Opioids Before Surgery Spell Less Pain Relief

Patients who use opioids before knee surgery experience less pain relief after surgery than non–opioid users, a study found. There was a 6-point difference in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain scores between the groups.

Researchers evaluated medical record data from participants in the Adding Value in Knee Arthroplasty Postoperative Care Navigation Trial in the study, published online May 17 in The Journal of Bone & Joint Surgery.

Led by Elena Losina, PhD, of Boston University, the investigators assessed reductions in pain after total knee arthroplasty (TKA) between patients who took opioids preoperatively and those who did not receive any prior opioid treatment.

Although opioids are effective for treating moderate-to-severe pain, there is growing concern about opioid use before TKA because opioid use has increased greatly over time.

An opioid was prescribed to about 40% of Medicare beneficiaries with knee osteoarthritis in 2009. Past studies have shown that patients who take opioids before TKA generally have worse outcomes; however, the studies had small samples sizes and did not take into account pain catastrophizing.

The study

This was a prospective cohort study of 156 patients at Brigham and Women’s Hospital who had TKA outcomes data. Patients who underwent primary unilateral TKA for osteoarthritis at age 40 years or older were included. Patients completed questionnaires within 6 weeks before surgery and again at 6 months after surgery. The questionnaires included validated measures, such as WOMAC, the 5-question Mental Health Inventory, and the Pain Catastrophizing Scale. Comorbidities also were assessed.

The researchers looked at medical records to determine opioid use within 2 years of TKA and 1 year after. Specifically, the following opioids were recorded: oxycodone, hydrocodone, hydromorphone, morphine, tramadol, and codeine. Other opioids were rare and thus coded as “other.”

About 36 of the 156 patients, or 23%, had at least 1 opioid prescription within the 2 years before TKA. The most frequently used opioids before surgery were oxycodone, hydrocodone, and tramadol.

After surgery, 150 patients or 96%, had at least 1 opioid prescription listed in their medical record. About 146 patients (94%) had prescriptions for multiple opioids. Oxycodone was the most frequently prescribed opioid after surgery, followed by hydrocodone.

The group that used opioids before TKA had a mean 6-month WOMAC pain-score reduction of 27.0 points (95% CI = 22.7 to 31.3) compared with 33.6 points (95% CI = 31.4 to 35.9) for the non–opioid-use group.

“Our study suggests that pain catastrophizing may play an important role in decisions by physicians and patients to use opioids,” wrote Losina and colleagues.

They concluded that clinicians should consider limiting pre-TKA opioid prescriptions to optimize the benefits of TKA.

Disclosures:

This study was funded by the NIH/National Institute of Arthritis and Musculoskeletal and Skin Diseases and Partners HealthCare.

References:

Savannah Smith, Jennifer Bido, Jamie E. Collins, et al. “Impact of Preoperative Opioid Use on Total Knee Arthroplasty Outcomes.” J Bone Joint Surg Am. 2017;99:803-808. doi: 10.2106/JBJS.16.01200.