[Possibilities for early detection of arthroses using imaging procedures]

Today early detection of osteoarthrosis (OA) must imply the recognition of initial changes of articular cartilage before radiological signs appear. A noninvasive imaging technique must meet the demands of imaging the articular cartilage layer with high contrast and surface irregularities (fibrillation) and changes within the substance. This can only be achieved by magnetic resonance imaging (MRI) with optimized conditions (3D-gradient echo sequence). In 80 patients, 62% of them without radiological signs of OA, articular cartilage of the knee joint was prospectively (70 patients) and retrospectively (10 patients) investigated with MRI and compared with the arthroscopic findings. Normal cartilage could be distinguished from pathological conditions with a specificity of more than 90% when evaluating surface morphology, signal homogeneity and, above all, signal intensity (40 patients). Full-thickness defects were identified in all cases. Cartilage fibrillation of differing depths (grades 1-3) could not be differentiated with a sufficient degree of reliability and requires a more subtle evaluation method by means of improved software. Thus, the noninvasive recognition of early pathological changes of articular cartilage in patients without radiological signs of OA has become possible.