A new test that promises to diagnose osteoarthritis in its early stages, when treatments are most helpful, could soon be available in the U.S., researchers say.

The new method uses a modified form of MRI imaging to determine the concentration of a polymer known as glycosaminogycan (GAG), a recognized marker for osteoarthritis. GAG gives cartilage (the material that cushions skeletal joints) its toughness and elasticity. Loss of this material triggers the onset of osteoarthritis.

The new test maps GAG in the joint, showing where levels are low and osteoarthritis is beginning. Lead researcher Dr Alexej Jerschow, from New York University, said that a method for early diagnosis could open a window of opportunity for preventing or reducing permanent damage.

The findings were presented this week at the 236th National Meeting of the American Chemical Society in Philadelphia.

Osteoarthritis, also known as degenerative arthritis or degenerative joint disease, is a clinical syndrome in which low-grade inflammation results in pain in the joints caused by abnormal wearing of the cartilage and destruction or decrease of synovial fluid that lubricates those joints.