Towards the identification of early stage osteoarthritis.

A variety of genetic and environmental factors contribute to the progressive develop of OA. It is necessary to identify people who are developing initial changes in cartilage and/or subchondral bone before onset of classical radiological features in order to detect early phase of OA. Recent quantitative MRI techniques can evaluate the structural, mechanical and biochemical characteristics of cartilage. T2 mapping is able to assess cartilage volume and defects measurement, delayed gadolinium enhanced MRI (dGEMRIC) and Contrast Enhanced Computed Tomography (CECT) can reveal Cartilage GAG content. Accurate and reliable serum, urine and synovial fluid biomarkers are also requested. Several biomarkers have been studied and proposed, but there are many critical issues to consider for inferring useful data from studies on biomarkers in early OA such as phase of disease, specific joint sites, systemic concentrations, circadian rhythm, their clearance from the joint, etc. Recently proteomics has produced great expectations to improve the early diagnosis of OA. These discoveries may open opportunities for the identification of early stage of OA leading to manage the symptoms and ultimately slow the progression of OA.