A Significant Correlation Between Osteoarthritis of the Atlantoaxial Facet Joint and a High-riding Vertebral Artery

Abstract

\n Background A high-riding vertebral artery (HRVA) is an intraosseous anomaly that narrows the trajectory for C2 pedicle screws. The prevalence of a HRVA is high in patients who need surgery at the craniovertebral junction, but reports about HRVAs among subaxial cervical spine disorders are limited. We sought to determine the prevalence of HRVAs among patients with subaxial cervical spine disorders to elucidate the potential risk for VA injury in subaxial cervical spine surgery. Methods We included 215 patients, 94 were with a main lesion from C3 to C7 (subaxial group) and 121 were with a main lesion from T1 to L5 (thoracolumbar group). A HRVA was defined as a maximum C2 pedicle diameter of <3.5mm on axial CT. The sex, age of patients, body mass index (BMI), osteoarthritis of the atlantoaxial (C1/2) facet joints and prevalence of a HRVA in the 2 groups were compared and logistic regression was used to identify the factors correlate with a HRVA. Results The patients of subaxial group were younger than those of the thoracolumbar group but the sex and BMI didn’t differ significantly between the 2 groups. The osteoarthritis grade of C1/2 facet joints of the subaxial group was statistically higher than the thoracolumbar group. A HRVA was found in 26 patients of 94 (27.7 %) in the subaxial group and in 19 of 121 (15.7%) in the thoracolumbar group. The prevalence of a HRVA in the subaxial group was statistically higher and logistic regression analysis indicated that osteoarthritis of C1/2 facet joints significantly correlated with HRVA. Conclusions The prevalence of a HRVA in patients with subaxial cervical spine disorders is higher than in those without cervical spine disorders, and osteoarthritis of C1/2 facet joints significantly correlated with a HRVA.