bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multidirectional flexibility analysis of cervical artificial disc reconstruction: in vitro human cadaveric spine model
Authors: Kotani Yoshihisa , Cunningham Bryan W. , Abumi Kuniyoshi , Dmitriev Anton E. , Ito Manabu , Hu Niabin , Shikinami Yasuo , McAfee Paul C. , Minami Akio 
Published: May 2009

Object. This in vitro experimental study was conducted to investigate the initial biomechanical effect of artificial intervertebral disc replacement in the cervical spine. The multidirectional flexibility of replaced and adjacent spinal segments were analyzed using a cadaveric cervical spine model.
Methods. The following three cervical reconstructions were sequentially performed at the C5–6 level after anterior discectomy in seven human cadaveric occipitocervical spines: anterior artificial disc replacement with a bioactive three-dimensional (3D) fabric disc (FD); anterior iliac bone graft; and anterior plate fixation with iliac bone graft. Six unconstrained pure moments were applied with a 6-df spine simulator, and 3D segmental motions at the operative and adjacent segments were measured with an optoelectronic motion measurement system. The 3D FD group demonstrated statistically equivalent ranges of motion (ROMs) when compared with intact values in axial rotation and lateral bending. The 45% increase in flexion—extension ROM was demonstrated in 3D FD group; however, neutral zone analysis did not reach statistical significance between the intact spine and 3D FD. The anterior iliac bone graft and iliac bone graft reconstructions demonstrated statistically lower ROMs when compared with 3D FD in all loading modes (p < 0.05). The adjacent-level ROMs of the 3D FD group demonstrated nearly physiological characteristics at upper and lower adjacent levels. Excellent stability at the interface was maintained during the whole testing without any device displacement and dislodgment.
Conclusions. The stand-alone cervical 3D FD demonstrated nearly physiological biomechanical characteristics at both operative and adjacent spinal segments in vitro, indicating an excellent clinical potential for cervical artificial disc replacement.
Subarachnoid pressure—dependent change in syrinx size in a patient with syringomyelia associated with adhesive arachnoiditis
Authors: Chang Han Soo , Joko Masahiro , Matsuo Naoki , Kim Sang Don , Nakagawa Hiroshi 
Published: May 2009

✓ The pathophysiology of syringomyelia is still not well understood. Current prevailing theories involve the assumption that cerebrospinal fluid (CSF) flows into the syrinx from the subarachnoid space through the perivascular space of Virchow—Robin. Reported here is the case of a patient with syringomyelia in which this course is clearly contradicted.
This patient with a holocord syrinx associated with adhesive arachnoiditis was treated 3 years previously with insertion of a subarachnoid—peritoneal shunt and had recently experienced worsening myelopathy. On surgical exploration, the shunt system was functioning normally. The medium-pressure shunt valve was replaced with an adjustable valve with a higher closing pressure setting, thus increasing the CSF pressure in the subarachnoid space. Contrary to prevailing theories, this procedure markedly reduced the size of the syrinx.
This case provides direct evidence that the syrinx size is inversely related to subarachnoid CSF pressure and supports the hypothesis that the pressure gradient across the spinal cord parenchyma is the force that generates syringes in syringomyelia.
Thoracic aortic pseudoaneurysm after spine trauma in ankylosing spondylitis
Authors: Lifshutz Jason , Lidar Zvi , Maiman Dennis 
Published: May 2009

✓ Ankylosing spondylitis (AS) is a rheumatic disease characterized by consolidation of the articulating surfaces and inflammation of the vertebral column. Because of its associated spine stiffness and secondary osteoporosis, patients with this disorder are at increased risk of vertebral fractures. Ankylosing spondylitis presents a significant challenge to spine surgeons because of its complex effects on the spine, extraarticular organ manifestations, and potential neurological and functional sequelae. Traumatic thoracic and lumbar spine injuries in this patient population may be associated with injury to the aorta either due to direct mechanical trauma or to blunt forces associated with the spine fracture. This complication and association is thought to be the result of pathophysiological changes that cause the aorta to become firmly adherent to the anterior longitudinal ligament.The authors present a case of AS in a patient with a thoracic spine fracture and in whom a delayed thoracic aortic pseudoaneurysm ruptured. To the best of the authors' knowledge, only five cases of this complex condition have been reported since 1980. Recognition of the potential for aortic injury in patients with AS should prompt early investigation of the aorta in cases involving numerous fractures and assist in surgical planning to avoid this lethal injury.
The changing role for neurosurgeons and the treatment of spinal deformity
Authors: Johnson J. Patrick , Pashman Robert S. , Lauryssen Carl , Anand Neel , Regan John J. , Bray Robert S. 
Published: May 2009

✓ Spinal deformity has classically and historically been studied by those in the discipline of orthopedic surgery. This may be attributable to the orthopedic interventionalists' experience with osseous fixation for long-bone and other skeletal fractures. Neurosurgeons have maintained a long-standing interest in complex cervical spinal disorders, and their interest in the larger field of complex spinal deformity has been expanding.An understanding of spinal deformity disorders, biomechanics, bone biology, and metallurgy is necessary before clinical, teaching, and research activities can be undertaken within neurosurgery.The authors describe basic and advanced concepts of spinal deformity management with cases to illustrate teaching points.
Operative management of metastatic and malignant primary subaxial cervical tumors
Authors: Bilsky Mark H. , Boakye Maxwell , Collignon Frederic , Kraus Dennis , Boland Patrick 
Published: May 2009

Object.The authors describe the preoperative assessment, intraoperative strategies, and long-term outcomes in 41 consecutive patients who underwent spinal reconstruction after resection of subaxial cervical neoplasms.Methods.Thirty-three tumors were metastatic and eight were primary. Preoperative studies included direct laryngoscopy and vertebral artery (VA) balloon occlusion tests in selected patients. Based on the tumor location, approaches included 12 anterior, 13 posterior, and 16 combined. All patients underwent aggressive intralesional resection and spinal reconstruction. In 12 patients, the VA was dissected from the periphery of the tumor, two cases of which required ligation. Fibula allograft and an anterior rigid plate fixation were most commonly used for anterior reconstruction. Posterior reconstruction was initially performed using lateral mass plates (LMPs) in 13 patients and screw/rod systems in the remaining patients.At follow up, pain level improved to mild or was absent in 39 patients (95%) who had presented with moderate or severe pain. The American Spinal Injury Association (ASIA) Scale scores were stable in 25 patients who presented with ASIA Score E and improved in 14 patients (88%) who presented with ASIA Score B, C, or D. Functional radiculopathy significantly improved in 16 (94%) of 17 patients.Complications occurred in 10 patients (24%) and included three fixation failures requiring revision. Two fixation failures involved cervical LMP screw pullout. The overall mean survival duration was 8.6 months for patients with metastatic tumors and 33.4 months for primary tumors.Conclusions.Surgery for the treatment of subaxial spine neoplasms is effective for relieving pain, encouraging functional nerve root recovery, and preserving spinal cord function with acceptable complication rates.
Outcome after lumbar sequestrectomy compared with microdiscectomy: a prospective randomized study
Authors: Thomé Claudius , Barth Martin , Scharf Johann , Schmiedek Peter 
Published: May 2009

Object. Microdiscectomy currently constitutes the standard treatment for herniated lumbar discs. Although limiting surgery to excision of fragments has occasionally been suggested, prospective data are lacking. Therefore, the objective of this study was to compare early outcome and recurrence rates after sequestrectomy and microdiscectomy.
Methods. Eighty-four consecutive patients 60 years of age or younger who harbored free, subligamentary, or transanular herniated lumbar discs refractory to conservative treatment were randomized to one of two treatment groups. Intraoperative parameters and findings were documented as well as pre- and postoperative symptoms such as pain, Patient Satisfaction Index (PSI), Prolo Scale score, and Short Form (SF)—36 subscale results. Follow up of at least 12 months was available in 73 patients (87%).
Preoperative intergroup symptoms did not differ significantly. Surgery was significantly shorter in the sequestrectomy-treated group. Overall, low-back pain and sciatica were drastically reduced in both groups and most sensorimotor deficits improved. At 4 to 6 months, SF-36 subscales and PSI scores showed a trend in favor of sequestrectomy, leaving 3% of patients unsatisfied compared with 18% of those treated with discectomy. Outcome according to the Prolo Scale was good or excellent in 76% of discectomy-treated patients and 92% of sequestrectomy-treated patients. Reherniation occurred in four patients after discectomy (10%) and two patients after sequestrectomy (5%) within 18 months.
Conclusions. Sequestrectomy does not seem to entail a higher rate of early recurrences compared with microdiscectomy. Analysis of early outcome demonstrated a trend toward superior results when sequestrectomy is performed. Although long-term follow-up data are mandatory, sequestrectomy may be an advantageous alternative to standard microdiscectomy.
Long-term outcome in 132 consecutive patients after posterior internal fixation and fusion for Grade I and II isthmic spondylolisthesis
Authors: Wenger Markus , Sapio Nicola , Markwalder Thomas-Marc 
Published: May 2009

Object.The authors assessed the late outcome of patients with Meyerding Grade I and II isthmic spondylolisthesis (IS) who underwent posterior instrumentation and posterolateral fusion (PLF). Decompression and posterior internal fixation with PLF is the classic surgical treatment for painful low-grade IS. Nevertheless, outcome data are scarce and of limited value mainly because they represent small numbers of patients, short follow-up periods, or both.Methods.The authors obtained data in the cases of 132 consecutive adult patients (mean age 40.6 years, range 15.2–69.9 years) with IS who underwent treatment between 1984 and 2003. Assessment involved analysis of responses to mailed questionnaires, clinical charts and, in cases in which unsatisfactory results were suspected, results of clinical reevaluations. Spondylolisthesis was present at L3–4 in three patients, L4–5 in 14, L3–4 in one, L3–5 in one, L5—S1 in 113, and S1–2 in one. Signs and symptoms included back and leg pain (65.3%), leg pain alone (26.3%), back pain alone (8.4%), and neurological dysfunction (18%).At a mean follow-up duration of 9.9 years (range 0.5–19.4 years), favorable results were reported for back and leg pain in 91.7 and 87.1% of patients, respectively. The mean visual analog scale scores were 2.13 for back and 1.59 for leg pain. Eighty-four patients resumed full- or part-time work, and 56.8% were capable of performing housework more easily. In 45.5% of the patients analgesic medications were not required, and 43.9% required them sporadically. The majority (63.6%) of patients reported they would undergo surgery again and recommended it to others. Thirteen (9.9%) suffered adjacent-segment morbidity, and in seven (5.3%) pseudarthrosis was documented. There were two deep and one superficial infections (2.3%).Conclusions.Posterior instrumentation and PLF, with possible neurodecompression, yielded favorable long-term results in this retrospective study of 132 patients with low-grade IS.
Unilateral progressive alterations in the lumbar spine: a biomechanical study
Authors: Tender Gabriel C. , Kutz Scott , Baratta Richard , Voorhies Rand M. 
Published: May 2009

Object. Lumbar radiculopathy secondary to foraminal stenosis can be treated by unilateral removal of the overlying pars interarticularis. The main concern after this procedure is spinal stability. In this study the authors evaluate the biomechanical behavior of the lumbar spine under torsional loading after unilateral progressive alterations, including resection of the pars.
Methods. Six human cadaveric L5—sacrum functional spinal units were tested while intact and then after the following sequential unilateral alterations: excision of the pars, capsulectomy, facetectomy, and discectomy. Specimens were tested in rotation by using a biomechanical testing machine, with an axial load of 280 N and torques of ± 7.5 Nm. The specimens remained in the machine throughout testing, and the angular displacements were recorded after each set of trials.
No statistically significant difference in any of the measured parameters was found between intact spines and those undergoing resection of the pars. For positive displacement (toward the side of the lesion), a significant difference from the intact condition was found after facetectomy and discectomy. For overall displacement (range of motion), spines treated with capsulectomy, facetectomy, and discectomy were significantly different from those in the intact condition.
Conclusions. Unilateral removal of the pars interarticularis does not increase spinal mobility in a statistically significant fashion. The clinical implication is that the spine may not become acutely unstable after unilateral resection of the pars.
Effects of epidural hypothermic saline infusion on locomotor outcome and tissue preservation after moderate thoracic spinal cord contusion in rats
Authors: Casas Carlos E. , Herrera Loren P. , Prusmack Chad , Ruenes Gladys , Marcillo Alexander , Guest James D. 
Published: May 2009

Object.Regionally delivered hypothermia has advantages over systemic hypothermia for clinical application following spinal cord injury (SCI). The effects of local hypothermia on tissue sparing, neuronal preservation, and locomotor outcome were studied in a moderate thoracic spinal cord contusion model.Methods.Rats were randomized to four treatment groups and data were collected and analyzed in a blinded fashion. Chilled saline was perfused into the epidural space 30 minutes postcontusion to achieve the following epidural temperatures: 24 ± 2.3°C (16 rats), 30 ± 2.4°C (13 rats), and 35 ± 0.9°C (13 rats). Hypothermia was continued for 3 hours when a 45-minute period of rewarming was instituted. In a fourth group a moderate contusion only was induced in 14 animals. Rectal (core) and T9–10 (epidural) temperatures were measured continuously. Locomotor testing, using the Basso-Beattie-Bresnahan (Ba-Be-Br) scale, was performed for 6 weeks, and rats were videotaped for subsequent analysis. The lesion/preserved tissue ratio was calculated throughout the entire lesion cavity and the total lesion, spinal cord, and spared tissue volumes were determined. The rostral and caudal extent of gray matter loss was also measured. At 6 weeks locomotor recovery was similar in all groups (mean Ba-Be-Br Scale scores 14.88 ± 3.71, 14.83 ± 2.81, 14.50 ± 2.24, and 14.07 ± 2.39 [p = 0.77] for all four groups, respectively). No significant differences in spared tissue volumes were found when control and treatment groups were compared, but gray matter preservation was reduced in the infusion-treated groups.Conclusions.Regional cooling applied 30 minutes after a moderate contusive SCI was not beneficial in terms of tissue sparing, neuronal preservation, or locomotor outcome. This method of cooling may reduce blood flow in the injured spinal cord and exacerbate secondary injury.
Spinal cord injury induction of lesional expression of profibrotic and angiogenic connective tissue growth factor confined to reactive astrocytes, invading fibroblasts and endothelial cells
Authors: Conrad Sabine , Schluesener Hermann J. , Adibzahdeh Mehdi , Schwab Jan M. 
Published: May 2009

Object. The glial scar composed of astrogliosis and extracellular matrix deposition represents a major impediment to axonal regeneration. The authors investigated the role of a novel profibrotic and angiogenic peptide connective tissue growth factor (CTGF [Hcs24/IGFBP-r2P]) in glial scar formation following spinal cord injury (SCI) in rats.
Methods. The effects of SCI on CTGF expression during glial scar maturation 1 day to 1 month post-SCI were investigated using fluorescein-activated cell sorter (FACS) immunohistochemical analysis; these findings were compared with those obtained in sham-operated (control) spinal cords.
The CTGF-positive cells accumulated at the spinal cord lesion site (p < 0.0001) corresponding to areas of glial scar formation. In the perilesional rim, CTGF expression was confined to invading vimentin-positive, glial fibrillary acidic protein (GFAP)—negative fibroblastoid cells, endothelial and smooth-muscle cells of laminin-positive vessels, and GFAP-positive reactive astrocytes. The CTGF-positive astrocytes coexpressed the activation-associated intermediate filaments nestin, vimentin (> 80%), and mesenchymal scar component fibronectin (50%).
Conclusions. The restricted accumulation of CTGF-reactive astrocytes and CTGF-positive fibroblastoid cells lining the laminin-positive basal neolamina suggests participation of these cells in scar formation. In addition, perilesional upregulation of endothelial and smooth-muscle CTGF expression points to a role in blood—brain barrier function modulating edema-induced secondary damage.
Anatomical landmarks for the lumbar plexus on the posterior abdominal wall
Authors: Tubbs R. Shane , Salter E. George , Wellons John C. , Blount Jeffrey P. , Oakes W. Jerry 
Published: May 2009

Object. Reports describing surgical landmarks with which to identify the branches of the lumbar plexus found on the posterior abdominal wall are lacking in the English-language literature.
Methods. The authors examined 22 sides from six female and five male cadavers. Measurements were made between the branches of the lumbar plexus and various bone landmarks such as the midline vertebral bodies, supracristal plane—a horizontal line connecting the superior-most aspect of the left and right iliac crests approximating the L4–5 vertebrae—and anterior superior iliac spine (ASIS).
The mean distances from the midline and as they emerged through or lateral to the psoas major muscle to the subcostal, iliohypogastric, ilioinguinal, lateral femoral cutaneous, genitofemoral, and femoral nerves, were 5.5, 6, 6.5, 6, 4.5, and 4.5 cm, respectively. At a vertical line through the midpoint between the ASIS and the midline, the subcostal, iliohypogastric, and ilioinguinal nerves were superior to the supracristal plane at mean distances of 8, 4, and 5 cm, respectively. Inferior to the supracristal plane and in a vertical line through a midpoint between the ASIS and the midline, the lateral femoral and femoral nerves were found to have mean distances of 5 and 5.5 cm, respectively. The obturator nerve had a mean distance of 3 cm lateral to the midline. Additionally, the lateral femoral cutaneous nerve had a mean distance of 1.5 cm inferomedial to the ASIS.
Conclusions. A good working knowledge of the locations and anatomy of the nerves of the lumbar plexus on the posterior abdominal wall is necessary for the surgeon who operates in this region. The measurements provided herein will aid the surgeon who wishes to expose or avoid these nerves, thus precluding injury.
Biomechanical studies of an artificial disc implant in the human cadaveric spine
Authors: Hitchon Patrick W. , Eichholz Kurt , Barry Christopher , Rubenbauer Paige , Ingalhalikar Aditya , Nakamura Satoshi , Follett Kenneth , Lim Tae Hong , Torner James 
Published: May 2009

Object. The authors compared the biomechanical performance of the human cadaveric spine implanted with a metallic ball-and-cup artificial disc at L4–5 with the spine's intact state and after anterior discectomy.
Methods. Seven human L2—S1 cadaveric spines were mounted on a biomechanical testing frame. Pure moments of 0, 1.5, 3.0, 4.5, and 6.0 Nm were applied to the spine at L-2 in six degrees of motion (flexion, extension, right and left lateral bending, and right and left axial rotation). The spines were tested in the intact state as well as after anterior L4–5 discectomy. The Maverick disc was implanted in the discectomy defect, and load testing was repeated.
The artificial disc created greater rigidity for the spine than was present after discectomy, and the spine performed biomechanically in a manner comparable with the intact state.
Conclusions. The results indicate that in an in vitro setting, this model of artificial disc stabilizes the spine after discectomy, restoring motion comparable with that of the intact state.
Technical advantages of an ultrasonic bone curette in spinal surgery
Authors: Nakagawa Hiroshi , Kim Sang-Don , Mizuno Junichi , Ohara Yukoh , Ito Kiyoshi 
Published: May 2009

Object.The authors discuss the safety and efficacy of an ultrasonic bone curette in various spinal surgeries and report its advantages in clinical application.Methods.Between April 2002 and September 2003, 76 patients with various spinal diseases (29 cervical, five thoracic, 40 lumbosacral, and two foramen magnum regions) were treated microsurgically by using a Sonopet ultrasonic bone curette with longitudinal and torsional tips and lightweight handpieces. The operations were performed successfully and the device was easy to handle. There were no instrument-related complications or -induced damage to any structure even when removing osseous spurs or ossified lesions near the dura mater, nerves, and vessels.Conclusions.The ultrasonic curette is a useful instrument for procedures performed near the dura mater or other neural tissue without excessive heat production or mechanical injury. This device is recommended for various spinal surgeries in addition to high-speed drills or other tools.