Pain is the single biggest driver of elective modern orthopedic surgery world-wide. While structural trauma like a torn ACL or rotator cuff is also up there, most of that is also driven by continued pain. In fact, at the end of the day, if something didn’t hurt at all regardless of activity, you wouldn’t go see the doctor in the first place. Despite this, the research of the last decade or so has shown that surgery is really bad at treating pain. A new research study on shoulder surgery outcomes and rotator cuff tear biology illustrates this nicely.
How did we get down this silly road that surgery was the best and most definitive option for treating pain? The structural model of pain is really what got us here. Let me explain.
When physicians first peered into early x-rays more than a century ago, doctors were hooked. In fact, Willhelm Rontgen (the father of the modern x-ray) had us at “hello”. The ability to see inside the living body was a miracle that allowed us to easily diagnose horrible things like broken spines and mangled hands. So in orthopedic endeavors like trauma, radiographic imaging was a Godsend. Then came MRI in the 70s and 80s and our world was again blown open by the ability of being able to find tumors early. Yet somewhere along that road we doctors tasted the forbidden fruit. We began to conceptualize that what we saw on those pretty images could predict why a patient hurt. This turned out to be about as accurate as a roll of the dice in a Vegas casino, but the allure was just as intoxicating as that same house of chance. It still is today. If you were to go to a major convention of family doctors, most of the physicians you would meet would still believe that imaging of your joints, bones, ligaments, and tendons was a highly accurate way to diagnose who has pain, despite hundreds of research studies showing the exact opposite.
The paper I’m reviewing this morning is a great example. It’s authors looked at 40 patients undergoing rotator cuff surgery for tears and took a sample of the tendon cells that make up that structure. They then looked at the cell activity in the sample and then followed up on 100% of the patients at two years after their surgical repair. While age impacted the activity of these tendon cells, that same activity nor age correlated to who healed their tear on follow-up MRI. In addition, there was no correlation between pain reports and the patients that healed their tear. Think about that for a moment. The problems the patients reported two years after the surgery were not related to healing on MRI. So the patients who healed the tear were was likely to report pain as the patients who didn’t and vice versa. Why?
Pain is a neurologic phenomenon-meaning it happens because nerves are activated and pissed off. While structure and pain can intersect (i.e. you tear a tendon and it hurts for a few weeks), most of the time structure and pain are agnostic to each other. So for example, as I’ve blogged before, while an entire medical industry has grown up around treating knee meniscus tears, high level research has shown that just as many middle aged and elderly people without pain have meniscus tears as those with pain. So why would we operate on patients with knee pain who happen to have a meniscus tear on MRI? This makes little sense and is likely why recent outcome studies show that such surgeries are no better than placebo surgeries or physical therapy.
The upshot? Operating on pain because there’s a pretty picture that seemingly explains the pain (but really doesn’t) isn’t supported by any science. Pain is a complex issue involving nerves that doesn’t lend itself to the quick knee jerk decisions we find in modern surgical care. As shown above and as other studies have shown, your final pain outcome isn’t determined by whether your shoulder rotator cuff heals. It’s likely more determined by what’s happening with the nerves and the local chemical environment around the tear. While healing the structure may be important for continuing to perform high levels of physical activity at maximal efficiency, there are also plenty of people out there functioning at moderate levels with rotator cuff tears who have no pain.