Treatment that reduces subchondral bone changes can relieve the pain of knee osteoarthritis, limit the progression of the disease and improve patients’ outcomes, Professor Jean-Pierre Pelletier, director of the Osteoarthritis Research Unit at the University of Montreal, has told #ANZBMS delegates.

The last decade has seen marked progress in understanding the role of joint geometry and bone changes in knee OA, with important contributions from research units in Melbourne and Hobart, he said.

MRI studies have suggested that subchondral bone marrow lesions – cysts and oedema – are correlated with cartilage loss, the severity of knee pain, progression of disease and the need for total knee replacement.

“And we now have evidence from randomised controlled trials that treatment can favourably influence bone changes as well as controlling symptoms,” Professor Pelletier said.

For example, treatment with the LOX/COX inhibitor licofelone reduced both the loss of cartilage and progression of bone marrow lesions compared to naproxen, and was associated with an encouraging trend to fewer joint replacements.

In an Australian-based study, zoledronic acid was found to limit the progression of bone marrow lesions and improve pain, and Professor Pelletier’s group has shown similar benefits with strontium ranelate.

“There is a strong rationale for therapeutic approaches that target subchondral bone in OA, inhibiting bone resorption and promoting matrix quality,” he said.

“More clinical trials exploring the effects of an anti-bone remodelling agent on the long term evolution of OA structural changes are needed.”

Professor Pelletier emphasised that there is still much to learn about the causes, pathogenesis, and progression of OA.

“Its slowly progressive and multifactorial nature has complicated our ability to fully understand this disease.

“Although OA was long considered to be mainly due to an imbalance between loss of cartilage and an attempt at repair, we now know that it also involves the synovium and subchondral bone.”