8 November 2021
International push for early-stage knee OA classification
The push for classification of early-stage knee osteoarthritis has been progressed at ACR2021, with the focus on identification at primary care level.
Researchers said an early-stage knee osteoarthritis (EsKOA) classification could help slow disease progression and will enable trials to reveal the infancy of disease mechanisms before secondary and tertiary processes kick in.
Professor Stefan Lohmander, of Lund University in Sweden, made the case for an EsKOA criteria saying that current management of osteoarthritis (OA) is too reactive. He cited the now common practice of identifying early diabetes, early cancer, early cardiovascular diease and early rheumatoid arthritis.
“So, why should our approach for managing OA be different?” he asked. “We argue it shouldn’t.”
Professor Lohmander said that EsKOA detection could, for possibly the first time, help identify the heterogeneity and phenotypes involved with the disease. He said it would also facilitate effective treatments before the complications of structural damage and pain sensitisation, as experienced by later-stage patients.
The criteria suggested by Professor Lohmander targeted initial identification at the community primary care level using easily applicable and affordable classification features such as demographics, history, x-rays, symptoms and signs. Relevant patients would then progress to a second level screening clinic to add further criteria using imaging and biomarkers. Then additional criteria could be added for enrolment into specific studies.
“Expanding the disease criteria may also be a bit of a problem for some patients,” Professor Lohmander said. He listed possible negative outcomes such as the risk of overdiagnosis, over treatment and “disease mongering by those that might benefit from increasing the patient population of OA.”
“We shouldn’t be identifying patients and slapping labels on them unless we can do something about it,” he said suggesting first line management such as education, exercise and weight control.
Dr Armaghan Mahmoudian is a post-doctoral researcher at Lund University, Sweden. Her research found that at the early stage of the disease, patients are typically presenting to health care with knee pain or symptoms from intermittent activity but that there are no, or only limited, structural changes able to be detected by radiographic imaging.
“This is the stage of disease that could hopefully serve as the window of opportunity to slow or arrest OA disease progress and optimistically restore joint homeostasis,” Dr Mahmoudian said.
She presented a review of previous knee OA classification criteria and based her research on validating and refining the proposed classification criteria at a workshop in 2018.
Preliminary findings included the onset and frequency knee pain being stronger predictors of disease progression than the severity of the knee pain. Dr Mahmoudian said that these kinds of findings could equip primary care practitioners with more effective questioning tools.
To create consensus on possible criteria Dr Mahmoudian gathered an international panel of experts including Australians Professor Kim Bennell and Dr Adam Culvenor.
Dr Mahmoudian said that the panel differed considerably in their judgements with respect to classifying symptomatic knees as early-stage OA. “Which further emphasises and highlights the need for a valid and reliable classification criteria set,” she said.
The audience were drawn into the process of establishing the criteria with their comments and poll results being taken back to the EsKOA classification steering committee.
One poll asked whether EsKOA should be designed for symptomatic or pre-symptomatic disease with the audience split cleanly in half with their response. More agreeable was the poll asking which joint should be the top priority when developing early OA classification criteria. The knee was voted by 83% of the audience, indicating a strong shared opinion.
Dr Gillian Hawker, professor of medicine at the University of Toronto, proposed an organisational structure for creating an international EsKOA classification advocating for a concerted international effort.
“We realise that there have been a few groups across the world all focused on the same conversation. And a classification for EsKOA is something that’s so important to us in the OA world, and more importantly to our patients who are at risk of OA, that it we really need it to be an international effort where we get everyone involved.”
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