New method for intraoperative determination of proper screw insertion or screw malposition

2000 ◽  
Vol 93 (1) ◽  
pp. 40-44 ◽  
Author(s):  
Sabri Cem Açıkbaş ◽  
Mehmet Recai Tuncer
Keyword(s):  
Imaging Techniques ◽  
New Method ◽  
Lumbar Region ◽  
Content Type ◽  
Screw Insertion ◽  
Transpedicular Instrumentation ◽  
Thoracolumbar Injury ◽  
Major Vessel ◽  
Fine Print

Object. Inadequate imaging techniques may lead to misjudgment of screw positioning when applying transpedicular instrumentation; this can create potential risks of major vessel and nerve damage. In this article the authors present a new method to determine screw malpositioning intraoperatively. Methods. The authors retrospectively evaluated pre- and postoperative plain radiographs of 97 spinal segments in which screws had been placed in 41 patients suffering from thoracolumbar injury who had previously undergone transpedicular screw fixation. They developed a new mathematical equation with which they determine the distance ratios of two screw tips in the same segment by comparing the distance between the pedicles on preoperative radiographs with those on postoperative radiographs. Subsequently, the results are compared with postoperative computerized tomography findings to determine which screws are in the correct position and which are penetrating the medial or lateral cortex of the pedicle. It was found that the ratio range of correctly placed screw tips was 46 ± 10% (mean ± standard deviation) in the thoracic region and 60 ± 9% in the lumbar region (ranges 43–50% and 57–63%, respectively, 95% confidence intervals). Higher ratios (higher percentages) than these values indicated extreme closeness of screw tips and therefore medial malpositioning. Lower ratios (lower percentages) indicated lateral malpositioning. Conclusions. This proposed method may provide intraoperative determination of correct screw positioning or malpositioning. This method allows surgeons to replace the malpositioned screw, and, consequently, early resolution of neurovascular injuries is made possible. Additionally, repositioning of the screw correctly will avoid rigidity failure of the fixation device.

A new method for testing the force of clips for aneurysms or experimental spinal cord compression

1979 ◽  
Vol 51 (2) ◽  
pp. 229-233 ◽  
Author(s):  
Eugen J. Dolan ◽  
Charles H. Tator
Keyword(s):  
Spinal Cord ◽  
Early Detection ◽  
Spinal Cord Compression ◽  
Cord Compression ◽  
New Method ◽  
Content Type ◽  
Cosine Law ◽  
Fine Print

✓ A new method is described for the determination of force-distance curves for aneurysm clips. A dissecting microscope with a goniometer eyepiece was used to determine the angle between the clip blades as various forces were applied to open the clip. The cosine law was then used to calculate the force-distance curves. The method allows accurate characterization of different clips and is especially useful for the early detection of clip weakening.

Chondroblastoma of the lumbar spine

2005 ◽  
Vol 2 (5) ◽  
pp. 596-600 ◽  
Author(s):  
Raphaël Vialle ◽  
Antoine Feydy ◽  
Ludovic Rillardon ◽  
Carla Tohme-Noun ◽  
Philippe Anract ◽  
...  
Keyword(s):  
Lumbar Spine ◽  
Local Recurrence ◽  
Osteolytic Lesion ◽  
Radicular Pain ◽  
Appendicular Skeleton ◽  
Lumbar Region ◽  
Content Type ◽  
Anterior Posterior ◽  
Fine Print

✓ Chondroblastoma is a benign cartilaginous neoplasm that generally affects the appendicular skeleton. Twenty-six cases of spinal chondroblastoma have been reported in the past 50 years, only six of which were located in the lumbar region. The authors report two cases involving this exceptional location. In both patients, low-back pain, in the absence of radicular pain, was the presenting symptom. In both cases, plain radiography and computerized tomography scanning revealed an osteolytic lesion surrounded by marginal sclerosis. Magnetic resonance imaging allowed the authors to study the tumor's local extension. Examination of a percutaneous fluoroscopy-guided biopsy sample revealed the following typical histological features of chondroblastoma: chondroid tissue, focally alternating with cellular areas, and no nuclear atypia or pleomorphism. To reduce the risk of local recurrence, vertebrectomy and anterior—posterior fusion were performed in both cases. In one case, a structural lumbar scoliosis was corrected during the posterior procedure. There was no postoperative complication. No recurrence was observed during the 3- to 6-year follow-up period. The surgery-related results were deemed successful. Although exceptional, the diagnosis of chondroblastoma is possible in lesions involving the lumbar spine. Other spinal locations are described in the literature, and frequency of recurrence is stressed. A vertebrectomy is advised to reduce the risk of local recurrence.

Intervertebral disc space cyst simulating a recurrent herniated nucleus pulposus

1988 ◽  
Vol 69 (1) ◽  
pp. 137-139 ◽  
Author(s):  
Jordan C. Grabel ◽  
Raphael Davis ◽  
Rosario Zappulla
Keyword(s):  
Intervertebral Disc ◽  
Preoperative Diagnosis ◽  
Relevant Literature ◽  
Radicular Pain ◽  
Lumbar Region ◽  
Intervertebral Disc Space ◽  
Disc Space ◽  
Content Type ◽  
Herniated Nucleus Pulposus ◽  
Fine Print

✓ The case presented is of a patient with an intervertebral disc space cyst producing recurrent radicular pain following microdiscectomy in the lumbar region. Difficulties with the preoperative diagnosis of this and other recurrent radicular syndromes are discussed, and a review of the relevant literature is presented.

The natural history of intracranial venous angiomas

1991 ◽  
Vol 75 (5) ◽  
pp. 715-722 ◽  
Author(s):  
Timothy B. Garner ◽  
O. Del Curling ◽  
David L. Kelly ◽  
D. Wayne Laster
Keyword(s):  
Natural History ◽  
Imaging Techniques ◽  
Venous Drainage ◽  
Vascular Lesion ◽  
Neurological Dysfunction ◽  
Content Type ◽  
History Of ◽  
Clinical Records ◽  
Venous Angiomas ◽  
Fine Print

✓ Cerebral venous angiomas are congenital anomalies of the intracranial venous drainage. Many believe that they are associated with a high risk of hemorrhage and neurological dysfunction, but newer neurodiagnostic imaging techniques are showing not only that they are more common than previously known but also that many have no associated symptoms. In this retrospective study, the natural history of venous angiomas was examined in 100 patients (48 males and 52 females) with radiographically identifiable lesions treated over a 14-year period. Information on the natural history of the lesion was obtained from clinical records and follow-up data. Imaging studies included angiography, computerized tomography, and magnetic resonance imaging. Angioma locations were classified as frontal (42 cases), parietal (24 cases), occipital (4 cases), temporal (2 cases), basal or ventricular (11 cases), cerebellar (14 cases), or brain stem (3 cases); 47 lesions were on the left side. Headache as a presenting symptom was common (36 patients) and often led to other radiographic studies, but this appeared to be related to the vascular lesion in only four patients. Other possibly related complications were hemorrhage in one patient, seizures in five, and transient focal deficits in eight. Fifteen patients had no neurological signs or symptoms. The mean patient age at last contact was 45.3 years (range 3 to 94 years). All patients have been managed without surgery. It is concluded that significant complications secondary to venous angiomas are infrequent and that surgical resection of these lesions and of surrounding brain is rarely indicated.

Resin sealant: a new method of methyl methacrylate cranioplasty

1991 ◽  
Vol 75 (2) ◽  
pp. 328-330 ◽  
Author(s):  
Akira Yanai
Keyword(s):  
Methyl Methacrylate ◽  
Cortical Bone ◽  
New Method ◽  
Skull Defect ◽  
Content Type ◽  
Cosmetic Appearance ◽  
Good Cosmetic ◽  
Resin Sealant ◽  
Fine Print

✓ A new method of cranioplasty is described. The skull defect is exposed and multiple angled holes are drilled in the outer cortical bone around the defect. A resin plate is conventionally molded to fit the defect. After the resin plate is positioned in the skull defect, newly prepared viscous resin putty is injected into the holes around the defect. The viscous resin comes into contact with the margin of resin plate and, when it hardens, a monoblock casting of resin is formed. The resin plate is sealed to the bone. This technique has the main advantage of strength and good cosmetic appearance.

Paragangliomas of the lumbar region

2005 ◽  
Vol 2 (3) ◽  
pp. 354-365 ◽  
Author(s):  
Miguel Gelabert-González
Keyword(s):  
Cauda Equina ◽  
Lumbar Region ◽  
Rare Tumor ◽  
Content Type ◽  
Fine Print

✓ The author reports two cases of cauda equina paraganglioma (CEP) and provides a review of all previously published cases. The current radiological, neurosurgical, and pathological literature on this rare tumor is also reviewed.

Extradural spinal involvement by gout

1979 ◽  
Vol 50 (2) ◽  
pp. 236-239 ◽  
Author(s):  
Steven L. Wald ◽  
James E. McLennan ◽  
Richard M. Carroll ◽  
Harold Segal
Keyword(s):  
Differential Diagnosis ◽  
Spinal Canal ◽  
Lumbar Region ◽  
Content Type ◽  
Spinal Involvement ◽  
Gouty Tophus ◽  
Fine Print

✓ A case of extradural gouty tophus in the lumbar region in a teen-age girl is presented as an addition to the differential diagnosis of erosive lesions of the spinal canal.

A method of estimating intracranial decompensation in man

1976 ◽  
Vol 45 (2) ◽  
pp. 155-158 ◽  
Author(s):  
Jerzy Szewczykowski ◽  
Pawel Dytko ◽  
Adam Kunicki ◽  
Jolanta Korsak-Sliwka ◽  
Stanislaw Sliwka ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Intracranial Pressure ◽  
Characteristic Feature ◽  
Computer System ◽  
Monitoring System ◽  
New Method ◽  
Icp Monitoring ◽  
Content Type ◽  
On Line ◽  
Fine Print

✓ A new method of estimating intracranial decompensation in man is described. An on-line computer system is connected to an intracranial pressure (ICP) monitoring system to compute regression plots of mean ICP vs standard deviation; standard deviation is used as a measure of ICP instability. Two zones with distinctly different slopes are a characteristic feature of these plots. It is thought that the changes of slope signify intracranial decompensation.

A comparison of radiographic methods of diagnosing constrictive lesions of the spinal canal

1978 ◽  
Vol 48 (3) ◽  
pp. 360-368 ◽  
Author(s):  
M. Judith Donovan Post ◽  
Fredie P. Gargano ◽  
Donald Q. Vining ◽  
Hubert L. Rosomoff
Keyword(s):  
Computerized Tomography ◽  
Cross Section ◽  
Spinal Canal ◽  
Relative Effectiveness ◽  
Ct Scanning ◽  
New Method ◽  
Cross Sectional ◽  
Content Type ◽  
Sectional Anatomy ◽  
Fine Print

✓ With the advent of computerized tomography (CT), a new method of visualizing the spinal canal in cross-section has been created. Before the introduction of CT scanning, evaluation of the cross-sectional anatomy of the spinal canal was accomplished chiefly by the Toshiba unit. This study compares these two forms of tomography and discusses their relative effectiveness in diagnosing constrictive lesions of the spinal canal.

Families, brain death, and traditional medical excellence

1984 ◽  
Vol 60 (6) ◽  
pp. 1192-1194 ◽  
Author(s):  
Rosa Lynn Pinkus
Keyword(s):  
Brain Death ◽  
Tertiary Care Hospital ◽  
Tertiary Care ◽  
Care Hospital ◽  
Personal Beliefs ◽  
Content Type ◽  
The Past ◽  
Transplant Center ◽  
Fine Print

✓ Staff neurosurgeons and residents at a tertiary care hospital designated as a transplant center were surveyed regarding personal opinions concerning brain death and family conferences. Compared to an extensive survey done in 1976, the responses indicated that, while a professional consensus regarding the definition and meaning of brain death has emerged in the past 10 years, a range of personal beliefs and opinions regarding the concept still exists. In spite of the professional consensus, it is still difficult for the physician to communicate gently, yet firmly, to families both the scientific groundwork that validates the determination of brain death, the concept, and the finality of the information.

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