Three Cases of Basilar Impression

Case 1: The 14 year old girl was admitted to our clinic with spastic gait and spastic weakness of the extremities on September, 1963.Although the first diagnosis was the tumor of upper cervical cord, the X-ray pictures revealed the odontoid process to be high and project into the foramen magnum.The narrowing of spinal cavity was found at the part of foramen magnum by myelography.Theese findings suggested that basilar impression caused her neurological signs.Case 2: The 40 year old female had sufferd from unsteady gait for 7 years. Numerous examinations could not explain the cause of her complaints befor she was admitted to our clinic.However, the diagnosis could be readily made by proving the odontoid process to project above Chamberlain's line and MacRae's line.Case 3: The 16 year old male revealed wry neck without tension of the sterno-mastoid muscle.In the lateral view of his cervical spine, the posterior arch of atlas was completely fused with occipital bone.The assymmetry of the atlanto-axial articulation was observed with the high position of the odontoid process.It is obvious that his wry neck is due to the rotation and the malformation of the atlantoaxial articulation.Although basilar impression has been mainly dealt by neurosurgeon, it should be given attention in the field of orthopedic surgery because it associates with malformation of atlas and axis and reveals the signs of cervical cord tumor.