bluuebunny/crossref_metadata_2025 huggingface dataset:
Myoarchitectonic spinolaminoplasty: efficacy in reconstituting the cervical musculature and preserving biomechanical function
Authors: Kim Phyo , Murata Hidetoshi , Kurokawa Ryu , Takaishi Yoshiyuki , Asakuno Keizo , Kawamoto Toshiki
Published: January 2008

Object

Laminoplasty has been used to expand the cervical spinal canal, based on the belief that reconstruction of the laminae preserves musculoskeletal function. The true efficacy of laminoplasty for maintaining spinal alignment, stability, and flexibility, however, remains to be proven. The authors have developed a new method, myoarchitectonic spinolaminoplasty (MSLP), which preserves all of the nuchal muscles and reconstitutes all of the musculoskeletal couplings to the posterior elements of the vertebrae. The details of this technique are described, and the efficacy of the technique in conserving muscle volume, alignment, and motion, as well as in preventing postoperative musculoskeletal discomfort, is assessed.

Methods

The authors' previous midline-splitting laminoplasty procedure, which utilized a hydroxyapatite (HA) implant as a substitute for the spinous process, was improved. Detachment of the muscles is avoided with this new technique by cutting inside the spinous process. The bone–muscle flaps are affixed to the HA spinous process. Radiographs, computed tomography scans, and neurological evaluations obtained at the 1-year follow-up in the groups of consecutive patients assessed immediately prior to and after the modification of the previous technique (the control and the MSLP groups, respectively) were analyzed and compared.

Results

The HA bone constructs became integrated due to osteoconduction. The cross-sectional area of the semispinalis capitis, semispinalis cervicis, and multifidus muscles remained significantly larger in the MSLP group. Slight attenuation in lordosis was observed in the control group, but was prevented in the MSLP group. Range of motion was somewhat restricted in the MSLP group, but the incidence of neck pain and shoulder strain was significantly reduced.

Conclusions

The new MSLP method was effective in preserving the volume and functions of the nuchal musculature and helping to minimize postoperative musculoskeletal complaints.
Human spinal arachnoid villi revisited: immunohistological study and review of the literature
Authors: Tubbs R. Shane , Hansasuta Ake , Stetler William , Kelly David R. , Blevins Danitra , Humphrey Rita , Chua Gina D. , Shoja Mohammadali M. , Loukas Marios , Oakes W. Jerry
Published: January 2008

Object

Few have described the relationship between arachnoid protrusions (villi) and adjacent spinal radicular veins, and the descriptions that do exist are conflicting. Some authors have even denied the presence of spinal arachnoid villi, suggesting that they play no role in cerebrospinal fluid (CSF) absorption.

Methods

To further elucidate these structures, laminectomies from C-2 inferiorly to S-2 were performed in 10 fresh human adult cadavers. Following removal of the laminae, the dural nerve sleeves were identified and the spinal nerves excised 1 cm lateral and medial to the intervertebral foramina. Samples were submitted for histological and immunohistological analysis.

Results

The authors identified arachnoid villi in all specimens. The length of these structures was approximately 50 to 170 μm. Regionally, these villi were more concentrated in the lumbar region, but they were not present at every vertebral level, with observed skip zones. Occasionally, more than one villus was identified per vertebral level. The majority of villi were intimately related to an adjacent radicular vein. There was a direct relationship between the size of the adjacent radicular vein, and the presence and number of arachnoid villi.

Conclusions

Findings in the present study have demonstrated that arachnoid villi exist and are morphologically associated with radicular veins. These data support the theory that CSF absorption occurs not only intracranially but also along the spinal axis. Further animal studies are necessary to prove that CSF traverses these villi and is absorbed into the spinal venous system.
Cortex of the pedicle of the vertebral arch. Part II: microstructure
Authors: İnceoğlu Serkan , Kilinçer Cumhur , Tami Andrea , McLain Robert F.
Published: January 2008

Object

Although the gross anatomy of the pedicle in the human spine has been investigated in great detail, knowledge of the microanatomy of trabecular and cortical structures of the pedicle is limited. An understanding of the mechanical properties and structure of the pedicle bone is essential for improving the quality of pedicle screw placement. To enhance this understanding, the authors examined human cadaveric lumbar vertebrae.

Methods

In this study, the authors obtained seven human cadaveric lumbar vertebrae. The lateral and medial cortices of these pedicle specimens were sectioned and embedded in polymethylmethacrylate. Cross-sectional slices of cortex were obtained from each specimen and imaged with the aid of a high-resolution light microscope. Assessments of osteonal orientation, determinations of relative dimensions, and histomorphometric studies were performed.

Results

The cortex of the pedicle in each human lumbar vertebra had an osteonal structure with haversian canals laid down mainly in the anteroposterior (longitudinal) direction. The organization of osteons across the transverse cross-section was not homogeneous. The layer of lamellar bone that typically envelops cortical bone structures (such as in long bones) was not observed, and the lateral cortex was significantly thinner than the medial cortex (p< 0.05).

Conclusions

The cortical bone surrounding the pedicle differed from bone in other anatomical regions such as the anterior vertebral body and femur. The osteonal orientation and lack of a lamellar sheath may account for the unique deformation characteristics of the pedicle cortex seen during pedicle screw placement.
Large intramedullary abscess of the spinal cord associated with an epidermoid cyst without dermal sinus
Authors: Gerlach Rüdiger , Zimmermann Michael , Hermann Elvis , Kieslich Matthias , Weidauer Stefan , Seifert Volker
Published: January 2008

✓ An intramedullary abscess of the spinal cord (IASC) represents a rare disease associated with a potentially devastating outcome. Few cases involving children suffering from an IASC have been reported in the neurosurgical literature. In the majority of the reported pediatric cases there were either congenital abnormalities, such as a dermal sinus, or signs of local infections leading to a secondary hemopoietic spread. The authors report the case of an 18-month-old girl with an extensive IASC associated with an epidermoid cyst extending from T-11 to S-2 without evidence of a dermal sinus or history of clinically apparent systemic infection. To their knowledge, this is the first case report of an IASC without a condition facilitating either direct contamination via a dermal sinus or hemopoietic spread from an infectious focus outside the central nervous system. Signs and symptoms, the clinical course, and imaging features are discussed and the relevant literature is reviewed.
Surgeon’s radiation exposure during percutaneous vertebroplasty
Authors: Synowitz Michael , Kiwit Juergen
Published: January 2008

Object

In this study the authors evaluated levels of radiation exposure to surgeons’ protected and unprotected hands during fluoroscopically assisted vertebroplasty.

Methods

The amount of radiation administered to 30 patients during 41 procedures in a controlled prospective trial over 6 months was assessed, comparing radiation exposure to the right and left hands in two neurosurgeons. Effective skin doses were evaluated using thermoluminescent finger dosimeters (ring dosimeters). The ratios of finger dosimeter exposure were compared between the glove-protected and unprotected left hands of two surgeons and both unprotected right hands. In addition, dose-area product (DAP) and fluoroscopy times were recorded in all patients.

The mean treatment-effective dose to the surgeons’ hands was 0.49 ± 0.4 mSv in the glove-protected left hand and 1.81 ± 1.31 mSv in the unprotected left hand (p < 0.05). The mean effective hand doses were 0.59 ± 0.55 mSv in the unprotected right hand of the glove-protected surgeon and 0.62 ± 0.55 mSv in the unprotected right hand of the control surgeon. The total corresponding fluoroscopy time was 38.55 minutes for the protected surgeon and 41.23 minutes for the unprotected one (p > 0.05). Lead glove shielding resulted in a radiation dose reduction of 75%. The total DAP for all procedures was 256,496 mGy/cm2 and 221,408 mGy/cm2 (p >0.05) for the protected and unprotected surgeons, respectively.

Conclusions

This study emphasizes the importance of surgeons wearing lead glove protection on their leading hands during percutaneous vertebroplasty procedures and demonstrates a 75% reduction rate of exposure to radiation.
Calcium phosphate cement–based vertebroplasty compared with conservative treatment for osteoporotic compression fractures: a matched case–control study
Authors: Nakano Masato , Hirano Norikazu , Ishihara Hirokazu , Kawaguchi Yoshiharu , Watanabe Hiroki , Matsuura Kousou
Published: January 2008

Object

Few studies have been conducted to compare vertebroplasty and conservative treatment for osteoporotic vertebral compression fractures (OVCFs). To investigate the effects of calcium phosphate cement (CPC)–based vertebroplasty on relief of pain and augmentation of the fractured vertebral body (VB), the authors compared the results of CPC-assisted vertebroplasty with those of conservative treatment alone.

Methods

Two groups of patients were examined: the vertebroplasty group (30 consecutive patients with primary OVCF) and the control group (30 patients matched for age, sex, interval from injury to treatment, and grade of the posterior wall defects of the fractured VB). Outcome measures included the visual analog scale (VAS) score of back pain and analgesic requirements, and the radiographically documented rate of the VB kyphosis.

The follow-up duration was more than 12 months (mean 17 months). The mean VAS score at 12 months after injury was 0.67 cm in the vertebroplasty group and 1.97 cm in the control group, and the mean improvement rates in the VAS scores were 91.6 and 73.6%, respectively (p < 0.0001). The mean duration of analgesic requirement was 8.3 days in the vertebroplasty group and 62.2 days in the control group (p = 0.0005). The mean kyphosis rate at 12 months after injury was 72.9% in the vertebroplasty group and 58% in the control group, and the mean recovery rate of kyphosis was + 8.4 and −21%, respectively (p < 0.0001).

Conclusions

The authors conclude that CPC-assisted vertebroplasty provides better clinical and radiological results than conservative treatment for primary OVCF.
Surgical management of tethered cord syndrome in adults: indications, techniques, and long-term outcomes in 60 patients
Authors: Lee Gabriel Y. F. , Paradiso Guillermo , Tator Charles H. , Gentili Fred , Massicotte Eric M. , Fehlings Michael G.
Published: January 2008

Object

The adult presentation of tethered cord syndrome (TCS) is well recognized but continues to pose significant diagnostic and management challenges. The authors performed a retrospective study of clinical outcomes after neurosurgical intervention in 60 adults with TCS.

Methods

All patients who underwent detethering surgery for caudal cord tethering at Toronto Western Hospital between August 1993 and 2004 were identified. Their clinical charts, operative records, and follow-up data were reviewed. Detethering procedures were performed in 62 patients (age range 17–72 years) for TCS of various origins. Long-term (mean 41.5 months) follow-up data were obtained in 60 patients. The tethering lesions were tight terminal filum in 29 patients, postrepair myelomeningocele in 15, lipomyelomeningocele/lipoma in nine, split cord malformation in four, and arachnoidal adhesions in three. Fifty-nine patients presented with progressive pain and/or neurological dysfunction. One patient underwent prophylactic sectioning of the terminal filum. Most patients (71%) had bladder dysfunction at presentation. Microsurgical release of the tethered cord was performed in each case while using multimodality intraoperative neurophysiological monitoring. The most common complication was cerebrospinal fluid leakage, which occurred in nine patients and was managed by reinforcement sutures in four patients, temporary external drainage in three, and the placement of a lumboperitoneal shunt in two. Infective complications included superficial wound infection in three patients, meningitis in one, and urinary tract infection in one. One patient who had undergone multiple previous intradural procedures experienced worsened foot weakness postoperatively. Another patient experienced temporary unilateral lower-limb numbness. At follow up, improvement was noted in the majority of patients presenting with back (78%) and leg (83%) pain. Improvement was more likely in patients with preoperative motor weakness than in those with sensory deficits. Overall, neurological status was improved or stabilized in 90% of patients. Subjective improvement in bladder function was noted in 50% of patients with bladder dysfunction at presentation.

Conclusions

Surgery in adult patients with TCS is safe and effective for improving pain and neurological status in the majority of patients; however, patients who have undergone previous intradural detethering procedures in general fare less well, and considerable judgment is required in their management.
SPIRE spinous process stabilization plate: biomechanical evaluation of a novel technology
Authors: Wang Jeremy C. , Spenciner David , Robinson James C.
Published: January 2008

Object

The authors studied the biomechanical properties of a novel spinous process stabilization plate (CD HORIZON SPIRE Spinal System) and present the results in comparison with those of other posterior fixation methods.

Methods

Ten functional cadaveric lumbar segments were subjected to nondestructive quasistatic loading forces in 10 different conditions: intact, destabilized (discectomy), fitted with spinous process plate (SPP) alone, with anterior-column support (ACS) alone, ACS with SPP, ACS with posterior translaminar facet screw (PTFS) fixation, ACS with unilateral pedicle screw and rod (UPSR) fixation, ACS with bilateral pedicle screw and rod (BPSR) fixation, UPSR alone, or BPSR alone. Stiffness and range of motion (ROM) data were compared using a repeated-measures, one-way analysis of variance.

The construct with greatest mean limitation of flexion–extension ROM was ACS/SPP at 4.14° whereas it was 5.75° for ACS/UPSR fixation, 5.03° for ACS/BPSR fixation, and 10.13° for the intact spine. The SPIRE plate alone also provided greater flexion and extension stiffness, with less ROM than other posterior stabilization options. Fixation with BPSR with or without ACS resulted in the stiffest construct in lateral bending and axial rotation. The SPP and UPSR fixation groups were equivalent in resisting lateral bending and axial rotation forces with or without ACS.

Conclusions

The SPIRE plate effectively stabilized the spine, and the test results compare favorably with other fixation techniques that are more time consuming to perform and have greater inherent risks.
Optimization of a mouse locomotor rating system to evaluate compression-induced spinal cord injury: correlation of locomotor and morphological injury indices
Authors: Li Yuesheng , Oskouian Rod J. , Day Yuan-Ji , Kern John A. , Linden Joel
Published: January 2008

Object

Due to the usefulness of mouse genetics, there is a need to improve procedures for producing and assessing spinal cord injury (SCI) in mice. The authors describe an improved locomotor scoring system for evaluating SCI. The modified Basso-Beattie-Bresnahan (mBBB) scoring system for mice is compared with existing procedures as well as histological SCI criteria.

Methods

Mice were subjected to SCI by placing a weight on the cord at T-12 for 5 to 15 minutes after laminectomy to produce spinal cord ischemia. Injury was assessed using mBBB scoring that incorporates elements of the rat BBB and the mouse motor function scoring systems that are best suited for precisely assessing mouse SCI. The mBBB score was found to be more discriminating than the inclined plane test, and in the authors’ laboratory it had a significantly lower coefficient of variation than the Basso mouse scale score. The mBBB score is well correlated with sparing of white matter as assessed by eriochrome cyanine staining of myelin.

Conclusions

Weight placement at T-12 in the mouse causes reproducible SCI. A new mBBB scoring system is useful for accurately assessing locomotor dysfunction following SCI in mice and is well correlated with histological assessment of spinal cord white matter.
Cordectomy for the treatment of posttraumatic syringomyelia
Authors: Laxton Adrian W. , Perrin Richard G.
Published: January 2008

✓Cordectomy is an effective treatment option in patients in whom posttraumatic syringomyelia develops following complete spinal cord injuries. Since the introduction of cordectomy, numerous approaches to the surgical treatment of posttraumatic syringomyelia have been developed. These newer developments have drawn the attention of surgeons and researchers away from cordectomy. In this report, the authors encourage a reconsideration of cordectomy for the treatment of posttraumatic syringomyelia after complete spinal cord injury. They describe four patients with posttraumatic syringomyelia who were treated successfully with cordectomy and review appropriate literature, examining the effectiveness of cordectomy in the treatment of posttraumatic syringomyelia. The findings of this review indicate that neurological improvement or stabilization occurred in 88% of patients in published reports of posttraumatic syringomyelia treated with cordectomy. The indications for cordectomy as well as factors that may contribute to the procedure’s success are discussed.
Recurrent subdural hematoma caused by cerebrospinal fluid leakage
Authors: Mizuno Junichi , Mummaneni Praveen V. , Rodts Gerald E. , Barrow Daniel L.
Published: January 2008

✓The authors report a case of a recurrent subdural hematoma (SDH) that was caused by a persistent cerebrospinal fluid (CSF) leak from an L1–2 fistula. A 34-year-old man experienced severe headaches due to SDH, and he underwent aspiration of subdural fluid four times due to recurrent collections. Further evaluation with computerized tomography (CT) myelography demonstrated extradural extravasation of contrast through an L1–2 fistula. The patient underwent an L1–2 laminectomy; a small dural defect with CSF leakage at the left nerve root sleeve was found and was repaired. Following the repair, the patient had no further recurrence of SDH. Recurrent SDH, caused by spontaneous CSF leakage through a lumbar CSF fistula, is extremely rare. In cases of recurrent SDH, radiographic workup with spinal CT myelography should be considered.
Treatment of symptomatic adjacent-segment degeneration after lumbar fusion with total disc arthroplasty by using the ProDisc prosthesis: a prospective study with 2-year minimum follow up
Authors: Bertagnoli Rudolf , Yue James J. , Fenk-Mayer Andrea , Eerulkar Jonathan , Emerson John W.
Published: January 2008

Object

The authors conducted a prospective longitudinal study to assess the efficacy of ProDisc arthroplasty in patients in whom symptomatic adjacent-segment degeneration has developed after remote lumbar fusion. The follow-up period was a minimum of 2 years.

Methods

The 20 patients in this study ranged in age from 18 to 67 years. They presented with disabling adjacent-level discogenic low-back pain with or without L1–S1 radicular pain. Patients with radiographic evidence of circumferential spinal stenosis or facet joint degeneration had been excluded. Patients were assessed preoperatively and postoperatively at 3, 6, 12, and 24 months.

Eighteen patients (90%) fulfilled all follow-up criteria. The median age of all patients was 50 years. Statistical improvements in visual analog scale, Oswestry Disability Index, and patient satisfaction scores were documented 3 months after arthroplasty. These improvements remained at the 24-month follow-up examinations. Patient satisfaction rates were 86% at 24 months. Radicular pain was also significantly decreased. No additional surgeries were necessary at affected or unaffected levels.

Conclusions

Analysis of early results indicates that ProDisc lumbar total disc arthroplasty is an efficacious treatment for symptomatic adjacent-segment lumbar discogenic low-back pain following remote fusion. Significant improvements in patient satisfaction and disability scores were observed by 3 months postoperatively and were maintained at the 2-year follow-up examination. No device-related complications occurred. Patients should be screened carefully for evidence of facet joint impingement/degeneration, hardware-induced pain, and/or nonunion at prior fusion levels before undergoing disc replacement surgery.
A biomechanical comparison of three anterior thoracolumbar implants after corpectomy: are two screws better than one?
Authors: Chou Dean , Larios Adolfo Espinoza , Chamberlain Robert H. , Fifield Mary S. , Hartl Roger , Dickman Curtis A. , Sonntag Volker K. H. , Crawford Neil R.
Published: January 2008

Object

A flexibility experiment using human cadaveric thoracic spine specimens was performed to determine biomechanical differences among thoracolumbar two-screw plate, single-screw plate, and dual-rod systems. A secondary goal was to investigate differences in the ability of the systems to stabilize the spine after a one- or two-level corpectomy.

Methods

The authors evaluated 21 cadaveric spines implanted with a titanium mesh cage and three types of anterior thoracolumbar supplementary instrumentation after one-level thoracic corpectomies. Pure moments were applied quasistatically while three-dimensional motion was measured optoelectronically. The lax zone, stiff zone, and range of motion (ROM) were measured during flexion, extension, left and right lateral bending, and left and right axial rotation. Corpectomies were expanded to two levels, and testing was repeated with longer hardware.

Biomechanical testing showed that the single-bolt plate system was no different from the dual-rod system with two screws in limiting ROM. The single-bolt plate system performed slightly better than the two-screw plate system. Across the same two levels, there was an average of 19% more motion after a two-level corpectomy than after a one-level corpectomy. In general, however, the difference across the different loading modes was insignificant.

Conclusions

Biomechanically, the single-screw plate system is equivalent to a two-screw dual-rod and a two-screw plate system. All three systems performed similarly in stabilizing the spine after one- or two-level corpectomies.
Amelioration of spinal cord compressive injury by pharmacological preconditioning with erythropoietin and a nonerythropoietic erythropoietin derivative
Authors: Grasso Giovanni , Sfacteria Alessandra , Erbayraktar Serhat , Passalacqua Marcello , Meli Francesco , Gokmen Necati , Yilmaz Osman , La Torre Domenico , Buemi Michele , Iacopino Domenico G. , Coleman Thomas , Cerami Anthony , Brines Michael , Tomasello Francesco
Published: January 2008

Object

Spinal cord injury (SCI) is a devastating clinical syndrome for which no truly efficacious therapy has yet been identified. In preclinical studies, erythropoietin (EPO) and its nonerythropoietic derivatives asialoEPO and carbamylated EPO have markedly improved functional outcome when administered after compressive SCI. However, an optimum treatment paradigm is currently unknown. Because the uninjured spinal cord expresses a high density of EPO receptor (EPOR) in the basal state, signaling through these existing receptors in advance of injury (pharmacological preconditioning) might confer neuroprotection and therefore be potentially useful in situations of anticipated damage.

Methods

The authors compared asialoEPO, a molecule that binds to the EPOR with high affinity but with a brief serum half-life (t1/2 < 2 minutes), to EPO to determine whether a single dose (10 μg/kg of body weight) administered by intravenous injection 24 hours before 1 minute of spinal cord compression provides benefit as determined by a 6-week assessment of neurological outcome and by histopathological analysis. Rats pretreated with asialoEPO or EPO and then subjected to a compressive injury exhibited improved motor function over 42 days, compared with animals treated with saline solution. However, pretreatment efficacy was substantially poorer than efficacy of treatment initiated at the time of injury. Serum samples drawn immediately before compression confirmed that no detectable asialoEPO remained within the systemic circulation. Western blot and immunohistochemical analyses performed using uninjured spinal cord 24 hours after a dose of asialoEPO exhibited a marked increase in glial fibrillary acidic protein, suggesting a glial response to EPO administration.

Conclusions

These results demonstrate that EPO and its analog do not need to be present at the time of injury to provide tissue protection and that tissue protection is markedly effective when either agent is administered immediately after injury. Furthermore, the findings suggest that asialoEPO is a useful reagent with which to study the dynamics of EPO-mediated neuroprotection. In addition, the findings support the concept of using a nonerythropoietic EPO derivative to provide tissue protection without activating the undesirable effects of EPO.
Evaluation of registration techniques for spinal image guidance
Authors: Holly Langston T. , Bloch Orin , Johnson J. Patrick
Published: January 2008

Object

Paired point matching alone and paired point matching combined with surface matching are the two techniques used for the registration step in preoperative computerized tomography–based spinal image guidance. In the present study the authors sought to compare paired point–matching registration alone with paired point matching supplemented with surface matching to determine if the addition of surface matching improves navigational accuracy.

Methods

Pedicle screws were placed in three embalmed human cervicothoracic spinal specimens during image guidance to serve as a reference points. The specimens were then rescanned, and each level was registered using paired point matching alone and then by paired point supplemented with surface matching. Navigational accuracy was assessed by placing the stereotactic probe in the center of the screw head, and measuring the apparent distance between the screw head and probe on the computer monitor. Statistical analysis was used to compare the registration error and navigational error between the two techniques.

Seventy-five screws were placed at 46 vertebral levels. The mean registration error for the paired point matching/surface matching technique (0.5 mm) was significantly lower (p < 0.001) than that of the paired point matching alone technique (1.2 mm); however, the intertechnique difference in navigational error was nearly equivalent (1.3 mm compared with 1.4 mm) and statistically insignificant (p > 0.05).

Conclusions

Although the addition of surface matching to paired point registration significantly decreased the mean registration error, the actual navigational accuracy between the two techniques was equivalent when easily distinguishable points were meticulously selected. The use of paired point matching alone did not compromise the accuracy of navigation and is likely to result in decreased operating time.
Percutaneous drainage and continuous irrigation in patients with severe pyogenic spondylitis, abscess formation, and marked bone destruction
Authors: Hanaoka Naoyoshi , Kawasaki Yoshiteru , Sakai Toshinori , Nakamura Taro , Nanamori Kazuhisa , Nakamura Eijiro , Uchida Ken , Yamada Hidehiro
Published: January 2008

Object

The use of percutaneous suction aspiration has recently become viewed as an effective management strategy for pyogenic spondylitis unresponsive to conservative treatment. What remains unclear is whether it can be effective for severe pyogenic spondylitis in which abscess formation or marked bone destruction is present. The authors undertook a study to clarify answers to this question.

Methods

The authors evaluated clinical and radiographic/neuroimaging data obtained in five patients with severe pyogenic spondylitis, extensive abscesses, and marked bone destruction. These patients had undergone percutaneous drainage and continuous irrigation because open surgery was considered contraindicated in light of their poor general health. The mean period during which continuous irrigation was applied was 9 days (range 7–11 days), and the mean period during which the drainage tube was in place was 19 days (range 13–38 days). All patients suffered from back pain, which was relieved by the percutaneous technique in four patients after a mean of 8 days. The abscesses and inflammation resolved in all patients. Progressive osseous destruction was not observed, and open surgery was performed in only one patient in whom back pain persisted as a result of spinal instability.

Conclusions

After an unsuccessful course of conservative treatment, severe pyogenic spondylitis with abscess formation or marked bone destruction was successfully treated using percutaneous drainage and continuous irrigation. Based on their results, the authors believe that this procedure can be used in patients with severe pyogenic spondylitis that was unresponsive to conservative treatment, particularly in those whose general health is poor.
A novel human osteoblast–derived severe combined immunodeficiency mouse model of bone metastasis
Authors: Schuster James , Zhang Jun , Longo Maria
Published: January 2008

Object

One of the major difficulties of conducting bone metastasis research is the lack of adequate models for studying the bone–tumor microenvironment. The limitations of current in vivo models include the following: non-human tumor or bone, variable reproducibility, limited supply, and an inability to be easily manipulated. The objective of the present study was to develop a uniform and reproducible model of bone/spine metastasis by utilizing bone derived from human osteoblasts grown subcutaneously in severe combined immunodeficiency (SCID) mice with subsequent introduction of human carcinoma cell lines.

Methods

Human osteoblasts were serially passed in culture and induced to differentiate into mature osteoblasts. They were subsequently loaded on hydroxyapatite-coated collagen sponges and implanted subcutaneously into the SCID mice. After allowing the bone to mature for 8 weeks, tumor cell suspensions were implanted percutaneously into the bone. The bone–tumor complexes were subsequently harvested, decalcified, and prepared for histological examination.

Conclusions

The authors have developed a novel, reproducible SCID mouse model of bone/spine metastasis by using bone derived from human osteoblasts and subsequently introduced human tumor lines. They believe this model will be useful for studying the basic biology of bone metastases.
En bloc marginal excision of a multilevel cervical chordoma
Authors: Bailey Christopher S. , Fisher Charles G. , Boyd Michael C. , Dvorak Marcel F. S.
Published: January 2008

✓ The purpose of this case report is to demonstrate that an en bloc resection with negative surgical margins can be successfully achieved in a case of a seemingly unresectable C-2 chordoma if appropriate preoperative staging and planning are performed. The management of chordomas is controversial and challenging because of their location and often large size at presentation. Because chordomas are malignant and will aggressively recur locally if intralesional resection is conducted, wide or true en bloc resection is generally recommended. The literature indicates, however, that surgeons are reluctant to perform wide or even marginal resections because of the lesion’s complex surrounding anatomy and the risk of significant neurological compromise when a tumor abuts the dura mater or neural tissues. In this report the authors outline the successful en bloc resection of a large C1–3 chordoma and discuss the importance of preoperative staging and planning.
Spondylolisthesis of the thoracic spine
Authors: Shimada Yoichi , Kasukawa Yuji , Miyakoshi Naohisa , Hongo Michio , Ando Shigeru , Itoi Eiji
Published: January 2008

✓ The thoracic spine is stabilized in the anteroposterior direction by the rib cage and the facet joints. Spondylolisthesis of the thoracic spine is less common than that of the lumbar spine. The authors describe a rare case of thoracic spondylolisthesis in which the patient suffered back pain and myelopathy. The patient was a 44-year-old woman. Plain radiography revealed Grade I T11–12 spondylolisthesis. The pedicle–facet joint angle at T-11 was 118°, greater than that of T-10 or T-12. Postmyelography computerized tomography scanning revealed posterior compression of the dural sac as well as enlargement of and degenerative changes in the facet joint at T-11. Magnetic resonance imaging showed anterior and posterior compression of the spinal cord at the level of the spondylolisthesis. To achieve posterior T10–12 decompression, the surgeons performed a laminectomy and posterolateral fusion in which a pedicle screw fixation system was placed. The patient’s back pain disappeared immediately after the operation. The authors conclude that the enlargement of the pedicle–facet joint angle and the degenerative changes of the facet joint caused the thoracolumbar spondylolisthesis.
Cervical osteophytes: a cause of potentially life-threatening laryngeal spasms
Authors: Farooqi Naeem Ahmed , Doran Mark , Buxton Neil
Published: January 2008

✓ This 80-year-old woman presented with acute breathing difficulty during neck flexion when cyanosis also developed. The only potential causes were detected on cervical magnetic resonance imaging: two large anterior cervical osteophytes compressing the retropharyngeal space. Excision of these osteophytes resulted in resolution of the symptoms.
Diagnosis and treatment of craniocervical dislocation in a series of 17 consecutive survivors during an 8-year period
Authors: Bellabarba Carlo , Mirza Sohail K. , West G. Alexander , Mann Frederick A. , Dailey Andrew T. , Newell David W. , Chapman Jens R.
Published: January 2008

Object

Craniocervical dissociation (CCD) is a highly unstable and usually fatal injury resulting from osseoligamentous disruption between the occiput and C-2. The purpose of this study was to elucidate systematic factors associated with delays in diagnosing and treating this life-threatening condition and to introduce an injury-severity classification with therapeutic implications.

Methods

In a retrospective evaluation of institutional databases, the authors reviewed medical records and original images obtained in 17 consecutive surviving patients with CCD treated between 1994 and 2002. Images and clinical results of treatment were evaluated, emphasizing the timing of diagnosis, clinical effect of delayed diagnosis, potential clinical or imaging warning signs, and response to treatment.

Craniocervical dissociation was identified or suspected on the initial lateral cervical spine radiograph acquired in two patients (12%) and was diagnosed based on screening computerized tomography findings in two additional patients (12%). A retrospective review of initial lateral x-ray films showed an abnormal dens–basion interval in 16 patients (94%). The 2-day average delay in diagnosis was associated with profound neurological deterioration in five patients (29%). Neurological status declined in one patient after a fixation procedure was performed. There were no cases of craniocervical pseudarthrosis or hardware failure during a mean 26-month follow-up period. The mean American Spinal Injury Association (ASIA) motor score of 50 improved to 79, and the number of patients with useful motor function (ASIA Grade D or E) increased from seven (41%) preoperatively to 13 (76%) postoperatively.

Conclusions

The diagnosis of CCD was frequently delayed, and the delay was associated with an increased likelihood of neurological deterioration. Early diagnosis and spinal stabilization protected against worsening spinal cord injury.
Pyogenic spinal infections and outcome according to the 36-Item Short Form Health Survey
Authors: Woertgen Chris , Rothoerl Ralf Dirk , Englert Carsten , Neumann Carsten
Published: January 2008

Object

Pyogenic vertebral infections are rare. In most papers investigators have focused on risk factors, clinical characteristics, and diagnostic findings, and discussed different management strategies. The optimal strategy for dealing with spinal infections, however, remains controversial. Additionally, outcome data regarding quality of life (QOL) after pyogenic spinal infections are sparse. The aim of this study was to provide further data in this field.

Methods

The authors retrospectively investigated 62 patients suffering from pyogenic spinal infections. In 37 patients (59%), lumbar lesions were observed; thoracic and thoracolumbar infections were documented in 19 (31%) and a cervical infection was demonstrated in six patients (10%). Overall 28 patients (45%) underwent conservative treatment, and 34 (55%) underwent surgery with or without the placement of instrumentation. At follow-up examination the authors recorded each patient’s satisfaction as well as QOL according to the 36-Item Short Form Health Survey. Quality of life after treatment of pyogenic spine infections did not reach the level of the normative sample. Most patients continued to suffer some sort of pain. Despite different indications, the surgically treated patients experienced a slightly better QOL and self-reported satisfaction levels, as well as a statistically significant better outcome, than patients treated conservatively.

Conclusions

The results obtained in the present study suggest that surgery, especially in conjunction with the placement of instrumentation, may be more beneficial than conservative treatment in patients with a spinal infection.
Early nuclear factor–κB activation and inducible nitric oxide synthase expression in injured spinal cord neurons correlating with a diffuse reduction of constitutive nitric oxide synthase activity
Authors: Miscusi Massimo , Ebner Florian , Ceccariglia Sabrina , Menegazzi Marta , Mariotto Sofia , Berra Luigi , Fa Aurora Del , Gangitano Carlo , Lauretti Liverana , Missori Paolo , Delfini Roberto , Suzuki Hisanori
Published: January 2008

Object

Because of toxicity at high concentrations, nitric oxide (NO) contributes to spinal cord injury (SCI) secondary lesions. At low concentrations NO modulates nuclear factor–κB (NF-κB) activation. The authors investigated the activity of neuronal and endothelial NO synthase (nNOS and eNOS) to determine correlations with NF-κB activation and inducible NOS (iNOS) expression soon after SCI.

Methods

In 48 adult male Wistar rats clip-based (50 g/mm2/10 seconds) SCI was induced, and spinal cords were removed at different intervals for the following evaluations: 1) assaying specific activity of nNOS and eNOS; 2) electrophoresis mobility shift assay for activated NF-κB; 3) Northern blotting for iNOS; 4) immunohistochemistry for iNOS and NF-κB; and 5) immunofluorescence for iNOS and NF-κB.

At 15 minutes postinjury, eNOS activity decreased significantly (p < 0.001), as did nNOS activity at 1 hour compared with these levels in control animals and rats killed at 15 and 30 minutes after SCI (p < 0.001). Basal NF-κB levels were variable in controls and at 15 and 30 minutes after injury. One hour postinjury, NF-κB activation was diffuse. Inducible NOS messenger RNA localized diffusely, peaking 6 hours after injury and remaining stable until 24 hours postinjury. Immunohistochemical analysis showed diffuse iNOS and NF-κB staining, especially in neurons inside and around the lesion. Immunofluorescence demonstrated that injured neurons were a source of NF-κB and iNOS soon after injury.

Conclusions

Both nNOS and eNOS exhibited different regulation and roles soon after injury: nNOS correlated with NF-κB activation, whereas eNOS may have participated in vascular changes of the injured spinal cord. Neurons seemed to play a pivotal role in modulating and amplifying the inflammatory response in the injured spinal cord.
Mid-term and long-term follow-up data after placement of the Graf stabilization system for lumbar degenerative disorders
Authors: Onda Akira , Otani Koji , Konno Shinichi , Kikuchi Shinichi
Published: January 2008

Object

The Graf pedicle screw and ligament device is designed to provide flexible stabilization to prevent abnormal spinal movement. The purpose of this study was to investigate radiographic and clinical outcomes during a minimal 5-year follow-up period.

Methods

Between 1991 and 1997, 43 consecutive patients (whose mean age was 61 years) with lumbar degenerative disease underwent decompression and stabilization in which the Graf system was placed. Data were available for 31 patients who attended follow up for the minimal 5-year period. In a retrospective review, the authors assessed measurements on radiographs, clinical results (using Japanese Orthopaedic Association [JOA] Scale scores), and low-back pain (using a visual analog scale [VAS] score), preoperatively and postoperatively at 1, 3, 5, and/or 10 years. Radiographic measurements included sagittal and frontal range of motion (ROM), regional lordosis, and posterior disc height as well as the extent of degenerative spondylolisthesis.

Final follow-up JOA and VAS scores were significantly better than preoperative scores. Sagittal and frontal ROM was significantly reduced at 1 and 5 years, respectively, compared with preoperative values, and a gradual reduction persisted throughout the follow-up period. Compared with its preoperative status, the disc height ratio (adjacent segments to the operated level) was reduced 5 years after surgery. A significant inhibition of the vertebral slippage was detected only in the flexion position.

Conclusions

Analysis of these data indicated that the Graf system eventually leads to successful fusion, suggesting the presence of stability in all three dimensions. The use of the Graf system should continue to be evaluated as an alternative device in the treatment of lumbar degenerative disease.
The effect of posterior bridging of C-1 on craniovertebral junction surgery
Authors: Senoglu Mehmet , Gümüşalan Yakup , Yüksel Kasim Zafer , Uzel Murat , Çelik Mustafa , Özbağ Davut
Published: January 2008

Object

The groove for the vertebral artery (VA) may be bridged on C-1, forming a canal through which the artery passes. Because this variant may significantly affect the commonly performed C-1 posterior laminectomy, the authors studied the incidence and radiological appearance of this anatomical feature in surgical specimens.

Methods

Anatomical measurements were performed using a Vernier caliper (accurate to 0.1 mm) on 166 dry C-1 vertebrae. In addition, a convenience sample of 172 cervical x-ray films was evaluated. Partial osseous bridging was detected in eight (4.8%), and a complete osseous bridge, forming the canalis arteriae vertebralis (canal for the VA), was seen unilaterally (eight on the left and two on the right) in 10 (6%) and bilaterally in eight (4.8%) of the dry vertebrae. On lateral radiography, a complete bone bridge was observed on nine (5.2%) and a partial bridge on 10 (5.8%) of the 172 studies.

Conclusions

The discovery of a common variant may necessitate an immediate change in surgical management, and this anomaly could even increase the rate of surgery-related complications. The VA canal, present in the C-1 vertebra in approximately 5% of the specimens evaluated, was a variant that may be protective against VA injury. Knowledge of this variant may help the surgeon undertaking procedures in the C-1 region.
Primary intradural extraarachnoid Hodgkin lymphoma of the cervical spine
Authors: Heran Navraj S. , Yong Raymund L. , Heran Manraj S. , Yip Steven , Fairholm David
Published: January 2008

✓ This 42-year-old man presented with an intradural extramedullary mass in his lower cervical spine. On imaging studies the lesion mimicked the appearance of a meningioma. At surgery, the mass was found to be an intradural extra-arachnoid tumor. An intraoperative pathological examination determined the lesion to be a Hodgkin lymphoma. The procedure was limited to biopsy sampling and the patient was treated further with adriamycin, bleomycin, vincristine, and dacarbazine chemotherapy, after which remission was demonstrated both clinically and on images. Analysis of a frozen section obtained during the procedure aided in the diagnosis of the tumor, thus preventing further resection and the potential neurological complications associated with more radical resection. To the authors’ knowledge this is the first reported case of a presumed primary intradural extraarachnoid Hodgkin lymphoma.
Peripheral primitive neuroectodermal tumor of the cauda equina in an elderly patient
Authors: Fabre Elizabeth , Guillevin Rémy , Chretien Fabrice , Le Guerinel Caroline , Duffau Hugues
Published: January 2008

✓ Primitive neuroectodermal tumors (PNETs) are aggressive neoplasms composed predominantly of undifferentiated cells that show evidence of neural differentiation. Although their classification remains disputed, PNETs are recognized as primary tumors in both the central and peripheral nervous systems. These rare tumors usually occur in children or young adults and are typically metastatic to the spinal cord. The authors report the case of a 70-year-old man with no significant medical history, in whom a peripheral PNET was demonstrated that, based on clinical and imaging findings, manifested as a nonspecific intrathecal tumoral process arising from the cauda equina. Although this lesion is rare in the elderly, the authors’ case illustrates the importance of making this diagnosis as early as possible so that a treatment plan may be devised. The use of chemotherapy in association with radiotherapy in relation to the resection of the tumor should be reconsidered.
Hypoglossal nerve palsy after posterior screw placement on the C-1 lateral mass
Authors: Hong Jae Taek , Lee Sang Won , Son Byung Chul , Sung Jae Hoon , Kim Il Sub , Park Chun Kun
Published: January 2008

✓ Atlantoaxial fixation in which C1–2 screw–rod fixation is performed is a relatively new method. Because reports about this technique are rather scant, little is known about its associated complications. In this report the authors introduce hypoglossal nerve palsy as a complication of this novel posterior atlantoaxial stabilization method.

A 67-year-old man underwent a C1–2 screw–rod fixation for persistent neck pain resulting from a Type 2 odontoid fracture that involved disruption of the transverse atlantal ligament. Posterior instrumentation in which a C-1 lateral mass screw and C-2 pedicle screw were placed was performed. Postoperatively, the patient suffered dysphagia with deviation of the tongue to the left side. At the 4-month follow-up examination, bone fusion was noted on plain x-ray studies of the cervical spine. His hypoglossal nerve palsy resolved completely 2 months postoperatively.

To the authors’ knowledge, this is the first report in the literature of hypoglossal nerve palsy following C1–2 screw–rod fixation. The hypoglossal nerve is one of the structures that can be damaged during C-1 lateral mass screw placement.
Infected vertebroplasty requiring 360° spinal reconstruction: long-term follow-up review
Authors: Mummaneni Praveen V. , Walker David H. , Mizuno Junichi , Rodts Gerald E.
Published: January 2008

✓ Transpedicular vertebroplasty has been established as a safe and effective treatment of thoracic and lumbar compression fractures. Complications are rare, and infectious complications requiring surgical management have only been reported once in the literature. The authors present two cases of infectious complications requiring surgical management. They emphasize that systemic infection is a contraindication to the performance of vertebroplasty. The serious nature of these infections, their surgical management, and strategies for avoiding them are discussed.