bluuebunny/crossref_metadata_2025 huggingface dataset:
A randomized prospective study of an anterior cervical interbody fusion device with a minimum of 2 years of follow-up results
Authors: Hacker Robert J.
Published: May 2009

Object. Despite variations in technique, inherent problems persist with current approaches to anterior cervical fusion. This study was performed to determine whether anterior cervical fusion performed using an investigational device was safe and effective in the treatment of degenerative cervical disc disorders and whether this device offered advantages over current techniques.

Methods. Fifty-four patients with radiculopathy with or without mild myelopathy due to one- or two-level cervical degenerative disc disease were randomized as part of a Food and Drug Administration device study. Following microsurgical discectomy, the control group was treated with iliac crest graft fusion; the experimental study group underwent insertion of an interspace cage and placement of a local autograft. All patients received postoperative follow-up care for at least 2 years.

Good or excellent results were found in approximately 97% of the experimental group and 88% of the control group. A solid fusion was achieved in all patients who underwent one-level cage placement, and a solid fusion at one or both levels was achieved in over 90% of both groups. Chronic donor site pain was reported by 31% of the control group.

Conclusions. In this study, the use of an interbody fusion cage avoided donor site morbidity and placement of autograft achieved a high rate of good or excellent results. Interbody fusion cages appear safe and effective, and their use helps to avoid some of the inherent problems in performing current anterior cervical fusion techniques.
Direct anterior screw fixation for recent and remote odontoid fractures
Authors: Apfelbaum Ronald I. , Lonser Russell R. , Veres Robert , Casey Adrian
Published: May 2009

Object. The management of odontoid fractures remains controversial. Only direct anterior screw fixation provides immediate stabilization of the spine and may preserve normal C1–2 motion. To determine the indications, optimum timing, and results for direct anterior screw fixation of odontoid fractures, the authors reviewed the surgery-related outcome of patients who underwent this procedure at two institutions.

Methods. One hundred forty-seven consecutive patients (98 males and 49 females) who underwent direct anterior screw fixation for recent (≤ 6 months postinjury [129 patients]) or remote (≥ 18 months postinjury [18 patients]) Type II (138 cases) or III (nine cases) odontoid fractures at the University of Utah (94 patients) and National Institute of Traumatology in Budapest, Hungary (53 patients) between 1986 and 1998 are included in this study (mean follow up 18.2 months). Data obtained from clinical examination, review of hospital charts, operative findings, and imaging studies were used to analyze the surgery-related results in these patients.

In patients with recent fractures there was an overall bone fusion rate of 88%. The rate of anatomical bone fusion of recent fractures was significantly (p ≤ 0.05) higher in fractures oriented in the horizontal and posterior oblique direction (compared with anterior oblique), but this finding was independent (p ≥ 0.05) of age, sex, number of screws placed (one or two), and the degree or the direction of odontoid displacement. In patients with remote fractures there was a significantly lower rate of bone fusion (25%). Overall, complications related to hardware failure occurred in 14 patients (10%) and those unrelated to hardware in three patients (2%). There was one death (1%) related to surgery.

Conclusions. Direct anterior screw fixation is an effective and safe method for treating recent odontoid fractures (< 6 months postinjury). It confers immediate stability, preserves C1–2 rotatory motion, and achieves a fusion rate that compares favorably with alternative treatment methods. In contradistinction, in patients with remote fractures (≥ 18 months postinjury) a significantly lower rate of fusion is found when using this technique, and these patients are believed to be poor candidates for this procedure.
Spinal nerve root repair and reimplantation of avulsed ventral roots into the spinal cord after brachial plexus injury
Authors: Carlstedt Thomas , Anand Praveen , Hallin Rolf , Vigay Misra Peter , Norén Georg , Seferlis Thanos
Published: May 2009

Object. The authors review the first series of 10 cases in which injured intraspinal brachial plexus were surgically repaired. They describe the technique of spinal cord implantation or repair of ruptured nerve roots, as well as patient outcome.

Methods. Spinal root repair/implantation was performed from 10 days to 9 months postinjury. There were nine male patients and one female patient. Postoperatively in most cases, regeneration of motor neurons from the spinal cord to denervated muscles could be demonstrated. The first signs of regeneration were noted approximately 9 to 12 months postoperatively. Useful function with muscle power of at least Medical Research Council Grade 3 occurred in three of 10 cases. Magnetic brain stimulation studies revealed a normal amplitude and latency from the cortex to reinnervated muscles on surgically treated and control sides. A certain degree of cocontraction between antagonistic muscles (for example, biceps—triceps) compromised function. With time there was a reduction of cocontractions, probably due to spinal cord plasticity. In these cases there was also, surprisingly, a return of sensory function, although the mechanism by which this occurred is uncertain. Sensory stimulation (thermal and mechanical) within the avulsed dermatomes was perceived abnormally and/or experienced at remote sites. There was some return of patients' sense of joint position.

Conclusions. A short time lag between the accident and the surgery was recognized as a significant factor for a successful outcome. Reimplantation of avulsed nerve roots may be combined with other procedures such as nerve transfers in severe cases of brachial plexus injury.
In vitro biomechanical investigation of the stability and stress-shielding effect of lumbar interbody fusion devices
Authors: Kanayama Masahiro , Cunningham Bryan W. , Haggerty Charles J. , Abumi Kuniyoshi , Kaneda Kiyoshi , McAfee Paul C.
Published: May 2009

Object. Interbody fusion devices are rapidly gaining acceptance as a method of ensuring lumbar interbody arthrodesis. Although different types of devices have been developed, the comparative reconstruction stability remains controversial. It also remains unclear how different stress-shielded environments are created within the devices. Using a calf spine model, this study was designed to compare the construct stiffness afforded by 11 differently designed lumbar interbody fusion devices and to quantify their stress-shielding effects by measuring pressure within the devices.

Methods. Sixty-six lumbar specimens obtained from calves were subjected to anterior interbody reconstruction at L4–5 by using one of the following interbody fusion devices: four different threaded fusion cages (BAK device, BAK Proximity, Ray TFC, and Danek TIBFD), five different nonthreaded fusion devices (oval and circular Harms cages, Brantigan PLIF and ALIF cages, and InFix device); two different types of allograft (femoral ring and bone dowel) were used. Construct stiffness was evaluated in axial compression, torsion, flexion, and lateral bending. Prior to testing, a silicon elastomer was injected into the cages and intracage pressures were measured using pressure needle transducers.

Conclusions. No statistical differences were observed in construct stiffness among the threaded cages and nonthreaded devices in most of the testing modalities. Threaded fusion cages demonstrated significantly lower intracage pressures compared with nonthreaded cages and structural allografts. Compared with nonthreaded cages and structural allografts, threaded fusion cages afforded equivalent reconstruction stiffness but provided more stress-shielded environment within the devices.
Effect of aluminum on neurological recovery in rats following spinal cord injury
Authors: Moutaery Khalaf Al , Deeb Saleh Al , Biary Nabil , Morais Christudas , Khan Haseeb Ahmad , Tariq Mohammad
Published: May 2009

Object. This investigation was undertaken to study the effect of aluminum on neurobehavioral, electrophysiological, structural, and biochemical changes in rats following spinal cord injury (SCI).

Methods. Adult male Sprague—Dawley rats classified into different groups were given aluminum sulfate—dosed drinking water in the concentrations of 0%, 0.25%, 0.5% and 1%, respectively. After 30 days of aluminum treatment, the animals were subjected to spinal cord trauma. Laminectomy was performed at T7–8 in anesthetized rats, followed by placement of a compression plate (2.2 × 5 mm) loaded with a 35-g weight over the exposed spinal cord for 5 minutes. Control animals underwent the same surgical procedure, but the compression injury was not induced (sham). Postoperative neurological function was assessed using the inclined-plane test and by obtaining a modified Tarlov score and vocal/sensory score daily for 10 days. Electrophysiological changes were assessed using corticomotor evoked potentials, whereas pathological changes were assessed by light microscopy. The level of vitamin E in the spinal cord was measured as an index of antioxidant defense. The behavioral, biochemical, and histological analyses were performed in a blinded fashion.

Conclusions. Analysis of results obtained in the behavioral studies revealed that the compression of spinal cord produced transient paraparesis in which a maximum motor deficit occurred at Day 1 following SCI and resolved over a period of 10 days. Administration of aluminum significantly impaired the recovery following SCI. Analysis of the results of the biochemical, electrophysiological, and histopathological studies also confirmed the deleterious effects of aluminum on recovery from SCI in rats.
Dorsal arachnoid web with spinal cord compression: variant of an arachnoid cyst?
Authors: Paramore Christopher G.
Published: May 2009

✓ Spinal arachnoid cysts are diverticula of the subarachnoid space that may compress the spinal cord; these lesions are most commonly found in the thoracic spine. Two patients who presented with thoracic myelopathy were noted on magnetic resonance imaging to have focal indentation of the dorsal thoracic cord, with syringomyelia inferior to the site of compression. Both patients were found at operation to have discrete arachnoid “webs” tenaciously attached to the dura mater and pia mater. These webs were not true arachnoid cysts, yet they blocked the flow of cerebrospinal fluid (CSF) and caused focal compression of the spinal cord. The mass effect appeared to be the result of a pressure gradient created by the obstruction of CSF flow in the dorsal aspect of the subarachnoid space. Both patients responded well to resection of the arachnoid web. Arachnoid webs appear to be rare variants of arachnoid cysts and should be suspected in patients with focal compression of the thoracic spinal cord.
Rotational compression of the vertebral artery at the point of dural penetration
Authors: Akar Ziya , Kafadar Ali M. , Tanriover Necmettin , Dashti Reza S. , Islak Civan , Kocer Naci , Kuday Cengiz
Published: May 2009

✓ Vertebrobasilar insufficiency (VBI) due to vertebral artery (VA) compression occurs in a significant number of patients. Rotational compression of the VA usually occurs below C-2, where the artery is pinched during head rotation, leading to thrombus formation and subsequent cerebellar infarction. Although this problem has been reported to occur at the atlantooccipital levels, a review of the literature revealed no published cases of VA compression at the point of dural penetration, which is located above the atlantooccipital membrane.

The authors report the case of a 30-year-old woman who presented with signs and symptoms of VBI. Dynamic angiography demonstrated left-sided VA compression at the site at which dural penetration had occurred, proximal to the posterior inferior cerebellar artery. Surgical decompression of the left VA at the point of dural penetration relieved the symptoms, and postoperative dynamic angiography demonstrated complete resolution of the positional compression of the left VA. Because of these findings, an additional possible location for rotational compression of the VA is described, namely, the point of dural penetration. The authors suggest a method of surgically treating rotational VA compression at this site.
Intraspinal extradural myxopapillary ependymoma of the sacrum arising from the filum terminale externa
Authors: Fourney Daryl R. , Fuller Gregory N. , Gokaslan Ziya L.
Published: May 2009

✓ Extradural ependymomas of the sacrococcygeal region are very rare, with most arising from the soft tissues of the presacral area or from the regions dorsal to the sacrum. In even rarer circumstances, the tumor may arise within the sacral canal, likely as a result of ependymal cells of the extradural filum terminale. Because of bone erosion caused by extension of the tumor into the pelvis or dorsal to the sacrum, a truly intraspinal extradural ependymoma in this region has until now never been clearly demonstrated. The authors present a patient with a myxopapillary ependymoma arising from the filum terminale externa in which there was no involvement of the intradural filum or extension outside the sacral canal. A review of the literature is presented, with emphasis on the pathogenesis and clinical management of these rare tumors.
Single-stage autogenous bone grafting and internal fixation in the surgical management of pyogenic discitis and vertebral osteomyelitis
Authors: Przybylski Gregory J. , Sharan Ashwini D.
Published: May 2009

Object. Patients with deep wound infections complicating previously placed internal instrumentation have been successfully treated by debridement and prolonged postoperative antibiotic therapy, which avoided removal of the hardware. Comparatively fewer patients with pyogenic discitis and vertebral osteomyelitis (PDVO) have undergone single-stage debridement, arthrodesis, and internal fixation. The purpose of this study was to determine the efficacy of combining debridement, arthrodesis in which iliac autograft is used, and segmental internal fixation in a single-stage procedure for patients in whom nonoperative management of PDVO has failed.

Methods. A retrospective analysis of 17 consecutive patients with PDVO treated between July 1996 and September 1999 was performed. Follow-up data (mean 30 months) included office examinations and telephone interviews, and patients were grouped according to the duration of preoperative antibiotic therapy. All patients experienced significant postoperative reduction in pain, and those with neurological deficits improved. Eleven patients were independently ambulatory, and three required a walker; only five had been ambulating independently preoperatively. Two patients died during the 1st postoperative week of medical complications; another developed a wound dehiscence that was managed with debridement, prolonged antibiotic administration, and removal of the hardware 1 year later. In no case was pseudarthrosis demonstrated on dynamic radiography. Most patients received only a 6-week course of intravenous antibiotics postoperatively.

Conclusions. The authors conclude that single-stage debridement, arthrodesis, and internal fixation can be effective in the treatment of PDVO. A 6-week course of postoperative intravenous antibiotics may be sufficient in patients with few risk factors. The harvesting of iliac autograft through the same operative exposure may not increase the risk of secondary infection.
Transcostovertebral approach for thoracic disc herniations
Authors: Dinh Dzung H. , Tompkins John , Clark Shawn B.
Published: May 2009

Object. The authors describe a new posterolateral transcostovertebral approach for the removal of herniated thoracic discs.

Methods. From January 1994 to January 2000, 28 thoracic discs in 22 patients were excised via a new transcostovertebral surgical approach. Seventeen patients (77%) presented with axial pain, 14 (64%) with radicular pain, 13 (59%) with myelopathy, eight (36%) with sensory loss, and 10 (45%) with genitourinary (GU) symptoms such as urinary hesitancy or incontinence. The affected discs were approached using a midline incision to gain access of the costovertebral junction. The surgical corridor was posterolateral; the costovertebral joint and lateral edge of the vertebral endplates were drilled to expose the lateral annulus. The ribs were preserved, obviating the need for insertion of a chest tube postoperatively.

The average operating time per level was 200.5 minutes (range 90–360 minutes). The average blood loss was 231 ml (50–750 ml). The average length of stay was 3.8 days. Most patients were discharged home on postoperative Day 2 or 3. No patients were worse postoperatively. Improvement was demonstrated in 13 (76%) of 17 patients with axial pain, 11 (79%) of 14 patients with radicular pain, 11 (85%) of 13 patients with myelopathy, seven (88%) of eight patients with sensory loss, and six (60%) of 10 patients with GU symptoms.

Conclusions. This procedure is well suited for any thoracic disc level and offers several advantages over the traditional costotransversectomy or transthoracic approaches: shorter operating time, less blood loss, less extensive soft-tissue and bone dissection, reduced postoperative pain, and shorter hospital stays.
Use of a collagen-based sealant to prevent in vivo epidural adhesions in an adult rat laminectomy model
Authors: Liu Song , Boutrand Jean Pierre , Tadie Marc
Published: May 2009

Object. The authors investigated the effect of a collagen-based sealant, Gel Amidon Oxydé (GAO), in the prevention of epidural scar adhesions in an adult rat model of laminectomy.

Methods. Seventy-two adult Sprague—Dawley rats underwent an L5–6 laminectomy, after which the dura mater and the left L-4 and L-5 nerve roots were exposed. In the 36 animals that received GAO, the sealant was applied over the dura and around the nerve roots, and it was used to fill the laminectomy cavity before it polymerized. In 36 control animals, the same surgical treatment was performed, but the rats did not receive GAO. During the early postoperative period, a significant decrease in the occurrence of epidural hematoma was found in the GAO-treated rats. In contrast to findings in control rats, a thin white connective tissue layer was found between the dura and surrounding muscles after GAO had degraded and been absorbed. One month posttreatment, no epidural scar adhesion was found between the tissue layer and the dura in the GAO-treated animals. Three months postoperatively, both gross inspection and histological examination further confirmed that formation of epidural adhesions was significantly inhibited in the rats treated with GAO. No special inflammatory reaction was observed, and the healing of skin and muscle lesions was not affected by either treatment.

Conclusions. The data obtained in this study suggest that the GAO collagen—based sealant may be an effective biomaterial to prevent epidural adhesions in vivo after laminectomy.
Effects of neck movements on stability and subsidence in cervical interbody fusion: an in vitro study
Authors: Kettler Annette , Wilke Hans-Joachim , Claes Lutz
Published: May 2009

Object. The aim of this in vitro study was to determine the influence of simulated postoperative neck movements on the stabilizing effect and subsidence of four different anterior cervical interbody fusion devices. Emphasis was placed on the relation between subsidence and spinal stability.

Methods. The flexibility of 24 human cervical spine specimens was tested before and directly after being stabilized with a WING, BAK/C, AcroMed I/F cage, or with bone cement in standard flexibility tests under 50 N axial preload. Thereafter, 700 pure moment loading cycles (± 2 Nm) were applied in randomized directions to simulate physiological neck movements. Additional flexibility tests in combination with measurements of the subsidence depth were conducted after 50, 100, 200, 300, 500, and 700 loading cycles.

In all four groups, simulated postoperative neck movements caused an increase of the range of motion (ROM) ranging from 0.4 to 3.1° and of the neutral zone from 0.1 to 4.2°. This increase in flexibility was most distinct in extension followed by flexion, lateral bending, and axial rotation. After cyclic loading, ROM tended to be lower in the group fitted with AcroMed cages (3.3° in right lateral bending, 3.5° in left axial rotation, 7.8° in flexion, 8.3° in extension) and in the group in which bone cement was applied (5.4°, 2.5°, 7.4°, and 8.8°, respectively) than in those fixed with the WING (6.3°, 5.4°, 9.7°, and 6.9°, respectively) and BAK cages (6.2°, 4.5°, 10.2°, and 11.6°, respectively).

Conclusions. Simulated repeated neck movements not only caused an increase of the flexibility but also subsidence of the implants into the adjacent vertebrae. The relation between flexibility increase and subsidence seemed to depend on the implant design: subsiding BAK/C cages partially supported stability whereas subsiding WING cages and AcroMed cages did not.
Effects of cervical spine posture on axial load bearing ability: a biomechanical study
Authors: Öktenoǧlu Tunç , Özer A. Fahir , Ferrara Lisa A. , Andalkar Niteen , Sarioǧlu Ali Çetin , Benzel Edward C.
Published: May 2009

Object. The authors conducted a study to assess the effects of cervical posture on the loadbearing ability of the cervical spine.

Methods. Twelve cervical spine specimens obtained in 12 adult sheep were tested. The specimens were randomly separated into two groups. In Group I the specimens were fixed in a lordotic posture, and in Group II they were fixed in a straight posture. Axial compressive loads were applied at a constant rate of 5 cm/minute. Load-to-failure, time-to-failure, piston displacement at failure, and failure modes were recorded. Statistical analyses were performed to detect differences between the groups.

There was no significant difference in load-to-failure values between the two groups. However, the time-to-failure and the piston displacement values for the straight spines were significantly less than those for the lordotic spines. Additionally, the straight spines failed predominantly through ventral elements, whereas the lordotic spines predominantly failed dorsally.

Conclusions. It is concluded that a loss of a lordosis increases the risk of injury to the cervical spine following axial loading.
Neurenteric cyst of the craniocervical junction
Authors: Filho Flavio Leitao , Tatagiba Marcos , Carvalho Gustavo A. , Weichhold Wiebke , Klekamp Jörg , Samii Madjid
Published: May 2009

✓ Neurenteric cysts of the craniocervical junction (CCJ) are very rare lesions. Their origin is the subject of long-standing controversy, but a failure during the embryogenic phase may be responsible for their formation. Accurate histopathological diagnosis may be difficult due to the similarity they share with other cystic lesions such as colloidal cysts, Rathke cysts, and cystic teratomas. Surgical removal is the treatment of choice for intracranial neurenteric cysts, but in some cases, infiltration of the surrounding structures may hinder complete resection. Three cases of neurenteric cysts located at the CCJ are reported.
Symptomatic C1–2 fusion failure due to a fracture of the lateral C-1 posterior arch in a patient with rheumatoid arthritis
Authors: Ecker Robert D. , Dekutoski Mark B. , Ebersold Michael J.
Published: May 2009

✓ The authors report a case in which the lateral C-1 arch fractured in a patient with rheumatoid arthritis and an intact fusion mass; this patient had previously undergone a C1–2 Brooks-type fusion. This unique complication occurred secondary to continued resorption of the C1–2 rheumatoid pannus. Two years after occipitocervical fusion the patient has made a complete neurological recovery.
Vascular reconstruction of a vertebral artery loop causing cervical radiculopathy and vertebrobasilar insufficiency
Authors: Sakaida Hiroshi , Okada Masahiko , Yamamoto Akitaka
Published: May 2009

✓ The authors present the case of a 62-year-old man with a 4-month history of progressive left-sided C-5 radiculopathy and dizziness. Neuroimaging studies revealed a looped vertebral artery (VA) that had migrated into the widened left C4–5 intervertebral foramen. The patient underwent vascular reconstruction of the VA loop, in which there was minimal manipulation of the C-5 nerve root, via a left-sided anterolateral approach after a balloon occlusion test. Postoperatively the patient's symptoms improved immediately, and there were no signs of recurrence within the 2-year follow-up period. This excellent outcome supports the belief that a proper surgical reconstruction of the compressive, tortuous VA should be the therapeutic option of choice, which carries a lower risk of the nerve root injury and improves the hemodynamics in the posterior circulation.
Intracerebral hemorrhage complicating cervical “hourglass” schwannoma removal
Authors: Morandi Xavier , Riffaud Laurent , Carsin-Nicol Beatrice , Guegan Yvon
Published: May 2009

✓ The authors report a case of infra- and supratentorial intracerebral hemorrhage complicating the postoperative course of a patient who had undergone surgical removal of a cervical schwannoma with an hourglass configuration. To their knowledge, this is the first case in which this neurosurgical procedure was followed by such a complication. Possible mechanisms are discussed; however, pathological events leading to this complication are unclear. The development of new neurological deficits not attributable to the surgical procedure should suggest this possibility.
Microdialysis study of amino acid neurotransmitters in the spinal dorsal horn of patients undergoing microsurgical dorsal root entry zone lesioning
Authors: Mertens Patrick , Ghaemmaghami Chantal , Bert Lionel , Perret-Liaudet Armand , Guenot Marc , Naous Hussein , Laganier Laurent , Later Roger , Sindou Marc , Renaud Bernard
Published: May 2009

✓ The aim of this study was to develop, for the first time in the human spinal dorsal horn (DH), an in vivo method for the study of amino acids (AAs).

A microdialysis technique was used to sample AAs in the extracellular fluid of the DH apex in eight patients in whom surgery in the dorsal root entry zone (DREZ) was performed. Before making microsurgical lesions, specific concentric-type microdialysis probes were implanted over a 60-minute period in the DREZ and directed to the DH apex (10 implantations). The AA concentrations in the dialysates were determined using high-performance liquid chromatography with fluorescence detection. The concentrations of excitatory AAs (glutamate and aspartate) and inhibitory AAs (γ-aminobutyric acid and glycine) decreased and were stabilized by 45 minutes after probe implantation, whereas the levels of nonneurotransmitter AAs (alanine and threonine) were not stabilized at 60 minutes. The ability of the probe to track the changes of extracellular AAs was demonstrated. Neither intra- nor postoperative microdialysis-related complications were observed (with a follow up of 18 months).

The present study demonstrates that microdialysis can be performed safely in the human DH during DREZ lesioning. Despite technical and analytical limitations related to the intraoperative conditions, this technique offers new possibilities for clinical research on neurotransmitters involved in some relevant pathological states, especially in chronic pain and spasticity.
Surgical and endovascular treatment of spinal dural arteriovenous fistulas: long-term disability assessment and prognostic factors
Authors: Song Joon K. , Viñuela Fernando , Gobin Y. Pierre , Duckwiler Gary R. , Murayama Yuichi , Kureshi Inam , Frazee John G. , Martin Neil A.
Published: May 2009

Object. The authors assessed clinical outcomes of patients with treated spinal dural arteriovenous fistulas (DAVFs) and investigated prognostic factors.

Methods. Thirty consecutive patients with spinal DAVFs were treated at the authors' institution during the past 15 years: seven underwent surgery; seven underwent surgery after failed embolization; and 16 underwent embolization alone. The outcomes of gait and micturition disability were analyzed. Follow up averaged 3.4 years (range 1 month–11.8 years). Age, duration of symptoms, pre- and postintervention magnetic resonance (MR) imaging findings, and preintervention disability were correlated with outcome.

Seventeen patients (57%) experienced improved gait, 12 (40%) were unchanged, and one (3%) was worse. In 11 patients (37%) micturition function was improved, in 15 (50%) it was unchanged, and in four (13%) it was worse. Gait disability, as measured by the Aminoff—Logue Scale, was significantly improved after treatment, from 3.4 ± 1.4 (average ± standard deviation) to 2.7 ± 1.5 (p = 0.007). Mean micturition disability scores decreased, but not significantly, from 1.9 ± 1 to 1.6 ± 1.1 (p = 0.20). Preintervention gait disability was not associated with improvement except for patients with Aminoff—Logue Scale Grade 4 disability (eight of nine improved; p = 0.024). For patients treated within 13 months of symptom onset, mean micturition disability decreased (p = 0.035). No association was found between clinical improvement and age, a symptom duration less than 30 months, or pre- and postintervention MR imaging—documented spinal cord edema.

Conclusions. Spinal DAVF treatment significantly improved patients' mean gait disability score by almost one grade at last follow up. The mean micturition disability score was not significantly improved, unless treatment was performed within 13 months of symptom onset. Longer and more uniform follow-up study is needed to determine if improved and stabilized clinical outcomes are sustained.
Surgery in adults with tethered cord syndrome: outcome study with independent clinical review
Authors: van Leeuwen Redmer , Notermans Nicolette C. , Vandertop W. Peter
Published: May 2009

Object. The authors conducted a study to evaluate the risks and short-term benefits of surgical treatment for tethered cord syndrome (TCS) in patients older than 18 years of age.

Methods. The authors studied a series of 57 consecutive adult patients with TCS of varying origins. Patients were examined by the same neurologist in a standardized fashion before and after surgery, and most were followed for at least 2 years postoperatively.

Patient age ranged from 19 to 75 years. The mean age at onset of symptoms and diagnosis was 30 years and 37 years, respectively. Muscle strength improved (15 cases) or showed no change postoperatively (38 cases) in a large majority of patients (93%). In four patients a minor decrease in muscle strength was demonstrated, and there was significant deterioration in two (3.5%). In the two latter patients, a rapid decline in motor function was present preoperatively. Subjective assessment of pain, gait, sensory function, and bladder/bowel function at 4 weeks, 6 months, and 2 years postsurgery revealed improvement in a substantial percentage of patients. No major surgery-related complications occurred.

Conclusions. This is the largest series to date in which adult patients with TCS comprise the report. Untethering procedures in these patients were safe and effective, at least in the short term. Patients with rapid loss of motor function, lipomyelomeningocele, or split cord malformation seem to be at a higher risk of postsurgery deterioration. A follow-up period of many more years will be necessary to determine whether aggressive surgery is beneficial in the long term.
Giant invasive spinal schwannomas: definition and surgical management
Authors: Sridhar K. , Ramamurthi Ravi , Vasudevan M.C. , Ramamurthi B.
Published: May 2009

Object. Confusion exists regarding the term giant spinal schwannoma. There are a variety of nerve sheath tumors that, because of their size and extent, justify the label “giant schwannoma.” The authors propose a classification system for spinal schwannomas as a means to define these giant lesions. The classification is confined to tumors that are essentially intraspinal, with or without extraspinal components. Lesions that erode the vertebral bodies (VBs) and extend posteriorly and laterally into the myofascial planes are classified as giant “invasive” spinal schwannomas.

Methods. The records of patients with giant invasive spinal schwannoma were analyzed. The radiological features, operative approaches, and intraoperative findings were noted.

Ten patients with giant invasive tumors were surgically treated over the last 8 years. Six patients were male. Erosion of the posterior surface of the VBs was the diagnostic finding demonstrated on plain x-ray films. Magnetic resonance imaging delineated the extent of the tumors and helped in preoperative planning. Radical excision of the tumors in multiple stages was possible in eight of the 10 patients. Dural reconstruction was required in four patients. All patients required fusion, and an additional stabilization procedure was undertaken in three patients.

Conclusions. The authors conclude that giant invasive schwannomas are uncommon lesions and propose a new classification system. Because of their locally “invasive” nature and extension in all directions, careful preoperative planning of the surgical approach is very important. Although radical excision is possible and promises good results, recurrences may occur and multiple surgical procedures may be required.
Transforaminal percutaneous endoscopic discectomy in the treatment of far-lateral and foraminal lumbar disc herniations
Authors: Lew Sean M. , Mehalic Thomas F. , Fagone Kristin L.
Published: May 2009

Object. Far-lateral (extraforaminal) and foraminal disc herniations comprise up to 11% of all herniated intervertebral discs. Operative management can be technically difficult, and the optimum surgical treatment remains controversial. Accessing these lateral disc herniations endoscopically via a percutaneous transforaminal approach offers several theoretical advantages over the more traditional procedures. The object of this study was to assess the safety and efficacy of treating patients with far-lateral and foraminal disc herniations via a percutaneous transforaminal endoscopic approach.

Methods. A retrospective analysis was performed of 47 consecutive patients who underwent surgery via this approach. All procedures were performed after induction of a local anesthetic on an outpatient basis. Outcome was measured with Macnab criteria and by determining a patient's return-to-work status. The median follow-up period was 18 months (range 4–51 months). Excellent or good outcome was obtained in 40 (85%) of 47 patients. Of the 38 patients working before the onset of symptoms, 34 (90%) returned to work. Five patients (11%) experienced poor outcomes and subsequently underwent open procedures at the same level. Of the 10 recipients of Workers' Compensation, Macnab criteria indicated a significantly worse outcome (70% excellent or good), but an excellent return-to-work status was maintained (90%). There were no complications.

Conclusions. Transforaminal percutaneous endoscopic discectomy is safe and efficacious in the treatment of far-lateral and foraminal disc herniations.
Long-lasting analgesic effect of radiofrequency treatment of the lumbosacral dorsal root ganglion
Authors: van Wijk Roelof M. A. W. , Geurts Jos W. M. , Wynne Herman J.
Published: May 2009

Object. The authors conducted a study to establish the benefit of radiofrequency (RF) treatment of the lumbosacral dorsal root ganglion (DRG) as a therapy to reduce symptomatic pain in patients with chronic spinal pain radiating to the leg.

Methods. Two hundred seventy-nine patients were evaluated after undergoing their first RF treatment of the DRG. A four-point pain perception scale was used. Short-term effect was documented after 2 months. The influence of surgical history on outcome was examined by using chi-square analysis. The mean duration of analgesic effect was calculated by applying a probit survival analysis.

Two months after undergoing RF treatment, 59% of patients reported satisfactory pain reduction. No serious adverse effects were noted. Surgical history was shown to have no significant effect on outcome. The long-term half-life time of pain reduction was 44.5 months.

Conclusions. The use of RF in the treatment of DRG appears to be a useful and safe therapy in patients with chronic spinal pain that radiates to the leg. The initial success rate is approximately 60%. It seems to lead to a time-limited effect on the target structure, and the mean duration of pain reduction is approximately 3.7 years. The mechanism of action remains unclear.
Evaluation of the neuroprotective effects of sodium channel blockers after spinal cord injury: improved behavioral and neuroanatomical recovery with riluzole
Authors: Schwartz Gwen , Fehlings Michael G.
Published: May 2009

Object. Persistent activation of voltage-sensitive Na+ channels is associated with cellular toxicity and may contribute to the degeneration of neural tissue following traumatic brain and spinal cord injury (SCI). Pharmacological blockade of these channels can attenuate secondary pathophysiology and reduce functional deficits acutely.

Methods. To determine the therapeutic effects of Na+ channel blockers on long-term tissue sparing and functional neurological recovery after traumatic SCI, the authors injected Wistar rats intraperitoneally with riluzole (5 mg/kg), phenytoin (30 mg/kg), CNS5546A, a novel Na+ channel blocker (15 mg/kg), or vehicle (2-HPβCD; 5 mg/kg) 15 minutes after induction of compressive SCI at C7—T1.

Functional neurological recovery of coordinated hindlimb function and strength, assessed 1 week postinjury and weekly thereafter for 6 weeks, was significantly enhanced in animals treated with riluzole compared with the other treatment groups. Seven weeks postinjury the preservation of residual tissue and integrity of descending axons were determined with digital morphometrical and fluorescent histochemical analysis. All three Na+ channel blockers significantly enhanced residual tissue area at the injury epicenter compared with control. Riluzole significantly reduced tissue loss in rostrocaudal regions surrounding the epicenter, with overall sparing of gray matter and selective sparing of white matter. Also, counts of red nuclei neurons retrogradely labeled with fluorogold introduced caudal to the injury site were significantly increased in the riluzole group.

Conclusions. Systemic Na+ channel blockers, in particular riluzole, can confer significant neuroprotection after in vivo SCI and result in behavioral recovery and sparing of both gray and white matter.
The denticulate ligament: anatomy and functional significance
Authors: Tubbs R. Shane , Salter George , Grabb Paul A. , Oakes W. Jerry
Published: May 2009

Object. The authors conducted a study to examine the detailed anatomy of the denticulate ligaments and to assess their classic role in spinal cord stability within the spinal canal.

Methods. Detailed observation of the denticulate ligaments in 12 adult cadavers was performed. Stress was applied in all major planes to discern when the ligaments would become taut, and at the same time, gross motion of the cord was observed at sites distal to the stresses applied. Tension necessary for avulsion of the ligaments in various areas of the spinal cord was also measured.

Conclusions. These results show that the denticulate ligaments do not inhibit cord motion to such discrete areas of the cord as was once thought. The authors have determined that the ligaments are stronger in the cervical region and that they decrease in strength as the spinal cord descends. These findings are demonstrative of the denticulate ligaments being more resistant to caudal compared with cephalad stresses in the cord. Anterior and posterior motion is constrained by these ligaments but to a limited degree, especially as one descends inferiorly along the cord. Further embryological and functional studies of these ligaments is needed in non—formalin fixed tissues.
Pathological fracture through a C-6 aneurysmal bone cyst
Authors: Kanamiya Takeshi , Asakawa Yasushi , Naito Masatoshi , Yoshimura Toyonobu , Isayama Teruto
Published: May 2009

✓ The authors describe the case of an 18-year-old man who presented with complaints of weakness and paresis in his arms following an injury. Radiological examination demonstrated an aneurysmal bone cyst of C-6. The patient underwent a two-stage operation. Satisfactory results were obtained after complete resection of the lesion, laminoplasty, and anterior fusion without placement of instrumentation. The authors consider a two-stage operation supplemented by fusion without instrumentation to be the best treatment for young patients with aneurysmal bone cysts occurring at C-6.
Isolated carcinoid tumor of the terminal filum
Authors: Locke Jay , True Lawrence D.
Published: May 2009

✓ The authors describe a patient with neurological symptoms caused by a carcinoid tumor at the terminal filum without carcinoid “flushing” syndrome or endocrinological abnormalities. The patient underwent subtotal resection and adjuvant radiotherapy. Extensive postoperative workup revealed no primary site of disease. To the authors' knowledge, this patient represents the first case of terminal filum carcinoid tumor.
Use of folded vascularized rib graft in anterior fusion after treatment of thoracic and upper lumbar lesions
Authors: Nakamura Hiroaki , Yamano Yoshiki , Seki Masahiko , Konishi Sadahiko
Published: May 2009

✓ For lesions involving the anterior and/or middle column of the spine, an anterior approach is adequate for curetting the lesion and restoring spinal stability. Materials such as autogenous bone grafts, cages with bone chips, some artificial materials, or allografts are used as strut materials. Rib material is usually removed when the anterior approach is conducted for thoracic or thoracolumbar lesions. A rib itself is not rigid enough to support the load, and a bone union is not easily obtained. The purpose of this paper is to describe a method of grafting vascularized rib in folded form to fill the defects left after removal of a spinal lesion.

The rib, with the artery and vein at two levels cranial to the involved vertebral body, was isolated from surrounding tissues such as the intercostal nerve, muscles, and pleura. After curetting the lesion, the rib was folded into three or four pieces to a length adequate to fill the defect and inserted as a pedicled vascularized graft.

A total of 23 cases, including 14 men and nine women, underwent surgery in which this grafting technique was used. The pathological conditions requiring anterior decompression and fusion were spinal trauma in nine cases, spinal infection in six cases, osteoporotic fracture in seven cases, and spinal metastasis in one case. In all cases a solid bone union was obtained and all infections resolved.

With vascularized rib graft folded into three to four pieces, solid bone union can be obtained without use of any other grafted materials even in cases of infection and osteoporosis.
Results of degenerative spondylolisthesis treated with posterior decompression alone via a new surgical approach
Authors: Kinoshita Tomoaki , Ohki Isao , Roth Kenneth R. , Amano Kageharu , Moriya Hideshige
Published: May 2009

Object. The purpose of this study was to assess radiologically demonstrated results and clinical outcomes in patients with degenerative spondylolisthesis who underwent posterior decompressive surgery via a new (unilateral) approach. This approach allows surgeons to perform central and bilateral decompression while only stripping the muscles unilaterally, thus preserving the posterior osteoligamentous complexes.

Methods. The authors evaluated 51 consecutive patients in whom surgery was performed between 1987 and 1996. The mean follow-up period was 4.7 years. There was no statistically significant difference between the pre- and postoperative measurements in percentage of vertebral slippage. Postoperative dynamic angulation statistically decreased compared with its preoperative value (p < 0.05). Improvement of an average of 67% was shown on the Japanese Orthopaedic Association scale, and in 78% of these patients, good to excellent results were demonstrated. Secondary fusion was required in only three patients (5.9%).

Conclusions. This new surgical technique offers a potential alternative for the treatment of degenerative spondylolisthesis in a minimally invasive manner, avoiding the risk of causing or aggravating postoperative spinal instability.
Clinical presentation, radiological findings, and treatment results of coccidioidomycosis involving the spine: report on 23 cases
Authors: Wrobel Charles J. , Chappell E. Thomas , Taylor William
Published: May 2009

Object. This study was conducted to review the presentation and management of patients with coccidioidomycosis involving the spine.

Methods. The authors reviewed 23 cases of spinal coccidioidomycosis treated at their institutions. There were 20 males and three females who ranged in age from 9 to 62 years. Non-Caucasian individuals were disproportionately represented. Spinal disease was the first manifestation of disseminated coccidioidomycosis in 10 cases. Thirteen patients with meningitis, soft-tissue involvement, or pulmonary involvement developed new spinal lesions despite undergoing continued systemic therapy with amphotericin and/or fluconazole. In all patients computerized tomography and magnetic resonance imaging studies demonstrated preferential involvement of the disc spaces, vertebral bodies, and pedicles with extensive paravertebral phlegmons and retropharyngeal, mediastinal, or psoas abscesses. Despite the significant imaging findings, only four patients presented with a significant neurological deficit. Local pain or radiculopathy was the most common complaint.

Twenty patients underwent invasive therapy. In five patients with prominent psoas abscesses and disc space disease, drainage was performed after inserting a percutaneous catheter. Progressive bone destruction necessitated debridement and fusion in one of these patients, and two others had poor outcomes after receiving antifungal therapy alone. Initially 15 patients underwent debridement and fusion in which instrumentation (10 cases) or bone graft alone was used (five cases). One patient worsened neurologically after surgery, and another patient required reoperation for a failed fusion and to correct progressive kyphosis. Four of the 23 patients died of complications related to fungemia. Most of the 15 surviving patients have required long-term antifungal therapy for spinal and extraspinal foci.

Conclusions. Spinal coccidioidomycosis can be an aggressive disease process. Systemic antifungal therapy fails to prevent de novo spinal involvement and is usually insufficient treatment for established spinal disease.