoperatively, and no wound complications occurred across both patient cohorts.

In terms of secondary endpoints, patients who received dexamethasone had significantly reduced pain during a 5-meter walk and 45-degree active knee flexion performed at 24, 30, 48, 54, and 72 hours postoperatively (all P <0.01). maximal pain at rest and visual analog scale scores for nausea were also lower for the dexamethasone versus control groups in the days immediately following surgery (table 2).>

Notably, scores for nausea reached zero in the dexamethasone group by 48 hours postoperatively but persisted through 72 hours postoperatively in the placebo group. The researchers also observed that patients who received dexamethasone had reduced opioid and anti-emetic medicine consumption within the first 48 hours after TKA compared to the patients who received placebo (P <0.01).>

“Perioperative IV dexamethasone could significantly decrease persistent postsurgical pain when comparing to placebo at 12 weeks following TKA,” Dr. Kitcharanant concluded.

“In addition, perioperative IV dexamethasone improved pain in the early postoperative setting, reduced postoperative nausea and vomiting, and reduced opioid and anti-emetic medicine consumption,” he added.

The study is limited by its 12-week follow-up period and relatively small patient population. Longer-term follow-up studies are needed to demonstrate the efficacy of dexamethasone at reducing persistent postoperative pain over longer intervals. The study will be presented as Paper 110 at 10:30 a.m. in Ballroom 6B.

Dr. Kitcharanant’s coauthor of “Effects of Perioperative Intravenous Dexamethasone on the Severity of Persistent Postsurgical Pain after Total Knee Arthroplasty: A Prospective, Randomized, Double-Blind, Placebo-Controlled Trial” is Warakorn Jingjit, MD.

Rebecca Araujo is the associate editor of AAOS Now. She can be reached at raraujo@aaos.org.