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find Keyword "下颈椎" 16 results
  • FINITE ELEMENT STUDY ON ANTERIOR TRANSPEDICULAR SCREW-ARTIFICIAL VERTEBRAL BODY FIXATION IN LOWER CERVICAL SPINE

    Objective To compare the biomechanical properties of the anterior transpedicular screw-artificial vertebral body (AVB) and conventional anterior screw plate system (AP) in lower cervical spine by finite element study. Methods CT images (C1-T1) were obtained from a 38-year-old female volunteer. The models of intact C3-7 (intact group), AP fixation (AP group), and AVB fixation (AVB group) were established and analyzed by Mimics 14.0, Geomagic Studio 2013, and ANSYS 14.0 softwares. The axial force of 74 N and moment couple of 1 N·m were loaded on the upper surface and upper facet joint surfaces of C3. Under conditions of flexion, extension, lateral bending, and rotation, the Von Mises stress distribution regularity and maximum equivalent stree of AP and AVB groups were recorded, and the range of motion (ROM) was also analyzed of 3 groups. Results The intact model of lower cervical spine (C3-7) was established, consisting of 286 382 elements and 414 522 nodes, and it was successfully validated with the previously reported cadaveric experimental data of Panjabi and Kallemeyn. The stress concentrated on the connection between plate and screw in AP group, while it distributed evenly in AVB group. Between AP and AVB groups, there was significant difference in maximum equivalent stress values under conditions of 74 N axial force, flexion, extension, and rotation. AVB group had smaller ROM of fixed segments and larger ROM of adjacent segments than AP group. Compared with intact group, whole ROM of the lower cervical spine decreased about 3°, but ROM of C3, 4 and C6, 7 segments increased nearly 5° in both AP and AVB groups. Conclusion As a new reconstruction method of lower cervical spine, AVB fixation provides better stability and lower risk of failure than AP fixation.

    Release date:2016-08-31 10:53 Export PDF Favorites Scan
  • 椎体沉头螺钉在下颈椎骨折伴脱位中的临床初步应用

    目的 总结颈椎椎体沉头螺钉在下颈椎骨折伴脱位内固定治疗中的临床应用价值。 方法 2007 年1 月- 2010 年5 月,收治16 例下颈椎骨折伴脱位患者。男12 例,女4 例;年龄21 ~ 52 岁,平均36.8 岁。累及间隙分别为C4、5 6 例,C5、6 8 例,C6、7 2 例。脊髓损伤程度按 Frankel 功能分级:B 级4 例,C 级6 例,D 级6 例。受伤至手术时间8 ~ 20 h,平均10.8 h。先行后路复位固定,再行前路减压椎间植骨融合,应用椎体沉头螺钉将自体髂骨块固定于上、下椎体。 结 果 患者无手术相关并发症发生。术后3 d X 线片示均获得完全复位,颈椎恢复正常序列及椎体高度。椎体沉头螺钉与椎体前缘夹角为平均28.3°,与椎体后缘距离为平均2.34 mm。16 例均获随访,随访时间6 ~ 24 个月,平均13.8个月。颈椎椎间高度、生理曲度和稳定性维持良好。植骨均于术后3 ~ 5 个月获骨性融合。脊髓损伤程度根据Frankel分级标准评定均有不同程度恢复,D ~ E 级所占比例为81.3%(13/16),显著高于治疗前的37.5%(6/16)(χ2=6.348,P=0.012)。 结论 在联合颈椎后路内固定的情况下,使用颈椎椎体沉头螺钉可有效重建下颈椎稳定性,手术操作简便。

    Release date:2016-08-31 05:42 Export PDF Favorites Scan
  • EXPERIMENTAL STUDY ON SCREW INSERTION IN LOWER CERVICAL PEDICLE ASSISTED BY MULTI-SPIRAL COMPUTERIZED TOMOGRAPHY THREE DIMENTIONAL RECONSTRUCTION TECHNIQUES

    Objective To assess the cl inical significance of transpedicular screw insertion in lower cervical vertebra assisted by multi-spiral CT (MSCT) three dimentional (3D) image reconstruction techniques. Methods Eight cervical vertebra specimens were examined by MSCT, and the messages were sent to SGI02 Workstation; according to the parameter requirements of lower cervical pedicle fixation, by using post-process of volume rendering (VR) the condition was judged and multi-plannar reformation (MPR) was used to do individual analysis; and the ideal path of screw insertion was obtained andthe related parameters were measured. After preoperative plan being finished, referring to these measured parameters, 3.5 mm screws were inserted into C3-7 pedicles of these 8 specimens. After insertion of screws, MSCT scanning and 3D reconstruction were performed again to evaluate the accuracy of lower cervical pedicle screw inserting. From May 2007 to November 2009, 28 patients who received screw insertion in lower cervical spines were given MSCT scanning and 3D reconstruction to evaluate the illness situation, to confirm shortest fixation volumes, and to collect the parameters of aim pedicle screw insertion. Results The time of insertion for each screw was (392 ± 62) seconds. It was found that one pedicle was clausura (1.25%, 1/80) and five pedicle diameters in coronal view were less than 3 mm (6.25%, 5/80), which all were not fit for screw insertion. A total of 74 screws were placed successfully. One-time success rate of screw insertion was 95.95% (71/74). The total accuracy rate was 91.89% (68/74). Six screws penetrated (8.11%). According to the Richter penetrating classification: grade one was 6.76% (5/74) and grade two was 1.35% (1/74). There were significant differences (P lt; 0.05) in penetrated rate between our study and anatomic landmark local ization (47.37%), Miller methods (25.00%), and there was no significant difference (P gt; 0.05) when compared with Abumi method (6.70%), hopper method (7.10%), pipel ine deoppilation method (5.20%) and navigation technique (11.30%). In cl inical 28 cases, 121 screws were inserted; one pedicle was clausura and one was fissure fracture, which all were unfit for insert screw in preoperative plan, the surgery project was adjusted. After operation, 17 patients (76 screws) were given MSCT scanning again. A total of 67 screws (88.16%) were placed successfully. Nine screws (11.84%) penetrated, grade one was 7.89% (6/76) and grade two was 3.95% (3/76). Conclusion It is accurate to apply MSCT 3D reconstruction techniques to measure the ideal screw canal in preoperative individual ized plan. Strictly following individual quantitative data, the safety and accuracy of the surgery can be improved. And it is feasible and available to use MSCT MPR imaging to evaluate the accuracy of pedicle screw insertion.

    Release date:2016-08-31 05:48 Export PDF Favorites Scan
  • SELECTION OF SURGICAL TREATMENT OF LOWER CERVICAL DISLOCATION

    Objective To discuss the selection of anterior or posterior or a combination of anterior and posterior surgical treatment of lower cervical dislocation. Methods A retrospectively study was performed on 28 patients with lower cervical dislocation who received operative treatment between January 2005 and October 2008. There were 19 males and 9 femaleswith an average age of 38 years (range, 19-57 years), including 21 cases of fresh dislocation and 7 cases of old dislocation. The time from injury to hospitalization was 3 hours to 58 days. According to Allen classification, all cases had flexion injury, including 19 cases of degree I dislocation, 2 cases of degree II, 5 cases of degree III, and 2 cases of degree IV. At admission according to Frankel classification, 7 cases were rated as grade A, 4 as grade B, 9 as grade C, 3 as grade D, and 5 as grade E. All patients received open reduction, internal fixation, and il iac bone graft spinal fusion. Of them, combined anterior and posterior approach operation were given in 4 cases, single anterior operation in 22 cases, and single posterior operation in 2 cases. Results All operations were completed successfully and the spinal cord injury did not deteriorate after operation. Esophageal fistula occurred in 1 case receiving anterior approach operation and was cured after 1 month. Infection of wound occurred in 1 case and was cured after dressing change. The other incisions healed by first intention. One case (Frankel grade A) died of pulmonary infection 6 weeks after operation. Twenty-seven patients were followed up 21-38 months. Two cases suffered from shoulder pain 12 months after operation. X-ray films showed complete reduction, normal height of vertebral space and normal sequence of cervical spine after operation. All cases obtained bone fusion after 3.5-6.0 months of operation (4.2 months on average). Frankel grades were improved in different degrees after operation. Conclusion The operation plan of lower cervical dislocation should be determined by the neurologic status of the patient, and the classification of the injury as a unilateral or bilateral dislocation. Anterior cervical discectomy, fusion, and fixation were available in the lower cervical dislocation.

    Release date:2016-09-01 09:03 Export PDF Favorites Scan
  • 下颈椎骨折合并齿状突骨折的手术治疗

    目的 总结手术治疗下颈椎骨折合并齿状突骨折的临床疗效和方法。 方法 2001 年3 月- 2008年6 月,在颅骨牵引基础上,采用颈前路减压病椎次全切除、自体髂骨植入、前路钛板内固定、齿状突骨折闭合复位空心加压螺钉内固定,治疗6 例下颈椎骨折合并齿状突骨折男性患者。年龄20 ~ 52 岁,平均34 岁。受伤至就诊时间6 h ~ 5 d。损伤节段:C4 1 例,C5 3 例,C6 2 例。下颈椎骨折根据ALLEN 分类,屈曲压缩型4 级2 例,纵向压缩型3 级4 例。齿状突骨折Anderson Ⅱ型2 例,浅Ⅲ型4 例。入院时脊髓损伤采用Frankel 分级:A 级2 例,B 级2 例,C 级2 例。 结果 术后患者切口均Ⅰ期愈合。6 例均获随访,随访时间6 ~ 72 个月,平均44 个月。齿状突骨折3 ~ 6 个月愈合,平均4.3 个月。1 例Frankel A 级患者术后6 个月死于肺感染,1 例Frankel A 级患者术后神经症状无改善,余4 例均有不同程度恢复。 结论 下颈椎骨折合并齿状突骨折临床少见,采用同一切口手术治疗不增加创伤,利于神经功能恢复,便于护理。

    Release date:2016-08-31 05:48 Export PDF Favorites Scan
  • THREE-DIMENSIONAL FINITE ELEMENT INVESTIGATION OF LATERAL MASS SCREW FIXATION AND TRANSARTICULAR SCREW FIXATION IN LOWER CERVICAL SPINE

    Objective To establ ish sophisticated three-dimensional finite element model of the lower cervical spine and reconstruct lower cervical model by different fixation systems after three-column injury, and to research the stress distribution of the internal fixation reconstructed by different techniques. Methods The CT scan deta were obtained from a 27-year-old normal male volunteer. Mimics 10.01, Geomagic Studio10.0, HyperMesh10.0, and Abaqus 6.9.1 softwares were usedto obtain the intact model (C3-7), the model after three-column injury, and the models of reconstructing the lower cervical spine after three-column injury through different fixation systems, namely lateral mass screw fixation (LSF) and transarticular screw fixation (TSF). The skull load of 75 N and torsion preload of 1.0 N•m were simulated on the surface of C3. Under conditions of flexion, extension, lateral bending, and rotation, the Von Mises stress distribution regularity of internal fixation system was evaluated. Results The intact model of C3-7 was successfully establ ished, which consisted of 177 944 elements and 35 668 nodes. The results of the biomechanic study agreed well with the available cadaveric experimental data, suggesting that they were accord with normal human body parameters and could be used in the experimental research. The finite element models of the lower cervical spine reconstruction after three-column injury were establ ished. The stress concentrated on the connection between rod and screw in LSF and on the middle part of screw in TSF. The peak values of Von Mises stress in TSF were higher than those in LSF under all conditions. Conclusion For the reconstruction of lower cervical spine, TSF has higher risk of screw breakage than LSF.

    Release date:2016-09-01 09:04 Export PDF Favorites Scan
  • 前后路联合复位固定术治疗严重下颈椎骨折脱位

    目的 观察颈椎前后路联合手术复位固定治疗严重下颈椎骨折脱位的临床效果。方法 2003年4月~2006年8月,采用前后路联合手术复位减压固定治疗严重下颈椎骨折脱位合并不同程度脊髓损伤者7例。男5例,女2例;年龄27~42岁。致伤原因:车祸伤5例,高处坠落伤2例,受伤部位C4、54例,C5、63例。Allen分类:屈曲压缩型Ⅴ度4例,牵张屈曲型Ⅲ度3例。完全性瘫痪1例;不完全性瘫痪6例,其中上肢肌力1~2级3例,3~4级3例。脊髓损伤按Frankel分级:A级1例,B级4例,D级2例。于伤后1~8 d手术。前路固定采用Orion带锁钢板(颈椎带锁钢板)7例,后路侧块钢板螺钉固定2例,后路钉棒系统固定5例。结果 本组术后伤口均Ⅰ期愈合,获随访4~24个月,平均6个月。X线片检查示损伤节段固定稳定,未见内植物松动、脱落及断裂。植骨于3~4个月内均融合。术后4个月脊髓功能按Frankel分级,术前1例A级,术后无恢复;术前4例B级,术后恢复至C级2例可行走,恢复至B级2例可扶拐行走,2例D级恢复至E级,能正常行走。术后4例行CT及MRI检查,颈椎序列均恢复,椎管矢状径达到正常,脊髓受压解除。结论 颈椎前后路联合手术复位固定严重下颈椎骨折脱位可使损伤节段获得早期稳定,方便术后护理和早期功能锻炼,有利于脊髓功能恢复。

    Release date:2016-09-01 09:23 Export PDF Favorites Scan
  • SURGICAL RECONSTRUCTION OF THE STABILITY OF LOWER CERVICAL SPINE IN CHILDREN

    OBJECTIVE: To investigate surgical reconstruction of stability of lower cervical spine in children suffering trauma, tuberculosis and tumor. METHODS: From January 1998 to September 2001, 8 cases of unstable lower cervical spine were treated by operations, of anterior decompression, massive iliac bone grafting, posterior fixation with spinous process tension band wiring, and fusion with heterogeneous iliac bone grafting. RESULTS: With an average following up of 1 year and 9 months (6 months to 4 years and 3 months), 3 cases recovered excellently, 4 cases recovered well and 1 case died of pulmonary infection. CONCLUSION: The above results indicate that anterior decompression, massive iliac bone grafting, posterior fixation with spinous process tension band wiring and fusion with heterogeneous iliac bone grafting can be used as one of the methods to reconstruct the stability of lower cervical spine in children.

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  • Finite Element Analysis of Biomechanics of Cervical Spine after Dynamic Cervical Implant Surgery

    This study aims to investigate the range of motion (ROM) and the stress variation in the intervertebral disc and the vertebral body on adjacent segments and the influence of force transmission mode after the dynamic cervical implant (DCI) surgery. Two types of surgery, DCI implantation and interbody fusion were used to establish the finite element model of the cervical C5, 6 segment degeneration treatment. The ROM and the adjacent discs and vertebral body stresses of two procedures under flexion, extension, lateral bending and axial rotation working conditions were analyzed. The results showed that ROM of the surgical segment in DCI model was well preserved and could restore to the normal ROM distributions (reduction of the amplitude was less than 25%), and the kinetic characteristics of adjacent segments was less affected. In fusion surgery model, however, ROM of the surgical segment was reduced by 86%-91%, while ROM, disc stress and vertebral stress of adjacent segments were increased significantly, and stress of the C5 vertebral body was increased up to 171.21%. Therefore DCI surgery has relatively small influence on cervical ROM and stress. The study provides a theoretical basis for DCI and fusion surgery in clinic.

    Release date:2016-10-02 04:55 Export PDF Favorites Scan
  • Development and Validation of a Three-Dimensional Finite Element Model of Inferior Cervical Spinal Segments C4-7 for a Healthy Person

    This study aims to develop and validate a three-dimensional finite element model of inferior cervical spinal segments C4-7 of a healthy volunteer, and to provide a computational platform for investigating the biomechanical mechanism of treating cervical vertebra disease with Traditional Chinese Traumotology Manipulation (TCTM). A series of computed tomography (CT) images of C4-7 segments were processed to establish the finite element model using softwares Mimics 17.0, Geromagic12.0, and Abaqus 6.13. A reference point (RP) was created on the endplate of C4 and coupled with all nodes of C4. All loads (±0.5, ±1, ±1.5 and ±2 Nm) were added to the RP for the six simulations (flexion, extension, lateral bending and axial rotation). Then, the range of motion of each segment was calculated and compared with experimental measurements of in vitro studies. On the other hand, 1 Nm moment was loaded on the model to observe the main stress regions of the model in different status. We successfully established a detail model of inferior cervical spinal segments C4-7 of a healthy volunteer with 591 459 elements and 121 446 nodes which contains the structure of the vertebra, intervertebral discs, ligaments and facet joints. The model showed an accordance result after the comparison with the in vitro studies in the six simulations. Moreover, the main stress region occurred on the model could reflect the main stress distribution of normal human cervical spine. The model is accurate and realistic which is consistent with the biomechanical properties of the cervical spine. The model can be used to explore the biomechanical mechanism of treating cervical vertebra disease with TCTM.

    Release date:2016-10-02 04:55 Export PDF Favorites Scan
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