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Background Intradural extramedullary spinal metastasis is a relatively rare condition. Furthermore, there are few reports with the initial presentation being a neurological symptom from an intradural metastasis. We report a case of a patient with metastasis to the cauda equina from breast cancer found due to neurological symptoms as the initial presentation. Case presentation A 76-year-old Japanese woman who was previously healthy presented to our hospital with bilateral severe buttock and lower extremity pain without any history of injury. A solitary intradural cauda equina mass was found by magnetic resonance imaging at the L2/3 level, and we suspected a schwannoma initially. The patient hoped to undergo surgery due to the severe pain. However, the chest computed tomographic scan obtained to assess the patient’s general status showed the suspected breast cancer of the left side and a lung metastasis. Hence, we considered the possibility of cauda equina tumor metastatic from the breast cancer. We performed an L1–3 laminectomy and tumor extirpation. The pathology revealed adenocarcinoma. After surgery, she had relief from pain, and her status remained satisfactory until she died 9 months after surgery. Conclusions It is difficult to clarify whether the cauda equina tumor is benign or malignant based only on Magnetic resonance imaging findings. Clinicians should consider the possibility of metastasis when planning the surgery for intradural cauda equina tumor extirpation.

Background Mayfield skull clamps are widely used and indispensable in current neurosurgery. Complications such as skull fractures or intracranial hematoma from using a Mayfield skull clamp have largely been reported in the pediatric population, are likely related to the relative thinness of the skull, such as in patients with hydrocephalus, and are extremely rare in adults. Here, we report a case of skull fracture and epidural hematoma caused by a Mayfield skull clamp used for posterior decompression surgery in an adult patient with chronic hemodialysis. Case presentation A 67-year-old Asian male patient with a history of dialysis-dependent chronic renal failure over 36 years suffered from severe cervical myelopathy. Neurological examination and radiographic images revealed cervical spondylotic myelopathy due to dialysis-related spondyloarthropathy. Laminoplasty was planned on patient consent. A Mayfield skull clamp was applied with the patient supine. Torque was applied to the screws with gentle care, but there was no resistance and it was not easy to reach the standard 60 lb (267 N) to 80 lb (356 N). Because a skull fracture was suspected, we canceled the surgery. Emergency head computed tomography showed depressed skull fractures underlying the single-pin sites with an associated epidural hematoma. The fractures and epidural hematoma were treated conservatively, and spontaneous resolution of the hematoma was confirmed. Cervical laminoplasty was performed successfully using a mask-type head holder on the subsequent day. Conclusions As a precaution for fractures and epidural hematoma in neurosurgical patients with bone fragility or a thin skull, use of a mask-type fixing device or halo ring is recommended.

We enrolled 100 patients who underwent preoperative CT angiography before cervical spine instrumentation and investigated the morphology of the C2 pedicle from the perspective of pedicle screw (PS) trajectory using volume rendering and multiplanar reconstruction. The narrowest portion of the pedicle was identified as the pedicle isthmus. Safe C2 PS insertion was regarded to be not feasible when the height of the medullary cavity of the pedicle isthmus and/or width of the medullary cavity of the pedicle isthmus was ⩽4mm. Forty-five (22.5%) pedicles were ⩽4mm in width, and safe insertion of a PS was determined to be not feasible. Among these, seven pedicles were ⩽4mm in both height and width. The remaining 38 pedicles were ⩽4mm in width with heights >4mm. There was no pedicle with a width >4mm and height

We performed a phase I/IIa clinical trial and confirmed the safety and feasibility of granulocyte colony-stimulating factor (G-CSF) as neuroprotective therapy in patients with acute spinal cord injury (SCI). In this study, we retrospectively analyzed the clinical outcome in SCI patients treated with G-CSF and compared these results to a historical cohort of SCI patients treated with high-dose methylprednisolone sodium succinate (MPSS). In the G-CSF group (n = 28), patients were treated from August 2009 to July 2012 within 48 h of the injury, and G-CSF (10 μg/kg/day) was administered intravenously for five consecutive days. In the MPSS group (n = 34), patients underwent high-dose MPSS therapy from August 2003 to July 2005 following the NASCIS II protocol. We evaluated the ASIA motor score and the AIS grade elevation between the time of treatment and 3-month follow-up and adverse events. The ΔASIA motor score was significantly higher in the G-CSF group than in the MPSS group (p

Study design An open-labeled multicenter prospective nonrandomized controlled clinical trial. Objective To confirm the feasibility of using granulocyte colony-stimulating factor (G-CSF) for treatment of acute spinal cord injury (SCI). Summary of background data We previously reported that G-CSF promotes functional recovery after compression-induced SCI in mice. On the basis of these findings, we conducted a multicenter prospective controlled clinical trial to assess the feasibility of G-CSF therapy for patients with acute SCI. Methods The trial ran from August 2009 to March 2011, and included 41 patients with SCI treated within 48 hours of onset. Informed consent was obtained from all patients. After providing consent, patients were divided into 2 groups. In the G-CSF group (17 patients), G-CSF (10 μg/kg/d) was intravenously administered for 5 consecutive days, and in the control group (24 patients), patients were similarly treated except for the G-CSF administration. We evaluated motor and sensory functions using the American Spinal Cord Injury Association score and American Spinal Cord Injury Association impairment scale at 1 week, 3 months, 6 months, and 1 year after onset. Results Only 2 patients did not experience American Spinal Cord Injury Association impairment scale improvement in the G-CSF group. In contrast, 15 patients in the control group did not experience American Spinal Cord Injury Association impairment scale improvement. In the analysis of increased American Spinal Cord Injury Association motor score, a significant increase in G-CSF group was detected from 1 week after the administration compared with the control group. After that, some spontaneous increase of motor score was detected in control group, but the significant increase in G-CSF group was maintained until 1 year of follow-up. Conclusion Despite the limitation that patient selection was not randomized, the present results suggest the possibility that G-CSF administration has beneficial effects on neurological recovery in patients with acute SCI. Level of evidence 3.

Context We report the autopsy of a 65-year-old woman who underwent a C3–C7 laminoplasty 4 years after the diagnosis of cervical spondylotic myelopathy (CSM). Her sensory disturbance, spasticity, and vesicorectal disturbance, which corresponded to long tract sign, had improved after surgery. Findings Cross sections at the C4–C5 level showed a triangular shape because of atrophied ventral gray matter. Moreover, despite the scarce glial scar formation around the cystic cavity, regeneration of gray matter had not occurred. In the white matter, the posterior and lateral funiculi were shrunken including three to four segments. Conclusion Pathological change of white matter did not coincide with relief of clinical symptoms in this case. These findings indicate that it may be better to operate earlier in cases of CSM, because delay may lead to irreversible histological change.

We evaluated the feasibility and reliability of open source Digital Imaging and COmmunication in Medicine (DICOM) imaging software, OsiriX (Antoine Rosset, 2003-2009), in spine surgery. CT data were used and processed with OsiriX and with commercial software for comparison. Images were reconstructed and compared in volume rendering (VR) and multi-planar reconstruction (MPR) mode. When all images were compared, the three-dimensional (3D) reconstructed images from both software packages showed considerable consistency in VR mode. Measurements in MPR mode also showed similar values with no statistically significant difference. These results demonstrate that OsiriX has approximately equivalent values to commercial software and provides reliable preoperative 3D information for the surgical field. In addition, any clinician, can obtain information using OsiriX at any time. Thus, OsiriX is a helpful tool in preoperative planning for spine surgery.

Postoperative C5 palsy is a common complication after cervical spine decompression surgery. However, the incidence, prognosis, and etiology of C5 palsy after anterior decompression with spinal fusion (ASF) have not yet been fully established. In the present study, we analyzed the clinical and radiological characteristics of patients who developed C5 palsy after ASF for cervical degenerative diseases. The cases of 199 consecutive patients who underwent ASF were analyzed to clarify the incidence of postoperative C5 palsy. We also evaluated the onset and prognosis of C5 palsy. The presence of high signal changes (HSCs) in the spinal cord was analyzed using T2-weighted magnetic resonance images. C5 palsy occurred in 17 patients (8.5%), and in 15 of them, the palsy developed after ASF of 3 or more levels. Among ten patients who had a manual muscle test (MMT) grade ≤2 at the onset, five patients showed incomplete or no recovery. Sixteen of the 17 C5 palsy patients presented neck and shoulder pain prior to the onset of muscle weakness. In the ten patients with a MMT grade ≤2 at the onset, nine patients showed HSCs at the C3-C4 and C4-C5 levels. The present findings demonstrate that, in most patients with severe C5 palsy after ASF, pre-existing asymptomatic damage of the anterior horn cells at C3-C4 and C4-C5 levels may participate in the development of motor weakness in combination with the nerve root lesions that occur subsequent to ASF. Thus, when patients with spinal cord lesions at C3-C4 and C4-C5 levels undergo multilevel ASF, we should be alert to the possible occurrence of postoperative C5 palsy.

Study design Case report. Objective To describe the usefulness of simulated surgery for evaluation of a patient with neurofibromatosis type-1 (NF-1) who had severe cervicothoracic kyphoscoliosis and an anomalous vertebral artery (VA). Summary of background data Several surgical procedures have been used in the treatment of cervicothoracic kyphoscoliosis associated with myelopathy in patients with NF-1. However, to our knowledge, there has been no report that describes a surgical procedure for NF-1 patients with anomalous VA at the cervical spine. Methods A 45-year-old man with NF-1 developed cervical myelopathy. Preoperative examinations revealed severe cervicothoracic kyphoscoliosis, dystrophic changes of the cervical vertebrae, and the anomalous course of a VA and VA aneurysms. To assist in the preoperative planning and intraoperative navigation, we created 3-dimensional (3D) full-scale models of the patient's spine. Using a model, we performed a simulation of the planned surgery for spinal cord decompression with spinal fusion through both anterior and posterior approaches. Results Through the simulation, we could evaluate the risk of VA injury at the process of corpectomy, and altered the surgical procedure for the spinal cord decompression with spinal fusion from a posterior approach and a bone graft alone from an anterior approach. We accomplished the surgery successfully without any neurovascular complications. After surgery, the patient experienced relief from myelopathy. Conclusion Preoperative surgical simulation using a 3D full-scale model was useful for improving the accuracy and safety of the surgery for cervicothoracic kyphoscoliosis with NF-1.

We studied 27 patients with cervical ossification of the posterior longitudinal ligament (OPLL) but no clinical symptoms of myelopathy. We investigated the occupation ratio of the spinal canal by OPLL with cervical radiographs, assessed the morphological types of OPLL, and measured the segmental range of motion (ROM) at the level of maximum cord compression on flexion and extension radiographs. Patients were classified as having continuous-type OPLL (17 patients), mixed-type OPLL (seven patients), or segmental-type OPLL (three patients). The segmental ROM was negatively correlated with the OPLL occupation ratio (r=-0.49, p

We evaluated the clinical results of posterior decompression with instrumented fusion (PDF) for thoracic myelopathy due to ossification of the posterior longitudinal ligament (OPLL). A total of 24 patients underwent PDF, and their surgical outcomes were evaluated by the Japanese Orthopaedic Association (JOA) scores (0–11 points) and by recovery rates calculated at 3, 6, 9 and 12 months after surgery and at a mean final follow-up of 4 years and 5 months. The mean JOA score before surgery was 3.7 points. Although transient paralysis occurred immediately after surgery in one patient (3.8%), all patients showed neurological recovery at the final follow-up with a mean JOA score of 8.0 points and a mean recovery rate of 58.1%. The mean recovery rate at 3, 6, 9 and 12 months after surgery was 36.7, 48.8, 54.0 and 56.8%, respectively. The median time point that the JOA score reached its peak value was 9 months after surgery. No patient chose additional anterior decompression surgery via thoracotomy. The present findings demonstrate that despite persistent anterior impingement of the spinal cord by residual OPLL, PDF can result in considerable neurological recovery with a low risk of postoperative paralysis. Since neurological recovery progresses slowly after PDF, we suggest that additional anterior decompression surgery is not desirable during the early stage of recovery.

For preoperative evaluation of the vertebral artery (VA) at the craniovertebral junction, 3-dimensional (3-D) computed tomography (CT) angiography can simultaneously and precisely depict the location of the VA and the circumferential osseous tissues. However, this procedure has the risk of contrast-induced nephropathy, especially when patients have pre-existing renal impairment. We report the case of a 73-year-old woman with rheumatoid arthritis and concomitant chronic renal failure in whom severe myelopathy developed due to atlantoaxial vertical subluxation and subaxial subluxation. We planned to perform C1 laminectomy and C3-C7 laminoplasty, but to avoid the risk of intraoperative VA injury, we applied a fusion image technique of 3-D magnetic resonance (MR) angiography and co-registered 3-D CT that allowed for virtual assessment preoperatively of the VA courses, instead of 3-D CT angiography. Through the 3-D hybrid MR angiography-CT images, we could predict, in detail, the VA courses and the surrounding bony structures. At surgery, we found that the locations of the VAs were identical to that predicted on the preoperative image fusion analysis. We conclude that our image fusion techniques possess accurate diagnostic value for detecting arterial course, and could be applicable for patients in whom administration of contrast media should be avoided due to specific conditions, such as drug allergy and chronic renal failure.

Study design Gene expression and protein localization of osteopontin (OPN) in spinal hyperostosis of the twy mouse by means of in situ hybridization, immunohistochemistry, and Northern blot analysis. Objective To verify the involvement of OPN in spinal hyperostosis in the twy mouse and elucidate its ossification pattern at molecular levels. Summary of background data OPN is a molecule that consistently colocalizes with ectopic calcification in human pathologic conditions. The twy mouse, which shows ectopic calcification of the spinal ligament resulting in hind limb paralysis, is considered to be a model for human ossification of the posterior longitudinal ligament of the spine. Methods Twenty-eight each of age-matched twy, heterozygote, and wild-type mice were killed at 2, 4, 8, 12, and 16 weeks old and subject to histologic and/or molecular analyses. Sections were hybridized with RNA probes for OPN and also stained with anti-OPN antibodies. Total cellular RNA was extracted from the cervicothoracic spine of each genotype at 2- and 16-week-old, and gene expression for OPN and COL10A1 was quantified by Northern blot analysis. Results Enhanced expression of OPN mRNA was observed in spinal hyperostotic lesions of the twy mouse, specifically in cells of the spinal ligament and chondrogenic cells in the outer layer of the anulus fibrosus. These trends were also confirmed by immunohistochemical analyses. Northern blot analysis showed that a considerable amount of OPN transcripts was detected in all genotypes at 2 weeks old, but the robust expression of OPN mRNA was maintained only in twy mice at 16 weeks old. COL10A1 transcripts were hardly detected regardless of the genotype at 16 weeks old. Conclusion OPN was overexpressed in the hyperostotic spinal lesions of twy mice, and the hyperostosis was induced mainly by ectopic ossification of the spinal ligament. Because OPN is considered to be an inhibitor of calcification, further studies will be necessary to verify whether OPN overexpressed in the twy mouse is functional.

Background. Prevention of graft dislodgement in multilevel cervical corpectomy and fusion has been an unresolved problem. Anterior plate fixation has a significant failure rate. External support with a halo-vest is uncomfortable for patients. In the present study, we report a new surgical technique of anterior pedicle screw (APS) fixation for multilevel cervical corpectomy and spinal fusion, and describe the safety and utility of the system. Method. After cervical corpectomy, the pedicles on the right side were visualised under oblique fluoroscopy. Guide wires were inserted into the pedicles from the inner wall of the excavated vertebral body until they were hidden in the pedicles. After a fibula autograft was placed, the graft was penetrated in the reverse direction by the guide wires. After drilling and tapping, cannulated screws were inserted into the pedicles through the grafted fibula along the guide wires. Findings. In 9 patients with cervical myelopathy, the surgery was accomplished with a fibula autograft using APS fixation. A total of 22 APSs were inserted, and 21 screws were placed precisely in the pedicles. There were no neurovascular complications. Patients were allowed to ambulate without a halo-vest on the second day after the surgery. Post-operatively, no dislodgement of the grated fibula occurred, and all patients improved neurologically. Conclusions. The insertion of APSs is feasible and safe. APS fixation enables us to obtain rigid fixation anteriorly, and we propose that APS fixation is an attractive option for multilevel cervical corpectomy and fusion.

Introduction We determined the incidence of vertebral artery (VA) anomalies at the craniovertebral junction (CVJ) in patients with Down syndrome, and characterized the VA anomalies. Methods The course of the VA in 46 consecutive patients who were due to undergo posterior arthrodesis surgery at the CVJ were evaluated by three-dimensional CT angiography (3DCTA). Included were five patients with Down syndrome who suffered from myelopathy due to atlantoaxial subluxation. All five patients with Down syndrome also had a simultaneous congenital skeletal anomaly, either os odontoideum or ossiculum terminale. Results Of the five patients with Down syndrome, three had VA anomalies at the CVJ, two had fenestration and one had a persistent first intersegmental artery. Of the other 41 patients without Down syndrome, five had VA anomalies at the CVJ. The incidence of VA anomalies at the CVJ was much higher in patients with Down syndrome than in those without Down syndrome. Conclusion In planning surgery in patients with Down syndrome with symptomatic atlantoaxial subluxation and a congenital skeletal anomaly at the CVJ, we should consider the possible presence of VA anomalies. Preoperative 3DCTA allows us to precisely identify an anomalous VA and evaluate the possible risk of intraoperative VA injury in advance.

✓ The authors report the case of a 62-year-old woman who suffered an accidental fall and complained of severe neck pain and right C-7 radiculopathy. A right C6–7 facet fracture–subluxation was diagnosed. Bone fragments impinged on the right C-7 nerve root at the neural foramen. The bilateral vertebral arteries (VAs) ascended at the anterior aspect of C-6 and C-5 and entered the transverse foramen at the C-4 level. Based on findings of anomalous VAs, the authors applied a pedicle screw (PS)/rod system to effect surgical correction of the deformity. Intraoperatively, they successfully performed reduction of the subluxation, decompression of the impinged nerve root, and minimum single-segment fusion involving the placement of a PS/rod system. After surgery, the patient's neurological deficit dramatically improved and spinal fusion was completed without any loss of deformity correction. Prior to surgery for cervical injuries, the possible presence of an abnormal VA course should be considered. Preoperative detection of anomalous VAs will affect decisions on the appropriate corrective surgery option in cases of cervical spine injuries.

Background Symptom of herpes zoster is sometimes difficult to distinguish from sciatica induced by spinal diseases, including lumbar disc herniation and spinal canal stenosis. Here we report a case of sciatica mimicking lumbar canal stenosis. Case presentation A 74-year-old Chinese male patient visited our hospital for left-sided sciatic pain upon standing or walking for 5 min of approximately 1 month’s duration. At the first visit to our hospital, there were no skin lesions. A magnetic resonance imaging showed spinal canal stenosis between the 4th and 5th lumbar spine. Thus, we diagnosed the patient with sciatica induced by spinal canal stenosis. We considered decompression surgery for the stenosis of 4th and 5th lumbar spine because conservative therapy failed to relieve the patient’s symptom. At that time, the patient complained of a skin rash involving his left foot for several days. A vesicular rash and erythema were observed on the dorsal and plantar surfaces of the great toe and lateral malleolus. The patient was diagnosed with herpes zoster in the left 5th lumbar spinal nerve area based on clinical findings, including the characteristics of the pain and vesicular rash and erythema in the 5th lumbar spinal dermatome. The patient was treated with famciclovir (1,500 mg/day) and non-steroidal anti-inflammatory drugs. After 1 week of medication, the skin rash resolved and pain relief was obtained. Conclusion In conclusion, spinal surgeons should keep in mind herpes zoster infection as one of the possible differential diagnoses of sciatica, even if there is no typical skin rash. Electronic supplementary material The online version of this article (doi:10.1186/s13104-015-1272-z) contains supplementary material, which is available to authorized users.

Posterior decompression with instrumented fusion (PDF) surgery has been previously reported as a relatively safe surgical procedure for any type of thoracic ossification of the longitudinal ligament (OPLL). However, mid- to long-term outcomes are still unclear. The aim of the present study was to elucidate the mid- to long-term clinical outcome of PDF surgery for thoracic OPLL patients. The present study included 20 patients who had undergone PDF for thoracic OPLL and were followed for at least 5years. Increment change and recovery rate of the Japanese Orthopaedic Association (JOA) score were assessed. Revision surgery during the follow-up period was also recorded. Average JOA scores were 3.5 preoperatively and 7.1 at final follow-up. The average improvement in JOA score was 3.8 points and the average recovery rate was 47.0%. The JOA score showed gradual increase after surgery, and took 9months to reach peak recovery. As for neurological complications, two patients suffered postoperative paralysis, but both recovered without intervention. Six revision surgeries in four patients were related to OPLL. Additional anterior thoracic decompression for remaining ossification at the same level of PDF surgery was performed in one patient. Decompression surgery for deterioration of symptoms of pre-existing cervical OPLL was performed in three patients. One patient had undergone lumbar and cervical PDF surgery for de novo ossification foci of the lumbar and cervical spine. PDF surgery for thoracic OPLL is thus considered a relatively safe and stable surgical procedure considering the mid- to long-term outcomes.

Introduction Epidermoid cysts are known as embryonic or acquired ectopic aberrations of the ectoderm. To the best of our knowledge, there are only a few reports of elderly onset intramedullary epidermoid cysts. We report a case of elderly onset intramedullary epidermoid cyst at the conus medullaris. Case presentation A 63-year-old Japanese woman working as a farmer presented with slowly progressive gait disturbance and voiding dysfunction. A magnetic resonance imaging scan revealed an intramedullary mass lesion at L1 to L3. We diagnosed the lesion as an intramedullary spinal cord tumor. A laminectomy was performed at the level of Th12 to L3. Upon spinal cord dissection, a yellowish milky exudation erupted from the cystic lesion. We resected white cartilage-like pieces from the cystic cavity. Because the wall of the cystic lesion tightly adhered to the spinal cord parenchyma, we abandoned complete resection of the cyst wall. The pathological diagnosis was an epidermoid cyst. Conclusions We propose that evacuation of the cyst contents is preferable, especially in cases with elderly onset and congenital origin. Electronic supplementary material The online version of this article (doi:10.1186/1752-1947-9-7) contains supplementary material, which is available to authorized users.

Transplantation of bone marrow stromal cells (BMSCs) for spinal cord injury (SCI) has been shown to improve functional outcome. BMSCs can be easily obtained from bone marrow aspirate and have fewer problems in the clinical application for human SCI from the ethical and legal points of view. Recently, we produced cells with neural stem and/or progenitor cell property and neural regeneration supporting capacity from human bone marrow stromal cells (human bone marrow stromal cell-derived neuroregenerative cells: hBMSC-NRs). The aim of the present study was to clarify the effectiveness of transplantation of hBMSC-NRs to injured spinal cord of severe combined immunodeficiency (NOD/SCID) mice. Neurite outgrowth assay of PC-12 cells was performed. One week after a T9-level contusion SCI, hBMSCs or hBMSC-NRs were transplanted into the spinal cord. After the transplantation, functional and histological examinations were performed. Conditioned media of hBMSC-NRs significantly promoted the neurite outgrowth of PC-12 cells in vitro. Transplanted hBMSC-NRs survived in the injured spinal cord 8 weeks after SCI. Immunohistochemistry revealed that the density of serotonin-positive fibers of the transplanted group was significantly higher than that of the control group at the epicenter and caudal segment to the injured site. The recovery of hind limb function of the hBMSC-NRs group was significantly better than that of the control group. In conclusion, hBMSC-NRs can be one of the realistic candidates for cell transplantation therapy for human SCI.

Object The use of human umbilical cord blood (HUCB) cells has been reported to improve functional recovery in cases of central nervous system injuries such as stroke, traumatic brain injury, and spinal cord injury (SCI). The authors investigated the effects of hemopoietic stem cells that were derived from HUCB and transplanted into the injured spinal cords of rats. Methods One week after injury, an HUCB fraction enriched in CD34-positive cells was transplanted into the experimental group. In control animals, vehicle (Matrigel) was transplanted. Recovery of motor functions was assessed using the Basso, Beattie, and Bresnahan Locomotor Scale, and immunohistochemical examinations were performed. Cells from HUCB that were CD34 positive improved functional recovery, reduced the area of the cystic cavity at the site of injury, increased the volume of residual white matter, and promoted the regeneration or sparing of axons in the injured spinal cord. Immunohistochemical examination revealed that transplanted CD34-positive cells survived in the host spinal cord for at least 3 weeks after transplantation but had disappeared by 5 weeks. The transplanted cells were not positive for neural markers, but they were positive for hemopoietic markers. There was no evidence of an immune reaction at the site of injury in either group. Conclusions These results suggest that transplantation of a CD34-positive fraction from HUCB may have therapeutic effects for SCI. The results of this study provide important preclinical data regarding HUCB stem cell–based therapy for SCI.

Case report. To report a case with giant cell tumor (GCT) of C6 vertebra, in which three-dimensional (3-D) full-scale modeling of the cervical spine was useful for preoperative planning and intraoperative navigation. A university hospital in Japan. A 27-year-old man with a GCT involving the C6 vertebra presented with severe neck pain. The C6 vertebra was collapsed and the tumor had infiltrated around both vertebral arteries (VAs). A single-stage operation combining anterior and posterior surgical procedures was scheduled to resect the tumor and stabilize the spine. To evaluate the anatomic structures within the surgical fields, we produced a 3-D full-scale model from the computed tomography angiography data. The 3-D full-scale model clearly showed the relationships between the destroyed C6 vertebra and the deviations in the courses of both VAs. Using the model, we were able to identify the anatomic landmarks around the VAs during anterior surgery and to successfully resect the tumor. During the posterior surgery, we were able to determine accurate starting points for the pedicle screws. Anterior iliac bone graft from C5 to C7 and posterior fixation with a rod and screw system from C4 to T2 were performed without any complications. Postoperatively, the patient experienced relief of his neck pain. The 3-D full-scale model was useful for simultaneously evaluating the destruction of the vertebral bony structures and the deviations in the courses of the VAs during surgery for GCT involving the cervical spine.

Study design This retrospective study was conducted to investigate the clinical outcomes of several surgical procedures for thoracic myelopathy caused by ossification of the posterior longitudinal ligament (OPLL). Objective To evaluate the effect of myelopathy treatment and safety of posterior decompression with instrumented fusion. Summary of background data Many different surgical procedures have been used for the treatment of thoracic OPLL. However, the possibility of postoperative paraplegia remains a major risk, and consistent protocols and procedures for surgical treatment of thoracic OPLL have also not been established. Methods A total of 51 patients who underwent surgery for thoracic OPLL were classified into 3 groups: (1) posterior decompression group (18 patients), which included 12 who underwent laminectomy and 6 who underwent cervicothoracic laminoplasty; (2) OPLL extirpation group (16 patients), which included 4 who underwent anterior decompression through thoracotomy and 12 who underwent anterior decompression through the posterior approach; and (3) posterior decompression and fusion group (17 patients), all of whom underwent laminectomy with posterior instrumented fusion. In each group, the Japanese Orthopedic Association score was used to evaluate thoracic myelopathy, and the recovery rate calculated 1 year after surgery and at final examination. Results Mean recovery rate at final follow-up was 41.9% in the posterior decompression group, 62.1% in the OPLL extirpation group, and 59.3% in the posterior decompression and fusion group. Postoperative paralysis occurred in 3 patients in the posterior decompression group and in 3 in the OPLL extirpation group. In the OPLL extirpation group, leakage of cerebrospinal fluid occurred in 8 patients and hydrothorax in 2. Late neurologic deterioration occurred in 7 patients in the posterior decompression group. There were no cases of postoperative paralysis or late neurologic deterioration in the posterior decompression and fusion group. Conclusions A considerable degree of neurologic recovery was obtained by posterior decompression with instrumented fusion, despite the anterior impingement of the spinal cord by OPLL remaining. In addition, the rate of postoperative complications was extremely low with this procedure. We recommend that 1-stage posterior decompression and instrumented fusion be selected for patients in whom the spinal cord is severely damaged before surgery and/or when extirpation of OPLL is associated with increased risk.

Study Design. This study examined the extraosseous and intraosseous anomalies of vertebral arteries in patients who underwent surgery of the craniovertebral junction. Objectives. To describe the usefulness of three-dimensional computed tomography angiography for evaluating vertebral artery anomalies before surgery. Summary of Background Data. Previous studies using catheter angiograms have identified anomalous courses of the vertebral artery at the craniovertebral junction. Studies using computed tomography reconstruction also showed deviation of the vertebral artery groove at the C2 isthmus, demonstrating a risk of vertebral artery injury for C1–C2 transarticular screw placement. These analyses provided us with useful information for identifying anomalies of the vertebral artery, but they could not visualize the artery and its circumferential osseous tissue simultaneously, nor could they analyze the reciprocal anatomy of both tissues. Methods. Thirty-one consecutive patients who submitted to surgery at the craniovertebral junction were evaluated before surgery by three-dimensional computed tomography angiography. Eleven of the patients had congenital osseous anomalies at the craniovertebral junction including os odontoideum and ossiculum terminale. Anomalous vertebral arteries at the extraosseous region were visualized by three-dimensional reconstruction images, and the intraosseous deviation of the vertebral artery at the C2 isthmus was evaluated by multiplanar reconstruction images. Results. Extraosseous and/or intraosseous vertebral artery anomalies were detected in 9 cases. Eight of the 9 cases had osseous anomalies at the craniovertebral junction. Abnormal courses of the vertebral artery at the extraosseous region were detected in 4 cases: 2 had fenestration and 2 had persistent first intersegmental artery. Asymmetry of bilateral vertebral arteries was found in 5 cases: the right was dominant in 3 cases and the left in 2 cases. A high-riding vertebral artery at the C2 isthmus was detected in 5 cases. Based on these findings, we modified our surgical approach and the screw placement; consequently, no vertebral artery injury occurred. Conclusions. In patients having osseous anomalies at the craniovertebral junction, the frequency of vertebral artery anomalies at the extraosseous and intraosseous regions is increased. With preoperative three-dimensional computed tomography angiography, we can precisely identify the anomalous vertebral artery and reduce the risk of intraoperative injury to the vertebral artery, in advance.

Case report. To report a case with thoracic myelopathy caused by ossification of the posterior longitudinal ligament (OPLL) and ossification of the ligamentum flavum (OLF), in which postoperative paralysis occurred after laminectomy and was reversed after an additional posterior instrumented fusion. A University Hospital in Japan. A 71-year-old woman, with a spastic palsy of both lower extremities, had OPLL and OLF at T10–T11, which pinched the spinal cord anteriorly and posteriorly. She underwent a laminectomy at T10–T11, and no further neurological deterioration was seen immediately after surgery. Over the next 18 h, however, myelopathy worsened, showing severe paraparesis. An additional posterior instrumented fusion at T7–L1 was performed without correction of the kyphosis. After fusion, neurological deficits gradually recovered, despite the presence of residual anterior impingement of spinal cord by the OPLL. The present case provides evidence for the possibility that laminectomy alone produces postoperative paralysis for combined thoracic OPLL and OLF, and we recommend that a posterior instrumented fusion should be added when posterior decompression is performed for this disorder.

Study design Case report of a Down syndrome patient with right vertebral artery fenestration and abnormalities of the craniovertebral junction. Objectives Describe the utility of 3-dimensional computed tomography angiography for evaluating vertebral artery anomalies before surgery. Summary of background data Previous reviews evaluating catheter angiograms identified various anomalies of vertebral artery at the craniovertebral junction. The frequency of vertebral artery anomalies is increased in patients having osseous anomalies at the craniovertebral junction. Down syndrome is associated with a high incidence of bone abnormalities at the craniovertebral junction, but there have been no published reports of vertebral artery anomalies per se at the craniovertebral junction. Methods A 16-year-old woman with trisomy 21 presented with gait abnormalities and myelopathy in association with bone abnormalities at the craniovertebral junction, including hypoplastic odontoid and ossiculum terminale. Computed tomography angiography showed that right vertebral artery bifurcated after exiting the C2 transverse foramen with one branch passing through the C1 transverse foramen, whereas the other turned posteromedially and entered the spinal canal between C1 and C2. Results Occipito-C2 posterior fusion was performed with a rod and screw system. Intraoperatively, the course of the anomalous right vertebral artery was identified by Doppler angiography, and the surgical approach was modified to allow safe pedicle screw insertion while avoiding vertebral artery injury. After surgery, myelopathy resolved within 3 months. Conclusions Before corrective surgery of craniovertebral junction anomalies in patients with Down syndrome, the possibility of vertebral artery anomalies associated with abnormal craniovertebral junction anatomy should be considered. With preoperative 3-dimensional computed tomography angiography, we can precisely identify the anomalous vertebral artery and modify the surgical approach to reduce the possible risk of intraoperative vertebral artery injury in advance.

A 60-year-old man presented with thoracic myelopathy due to ossification of the posterior longitudinal ligament (OPLL). His spinal cord was severely impinged anteriorly by a beak-type OPLL and posteriorly by ossification of the ligamentum flavum at T4/5. He underwent surgical posterior decompression with instrumented fusion (PDF). Immediately after surgery, he developed a Brown-Séquard-type paralysis, which spontaneously resolved without requiring the addition of OPLL extirpation. This example highlights that the risk of postoperative neurological deterioration cannot be eliminated even when PDF is selected as the surgical procedure for thoracic OPLL, especially in instances in which the spinal cord is severely compressed.

The motion at the non-ossified segment of the ossification of the posterior longitudinal ligament (OPLL) is thought to be highly correlated to aggravation of symptoms of myelopathy. The rationale for posterior decompression with instrumented fusion (PDF) surgery is to limit the motion of the non-ossified segment of OPLL by stabilization. The purpose of the present study was to elucidate the course of bone union and remodelling of the non-ossified segment of thoracic OPLL (T-OPLL) after PDF surgery. A total of 29 patients who underwent PDF surgery for T-OPLL were included in this study. We measured the thickness of the OPLLs by determining the thickest part of the OPLL in the sagittal multi-planer reconstruction CT images pre- and post-operatively. Five experienced spine surgeons independently performed CT measurements of OPLL thickness twice. Japanese Orthopaedic Association score for thoracic myelopathy was measured as clinical outcome measure. Non-ossified segment of OPLLs fused in 24 out of 29 (82.8 %) patients. The average thickness of the OPLL at its thickest segment was 8.0 mm and decreased to 7.3 mm at final follow-up. The decrease in ossification thickness was significantly larger in the patients who showed fusion of non-ossified segments of OPLL compared with that in the patients did not show fusion. There was no significant correlation between the clinical outcome and the decrease in thickness of the OPLLs. The results of this study showed that remodelling of the OPLLs, following fusion of non-ossified segment of OPLLs, resulted in a decreased OPLL thickness, with potential for a reduction of spinal cord compression.

OPLL (ossification of the posterior longitudinal ligament of the spine) is a common form of human myelopathy with a prevalence of as much as 4% in a variety of ethnic groups. To clarify the genetic factors that predispose to OPLL, we have studied ttw (tiptoe walking), a mouse model that presents ectopic ossification of the spinal ligaments similar to OPLL and have found that the ttw phenotype is caused by the nonsense mutation of the gene encoding nucleotide pyrophosphatase (NPPS), a membrane-bound glycoprotein thought to produce inorganic pyrophosphate, a major inhibitor of calcification and mineralization. To investigate a possible role of NPPS in the etiology of OPLL, we have examined its genetic variations in OPLL patients. A total of 323 OPLL patients was screened by means of polymerase chain reaction/single-strand conformation polymorphism analysis covering all the exons and their surrounding introns, plus about 1.5-kb of the promoter region. We identified ten nucleotide variations in the NPPS gene; five of the alterations caused amino-acid substitutions, and two of them were found specifically in OPLL patients. Subsequently, we performed an association study using these variations and found a significant association of an allele, viz., a deletion of T at a position 11 nucleotides upstream from the splice acceptor site of intron 20 (IVS20-11delT), with OPLL; the proportion of the individuals having this deletion was significantly higher (P = 0.0029) in OPLL patients than in controls, indicating that those who have this variation may be more susceptible to the abnormal ossification of the spinal ligaments. Thus, our study suggests that NPPS plays an important role in the etiology of human OPLL.

To confirm the feasibility and safety of granulocyte colony-stimulating factor (G-CSF) for treating spinal neuropathic pain associated with compression myelopathy, we have initiated an open-label single-center prospective clinical trial.Between January 2009 and February 2011, 17 patients were accrued and were divided into two groups. One group included 7 patients who complained of pain associated with worsening symptoms of myelopathy (progressing myelopathy-related pain group). The other group included 10 patients who complained of pain that persisted after surgery for compression myelopathy (post-operative persistent pain group). All patients underwent intravenous administration of G-CSF (10 μg/kg/day) for 5 consecutive days. Pain severity was evaluated using a visual analog scale (VAS) before and after G-CSF administration.In 14 of the 17 patients, pain was relieved within several days after G-CSF administration. Pain disappeared completely in 3 patients. In the progressing myelopathy-related pain group, the mean VAS score was 71.4/100 before G-CSF administration, and decreased to 35.9/100 at 1 week after G-CSF administration (p0.05). In the post-operative persistent pain group, the mean VAS score was 72.0/100 before G-CSF administration, and decreased to 51.7/100 at 1 week after G-CSF administration (p0.05). No severe adverse events occurred during or after G-CSF administration.The present results provide us with the possibility that G-CSF has a pain-relieving effect for neuropathic pain in patients with compression myelopathy.

STUDY DESIGN Retrospective clinical study. OBJECTIVE To report the surgical outcomes of patients with cervical myelopathy associated with athetoid cerebral palsy and to assess whether a halo vest is necessary for postoperative external immobilization. SUMMARY OF BACKGROUND DATA Although a halo vest has remained the first choice for postoperative external immobilization of patients with cervical myelopathy associated with cerebral palsy, simplification of this method has been attempted in recent years. Studies focusing on postoperative external immobilization are rare. METHODS Since 2001, 20 patients underwent surgery with posterior instrumented fusion or posterior fixation and anterior decompression with fusion with a year or longer follow-up. Before 2004, all patients were given a halo vest for postoperative external immobilization. After 2004, halo vests were not used, and when abnormal involuntary neck movements were severe, an intramuscular injection of botulinum toxin was administered before and after surgery. Surgical outcomes, surgical methods and complications were compared between the group that used a halo vest and the group that did not use a halo vest. RESULTS In the halo vest group, the average Japanese Orthopedic Association score was 6.9 points before surgery and 9.3 points at 1-year follow-up. The average recovery rate was 25.0%. In the group without halo vest use, the average Japanese Orthopedic Association score was 5.8 points before surgery and 9.9 points at 1-year follow-up. The average recovery rate was 35.7%. The group without halo vest use achieved outcomes equal to those achieved in the group with halo vest use. The frequency of complications was less without halo vest use than with halo vest use. CONCLUSION No inferiority in clinical outcomes was seen if postoperative halo vest use was omitted. Progress in surgical instrumentation and injection of botulinum toxin may explain this result.

Study design Consecutive case series and literature review. Objective To describe the utility of 3-dimensional computed tomographic angiography (3D CTA) for evaluating vertebral artery (VA) anomalies before surgery. Summary of background data Recent advances in instrumentation surgery at the craniovertebral junction (CVJ) enable us to perform rigid internal fixation. However, the risk of VA injury as a complication of the surgery has become a major problem. Thus, the importance of preoperative evaluation of the VA course has been emphasized. Methods Cases of 100 consecutive patients who underwent CVJ instrumentation surgery since July 1998 were analyzed. Occipitocervical/thoracic or C1-C2 posterior fusion was performed for atlantoaxial subluxation (AAS) in 59 patients and cervical fixation including C2 was required for middle-to-lower cervical lesions in 41 patients. Twenty-seven patients with AAS had a congenital skeletal anomaly (CSA) at the CVJ including os odontoideum and occipitalization of C1 (AAS-CSA[+] group). Anomalous VAs at the extra- and intraosseous regions were evaluated by 3D CTA. Results No neurovascular injury occurred during surgery. Abnormal courses of the VA at the extraosseous region were detected in 10 cases: 2 had fenestration and 8 had a persistent first intersegmental artery. All 10 cases were in the AAS-CSA(+) group. A high-riding VA was detected in 31 cases. Fourteen out of the 31 cases were in the AAS-CSA(+) group, indicating 51.9% of the AAS-CSA(+) group had high-riding VA. In the AAS-CSA(+) group, a C1-C2 transarticular screw and C2 pedicle screw were actually inserted in 58% and 31% of the planned insertions, respectively. Conclusion The present findings suggest that the frequency of an abnormal VA at the extra- and intraosseous regions is increased when patients have AAS and CSA at the CVJ. Using preoperative 3D CTA, we can precisely identify anomalous VAs and thereby reduce the risk of their intraoperative injury.

STUDY DESIGN An open-labeled multicenter prospective controlled clinical trial. OBJECTIVE To confirm the feasibility of granulocyte colony-stimulating factor (G-CSF) administration for patients with thoracic myelopathy. SUMMARY OF BACKGROUND DATA Although G-CSF is best known as an important cytokine commonly used to treat neutropenia, it also has nonhematopoietic functions. Previous experimental studies have shown that G-CSF can enhance tissue regeneration of several organs, such as the heart and the brain. We previously reported that G-CSF promotes functional recovery after spinal cord injury in rodents. On the basis of those findings, we started a clinical trial of neuroprotective therapy, using G-CSF for patients with worsening symptoms of thoracic myelopathy. METHODS Patients whose Japanese Orthopaedic Association (JOA) score for thoracic myelopathy had decreased 2 points or more during a recent 1-month period were eligible for entry. After giving informed consent, patients were assigned to G-CSF and control groups. The G-CSF group (n = 10) received G-CSF 10 μg/kg per day intravenously for 5 consecutive days. The control group (n = 14) received similar treatments as the G-CSF group except for G-CSF administration. The primary outcome was JOA recovery rate at 1 month after G-CSF administration or initial treatment. RESULTS There was greater improvement in neurological functioning between baseline and 1-month follow-up in the G-CSF group (JOA recovery rate: 29.1 ± 20.5%) than in the control group (JOA recovery rate: 1.1 ± 4.2%) (P < 0.01). No serious adverse events occurred during or after the G-CSF administration. CONCLUSION The results provide evidence that G-CSF administration caused neurological recovery in patients with worsening symptoms of thoracic compression myelopathy.

Granulocyte colony-stimulating factor (G-CSF) is a cytokine that is clinically used to treat neutropenia. G-CSF also has non-hematopoietic functions and could potentially be used to treat neuronal injury. To confirm the safety and feasibility of G-CSF administration for acute spinal cord injury (SCI), we have initiated a phase I/IIa clinical trial of neuroprotective therapy using G-CSF.The trial included a total of 16 SCI patients within 48 h of onset. In the first step, G-CSF (5 μg/kg/day) was intravenously administered for 5 consecutive days to 5 patients. In the second step, G-CSF (10 μg/kg/day) was similarly administered to 11 patients. We evaluated motor and sensory functions of patients using the American Spinal Cord Injury Association (ASIA) score and ASIA impairment scale (AIS) grade.In all 16 patients, neurological improvement was obtained after G-CSF administration. AIS grade increased by one step in 9 of 16 patients. A significant increase in ASIA motor scores was detected 1 day after injection (P0.01), and both light touch and pin prick scores improved 2 days after injection (P0.05) in the 10 μg group. No severe adverse effects were observed after G-CSF injection.These results indicate that intravenous administration of G-CSF (10 μg/kg/day) for 5 days is essentially safe, and suggest that some neurological recovery may occur in most patients. We suggest that G-CSF administration could be therapeutic for patients with acute SCI.

ObjectThe aim of this study was to evaluate the outcomes of fusion surgery in patients with ossification of the posterior longitudinal ligament in the thoracic spine (T-OPLL) and to identify factors significantly related to surgical outcomes.MethodsThe study included 76 patients (34 men and 42 women with a mean age of 56.3 years) who underwent fusion surgery for T-OPLL at 7 spine centers during the 5-year period from 2003 to 2007. The authors evaluated the patient demographic data, underlying disease, preoperative comorbidities, history of spinal surgery, radiological findings, surgical methods, surgical outcomes, and complications. Surgical outcomes were assessed using the Japanese Orthopaedic Association (JOA) scale score for thoracic myelopathy (11 points) and the recovery rate.ResultsThe mean JOA scale score was 4.6 ± 2.1 points preoperatively and 7.7 ± 2.5 points at the time of the final follow-up examination, yielding a mean recovery rate of 45.4% ± 39.1%. The recovery rates by surgical method were 38.5% ± 37.8% for posterior decompression and fusion, 65.0% ± 35.6% for anterior decompression and fusion via an anterior approach, 28.8% ± 41.2% for anterior decompression via a posterior approach, and 57.5% ± 41.1% for circumferential decompression and fusion. The recovery rate was significantly higher in patients without diabetes mellitus (DM) than in those with DM. One or more complications were experienced by 31 patients (40.8%), including 20 patients with postoperative neurological deterioration, 7 with dural tears, 5 with epidural hematomas, 4 with respiratory complications, and 10 with other complications.ConclusionsThe outcomes of fusion surgery for T-OPLL were favorable. The absence of DM correlated with better outcomes. However, a high rate of complications was associated with the fusion surgery.

Based on the neuroprotective effects of granulocyte colony-stimulating factor (G-CSF) on experimental spinal cord injury, we initiated a clinical trial that evaluated the safety and efficacy of neuroprotective therapy using G-CSF for patients with worsening symptoms of compression myelopathy.We obtained informed consent from 15 patients, in whom the Japanese Orthopaedic Association (JOA) score for cervical myelopathy decreased two points or more during a recent 1-month period. G-CSF (5 or 10 μg/kg/day) was intravenously administered for five consecutive days. We evaluated motor and sensory functions of the patients and the presence of adverse events related to G-CSF therapy.G-CSF administration suppressed the progression of myelopathy in all 15 patients. Neurological improvements in motor and sensory functions were obtained in all patients after the administration, although the degree of improvement differed among the patients. Nine patients in the 10-μg group (n=10) underwent surgical treatment at 1 month or later after G-CSF administration. In the 10-μg group, the mean JOA recovery rates 1 and 6 months after administration were 49.9±15.1 and 59.1±16.3%, respectively. On the day following the start of G-CSF therapy, the white blood cell count increased to more than 22,700 cells/mm3. It varied from 12,000 to 50,000 and returned to preadministration levels 3 days after completing G-CSF treatment. No serious adverse events occurred during or after treatment.The results indicate that G-CSF administration at 10 μg/kg/day is safe for patients with worsening symptoms of compression myelopathy and may be effective for their neurological improvement.

Obesity is a risk factor for ossification of the posterior longitudinal ligament (OPLL) of the spine, which is characterized by heterotopic bone formation in the posterior longitudinal spinal ligament. Hyperleptinemia is a common feature of obese people and leptin is believed to be an important factor in the pathogenesis of OPLL. However, the association between leptin and bone metabolism and the development of OPLL is not understood fully. The objective of the present study was to determine the association between serum leptin concentration and bone metabolic markers and the extent of heterotopic ossification of the spinal ligament in patients with OPLL. The serum concentrations of leptin, insulin, fructosamine, bone-specific alkaline phosphatase, and carboxyterminal propeptide of type I procollagen, urine deoxypyridinoline levels, and the number of vertebrae with OPLL involvement were measured in 125 (68 males and 57 females) patients with OPLL. The correlation between leptin and these other factors was then examined. Serum leptin and insulin concentrations were increased significantly in OPLL females compared to non-OPLL female controls. In the females with OPLL, serum leptin concentrations corrected for body mass index correlated positively with the number of vertebrae with OPLL involvement. In females, serum leptin levels were significantly higher in patients in whom OPLL extended to the thoracic and/or lumbar spine than in patients in whom OPLL was limited to the cervical spine. Our results suggest that hyperleptinemia, in combination with hyperinsulinemia, may contribute to the development of heterotopic ossification of the spinal ligament in female patients with OPLL.

The aim of this study was to evaluate whether transplantation of human bone marrow stromal cell-derived Schwann cells (hBMSC-SC) promotes functional recovery after contusive spinal cord injury of adult rats. Human bone marrow stromal cells (hBMSC) were cultured from bone marrow of adult human patients and induced into Schwann cells (hBMSC-SC) in vitro. Schwann cell phenotype was confirmed by immunocytochemistry. Growth factors secreted from hBMSC-SC were detected using cytokine antibody array. Immunosuppressed rats were laminectomized and their spinal cords were contused using NYU impactor (10 g, 25 mm). Nine days after injury, a mixture of Matrigel and hBMSC-SC (hBMSC-SC group) was injected into the lesioned site. Five weeks after transplantation, cresyl-violet staining revealed that the area of cystic cavity was smaller in the hBMSC-SC group than that in the control group. Immunohistochemistry revealed that the number of anti-growth-associated protein-43-positive nerve fibers was significantly larger in the hBMSC-SC group than that in the control group. At the same time, the number of tyrosine hydroxylase- or serotonin-positive fibers was significantly larger at the lesion epicenter and caudal level in the hBMSC-SC group than that in the control group. In electron microscopy, formation of peripheral-type myelin was recognized near the lesion epicenter in the hBMSC-SC group. Hind limb function recovered significantly in the hBMSC-SC group compared with the control group. In conclusion, the functions of hBMSC-SC are comparable to original Schwann cells in rat spinal cord injury models, and are thus potentially useful treatments for patients with spinal cord injury.

The CILP gene encodes a proform of two polypeptides. One of them, cartilage intermediate layer protein (CILP), is a non-collagenous protein recently isolated from human articular cartilage. The other is homologous to a porcine nucleotide pyrophosphohydrolase (NTPPHase) whose enzymatic activity is highest in articular tissue. The investigation reported here revealed that the CILP gene consists of nine exons spanning approximately 15 kb of genomic DNA on chromosome 15q22. We also report six single nucleotide variations in this gene; five of them cause amino acid changes and the most common of them substitutes isoleucine for threonine at codon 395.

STUDY DESIGN To report a new index, the K-line, for deciding the surgical approach for cervical ossification of the posterior longitudinal ligament (OPLL). OBJECTIVE To analyze the correlation between the K-line-based classification of cervical OPLL patients and their surgical outcome. SUMMARY OF BACKGROUND DATA Previous studies showed that kyphotic alignment of the cervical spine and a large OPLL are major factors causing poor surgical outcome after laminoplasty for cervical OPLL patients. However, no report has evaluated these 2 factors in 1 parameter. METHODS The K-line was defined as a line that connects the midpoints of the spinal canal at C2 and C7. Twenty-seven patients who had cervical OPLL and underwent posterior decompression surgery were classified into 2 groups according to their K-line classification. OPLL did not exceed the K-line in the K-line (+) group and did exceed it in the K-line (-) group. By intraoperative ultrasonography, we evaluated the posterior shift of the spinal cord after the posterior decompression procedure. The Japanese Orthopedic Association scores before surgery and 1 year after surgery were evaluated, and the recovery rate was calculated. RESULTS Eight patients were classified as K-line (-), and 19 patients were classified as K-line (+). The mean recovery rate was 13.9% in the K-line (-) group and 66.0% in the K-line (+) group (P < 0.01). Ultrasonography showed that the posterior shift of the spinal cord was insufficient in the K-line (-) group. CONCLUSION The present results demonstrate that a sufficient posterior shift of the spinal cord and neurologic improvement will not be obtained after posterior decompression surgery in the K-line (-) group. Our new index, the K-line, is a simple and practical tool for making decisions regarding the surgical approach for cervical OPLL patients.

Study design Case report. Objective To report an adult case with Down syndrome, in whom infection-related atlantoaxial subluxation (Grisel syndrome) developed. Summary of background data Atlantoaxial instability is a common complication in Down syndrome patients; however, there have been limited reports of adult-onset atlantoaxial subluxation with myelopathy. Grisel syndrome has been characterized as a nontraumatic atlantoaxial subluxation associated with pharyngeal infection. It usually affects children, and the subluxation can be successfully reduced by conservative treatments in most cases. Methods A 26-year-old man with Down syndrome suffered from retropharyngeal infection, after which his atlantoaxial subluxation was aggravated and myelopathy developed. He was treated with administration of antibiotics and application of a halo-vest. Results The conservative treatments failed to reduce the atlantoaxial subluxation. We performed a C1 laminectomy and posterior occipitocervical fusion, which successfully relieved his symptoms. CONCLUSION.: This experience suggests that when Down syndrome patients have retropharyngeal infection, we should consider the possible aggravation of atlantoaxial instability and development of myelopathy, even if the patient is an adult.

A 49-year-old man presented with progressive cervical myelopathy caused by a retro-odontoid mass, with associated developmental canal stenosis at C1, and C1-C2 instability. Surgery was scheduled for a dome-like laminotomy at C1, posterior C1-C2 fixation using C1 lateral mass screws and C2 pedicle screws, and structural bone grafting between C1 and C2. Prior to surgery, we produced a 3-dimensional full-scale model of the patient's cervical spine and performed a simulation of the scheduled surgery. Through the simulation, we accurately evaluated the laminotomy sites and the screw insertion points. During the actual surgery, all procedures were successful. After surgery, the patient's neurological deficits markedly improved. Successful C1-C2 fusion, adequate decompression of the spinal cord, and spontaneous regression of the retro-odontoid mass were achieved by this procedure without any apparent restriction in neck movement.

Study design Case report. Objective We describe the usefulness of 3-dimensional full-scale modeling for preoperative simulation of surgery in a patient with old cervical fracture-dislocation. Summary of background data Many different surgical procedures have been used in the treatment of unilateral cervical fracture-dislocation. However, consistent protocols and procedures for the surgical correction of old fracture-dislocations associated with nerve root lesions have not been established. Methods Two months after an automobile accident, a 50-year-old man developed symptoms of left C5 palsy. Four months after the accident, he was diagnosed with a fracture-dislocation at left C4-C5 facet with impingement of the left C5 root at the neural foramen. In addition, his left vertebral artery was completely occluded. Spontaneous bony fusion had progressed around the left facet and the anterior aspect of the vertebrae at C4-C5. Before surgery, a 3-dimensional full-scale model in the patient's cervical spine was made in order to simulate the planned surgical reconstruction. Results Through this simulation, we were able to accurately evaluate the deformed bony structures around the fractured C4-C5 facet. During the actual surgery, all the planned procedures were successfully achieved, including anterior release, insertion of pedicle screws at left C4 and C5, unroofing of the left C5 root, reduction of the displaced facet with the pedicle screw-rod system, and spinal fusion at C4-C5. After surgery, the patient's left C5 palsy was dramatically relieved and the spinal fusion went on to successful healing. Conclusion The surgical simulation made possible by the 3-dimensional full-scale model appeared to simplify the surgical procedure and may enhance the safety of the complex spinal reconstruction.

We compared the surgical outcome of anterior decompression with spinal fusion (ASF) with the surgical outcome of laminoplasty for patients with cervical myelopathy due to ossification of the posterior longitudinal ligament.The study group comprised 19 ASF patients (A-group) and 40 laminoplasty patients (P-group) treated from 1993 to 2002 with 1 year or longer follow-up. The Japanese Orthopedic Association scoring system was used to evaluate cervical myelopathy, and the recovery rate calculated 1 year after surgery.The mean recovery rate was 68.4% in the A-group and 52.5% in the P-group (P0.05). Fifteen patients had a recovery rate less than 40%: 2 in the A-group and 13 in the P-group. One P-group patient and none of the A-group patients developed postoperative aggravation of their neurologic status. The P-group was divided into 2 subgroups: a good outcome group comprising patients whose recovery rate was 40% or higher (n=27) and a poor outcome group comprising patients whose recovery rate was less than 40% (n=13). The mean age at surgery was 59.9 years in the good outcome group and 68.0 years in the poor outcome group (P0.05). The mean range of intervertebral mobility at maximum cord compression level before surgery was 6.9 degrees in the good outcome group and 10 degrees in the poor outcome group (P0.05).These results demonstrated that the surgical outcome of ASF was superior to the surgical outcome of laminoplasty. Elderly patients treated with laminoplasty showed an especially poor surgical outcome. We suggest that hypermobility of vertebrae at the cord compression level is a risk factor for poor surgical outcome after laminoplasty. Based on these results, we recommend that ASF should be the first choice of treatment for patients with significant ossification of the posterior longitudinal ligament and a hypermobile cervical spine. When laminoplasty is used for such cases, the addition of posterior instrumented fusion would be desirable for stabilizing the spine and decreasing damage to the spinal cord.

Ossification of the posterior longitudinal ligament of the spine (OPLL) is a common form of human myelopathy caused by a compression of the spinal cord by ectopic ossification of spinal ligaments. To elucidate the genetic basis for OPLL, we have been studying the ttw (tiptoe walking; previously designated twy) mouse, a naturally occurring mutant which exhibits ossification of the spinal ligaments very similar to human OPLL (refs 3,4). Using a positional candidate-gene approach, we determined the ttw phenotype is caused by a nonsense mutation (glycine 568 to stop) in the Npps gene which encodes nucleotide pyrophosphatase. This enzyme regulates soft-tissue calcification and bone mineralization by producing inorganic pyrophosphate, a major inhibitor of calcification. The accelerated bone formation characteristic of ttw mice is likely to result from dysfunction of NPPS caused by predicted truncation of the gene product, resulting in the loss of more than one-third of the native protein. Our results may lead to novel insights into the mechanism of ectopic ossification and the aetiology of human OPLL.

Case report of a child with a congenital skeletal anomaly who underwent instrumented surgery at the craniovertebral junction (CVJ).To describe the utility of surgical simulation using three-dimensional full-scale models for preoperative planning.Instrumented fusion of cervical spine with pedicle screws has several advantages compared with conventional sublaminar wiring, such as stronger fixation and reduction of malalignment. However, studies have reported a risk of injury to the vertebral artery (VA) from the insertion of screws. Especially in pediatric patients, the safety of pedicle screw insertion has not been fully established.A 7-year-old girl with a congenital skeletal anomaly presented with gait disturbance and clumsiness of her right hand. Radiographs showed dysplasia of the C1 posterior arch, leading to compression of the spinal cord posteriorly. Data from three-dimensional computed tomography (CT) angiography showed that the right VA was dominant and was shifted medially at the C2 pedicle. A surgical procedure was scheduled to resect the C1 posterior arch and perform an instrumented occiput-C2 fusion with a system of rod and screws. To evaluate the adaptation of the system to the small and deformed anatomic structure of her CVJ, we produced a three-dimensional full-scale model from CT data and performed a simulation of the scheduled surgery.Simulation of the surgery on the model showed acceptable adaptation of the system. However, the right C2 pedicle screw penetrated the medial wall of the VA foramen. In response to these results, we altered the surgical procedure and performed occiput-C3 fixation with a system of contoured loop and wiring. Although the patient had to use a halo-vest for 2 months, no complication occurred during surgery, and she experienced relief of her myelopathy after surgery.The three-dimensional full-scale model was useful for determining the safety of instrumented posterior occipitocervical fusion for a pediatric patient with a skeletal anomaly.

Study Design. A case-control study using radiograph findings and the PCR assay with regard to the susceptibility and the severity of ossification of posterior longitudinal ligament of the spine (OPLL). Objective. To analyze whether polymorphisms of the nucleotide pyrophosphatase (NPPS) gene and the leptin receptor gene predispose to an increased frequency and severity of OPLL. Summary of Background Data. The NPPS gene is responsible for ectopic ossification in the ttw mouse, an animal model for OPLL. The Zucker fatty rat, another animal model for OPLL, has a missense mutation in the leptin receptor gene. Methods. Analysis of 172 OPLL patients and 93 non-OPLL controls was performed. Radiographs of the cervical, thoracic and lumber spine were analyzed to determine whether OPLL was present and to what degree. Genomic DNA was extracted from all participants. Polymorphisms of the NPPS gene and the leptin receptor gene were analyzed using the PCR assay. The association of the polymorphisms with the development and extent of OPLL were statistically evaluated. Results. No significant association was found between the polymorphisms and the existence of OPLL in both the NPPS and the leptin receptor genes. However, the IVS20–11delT variant in the NPPS gene and the A861G variant in the leptin receptor gene were more frequent in patients with OPLL in the thoracic spine compared with patients whose OPLL was restricted to the cervical spine. Conclusion. The present results suggest that the IVS20–11delT variant of the NPPS gene and the A861G variant of the leptin receptor gene are associated with more extensive OPLL, but not with the frequency with which it occurs.

Migration of neurogenic spinal tumours is uncommon. However, such possible mobility should be kept in mind during surgery for neurogenic tumours whenever the lesion is not found at the anticipated level. Conventional static imaging techniques, such as myelography and MRI, have not documented dynamic motion of tumours. A 12-year-old boy was diagnosed with a neurogenic spinal tumour in the thoracolumbar region. To assess the migratory tendency of the tumour, cine MRI was performed to acquire dynamic images under postural change. Cine MRI showed that the tumour migrated up to the lower part of the T12 vertebra from the upper part of the L1 vertebra during a change in spinal posture from cervical flexion to extension. The tumour was completely removed and histological examination revealed the tumour to be an ependymoma. Cine MRI is useful for dynamically and non-invasively assessing the migratory tendency of spinal tumours.