The atlantoaxial joint is a complex structure which facilitates rotation of the head on the neck. The transverse atlantal ligament is essential to retain the odontoid process of C2 in the anterior part of the C1 ring. Disruption or laxity of the transverse ligament, some odontoid process fracture result in atlantoaxial instability. In case of instability, stabilization is desirable to relieve pain and reduce the risk of neural damage. The isolated atlantoaxial instability with normal occipitoatlantal joint is generally treated by a monosegmental fusion. The standard fixation for C1-2 instability is posterior wiring using the Gallie, Brooks technique or their modifications. The most recent and innovative development in the evolution of upper cervical spine fixation is the use of C1-2 transarticular screw fixation. The transarticular screw fixation technique can be employed in situation where the posterior arch of C1 is absent or fractured and standard wiring technique risk posterior subluxation of C1, on C2, or for congenital odontoid anomalies and multiple failures of standard wiring techniques. The transarticular screw fixation of the atlantoaxial joints, with posterior bone grafting, provides good fixation and is biomechanically superior to wring methods. This paper presents the comparison of posterior fixation methods and the detailed introduction of posterior C1-2 transarticular screw fixation technique.
Atlanto-Axial Joint ; Bone Transplantation ; Head ; Joints ; Ligaments ; Neck ; Odontoid Process ; Spine

The object of this investigation was to study the effects of mannitol and high dose of methylprednisolone(MP)upon evolution of cerebral infarction in cats after acute left middle cerebral artery(MCA) occlusion and following reperfusion. The acute occlusion of left proximal MCA of thirty cats for 2, 4 and 6 hours respectively were accomplished by applying the Heifetz clip through the retroorbital extradural approach and followed by 2 hours of recirculation. Fifteen cats were untreated as a control group and the fifteen cats were given a combination of mannitol(2g/kg) and MP (15mg/kg) at 30 minutes after occlusion initially, and then every one and a half hour. Results of morphologic examination of the brain demonstrated that untreated cats undergoing 2-hour or 4-hour occlusion mannitol and MP improved the ischemic edema and infarction, but in treated cats undergoing 6-hour occlusion they had little protective effect in ischemic brain injury(swelling, neuronal damage and hemorrhagic infarction). Electronecephalography(EEG) in cats undergoing 2-or 4-hour occlusion showed more increasing activities and voltage than in untreated groups, but in cats undergoing 6-hour occlusion low. voltage and slow waves with poor activity, i.e, generally suppressed pattern, were observed and were not significantly different between treated and untreated groups. Our experimental studies of the therapeutic beneficial effects of mannitol and MP were observed in cats of 2-or 4-hour occlusion of MCA with 2 hour recirculation. Therefore, it was suggested that mannitol and MP will prolong the period of potential reversibility of cerebral ischemia following reperfusion within 4 hours of ischemia.
Animals ; Brain ; Brain Ischemia ; Cats ; Cerebral Infarction* ; Edema ; Infarction ; Ischemia ; Mannitol* ; Methylprednisolone* ; Neurons ; Reperfusion

Five cases presenting with hemiparesis, disturbed consciouness, and visual dimness gave no history suggestive of subarachnoid or intracerebral hemorrhage. Carotid angiograms were performed, and in each case failed to demonstrate a vascular malformation. The CT scans in five cases showed intracerebral hematoma that could suggest vascular malformation as a diagnostic possibility. Surgical exploration was done in each case and pathological features revealed a arteriovenous malformation in each specimen.
Arteriovenous Malformations* ; Cerebral Angiography ; Cerebral Hemorrhage ; Hematoma ; Paresis ; Tomography, X-Ray Computed ; Vascular Malformations

Surgical treatment for chronic back pain in degenerative lumbar spine has been still complicated. Several kinds of devices for spine fusions have been developed, but they have had both some advantages and disadvantages. Recently, the TFC(Threaded fusion cage) instrument has been introduced in treating lumbar spinal disorders associated with degenerative changes. The authors analysed 15 cases of lumbar degenerative disease treated with adequate decompression and TFC instrumentation between October 1993 and March 1994 at Ewha Womans University Mokdong Hospital. There were 10 females and 5 males. The main surgical indication was serious limitation of daily activity, which was not treated conservatively. The preoperative diagnoses were 6 degenerative stenosis with disc, 6 degenerative spondylolisthesis, 2 spondylosis and spondylolytic spondylolisthests, and 1 FBSS. We observed that 93% of patients(14 of 15) had more than good results and preoperative back pain was markedly reduced. Intervertebral disc space was well restored, and the reduction was possible in spondylolisthesis patients. In our opinion, TFC instrument will be one of good surgical modality in the treatment of degenerative lumbar spine.
Back Pain ; Constriction, Pathologic ; Decompression ; Diagnosis ; Female ; Humans ; Intervertebral Disc ; Male ; Spine ; Spondylolisthesis ; Spondylosis

With the advent of magnetic resonance image (MRI), direct visualization of the spinal cord tumors and their relationship to the surrounding structures becomes possible. A clinical analysis was done retrospectively in forty patients suffering from primary spinal tumors and were treated surgically from November 1991 to November 1995. There were 19 male and 21 female patients, peak incidence occurs in the sixth decade of life. The tumor with the highest incidence was neurogenic tumor (42.5%), followed by glial tumor and meningioma. The most frequent symptom was pain. On radiological evaluation, simple plain X-ray showed abnormality in 37.5% of cases, in which the most common positive finding was pedicle erosion (20%). CT was performed in 38 cases and MRI in 31. The MRI reveals not only morphologic abnormalities but also diversities in signal intensity. These findings helped us to establish pathologic diagnosis and operative planning. Surgery was performed via anterior(5%) and posterior(95%) approaches. Total removal was possible in 70% of the cases and subtotal removal in 30%. Evaluation of the patient's symptom and neurologic deficit was done one month after operation, it was found that about 80% of the patients recovered or have their conditions improved. Complications were developed in 3 cases.
Diagnosis ; Female ; Humans ; Incidence ; Magnetic Resonance Imaging ; Male ; Meningioma ; Neurologic Manifestations ; Retrospective Studies ; Spinal Cord Neoplasms