Variations in the Number of Vertebrae, Prevalence of Lumbosacral Transitional Vertebra and Prevalence of Cervical Rib among Surgical Patients with Adolescent Idiopathic Scoliosis: An Analysis of 998 Radiographs.

In this series, we identified a total of 7 different variations in the number of cervical, thoracic and lumbar vertebrae. The total prevalence of patients with atypical vertebrae variation was 15.5%. LSTV was found in 25.1% of the cohort. It is important to ascertain atypical vertebrae variations rather than the absolute number of vertebrae because variants such as 7C11T6L and 7C13T4L may still have typical numbers of vertebrae in total. However, due to the differences in the number of morphologically thoracic and lumbar vetrebrae, there may still be a risk of inaccurate identification.