Researchers review a large database to identify trends
Information from a paper presented at the AAOS 2018 Annual Meeting may help identify patients who would benefit from multimodal pain management strategies to minimize opioid use.

“What are the risk factors for prolonged postoperative opioid use after knee arthroscopy?” asked Samuel R.H. Steiner, MD, who presented Paper 673, “Risk Factors for Prolonged Narcotic Use Following Knee Arthroscopy.”

“We reviewed database information on a large group of patients for trends in preoperative and prolonged postoperative opioid use in patients who undergo a knee ‘scope,’” he continued. “We also investigated opioid use as a risk factor for complications following knee arthroscopy. Knee arthroscopy is one of the most common procedures performed in orthopaedic surgery, and it’s one of the less invasive procedures. Most patients should be off any sort of pain medication within a relatively short period of time after surgery, so it’s a good candidate for understanding factors linked to continued opioid use.”

Large database study
Dr. Steiner and his colleagues queried a national database for patients who underwent simple arthroscopic knee procedures from 2007 through 2015.

They found 75,372 patients who met inclusion criteria, of which 18,020 (23.9 percent) were prescribed opioids preoperatively between four months and one month prior to surgery, and of which 17,038 (22.6 percent) demonstrated prolonged postoperative opioid use, defined as a new prescription between three and six months following surgery.

The researchers utilized linear regression analysis to evaluate trends in prescribing patterns. Through logistic regression analysis, they examined patient-related risk factors for prolonged postoperative opioid use and evaluated associations between opioid use and complications.

The researchers noted several independent risk factors for prolonged opioid use postoperatively, the most significant of which was preoperative opioid prescriptions, with an odds ratio (OR) of 5.33. They found that increasing numbers of preoperative opioid prescriptions were associated with increased likelihood of prolonged postoperative opioid use. Other risk factors for prolonged opioid use included age younger than 50 years (OR 1.6), preoperative knee osteoarthritis (OR 1.49), morbid obesity (OR 1.24), depression (OR 1.44), and back pain (OR 1.6).

In addition, they found that preoperative opioid use was independently associated with an increased risk of emergency department (ED) visits within 30 days (OR 1.25), hospital admission (OR 1.5), and infection (OR 1.31), while prolonged postoperative opioid use was associated with significantly increased rates of subsequent ipsilateral knee arthroscopy (OR 1.64) and subsequent ipsilateral total knee arthroplasty (OR 1.98).

At-risk patients
The researchers anticipated and verified that the more prescriptions people were on prior to surgery, the greater the risk that they would remain on opioids for a prolonged period postoperatively.

They also found that patients taking other medications, such as analgesics and muscle relaxants, are also at increased risk. Finally, they noted that patients who were on opioids preoperatively or prolonged postoperatively were at an increased risk for ED visits and infection after surgery.

“What we’ve tried to do is help identify ahead of time patients who may be at increased risk,” Dr. Steiner continued. “It’s impractical to have an in-depth discussion with every surgical patient regarding opioids, associated risks, and how we prefer to wean them off such drugs within a relatively short time after surgery.

“Early identification of at-risk patients can help clinicians focus their efforts where they’ll do the most good. I try to tell my patients, ‘You should be off opioids at this point in time, and here’s what we’re going to do to help you transition, these are the medications you’ll be prescribed.’ When you inform patients ahead of time, they tend to be more responsive than if they simply call you four weeks after surgery to request more hydrocodone,” he added.

With more than 75,000 patients, the study was well-powered, but Dr. Steiner identified several limitations due to the use of retrospective, database information.

“We were limited by certain factors,” he said. “We could count the number of prescriptions, but not their size, so four 20-pill prescriptions look like a higher count than one 80-pill prescription. We were also reliant on what factors individual providers chose to document, such as tobacco use, back pain, and depression, or the presence, type, and severity of any arthritis. We’re limited by the codes that are in the medical records. Still, it’s a good study, and we answered the questions we set out to answer.”

Dr. Steiner’s coauthors are Jourdan M. Cancienne, MD; and Brian C. Werner, MD. Peter Pollack is the senior staff writer for AAOS Now. He can be reached at ppollack@aaos.org.