Investigation of incidence rate of nuchal ligament calcification in asymptomatic populations

English Keywords:Asymptomatic populations  Calcification of the nuchal ligament  Imaging

English Abstract:

  【Abstract】 Objectives: To investigate the imaging characteristics and incidence rate of nuchal ligament calcification in asymptomatic population. Methods: The clinical and imaging data of 318 asymptomatic volunteers were analyzed retrospectively, including the incidence, morphological classification, and segmental distribution of nuchal ligament calcification. The volunteers were divided into two groups based on the presence of nuchal ligament calcification, and differences in gender, age, body mass index(BMI), and lower cervical intervertebral parameters between the two groups were analyzed. Based on the Roussouly classification, differences in cervicothoracic parameters between the groups were analyzed. Finally, the correlation between the degree of nuchal ligament calcification and the aforementioned factors was studied to identify the risk factors for nuchal ligament calcification. Results: Among the 318 asymptomatic subjects, the incidence of nuchal ligament calcification was 23.27%. There were statistically significant differences in gender ratio, age, and BMI between the calcification of nuchal ligament group(ONL+) and non-calcification of nuchal ligament group(ONL-)(P<0.001). The calcification of nuchal ligament was classified morphologically as follows: Local calcification 50.0%, continuous calcification 27.0%, segmental calcification 7.0%, mixed calcification 9.0% and unclassified calcification 7.0%. The incidence of nuchal ligament calcification in each segment was as follows: C2/3 1.4%, C3/4 9.5%, C4/5 55.4%, C5/6 63.5%, and C6/7 18.9%. Compared with the ONL- group, the angular displacement(AD) and horizontal displacement(HD) of the ONL+ group were significantly increased(P<0.001). Based on the Roussouly classification, significant statistical differences in cervicothoracic parameters such as O-C2, C2-C7 SVA, and T1 slope(TS) were found between the ONL+ group and the ONL-group(P<0.05). Pearson correlation analysis showed that the degree of nuchal ligament calcification had a moderate correlation with AD, O-C2, and C2-C7 SVA, and a strong correlation with HD and TS. Multivariate logistic analysis revealed that HD was the most significant risk factor for nuchal ligament calcification, followed by O-C2, age, and AD. Conclusions: The incidence of nuchal ligament calcification was higher in asymptomatic men who were older and had a high body mass index. Cervicothoracic parameters (O-C2, C2-C7 SVA and TS) and segmental parameters(AD, HD) were significantly increased in the group of nuchal ligament calcification, and were correlated with the degree of nuchal ligament calcification.