bluuebunny/crossref_metadata_2025_split huggingface dataset:
Clinical significance of the redundant nerve roots of the cauda equina documented on magnetic resonance imaging
Authors: Ono Atsushi , Suetsuna Futoshi , Irie Tomoyuki , Yokoyama Toru , Numasawa Takuya , Wada Kanichiro , Toh Satoshi 
Published: January 2008

Object
Previous reports of redundant nerve roots (RNRs) of the cauda equina have been limited to evaluations based on myelography. Neither the imaging nor the clinical features of RNRs in relation to magnetic resonance (MR) imaging have been elaborated. The MR imaging characteristics of RNRs were evaluated using the Japanese Orthopaedic Association score before and after the surgery.

Methods
There were 44 patients with L4–5 spondylolisthesis in which a complete blockage was demonstrated on myelography. All patients underwent posterior L4–5 interbody fusion. Based the myelographic and MR imaging findings, the patients were stratified into the following three groups: RNRs recognized on both myelographic and MR imaging (Group A); RNRs recognized on myelography but not very evident on MR imaging (Group B); and RNRs not recognized on either myelographic or MR imaging (Group C). Among these three groups, pre- and postoperative clinical symptoms were compared.

Results
There were 16 patients in Group A, 14 in Group B, and 14 in Group C. In terms of preoperative clinical symptoms, there was a significant difference between Groups A and C in the incidence of leg pain and tingling sensation. Significant differences were also noted between Groups A and C and between Groups B and C in ambulatory ability. Evaluation of postoperative clinical symptoms showed a significant difference between Groups A and C in ambulatory ability.

Conclusions
Patients with MR imaging evidence of RNRs presented with more severe clinical symptoms. It is believed that the RNR features derived from MR images represent important findings.
Palliative dual iliac screw fixation for lumbosacral metastasis
Authors: Fujibayashi Shunsuke , Neo Masashi , Nakamura Takashi 
Published: January 2008

✓ Spinal fixation for destructive metastatic lesions at the lumbosacral junction is challenging because of the large and unique load-bearing characteristics present. In particular, caudal fixation is difficult in cases of sacral destruction because of insufficient S-1 pedicle screw anchorage. The authors describe their surgical technique for secure iliac screw placement and the clinical results obtained in five patients with metastatic spinal disease. All patients in this study underwent palliative operations with dual iliac screw fixation between April 1999 and October 2002, and the clinical and radiological findings were assessed. In all five patients, spinal metastases extended into the sacrum. The metastases were from renal cell carcinomas in two patients, lung cancer in two, and a paraganglioma in one patient.
Postoperative follow-up periods ranged from 3 months to 6 years (mean 28.4 months). Preoperatively, four patients could not walk due to severe pain or neurological compromise. Postoperatively, all patients reported a reduction in pain and regained the ability to walk. Complications included one case of early wound infection. In the patients with long survival after the operation, there was one case of iliac screw loosening and one case of rod breakage. The dual iliac screw fixation technique provided sufficient immediate stability for destructive lumbosacral metastasis.
Occipitocervical fusion with rigid internal fixation: long-term follow-up data in 69 patients
Authors: Nockels Russ P. , Shaffrey Christopher I. , Kanter Adam S. , Azeem Syed , York Julie E. 
Published: January 2008

Object.
Instability of the occipitocervical junction may result from degenerative disease, infection, tumor, and trauma. Surgical stabilization involving screw fixation and rigid implants has been found to be biomechanically superior to wire-based implants. To evaluate the long-term results in a large and diverse patient population, the authors prospectively studied a consecutive group of 69 patients.

Methods.
All patients underwent occipitocervical fusion in which rigid posterior instrumentation included either plates or rods and screws. Patients ranged in age from 11 to 90 years (mean 51.4 years); there were 34 female and 35 male patients. The mean follow-up duration was 37 months (range 6–66 months). Fifty-seven (83%) of the 69 patients had long-standing occipitocervical anomalies, whereas the remainder presented with acute instability. Basilar invagination was present in 20 patients.

Results.
Correction of a severe cervical kyphotic deformity was accomplished in six patients. There were no fatalities or medical complications associated with the procedures. During the follow-up period, 87% of the patients exhibited improvement in their myelopathic symptoms; in 13% the symptoms were unchanged. Complications were minimal. Stability was demonstrated on flexion/extension studies in all cases. There were no treatment-related deaths, although four patients died within the follow-up period, all due to progression of metastatic disease.

Conclusions.
The authors found that rigid internal fixation of the occipitocervical complex was safe, effective, and technically possible for spine surgeons familiar with occipital bone anatomy and lateral mass fixation.
Wear simulation of the ProDisc-L disc replacement using adaptive finite element analysis
Authors: Rawlinson Jeremy J. , Punga Karan P. , Gunsallus Kirk L. , Bartel Donald L. , Wright Timothy M. 
Published: January 2008

Object.
An understanding of the wear potential of total disc replacements (TDRs) is critical as these new devices are increasingly introduced into clinical practice. The authors analyzed the wear potential of a ProDisc-L implant using an adaptive finite element (FE) technique in a computational simulation representing a physical wear test.

Methods.
The framework for calculating abrasive wear, first validated using a model of a total hip replacement (THR), was then used to model the ProDisc-L polyethylene component that is fixed to the inferior endplate and articulates with the rigid superior endplate. Proposed standards for spine wear testing protocols specified the inputs of flexion–extension (6/−3°), lateral bending (± 2°), axial twist (± 1.5°), and axial load (200–1750 N or 600–2000 N) applied to the model through 10 million simulation cycles. The model was calibrated with a wear coefficient determined from an experimental wear test. Implicit FE analyses were then performed for variations in coefficient of friction, polyethylene elastic modulus, radial clearance, and polyethylene component thickness to investigate their effects on wear.

Results.
Using the initial loading protocol (single-peaked axial load profile of 300–1750 N) from the experimental wear test, the polyethylene wear rate was 9.82 mg per million cycles. When a double-peaked loading profile (600–2000 N) was applied, the wear rate increased to 11.77 mg per million cycles. Parametric design variations produced only small changes in wear rates for this simulation.

Conclusions.
The chosen design variables had little effect on the resultant wear rates. The comparable wear rate for the THR validation analysis was 16.17 mg per million cycles, indicating that, using this framework, the wear potential of the TDR was equivalent to, if not better, than the THR using joint-specific loading standards.
Local delivery of OncoGel delays paresis in rat metastatic spinal tumor model
Authors: Bagley Carlos A. , Bookland Markus J. , Pindrik Jonathan A. , Ozmen Tolga , Gokaslan Ziya L. , Witham Timothy F. 
Published: January 2008

Object.
Spinal column metastatic disease clinically affects thousands of cancer patients every year. Local chemotherapy represents a new option in the treatment of metastatic disease of the spine. Despite the clinical impact of metastatic spine disease, the literature currently lacks an accurate animal model for the effective dosing of local chemotherapeutic agents within the vertebral column.

Methods.
Female Fischer 344 rats, weighing 150 to 200 g each, were used in this study. After induction of anesthesia, a transabdominal approach to the ventral vertebral body of L-6 was performed. A small hole was drilled and 5 μL of ReGel (blank polymer), OncoGel (paclitaxel and ReGel) 1.5%, OncoGel 3.0%, or OncoGel 6.0% were immediately injected to determine drug toxicity. Based on these results, efficacy studies were performed by intratumoral injection of 5 μL of ReGel, OncoGel 3.0%, and OncoGel 6.0% on Day 6 in a CRL-1666 breast adenocarcinoma metastatic spine tumor model. Hind limb function was tested pre- and postoperatively using the Basso-Beattie-Bresnahan rating scale. Histological analysis of the spinal cord and vertebral column was performed when the animal died or was killed.

Results.
There were no signs of toxicity observed in association with any of the agents under study. No increased benefit was seen in the blank polymer group compared with the control group (tumor only). OncoGel 3.0% and OncoGel 6.0% were effective in delaying the onset of paralysis in the respective study groups.

Conclusions.
These findings demonstrate the potential benefit of OncoGel in cases of subtotal resections of metastatic spinal column tumors. OncoGel 6.0% is the most efficacious drug concentration and offers the best therapeutic option in this experimental model. These results provide promise for the development of local chemotherapeutic means to treat spinal metastases.
A comparison of single and incremental impact approaches for producing experimental thoracolumbar burst fractures
Authors: Wang Xiang-Yang , Dai Li-Yang , Xu Hua-Zi , Chi Yong-Long 
Published: January 2008

Object.
Experimental burst fracture models are often developed by using either single or incremental impacts. In both protocols, the weight-drop technique produces the impact. However, to the authors' knowledge in no study have researchers attempted to compare the equivalence of the spine burst fracture produced using the different impact protocols. This study was performed to investigate whether the single and incremental trauma approaches produce equivalent degrees of severity in thoracolumbar burst fractures.

Methods.
Twenty bovine thoracolumbar spines comprising three vertebrae were divided evenly into the single impact and incremental impact groups. The specimens in the incremental impact group were subjected to three axial compressive impacts of increasing energy (78.4, 107.8, and 137.2 J), whereas specimens in the other group were subjected to a single impact (137.2 J). Before and after the final trauma, multidirectional flexibility of each specimen was measured under flexion/extension, right/left lateral bending, and right/left axial rotation, thus quantifying the instability of the fracture. The flexibility parameters were then compared between the two groups.

Results.
A significant increase in flexibility parameters was found after the final trauma in both groups, indicating the instability of the spine (p < 0.01). No significant differences in flexibility parameters were observed in either intact status or injured status between the two groups (p > 0.05).

Conclusions.
In this study the authors have confirmed that the single and incremental impact protocols produced a similar degree of severity in producing an in vitro bovine burst fracture. The results of this study support the use of the incremental impact protocol in future experimental biomechanical studies.
Use of intraoperative sodium tetradecyl sulfate for the treatment of a spinal epidural hemangioma
Authors: Baig Mirza N. , Saquib Syed , Christoforidis Greg , Caragine Louis P. 
Published: January 2008

✓Spinal hemangiomas can be categorized into three different groups based on location. Vertebral body (VB) heman-giomas are frequent incidental findings on magnetic resonance (MR) imaging. There is a subdivision of these with spinal epidural extension that have been reported in the literature. Spinal hemangiomas can also be epidural without VB involvement; these are extremely rare with few reported cases in the thoracic epidural spinal column. The diagnosis and imaging characteristics as well as the surgical tools used in gross-total resection of spinal epidural hemangioma are not well understood.
The authors present a detailed characterization of a spinal epidural hemangioma in a 30-year-old woman who presented with complaints of gradual onset of low-back pain that worsened over 1 year. The MR imaging findings indicated a large L2–S1 epidural spinal mass causing thecal sac compression. The patient underwent an L2–S1 laminectomy, and a vascular extradural mass was noted on the posterior aspect of the dura mater. Preoperative spinal angiography as well as intraoperative angiography was performed.
Total resection of the tumor was achieved using intraoperative embolization with sodium tetradecyl sulfate and microscopic dissection. The postoperative MR imaging findings and clinical outcome were excellent.
The findings and use of sodium tetradecyl sulfate in gross-total resection are discussed. The authors also review treatment modalities and demonstrate the utility and effectiveness of intraoperative sodium tetradecyl sulfate in gross-total resection of large difficult spinal epidural hemangiomas.
Tethering tracts in spina bifida occulta: revisiting an established nomenclature
Authors: Rajpal Sharad , Salamat M. Shahriar , Tubbs R. Shane , Kelly David R. , Oakes W. Jerry , Iskandar Bermans J. 
Published: January 2008

Object
The goal of the present study goal was to systematically confirm the previously recognized nomenclature for tethering tracts that are part of the spectrum of occult spinal dysraphic lesions.

Methods
The tethering tract in 20 patients with spina bifida occulta underwent histological examination with H & E staining and epithelial membrane antigen (EMA) immunolabeling, and additional selected specimens were stained with Masson trichrome.

Results
All tethering tracts contained fibrous connective tissue. Four tracts were lined with epithelial cells and either originated within a dermoid cyst, terminated at a skin dimple/sinus opening, or had both of these characteristics. No tethering tracts exhibited EMA positivity or meningeal elements. Although all tethering tracts originated in juxtaposition to the spinal cord, their termination sites were variable.

Conclusions
Based on histological findings and presumed embryological origin, the authors broadly classified tethering tracts terminating within the dura mater, epidural space, or lamina as “short tethering tracts” (STTs). The STTs occurred mostly in conjunction with split cord malformations and had a purely fibrous composition. Tethering tracts terminating superficial to the overlying lamina were classified as “long tethering tracts” (LTTs), and the authors propose that these are embryologically distinct from STTs. The LTTs were of two varieties: epithelial and nonepithelial, the former being typically associated with a skin dimple or spinal cord (epi)dermoid cyst. In fact, analysis of the data suggested that not every tethering tract terminating in or on the skin should be classified as a dermal sinus tract without histological confirmation, and because no evidence of meningeal tissue–lined tracts was detected, the use of the term “meningocele manqué” may not be appropriate.
Fractionated, single-port radiotherapy delays paresis in a metastatic spinal tumor model in rats
Authors: Bagley Carlos A. , Bookland Markus J. , Pindrik Jonathan A. , Ozmen Tolga , Gokaslan Ziya L. , Wolinsky Jean-Paul , Witham Timothy F. 
Published: January 2008

Object
Spinal column metastatic disease affects thousands of cancer patients every year. Radiation therapy frequently represents the primary treatment for this condition. Despite the enormous clinical impact of spinal column metastatic disease, the literature currently lacks an accurate animal model for testing the efficacy of irradiation on spinal column metastases.

Methods
After anesthesia was induced, female Fischer 344 rats underwent a transabdominal approach to the ventral vertebral body (VB) of L-6. A 2- to 3-mm-diameter bur hole was drilled for the implantation of a section of CRL-1666 breast adenocarcinoma. After the animals had recovered from the surgery, they underwent fractionated, single-port radiotherapy beginning on postoperative Day 7. Each group of animals underwent five daily fractions of radiation treatment. Group I animals received a total dose of 10 Gy in 200-cGy daily fractions, Group II animals received a total dose of 20 Gy in 400-cGy daily fractions, and Group III animals received a total dose of 30 Gy in 600-cGy daily fractions. A control group of rats with implanted VB lesions did not receive radiation. To test the effects of radiation toxicity alone, additional rats without implanted tumors received radiation treatments in the same fractions as the rats with tumors. Hindlimb function in all rats was rated before and after radiation treatment using the Basso-Beattie-Bresnahan locomotor rating scale. Histological analysis of spinal cord and vertebral column sections was performed after each animal's death.

Results
Functional assessments demonstrated a statistically significant delay in the onset of paresis between the three treatment groups and the control group (tumor implanted but no radiotherapy). The rats in the three treatment groups, however, did not exhibit any significant differences related to hindlimb function. A dose-dependent relationship was found for the percentage of animals who had become paralyzed at the time of death, with all members of the control group and no members of the 30-Gy group exhibiting paralysis. The results of this study do not indicate any overall survival benefit for any level of radiation dose.

Conclusions
These findings demonstrate the efficacy of focal spinal irradiation in delaying the onset of paralysis in a rat metastatic spine tumor model, but without a clear survival benefit. Because of the dose-related toxicity observed in the rats treated with 30 Gy, this effect was most profound for the 20-Gy group. This finding parallels the observed clinical course of spinal column metastatic disease in humans and provides a basis for the future comparison of novel local and systemic treatments to augment the observed effects of focal irradiation.
A prospective randomized comparison of rectangular titanium cage fusion and iliac crest autograft fusion in patients undergoing anterior cervical discectomy
Authors: Thomé Claudius , Leheta Olaf , Krauss Joachim K. , Zevgaridis Dimitris 
Published: January 2008

Object
The authors compare clinical outcome and fusion rates after iliac crest autograft (ICAG)– and rectangular titanium cage (RTC)–augmented fusion in patients undergoing anterior cervical discectomy (ACD).

Methods
One hundred consecutive patients with 127 levels of cervical disc disease refractory to conservative treatment were randomized into one of the two treatment groups (ICAG/RTC fusion). The visual analog scale was used by the patient to rate overall pain and head, neck, arm, and donor site pain separately. Myelopathy was documented according to Japanese Orthopaedic Association and Nurick grading systems. Outcome was analyzed using Odom criteria, the 36-Item Short Form (SF-36), and Patient Satisfaction Index scales. Fusion rates were assessed on standard and flexion–extension radiographs. Follow-up data of at least 12 months' duration were available for 95 patients.
More residual overall pain after 12 months was documented in patients who underwent ICAG fusion (3.3 ± 2.5 [ICAG] and 2.2 ± 2.4 [RTC]; p < 0.05). Although arm and head pain were minimal in both groups, neck pain proved to be the predominant symptom (2.7 ± 2.5 [ICAG] and 1.9 ± 2.1 [RTC]), which resolved in only 67 and 48% of RTC-and ICAG-treated patients, respectively (p < 0.05). Myelopathy improved comparably in both groups. Regardless of increased pain in ICAG-treated patients, PSI and SF-36 scores were not significantly different between groups (only four [8%] of 47 ICAG-treated patients and five [10%] of 48 RTC-treated patients were unsatisfied). Good to excellent functional recovery according to Odom criteria was observed in 75 and 79% of ICAG- and RTC-treated patients, respectively. Fusion rates were 81 and 74%, respectively (p = 0.51).

Conclusions
Fusion rates and clinical outcome at 12 months after ACD were comparable between patients who underwent ICAG and RTC fusion. The use of rectangular cages, however, avoids donor site morbidity and reduces overall pain and, thus, seems to be an advantageous treatment alternative.
Prospective randomized controlled study of the Bryan Cervical Disc: early clinical results from a single investigational site
Authors: Coric Domagoj , Finger Frederick , Boltes Peggy 
Published: January 2008

Object
The authors report on a prospective randomized controlled multicenter trial in which they compared the clinical outcomes obtained in patients who underwent the placement of a Bryan Cervical Disc System with those obtained in patients who underwent anterior cervical discectomy and fusion (ACDF). In the present study, they evaluated the safety and effectiveness of the artificial disc based on data obtained at a single investigational site.

Methods
Patients with primary, single-level cervical disc disease producing radiculopathy and/or myelopathy were randomized prospectively to undergo anterior cervical discectomy with either fusion or artificial disc placement. The patients were evaluated with pre- and postoperative serial radiographic studies; the authors also evaluated neck disability indices, visual analog scale scores for pain, 36-Item Short Form Health Survey scores, and neurological status at 1.5, 3, 6, 12, and 24 months.
Analysis of the early results obtained in the 33 patients indicated an absence of device-related complications. Preliminary analysis revealed that improvement in all clinical outcome measures was excellent for both treatment groups; however, in patients treated with the artificial cervical disc, motion at the treated level was maintained.

Conclusions
The preliminary results documented at this investigational site are encouraging. Evaluation of data acquired in the Bryan disc treatment group showed that improvements in the clinical parameters were similar to those in the fusion group. Additionally in the artificial disc–treated group, there was radiographic evidence that motion was maintained.
It is theorized that motion preservation may potentially reduce the rate of adjacent-level cervical disc disease that has been documented in patients who undergo ACDF.