Working Group Overview

What is flare in Osteoarthritis?

Osteoarthritis (OA) is a condition that involves the whole joint and is associated with changes in the articular cartilage, menisci, subchondral bone, synovial lining, synovial fluid and surrounding ligaments, bursae and muscles. Any joint can be involved but the hands primarily affect harms cartilage, often affecting hands, feet, hips and knees are the most common. There is substantial morbidity associated with OA, including disability and reduced quality of life. OA is the leading cause of lower extremity disability in older adults and is also associated with some increase in mortality. Hip and knee OA has accounted for 2.4 percent of all years lived with disability.

Trends in years lived with disease from 1990 to 2016 show that of the top 20 contributors, OA was ranked as the second most rapidly rising condition associated with disability. OA had a 46 percent increase in years lived with disease, just behind diabetes at 52 percent. With the aging population and higher rates of obesity, this burden is expected to rise. The rapid increase in prevalence of OA will lead to a growing impact and major challenges for health care and public health systems.

Patients with OA can suddenly experience a ‘flare’ up of symptoms which can cause significant pain and disability. 

Read More


OMERACT 2020 Workshop Session

Thursday April 23rd 8:30am - 11:00am



Guillemin, F.; Ricatte, C.; Barcenilla-Wong, A.; Schoumacker, A.; Cross, M.; Alleyrat, C.; Buttel, T.; Cembalo, M.; Manseur, H.; Urban, H.; et al. Developing a Preliminary Definition and Domains of Flare in Knee and Hip Osteoarthritis (OA): Consensus Building of the Flare-in-OA OMERACT Group. J. Rheumatol.2019.


  • Thomas Buttel
  • Leigh Callahan
  • Michael Cembalo
  • Marita Cross
  • Amandine Schoumacker
  • Elizabeth Spitz
  • Hemalatha Umapathy
  • Ludovic Dubouis
  • Gillian Hawker
  • Bruno Fautrel
  • Camille Ricatte
  • Claudia Rutherford
  • Peter Tugwell
  • Matthieu Mangin
  • Camille Alleyrat
  • Annica Barcenilla
  • Phil Conaghan