Science-- there's something for everyone

Friday, November 18, 2011

Bad news for people needing knee replacement

People who need to have a knee replaced have almost certainly been enduring a considerable amount of pain for some time prior to their surgery.  Unfortunately, if they’ve become dependent on narcotic pain relievers (opioids), their prognosis after the surgery will be worse.  So says a new study led by Michael Mont at Sinai Hospital of Baltimore.

The researchers compared 49 patients who had been using opioids for pain management with a group of matched controls who had not used narcotics. In all categories (length of hospital stay, number of complications, amount of post-operative pain), the opioid users did worse.  They even had poorer recovery of motion and function in the replaced knee.

It’s not clear why regularly taking narcotics prior to knee replacement has this effect.  One possibility is that subjects who resort to opioids have lower pain thresholds to begin with.  As a group, they may also be less compliant with recommended rehabilitation and physical therapy.

What can be done to help people who need knee replacement?  The authors suggest that patients be weaned off strong opioids prior to the surgery.  That sounds a lot easier said than done, especially if these are the very people who feel pain more intensely.  If these patients could have been made comfortable with milder pain medications they probably wouldn’t have been using narcotics in the first place.

Although this sounds like a no-win situation for people with bad knee pain, it’s still good to be aware of it.  Perhaps this knowledge can motivate patients to work hard at reducing their pain medication levels prior to surgery in order to improve their outcomes.