A Biomechanical, Radiologic, and Clinical Comparison of Outcome After Multilevel Cervical Laminectomy or Laminoplasty in the Rabbit FIELDS Michael J. 1 HOSHIJIMA Kazuo 2 FENG Alexander H. P. 3 RICHARDSON William J. 4 MYERS Barry S. 5 Spine Vol.25, No.22 (20001115) pp. 2925-2931 2000
Clinical outcome scales for use in a rabbit model of cervical myelopathy MJ Fields, K Hoshijima, WJ Richardson, BS Myers J Spinal Disord 13 (2):124-30 2000
Evaluation of the spinal balance after correction of the scoliotic deformity by CD instrumentation SAWAMOTO TAKESHI YAMAMOTO HIROSHI HOSHIJIMA KAZUO INOUE HIROFUMI Spinal Deformity VOL.12;NO.1;PAGE.121-124(1997) 1997 Abstract;We have reviewed thirty-two cases of idiopathic scoliosis who had underwent posterior correction surgery by CD instrumentation. Mean age was fifteen years and six months and the mean following period was two years and five months postoperatively. Cobb angle ranged from 40 to 86 degrees (mean 55.5 degrees) preoperatively and from 15 to 53 degrees (mean 30.4 degrees) postoperatively. Spinal balance was determined by the deviation of T1 from the center of the sacrum. Mean deviation of T1 in the lateral direction was 4.2 mm to the right preoperatively and 5.0 mm to the left postoperatively. Change of the position of T1 was statistically significant (p<0.01, T test). Mean preoperative deviation of T1 was 6.7 mm to the left in King type 2 curves (11 cases) and 9.2 mm to the right in King type 3 curves (18 cases). Postoperative deviation of T1 were 12.4 mm to the left in King type 2 and 0.2 mm to the left in King type 3. In King type 2 curves, T1 was deviated to the left both pre and postoperatively and the difference was statistically significant (p<0.01, T test). In King type 2 curves, six cases showed poor lower curve correction and the rest of five cases showed good results. T1 of the poor lower curve correction group tend to deviate to the left more than rest of the cases (p=0.06). In King type 2 curves, especially whose T1 is deviated to the left, we should pay much attention to their spinal balance. (author abst.)
Mechanical strength and bone bonding of a titanium fiber mesh block for intervertebral fusion KITAOKA KENICHI YAMAMOTO HIROSHI ,TANI TOSHIKAZU HOSHIJIMA KAZUO NAKAUCHI MUTSURO Journal of orthopaedic science Vol.2, No.2 (19970301) pp. 106-113 1997
経椎弓根的生体活性セメント充填モデルの有限要素解析 大谷昌弘*1, 星島一夫*1, 池内昌彦*1, 山本博司*1, 亀山寛司*2 日本臨床バイオメカニクス学会誌 18 : 159-162, 1997 Abstract;For the treatment of intra-vertebral lesion, we perform a new augmentative method using transpedicular implantation of bioactive cement(BC) instead of autogenous bone graft. However, the mechanical strength of implanted vertebral body is still unknown. Therefore, the purpose of this study was to evaluate biomechanically whether trans-pedicular bioactive cement implantation can reinforce the strength of vertebral body by using three dimensional finite element(FE) analysis. A single vertebral FE model was made based on the contour data obtained from CT images of the first lumber vertebra. Three types of BC implant model were made according to the amount of BC implanted into vertebral body. The base of model was completely restricted, and 2000N compressive load was evenly applied to the nodes on the superior endplate. Static linear analysis were performed for the both models. The maximum strain was reduced after BC was implanted, the region of high strain was also reduced and was dispersed around BC. Therefore, it was considered that BC implanted into the cancellous bone would become mechanical support sharing the load applied from centrum to the posterior region of vertebral body. The results suggest that bioactive cement implantation into the anterior region of vertebral body could reinforce the mechanical strength of vertebral body. (author abst.)