bluuebunny/crossref_metadata_2025 huggingface dataset:
Application accuracy in frameless image-guided neurosurgery: a comparison study of three patient-to-image registration methods
Authors: Woerdeman Peter A. , Willems Peter W. A. , Noordmans Herke J. , Tulleken Cornelis A. F. , van der Sprenkel Jan Willem Berkelbach
Published: January 2008

Object

The aim of this study was to compare three patient-to-image registration methods in frameless stereotaxy in terms of their application accuracy (the accuracy with which the position of a target can be determined intraoperatively). In frameless stereotaxy, imaging information is transposed to the surgical field to show the spatial position of a localizer or surgical instrument. The mathematical relationship between the image volume and the surgical working space is calculated using a rigid body transformation algorithm, based on point-pair matching or surface matching.

Methods

Fifty patients who were scheduled to undergo a frameless image-guided neurosurgical procedure were included in the study. Prior to surgery, the patients underwent either computerized tomography (CT) scanning or magnetic resonance (MR) imaging with widely distributed adhesive fiducial markers on the scalp. An extra fiducial marker was placed on the head as a target, as near as possible to the intracranial lesion. Prior to each surgical procedure, an optical tracking system was used to perform three separate patient-to-image registration procedures, using anatomical landmarks, adhesive markers, or surface matching. Subsequent to each registration, the target registration error (TRE), defined as the Euclidean distance between the image space coordinates and world space coordinates of the target marker, was determined.

Independent of target location or imaging modality, mean application accuracy (± standard deviation) was 2.49 ± 1.07 mm when using adhesive markers. Using the other two registration strategies, mean TREs were significantly larger (surface matching, 5.03 ± 2.30 mm; anatomical landmarks, 4.97 ± 2.29 mm; p < 0.001 for both).

Conclusions

The results of this study show that skin adhesive fiducial marker registration is the most accurate noninvasive registration method. When images from an earlier study are to be used and accuracy may be slightly compromised, anatomical landmarks and surface matching are equally accurate alternatives.
Association between absence of epidermal growth factor receptor immunoreactivity and poor prognosis in patients with atypical meningioma
Authors: Smith Justin S. , Lal Anita , Harmon-Smith Miranda , Bollen Andrew W. , McDermott Michael W.
Published: January 2008

Object

The clinical behavior of meningiomas is variable. Because multiple growth factor receptors have been identified in these tumors, the authors sought to assess the capacity of the expression patterns of a subset of these receptors to stratify meningioma cases.

Methods

Eighty-four meningiomas were analyzed, including 36 benign, 29 atypical, and 19 malignant lesions. Immunohistochemical staining was performed for epidermal growth factor receptor (EGFR), platelet-derived growth factor receptor (PDGFR)–β, basic fibroblast growth factor receptor (BFGFR), and MIB-1. Survival analyses were performed using follow-up data obtained in patients with newly diagnosed tumors.

Immunoreactivity for EGFR was observed in 47% of benign, 48% of atypical, and 42% of malignant tumors. Staining for BFGFR was identified in 89% of benign, 97% of atypical, and 95% of malignant lesions. Immunostaining for PDGFR-β was evident in all the lesions assessed. Mean MIB-1 indices for benign, atypical, and malignant cases were 3.6 (range 0.5–15.3), 8.2 (range 1.5–23.1) and 18.3 (range 1.0–55.8), respectively. Overall mean follow-up duration was 9.0 years (range 5.1–18.8 years). Lack of EGFR immunoreactivity was identified as a strong predictor of shorter overall survival in patients with atypical meningioma (p = 0.003, log-rank test). This association was not evident in cases of benign or malignant meningiomas.

Conclusions

There is a significant association between EGFR immunoreactivity and prolonged survival in patients with atypical meningioma. Given the variable behavior of atypical meningiomas, EGFR assessment could improve existing strategies for patient stratification and treatment.
Microsurgical anatomy of the superior petrosal venous complex: new classifications and implications for subtemporal transtentorial and retrosigmoid suprameatal approaches
Authors: Tanriover Necmettin , Abe Hiroshi , Rhoton Albert L. , Kawashima Masatou , Sanus Galip Z. , Akar Ziya
Published: January 2008

Object

The purpose of this study was to define the patterns of drainage of the superior petrosal venous complex (SPVC) along the petrous ridge in relation to the Meckel cave and internal acoustic meatus (IAM) and to delineate its effect on the surgical exposures obtained in subtemporal transtentorial and retrosigmoid suprameatal approaches.

Methods

The patterns of drainage of the SPVC along the petrous ridge were characterized according to their relation to the Meckel cave and the IAM based on an examination of 30 hemispheres. Subtemporal transtentorial and retro-sigmoid suprameatal approaches were performed in three additional cadavers to demonstrate the effect of the drainage pattern on the surgical exposures.

Conclusions

The SPVC emptied into the superior petrosal sinus (SPS) within a distance of 1 cm from the midpoint of the Meckel cave. The patterns of drainage of the SPVC were classified into three groups. Type I emptied into the SPS above and lateral to the boundaries of the IAM. The most common type, Type II, emptied between the lateral limit of the trigeminal nerve at the Meckel cave and the medial limit of the facial nerve at the IAM, within an area of approximately 13 mm. Type III emptied into the SPS above or medial to the Meckel cave. The ideal SPVC for a subtemporal transtentorial approach (with or without anterior extradural petrosectomy) seems to be a Type I. In SPVC Type III and those Type II cases in which the SPVC is located near the Meckel cave, the amount of working space is significantly limited in a subtemporal transtentorial approach. In contrast, the ideal type of SPVC for a retrosigmoid suprameatal approach would be a Type III, and the SPVC must be divided in the majority of Type I and II cases for a satisfactory surgical exposure along the Meckel cave and middle fossa dura. The proposed modified classification system and its effect on the surgical exposure may aid in planning the approach directed along the petrous apex and may reduce the probability of venous complications.
Sensitivity of patient-specific numerical simulation of cerebal aneurysm hemodynamics to inflow boundary conditions
Authors: Venugopal Prem , Valentino Daniel , Schmitt Holger , Villablanca J. Pablo , Viñuela Fernando , Duckwiler Gary
Published: January 2008

Object

Due to the difficulty of obtaining patient-specific velocity measurements during imaging, many assumptions have to be made while imposing inflow boundary conditions in numerical simulations conducted using patient-specific, imaging-based cerebral aneurysm models. These assumptions can introduce errors, resulting in lack of agreement between the computed flow fields and the true blood flow in the patient. The purpose of this study is to evaluate the effect of the assumptions made while imposing inflow boundary conditions on aneurysmal hemodynamics.

Methods

A patient-based anterior communicating artery aneurysm model was selected for this study. The effects of various inflow parameters on numerical simulations conducted using this model were then investigated by varying these parameters over ranges reported in the literature. Specifically, we investigated the effects of heart and blood flow rates as well as the distribution of flow rates in the A1 segments of the anterior cerebral artery.

The simulations revealed that the shear stress distributions on the aneurysm surface were largely unaffected by changes in heart rate except at locations where the shear stress magnitudes were small. On the other hand, the shear stress distributions were found to be sensitive to the ratio of the flow rates in the feeding arteries as well as to variations in the blood flow rate.

Conclusions

Measurement of the blood flow rate as well as the distribution of the flow rates in the patient's feeding arteries may be needed for numerical simulations to accurately reproduce the intraaneurysmal hemodynamics in a specific aneurysm in the clinical setting.
Malignant transformation of intracranial mature teratoma to yolk sac tumor after late relapse
Authors: Utsuki Satoshi , Oka Hidehiro , Sagiuchi Takao , Shimizu Satoru , Suzuki Sachio , Fujii Kiyotaka
Published: January 2008

✓ The recurrence of intracranial mature teratomas as germ cell tumors of different histological types is rarely reported. The authors describe the first case of the malignant transformation of an intracranial mature teratoma into a yolk sac tumor in a 16-year-old boy who presented with a 1-month history of anorexia and somnolence. Seven years prior to this presentation, the boy had undergone surgery for extirpation of a mature pineal teratoma. Computed tomography images obtained at his second presentation revealed a homogeneously enhanced mass within the third ventricle. The tumor was resected and the results of a histological examination were consistent with a yolk sac tumor. After resection, the patient underwent radiation therapy followed by chemotherapy with cisplatin and etoposide but died of tumor progression 15 months after his second hospitalization.
Use of 5-aminolevulinic acid in fluorescence-guided resection of meningioma with high risk of recurrence
Authors: Kajimoto Yoshinaga , Kuroiwa Toshihiko , Miyatake Shin-Ichi , Ichioka Tsugumichi , Miyashita Minoru , Tanaka Hidekazu , Tsuji Motomu
Published: January 2008

✓It has been established that fluorescence-guided resection using 5-aminolevulinic acid (5-ALA) is useful in glioma surgery. The authors report on a 65-year-old woman who had a huge atypical left-hemisphere meningioma, which extended into the skull and to the superior sagittal sinus and demonstrated fluorescence in response to administration of 5-ALA. After the tumor was removed, the operative field was observed under the fluorescent mode of a fluorescence surgical microscopy system. Several minute areas of residual tumor tissue were visualized as strong fluorescence behind the vein and sinus, in a part of the hypertrophic dura, and along the edge of the skull. These remnants were completely removed. The authors concluded that fluorescence-guided resection using 5-ALA is useful in cases of atypical meningiomas with a high risk of recurrence.
Insertion of subdural strip electrodes for the investigation of temporal lobe epilepsy
Authors: Steven David A. , Andrade-Souza Yuri M. , Burneo Jorge G. , McLachlan Richard S. , Parrent Andrew G.
Published: January 2008

✓ Temporal lobe epilepsy (TLE) is the most common type of surgically treatable epilepsy, with a considerable number of patients needing invasive electroencephalography monitoring. The authors describe a surgical technique used in the placement of subdural strip electrodes for coverage of the temporal lobe. The electrodes are inserted through an enlarged temporooccipital bur hole using fluoroscopic guidance. With this technique, subdural electrode strips can be safely placed to cover the mesial, inferior, and lateral temporal surfaces, and the seizure focus can be lateralized and localized within the temporal lobe. The technique does not require the use of a craniotomy, stereotactic frame, or neuronavigation systems. The authors compare this technique with previous descriptions of subdural electrode placement for the evaluation of TLE.
Neurosurgical experience with malpractice litigation: an analysis of closed claims against neurosurgeons in New York State, 1999 through 2003
Authors: Rovit Richard L. , Simon Arlene Stolper , Drew Josephine , B.B.A.  , Murali Raj , Robb James
Published: January 2008

Object

Neurosurgeons are a high-risk group for allegations of malpractice. To determine the kinds of cases and the neurosurgical practice patterns associated with the highest proportion of litigation, the authors examined the experience over a 5-year period of a major physician-owned and -administered insurance company dealing with this issue, the Medical Liability Mutual Insurance Company (MLMIC) of New York. With the MLMIC cases as a basis, the authors also analyzed areas of physician vulnerability and determined the steps neurosurgeons can take to reduce potential litigation.

Methods

All cases closed against MLMIC-insured neurosurgeons from January 1, 1999, through December 30, 2003, were reviewed. Variables examined included allegation, anatomical site, and the ultimate resolution of the case. Of the 280 cases against neurosurgeons that were closed during the study period, 156 (56%) involved the spine, 109 (39%) involved the head and/or brain, and 15 (5%) reflected miscellaneous allegations. These proportions are relatively similar to the 1999 procedural statistics for neurosurgical practices. Of the cases examined, 98 were closed with a total loss indemnity of approximately $50 million, and 182 resulted in no indemnity payment.

Conclusions

A neurosurgeon's chances of being sued for malpractice are not necessarily related to the medical complexity of a particular case but rather to the types of cases with which the physician is involved. Elective spinal surgery cases constitute the majority of litigation. Neurosurgeons can take steps to reduce their vulnerability to potential litigation and to increase the odds of a successful defense.
Gamma Knife surgery for Cushing's disease
Authors: Jagannathan Jay , Sheehan Jason P. , Pouratian Nader , Laws Edward R. , Steiner Ladislau , Vance Mary Lee
Published: January 2008

Object

In this study the authors address the efficacy and safety of Gamma Knife surgery (GKS) in patients with adrenocorticotropic hormone–secreting pituitary adenomas.

Methods

A review of data collected from a prospective GKS database between January 1990 and March 2005 was performed in patients with Cushing's disease. All but one patient underwent resection for a pituitary tumor, without achieving remission. Successful endocrine outcome after GKS was defined as a normal 24-hour urinary free cortisol (UFC) concentration posttreatment after a minimum of 1 year of follow up. Patient records were also evaluated for changes in tumor volume, development of new hormone deficiencies, visual acuity, cranial nerve neuropathies, and radiation-induced imaging changes. Ninety evaluable patients had undergone GKS, with a mean endocrine follow-up duration of 45 months (range 12–132 months). The mean dose to the tumor margin was 23 Gy (median 25 Gy).

Normal 24-hour UFC levels were achieved in 49 patients (54%), with an average time of 13 months after treatment (range 2–67 months). In the 49 patients in whom a tumor was visible on the planning magnetic resonance (MR) image, a decrease in tumor size occurred in 39 (80%), in seven patients there was no change in size, and tumor growth occurred in three patients. Ten patients (20%) experienced a relapse of Cushing's disease after initial remission; the mean time to recurrence was 27 months (range 6–60 months). Seven of these patients underwent repeated GKS, with three patients achieving a second remission. New hormone deficiencies developed in 20 patients (22%), with hypothyroidism being the most common endocrinopathy after GKS. Five patients experienced new visual deficits or third, fourth, or sixth cranial nerve deficits; two of these patients had undergone prior conventional fractionated radiation therapy, and four of them had received previous GKS. Radiation-induced changes were observed on MR images in three patients; one had symptoms attributable to these changes.

Conclusions

Gamma Knife surgery is an effective treatment for persistent Cushing's disease. Adenomas with cavernous sinus invasion that are not amenable to resection are treatable with the Gamma Knife. A second GKS treatment appears to increase the risk of cranial nerve damage. These results demonstrate the value of combining two neurosurgical treatment modalities—microsurgical resection and GKS—in the management of pituitary adenomas.
Gamma Knife surgery for adrenocorticotropic hormone–producing pituitary adenomas after bilateral adrenalectomy
Authors: Mauermann William J. , Sheehan Jason P. , Chernavvsky Daniel R. , Laws Edward R. , Steiner Ladislau , Vance Mary Lee
Published: January 2008

Object

Patients with adrenocorticotropic hormone (ACTH)–secreting pituitary adenomas may require a bilateral adrenalectomy to treat their Cushing's disease. Approximately one third of these patients, however, will experience progressive enlargement of the residual pituitary adenoma, develop hyperpigmentation, and have an elevated level of serum ACTH. These patients with Nelson's syndrome can be treated with Gamma Knife surgery (GKS).

Methods

The prospectively collected University of Virginia Gamma Knife database of patients with pituitary adenomas was reviewed to identify all individuals with Nelson's syndrome who were treated with GKS. Twenty-three patients with a minimum of 6 months of follow up were identified in the database. These patients were assessed for tumor control (that is, lack of tumor growth over time) with neuroimaging studies (median follow-up duration 22 months) and for biochemical normalization of their ACTH levels (median follow-up duration 50 months). Neuroimaging follow-up studies were available for 22 patients, and endocrine follow up was available for 15 patients in whom elevation of ACTH levels was documented prior to GKS.

In the 22 patients in whom neuroimaging follow-up studies were available, 12 had a decrease in tumor size, eight had no tumor growth, and two had an increase in tumor volume. Ten of 15 patients with elevated ACTH levels prior to GKS showed a decrease in their ACTH levels at last follow up; three of these 10 patients achieved normal ACTH levels (< 50 pg/ml) and the other five patients with initially elevated values had an increase in ACTH levels.

Ten patients were thoroughly evaluated for post-GKS pituitary function; four were found to have new pituitary hormone deficiency and six did not have hypopituitarism after GKS. One patient suffered a permanent third cranial nerve palsy and four patients are now deceased.

Conclusions

Gamma Knife surgery may control the residual pituitary adenoma and decrease ACTH levels in patients with Nelson's syndrome. Delayed hypopituitarism or cranial nerve palsies can occur after GKS. Patients with Nelson's syndrome require continued multidisciplinary follow-up care. Given the difficulties associated with management of Nelson's syndrome, even the modest results of GKS may be helpful for a number of patients.
A prospective randomized controlled trial of anterior compared with posterior stabilization for unilateral facet injuries of the cervical spine
Authors: Kwon Brian K. , Fisher Charles G. , Boyd Michael C. , Cobb John , Jebson Hilary , Noonan Vanessa , Wing Peter , Dvorak Marcel F.
Published: January 2008

Object

Unilateral facet injuries can be treated with either anterior or posterior fixation techniques with reportedly good outcomes. The two approaches have not been directly compared, however, and consensus is lacking as to which is the optimal method. The primary objective of this study was to determine whether acute postoperative morbidity differed between anteriorly and posteriorly treated patients with unilateral facet injuries.

Methods

Forty-two patients were prospectively randomized to undergo either anterior cervical discectomy and fusion or posterior fixation. The primary outcome measure was the postoperative time required to achieve a predefined set of discharge criteria. Secondary outcome measures included postoperative pain, wound infections, radiographically demonstrated fusion and alignment, and patient-reported outcome measures.

Results

The median time to achieve the discharge criteria was 2.75 and 3.5 days for anterior and posterior groups, respectively, a difference that did not reach statistical significance (p = 0.096). Compared with those treated using posterior fixation, anteriorly treated patients exhibited somewhat less postoperative pain, a lower rate of wound infection, a higher rate of radiographically demonstrated union, and better radiographically proven alignment. Nonetheless, the anterior approach was accompanied by a risk of swallowing difficulty in the early postoperative period. Patient-reported outcome measures did not reveal a difference between anterior and posterior fixation procedures.

Conclusions

This prospective randomized controlled trial provided level 1 evidence that both the anterior and posterior fixation approaches appear to be valid treatment options. Although statistical significance was not reached in the primary outcome measure, some secondary outcome measures favored anterior fixation and others favored posterior treatment for unilateral facet injuries.
Results of surgical treatment for thoracic myelopathy: minimum 2-year follow-up study in 132 patients
Authors: Aizawa Toshimi , Sato Tetsuro , Sasaki Hirotoshi , Matsumoto Fujio , Morozumi Naoki , Kusakabe Takashi , Itoi Eiji , Kokubun Shoichi
Published: January 2008

Object

Thoracic myelopathy is uncommon compared with cervical myelopathy. In this study, data obtained in patients with thoracic myelopathy caused by degenerative processes of the spine were retrospectively analyzed to clarify the surgical outcomes and to examine the various factors affecting the postoperative improvement.

Methods

Between 1988 and 2002, 132 patients with thoracic myelopathy underwent surgery and a minimum 2-year observation period. Clinical data were collected from medical and operative records, and sagittal alignment of the spine was measured on radiographs. The patients were evaluated pre- and postoperatively using the modified Japanese Orthopaedic Association (JOA) scale (maximum score 11). The relationships among various factors affecting the preoperative severity of myelopathy and postoperative improvement were also examined.

Results

The population consisted of 97 men (mean age at surgery was 58 years) and 35 women (mean age at surgery 62 years). Myelopathy was caused by ossification of the ligamentum flavum (OLF) in 73 patients, ossification of the posterior longitudinal ligament (OPLL) in 21, combined OLF–OPLL in 10, intervertebral disc herniation (IDH) in 15, posterior bone spur in 11, and OLF with IDH or posterior bone spur in one patient each. The surgical outcome was relatively good: a mean preoperative JOA score of 5.3 improved to a mean score of 7.8 at the last follow-up, 50 months on average after surgery. Thoracic myelopathy caused by OPLL, however, was associated with lower postoperative scores and recovery rates. In more than half of the patients the authors documented an increase of kyphosis of less than 2°.

Conclusions

Patients with a shorter preoperative duration of symptoms and milder myelopathy experienced significantly better postoperative neurological conditions, which indicated that those who present earlier with fewer disabilities should be recommended to undergo surgery in time, although the surgical treatment for OPLL still involves many problems.
A biomechanical cadaveric analysis of polymethylmethacrylate-augmented pedicle screw fixation
Authors: Frankel Bruce M. , D'Agostino Sabino , Wang Chiang
Published: January 2008

Object

Instrumentation of the osteoporotic spine can be fraught with complications such as hardware failure. A cadaver study was performed to determine the biomechanical performance of polymethylmethacrylate (PMMA)–augmented pedicle screws.

Methods

Three osteoporotic human cadaveric specimens with a mean bone mineral density of 0.70 g/cm2 were used to evaluate the performance of a novel fenestrated bone tap in pedicle screw augmentation. On this device, tap threads serve a dual purpose in preventing backflow of cement toward neural elements while allowing for a custom form for subsequent screw placement. The tap was used to inject a mean volume of 3.7 ml PMMA/pedicle (range 2–8.0 ml PMMA/pedicle) followed by pedicle screw placement between L-5 and T-5, alternating between augmented and nonaugmented instrumentation. Axial pullout testing was then performed.

Results

Pedicle screw pullout strength was increased in both primary and salvage procedures by 119% (p = 0.001) and 162% (p = 0.01), respectively, after PMMA augmentation. Additionally, the injected cement volumes were divided into two groups, a low-cement group (≤ 2.8 ml/pedicle) and a high-cement group (≥ 5.5 ml/pedicle). Interestingly, the pullout strength did not significantly change with increased cement usage between the two groups (p > 0.05 for all comparisons).

Conclusions

Polymethylmethacrylate-augmented pedicle screw fixation results in a significant increase in the axial pullout strength of augmented pedicle screws in both primary and revision procedures. This technique may be a valuable adjunct in cases in which bolstering of the screw–bone interface is necessary.
Hypoxia-inducible expression of vascular endothelial growth factor for the treatment of spinal cord injury in a rat model
Authors: Choi Byung Hyune , Ha Yoon , Huang Xian , Park So Ra , Chung Joonho , Hyun Dong Keun , Park Hyeonseon , Park Hyung Chun , Kim Sung Wan , Lee Minhyung
Published: January 2008

Object

Vascular endothelial growth factor (VEGF) has been investigated as a therapy for many disorders and injuries involving ischemia. In this report, we constructed and evaluated a hypoxia-inducible VEGF expression system as a treatment for spinal cord injury (SCI).

Methods

The hypoxia-inducible VEGF plasmid was constructed using the erythropoietin (Epo) enhancer with the Simian virus 40 (SV40) promoter (pEpo-SV-VEGF) or the RTP801 promoter (pRTP801-VEGF). The expression of VEGF in vitro was evaluated after transfection into N2A cells. The plasmids were then injected into rat spinal cords with contusion injuries. The expression of VEGF in vivo was measured using reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay. Locomotor recovery in the rats was evaluated using the Basso, Beattie and Bresnahan (BBB) scale for locomotor analysis.

Results

In vitro transfection showed that pEpo-SV-VEGF or pRTP801-VEGF induced VEGF expression under hypoxic conditions, whereas pSV-VEGF did not. The VEGF level was higher in the pEpo-SV-VEGF and pRTP801-VEGF groups than in the control group. The VEGF expression was detected in neurons and astrocytes of the spinal cord. Locomotor recovery was improved in the pEpo-SV-VEGF and pRTP801-VEGF groups, and BBB scores were higher than in the control group. Staining using terminal deoxynucleotidyl transferase–mediated deoxyuridine triphosphate nick-end labeling showed that the number of apoptotic cells decreased in the plasmid-injected groups compared with the control group, and significant differences were observed between the hypoxia-responsive groups and the pSV-VEGF group.

Conclusions

These results suggest that the hypoxia-inducible VEGF expression system may be useful for gene therapy of SCI.
Lumbar vertebral hemangioma presenting with the acute onset of neurological symptoms
Authors: Chen H. Isaac , Heuer Gregory G. , Zaghloul Kareem , Simon Scott L. , Weigele John B. , Grady M. Sean
Published: January 2008

✓Vertebral hemangiomas are common entities that rarely present with neurological deficits. The authors report the unusual case of a large L-3 vertebral hemangioma with epidural extension in a 27-year-old woman who presented with hip flexor and quadriceps weakness, foot drop, and leg pain. The characteristics of the mass on magnetic resonance imaging suggested an aggressive, hypervascular lesion. The patient underwent embolization of the lesion followed by direct intralesional injection of ethanol. Significant resolution of clinical symptoms was observed immediately after the procedure and at her follow-up visits. Follow-up imaging studies obtained 9 months after the procedure also documented a considerable reduction in the size of the hemangioma with minimal loss of vertebral height and a mild kyphosis at the affected level. On repeated imaging studies obtained 21 months postoperatively, the size of the hemangioma and the degree of vertebral body compression were stable. As demonstrated in this case, patients with vertebral hemangiomas can present with acute nerve root compression and signs and symptoms similar to those of disc herniation. Vertebral hemangiomas can be treated effectively with interventional techniques such as embolization and ethanol injection.
Atlantoaxial joint jamming as a treatment for atlantoaxial dislocation: a preliminary report
Authors: Goel Atul
Published: January 2008

✓In this report the author describes an alternative technique of atlantoaxial fixation that involves blocking or “jamming” of movements of the atlantoaxial joint. The technique involves forcible impaction of spiked titanium metal spacers and bone grafts within the distracted atlantoaxial facet joints. Between January 2003 and January 2006, four patients underwent this method of fixation at the Department of Neurosurgery at King Edward Memorial Hospital in Mumbai, India. All four patients had posttraumatic mobile and reducible atlantoaxial dislocation. The mean follow-up period was 16 months (range 5–35 months). Successful atlantoaxial stabilization along with ultimate bone fusion was achieved in all patients and was documented on dynamic radiographs. There were no neurological, vascular, or infection-associated complications.

The author concludes that the described method of atlantoaxial fixation provides an alternative treatment strategy. “Joint jamming” as a stand-alone method or in combination with other fixation methods may provide firm stabilization in cases of atlantoaxial dislocation.
Percutaneous fibrin glue therapy for meningeal cysts of the sacral spine with or without aspiration of the cerebrospinal fluid
Authors: Zhang Tao , Li Zhenhua , Gong Weiming , Sun Bingwei , Liu Shuheng , Zhang Kai , Yin Dezhen , Xu Peng , Jia Tanghong
Published: January 2008

Object.

The authors assessed the efficacy of computed tomography (CT)–guided percutaneous injection of fibrin glue to treat meningeal cysts of the sacral spine in patients with back pain, and evaluated the necessity for cerebrospinal fluid (CSF) aspiration before glue injection.

Methods.

Of the 31 patients in this study, 15 underwent injection of fibrin glue under CT guidance after aspiration of more than 15 ml of CSF (Group A), and 16 patients were treated with the glue but without CSF aspiration (Group B). Clinical results were evaluated after an average of 23 months of follow-up, and changes on the imaging studies were also evaluated. The clinical outcome and postoperative complications were analyzed.

Results.

All 31 patients experienced resolution or marked improvement of symptoms for as long as 28 months after fibrin glue therapy. No patient experienced recurrence of symptoms during the follow-up interval. The postoperative pain relief was statistically significant (p < 0.001) according to evaluations in which a 100-mm visual analog pain scale was used. There were no statistical differences between the two groups (p > 0.05).

Conclusions.

Percutaneous CT-guided fibrin glue therapy for sacral arachnoid cysts may be a definitive therapy. It is unnecessary to aspirate the CSF before injection of the fibrin glue.
Phase I/II study of stereotactic body radiotherapy for spinal metastasis and its pattern of failure
Authors: Chang Eric L. , Shiu Almon S. , Mendel Ehud , Mathews Leni A. , Mahajan Anita , Allen Pamela K. , Weinberg Jeffrey S. , Brown Barry W. , Wang Xin Shelly , Woo Shiao Y. , Cleeland Charles , Maor Moshe H. , Rhines Laurence D.
Published: January 2008

Object.

The authors report data concerning the safety, effectiveness, and patterns of failure obtained in a Phase I/II study of stereotactic body radiotherapy (SBRT) for spinal metastatic tumors.

Methods.

Sixty-three cancer patients underwent near-simultaneous computed tomography–guided SBRT. Spinal magnetic resonance imaging was conducted at baseline and at each follow-up visit. The National Cancer Institute Common Toxicity Criteria 2.0 assessments were used to evaluate toxicity.

Results.

The median tumor volume of 74 spinal metastatic lesions was 37.4 cm3 (range 1.6–358 cm3). No neuropathy or myelopathy was observed during a median follow-up period of 21.3 months (range 0.9–49.6 months). The actuarial 1-year tumor progression–free incidence was 84% for all tumors. Pattern-of-failure analysis showed two primary mechanisms of failure: 1) recurrence in the bone adjacent to the site of previous treatment, and 2) recurrence in the epidural space adjacent to the spinal cord. Grade 3 or 4 toxicities were limited to acute Grade 3 nausea, vomiting, and diarrhea (one case); Grade 3 dysphagia and trismus (one case); and Grade 3 noncardiac chest pain (one case). There was no subacute or late Grade 3 or 4 toxicity.

Conclusions.

Analysis of the data obtained in the present study supports the safety and effectiveness of SBRT in cases of spinal metastatic cancer. The authors consider it prudent to routinely treat the pedicles and posterior elements using a wide bone margin posterior to the diseased vertebrae because of the possible direct extension into these structures. For patients without a history of radiotherapy, more liberal spinal cord dose constraints than those used in this study could be applied to help reduce failures in the epidural space.
Motion in the unstable cervical spine: comparison of manual turning and use of the Jackson table in prone positioning
Authors: Bearden Brook G. , Conrad Bryan P. , Horodyski MaryBeth , Rechtine Glenn R.
Published: January 2008

Object.

The purpose of this study was to compare manual maneuvering with the use of a Jackson table when moving patients with cervical spine instability from the supine to the surgically appropriate prone position.

Methods.

The range of motion (ROM) of the cervical spine of a fresh cadaver was measured. A ligamentous instability was created at the C5–6 level, and the increased ROM was confirmed. Sensors for an electromagnetic motion analysis device were fixed to the anterior portions of the C-5 and C-6 vertebral bodies (VBs) using machined polyethylene mounts and carbon fiber rods that were inserted into the VBs. The sensors were used to measure cervical flexion, lateral bending, and axial rotation during the two transfer procedures. The cadaver was then moved from the supine position on a hospital bed to the prone position for surgery. The manual technique was performed by four trained individuals who moved the cadaver from the hospital bed while rotating it 180° axially onto the surgical table. In using the Jackson table, the cadaver was moved from the bed to the table in the supine position and then the Jackson table rotated the cadaver to the prone position. The two techniques were tested with and without the use of a collar and were repeated five times.

Results.

Analysis of the data indicated that when moving a patient into the prone surgical position, the use of a cervical collar and the Jackson table significantly reduced the cervical motion in all angular planes compared with that of manual transfer.

Conclusions.

The use of a cervical collar and the Jackson table may reduce the possibility of further spinal cord compromise. Because manual transfers are performed routinely, this warrants further study.
Ossification of the posterior longitudinal ligament of the cervical spine: histopathological findings around the calcification and ossification front
Authors: Sato Ryuichiro , Uchida Kenzo , Kobayashi Shigeru , Yayama Takafumi , Kokubo Yasuo , Nakajima Hideaki , Takamura Takaharu , Bangirana Alexander , Itoh Hiroshi , Baba Hisatoshi
Published: January 2008

Object.

The authors studied the histological and immunohistochemical features of ossified posterior longitudinal ligament (PLL) of the cervical spine, especially in the calcification and ossification front.

Methods.

Samples of en bloc ossified PLL plaque obtained in 31 patients were stained with H & E and immuno-histochemically prepared for collagens (types I and II), vascular endothelial growth factor (VEGF), transforming growth factor (TGF)–β, and bone morphogenetic protein (BMP)–2, and by terminal deoxynucleotidyl transferase–mediated deoxyuridine triphosphate nick-end labeling method for apoptosis.

Results.

Enchondral ossification was evident between the ligamentous enthesis and deep layer of the ligament, with irregularly disorganized arrangement of elastic fibers in association with advancement of the degenerative process. In the ossification front, many hypertrophic metaplastic chondrocytes were noted in the ossifying plaque immediately contiguous to the ligament fibers, together with a considerable degree of neovascularization. Both TGFβ and BMP-2 were highly expressed in metaplastic hypertrophic chondrocytes in the ossification front, and BMP-2 was also expressed in fibroblastic cells near the ossified PLL plaque. Expression of type I collagen was significant in the matrix of the ossified PLL lesion, whereas that of type II was marked in metaplastic chondrocytes in the ossification front. Apoptotic hypertrophic chondrocytes were observed mainly in the fibrocartilaginous area near the calcification front.

Conclusions.

The enchondral ossification process in the ossified PLL was closely associated with degenerative changes of elastic fibers and cartilaginous cartilage formation, together with the appearance of metaplastic hypertrophic cartilage cells and neovascularization. The authors also found that VEGF-positive metaplastic chondrocytes in the ossification front and different expression patterns of collagens probably play some role in the extension of the ossified PLL from the ossification front.
Angiographically occult spinal dural arteriovenous fistula located using selective computed tomography angiography
Authors: Sugawara Taku , Hirano Yoshitaka , Itoh Yasunobu , Kinouchi Hiroyuki , Takahashi Satoshi , Mizoi Kazuo
Published: January 2008

✓Spinal dural arteriovenous fistula (DAVF) is the most common type of spinal arteriovenous malformation and may cause progressive myelopathy but is usually treatable in the early stages by direct surgery or intravascular embolization. Selective spinal angiography has been the gold standard for diagnosis, but angiographically occult DAVF is not uncommon. A 67-year-old man presented with a 2-year history of progressive paraparesis. Magnetic resonance (MR) imaging demonstrated segmental atrophy of the spinal cord and dilated coronary veins on the dorsal surface of the spinal cord. A DAVF was suspected, but repeated selective angiography failed to demonstrate the fistula. Findings from spoiled gradient echo MR imaging suggested that the draining vein flowed into the dilated venous plexus at the T-9 level. Selective computed tomography (CT) angiography of the right T-9 intercostal artery confirmed the location of the fistula. The authors successfully occluded the draining vein through surgery, and they observed that the fistula was low flow. The patient exhibited improvement in his symptoms, and postoperative MR imaging confirmed closure of the fistula. Selective CT angiography is useful in locating the draining vein of angiographically occult DAVF and therefore minimizing the extent of the surgical procedure.
Iatrogenic splenic injury during anterior thoracolumbar spinal surgery
Authors: Sin Anthony , Smith Donald , Nanda Anil
Published: January 2008

✓The proximity of major abdominal structures encountered in the approach for an anterior thoracolumbar spinal operation makes patients vulnerable to potential intraoperative complications. The spleen, in particular, can be easily injured during manipulation or from being under retractors for a number of hours, although it is a rarely reported phenomenon in the literature. The authors report on a 52-year-old man who suffered a spleen laceration following anterior L1–2 corpectomy and fusion for osteomyelitis of the lumbar spine. The patient required an emergency splenectomy, but he made a full recovery.
Dural damage due to a loosened hydroxyapatite intraspinous spacer after spinous process–splitting laminoplasty
Authors: Ono Atsushi , Yokoyama Toru , Numasawa Takuya , Wada Kanichiro , Toh Satoshi
Published: January 2008

✓Excellent results from laminoplasty for cervical spinal myelopathy have been reported in many studies. Nevertheless, C-5 nerve root palsy or axial pain such as neck and shoulder pain after laminoplasty are known postoperative complications. To the authors' knowledge, dural damage from dislocation of the hydroxyapatite intraspinous spacer due to absorption of the tip of the spinous process has not been reported. Two cases of dural damage from dislocation of the hydroxyapatite intraspinous spacer after laminoplasty are described.

Radiographs, computed tomography myelography, and magnetic resonance (MR) imaging revealed the dislocation of the hydroxyapatite intraspinous spacer, the absorption of the tip of the spinous process, and dural sac compression due to the hydroxyapatite intraspinous spacer. In one patient, the MR imaging studies revealed liquorrhea around the hydroxyapatite intraspinous spacers. Both patients underwent removal of the hydroxyapatite intraspinous spacer and attained good neurological recovery.

In patients with dislocation of the hydroxyapatite intraspinous spacer associated with absorption of the tip of the spinous process after spinous process–splitting laminoplasty, each case should be evaluated for aggravating symptoms of myelopathy, dural damage, and liquorrhea around the spacer.
Pigmented villonodular synovitis associated with pathological fracture of the odontoid and atlantoaxial instability
Authors: Finn Michael A. , McCall Todd D. , Schmidt Meic H.
Published: January 2008

✓Pigmented villonodular synovitis (PVNS) is a proliferative disorder of the synovium with a predisposition for the appendicular skeleton. Rarely PVNS can arise from the spine, where this disorder usually presents with localized or radicular pain secondary to involvement of the posterior elements. The authors report the case of an 82-year-old woman who presented with long-standing neck pain and acute upper-extremity numbness and weakness. Computed tomography imaging revealed a mixed sclerotic and lucent lesion affecting the dens and right lateral mass of C-2. There was also a pathological fracture at the base of the dens with 8 mm of anterior dens displacement. Magnetic resonance imaging demonstrated a diffusely infiltrative process that was nonenhancing. Because of instability, the patient underwent transarticular screw fixation, and a biopsy of the lesion was also performed at this time. Histopathological analysis was consistent with a diagnosis of PVNS. To the authors' knowledge, this is the first report of PVNS involving the C-2 vertebra or causing a pathological fracture.
A huge presacral Tarlov cyst
Authors: Ishii Kazuhiko , Yuzurihara Masahito , Asamoto Shunji , Doi Hiroshi , Kubota Motoo
Published: January 2008

✓ Perineural cysts have become a common incidental finding during lumbosacral magnetic resonance (MR) imaging. Only some of the symptomatic cysts warrant treatment. The authors describe the successful operative treatment of a patient with, to the best of their knowledge, the largest perineural cyst reported to date.

A 29-year-old woman had been suffering from long-standing constipation and low-back pain. During an obstetric investigation for infertility, the clinician discovered a huge presacral cystic mass. Computed tomography myelography showed the lesion to be a huge Tarlov cyst arising from the left S-3 nerve root and compressing the ipsilateral S-2 nerve. The cyst was successfully treated by ligation of the cyst neck together with sectioning of the S-3 nerve root. Postoperative improvement in her symptoms and MR imaging findings were noted.

Identification of the nerve root involved by the cyst wall, operative indication, operative procedure, and treatment of multiple cysts are important preoperative considerations.
A comparison of long-term outcomes of translaminar facet screw fixation and pedicle screw fixation: a prospective study
Authors: Tuli Jayshree , Tuli Sagun , Eichler Marc E. , Woodard Eric J.
Published: January 2008

Object

In this paper, the authors compare the long-term outcomes of translaminar facet screw fixation (TFSF) and pedicle screw fixation (PSF) in the treatment of degenerative lumbosacral disease.

Methods

This prospective analytical study was performed to compare the long-term outcomes of TFSF and PSF for degenerative lumbosacral disease. Outcomes were defined as the need for reoperation for the development of a nonunion, end-fusion degeneration, or for explantation of hardware.

Results

A total of 77 patients were analyzed. Thirty-seven patients underwent PSF and 40 received TFSF. Twenty-three of the 77 patients required a reoperation: 13 (32.5%) of the 40 patients in the TFSF group and 10 (27%) of the 37 the patients in the PSF group. The overall mean time to reoperation (regardless of outcome) was 4.05 years. For patients in the TFSF group the mean time to reoperation was 2.94 years, whereas it was 4.35 years in the PSF group (p = 0.34). Nonunion was noted in seven of the 40 patients in the TFSF group and one of 37 in the PSF group. The mean time to surgery for nonunion for patients in the TFSF group was 3.46 years and for those in the PSF group it was 6.27 years (p = 0.04). Surgery for end-fusion degeneration was performed in two patients in the TFSF group and five in the PSF group (p = 0.43). Explantation of hardware was performed in two patients with TFSF and four patients with PSF.

Multivariable analysis revealed a statistically significant difference in the time to surgery for nonunion between PSF and TFSF (p = 0.048), with a hazard ratio of 0.097 (95% confidence interval 0.01–0.98).

Conclusions

Findings from the current prospective study suggest that there is an increased risk of requirement for a reoperation for nonunion among TFSF cases compared with PSF cases.