Amyloid deposits in human knee and hip joints.

A systematic search for articular amyloidosis was carried out on both knees of 53 autopsy cases and on 26 femoral heads resected during surgery for hip prosthesis. Typical amyloid deposits exhibiting green apple birefringence following Congo red staining and thioflavin T fluorescence were found in 58.5% and 29% of the cases, in the knee and hip joint respectively. They occurred more frequently in articular cartilage than in the synovium, and in elderly subjects more than young ones. In the knee joint, the osteoarthritic changes and to a minor extent synovial inflammation appear to be positively correlated for the presence of intraarticular amyloid deposits. Such a correlation was not observed for the presence of calcium pyrophosphate dihydrate crystal deposits.