Obese patients may not need to lose weight prior to joint replacement surgery after all, suggests a recent study, adding that normal-weight and obese patients experienced virtually the same pain relief and improved function 6 months postsurgery.

“Our data shows it’s not necessary to ask patients to lose weight prior to surgery,” says Wenjun Li, PhD, associate professor of medicine and lead author on of the study, published recently in the Journal of Bone and Joint Surgery.

“It’s challenging for a patient who is severely overweight and suffering in pain to exercise—often they just can’t do it. Our evidence showed that severe morbidly obese patients can benefit almost equally as normal weight patients in pain relief and gains in physical function,” adds Li, in a media release from the University of Massachusetts Medical School.

Prior research has suggested that obesity is associated with a small, but increased likelihood of infection after total knee replacement. “However, in this paper we report that obese patients have comparable pain relief and functional outcomes after surgery,” states Patricia Franklin, MD, MBA, MPH, professor of orthopedics & physical rehabilitation. “Patients should know that these benefits may outweigh risks.”

In the study, the release explains, the researchers collected preoperative and 6-month postoperative data on function, joint pain and body mass index (BMI) from a national sample of 2,040 patients who had undergone total hip replacement and 2,964 who had undergone total knee replacement from May 2011 to March 2013. They also evaluated preoperative and postoperative function and pain according to BMI status.

A greater obesity level was associated with worse pain at baseline but greater postoperative pain relief, with average postoperative pain scores at 6 months similar across the BMI levels.

“This surprised us a little bit. Past analysis showed that obesity is associated with outcomes to some degree, but here we see the magnitude is so small it won’t make much difference, and severely obese patients can benefit a lot from the surgery,” Li says.

“This manuscript adds to our collective knowledge regarding the risk benefit ratio of total joint replacement surgery in obese patients,” Ayers shares.

“The debate will continue in the morbidly obese patients with BMI over 40, and the super obese with a BMI over 50, regarding what steps can and should be taken to lower the risks before these elective surgical procedures.”

[Source(s): University of Massachusetts Medical School, Science Daily]