bluuebunny/crossref_metadata_2025 huggingface dataset:
A comparison of simulator-tested and -retrieved cervical disc prostheses
Authors: Anderson Paul A. , Rouleau Jeffrey P. , Toth Jeffrey M. , Riew K. Daniel
Published: May 2009

Object. Total joint arthroplasties most commonly fail because the implant becomes worn and a host inflammatory response subsequently develops. Both the material response to the biological environment and the host response to the device must be thoroughly evaluated to establish the efficacy of cervical arthroplasty. Analyses of devices explanted in humans allow evaluation of both responses. Hypothetical wear rates can be determined by comparing in vivo wear with simulator-derived wear. The purpose of this study was to perform explant analyses involving the Bryan and Prestige discs and compare these results with those obtained using spine simulators.

Methods. Of the approximately 5500 patients treated with the Bryan disc, 11 have undergone explantation of the device. Six of these devices were analyzed for dimensional and chemical changes. Three of the approximately 300 implanted Prestige discs were retrieved, and two were examined microscopically. Histological specimens were assessed for wear particles and host inflammatory response. Additionally, the extent of simulator-produced wear was compared with that demonstrated in the retrieved specimens.

Conclusions. The simulator-generated results predict adequate wear-related characteristics for both the Bryan and Prestige prostheses for a minimum of 40 years. Comparison of data with those of the retrieved specimens indicates that the wear was more minimal than predicted in simulators by five- to 10-fold. In no instance did the revisions result from failure of the device due to a reaction to wear debris, fracture, polymer oxidation, or metal corrosion. The inflammatory response seen in the periprosthetic tissues was minimal and not characteristic of inflammatory responses in failed diarthrodial joint arthroplasties.
Prospective outcomes evaluation after decompression with or without instrumented fusion for lumbar stenosis and degenerative Grade I spondylolisthesis
Authors: Ghogawala Zoher , Benzel Edward C. , Amin-Hanjani Sepideh , Barker Fred G. , Harrington J. Fred , Magge Subu N. , Strugar John , Coumans Jean-Valéry C.E. , Borges Lawrence F.
Published: May 2009

Object. There is considerable debate among spine surgeons regarding whether fusion should be used to augment decompressive surgery in patients with symptomatic lumbar spinal stenosis involving Grade I degenerative spondylolisthesis. The authors prospectively evaluated the outcomes of patients treated between 2000 and 2002 at two institutions to determine whether fusion improves functional outcome 1 year after surgery.

Methods. Patients ranged in age from 50 to 81 years. They presented with degenerative Grade I (3- to 14-mm) spondylolisthesis and lumbar stenosis without gross instability (< 3 mm of motion at the level of subluxation). Those in whom previous surgery had been performed at the level of subluxation were excluded. Each patient completed Oswestry Disability Index (ODI) and Short Form—36 (SF-36) questionnaires preoperatively and at 6 to 12 months postoperatively.

Some patients underwent decompression alone (20 cases), whereas others underwent decompression and posterolateral instrumentation-assisted fusion (14 cases), at the treating surgeon's discretion. Baseline demographic data, radiographic features, and ODI and SF-36 scores were similar in both groups. The 1-year fusion rate was 93%.

Both forms of surgery independently improved outcome compared with baseline status, based on ODI and SF-36 physical component summary (PCS) results (p < 0.001). Decompression combined with fusion led to an improvement in ODI scores of 27.5 points, whereas decompression alone was associated with a 13.6-point increase (p = 0.02). Analysis of the SF-36 PCS data also demonstrated a significant intergroup difference (p = 0.003).

Conclusions. Surgery substantially improved 1-year outcomes based on established outcomes instruments in patients with Grade I spondylolisthesis and stenosis. Fusion was associated with greater functional improvement.
Treatment of basilar invagination by atlantoaxial joint distraction and direct lateral mass fixation
Authors: Goel Atul
Published: May 2009

Object. The author discusses the successful preliminary experience of treating selected cases of basilar invagination by performing atlantoaxial joint distraction, reduction of the basilar invagination, and direct lateral mass atlantoaxial plate/screw fixation.

Methods. Twenty-two patients with basilar invagination—in which the odontoid process invaginated into the foramen magnum and the tip of the odontoid process was above the Chamberlain, McRae foramen magnum, and Wackenheim clival lines—were selected to undergo surgery. In all patients fixed atlantoaxial dislocations were documented.

The 16 male and six female patients ranged in age from 8 to 50 years. A history of trauma prior to the onset of symptoms was documented in 17 patients. Following surgery, the author observed minimal-to-significant reduction of basilar invagination and alteration in other craniospinal parameters resulting in restoration of alignment of the tip of the odontoid process and the clivus and the entire craniovertebral junction in all patients. In addition to neurological and radiological improvement, preoperative symptoms of torticollis resolved significantly in all patients. The minimum follow-up period was 12 months and the mean was 28 months.

Conclusions. Joint distraction and firm lateral mass fixation in selected cases of basilar invagination is a reasonable surgical treatment for reducing the basilar invagination, restoring craniospinal alignment, and establishing fixation of the atlantoaxial joint.
The V2 segment of the vertebral artery and its branches
Authors: Özgen Serdar , Pait T. Glenn , ÇağLar Y. Şsükrü
Published: May 2009

Object.The goal of this study was to demonstrate the origins, courses, anastomoses, and target tissues of the arterial branches that arise from the V2segment of the vertebral artery.

Methods.Ten adult cadaveric necks (20 V2segment specimens) were examined (magnification × 40) after injection of colored silicon. The branches at each cervical level were classified in a new system according to anatomical features and target tissues—anterior, posterior, medial, and lateral. Incidence with which each branch category was observed at each cervical level was calculated.

Anterior branches were observed at C-3 in all 20 V2segment specimens. The incidence with which the posterior branch was present at C-4 was 45%, whereas the corresponding rates at segments superior and inferior were lower. The medial V2segment branches were assessed in four subcategories. The anterior spinal artery was present at C-3 in all specimens, whereas the mean incidence at the C4–6 level was 46.7%. The posterior spinal artery was most frequently detected at C-3 (60%). The anterior radicular artery (RA) was present at C-5 in 50% of the specimens, whereas the posterior RA was detected at C-5 in only 35%. Lateral branches were most frequently detected at C-3.

Conclusions.The authors provide detailed anatomical information about the origins, courses, anastomoses, and target tissues of the vessels that arise from the V2segment. This new classification allows for better understanding of the vasculature of the C3–6 region.
Minimally invasive delivery of stem cells for spinal cord injury: advantages of the lumbar puncture technique
Authors: Bakshi Ajay , Hunter Corey , Swanger Sharon , Lepore Angelo , Fischer Itzhak
Published: May 2009

Object. Stem cell therapy has been shown to have considerable therapeutic potential for spinal cord injuries (SCIs); however, most experiments in animals have been performed by injecting cells directly into the injured parenchyma. This invasive technique compromises the injured spinal cord, although it delivers cells into the hostile environment of the acutely injured cord. In this study, the authors tested the possibility of delivering stem cells to injured spinal cord by using three different minimally invasive techniques.

Methods. Bone marrow stromal cells (BMSCs) are clinically attractive because they have shown therapeutic potential in SCI and can be obtained in patients at the bedside, raising the possibility of autologous transplantation. In this study transgenically labeled cells were used for transplantation, facilitating posttransplantation tracking. Inbred Fisher-344 rats received partial cervical hemisection injury, and 2 × 106 BMSCs were intravenously, intraventricularly, or intrathecally transplanted 24 hours later via lumbar puncture (LP). The animals were killed 3, 10, or 14 days posttransplantation, and tissue samples were submitted to histochemical and immunofluorescence analyses. For additional comparison and validation, lineage restricted neural precursor (LRNP) cells obtained from E13.5 rat embryos were transplanted via LP, and these findings were also analyzed.

Conclusions. Both BMSCs and LRNP cells home toward injured spinal cord tissues. The use of LP and intraventricular routes allows more efficient delivery of cells to the injured cord compared with the intravenous route. Stem cells delivered via LP for treatment of SCI may potentially be applicable in humans after optimal protocols and safety profiles are established in further studies.
Anomalous vertebral artery at the craniovertebral junction in a patient with Down syndrome
Authors: Yamazaki Masashi , Koda Masao , Yoneda Minori , Aiba Atsuomi , Moriya Hideshige
Published: May 2009

✓ The authors report a case of a patient with Down syndrome in whom the abnormal course of the right vertebral artery (VA) at the craniovertebral junction (CVJ) was accurately demonstrated on three-dimensional (3D) computerized tomography (CT) angiography. The patient was a 5-year-old boy, who developed severe myelopathy. Bone abnormalities were also present at the CVJ, including atlantoaxial and occipitoatlantal instabilities, a hypoplastic odontoid process, and ossiculum terminale. Three-dimensional CT angiography revealed that the right VA was duplicated after emerging from the C-2 transverse foramen. One half of the duplication, an artery that was as large as the left VA, turned posteromedially and entered the spinal canal between C-1 and C-2. The other half, a very small artery, ran as usual and passed through the C-1 transverse foramen. The authors performed an occipitocervical posterior fusion and a C-1 laminectomy. Intraoperatively the course of the anomalous VA was identified on Doppler ultrasonography, and the surgical approach and bone excision were undertaken carefully to avoid VA injury. Postoperatively, resolution of myelopathy was marked. In the surgical treatment of patients with Down syndrome, surgeons should consider the possibility that a VA anomaly is present at the CVJ. With preoperative 3D CT angiography, the anomalous VA can be identified precisely and the possible risk of intraoperative VA injury predetermined.
Trevor disease of the spine
Authors: Schrot Rudolph J. , Kim Kee D. , Fedor Mark
Published: May 2009

✓ The authors report the case of a 15-year-old boy who presented with left shoulder pain and paresthesia of the left hand. Imaging studies revealed an osseous lesion compressing the C-8 nerve root. The patient underwent tumor resection followed by instrumentation-augmented fusion. Histological findings were consistent with osteochondroma. The tumor most likely originated from the articular cartilage between the first rib and T-1 or between C-7 and T-1. The correct diagnosis, therefore, was dysplasia epiphysialis hemimelica (DEH), also known as Trevor disease. To the authors' knowledge, this is the first report of DEH involving the spine.
Accelerated spondylotic changes adjacent to the fused segment following central cervical corpectomy: magnetic resonance imaging study evidence
Authors: Kulkarni Vaijayantee , Rajshekhar Vedantam , Raghuram Lakshminarayan
Published: May 2009

Object. The authors studied whether cervical spine motion segments adjacent to a fused segment exhibit accelerated degenerative changes on short-term follow-up magnetic resonance (MR) imaging.

Methods. Preoperative and short-term follow-up (mean duration 17.5 months, range 10–48 months) cervical MR images obtained in 44 patients who had undergone one- or two-level corpectomy for cervical spondylotic myelopathy were evaluated qualitatively and quantitatively. The motion segment adjacent to the fused segment and a segment remote from the fused segment were evaluated for indentation of the thecal sac, disc height, and sagittal functional diameter of the spinal canal on midsagittal T2-weighted MR images. Thecal sac indentations were classifed as mild, moderate, and severe. New indentations of the thecal sac of varying severity (mild in 17 patients [38.6%], moderate in 10 [22.7%], and severe in six [13.6%]) had developed at the adjacent segments in 33 (75%) of 44 patients. The degenerative changes were seen at the superior level in 11 patients, inferior level in 10 patients, and at both levels in 12 patients and resulted from both anterior and posterior element degeneration in the majority (23 [69.6%]) of patients. The remote segments showed mild thecal sac indentations in seven patients and moderate indentations in two patients (nine [20.5%] of 44). Compared with the changes at the remote segment, the canal size was significantly decreased at the superior adjacent segment by 0.9 mm (p = 0.007). No patient sustained a new neurological deficit due to adjacent-segment changes.

Conclusions. On short-term follow-up MR imaging, levels adjacent to the fused segment exhibited more pronounced degenerative changes (compared with remote levels) in 75% of patients who had undergone one- or two-level central corpectomy.
Intravertebral vacuum phenomenon in osteoporotic compression fracture: report of 67 cases with quantitative evaluation of intravertebral instability
Authors: Kim Dong-Yun , Lee Sang-Ho , Jang Jee Soo , Chung Sang Ki , Lee Ho-Yeon
Published: May 2009

Object. The objectives of this study were to: 1) describe the incidence and clinical features of intravertebral vacuum phenomenon (IVVP) in a relatively large number of cases; 2) quantitatively evaluate intravertebral instability and determine the factors affecting instability; and 3) evaluate the efficacy of percutaneous vertebroplasty in the treatment of this phenomenon.

Methods. A retrospective review was conducted of the records of 67 patients with IVVP among 652 consecutive cases of osteoporotic compression fracture. Comparisons between the IVVP group and a control group, a stable group, and an unstable group were conducted. Percutaneous vertebroplasty was performed in all patients.

There were 67 patients (10.3%) in whom there were 70 vacuum phenomena of the intravertebral space. Intravertebral vacuum phenomena occurred predominantly in the thoracolumbar junction (81%) and in patients with a longer duration of symptoms (10.6 ± 9.8 months) compared with the control group. Of 59 vertebrae for which flexion—extension radiographs were available, 26 vertebrae were categorized as stable and 33 as unstable. Twenty-one vertebrae (64%) had undergone compression fracture in the unstable group compared with nine (35%) compression fractures in the stable group. There were 28 (85%) fractures of the wedged vertebrae in the unstable group compared with 16 (61%) fractures in wedged vertebrae in the stable group. Percutaneous vertebroplasty was performed with successful clinical outcome.

Conclusions. Intravertebral vacuum phenomenon is more common than has been previously appreciated. The results of this study indicate that biomechanics, not ischemic or avascular theory, may play an important role in pathogenesis of this phenomenon. Percutaneous vertebroplasty was found to be a minimally invasive and effective procedure for the treatment of IVVP.
Microsurgical interlaminary vertebro- and kyphoplasty for severe osteoporotic fractures
Authors: Boszczyk Bronek M. , Bierschneider Michael , Schmid Katharina , Grillhösl Andreas , Robert Björn , Jaksche Hans
Published: May 2009

Object. Percutaneous vertebro- and kyphoplasty have become established methods for the treatment of uncomplicated osteoporotic vertebral fractures. In the setting of severe fractures involving fragmentation of the posterior wall and neural compromise, however, decompressive surgery cannot be performed and epidural cement leakage is poorly controlled. A microsurgical interlaminary approach for vertebro- and kyphoplasty was developed to allow spinal decompression and control of the spinal canal during augmentation.

Methods. Interlaminary vertebro- or kyphoplasty was performed in 24 patients with osteoporotic fractures involving neural compression or posterior wall fragmentation. After unilateral microsurgical fenestration, decompression of the spine, and gentle mobilization of the thecal sac, vertebro- or kyphoplasty was performed directly through the posterior wall of the fractured vertebral body. Cement was injected under microscopic and fluoroscopic control, with the option of immediate exploration of the exposed spinal canal. Thirty-four levels (T-8 to L-5) were treated. Mean blood loss was less than 100 ml and augmentation added 10 to 40 minutes to the entire procedure. Cement leakage associated with the kyphoplasty procedure was less than that in vertebroplasty. There were no major complications. One patient was lost to follow up. Clinical outcome was good or excellent in 17 of the 23 patients available for follow-up (1 to 31—month) evaluation.

Conclusions. The present microsurgical interlaminary approach for vertebro- and kyphoplasty enables treatment of severe osteoporotic fractures involving fragmentation of the posterior wall and neural compromise. Decompressive surgery is possible and the risk of epidural cement leakage is controlled intraoperatively. This technique can be regarded as a procedure on the treatment continuum between percutaneous augmentation and conventional open reconstruction.
Rotational and transpositional flaps for the treatment of spinal wound dehiscence and infections in patient populations with degenerative and oncological disease
Authors: Vitaz Todd W. , Oishi Masaki , Welch William C. , Gerszten Peter C. , Disa Joseph J. , Bilsky Mark H.
Published: May 2009

Object. Wound-related complications following complex posterior spine procedures may result in the need for serial debridements and may place the instrumentation at risk. Numerous treatments have been advocated for this problem, but each has limitations. In this article the authors discuss the experience from two large teaching institutions at which rotational and transpositional flaps were used in the management of deep wound infections and dehiscences.

Methods. The authors generated a list of patients treated via posterior or posterolateral approaches for metastatic tumors or complex degenerative disorders in whom wound complications subsequently developed. Data were obtained from the medical records and reviewed retrospectively.

Thirty-seven patients were treated with rotational or transpositional flaps at the two institutions during the study period. Patients underwent a mean of 1.3 procedures for the treatment of wound healing problems, and cultures were positive in 70%. In three patients (8%) this treatment failed due to protrusion of hardware through the skin or repeated dehiscence requiring reclosure. Spinal instrumentation was salvaged in 97% of the cases.

Conclusions. The use of local tissue flaps is advantageous for treatment of posterior wound complications due to spine surgery. In this procedure highly vascularized tissue is used to increase healing, accelerate clearance of bacteria, and fill any dead space.
Bladder function after incomplete spinal cord injury in mice: quantifiable outcomes associated with bladder function and efficiency of dehydroepiandrosterone as a therapeutic adjunct
Authors: Mure Pierre-Yves , Galdo Mark , Compagnone Nathalie
Published: May 2009

Object. The authors conducted a study to establish outcomes associated with bladder function in a mouse model of spinal cord injury (SCI) and to assess the sensitivity of these outcomes in determining the efficacy of pharmacological treatments.

Methods. A mouse model of moderate contusive SCI was used. Outcome parameters included physiological, behavioral, and morphological measurements. To test the sensitivity of these outcomes, the authors used a dehydroepiandrosterone (DHEA) treatment that they had previously shown to promote neurological recovery effectively after SCI.

A behavioral scale was used to identify the day at which autonomic function of the bladder was recovered. The reduction in the daily volume of urine during the period of functional recovery paralleled this scale. They then determined the day postinjury at which the functional differences between the vehicle- and DHEA-treated mice exhibited the maximal amplitude. Changes were measured in the composition of the extracellular matrix relative to collagen expression in the layer muscularis of the detrusor at this time point. They found that SCI increases the ratio of collagen type III to collagen type I in the detrusor. Moreover, in the DHEA-treated group, this ratio was similar to that demonstrated in sham-operated mice, establishing the sensitivity of this outcome to assess therapeutic benefits to the bladder function. They next examined the relationship between measurements of neurological recovery and controlled voiding by using cluster analysis.

Conclusions. The authors found that early recovery of controlled voiding is predictive of motor recovery.
Open reduction of pediatric atlantoaxial rotatory fixation: long-term outcome study with functional measurements
Authors: Crossman John E. , David Karoly , Hayward Richard , Crockard H. Alan
Published: May 2009

Object. Atlantoaxial rotatory fixation (AARF) is an uncommon disorder of childhood in which resolution usually occurs spontaneously or after traction therapy. In a minority of children irreducible or chronic fixation develop, and the natural history then usually involves restriction of head on neck movement, abnormal head position, and progressive facial asymmetry. The conventional management in these cases has been a posterior fusion.

Methods. The authors performed an open reduction via the extreme-lateral approach without adjunctive fixation surgery in 13 children who ranged in age from 4 to 11 years. Postoperatively, halo jacket therapy was undertaken for 8 to 12 weeks. There were no neurological complications despite damage to one vertebral artery and one wound infection.

Functional outcome was assessed after a minimum of 24 months (range 29–72 months). Facial asymmetry markedly improved. Sagittal movements were similar to those observed in control individuals. Axial rotation, although reduced compared with that in controls, was present but usually asymmetrical.

Conclusions. In the authors' opinion, open reduction provides the best possibility of normal facial development and return of axial movement in cases of AARF.
Retrospective study of surgery-related outcomes in patients with syringomyelia associated with Chiari I malformation: clinical significance of changes in the size and localization of syrinx on pain relief
Authors: Nakamura Masaya , Chiba Kazuhiro , Nishizawa Takashi , Maruiwa Hirofumi , Matsumoto Morio , Toyama Yoshiaki
Published: May 2009

Object. Pain is one of the major symptoms in patients with syringomyelia; however, its origin is not fully understood, and postoperative improvement of pain is difficult to predict. The objectives of this study were to assess the surgery-related results obtained in patients who underwent treatment for syringomyelia associated with Chiari I malformation, particularly related to pain status, and to identify factors that may influence improvement in postoperative pain by comparing pre- and postoperative magnetic resonance (MR) imaging findings.

Methods. The correlation between pre- and postoperative changes in the size and the location of the syrinx and pain improvement was investigated in 25 patients. The shapes of the syringes were classified into three types: central, enlarged, and deviated. In most cases in which the syrinx deviated toward the posterolateral aspect of the spinal cord at the level corresponding to dermatomal distribution of preoperative pain, the lesion remained at the same position postoperatively, and improvement in pain was poor. On the other hand, enlarged-type syringes were the most frequently observed prior to surgery, exhibited diverse changes postoperatively, and improvement in pain status was difficult to predict. When postoperative MR imaging revealed a transformation to the deviated type, poor pain improvement was noted.

Conclusions. Neurons in the dorsal horn were thought to be involved in the development of pain as a result of the deafferentiation mechanism in cases of syringomyelia.
Vascular complications related to lumbar disc surgery
Authors: Bingol Hakan , Cingoz Faruk , Yilmaz Ahmet Turan , Yasar Mehmet , Tatar Harun
Published: May 2009

Object. Vascular complications related to lumbar disc operations are rare but extremely fatal conditions. The authors analyzed data retrospectively obtained in 13 patients with vascular complications that occurred during lumbar disc operations performed between January 1990 and January 2002.

Methods. One patient underwent an L5—S1 procedure and the remaining underwent L4–5 surgery. Missed injuries, which were found during the late postoperative period, included pseudoaneurysm in four cases and an arteriovenous fistula in one. In all cases except one in which complication occurred early in the postoperative period, the retroperitoneal area was reached via a transperitoneal approach. In eight patients with complications occurring early in the postoperative period, Dacron graft was placed in four with arterial injuries and saphenous vein graft in one. In three cases of arterial injury and five of venous injury, the lesion was repaired using the primer suture technique.

The most commonly affected vessels were left common iliac arteries (76.9%) and left common iliac vein (30.8%). In eight early cases, shock or preshock due to hemorrhage developed during the early phase. During the late postoperative period, graft-related infection occurred in two cases in which Dacron graft was placed, and axillofemoral extraanatomical bypass surgery was later performed. There was no surgery-related death. During a mean follow-up period of 5.6 years, none of the patients suffered any problems related to vascular injury.

Conclusions. Despite its low incidence, iatrogenic vascular injury related to lumbar disc surgery is a possible complication. During lumbar disc operations early diagnosis of vascular injuries and urgent transperitoneal surgery can save patients' lives.
Safety and efficacy of spinal cord stimulation for the treatment of chronic pain: a 20-year literature review
Authors: Cameron Tracy
Published: May 2009

Object. The purpose of this report was to examine the available literature to determine the safety and efficacy of spinal cord stimulation (SCS) for the treatment of chronic pain of the trunk and limbs.

Methods. The author identified 68 studies that fulfilled the efficacy inclusion/exclusion criteria, grouped on the basis of pain indication, with an overall population of 3679 patients. Fifty-one studies fulfilled all safety inclusion/exclusion criteria. Based on the literature review, the author found that SCS had a positive, symptomatic, long-term effect in cases of refractory angina pain, severe ischemic limb pain secondary to peripheral vascular disease, peripheral neuropathic pain, and chronic low-back pain, and that, in general, SCS was a safe and effective treatment for a variety of chronic neuropathic conditions.

Conclusions. Despite the positive findings, there is an urgent need for randomized, controlled, long-term studies on the efficacy of SCS involving larger patient sample sizes.
Cervical peridural calcification in patients undergoing long-term hemodialysis
Authors: Shiraishi Tateru , Ikegami Takeshi , Okubo Yasuhiro , Yato Yoshiyuki , Honda Masanori
Published: May 2009

✓ The authors report on two patients undergoing long-term hemodialysis in whom cervical myelopathy was caused by calcification related to the cervical dural sac. The lesions were demonstrated on plain computerized tomography (CT) scans as dotted curvilinear bands outlining the dural sacs in almost the whole of their cervical spines. During posterior decompressive surgery in both cases, the CT scanning—documented curvilinear bands were identified as calcified plaques infiltrating the fibrous membranes beneath the ligamenta flava, constricting the cervical dural tube. In each case, the spinal cord could not be decompressed by merely enlarging the osseous spinal canal; rather, it required removal of the calcified membrane from the posterior surface of the dura. Based on the operative findings, the lesion should be described as cervical peridural calcification.
Spinal meningeal melanocytoma
Authors: Turhan Tuncer , Oner Kazim , Yurtseven Taskin , Akalin Taner , Ovul Izzet
Published: May 2009

✓ The authors report on two patients with spinal meningeal melanocytoma and review the literature on this lesion. One case is particularly interesting because of the lesion's thoracic intramedullary localization. Meningeal melanocytoma is a benign but locally aggressive lesion and is very rarely associated with spinal localizations. This patient presented with paraparesis. Clinical and radiological examinations suggested the possibility of an intramedullary solid tumor. Thoracic laminectomy, posterior myelotomy, and tumor resection were performed; the mass was totally removed. The patient suffered no additional neurological deficit. During a 3-year follow-up period in which radiotherapy was not performed, the lesion did not recur. Total excision of the tumor is the best therapeutic option.
Gadolinium leakage into the surgical bed mimicking residual enhancement following spinal cord surgery
Authors: Walker Matthew , Khawar Saquib , Shaibani Ali , Reddy Sireen , Ganju Aruna , Gupta Manu
Published: May 2009

✓ Intramedullary spinal cord surgery can disrupt the blood—spinal cord barrier and cause intravascular contents to leak into the surgical cavity. Immediate postoperative Gd-enhanced magnetic resonance (MR) imaging can demonstrate leakage of contrast into the surgical bed and complicate the assessment of whether a residual enhancing tumor is present. The authors report a case in which the preoperative lesion was nonenhancing and not expected to enhance on postoperative imaging. A Gd-enhanced MR imaging study obtained less than 24 hours after surgery revealed that the intramedullary surgical cavity was filled with contrast material. Because of the time course and the lesion's preoperative appearance, this “enhancement” was known to be caused by the leakage of medium into the resection cavity rather than of pathological soft-tissue enhancement
Thoracic pedicle screws: postoperative computerized tomography scanning assessment
Authors: Heary Robert F. , Bono Christopher M. , Black Margaret
Published: May 2009

Object. The authors evaluated the accuracy of placement of thoracic pedicle screws by performing postoperative computerized tomography (CT) scanning. A grading system is presented by which screw placement is classified in relation to neurological, bone, and intrathoracic landmarks.

Methods. One hundred eighty-five thoracic pedicle screws were implanted in 27 patients with the assistance of computer image guidance or fluoroscopy. Postoperative CT scanning was conducted to determine a grade for each screw: Grade I, entirely contained within pedicle; Grade II, violates lateral pedicle but screw tip entirely contained within the vertebral body (VB); Grade III, tip penetrates anterior or lateral VB; Grade IV, breaches medial or inferior pedicle; and Grade V, violates pedicle or VB and endangers spinal cord, nerve root, or great vessels and requires immediate revision. Based on anatomical morphometry, the spine was subdivided into upper (T1–2), middle (T3–6), and lower (T7–12) regions. Statistical analyses were performed to compare regions. The mean follow-up period was 37.6 months.

The following postoperative CT scanning—documented grades were determined: Grade I, 160 screws (86.5%); Grade II, 15 (8.1%); Grade III, six (3.2%); Grade IV, three (1.6%); and Grade V, one (0.5%). Among cases involving screw misplacements, Grade II placement was most common, and this occurred most frequently in the middle thoracic region.

Conclusions. The authors' grading system has advantages over those previously described; however, further study to determine its reliability, reproducibility, and predictive value of clinical sequelae is warranted. Postoperative CT scanning should be considered the gold standard for evaluating thoracic pedicle screw placement.
Dural closure, cord approximation, and clot removal: enhancement of tissue sparing in a novel laceration spinal cord injury model
Authors: Zhang Yi Ping , Iannotti Christopher , Shields Lisa B. E. , Han Yingchun , Burke Darlene A. , Xu Xiao-Ming , Shields Christopher B.
Published: May 2009

Object. Laceration-induced spinal cord injury (SCI) results in the invasion of a connective tissue scar, progressive damage to the spinal cord due to complex secondary injury mechanisms, and axonal dieback of descending motor pathways. The authors propose that preparation of the spinal cord for repair strategies should include hematoma removal and dural closure, resulting in apposition of the severed ends of the spinal cord. Such procedures may reduce the size of the postinjury spinal cord cyst as well as limit scar formation.

Methods. Using a novel device, the Vibraknife, the authors created a dorsal hemisection of the spinal cord at C-6 in the adult rat. In Group 1 (eight rats), the dura mater was repaired with apposition of the two stumps of the spinal cord to reduce the lesion gap. In Group 2 (10 rats), the dura was not closed and the two cord stumps were not approximated. All rats were killed at 4 weeks postinjury, and the spinal cords from each group were removed and examined using histological, stereological, and immunohistochemical methods.

In Group 1 rats a significant reduction of the total lesion volume and connective tissue scar was observed compared with those in Group 2 (Student t-test, p < 0.05). Approximation of the stumps did not promote the regeneration of corticospinal tract fibers or sensory axons through the lesion site.

Conclusions. Apposition of the severed ends of the spinal cord by dural closure reduces the lesion gap, cystic cavitation, and connective tissue scar formation. These outcomes may collectively reduce secondary tissue damage at the injury site and shorten the length of the lesion gap, which will facilitate transplantation-mediated axonal regeneration after laceration-induced SCI.
Cough induced by ossification of the ligamentum flavum in the high cervical spine
Authors: Chou Yu-Cheng , Lee Chau-Chin , Yen Pao-Sheng , Lin Jui-Feng , Su Chain-Fa , Lin Shinn-Zong , Chen Wu-Fu
Published: May 2009

✓ The authors report a very rare case of high cervical ossification of the ligamentum flavum (OLF) in a 40-year-old woman who developed an intractable cough after a traffic accident. The patient's symptoms subsided immediately after decompressive laminectomy and removal of the lesion. To the authors' knowledge, this is the first reported case of high cervical OLF in a patient who presented with a cough. The pathophysiological mechanism underlying the cough was determined to be symptomatic of high cervical spine OLF.
Intracerebral pneumocephalus and hemiparesis as a complication of a halo vest in a patient with multiple myeloma
Authors: Hashimoto Yasushi , Doita Minoru , Hasuda Keiichiro , Korosue Kazuyoshi
Published: May 2009

✓ A halo orthosis is often used to immobilize the cervical spine after severe injury in patients who cannot tolerate surgery. Although complications such as pin loosening or brain abscess have been reported, there are no reported cases of hemiparesis following pneumocephalus associated with halo use. The authors report the case of a 77-year-old man with multiple myeloma who, after undergoing halo vest therapy and chemotherapy, suddenly developed hemiparesis and speech disturbance. Diagnostic neuroimaging demonstrated penetration of the inner table at the right posterior pin site and intracerebral pneumocephalus at the parietal lobe. Intraoperative inspection revealed only air and no purulent materials or cerebrospinal fluid in the cystic lesion. When a halo device is used, attention to detail in pin application, maintenance, and proper pin-site care must be undertaken to minimize complications. The tightening of the pin in cases in which late-onset loosening has occurred should not be performed. Additionally, because late loosening of the pin and pin-site infection increase the risks of complications, a halo vest should be used only as a short-term treatment, and the clinician should be aware of the possible increased risk of serious complications such as pneumocephalus or subdural abscess formation.
Monostotic fibrous dysplasia of the thoracic spine: clinopathological description and follow up
Authors: Arazi Mehmet , Guney Onder , Ozdemir Mustafa , Uluoglu Omer , Uzum Nuket
Published: May 2009

✓ The authors report the case of a 53-year-old woman with monostotic fibrous dysplasia of the thoracic spine. The patient presented with a 1-month history of pain in the thoracic spinal region. En bloc resection of the lesion was successfully performed via a transthoracic approach, and a histopathological examination confirmed the diagnosis of fibrous dysplasia. At 24-month follow-up examination, pain and vertebral instability were absent.

The findings in this case illustrate that, although very rare, monostotic fibrous dysplasia of the thoracic spine should be considered in the differential diagnosis of spinal tumors. Although a consensus for management of this disease has not been achieved, the authors recommend radical removal of all involved bone as well as internal fixation or bone graft—assisted fusion to achieve long-term stabilization.
Dural arteriovenous fistula of the lumbar spine presenting with subarachnoid hemorrhage
Authors: Koch Christoph , Gottschalk Stefan , Giese Alf
Published: May 2009

✓ The authors report on a patient presenting with subarachnoid hemorrhage (SAH) that was initially attributed to an aneurysm of the right internal carotid artery. During surgical exploration and placement of a clip, however, it was observed that the aneurysm had not ruptured. Diagnostic workup including spinal magnetic resonance imaging revealed a vascular malformation of the lumbar spinal canal within a subarachnoid hematoma. Spinal angiography demonstrated a spinal dural arteriovenous fistula (DAVF) (Type I spinal arteriovenous malformation) with a feeding vessel arising from the L-4 radicular artery. In the literature, SAH due to spinal DAVFs is rare; only cases of dural fistulas of the craniocervical junction and the cervical spine have been reported. This is the first case of SAH that can be attributed to a lumbar DAVF. Although unusual even in cases of cervical DAVF, SAH as a presenting symptom may occur in spinal DAVF of any location. Nontraumatic SAH should not be prematurely attributed to the rupture of an intracranial aneurysm if the clinical findings and imaging results are inconclusive.
Closed reduction vertebroplasty for the treatment of osteoporotic vertebral compression fractures
Authors: Lee Shih-Tseng , Chen Jyi-Feng
Published: May 2009

✓ The purpose of this study was to determine the efficacy and feasibility of closed reduction vertebroplasty for the treatment of osteoporotic vertebral compression fractures.

Two hundred consecutive patients (183 women and 17 men) with single-level osteoporotic vertebral compression fracture were included in this study. After induction of general anesthesia, the patient was placed prone on an operating table. Closed reduction of the fractured and kyphotic spine was achieved by extending the table to restore the kyphotic angle and vertebral body (VB) height. Percutaneous vertebroplasty was then performed to treat the fractured vertebra. The results were quantitatively evaluated, according to the concept of estimated VB height. The anterior, middle, and posterior VB heights of the fractured vertebra were measured preoperatively and immediately after surgery by studying plain standing lateral radiographs.

In 162 (81%) of the compression fractures the anterior VB height was restored (57.1 ± 24.8% of lost anterior VB height); in 152 (76%) of the compression fractures the middle VB height was restored (61.4 ± 20.6% of lost middle VB height); and in 52 (26%) of the compression fractures the posterior VB height was restored (51.3 ± 23.1% of lost posterior VB height). In 141 (71.5%) of the compression fractures kyphosis was corrected by 12.5 ± 3.8° [mean 61.6 ± 23.7%]).

Closed reduction vertebroplasty is an efficacious and simple method in the treatment of osteoporotic vertebral compression fracture and was able to restore the VB height and kyphotic angle in postions of fractured vertebrae. Its associated, long-term effects on treated vertebrae, however, need further evaluation.
Impact of interlaminar graft materials on the fusion status in atlantoaxial transarticular screw fixation
Authors: Matsumoto Morio , Chiba Kazuhiro , Nakamura Masaya , Ogawa Yuto , Toyama Yoshiaki , Ogawa Jun
Published: May 2009

Object. Structural interlaminar graft materials were used for atlantoaxial transarticular screw fixation (TSF), and its impact on the fusion status was investigated.

Methods. Forty-two patients (10 men, 32 women, mean age 51 years, mean follow-up period 45 months; 30 with rheumatoid arthritis, and 12 with os odontoideum) underwent TSF and modified Brooks posterior wiring involving titanium cables. As interlaminar graft materials, autologous bone from posterior iliac crest alone was used in 20 patients (Group A), and a structural spacer (13 ceramic spacers, nine titanium mesh cages) in 22 (Group B). Lateral radiographs were evaluated to determine bone fusion, alignment of the cervical spine, and wire loosening. Solid osseous fusion was obtained in 95% of Group A and 96% of Group B patients. The mean atlantoaxial angle was 19.1 ± 9.7° and 16.7 ± 10.4° before surgery (p = 0.45), and 27.4± 7.8° and 22.1 ± 5.5° after surgery (p = 0.02) in Groups A and B, respectively. Atlantoaxial hyperlordosis (atlantoaxial angle ≥ 30°) was observed in 32% of Group A and 18% of Group B patients (p = 0.26). Postoperative kyphosis occurred in 40% of Group A and 23% of Group B patients (p = 0.28). Loosening of the cable was demonstrated in 50% of Group A and 36% of Group B patients (p = 0.37). In Group B patients maintenance of cervical lordosis was more likely than in those in Group A, although the differences did not reach statistical significance.

Conclusions. These results indicate that structural interlaminar spacers can maintain proper cervical alignment without a decease in the fusion rate; the authors recommend their use in conjunction with TSF.
Calcium phosphate cement leakage after percutaneous vertebroplasty for osteoporotic vertebral fractures: risk factor analysis for cement leakage
Authors: Nakano Masato , Hirano Norikazu , Ishihara Hirokazu , Kawaguchi Yoshiharu , Matsuura Kousou
Published: May 2009

Object. The purpose of this study was to analyze the risk factors for leakage of calcium phosphate cement (CPC) after vertebroplasty for osteoporotic vertebral fractures and to determine whether the vertebral body (VB) leakage caused any changes in the therapeutic benefits.

Methods. Between August 2000 and April 2002, the authors performed 65 CPC-assisted vertebroplasty procedures in 55 patients with thoracic or lumbar osteoporotic vertebral fractures. Back and low-back pain were evaluated using the visual analog scale and the duration of analgesic medication requirement. Factors related to CPC leakage and the postoperative outcome were analyzed.

There was a small amount of VB CPC leakage in 23 cases. In 10 of 23 cases, leakage into the epidural space was found. Although VB CPC leakage was independently associated with high initial age, female sex, high bone mineral density (BMD), short injury—surgery interval, and injection via the unipedicular route in the logistic regression analysis, there was no factor associated with CPC leakage into the epidural space. Cement leakage into the epidural space reduced the immediate therapeutic effects on fracture-related pain (p = 0.0128). All patients in whom cement leaked into the epidural space had improved by the 2-week follow-up examination.

Conclusions. Advanced initial age, female sex, high BMD, a short interval from injury to surgery, and injection via the unipedicular route may increase the incidence of CPC leakage. Cement leakage into the epidural space attenuated only the immediate therapeutic effects of CPC-assisted vertebroplasty.
Postoperative fibrosis after surgical treatment of the porcine spinal cord: a comparison of dural substitutes
Authors: Haq Iftikharul , Cruz-Almeida Yenisel , Siqueira Edir B. , Norenberg Michael , Green Barth A. , Levi Allan D.
Published: May 2009

Object. Postoperative adhesion- and fibrosis-induced spinal cord tethering is not uncommon and may be associated with delayed clinical sequelae. Multiple dural substitutes have been used in surgery without a full appreciation of the grafts' adverse effects. The authors conducted a comparative animal experimental study to evaluate the degree of chronic inflammatory reactions, adhesions, and fibrosis caused by the use of four dural substitutes—Surgicel, Durasis, DuraGen, and Preclude.

Methods. Twenty-six pigs weighing 30 to 40 kg underwent a two-level lumbar laminectomy (a midline durotomy, implantation of a 2-cm dural substitute in the subarachnoid space, and watertight dural closure). After 8 weeks the animals were killed, and two independent neuropathologists blinded to the dural substitute group evaluated several sites along the implants, providing descriptions and quantitative scoring of fibrosis, chronic inflammatory reactions, foreign-body reactions, and spinal cord changes. Kruskal—Wallis one-way analysis of variance for ranks corrected for multiple comparisons was used to examine differences among the materials.

Conclusions. The DuraGen dural substitute produced the least amount of inflammation in the subarachnoid space and Preclude generated the most (p < 0.001). Surgicel and DuraGen were completely resorbed on histological sections, but both produced some inflammation, which diminished gradually from the dural implant center. Histological evaluation of the nonresorbed grafts demonstrated that Durasis caused the least degree of inflammatory cell infiltration (p < 0.001). The Preclude dural substitute consistently demonstrated encapsulation and arachnoidal reaction. There was no evidence of implant-related adverse effects on the underlying pia mater and white matter regardless of the substitute type.
Diagnosis-related pitfall of a lateral sacral cyst
Authors: Heckly Anne , Carsin-Nicol Beatrice , Poulain Patrice , Hamlat Abderrahmane
Published: May 2009

✓ Because physical examination typically demonstrates normal findings in cases of low-back pain, diaglosis of the cause can be challenging. Frequent magnetic resonance imaging studies of the lumbosacral spine can typically lead to discovery of benign diseases and thus misinterpretation of these images.

The authors report an unusual case in which a functional ovarian cyst was incidentally associated with a perineural cyst and mimicked a lateral sacral meningocele. In light of this, the authors recommend repeated examinations to avoid mistakes.