Patients taking opioids for at least 3 months before spinal fusion surgery in the lower spine are much more likely to continue taking opioids 1 year after surgery, reports a study in Spine. The journal is published in the Lippincott portfolio by Wolters Kluwer.

"We found over 40% of chronic preoperative users still were filling opioid prescriptions 12 months after surgery," write Andrew J. Pugely and colleagues of University of Iowa Hospitals and Clinics, Iowa City. Their study includes an online calculator to help surgeons assess the risk of prolonged postoperative opioid use in patients undergoing spinal fusion surgery.

Preoperative opioids are strongest risk factor for prolonged opioid use

The study included approximately 26,500 patients undergoing lower spine fusion surgery (lumbar arthrodesis) between 2007 and 2015. Patients were identified from a nationwide insurance database; more than 90% were aged 50 years or older and about 60% were women.

Overall, about 58% of patients had an active opioid prescription within three months before lumbar arthrodesis. Using 1-year follow-up data, the researchers compared opioid prescription filling rates for patients with preoperative opioid use (OU) versus "opioid-naive" (ON) patients who didn't take opioids in the 3 months before surgery.

Throughout the year after spinal fusion, patients who had been taking opioids before surgery were more likely to continue to fill opioid prescriptions:

• At 1 month, about 83% of patients with preoperative opioid use had filled an opioid prescription, compared to 60 %of opioid-naive patients.
• By 3 months, rates of prescription opioids declined, but remained higher in the OU group: 54%, compared to 14% in the ON group. After 6 months, rates of opioid prescriptions leveled off.
• At 1 year, about 42% of the OU group were still filling opioid prescriptions, compared to nine percent of the ON group.

Preoperative opioid use was by far the strongest predictor of continued opioid use at 1 year. Risk was more than four times higher for patients in the OU group compared to the ON group. The magnitude of the risk increase varied for different types of spinal fusion surgery.

Other risk factors included depression/anxiety, alcohol abuse, and drug dependence (besides opioids). Based on the risk factors identified, the researchers created an interactive app for surgeons to use in estimating the risk of opioid use one year after spinal fusion surgery.

Studies have shown that opioid use before major orthopedic surgery is associated with worse outcomes as well as an increased risk of prolonged opioid use. Few studies have looked at the outcomes and risk factors for chronic opioid use after spine surgery. Lumbar arthrodesis is widely performed for various types of lower spine disorders.

The new study highlights preoperative opioid consumption as a major risk factor for continued opioid use up to 1 year after lower spine fusion surgery.

"In our experience, this prolonged opioid use after spine fusion surgery may be largely inappropriate," Dr. Pugley and coauthors write. They emphasize that they do not advocate eliminating the use of opioids for pain treatment after spinal surgery: "Opioid overuse should not be confused with appropriate use."

However, they do recommend appropriate steps to prevent long-term opioid use after spinal fusion surgery. Dr. Pugley and colleagues conclude: "The identified risk factors and the proposed clinical utility app can be used as an adjunct to risk stratification and patient counseling for encouraging discontinuation of presurgical narcotic use, and opioid weaning strategies."