Reducing weight and wait lists for osteoarthritis patients

Wendy Brown with patient
Professor Wendy Brown with a patient.

A team of Melbourne researchers has discovered the significant positive impact of weight loss surgery for patients with obesity in delaying, and in some cases removing, the need for total knee joint replacement. Their study has been published in the prestigious journal JAMA, The Journal of the American Medical Association.

According to the Australian Bureau of Statistics, more than 2.2 million Australians have activity-limiting osteoarthritis of the hip or knee. Osteoarthritis is the most common condition leading to joint replacement surgery.

The first randomised trial of its kind in the world, funded by the NHMRC and led by Professor Peter Choong and Professor Michelle Dowsey from University of Melbourne / St Vincent’s Hospital Melbourne, in collaboration with Monash University’s Professor Wendy Brown, Professor Danny Liew and Dr Paul Burton, assessed the efficacy of substantial weight loss induced by bariatric surgery in reducing complication risk after total knee arthroplasty (TKA) in patients with severe obesity and osteoarthritis.

The study of 82 participants aged 65 and younger, conducted at St Vincent’s Hospital Melbourne and The Avenue Hospital in Melbourne, involved people with a body mass index (BMI) of 35 or higher who were wait-listed for primary TKA. Of those participants who underwent bariatric surgery, fewer experienced complications of their knee replacement compared with those who underwent knee replacement without prior bariatric surgery to induce weight loss.

Twenty-nine per cent of those who underwent weight loss surgery were able to significantly delay the need for a TKA. Professor Peter Choong said the trial unequivocally demonstrates the positive impact of weight loss on avoiding postsurgery complications.

“While it wasn’t the primary aim of the trial, a positive incidental finding was that most of the participating patients, resulting from significant weight loss, had improved their knee symptoms. In many cases, their clinical outcomes - both mental and physical, were so good they were able to delay surgery for a significant amount of time,” said Professor Choong.

Monash University’s Professor Wendy Brown says with elective surgery wait lists ballooning during the pandemic, this research suggests helping people to lose weight may be a way to reduce the need for knee replacement surgery altogether.

“A year after bariatric surgery, the participants in our study lost an average of 16.5 kilograms and almost 30 per cent of these people never went on to have a knee replacement, even though they had all had very severe arthritis when we first met them. If we could help people with obesity considering knee replacement lose weight, it is possible that we will improve their symptoms to the point they no longer need a knee replacement. If they do ultimately need a replacement, being lighter will also make the knee replacement surgery safer,” said Professor Brown.

Dowsey MM, Brown WA, Cochrane A, Burton PR, Liew D, Choong PF. Effect of Bariatric Surgery on Risk of Complications After Total Knee Arthroplasty: A Randomized Clinical Trial. JAMA Netw Open. 2022;5(4):e226722. doi:10.1001/jamanetworkopen.2022.6722