Measurement of Deformity at the Craniovertebral Junction: Correlation of Triangular Area and Myelopathy

Abstract

Objective: Diseases of the craniovertebral junction (CVJ) are commonly associated with deformity, malalignment, and subsequent myelopathy. The misaligned CVJ might cause compression of neuronal tissues and subsequently clinical symptoms. The triangular area (TA), measured by magnetic resonance imaging/images (MRI/s), is a novel measurement for quantification of the severity of compression to the brain stem. This study aimed to as-sess the normal and pathological values of TA by a comparison of patients with CVJ disease to age-and sex-matched controls. Moreover, postoperative TAs were correlated with out-comes. Methods: Consecutive patients who underwent surgery for CVJ disease were included for comparison to an age-and sex-matched cohort of normal CVJ persons as controls. The de-mographics, perioperative information, and pre-and postoperative 2-year cervical MRIs were collected for analysis. Cervical TAs were measured and compared. Results: A total of 201 patients, all of whom had pre-or postoperative MRI, were analyzed. The TA of the CVJ deformity group was larger than the healthy control group (1. 62 ± 0. 57 cm2 vs. 1.01 ± 0.18 cm2, p < 0.001). Moreover, patients who had combined anterior odon-toidectomy and posterior laminectomy with fixation had the greatest reduction in the TA (1. 18 ± 0. 58 cm2). Conclusion: In CVJ deformity, the measurement of the cervical TA could indicate the severity of brain stem compression. After surgery, the TA had a varying degree of improve-ment, which could represent the efficacy of surgery.