Preoperative Opioid Use Lessens Pain Relief After Knee Replacement Surgery

As the opioid epidemic continues to spiral out of control, health care professionals have taken a more cautious approach to prescribing pain medications.

In the United States, more than $1.5 billion per year is spent on prescription opioids for patients with knee osteoarthritis. In 2009, nearly 40% of Medicare patients with knee osteoarthritis received at least 1 opioid prescription, as the use of opioids to manage knee osteoarthritis pain has become a growing concern.

Prior studies have suggested that using opioids preoperatively is associated with poor pain outcomes, but they were based on limited sample sizes and pain catastrophizing was not considered.

In a new study published in the Journal of Bone and Joint Surgery, investigators evaluated pain relief associated with total knee replacement (TKR) in patients who used opioids before the procedure compared with patients who did not.

The results of the study showed that patients with higher pain catastrophizing—–degree of an exaggerated, negative response to pain––were more likely to take opioids for pain relief. However, preoperative opioid use was linked to less pain relief after the TKR.

“With these study results, we’d encourage physicians to consider discussing long-term implications of opioid therapy with their patients,” said lead author Elena Losina, PhD. “Although each patient case is different, patients and physicians should discuss the potential impact of using opioids in patients with knee osteoarthritis who are likely to consider total knee replacement within the next 2 years.”

For the study, investigators reviewed data from 156 patients with an average age of 66 years who underwent a TKR. Patient reported outcomes and demographic data were collected before and 6 months after surgery, as well as abstracted data on opioid use from the patients’ medical records. The investigators found that 23% of patients had at least 1 opioid prescription prior to surgery.

The investigators used the standard pain scales: Pain Catastrophizing Scale, the Western Ontario, and the McMaster Universities Osteoarthritis Index (WOMAC), to quantify the pain of patients undergoing TKR.

Analytical methods were used to compare the change in the WOMAC pain score 6 months post-surgery. The results of the study showed that patients who used opioids prior to surgery had approximately 9% less pain reduction at 6 months following surgery.

“Our findings support previous research that indicated preoperative opioid use was associated with worse clinical outcomes,” Losina said. “This data demonstrates that preoperative opioid use may also lead to lesser pain relief in the early postoperative period.”