bluuebunny/crossref_metadata_2025_split huggingface dataset:
Syringomyelia associated with foramen magnum arachnoiditis
Authors: Klekamp Jörg , Iaconetta Giorgio , Batzdorf Ulrich , Samii Madjid 
Published: May 2009

Object. Syringomyelia is often linked to pathological lesions of the foramen magnum. The most common cause is hindbrain herniation, usually referred to as Chiari I or II malformation. Foramen magnum arachnoiditis without either Chiari I or II malformation is a rare cause of syringomyelia. The authors undertook a retrospective analysis of 21 patients with foramen magnum arachnoiditis (FMA) and syringomyelia treated between 1978 and 2000 to determine clinical course and optimum management.
Methods. In the review of records, 21 patients with FMA and syringomyelia were documented. A stable clinical course was demonstrated in three patients in whom surgery was not performed, and one patient refused surgical intervention. Seventeen patients underwent 23 operations to treat progressive neurological disease. Of these 23 operations, 18 involved opening of the foramen magnum, arachnoid dissection, and placement of a large dural graft. One patient underwent insertion of a ventriculoperitoneal shunt for treatment of accompanying hydrocephalus, one patient received a cystoperitoneal shunt for an accompanying arachnoid cyst; two syringoperitoneal and one syringosubarachnoid shunts were also inserted. Hospital and outpatient files, neuroimaging studies, and intraoperative photographic and video material were analyzed. Additional follow-up information was obtained by telephone interview and questionnaires.
Standard and cardiac-gated magnetic resonance imaging studies are the diagnostic procedures of choice in these patients. Sensory disturbances, dysesthesias, and pain were the only symptoms likely to improve after foramen magnum surgery. Motor weakness and gait disturbances, which were severe in a considerable number of patients, and swallowing disorders tended to remain unchanged. As a consequence of the rather severe arachnoid lesions in most patients, clinical recurrences were observed in 57% over a 5-year period.
Conclusions. Surgery for FMA and syringomyelia has to provide clear cerebrospinal fluid pathways between the cerebellopontine cisterns, spinal canal, and fourth ventricle. If this can be achieved successfully, the syrinx decreases in size and the clinical course of the patient may even improve. In patients with severe and widespread areas of arachnoiditis, however, multiple operations may be required at least to stabilize the clinical course.
Preliminary experience with the DOC dynamic cervical implant for the treatment of multilevel cervical spondylosis
Authors: Steinmetz Michael P. , Warbel Ann , Whitfield Melvin , Bingaman William 
Published: May 2009

Object. Despite the wide use of anterior cervical instrumentation in the management of multilevel cervical spondylosis, the incidences of pseudarthrosis and instrument-related failure remain high. The use of a dynamic implant may aid in the prevention of these complications. The purpose of this study was to evaluate the DOC dynamic cervical implant in the treatment of multilevel cervical spondylosis.
Methods. The authors evaluated 34 cases in which anterior multilevel cervical decompression and fusion were performed using the DOC Ventral Cervical Stabilization System. Postoperatively, and at each follow-up visit, the sagittal angle and the degree of subsidence that developed were measured. Fusion rates and clinical outcomes were also evaluated.
The mean postoperative sagittal angle was 14° of lordosis. The mean change in the sagittal angle during the follow-up period was 0.4° of lordosis. By 6 months postoperatively some subsidence had occurred in most patients, with no subsidence occurring in only 15%. By 3 months greater than or equal to 2 mm of subsidence was demonstrated in 61% of cases. The overall fusion rate was 91%. In the majority of patients (79%) symptoms were judged to be improved or resolved.
Conclusions. The DOC dynamic cervical implant permitted controlled subsidence and prevented progression of kyphotic deformity. There was one construct failure (related to a motor vehicle accident) and an overall fusion rate of 91%. The DOC implant is a safe and effective cervical construct for multilevel spondylotic disease.
Surgical approach to anterior compression in the upper thoracic spine
Authors: Seol Ho Jun , Chung Chun Kee , Kim Hyun Jib 
Published: May 2009

Object. The anterior upper thoracic spine (T1–3) is difficult to access because most neurosurgeons are unfamiliar with the anatomy. This study was performed to evaluate the different surgical options by retrospectively analyzing data on operations performed for anterior upper thoracic compression at the authors' institution.
Methods. Eighteen patients underwent surgery between November 1993 and May 2001. There were eight men and 10 women; their mean age was 55 years (range 28–80 years). All patients presented with pain and/or neurological deficits. The causes of anterior compression were diverse, although metastatic spinal tumor was most common. The approach chosen was primarily dictated by the axial involvement of the lesion. Anterior approaches, mainly the transmanubrium approach, were performed in six and posterior approaches in 12. In all cases except one, in which only an iliac bone graft was placed, instrumentation was used. The mean follow-up period was 11.4 months (range 1–57 months). One postoperative death occurred. Postoperative follow-up imaging studies, especially plain radiography, demonstrated no instrumentation failure. Improvement was shown in eight patients, an aggravation of symptoms in one, and stable clinical status in eight.
Conclusions. Decompression may be achieved on the anterior side of the upper thoracic spine if the operative approach is scrupulously chosen; this choice involves consideration of the locations of the lesion, the nature of the primary disease, and the surgery-related risk.
Quantitative anatomy of the transverse ligament tubercles
Authors: Tubbs R. Shane , Wellons John C. , Banks Jason , Blount Jeffrey P. , Oakes W. Jerry 
Published: May 2009

Object. The medial tubercles of the atlas serve as the attachments of the transverse ligament and provide an important anchoring site for which no discussion of their fine anatomy is published in the literature. In this study the authors examine this anatomy along with its osseous relationships.
Methods. One hundred dry cadaveric atlantal tubercles were assessed for size and relationship to nearby anatomical osseous structures. In addition, eight cadaveric specimens were evaluated for their anatomy in this area.
All specimens exhibited atlantal tubercles for the attachment of the transverse portion of the cruciate ligament of the atlas. Right-sided tubercles tended to be of a larger caliber. Overall, right-sided vertical distances between these tubercles and the superior articular facets and inferior articular facets were greater, although distances from each tubercle to the lateral margin of the dental facets anteriorly were found to be constant, as were intertubercular distances. The mean angle formed between both tubercles and the dental facet was 75°.
Conclusions. The data derived in this study should be useful to the clinician for whom the craniocervical junction is a vital anatomical area.
Beta—tricalcium phosphate as a substitute for autograft in interbody fusion cages in the canine lumbar spine
Authors: Ohyama Takashiro , Kubo Yoshichika , Iwata Hiroo , Taki Waro 
Published: May 2009

Object. An interbody fusion cage has been introduced for cervical anterior interbody fusion. Autogenetic bone is packed into the cage to increase the rate of union between adjacent vertebral bodies. Thus, donor site—related complications can still occur. In this study a synthetic ceramic, β—tricalcium phosphate (TCP), was examined as a substitute for autograft bone in a canine lumbar spine model.
Methods. In 12 dogs L-1 to L-4 vertebrae were exposed via a posterolateral approach, and discectomy and placement of interbody fusion cages were performed at two intervertebral disc spaces. One cage was filled with autograft (Group A) and the other with TCP (Group B). The lumbar spine was excised at 16 weeks postsurgery, and biomechanical, microradiographic, and histological examinations were performed.
Both the microradiographic and histological examinations revealed that fusion occurred in five (41.7%) of 12 operations performed in Group A and in six (50%) of 12 operations performed in Group B. The mean percentage of trabecular bone area in the cages was 54.6% in Group A and 53.8% in Group B. There were no significant intergroup differences in functional unit stiffness.
Conclusions. Good histological and biomechanical results were obtained for TCP-filled interbody fusion cages. The results were comparable with those obtained using autograft-filled cages, suggesting that there is no need to harvest iliac bone or to use allo- or xenografts to increase the interlocking strength between the cage and vertebral bone to achieve anterior cervical interbody fusion.
Spinal cord compression by multistrand cables after solid posterior atlantoaxial fusion
Authors: Sudo Hideki , Abumi Kuniyoshi , Ito Manabu , Kotani Yoshihisa , Minami Akio 
Published: May 2009

✓ The sublaminar wiring procedure has been commonly used for stabilizing the atlantoaxial complex. Multistrand braided cables were introduced in the early 1990s. In previous biomechanical studies these cables were demonstrated to be superior to monofilament wires in terms of their flexibility, mechanical strength, and fatigue-related characteristics. To the authors' knowledge, they are the first to describe clinically the occurrence of delayed spinal cord compression resulting from multistrand cables after the completion of rigid spinal arthrodesis in the upper cervical spine.
Three patients underwent posterior atlantoaxial fusion in which two sublaminar multistrand cables were placed. Between 15 and 48 months postoperatively, they suffered from upper- and lower-extremity numbness as well as gait disturbance. Plain radiography and computerized tomography myelography revealed spinal cord compression caused by the sublaminar cables, although fusion was complete and physiological alignment was maintained at the fused segment. The radiographs obtained immediately after surgery demonstrated that the initial cable placement had been properly performed. The shape of the cable at the initial surgery was oval and then gradually became circular. The anterior arc of the circular shape of the cable in fact led to the spinal cord compression.
Considering the mechanism of this late complication, a cable tends to spring open because of its high flexibility and becomes circular shaped even after the complete arthrodesis. When applying multistrand cables for intersegmental fixation at the atlantoaxial complex, delayed complications related to bowing of the cables is possible.
Spontaneous osteoporotic fractures of the sacrum causing neurological damage
Authors: Finiels Pierre-Jacques , Finiels Hélène , Strubel Denise , Jacquot Jean-Marc 
Published: May 2009

✓ Although osteoporotic fractures of the sacrum seem to be a well-known entity, their associated rate of neurological complications has not been assessed in the literature. The authors report three such cases of nerve root compromise in elderly women and conduct a literature review. Based on their review, they estimate the incidence to be approximately 2%.
The true incidence is probably higher because many case reports provide only scant information on symptoms; furthermore, sphincter dysfunction and lower-limb paresthesias are the most common symptoms and can readily be overlooked or misinterpreted in elderly patients with multiple health problems. The neurological manifestations were delayed in some cases. A full recovery is the rule. The characteristics of the sacral fracture are not consistently related with the risk of neurological compromise. In most reviewed cases the authors found no displacement and in many the foramina were not involved.
The pathophysiology of the neurological manifestations remains unclear. The authors suggest that patients with sacral osteoporotic fractures should be carefully monitored for neurological manifestations.
Traumatic neuroma of the anterior cervical nerve root with no subjective episode of trauma
Authors: Nomura Hiroshi , Harimaya Katsumi , Orii Hisaya , Shiba Keiichiro , Ueta Takayoshi , Iwaki Toru 
Published: May 2009

✓ The authors report four cases of traumatic neuroma in the cervical nerve root in patients with no history of trauma. In one case the patient presented with intractable pain in the left upper extremity and motor paresis of the left shoulder, and in another case the patient suffered neuropathic pain in the left forearm. In both cases, magnetic resonance (MR) imaging revealed an intradural extramedullary mass lesion in the ipsilateral cervical nerve root; these MR imaging signals were similar to the intensity of the spinal cord. Intraoperatively, fusiform enlargement of the anterior cervical nerve root was detected in the subarachnoid space. Histological examination showed a meandering change of axons accompanied by mild axonal swelling and a thin myelin sheath, which are consistent with the typical pathological features of traumatic neuroma. Postoperatively, pain resolved in both cases. The authors also investigated two traumatic neuromas of the anterior cervical nerve root in autopsy cases in which there was no history of trauma and no significant neurological signs suggestive of traumatic neuroma.
The authors conclude that traumatic neuroma of the anterior cervical nerve root may develop following an unnoticed minor brachial plexus injury at birth or a forgotten traction injury of the upper extremity in childhood, and the lesion may be accompanied by various case-specific clinical features.
Resorbable cages for spinal fusion: an experimental goat model
Authors: Wuisman P. I. J. M. , van Dijk M. , Smit T. H. 
Published: May 2009

Object: A biomechanical cadaveric study and an in vivo monosegmental spinal fusion study were performed to evaluate a novel bioresorbable poly(l-lactic acid) (PLLA) cage.
Methods: The yield strength of a spinal segment was chosen as the main design parameter for the resorbable cages to be used in a goat model. In a 3-year in vivo study the authors found fusion to be significantly faster and more complete when using PLLA cages compared to titanium cages with the same dimensions. In the PLLA group, the inter-vertebral grafting height did not change and bone remodeling within the cage was completed 2 years after implantation. In terms of degradation of the PLLA, similar features were observed in vivo and in vitro.
Conclusions. Degradation was almost completed 3 years after implantation. Tissue reaction was mild during the 3-year period.
Bioabsorbable anterior lumbar plate fixation in conjunction with cage-assisted anterior interbody fusion
Authors: DiAngelo Denis J. , Scifert Jeffrey L. , Kitchel Scott , Cornwall G. Bryan , McVay Bobby J. 
Published: May 2009

Object. An in vitro biomechanical study was conducted to determine the effects of anterior stabilization on cage-assisted lumbar interbody fusion biomechanics in a multilevel human cadaveric lumbar spine model.
Methods. Three spine conditions were compared: harvested, bilateral multilevel cages (CAGES), and CAGES with bioabsorbable anterior plates (CBAP), tested under flexion—extension, lateral bending, and axial rotation. Measurements included vertebral motion, applied load, and bending/rotational moments. Application of anterior fixation decreased local motion and increased stiffness of the instrumented levels. Clinically, this spinal stability may serve to promote fusion.
Conclusions. Coupled with the bioabsorbability of the plating material, the bioabsorbable anterior lumbar plating system is considered biomechanically advantageous.
Use of a resorbable sheet in iliac crest reconstruction in a sheep model
Authors: Cornwall G. Bryan , Wheeler Donna L. , Thomas Kevin A. , Taylor William R. , Turner A. Simon 
Published: May 2009

Object. Iliac crest bone graft harvesting can result in major complications, the rates of which range from approximately 6 to 8%. The objective of this study was to evaluate the postoperative regeneration of iliac crest donor defects in an animal model after harvesting a full-thickness tricortical graft.
Methods. In skeletally mature sheep, a tricortical iliac crest graft was harvested. The graft sites were allowed to heal unprotected or protected with the resorbable polylactic acid sheet material, MacroPore OS Protective Sheeting. After 6 months of healing, the sites were assessed by examination of undecalcified histological sections. Histomorphometric measurements of the original defect area, the area of new bone within the defect site, and the percentage of defect filled with new bone were quantified for both control and protected groups. In all histological sections, new bone growth within the defect sites appeared normal, with no observed excessive inflammatory cells. The developing bone tissue appeared to be remodeling normally. For the unprotected sites, the area of new bone averaged 16.3 mm2 (± 7.2 mm2), and the percentage of the defect area filled with bone averaged 10.7% (± 6.5%). In the protected sites, the area of new bone averaged 64.8 mm2 (± 11.6 mm2) and the percentage of the defect area filled with bone averaged 25.9% (± 1.6%). Both differences in area of new bone growth and percentage of defect area filled were statistically significant. Literature review has indicated that regeneration of donor site defects is desirable.
Conclusions. Based on the results of the present study, MacroPore resorbable Protective Sheeting can improve bone regeneration significantly within the donor site following tricortical iliac crest graft harvesting.
Resorbable polymer implants in unilateral transforaminal lumbar interbody fusion
Authors: Lowe Thomas G. , Coe Jeffrey D. 
Published: May 2009

Object. Sixty patients underwent instrumentation-assisted posterior transforaminal lumbar interbody fusion (TLIF) with resorbable polymer cages and autograft bone for degenerative disease. This article discusses the technique of TLIF and its early outcomes.
Methods. Although the follow-up period is short and results are preliminary, no adverse events or complications were attributed to the resorbable polymer.
Conclusions. Further multicenter clinical studies are underway with a minimum 2-year follow-up period chosen as an endpoint to provide insight as to the future of biodegradable polymers as spinal interbody devices.
Anterior cervical arthrodesis using DOC dynamic stabilization implant for improvement in sagittal angulation and controlled settling
Authors: Bose Bikash 
Published: May 2009

Object. Placing instrumentation in the anterior cervical spine is a common procedure. The bi- and unicortical systems currently available, however, have distinct advantages and disadvantages. The author reports a prospective series in which a new dynamized anterior cervical fixation system was evaluated.
Methods. Thirty-seven patients underwent anterior cervical discectomy and fusion in which the DOC ventral cervical stabilization system was used for indications including cervical spondylotic radiculopathy, disc herniation, trauma, and myelopathy. Patients underwent anterior cervical discectomy and interbody fusion and/or corpectomy. Preoperative and postoperative clinical data included assessment of spinal cord and nerve root deficit, function, neck pain, and arm pain. Preoperative and postoperative radiographic data included sagittal angle, translation, and settling of the graft. Fusion status was determined by the presence of trabecular bridging bone on plain anteroposterior and lateral cervical radiographs.
At a mean follow-up time of 1.3 years, postoperative neck or arm pain was resolved in 52% of the patients, restriction on function was mild or absent in 88%, and fusion was successful in 80% of patients and 88% of the treated levels. There was one implant-related complication, one significant dysphagia complication, and a 10.8% donor graft site complication rate.
Conclusions. The use of this system led to a high percentage of pain relief and radiographic fusion. The sagittal angle was controlled while allowing for graft settling. There were no implant failures.
Kryorhizotomy: an alternative technique for lumbar medial branch rhizotomy in lumbar facet syndrome
Authors: Bärlocher Christian B. , Krauss Joachim K. , Seiler Rolf W. 
Published: May 2009

Object. The authors conducted a prospective study to investigate the efficacy of kryorhizotomy, an alternative procedure for lumbar medial branch neurotomy, in the treatment of lumbar facet syndrome (LFS).
Methods. Fifty patients with chronic low-back pain, in whom pain was relieved by controlled diagnostic medial branch blocks of the lumbar zygapophyseal (facet) joints, underwent lumbar medial branch kryorhizotomy. Outcome was evaluated using the Visual Analog Pain Scales and assessment of work capacity. All outcome measures were repeated at 6 weeks, 6 months, and 1 year after surgery. At 1-year follow-up examination, 31 (62%) of 50 patients experienced a good response to lumbar facet kryorhizotomy. Good results with pain relief of 50% or more were obtained in 85% of patients without previous spinal surgery but only in 46% who had undergone previous spinal surgery. This difference was statistically significant. In five patients (16%) in whom a good initial benefit was observed but who experienced increased pain within 6 weeks after kryorhizotomy, the beneficial result was regained after an early repeated procedure. There were no side effects. Overall, 19 (38%) of 50 procedures were not considered successful. In six of these 19 cases a rigid stabilization of the involved segment provided permanent pain relief.
Conclusions. Based on this study, patients with LFS who have not undergone previous spinal surgery benefit significantly from percutaneous lumbar kryorhizotomy. Kryorhizotomy, which has virtually no risk, seems to be a valuable alternative technique to lumbar medial branch neurotomy.
Inclination of the odontoid process in the pediatric Chiari I malformation
Authors: Tubbs R. Shane , Wellons John C. , Blount Jeffrey P. , Grabb Paul A. , Oakes W. Jerry 
Published: May 2009

Object. The quantitative analysis of odontoid process angulation has had scant attention in the Chiari I malformation population. In this study the authors sought to elucidate the correlation between posterior angulation of the odontoid process and patients with Chiari I malformation.
Methods. Magnetic resonance images of the craniocervical junction obtained in 100 children with Chiari I malformation and in 50 children with normal intracranial anatomy (controls) were analyzed. Specific attention was focused on measuring the degree of angulation of the odontoid process and assigning a score to the various degrees. Postoperative outcome following posterior cranial fossa decompression was then correlated to grades of angulation. Other measurements included midsagittal lengths of the foramen magnum and basiocciput, the authors' institutions' previously documented pB—C2 line (a line drawn perpendicular to one drawn between the basion and the posterior aspect of the C-2 body), level of the obex from a midpoint of the McRae line, and the extent of tonsillar herniation.
Higher grades of odontoid angulation (retroflexion) were found to be more frequently associated with syringomyelia and particularly holocord syringes. Higher grades of angulation were more common in female patients and were often found to have obices that were caudally displaced greater than three standard deviations below normal.
Conclusions. These results not only confirm prior reports of an increased incidence of a retroflexed odontoid process in Chiari I malformation but quantitatively define grades of inclination. Grades of angulation were not found to correlate with postoperative outcome. It is the authors' hopes that these data add to our current limited understanding of the mechanisms involved in hindbrain herniation.