Arthropathy in calcium pyrophosphate dihydrate crystal deposition disease. Pathologic study of 12 cases

The pathologic features of calcium pyrophosphate crystal deposition disease (CPDD), particularly the synovial abnormalities, have not been adequately described or depicted in textbooks or journals; this report details the findings in 12 cases. Attention is drawn to the practical reasons for distinguishing CPDD arthropathy from other arthropathies, particularly osteoarthritis; clinical and gross pathologic features that should suggest CPDD arthropathy in cases that are not suspected preoperatively; and characteristics of the tophaceous deposits in CPDD.