Exploration for reliable radiographic assessment method for hinge-like hypermobility at atlanto-occipital joint

[摘要] PurposeHinge-like hyper-mobility is occasionally observed at the atlanto-occipital (O-C1) joint. However, it has not been clear if this kind of hinge-like hyper-mobility at the O-C1 joint should be regarded as “pathologic”, or referred to as “instability”. To solve this issue, we aimed to establish a reliable radiographic assessment method for this specific type of O-C1 instability and figure out the “standard value” for the range of motion (ROM) of the O-C1 joint.

[学科分类] 骨科学

[关键词] Atlanto-occipital (O-C1) instability;Classification;Radiographic assessment method;Dynamic magnetic resonance imaging;O-C1 angle