In 2010, Jonathan Samuels, MD, associate professor in the Department of Medicine and recently appointed associate director, clinical initiatives, began treating a morbidly obese 51-year-old woman who had been previously diagnosed with tricompartmental osteoarthritis (OA) in both knees. Since the 2004 onset of pain in her left knee and subsequent involvement of her right knee two years later, the patient faced increasing difficulty walking from the train station to her office during her daily commute to work. Despite Tylenol®, nonsteroidal anti-inflammatory drugs (NSAIDs), physical therapy, and injections into the joints with corticosteroids or hyaluronic acid viscosupplementation, the growing pain eventually forced her to use a cane to walk.

By 2010, the patient couldn’t walk two blocks at a time and had considerable difficulty climbing stairs. “She was struggling,” says Dr. Samuels. “You could see her progression from having trouble walking fully on her own from the subway, to needing a cane, to at times needing painkillers and narcotics because the pain was so bad.”

X-rays taken in 2011 revealed a worsening of the tricompartmental OA that was particularly prominent in the patient’s left knee, with a significant loss of the joint space and near bone-on-bone contact of the left medial femoral condyle and medial tibial plateau. She had no viable medication options other than pain control with anti-inflammatories and narcotics.

Unfortunately, with a body mass index (BMI) that exceeded 45, the patient was a poor candidate for knee replacement surgery since a BMI above 40 increases risk for postoperative infections and additional complications. Because the patient was obese, she was caught in a spiral in which she had increased pain, trouble exercising, resultant weakening of her muscles, and ultimately, further weight gain.

The natural progression of OA cannot be stopped once it has begun to develop since there are no proven disease-modifying drugs. This is in contrast to the biologics and other immunosuppressives that revolutionized the treatment of rheumatoid arthritis and psoriatic arthritis 20 years ago. Cutting-edge research on halting OA progression centers on the interleukin-1 pathway, which has been a key focus of the lab of Steven Abramson, MD, the Frederick H. King Professor of Internal Medicine in the Department of Medicine and chair of the Department of Medicine at NYU Langone. In collaboration with Dr. Samuels and other researchers, Dr. Abramson’s recent publication in Annals of the Rheumatic Diseases describes how the IL1RN TTG haplotype, a cluster set of variations of the IL1RN gene, which encodes for the interleukin 1 receptor antagonist, predicted radiographic severity of knee OA and risk of incident disease. Even if this haplotype proves to be a viable molecular target, however, it could still take many years for successful drug development and validation in the OA clinic.

A Life-Changing Resolution Through Bariatric and Arthroplasty Surgeries

Fortunately for the patient, obesity is the most modifiable risk factor for OA progression. Dr. Samuels’ close collaboration with NYU Langone Health’s Division of Bariatric Surgery and his continued encouragement of the patient helped facilitate a successful laparoscopic sleeve gastrectomy in 2013. “Surgeries like the one she had are game-changing because they take off enormous amounts of weight,” Dr. Samuels says. “And we’re learning that the benefits are not limited to just the mechanical load reduction.” Beyond alleviating pressure on the knees, altered metabolic cascades triggered by the loss of fat tissue may intervene with pathways that contribute to pain.

The surgery helped the patient lose more than 100 pounds and reach a BMI of 29. “We still provided some localized injections and treatment for her knees, but the immense weight loss allowed those other interventions to provide much more relief,” Dr. Samuels says. The bariatric surgery not only lessened her pain but also made her a much better candidate for eventual knee arthroplasty. In addition, the weight loss led to a “drastic” improvement in her hypertension, further decreasing her surgical risk.

The patient’s OA and pain gradually progressed, though at a slower rate than it would have without the weight-loss surgery. Walking longer distances again became increasingly difficult. To address the underlying cause, the patient underwent a left total knee arthroplasty with patellar resurfacing in March 2019, followed by arthroplasty on her right knee in September 2019.

Surgeons noted a profound improvement in the patient’s mobility after the first arthroplasty and are similarly encouraged by the patient’s progress after the second. Careful management coupled with well-planned timing of her bariatric and knee replacement surgeries, Dr. Samuels says, effectively broke the cycle that had severely diminished her quality of life. “I think it was a huge success for the patient to go through the processes that she did,” he says, noting that the patient now has extensive travel plans that include a lot of walking. “She has been able to do more than she had done in years. So it greatly improved her quality of life, and as a young retiree in her early 60s, she is able to do more than she ever imagined 10 years ago.”

An Uncommon Collaborative Focus Delivers Results

As one of the nation’s top centers for treating obese patients with OA, NYU Langone is the leading recruitment center for a multicenter trial that is investigating whether bariatric surgery can eliminate the need for knee replacement surgery and improve surgical outcomes for other arthroplasty patients. Accumulating data suggest promising results on both fronts, and NYU Langone’s uniquely strong collaboration among rheumatology, orthopedics, and bariatric surgery has helped the study recruit about half of all participants toward an overall goal of 300 enrollees.

“When a medical center is fortunate enough to have expertise in both of these surgical specialties, rheumatologists can be a helpful link between the two because we see so many obese patients with OA in the office and clinic,” Dr. Samuels says. Over the past decade, he and his colleagues have played a key role in establishing NYU Langone as a leader in addressing both sides of the equation for hundreds of obese OA patients. “It’s important for us to make sure that these patients have all of the right tools and options available to them and that we’re not having tunnel vision in terms of treating one problem, because these processes are intertwined and really can impact patients in so many ways,” he says.

Building on that success, Dr. Samuels and colleagues are working with bariatric surgeons and orthopedists to study metabolic markers, the gut microbiome, and other potential factors that can influence OA pain. Combined, the efforts are aimed at giving providers new insights to help further improve patient outcomes.