Calcification of the transverse ligament of the atlas in chondrocalcinosis: computed tomography study.

OBJECTIVE: To seek an association between articular chondrocalcinosis (AC) and calcification of the transverse ligament of the atlas (TLA), and to evaluate the frequency and the main computed tomography appearances of such calcification. METHODS: Axial computed tomography slices of the cervico-occipital hinge were performed routinely in 21 patients with AC (three men, 18 women; mean age 79 years, range 67-87) and compared with those from a control group of 21 age and gender matched patients without AC. RESULTS: Calcification of the TLA was present in 14 of the 21 patients (66%) in the AC group and in none of the 21 patients (0%) in the control group (chi 2 test: p < 0.001). Calcification was localised behind the odontoid process, inserted upon the osseous tubercles of the lateral masses of C1, and had a curvilinear profile; it varied in height (1.5 to 9 mm) and appearance (thin = < 1 mm; thick = > 1 mm) and formed either a single or a double band. CONCLUSION: This study has demonstrated a relationship between AC and calcification of the TLA. Although such calcification often remains asymptomatic (nine of 14 patients in our study), it may be associated with attacks of acute neck pain with segmentary stiffness, fever, and an increased erythrocyte sedimentation rate, sometimes revealing AC.