Cervical Computed Tomography Dependent Diagnosis of Crowned Dens Syndrome in Calcium Pyrophosphate Dihydrate Crystal Deposition Disease.

OBJECTIVE: The purpose of this study is to assess the presence of Crowned Dens Syndrome (CDS) in patients with Calcium pyrophosphate disease (CPPD). We report 34 patients with Crowned Dens Syndrome in one of the largest series from a single tertiary medical center in North America.

METHODS: A retrospective chart review was conducted at the University of Kansas Medical Center from 11/1/2005-11/01/2017. 191 patients with Calcium pyrophosphate disease diagnosis were identified. The available cervical computed tomography (CT) scans were analyzed by a musculoskeletal radiologist for the presence of periodontoid calcifications and erosions.

RESULTS: Of the 191 patients with Calcium pyrophosphate disease, 57 had cervical computed tomography obtained; 34 of whom (34/57, 59.64%) had periodontoid calcifications. Only 12/34 patients were formally evaluated and diagnosed with Crowned Dens Syndrome by rheumatologists. 22/34 were either not seen by a rheumatologist or were not diagnosed with Crowned Dens Syndrome. The median age was 78.5years, with (73.52%) over 70years old. 24/34 (70.58%) were female. 17/34 patients (50%) were symptomatic. 28/34 (82.35%) had additional sites of chondrocalcinosis on available radiographs; 8 (28.57%) had 3 or more sites of chondrocalcinosis in typical Calcium pyrophosphate disease locations. 6 patients did not have any radiographs.

CONCLUSION: Crowned Dens Syndrome is an under-recognized entity which should be considered in elderly patients with neck pain in the setting of Calcium pyrophosphate disease. Our data demonstrates a high percentage (about 60%) of patients with Calcium pyrophosphate disease who had cervical computed tomography findings consistent with Crowned Dens Syndrome. This underscores the importance of performing cervical computed tomography when evaluating patients with neck pain and Calcium pyrophosphate disease.