bluuebunny/crossref_metadata_2025 huggingface dataset:
Early results after ProDisc-C cervical disc replacement
Authors: Bertagnoli Rudolf , Yue James J. , Pfeiffer Frank , Fenk-Mayer Andrea , Lawrence James P. , Kershaw Trace , Nanieva Regina
Published: May 2009

Object.Cervical anterior decompression and total-disc replacement is currently being investigated as an alternative treatment in patients with symptomatic intervertebral cervical spondylosis with and without radiculopathy. The authors prospectively investigated the safety and efficacy of using the ProDisc-C disc for cervical arthroplasty in the treatment of symptomatic cervical spondylosis.

Methods.Sixteen patients in whom a diagnosis of symptomatic cervical spondylosis had been established were prospectively treated with complete anterior cervical discectomy and ProDisc-C cervical disc arthroplasty. Overall 12 single- and four two-level procedures were performed (20 prostheses). Patients underwent pre- and multiple postoperative assessments (3 and 6 weeks and 3, 6, and 12 months).

The median age of all patients was 50 years (range 32–60 years). Levels of surgery included seven C5–6, six C6–7, and three C4–5. Neck and arm pain as well as disability scores were significantly improved by 3 months and remained significantly improved at 1 year. No additional fusion surgeries were necessary at the affected or unaffected levels. Radiography revealed an affected disc motion from 4 to 12°. No surgery- or device-related complications were documented.

Conclusions.Analysis of preliminary results involving ProDisc-C arthroplasty indicates significant improvement in pain and functional outcome scores. No spontaneous fusions at the level of surgery or at adjacent levels were noted. Long-term follow-up studies will be necessary before more definitive treatment recommendations can be formulated.
Long-term health-related quality of life outcomes following Jefferson-type burst fractures of the atlas
Authors: Dvorak Marcel F. , Johnson Michael G. , Boyd Michael , Johnson Garth , Kwon Brian K. , Fisher Charles G.
Published: May 2009

Object.The primary goal of this study was to describe the long-term health-related quality of life (HRQOL) outcomes in patients who have suffered Jefferson-type fractures. These outcomes were compared with matched normative HRQOL data and with the patient's perceptions of their HRQOL prior to the injury. Variables that potentially influence these HRQOL outcomes were analyzed.

No standardized outcome assessments have been published for patients who suffer these fractures; their outcomes have long thought to be excellent following treatment. Determining the optimal surrogate measure to represent preinjury HRQOL in trauma patients is difficult.

Methods.A retrospective review, radiographic analysis, and cross-sectional outcome assessment were performed. The Short Form (SF)—36 and the American Academy of Orthopaedic Surgeons/North American Spine Society (AAOS/NASS) outcome instruments were filled out by patients at final follow-up examination (follow-up period 75 months, range 19–198 months) to represent their current status as well as their perceptions of preinjury status.

In 34 patients, the SF-36 physical component score and the AAOS/NASS pain values were significantly lower than normative values. There was no significant difference between normative and preinjury values. Spence criteria greater than 7 mm and the presence of associated injuries predicted poorer outcome scores during the follow-up period.

Conclusions.Long-term follow-up examination of patients with Jefferson fractures indicated that patients' status does not return to the level of their perceived preinjury health status or that of normative population controls. Those with other injuries and significant osseous displacement (≥ 7 mm total) may experience poorer long-term outcomes. Limitations of the study included a relatively low (60%) response rate and the difficulties of identifying an appropriate baseline outcome in a trauma population with which the follow-up outcomes can be compared.
Quantitative changes in gait parameters after central corpectomy for cervical spondylotic myelopathy
Authors: Moorthy Ranjith K. , Bhattacharji Suranjan , Thayumanasamy Ganesh , Rajshekhar Vedantam
Published: May 2009

Object.In this study, quantitative gait analysis is used to describe the changes in the kinematic and kinetic parameters of gait after central corpectomy in patients with cervical spondylotic myelopathy (CSM).

Methods.Six men with CSM that was categorized preoperatively as Nurick Grade 3 or 4 were assessed using quantitative gait analysis. The values of various kinematic and kinetic parameters, physiological cost index, and range of motion (ROM) in the lower-limb joints were computed preoperatively as well as at follow-up review 12 months or more postoperatively. Patients also received scores based on the Nurick and Japanese Orthopaedic Association (JOA) lower-limb functional scales pre- and postoperatively.

The mean Nurick grade improved from 3.3 to 2 (p = 0.02) and the mean JOA lower-limb score improved from 4.2 to 6 (p = 0.02). The forward ground reaction force showed a statistically significant increase from 10.8 ± 4.1% body weight to 12.1 ± 3.6% body weight (p = 0.04). There was a significant improvement in the ROM at the knees, from 48.6 ± 7.7° to 54.2 ± 5.2° (p = 0.03). There was an increase in the mean walking speed, stride length, percentage of single-limb support time, vertical and backward ground reaction forces, and ROM at the hips in the postoperative gait analysis. These results indicate an improved stability of gait as well as greater flexibility in the knee after decompression of the spinal cord. These changes correlated with an improvement in the functional status of patients with CSM after central corpectomy.

Conclusions.Gait analysis can be used as a quantitative tool in the pre- and postoperative evaluation of patients with CSM.
Dural ossification associated with cervical ossification of the posterior longitudinal ligament: frequency of dural ossification and comparison of neuroimaging modalities in ability to identify the disease
Authors: Mizuno Junichi , Nakagawa Hiroshi , Matsuo Naoki , Song Joonsuk
Published: May 2009

Object. The authors' goal in this study was to understand the frequency and pattern of dural ossification (DO, and to evaluate the effectiveness of neuroimaging modalities used to identify this disease in association with ossification of the posterior longitudinal ligament (OPLL).

Methods. One hundred eleven patients with OPLL underwent anterior procedures. Of these patients, 17 (15.3%) had associated ossification of the dura mater. There were 10 cases of DO in the 94 patients with segmental OPLL and seven in the 17 patients with nonsegmental OPLL (seven continuous and 10 mixed-type OPLL). Retrospective evaluation of DO was performed by examining plain x-ray films, polytomography studies, computerized tomography (CT) scans, and magnetic resonance (MR) images. A positive correlation was found between the type of OPLL and the frequency of DO (p < 0.01).

The DO was classified into the following three types according to shape: 1) isolated type, 2) double-layer type, and 3) en bloc type, based on its relationship with OPLL. There were 10 lesions of the double-layer type, four en bloc type, and three isolated type; the double-layer pattern of DO was the most common. All DOs as well as OPLLs (17 cases) were identified using bone-window CT scanning. Polytomography was used successfully to identify all 12 OPLLs, whereas DO was recognized in seven of the 12 cases. Magnetic resonance imaging could not identify DO (none of the 17 cases), although OPLL was identified on MR imaging in 12 of the 17 cases.

Conclusions. Three patterns of DO associated with OPLL, that is, isolated, double-layer, and en bloc types, were confirmed by retrospective analysis of neuroimaging findings. Nonsegmental OPLL was likely to be accompanied by DO. Bone-window CT scanning was most useful for identification of DO as well as OPLL, whereas MR imaging was ineffective in recognizing DO.
A three-dimensional collagen matrix as a suitable culture system for the comparison of cyclic strain and hydrostatic pressure effects on intervertebral disc cells
Authors: Neidlinger-Wilke Cornelia , Würtz Karin , Liedert Astrid , Schmidt Carla , Börm Wolfgang , Ignatius Anita , Wilke Hans-Joachim , Claes Lutz
Published: May 2009

Object. To study intervertebral disc cell mechanobiology, the authors developed experimental systems that allow the application of cyclic strain and intermittent hydrostatic pressure (IHP) on isolated disc cells under equal three-dimensional (3D) culture conditions. The purpose of the study was to characterize disc cell proliferation, viability, morphology, and gene expression in 3D collagen matrices.

Methods. The effects of cyclic strain (1, 2, 4, and 8% strain; 1 Hz) and IHP (0.25 MPa, 0.1 Hz) on gene expression (real-time polymerase chain reaction) of anabolic and catabolic matrix proteins were investigated and compared with those derived from mechanically unstimulated controls. Intervertebral disc cells proliferated in the collagen gels (mean viability 91.6%) and expressed messenger RNA for collagen I, collagen II, aggrecan, matrix metalloproteinase (MMP)—2, and MMP-3. Morphologically, both spindle-shaped cells with longer processes and rounded cells were detected in the collagen scaffolds. Cyclic strain increased collagen II and aggrecan expression and decreased MMP-3 expression of anulus fibrosus cells. No significant difference between the four strain magnitudes was found. Intermittent hydrostatic pressure tended to increase collagen I and aggrecan expression of nucleus cells and significantly decreased MMP-2 and -3 expression of nucleus cells, whereas aggrecan expression of anulus cells tended to decrease.

Conclusions. Based on these results, the collagen matrix appeared to be a suitable substrate to apply both cyclic strain and IHP to intervertebral disc cells under 3D culture conditions. Individual variations may be influenced by the extent of degeneration of the disc specimens from which the cells were isolated. This experimental setup may be suitable for studying the influence of degeneration on the disc cell response to mechanical stimuli.
A novel dynamic model for experimental spinal cord compression
Authors: Marquardt Gerhard , Setzer Matthias , Theisen Alf , Dettmann Edgar , Seifert Volker
Published: May 2009

Object. The goal of this study was to develop a novel dynamic model for experimental spinal cord compression that closely approximates neoplastic epidural compression of the spinal cord in humans.

Methods. In 30 New Zealand white rabbits, the thoracic spine was exposed via a posterior approach. On each side of one vertebral lamina a small hole was drilled caudal to the articular process. A silicone band was passed through these holes, forming a loop. The spinal dura mater was exposed via an interlaminar approach. The loop was brought into contact with the dura mater and fixed in its position encircling 270° of the circumference of the spinal cord. Thereafter, the loop was gradually tightened at set times by pulling at the ends of the band and fixing them again in their new position. The spinal cord was thus increasingly compressed in a circular and dynamic manner.

Neurological deficits of various degrees were created in all animals in the compression group, and the compressive effect of the loop was reliably demonstrated on MR imaging. After decompression of the spinal cord, the neurological deficits were reversible in the majority of animals, and MR imaging revealed either no signal changes or only circumscribed ones within the cord. In contrast, MR images obtained in animals that did not recover revealed the occurrence of extensive chronic myelopathy.

Conclusions. This novel model features reproducibility of paresis and neurological recovery. It is a dynamic model simulating circular tumor growth and is characterized by its easy, straightforward, and cost-saving applicability.
Reduction of fixed atlantoaxial dislocation in 24 cases
Authors: Goel Atul , Kulkarni Arvind G. , Sharma Praveen
Published: May 2009

✓ The authors describe an alternative method of C1–2 joint distraction, reduction, and fixation in the treatment of 24 patients with fixed atlantoaxial dislocation. Based on their results, they conclude that there is a place for reduction of fixed atlantoaxial dislocation and subsequent fixation in a procedure that does not require removal of any osseous spinal element.
A novel surgical treatment of lumbar disc herniation in patients with long-standing degenerative disc disease
Authors: Wenger Markus , Markwalder Thomas-Marc
Published: May 2009

Object. In patients with long-standing lumbar degenerative disc disease (DDD) conventional surgical therapy of a herniated disc may worsen back pain due to further destabilization of the affected motion segment. In recent years, total-disc arthroplasty has been introduced to treat DDD while maintaining segmental mobility. To the best of the authors' knowledge, this is the first report involving lumbar disc herniation and long-standing DDD submitted to combined anterior microdiscectomy with sequestrectomy and total-disc arthroplasty.

Methods. Fourteen patients with long-standing DDD and a recently herniated disc underwent total anterior lumbar microdiscectomy, with removal of the herniated disc, and total-disc arthroplasty. There were nine women and five men whose mean age was 39.6 years (range 22–56 years) in whom back and leg pain had been present for a mean of 75.4 (range 9–360) and 9.4 (range 0.33–36) months, respectively. Thirteen patients underwent L5—S1 and one underwent L4–5 surgery. In all cases the procedure and the postoperative courses were uneventful. After a mean follow-up period of 12.5 months (range 3.9–21.1 months), outcome was excellent in 11 and good in three patients.

Conclusions. The aforementioned surgical treatment of a recently herniated lumbar disc in patients with long-standing DDD yielded very favorable early results.
Anterior cervical discectomy and fusion involving a polyetheretherketone spacer and bone morphogenetic protein
Authors: Boakye Maxwell , Mummaneni Praveen V. , Garrett Mark , Rodts Gerald , Haid Regis
Published: May 2009

Object. The authors reviewed clinical and radiographic outcomes in patients who had undergone anterior cervical discectomy and fusion (ACDF) involving the placement of polyetheretherketone (PEEK) spacers filled with recombinant human bone morphogenetic protein (rhBMP)—2.

Methods. Data obtained in 24 cases were retrospectively evaluated. The follow-up period ranged from 12 to 16 months (mean 13 months). Fifteen patients presented with radiculopathy, eight with myeloradiculopathy, and one with quadriparesis. Single-level ACDF was performed in 12 patients, two-level ACDF in nine, and three-level ACDF in three. Clinical outcomes were assessed using Odom criteria, and fusion was assessed by examining flexion—extension radiographs and computerized tomography scans in cases in which arthrodesis was questionable. Follow-up data were available for 23 patients. One patient died of medical complications unrelated to surgery 4 weeks after ACDF. Clinical outcomes were rated as good/excellent in 22 patients (95%) and fair in one (5%). Solid radiographically documented fusion, with evidence of solid bridging bone and no instability on flexion—extension x-ray films, was present in all cases. Complications included transient recurrent laryngeal nerve injury in one case, transient C-5 paresis in one, cerebrospinal fluid leakage in one, and transient dysphagia in two.

Conclusions. Analysis of the results indicated that ACDF involving an rhBMP-2—filled PEEK spacer leads to good clinical outcomes (by Odum criteria) and solid fusion (even in multilevel cases) while avoiding the complications associated with harvesting iliac crest bone grafts.
Multimodal assessment after surgery for cervical spondylotic myelopathy
Authors: King Joseph T. , Moossy John J. , Tsevat Joel , Roberts Mark S.
Published: May 2009

Object. Investigators reporting decompressive surgery to treat patients with cervical spondylotic myelopathy (CSM) have described inconsistent benefits. In the present study the authors used three types of outcomes instruments to assess the results of CSM surgery.

Methods. The authors collected prospective baseline and 6-month follow-up data in a cohort of 62 patients with CSM. Data collection included those pertaining to demographics; symptoms; physical findings; myelopathy severity; health status measured with the Short Form—36; and health values according to the standard gamble, time trade-off, visual analog scale, and willingness to pay. Rank-order methods were used to compare surgical and nonsurgical patients, and multivariate regression techniques adjusting for baseline characteristics were performed to examine the effects of surgery.

During the study period, 28 patients underwent surgery, 34 did not, and there were no baseline differences between the two groups in demographics, symptoms, myelopathy scores, health status, or health values (p ≥ 0.120 in all domains); there was a greater prevalence of hand intrinsic muscle atrophy (p = 0.035) and Hoffmann sign (p = 0.006) in the surgery-treated group. Neither raw comparisons nor regression analyses showed a consistent surgery-related benefit. There were sporadic associations between worse outcomes and older patients, higher income, Babinski sign, longer duration of CSM symptoms, hand clumsiness, lower-extremity numbness, and multilevel surgery (p ≤ 0.049 for all).

Conclusions. Analysis of results obtained in the 62 patients with CSM failed to show a surgery-related benefit despite the use of three classes of outcomes instruments. Patient demographics, symptoms, physical signs, and the surgical approach may explain some of the variation in outcomes in patients with CSM.
CyberKnife stereotactic radiosurgical treatment of spinal tumors for pain control and quality of life
Authors: Degen Jeffrey W. , Gagnon Gregory J. , Voyadzis Jean-Marc , McRae Donald A. , Lunsden Michael , Dieterich Sonja , Molzahn Inge , Henderson Fraser C.
Published: May 2009

Object.The authors conducted a study to assess safety, pain, and quality of life (QOL) outcomes following CyberKnife radiosurgical treatment of spinal tumors.

Methods.Data obtained in all patients with spinal tumors who underwent CyberKnife radiosurgery at Georgetown University Hospital between March 2002 and March 2003 were analyzed. Patients underwent examination, visual analog scale (VAS) pain assessment, and completed the 12-item Short Form Health Survey (SF-12) before treatment and at 1, 3, 6, 8, 12, 18, and 24 months following treatment.

Fifty-one patients with 72 lesions (58 metastatic and 14 primary) were treated. The mean follow-up period was 1 year. Pain was improved, with the mean VAS score decreasing significantly from 51.5 to 21.3 at 4 weeks (p < 0.001). This effect on pain was durable, with a mean score of 17.5 at 1 year, which was still significantly decreased (p = 0.002).

Quality of life was maintained throughout the study period. After 18 months, physical well-being was 33 (initial score 32; p = 0.96) and mental well-being was 43.8 (initial score 44.2; p = 0.97). (The mean SF-12 score is 50 ± 10 [standard deviation].) Adverse effects included self-limited dysphagia (three cases), diarrhea (two cases), lethargy (three cases), paresthesias (one case), and wound dehiscence (one case).

Conclusions.CyberKnife radiosurgery improves pain control and maintains QOL in patients treated for spinal tumors. Early adverse events are infrequent and minor. The authors await long-term follow-up data to determine late complications and tumor control rates.
Surgical management of metastatic disease of the lumbar spine: experience with 139 patients
Authors: Holman Paul J. , Suki Dima , McCutcheon Ian , Wolinsky Jean-Paul , Rhines Laurence D. , Gokaslan Ziya L.
Published: May 2009

Object.The surgical treatment of metastatic spinal tumors is an essential component of the comprehensive care of cancer patients. In most large series investigators have focused on the treatment of thoracic lesions because 70% of cases involve this region. The lumbar spine is less frequently involved (20% cases), and it is unclear whether its unique anatomical and biomechanical features affect surgery-related outcomes. The authors present a retrospective study of a large series of patients with lumbar metastatic lesions, assessing neurological and pain outcomes, complications, and survival.

Methods.The authors retrospectively reviewed data obtained in 139 patients who underwent 166 surgical procedures for lumbar metastatic disease between August 1994 and April 2001. The impact of operative approach on outcomes was also analyzed.

Among the wide variety of metastatic lesions, pain was the most common presenting symptom (96%), including local pain, radicular pain, and axial pain due to instability. Patients underwent anterior, posterior, and combined approaches depending on the anatomical distribution of disease. One month after surgery, complete or partial improvement in pain was demonstrated in 94% of the cases. The median survival duration for the entire population was 14.8 months.

Conclusions.The surgical treatment of metastatic lesions in the lumbar spine improved neurological and ambulatory function, significantly reducing axial spinal pain; results were comparable with those for other spinal regions. Analysis of results obtained in the present study suggests that outcomes are similar when the operative approach mirrors the anatomical distribution of disease. When lumbar vertebrectomy is necessary, however, anterior approaches minimize blood loss and wound-related complications.
Surgical management of spinal metastases: analysis of prognostic factors during a 10-year experience
Authors: North Richard B. , LaRocca Vito R. , Schwartz Jacob , North Catherine A. , Zahurak Marianna , Davis Randy F. , McAfee Paul C.
Published: May 2009

Object.Refinement of surgical techniques, especially anterior approaches, for the management of spinal metastases has improved patient outcomes, despite the fact that a complete analysis of the prognostic factors that would inform patient selection has not been undertaken. The authors sought to identify such prognostic factors for neurological outcome and life expectancy in patients with spinal metastases.

Methods.The authors used Kaplan—Meier techniques, log-rank comparisons, and a multivariate model stratified by tumor type to identify prognostic factors for duration of ability to walk and survival in patients who underwent surgical treatment for spinal metastases during a decade when all current treatment options were available.

Preoperatively, 53 (87%) of the 61 patients in the study population suffered neurological symptoms (for example, weakness) and 52 (85%) were ambulatory. Postoperatively, 59 (97%) were ambulatory. Most patients who survived 6 months (81%) remained ambulatory, as did 66% of those alive at 1.6 years. The median postoperative survival was 10 months. The risk factors for loss of ambulation were preoperative loss of ambulatory ability, recurrent or persistent disease after primary radiotherapy of the operative site, a procedure other than corpectomy, and tumor type other than breast cancer. Prognostic factors for reduced survival were surgical intervention extending over two or more spinal segments, recurrent or persistent disease after primary radiotherapy involving the operative site, diagnosis other than breast cancer, and a cervical spinal procedure.

Conclusions.The results of this analysis allowed the authors to create a simple prognostic factor scoring system that can be applied to individual patients. The positive experience derived from this study supports an expanded role for the surgical treatment of metastatic spinal disease.
Positive feedback loop of interleukin-1β upregulating production of inflammatory mediators in human intervertebral disc cells in vitro
Authors: Jimbo Kotaro , Park Jin Soo , Yokosuka Kimiaki , Sato Kimiaki , Nagata Kensei
Published: May 2009

Object.Interleukin-1β (IL-1β) induces neurological symptoms in intervertebral disc herniation (IDH). Recently, the existence of a positive feedback loop of IL-1β, which encourages an inflammatory reaction or degeneration in the cells of tendon, has been reported. The authors hypothesized that there is a positive feedback loop of IL-1β in the cells of IDH.

Methods.Eight human intervertebral disc specimens were harvested during spinal surgery for lumbar disc herniation. The cells were stimulated in serum-free medium with or without exogenous IL-1β. The messenger RNA (mRNA) was extracted for reverse-transcription polymerase chain reaction (PCR) and real-time PCR to quantify the mRNA of endogenous IL-1β, IL-6, cyclooxygenase-2 (COX-2), and matrix metalloproteinases (MMPs). The cells were then stimulated in serum-free medium with or without exogenous IL-1β, and then exogenous IL-1β was removed. After 2, 4, and 6 days, the medium was collected, and enzyme-linked immunosorbent assay was used to measure the protein concentration of endogenous IL-1β. The mRNA expressions of endogenous IL-1β, IL-6, COX-2, and MMPs were increased significantly depending on the concentration of exogenous IL-1β. The protein concentration of endogenous IL-1β was increased over time.

Conclusions.There was a positive feedback loop of IL-1β in the cells of IDH. Furthermore, the productions of IL-6, COX-2, MMP-1, and MMP-3 were upregulated as a result of the increasing concentration of IL-1β in a positive feedback loop of IL-1β. The authors concluded that this positive feedback loop of IL-1β upregulated the production of mediators and thus can cause cessation of symptoms in IDH.
Chondroblastoma of the lumbar spine
Authors: Vialle Raphaël , Feydy Antoine , Rillardon Ludovic , Tohme-Noun Carla , Anract Philippe , Colombat Magali , De Pinieux Gonzague , Drapé Jean-Luc , Guigui Pierre
Published: May 2009

✓ Chondroblastoma is a benign cartilaginous neoplasm that generally affects the appendicular skeleton. Twenty-six cases of spinal chondroblastoma have been reported in the past 50 years, only six of which were located in the lumbar region. The authors report two cases involving this exceptional location. In both patients, low-back pain, in the absence of radicular pain, was the presenting symptom. In both cases, plain radiography and computerized tomography scanning revealed an osteolytic lesion surrounded by marginal sclerosis. Magnetic resonance imaging allowed the authors to study the tumor's local extension. Examination of a percutaneous fluoroscopy-guided biopsy sample revealed the following typical histological features of chondroblastoma: chondroid tissue, focally alternating with cellular areas, and no nuclear atypia or pleomorphism. To reduce the risk of local recurrence, vertebrectomy and anterior—posterior fusion were performed in both cases. In one case, a structural lumbar scoliosis was corrected during the posterior procedure. There was no postoperative complication. No recurrence was observed during the 3- to 6-year follow-up period. The surgery-related results were deemed successful.

Although exceptional, the diagnosis of chondroblastoma is possible in lesions involving the lumbar spine. Other spinal locations are described in the literature, and frequency of recurrence is stressed. A vertebrectomy is advised to reduce the risk of local recurrence.
Propriospinal myoclonus due to cervical disc herniation
Authors: Capelle Hans-Holger , Wöhrle Johannes C. , Weigel Ralf , Grips Eva , Bäzner Hans-Jörg , Krauss Joachim K.
Published: May 2009

✓ Propriospinal myoclonus is a rare form of spinal myoclonus. In most cases the cause has remained unclear. Secondary propriospinal myoclonus has been described secondary to various disorders including trauma, tumor, and infection. Thus far, propriospinal myoclonus caused by cervical disc herniation has not been reported. In the present report, the authors describe the case of a 53-year-old man who presented with radicular symptoms of the right C-6 nerve root and myoclonic twitches predominantly affecting the abdominal muscles but spreading to adjacent muscles. The spread was triggered and enforced by certain movements. Magnetic resonance imaging studies revealed a C-6 nerve root compression at the C5–6 level on the right side but no cervical myelopathy. Electromyography studies confirmed the diagnosis of propriospinal myoclonus. After discectomy and cage-augmented fusion via an anterior approach, the myoclonic movement disorder gradually subsided. To the authors' knowledge, this is the first report on successful treatment of propriospinal myoclonus by spinal disc surgery.
Extrathecal intraradicular nerve sheath tumor
Authors: Celli Paolo , Trillò Giuseppe , Ferrante Luigi
Published: May 2009

Object. The purpose of this study was to analyze the clinical profile of patients harboring extrathecal and intraradicular nerve sheath tumors (NSTs), located inside the sleeve of an extrathecal nerve root and very often within the proximal portion of the spinal nerve, and to evaluate the incidence of long-term dysfunction of the tumor-affected roots if resected. These tumors have not received particular attention in the literature.

Methods. A single-institution series of 16 patients who had undergone surgery for intraradicular NSTs during a 50-year period was selected retrospectively. Data pertaining to clinical features, tumor characteristics, and results of surgery were analyzed.

Conclusions. Extrathecal and intraradicular neurofibromas or schwannomas more frequently affect the lumbar and S-1 nerve roots, often producing root pain only. Selective en bloc enucleation sparing at least part of the motor rootlets is possible for small schwannomas of the extrathecal—preganglion segment of the radix, whereas total resection of the affected root is generally required for radical removal of neurofibromas and large schwannomas. In the authors' experience, neither deafferentation pain nor severe radicular weakness occurs after division of the nerve root harboring the tumor.
Functional outcome after surgical treatment of spontaneous and nonspontaneous spinal subdural hematomas
Authors: Thiex Ruth , Thron Armin , Gilsbach Joachim M. , Rohde Veit
Published: May 2009

Object. Because of the rarity of spinal subdural hematomas (SDHs), the literature offers scarce estimates of the outcome and predictive factors in patients suffering from these lesions. In addition, single-institution surgical series are still lacking. Therefore, the authors retrospectively evaluated the early and long-term functional outcomes measured in eight patients with spontaneous and nonspontaneous spinal SDHs in whom the clot had been evacuated.

Methods. The patients' charts were evaluated for origin of the lesion, risk factors, and neurological deficits at symptom onset and at 28 days after extirpation of the spinal SDH. Long-term clinical outcome (Barthel Index [BI]) was evaluated by administering a telephone questionnaire to the patient or a relative.

Only one patient with a spontaneous spinal SDH was identified. Four patients were undergoing anticoagulant therapy, and three patients had undergone a previous anesthetic/diagnostic spinal procedure. Twenty-eight days postoperatively, neurological deficits improved in six of eight patients; however, in two of the six patients, the improvement did not allow the patients to become independent again. In two patients, surgery did not affect the complete sensorimotor deficits. In the long-term survivors (median 45 months) a median BI of 55 was achieved. The latency between symptom onset and surgery did not correlate with functional outcome in this series. The preoperative neurological condition and location of the hematoma correlated positively with early and long-term functional outcome.

Conclusions. To the best of their knowledge, the present study is the largest single-institutional study of patients with surgically treated spinal SDHs. Despite some postoperative improvement of sensorimotor deficits in most patients, the prognosis is poor because 50% of the patients remain dependent. Their outcome was determined by the preoperative sensorimotor function and spinal level of the spinal SDH.
Multicenter study investigating the postoperative progression of ossification of the posterior longitudinal ligament in the cervical spine: a new computer-assisted measurement
Authors: Chiba Kazuhiro , Yamamoto Itsuo , Hirabayashi Hisashi , Iwasaki Motoki , Goto Hiroshi , Yonenobu Kazuo , Toyama Yoshiaki
Published: May 2009

Object. Ossification of the posterior longitudinal ligament (OPLL) often progresses after surgery, and this may cause late-onset neurological deterioration. There have been few studies, however, to clarify any correlation between progression and clinical outcome, partly because of the lack of studies involving reliable and reproducible methods by which detection of progression is made possible. The authors conducted a multicenter study to investigate the occurrence of postoperative progression and to elucidate the possible risk factors in a large-scale patient population, and a novel computer-assisted measurement method was used to provide the basis for future clinical studies.

Methods. The authors analyzed lateral plain radiographs obtained immediately and at 1 and 2 years after surgery in 131 patients who underwent posterior decompression at 13 institutions. The x-ray films were transformed via scanner into digital images; the length and thickness of ossifications were measured using a new computer-assisted measurement system, and the incidence of progression was determined. Odds ratios for progression according to age group and types of OPLL were determined and compared to elucidate significant risk factors of progression.

Conclusions. This is the first multicenter study to investigate the incidence of OPLL progression after posterior decompression by using a standardized measurement method. The rate of postoperative progression at 2 years was 56.5%, which was comparable with results reported in other studies. Progression occurred more frequently in younger-age rather than in older-age patient populations at both 1 and 2 years postoperatively. Mixed-type and continuous-type OPLL progressed more frequently than the segmental-type lesion at 2 years. The results of the present study could serve as basis for future studies to assess the efficacy of drug therapy to prevent OPLL progression.
En bloc laminoplasty without dissection of paraspinal muscles
Authors: Hosono Noboru , Sakaura Hironobu , Mukai Yoshihiro , Ishii Takahiro , Yoshikawa Hideki
Published: May 2009

Object. Although conducting cervical laminoplasty in patients with multisegmental cord compression provides good neurological results, it is not without shortcomings, including C-5 palsy, axial neck pain, and undesirable radiologically detectable changes. Postoperative kyphosis and segmental instability can cause neurological problems and are believed mainly to result from neck muscle disruption. The authors developed a new laminoplasty technique, with the aim of preserving optimal muscle function.

Methods. The present technique is a modification of unilateral open-door laminoplasty. By using an ultrasonic osteotome in small gaps of muscle bellies, a gutter is made without disrupting muscles, spinous processes, or their connections on the hinged side. Ceramic spacers are then positioned between elevated laminae and lateral masses at C-3, C-5, and C-7 on the opened side, which is exposed in a conventional manner.

This new procedure was used to treat 37 consecutive patients with compression myelopathy. Postoperative computerized tomography (CT) scanning revealed a significant difference in a cross-sectional area of muscles between the hinged and opened side. The mean follow-up period was 40.2 months (range 24–54 months). Changes in alignment were observed in only one patient, and vertebral slippage developed in two. Performed at regular intervals, CT scanning demonstrated that the elevated laminae remained in situ throughout the study period.

Conclusions. In using the present unilateral open-door laminoplasty technique, deep extensor muscles are left intact along with their junctions to spinous processes on the hinged side. Radiologically documented changes were minimal because the preserved muscles functioned normally immediately after the operation.
Murine spinal fusion induced by engineered mesenchymal stem cells that conditionally express bone morphogenetic protein—2
Authors: Hasharoni Amir , Zilberman Yoram , Turgeman Gadi , Helm Gregory A. , Liebergall Meir , Gazit Dan
Published: May 2009

Object.The authors hypothesized that spinal fusion can be achieved and monitored by using cell-mediated gene therapy. Mesenchymal stem cells (MSCs) genetically engineered to express recombinant human bone morphogenetic protein—2 (rhBMP-2) conditionally, were implanted into the paraspinal muscles of mice to establish spinal fusion. The goal was to demonstrate an MSC-based gene therapy platform in which controlled gene expression is used to obtain spinal fusion in a murine model.

Methods.Mesenchymal stem cells expressing therhBMP-2gene were injected into the paravertebral muscle in mice. Bone formation in the paraspinal region was longitudinally followed by performing micro—computerized tomography scanning, histological studies, and an analysis ofosteocalcinexpression to demonstrate the presence of engrafted engineered MSCs. The minimal period of rhBMP-2 expression by the engineered MSCs required to induce fusion was determined.

The results of this study demonstrate that genetically engineered MSCs induce bone formation in areas adjacent to and touching the posterior elements of the spine. This newly formed bone fuses the spine, as demonstrated by radiological and histological studies. The authors demonstrate that injected cells induce active osteogenesis at the site of implantation for up to 4 weeks postinjection. They found that a 7-day induction of rhBMP-2 expression in genetically engineered MSCs was sufficient to form new bone tissue, although the quantity of this bone increased as longer expression periods were implemented.

Conclusions.After their injection genetically engineered MSCs can efficiently form new bone in the paraspinal muscle of the mouse to obtain spinal fusion. The extent and quantity of this newly formed bone can be monitored by controlling the duration ofrhBMP-2gene expression.
Mexiletine treatment—induced inhibition of caspase-3 activation and improvement of behavioral recovery after spinal cord injury
Authors: Kaptanoglu Erkan , Caner Hakan , Solaroglu Ihsan , Kilinc Kamer
Published: May 2009

Object. It has been demonstrated in several experimental studies that apoptosis contributes to cellular damage after spinal cord injury (SCI). During apoptosis dying cells secrete additional mediators of apoptosis such as cytokines and free radicals which have additional toxic effects and exacerbate neuronal death. The aim of this laboratory study was to investigate the effects of mexiletine on caspase-3 activation and functional recovery and compare its post-SCI effectiveness with methylprednisolone.

Methods. The rats were divided into five groups. Animals in the trauma group underwent traumatic interventions after laminectomy. Spinal cord contusion injury was produced using the weight-drop method. Animals in treatment groups received a single dose of methylprednisolone sodium succinate (Group C), single dose of mexiletine (Group D), or vehicle solution (saline; Group E) intraperitoneally immediately after injury. Hind-limb functions were assessed using the inclined plane technique and caspase-3 activity in tissue samples was measured 24 hours after SCI. Traumatic injury was found to increase tissue caspase-3 activity. In both treatment groups the drug prevented an increase in caspase-3 activity. Mexiletine treatment improved early behavioral recovery after SCI.

Conclusions. The results obtained in this study demonstrated that mexiletine treatment inhibits caspase-3 activation and preserve/restore better neuronal function compared with methylprednisolone after experimental SCI.
Late vertebral body fracture after lumbar transpedicular fixation
Authors: Missori Paolo , Ramieri Alessandro , Costanzo Giuseppe , Peschillo Simone , Paolini Sergio , Miscusi Massimo , D'Andrea Giancarlo , Delfini Roberto
Published: May 2009

✓ Late-onset vertebral body (VB) fracture after lumbar transpedicular fixation has not been previously described in the literature. The authors present three cases in which VB fracture occurred several months after posterolateral fixation in patients with degenerative disease or traumatic injury. The authors suggest that postoperative osteopenia, modified load-sharing function, and intravertebral clefts were responsible for the fractures.

Two women and one man were evaluated at a mean follow-up interval of 3 months. Two patients suffered recurrent lumbar pain. Radiography and magnetic resonance imaging revealed fracture of some of the instrumentation-treated VBs. These two patients underwent surgical superior or inferior extension of instrumentation. The third, an asymptomatic patient, received conservative management. The two patients who underwent reoperation made complete recoveries, and there was no evidence of further bone collapse in any case.

The authors speculate that alterations in the VBs may occur following application of spinal instrumentation. In rare cases, the device can fracture and consequently lead to recurrent lumbar back pain. Recovery can be achieved by extending the instrumentation in the appropriate direction.
Schistosomiasis of the spinal cord presenting as progressive myelopathy
Authors: Kamel Mahmoud Hamdy , Murphy Martin , Kelleher Michael , Aquilina Kristian , Lim Chris , Marks Charles
Published: May 2009

✓ The authors report on a case of schistosomiasis of the spinal cord in an individual returning to Ireland after a 25-year residence in Africa, where the infection affects approximately 200 million people.
Endolymphatic sac tumor metastatic to the spine
Authors: Bambakidis Nicholas C. , Rodrigue Tina , Megerian Cliff A. , Ratcheson Robert A.
Published: May 2009

✓ Endolymphatic sac tumors (ELSTs) are aggressive papillary lesions of the temporal bone. Although histologically benign, they may exhibit invasive growth and destruction of the skull base. Patients generally present with symptoms referable to the lesion's location within the middle or posterior cranial fossa. Although well characterized as a distinct entity, ELSTs involved in metastatic dissemination have never been reported. In the present report the authors describe a case of ELST metastatic to the spine treated with resection.
Novel use of a threadwire saw for high sacral amputation
Authors: Bohinski Robert J. , Mendel Ehud , Rhines Laurence D.
Published: May 2009

✓ The authors describe and demonstrate an innovative modification of the osteotomy procedure required to achieve a supraforaminal high sacral amputation in a patient harboring a large sacral chordoma. Via a combined anterior—posterior approach, three carefully placed threadwire saws were used to create releasing osteotomies through specific portions of the dorsal iliac crests and through the axial midportion of the S-1 vertebral body. The threadwire saws are pulled away from neurovascular and visceral structures, ensuring greater protection. Other advantages include markedly reduced blood loss while performing the osteotomies, a high degree of cutting accuracy, negligible bone loss, and ease and speed of bone cutting.
Minimally invasive microendoscopy-assisted transforaminal lumbar interbody fusion with instrumentation
Authors: Isaacs Robert E. , Podichetty Vinod K. , Santiago Paul , Sandhu Faheem A. , Spears John , Kelly Kevin , Rice Laurie , Fessler Richard G.
Published: May 2009

Object

The authors have developed a novel technique for percutaneous fusion in which standard microendoscopic discectomy is modified. Based on data obtained in their cadaveric studies they considered that this minimally invasive interbody fusion could be safely implemented clinically. The authors describe their initial experience with a microendoscopic transforaminal lumbar interbody fusion (METLIF) technique, with regard to safety in the placement of percutaneous instrumentation, perioperative morbidity, and early postoperative results.

Methods

The METLIF procedure was performed unilaterally in 20 patients with single-level lumbar spondylolisthesis or pure mechanical back pain with endoscopic assistance, hemilaminectomy, unilateral facetectomy, and microdiscectomy. Two interbody grafts were placed via the lateral exposure of the disc space. Bilateral percutaneous pedicle screws were then inserted.

Compared with patients who had undergone single-level posterior LIF at the same institutions, intraoperative blood loss, hospital length of stay (LOS), and postoperative narcotic agent use were significantly lower in the METLIF group. The mean LOS for the percutaneous fusion group was 3.4 days (5.1 days in those who underwent PLIF; p < 0.02). There have been no procedure-related complications in this series to date.

Conclusions

The METLIF technique provided an option for percutaneous interbody fusion similar to that in open surgery while minimizing destruction to adjacent tissues. This technique was safe and exhibited a trend toward decreased intraoperative blood loss, postoperative pain, total narcotic use, and the risk of transfusion.
Osteoradionecrosis of the cervical spine resulting from radiotherapy for primary head and neck malignancies: operative and nonoperative management
Authors: Donovan Daniel J. , Huynh Thanh V. , Purdom Eric B. , Johnson Robert E. , Sniezek Joseph C.
Published: May 2009

✓ Osteoradionecrosis is a process of dysvascular bone necrosis and fibrous replacement following exposure to high doses of radiation. The poorly vascularized necrotic tissue may cause pain and/or instability, and it cannot resist infection well, which may result in secondary osteomyelitis. When these processes affect the cervical spine, the resulting instability and neurological deficits can be devastating, and immediate reestablishment of spinal stability is paramount. Reconstruction of the cervical spine can be particularly challenging in this subgroup of patients in whom the spine is poorly vascularized after radical surgery, high-dose irradiation, and infection. The authors report three cases of cervical spine osteoradionecrosis following radiotherapy for primary head and neck malignancies. Two patients suffered secondary osteomyelitis, severe spinal deformity, and spinal cord compression. These patients underwent surgery in which a vascularized fibular graft and instrumentation were used to reconstruct the cervical spine; subsequently hyperbaric oxygen (HBO) therapy was instituted. Fusion occurred, spinal stability was restored, and neurological dysfunction resolved at the 2- and 4-year follow-up examinations, respectively. The third patient experienced pain and dysphagia but did not have osteomyelitis, spinal instability, or neurological deficits. He underwent HBO therapy alone, with improved symptoms and imaging findings. Hyperbaric oxygen is an essential part of treatment for osteoradionecrosis and may be sufficient by itself for uncomplicated cases, but surgery is required for patients with spinal instability, spinal cord compression, and/or infection. A vascularized fibular bone graft is a very helpful adjunct in these patients because it adds little morbidity and may increase the rate of spinal fusion.