Up to the present, we could only hope to reduce the symptoms of arthrosis, or be satisfied with replacing the affected joint. A study involving a “new” molecule has changed things. In effect, strontium ranelate has slowed down the progression of disease in the patients’ knees. These results should accelerate the development of a new form of treatment.

Thank you indeed. Logically, this is what people suffering from arthrosis should say to those who are faced with osteoporosis. Why such gratitude? Because a study (1) has just shown that a molecule, strontium ranelate, prescribed for osteoporosis, could change the development of arthrosis of the knee. Indeed, it is the first time that a treatment has shown such a result.  Indirectly, osteoporosis is perhaps going to change the way arthrosis is thought about and treated. For patients suffering from arthrosis, there could be a  “before “  and “after”  this study of which Professor Jean-Yves Reginster, director of the Bone and cartilage metabolism research unit at the University of  Liège, has been one of the  main researchers.

The mysteries of the joint 

In case of arthrosis in a joint (here, mainly the knee, the hip, the big toe or fingers), the damaged cartilage disappears little by little; the bone which it covers (the subchondral bone) then directly rubs against the bone or adjacent cartilage, with the risk of cracking and causing pain. It is believed that 10 % of the population is affected by this degenerative joint disease, and women are particularly affected. 

This disease of the joints –the most common of this type of pathology- is largely associated with ageing. It is also linked to excess weight. It can also have its roots in family history. Finally, it does not spare sports people, due to the repeated shocks their joints are subjected to. The “joys” of arthrosis are often visited upon them at an early age. All causes combined, it is estimated that 40 % of over-65s are affected by arthrosis of the knee or hip.

“For a long time it was thought that arthrosis stemmed from a process of degeneration of cartilage. Then, quite recently, we realized that it affected all the joint structures.  In fact arthrosis is a complex phenomenon which involves a series of intricate problems. Some are metabolic, with a reduction in synthesis of cartilage matrix by the chondrocyte (the cell that forms cartilage. Others are inflammatory, with the release of a series of mediators by the synovial (the tissue that covers the inside of joints). Mechanical problems can also be added to the list, with progressive sclerosis of the subchondral bone, situated at the extremities of the bones, under the cartilage. This progressive sclerosis prevents the nutrition of the cartilage which, normally, is ensured by diffusion from the subchondral bone, because there are no blood vessels in the cartilage. In addition, this sclerosis also reduces the absorption of mechanical shocks by the subchondral bone: the entire impact of the shocks is transferred to the chondrocyte”, Professor Jean-Yves Reginster explains.

(1) Efficacy and safety of oral strontium ranelate for the treatment of knee osteoarthritis ; rational and design of randomised, double-blind, placebo-controlled trial. Cyrus Cooper, Jean-Yves Reginster, Roland Chapurlat, Claus Christiansen, Harry Genant, Nicholas Bellamy, William Bensen, Federico Navarro, Janusz Badurski, Evgeny Nasonov, Xavier Chevalier, Philip N.Sambrook, in Current medcial Research&Opinion. Vol 28.N°2, 2012, 231-239.