bluuebunny/crossref_metadata_2025 huggingface dataset:
Accuracy of pedicle screw placement in the lumbosacral spine using conventional technique: computed tomography postoperative assessment in 102 consecutive patients
Authors: Amato Vincenzo , Giannachi Luigi , Irace Claudio , Corona Claudio
Published: February 2011

Object

The goal of this study was to determine the incidence of screw misplacement and complications in a group of 102 patients who underwent transpedicle screw fixation in the lumbosacral spine with conventional open technique and intraoperative fluoroscopy. The results are compared with published data.

Methods

Cases involving 102 consecutive patients (424 inserted screws) were reviewed. Surgery was performed in all cases by the same surgeon's team, using the same implant, and all results were assessed by means of a specific CT protocol. The screw position was assessed by the authors and an independent observer. Screw position was classified as correct when the screw was completely surrounded by the pedicle cortex, as “cortical encroachment” (questionable violation) if the pedicle cortex could not be visualized, and as “frank penetration” when the screw was outside the pedicular boundaries. Frank penetration was further subdivided as minor (when the edge of the screw thread was up to 2.0 mm outside the pedicle cortex), moderate (2.1–4 mm), and severe (> 4 mm). The incidence of intra- and postoperative complications not related to screw position as well as hardware failures were also registered, with a minimum follow-up duration of 8 months.

Results

The rate of frank pedicle screw misplacement was 5%. The rate of minimal or questionable pedicle wall violation was 2.8%. Among the frank misplacements, 6 were classified as minor, 12 as moderate, and 3 as severe penetration. Two patients (2%) had radicular pain and neurological deficits (inferomedial and inferolateral minor misplacement at L-4 and L-5, respectively), and 5 patients (4.9%) complained only of radicular pain. At the follow-up examination all patients had completely recovered their neurological function and radicular pain was resolved in all cases. The complications not related to screw malposition were 2 pedicle fractures (2% of patients), 1 nerve root injury (1%), and 1 dural laceration (1%). Five patients (4.8%) had postoperative anemia and required transfusions. Superficial or deep wound infection was noted in 3 patients (2.9%). Late hardware failure occurred in 2 patients (2%). One patient developed adjacent segmental instability and required additional surgery to extend the fusion.

Conclusions

Our rates of screw misplacement and complications compare favorably with the lowest rates of the series in which conventional technique was used and are close to the rates reported for image-guided methods. The risk of malpositioning may be reduced with careful preoperative surgical planning, accurate knowledge of the spinal anatomy, surgical experience, and correct indication for conventional surgery. The conventional technique still remains a practical, safe, and effective surgical method for lumbosacral fixation.
Intradiscal electrothermal therapy for symptomatic internal disc disruption: 24-month results and predictors of clinical success
Authors: Assietti Roberto , Morosi Mario , Block Jon E.
Published: February 2011

Object

Degeneration of the intervertebral disc can be the source of severe low-back pain. Intradiscal electrothermal therapy (IDET) is a minimally invasive treatment option for patients with symptomatic internal disc disruption unresponsive to conservative medical care. This study was undertaken in the neurosurgical setting to evaluate 24-month pain and functional outcomes and predictors of clinical success in patients with discogenic back pain treated with IDET.

Methods

Using MR imaging and discography findings, 50 patients with lumbar discogenic pain were identified, underwent IDET treatment, and were followed up for 24 months. Outcomes included assessments of back pain severity based on an 11-point numeric scale and back function based on the Oswestry Disability Index. The Prolo scale was applied to determine economic and functional status at 24 months.

Results

There was an average 68 and 66% improvement in back pain and function, respectively, between pretreatment and 24 months after treatment (p < 0.0001 for both comparisons). A maximum score of 5 on the Prolo scale for economic and functional status was achieved in 63 and 22% of patients, respectively. The global clinical success rate was 78% (39 of 50 patients) based on no reoperations at the affected level due to persistent symptoms, with a ≥ 2-point improvement in pain severity and a ≥ 15-point improvement in back function. Predictors of 24-month clinical success included discographic concordance (p < 0.0001), a high-intensity zone on MR imaging (p = 0.0003), low Pfirrmann grade (p = 0.0002), and more extensive anulus coverage (p < 0.0001). There were no procedure-related adverse events.

Conclusions

The findings of this study suggest that durable clinical improvements can be realized after IDET in highly select surgical candidates with mild disc degeneration, confirmatory imaging evidence of anular disruption, and highly concordant pain provocation on low-pressure discography.
Biomechanical study of the effect of degree of static compression of the spinal cord in ossification of the posterior longitudinal ligament
Authors: Kato Yoshihiko , Kanchiku Tsukasa , Imajo Yasuaki , Kimura Kotaro , Ichihara Kazuhiko , Kawano Syunichi , Hamanaka Daisuke , Yaji Kentaro , Taguchi Toshihiko
Published: February 2011

Object

The authors evaluated the biomechanical effect of 3 different degrees of static compression in a model of the spinal cord in order to investigate the effect of cord compression in patients with ossification of the posterior longitudinal ligament (OPLL).

Methods

A 3D finite element spinal cord model consisting of gray matter, white matter, and pia mater was established. As a simulation of OPLL-induced compression, a rigid plate compressed the anterior surface of the cord. The degrees of compression were 10, 20, and 40% of the anteroposterior (AP) diameter of the cord. The cord was supported from behind by the rigid body along its the posterior border, simulating the lamina. Stress distributions inside of the cord were evaluated.

Results

The stresses on the cord were very low under 10% compression. At 20% compression, the stresses on the cord increased very slightly. At 40% compression, the stresses on the cord became much higher than with 20% compression, and high stress distributions were observed in gray matter and the lateral and posterior funiculus. The stresses on the compressed layers were much higher than those on the uncompressed layer.

Conclusions

The stress distributions at 10 and 20% compression of the AP diameter of the spinal cord were very low. The stress distribution at 40% compression was much higher. The authors conclude that a critical point may exist between 20 and 40% compression of the AP diameter of the cord such that when the degree of the compression exceeds this point, the stress distribution becomes much higher, and that this may contribute to myelopathy.
Cystic deterioration of the C1–2 articulation: clinical implications and treatment outcomes
Authors: Van Gompel Jamie J. , Morris Jonathan M. , Kasperbauer Jan L. , Graner Darlene E. , Krauss William E.
Published: February 2011

Object

Synovial cysts of the cervical spine are rare. Further, synovial cysts of the C1–2 articulation, or retroodontoid cysts, are very rare, with fewer than 20 cases reported overall. The authors report on a single-institution series of 10 patients with C1–2 retroodontoid synovial cysts.

Methods

The charts of 10 patients with pathologically confirmed synovial cysts following resection between January 1998 and June 2009 were reviewed. The clinical presentation, radiographic findings, surgical management, and pre- and postoperative functional levels (reported as a modified Rankin outcome) are reported.

Results

All 10 patients underwent attempts at complete resection of the synovial cyst; none of the lesions were simply aspirated. All 4 patients with an initial recommendation of observation alone ultimately underwent surgery because of their swift neurological deterioration. The mean age at surgery was 75.4 ± 4.6 years (range 54–81 years). The mean presenting cyst volume was 4.6 ± 1.7 cm3. Nine of 10 patients underwent transoral resection of the cyst with posterior fusion. Six of the 10 patients underwent additional posterior laminectomy for decompression. The hospital length of stay varied from 2 to 45 days, with a mean of 19 ± 7 days. All patients undergoing transoral decompression had varying degrees of difficulty with postoperative dysphagia, diagnosed using videofluoroscopy. All patients improved in their modified Rankin Scale score after surgical intervention with a mean follow-up of 42 months (95% CI 12–72 months).

Conclusions

Synovial cysts of the atlantoaxial joint are rare. They occur in older patients in whom clinical deterioration is likely to occur. In most cases, these cysts can be diagnosed preoperatively. Transoral decompression with posterior fusion is an effective treatment for C1–2 degenerative cysts and can be accomplished with few complications. However, the ideal treatment for these lesions remains unknown.
Military aeromedical evacuation, with special emphasis on craniospinal trauma
Authors: Reno Joseph
Published: February 2011

This brief intends to educate civilian neurosurgeons on the structure and function of the US military aeromedical evacuation (AE) system, with special focus on the role of the military neurosurgeon. It highlights the thought process required to participate as a surgical provider in the AE system. It further clarifies the expanded role the AE system plays in nonbattle evacuation.
Can surgery improve neurological function in penetrating spinal injury? A review of the military and civilian literature and treatment recommendations for military neurosurgeons
Authors: Klimo Paul , Ragel Brian T. , Rosner Michael , Gluf Wayne , McCafferty Randall
Published: February 2011

Object

Penetrating spinal injury (PSI), although an infrequent injury in the civilian population, is not an infrequent injury in military conflicts. Throughout military history, the role of surgery in the treatment of PSI has been controversial. The US is currently involved in 2 military campaigns, the hallmark of both being the widespread use of various explosive devices. The authors reviewed the evidence for or against the use of decompressive laminectomy to treat PSI to provide a triservice (US Army, Navy, and Air Force) consensus and treatment recommendations for military neurosurgeons and spine surgeons.

Methods

A US National Library of Medicine PubMed database search that identified all literature dealing with acute management of PSI from military conflicts and civilian urban trauma centers in the post–Vietnam War period was undertaken.

Results

Nineteen retrospective case series (11 military and 8 civilian) met the study criteria. Eleven military articles covered a 20-year time span that included 782 patients who suffered either gunshot or blast-related projectile wounds. Four papers included sufficient data that analyzed the effectiveness of surgery compared with nonoperative management, 6 papers concluded that surgery was of no benefit, 2 papers indicated that surgery did have a role, and 3 papers made no comment. Eight civilian articles covered a 9-year time span that included 653 patients with spinal gunshot wounds. Two articles lacked any comparative data because of treatment bias. Two papers concluded that decompressive laminectomy had a beneficial role, 1 paper favored the removal of intracanal bullets between T-12 and L-4, and 5 papers indicated that surgery was of no benefit.

Conclusions

Based on the authors' military and civilian PubMed literature search, most of the evidence suggests that decompressive laminectomy does not improve neurological function in patients with PSI. However, there are serious methodological shortcomings in both literature groups. For this and other reasons, neurosurgeons from the US Air Force, Army, and Navy collectively believe that decompression should still be considered for any patient with an incomplete neurological injury and continued spinal canal compromise, ideally within 24–48 hours of injury; the patient should be stabilized concurrently if it is believed that the spinal injury is unstable. The authors recognize the highly controversial nature of this topic and hope that this literature review and the proposed treatment recommendations will be a valuable resource for deployed neurosurgeons. Ultimately, the deployed neurosurgeon must make the final treatment decision based on his or her opinion of the literature, individual abilities, and facility resources available.
An historical context of modern principles in the management of intracranial injury from projectiles
Authors: Agarwalla Pankaj K. , Dunn Gavin P. , Laws Edward R.
Published: February 2011

The contemporary management of projectile head injuries owes much to the lessons neurosurgeons have distilled from their experiences in war. Through early investigation and an increasingly detailed account of wartime clinical experience, neurosurgeons—including the field's early giants—began to gain a greater understanding not only of intracranial missile pathophysiology but also of appropriate management. In this paper, the authors trace the development of the principles of managing intracranial projectile injury from the Crimean War in the 19th century through the Vietnam War to provide a context that frames a summary of today's core management principles.
Wartime decompressive craniectomy: technique and lessons learned
Authors: Ragel Brian T. , Klimo Paul , Martin Jonathan E. , Teff Richard J. , Bakken Hans E. , Armonda Rocco A.
Published: February 2011

Object

Decompressive craniectomy (DC) with dural expansion is a life-saving neurosurgical procedure performed for recalcitrant intracranial hypertension due to trauma, stroke, and a multitude of other etiologies. Illustratively, we describe technique and lessons learned using DC for battlefield trauma.

Methods

Neurosurgical operative logs from service (October 2007 to September 2009) in Afghanistan that detail DC cases for trauma were analyzed. Illustrative examples of frontotemporoparietal and bifrontal DC that depict battlefield experience performing these procedures are presented with attention drawn to the L.G. Kempe hemispherectomy incision, brainstem decompression techniques, and dural onlay substitutes.

Results

Ninety craniotomies were performed for trauma over the time period analyzed. Of these, 28 (31%) were DCs. Of the 28 DCs, 24 (86%) were frontotemporoparietal DCs, 7 (25%) were bifrontal DCs, and 2 (7%) were suboccipital DCs. Decompressive craniectomies were performed for 19 penetrating head injuries (13 gunshot wounds and 6 explosions) and 9 severe closed head injuries (6 war-related explosions and 3 others).

Conclusions

Thirty-one percent of craniotomies performed for trauma were DCs. Battlefield neurosurgeons use DC to allow for safe transfer of neurologically ill patients to tertiary military hospitals, which can be located 8–18 hours from a war zone. The authors recommend the L.G. Kempe incision for blood supply preservation, large craniectomies to prevent brain strangulation over bone edges, minimal brain debridement, adequate brainstem decompression, and dural onlay substitutes for dural closure.
Analysis of load sharing on uncovertebral and facet joints at the C5–6 level with implantation of the Bryan, Prestige LP, or ProDisc-C cervical disc prosthesis: an in vivo image-based finite element study
Authors: Kang Heesuk , Park Paul , La Marca Frank , Hollister Scott J. , Lin Chia-Ying
Published: February 2011

Object

The goal of this study was to evaluate and compare load sharing of the facet and uncovertebral joints after total cervical disc arthroplasty using 3 different implant designs.

Methods

Three-dimensional voxel finite element models were built for the C5–6 spine unit based on CT images acquired from a candidate patient for cervical disc arthroplasty. Models of facet and uncovertebral joints were added and artificial discs were placed in the intervertebral disc space. Finite element analyses were conducted under normal physiological loads for flexion, extension, and lateral bending to evaluate von Mises stresses and strain energy density (SED) levels at the joints.

Results

The Bryan disc imposed the greatest average stress and SED levels at facet and uncovertebral joints with flexion-extension and lateral bending, while the ProDisc-C and Prestige LP discs transferred less load due to their rigid cores. However, all artificial discs showed increased loads at the joints in lateral bending, which may be attributed to direct impinging contact force.

Conclusions

In unconstrained/semiconstrained prostheses with different core rigidity, the shared loads at the joints differ, and greater flexibility may result in greater joint loads. With respect to the 3 artificial discs studied, load sharing of the Bryan disc was highest and was closest to normal load sharing with the facet and uncovertebral joints. The Prestige LP and ProDisc-C carried more load through their rigid core, resulting in decreased load transmission to the facet and uncovertebral joints.
Effect of arthroplasty design on cervical spine kinematics: analysis of the Bryan Disc, ProDisc-C, and Synergy Disc
Authors: Lazaro Bruno C. R. , Yucesoy Kemal , Yuksel Kasim Z. , Kowalczyk Izabela , Rabin Doron , Fink Marie , Duggal Neil
Published: February 2011

Object

Cervical total disc replacement has emerged as a surgical option to preserve motion and potentially avoid adjacent-segment disease after anterior cervical discectomy and fusion. Recently, much attention has been directed at the ability of a given device to maintain and/or restore normal segmental alignment. Nonphysiological disc and segmental angulation could result in increased stresses transmitted to the facet joints and posterior elements, conflicting with the essence of arthroplasty and potentially leading to adjacent-segment disease. The goal of this study was to contrast device alignment and segmental kinematics provided by 3 different cervical disc prostheses.

Methods

Sixty patients were retrospectively analyzed and divided into 3 groups receiving the Bryan, ProDisc-C, or Synergy disc. Only single-level arthroplasty cases were included in the study. Lateral dynamic radiographs of the cervical spine were analyzed using quantitative motion analysis software (Medical Metrics, Inc.) to analyze the kinematics at the index level both preoperatively and postoperatively. Several parameters were noted, including range of motion, disc angles, shell angles, anterior and posterior disc heights, translation, and center of rotation. Preoperative and postoperative data were compared using the Student t-test with a significance level of p < 0.05.

Results

Postoperatively, all 3 disc groups maintained adequate range of motion at the implanted level. With respect to the shell angles, the Synergy disc demonstrated the least variability, maintaining 6° lordotic configuration between the device endplates. In the Bryan disc group, significant shell kyphosis developed postoperatively (p < 0.0001). Both ProDisc-C and Synergy discs significantly increased anterior and posterior disc heights (p < 0.0001). The Bryan and Synergy discs maintained the natural center of rotation, whereas significant anterior shift occurred with ProDisc-C.

Conclusions

The goal for motion preservation at the implanted level was achieved using all 3 devices. The Synergy disc was unique in its ability to alter device angulation by 6°. The Bryan disc demonstrated device endplate kyphosis. Both the Synergy disc and ProDisc-C increased disc space height.
Biomechanical evaluation of posterior thoracic transpedicular discectomy
Authors: Deniz Fatih Ersay , Brasiliense Leonardo B. C. , Lazaro Bruno C. R. , Reyes Phillip M. , Sawa Anna G. U. , Sonntag Volker K. H. , Crawford Neil R.
Published: February 2011

Object

The authors investigated the biomechanical properties of transpedicular discectomy in the thoracic spine and compared the effects on spinal stability of a partial and total facetectomy.

Methods

Human thoracic specimens were tested while intact, after a transpedicular discectomy with partial facetectomy, and after an additional total facetectomy was incorporated. Nonconstraining pure moments were applied under load control (maximum 7.5 Nm) to induce flexion, extension, lateral bending, and axial rotation while spinal motion was measured at T8–9 optoelectronically. The range of motion (ROM) and lax zone were determined in each specimen and compared among conditions.

Results

Transpedicular discectomy with and without a total facetectomy significantly increased the ROM and lax zone in all directions of loading compared with the intact spine (p < 0.008). The segmental increase in ROM observed with the transpedicular discectomy was 25%. The additional total facetectomy created an insignificant 3% further increase in ROM compared with medial facetectomy (p > 0.2).

Conclusions

Transpedicular discectomy can be performed in the thoracic spine with a modest decrease in stability expected. Because the biomechanical behavior of a total facetectomy is equivalent to that of a medial facetectomy, the additional facet removal may be incorporated without further biomechanical consequences.
Adult cervical intramedullary teratoma: first reported immature case
Authors: Moon Hong Joo , Shin Bong-Kyung , Kim Joo Han , Kim Jong-Hyun , Kwon Taek-Hyun , Chung Hung-Seob , Park Youn-Kwan
Published: February 2011

Intramedullary teratomas, particularly adult cervicothoracic lesions, are extremely rare. Up to now only 6 cases of intramedullary cervical teratomas have been reported in adults, and all of these were histologically mature. The authors present the case of a 35-year-old man with progressive myelopathic symptoms who was admitted through an outpatient clinic and was surgically treated. The characteristics, diagnosis, epidemiology, and treatment of cervical intramedullary teratomas in adults are also reviewed. Postoperative MR imaging showed that the tumor had been near totally removed, and severely adherent tissue remained ventrocranially with tiny focal enhancement on follow-up MR imaging. Pathological examinations revealed immature teratoma without any malignant component. Adjuvant therapy was not performed. Although no change in neurological findings and symptoms was apparent postoperatively, lesion regrowth was demonstrated on MR imaging 4 months after surgery. At 8 months postoperatively, myelopathic symptoms had developed and a huge intramedullary tumor recurred according to MR imaging. This case is the seventh reported instance of intramedullary cervical teratoma in an adult, and the first case report of the immature type with malignant features.
Ball tip technique for thoracic pedicle screw placement in patients with adolescent idiopathic scoliosis
Authors: Watanabe Kota , Matsumoto Morio , Tsuji Takashi , Ishii Ken , Takaishi Hironari , Nakamura Masaya , Toyama Yoshiaki , Chiba Kazuhiro
Published: February 2011

Object

The aim in this study was to evaluate the efficacy of the ball tip technique in placing thoracic pedicle screws (TPSs), as compared with the conventional freehand technique, in both a cadaveric study and a clinical study of patients with adolescent idiopathic scoliosis. Although posterior spinal surgery using TPSs has been widely applied, these screws are associated with the potential risk of vascular, pulmonary, or neurological complications. To further enhance the accuracy and safety of TPS placement, the authors developed the ball tip technique.

Methods

After creating an appropriate starting point for probe insertion, a specially designed ball tip probe consisting of a ball-shaped tip with a flexible metal shaft is used to make a guide hole into the pedicle. Holding the probe with the fingertips while using an appropriate amount of pressure or by tapping it gently and continuously with a hammer, one can safely insert the ball tip probe into the cancellous channel in the pedicle.

In a cadaveric study, 5 spine fellows with similar levels of experience in placing TPSs applied the ball tip or the conventional technique to place screws in 5 cadavers with no spinal deformities. The incidence of misplaced screws was evaluated by dissecting the spines. In a clinical study, 40 patients with adolescent idiopathic scoliosis underwent posterior surgery with TPS placement via the ball tip or conventional technique (20 patients in each treatment group). The accuracy of the TPS placements was evaluated on postoperative axial CT scanning.

Results

In the cadaveric study, 100 TPSs were evaluated, and the incidence of misplaced screws was 14% in the ball tip group and 34% in the conventional group (p = 0.0192). In the clinical study, 574 TPSs were evaluated. One hundred seventy-one intrapedicular screws (67%) were recognized in the conventional group and 288 (90%) in the ball tip group (p < 0.01). In the conventional and ball tip groups, the respective numbers of TPSs with a pedicle breach of ≤ 2 mm were 20 (8%) and 15 (5%), those with a pedicle breach of > 2 mm were 32 (13%) and 9 (3%; p < 0.01), and those located in the costovertebral joints were 32 (13%) and 7 (2%).

Conclusions

In both cadaveric and clinical studies the ball tip technique enhanced the accuracy of TPS placement as compared with the conventional freehand technique. Thus, the ball tip technique is useful for the accurate and safe placement of TPSs in deformed spines.
Omovertebral bone associated with Sprengel deformity and Klippel-Feil syndrome leading to cervical myelopathy
Authors: Füllbier Lars , Tanner Philipp , Henkes Hans , Hopf Nikolai J.
Published: February 2011

The unusual association of an omovertebral bone with Sprengel deformity and Klippel-Feil syndrome is a complex bone anomaly of unknown incidence and etiology. However, several cases of this rare disease pattern have been reported in the literature. In this paper, the authors present the case of a 34-year-old woman with a 5-month history of progressive gait ataxia and intermittent urinary incontinence, which was found to be caused by aberrant bone growth into the spinal canal from an omovertebral bone that extended from the left scapula pressing into the C-6 vertebral arch and subsequently causing cervical myelopathy. The patient underwent isolated resection of the omovertebral bone and decompression of the spinal canal, and her functional and neurological outcome was favorable.
Topographic relationship between the medial intermuscular septum and the ulnar nerve in the upper arm
Authors: Won Hyung-Sun , Han Seung-Ho , Oh Chang-Seok , Chung In-Hyuk , Kim Seung Min , Lim So Young
Published: February 2011

Object

The authors have observed that the ulnar nerve (UN) passes through the medial intermuscular septum (MIMS) into the posterior compartment of the upper arm in more complicated patterns than those described in anatomy textbooks. Given that these unreported patterns might be related to the idiopathic UN entrapment at the midarm, this study focused on the relationship between the MIMS and the UN.

Methods

One hundred upper arms were dissected. The site at which the UN pierced the MIMS was analyzed and measured from the medial epicondyle.

Results

The relationship between the MIMS and the UN could be classified into 3 types according to whether the nerve pierced the MIMS and whether it ran through a fibrous tunnel within the septum. The UN pierced the MIMS in the middle third of the upper arm.

Conclusions

The results of this study are expected to further understanding of the relationship between the MIMS and the UN. They could also be helpful for surgeons aiming to relieve UN entrapment at the midarm, especially in nerve lesions of idiopathic origin.
Localization of focal epileptic discharges using functional connectivity magnetic resonance imaging
Authors: Stufflebeam Steven M. , Liu Hesheng , Sepulcre Jorge , Tanaka Naoaki , Buckner Randy L. , Madsen Joseph R.
Published: February 2011

Object

In patients with medically refractory epilepsy the accurate localization of the seizure onset zone is critical for successful surgical treatment. The object of this study was to investigate whether the degree of coupling of spontaneous brain activity as measured with functional connectivity MR imaging (fcMR imaging) can accurately identify and localize epileptic discharges.

Methods

The authors studied 6 patients who underwent fcMR imaging presurgical mapping and subsequently underwent invasive electroencephalography.

Results

Focal regions of statistically significant increases in connectivity were identified in 5 patients when compared with an ad hoc normative sample of 300 controls. The foci identified by fcMR imaging overlapped the epileptogenic areas identified by invasive encephalography in all 5 patients.

Conclusions

These results suggest that fcMR imaging may provide an effective high–spatial resolution and noninvasive method of localizing epileptic discharges in patients with refractory epilepsy.
Infiltrative astrocytomas of the thalamus
Authors: Krouwer Hendrikus G. J. , Prados Michael D.
Published: February 2011

✓ Clinical characteristics and outcome in 57 patients with infiltrative thalamic astrocytomas were analyzed retrospectively. The median patient age was 22 years (range 1 to 69 years). Fourteen patients had no surgery, 37 had biopsy, and six had subtotal resection. The histological diagnosis was astrocytoma in 14 patients, anaplastic astrocytoma in 25, and glioblastoma multiforme in two; two specimens were nondiagnostic. The initial treatment was conventional radiation therapy (RT) in 20 patients (one also received interstitial brachytherapy), RT followed by chemotherapy in 18, hyperfractionated RT in 17 (one also received chemotherapy), and chemotherapy alone in two. The median time to tumor progression was 47 weeks (range 5 to 388 weeks); median survival was 73 weeks (range 11 to 502 weeks). Actuarial 1-, 2-, 3-, and 5-year survival rates were 67%, 35%, 24%, and 20%, respectively. Tumor progression was usually treated with chemotherapy. The assessed treatment failure was within 2 months after RT in 12 patients in whom the findings of the neurological and radiological examinations did not correspond. This assessment showed false-negative diagnosis of radiation-induced changes in five patients (42%); false-positive diagnosis of tumor progression could not be ascertained. In univariate Cox proportional-hazards analysis, histological diagnosis of astrocytoma, age under 18 years, and open biopsy were prognostically favorable features; in multivariate analysis, only open biopsy was favorable. Infiltrative astrocytomas of the thalamus carry a dismal prognosis, regardless of the type of treatment. Hyperfractionated RT does not increase toxicity but its benefit over conventional RT remains unproven.
Dorsal root entry zone localization using direct spinal cord stimulation: an experimental study
Authors: Fazl Mahmood , Houlden David A.
Published: February 2011

✓ Direct spinal cord stimulation and recording was performed in five dogs to identify the dorsal root entry zone (DREZ) and long tracts within the dorsal and dorsolateral spinal cord using electrophysiological mapping techniques. Intrathecal recordings were obtained from sites distal to the site of stimulation. Conduction velocity in the fastest conducting fibers was higher following low-intensity stimulation of the dorsolateral spinal cord than after dorsal spinal cord stimulation. The evoked response was larger following dorsolateral than dorsal spinal cord stimulation at a specific stimulus intensity. This technique is useful in identifying the DREZ using electrophysiological criteria alone.
An unusual presentation of Paget disease: pathological fracture of the odontoid
Authors: Sawardekar Umayal G. , Nadimpalli Surya Prakash Rao , Weisenberg Elliot , Kranzler Leonard
Published: February 2011

Paget disease of the cervical spine is a common disease in an uncommon location. The authors present an unusual case of a 58-year-old woman with a pathological fracture through the base of the odontoid vertebra secondary to Paget disease. The purpose of this case report is to describe the radiological features of Paget disease and their important application to treatment management.
Does developmental canal stenosis influence surgical results of bilateral open-door laminoplasty for cervical spondylotic myelopathy?
Authors: Shigematsu Hideki , Ueda Yurito , Koizumi Munehisa , Takeshima Toshichika , Tanaka Yasuhito , Satoh Nobuhisa , Matsumori Hiroaki , Oshima Takuya , Matsuyama Etsuhiro , Kugai Atsuo , Takakura Yoshinori
Published: February 2011

Object

The purpose of this study was to investigate the prevalence of developmental canal stenosis in patients with cervical spondylotic myelopathy (CSM), and the correlation between surgical results and degree of developmental canal stenosis.

Methods

A total of 112 patients who eventually had surgical treatment for CSM were evaluated. Male patients whose sagittal spinal diameter was < 14 mm and females whose sagittal diameter was < 13 mm even at one level were classified as having developmental canal stenosis. Two groups of patients were used in this study; the “positive” group (57 cases) included patients with developmental canal stenosis preoperatively, whereas the “negative” group (55 cases) excluded such patients. Lateral functional radiographs obtained in patients in the 2 groups were compared for range of motion and clinical results.

Results

Developmental canal stenosis was found in 50.9% of all cases. Based on clinical results, there was no significant difference between the 2 groups.

Conclusions

Patients with CSM showed a high incidence of preoperative developmental canal stenosis. However, there were no significant differences in clinical results between patients with and without this disorder. These results indicate that developmental canal stenosis is not a factor that influences surgical results.
Extranodal hairy cell leukemia presenting in the lumbar spine
Authors: Rosen David S. , Smith Sonali , Gurbuxani Sandeep , Yamini Bakhtiar
Published: February 2011

The authors report on a 54-year-old man who presented with a lumbar vertebral body lesion and an adjacent epidural lesion that was found to be hairy cell leukemia (HCL). The patient presented with gradual onset of back pain and intermittent lower-extremity radicular symptoms. He did not have splenomegaly or peripheral blood count abnormalities. Admission MR imaging revealed an L-5 vertebral body lesion and a lumbar epidural lesion extending from L-3 to S-2. An [18F]fluorodeoxyglucose–PET study showed numerous sites of osseous involvement. The patient underwent minimally invasive surgical biopsy sampling of the epidural lesion. Histopathological examination revealed extranodal HCL. After treatment with a 5-day course of cladribine, the patient's symptoms resolved, and at the 16-week follow-up visit there was no radiographic or metabolic evidence of disease. Hairy cell leukemia rarely involves neurological structures, but this patient responded well to standard treatment. This case demonstrates the value of tissue biopsy procedures instead of aggressive resection and the use of minimally invasive techniques to treat an HCL spinal lesion.
Posterior stabilization strategies following resection of cervicothoracic junction tumors: review of 90 consecutive cases
Authors: Placantonakis Dimitris G. , Laufer Ilya , Wang Jeremy C. , Beria Jasmine S. , Boland Patrick , Bilsky Mark
Published: February 2011

Object

In this retrospective analysis the authors describe the assessment and outcomes of 90 patients who underwent placement of posterior instrumentation at the cervicothoracic junction following the resection of a primary or metastatic tumor during a 10-year period.

Methods

All patients underwent a posterolateral laminectomy including uni- or bilateral facetectomy, and 44 patients additionally required vertebral body resection and reconstruction. In patients who underwent C-6 or C-7 decompression, the posterior instrumentation strategies changed from the use of lateral mass plate systems (LMPSs) to lateral mass screw/rod systems (LMSRSs). Similarly, for T1–3 tumor decompression, the strategy shifted from sublaminar hook/rod systems (SHRSs) to the use of pedicle screw systems (PSSs) in which the surgeon used either a 6.25-mm rod or dual-diameter rods with or without a connector.

Results

The overall surgical complication rate was 19% including fixation failure in 11 patients (12%), 6 of whom required reoperation. Fixation failure rates for cervical decompression decreased from 2 (29%) of 7 patients in the LMPS group to 0 (0%) of 8 in the LMSRS group (p = 0.2). The fixation failure rates for thoracic decompression were 7 (15%) of 48 patients in the SHRS group, and there was a decrease to 2 (7%) of 27 in the PSS group (p = 0.48). Neurological and functional outcomes including American Spinal Injury Association, Eastern Cooperative Oncology Group, and Medical Research Council muscle strength and pain scores remained stable or improved in 94, 96, 100, and 96% of patients, respectively.

Conclusions

Current posterior instrumentation strategies involving LMSRSs and PSSs provide excellent and safe stabilization of the cervicothoracic junction following resection of primary or metastatic tumors.
Intrathecal catheter-tip inflammatory masses: an intraparenchymal granuloma
Authors: Jhas Sumit , Tuli Sagun
Published: February 2011

The authors report the case of a 54-year-old woman who presented with an intraparenchymal granuloma in her lower thoracic spinal cord. On imaging studies there was an intramedullary enhancement at the left dorsal aspect of the cord immediately adjacent to the tip of an intrathecal arachnoid catheter used for intraspinal drug therapy. At surgery, it was apparent that once this superficial component of the catheter and inflammatory mass was removed, there was a granulomatous component that extended into the spinal cord. A 5-mm caseating chalklike granuloma was carefully dissected away. To the authors' knowledge, this is the first reported case of an intrathecal catheter-tip granuloma growing inside the spinal cord parenchyma.
Pharyngoesophageal diverticulum following cervical corpectomy and plating
Authors: Joanes Vicente , Belinchón Jose
Published: February 2011

This case of a pharyngoesophageal diverticulum was diagnosed 3 years after a corpectomy and fusion for a cervical fracture. The diverticulum was excised, the plate and screws were removed, and the patient was asymptomatic 3 years later. The dense scar tissue around the hardware probably caused traction on the posterior pharyngoesophageal region, followed by development of the diverticulum. The authors speculate that the malpositioning of the hardware was an irritative factor promoting such a scar. To the best of their knowledge, this is the first reported case of pharyngoesophageal diverticulum following cervical corpectomy and plating.
Surgical treatment for delayed pyogenic spondylitis after percutaneous vertebroplasty and kyphoplasty
Authors: Shin Jae-Hyuk , Ha Kee-Yong , Kim Ki-Won , Lee Jun-Seok , Joo Min-Wook
Published: February 2011

Only 6 cases of pyogenic spondylitis following vertebroplasty or kyphoplasty have been reported, and their causes remained unclear. The authors report on 4 cases of delayed pyogenic spondylitis (DPS) following vertebroplasty or ky-phoplasty for osteoporotic compression fractures and metastatic disease.

Four patients presented with DPS after vertebroplasty or kyphoplasty and underwent surgical treatment. Clinical history, laboratory examination, and MR imaging confirmed the diagnosis of DPS. Anterior debridement, reconstruction, and posterior instrumented fusion were performed.

The mean interval for the delayed occurrence of pyogenic spondylitis after surgery was 12.3 months. The infections were primarily bacterial in origin, but most patients also suffered diverse medical comorbidities. Despite successful treatment of the infections, comorbidity was and is a factor that compromises good results.

Medical comorbidities associated with compromised immunity may increase susceptibility to DPS after vertebroplasty or kyphoplasty. In cases of incapacitating back pain after a pain-free period following either of these surgeries, evaluation of the erythrocyte sedimentation rate and C-reactive protein level and examination of contrast-enhanced MR imaging studies are essential to rule out delayed vertebral infection. Surgical treatment requires cement removal and anterior reconstruction with or without additional posterior instrumented fusion.
Biomechanical evaluation of conventional anulus fibrosus closure methods required for nucleus replacement
Authors: Heuer Frank , Ulrich Sina , Claes Lutz , Wilke Hans-Joachim
Published: February 2011

Object

Nucleus replacement implants became increasingly attractive as an alternative to fusion, discectomy, or total disc replacement. The goals of nucleus replacement are to restore disc height and flexibility and to preserve the anatomy. However, implant extrusions have been reported and are the major concern. In this study the authors investigated different conventional surgical methods for anulus closure: suture alone, and fibrin glue and cyanoacrylate glue, alone and with suture.

Methods

The in vitro testing was conducted using 30 lumbar spinal segments obtained from calves. In each specimen, an incision was made; the nucleus was removed and subsequently replaced by a collagen matrix. The incisions were treated with anulus closure methods in 5 groups of animals. Flexibility was assessed in a spine tester. Subsequently, specimens were exposed to cyclic fatigue loading by using a hydraulic loading frame. Specimens were excentrically loaded in sine waveform up to a maximum of 100,000 cycles with 4–24 Nm at 5 Hz while being rotated at 360°/minute.

Results

Removal of the nucleus caused a significant loss of stability. The segmental stability could be restored after the implantation. Fatigue testing indicated that suturing was able to sustain 3400 cycles. Fibrin glue failed earlier than cyanoacrylate glue. Both combinations (suture with glue) provided longer stability to the anulus closure.

Conclusions

The results suggested that closing the anulus incision with suture or fibrin glue alone might not be appropriate. The authors found that the best method was cyanoacrylate glue with suture. Although this method provided the longest duration of closure, it could not sustain the maximum number of fatigue cycles. Conventional methods could improve the outcome compared with using no closure. Nonetheless, the authors' findings highlight the demand for an appropriate anulus reconstruction method or device with good long-term reliability.
Bibliographical forgery, with special reference to George Washington Sleeper
Authors: COLLINS J.
Published: February 2011

George Washington Sleeper (1826-1903) was a minor American eccentric who wrote a pamphlet entitled Shall we have common sense. Although dated 1849, this pamphlet was shown by Professor E. B. Poulton in 1913-1914 to be almost certainly later than 1870. It purported anticipation of Darwin and others and is therefore fraudulent. The pamphlet was re-assessed in the light of recent advances in physical bibliography and proved to be a fake. This certainty in turn led to a reconsideration of the whole circumstances surrounding its publication and it was suggested that the author's son was a party to the fraud, and may have instigated it. Other bibliographical fakes were also considered, particularly those of T. J. Wise, H. B. Forman and F. Prokosch, and an attempt was made to assess the Sleepers in their company and to draw some general conclusions.
The Relationships between Weather-Related Factors and Daily Outdoor Physical Activity Counts on an Urban Greenway
Authors: Wolff Dana , Fitzhugh Eugene C.
Published: February 2011

The purpose of this study was to examine relationships between weather and outdoor physical activity (PA). An online weather source was used to obtain daily max temperature [DMT], precipitation, and wind speed. An infra-red trail counter provided data on daily trail use along a greenway, over a 2-year period. Multiple regression analysis was used to examine associations between PA and weather, while controlling for day of the week and month of the year. The overall regression model explained 77.0% of the variance in daily PA (p < 0.001). DMT (b = 10.5), max temp-squared (b = −4.0), precipitation (b = −70.0), and max wind speed (b = 1.9) contributed significantly. Conclusion: Aggregated daily data can detect relationships between weather and outdoor PA.
In Vitro and in Vivo Anti-Hyperglycemic Effects of Omija (Schizandra chinensis) Fruit
Authors: Jo Sung-Hoon , Ha Kyoung-Soo , Moon Kyoung-Sik , Lee Ok-Hwan , Jang Hae-Dong , Kwon Young-In
Published: February 2011

The entrocytes of the small intestine can only absorb monosaccharides such as glucose and fructose from our diet. The intestinal absorption of dietary carbohydrates such as maltose and sucrose is carried out by a group of a-glucosidases. Inhibition of these enzymes can significantly decrease the postprandial increase of blood glucose level after a mixed carbohydrate diet. Therefore, the inhibitory activity of Omija (Schizandra chinensis) extract against rat intestinal a-glucosidase and porcine pancreatic a-amylase were investigated in vitro and in vivo. The in vitro inhibitory activities of water extract of Omija pulp/skin (OPE) on a-glucosidase and a-amylase were potent when compared to Omija seeds extract (OSE). The postprandial blood glucose lowering effect of Omija extracts was compared to a known type 2 diabetes drug (Acarbose), a strong a-glucosidase inhibitor in the Sprague-Dawley (SD) rat model. In rats fed on sucrose, OPE significantly reduced the blood glucose increase after sucrose loading. Furthermore, the oxygen radical absorbance capacity (ORAC) of OSE and OPE was evaluated. OPE had higher peroxyl radical absorbing activity than OSE. These results suggest that Omija, which has high ORAC value with a-glucosidase inhibitory activity and blood glucose lowering effect, could be physiologically useful for treatment of diabetes, although clinical trials are needed.
Continuous Membrane-Based Screening System for Biocatalysis
Authors: Lyagin Evgenij , Drews Anja , Bhattacharya Subhamoy , Kraume Matthias
Published: February 2011

The use of membrane reactors for enzymatic and co-factor regenerating reactions offers versatile advantages such as higher conversion rates and space-time-yields and is therefore often applied in industry. However, currently available screening and kinetics characterization systems are based on batch and fed-batch operated reactors and were developed for whole cell biotransformations rather than for enzymatic catalysis. Therefore, the data obtained from such systems has only limited transferability for continuous membrane reactors. The aim of this study is to evaluate and to improve a novel screening and characterization system based on the membrane reactor concept using the enzymatic hydrolysis of cellulose as a model reaction. Important aspects for the applicability of the developed system such as long-term stability and reproducibility of continuous experiments were very high. The concept used for flow control and fouling suppression allowed control of the residence time with a high degree of precision (±1% accuracy) in a long-term study (>100 h).
Dihydroberkleasmin A: A New Eremophilane Sesquiterpenoid from the Fermentation Broth of the Plant Endophytic Fungus Pestalotiopsis photiniae
Authors: Yang Xiao-Long , Zhang Su , Zhu Hua-Jie , Luo Du-Qiang
Published: February 2011

Dihydroberkleasmin A (1), a new ester-substituted sesquiterpenoid related to the eremophilane class, together with the known compound berkleasmin C (2), were isolated from the fermentation broth of the plant endophytic fungus Pestalotiopsis photiniae. The structure of dihydroberkleasmin A (1) was elucidated by extensive spectroscopic analysis. The stereochemistry was assigned by comparison of the NMR spectroscopic data with those of berkleasmin A.