By Mary Carpenter
JOINT dysfunction that occurs without any acute physical injury or after one has been resolved can involve two different issues. Arthritis is the most common cause of physical or structural problems, which are visible on scans and diagnosed by health practitioners.
But pain, the second kind of issue, can be difficult to trace, document and diagnose—with scans of arthritic joints often a distraction from the real cause. In the DC area, a writer’s shooting pain down one leg initially blamed on her arthritic back turned out to be coming from a torn meniscus (in the knee). For another woman, scheduled for replacement of a painful arthritic hip, the problem was a small piece of spinal cartilage pressing on a nerve. She needed a simple cortisone shot to dissolve it.
Chronic pain poses the greatest conundrums, with several factors contributing to the establishment of neural pathways that cause pain to persist. “Approximately 85% of back pain and 78% of headaches don’t have an identifiable trigger,” according to Dartmouth neuroscientist Tor Wager. Instead, circuitry malfunctions in the brain can prolong, amplify and even create pain— the result of ongoing stressors, known to promote inflammation in the spinal cord and brain; or to early adversity, such as child abuse and neglect.
Discovery of this “phenomenon of central sensitization” in the early 1980s led to the understanding that pain is not always a symptom reflecting a disease but “often is a consequence of a disease state of the nervous system itself,” Harvard neurobiologist Clifford Woolf told the New York Times. The pain of fibromyalgia, for example, does not emanate from a single problem but occurs throughout the body and may be, Woolf said, “solely a problem of the central nervous system.”
Determining the best treatment for an individual’s joint dysfunction can be difficult when structural symptoms and pain exist together as occurs in osteoarthritis (OA). According to WebMD, “Using your joints over and over damages the cartilage, leading to pain and swelling. Water builds up in the cartilage, and its proteins break down…in severe cases you can lose all the cartilage between the bones of a joint.”
“The fundamental problem of osteoarthritis is thought to be the imbalance between natural degradation [the joint surface wearing away with use] and fresh cartilage production,” according to verywellhealth. The body’s inability to compensate for lost cartilage “is partly normal wear and tear and partly disease process,” which can cause damage to the bone as well as inflammation of the soft tissues.
Where doctors often disagree is for patients whose scans show joints riddled with arthritis or without any cartilage left, but they experience little or no pain. Looking at the disconnect between pain and progression of osteoporosis, researchers in Boston and Korea described reports that, “knee pain is a better predictor of disability than radiographic changes.”
Among drawbacks weighed against the benefits of joint replacement is the risk of chronic postsurgical pain. In a British study of 34 people, postsurgical discomfort included “heaviness, numbness, pressure and tightness associated with the prosthesis.” In addition, infection occurs in about 1% of patients following joint replacement surgery.
But worries about a lengthy rehab is the main reason many hesitate to have joints replaced. For knee replacement, “average recovery time is approximately six months…it can take roughly 12 months to fully return to physically demanding activities,” according to Tri-State Orthopedics. If the joint is not replaced, on the other hand, physical impairments with or without pain can cause instability and structural changes in posture or lead to the need for replacement at an older age when surgery poses additional challenges.
Body weight is another source of disagreement, along with the usefulness of BMI measurements. Following orthopedists’ advice to lose weight has, for some patients, led to joint pain improving or disappearing entirely. And some orthopedists require patients to lose weight before joint replacement, citing evidence that patients with a BMI above 40 are more likely to experience serious complications during and after surgery.
Replacing the painful joint for patients with high BMI scores, however, can enable them to exercise more and lead to better overall health. And BMI scores are not always good predictors of surgical outcomes because they don’t account for variables such as fitness, genetics and pre-existing conditions.
Many patients with joint complaints choose to tackle pain symptoms before deciding about surgery. One option is a course of NSAIDS: for example, taking a “medical dose” of Alleve (two 220 mg. pills) morning and night for four or five days, with analgesic effects building up over time. Another drug option, cortisone shots, can both reduce inflammation and dissolve problematic tissue.
Electrical stimulation of nerves or muscles offers a different approach to chronic pain. Transcutaneous Electrical Nerve Stimulation (TENS) employs electrodes attached to the skin that send an electric current to the nerves—which in turn overrides pain signals from the brain. The current may also trigger the release from the brain of endorphins that are considered “natural pain killers.”
Neuromuscular Electrical Stimulation (NMES) involves electrical impulses strong enough to make the muscles contract—which, combined with an exercise program, can strengthen muscles that support weakened joints. In a 12-week home exercise program for knees, NMES reduced pain in 64% of patients compared to 42% in the control group who received sham (placebo) treatment—and improved strength and stability in the knees.
Engaging the brain is a different route to pain reduction—in line with the concept of central sensitization that pain is a “brain response [to perceived danger] like…elevated heart rate,” writes Cornell University researcher Nathaniel Frank in the Washington Post. In research on 151 patients at the University of Colorado at Boulder, the group of patients receiving eight one-hour sessions of “pain reprocessing therapy” (PRT) learned to “reinterpret pain as a neutral sensation coming from the brain.
Teaching PRT patients that their pain might be uncomfortable—but did not signal a dangerous physical condition—led their brains to rewire those neural pathways that were generating pain signals, Frank explained. Of patients receiving PRT, 66% were nearly pain-free and 98% had some improvement. In a separate study on psychophysiologic symptom relief therapy by Harvard researchers, mind-body therapy courses that focused on pain were significantly more effective than other mindfulness and stress-reduction programs.
For me, most joints are “full of arthritis,” as one orthopedist put it—neck, shoulder, back, hip and knee—but rarely painful. When I once mentioned occasional pain if standing with a bent knee in yoga class, the orthopedist’s response was a resounding, “You must never do yoga!” But several others, using the same wording, said that in the absence of pain, I “might not be happy” with new joints.
Other issues with my knees and hips, such as instability, may at some point convince me to have replacements. Meanwhile, I wear protective bands and braces, occasionally take a short course of strong NSAIDS and am otherwise engaged in a lifelong quest for stress reduction and mindfulness—with the idea that these could at least keep instability from doing me in.
—Mary Carpenter regularly reports on need-to-know topics in health and medicine.