NEW YORK – In a chart review of 264 patients who underwent bariatric surgery, near-complete resolution of osteoarthritis knee pain was reported by many patients.
Specifically, 71% of those who underwent roux-en-Y gastric bypass (RYGB) reported resolution of knee pain associated with osteoarthritis (OA), as did 63% of those who underwent laparoscopic sleeve gastrectomy (LSG) and 51% of those who underwent laparoscopic adjustable gastric banding (LAGB), according to coauthor Dr. Steven B. Abramson, who reported the findings at a rheumatology meeting sponsored by New York University.
Dr. Steven B. Abramson
"I predict bariatric surgery will become increasingly used as a treatment for osteoarthritis," said Dr. Abramson, professor of medicine and pathology and senior vice president and vice dean for education, faculty, and academic affairs and director of the division of rheumatology at NYU Langone Medical Center.
The study was originally presented by James X. Lui, a medical student at New York University, at the 2011 World Congress of the Osteoarthritis Research Society International (OARSI) (Abst. 17).
Patients underwent bariatric surgery at Bellevue Hospital Center between January 2008 and March 2010. The average age was 42.5 years, 92% were female, and the average presurgical body mass index was 44.2 kg/m2. Of the 264 patients, LAGB was performed in 192, RYGB in 53, and LSG in 19. OA was present in 88% of the patients, making it the most common obesity-related comorbidity.
At a mean 17.2 months’ follow-up, patients lost 28.4% of excess weight. Significant differences in weight loss was seen among the three types of surgeries (P less than .001), with those undergoing RYGB losing 43.6% of excess weight, compared with 37.4% in those undergoing LSG and 23.3% in those who underwent LAGB.
The investigators used the Assessment of Obesity-Related Comorbidities (AORC) to rate 10 comorbid conditions. For OA, the severity was rated as ranging from 0 (pain not present) to 5 (awaiting or has undergone joint replacement). There was no difference in preoperative AORC mean scores between surgical groups.
The three bariatric surgeries produced statistically significant resolution of all obesity-related comorbidities (P less than .001). Scores on the AORC decreased the most overall in patients who underwent RYGB (66%) versus 60% for LSG and 44% for LAGB, respectively.
Comparing postoperative to preoperative scores, OA improved following all three types of surgeries. The greatest change was seen in those who underwent RYGB (2 points), compared with those who underwent LSG (1.6 point change) or LAGB (1.2 point change).
"I predict bariatric surgery will become increasingly used as a treatment for osteoarthritis."
The highest proportion of patients who had marked improvement of OA symptoms (postsurgical score of 0 on the AORC) was found in the RYGB group (71%), although good outcomes were also seen for 63% of the LSG and 51% of the LAGB groups.
Bariatric surgery lessened other comorbidities as well. For instance, resolution of hypertension was seen in 57% of the RYGB group, 29% of the LSG group, and 23% of the LAGB group. The effects on diabetes were less pronounced, with between 29% and 43% of patients reaching resolution, depending on the type of surgery.
Dr. Abramson suggests that the threshold for BMI as an indication for bariatric surgery could drop from BMI greater than 35 to BMI greater than 30 if there are comorbid conditions. "This includes a substantial percentage of U.S. patients with symptomatic knee OA who could become potential candidates for LAGB surgery if our preliminary studies were validated by prospective clinical trials," said Dr. Abramson.
Dr. Abramson also discussed the results of a study by Dr. Pascal Richette of the University of Paris who studied 140 obese patients with painful knee OA undergoing bariatric surgery (Ann. Rheum. Dis. 2011;70:139-44). As expected, a significant decrease in BMI resulted from surgery, as did a decrease in knee pain on the Western Ontario and McMaster Universities Osteoarthritis Index. Changes in levels of joint biomarkers, such as a significant increase of the N-terminal propeptide of type IIA collagen levels (a biomarker of cartilage synthesis) and a significant decrease in cartilage oligomeric protein (COMP) (a biomarker of cartilage degradation) suggests that structural effects on cartilage result from weight loss.
Dr. Abramson reported no relevant financial relationships.
