Bilateral open-door cervical expansive laminoplasty with hydroxyapatite spacers and titanium screws

2002 ◽  
Vol 96 (1) ◽  
pp. 22-28 ◽  
Author(s):  
Masakazu Takayasu ◽  
Teruhide Takagi ◽  
Toshihisa Nishizawa ◽  
Koji Osuka ◽  
Takehiko Nakajima ◽  
...  
Keyword(s):  
Screw Fixation ◽  
Cervical Spinal Cord ◽  
Intraoperative Complications ◽  
Fixation Strength ◽  
Open Door ◽  
Quick Method ◽  
Simple Method ◽  
Content Type ◽  
Titanium Screws ◽  
Fine Print

Object. The authors report a simple method for bilateral open-door cervical expansive laminoplasty in which hydroxyapatite (HA) spacers are secured by titanium screws. A biomechanical study was also conducted to confirm the strength of the screw fixation. Methods. A unilateral posterior approach was used to allow preservation of the posterior supporting elements (the posterior tension band) until the laminae were cut at the base. A bilateral open-door expansive laminotomy was then performed in standard fashion. Appropriate-sized HA spacers were selected, held with a specially designed holder, and placed between the split laminae. The screw holes were made in the laminae along the direction of the screw holes in the spacer, and two screws were inserted ventrolaterally to the laminae, resulting in instantaneous fixation. This procedure was performed in 15 patients; clinical results were successful, and there were no significant intraoperative complications. Follow-up radiological studies revealed no evidence of displacement of the spacers or screw backout. The screw artifacts observed on magnetic resonance imaging were minimal, allowing evaluation of the cervical spinal cord. The sagittal alignment of the cervical spine was well preserved. In the biomechanical studies the authors found that the screw fixation was of satisfactory strength, compared with other methods of fixation. Conclusions. Bilateral open-door cervical expansive laminoplasty in which HA spacers are secured by titanium screws is a simple and quick method that yields sufficient fixation strength.

Enhanced primary stability through additional cementable cannulated rescue screw for anterior thoracolumbar plate application

2003 ◽  
Vol 98 (1) ◽  
pp. 50-55 ◽  
Author(s):  
Markus Schultheiss ◽  
Lutz Claes ◽  
Hans-Joachim Wilke ◽  
Lothar Kinzl ◽  
Erich Hartwig
Keyword(s):  
Bone Quality ◽  
Screw Fixation ◽  
Burst Fracture ◽  
Primary Stability ◽  
Fixation Strength ◽  
Lateral Bending ◽  
Poor Bone Quality ◽  
Content Type ◽  
Flexion Extension ◽  
Fine Print

Object. The authors conducted a study to investigate the biomechanical in vitro influence of a new anchorage system for fixation of anterior stabilization devices and the possibility of using additional cement after screw insertion to compensate for poor bone quality. The incidence of osteoporosis-related fractures has increased nearly twofold in the last decade. Because of problems associated with anterior screw fixation such as loosening, mechanical failure, and the weakness of osteoporotic bone, current surgical treatments of vertebral body (VB) fractures are problematic. This is due to poor fixation strength of anterior screws in the adjacent segments. The aim of this study was to determine whether a new cemented and uncemented VB screw provides improved primary stability following placement of anterior instrumentation in cases of fracture. Methods. The primary stability-related parameters of a new uncemented/cemented screw were compared with those of conventional monocortical screw fixation in a burst fracture model in which strut graft and anterior overbridging instrumentation were used. The use of the new uncemented screw improved the range of motion (ROM) of the stabilized spine in flexion—extension by approximately 22%, in rotation by 20%, and in lateral bending by 15%. Additional cementation improved the ROM by approximately 41% in flexion—extension, 32% in rotation, and 30% in lateral bending compared with conventional monocortical screw fixation. Conclusions. The new cannulated screw improves fixation strength and primary stability parameters. It is useful in the initial treatment of fractures in cases of poor bone quality and as a rescue device if previously inserted screws do not remain securely in place.

En bloc laminoplasty without dissection of paraspinal muscles

2005 ◽  
Vol 3 (1) ◽  
pp. 29-33 ◽  
Author(s):  
Noboru Hosono ◽  
Hironobu Sakaura ◽  
Yoshihiro Mukai ◽  
Takahiro Ishii ◽  
Hideki Yoshikawa
Keyword(s):  
Ct Scanning ◽  
Cord Compression ◽  
Neck Muscle ◽  
Open Door ◽  
En Bloc ◽  
Cross Sectional ◽  
Content Type ◽  
Spinous Processes ◽  
Significant Difference ◽  
Fine Print

Object. Although conducting cervical laminoplasty in patients with multisegmental cord compression provides good neurological results, it is not without shortcomings, including C-5 palsy, axial neck pain, and undesirable radiologically detectable changes. Postoperative kyphosis and segmental instability can cause neurological problems and are believed mainly to result from neck muscle disruption. The authors developed a new laminoplasty technique, with the aim of preserving optimal muscle function. Methods. The present technique is a modification of unilateral open-door laminoplasty. By using an ultrasonic osteotome in small gaps of muscle bellies, a gutter is made without disrupting muscles, spinous processes, or their connections on the hinged side. Ceramic spacers are then positioned between elevated laminae and lateral masses at C-3, C-5, and C-7 on the opened side, which is exposed in a conventional manner. This new procedure was used to treat 37 consecutive patients with compression myelopathy. Postoperative computerized tomography (CT) scanning revealed a significant difference in a cross-sectional area of muscles between the hinged and opened side. The mean follow-up period was 40.2 months (range 24–54 months). Changes in alignment were observed in only one patient, and vertebral slippage developed in two. Performed at regular intervals, CT scanning demonstrated that the elevated laminae remained in situ throughout the study period. Conclusions. In using the present unilateral open-door laminoplasty technique, deep extensor muscles are left intact along with their junctions to spinous processes on the hinged side. Radiologically documented changes were minimal because the preserved muscles functioned normally immediately after the operation.

Herniation of the spinal cord into an iatrogenic meningocele

1973 ◽  
Vol 39 (4) ◽  
pp. 533-536 ◽  
Author(s):  
Cully Cobb ◽  
George Ehni
Keyword(s):  
Spinal Cord ◽  
Cervical Spinal Cord ◽  
Content Type ◽  
Fine Print

✓ The authors describe a case in which the cervical spinal cord became incarcerated in the mouth of an iatrogenic meningocele or “pseudocyst.”

Cruciate paralysis

1986 ◽  
Vol 65 (1) ◽  
pp. 108-110 ◽  
Author(s):  
Daniel Dumitru ◽  
James E. Lang
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Rare Case ◽  
Motor Vehicle ◽  
Motor Vehicle Accident ◽  
Cervical Spinal Cord ◽  
Content Type ◽  
Vehicle Accident ◽  
Cord Injury ◽  
Fine Print

✓ A rare case of cruciate paralysis is reported in a 39-year-old man following a motor-vehicle accident. The differentiation of this syndrome from a central cervical spinal cord injury is delineated.

Deformation of the cervicomedullary junction and spinal cord in a surgically treated adult Chiari I hindbrain hernia associated with syringomyelia: a magnetic resonance microscopic and neuropathological study

1996 ◽  
Vol 85 (4) ◽  
pp. 701-708 ◽  
Author(s):  
Emile A. M. Beuls ◽  
Marie-Anne M. Vandersteen ◽  
Linda M. Vanormelingen ◽  
Peter J. Adriaensens ◽  
Gerard Freling ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Magnetic Resonance ◽  
Cervical Spinal Cord ◽  
Cervical Cord ◽  
Magnetic Resonance Microscopy ◽  
Type I ◽  
Additional Advantage ◽  
Content Type ◽  
Hindbrain Hernia ◽  
Fine Print

✓ The lower brainstem and cervical spinal cord from an ordinarily treated case of Chiari Type I hindbrain hernia associated with syringomyelia was examined using high-resolution magnetic resonance microscopy and standard neuropathological techniques. Magnetic resonance microscopy allows total screening and visualizes the disturbed internal and external microanatomy in the three orthogonal planes with the resolution of low-power optical microscopy. An additional advantage is the in situ visualization of the shunts. Afterwards the intact specimen is still available for microscopic examination. Part of the deformation of the medulla is caused by chronic tonsillar compression and molding inside the foramen magnum. Other anomalies, such as atrophy caused by demyelination, elongation, and unusual disturbances at the level of the trigeminal and solitary nuclear complexes contribute to the deformation. At the level of the syrinx-free upper part of the cervical cord, anomalies of the dorsal root and the dorsal horn are demonstrated.

Cervical spinal cord in experimental hydrocephalus

1972 ◽  
Vol 37 (5) ◽  
pp. 538-542 ◽  
Author(s):  
George J. Dohrmann
Keyword(s):  
Spinal Cord ◽  
Brain Stem ◽  
Cervical Spinal Cord ◽  
Central Canal ◽  
Content Type ◽  
Experimental Hydrocephalus ◽  
Physiological Pressure ◽  
The Brain ◽  
Shunting Procedure ◽  
Fine Print

✓ Adult dogs were rendered hydrocephalic by the injection of kaolin into the cisterna magna. One group of dogs was sacrificed 1 month after kaolin administration, and ventriculojugular shunts were performed on the other group. Hydrocephalic dogs with shunts were sacrificed 1 day or 1 week after the shunting procedure. All dogs were perfused with formalin at physiological pressure, and the brain stem and cervical spinal cord were examined by light microscopy. Subarachnoid granulomata encompassed the superior cervical spinal cord and dependent surface of the brain stem. Rarefaction of the posterior white columns and clefts or cavities involving the gray matter posterior to the central canal and/or posterior white columns were present in the spinal cords of both hydrocephalic and shunted hydrocephalic dogs. Predominantly in the dogs with shunts, hemorrhages were noted in the spinal cord in association with the clefts or cavities. A mechanism of ischemia followed by reflow of blood is postulated to explain the hemorrhages in the spinal cords of hydrocephalic dogs with shunts.

Anatomical suitability of C1–2 transarticular screw placement in pediatric patients

2000 ◽  
Vol 92 (1) ◽  
pp. 7-11 ◽  
Author(s):  
Douglas L. Brockmeyer ◽  
Julie E. York ◽  
Ronald I. Apfelbaum
Keyword(s):  
Pediatric Patients ◽  
Screw Fixation ◽  
Vascular Complications ◽  
Screw Placement ◽  
Atlantoaxial Instability ◽  
Os Odontoideum ◽  
Transarticular Screw ◽  
Content Type ◽  
Transarticular Screw Fixation ◽  
Fine Print

Object. Craniovertebral instability is a challenging problem in pediatric spinal surgery. Recently, C1–2 transarticular screw fixation has been used to assist in craniovertebral joint stabilization in pediatric patients. Currently there are no available data that define the anatomical suitability of this technique in the pediatric population. The authors report their experience in treating 31 pediatric patients with craniovertebral instability by using C1–2 transarticular screws. Methods. From March 1992 to October 1998, 31 patients who were 16 years of age or younger with atlantooccipital or atlantoaxial instability, or both, were evaluated at our institution. There were 21 boys and 10 girls. Their ages ranged from 4 to 16 years (mean age 10.2 years). The most common causes of instability were os odontoideum (12 patients) and ligamentous laxity (eight patients). Six patients had undergone a total of nine previous attempts at posterior fusion while at outside institutions. All patients underwent extensive preoperative radiological evaluation including fine-slice (1-mm) computerized tomography scanning with multiplanar reconstruction to evaluate the anatomy of the C1–2 joint space. Preoperatively, of the 62 possible C1–2 joint spaces in 31 patients, 55 sides (89%) were considered suitable for transarticular screw placement. In three patients the anatomy was considered unsuitable for bilateral screw placement. In three patients the anatomy was considered inadequate on one side. Fifty-five C1–2 transarticular screws were subsequently placed, and there were no neurological or vascular complications. Conclusions. The authors conclude that C1–2 transarticular screw fixation is technically possible in a large proportion of pediatric patients with craniovertebral instability.

Application of frameless stereotaxy to pedicle screw fixation of the spine

1995 ◽  
Vol 83 (4) ◽  
pp. 641-647 ◽  
Author(s):  
Iain H. Kalfas ◽  
Donald W. Kormos ◽  
Michael A. Murphy ◽  
Rick L. McKenzie ◽  
Gene H. Barnett ◽  
...  
Keyword(s):  
Pedicle Screw ◽  
Spinal Surgery ◽  
Screw Fixation ◽  
Ct Images ◽  
Pedicle Screw Fixation ◽  
Lumbosacral Spine ◽  
Frameless Stereotaxy ◽  
Content Type ◽  
Screw Length ◽  
Fine Print

✓ Interactive frameless stereotaxy has been successfully applied to intracranial surgery. It has contributed to the improved localization of deep-seated brain lesions and has demonstrated a potential for reducing both operative time and morbidity. However, it has not been as effectively applied to spinal surgery. The authors describe the application of frameless stereotactic techniques to spinal surgery, specifically pedicle screw fixation of the lumbosacral spine. Preoperative axial computerized tomography (CT) images of the appropriate spinal segments are obtained and loaded onto a high-speed graphics supercomputer workstation. Intraoperatively, these images can be linked to the appropriate spinal anatomy by a sonic localization digitizer device that is interfaced with the computer workstation. This permits the surgeon to place a pointing device (sonic wand) on any exposed spinal bone landmark in the operative field and obtain multiplanar reconstructed CT images projected in near-real time on the workstation screen. The images can be manipulated to assist the surgeon in determining the proper entry point for a pedicle screw as well as defining the appropriate trajectory in the axial and sagittal planes. It can also define the correct screw length and diameter for each pedicle to be instrumented. The authors applied this device to the insertion of 150 screws into the lumbosacral spines of 30 patients. One hundred forty-nine screws were assessed to be satisfactorily placed by postoperative CT and plain film radiography. In this report the authors discuss their use of this device in the clinical setting and review their preliminary results of frameless stereotaxy applied to spinal surgery. On the basis of their findings, the authors conclude that frameless stereotactic technology can be successfully applied to spinal surgery.

Outcome analysis for adults with spondylolisthesis treated with posterolateral fusion and transpedicular screw fixation

1997 ◽  
Vol 86 (1) ◽  
pp. 56-63 ◽  
Author(s):  
Charles L. Schnee ◽  
Andrew Freese ◽  
Lee V. Ansell
Keyword(s):  
Pedicle Screw ◽  
Screw Fixation ◽  
Fusion Rate ◽  
Pedicle Screw Fixation ◽  
Outcome Analysis ◽  
Low Grade ◽  
Content Type ◽  
Poor Outcomes ◽  
Transpedicular Screw Fixation ◽  
Fine Print

✓ The outcomes of 52 adult patients with symptomatic low-grade spondylolisthesis treated with autologous posterolateral arthrodesis and pedicle screw fixation were retrospectively reviewed. Although a 90% rate of successful fusion was obtained using this technique, only 60% of patients were considered to have good outcomes. Treatment failures consisted mostly of back pain and were not predicted by preoperative symptoms. Compensation claims and smoking had very significant adverse impacts on both employment and pain results despite high fusion rates, particularly in patients under the age of 55 years. Overall, patients who required more than one operation demonstrated poor outcomes compared to those who only needed one. However, patients with at least two prior operations or preoperative pseudoarthrosis fared particularly poorly, whereas those who had undergone only one prior surgery and had no attendant compensation issue reported good results. A trend toward poor outcome was observed in patients with postlaminectomy spondylolisthesis, versus those with isthmic or degenerative etiologies. Gender did not exert an impact on outcome. The authors conclude that autologous posterolateral arthrodesis combined with pedicle screw fixation resulted in a high fusion rate, and contributed to successful outcomes in the treatment of certain subgroups of adults with spondylolisthesis. In the absence of other risk factors, patients may obtain significant benefit from surgery despite older age and a single failed operation. Careful patient selection appears critical in predicting the maximum benefit from this technique.

Biomechanical evaluation of a bioresorbable odontoid screw

2005 ◽  
Vol 2 (2) ◽  
pp. 182-187 ◽  
Author(s):  
Christopher P. Ames ◽  
Neil R. Crawford ◽  
Robert H. Chamberlain ◽  
Vivek Deshmukh ◽  
Belma Sadikovic ◽  
...  
Keyword(s):  
Ultimate Strength ◽  
Odontoid Process ◽  
Type Ii ◽  
Content Type ◽  
Odontoid Fractures ◽  
Titanium Screws ◽  
Piston Displacement ◽  
Initial Fracture ◽  
Strength And Stiffness ◽  
Fine Print

Object. The authors tested the ability of a resorbable cannulated lag screw composed of a polylactide copolymer to repair Type II odontoid fractures. The resorbable screw was evaluated for its ability to restore strength and stiffness to the fractured odontoid process compared with traditional titanium screws. Methods. Type II odontoid fractures were created in 14 human cadaveric C-2 vertebrae by applying a posterolaterally directed load and piston displacement was measured. Seven of these specimens were repaired using metal screws and seven were repaired using resorbable screws. Specimens were reinjured using the same mechanism as the initial fracture. Values of ultimate strength and stiffness during failure were statistically compared between metal and resorbable screws and between initial fracture and reinjury. Conclusions. The stiffness and ultimate strength during initial fracture were significantly greater than those during reinjury in specimens repaired using resorbable screws or titanium screws (p < 0.001). The resorbable and titanium screws both restored 31% of the initial ultimate strength of the intact specimen (p = 0.95). The stiffness of the fractured odontoid process was restored to 15 and 23% of its initial value by repair with resorbable and metal screws, respectively (p = 0.07). The mode of failure in resorbable screws was usually breakage or bending, whereas that in metal screws was consistently cutout of the proximal shaft of the screw through the anterior C-2 vertebral body.

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