Correlation between ossification of the stylohyoid ligament and osteophytes of the cervical spine

Abstract

Objective. To investigate the correlation between ligamentous ossification or osteophytes of the cervical spine and ossification of the styloid process and stylohyoid ligament, and to determine any relation between diffuse idiopathic skeletal hyperostosis (DISH) of the thoracic spine and ossification of the styloid process and stylohyoid ligament. Methods. Four patients having cervical spine DISH, an elongated styloid process and/or variable patterns of stylohyoid ligament ossification, and clinical findings compatible with Eagle's syndrome are described. Cervical computed tomography scans of 100 patients who also had lateral radiographs of the thoracic spine were reviewed. Point biserial and Spearman rank correlation analysis, McNemar test, chi-squared test, and Fisher's exact test were used to determine correlation between elongation of the styloid process and/or ossification of the stylohyoid ligament and (1) ligamentous ossification or osteophytes of the cervical spine (the characteristic spinal manifestation of DISH), and/or (2) DISH of the thoracic spine. Results. (1) Elongation of the styloid process and variable patterns of ossification of the proximal, middle, and distal parts of the stylohyoid ligament, and (2) enlargement of this ligament were significantly correlated with transverse and anteroposterior dimensions of ligamentous ossification or osteophytes of the cervical spine at various levels. The prevalence of such abnormalities of this process and ligament was not significantly different between the patients with and without thoracic spine DISH. Conclusion. Variable types of styroid process-stylohyoid ligament complex abnormalities have significant correlation with ligamentous ossification and osteophytes of the cervical spine.