Vertebral involvement in calcium pyrophosphate dihydrate crystal deposition disease. Radiographic-pathological correlation.

The authors conducted a comprehensive radiographic and pathological investigation of more than 1,000 postmortem spinal specimens and documented many examples of calcium pyrophosphate dihydrate crystal deposition disease (CPPD/CDD) in a variety of vertebral structures, including not only the intervertebral disk but also the apophyseal and sacroiliac joints, posterior longitudinal ligament, interspinous and supraspinous ligaments, ligamentum flavum, interosseous sacroiliac ligament, transverse atlas ligament, and posterior median atlanto-axial joint. Such crystal accumulation supports previous reports of abnormal calcification and structural damage on radiographs of the axial skeleton in patients with CPPD/CDD and may explain not only the associated spinal symptoms and signs but also spinal stenosis, spondylolisthesis, and atlanto-axial subluxation.