Home › Blog › Opioids Before Knee Replacement Increase Pain After Surgery

If you have knee pain that over-the-counter medications haven’t seemed to touch, your doctor may prescribe an opioid, a more powerful narcotic medication. However, if you are considering a knee replacement, a new study suggests opioids and knee replacement is a problematic combination and you may want to rethink the opioid. In fact, you may want to rethink the knee replacement, too, but I’ll get to that later. First, let’s look at opioids and the new study.

What You Need to Know About Opioids

Opioids include prescription drugs such as codeine, hydrocodone, Lorcet, Vicodin, methadone, morphine, oxycodone, Percocet, and many more. They work by modifying the message that would normally relay to your brain that your knee, for example, hurts. On the surface, reducing the pain might seem like a great idea, but when we dive beneath, we see all the problems that come with opioid use.

The short-term use of narcotics can actually lead to chronic pain. I can’t emphasize this point enough. We actually have research that shows that taking an opioid medication rewires your pain sensors so that you feel more pain. So while these medications help the pain in the short run, they increase it in the long run.

Additionally, opioids are highly addictive drugs with 1 in 5 users becoming addicted with as little as a 10-day prescription. Because of this, the drugs require a weaning process to come off them to help control any withdrawal symptoms. We also know from a study I covered last year that compared to many other common surgeries, patients are five times more likely to follow up a knee replacement with a post-surgery narcotic addiction.

Today’s feature study reveals the issue of opioids and knee replacement is bigger than we realized as it isn’t just the use of these drugs following knee replacement—we also need to be concerned about issues with opioid use prior to knee replacement.

Opioids and Knee Replacement: The New Study on Opioid Use Prior to Knee Replacement

 The new study investigated if patients who used opioids prior to their knee replacement experienced more pain six months following the surgery than those who did not use opioids. Of the 156 subjects 23% had received at least one opioid prescription for pain within the two years prior to their surgery (9% had received multiple opioid prescriptions). On a scale of 100, the mean pain score for the non-opioid group reduced by 33.6 points (78%), while the mean pain score for the opioid group reduced by only 27 points (58%). Researchers, of course, concluded that patients who used opioids up to two years prior to their knee replacement had less reduction in pain following their surgery.

The researchers also pointed out central sensitization, where pain signals can actually become amplified due to narcotic or opioid use in patients with chronic pain. The idea here is that these patients may have had more central sensitization before the procedure or that it was caused by the opioids. We may never know for sure.

Opioid Use or Not, Eliminating Knee Pain Isn’t a Given with Knee Replacement

Most patients who undergo knee replacement do so to address their severe knee pain. If the pain isn’t truly as bad as the patient believes it is, and even if it is in many cases, we have to ask if knee replacement is the right option. I mentioned that you may want to rethink opioid use if knee replacement is in your future, but I also think you might want to rethink the knee replacement because knee pain often continues after knee replacement. Let’s review:

• The source of the knee pain may not actually be the knee joint.
• Knee pain can be caused by a problem in the lower back, whether there is pain in the lower back or not.
• Pain is still present at a year following knee replacement in 40% or more of patients with pain levels averaging 3 out of 10 and as high as 5 out of 10.
• At three to four years post knee replacement, 44% of patients report ongoing knee pain, with 15% reporting severe persisting pain.
• Not just metal allergies but any allergy in general can be a risk factor for more pain following a knee replacement.
• Younger (age 55 and under) patients experience more pain following knee replacement, and 15% will undergo revisions within five years.
• Nearly half of knee-replacement patients will start popping new pain medication within the year following surgery.
• A recent randomized controlled trial of knee replacement demonstrated lackluster results
• In addition, a recent cost-benefit analysis concluded that knee replacement wasn’t cost-effective in the majority of patients who got the procedure

The upshot? Whether before knee replacement or after, or both, we know opioids and knee replacement are not a good combination as opioid use can negatively affect pain after the surgery. There’s also the interesting factoid that opioids can cause amplified pain (central sensitization), so by the time a patient decides to undergo a knee replacement, the patient may not even know what his or her true level of pain is. So while throwing risky, addictive opioids at the pain might be quick and easy, finding alternative ways to manage or address the pain would be a better solution for many patients.

Chris Centeno, MD is a specialist in regenerative medicine and the new field of Interventional Orthopedics. Centeno pioneered orthopedic stem cell procedures in 2005 and is responsible for a large amount of the published research on stem cell use for orthopedic applications. View Profile