The use of opioid painkillers in the period prior to knee replacement surgery results in worse pain outcomes for patients, according to a new study by US researchers.
They found patients who took opioids before knee surgery experienced about 9% less pain reduction at six months following surgery, compared to patients who did not.
“We’d encourage discussing long-term implications of opioid therapy with patients”
There was growing concern regarding opiod use prior to a total knee replacement, they said, and recent research had suggested that pre-operative opioid use may lead to worse pain after surgery.
Researchers from Brigham and Women’s Hospital in Boston evaluated pain relief associated with total knee replacement in patients who had used opioids before their procedure and compared it to pain relief in patients who had not.
The study, published in the Journal of Bone and Joint Surgery, indicated that patients who had a more exaggerated, negative response to pain were more likely to take opioids for pain relief.
They found that patients who used opioids to manage their knee pain before their total knee replacement had less successful pain relief after the operation.
While a total knee replacement is an effective treatment in relieving pain and restoring function, patients spend an average of 13 years using non-surgical options for pain management including the use of non-steroidal anti-inflammatory drugs, physical therapy, and intra-articular injections.
Although previous studies have suggested using opiods pre-operatively is associated with poor pain outcomes, they were based on limited sample sizes and pain catastrophizing was not considered.
“Opioid use may also lead to lesser pain relief in the early post-operative period”
The team reviewed data from 156 patients who had total knee replacement at an average age of 66. They collected patient-reported outcomes and demographic data both before and six months after surgery, and abstracted data regarding opiod use from medical records.
The researchers found that, prior to surgery, 23% of patients had at least one opioid prescription.
Using standard pain scales, they quantified the pain experiences of patients undergoing knee replacement. They compared the change in pain scores six months after knee surgery and calculated the difference between patients who had used opioids before knee replacement and those who had not.
Researchers found that the patients who used opioids prior to surgery had about 9% less pain reduction at six months following surgery.
Lead study author Elena Losina said: “Our findings support previous research that indicated pre-operative opiod use was associated with worse clinical outcomes.
“This data demonstrates that pre-operative opioid use may also lead to lesser pain relief in the early post-operative period,” she added.
She said the study results should encourage clinicians to discuss the long-term implications of opioid therapy with patients who have osteoarthritis and are likely to need total knee replacement within the next two years, while noting that “each patient case is different”.