1. A new subtype of Atlantoaxial Rotatory Fixation (Type IIIa) has been identified, which is characterized by C1 anterior displacement of >5 mm and one lateral mass displaced anteriorly and the other posteriorly.
2. Imaging features of type IIIa AARF include an atlanto-dental interval of >5 mm, one lateral mass of C1 displaced anteriorly and the other posteriorly, and a larger C1-C2 separation angle than type III AARF.
3. Type IIIa AARF should not be confused with type III AARF due to differences in biomechanics and imaging parameters.
The article is generally reliable as it provides detailed information about the new subtype of Atlantoaxial Rotatory Fixation (Type IIIa). The authors have provided evidence for their claims by citing relevant studies and providing data from 10 cases of AARF with anterior C1 displacement of >5 mm. The article also includes a comprehensive discussion on the differences between type IIIa AARF and type III AARF in terms of biomechanics and imaging parameters.
However, there are some potential biases that should be noted. For example, the study only included 10 cases which may not be representative enough to draw conclusions about this new subtype. Additionally, the study did not explore any possible risks associated with this condition or provide any counterarguments to its findings. Furthermore, there is no mention of any promotional content or partiality in the article which could potentially influence readers’ opinions on this topic.