bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enhanced primary stability through additional cementable cannulated rescue screw for anterior thoracolumbar plate application
Authors: Schultheiss Markus , Claes Lutz , Wilke Hans-Joachim , Kinzl Lothar , Hartwig Erich 
Published: May 2009

Object. The authors conducted a study to investigate the biomechanical in vitro influence of a new anchorage system for fixation of anterior stabilization devices and the possibility of using additional cement after screw insertion to compensate for poor bone quality. The incidence of osteoporosis-related fractures has increased nearly twofold in the last decade. Because of problems associated with anterior screw fixation such as loosening, mechanical failure, and the weakness of osteoporotic bone, current surgical treatments of vertebral body (VB) fractures are problematic. This is due to poor fixation strength of anterior screws in the adjacent segments.
The aim of this study was to determine whether a new cemented and uncemented VB screw provides improved primary stability following placement of anterior instrumentation in cases of fracture.
Methods. The primary stability-related parameters of a new uncemented/cemented screw were compared with those of conventional monocortical screw fixation in a burst fracture model in which strut graft and anterior overbridging instrumentation were used.
The use of the new uncemented screw improved the range of motion (ROM) of the stabilized spine in flexion—extension by approximately 22%, in rotation by 20%, and in lateral bending by 15%. Additional cementation improved the ROM by approximately 41% in flexion—extension, 32% in rotation, and 30% in lateral bending compared with conventional monocortical screw fixation.
Conclusions. The new cannulated screw improves fixation strength and primary stability parameters. It is useful in the initial treatment of fractures in cases of poor bone quality and as a rescue device if previously inserted screws do not remain securely in place.
Age-related changes in expression of transforming growth factor-β and receptors in cells of intervertebral discs
Authors: Matsunaga Shunji , Nagano Satoshi , Onishi Toshiyuki , Morimoto Norio , Suzuki Shusaku , Komiya Setsuro 
Published: May 2009

Object. The authors conducted a study to determine age-related changes in expression of transforming growth factor (TGF)—β1, —β2, —β3, and Type I and Type II receptors in various cells in the nucleus pulposus and anulus fibrosus.
Immunolocalization of TGFβs and Type I and II receptors was examined during the aging process of cervical intervertebral discs in senescence-accelerated mice (SAM). The TGFβ family has important roles for cellular function of various tissues. Its role in disc aging, however, is unknown. Detailed information on the temporal and spatial localization of TGFβs and their receptors in discs is required before discussing introduction of them clinically into the intervertebral disc.
Methods. Three groups of five SAM each were used. The groups of SAM were age 8, 24, and 50 weeks, respectively. Hematoxylin and eosin staining and immunohistochemical study involving specific antibodies for TGFβ1, -β2, -β3, and Types I and II TGF receptors were performed.
Intervertebral discs exhibited degenerative change with advancing age. The TGFβs and their receptors were present in the fibrocartilaginous cells within the anulus fibrosus and notochord-like cells within the nucleus pulposus of young mice. Expression of TGFβs and Type I and Type II receptors changed markedly in the cells within the anulus fibrosus during the aging process.
Conclusions. The TGFβs and their receptors were present in cells within the nucleus pulposus and the anulus fibrosus of young mice, and their expression decreased with age.
Posterior atlantoaxial dislocation without fracture
Authors: Yoon Do Heum , Yang Kook Hee , Kim Keung Nyun , Oh Sung Han 
Published: May 2009

✓ Posterior dislocation of the atlas onto the axis without related fracture of the odontoid process is a very rare traumatic condition of which five cases have been previously reported.
The authors present a sixth case in which management was different from the others. The patient was successfully treated by open reduction of the dislocation and C1–2 transarticular screw fixation. The rarity of the lesion, the differences in diagnostic studies, and the successful treatment by safe intraoperative reduction and fixation are factors of interest in this case.
Intraoperative cervical epidurography: a simple modality for assessing the adequacy of decompression during anterior cervical procedures
Authors: Hejazi Nedal , Witzmann Alfred , Hassler Werner 
Published: May 2009

Object. Intraoperative cervical epidurography (ICE) was used during anterior cervical procedures to assess the success of bone resection and indicate the need for immediate correction in the event of inadequate decompression.
Methods. The adequacy of decompression was assessed by the operating neurosurgeon who performed ICE after anterior microdiscectomy with exposure of the dura mater. If the decompression was deemed inadequate, additional bone was removed using a high-speed drill. Epidurography was conducted after each subsequent decompression until adequate bone removal was achieved. This was undertaken in 39 patients undergoing anterior cervical procedures. Nine patients underwent corpectomy, 21 one-level, and nine two-level discectomy. The ICE revealed insufficient resections requiring additional bone removal in 14 (36%) of the 39 patients.
Conclusions. The goal of ICE is to ensure adequate decompression, and if such has not been achieved, to allow for additional immediate bone excision. Furthermore, ICE provides additional real-time control of the position of cages and screws to avoid dural tear or spinal cord compression. Because of this immediate feedback, the success rate of anterior cervical procedures can be improved. The advantages of this modality include real-time assessment, low cost, simplicity, and speed.
Guide device for percutaneous placement of translaminar facet screws after anterior lumbar interbody fusion
Authors: Jang Jee Soo , Lee Sang Ho , Lim Sang Rak 
Published: May 2009

Because the degree of immediate stabilization provided by cage-assisted anterior lumbar interbody fusion (ALIF) has been shown by several studies to be inadequate, supplementary posterior fixation, such as that created by translaminar or transpedicle screw fixation, is necessary. In this study, the authors studied the ALIF-augmentation procedure in which a special guide device is used to place percutaneously translaminar facet screws in 18 patients with degenerative lumbar disease. The minimum follow-up period was 1 month (mean 6 months, range 1–13 months). Degenerative spondylolisthesis with foraminal stenosis was diagnosed in nine patients, associated degenerative disc disease alone or combined with foraminal stenosis in eight, and recurrent disc herniation in one. Following screw placement, computerized tomography scanning was conducted to evaluate the accuracy of the facet screw positioning.
All screws were properly placed. No screw penetrated the spinal canal or injured the neural structures. Excellent or good clinical outcomes were demonstrated in all patients at the last follow up.
The use of this guide device for post—ALIF percutaneous translaminar facet screw fixation represents a safe, accurate, and minimally invasive modality with which to achieve immediate solid fixation in the lumbar spine.
Evaluation of pedicle screw position on computerized tomography scans
Authors: Yeom Jin Sup , Chung Moon Sang , Lee Choon-Ki , Kim Yeongho , Kim Namkug , Lee Jae Bum 
Published: May 2009

✓ The quality of a computerized tomography (CT) scan is significantly reduced by metal artifact caused by a pedicle screw system. The purpose of this study was to develop a method of facilitating the evaluation of pedicle screw position on CT scans obtained after screw insertion.
The authors developed an algorithm to process spiral CT scans in a personal computer. This uses a digital image enhancement technique, the curve change-based intensity transformation algorithm. This method can generate a clear image of the screw outlines while reducing metal artifact. The resulting images are displayed in arbitrary planes as well as in axial, coronal, and sagittal planes, to support better the evaluation of pedicle screw position.
The algorithm was tested using CT scans obtained in 37 patients in whom 186 pedicle screws had been placed. There were five types of screw systems, all of which were made of titanium alloys. In all cases algorithm-based determination of screw position became more convenient and more accurate than when using the conventional bone window setting. In addition, it provided better soft-tissue visualization than the bone window.
The software, by displaying clear outlines of screws and decreasing metal artifact, as well as by reconstructing the images in arbitrary planes, was more helpful in identifying the position of pedicle screws than the conventional bone window setting.
Cervicothoracic radiculopathy treated using posterior cervical foraminotomy/discectomy
Authors: Harrop James S. , Silva Marco T. , Sharan Ashwini D. , Dante Steven J. , Simeone Frederick A. 
Published: May 2009

Object. The authors conducted a study to identify the effectiveness and morbidity rate associated with treating cervicothoracic disc disease (radiculopathy) via a posterior approach.
Methods. Nineteen patients underwent posterior cervicothoracic laminoforaminotomy during a 5.6-year period. Medical records, imaging studies, office charts, hospital records, and phone interview data were reviewed. Specific information analyzed included patient demographics, side of lesion, and conservative treatment, symptoms, and pre- and postoperative pain levels. Pain was rated using a visual analog scale and classified into a radicular and neck component.
Data in 19 patients (seven women and 12 men) who underwent 20 procedures (one patient underwent separate bilateral foraminotomies) were analyzed. The mean patient age was 54.8 years (range 38–73 years), and the follow-up period ranged from 23 to 62 months. Symptom duration ranged from 1 to 14 months (mean 3.4 months) and consisted of weakness, numbness, and painful radiculopathies in 11, 16, and 20 cases, respectively. Motor weakness was identified in 11 of 19 patients (mean grade of 4.35), and postoperatively strength normalized in eight of 11 (mean grade of 4.79). The improvement in motor scores was significant (p = 0.007). Pain was the most common presenting symptom. Preoperative radiculopathies were rated between 0 and 10 (mean 7.45), and postoperatively scores were reduced to 0 to 3 (mean 0.2) which was significant (p < 0.0001). Preoperative neck pain was rated between 0 and 8 (mean 2.55), and on follow up ranged from 0 to 2 (mean 0.5), which was also significant (p = 0.001).
Conclusions. Posterior cervicothoracic foraminotomy was a safe and effective procedure in the treatment of patients with laterally located disc herniations.
Endoscopic anterior cervical foraminotomy for unilateral radiculopathy: anatomical morphometric analysis and preliminary clinical experience
Authors: Saringer Walter F. , Reddy Brian , Nöbauer-Huhmann Iris , Regatschnig Rene , Reddy Marion , Tschabitscher Manfred , Knosp Engelbert 
Published: May 2009

Object. Cervical radiculopathy is typically caused by posterolateral disc herniation or spondylotic foraminal stenosis, either of which may compress the ventral aspect of the nerve root. The authors undertook a study to establish the feasibility of performing an endoscopic approach for anterior cervical foraminotomy (ACFor) in a clinical setting.
Methods. Application of this method on cadavers was conducted to verify the practicability of this technique. The clinical study included 16 patients (eight men and eight women; mean age 46.6 years) all presenting with unilateral radicular symptoms (one at two adjacent ipsilateral levels), which were associated with various degrees of neck pain. Disc herniations and/or uncovertebral osteophytes were confirmed on magnetic resonance imaging and high-resolution computerized tomography scanning. A total of 17 endoscopic ACFors (one two-level procedure) were performed using a rigid glass endoscope (25° angled, 3-mm diameter, 10-mm length) mounted on a tubular retractor.
No major surgery-related complications were encountered. During a mean follow-up period of 13.8 months an average absolute improvement of 44% (p > 0.05) in the neck disability index score and of 96% (p > 0.05) in the visual analog scale score for radicular pain (compared with the preoperative score) was observed. During the follow-up period strength improved to normal in 84% and sensory deficit in 80% of the patients. The overall subjective patient satisfaction rate was 87.6%; the return-to-work rate after 4 weeks was 81.4%.
Conclusions. The advantages of endoscopic ACFor include minimial surgical exposure, improved intraoperative visualization, direct decompression of the nerve root, and the preservation of the intervertebral disc and the motion segment.
Suitability of bioresorbable cages for anterior cervical fusion
Authors: Cahill David W. , Martin George J. , Hajjar Michael V. , Sonstein William , Graham Lloyd B. , Engelman Robert W. 
Published: May 2009

Object. The authors conducted a pilot study to determine whether a bioresorbable intervertebral fusion device composed of 85/15 polylactide—polyglycolide (PLA-PGA) copolymer packed with bone autograft is a suitable alternative to promote arthrodesis after anterior cervical discectomy (ACD) in a caprine model.
Methods. The caprine cervical spine model has been used to evaluate interbody healing and fusion after application of bone grafts and instrumentation. Whether a bioresorbable device is suitable for facilitating intervertebral bone union has not been determined. Twelve goats underwent two-level ACD and fusion; eight received bioresorbable cages packed with autologous bone, and four received autologous bone alone. Goats were maintained without an orthosis and after 12 weeks underwent physical, radiographic, and histological evaluation.
Cages had structurally degraded, and two had become extruded. Stable intervertebral union developed in three (19%) of 16 cage-implanted interspaces, and one (14%) of seven bone autograft—implanted interspaces; each was judged manually to be rigid (Grade 2), radiographically to be bridged by new osseous densities (Grade 2), and histologically to have marked new bone formation (Grade 3). A primarily fibrous union, however, stabilized the cage-implanted interspaces, and eight (50%) had developed a 4 to 6—mm foreign body granuloma. These interposed soft tissues were not present in the stable autologous bone—implanted interspace, which had successfully become fused.
Conclusions. Interbody cages composed of 85/15 PLA-PGA copolymer contributed to a stable fibrous union, degraded, and produced granuloma after 12 weeks. Additional evaluations are necessary to determine whether other copolymer mixtures, or other bioresorbable materials, can contribute to an arthodesis without deleterious consequences.
Craniovertebral junction fixation with transarticular screws: biomechanical analysis of a novel technique
Authors: Gonzalez L. Fernando , Crawford Neil R. , Chamberlain Robert H. , Perez Garza Luis E. , Preul Mark C. , Sonntag Volker K. H. , Dickman Curtis A. 
Published: May 2009

Object. The authors compared the biomechanical stability resulting from the use of a new technique for occipitoatlantal motion segment fixation with an established method and assessed the additional stability provided by combining the two techniques.
Methods. Specimens were loaded using nonconstraining pure moments while recording the three-dimensional angular movement at occiput (Oc)—C1 and C1–2. Specimens were tested intact and after destabilization and fixation as follows: 1) Oc—C1 transarticular screws plus C1–2 transarticular screws; 2) occipitocervical transarticular (OCTA) plate in which C1–2 transarticular screws attach to a loop from Oc to C-2; and (3) OCTA plate plus Oc—C1 transarticular screws.
Occipitoatlantal transarticular screws reduced motion to well within the normal range. The OCTA loop and transarticular screws allowed a very small neutral zone, elastic zone, and range of motion during lateral bending and axial rotation. The transarticular screws, however, were less effective than the OCTA loop in resisting flexion and extension.
Conclusions. Biomechanically, Oc—C1 transarticular screws performed well enough to be considered as an alternative for Oc—C1 fixation, especially when instability at C1–2 is minimal. Techniques for augmenting these screws posteriorly by using a wired bone graft buttress, as is currently undertaken with C1–2 transarticular screws, may be needed for optimal performance.
In vitro high-field magnetic resonance imaging—documented anatomy of a fetal myelomeningocele at 20 weeks' gestation. A contribution to the rationale of intrauterine surgical repair of spina bifida
Authors: Beuls Emile A. M. , Vanormelingen Linda , van Aalst Jasper , Vandersteen Marjan , Adriaensens Peter , Cornips Erwin M. J. , Vles Hans J. S. , Gelan Jan 
Published: May 2009

Object. It remains uncertain if closure of a myelomeningocele at midgestation changes the neurological condition at birth in an infant born with spina bifida. The authors conducted a study to provide a detailed analysis of the morphology of the spinal cord with the myelomeningocele at the time fetal surgery usually is performed.
Methods. The myelomeningocele of a 20-week-gestation-age fetus was examined, and data were compared with those obtained in a neurologically intact specimen of the same age. In vitro high-field 9.4-tesla magnetic resonance (MR) microscopy was used to examine the fetal material.
High-field MR spectroscopy provided images in the three orthogonal planes with a resolution comparable with low-power optical microscopy. The authors observed that the fetal cord of the myelomeningocele specimen was tapered and tethered at S3–4 while the conus medullaris in the normal fetus reaches L-4.
No neurulation defects were noted. The axial MR images clearly revealed the nonfusion of the mesodermal structures.
The absence of neurulation defects suggests that at least in some cases of spina bifida the spinal cord initially is well developed but is damaged later on chemically and mechanically. This might be an argument in favor of intrauterine myelomeningocele repair. By 20 weeks' gestation, however, the deformation of the cord inside the myelomeningocele is severe. An optimization of the preoperative assessment by means of MR imaging therefore might be considered a valuable contribution to intrauterine surgery. The in vitro high-field MR microscopic findings of this study could be used as references for clinical intrauterine MR imaging.
Conclusions. The detailed in vitro high-field MR analysis of a 20-week-gestation-age fetus with spina bifida demonstrated that an improvement of the preoperative intrauterine imaging should be pursued to detect those cases without neurulation defects and with minimal deformation of the spinal cord.
The Wilhelm Tell technique for anterior lumbar interbody fusion
Authors: Markwalder Thomas-Marc , Wenger Markus , Elsig Jean-Pierre , Laloux Etienne 
Published: May 2009

✓ Experience indicates that stand-alone cages may lack the necessary stability to secure highly unstable motion segments at the lumbosacral junction.
The authors have designed a special carbon fiber composite interbody cage that allows additional screw placement in anterior lumbar interbody fusion procedures performed at the lumbosacral junction.
Cervical laminoplasty: a critical review
Authors: Ratliff John K. , Cooper Paul R. 
Published: May 2009

Object. The technique of cervical laminoplasty was developed to decompress the spinal canal in patients with multilevel anterior compression caused by ossification of the posterior longitudinal ligament or cervical spondylosis. There is a paucity of data confirming its superiority to laminectomy with regard to neurological outcome, preserving spinal stability, preventing postlaminectomy kyphosis, and the development of the “postlaminectomy membrane.”
Methods. The authors conducted a metaanalysis of the English-language laminoplasty literature, assessing neurological outcome, change in range of motion (ROM), development of spinal deformity, and complications. Seventy-one series were reviewed, comprising more than 2000 patients.
All studies were retrospective, uncontrolled, nonrandomized case series. Forty-one series provided postoperative recovery rate data in which the Japanese Orthopaedic Association Scale was used for assessing myelopathy. The mean recovery rate was 55% (range 20–80%). The authors of 23 papers provided data on the percentage of patients improving (mean ∼80%). There was no difference in neurological outcome based on the different laminoplasty techniques or when laminoplasty was compared with laminectomy. There was postlaminoplasty worsening of cervical alignment in approximately 35% and with development of postoperative kyphosis in approximately 10% of patients who underwent long-term follow-up review. Cervical ROM decreased substantially after laminoplasty (mean decrease 50%, range 17–80%). The authors of studies with long-term follow up found that there was progressive loss of cervical ROM, and final ROM similar to that seen in patients who had undergone laminectomy and fusion. In their review of the laminectomy literature the authors could not confirm the occurrence of postlaminectomy membrane causing clinically significant deterioration of neurological function. Postoperative complications differed substantially among series. In only seven articles did the writers quantify the rates of postoperative axial neck pain, noting an incidence between 6 and 60%. In approximately 8% of patients, C-5 nerve root dysfunction developed based on the 12 articles in which this complication was reported.
Conclusions. The literature has yet to support the purported benefits of laminoplasty. Neurological outcome and change in spinal alignment are similar after laminectomy and laminoplasty. Patients treated with laminoplasty develop progressive limitation of cervical ROM similar to that seen after laminectomy and fusion.
Ultrasonographic screening in infants with isolated spinal strawberry nevi
Authors: Allen Rebecca M. , Sandquist Michael A. , Piatt Joseph H. , Selden Nathan R. W. 
Published: May 2009

Object. The authors performed spinal ultrasonography and/or magnetic resonance (MR) imaging in 20 consecutive newborns with spinal strawberry nevi.
Methods. In 15 patients the strawberry nevi were isolated and in five they were associated with other cutaneous markers of occult spinal dysraphism (OSD). In four of five patients with additional cutaneous markers, but in none of those without, MR imaging and surgical exploration demonstrated OSD. The authors found that strawberry nevi in isolation do not appear to indicate underlying dysraphic states. The sparse clinical literature on this topic, which is reviewed, confirms an association between OSD and strawberry nevi presenting in conjunction with other cutaneous signatures. By contrast, spinal strawberry nevi occurring alone may not indicate the presence of underlying dysraphism.
Conclusions. A prospective study of larger numbers of patients with isolated strawberry nevi, undergoing MR imaging evaluation, is necessary to determine whether neuroimaging screening in these patients is indicated.