巨大に鞍状に発育した第一頸椎

抄録

A thirty-four year-old male was admitted with the chief complaint of his left shoulder pain.
No positive physical and neurological findings were seen around the shoulder, but at that time markedly limited movement, especially rotation and anteflexion, of the neck was noticed out.
Antero-posterior roentgenogram of the atlas revealed increased height of the massa lateralis or distance between the fovea articularis superior and the facies articularis inferior, and lateral roentgenogram revealed deep saddle form conture of the atlantoccipital joint.
Extension and flexion of the neck measured by roentgenograms showed normal range of motion at the atlantooccipital joint and rigid articulatio atlantoaxialis lateralis.