Consensus statements on the management of knee osteoarthritis have not thoroughly addressed the use of opioid medications in patients undergoing total knee arthroplasty (TKA). In order to reduce postoperative pain, most reports recommend that mild analgesics (eg, acetaminophen) be used initially after TKA, followed by NSAIDs and opioids. More recently, concerns have been raised about using opioids because of tolerance issues with these drugs as well as increased responses to pain. Other studies have suggested that opioids can worsen treatment outcomes.
Opioid Dependence Worsens Outcomes
In the November 2, 2011 Journal of Bone & Joint Surgery, my colleagues and I had a study published in which we compared the perioperative course, complication rates, and clinical outcomes of patients who underwent TKA and if they were treated with chronic preoperative oral opioid analgesics. We looked at 49 knees in patients who had regularly used opioids for pain control prior to TKA and compared them with patients who didn’t use these medications.
According to our results, chronic opioid use prior to TKA made it much more difficult for patients to recover after their surgery. Patients who used opioids before their surgery had longer hospital stays, more postoperative pain, and higher complication rates than those who weren’t opioid dependent. They were also more likely to need additional procedures, require referrals for pain management, suffer from unexplained pain or stiffness, and have lower function and less motion in the replaced knee. The differences between patient groups in our study were even greater than we expected, and chronic opioid use was linked to poorer outcomes across the board.
Seize Opportunities to Educate Patients About Opioids
Physicians should take time to educate patients about the risks associated with chronic opioid use. Surgical results may not be optimal if patients chronically use these powerful medications before TKA. It’s important to work collaboratively with patients who use these drugs regularly so that we can improve outcomes. Several strategies should be considered, including:
Weaning patients off opioids prior to surgery.
Prescribing alternate, non-opioid pain medications.
Considering non-pharmaceutical pain management strategies.
Some patients who are dependent on opioids before surgery may have lower pain thresholds than those who lack this dependency. Such patients may also be less compliant with rehabilitation plans and other postoperative treatments. Previous studies have also showed that patients who use opioids are more dissatisfied after TKA. Several reasons may explain why preoperative chronic opioid use increases time to discharge, including a higher prevalence of in-hospital complications (eg, ileus). Larger and more rigorous research is necessary to further elucidate the specific reasons for our findings on preoperative chronic opioid use and outcomes following TKA. That said, our study results are robust enough to warrant greater attention to this issue in both the orthopedic and general healthcare communities.
JonN