Microdeposition of amyloid in the joints.

The distribution of amyloid in various organs, including the hip and the sternoclavicular joints, was systemically investigated in a prospective necropsy study of 91 unselected individuals whose median age was 70 years. The overall incidence of amyloid microdeposits in both joints was 56%. Their presence correlated significantly with age only. The deposition began earlier in the sternoclavicular joint, where the fibrocartilaginous disc was almost exclusively affected. The myocardium was the next most frequently affected organ, with an incidence of 12.2%. Minor amyloidosis of the articular tissues had no significant clinical counterpart, neither was it associated with any particular disease. It seemingly represents a localised and isolated degenerative phenomenon, whose morphological aspects invite speculation about the pathogenic role of long-lasting mechanical stress.