Posterior Lumbar Interbody Fusion(PLIF) by Facetolaminoplasty in Lumbar Spine Revision Surgery

OBJECTIVE: There has been a lack of enthusiasm for posterior lumbar interbody fusion(PLIF) in revision surgery. PLIF in revision surgery requires more excessive distraction of neural structures and excessive removal of the facet-laminar structure which plays a significant mechanical role, especially in rotatory stability. The author reports facetolaminoplastic PLIF which provides safe and effective PLIF and even natural circumferential fusion as well. PATIENTS AND METHODS: This study consistes of 6 patients. The facetolaminotomy was performed by osteotomizing bilateral pars interarticularis with a Gigli saw. PLIF was performed through more widely exposed intervertebral space by inserting a pair of carbon fiber cages and medial iliac bone blocks between the cages. The facetolaminotomy flap was returned to the previous site and was fixed by trans-laminar and trans-isthmic screw fixation. Bilateral facet arthrodesis was also performed. RESULTS: There were no neural complications related to facetolaminotomy nor were there any complications related to the screw fixation for the restoration of the posterior construct. Of these 6 cases, radiological union at the interbody fusion site and at both pars interarticularis was noted in 5 cases at a 6-month postoperative follow-up. An incomplete union at unilateral pars interarticularis was noted in remaining one case. CONCLUSIONS: The PLIF by facetolaminoplasty in revision surgery not only provides a wide interspace for safe and effective PLIF but also restores the posterior constructs, thereby preserving its important mechanical roles and often even achieving natural circumferential arthrodesis.

Spontaneous Spinal Epidural Hematoma Associated with the Ossification of Ligamentum Flavum of the Thoracic Spine

Spontaneous Spinal Epidural Hematoma has been reported to be associated with vascular malformations, tumors, infections, pregnancy, ankylosing spondylitis, rheumatoid arthritis, artherosclerosis, and hypertension. Approximately half of the cases, however, have no apparent cause. The most widely accepted hypothesis of the source of bleeding is that epidural veins are torn by the variations of abdominal or thoracic pressure. The normal hemodynamic fluctuations during usual daily activities are not, however, enough to explain the rare incidence of the spontaneous spinal epidural hematoma, requiring further consideration of the pathogenic factors. The author experienced a case of spontaneous spinal epidural hematoma associated with the ossification of the ligamentum flavum at the lower portion of the hematoma. Venous bleeding from distended epidural veins was observed at the lateral sides of the dural sac after removal of the hematoma. In addition, no vascular malformation was not found in the operative field. Consequently, the auther cautiously suggests that the ossification of the ligamentum flavum may have resulted in the formation of an abnormally dilated vein which ultimately caused bleeding in the patient.

Application of C1-C3 Halifax Interlaminar Clamps in Addition to C1-C2 Cable Fixation

C1-C2 transarticular screw fixation has been a preferred method for the fixation of atlantoaxial subluxation caused by the rheumatoid arthritis or recurrent subluxation caused by postoperative non-union. However, it has required extensive occipitocervical fusion or rigid external orthoses such as halo brace after cable fixation especially when the patient has the prominent transverse foramen precluding the safe placement of the C1-C2 transarticular screw. The author applied a pair of Halifax interlaminar clamps from C1 to C3 following the C1-C2 cable fixation in one patient with rheumatoid atlantoaxial subluxation and the other with recurrent subluxation after postoperative non-union. The prominent transverse foramen in both patients precluded the safe passage of the C1-C2 transarticular screw. Both patients were maintained in semirigid external orthoses by using philadelphia collar for 3 months after surgery. One has been doing well for 1 year and the other for 5 months following surgery. In conclusion, the application of the Halifax interlaminar clamps from C1 to C3 in addition to the C1-C2 cable fixation can be a useful alternative procedure circumventing extensive occipitocervical fusion for patients with the prominent transverse foramen precluding the safe placement of the C1-C2 transarticular screw, thereby not sacrificing the motion between occiput and atlas.

Anatomical Suitability of Posterior C1/2 Transarticular Screw Fixation in Korean

Although C1-C2 transarticular screw fixation has become a popular surgical method of treating atlantoaxial instability, we remain concerned about the potential for injury to the vertebral artery. Because of the lack of an objective measuring method, surgical unsuitability has been decided on the basis of individual experiences as reported in 18-23% of cases. In this study, the point of screw intersection(the passing points) on the superior articular surface of C2 were measured and the directions of these were thus objectified. Sixty-four healthy volunteers underwent 1mm fine-slice C1-C2 CT scanning, and sagittal images were reconstructed at 3.5mm(3.5mm lateral image) and 6mm(6mm lateral image) lateral to the spinal canal. The C1/2 transarticular screw trajectories making the longest paths or violating the transverse foramen(dangerous trajectory) were drawn and the distance from their points of screw intersection on the superior articular surface of C2 were measured from the posterior rim of the superior articular surface of C2. When the space available for screw(SAS) posterior to the passing point of the dangerous trajectory was equal to or less than 3.5mm(major diameter of the commonly used screw), the case was considered unacceptable, when SAS was over 3.5mm but equal to or less than 4.5mm, screw placement were considered risky. The trajectories made the longest paths when they passed 3.6+/-1.6mm(mean+/-S.D.) and 2.8+/-1.7mm(mean+/-S.D.) anterior to the posterior rim of the posterior articular surface of C2 as seen on 3.5mm lateral images and 6mm lateral images, respectively. While four of 64 cases(6.3%) were unilaterally unacceptable or risky on 3.5mm lateral images, 21 cases(32.8%) were unacceptable or risky on 6mm lateral images(unilateral, 15cases; bilateral, 6 cases). When the trajectories inclined forward to 0%, 25%, 50%, 75% and 100% points of AP diameter of the superior articular surface of C2 from the posterior rim, the respective risks of the involvement of the transverse foramen increased to 0.78%, 1.5%, 25%, 74% and 100%, as seen on 3.5mm lateral images and 10.9%, 14%, 62.5%, 95% and 100%, on 6mm lateral images.

C1/2 Transarticular Screw Fixation for Complicated Os Odontoideum: Case Report

C1/2 posterior transarticular screw fixation has become an accepted method of rigid internal fixation for patients requiring posterior C1/2 fusion. Especially,Surgery for Os odontoideum can be troublesome due to its severe tranlational instability, canal stenosis requiring decompressive laminectomy and defective C1 posterior arch. The author reports three cases of complicated Os odontoideum(one case of failed occipito-C2 fusion, two cases requiring C1 laminectomy) with C1/2 transarticular screw fixation and interarticular bone fusion. All required decompressive laminectomy and demonstrated highly unstable translational instabilities. On the basis of these experiences, it is postulated that C1/2 transarticular screw fixation seems to be superior to other methods in stabilization and fusion for complicated Os-odontoideum.

Cervical tuberculous Spondylitis: Report of 2 Cases

Tuberculous spondylitis occurs about 1% of all newly diagnosed cases of tuberculosis and it is the most common and most dangerous form of skeletal tuberculosis. It usually involve the lower thoracic and lumbar spine and the cervical involvement is rare. Therapy should consist of administration of antituberculotic agents and if indicted, surgical curettage and stabilization. The early diagnosis and management was important. Due to the MR imaging for the evaluation of spinal disorders and the recent increase of patients with AIDS suggest that the prevalence of skeletal tuberculosis including tuberculous spondylitis is increasing. Authors report two cases of cervical tuberculous spondylitis with review of literatures.

Percutaneous LASER Disc Decompression for Lumbar Disc Herniations: Preliminary Report

After attempts of percutaneous laser disc decompression on 14 patients of lumbar disc herniations, disappointing results were recorded as follows, 2 cases(14.2%) were considered excellent, 2 cases(14.2%) good, 2 cases(14.2%) fair and 8 cases(57.1%) poor. While successfully treated patients had minimal subligamentous extension of nucleus pulposus, failed cases had moderate to severe subligamentous extension of nucleus pulposus through the annular tearing. In preliminary conclusion of percutaneous laser disc decompression, successful result can be expected only on the minimal subligamentous extension cases, and chemonucleolysis will be better choice for the moderate to severe subligamentous extension cases.

The Normal Angulation and the Translation on Dynamic Lumbar Radiography in Korean

The authors measured the translation and the angulation on dynamic lumber radiography to get Korean standard data in 53 normal Korean male aged 25 to 30 without any back problem. Mean angulations on L2/3, L3/4, L4/5 and L5/S1 interspace were -2.6 degrees, -3.3 degrees, -3.4 degrees and 2.6 degrees on flexion and 11.6 degrees, 12.2 degrees, 14.2 degrees and 19.6 degrees on extension, respectively. Mean sums of angulations on flexion and extension on L2/3, L3/4, L4/5 and L5/S1 interspace were 14.1 degrees, 5.5 degrees, 17.6 degrees and 16.9 degrees, respectively. Mean translations, expressed in percentage of vertebral AP diameter, on L2/3, L3/4, L4/5 and L5/S1 interspace were 0.4%, 0.6%, 0.2% and 6% on flexion and 4.5%, 5.2%, 5.9% and 7.3% on extension, respectively. We hope that these data would help to make decision on lumbar segmental instability in conjunction with other studies.

The Effects of Continuous and Intermittent Interruption of the Cerebral Blood Flow on Brain Edema and Ischemic Neuronal Injury in Gerbils

Temporary occlusion of the cerebral blood flow is an effective maneuver to prevent and/or to control excessive bleeding during neurosurgical operations. Many studies have been reported employing single occlusion of various durations. However, there has been only a few studies examing the consequences of repeated occlusions on the development of cerebral edema and neuronal injury in the gerbil. Three separate episodes of 5-minute ischemia spaced at varied time interval was produced in Mongolian gerbils by occlusion of bilateral common carotid arteries. Quantitative estimates of cerebral edema and neuronal injury were obtained 24 hours after the third occlusion. The result was compared to that of single 15-minute occlusion. In gerbils with three 5-minute occlusions at 10-minute intervals, cerebral edema was not significant. However, the animals killed 24 hours after three 5-minute occlusions at 1-hour intervals or single 15-minute occlusion showed severe cerebral edema. Such animals showed significantly more neuronal injury than in animals with three 5-minute occlusions at 10-minute intervals. These results suggest that ischemic brain damage may be reduced with repeated vascular occlusions spaced at short intervals.

Comparison of Diagnostic Accuracy between CT Scan and MRI on Degenerative Lumbar Spine Diseases

Both CT scan and MRI were taken on 200 randomly chosen patients of degenerative lumbar spine diseases for the double blind comparison of the diagnostic accuracy of these studies. While osseous changes such as canal stenosis, lateral recess stenosis and facet hypertrophy were graded more severe on CT scan than on MRI, facet joint laxity was graded more severe on MRI than on CT scan. MRI could not detect 44% of ligament ossifications and 45.3% of vertebral osteoplytes which were diagnosed on CT scan. MRI gave more valuable information about the direction of the disc herniation than CT scan.

Graf Soft Fixation in Degenerative Lumbar Spine Instability: Preliminary Report

Although various kinds of spine stabilizing instruments have been developed over the past years, the subject is still controversial and contradictory reports are seen in the literature. Among such instruments, Graf instrument has attracted much interest because of the originality of the idea as a soft stabilizer. We have performed Graf instrumentation on 34 cases of degenerative lumbar spine diseases from September 1993 to March 1994, and after more than 3 months of postoperative follow-up, we conclude as follows: 1) Out of the 34 operated cases, the short term postoperative follow-up results for low back pain was excellent in 15 cases(44.1%), good in 5 cases(44.1%), fair in 3 cases(8.8%), and poor in 1 case(2.9%). 2) As a soft fixator developed on the basis of physiological mechanism, Graf instrumentation can avoid unwanted effects of hard fixation and is thought to be less destructive and more effective physiologically.

Agenesis of Corpus Callosum

Thirty three cases with agenesis of the corpus callosum were reviewed from the base of brain CT findings for last 7 years. Clinical features, associated clinical anomalies and CT findings were also analysed and the embryological basis for agenesis of the corpus callosum were reviewed from the literature.

Intrahepatic Migration of a Peritoneal Shunt Catheter: Case Report

The intraphepatic migration of a distal ventriculopritoneal shunt tube(Accu-flo shunt system medium pressure) is reported. This is rare complication of ventriculoperitoneal shunt, which was diagnosed by abdominal computed tomography. To our knowledge, this is the third reported case complication with migration of a peritoneal shunt tube into the liver.

A Case of Pediatric Odontoid Base Fracture Treated by Halovest Fixation

The authors presented a case of fracture and dislocation at odontoid base in 3 year old patient. This fracture and dislocation was successfully treated by the Gardner's tong traction followed by Halovest application. We also reviewed the characteristics, treatment and prognosis of the pediatric odontoid process fracture.

Slit Ventricle Syndrome

Authors report four cases of hydrocephalic patients with slit ventricle syndrome, three of whom evidenced reexpansion of the ventricular system following insertion of high resistance value or anti-siphon devices. The results of the treatment were dramatic in two cases of anti-siphon divice application and relatively good in one case of high resistance valve application. The authors reviewed the pathogenesis, diagnosis and treatment of the slit ventricle syndrome.

Syringomyelia Associated with Spinal Intramedullary Giloblastoma Multoforme: Report of a Case

A case of cervicothoracic intramedullary glioblastoma multiforme associated with syringomyelia is reported. The tumor was located between C5 and T1 level and a large syrinx was found below the tumor, T1-T12. Intramedullary uptake of contrast dye in the delayed CT scan after myelography was seen. The tumor was removed gross totally. And terminal syringotomy was performed.