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Yamagata-shi, Japan

Aizawa T.,Tohoku University | Kokubun S.,NHO Sendai Nishitaga Hospital | Ozawa H.,Tohoku University | Kusakabe T.,Tohoku Rosai Hospital | And 15 more authors.
Tohoku Journal of Experimental Medicine | Year: 2016

Spinal disorders affect mainly older people and cause pain, paralysis and/or deformities of the trunk and/or extremities, which could eventually disturb locomotive functions. For ensuring safe and high-quality treatment of spinal disorders, in 1987, the Tohoku University Spine Society (TUSS) was established by orthopedic departments in Tohoku University School of Medicine and its affiliated hospitals in and around Miyagi Prefecture. All spine surgeries have been enrolled in the TUSS Spine Registry since 1988. Using the data from this registration system between 1988 and 2012, we demonstrate here the longitudinal changes in surgical trends for spinal disorders in Japan that has rushed into the most advanced “aging society” in the world. In total, data on 56,744 surgeries were retrieved. The number of spinal surgeries has annually increased approximately 4-fold. There was a particular increase among patients aged ≥ 70 years and those aged ≥ 80 years, with a 20- to 90-fold increase. Nearly 90% of the spinal operations were performed for degenerative disorders, with their number increasing approximately 5-fold from 705 to 3,448. The most common disease for surgery was lumbar spinal stenosis (LSS) (35.9%), followed by lumbar disc herniation (27.7%) and cervical myelopathy (19.8%). In 2012, approximately half of the patients with LSS and cervical myelopathy were ≥ 70 years of age. In conclusion, the number of spinal operations markedly increased during the 25-year period, particularly among older patients. As Japan has a notably aged population, the present study could provide a near-future model for countries with aging population. © 2016 Tohoku University Medical Press. Source


Ngo L.M.,Tohoku University | Aizawa T.,Tohoku University | Hoshikawa T.,Tohoku Central Hospital | Tanaka Y.,Tohoku Central Hospital | And 3 more authors.
European Spine Journal | Year: 2012

Purpose The combination of a facet fracture and a contralateral facet dislocation at the same intervertebral level of the cervical spine (a fracture and contralateral dislocation of the twin facet joints) has not been described in detail. The aims of this study are to report a series of 11 patients with this injury, to clarify the clinical features and to discuss its pathomechanism. Methods Among 251 patients with lower cervical spine fractures and/or dislocations surgically treated, 11 (9 males and 2 females, averaged age, 52 years) had this kind of injury. Medical charts and medical images were reviewed retrospectively. Results Injury levels were C4-5, C5-6 and C6-7 in 1, 4 and 6 patients, respectively. A fracture was found at the superior facet in 6, and at the inferior facet in 5. The anterior displacement of the vertebral body ranged from 7 to 19 mm. The unilateral horizontal facet appearance on an anteroposterior radiograph and the triple image on a CT composed of a separated fracture fragment, the base of the fractured facet, and the neighboring non-fractured facet were characteristic. All patients had neurological deficits from Frankel A to D, and were surgically treated by posterior fusion using wire or cable, or combined anterior and posterior spinal fusion. Conclusions The fracture and contralateral dislocation of the twin facet joints can cause severe neurological deficits because of its gross anterior displacement. Its plausible pathomechanism is extension force exerted to the cervical spine when it is maximally bent laterally. © 2011 Springer-Verlag. Source


Ohno-Matsui K.,Tokyo Medical and Dental University | Kawasaki R.,Yamagata University | Jonas J.B.,University of Heidelberg | Cheung C.M.G.,National University of Singapore | And 15 more authors.
American Journal of Ophthalmology | Year: 2015

Purpose To develop a classification and grading system for myopic maculopathy. Design Development and evaluation of a classification system for myopic maculopathy based on observational case series. Methods A comprehensive set of myopic macular lesions was defined via literature review and through consensus meetings among retinal specialists and clinician scientists. A classification of myopic maculopathy was formulated based on fundus photographs and a modified Delphi process and consensus. Inter- and intraobserver reproducibility, assessed as agreement (%) and weighted kappa values, were evaluated. One hundred retinal photographs with myopia and myopic macular lesions were selected from case series at the High Myopia Clinic of the Tokyo Medical and Dental University, Tokyo, Japan. Results We defined 5 categories of myopic maculopathy including "no myopic retinal degenerative lesion" (Category 0), "tessellated fundus" (Category 1), "diffuse chorioretinal atrophy" (Category 2), "patchy chorioretinal atrophy" (Category 3), and "macular atrophy" (Category 4). Three additional features to supplement these categories were defined as "plus" lesions, namely, lacquer cracks, myopic choroidal neovascularization, and Fuchs spot. Posterior staphyloma was considered as a further, important sign of myopic retinopathy. The intraobserver agreement was ≥85% and the corresponding weighted kappa statistic was ≥0.6 between observations. After a brief training session, interobserver kappa statistics reached the predefined satisfactory level (≥0.4), considered as above moderate agreement. Conclusions We propose a classification system for myopic maculopathy that was found to be reproducible. Applying a uniform classification in different studies will facilitate communication and comparison of findings from clinical trials and epidemiologic studies. © 2015 by Elsevier Inc. All rights reserved. Source


Aizawa T.,Tohoku University | Ozawa H.,Tohoku University | Kusakabe T.,Tohoku Rosai Hospital | Tanaka Y.,Tohoku Central Hospital | And 9 more authors.
Paleontological Journal | Year: 2014

Purpose: Fenestration is the gold standard surgery for lumbar spinal canal stenosis in Japan. Several previous studies have analyzed the reoperation rates in large numbers of patients undergoing several surgical procedures such as laminectomy with or without instrumented spinal fusion; however, there have been few studies focusing solely on fenestration. The purpose of this study was to calculate the reoperation rates after fenestration using the survival function method.Methods: Form 1988–2007, 6,998 surgeries for lumbar spinal canal stenosis occurred in Miyagi prefecture, Japan, and these patients were enrolled by the spinal surgery registration system of the Department of Orthopaedic Surgery, Tohoku University. Among these, 5,835 surgeries involved fenestration as a primary surgery and for those who underwent ≥2 lumbar surgeries we analyzed the reoperation rates using the Kaplan–Meier method.Results: Among the 5,835 patients undergoing primary fenestration, 215 patients underwent 221 revisions; 112 included the same spinal levels and 103 were revised only at other levels as primary fenestration. The overall reoperation rates were 0.8 % at 1 year, 2.9 % at 5 years, 5.2 % at 10 years, 7.5 % at 15 years and 8.6 % at >17.7 years. Reoperation rates for those at the same spinal levels were 0.6 % at 1 year, 1.7 % at 5 years, 2.7 % at 10 years, 3.8 % at 15 years, and 4.1 % at >17.0 years.Conclusions: Fenestration can be performed at low cost using standard spinal surgery equipments. The reoperation rates of this procedure were lower than previously reported for several other surgical procedures. © 2014, Springer-Verlag Berlin Heidelberg. Source


Kokubun S.,Tohoku University | Ozawa H.,Tohoku University | Aizawa T.,Tohoku University | Ly N.M.,Tohoku University | Tanaka Y.,Tohoku Central Hospital
Journal of Neurosurgery: Spine | Year: 2011

Object. Tethered cord syndrome (TCS) is a disorder involving an abnormal stretching of the tethered spinal cord caused by several pathological conditions and presents with a variety of neurological symptoms. Untethering (tethered cord release) is the gold standard treatment for TCS. However, untethering carries risks of spinal cord injury and postoperative retethering. To avoid these potential risks, the authors applied spine-shortening osteotomy to adult patients with TCS, and report on the surgical procedure and treatment outcomes. Methods. Eight patients with TCS caused by a lipomyelomeningocele were surgically treated by the authors' original procedure of spine-shortening osteotomy. Six patients were male and 2 were females; average age at the time of surgery was 31 years old. Spine-shortening osteotomy was performed at the level of L-1 in all but 2 patients, in whom it was performed at T-12, with spinal fusion between T-12 and L-2 or T-11 and L-1 using a pedicle screw-rod system. The average follow-up period was 6.2 years and the patients' pre- and postoperative conditions were evaluated clinically and radiologically. Results. Preoperatively, all patients displayed severe neurological deficits such as motor disturbance, muscle atrophy, and bladder dysfunction. Several months before surgery, all showed progressive symptoms. Those symptoms showed initial improvement in 6 patients and stabilized in 2 postoperatively, but the improved symptoms worsened again in 4 of the 6 patients. The osteotomized vertebrae were shortened by 21 mm on average, and all spines showed complete bone union without loss of correction. At the final follow-up evaluations, 6 patients showed stabilization as per the modified Japanese Orthopaedic Association score for thoracic myelopathy. Conclusions. Spine-shortening osteotomy successfully helps reduce the spinal cord tension without causing direct neural damage. At minimum, it stabilized the patients' symptoms and/or helped delay neurological deterioration for a period of time. Spine-shortening osteotomy might be a feasible mode of treatment for adult TCS caused by a spinal lipoma. Source

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