This case nicely demonstrates the extensive polyarticular involvement that can be seen with calcium pyrophosphate deposition disease (CPPD). With extensive involvement of the periodontoid region (giving the "crowned dens" appearance with a halo of calcification around the dens) crowned dens syndrome should be expected if the patient reports severe neck pain and headaches ^3,4. Hydroxyapatite crystals have also been described causing similar radiographic findings and clinical symptoms ⁵. 

Due to the widespread extent of chondrocalcinosis in this relatively young patient, familial calcium pyrophosphate dihydrate deposition disease is suspected, which has an autosomal-dominant mode of inheritance ^1,2. Other considerations could include hemochromatosis or hyperparathyroidism as underlying causes of the chondrocalcinosis, but there are no other features of these diseases to raise suspicion in this case.

This case is courtesy of Deborah M. Forrester, MD who kindly shared it with me.