A scanning electron microscopy study of articular cartilage obtained from contracted joints of denervated hands

Samples of articular cartilage obtained from joints with flexion contractures, in denervated hands of patients with leprosy were studied with the scanning electron microscope.Varying degree of degenerative changes was noted affecting the surface and all levels of the cartilage. In advanced degradation there was a decrease in total thickness with loss of identity of the three zones.A decrease in the porosity of the matrix was especially evident in the midzone, and the lacunae with chondrocytes were smaller and lacked the morphological appearance of the chondrocyte in normal cartilage.Areas of increased density, suggesting calcification of the matrix, varied in extent. With lesser involvement, it was usually localised to raised areas, as the edge of exposed lacunae, whereas generalised involvement was observed less frequently.It is our opinion that these findings indicate degenerative processes produced by a combination of factors including increased intrinsic forces and joint incongruity compression with immobilisation. The relatively extensive degrees of degradation are attributed to lack of pain perception in denervated extremities.