New tools in detecting early cartilage breakdown before morphologic changes.

Recent advances in magnetic resonance imaging (MRI) allow detection of changes in molecular matrix of cartilage and thus allow the earliest detection of its breakdown. These MRI techniques are collectively referred to as "cartilage mapping," which attempts to designate a qualitative assessment of cartilage at each given location on the cartilage surface. These qualitative abnormalities can occur even in the setting of normal cartilage thickness and morphology. This article introduces the molecular biology behind this new technique, discusses some potential clinical applications, and discusses value added over traditional MRI cartilage evaluation.