AtlantoaxialGelenk

The atlantoaxial joint, known in German as "Atlantoaxialgelenk," is a pivotal articulation located between the first and second cervical vertebrae, namely the atlas (C1) and the axis (C2). This joint plays a crucial role in allowing rotational movement of the head, enabling actions such as turning the head from side to side.

Anatomically, the atlantoaxial joint consists of three articulations: two lateral atlantoaxial joints between the articular facets of C1 and C2, and one median joint involving the dens (odontoid process) of C2 and the anterior arch of C1. The joint is stabilized by several ligaments, including the transverse ligament of the atlas, which secures the dens against the anterior arch of C1, and the alar ligaments that connect the dens to the occipital bone.

Range of motion at the atlantoaxial joint is primarily rotational, allowing the head to turn approximately 45 degrees to either side. Flexion and extension movements are limited at this joint, with most of the nodding motion occurring at the atlanto-occipital joint.

The atlantoaxial joint is innervated by the cervical spinal nerves and supplied with blood through branches of the ascending pharyngeal and vertebral arteries. Pathologies associated with this joint include instability due to trauma, congenital anomalies such as odontoid hypoplasia, and rheumatoid arthritis, which can compromise the stability and function of the joint.

Due to its importance in head movement and its proximity to the spinal cord and vertebral arteries, injuries or diseases affecting the atlantoaxial joint require careful clinical assessment and management.