Studies have shown that for people who are overweight, even a modest amount of weight loss can have a significant effect on knee OA pain. But for those who have more than a modest amount of weight to lose or for whom excessive weight is a taking a toll on more than the knees, a growing body of research shows bariatric surgery can help relieve the pain of OA as well as some of the health problems that often accompany the disease.

What is Bariatric Surgery?

Bariatric surgery is surgery designed specifically to promote weight loss. In the U.S., the three most commonly performed bariatric procedures are:

• Laparoscopic gastric banding, which involves placing a plastic band around the upper end of the stomach. This greatly reduces food intake by decreasing the amount of food it takes to make you feel full.
• Vertical sleeve gastrectomy, which involves stapling off and removing a portion of the stomach, leaving only a small pouch for food. Like laparoscopic gastric banding it reduces food intake by decreasing the amount it takes to make you to feel full.
• Gastric bypass, which involves stapling off the upper portion of the stomach to create a small pouch and then dividing the small intestine attaching one end of the intestine to the pouch and the other farther down on the intestine. Gastric bypass works in two ways: by decreasing the amount you can eat and decreasing absorption of calories from the food you eat. It is the most complex, but most effective form of weight-loss surgery.

Relief for Painful Joints

Several studies have shown that the weight loss from bariatric surgery is effective against OA pain, particularly of the knee.

In one study presented at a 2011 meeting of the American Orthopaedic Society for Sports Medicine researchers at Penn State College of Medicine followed 24 patients with clinical and radiographic evidence of knee undergoing bariatric surgery. The patients, who ranged in age from 30 to 67, completed a survey evaluating pain, stiffness and physical function at six and 12 months after surgery.

In the six-month survey, the patients, who had lost an average of 57 pounds, reported significant improvement in knee pain and stiffness, physical function, quality of life and activities of daily living – without medications, says researcher Christopher Edwards, a fourth-year medical student at Penn State.

In a separate study, researchers at New York University reviewed the charts of 264 patients who underwent bariatric surgery – 192 who had laprascopic gastric banding, 53 who had gastric bypass and 19 who had vertical sleeve gastrectomy. At an average follow-up of 17.2 months, patients had lost 28.4 percent of their excess weight. In the process, many had also lost their arthritis pain.

Seventy-one percent of those undergoing gastric bypass, 63 percent with sleeve gastrectomy and 51 percent who had the lap band reported a resolution of knee OA pain.

While bariatric surgery can help people lose the weight they need to relieve OA pain, naturally the surgery does not reverse the arthritis itself, says Michael A. Edwards, MD, chief of the Minimally Invasive and Digestive Surgery Section at Georgia Health Sciences University in Augusta. But even when joint damage has progressed to the point of requiring joint replacement, bariatric surgery can help. “If you talk to our orthopaedic colleagues, they don’t feel that they are doing patients a service to do a joint replacement if they are morbidly obese,” he says. “It is better to address weight loss before surgery."
 

Joint replacement surgery performed on non-obese patients is easier and associated with less risk, says Dr. Edwards. Losing weight, if needed, before surgery will make recovery faster and improve chances of success with the new joint.

Help with Other Health Problems

But pain relief and improved surgical success are not the only benefits people with OA can expect from bariatric surgery. Numerous studies have shown it can relieve many of the other problems that commonly occur in people with OA, including hypertension, high triglycerides and obstructive sleep apnea, says Dr. Edwards. But some of the most compelling research is for its effects on type-2 diabetes.

According to the Centers for Disease Control and Prevention, more than half of people with diabetes also have arthritis. Bariatric surgery has shown to be one of the most effective treatments for type-2 diabetes. In fact, two studies published earlier this year in the New England Journal of Medicine showed that for many people, gastric bypass and sleeve gastrectomy may actually reverse the disease.

In one of the two studies, researchers at the Cleveland Clinic assigned 150 volunteers with type-2 diabetes to receive one of three treatments: their standard diabetes medications, gastric bypass or sleeve gastrectomy. While half of the patients required insulin injections prior to the surgery, 12 months afterward only 4 percent who underwent gastric bypass and 8 percent who had sleeve gastrectomy were still receiving insulin injections. Similarly, most patients undergoing one of the two procedures were able to give up their oral diabetes medications.

In the second study in the same issue of the journal, researchers at the Catholic University of Rome assigned 60 type-2 diabetes patients to receive either medication or one of two bariatric surgeries – gastric bypass or bilio-pancreatic diversion, a similar surgery less commonly performed in the United States. Similar to the other study, patients undergoing bariatric surgery experienced a reversal of diabetes – for 75 percent of those who underwent gastric bypass and 95 percent who had  had bilio-pancreatic procedure blood glucose levels returned to normal.

Risks

As with any surgical procedure, bariatric surgery carries risks. Immediate risks of the surgeries are the same for all surgeries including infection, bleeding and risks from general anesthesia. As with other abdominal surgeries, bariatric surgery can result in intestinal obstructions, damage to the spleen or complications with the heart and lungs.

Longer-term risks or surgery may include ulcers of the stomach or small intestine, particularly for people who take nonsteroidal anti-inflammatory drugs; diarrhea and stomach cramps, particularly after eating certain types of foods; and deficiencies in nutrients, including vitamins, iron and calcium. 

The specific risks will vary depending on the type of surgery.

Who Needs It?

People who are interested in bariatric surgery should discuss the different options as well as risk and benefits with their doctors.

According to NIH guidelines, bariatric surgery is appropriate for people who have a BMI of at least 40 or a BMI of 35 in the presence of obesity-related health problems such as high blood pressure, sleep apnea or diabetes. However, the researchers hope their studies’ findings may encourage a change in guidelines that would lower the BMI limits for people with type-2 diabetes.