Cervical myelopathy caused by the anomalous vertebral artery. A case report.

STUDY DESIGN: A case of cervical myelopathy caused by an anomalous vertebral artery is reported. OBJECTIVES: To report a case of high cervical myelopathy resulting from spinal cord compression by an anomalous vertebral artery. Authors believe that this is the first reported case in which the nutrient artery to the abnormal artery originated from the posterior inferior cerebellar artery. SUMMARY OF BACKGROUND DATA: Although fenestration of the vertebral artery is net an unusual anomaly to the best of the authors knowledge, three cases of high cervical myelopathy resulting from the anomaly were reported. There is no reported case in which an abnormal artery originated from the posterior inferior cerebellar artery. METHODS: The clinical features of the case are reported and discussed with a review of the previously documented cases. RESULTS: The cord compression war relieved surgically, and the patient's symptoms improved postoperatively. CONCLUSIONS: A fenestrated vertebral artery should be included in the differential diagnosis of the upper cervical or the craniovertebral junctional lesions of unknown origin. Magnetic resonance imaging is useful for the diagnosis. In the present case, there was an anomalous branch entered as a nutrient artery from the posterior inferior cerebellar artery. Careful management for similar abnormal arteries includes surgery.

Three-dimensional motion of the upper cervical spine in rheumatoid arthritis.

Rheumatoid arthritis frequently contributes to instability of the upper cervical spine. Rotational instability of the upper cervical spine was evaluated in rheumatoid arthritis patients using biplanar x-ray photogrammetry. Three-dimensional cervical motion and the instantaneous axis of rotation of the atlas relative to the axis were evaluated in normal and rheumatoid arthritis patients during axial rotation in the horizontal plane. Anterior atlantoaxial subluxation did not increase during axial head rotation in either the atlantoaxial subluxation or the vertical subluxation groups, while the instantaneous axes of rotation were distributed posteriorly in the dens in the RA-normal group, but were widely scattered in the atlantoaxial subluxation group.

Three-dimensional motion analysis of the upper cervical spine during axial rotation.

Rotational motion of the normal upper cervical spine was analyzed in 20 men using biplanar roentgenograms, a system digitizer, and a personal computer. To detect the bony landmarks of the atlas, the subjects' heads were fixed and their trunks rotated in the reference frame while these biplanar studies were obtained. Coupling motions observed included 10 degrees extension at C0-C1, with 11 degrees of lateral bending between C1-C2. Almost all (80%) cervical axial rotation took place at C1-C2, whereas only 4 degrees of rotation occurred at C0-C1. Furthermore, as C1-C2 axial rotation increased, so did rotation in the opposite direction at C0-C1 while less rotation was noted below C2. The instantaneous axis of rotation was located anterior to the foramen magnum at the C0-C1 level, in the central portion of the dens at C1-C2.

Distraction in the lateral position in elbow arthroscopy.

To perform successful elbow arthroscopy, it is very important to have precise positioning and to distract the joint during arthroscopy. We have developed a method of distraction during elbow arthroscopy that enlarges the articular space while ensuring the stability of the elbow. Our method is simple and requires no expensive specialized instruments. Our distraction method using lateral positioning is useful and safe for elbow arthroscopy. Because the articular space is widened sufficiently, stability of the elbow is maintained and no complication was seen.