Osteoarthritis Cartilage Defects: Does Size Matter?

Abstract

Osteoarthritis is generally thought to be a disease of articular cartilage characterised by the formation of defects. A number of diagnostic and treatment options have been developed to identify and treat these large lesions. There has been evidence of early cartilage changes consisting of ‘splits’ or ‘cracks’ which have not received much attention or research in the literature. The structure of articular cartilage and the way in which it responds to physiological loading by sometimes acting as a brittle substance may explain how these ‘cracks’ form. Particular types of ‘ cracks ’ may cause the formation of larger defects. In particular, those at 45° to the bone-cartilage interface may progress and ultimately lead to large areas of cartilage lifting off subchondral bone. Surface ‘cracks’ can also become unsafe if joint congruity changes. The clinical relevance of these ‘cracks’ remains uncertain. Further research is needed to determine if these ‘cracks’ do progress, whether they lead to pain, whether it is possible to accurately diagnose them, whether it is possible or necessary to treat them and whether current grading systems of articular cartilage lesions should include these ‘crack’s in their classification systems. This may be particularly relevant in the asymptomatic individual to retard or prevent progression to established osteoarthritis.