bluuebunny/crossref_metadata_2025_split huggingface dataset:
Factors affecting reduction in low-grade lumbosacral spondylolisthesis
Authors: Naderi Sait , Manisali Metin , Acar Feridun , Özaksoy Dinç , Mertol Tansu , Arda M. Nuri 
Published: May 2009

Object. Lumbosacral spondylolisthesis (LSS) is a common disorder that often requires a stabilization and fusion procedure. The aim of this study was to determine the early neuroimaging-detected results of instrumentation-assisted (in situ) fusion with no attempt at surgical reduction of the deformity in patients with low-grade LSS. The neuroimaging results were evaluated to determine the extent of reduction and its correlation with different parameters.
Methods. Thirty patients with low-grade LSS underwent short-segment transpedicular screw fixation; surgical reduction was not attempted. All patients underwent plain anteroposterior and lateral lumbar radiography, flexion—extension lateral lumbar radiography, and computerized tomography and magnetic resonance imaging of the lumbar spine before and after surgery. Postoperative measurements were determined on the late (9 to 12—month) postoperative radiographs. The findings were recorded and grouped. Correlation analysis was performed among the radiological findings, body mass index, age, and sex. Paired-sample t-tests were performed for each paired group to determine statistically significant differences.
There was no significant difference in extent of deformity reduction in patients with different lordotic angles, sagittal-plane rotation angles, and intervertebral disc heights. The extent of reduction was statistically significant at the L4–5 level (p < 0.05), in patients younger than 50 years of age (p < 0.05), and in those in whom the facet joint angle was increased (p < 0.05).
Conclusions. The authors found that in cases of low-grade LSS, short-segment posterior stabilization (in situ fusion and fixation) does not require surgical reduction and in fact is associated with a measurable reduction when used as the sole treatment.
Thoracic myelopathy caused by ossification of the ligamentum flavum: a report of 18 cases
Authors: Hamouda Karim Ben , Jemel Hafedh , Haouet Slim , Khaldi Moncef 
Published: May 2009

Object. Thoracic myelopathy caused by ossification of the ligamentum flavum (OLF) is a rare entity, most evident in Japan. The authors studied the clinical manifestations, radiological aspects, surgical treatment, and pathogenesis of this disease.
Methods. Eighteen patients with OLF-induced thoracic myelopathy underwent laminectomy. The severity of myelopathy varied. Complete paraplegia was seen in three cases. Compression of the upper and middle third of the thoracic spine was evident in six cases and of the lower third in 12 cases. Multilevel OLF was demonstrated in 13 cases. In most cases, the ossified ligamentum flavum appears as a V-shaped lesion on computerized tomography and magnetic resonance images. In all patients the diameter of the posterior spinal canal, already narrowed, was further exacerbated by the OLF.
Laminectomy was limited to the levels of compression, and the ligamentum flavum was resected in all cases. The symptoms and signs improved in 13 cases and stabilized in four cases. In one case symptoms recurred as a result of ossified lesions forming at other sites. Histological examination showed that the mode of development of the ossified ligaments was endochondral ossification.
Conclusions. Reports of OLF-induced myelopathy are rare and mainly described in Japan. The incidence also seems high in North Africa. An early laminectomy limited to the level of compression is recommended. Ossified ligamentum flavum is different from the calcification of the ligamentum flavum, which is due to crystal deposits.
Prevention of postoperative posterior tethering of spinal cord after resection of ependymoma
Authors: Goto Takeo , Ohata Kenji , Takami Toshihiro , Nishikawa Misao , Nishio Akimasa , Morino Michiharu , Tsuyuguchi Naohiro , Hara Mitsuhiro 
Published: May 2009

Object. The authors evaluated an alternative method to avoid postoperative posterior tethering of the spinal cord following resection of spinal ependymomas.
Methods. Twenty-five patients with spinal ependymoma underwent surgery between 1978 and 2002. There were 16 male and nine female patients whose ages at the time of surgery ranged from 14 to 64 years (mean 41.8 years). The follow-up period ranged from 6 to 279 months (mean 112.4 months). In the initial 17 patients (Group A), the procedure to prevent arachnoidal adhesion consisted of the layer-to-layer closure of three meninges and laminoplasty. In the subsequently treated eight patients (Group B), the authors performed an alternative technique that included pial suturing, dural closure with Gore-Tex membrane—assisted patch grafting, and expansive laminoplasty. In Group A, postoperative adhesion was radiologically detected in eight cases (47%), and delayed neurological deterioration secondary to posterior tethering of the cord was found in five cases. In Group B, there was no evidence of adhesive posterior tethering or delayed neurological deterioration. A significant intergroup statistical difference was demonstrated for radiologically documented posterior tethering (p < 0.05, Fisher exact test). Moreover, patients with radiologically demonstrated posterior tethering suffered a significant delayed neurological functional deterioration (p < 0.01, Fisher exact test).
Conclusions. This new technique for closure of the surgical wound is effective in preventing of postoperative posterior spinal cord tethering after excision of spinal ependymoma.
In vitro biomechanical effects of reconstruction on adjacent motion segment: comparison of aligned/kyphotic posterolateral fusion with aligned posterior lumbar interbody fusion/posterolateral fusion
Authors: Sudo Hideki , Oda Itaru , Abumi Kuniyoshi , Ito Manabu , Kotani Yoshihisa , Hojo Yoshihiro , Minami Akio 
Published: May 2009

Object. Posterior lumbar interbody fusion (PLIF) was developed to overcome the limitations of posterolateral fusion in correcting spinal deformity and maintaining lumbar lordosis. In this study the authors compare the biomechanical effects of three different posterior reconstructions on the adjacent motion segment.
Methods. Ten calf spinal (L2—S1) specimens underwent nondestructive flexion—extension testing (± 6 Nm). The specimens were destabilized at the L5—S1 levels after intact testing. This was followed by pedicle screw fixation with and without interbody cages as follows: 1) with straight rods (“aligned” posterolateral fusion); 2) with kyphotically prebent rods (“kyphotic” posterolateral fusion); and 3) with interbody cages combined with straight rods (“aligned” PLIF/posterolateral fusion). The range of motion (ROM) of the operative segments, the intradiscal pressure (IDP), and longitudinal lamina strain in the superior adjacent segment (L4–5) were analyzed.
The ROM associated with aligned PLIF/posterolateral fusion-treated specimens was significantly less than both the aligned and kyphotic posterolateral fusion-treated procedures in both flexion and extension loading (p < 0.05). The aligned PLIF/posterolateral fusion was associated with greater IDP and the lamina strain compared with the aligned and kyphotic posterolateral fusion groups in flexion loading. Under extension loading, greater IDP and lamina strain were present in the kyphotic posterolateral fusion group than in the aligned posterolateral fusion group. The highest IDP and lamina strain were shown in the aligned PLIF/posterolateral fusion group.
Conclusions. Compared with kyphotic posterolateral fusion, PLIF may lead to even higher load at the superior adjacent level because of the increased stiffness of the fixed segments even if local kyphosis is corrected by PLIF.
One-level one-sided lumbar disc surgery with and without microscopic assistance: 1-year outcome in 114 consecutive patients
Authors: Türeyen Kudret 
Published: May 2009

Object. The aim of this study was to compare the outcomes following macrodiscectomy and microsurgery for one-level one-sided lumbar disc excision.
Methods. The authors prospectively studied 114 consecutive patients who underwent microdiscectomy (Group A, 63 patients [36 men, 27 women]) and macrodiscectomy (Group B, 51 patients [29 men, 22 women]) for one-level unilateral first-time lumbar disc herniation. Microdiscectomy was considered to involve a small incision with removal or opening of the ligamentum flavum, no or minimal bone excision, and use of the operating microscope to remove the disc material. Laminectomy combined with macrodiscectomy was defined as any operation requiring a large opening in or complete removal of the unilateral lamina. Diagnosis was confirmed by magnetic resonance imaging. A 1-year follow-up investigation was also conducted. Relief of radicular pain, improvement in muscle power, and changes in sensory and/or reflex abnormality were documented. Assessment of outcome was performed using the modified Stauffer—Coventry criteria.
Good or excellent results were demonstrated in 90% of Group A and 89% of Group B patients (p > 0.05). One patient in each group underwent reoperation. There was infection over the fascia in two Group A patients. Mean operative time (± standard deviation) was 54 ± 5.65 minutes in Group A and 25 ± 7.07 minutes in Group B (p < 0.01). Median length of the incision was 4 and 6 cm in Group A and Group B, respectively (p < 0.05). The length of postoperative inpatient stay was 1 day in both groups (p > 0.05). Patients in the microsurgery-treated group returned to work in less time: 85% of Group A and 58% of Group B patients returned to their work within 4 weeks (p < 0.001). Some patients in each group (15% in Group A and 45% in Group B) needed narcotic analgesic medication at least twice between the 1st month and 1st year after the surgery (p < 0.001).
Conclusions. Microdiscectomy allows the surgeon good visualization and is less traumatic to the involved tissues. Interestingly, the results of this study indicated that microsurgery does not reduce hospitalization time, nor does it improve the overall surgery-related outcome. The main differences between the two procedures were length of the incision and operative time. The author found that lumbar microdiscectomy allows patients earlier return to work and/or normal life with less reliance on postoperative narcotic analgesic agents.
Clinical and radiological evaluation of the Codman semiconstrained load-sharing anterior cervical plate: prospective multicenter trial and independent blinded evaluation of outcome
Authors: Casha Steven , Fehlings Michael G. 
Published: May 2009

Object. Semiconstrained load-sharing implants for spinal fixation accommodate change in the screw—plate interface as bone grafts shrink. The authors evaluated the clinical and radiological outcome in patients after placement of the Codman anterior cervical plate (ACP) system, which allows change in the screw—plate angle.
Methods. The authors undertook a 10-center prospective study with independent blinded evaluation. All patients underwent cervical fusion and placement of ACPs. Clinical and radiological evaluations were performed at 1, 3, 6, 12, and 24 months. Radiographs were examined for screw angles, construct height, fusion, and screw fracture or displacement.
One hundred ninety-five patients were enrolled. The mean follow-up period was 17 months. At 24 months neurological improvement was demonstrated in 68.7% and pain improvement in 76.6% of the patients. Fusion was successful in 93.8%. Varying degrees (most minor) of hardware-related failure occurred in 10.4% of cases; however, reoperation was required in only four (2.1%). A significant change in screw angles occurred over time (mean 6.4° in caudal screw angle [p < 0.001] and 2.4° in the rostral screw angle [p = 0.003]). These changes plateaued by 6 months. A change in construct height (mean 3.48 mm) occurred by 6 months (p < 0.05).
Conclusions. Based on an independent blinded evaluation, the Codman ACP provides effective fixation with load sharing and is effective in achieving fusion with a 94% success rate. Direct comparison with rigidly locked devices is required to establish definitively the optimal method for anterior cervical fixation.
Low-dose radiotherapy for the inhibition of peridural fibrosis after reexploratory nerve root decompression for postlaminectomy syndrome
Authors: Gerszten Peter C. , Moossy John J. , Flickinger John C. , Welch William C. 
Published: May 2009

Object. The authors of clinical studies have demonstrated a significant association between the presence of extensive post—lumbar discectomy peridural scar formation and the recurrence of low-back and radicular pain. Low-dose perioperative radiotherapy has been demonstrated to inhibit peridural fibrosis after laminectomy in animal models. The present study was designed to evaluate the clinical efficacy of preoperative irradiation in patients with failed—back surgery syndrome due to peridural fibrosis who underwent reexploration and nerve root decompression.
Methods. Ten patients with symptomatic post—discectomy peridural fibrosis were randomized. Half of the patients underwent 700-cGy external-beam irradiation to the operative site 24 hours prior to reexploration and decompressive treatment of their symptomatic nerve root(s) (treatment group) and the other half underwent reexploration and decompressive treatment without preoperative irradiation (control group). All patients underwent simulated irradiation so neither patient nor surgeon was aware of the patient's group. In all patients the antiadhesion product ADCON-L was placed over the affected nerve root at the time of surgery. Clinical outcome was assessed using the American Association of Neurological Surgeons/Congress of Neurological Surgeons Joint Section Lumbar Disc Herniation Study Questionnaire at baseline, 6 weeks, 3 months, and 1 year follow up.
Five men and five women (mean age 42 years) underwent randomization and surgery. Three patients underwent reexploration at L4–5, four at L5—S1, and three at both levels. No complication was associated with irradiation, and no new neurological deficits occurred. At 1-year follow-up examination, three irradiation-treated patients were pain free and two experienced improvement. In the control group, three patients experienced improved pain relief and two were unchanged. There was a trend toward better outcome at 1 year in the radiotherapy-treated group (p = 0.056).
Conclusions. Preoperative low-dose external-beam irradiation improved clinical outcomes after reexploration and decompression of nerve roots affected by postlaminectomy peridural fibrosis causing radicular pain. The addition of preoperative irradiation may improve outcome in patients who undergo reoperation for recurrent radicular pain associated with a significant amount of peridural fibrosis, particularly now that no antiadhesion product is available for clinical use.
Mechanism of the spinal cord injury and the cervical spondylotic myelopathy: new approach based on the mechanical features of the spinal cord white and gray matter
Authors: Ichihara Kazuhiko , Taguchi Toshihiko , Sakuramoto Itsuo , Kawano Shunichi , Kawai Shinya 
Published: May 2009

Object. The authors have previously investigated the mechanical properties of the white and gray matter in the bovine cervical spinal cord, demonstrating that the gray matter is more rigid, although more fragile, than the white matter. In the present study they conducted additional tensile tests on the bovine cervical spinal cord by changing strain levels and strain rates applied to the white and gray matter.
Methods. Based on their testing, the authors found the following: 1) Stress within the spinal cord relaxes over time. 2) Intracord stress is related to the strain rates or levels. The finite element method was used to compute the stress distribution within the spinal cord under three compressive loading conditions. Results from the computations showed a different stress distribution in the white and gray matter, where the distribution of stress varied with strain rate, compression volume, and the position of compression.
Conclusions. These differences in mechanical properties between the white and gray matter constitute different mechanisms contributing to the development of tissue damage and clinical symptoms.
Changes in nerve root motion and intraradicular blood flow during intraoperative femoral nerve stretch test
Authors: Kobayashi Shigeru , Suzuki Yoshihiko , Asai Takahiro , Yoshizawa Hidezo 
Published: May 2009

Object. It is not known whether changes in intraradicular blood flow (IRBF) occur during the femoral nerve stretch test (FNST) in patients with lumbar disc herniation. An FNST was conducted in patients with lumbar disc herniation to observe the changes in IRBF, and results were then compared with clinical features.
Methods. The study was composed of four patients with L3–4 disc herniation who underwent microdiscectomy. Patients were placed prone immediately before surgery, so that their knee flexed on the operating table with the hip joint kept in hyperextension, and the FNST was performed to confirm at which region pain developed in the anterolateral thigh. During the operation, the hernia-affected nerve roots were visualized under a microscope. The needle sensor of a laser Doppler flowmeter was then inserted into each nerve root immediately above the hernia, and the change in IRBF was measured during the intraoperative FNST. After removal of the herniated disc, a similar procedure was repeated and IRBF was measured again.
The intraoperative FNST showed that the hernia compressed the nerve roots and there was marked disturbance of gliding, which was reduced to only a few millimeters. During the test, IRBF decreased by 92.8 to 100% (mean 96.9 ± 3.7% [± standard error of the mean]) relative to the blood flow before the test. This study demonstrated that the blood flow in the nerve root is reduced when the nerve root is compressed in vivo.
Conclusions. The intraoperative FNST showed that the hernia compressd the nerve roots and there was marked disturbance of gliding, which was reduced to only a few millimeters. During the test, IRBF decreased by 92.8 to 100% (96.9 ± 3.7% [mean ± standard error of the mean]).
Three-dimensional fluoroscopy-guided percutaneous thoracolumbar pedicle screw placement
Authors: Holly Langston T. , Foley Kevin T. 
Published: May 2009

✓ The authors sought to evaluate the feasibility and accuracy of three-dimensional (3D) fluoroscopic guidance for percutaneous placement of thoracic and lumbar pedicle screws in three cadaveric specimens.
After attaching a percutaneous dynamic reference array to the surgical anatomy, an isocentric C-arm fluoroscope was used to obtain images of the region of interest. Light-emitting diodes attached to the C-arm unit were tracked using an electrooptical camera. The image data set was transferred to the image-guided workstation, which performed an automated registration. Using the workstation display, pedicle screw trajectories were planned. An image-guided drill guide was passed through a stab incision, and this was followed by sequential image-guided pedicle drilling, tapping, and screw placement. Pedicle screws of various diameters (range 4–6.5 mm) were placed in all pedicles greater than 4 mm in diameter. Postoperatively, thin-cut computerized tomography scans were obtained to determine the accuracy of screw placement.
Eighty-nine (94.7%) of 94 percutaneous screws were placed completely within the cortical pedicle margins, including all 30 lumbar screws (100%) and 59 (92%) of 64 thoracic screws. The mean diameter of all thoracic pedicles was 6 mm (range 2.9–11 mm); the mean diameter of the five pedicles in which wall violations occurred was 4.6 mm (range 4.1–6.3 mm). Two of the violations were less than 2 mm beyond the cortex; the others were between 2 and 3 mm.
Coupled with an image guidance system, 3D fluoroscopy allows highly accurate spinal navigation. Results of this study suggest that this technology will facilitate the application of minimally invasive techniques to the field of spine surgery.
Cervical magnetic resonance imaging abnormalities not predictive of cervical spine instability in traumatically injured patients
Authors: Horn Eric M. , Lekovic Gregory P. , Feiz-Erfan Iman , Sonntag Volker K. H. , Theodore Nicholas 
Published: May 2009

Object.Identifying instability of the cervical spine can be difficult in traumatically injured patients. The goal of this study was to determine whether cervical abnormalities demonstrated on magnetic resonance (MR) imaging are predictive of spinal instability.Methods.Data in all patients admitted through the Level I trauma service at the authors' institution who had undergone cervical MR imaging were retrospectively reviewed. The reasons for MR imaging screening were neurological deficit, fracture, neck pain, and indeterminate clinical examination (for example, coma). Abnormal soft-tissue (prevertebral or paraspinal) findings on MR imaging were correlated with those revealed on computerized tomography (CT) scanning and plain and dynamic radiography to determine the presence/absence of cervical instability.Of 6328 patients admitted through the trauma service, 314 underwent MR imaging of the cervical spine. Of 166 patients in whom CT scanning or radiography demonstrated normal findings, 70 had undergone MR imaging that revealed abnormal findings. Of these 70 patients, 23 underwent dynamic imaging, the findings of which were normal. In each case of cervical instability (65 patients) CT, radiographic, and MR imaging studies demonstrated abnormalities. Furthermore, there were 143 patients with abnormal CT or radiographic study findings, in 13 of whom MR imaging revealed normal findings. Six of the latter underwent dynamic testing, which demonstrated normal results.Conclusions.Magnetic resonance imaging is sensitive to soft-tissue injuries of the cervical spine. When CT scanning and radiography detect no fractures or signs of instability, MR imaging does not help in determining cervical stability and may lead to unnecessary testing when not otherwise indicated.