Shuichi Kaneyama

Kobe Rosai Hospital, Edo, Tōkyō, Japan

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Publications (11)21.88 Total impact

  • Shuichi Kaneyama · Taku Sugawara · Masatoshi Sumi ·
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    ABSTRACT: Study Design. Clinical trial for mid-cervical pedicle screw insertion using a novel patient-specific intraoperative screw guiding device.Objective. To evaluate the availability of the Screw Guide Template (SGT) system for insertion of mid-cervical pedicle screws.Summary of Background Data. In spite of many efforts for accurate mid-cervical pedicle screw insertion, there still remain unacceptable rate of screw malpositioning which might cause neurovascular injuries. We developed patient-specific SGT system for safe and accurate intraoperative screw navigation tool and have reported its availability for the screw insertion to C2 vertebra and thoracic spine.Methods. Preoperatively, the bone image on CT was analyzed and the trajectoris of the screws were designed three-dimensionally. Three types of templates were created for each lamina: location template, drill guide template and screw guide template. During the operations, after engaging the templates directly with the laminae, drilling, tapping, and screwing were performed with each template. We placed 80 mid-cervical pedicle screws for 20 patients. The accuracy and safety of the screw insertion by SGT system were evaluated using postoperative CT scan by calculation of screw deviation from the preplanned trajectory and evaluation of screw breach of pedicle wall.Results. All templates fitted the laminae and screw navigation procedures proceeded uneventfully. All screws were inserted accurately with the mean screw deviation from planned trajectory of 0.29 ± 0.31 mm and no neurovascular complication was experienced.Conclusion. We demonstrated our SGT system could support the precise screw insertion in mid-cervical pedicle. SGT prescribes the safe screw trajectory in a 3D manner and the templates fit and lock directly to the target laminae, which prevents screwing error along with the change of spinal alignment during the surgery. These advantages of the SGT system guarantee the high accuracy in screw insertion, which allowed surgeons to insert cervical pedicle screws safely.
    Spine 01/2015; 40(6). DOI:10.1097/BRS.0000000000000772 · 2.30 Impact Factor
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    ABSTRACT: Study design: A retrospective study. Objective: To investigate the relationship among the craniocervical alignment, the oropharyngeal space and the incidence of dysphagia after occipitothoracic fusion (OTF). Summary of Background Data: Craniocervical malalignment after occipitothoracic fusion is one of a trigger of dysphagia. However, there has been no logical explanation for the etiology yet. Methods: A total of 32 patients who underwent OTF (5 male, 27 female) were reviewed. Following four parameters on the lateral cervical radiogram, pharyngeal tilt angle (PTA); the angle between the McGregor's line and the line that links the center of C2 pedicle and the center of vertebral body at the apex of cervical sagittal curvature, diameter of oropharyngeal airway space (dPS), O-C2 angle and C2-C7 angle were measured at follow-up and then the relationship of these parameters and their influence to the incidence of dysphagia were analyzed. Results: Six of 32 cases (18.8%) exhibited postoperative dysphagia. ROC curves showed that PTA and dPS had moderate accuracy for the predictor of the dysphagia after OTF with the area under the curve (AUC) of 0.76 and 0.86 respectively, whereas O-C2 angle had low accuracy with AUC of 0.69 and C2-C7 angle was almost useless for prediction of postoperative dysphagia with AUC of 0.51. A multiple linear regression analysis showed that only PTA was significantly correlated with dPS ([beta]=0.822, P=0.014), whereas the O-C2 angle ([beta]=0.101, P=0.779) and C2-C7 angle ([beta]=0.352, P=0.157) had negligibly small influence on dPS. Conclusions: Our results demonstrated strong relationships between PTA and the value of dPS, and the incidence of dysphagia. Since PTA reflects anterior protrusion of mid-cervical spine, these results indicated that dysphagia after OTF is caused by narrowing of oropharyngeal space due to direct compression from anteirorly protruded mid-cervical spine.
    Journal of Spinal Disorders & Techniques 10/2014; DOI:10.1097/BSD.0000000000000190 · 2.20 Impact Factor
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    ABSTRACT: Object: Accurate insertion of C-2 cervical screws is imperative; however, the procedures for C-2 screw insertion are technically demanding and challenging, especially in cases of C-2 vertebral abnormality. The purpose of this study is to report the effectiveness of the tailor-made screw guide template (SGT) system for placement of C-2 screws, including in cases with abnormalities. Methods: Twenty-three patients who underwent posterior spinal fusion surgery with C-2 cervical screw insertion using the SGT system were included. The preoperative bone image on CT was analyzed using multiplanar imaging software. The trajectory and depth of the screws were designed based on these images, and transparent templates with screw guiding cylinders were created for each lamina. During the operation, after templates were engaged directly to the laminae, drilling, tapping, and screwing were performed through the templates. The authors placed 26 pedicle screws, 12 pars screws, 6 laminar screws, and 4 C1-2 transarticular screws using the SGT system. To assess the accuracy of the screw track under this system, the deviation of the screw axis from the preplanned trajectory was evaluated on postoperative CT and was classified as follows: Class 1 (accurate), a screw axis deviation less than 2 mm from the planned trajectory; Class 2 (inaccurate), 2 mm or more but less than 4 mm; and Class 3 (deviated), 4 mm or more. In addition, to assess the safety of the screw insertion, malpositioning of the screws was also evaluated using the following grading system: Grade 0 (containing), a screw is completely within the wall of the bone structure; Grade 1 (exposure), a screw perforates the wall of the bone structure but more than 50% of the screw diameter remains within the bone; Grade 2 (perforation), a screw perforates the bone structures and more than 50% of the screw diameter is outside the pedicle; and Grade 3 (penetration), a screw perforates completely outside the bone structure. Results: In total, 47 (97.9%) of 48 screws were classified into Class 1 and Grade 0, whereas 1 laminar screw was classified as Class 3 and Grade 2. Mean screw deviations were 0.36 mm in the axial plane (range 0.0-3.8 mm) and 0.30 mm in the sagittal plane (range 0.0-0.8 mm). Conclusions: This study demonstrates that the SGT system provided extremely accurate C-2 cervical screw insertion without configuration of reference points, high-dose radiation from intraoperative 3D navigation, or any registration or probing error evoked by changes in spinal alignment during surgery. A multistep screw placement technique and reliable screw guide cylinders were the key to accurate screw placement using the SGT system.
    Journal of neurosurgery. Spine 05/2014; 21(2). DOI:10.3171/2014.3.SPINE13730 · 2.38 Impact Factor
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    ABSTRACT: Object: Pedicle screw fixation is a standard procedure of spinal instrumentation, but accurate screw placement is essential to avoid injury to the adjacent structures, such as the vessels, nerves, and viscera. The authors recently developed an intraoperative screw guiding method in which patient-specific laminar templates were used, and verified the accuracy of the multistep procedure in the thoracic spine. Methods: Preoperative bone images of the CT scans were analyzed using 3D/multiplanar imaging software and the trajectories of the screws were planned. Plastic templates with screw guiding structures were created for each lamina by using 3D design and printing technology. Three types of templates were made for precise multistep guidance, and all templates were specially designed to fit and lock on the lamina during the procedure. Plastic vertebra models were also generated and preoperative screw insertion simulation was performed. Surgery was performed using this patient-specific screw guide template system, and the placement of screws was postoperatively evaluated using CT scanning. Results: Ten patients with thoracic or cervicothoracic pathological entities were selected to verify this novel procedure. Fifty-eight pedicle screws were placed using the screw guide template system. Preoperatively, each template was found to fit exactly and to lock on the lamina of the vertebra models, and screw insertion simulation was successfully performed. Intraoperatively the templates also fit and locked on the patient lamina, and screw insertion was completed successfully. Postoperative CT scans confirmed that no screws violated the cortex of the pedicles, and the mean deviation of the screws from the planned trajectories was 0.87 ± 0.34 mm at the coronal midpoint section of the pedicles. Conclusions: The multistep, patient-specific screw guide template system is useful for intraoperative pedicle screw navigation in the thoracic spine. This simple and economical method can improve the accuracy of pedicle screw insertion and reduce the operating time and radiation exposure of spinal fixation surgery.
    Journal of neurosurgery. Spine 05/2013; 19(2). DOI:10.3171/2013.4.SPINE121059 · 2.38 Impact Factor
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    ABSTRACT: Because the main pathology of cervical spondylotic myelopathy (CSM) is spinal cord damage due to compression, surgical treatment is usually recommended to improve patient symptoms and prevent exacerbation. However, lack of clarity of prognosis in cases that present with insignificant symptoms, particularly those of mild CSM, lead one to question the veracity of this course of action. The purpose of this study was to elucidate the prognosis of mild CSM without surgical intervention by evaluation of clinical symptoms and MR imaging findings. Sixty cases of mild CSM (42 males and 18 females, average age 57.2 years) presenting with scores of 13 or higher on the Japanese Orthopaedic Association (JOA) scale were treated initially by in-bed Good Samaritan cervical traction without surgery. These patients were enrolled between 1995 and 2003 and followed up periodically until the date of myelopathy deterioration or until the end of March 2009. The deterioration of myelopathy was defined as a decline in JOA score to less than 13 with a decrease of at least 2 points. As a prognostic factor, the authors used their classification of spinal cord shapes at their lateral sides on axial T1-weighted MR imaging. "Ovoid deformity" was classified as a situation in which both sides were round and convex, and "angular-edged deformity" where one or both sides exhibited an acute-angled lateral corner. The duration of follow-up was assessed as the tolerance rate of mild CSM using Kaplan-Meier survival analysis and compared between 2 groups classified by MR imaging findings. Furthermore, differences between groups were analyzed by various applications of the log-rank test. Of the initial 60 cases, follow-up records existed for 55, giving a follow-up rate of 91.7% (38 males and 17 females, average age 56.1 years). The mean JOA score at end point was 14.1, which was not statistically different from the mean of 14.5 at the initial visit. Deterioration in myelopathy was observed in 14 (25.5%) of 55 cases, whereas 41 (74.5%) of 55 cases maintained mild extent myelopathy without deterioration through the follow-up period (mean 94.3 months). The total tolerance rate of mild CSM was 70%. However, there was a significant difference in the tolerance rate between the cases with angular-edged deformity (58%) and cases with ovoid deformity (95%; p = 0.049). The tolerance rate of mild CSM was 70% in this study, which proved that the prognosis of mild CSM without surgical treatment was relatively good. However, the tolerance rate of the cases with angular-edged deformity was 58%. Therefore, surgical treatment should be considered when mild CSM cases show angular-edged deformity on axial MR imaging, even if patients lack significant symptoms.
    Journal of neurosurgery. Spine 01/2012; 16(1):8-14. DOI:10.3171/2011.8.SPINE11395 · 2.38 Impact Factor
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    ABSTRACT: A prospective comparative study about the incidence of postoperative C5 palsy and multivariate analysis of the risk factors of C5 palsy. To clarify the risk factors of occurrence of C5 palsy after laminoplasty (LP) by comparing the 2 surgical procedures of open-door and double-door LP prospectively. The incidence of C5 palsy has been reported to average 4.6%, and there has been no difference of the incidence among surgical procedures. However, there were only indirect retrospective studies. A total of 146 patients who underwent the LP procedure between 2006 and 2007 were studied prospectively. In 2006, the patients were assigned to undergo the open-door LP, and in 2007, they were assigned to undergo the double-door LP. The incidence of postoperative C5 palsy was compared prospectively between these 2 LP procedures, and the risk factors of C5 palsy were detected with multivariate logistic regression analysis. Postoperative C5 palsy occurred in 7 of 73 cases after open-door LP (9.6%) and in 1 of 73 cases after double-door LP (1.4%). The incidence of C5 palsy after open-door LP was statistically higher than the one after double-door LP (P = 0.029), and open-door LP was recognized as a significant risk factor for postoperative C5 paralysis (odds ratio: 69.6, P = 0.043). In addition, ossification of posterior longitudinal ligament (OPLL) was recognized as a significant risk factor for postoperative C5 paralysis (odds ratio: 43.8, P = 0.048). This study showed significant evidence indicating the higher risk of postoperative C5 palsy in open-door LP than double-door LP. Because OPLL as well as open-door LP were recognized as the risk factors of C5 palsy, asymmetric decompression by open-door LP might introduce imbalanced rotational movement of spinal cord and result in C5 palsy. We recommend double-door LP to minimize the postoperative C5 palsy, in particularly, if the patient has OPLL.
    Spine 12/2010; 35(26):E1553-8. DOI:10.1097/BRS.0b013e3181ce873d · 2.30 Impact Factor
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    ABSTRACT: The rodent static compression loading-induced disc degeneration model still has important gaps among the radiographic, magnetic resonance imaging (MRI), and histological schemes and the acute and chronic expression of catabolic genes such as matrix metalloproteinase (MMP)-3. Our objectives were to assess the validity of a rat tail two-disc static compression model and to elucidate a representative catabolic marker, MMP-3 gene alterations, throughout the degenerative process. Static compression at 1.3 MPa for up to 56 days produced progressive disc height loss in radiographs, lower nucleus intensity on T2-weighted MRIs, and histomorphological degeneration. Real-time RT-PCR mRNA quantification showed significant MMP-3 up-regulation in nucleus pulposus cells from 7 days and a significantly progressive increase as the loading duration lengthened, with high correlations to radiological degenerative scores. Immunohistochemistry demonstrated progressively increased positive staining for MMP-3. These results validate this animal model for disc degeneration research. Progressive mRNA and protein-distributional up-regulations indicate the significant role of MMP-3 and its feasibility as a disc degenerative marker. This model should prove useful for investigating the pathomechanism and for evaluating molecular therapies for degenerative disc disease.
    Journal of Orthopaedic Research 08/2010; 28(8):1026-32. DOI:10.1002/jor.21116 · 2.99 Impact Factor
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    ABSTRACT: An abstract is unavailable. This article is available as HTML full text and PDF.
    Current Orthopaedic Practice 03/2009; 20(2):196–199. DOI:10.1097/BCO.0b013e3181926d92
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    ABSTRACT: Case series. To report rare cases of thoracic myelopathy due to ossification of the yellow ligament (OYL) in relatively young baseball pitchers and show clinical evidence of the role of dynamic mechanical stress on the development of OYL. The pathogenesis of OYL is still unclear. The majority of cases of OYL occur in middle-aged men whereas younger people are rarely affected. This has lead to the hypothesis that diffuse mechanical stress and degenerative changes correlate with the development of OYL. However, there have been no clinical reports demonstrating the critical role of mechanical stress in the ossification. Two young highly active baseball pitchers with thoracic myelopathy due to OYL are presented. Both had no previous systemic disorders or family history of treatment for OYL. Magnetic resonance imaging and computed tomography demonstrated compression of the spinal cord by unilateral left sided OYL at the level of the thoracolumbar junction. Both patients were treated with posterior decompression. They recovered full muscle power after operation and resumed pitching training. Patients had no other factors influencing the development of OYL and the lesions were localized at the left side in the thoracolumbar junction, indicating that repeated, localized rotatory mechanical stress caused by the pitching motion probably influenced the development of OYL in these young baseball pitchers.
    Journal of Spinal Disorders & Techniques 03/2008; 21(1):68-71. DOI:10.1097/BSD.0b013e31811dfc2d · 2.20 Impact Factor
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    ABSTRACT: The intervertebral disc has been reported to be an immunologically privileged environment, possibly mediated by Fas ligand (FasL) expression. On the other hand, recent studies have shown the infiltration of host immune cells into the degenerated disc, which may indicate the failure of the immune-privilege feature of the disc with degeneration. However, the relationship between FasL expression and disc degeneration is still unclear. Therefore, the purpose of this study was to clarify the relationship between FasL expression and disc degeneration. Ten human degenerated disc specimens were obtained from spondylolisthesis patients and ten nondegenerated discs from idiopathic scoliosis patients during surgical procedures. Immunohistochemical staining was performed to determine the presence of FasL in cross-sections of those discs. Parts of the disc tissues were used to examine FasL expression quantitatively with Western blot analysis. To examine whether the change in FasL expression was influenced by aging, an animal study comparing the discs from young and old rats were performed using magnetic resonance imaging (MRI) and real-time polymerase chain reaction (PCR) assessment. Nucleus pulposus cells showed strong positive staining for FasL in all specimens examined. Quantitative examination demonstrated a significant decrease in FasL expression in the degenerated group compared with the nondegenerated group (average 67.6%, P<0.05). MRI showed no significant differences in the grade of disc degeneration between young and old rats, and also no significant difference in FasL mRNA in real-time PCR assay. The current results indicate that FasL and its potential mechanism of immunological privilege could influence the protection of the intervertebral disc against degeneration.
    Journal of Orthopaedic Science 03/2008; 13(2):130-5. DOI:10.1007/s00776-007-1204-4 · 0.94 Impact Factor
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    ABSTRACT: We report a case of an avulsion fracture of the ischial tuberosity treated with a new surgical approach early after injury. Although surgical treatment of this fracture is usually avoided because of the difficulty of the procedure and the risk of sciatic nerve complication, we believe our subgluteal approach is simple and safe. We therefore recommend it for treating avulsion fractures of the ischial tuberosity, especially when the fragment is displaced by >2 cm and the sciatic nerve is not involved. If there is clinical evidence of sciatic nerve disturbance, it is likewise an indication for surgery. However, the incision needs to be deepened to approach the nerve, along the lines of the incisions advocated by both Miller and Spinner.
    Journal of Orthopaedic Trauma 05/2006; 20(5):363-5. DOI:10.1097/00005131-200605000-00012 · 1.80 Impact Factor