bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of time-dependent spread of tissue damage in experimental spinal cord injury by killed-end evoked potential: effect of high-dose methylprednisolone
Authors: Fukaya Chikashi , Katayama Yoichi , Kasai Masahiko , Kurihara Jun , Maejima Sadahiro , Yamamoto Takamitsu 
Published: May 2009

Object. Histopathological studies on spinal cord injury (SCI) have demonstrated time-dependent spread of tissue damage during the initial several hours postinjury. When the long tract within the spinal cord is stimulated, a large monophasic positivity occurs at the injury site. This type of potential, termed the killed-end evoked potential (KEEP), indicates that a nerve impulse approaches but does not pass beyond the injury site. The authors tested the hypothesis that the damage spread can be evaluated as a progressive shift of the KEEP on a real-time basis. The effect of high-dose methylprednisolone sodium succinate (MPSS) on the spread of tissue damage was also examined by this methodology.
Methods. The KEEP was recorded using an electrode array placed on the spinal cord at the T-10 level in cats. This electrode array consisted of multiple 0.2-mm-diameter electrodes, each separated by 0.5 mm. Spinal cord injury was induced using a vascular clip (65 g pinching pressure for 30 seconds). The midline posterior surface of the spinal cord was stimulated bipolarly at the C-7 level by applying a single pulse at supramaximal intensity. During the initial period of 6 hours postinjury, the localization of the largest KEEP shifted progressively up to 2.5 mm rostral from the injury site. The amplitude of the KEEP recorded at the injury site decreased to 55 to 70% and became slightly shortened in latency as the localization of the largest KEEP shifted rostrally. These findings imply that the injury site KEEP represents the volume-conducted potential of the largest KEEP at the site of the conduction block. It moved away from the injury site in association with the damage spread, and this was confirmed histopathologically. A decrease in amplitude of KEEP at the injury site appeared to be the most sensitive measure of the damage spread, because the amplitude of the volume-conducted KEEP is inversely proportional to the square of the distance between the recording site and site of conduction block. Administered immediately after SCI, MPSS clearly inhibited these events, especially within 30 minutes postinjury.
Conclusions. The KEEP enables sequential evaluation to be made of the time-dependent spread of tissue damage in SCI in the same animal. It is, therefore, useful for detecting the effect of therapeutic interventions and for determining the therapeutic time window. The efficiency of MPSS to inhibit the spread of damaged tissue appeared to be maximized when it was administered within the initial 30-minute period postinjury.
Surgical removal of epidural and intradural polymethylmethacrylate extravasation complicating percutaneous vertebroplasty for an osteoporotic lumbar compression fracture
Authors: Shapiro Scott , Abel Todd , Purvines Scott 
Published: May 2009

✓ The authors report the case of patient with a lumbar vertebral body osteoporotic compression fracture who underwent percutaneous transpedicular polymethylmethacrylate (PMMA)—assisted vertebroplasty in whom extravasation of the cement into the spinal canal caused immediate neurological deterioration.
Lateral lumbar radiography and computerized tomography scanning demonstrated the presence of intraspinal PMMA. The patient suffered severe low-back pain, left-sided sciatica, and profound left L2–4 distribution weakness and numbness. She underwent immediate L-2 laminectomy, the extra- and intradural PMMA was removed, and instrumentation-assisted lateral mass fusion was performed. The patient recovered without incident and her neurological deficit improved.
Extravasation of cement into the spinal canal, neural foramen, paraspinal veins, or disc space has been reported in 11 to 73% of percutaneous transpedicular PMMA-assisted vertebroplasty procedures. It is disturbing that more than one group of authors has documented symptomatic spinal canal PMMA extravasation and that the patients were left severely handicapped because of a stated fear that surgery to remove the cement would be difficult and make them worse. The results achieved in this case refute that published notion. It is important to document that decompressive surgery and PMMA removal from the spinal canal are easy and can lead to immediate neurological improvement. With the increasing popularity of percutaneous transpedicular PMMA-assisted vertebroplasty, the authors suspect that more of these cases will be seen.
Failed anterior cervical foraminotomy
Authors: Hacker Robert J. , Miller Christopher G. 
Published: May 2009

Object. Anterior cervical foraminotomy has been advocated as a procedure that preserves the motion segment while treating radiculopathy due to degenerative cervical disc disease. Because the medical literature contains no long-term follow up or randomized studies related to this procedure, the authors reviewed their results, specifically examining cases of failure to determine the efficacy of the approach.
Methods. The authors identified 23 patients in whom unilateral cervical radiculopathy due to degenerative cervical disc disease was refractory to conservative therapy and in whom anterior cervical foraminotomy was performed between 1998 and 2000. The procedure involves ipsilateral exposure, microsurgical removal of the uncovertebral joint to identify the nerve root, and partial removal of the lateral anulus and or disc fragments. Data in those patients who underwent reoperation(s) were reviewed specifically for the procedure type, interval between index procedure and reoperation, and whether multiple procedures were performed. Of the 23 patients, 30% required at least one additional procedure. A good or excellent outcome at last follow-up examination was achieved in only 12 patients.
Conclusions. In the current study the authors found a reoperation rate that is considerably higher than that in most series of anterior cervical surgery for radiculopathy. The presumed benefit of anterior cervical foraminotomy is preservation of the disc interspace; however, in this study, a significant number of patients failed to experience a satisfying outcome. Currently the authors do not recommend anterior cervical foraminotomy as a stand-alone procedure.
Cervical laminoplasty: evaluation of bone bonding of a high porosity hydroxyapatite spacer
Authors: Iguchi Tetsuhiro , Kanemura Aritetsu , Kurihara Akira , Kasahara Koichi , Yoshiya Shinichi , Doita Minoru , Nishida Kotaro 
Published: May 2009

Object. The purpose of this study was to evaluate the usefulness of a high-porosity hydroxyapatite (HA) spacer in cervical laminoplasty. Bone—spacer bonding rates, complications associated with the implant, and factors related to bone bonding were examined.
Methods. The authors evaluated 33 consecutive patients with cervical myelopathy who underwent high-porosity HA spacer—assisted laminoplasty and were followed for at least 1 year (mean 30 months). The results of bone—spacer bonding of the 147 implants were evaluated using computerized tomography (CT) scanning. The symptoms significantly improved in 30 patients. No difference in results was detected between patients with cervical spondylosis and those with ossification of posterior longitudinal ligament. Breakage of seven spacers occurred in four patients without causing neck pain or neurological deficits. There were no other HA spacer—related complications. The spacers became rigidly bound to bone in 61% of the cases, and bone regrowth developed around the spacer in 91%. The rate of bone—spacer bonding increased over time, and the CT-documented attenuation value (Hounsfield unit) of the spacer adjacent to the bone—spacer junction in the group in which union occurred was significantly higher than in the nonunion group.
Conclusions. High-porosity HA spacer—augmented laminoplasty produced good bonding-related results. Bone bonding continued to progress 1 year after surgery, indicating the good osteoconductive capability of high-porosity HA. To avoid breakage of a spacer, a minimum 7-mm distance between spacers is necessary.
Implantation of an empty carbon fiber composite frame cage after single-level anterior cervical discectomy in the treatment of cervical disc herniation: preliminary results
Authors: Payer Michael , May Daniel , Reverdin Alain , Tessitore Enrico 
Published: May 2009

Object. The authors sought to evaluate retrospectively the radiological and clinical outcome of anterior cervical discectomy followed by implantation of an empty carbon fiber composite frame cage (CFCF) in the treatment of patients with cervical disc herniation and monoradiculopathy.
Methods. Twenty-five consecutive patients (12 men, 13 women, mean age 45 years) with monoradiculopathy due to cervical disc herniation were treated by anterior cervical discectomy followed by implantation of an empty CFCF cage. On lateral flexion—extension radiographs segmental stability at a mean follow up of 14 months (range 5–31 months) was demonstrated in all 25 patients, and bone fusion was documented in 24 of 25 patients. The mean anterior intervertebral body height was 3.4 mm preoperatively and 3.8 mm at follow up in 20 patients. In these patients the mean segmental angle (angle between lower endplate of lower and upper vertebra) was 0.9° preoperatively and 3.1° at follow up. In the remaining five patients preoperative images were not retrievable.
Self-scored neck pain based on a visual analog scale (1, minimum; 10, maximum) changed from a preoperative average of 5.6 to an average of 2 at follow up; radicular pain was reduced from 7.7 to 2.1 postoperatively. Analysis of the SF12 questionnaires showed a significant improvement in both the physical capacity score (preoperative mean 32.4 points; follow up 46 points) and the mental capacity score (preoperative mean 45.8 points; follow up 57.5 points).
Conclusions. Implantation of an empty CFCF cage in the treatment of cervical disc herniation and monoradiculopathy avoids donor site morbidity associated with autologous bone grafting as well as the use of any supplementary material inside the cage. Restoration or maintenance of intervertebral height and thus segmental lordosis and a very high rate of segmental stability and fusion are achieved using this technique.
Risk factors for surgical site infection in spinal surgery
Authors: Olsen Margaret A. , Mayfield Jennie , Lauryssen Carl , Polish Louis B. , Jones Marilyn , Vest Joshua , Fraser Victoria J. 
Published: May 2009

Object. The objective of this study was to identify specific independent risk factors for surgical site infections (SSIs) occurring after laminectomy or spinal fusion.
Methods. The authors performed a retrospective case-control study of data obtained in patients between 1996 and 1999 who had undergone laminectomy and/or spinal fusion. Forty-one patients with SSI or meningitis were identified, and data were compared with those acquired in 178 uninfected control patients. Risk factors for SSI were determined using univariate analyses and multivariate logistic regression.
The spinal surgery—related SSI rate (incisional and organ space) during the 4-year study period was 2.8%. Independent risk factors for SSI identified by multivariate analysis were postoperative incontinence (odds ratio [OR] 8.2, 95% confidence interval [CI] 2.9–22.8), posterior approach (OR 8.2, 95% CI 2–33.5), procedure for tumor resection (OR 6.2, 95% CI 1.7–22.3), and morbid obesity (OR 5.2, 95% CI 1.9–14.2). In patients with SSI the postoperative hospital length of stay was significantly longer than that in uninfected patients (median 6 and 3 days, respectively; p < 0.001) and were readmitted to the hospital for a median additional 6 days for treatment of their infection. Repeated surgery due to the infection was required in the majority (73%) of infected patients.
Conclusions. Postoperative incontinence, posterior approach, surgery for tumor resection, and morbid obesity were independent risk factors predictive of SSI following spinal surgery. Interventions to reduce the risk for these potentially devastating infections need to be developed.
Results of preoperative embolization for metastatic spinal neoplasms
Authors: Prabhu Vikram C. , Bilsky Mark H. , Jambhekar Kedar , Panageas Katherine S. , Boland Patrick J. , Lis Eric , Heier Linda , Nelson P. Kim 
Published: May 2009

Object. Arterial embolization reduces blood loss in patients undergoing surgery for hypervascular spinal tumors. The objectives of this study were twofold: 1) to evaluate the role of magnetic resonance (MR) imaging in predicting tumor vascularity and 2) to assess the effectiveness of preoperative embolization in devascularizing these tumors.
Methods. Fifty-one patients with metastatic spinal neoplasms underwent angiography, preoperative embolization, and excision of the lesion between 1995 and 2000. The MR imaging studies were correlated with tumor vascularity on angiograms. Embolization was angiographically graded on a five-point scale ranging from no embolization (Grade A) to total embolization (Grade E). The embolization grade was correlated with intraoperative blood loss.
The mean age was 57 years, the male/female ratio was 1.2:1, and back pain was present in all patients. Metastatic renal cell carcinoma (30 cases) and thoracic spine involvement (33 cases) were most frequent. The positive predictive value of MR imaging in determining tumor vascularity was 77%, whereas the negative predictive value was 21%. Total embolization (Grade E) was achieved in 34 patients. A shared vascular pedicle between a radiculomedullary artery (RMA) and a tumor diminished the likelihood of complete embolization (p = 0.02). Small asymptomatic cerebellar infarctions were demonstrated in two cases. The mean intraoperative blood loss was 2586 ml. Following Grade D or E embolization, intraoperative bleeding was largely related to unembolized epidural veins.
Conclusions. Tumor histology and MR imaging findings are predictive of hypervascularity; however, hypervascular tumors may not be detected by standard MR imaging sequences. Superselective catheterization permits Grade D or E embolization in 80% of patients. Shared blood supply with an RMA is the most important factor precluding complete embolization.
Management of atlantoaxial metastases with posterior occipitocervical stabilization
Authors: Fourney Daryl R. , York Julie E. , Cohen Zvi R. , Suki Dima , Rhines Laurence D. , Gokaslan Ziya L. 
Published: May 2009

Object. The treatment of atlantoaxial spinal metastases is complicated by the region's unique biomechanical and anatomical characteristics. Patients most frequently present with pain secondary to instability; neurological deficits are rare. Recently, some authors have performed anterior approaches (transoral or extraoral) for resection of upper cervical metastases. The authors review their experience with a surgical strategy that emphasizes posterior stabilization of the spine and avoidance of poorly tolerated external orthoses such as the rigid cervical collar or halo vest.
Methods. The authors performed a retrospective review of 19 consecutively treated patients with C-1 or C-2 metastases who underwent surgery at The University of Texas M. D. Anderson Cancer Center between 1994 and 2001.
Visual analog pain scores were reduced at 1 and 3 months (p < 0.005, Wilcoxon signed-rank test); however, evaluation of pain at 6 months and 1 year was limited by the remaining number of surviving patients. Analgesic medication consumption was unchanged. There were no cases of neurological decline or sudden death secondary to residual or recurrent atlantoaxial disease during the follow-up period. One patient underwent revision of hardware at 11 months. The mean follow-up period was 8 months (range 1–32 months). Median survival determined by Kaplan—Meier analysis was 6.1 months (95% confidence interval 2.99–9.21).
Conclusions. Occipitocervical stabilization provided durable pain relief and preservation of ambulatory status over the remaining life span of patients. Because of the palliative goals of surgery, the authors have not found an indication for anterior-approach tumor resection in these patients. Successful stabilization obviates the need for an external orthosis.
Nuclear factor—κB-regulated cyclooxygenase-2 expression in surgery-associated paraspinal muscle injury in rats
Authors: Lu Kang , Liang Cheng-Loong , Chen Han-Jung , Chen Shang-Der , Hsu Huan-Chen , Chen Yun-Ching , Hsu Fu-Fei , Cho Chung-Lung 
Published: May 2009

Object. Paraspinal muscle injury is a common but neglected complication of posterior spinal surgery. Evidence suggests that surgical retraction places mechanical and oxidative stress on the paraspinal muscles and that inflammation is a major postoperative pathological finding in the muscles. The roles of cyclooxygenase (COX)—2 and nuclear factor (NF)—κB in the inflammatory processes after retraction remains to be clarified.
Methods. In the control group, paraspinal muscles were dissected from the spine via a posterior incision and then laterally retracted. Paraspinal muscle specimens were harvested before as well as at designated time points during and after persistent retraction. The time course of NF-κB activation was determined by gel shift assay. Expression of COX-2 was examined using Western blot analysis and immunohistochemistry. The severity of inflammation was evaluated based on histopathology and myeloperoxidase (MPO) activity. The NF-κB activation was inhibited by the administration of pyrrolidine dithiolcarbamate (PDTC) in the PDTC-treated group. Retraction induced early activation of NF-κB in paraspinal muscle cells. The expression of COX-2 could not be detected until 1 day postoperativley, reaching a peak at 3 days. The time course of COX-2 expression correlated with that of inflammatory responses and MPO activity. Pretreatment with PDTC inhibited intraoperative NF-κB activation and greatly downregulated postoperative COX-2 expression and inflammation in the muscles. Postinflammation fibrosis was also abolished by PDTC administration.
Conclusions. Both NF-κB-regulated COX-2 expression and inflammation play an important role in the pathogenesis of surgery-associated paraspinal muscle injury. The therapeutic strategy of NF-κB inhibition may be applicable to the prevention of such injury.
The transverse process, intertransverse space, and vertebral artery in anterior approaches to the lower cervical spine
Authors: Kawashima Masatou , Tanriover Necmettin , Rhoton Albert L. , Matsushima Toshio 
Published: May 2009

Object. The microsurgical anatomy of the C3–6 transverse processes and their relationship to the intertransverse space and vertebral artery (VA) were examined with special attention to the aspect exposed in the anterior surgical approach.
Methods. Ten adult cadaveric spines were examined (magnification levels × 3–40) after perfusion of the arteries and veins with colored silicone. The morphological detail of the transverse process and intertransverse space, the distances between selected surgical landmarks and the VA were measured, and the means and standard deviations were calculated. The osseous changes in the anterior root of the transverse process were classified according to their extent.
The transverse processes became smaller, and the anterior intertransverse spaces and the width of the VA exposed in the space increased in size proceeding from caudal to rostral levels, thus exposing the VA to increased risk of injury during procedures at cephalad levels. The distance between the medial border of the longus colli muscle and the VA decreased when proceeding caudally from C2–3 to C4–5 interspaces but began to increase at the level of C5–6. The VA coursed closer to the lateral border of the vertebral body than to the medial border of the anterior tubercle of the transverse process. Osseous changes consisting of thinning or defects in the anterior root of the transverse process were observed from C-3 to C-5. The thinning was most prominent in the lower half of the anterior root just above where the VA ascends behind the lower edge of the anterior root. The osseous change may reflect the erosive effect of the VA on the anterior root of the transverse process.
Conclusions. This study provides new information regarding the transverse process and especially the anterior root. An awareness of the thinness and defects in the anterior root of the transverse process and the relationships to the surrounding area will aid in reducing VA injury during anterior approaches to the cervical spine.
Occipitocervical reconstruction with the Ohio Medical Instruments Loop: results of a multicenter evaluation in 30 cases
Authors: Singh Sheila K. , Rickards Lynda , Apfelbaum Ronald I. , Hurlbert R. John , Maiman Dennis , Fehlings Michael G. 
Published: May 2009

Object. Stabilization of the craniocervical junction (CCJ) remains a significant challenge. In this multicenter study, the authors present the results of an evaluation of a precontoured titanium implant, the Ohio Medical Instruments (OMI) Loop, for craniocervical fixation.
Methods. In this multicenter retrospective study the authors evaluated 30 patients (16 female, 14 male; mean age 53.8 years) with rheumatoid arthritis (15 cases), traumatic occipitoatlantoaxial instability (six cases), congenital vertebral anomalies (two cases), instability due to basilar invagination in the setting of Chiari malformation (two cases), or Down syndrome (one case), tumor (one case), os odontoideum (two cases), and pseudarthrosis/other (one case), who underwent OMI Loop—assisted occipitocervical reconstruction. The mean follow-up period was 25.4 months (range 6–60 months).
A solid reconstruction was achieved in 29 of 30 cases; there was only one case of hardware failure requiring reoperation. Noncritical hardware failure occurred in two patients in whom partial occipital screw backout occurred but did not necessitate reoperation. There were no perioperative neurological complications. One patient (3.3%) experienced a delayed postoperative worsening of myelopathy at 1 year that resolved with further surgery. Postoperatively, in 66.6% of patients the degree of myelopathy remained stable (as measured by American Spinal Injury Association [ASIA] scores), whereas 30% improved by one or more ASIA grade. The rate of osseous fusion was 96.6% at a mean follow-up period of 25.4 months.
Conclusions. The authors found that the OMI Loop is a versatile precontoured occipitocervical fixation device that can be applied to a wide range of CCJ lesions. It provides excellent immediate rigid fixation of the CCJ, a high rate of osseous fusion, and a low rate of hardware failure.