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Sample records for monoaxial pedicle screws

  1. Monoaxial Pedicle Screws Are Superior to Polyaxial Pedicle Screws and the Two Pin External Fixator for Subcutaneous Anterior Pelvic Fixation in a Biomechanical Analysis

    Directory of Open Access Journals (Sweden)

    Rahul Vaidya

    2013-01-01

    Full Text Available Purpose. Comparison of monoaxial and polyaxial screws with the use of subcutaneous anterior pelvic fixation. Methods. Four different groups each having 5 constructs were tested in distraction within the elastic range. Once that was completed, 3 components were tested in torsion within the elastic range, 2 to torsional failure and 3 in distraction until failure. Results. The pedicle screw systems showed higher stiffness (4.008 ± 0.113 Nmm monoaxial, 3.638 ± 0.108 Nmm Click-x; 3.634 ± 0.147 Nmm Pangea than the exfix system (2.882 ± 0.054 Nmm in distraction. In failure testing, monoaxial pedicle screw system was stronger (360 N than exfixes (160 N and polyaxial devices which failed if distracted greater than 4 cm (157 N Click-x or 138 N Pangea. The exfix had higher peak torque and torsional stiffness than all pedicle systems. In torsion, the yield strengths were the same for all constructs. Conclusion. The infix device constructed with polyaxial or monoaxial pedicle screws is stiffer than the 2 pin external fixator in distraction testing. In extreme cases, the use of reinforcement or monoaxial systems which do not fail even at 360 N is a better option. In torsional testing, the 2 pin external fixator is stiffer than the pedicle screw systems.

  2. Design and biomechanical study of a modified pedicle screw

    Institute of Scientific and Technical Information of China (English)

    LIU Tao; ZHENG Wen-jie; LI Chang-qing; LIU Guo-dong; ZHOU Yue

    2010-01-01

    Objective: In pedicle screw fixation,the heads of monoaxial screws need to be directed in the same straight line to accommodate the rod placement by backing out during operation, which decreases the insertional torque and internal fixation strength. While polyaxial screws facilitate the assembly of the connecting rod, but its ball-in-cup locking mechanism reduces the static compressive bending yield strength as compared with monoaxial screws. Our study aimed to assess the mechanical performance of a modified pedicle screw.Methods: In this study, the tail of the screw body of the modified pedicle screw was designed to be a cylindershaped structure that well matched the inner wall of the screw head and the screw head only rotated around the cyclinder. Monoaxial screws, modified screws and polyaxial screws were respectively assembled into 3 groups ofvertebrectomy models simulated by ultra high molecular weight polyethylene (UHMWPE) blocks. This model was developed according to a standard for destructive mechanical testing published by the American Society for Testing Materials (ASTM F1717-04). Each screw design had 6 subgroups, including 3 for static tension, load compression and torsion tests, and the rest for dynamic compression tests. In dynamic tests, the cyclic loads were 25%, 50%, and 75% of the compressive bending ultimate loads respectively.Yield load, yield ultimate load, yield stiffness, torsional stiffness, cycles to failure and modes of failure for the 3 types of screws were recorded. The results of modified screws were compared with those ofmonoaxial and polyaxial screws.Results: In static tests, results of bending stiffness,yield load, yield torque and torsional stiffness indicated no significant differences between the modified and monoaxial screws (P>0.05), but both differed significantly from those ofpolyaxial screws (P<0.05). In dynamic compression tests,both modified and monoaxial screws showed failures that occurred at the insertion point of screw

  3. Biomechanical comparison of cervical transfacet pedicle screws versus pedicle screws

    Institute of Scientific and Technical Information of China (English)

    LIU Guan-yi; XU Rong-ming; MA Wei-hu; SUN Shao-hua; HUANG Lei; YING Jiang-wei; JIANG Wei-yu

    2008-01-01

    Background Transfacet pedicle screws provide another alternative for standard pedicle screw placement for plate fixation in the Iumbar spine. However, few studies looking at transfacet pedicle screw fixation in the cervical spine are available. Therefore, cervical transfacet pedicle screw fixation and standard pedicle screw fixation techniques were biomechanically compared in this study.Methods Ten fresh human cadaveric cervical spines were harvested. On one side, transfacet pedicle screws were placed at the C3-4, C5-6, and C7-T1 levels. On the other side, pedicle screws were placed at the C3, C5, and C7 levels. The screw insertion technique at each level was randomized for right or left. The starting point for the transfacet pedicle screw insertion was located at the midpoint of the inferolateral quadrant of the lateral mass and the direction of the screw was about 50° caudally in the sagittal plane and about 45° toward the midline in the axial plane. Screws were placed from the inferior articular process, across the facet complex and the pedicle into the body of the caudal vertebra. The entry point for the pedicle screw was located at the midpoint of the superolateral quadrant of the lateral mass, and the direction of the screw was about 45° toward the midline in the axial plane and toward the upper third of the vertebral body in the sagittal plane. After screw placement we performed axial pullout testing.Results All the cervical transfacet pedicle screws and the pedicle screws were inserted successfully. The mean pullout strength for the transfacet pedicle screws was 694 N, while for the pedicle screws 670 N (P=-0.013). In all but six instances (10%), the pedicle screw pullout values exceeded the values for the transfacet pedicle screws; this occurred three times at the C3/C4 level, twice at the C5/C6 level and once at the C7/T1 level. The greatest pullout strength difference at a single level was observed at the C5/C6 level, with a mean difference of 38 N (t

  4. The pullout performance of pedicle screws

    CERN Document Server

    Demir, Teyfik

    2015-01-01

    This brief book systematically discusses all subjects that affect the pullout strength of pedicle screws. These screws are used in spinal surgeries to stabilize the spine. The holding strength of the pedicle screw is vital since loosening of the pedicle screws can cause revision surgeries. Once the pedicle screw is pulled out, it is harder to obtain same stabilization for the fused vertebrae. The book reviews the effect of screw designs, application techniques, cement augmentation, coating of the screw and test conditions on the pullout strength. The studies with finite element analysis were also included.

  5. Biomechanical effects of polyaxial pedicle screw fixation on the lumbosacral segments with an anterior interbody cage support

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    Chen Hsiang-Ho

    2007-03-01

    Full Text Available Abstract Background Lumbosacral fusion is a relatively common procedure that is used in the management of an unstable spine. The anterior interbody cage has been involved to enhance the stability of a pedicle screw construct used at the lumbosacral junction. Biomechanical differences between polyaxial and monoaxial pedicle screws linked with various rod contours were investigated to analyze the respective effects on overall construct stiffness, cage strain, rod strain, and contact ratios at the vertebra-cage junction. Methods A synthetic model composed of two ultrahigh molecular weight polyethylene blocks was used with four titanium pedicle screws (two in each block and two rods fixation to build the spinal construct along with an anterior interbody cage support. For each pair of the construct fixed with polyaxial or monoaxial screws, the linked rods were set at four configurations to simulate 0°, 7°, 14°, and 21° lordosis on the sagittal plane, and a compressive load of 300 N was applied. Strain gauges were attached to the posterior surface of the cage and to the central area of the left connecting rod. Also, the contact area between the block and the cage was measured using prescale Fuji super low pressure film for compression, flexion, lateral bending and torsion tests. Results Our main findings in the experiments with an anterior interbody cage support are as follows: 1 large segmental lordosis can decrease the stiffness of monoaxial pedicle screws constructs; 2 polyaxial screws rather than monoaxial screws combined with the cage fixation provide higher compression and flexion stiffness in 21° segmental lordosis; 3 polyaxial screws enhance the contact surface of the cage in 21° segmental lordosis. Conclusion Polyaxial screws system used in conjunction with anterior cage support yields higher contact ratio, compression and flexion stiffness of spinal constructs than monoaxial screws system does in the same model when the spinal segment

  6. Guided pedicle screw insertion: techniques and training.

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    Manbachi, Amir; Cobbold, Richard S C; Ginsberg, Howard J

    2014-01-01

    In spinal fusion surgery, the accuracy with which screws are inserted in the pedicle has a direct effect on the surgical outcome. Accurate placement generally involves considerable judgmental skills that have been developed through a lengthy training process. Because the impact of misaligning one or more pedicle screws can directly affect patient safety, a number of navigational and trajectory verification approaches have been described and evaluated in the literature to provide some degree of guidance to the surgeon. To provide a concise review to justify the need and explore the current state of developing navigational or trajectory verification techniques for ensuring proper pedicle screw insertion along with simulation methods for better educating the surgical trainees. Recent literature review. To justify the need to develop new methods for optimizing pedicle screw paths, we first reviewed some of the recent publications relating to the statistical outcomes for different types of navigation along with the conventional freehand (unassisted) screw insertion. Second, because of the importance of providing improved training in the skill of accurate screw insertion, the training aspects of relevant techniques are considered. The third part is devoted to the description of specific navigational assist methods or trajectory verification techniques and these include computer-assisted navigation, three-dimensional simulations, and also electric impedance and optical and ultrasonic image-guided methods. This article presents an overview of the need and the current status of the guidance methods available for improving the surgical outcomes in spinal fusion procedures. It also describes educational aids that have the potential for reducing the training process. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Lumbar pedicle cortical bone trajectory screw

    Institute of Scientific and Technical Information of China (English)

    Song Tengfei; Wellington K Hsu; Ye Tianwen

    2014-01-01

    Objective The purpose of this study was to demonstrate the lumbar pedicle cortical bone trajectory (CBT) screw fixation technique,a new fixation technique for lumbar surgery.Data sources The data analyzed in this review are mainly from articles reported in PubMed published from 1994 to 2014.Study selection Original articles and critical reviews relevant to CBT technique and lumbar pedicle fixation were selected.Results CBT technique was firstly introduced as a new fixation method for lumbar pedicle surgery in 2009.The concepts,morphometric study,biomechanical characteristics and clinical applications of CBT technique were reviewed.The insertional point of CBT screw is located at the lateral point of the pars interarticularis,and its trajectory follows a caudocephalad path sagittally and a laterally directed path in the transverse plane.CBT technique can be used for posterior fixation during lumbar fusion procedures.This technique is a minimally invasive surgery,which affords better biomechanical stability,fixation strength and surgical safety.Therefore,CBT technique has the greatest benefit in lumbar pedicle surgery for patients with osteoporosis and obesity.Conclusion CBT technique is a better alternative option of lumbar pedicle fixation,especially for patients with osteoporosis and obesity.

  8. Strategy for salvage pedicle screw placement: A technical note.

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    Fujibayashi, Shunsuke; Takemoto, Mitsuru; Neo, Masashi; Matsuda, Shuichi

    2013-01-01

    Salvage surgery for failed lumbar spine fusion with a loosened pedicle screw is challenging. In general, the strategy includes replacement with larger and longer pedicle screws, augmentation with polymethylmethacrylate cement or hydroxyapatite granules, and extension of fused segments. The purpose of this study is to introduce a new technique for pedicle screw replacement after failed lumbar spine fusion. Five salvage operations were performed using a different trajectory (DT) pedicle screw replacement technique based on 3-dimensional radiological information. Position of the alternative pedicle screws was planned carefully on the computer screen of a computed tomography-based navigation system before the operation. To obtain sufficient initial stability, 1 of 2 techniques was chosen, depending on the patient. One technique created a completely new route, which did not interfere with the existing screw hole, and the other involved penetration of the existing screw hole. DT pedicle screws were replaced successfully according to the preoperative plan. In all patients, bony union were achieved at the final follow-up period without any instrument failure. Extension of the fused segments could be avoided by using the DT pedicle screw replacement technique combined with transforaminal lumbar interbody fusion. The DT pedicle screw replacement technique is a treatment option for salvage lumbar spine surgery. The current technique is a treatment option for salvage operations that can both avoid extension of a fused segment and achieve successful bony union.

  9. [Cement augmentation of pedicle screws : Pros and cons].

    Science.gov (United States)

    Schnake, K J; Blattert, T R; Liljenqvist, U

    2016-09-01

    Cement augmentation of pedicle screws biomechanically increases screw purchase in the bone. However, clinical complications may occur. The pros and cons of the technique are discussed from different clinical perspectives.

  10. Biomechanical evaluation of an expansive pedicle screw in calf vertebrae

    Institute of Scientific and Technical Information of China (English)

    雷伟; 吴子祥

    2005-01-01

    Objective: To obtain a comprehensive understanding of the effect of the improvement of fixation strength of a newly designed expansive pedicle screw through biomechanical analyses.Metheds: 100 (200 pedicles) fresh calf lumber vertebrae were used. A total of four instrumentation systems were tested including CDH (CD Horizon), USS (Universal Spine System pedicle screw), Tenor (Sofamor Denek) and expansive pedicle screw (EPS). Pullout and turning-back tests were performed to compare the holding strength of the expansive pedicle screw with conventional screws, i.e. USS, CDH and Tenor. Revision tests were performed to evaluate the mechanical properties of the expansive pedicle screw as a "rescue" revision screw. A fatigue simulation using perpendicular load up to 1 500 000 cycles was carried out.Results: The turning back torque (Tmax) and pull-out force (Fmax) of EPS were significantly greater than those of USS, Tenor and CDH screws (6.5 mm×40 mm). In revision tests, the Fmax of both kinds of EPS (6.5 mm×40 mm; 7.0 mm×40 mm) were greater than that of CDH, USS and Tenor screws significantly (P<0.05). No screws were broken or bent at the end of fatigue tests.Conclusions: EPS can significantly improve the bone purchase and the pull-out strength compared to USS, Tenor and CDH screws with similar dimensions before and after failure simulation. The fatigue characteristic of EPS is similar to that of CDH, USS and Tenor screws.

  11. Posterior spinal fusion using pedicle screws.

    Science.gov (United States)

    Athanasakopoulos, Michael; Mavrogenis, Andreas F; Triantafyllopoulos, George; Koufos, Spiros; Pneumaticos, Spiros G

    2013-07-01

    Few clinical studies have reported polyetheretherketone (PEEK) rod pedicle screw spinal instrumentation systems (CD-Horizon Legacy PEEK rods; Medtronic, Minneapolis, Minnesota). This article describes a clinical series of 52 patients who underwent posterior spinal fusion using the PEEK Rod System between 2007 and 2010. Of the 52 patients, 25 had degenerative disk disease, 10 had lateral recess stenosis, 6 had degenerative spondylolisthesis, 6 had lumbar spine vertebral fracture, 4 had combined lateral recess stenosis and degenerative spondylolisthesis, and 1 had an L5 giant cell tumor. Ten patients had 1-segment fusion, 29 had 2-segment fusion, and 13 had 3-segment fusion. Mean follow-up was 3 years (range, 1.5-4 years); no patient was lost to follow-up. Clinical evaluation was performed using the Oswestry Disability Index and a low back and leg visual analog pain scale. Imaging evaluation of fusion was performed with standard and dynamic radiographs. Complications were recorded. Mean Oswestry Disability Index scores improved from 76% preoperatively (range, 52%-90%) to 48% at 6 weeks postoperatively, and to 34%, 28%, and 30% at 3, 6, and 12 months postoperatively, respectively. Mean low back and leg pain improved from 8 and 9 points preoperatively, respectively, to 6 and 5 points immediately postoperatively, respectively, and to 2 points each thereafter. Imaging union of the arthrodesis was observed in 50 (96%) patients by 1-year follow-up. Two patients sustained screw breakage: 1 had painful loss of sagittal alignment of the lumbar spine and underwent revision spinal surgery with pedicle screws and titanium rods and the other had superficial wound infection and was treated with wound dressing changes and antibiotics for 6 weeks. No adjacent segment degeneration was observed in any patient until the time of this writing. Copyright 2013, SLACK Incorporated.

  12. Clinical pedicle screw accuracy and deviation from planning in robot-guided spine surgery: robot-guided pedicle screw accuracy

    NARCIS (Netherlands)

    Dijk, van Joris D.; Ende, Roy P.J.; Stramigioli, Stefano; Köchling, Matthias; Höss, Norbert

    2015-01-01

    STUDY DESIGN: A retrospective chart review was performed for 112 consecutive minimally invasive spinal surgery patients who underwent pedicular screw fixation in a community hospital setting. OBJECTIVE: To assess the clinical accuracy and deviation in screw positions in robot-assisted pedicle screw

  13. Lumbar pedicle screw placement: Using only AP plane imaging

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    Anil Sethi

    2012-01-01

    Conclusion: Placement of pedicle screws under fluoroscopic guidance using AP plane imaging alone with tactile guidance is safe, fast, and reliable. However, a good understanding of the radiographic landmarks is a prerequisite.

  14. A Novel Pedicle Screw with Mobile Connection: A Pilot Study

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    Yasuaki Tokuhashi

    2014-01-01

    Full Text Available To prevent adjacent disc problems after spinal fusion, a pedicle screw with a mobile junction between the head and threaded shaft was newly developed. The threaded shaft of the screw has 10 degrees mobility in all directions, but its structure is to prevent abnormal translation and tilting. This screw was evaluated as follows: (1 endurance test: 106 times rotational stress was applied; (2 biological reactions: novel screws with a mobile head and conventional screws with a fixed head were inserted into the bilateral pedicles of the L3, L4, and L5 in two mini pigs with combination. Eight months after surgery, vertebral units with the screw rod constructs were collected. After CT scan, the soft and bony tissues around the screws were examined grossly and histologically. As a result, none of the screws broke during the endurance test stressing. The mean amount of abrasion wear was 0.0338 g. In the resected mini pig section, though zygapophyseal joints between fixed-head screws showed bony union, the amount of callus in the zygapophyseal joints connected with mobile-head screws was small, and joint space was confirmed by CT. No metalloses were noted around any of the screws. Novel screws were suggested to be highly durable and histologically safe.

  15. Pediatric lumbar pedicle screw placement using navigation templates: A cadaveric study

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    Xing Wang

    2017-01-01

    Full Text Available Background: Pedicle screw technique is commonly used treatment of adult spinal trauma, tumor, degeneration. The application of pedicle screws is very challenging in children because children have a fast growing spine and spinal pedicle morphology of children and adult has large difference. 3 D reconstruction individual navigation templates improve the success rate of pediatric pedicle screw system. This study is aimed to provide a precise method for lumbar spine pedicle screw placement in children using computer-aided design and rapid prototyping technology. Materials and Methods: Computed tomography (CT scans of cadaver specimens of 4 children were obtained, and the raw data were reconstructed using three-dimensional reconstruction software. Pedicle screws were placed using the conventional method or by using individually designed navigation templates based on the principles of reverse engineering and rapid prototyping technology. Results: We evaluated the accuracy of the pedicle screws placed using the two methods by CT scan. Ten navigation templates were designed for placement of 20 lumbar pedicle screws in the navigation group, and CT scan confirmed that all the screws were placed accurately in the corresponding pedicle. Conversely, of the 20 lumbar pedicle screws placed using the conventional method, 3 screws perforated the pedicle. The findings showed that lumbar pedicle screw placement was successful using navigation templates in children. Conclusions: This technique is simple, easy to master, and allows personalized screw placement, thus providing a new and feasible method for lumbar pedicle screw placement in children.

  16. Positioning of pedicle screws in adolescent idiopathic scoliosis using electromyography

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    Bruno Moreira Gavassi

    2015-06-01

    Full Text Available OBJECTIVE: To analyze the occurrence of poor positioning of pedicle screws inserted with the aid of intraoperative electromyographic stimulation in the treatment of Adolescent Idiopathic Scoliosis (AIS.METHODS: This is a prospective observational study including all patients undergoing surgical treatment for AIS, between March and December 2013 at a single institution. All procedures were monitored by electromyography of the inserted pedicle screws. The position of the screws was evaluated by assessment of postoperative CT and classified according to the specific AIS classification system.RESULTS: Sixteen patients were included in the study, totalizing 281 instrumented pedicles (17.5 per patient. No patient had any neurological deficit or complaint after surgery. In the axial plane, 195 screws were found in ideal position (69.4% while in the sagittal plane, 226 screws were found in ideal position (80.4%. Considering both the axial and the sagittal planes, it was observed that 59.1% (166/281 of the screws did not violate any cortical wall.CONCLUSION: The use of pedicle screws proved to be a safe technique without causing neurological damage in AIS surgeries, even with the occurrence of poor positioning of some implants.

  17. Rapid prototyping drill guide template for lumbar pedicle screw placement

    Institute of Scientific and Technical Information of China (English)

    LU Sheng; XU Yong-qing; ZHANG Yuan-zhi; LI Yan-bing; SHI Ji-hong; CHEN Guo-ping; CHEN Yu-bing

    2009-01-01

    To develop a novel method of spinal pedical stereotaxy by reverse engineering and rapid prototyping techniques, and to validate its accuracy by experimental and clinical studies. Methods: A 3D reconstruction model for the desired lumbar vertebra was generated by using the Mimics 10.11 software, and the optimal screw size and orientation were determined using the reverse engineering software. Afterwards, a drill template was created by reverse engi-neering principle, whose surface was the antitemplate of the vertebral surface. The drill template and its correspond-ing vertebra were manufactured using the rapid prototyping technique. Results: The accuracy of the drill template was con-firmed by drilling screw trajectory into the vertebral biomodel preoperatively. This method also showed its ability to cus-tomize the placement and size of each screw based on the unique morphology of the lumbar vertebra.The drill tem-plate fits the postural surface of the vertebra very well in the cadaver experiment. Postoperative CT scans for controlling the pedicle bore showed that the personalized template had a high precision in cadaver experiment and clinical application. No misplacement occurred by using the per-sonalized template. During surgery, no additional computer assistance was needed.Conclusions: The authors have developed a novel drill template for lumbar pedicle screw placement with good applicability and high accuracy. The potential use of drill templates to place lumbar pedicle screws is promising. Our methodology appears to provide an accurate technique and trajectory for pedicle screw placement in the lumbar spine.

  18. Pedicle screw fixation against burst fracture of thoracolumbar vertebrae

    Institute of Scientific and Technical Information of China (English)

    L(U) Fu-xin; HUANG Yong; ZHANG Qiang; SHI Feng-lei; ZHAO Dong-sheng; HU Qiao

    2007-01-01

    Objective: To analyze the application of vertebral pedicle screw fixation in the treatment of burst fracture of thoracolumbar vertebrae.Methods: A total of 48 cases (31 males and 17 females, aged from 18-72 years, mean: 41.3 years) with thoracolumbar vertebrae burst fracture were treated by pedicle screw system since January 2004. According to the AO classification of thoracolumbar vertebrae fracture,there are 36 cases of Type A, 9 of Type B and 3 of Type C.Results: All patients were followed up for 6-25 months (average 12 months ), no secondary nerve root injury, spinal cord injury, loosening or breakage of pedicle screw were observed. The nerve function of 29 patients with cauda equina nerve injury was restored to different degrees. The vertebral body height returned to normal level and posterior process angle was rectified after operation.Conclusions: The vertebral pedicle screw internal fixation was technologically applicable, which can efficiently reposition and stablize the bursting fractured vertabrae,indirectly decompress canalis spinalis, maintain spine stablity, scatter stress of screw system, reduce the risk of loosening or breakage of screw and loss of vertebral height,and prevent the formation of posterior convex after operation.

  19. Pullout strength of misplaced pedicle screws in the thoracic and lumbar vertebrae - A cadaveric study

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    Shyam K Saraf

    2013-01-01

    Full Text Available Background: The objective of this cadaveric study was to analyze the effects of iatrogenic pedicle perforations from screw misplacement on the mean pullout strength of lower thoracic and lumbar pedicle screws. We also investigated the effect of bone mineral density (BMD, diameter of pedicle screws, and the region of spine on the pullout strength of pedicle screws. Materials and Methods: Sixty fresh human cadaveric vertebrae (D10-L2 were harvested. Dual-energy X-ray absorptiometry (DEXA scan of vertebrae was done for BMD. Titanium pedicle screws of different diameters (5.2 and 6.2 mm were inserted in the thoracic and lumbar segments after dividing the specimens into three groups: a standard pedicle screw (no cortical perforation; b screw with medial cortical perforation; and c screw with lateral cortical perforation. Finally, pullout load of pedicle screws was recorded using INSTRON Universal Testing Machine. Results: Compared with standard placement, medially misplaced screws had 9.4% greater mean pullout strength and laterally misplaced screws had 47.3% lesser mean pullout strength. The pullout strength of the 6.2 mm pedicle screws was 33% greater than that of the 5.2 mm pedicle screws. The pullout load of pedicle screws in lumbar vertebra was 13.9% greater than that in the thoracic vertebra ( P = 0.105, but it was not statistically significant. There was no significant difference between pullout loads of vertebra with different BMD ( P = 0.901. Conclusion: The mean pullout strength was less with lateral misplaced pedicle screws while medial misplaced pedicle screw had more pullout strength. The pullout load of 6.2 mm screws was greater than that of 5.2 mm pedicle screws. No significant correlation was found between bone mineral densities and the pullout strength of vertebra. Similarly, the pullout load of screw placed in thoracic and lumbar vertebrae was not significantly different.

  20. Pullout performance comparison of novel expandable pedicle screw with expandable poly-ether-ether-ketone shells and cement-augmented pedicle screws.

    Science.gov (United States)

    Aycan, Mehmet Fatih; Tolunay, Tolga; Demir, Teyfik; Yaman, Mesut Emre; Usta, Yusuf

    2017-02-01

    Aim of this study is to assess the pullout performance of various pedicle screws in different test materials. Polyurethane foams (Grade 10 and Grade 40) produced in laboratory and bovine vertebrae were instrumented with normal, cannulated (cemented), novel expandable and normal (cemented) pedicle screws. Test samples were prepared according to the ASTM F543 standard testing protocols and surgical guidelines. To examine the screw placement and cement distribution, anteriosuperior and oblique radiographs were taken from each sample after insertion process was completed. Pullout tests were performed in an Instron 3369 testing device. Load versus displacement graphs were recorded and the ultimate pullout force was defined as the maximum load (pullout strength) sustained before failure of screw. Student's t-test was performed on each group whether the differences between pullout strength of pedicle screws were significant or not. While normal pedicle screws have the lowest pullout strength in all test materials, normal pedicle screws cemented with polymethylmethacrylate exhibit significantly higher pullout performance than others. For all test materials, there is a significant improvement in pullout strength of normal screws by augmentation. While novel expandable pedicle screws with expandable poly-ether-ether-ketone shells exhibited lower pullout performance than normal screws cemented with polymethylmethacrylate, their pullout performances in all groups were higher than the ones of normal and cannulated pedicle screws. For all test materials, although cannulated pedicle screws exhibit higher pullout strength than normal pedicle screws, there are no significant differences between the two groups. The novel expandable pedicle screws with expandable poly-ether-ether-ketone shells may be used instead of normal and cannulated pedicle screws cemented with polymethylmethacrylate due to their good performances.

  1. Virtual estimates of fastening strength for pedicle screw implantation procedures

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    Linte, Cristian A.; Camp, Jon J.; Augustine, Kurt E.; Huddleston, Paul M.; Robb, Richard A.; Holmes, David R.

    2014-03-01

    Traditional 2D images provide limited use for accurate planning of spine interventions, mainly due to the complex 3D anatomy of the spine and close proximity of nerve bundles and vascular structures that must be avoided during the procedure. Our previously developed clinician-friendly platform for spine surgery planning takes advantage of 3D pre-operative images, to enable oblique reformatting and 3D rendering of individual or multiple vertebrae, interactive templating, and placement of virtual pedicle implants. Here we extend the capabilities of the planning platform and demonstrate how the virtual templating approach not only assists with the selection of the optimal implant size and trajectory, but can also be augmented to provide surrogate estimates of the fastening strength of the implanted pedicle screws based on implant dimension and bone mineral density of the displaced bone substrate. According to the failure theories, each screw withstands a maximum holding power that is directly proportional to the screw diameter (D), the length of the in-bone segm,ent of the screw (L), and the density (i.e., bone mineral density) of the pedicle body. In this application, voxel intensity is used as a surrogate measure of the bone mineral density (BMD) of the pedicle body segment displaced by the screw. We conducted an initial assessment of the developed platform using retrospective pre- and post-operative clinical 3D CT data from four patients who underwent spine surgery, consisting of a total of 26 pedicle screws implanted in the lumbar spine. The Fastening Strength of the planned implants was directly assessed by estimating the intensity - area product across the pedicle volume displaced by the virtually implanted screw. For post-operative assessment, each vertebra was registered to its homologous counterpart in the pre-operative image using an intensity-based rigid registration followed by manual adjustment. Following registration, the Fastening Strength was computed

  2. Pedicle screw placement in the lumbar spine: effect of trajectory and screw design on acute biomechanical purchase.

    Science.gov (United States)

    Wray, Steven; Mimran, Ronnie; Vadapalli, Sasidhar; Shetye, Snehal S; McGilvray, Kirk C; Puttlitz, Christian M

    2015-05-01

    OBJECT Low bone mineral density in patients undergoing lumbar spinal surgery with screws is an especially difficult challenge because poor bone quality can severely compromise the maximum achievable purchase of the screws. A relatively new technique, the cortical bone screw trajectory, utilizes a medialized trajectory in the caudocephalad direction to engage a greater amount of cortical bone within the pars interarticularis and pedicle. The objectives of this cadaveric biomechanical study were to 1) evaluate a cortical screw system and compare its mechanical performance to the traditional pedicle screw system; 2) determine differences in bone quality associated with the cortical screw trajectory versus the normal pedicle screw insertion technique; 3) determine the cortical wall breach rate with both the cortical and traditional screw trajectories; and 4) determine the performance of the traditional screw in the cortical screw trajectory. METHODS Fourteen fresh frozen human lumbar spine sections (L1-5) were used in this study (mean age 57 ± 19 years). The experimental plan involved drilling and tapping screw holes for 2 trajectories under navigation (a traditional pedicle screw and a cortical screw) in both high-and low-quality vertebrae, measuring the bone quality associated with these trajectories, placing screws in the trajectories, and evaluating the competence of the screw purchase via 2 mechanical tests (pullout and toggle). The 3 experimental variants were 1) traditional pedicle screws placed in the traditional pedicle screw trajectory, 2) traditional pedicle screws placed in the cortical screw trajectory, and 3) cortical screws placed in the cortical screw trajectory. RESULTS A statistically significant increase in bone quality was observed for the cortical trajectories with a cortical screw (42%; p parameter comparisons (screw type and trajectory) between high-quality and lowquality samples were significant (p parameters determined from pullout and toggle

  3. Augmentation of Pedicle Screw Fixation with Calcium Phosphate Cement

    Institute of Scientific and Technical Information of China (English)

    YANG Shu-hua; FU De-hao; LI Jin; XU Wei-hua; YANG Cao; YE Zhe-wei; ZUO Xiao-yan

    2004-01-01

    To determine whether a biodegradable calcium phosphate cement(CPC) provides significant augmentation of pedicle screw fixation or not,an in vitro biomechanical study was carried out to evaluate the biomechanical effect of CPC in the restoration and augmentation of pedicle screw fixation.Axial pullout test and cyclic bending resistance test were employed in the experiment,and polymethylmethacrylate (PMMA) was chosen as control.The results demonstrate that the pullout strengths following CPC restoration and augmentation are 74% greater on an average than those of the control group,but less than those of PMMA restoration group and augmentation group respectively (increased by 126% versus control).In cyclic bending resistance test,the CPC augmented screws are found to withstand a greater number of cycles or greater loading with less displacement before loosening,but the augmentation effect of PMMA is greater than that of CPC.

  4. Free-hand thoracic pedicle screws placed by neurosurgery residents: a CT analysis

    OpenAIRE

    Wang, Vincent Y.; Chin, Cynthia T.; Lu, Daniel C.; Smith, Justin S.; Chou, Dean

    2010-01-01

    Free-hand thoracic pedicle screw placement is becoming more prevalent within neurosurgery residency training programs. This technique implements anatomic landmarks and tactile palpation without fluoroscopy or navigation to place thoracic pedicle screws. Because this technique is performed by surgeons in training, we wished to analyze the rate at which these screws were properly placed by residents by retrospectively reviewing the accuracy of resident-placed free-hand thoracic pedicle screws u...

  5. Prediction of Deformity Correction by Pedicle Screw Instrumentation in Thoracolumbar Scoliosis Surgery

    Science.gov (United States)

    Kiriyama, Yoshimori; Yamazaki, Nobutoshi; Nagura, Takeo; Matsumoto, Morio; Chiba, Kazuhiro; Toyama, Yoshiaki

    In segmental pedicle screw instrumentation, the relationship between the combinations of pedicle screw placements and the degree of deformity correction was investigated with a three-dimensional rigid body and spring model. The virtual thoracolumbar scoliosis (Cobb’s angle of 47 deg.) was corrected using six different combinations of pedicle-screw placements. As a result, better correction in the axial rotation was obtained with the pedicle screws placed at or close to the apical vertebra than with the screws placed close to the end vertebrae, while the correction in the frontal plane was better with the screws close to the end vertebrae than with those close to the apical vertebra. Additionally, two screws placed in the convex side above and below the apical vertebra provided better correction than two screws placed in the concave side. Effective deformity corrections of scoliosis were obtained with the proper combinations of pedicle screw placements.

  6. A biomechanical study of two different pedicle screw methods for fixation in osteoporotic and nonosteoporotic vertebrae.

    Science.gov (United States)

    Higashino, Kosaku; Kim, Jin Hwan; Horton, William C; Hutton, William C

    2012-01-01

    In reconstruction of the osteoporotic spine, patients often show poor outcome because of pedicle screw failure. This study used osteoporotic and nonosteoporotic vertebrae to determine the difference in fixation strength between pedicle screws inserted straight forward and pedicle screws inserted in an upward trajectory toward the superior end plate (i.e., end-plate screws). There is some evidence to suggest that end-plate screws have a strength advantage. The particular focus was on osteoporotic vertebrae. Thirty-three vertebrae (T10-L2) were harvested. The bone mineral density (BMD) was measured: 15 vertebrae were greater than 0.8 g/cm(2) and designated as nonosteoporotic (average BMD 1.146 ± 0.186 g/cm(2)) and 18 vertebrae were designated as osteoporotic (average BMD 0.643 ± 0.088 g/cm(2)). On one pedicle the screw was inserted straight forward and on the other pedicle the screw was inserted as an end-plate screw. The torque of insertion was measured (Proto 6106 torque screwdriver). Using an MTS Mini Bionix, two types of mechanical testing were carried out on each pedicle: (a) cephalocaudad toggling was first carried out to simulate some physiological type loading: 500 cycles at 0.3 Hz, at ±50 N; and (b) then each pedicle screw was pulled out at a displacement rate of 12.5 cm/min.There was no difference in pullout force between the pedicle screws inserted straight forward and the pedicle screws inserted as end-plate screws. This result applies whether the vertebrae were osteoporotic or nonosteoporotic. For both the straight-forward screws and the end-plate screws, a statistically significant correlation was observed between torque of insertion and pullout force. The results of this experiment indicate that pedicle screws inserted as end-plate screws do not provide a strength advantage over pedicle screws inserted straight forward, whether the vertebrae are osteoporotic or not.

  7. Comparison of expansive pedicle screw and polymethylmethacrylate-augmented pedicle screw in osteoporotic sheep lumbar vertebrae: biomechanical and interfacial evaluations.

    Directory of Open Access Journals (Sweden)

    Da Liu

    Full Text Available BACKGROUND: It was reported that expansive pedicle screw (EPS and polymethylmethacrylate-augmented pedicle screw (PMMA-PS could be used to increase screw stability in osteoporosis. However, there are no studies comparing the two kinds of screws in vivo. Thus, we aimed to compare biomechanical and interfacial performances of EPS and PMMA-PS in osteoporotic sheep spine. METHODOLOGY/PRINCIPAL FINDINGS: After successful induction of osteoporotic sheep, lumbar vertebrae in each sheep were randomly divided into three groups. The conventional pedicle screw (CPS was inserted directly into vertebrae in CPS group; PMMA was injected prior to insertion of CPS in PMMA-PS group; and the EPS was inserted in EPS group. Sheep were killed and biomechanical tests, micro-CT analysis and histological observation were performed at both 6 and 12 weeks post-operation. At 6-week and 12-week, screw stabilities in EPS and PMMA-PS groups were significantly higher than that in CPS group, but there were no significant differences between EPS and PMMA-PS groups at two study periods. The screw stability in EPS group at 12-week was significantly higher than that at 6-week. The bone trabeculae around the expanding anterior part of EPS were more and denser than that in CPS group at 6-week and 12-week. PMMA was found without any degradation and absorption forming non-biological "screw-PMMA-bone" interface in PMMA-PS group, however, more and more bone trabeculae surrounded anterior part of EPS improving local bone quality and formed biological "screw-bone" interface. CONCLUSIONS/SIGNIFICANCE: EPS can markedly enhance screw stability with a similar effect to the traditional method of screw augmentation with PMMA in initial surgery in osteoporosis. EPS can form better biological interface between screw and bone than PMMA-PS. In addition, EPS have no risk of thermal injury, leakage and compression caused by PMMA. We propose EPS has a great application potential in augmentation of

  8. Subaxial cervical pedicle screw insertion with newly defined entry point and trajectory: accuracy evaluation in cadavers.

    Science.gov (United States)

    Zheng, Xiujun; Chaudhari, Rahul; Wu, Chunhui; Mehbod, Amir A; Transfeldt, Ensor E

    2010-01-01

    Successful placement of cervical pedicle screws requires accurate identification of both entry point and trajectory. However, literature has not provided consistent recommendations regarding the direction of pedicle screw insertion and entry point location. The objective of this study was to define a guideline regarding the optimal entry point and trajectory in placing subaxial cervical pedicle screws and to evaluate the screw accuracy in cadaver cervical spines. The guideline for entry point and trajectory for each vertebra was established based on the recently published morphometric data. Six fresh frozen cervical spines (C3-C7) were used. There were two men and four women. After posterior exposure, the entry point was determined and the cortical bone of the entry point was removed using a 2-mm burr. Pilot holes were created with a cervical probe based on the guideline using fluoroscopy. After tapping, 3.5-mm screws with appropriate length were inserted. After screw insertion, every vertebra was dissected and inspected for pedicle breach. The pedicle width, height, pedicle transverse angulation and actual screw insertion angle were measured. A total of 60 pedicle screws were inserted. No statistical difference in pedicle width and height was found between the left and right sides for each level. The overall accuracy of pedicle screws was 83.3%. The remaining 13.3% screws had noncritical breach, and 3.3% had critical breach. The critical breach was not caused by the guideline. There was no statistical difference between the pedicle transverse angulation and the actual screw trajectory created using the guideline. There was statistical difference in pedicle width between the breach and non-breach screws. In conclusion, high success rate of subaxial cervical pedicle screw placement can be achieved using the recently proposed operative guideline and oblique views of fluoroscopy. However, careful preoperative planning and good surgical skills are still required to

  9. Placement of thoracic transvertebral pedicle screws using 3D image guidance.

    Science.gov (United States)

    Nottmeier, Eric W; Pirris, Stephen M

    2013-05-01

    Transvertebral pedicle screws have successfully been used in the treatment of high-grade L5-S1 spondylolisthesis. An advantage of transvertebral pedicle screws is the purchase of multiple cortical layers across 2 vertebrae, thereby increasing the stability of the construct. At the lumbosacral junction, transvertebral pedicle screws have been shown to be biomechanically superior to pedicle screws placed in the standard fashion. The use of transvertebral pedicle screws at spinal levels other than L5-S1 has not been reported in the literature. The authors describe their technique of transvertebral pedicle screw placement in the thoracic spine using 3D image guidance. Twelve patients undergoing cervicothoracic or thoracolumbar fusion had 41 thoracic transvertebral pedicle screws placed across 26 spinal levels using this technique. Indications for placement of thoracic transvertebral pedicle screws in earlier cases included osteoporosis and pedicle screw salvage. However, in subsequent cases screws were placed in patients undergoing multilevel thoracolumbar fusion without osteoporosis, particularly near the top of the construct. Image guidance in this study was accomplished using the Medtronic StealthStation S7 image guidance system used in conjunction with the O-arm. All patients were slated to undergo postoperative CT scanning at approximately 4-6 months for fusion assessment, which also allowed for grading of the transvertebral pedicle screws. No thoracic transvertebral pedicle screw placed in this study had to be replaced or repositioned after intraoperative review of the cone beam CT scans. Review of the postoperative CT scans revealed all transvertebral screws to be across the superior disc space with the tips in the superior vertebral body. Six pedicle screws were placed using the in-out-in technique in patients with narrow pedicles, leaving 35 screws that underwent breach analysis. No pedicle breach was noted in 34 of 35 screws. A Grade 1 (fusion was observed

  10. A Biomechanical Comparison of Expansive Pedicle Screws for Severe Osteoporosis: The Effects of Screw Design and Cement Augmentation.

    Directory of Open Access Journals (Sweden)

    Ching-Lung Tai

    Full Text Available Expansive pedicle screws significantly improve fixation strength in osteoporotic spines. However, the previous literature does not adequately address the effects of the number of lengthwise slits and the extent of screw expansion on the strength of the bone/screw interface when expansive screws are used with or without cement augmentation. Herein, four designs for expansive pedicle screws with different numbers of lengthwise slits and different screw expansion levels were evaluated. Synthetic bones simulating severe osteoporosis were used to provide a comparative platform for each screw design. The prepared specimens were then tested for axial pullout failure. Regardless of screw design, screws with cement augmentation demonstrated significantly higher pullout strength than pedicle screws without cement augmentation (p 0.05. Taken together, our results show that pedicle screws combined with cement augmentation may greatly increase screw fixation regardless of screws with or without expansion. An increase in both the number of slits and the extent of screw expansion had little impact on the screw-anchoring strength. Cement augmentation is the most influential factor for improving screw pullout strength.

  11. Applied anatomy of the lower cervical pedicle screw insertion

    Institute of Scientific and Technical Information of China (English)

    LI Xing-guo; LIU Zong-liang; HE Yun; ZHAO Yan; ZOU Zhi-rong; ZHANG Peng; LUO Ji-hong; GUO Yong-fu; ZHANG Yang-jie; ZHANG Yu-ran

    2007-01-01

    Objective: To ascertain an accurate approach to inserting the pedicle screw into C3-C7 segments of the cervical vertebra.Methods: Anatomic morphology of lateral mass and pedicle, and their anatomic relationship with the adjacent tissue were observed on C3-C7 segments of 25 adult embalmed cadavers (50 sides).Results: 1 ) The inferior edge of the base of the posterior tubercle of the transverse process and the inferior edge of the pedicle were connected with each other on 25 adult embalmed cadavers (50 sides ). The transverse section which passed through the median point between the superior edge and the inferior edge of the base of the posterior tubercle of the transverse process, and the transverse section which passed through the central axis between the superior edge and the inferior edge of the pedicle, were in the same horizontal plane. The superior and inferior position of placing the pedicle screw was determined by this transverse section, which passed through the median point between the superior and the inferior edge of the base of the posterior tubercle of the transverse process. 2 ) There was a directed internaldownwards "triangular sulcule" between the base of the posterior tubercle of the transverse process and the anterolateral edge of the inferior articular process. The anterior wall of the triangular sulcule was the base of the posterior tubercle of the transverse process, the posterior wall was the anterolateral edge of the inferior articular process, and the bottom of the sulcule was connected with the interior edge of the pedicle. The vertical length between the top of triangle and the planes of inferior edge of the pedicle was (2.78 ± 1.71 ) mm. The inferior edge of the cervical pedicle could be detected using a blunt probe along the "triangular sulcule" between the base of the posterior tubercle of the transverse process and the anterolateral edge of the inferior articular process in surgical operation. 3 )The lateral fovea of the articular

  12. Accuracy and safety of free-hand pedicle screw fixation in age less than 10 years

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    Hyoung Yeon Seo

    2013-01-01

    Full Text Available Background: Pedicle screws are being used commonly in the treatment of various spinal disorders. However, use of pedicle screws in the pediatric population is not routinely recommended because of the risk of complications. The present study was to evaluate the safety of pedicle screws placed in children aged less than 10 years with spinal deformities and to determine the accuracy and complication (early and late of pedicle screw placement using the postoperative computed tomography (CT scans. Materials and Methods: Thirty one patients (11 males and 20 females who underwent 261 pedicle screw fixations (177 in thoracic vertebrae and 84 in lumbar vertebrae for a variety of pediatric spinal deformities at a single institution were included in the study. The average age of patients was 7 years and 10 months. These patients underwent postoperative CT scan which was assessed by two independent observers (spine surgeons not involved in the treatment. Results: Breach rate was 5.4% (14/261 screws for all pedicles. Of the 177 screws placed in the thoracic spine, 13 (7.3% had breached the pedicle, that is 92.7% of the screws were accurately placed within pedicles. Seven screws (4% had breached the medial pedicle wall, 4 screws (2.3% had breached the lateral pedicle wall and 2 screws (1.1% had breached the superior or inferior pedicle wall respectively. Of the 84 screws placed in the lumbar spine, 83 (98.8% screws were accurately placed within the pedicle. Only 1 screw (1.2% was found to be laterally displaced. In addition, the breach rate was found to be 4.2% (11/261 screws with respect to the vertebral bodies. No neurological, vascular or visceral complications were encountered. Conclusions: The accuracy of pedicle screw placement in pedicles and vertebral bodies were 94.6% and 95.8% respectively and there was no complication related to screw placement noted until the last followup. These results suggest that free-hand pedicle screw fixation can be safely

  13. Biomechanical impact of C2 pedicle screw length in an atlantoaxial fusion construct

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    Risheng Xu

    2014-01-01

    Full Text Available Background: Posterior, atlantoaxial (AA fusions of the cervical spine may include either standard (26 mm or short (16 mm C2 pedicle screws. This manuscript focused on an in vitro biomechanical comparison of standard versus short C2 pedicle screws to perform posterior C1-C2 AA fusions. Methods: Twelve human cadaveric spines underwent C1 lateral mass screw and standard C2 pedicle screw (n = 6 versus short C2 pedicle screw (n = 6 fixation. Six additional controls were not instrumented. The peak torque, peak rotational interval, and peak stiffness of the constructs were analyzed to failure levels. Results: The peak torque to construct failure was not statistically significantly different among the control spine (12.2 Nm, short pedicle fixation (15.5 Nm, or the standard pedicle fixation (11.6 Nm, P = 0.79. While the angle at the peak rotation statistically significantly differed between the control specimens (47.7° of relative motion and the overall instrumented specimens (P < 0.001, the 20.7° of relative rotation in the short C2 pedicle screw specimens was not statistically significantly higher than the 13.7° of relative rotation in the standard C2 pedicle screw specimens (P = 0.39. Similarly, although the average stiffness was statistically significantly lower in control group (0.026 Nm/degree versus the overall instrumented specimens (P = 0.001, the standard C2 pedicle screws (2.54 Nm/degree did not differ from the short C2 pedicle screws (1.69 Nm/degree (P = 0.30. Conclusions: Both standard and short C2 pedicle screws allow for equally rigid fixation of C1 lateral mass-C2 AA fusions. Usage of a short C2 pedicle screw may be an acceptable method of stabilization in carefully selected patient populations.

  14. Posterior thoracic segmental pedicle screw instrumentation: Evolving methods of safe and effective placement

    Directory of Open Access Journals (Sweden)

    Zeiller S

    2005-01-01

    Full Text Available The use of pedicle screw instrumentation in the spine has evolved over the last two decades. The initial use of pedicle screws began in the lumbar spine. As surgeons have become more comfortable with the complex anatomy required for accurate screw placement, the use of pedicle instrumentation has evolved to include their use in the thoracolumbar and thoracic spine. The impetus behind their increased use is a result of the many advantages that pedicle screw anchorage offers over traditional hook and rod constructs. Improved deformity correction and overall construct rigidity are two important advantages of pedicle screw instrumentation due its three-column control over the spinal elements. First, pedicle screw instrumentation obviates the need to place instrumentation within the spinal canal with its inherent risk of neurologic injury. Second, the placement of pedicle screws is independent of facet or laminar integrity and thus has been extremely useful in traumatic, neoplastic, and degenerative conditions. The benefits of pedicle screws in the thoracic spine has been tempered by the potential for catastrophic neurological or soft tissue injuries due to the close proximity of these structures. The narrow and inconsistent shape of the thoracic pedicles, especially in spinal deformity, makes their placement technically challenging. As a result, surgeons have employed a number of techniques to ensure the safe and efficacious placement of thoracic pedicle screws. Detailed anatomic landmarks used to determine pedicle location, intraoperative imaging including navigation, and neurophysiological monitoring are some of the techniques currently used by surgeons. The implementation of these techniques and a thorough understanding of the complex three-dimensional anatomy have allowed surgeons to successfully place thoracic and thoracolumbar pedicle screws.

  15. Screw placement of pedicle of vertebral arch-pay great attention to segmental differences of the pedicle

    Institute of Scientific and Technical Information of China (English)

    殷渠东; 郑祖根; 董启榕; 唐平

    2002-01-01

    Objective: To investigate appropriate ways for screw placement of pedicle of vertebral arch in the horizontal plane.Methods: Fifteen preserved thoracolumbar spine specimens (T11-L5) were used and divided into three groups at random. Firstly four anatomic parameters indicating screw positions in the horizontal plane were measured. Secondly the methods of Roy-camille, Magerl, and authors segmental differences were used to place successively the screws of the pedicles with 5 mm, 6 mm, and 7 mm in diameter. Coincidences between the drilling point, drilling direction and pedicle axis, and ruptures of the pedicle as well as the length of the screw in the vertebral body were observed. Results: Four anatomic parameters at various segments showed significant differences (P <0.05). The drilling point by the Roy-camilles method deviated medial to pedicle axis in most segments, and its drilling direction did not coincide well with most E-angles of the pedicles. The drilling point by Magerls method coincided relatively well with pedicle axis in lumbar vertebrae, but there were still some differences between its drilling direction and E-angles of the pedicles. The method of segmental differences coincided the best with the pedicle axis. The lengths of screw in the vertebra were relatively long by both Magerl and segmental difference methods. When 5 mm diametral screw was used by the three methods, the rupture rate was very low. When 6 mm and 7 mm diametral screws were placed, the rupture rate was accordingly increased. Of the three methods, Roy-camilles method showed a relatively high rupture rate, while the method of segmental differences a comparatively low rupture rate. Various degrees of rupture of the pedicle of vertebral arch were found at the juncture of the thoracic and lumbar vertebrae when 6 mm or 7 mm diametral screws was used by any screw placement method. In contrast, the rupture was seldom seen at the lower lumbar vertebrae when 7 mm diametral screws

  16. Comparison between Bilateral C2 Pedicle Screwing and Unilateral C2 Pedicle Screwing, Combined with Contralateral C2 Laminar Screwing, for Atlantoaxial Posterior Fixation

    OpenAIRE

    Miyakoshi, Naohisa; HONGO, MICHIO; Kobayashi, Takashi; Suzuki, Tetsuya; Abe, Eiji; Shimada, Yoichi

    2014-01-01

    Study Design A retrospective study. Purpose To compare clinical and radiological outcomes between bilateral C2 pedicle screwing (C2PS) and unilateral C2PS, combined with contralateral C2 laminar screwing (LS), for posterior atlantoaxial fixation. Overview of Literature Posterior fixation with C1 lateral mass screwing (C1LMS) and C2PS (C1LMS-C2PS method) is an accepted procedure for rigid atlantoaxial stabilization. However, conventional bilateral C2PS is not always allowed in this method due ...

  17. Robot assisted navigated drilling for percutaneous pedicle screw placement: A preliminary animal study

    Directory of Open Access Journals (Sweden)

    Hongwei Wang

    2015-01-01

    Conclusions: The preliminary study supports the view that computer assisted pedicle screw fixation using spinal robot is feasible and the robot can decrease the intraoperative fluoroscopy time during the minimally invasive pedicle screw fixation surgery. As spine robotic surgery is still in its infancy, further research in this field is worthwhile especially the accuracy of spine robot system should be improved.

  18. Complications of pedicle screws in lumbar and lumbosacral fusions in 105 consecutive primary operations

    NARCIS (Netherlands)

    Jutte, PC

    2002-01-01

    Pedicle screw fixation is technically demanding and associated with high complication rates. The aim of this study was to identify and quantify the pedicle screw-related complications in 105 consecutive operations. We retrospectively analysed 105 consecutive primary operations. We found complication

  19. Screw placement of pedicle of vertebral arch—pay great attention to segmental differences of the pedicle

    Institute of Scientific and Technical Information of China (English)

    殷渠东; 郑祖根; 等

    2002-01-01

    Objective:To investigate appropriate ways for screw placement of pedicle of vertebral arch in the horizontal plane.Methods:Fifteen prreserved thoracolunbar spine specimens(T11-L5)were used and divided into three groups at random.Firstly four anatomic parameters indicating screw positions in the horizontal plae were measured.Secondly the methods of Roy-camille,Magerl,and authors'segmental differences were used to place successively the scews of the pedicles with 5mm,6mm,and7mm in diameter.Coincidences between the drilling point,drilling direction and pedicle axis,and ruptures of the pedicle as well as the length of the screw in the vertebral body were observed.Results:Four anatomic parameters at various segments showed significant differences(P<0.05),The drilling point by the Roy-camille's method deviated medial to pedicle axis in most segments,and its drilling direction did not coincide well with most E-angles of the pedicles.The drilling point by Magerl's method coincided relatively well with pedicle axis in lumbar vertebrae,but there were still some differences between its drilling direction and E-angles of the pedicles.The method of segmental differemces coincided the best with the pedicle axis.The lengths of screw in the vertebra were relatively long by blth Magerl and segmental difference methods.When5mm diametral screw was used by the three methods,the rupture rate wsa very low.When 6mmand7mm diametral screws were placed,the rupture rate was accordingly increased.Of the three methods.Roy-camille's method showed a relatively high rupture rate,while the method of segmental differences a comparatively low rupture rate.Various degrees of rupture of the pedicle of vertebral arch were found at the juncture of the thoracic and lunbar vertebrae when6mmor7mm diametral screws was used by any screw placement method.In contrast,the rupture was seldom seen at the lower lumbar vertebrae when 7mm diametral screws were used.Conclusions:The segmental difference methodis

  20. Pedicle Screw-Based Posterior Dynamic Stabilization: Literature Review

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    Dilip K. Sengupta

    2012-01-01

    Full Text Available Posterior dynamic stabilization (PDS indicates motion preservation devices that are aimed for surgical treatment of activity related mechanical low back pain. A large number of such devices have been introduced during the last 2 decades, without biomechanical design rationale, or clinical evidence of efficacy to address back pain. Implant failure is the commonest complication, which has resulted in withdrawal of some of the PDS devices from the market. In this paper the authors presented the current understanding of clinical instability of lumbar motions segment, proposed a classification, and described the clinical experience of the pedicle screw-based posterior dynamic stabilization devices.

  1. Preliminary experimental results of radiofrequency-cement-augmented and cannulated pedicle screws

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    Goost H

    2011-01-01

    Full Text Available The risk of cut-out of a pedicle screw is high in the presence of osteoporotic bone. In cadaver studies it was found that cement augmentation of pedicle screws markedly increases pullout forces. However, the use of conventional low viscosity vertebroplasty or kyphoplasty cement is associated with the risk of cement extravasation. The risk might be reduced by using high viscosity, radiofrequency-activated bone cement. After performing DEXA scans, six fresh-frozen vertebral bodies of different bone densities were obtained from cadavers. Two pedicle screws (WSI Expertise-Inject, Peter Brehm, Germany were placed in the pedicles. About 3 ml of radiofrequency-activated, ultra-high viscosity cement (ER2 Bone Cement, DFine Europe GmbH, Germany was injected through the right pedicle. The left pedicle screw was left uncemented and served as control. Axial pullout tests were performed using a material testing device (Zwick/Roell Zmartpro, Ulm, Germany. The tests revealed that cementaugmented pedicle screws were able to withstand markedly higher pullout forces. Extravasation of cement did not occur. The value of the study is limited by the fact that only six samples were investigated. Further cadaver studies and clinical evaluation will be needed in the future. However, this pilot study showed that combining cannulated pedicle screws with ultra-high viscosity bone cement is a successful approach. Revision due to cut-out and complications secondary to cement extravasation can be reduced by this method.

  2. Accuracy and safety of pedicle screw placement in neuromuscular scoliosis with free-hand technique.

    Science.gov (United States)

    Modi, Hitesh N; Suh, Seung Woo; Fernandez, Harry; Yang, Jae Hyuk; Song, Hae-Ryong

    2008-12-01

    It is a retrospective analytic study of 1,009 transpedicular screws (689 thoracic and 320 lumbosacral), inserted with free-hand technique in neuromuscular scoliosis using postoperative CT scan. The aim of paper was to determine the accuracy and safety of transpedicular screw placement with free-hand technique in neuromuscular scoliosis and to compare the accuracy at different levels in such population. All studies regarding accuracy and safety of pedicle screw in scoliosis represent idiopathic scoliosis using various techniques such as free-hand, navigation, image intensifier, etc., for screw insertion. Anatomies of vertebrae and pedicle are distorted in scoliosis, hence accurate and safe placement of pedicle screw is prerequisite for surgery. Between 2004 and 2006, 37 consecutive patients, average age 20 years (9-44 years), of neuromuscular scoliosis were operated with posterior pedicle screw fixation using free-hand technique. Accuracy of pedicle screws was studied on postoperative CT scan. Placement up to 2 mm medial side and 4 mm lateral side was considered within-safe zone. Of the 1,009 screws, 273 screws were displaced medially, laterally or on the anterior side showing that 73% screws (68% in thoracic and 82.5% in lumbar spine) were accurately placed within pedicle. Considering the safe zone, 93.3% (942/1009, 92.4% in thoracic and 95.3% in lumbar spine) of the screws were within the safe zone. Comparing accuracy according to severity of curve, accuracy was 75% in group 1 (curve 90 degrees) with a safety of 94.8 and 91.2%, respectively (P = 0.35). Comparing the accuracy at different thoracic levels, it showed 67, 64 and 72% accuracy in upper, middle and lower thoracic levels with safety of 96.6, 89.2 and 93.1%, respectively, exhibiting no statistical significant difference (P = 0.17). Pedicle screw placement in neuromuscular scoliosis with free-hand technique is accurate and safe as other conditions.

  3. Spinal pedicle screw planning using deformable atlas registration

    Science.gov (United States)

    Goerres, J.; Uneri, A.; De Silva, T.; Ketcha, M.; Reaungamornrat, S.; Jacobson, M.; Vogt, S.; Kleinszig, G.; Osgood, G.; Wolinsky, J.-P.; Siewerdsen, J. H.

    2017-04-01

    Spinal screw placement is a challenging task due to small bone corridors and high risk of neurological or vascular complications, benefiting from precision guidance/navigation and quality assurance (QA). Implicit to both guidance and QA is the definition of a surgical plan—i.e. the desired trajectories and device selection for target vertebrae—conventionally requiring time-consuming manual annotations by a skilled surgeon. We propose automation of such planning by deriving the pedicle trajectory and device selection from a patient’s preoperative CT or MRI. An atlas of vertebrae surfaces was created to provide the underlying basis for automatic planning—in this work, comprising 40 exemplary vertebrae at three levels of the spine (T7, T8, and L3). The atlas was enriched with ideal trajectory annotations for 60 pedicles in total. To define trajectories for a given patient, sparse deformation fields from the atlas surfaces to the input (CT or MR image) are applied on the annotated trajectories. Mean value coordinates are used to interpolate dense deformation fields. The pose of a straight trajectory is optimized by image-based registration to an accumulated volume of the deformed annotations. For evaluation, input deformation fields were created using coherent point drift (CPD) to perform a leave-one-out analysis over the atlas surfaces. CPD registration demonstrated surface error of 0.89  ±  0.10 mm (median  ±  interquartile range) for T7/T8 and 1.29  ±  0.15 mm for L3. At the pedicle center, registered trajectories deviated from the expert reference by 0.56  ±  0.63 mm (T7/T8) and 1.12  ±  0.67 mm (L3). The predicted maximum screw diameter differed by 0.45  ±  0.62 mm (T7/T8), and 1.26  ±  1.19 mm (L3). The automated planning method avoided screw collisions in all cases and demonstrated close agreement overall with expert reference plans, offering a potentially valuable tool in support

  4. Innovative approach in the development of computer assisted algorithm for spine pedicle screw placement.

    Science.gov (United States)

    Solitro, Giovanni F; Amirouche, Farid

    2016-04-01

    Pedicle screws are typically used for fusion, percutaneous fixation, and means of gripping a spinal segment. The screws act as a rigid and stable anchor points to bridge and connect with a rod as part of a construct. The foundation of the fusion is directly related to the placement of these screws. Malposition of pedicle screws causes intraoperative complications such as pedicle fractures and dural lesions and is a contributing factor to fusion failure. Computer assisted spine surgery (CASS) and patient-specific drill templates were developed to reduce this failure rate, but the trajectory of the screws remains a decision driven by anatomical landmarks often not easily defined. Current data shows the need of a robust and reliable technique that prevents screw misplacement. Furthermore, there is a need to enhance screw insertion guides to overcome the distortion of anatomical landmarks, which is viewed as a limiting factor by current techniques. The objective of this study is to develop a method and mathematical lemmas that are fundamental to the development of computer algorithms for pedicle screw placement. Using the proposed methodology, we show how we can generate automated optimal safe screw insertion trajectories based on the identification of a set of intrinsic parameters. The results, obtained from the validation of the proposed method on two full thoracic segments, are similar to previous morphological studies. The simplicity of the method, being pedicle arch based, is applicable to vertebrae where landmarks are either not well defined, altered or distorted.

  5. Posterior lumbar inter-body fusion (PLIF) using autogenous bone and cage with pedicle screw instrumentation versus PLIF using cage with pedicle screw instrumentation in adult spondylolisthesis

    Institute of Scientific and Technical Information of China (English)

    Dou Yusheng; Hao Dingjun; Wen Shiming

    2005-01-01

    Objective: To compare the clinical outcomes of PLIF using autogenous bone and cage with pedicle screw fixation (group 2) and simple cage fusion with pedicle screw fixation (group 1) in adult spondylolisthesis.Methods: 27 patients with minimum follow-up of 24 months, treated by inter-body fusion with pedicle screw fixation were prospectively studied. Disc space height, degree of slippage and fusion rate had been compared before and after operation between the two groups. Results: After minimum 24 month's follow-up, there was no significant difference between the two groups in terms of the amount of blood loss, duration of hospital stay, back pain,radiating pain, fusion rate, or complication (P>0.05). however, there was a significant difference between the two groups in terms of disc space height and percentage of slippage (P<0.05). Conclusion: PLIF using autogenous bone and cage with pedicle screw fixation more beneifical to improve fusion rate and prevent long-term instabilities than simple cage fusion with pedicle screw fixation in adult spondylolisthesis.

  6. Anatomic considerations for C2 pedicle screw placement: the use of computerized tomography measurements

    OpenAIRE

    Adebukoa Onibokun; Simona Bistazzoni; Marco Sassi; Khoo, Larry T.

    2009-01-01

    OBJECTIVE: more detailed anatomical knowledge of the C2 pedicle is required to optimize and minimize the risk of screw placement. The aim of this study was to evaluate the linear and angular dimensions of the true C2 pedicle using axial CT. METHODS: ninety three patients (47 males, 46 females mean age 48 years) who had cervical spinal CT imaging performed were evaluated for this study. Axial images of the C2 pedicle were selected and the following pedicle parameters were determined: pedicle w...

  7. Accuracy of robot-assisted pedicle screw placement for adolescent idiopathic scoliosis in the pediatric population.

    Science.gov (United States)

    Macke, Jeremy J; Woo, Raymund; Varich, Laura

    2016-06-01

    This is a retrospective review of pedicle screw placement in adolescent idiopathic scoliosis (AIS) patients under 18 years of age who underwent robot-assisted corrective surgery. Our primary objective was to characterize the accuracy of pedicle screw placement with evaluation by computed tomography (CT) after robot-assisted surgery in AIS patients. Screw malposition is the most frequent complication of pedicle screw placement and is more frequent in AIS. Given the potential for serious complications, the need for improved accuracy of screw placement has spurred multiple innovations including robot-assisted guidance devices. No studies to date have evaluated this robot-assisted technique using CT exclusively within the AIS population. Fifty patients were included in the study. All operative procedures were performed at a single institution by a single pediatric orthopedic surgeon. We evaluated the grade of screw breach, the direction of screw breach, and the positioning of the patient for preoperative scan (supine versus prone). Of 662 screws evaluated, 48 screws (7.2 %) demonstrated a breach of greater than 2 mm. With preoperative prone position CT scanning, only 2.4 % of screws were found to have this degree of breach. Medial malposition was found in 3 % of screws, a rate which decreased to 0 % with preoperative prone position scanning. Based on our results, we conclude that the proper use of image-guided robot-assisted surgery can improve the accuracy and safety of thoracic pedicle screw placement in patients with adolescent idiopathic scoliosis. This is the first study to evaluate the accuracy of pedicle screw placement using CT assessment in robot-assisted surgical correction of patients with AIS. In our study, the robot-assisted screw misplacement rate was lower than similarly constructed studies evaluating conventional (non-robot-assisted) procedures. If patients are preoperatively scanned in the prone position, the misplacement rate is further

  8. Robot assisted navigated drilling for percutaneous pedicle screw placement: A preliminary animal study.

    Science.gov (United States)

    Wang, Hongwei; Zhou, Yue; Liu, Jun; Han, Jianda; Xiang, Liangbi

    2015-01-01

    There is much more radiation exposure to the surgeons during minimally invasive pedicle screws placement. In order to ease the surgeon's hand-eye coordination and to reduce the iatrogenic radiation injury to the surgeons, a robot assisted percutaneous pedicle screw placement is useful. This study assesses the feasibility and clinical value of robot assisted navigated drilling for pedicle screw placement and the results thus achieved formed the basis for the development of a new robot for pedicle screw fixation surgery. Preoperative computed tomography (CT) of eight bovine lumbar spines (L1-L5) in axial plane were captured for each vertebra, the entry points and trajectories of the screws were preoperatively planned. On the basis of preoperative CT scans and intraoperative fluoroscopy, we aligned the robot drill to the desired entry point and trajectory, as dictated by the surgeon's preoperative plan. Eight bovine lumbar spines were inserted 80 K-wires using the spine robot system. The time for system registration and pedicle drilling, fluoroscopy times were measured and recorded. Postoperative CT scans were used to assess the position of the K-wires. Assisted by spine robot system, the average time for system registration was (343.4 ± 18.4) s, the average time for procedure of drilling one pedicle screw trajectory was (89.5 ± 6.1) s, times of fluoroscopy for drilling one pedicle screw were (2.9 ± 0.8) times. Overall, 12 (15.0%) of the 80 K-wires violated the pedicle wall. Four screws (5.0%) were medial to the pedicle and 8 (10.5%) were lateral. The number of K-wires wholly within the pedicle were 68 (85%). The preliminary study supports the view that computer assisted pedicle screw fixation using spinal robot is feasible and the robot can decrease the intraoperative fluoroscopy time during the minimally invasive pedicle screw fixation surgery. As spine robotic surgery is still in its infancy, further research in this field is worthwhile especially the accuracy

  9. Intra-osseous ultrasound for pedicle screw positioning in the subaxial cervical spine: an experimental study.

    Science.gov (United States)

    Kantelhardt, Sven Rainer; Bock, Hans Christoph; Siam, Laila; Larsen, Jörg; Burger, Ralf; Schillinger, Wolfgang; Bockermann, Volker; Rohde, Veit; Giese, Alf

    2010-04-01

    In contrast to other regions of the human spine, dorsal fixation with rods and pedicle screws is comparatively rarely performed in the cervical spine. Although this technique provides a higher mechanical strength than the more frequently used lateral mass screws, many surgeons fear the relatively high rate of misplacements. This higher incidence is mainly due to the complex vertebral anatomy in this spinal segment. For correct screw placement, the availability of an immediate and efficient intra-operative imaging tool to ascertain the accuracy of the pedicle screw hole position would be beneficial. We have previously investigated the usefulness of an intraspinal, specifically, intra-osseous ultrasound technique in the lumbar spine. In this study its accuracy as a means of controlling intrapedicular screw hole positioning has been evaluated in the cervical spine. An endovascular ultrasound transducer was used for the intra-luminal scanning of 54 pedicle screw holes in cadaveric human spine specimens. Twenty-three of these had been intentionally misplaced (cortex breached). The resulting image files were assessed by three investigators blinded to both the procedure and the corresponding CT findings. The investigators differentiated correctly between adequately and poorly placed pedicle screw holes in 96% of cases. False negatives and false positives both occurred in no more than 1.8% of cases. Intrapedicular ultrasonography of pedicle screw holes in the cervical spine is a promising technique for the intra-operative assessment of bore hole placement and may increase operative safety and postoperative outcome in posterior cervical fusion surgery.

  10. Treatment of neuromuscular scoliosis with posterior-only pedicle screw fixation

    OpenAIRE

    Fernandez Harry M; Song Hae-Ryong; Suh Seung-Woo; Modi Hitesh N; Yang Jae-Hyuk

    2008-01-01

    Abstract Background To determine whether posterior-only approach using pedicle screws in neuromuscular scoliosis population adequately addresses the correction of scoliosis and maintains the correction over time. Methods Between 2003 and 2006, 26 consecutive patients (7 cerebral palsy, 10 Duchenne muscular dystrophy, 5 spinal muscular atrophy and 4 others) with neuromuscular scoliosis underwent posterior pedicle screw fixation for the deformity. Preoperative, immediate postoperative and final...

  11. Comparative analysis of pedicle screw versus hybrid instrumentation in adolescent idiopathic scoliosis surgery

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    Sohail Rafi

    2016-01-01

    Full Text Available Introduction: Adolescent idiopathic scoliosis is the most common type of scoliosis. A Cobb angle of 50° will progress beyond the age of spinal maturity. Surgery over bracing is advised at a Cobb angle above or equal to 50°. The aim of surgery is to bring the Cobb angle down below 50° to prevent reprogression as well as improve the quality of life. The objective of the study is to analyze the efficacy and significance in lifestyle improvement of pedicle screw-only fixation system versus the more common hybrid instrumentation system used for the surgical treatment of adolescent idiopathic scoliosis. Materials and Methods: A prospective cohort study was conducted involving two groups of patients were included in the study. One group was operated with pedicle screw-only method while the other with hybrid instrumentation system. The pre- and post-operative Cobb's angles were taken across a follow-up of 4 years. An SRS-30 questionnaire was given in a yearly follow-up to assess the lifestyle improvement of the patient. Results: Pedicle screw-only method was significantly more effective in reducing Cobb's angle (P = 0.0487. It was showed less loss of correction (P = 0.009 pedicle screw-only surgery was also better at reducing thoracic curves (P = 0.001. There seemed a better recovery time with pedicle screw surgery (P = 0.003. Conclusion: Pedicle screws are more effective and durable than hybrid systems at when treating adolescent idiopathic scoliosis.

  12. Comparative analysis of pedicle screw versus hybrid instrumentation in adolescent idiopathic scoliosis surgery

    Science.gov (United States)

    Rafi, Sohail; Munshi, Naseem; Abbas, Asad; Shaikh, Rabia Hassan; Hashmi, Imtiaz

    2016-01-01

    Introduction: Adolescent idiopathic scoliosis is the most common type of scoliosis. A Cobb angle of 50° will progress beyond the age of spinal maturity. Surgery over bracing is advised at a Cobb angle above or equal to 50°. The aim of surgery is to bring the Cobb angle down below 50° to prevent reprogression as well as improve the quality of life. The objective of the study is to analyze the efficacy and significance in lifestyle improvement of pedicle screw-only fixation system versus the more common hybrid instrumentation system used for the surgical treatment of adolescent idiopathic scoliosis. Materials and Methods: A prospective cohort study was conducted involving two groups of patients were included in the study. One group was operated with pedicle screw-only method while the other with hybrid instrumentation system. The pre- and post-operative Cobb's angles were taken across a follow-up of 4 years. An SRS-30 questionnaire was given in a yearly follow-up to assess the lifestyle improvement of the patient. Results: Pedicle screw-only method was significantly more effective in reducing Cobb's angle (P = 0.0487). It was showed less loss of correction (P = 0.009) pedicle screw-only surgery was also better at reducing thoracic curves (P = 0.001). There seemed a better recovery time with pedicle screw surgery (P = 0.003). Conclusion: Pedicle screws are more effective and durable than hybrid systems at when treating adolescent idiopathic scoliosis. PMID:27695235

  13. Individualized 3D printing navigation template for pedicle screw fixation in upper cervical spine

    Science.gov (United States)

    Guo, Fei; Dai, Jianhao; Zhang, Junxiang; Ma, Yichuan; Zhu, Guanghui; Shen, Junjie; Niu, Guoqi

    2017-01-01

    Purpose Pedicle screw fixation in the upper cervical spine is a difficult and high-risk procedure. The screw is difficult to place rapidly and accurately, and can lead to serious injury of spinal cord or vertebral artery. The aim of this study was to design an individualized 3D printing navigation template for pedicle screw fixation in the upper cervical spine. Methods Using CT thin slices data, we employed computer software to design the navigation template for pedicle screw fixation in the upper cervical spine (atlas and axis). The upper cervical spine models and navigation templates were produced by 3D printer with equal proportion, two sets for each case. In one set (Test group), pedicle screws fixation were guided by the navigation template; in the second set (Control group), the screws were fixed under fluoroscopy. According to the degree of pedicle cortex perforation and whether the screw needed to be refitted, the fixation effects were divided into 3 types: Type I, screw is fully located within the vertebral pedicle; Type II, degree of pedicle cortex perforation is 1 mm or with the poor internal fixation stability and in need of renovation. Type I and Type II were acceptable placements; Type III placements were unacceptable. Results A total of 19 upper cervical spine and 19 navigation templates were printed, and 37 pedicle screws were fixed in each group. Type I screw-placements in the test group totaled 32; Type II totaled 3; and Type III totaled 2; with an acceptable rate of 94.60%. Type I screw placements in the control group totaled 23; Type II totaled 3; and Type III totaled 11, with an acceptable rate of 70.27%. The acceptability rate in test group was higher than the rate in control group. The operation time and fluoroscopic frequency for each screw were decreased, compared with control group. Conclusion The individualized 3D printing navigation template for pedicle screw fixation is easy and safe, with a high success rate in the upper cervical spine

  14. Easy retrieval of polyaxial tulip-head pedicle screws by “U” rod technique

    Science.gov (United States)

    Isik, Cengiz; Altinel, Levent; Ates, Ali; Ozdemir, Mustafa

    2009-01-01

    The number of fusion surgeries increase each year which also increase the need for implant removal. In some cases, it can be extremely hard to remove a pedicle screw especially when there is a mismatch of the screw and the screwdriver. Also the screwdrivers can be contaminated during the operation, and this will cause a delay till the instruments are re-sterilized. There is a need for the removal of screws without special instruments. We describe a method for removing tulip-head polyaxial pedicle screws without special instruments. The screws are removed using an Allen key, a rod bender and a “U” shaped rod. We successfully removed 76 screws in 11 recent cases without any complications. The “U” rod technique is a simple and useful technique for the removal of tulip-head polyaxial screws. PMID:19618219

  15. Easy retrieval of polyaxial tulip-head pedicle screws by "U" rod technique.

    Science.gov (United States)

    Kose, Kamil Cagri; Isik, Cengiz; Altinel, Levent; Ates, Ali; Ozdemir, Mustafa

    2010-01-01

    The number of fusion surgeries increase each year which also increase the need for implant removal. In some cases, it can be extremely hard to remove a pedicle screw especially when there is a mismatch of the screw and the screwdriver. Also the screwdrivers can be contaminated during the operation, and this will cause a delay till the instruments are re-sterilized. There is a need for the removal of screws without special instruments. We describe a method for removing tulip-head polyaxial pedicle screws without special instruments. The screws are removed using an Allen key, a rod bender and a "U" shaped rod. We successfully removed 76 screws in 11 recent cases without any complications. The "U" rod technique is a simple and useful technique for the removal of tulip-head polyaxial screws.

  16. Biomechanical analysis of pedicle screw density in spinal instrumentation for scoliosis treatment: first results.

    Science.gov (United States)

    Wang, Xiaoyu; Aubin, Carl-Eric; Larson, A Noelle; Labelle, Hubert; Parent, Stefan

    2012-01-01

    Clinical studies reveal remarkable variation in screw patterns, or screw density in spinal instrumentation. Screw density may have a great impact on blood loss, operative time, radiation, risk of screw malposition, and cost. Thus, there is a need to understanding of the biomechanical effects of screw density so as to minimize the number of pedicle screws while ensuring safe and effective instrumentation. The objective of this study was to compare the deformity correction effects and bone-screw loadings of different pedicle screw densities in spinal instrumentation for scoliosis treatment. Spinal instrumentation simulations were performed on three scoliosis patients using 3 screw density patterns (low, preferred, and high screw density) proposed by two experienced surgeons and basic correction techniques: concave rod attachment, rod derotation, apical vertebral derotation, and convex side rod attachment. Simulation results showed that all tested screw densities generated quite similar correction, with differences between the achieved corrections all below 3°. The average bone-screw forces were 244±67N, 214±66 N, and 210±71 N, respectively for low, preferred, and high densities. It remains a complex challenge balancing the benefit of load sharing between more implants with the overconstraints and limited degrees of freedom introduced by the increased number of implants. Studies on additional screw densities and patterns proposed by more surgeons for a variety of cases, and using more diverse correction techniques are necessary to draw stronger conclusions and to recommend the optimal screw density.

  17. Reduction in radiation (fluoroscopy while maintaining safe placement of pedicle screws during lumbar spine fusion

    Directory of Open Access Journals (Sweden)

    Christopher D. Chaput

    2013-01-01

    Full Text Available OBJECTIVE: The purpose of this study is to report the results using PediGuard (electrical conductivity device to reduce radiation exposure while drilling the pilot hole for pedicle screw placement. METHOD: Eighteen patients diagnosed with a degenerative lumbar spine, that required a posterior spinal fusion. Average age of the patients were 55 ± 12 years. Patients received postoperative CT scans of all screws. Scans were reviewed by an independent reviewer grading 'in' 2 mm of breach. In a randomized fashion, the surgeon created pilot holes with either his standard technique or by using the PediGuard. Fluoroscopy was used for each drilling as necessary. Once the pilot hole was created, the surgeon inserted titanium screws into the pedicle pilot holes. A total of 78 screws (39 standard probe and 39 PediGuard were analyzed. RESULTS: 78 screws (39 standard probe and 39 PediGuard were analyzed. No significant difference in breach rate > 2mm by either method (p=1.000, with one screw out in each group. Fluoroscopy shots averaged 5.2 (range, 0 to 15, average decrease of 2.3 (30% per screw in the PediGuard group vs. 7.5 (range, 2 to 17 in the standard group (p< .001. CONCLUSION: This trial to assess pedicle probe location within the pedicle and vertebral body showed the number of fluoroscopy shots were reduced by 30%, compared to a standard probe while maintaining a 97.5% screw placement accuracy.

  18. [Design and experimental study of individual drill templates for atlantoaxial pedicle screw fixation].

    Science.gov (United States)

    Qin, Wei; Quan, Zhengxue; Liu, Yang; Ou, Yunsheng

    2010-10-01

    To explore and evaluate the accuracy and feasibility of individual rapid prototype (RP) drill templates for atlantoaxial pedicle screw implantation. Volumetric CT scanning was performed in 8 adult cadaveric atlas and axis to collect Dicom format datas. Then three-dimensional (3D) images of atlas and axis were reconstructed and the parameters of pedicles of 3D model were measured by using software Mimics 10.01. The 3D model was saved by STL format in Mimics. The scattered point cloud data of 3D model were processed and the 3D coordinate system was located in software Imageware 12.1. The curves and surfaces of 3D model were processed in software Geomagic Studio 10. The optimal trajectory of pedicle screw was designed and a template was constructed which accorded with the anatomical morphology of posterior arch of atlas and lamina of axis by using software Pro/Engineer 4.0. The optimal trajectory of pedicle screw and the template were integrated into a drill template finally. The drill template and physical models of atlas and axis were manufactured by RP (3D print technology). The accuracy of pilot holes of drill templates was assessed by visually inspecting and CT scanning. The individual drill template was used conveniently and each template could closely fit the anatomical morphology of posterior arch of atlas and lamina of axis. Template loosening and shifting were not found in the process of screw implantation. Thirty-two pedicle screws were inserted. Imaging and visual inspection revealed that the majority of trajectories did not penetrate the pedicle cortex, only 1 cortical penetration was judged as noncritical and did not injury the adjacent spinal cord, nerve roots, and vertebral arteries. The accuracy of atlas pedicle screw was grade 0 in 15 screws and grade I in 1 screw, and the accuracy of axis pedicle screw was grade 0 in 16 screws. The potential of individual drill templates to aid implantation of atlantoaxial pedicle screw is promising because of its

  19. Adolescent idiopathic scoliosis: sagital plane and low density pedicle screws

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    Rodrigo Augusto do Amaral

    2014-03-01

    Full Text Available OBJECTIVE: To examine the sagittal curves of patients treated with CD instrumentation using exclusively pedicle screws. METHODS: Image analysis of medical records of 27 patients (26 M and 1 F with a minimum follow-up of 6 months, who underwent surgical treatment in our service between January 2005 and December 2010. The curves were evaluated on coronal and sagittal planes, taking into account the potential correction of the technique. RESULTS: In the coronal plan the following curves were evaluated: proximal thoracic (TPx, main thoracic (TPp, and thoracolumbar; lumbar (TL, L, and the average flexibility was 52%, 52%, and 92% and the capacity of correction was 51%, 72%, and 64%, respectively. In the sagittal plane there was a mean increase in thoracic kyphosis (CT of 41% and an average reduction of lumbar lordosis (LL of 17%. Correlation analysis between variables showed Pearson coefficient of correlation of 0.053 and analysis of dispersion of R2 = <0.001. CONCLUSION: The method has shown satisfactory results with maintenance of kyphosis correction in patients with normal and hyper kyphotic deformities.

  20. Intra-operative computer navigation guided cervical pedicle screw insertion in thirty-three complex cervical spine deformities

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    S Rajasekaran

    2010-01-01

    Full Text Available Background: Cervical pedicle screw fixation is challenging due to the small osseous morphometrics and the close proximity of neurovascular elements. Computer navigation has been reported to improve the accuracy of pedicle screw placement. There are very few studies assessing its efficacy in the presence of deformity. Also cervical pedicle screw insertion in children has not been described before. We evaluated the safety and accuracy of Iso-C 3D-navigated pedicle screws in the deformed cervical spine. Materials and Methods: Thirty-three patients including 15 children formed the study group. One hundred and forty-five cervical pedicle screws were inserted using Iso-C 3D-based computer navigation in patients undergoing cervical spine stabilization for craniovertebral junction anomalies, cervico-thoracic deformities and cervical instabilities due to trauma, post-surgery and degenerative disorders. The accuracy and containment of screw placement was assessed from postoperative computerized tomography scans. Results: One hundred and thirty (89.7% screws were well contained inside the pedicles. Nine (6.1% Type A and six (4.2% Type B pedicle breaches were observed. In 136 levels, the screws were inserted in the classical description of pedicle screw application and in nine deformed vertebra, the screws were inserted in a non-classical fashion, taking purchase of the best bone stock. None of them had a critical breach. No patient had any neurovascular complications. Conclusion: Iso-C navigation improves the safety and accuracy of pedicle screw insertion and is not only successful in achieving secure pedicle fixation but also in identifying the best available bone stock for three-column bone fixation in altered anatomy. The advantages conferred by cervical pedicle screws can be extended to the pediatric population also.

  1. Posterior fixation and fusion with atlas pedicle screw system for upper cervical diseases

    Institute of Scientific and Technical Information of China (English)

    LI Lei; ZHOU Feng-hua; WANG Huan; CUI Shao-qian

    2008-01-01

    Objective: To evaluate the feasibility, safety and efficacy of atlas pedicle screws system fixation and fusion for the treatment of upper cervical diseases. Methods: Twenty-three consecutive patients with up-per cervical disorders requiring stabilization, including 19 cases of atlantoaxial dislocation (4 congenital odontoid disconnections, 6 old odontoid fractures, 4 fresh odontoid fractures of Aderson Ⅱ C, 3 ruptures of the C1 transverse ligament, and 2 fractures ofC1), 2 cases ofC2 tumor (instability after the resection of the tumors), and 2 giant neurilemomas of C2-C3(instability after resection of the tumors), were treated by posterior fixation and fusion with the atlas pedicle screw system, in which the screws were inserted through the posterior arch of Cr The operative time, bleeding volume and complications were reported. All patients were immobilized without external fixation or with rigid cervical collars for 1-3 months. All patients were followed up and evaluated with radiographs and CT. Results: In the 23 patients, 46 C1 pedicle screws, 42 C2 pedicle screws and 6 lower cervical lateral mass screws and 2 lower cervical pedicle screws were placed. The mean operative time and bleeding volume was 2.7 hours and 490 ml respectively. No intraoperative complications were directly related to surgical technique. No neurological, vascular or infective complications were encountered. All patients were followed up for 3-36 months (average 15 months). Firm bony fusion was documented in all patients after 3-6 months. One patient with atlas fracture showed anterior occipitocervical fusion. There was no implant failure. Conclusions: Posterior fixation and fusion of the atlas pedicle screw system is feasible and safe for the treatment of upper cervical diseases, and may be applicable to a larger number of patients.

  2. A new alternative to expandable pedicle screws: Expandable poly-ether-ether-ketone shell.

    Science.gov (United States)

    Demir, Teyfik

    2015-05-01

    Screw pullout is a very common problem in the fixation of sacrum with pedicle screws. The principal cause of this problem is that the cyclic micro motions in the fixation of sacrum are higher than the other regions of the vertebrae that limit the osteo-integration between bone and screw. In addition to that, the bone quality is very poor at sacrum region. This study investigated a possible solution to the pullout problem without the expandable screws' handicaps. Newly designed poly-ether-ether-ketone expandable shell and classical pedicle screws were biomechanically compared. Torsion test, pullout tests, fatigue tests, flexion/extension moment test, axial gripping capacity tests and torsional gripping capacity tests were conducted in accordance with ASTM F543, F1798 and F1717. Standard polyurethane foam and calf vertebrae were used as embedding medium for pullout tests. Classical pedicle screw pullout load on polyurethane foam was 564.8 N compared to the failure load for calf vertebrae's 1264 N. Under the same test conditions, expandable poly-ether-ether-ketone shell system's pullout loads from polyurethane foam and calf vertebrae were 1196.3 and 1890 N, respectively. The pullout values for expandable poly-ether-ether-ketone shell were 33% and 53% higher than classical pedicle screw on polyurethane foam and calf vertebrae, respectively. The expandable poly-ether-ether-ketone shell exhibited endurance on its 90% of yield load. Contrary to poly-ether-ether-ketone shell, classical pedicle screw exhibited endurance on 70% of its yield load. Expandable poly-ether-ether-ketone shell exhibited much higher pullout performance than classical pedicle screw. Fatigue performance of expandable poly-ether-ether-ketone shell is also higher than classical pedicle screw due to damping the micro motion capacity of the poly-ether-ether-ketone. Expandable poly-ether-ether-ketone shell is a safe alternative to all other expandable pedicle screw systems on mechanical perspective

  3. Early clinical results with cortically based pedicle screw trajectory for fusion of the degenerative lumbar spine.

    Science.gov (United States)

    Glennie, R Andrew; Dea, Nicolas; Kwon, Brian K; Street, John T

    2015-06-01

    This study reviews the outcomes and revision rates of degenerative lumbar fusion surgery using cortical trajectory pedicle screws in lieu of traditional pedicle screw instrumentation. Pedicle screw fixation can be a challenge in patients with low bone mineral density. Wide posterior approaches to the lumbar spine exposing lateral to the facet joints and onto transverse processes causes an additional degree of muscular damage and blood loss not present with a simple laminectomy. A cortical bone trajectory pedicle screw has been proposed as an alternative to prevent screw pullout and decrease the morbidity associated with the wide posterior approach to the spine. We present a series of eight consecutive patients using a cortical bone trajectory instead of traditional pedicle screw fixation for degenerative conditions of the lumbar spine. A retrospective review of our institutional registry data identified eight patients who had cortical screws placed with the assistance of O-arm Stealth navigation (Medtronic Sofamor Danek, Memphis, TN, USA) from 2010-2013. We analyzed the need for revision, the maintenance of reduction and the incidence of screw pullout or breakage. Our review demonstrated that two of eight patients were revised at an average of 12months. The reasons for these revisions were pseudarthrosis and caudal adjacent segment failure. All patients who were revised had frank screw loosening. We present early clinical results of a new technique that has been shown to have a better fixation profile in laboratory testing. Our less than favorable early clinical results should be interpreted with caution and highlight important technical issues which should be considered. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Ipsilateral pedicle screw placement with contralateral percutaneous facet screws: Early results with an alternative in lumbar arthrodesis

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    Richard B Rhiew

    2009-03-01

    Full Text Available Richard B Rhiew, Sunil Manjila, Andrew M Lozen, David Hong, Murali Guthikonda, S S RengacharyDepartment of Neurosurgery, Wayne State University, Detroit, MI, USAAbstract: Transforaminal lumbar interbody fusion (TLIF is a widely used method of surgical treatment for a variety of lumbar spinal disorders. Bilateral transpedicular instrumentation is routinely used in conjunction with an interbody graft to provide additional stability. In this technical note, we describe our fusion construct using ipsilateral pedicle screw placement on the side of TLIF and contralateral facet screw placement. We performed this construct at six levels in four patients. Suggested advantages include: low morbidity, small incision and lower cost. Outcomes parameters included radiographic evidence of solid union at four months and improvement in Oswestry Disability Index. A mean improvement from a preoperative score of 73 to 26 after surgery was observed at one-year follow-up. There were no instrument-related complications. In conclusion, this hybrid screw system minimizes contralateral dissection and is an attractive alternative to standard bilateral pedicle screw fixation.Keywords: TLIF, facet screw, pedicle screw, lumbar spine fusion

  5. Sextant percutaneous pedicle screw fixation for correcting single-segment thoracolumbar fractures

    Institute of Scientific and Technical Information of China (English)

    Ming Jiang-hua; Zheng Hui-feng; Zhao Qi; Chen Qing; Wang Gang

    2014-01-01

    BACKGROUND:Though the effects of conservative or traditional open reduction and internal fixation in the treatment of thoracolumbar fractures are reliable and satisfactory for most cases, two methods also have shortages. Minimal-invasive percutaneous pedicle screw system provides a new available method. OBJECTIVE:To investigate the clinical effect of Sextant percutaneous pedicle screw system in the treatment of thoracolumbar fractures. METHODS:A total of 55 patients, who had undergone percutaneous pedicle screw fixation using Sextant system (25 patients) or traditional open internal fixation (30 patients) for single-level vertebral body compression fractures in Department of Orthopedics of Renmin Hospital of Wuhan University from February 2011 to January 2013, were enrol ed in this study. RESULTS AND CONCLUSION:Except two patients in traditional open internal fixation group were lost after discharge, al other patients were fol owed up for 8-14 months. Operative time, intraoperative blood loss, postoperative drainage amount and hospital day were better in percutaneous pedicle screw fixation group than in the traditional open internal fixation group (P0.05). The results show that percutaneous pedicle screw fixation using Sextant system has a satisfactory outcome in the treatment of thoracolumbar fractures. However, obeying indication strictly is very important for clinical application.

  6. Quantitative dual-energy CT for phantomless evaluation of cancellous bone mineral density of the vertebral pedicle: correlation with pedicle screw pull-out strength

    Energy Technology Data Exchange (ETDEWEB)

    Wichmann, Julian L.; Booz, Christian; Bauer, Ralf W.; Kerl, J.M.; Fischer, Sebastian; Lehnert, Thomas; Vogl, Thomas J.; Khan, M.F. [University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt am Main (Germany); Wesarg, Stefan [Fraunhofer IGD, Cognitive Computing and Medical Imaging, Darmstadt (Germany); Kafchitsas, Konstantinos [Spine Center, Asklepios Klinik Lindenlohe, Schwandorf (Germany)

    2015-06-01

    To evaluate quantitative dual-energy computed tomography (DECT) for phantomless analysis of cancellous bone mineral density (BMD) of vertebral pedicles and to assess the correlation with pedicle screw pull-out strength. Twenty-nine thoracic and lumbar vertebrae from cadaver specimens were examined with DECT. Using dedicated post-processing software, a pedicle screw vector was mapped (R1, intrapedicular segment of the pedicle vector; R2, intermediate segment; R3, intracorporal segment; global, all segments) and BMD was calculated. To invasively evaluate pedicle stability, pedicle screws were drilled through both pedicles and left pedicle screw pull-out strength was measured. Resulting values were correlated using the paired t test and Pearson's linear correlation. Average pedicle screw vector BMD (R1, 0.232 g/cm{sup 3}; R2, 0.166 g/cm{sup 3}; R3, 0.173 g/cm{sup 3}; global, 0.236 g/cm{sup 3}) showed significant differences between R1-R2 (P < 0.002) and R1-R3 (P < 0.034) segments while comparison of R2-R3 did not reach significance (P > 0.668). Average screw pull-out strength (639.2 N) showed a far stronger correlation with R1 (r = 0.80; P < 0.0001) than global BMD (r = 0.42; P = 0.025), R2 (r = 0.37; P = 0.048) and R3 (r = -0.33; P = 0.078) segments. Quantitative DECT allows for phantomless BMD assessment of the vertebral pedicle. BMD of the intrapedicular segment shows a significantly stronger correlation with pedicle screw pull-out strength than other segments. (orig.)

  7. Design of three-dimensional visualization based on the posterior lumbar pedicle screw fixation

    Directory of Open Access Journals (Sweden)

    Kai XU

    2011-09-01

    Full Text Available Objective To establish a three-dimensional visualization model of posterior lumbar pedicle screw fixation.Methods A patient with lumbar intervertebral disc hernia and another patient with compression fracture of lumbar vertebra were involved in the present study.Both patients underwent multi-slice spiral CT scan before and after lumbar pedicle screw fixation.The degree of preoperative vertebral compression,vertebral morphology before and after surgery,postoperative pedicle screw position,and decompression effects were observed.The original data of the multi-slice spiral CT were inputted into the computer.The three-dimensional reconstructed images of the lumbar and implanted screws were obtained using the software Amira 4.1 to show the three-dimensional shape of the lumbar vertebrae before and after surgery and the location of the implanted screws.Results The morphology and structure of the lumbar vertebrae before and after surgery and of the implanted screws were reconstructed using the digital navigation platform.The reconstructed 3D images could be displayed in multicolor,transparent,or arbitrary combinations.In the 3D surface reconstruction images,the location and structure of the implanted screws could be clearly observed,and the decompression of the spinal cord or nerve roots and the severity of the fracture and the compression of lumbar vertebrae could be fully evaluated.The reconstructed images before operation revealed the position of the vertebral pedicles and provided reference for intraoperative localization.Conclusions The three-dimensional computerized reconstructions of lumbar pedicle screw fixation may be valuable in basic research,clinical experiment,and surgical planning.The software Amira is one of the bases of three-dimensional reconstruction.

  8. Morphometric analysis of the seventh cervical vertebra for pedicle screw insertion

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    Wensheng Liao

    2015-01-01

    Conclusion: The junction site of the middle 1/3 and outer 1/3 segments of line G are the projection points of C7 pedicles on the lateral mass. The junction site anatomical position was simply and easy to be controlled during surgery, simultaneously avoided uncertainty of other methods. This study provides a new method for determining an Ep for C7 pedicle screw insertion.

  9. FREE-HAND PLACEMENT OF C7 PEDICLE SCREWS: A CADAVERIC STUDY

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    Emiliano Vialle

    2015-12-01

    Full Text Available Objective : To evaluate the accuracy of free-hand pedicle screws placement at the seventh cervical vertebra. Methods : The authors have exposed the cervicothoracic junction of 9 adult cadavers (7 male and 2 female preserved in formalin from the Faculty of Medicine of the Universidad Andina Néstor Cáceres Velásquez, city of Juliaca, Puno - Peru, locating the C7 vertebra based on anatomical parameters. According to previous publications, the entry point for the C7 pedicle was determined as 3-4mm lateral and 5-6mm superior to the center of the lateral mass, and the pedicle was drilled manually and instrumented with 3.5mm screws. After the screws placement, the C7 vertebrae were removed for radiographic analysis. Results : The authors were able to adequately locate the C7 entry point in 12 pedicles (66.6% accuracy, finding a great variability both laterally (2-5mm and cranially (3-10mm. The angulation in the coronal plane was correct in 13 pedicles (72.3%, despite the incorrect location of the entry point. Angle values in the coronal plane ranged from 38 to 62 degrees. In the sagittal plane angulation, 2 screws were placed in the C6-C7 disc. The midtransversal diameter of the 18 pedicles ranged from 4 to 7mm. Conclusions : The location of the entry point for placement of C7 pedicle screws with pure free-hand technique is very variable due to anatomical differences and the authors recommend some type of guidance for increased safety and accuracy.

  10. In vivo study of extracellular matrix coating enhancing fixation of the pedicle screw-bone's interface

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    LIU Guo-min; ZHANG Xing-yi; XU Chuan-jie; ZHU Xiao-min; WANG Jun; LIU Yi

    2011-01-01

    Background Based on in vivo research on the effect of the coating of the extracellular matrix composition of pedicle screws on the conduction and induction of bone formation in young sheep,the aim of this study was to investigate the application of coated pedicle screws in sheep with scoliosis whose spines are under constant development.Methods Four groups of pedicle screws were randomly implanted into bilateral L2-L5 pedicles of 2.5- to 3-month-old sheep.A static experiment was performed on one side and a loading test was performed on the other side by implanting connecting rods at the L2-L3 and L4-L5 segments.The changes in the force on the coated screws and the combination of the surface of the coated screws with the surrounding bone in the growth process of young sheep's spines with aging were observed.After 3 months,the lumbar vertebrae with the screws were removed and examined by micro-CT,histological,and biomechanical analyses.Results Under nonloading conditions,there is bone formation around the surfaces of coated screws.The bone forming on the surface of collagen/chondroitin sulfate/hydroxyapatite coating of pedicle screws is the most,the one of the collagen / chondrcitin sulfate coating and hydroxyapatite coating is followed,and no significant difference between the two groups.In terms of the trabecular bone morphology parameters of the region of interest around the surface of the pedicle screws,such as bone mineral content,bone mineral density,tissue mineral content,tissue bone mineral density,bone volume fraction,and connection density,those associated with collagen/chondroitin sulfate/hydroxyapatite coatings are largest and those unassociated with coatings are smallest.Under nonloading conditions,the pullout strength of the collagen/chondroitin sulfate/hydroxyapatite-coated screws was largest,and that of the uncoated screws was minimal (P <0.01).Under loading conditions,the maximum pullout strength of each group of pedicle screws was less than that

  11. Pullout strength of pedicle screws with cement augmentation in severe osteoporosis: A comparative study between cannulated screws with cement injection and solid screws with cement pre-filling

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    Lee Yen-Chen

    2011-02-01

    Full Text Available Abstract Background Pedicle screws with PMMA cement augmentation have been shown to significantly improve the fixation strength in a severely osteoporotic spine. However, the efficacy of screw fixation for different cement augmentation techniques, namely solid screws with retrograde cement pre-filling versus cannulated screws with cement injection through perforation, remains unknown. This study aimed to determine the difference in pullout strength between conical and cylindrical screws based on the aforementioned cement augmentation techniques. The potential loss of fixation upon partial screw removal after screw insertion was also examined. Method The Taguchi method with an L8 array was employed to determine the significance of design factors. Conical and cylindrical pedicle screws with solid or cannulated designs were installed using two different screw augmentation techniques: solid screws with retrograde cement pre-filling and cannulated screws with cement injection through perforation. Uniform synthetic bones (test block simulating severe osteoporosis were used to provide a platform for each screw design and cement augmentation technique. Pedicle screws at full insertion and after a 360-degree back-out from full insertion were then tested for axial pullout failure using a mechanical testing machine. Results The results revealed the following 1 Regardless of the screw outer geometry (conical or cylindrical, solid screws with retrograde cement pre-filling exhibited significantly higher pullout strength than did cannulated screws with cement injection through perforation (p = 0.0129 for conical screws; p = 0.005 for cylindrical screws. 2 For a given cement augmentation technique (screws without cement augmentation, cannulated screws with cement injection or solid screws with cement pre-filling, no significant difference in pullout strength was found between conical and cylindrical screws (p >0.05. 3 Cement infiltration into the open cell of

  12. Comparison of low density and high density pedicle screw instrumentation in Lenke 1 adolescent idiopathic scoliosis.

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    Shen, Mingkui; Jiang, Honghui; Luo, Ming; Wang, Wengang; Li, Ning; Wang, Lulu; Xia, Lei

    2017-08-02

    The correlation between implant density and deformity correction has not yet led to a precise conclusion in adolescent idiopathic scoliosis (AIS). The aim of this study was to evaluate the effects of low density (LD) and high density (HD) pedicle screw instrumentation in terms of the clinical, radiological and Scoliosis Research Society (SRS)-22 outcomes in Lenke 1 AIS. We retrospectively reviewed 62 consecutive Lenke 1 AIS patients who underwent posterior spinal arthrodesis using all-pedicle screw instrumentation with a minimum follow-up of 24 months. The implant density was defined as the number of screws per spinal level fused. Patients were then divided into two groups according to the average implant density for the entire study. The LD group (n = 28) had fewer than 1.61 screws per level, while the HD group (n = 34) had more than 1.61 screws per level. The radiographs were analysed preoperatively, postoperatively and at final follow-up. The perioperative and SRS-22 outcomes were also assessed. Independent sample t tests were used between the two groups. Comparisons between the two groups showed no significant differences in the correction of the main thoracic curve and thoracic kyphosis, blood transfusion, hospital stay, and SRS-22 scores. Compared with the HD group, there was a decreased operating time (278.4 vs. 331.0 min, p = 0.004) and decreased blood loss (823.6 vs. 1010.9 ml, p = 0.048), pedicle screws needed (15.1 vs. 19.6, p density and high density pedicle screw instrumentation achieved satisfactory deformity correction in Lenke 1 AIS patients. However, the operating time and blood loss were reduced, and the implant costs were decreased with the use of low screw density constructs.

  13. Cervical pedicle screw fixation at C6 and C7 A cadaveric study

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    Ye Li

    2015-01-01

    Conclusion: The intersection of the horizontal line through the midpoint of the transverse process root and vertical line through the intersection of the posterolateral and posterior planes of the isthmus can be used as an entry point for C6 and C7 pedicle screw fixation. The screws should be inserted at 60 or 90° with the posterolateral isthmus in the horizontal plane and at 75° with the posterior isthmus in the sagittal plane. The LSC should not exceed 30 mm.

  14. Clinical Accuracy of Three-Dimensional Fluoroscopy (IsoC-3D-Assisted Upper Thoracic Pedicle Screw Insertion

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    Sugimoto,Yoshihisa

    2010-06-01

    Full Text Available Correct screw placement is especially difficult in the upper thoracic vertebrae. At the cervicothoracic junction (C7-T2, problems can arise because of the narrowness of the pedicle and the difficulty of using a lateral image intensifier there. Other upper thoracic vertebrae (T3-6 pose a problem for screw insertion also because of the narrower pedicle. We inserted 154 pedicle screws into 78 vertebrae (C7 to T6 in 38 patients. Screws were placed using intraoperative data acquisition by an isocentric C-arm fluoroscope (Siremobile Iso-C3D and computer navigation. Out of 90 pedicle screws inserted into 45 vertebrae between C7 and T2, 87 of the 90 (96.7% screws were classified as grade 1 (no perforation. Of 64 pedicle screws inserted into 33 vertebrae between T3 and T6, 61 of 64 (95.3% screws were classified as grade 1. In this study, we reduced pedicle screw misplacement at the level of the C7 and upper thoracic (T1-6 vertebrae using the three-dimensional fluoroscopy navigation system.

  15. Error rate of multi-level rapid prototyping trajectories for pedicle screw placement in lumbar and sacral spine

    Institute of Scientific and Technical Information of China (English)

    Matjaz Merc; Igor Drstvensek; Matjaz Vogrin; Tomaz Brajlih; Tomaz Friedrich; Gregor Recnik

    2014-01-01

    Objective:Free-hand pedicle screw placement has a high incidence of pedicle perforation which can be reduced with fluoroscopy,navigation or an alternative rapid prototyping drill guide template.In our study the error rate of multi-level templates for pedicle screw placement in lumbar and sacral regions was evaluated.Methods:A case series study was performed on 11 patients.Seventy-two screws were implanted using multilevel drill guide templates manufactured with selective laser sintering.According to the optimal screw direction preoperatively defined,an analysis of screw misplacement was performed.Displacement,deviation and screw length difference were measured.The learning curve was also estimated.Results:Twelve screws (17%) were placed more than 3.125 mm out of its optimal position in the centre of pedicle.The tip of the 16 screws (22%) was misplaced more than 6.25 mm out of the predicted optimal position.According to our predefined goal,19 screws (26%) were implanted inaccurately.In 10 cases the screw length was selected incorrectly:1 (1%) screw was too long and 9 (13%) were too short.No clinical signs of neurovascular lesion were observed.Learning curve was insignificantly noticeable (P=0.129).Conclusion:In our study,the procedure of manufacturing and applying multi-level drill guide templates has a 26% chance of screw misplacement.However,that rate does not coincide with pedicle perforation incidence and neurovascular injury.These facts along with a comparison to compatible studies make it possible to summarize that multi-level templates are satisfactorily accurate and allow precise screw placement with a clinically irrelevant mistake factor.Therefore templates could potentially represent a useful tool for routine pedicle screw placement.

  16. Lower cervical spine injury treated with lateral mass plates and pedicle screws through posterior approach

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    ZHAO Xue-ling; ZHAO Hong-bin; WANG Bin; ZHU Xiao-song; LI Lin-zhi; ZHANG Chun-qiang

    2005-01-01

    Objective: To treat injury of the lower cervical spine C6 to C7 with cervical lateral mass plates and T1 pedicle screws through posterior approach. Methods: The data of 8 patients with lower cervical spine C6 or C7 injury (6 patients with fracture and dislocation in C6 and C7 and 2 with fracture in C7) were analyzed retrospectively in this study. For the preoperative American Spinal Injury Association (ASIA) classification, Grade C was found in 3 cases and Grade D in 5 cases. Screws were placed on the lateral masses and the first thoracic pedicle with Margerl technique. Lamina or facet bone allografting was used to achieve a long-term stability. Results: All the 8 patients were followed up for 5-37 months (mean: 15 months). No operative death occurred. There were no examples of aggravation of spinal cord injury or vertebral artery injury, cerebrospinal fluid leak, nerve roots injury, screw malposition or back-out, loose of alignment or implant failure. Clinical symptoms and ASIA classification were improved in all the patients. Postoperative MRI scanning confirmed the satisfactory screw placement in all the cases. Conclusions: Lateral mass plates and pedicle screws through posterior approach are safe and beneficial for patients with lower cervical spine C6 or C7 injury.

  17. Pedicle screw placement accuracy of bone-mounted miniature robot system

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    Tsai, Tai-Hsin; Tzou, Rong-Dar; Su, Yu-Feng; Wu, Chieh-Hsin; Tsai, Cheng-Yu; Lin, Chih-Lung

    2017-01-01

    Abstract This article describes factors affecting the accuracy of transpedicle screw placements performed with the Renaissance robot-guided system and reviews the relevant literature. Between January 2013 and January 2015, Renaissance robot-guided spinal surgery was performed in 125 patients at Kaohsiung Medical University Hospital in Kaohsiung, Taiwan. The surgeries included 662 transpedicle screw implants and 49 Kirschner wire (K-wire) reimplants performed by intraoperative repositioning. The lead author evaluated the accuracy of all K-wire insertions and classified their accuracy into 3 categories relative to the preoperative plan for transpedicle screw placement. For cases in which screws required repositioning after the registration step, factors affecting pedicle screw placement were determined according to the consensus of 3 experienced spinal surgeons. According to the scheme developed by Kuo et al (PLoS One 2016;11:e0153235), the K-wire placement accuracies before and after repositioning were respectively classified as follows: 76.1% and 77.6% in type I; 12.2% and 17.7% in type IIa; 4.3% and 4.5% in type IIb; 6.4% and 0% in type IIIa; and 1% and 1% in type IIIb. The percentage of screws requiring repositioning due to drilling error was 85.7% (42/49). Comparisons of preoperative and postoperative function showed significantly improved accuracy. This study showed that inaccurate pedicle screw placement mainly results from errors in preoperative planning, mounting, registration, drilling, and robot assembly. Pedicle screw placement using a bone-mounted miniature robot system requires meticulous preoperative planning to minimize these errors. PMID:28099339

  18. Pedicle screw placement accuracy of bone-mounted miniature robot system.

    Science.gov (United States)

    Tsai, Tai-Hsin; Tzou, Rong-Dar; Su, Yu-Feng; Wu, Chieh-Hsin; Tsai, Cheng-Yu; Lin, Chih-Lung

    2017-01-01

    This article describes factors affecting the accuracy of transpedicle screw placements performed with the Renaissance robot-guided system and reviews the relevant literature. Between January 2013 and January 2015, Renaissance robot-guided spinal surgery was performed in 125 patients at Kaohsiung Medical University Hospital in Kaohsiung, Taiwan. The surgeries included 662 transpedicle screw implants and 49 Kirschner wire (K-wire) reimplants performed by intraoperative repositioning. The lead author evaluated the accuracy of all K-wire insertions and classified their accuracy into 3 categories relative to the preoperative plan for transpedicle screw placement. For cases in which screws required repositioning after the registration step, factors affecting pedicle screw placement were determined according to the consensus of 3 experienced spinal surgeons. According to the scheme developed by Kuo et al (PLoS One 2016;11:e0153235), the K-wire placement accuracies before and after repositioning were respectively classified as follows: 76.1% and 77.6% in type I; 12.2% and 17.7% in type IIa; 4.3% and 4.5% in type IIb; 6.4% and 0% in type IIIa; and 1% and 1% in type IIIb. The percentage of screws requiring repositioning due to drilling error was 85.7% (42/49). Comparisons of preoperative and postoperative function showed significantly improved accuracy. This study showed that inaccurate pedicle screw placement mainly results from errors in preoperative planning, mounting, registration, drilling, and robot assembly. Pedicle screw placement using a bone-mounted miniature robot system requires meticulous preoperative planning to minimize these errors.

  19. Anatomic and radiological study on posterior pedicle screw fixation in the atlantoaxial vertebrae of children

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    DENG Xiong-wei; MIN Zhi-hai; LIN Bin; ZHANG Fa-hui

    2010-01-01

    Objective: To investigate the feasibility of posterior fixation with 3.5-mm pedicle screws in the atlantoaxial vertebrae of children.Methods: In this study, atlantoaxial vertebrae specimens were obtained from 10 cadavers of children aged 6-8 years. We measured the height and width of the C1 pedicle and the midportion of C1 lateral mass; the width of C1 posterior arch under the vertebral artery groove and the height of the external and internal one-third of this part; the external,internal height and the superior, middle, inferior width of the C2 pedicle (transverse foramen). Furthermore, computed tomography (CT) axial scan was performed on 20 agematched volunteers to obtain relative data of their atlantoaxial vertebrae. We measured the length and width of the C1 and C2 pedicles in the atlantoaxial cross-sectional plane. On CT workstation, we also measured the angles between the longitudinal axes of the atlantoaxial pedicles and the midsagittal plane.Results: For the cadaveric specimen group, the height and width of the C1 pedicle were (5.26±0.44) mm and (6.26±0.75) mm respectively. The height of the medial one-third of the C1 posterior arch under the vertebral artery groove was (4.07±0.24) mm. The external, internal height and superior,middle, inferior width of the C2 pedicle was (6.86±0.48) mm,(6.67±0.49) mm, (6.63 ±0.61 ) mm, (5.41±0.39) mm and (3.71±0.30) mm, respectively. For the volunteer group measured by CT scan, the height and width of the Ct pedicle were (5.47±0.34) mm and (6.63±0.54) mm respectively, while (6.59±0.51) mm and (5.13±0.42) mm of the C2 pedicle. The angles between the atlas, axis pedicles and the midsagittal plane were (9.60±1.32)° and (27.80±2.22)° respectively.Conclusion: It is feasible to place a 3.5-mm pedicle screw in the C1 and C2 pedicles of children aged 6-8 years old.

  20. Novel free-hand T1 pedicle screw method: Review of 44 consecutive cases

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    Mark A Rivkin

    2014-01-01

    Full Text Available Summary of Background Data: Multilevel posterior cervical instrumented fusions are becoming more prevalent in current practice. Biomechanical characteristics of the cervicothoracic junction may necessitate extending the construct to upper thoracic segments. However, fixation in upper thoracic spine can be technically demanding owing to transitional anatomy while suboptimal placement facilitates vascular and neurologic complications. Thoracic instrumentation methods include free-hand, fluoroscopic guidance, and CT-based image guidance. However, fluoroscopy of upper thoracic spine is challenging secondary to vertebral geometry and patient positioning, while image-guided systems present substantial financial commitment and are not readily available at most centers. Additionally, imaging modalities increase radiation exposure to the patient and surgeon while potentially lengthening surgical time. Materials and Methods: Retrospective review of 44 consecutive patients undergoing a cervicothoracic fusion by a single surgeon using the novel free-hand T1 pedicle screw technique between June 2009 and November 2012. A starting point medial and cephalad to classic entry as well as new trajectory were utilized. No imaging modalities were employed during screw insertion. Postoperative CT scans were obtained on day 1. Screw accuracy was independently evaluated according to the Heary classification. Results: In total, 87 pedicle screws placed were at T1. Grade 1 placement occurred in 72 (82.8% screws, Grade 2 in 4 (4.6% screws and Grade 3 in 9 (10.3% screws. All Grade 2 and 3 breaches were <2 mm except one Grade 3 screw breaching 2-4 mm laterally. Only two screws (2.3% were noted to be Grade 4, both breaching medially by less than 2 mm. No new neurological deficits or returns to operating room took place postoperatively. Conclusions: This modification of the traditional starting point and trajectory at T1 is safe and effective. It attenuates additional bone

  1. Computer navigation versus fluoroscopy-guided navigation for thoracic pedicle screw placement: a meta-analysis.

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    Meng, Xiao-Tong; Guan, Xiao-Fei; Zhang, Hai-Long; He, Shi-Sheng

    2016-07-01

    Although application of intraoperative computer navigation technique had been integrated into placement of pedicle screws (PSs) in thoracic fusion for years, its security and practicability remain controversial. The aim of this study is to evaluate the accuracy, the operative time consumption, the amount of intraoperative blood loss, time of pedicle insertion and the incidence of complications of thoracic pedicle screw placement in patients with thoracic diseases such as scoliosis and kyphosis. Pubmed, Web of Knowledge, and Google scholar were searched to identify comparative studies of thoracic pedicle screw placement between intraoperative computer navigation and fluoroscopy-guided navigation. Outcomes of malposition rate, operative time consumption, insertion time, intraoperative blood loss, and the incidence of complications are evaluated. Fourteen articles including 1723 patients and 9019 PSs were identified matching inclusion criteria. The malposition rate was lower (RR: 0.33, 95 % CI: 0.28-0.38, P navigation group than that in fluoroscopy-guided navigation group; the operative time was significantly longer [weighted mean difference (WMD) = 23.66, 95 % CI: 14.74-32.57, P navigation group than that in fluoroscopy-guided navigation group. The time of insertion was shorter (WMD = -1.88, 95 % CI: -2.25- -1.52, P navigation group than that in fluoroscopy-guided navigation group. The incidence of complications was lower (RR = 0. 23, 95 % CI: 0.12-0.46, P navigation group than that in the other group. The intraoperative blood loss was fewer (WMD = -167.49, 95 % CI: -266.39- -68.58, P navigation group than that in the other. In conclusion, the meta-analysis of thoracic pedicle screw placement studies clearly demonstrated lower malposition rate, less intraoperative blood loss, and fewer complications when using computer navigation. This result provides strong evidence that computer technology could be safer and more reliable than

  2. SU-E-T-609: Perturbation Effects of Pedicle Screws On Radiotherapy Dose Distributions

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    Bar-Deroma, R; Borzov, E; Nevelsky, A [Rambam Medical Center, Haifa (Israel)

    2015-06-15

    Purpose: Radiation therapy in conjunction with surgical implant fixation is a common combined treatment in case of bone metastases. However, metal implants generally used in orthopedic implants perturb radiation dose distributions. Carbon-Fiber Reinforced (CFR) PEEK material has been recently introduced for production of intramedullary screws and plates. Gold powder can be added to the CFR-PEEK material in order to enhance visibility of the screws during intraoperative imaging procedures. In this work, we investigated the perturbation effects of the pedicle screws made of CFR-PEEK, CFR-PEEK with added gold powder (CFR-PEEK-AU) and Titanium (Ti) on radiotherapy dose distributions. Methods: Monte Carlo (MC) simulations were performed using the EGSnrc code package for 6MV beams with 10×10 fields at SSD=100cm. By means of MC simulations, dose distributions around titanium, CFR- PEEK and CFR-PEEK-AU screws (manufactured by Carbo-Fix Orthopedics LTD, Israel) placed in a water phantom were calculated. The screw axis was either parallel or perpendicular to the beam axis. Dose perturbation (relative to dose in homogeneous water phantom) was assessed. Results: Maximum overdose due to backscatter was 10% for the Ti screws, 5% for the CFR-PEEK-AU screws and effectively zero for the CFR-PEEK screws. Maximum underdose due to attenuation was 25% for the Ti screws, 15% for the CFR-PEEK-AU screws and 5% for the CFR-PEEK screws. Conclusion: Titanium screws introduce the largest distortion on the radiation dose distribution. The gold powder added to the CFR-PEEK material improves visibility at the cost of increased dose perturbation. CFR-PEEK screws caused minimal alteration on the dose distribution. This can decrease possible over and underdose of adjacent tissue and thus favorably influence treatment efficiency. The use of such implants has potential clinical advantage in the treatment of neoplastic bone disease.

  3. Fretting corrosion behavior of nitinol spinal rods in conjunction with titanium pedicle screws.

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    Lukina, Elena; Kollerov, Mikhail; Meswania, Jay; Khon, Alla; Panin, Pavel; Blunn, Gordon W

    2017-03-01

    Untypical corrosion damage including erosions combined with the build-up of titanium oxide as a corrosion product on the surface of explanted Nitinol spinal rods in the areas where it was in contact with titanium pedicle screw head is reported. It was suggested that Nitinol rods might have inferior fretting corrosion resistance compared with that made of titanium or CoCr. Fretting corrosion of Nitinol spinal rods with titanium (Ti6Al4V) pedicle screws were tested in-vitro by conducting a series of potentiostatic measurements of the peak-to-peak values of fretting corrosion current under bending in a 10% solution of calf serum in PBS. The test included Nitinol rods locked in titanium pedicle screws of different designs. Performance of commercially available titanium (Ti6Al4V) and CoCr spinal rods was also investigated for a comparison. Corrosion damage observed after the in-vitro tests was studied using SEM and EDAX analysis and was compared with patterns on Nitinol rods retrieved 12months after initial surgery. Metal ions level was measured in the test media after in-vitro experiments and in the blood and tissues of the patients who had the rods explanted. The results of this study revealed that Nitinol spinal rods locked in Ti pedicle screws are susceptible to fretting corrosion demonstrating higher fretting corrosion current compared with commercially used Ti6Al4V and CoCr rods. On the surface of Nitinol rods after in-vitro tests and on those retrieved from the patients similar corrosion patterns were observed. Improved resistance to fretting corrosion was observed with Nitinol rods in the in-vitro tests where pedicle screws were used with a stiffer locking mechanism. Since the development of the localized corrosion damage might increase the risk of premature fatigue failure of the rods and result in leaching of Ni ions, it is concluded that Nitinol rods should not be used in conjunction with Ti pedicle screws without special protection especially where the

  4. Analysis of lumbar pedicle morphology in degenerative spines using multiplanar reconstruction computed tomography: what can be the reliable index for optimal pedicle screw diameter?

    Science.gov (United States)

    Makino, Takahiro; Kaito, Takashi; Fujiwara, Hiroyasu; Yonenobu, Kazuo

    2012-08-01

    The measurement of transverse pedicle width is still recommended for selecting a screw diameter despite being weakly correlated with the minimum pedicle diameter, except in the upper lumbar spine. The purpose of this study was to reveal the difference between the minimum pedicle diameter and conventional transverse or sagittal pedicle width in degenerative lumbar spines. A total of 50 patients with degenerative lumbar disorders without spondylolysis or lumbar scoliosis of >10° who preoperatively underwent helical CT scans were included. The DICOM data of the scans were reconstructed by imaging software, and the transverse pedicle width (TPW), sagittal pedicle width (SPW), minimum pedicle diameter (MPD), and the cephalocaudal inclination of the pedicles were measured. The mean TPW/SPW/MPD values were 5.46/11.89/5.09 mm at L1, 5.76/10.44/5.39 mm at L2, 7.25/10.23/6.52 mm at L3, 9.01/9.36/6.83 mm at L4, and 12.86/8.95/7.36 mm at L5. There were significant differences between the TPW and MPD at L3, L4, and L5 (p < 0.01) and between the SPW and MPD at all levels (p < 0.01). The MPD was significantly smaller than the TPW and SPW at L3, L4, and L5. The actual measurements of the TPW were not appropriate for use as a direct index for the optimal pedicle screw diameter at these levels. Surgeons should be careful in determining pedicle screw diameter based on plain CT scans especially in the lower lumbar spine.

  5. Ergotropic effect of bone cement on pedicle screw fixation in treatment of osteoporotic thoracolumbar fracture

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    Da LIU

    2017-02-01

    Full Text Available Objective To evaluate the ergotropic effect of bone cement on pedicle screw fixation in treatment of osteopo¬rotic thoracolumbar fracture. Methods Fifty-three patients with osteoporotic thoracolumbar fracture, admitted from Jun. 2013 to Dec. 2014, were included for treatment by augmentation of pedicle screw fixation with bone cement. All patients underwent pre-operative examination of bone mineral density with T-score ≤-2.5 and augmentation of pedicle screw fixation with injection of 1.5 ml bone cement in adjacent to fractured vertebra. All patients were treated with anti-osteoporosis therapy pre- and post-operation, ob¬served and recorded with basic conditions and complications. At pre-operation, one-week post-operation and last follow-up, pain vi¬sual analogue scale (VAS and neurological function score (ASIA of all patients were recorded, and the compression rats of anterior and posterior edge of fractured vertebra, and compression rats of spinal canal and Cobb angel of all patients were measured. Results All the 53 patients were successfully undergone operation in about 90-140 min with blood loss of about 150-350 ml. No spinal cord or nerve injury, dural tear and obvious leakage of bone cement and screw loosening occurred during operation. All patients were followed up for 12 to 36 months and the neurological function obviously recovered contrasted with pre-operation. X-ray and CT examination at last follow-up showed good fractures healing, good position and non-loosening of internal fixation device and non-leakage of bone cement. At one week post-operation and last follow-up, VAS, compression rats of anterior edge and posterior edge of fractured vertebra, compression rats of spinal canal and Cobb angel were significantly lower than those at pre-operation (P0.05. Conclusions Augmentation of pedicle screw fixation with bone cement can effectively strengthen the initial stability of pedicle screw in osteo¬porosis, restore the

  6. Biomechanical comparison of translaminar versus pedicle screws at T1 and T2 in long subaxial cervical constructs.

    Science.gov (United States)

    McGirt, Matthew J; Sutter, Edward G; Xu, Risheng; Sciubba, Daniel M; Wolinsky, Jean-Paul; Witham, Timothy F; Gokaslan, Ziya L; Bydon, Ali

    2009-12-01

    The first in vitro biomechanical investigation comparing the immediate and postcyclical rigidities of thoracic translaminar versus pedicle screws in posterior constructs crossing the cervicothoracic junction (CTJ). Ten human cadaveric spines underwent C4-C6 lateral mass screw and T1-T2 translaminar (n = 5) versus pedicle (n = 5) screw fixation. Spines were then potted in polymethylmethacrylate bone cement and placed on a materials testing machine. Rotation about the axis of bending was measured using passive retroreflective markers and infrared motion capture cameras. The motion of C6 relative to T2 in flexion-extension and lateral bending was assessed uninstrumented, immediately after instrumentation, and after 40,000 cycles of 4 N.m flexion-extension and lateral bending moments at 1 Hz. The effect of instrumentation and cyclical loading on rotational motion across the CTJ was analyzed for significance. Compared with preinstrumented spines, pedicle and translaminar screw constructs significantly (P bending. After cyclical loading, rotational motion at the CTJ was significantly increased (P bending in both groups. With flexion-extension, the mean rotational motion across the CTJ was similar in the translaminar and pedicle constructs immediately after fixation, but slightly greater (P = 0.03) after cyclical loading in the translaminar versus the pedicle screw constructs (0.39 degrees versus 0.26 degrees). Nevertheless, after cyclical loading, the mean angular motion across the CTJ remained less than one half of a degree in both groups. With lateral bending, the mean rotational motion was similar in both translaminar and pedicle screw constructs. Both upper thoracic translaminar and pedicle screws allow for rigid fixation at the CTJ. Although translaminar screw constructs demonstrated one eighth of a degree more motion at the CTJ after cycling, this minimal difference is likely less than would influence the biological fusion process. Upper thoracic translaminar

  7. Functionality Evaluation of a Novel Smart Expandable Pedicle Screw to Mitigate Osteoporosis Effect in Bone Fixation: Modeling and Experimentation

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    Ahmadreza Eshghinejad

    2013-01-01

    Full Text Available This paper proposes a novel expandable-retractable pedicle screw and analyzes its functionality. A specially designed pedicle screw is described which has the ability to expand and retract using nitinol elements. The screw is designed to expand in body temperature and retract by cooling the screw. This expansion-retraction function is verified in an experiment designed in larger scale using a nitinol antagonistic assembly. The results of this experiment are compared to the results of a finite element model developed in Abaqus in combination with a user material subroutine (UMAT. This code has been developed to analyze the nonlinear thermomechanical behavior of shape memory alloy materials. The functionality of the proposed screw is evaluated with simulation and experimentation in a pullout test as well. The pullout force of a normal screw inserted in a normal bone was simulated, and the result is compared with the results of the expandable screw in osteoporotic bone. Lastly, strength of the designed pedicle screw in a foam block is also verified with experiment. The reported finite element simulations and experiments are the proof for the concept of nitinol expandable-retractable elements on a pedicle screw which validate the functionality in a pullout test.

  8. Designs and Techniques That Improve the Pullout Strength of Pedicle Screws in Osteoporotic Vertebrae: Current Status

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    Thomas M. Shea

    2014-01-01

    Full Text Available Osteoporosis is a medical condition affecting men and women of different age groups and populations. The compromised bone quality caused by this disease represents an important challenge when a surgical procedure (e.g., spinal fusion is needed after failure of conservative treatments. Different pedicle screw designs and instrumentation techniques have been explored to enhance spinal device fixation in bone of compromised quality. These include alterations of screw thread design, optimization of pilot hole size for non-self-tapping screws, modification of the implant’s trajectory, and bone cement augmentation. While the true benefits and limitations of any procedure may not be realized until they are observed in a clinical setting, axial pullout tests, due in large part to their reproducibility and ease of execution, are commonly used to estimate the device’s effectiveness by quantifying the change in force required to remove the screw from the body. The objective of this investigation is to provide an overview of the different pedicle screw designs and the associated surgical techniques either currently utilized or proposed to improve pullout strength in osteoporotic patients. Mechanical comparisons as well as potential advantages and disadvantages of each consideration are provided herein.

  9. Designs and techniques that improve the pullout strength of pedicle screws in osteoporotic vertebrae: current status.

    Science.gov (United States)

    Shea, Thomas M; Laun, Jake; Gonzalez-Blohm, Sabrina A; Doulgeris, James J; Lee, William E; Aghayev, Kamran; Vrionis, Frank D

    2014-01-01

    Osteoporosis is a medical condition affecting men and women of different age groups and populations. The compromised bone quality caused by this disease represents an important challenge when a surgical procedure (e.g., spinal fusion) is needed after failure of conservative treatments. Different pedicle screw designs and instrumentation techniques have been explored to enhance spinal device fixation in bone of compromised quality. These include alterations of screw thread design, optimization of pilot hole size for non-self-tapping screws, modification of the implant's trajectory, and bone cement augmentation. While the true benefits and limitations of any procedure may not be realized until they are observed in a clinical setting, axial pullout tests, due in large part to their reproducibility and ease of execution, are commonly used to estimate the device's effectiveness by quantifying the change in force required to remove the screw from the body. The objective of this investigation is to provide an overview of the different pedicle screw designs and the associated surgical techniques either currently utilized or proposed to improve pullout strength in osteoporotic patients. Mechanical comparisons as well as potential advantages and disadvantages of each consideration are provided herein.

  10. 21 CFR 888.3070 - Pedicle screw spinal system.

    Science.gov (United States)

    2010-04-01

    ... treatment of the following acute and chronic instabilities or deformities of the thoracic, lumbar, and... conditions are significant mechanical instability or deformity of the thoracic, lumbar, and sacral spine... screw spinal system because this is a technically demanding procedure presenting a risk of...

  11. Short segmental pedicle screw fixation combined with percutaneous vertebroplasty in treatment of nonadjacent thoracolumbar fractures

    Institute of Scientific and Technical Information of China (English)

    HE Qing-yi; XU Jian-zhong

    2009-01-01

    To evaluate the short-term outcomes of short segmental pedicle screw fixation combined with per-cutaneous vertebroplasty in treatment of nonadjacent tho-racolumbar fractures. Methods: Twenty patients who suffered from nonadja-cent thoracolumbar fractures were treated by short segmental pedicle screw fixation for burst fracture and by percutane-ous vertebroplasty for compression fracture. X-rays, CT and MRI scans were conducted using the same protocol before and after surgery and during follow-up. Pre- and post-operative American Spinal Injury Association (ASIA) grades, fusion of fracture sites, visual analog scale (VAS) of back pain, and Oswestry disability index (ODI) were accessed. Results: All patients were followed up for an average period of 12 months. The sagittal profile of the thoracolum-bar spine was restored satisfactorily. No patient had neuro-logic deterioration after surgery, and 9 patients with incom-plete lesions improved postoperatively by at least one ASIA grade. The fusion rate was 100%. The average VAS of back pain was 7.6 preoperatively and 3.2 postoperatively. The average ODI was 72.5 preoperatively and 35.5 postoperatively. Conclusions: Short segmental pedicle screw fixation combined with percutaneous vertebroplasty in treatment of nonadjacent thoracolumbar fractures exhibits such advan-tages as preserving functional segment units, reliable fixation, good neurologic recovery and early mobilization and, therefore, is suitable for treating nonadjacent thora-columbar fractures.

  12. Treatment of neuromuscular scoliosis with posterior-only pedicle screw fixation.

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    Modi, Hitesh N; Suh, Seung-Woo; Song, Hae-Ryong; Fernandez, Harry M; Yang, Jae-Hyuk

    2008-06-10

    To determine whether posterior-only approach using pedicle screws in neuromuscular scoliosis population adequately addresses the correction of scoliosis and maintains the correction over time. Between 2003 and 2006, 26 consecutive patients (7 cerebral palsy, 10 Duchenne muscular dystrophy, 5 spinal muscular atrophy and 4 others) with neuromuscular scoliosis underwent posterior pedicle screw fixation for the deformity. Preoperative, immediate postoperative and final follow-up Cobb's angle and pelvic obliquity were analyzed on radiographs. The average age of the patients was 17.5 years (range, 8-44 years) and the average follow-up was 25 months (18-52 months). Average Cobb's angle was 78.53 degrees before surgery, 30.70 degrees after surgery (60.9% correction), and 33.06 degrees at final follow-up (57.9% correction) showing significant correction (p vertebral column resection due to the presence of a rigid curve. The average spinal-pelvic obliquity was 16.27 degrees before surgery, 8.96 degrees after surgery, and 9.27 degrees at final follow-up exhibited significant correction (p maintained with posterior-only pedicle screw instrumentation without anterior release procedure.

  13. Treatment of neuromuscular scoliosis with posterior-only pedicle screw fixation

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    Fernandez Harry M

    2008-06-01

    Full Text Available Abstract Background To determine whether posterior-only approach using pedicle screws in neuromuscular scoliosis population adequately addresses the correction of scoliosis and maintains the correction over time. Methods Between 2003 and 2006, 26 consecutive patients (7 cerebral palsy, 10 Duchenne muscular dystrophy, 5 spinal muscular atrophy and 4 others with neuromuscular scoliosis underwent posterior pedicle screw fixation for the deformity. Preoperative, immediate postoperative and final follow-up Cobb's angle and pelvic obliquity were analyzed on radiographs. The average age of the patients was 17.5 years (range, 8–44 years and the average follow-up was 25 months (18–52 months. Results Average Cobb's angle was 78.53° before surgery, 30.70° after surgery (60.9% correction, and 33.06° at final follow-up (57.9% correction showing significant correction (p Conclusion Results indicate that in patients with neuromuscular scoliosis, acceptable amounts of curve correction can be achieved and maintained with posterior-only pedicle screw instrumentation without anterior release procedure.

  14. Basic study for ultrasound-based navigation for pedicle screw insertion using transmission and backscattered methods.

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    Ziqiang Chen

    Full Text Available The purpose of this study was to understand the acoustic properties of human vertebral cancellous bone and to study the feasibility of ultrasound-based navigation for posterior pedicle screw fixation in spinal fusion surgery. Fourteen human vertebral specimens were disarticulated from seven un-embalmed cadavers (four males, three females, 73.14 ± 9.87 years, two specimens from each cadaver. Seven specimens were used to measure the transmission, including tests of attenuation and phase velocity, while the other seven specimens were used for backscattered measurements to inspect the depth of penetration and A-Mode signals. Five pairs of unfocused broadband ultrasonic transducers were used for the detection, with center frequencies of 0.5 MHz, 1 MHz, 1.5 MHz, 2.25 MHz, and 3.5 MHz. As a result, good and stable results were documented. With increased frequency, the attenuation increased (P0.05. At about 0.6 cm away from the cortical bone, warning signals were easily observed from the backscattered measurements. In conclusion, the ultrasonic system proved to be an effective, moveable, and real-time imaging navigation system. However, how ultrasonic navigation will benefit pedicle screw insertion in spinal surgery needs to be determined. Therefore, ultrasound-guided pedicle screw implantation is theoretically effective and promising.

  15. Accuracy and postoperative assessment of pedicle screw placement during scoliosis surgery with computer-assisted navigation: a meta-analysis.

    Science.gov (United States)

    Tian, Wei; Zeng, Cheng; An, Yan; Wang, Chao; Liu, Yajun; Li, Jianing

    2017-03-01

    Accurate insertion of pedicle screws in scoliosis patients is a challenge for surgeons. Computer-assisted navigation techniques might help improve the accuracy of screw placement, thereby avoiding complications. Thus, the objective of this present work is to compare the accuracy and postoperative assessment of pedicle screw placement in scoliosis patients using a computer-assisted navigation technique and using a conventional free-hand method. A search of the PubMed, Cochrane, and Web of Science databases was executed. In vivo comparative studies that assessed the accuracy and postoperative evaluation of pedicle screw placement in scoliosis patients with or without navigation techniques were chosen and analyzed. The accuracy of pedicle screw insertion was significantly increased when using the navigation system, although the average operative time and correction rate was not significantly different from that with non-navigated surgery. The navigation technique improves the accuracy of pedicle screw placement during scoliosis surgery without prolonging the operative time or decreasing the deformity correction effect. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  16. Accuracy of robot-guided versus freehand fluoroscopy-assisted pedicle screw insertion in thoracolumbar spinal surgery.

    Science.gov (United States)

    Molliqaj, Granit; Schatlo, Bawarjan; Alaid, Awad; Solomiichuk, Volodymyr; Rohde, Veit; Schaller, Karl; Tessitore, Enrico

    2017-05-01

    OBJECTIVE The quest to improve the safety and accuracy and decrease the invasiveness of pedicle screw placement in spine surgery has led to a markedly increased interest in robotic technology. The SpineAssist from Mazor is one of the most widely distributed robotic systems. The aim of this study was to compare the accuracy of robot-guided and conventional freehand fluoroscopy-guided pedicle screw placement in thoracolumbar surgery. METHODS This study is a retrospective series of 169 patients (83 women [49%]) who underwent placement of pedicle screw instrumentation from 2007 to 2015 in 2 reference centers. Pathological entities included degenerative disorders, tumors, and traumatic cases. In the robot-assisted cohort (98 patients, 439 screws), pedicle screws were inserted with robotic assistance. In the freehand fluoroscopy-guided cohort (71 patients, 441 screws), screws were inserted using anatomical landmarks and lateral fluoroscopic guidance. Patients treated before 2009 were included in the fluoroscopy cohort, whereas those treated since mid-2009 (when the robot was acquired) were included in the robot cohort. Since then, the decision to operate using robotic assistance or conventional freehand technique has been based on surgeon preference and logistics. The accuracy of screw placement was assessed based on the Gertzbein-Robbins scale by a neuroradiologist blinded to treatment group. The radiological slice with the largest visible deviation from the pedicle was chosen for grading. A pedicle breach of 2 mm or less was deemed acceptable (Grades A and B) while deviations greater than 2 mm (Grades C, D, and E) were classified as misplacements. RESULTS In the robot-assisted cohort, a perfect trajectory (Grade A) was observed for 366 screws (83.4%). The remaining screws were Grades B (n = 44 [10%]), C (n = 15 [3.4%]), D (n = 8 [1.8%]), and E (n = 6 [1.4%]). In the fluoroscopy-guided group, a completely intrapedicular course graded as A was found in 76% (n = 335). The

  17. Comparison between two pedicle screw augmentation instrumentations in adult degenerative scoliosis with osteoporosis

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    Xie Yang

    2011-12-01

    Full Text Available Abstract Background The operative treatment of adult degenerative scoliosis combined with osteoporosis increase following the epidemiological development. Studies have confirmed that screws in osteoporotic spines have significant lower-screw strength with more frequent screw movements within the vertebra than normal spines. Screws augmented with Polymethylmethacrylate (PMMA or with autogenous bone can offer more powerful corrective force and significant advantages. Methods A retrospective analysis was conducted on 31 consecutive patients with degenerative lumbar scoliosis combined with osteoporosis who had surgery from December 2000. All had a minimum of 2-year follow-up. All patients had posterior approach surgery. 14 of them were fixed with pedicle screw by augmentation with Polymethylmethacrylate (PMMA and the other 17 patients with autogenous bone. Age, sex and whether smoking were similar between the two groups. Surgical time, blood loss, blood transfusion, medical cost, post surgery ICU time, hospital day, length of oral pain medicines taken, Pre-and postoperative Oswestry disability index questionnaire and surgical revision were documented and compared. Preoperative, postoperative and final follow up Cobb angle, sagittal lumbar curve, correction rate, and Follow up Cobb loss were also compared. Results No significant differences were found between the autogenous bone group and Polymethylmethacrylate group with regards to all the targets above except for length of oral pain medicines taken and surgery cost. 2 patients were seen leakage during operation, but there is neither damage of nerve nor symptom after operation. No revision was needed. Conclusion Both augmentation pedicle screw with Polymethylmethacrylate (PMMA and autogenous bone treating degenerative lumbar scoliosis combined with osteoporosis can achieve a good surgical result. Less oral pain medicines taken are the potential benefits of Polymethylmethacrylate augmentation, but

  18. A comparative study of pedicle screw fixation in dorsolumbar spine by freehand versus image-assisted technique: A cadaveric study

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    Archit Agarwal

    2016-01-01

    Full Text Available Background: New and expensive technology such as three-dimensional computer assisted surgery is being used for pedicle screw fixation in dorsolumbar spine. Their availability, expenses and amount of radiation exposure are issues in a developing country. On the contrary, freehand technique of pedicle screw placement utilizes anatomic landmarks and tactile palpation without fluoroscopy or navigation to place pedicle screws. The purpose of this study was to analyze and compare the accuracy of freehand and image-assisted technique to place pedicle screws in the dorsolumbar spine of cadavers by an experienced surgeon and a resident. Evaluation was done using dissection of pedicle and computed tomography (CT imaging. Materials and Methods: Ten cadaveric dorsolumbar spines were exposed by a posterior approach. Titanium pedicle screws were inserted from D5 to L5 vertebrae by freehand and image-assisted technique on either side by an experienced surgeon and a resident. CT was obtained. A blinded radiologist reviewed the imaging. The spines were then dissected to do a macroscopic examination. Screws, having evidence of cortical perforation of more than 2 mm on CT, were considered to be a significant breach. Results: A total of 260 pedicle screws were placed. The surgeon and the resident placed 130 screws each. Out of 130 screws, both of them placed 65 screws each by freehand and image- assisted technique each. The resident had a rate of 7.69% significant medial and 10.76% significant lateral breach with freehand technique while with image-assisted had a rate of 3.07% significant medial and 9.23% significant lateral breach. The expert surgeon had a rate of 6.15% significant medial and 1.53% significant lateral breach with freehand technique while with image-assisted had a rate of 3.07% significant medial and 6.15% significant lateral breach on CT evaluation. Conclusion: Freehand technique is as good as the image-assisted technique. Under appropriate

  19. Surgical complications in neuromuscular scoliosis operated with posterior- only approach using pedicle screw fixation

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    Singh Surya Udai

    2009-05-01

    Full Text Available Abstract Background There are no reports describing complications with posterior spinal fusion (PSF with segmental spinal instrumentation (SSI using pedicle screw fixation in patients with neuromuscular scoliosis. Methods Fifty neuromuscular patients (18 cerebral palsy, 18 Duchenne muscular dystrophy, 8 spinal muscular atrophy and 6 others were divided in two groups according to severity of curves; group I ( 90°. All underwent PSF and SSI with pedicle screw fixation. There were no anterior procedures. Perioperative (within three months of surgery and postoperative (after three months of surgery complications were retrospectively reviewed. Results There were fifty (37 perioperative, 13 postoperative complications. Hemo/pneumothorax, pleural effusion, pulmonary edema requiring ICU care, complete spinal cord injury, deep wound infection and death were major complications; while atelectesis, pneumonia, mild pleural effusion, UTI, ileus, vomiting, gastritis, tingling sensation or radiating pain in lower limb, superficial infection and wound dehiscence were minor complications. Regarding perioperative complications, 34(68% patients had at least one major or one minor complication. There were 16 patients with pulmonary, 14 with abdominal, 3 with wound related, 2 with neurological and 1 cardiovascular complications, respectively. There were two deaths, one due to cardiac arrest and other due to hypovolemic shock. Regarding postoperative complications 7 patients had coccygodynia, 3 had screw head prominence, 2 had bed sore and 1 had implant loosening, respectively. There was a significant relationship between age and increased intraoperative blood loss (p = 0.024. However it did not increased complications or need for ICU care. Similarly intraoperative blood loss > 3500 ml, severity of curve or need of pelvic fixation did not increase the complication rate or need for ICU. DMD patients had higher chances of coccygodynia postoperatively. Conclusion

  20. New parameters to represent the position of the aorta relative to the spine for pedicle screw placement.

    Science.gov (United States)

    Takeshita, Katsushi; Maruyama, Toru; Ono, Takashi; Ogihara, Satoshi; Chikuda, Hirotaka; Shoda, Naoki; Nakao, Yusuke; Matsudaira, Ko; Seichi, Atsushi; Nakamura, Kozo

    2010-05-01

    Parameters of the position of the aorta in previous reports were determined for anterior surgery. This study evaluated the relative position of the aorta to the spine by new parameters, which could enhance the safety of pedicle screw placement. Three parameters were defined in a new Cartesian coordinate system. We selected an entry point of a left pedicle screw as the origin. The transverse plane was determined to include both the bases of the superior facet and to be parallel to the upper endplate of the vertebral body. A line connecting the entry points of both sides was defined as the X-axis. The angle formed by the Y-axis and a line connecting the origin and the center of the aorta was defined as the left pedicle-aorta angle. The length of a line connecting the origin and the aorta edge was defined as the left pedicle-aorta distance. Distance from the edge of the aorta to the X-axis was defined as the pedicular line-aorta distance. These parameters were measured preoperatively in 293 vertebral bodies of 24 patients with a right thoracic curve. We simulated the placement of the pedicle screw with variable length and with some direction error. We defined a warning pedicle as that when the aorta enters the expected area of the screw. Sensitivity analysis was performed to find the warning pedicle ratio in 12 scenarios. The left pedicle-aorta angle averaged 29.7 degrees at the thoracic spine and -16.3 degrees at the lumbar spine; the left pedicle-aorta distance averaged 23.7 and 55.2 mm; the pedicular line-aorta distance averaged 18.3 and 51.0 mm, respectively. The ratio of warning pedicles was consistently high at T4-5 and T10-12. When a left pedicle screw perforates an anterior/lateral wall of the vertebral body, the aorta may be at risk. These new parameters enable surgeons to intuitively understand the position of the aorta in surgical planning or in placement of a pedicle screw.

  1. C1-c2 pedicle screw fixation for treatment of old odontoid fractures.

    Science.gov (United States)

    Qi, Lei; Li, Mu; Zhang, Shuai; Si, Haipeng; Xue, Jingsong

    2015-02-01

    Nonunion and C1-C2 instability of odontoid fractures usually result from delayed diagnosis and inappropriate treatment. However, the available treatment options for odontoid fractures remain controversial. The authors evaluated the effectiveness of internal screw fixation via the C1 and C2 pedicle in cases of old odontoid fractures. This retrospective study included 21 patients with old odontoid fractures (13 men and 8 women; mean age, 46.5 years; range, 24-69 years). Internal screw fixation via the C1 and C2 pedicle was performed in all patients. Fracture reduction and C1-C2 fusion were assessed with imaging. The neck pain visual analog scale score and cervical spinal cord functional Japanese Orthopaedic Association score (for those who had cervical spinal cord injury) were used to evaluate the effectiveness of treatment. Postoperative complications were recorded. Postoperative imaging showed that the C1-C2 dislocation was satisfactorily repositioned in all patients. Bone fusion was observed 1 year after surgery in all patients. No loosening or breaking of internal fixation occurred. The preoperative neck pain visual analog scale score was 5.9±1.5 and improved significantly to 1.8±0.8 after surgery (PC2 pedicle was found to be an effective and safe surgical approach for the treatment of old odontoid fractures with C1-C2 dislocation or instability.

  2. Biomechanical assessment of unilateral pedicle screws plus contralateral transfacetopedicular screws after transforaminal lumbar interbody fusion with two cages.

    Science.gov (United States)

    Xue, Zhong-Lin; Chen, Zhong-Xian; Fu, Chao-Hua; Lei, Hong-Jun; Yuan, Xiang-Wei

    2013-11-01

    To assess the biomechanical stability of unilateral pedicle screws (UPS) plus contralateral transfacetopedicular screws (TFPS) after transforaminal lumbar interbody fusion (TLIF) with two cages. Range of motion (ROM) testing was performed in 28 fresh-frozen human cadaveric lumbar spine motion segments. The sequential test configurations included supplemental constructs after TLIF such as UPS, UPS plus contralateral TFPS and bilateral pedicle screws (BPS). All test specimens were fixated in the normal lordotic lignment, then mounted in a three-dimensional (3-D) motion testing machine and fixed to the load frame of a six degrees of freedom spine simulator. Each of the test constructs were subjected to three load-unload cycles in each of the physiologic planes generating flexion-extension, right-left lateral bending and right-left axial rotation load-displacement curves. Statistical analysis was performed on the ROM data. Comparison of data was performed by repeated-measures analysis of variance for independent samples followed by Bonferroni analysis for multiple comparison procedures. The ROMs for UPS, BPS and UPS plus TFPS fixation after TLIF were significantly smaller than those of the intact spine in all modes. The ROM for UPS plus TFPS fixation was between the largest for UPS and the smallest for BPS. The differences between ROMs of UPS and UPS plus TFPS were significant for both lateral bending and rotation. There were no significant differences between BPS and UPS plus TFPS in any mode. Because the UPS construct provides the least stability, especially during lateral bending and rotation, it should be used prudently. After TLIF with two cages, UPS plus TFPS provides stability comparable to that of TLIF with BPS. It is thus an acceptable option in minimally invasive surgery. © 2013 Chinese Orthopaedic Association and Wiley Publishing Asia Pty Ltd.

  3. Feasibility study of patient-specific surgical templates for the fixation of pedicle screws.

    Science.gov (United States)

    Salako, F; Aubin, C-E; Fortin, C; Labelle, H

    2002-01-01

    Surgery for scoliosis, as well as other posterior spinal surgeries, frequently uses pedicle screws to fix an instrumentation on the spine. Misplacement of a screw can lead to intra- and post-operative complications. The objective of this study is to design patient-specific surgical templates to guide the drilling operation. From the CT-scan of a vertebra, the optimal drilling direction and limit angles are computed from an inverse projection of the pedicle limits. The first template design uses a surface-to-surface registration method and was constructed in a CAD system by subtracting the vertebra from a rectangular prism and a cylinder with the optimal orientation. This template and the vertebra were built using rapid prototyping. The second design uses a point-to-surface registration method and has 6 adjustable screws to adjust the orientation and length of the drilling support device. A mechanism was designed to hold it in place on the spinal process. A virtual prototype was build with CATIA software. During the operation, the surgeon places either template on patient's vertebra until a perfect match is obtained before drilling. The second design seems better than the first one because it can be reused on different vertebra and is less sensible to registration errors. The next step is to build the second design and make experimental and simulations tests to evaluate the benefits of this template during a scoliosis operation.

  4. Navigation of Pedicle Screws in the Thoracic Spine with a New Electromagnetic Navigation System: A Human Cadaver Study

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    Patrick Hahn

    2015-01-01

    Full Text Available Introduction. Posterior stabilization of the spine is a standard procedure in spinal surgery. In addition to the standard techniques, several new techniques have been developed. The objective of this cadaveric study was to examine the accuracy of a new electromagnetic navigation system for instrumentation of pedicle screws in the spine. Material and Method. Forty-eight pedicle screws were inserted in the thoracic spine of human cadavers using EMF navigation and instruments developed especially for electromagnetic navigation. The screw position was assessed postoperatively by a CT scan. Results. The screws were classified into 3 groups: grade 1 = ideal position; grade 2 = cortical penetration <2 mm; grade 3 = cortical penetration ≥2 mm. The initial evaluation of the system showed satisfied positioning for the thoracic spine; 37 of 48 screws (77.1%, 95% confidence interval [62.7%, 88%] were classified as group 1 or 2. Discussion. The screw placement was satisfactory. The initial results show that there is room for improvement with some changes needed. The ease of use and short setup times should be pointed out. Instrumentation is achieved without restricting the operator’s mobility during navigation. Conclusion. The results indicate a good placement technique for pedicle screws. Big advantages are the easy handling of the system.

  5. Improving fixation strength of pedicle screw by microarc oxidation treatment: an experimental study of osteoporotic spine in sheep.

    Science.gov (United States)

    Shi, Lei; Wang, Ling; Zhang, Yang; Guo, Zheng; Wu, Zi-xiang; Liu, Da; Gao, Ming-xuan; Chen, Huan; Fu, Suo-chao; Lei, Wei

    2012-08-01

    Failure of fixation caused by loosening of pedicle screws in osteoporosis is a problem in spinal surgery. We compared the in vivo fixation strength between pedicle screws treated with microarc oxidation (MAO) and untreated screws in an osteoporotic model of ovariectomized sheep. The MAO treated and untreated screws were placed in lumbar vertebral bodies. After 3 months of implantation, biomechanical tests, micro-CT analysis, and histological observations were conducted to examine the performance of the two groups. At time 0, no significant difference was found between the two groups in biomechanical tests (p > 0.05); 3 months later, higher pull-out strength and load with less displacement were detected in the MAO-treated group (p sheep.

  6. Comparison of therapeutic effect between percutaneous kyphoplasty and pedicle screw system on vertebral compression fracture

    Institute of Scientific and Technical Information of China (English)

    MING Jiang-hua; ZHOU Jian-lin; ZHOU Pang-hu; ZHOU Jian-peng

    2007-01-01

    Objective:To compare the clinical efficacy of percutaneous kyphoplasty (PKP) with pedicle screw system(PS) in the treatment of vertebral compression fracture(VCF). Methods:Eighty-six patients with VCF were treated either by PKP (Group A,n = 30) ) or PS ( Group B,n =56).The anterior,intermediate,and posterior heights of the vertebrae body,visual analogue pain scale(VAS) before and after operation,the duration of operation,and amount of blood loss between two groups were compared. Results:No statistical difference was noted regarding the vertebral height between two groups. Significant difference was seen in VAS,duration of operation and amount of blood loss between the two groups ( P < 0.01). Conclusions:Percutaneous kyphoplasty has the similar therapeutic efficacy with pedicle screw system in treatment of VCF with a minimal invasion,less operation time and blood loss. For those with posterior wall destruction,PS is deemed favorable.

  7. CORRELATION BETWEEN QUALITY OF LIFE AND OSTEOLYSIS AROUND LUMBAR PEDICLE SCREWS

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    MARCELO ITALO RISSO NETO

    Full Text Available ABSTRACT Objective: To evaluate whether the presence of osteolysis around the pedicle screws affects the quality of life of patients who underwent posterolateral arthrodesis of the lumbosacral spine. Methods: A retrospective study of patients undergoing lumbar posterolateral or lumbosacral arthrodesis due to spinal degenerative disease. CT scans of the operated segments were performed at intervals of 45, 90, 180, and 360 postoperatively. In these tests, the presence of a peri-implant radiolucent halo was investigated, which was considered present when greater than 1mm in the coronal section. Concurrently with the completion of CT scans, the participants completed the questionnaire Oswestry Disability Index (ODI to assess the degree of disability of the patients. Results: A total of 38 patients were evaluated, and 14 (36.84% of them showed some degree of osteolysis around at least one pedicle screw at the end of follow-up. Of the 242 analyzed screws, 27 (11.15% had osteolysis in the CT coronal section, with the majority of these occurrences located at the most distal level segment of the arthrodesis. There was no correlation between the presence of the osteolysis to the quality of life of patients. The quality of life has significantly improved when comparing the preoperative results with the postoperative results at different times of application of ODI. This improvement in ODI maintains linearity over time. Conclusion: There is no correlation between the presence of peri-implant osteolysis to the quality of life of patients undergoing lumbar or posterolateral lumbosacral arthrodesis in the follow-up period up to 360 days. The quality of life in postoperative has significantly improvement when compared to the preoperative period.

  8. Micro-CT evaluation and histological analysis of screw-bone interface of expansive pedicle screw in osteoporotic sheep

    Institute of Scientific and Technical Information of China (English)

    WAN Shi-yong; LEI Wei; WU Zi-xiang; L(U) Rong; WANG Jun; FU Suo-chao; LI Bo; ZHAN Ce

    2008-01-01

    To investigate the properties of screwbone interface of expansive pedicle screw(EPS)in osteoporotic sheep by micro-CT and histological observation.Methods:Six female sheep with bilateral ovariectomyinduced osteoporosis were employed in this experiment.After EPS insertion in each femoral condvle, the sheep were randomly divided into two groups:3 sheep were bred for 3 months(Group A),while the other 3 were bred for 6 months(Group B). After the animals being killed,the femoral condyles with EPS were obtained,which were three-dimensionally-imaged and reconstructed by micro-CT. Histological evaluation was made thereafter.Results:The trabecular microstructure was denser at the screw-bone interface than in the distant parts in expansive section,especially within the spiral marking.In the nonexpansive section,however,there was no significant difference between the interface and the distant parts. The regions of interest(ROI)adjacent to EPS were reconstructed and analyzed by micro-CT with the same thresholds. The three-dimensional(3-D)parameters,including tissue mineral density(TMD),bone volume fraction(BVF,BV/TV),bone surface/bone volume(BS/BV) ratio, trabecular thickness(Tb. Th),and trabecular separation(Tb. Sp),were significantly better in expansive sections than non-expansive sections(P<0.05).Histologically,newly-formed bony trabeculae crawled along the expansive fissures and into the center of EPS. The newly-formed bones,as well as the bones at the bone-screw interface,closely contacted with the EPS and constructed four compartments.Conclusions:The findings of the current study,based on micro-CT and histological evaluation, suggest that EPS can significantly provide stabilization in osteoporotic cancellous bones.

  9. Learning curve of 3D fluoroscopy image-guided pedicle screw placement in the thoracolumbar spine.

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    Ryang, Yu-Mi; Villard, Jimmy; Obermüller, Thomas; Friedrich, Benjamin; Wolf, Petra; Gempt, Jens; Ringel, Florian; Meyer, Bernhard

    2015-03-01

    During the past decade, a disproportionate increase of spinal fusion procedures has been observed. Along with this trend, image-guided spine surgery has been experiencing a renaissance in the recent years. A wide range of different navigation systems are available on the market today. However, only few published studies assess the learning curves concerning these new spinal navigation techniques. So far, a study on the learning curve for intraoperative three-dimensional fluoroscopy (3DFL)-navigated pedicle screw (PS) placement is still lacking. The purpose of the study was to analyze the learning curve for 3DFL-navigated thoracolumbar PS placement. The study design included a prospective case series. A cohort of 145 patients were recruited from January 2011 to June 2012. The outcome measures were duration of intraoperative 3D scans, PS placement, PS accuracy on postoperative computed tomography (CT) scans, and PS-related revisions and complications. From the introduction of spinal navigation to our department in January 2011 until June 2012, the learning curve for the duration of intraoperative 3D scan acquisition (navigation or control scan) and placement time per screw, intraoperative screw revisions, screw-related complications, revision surgeries, and PS accuracy on postoperative CT scans were assessed in 145 patients undergoing dorsal navigated instrumentation for 928 PS (736 lumbosacral and 192 thoracic). The observed time span was divided into four intervals. Results of the second, third, and last periods were compared with the first (reference) period, respectively. The mean navigation 3D scan time decreased (first and fourth periods) from 15.4±7.8 (range, 4-40) to 8.4±3.3 (3-15) minutes (plearning effect was found with respect to intraoperative screw revisions. There was one revision surgery. We could demonstrate significant learning effects for 3DFL-navigated PS placement with regard to intraoperative 3D scan acquisition, PS placement time, and PS

  10. Metal artifacts reduction using monochromatic images from spectral CT: Evaluation of pedicle screws in patients with scoliosis

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    Wang, Yang, E-mail: wangzhang227@163.com [Department of Radiology, The Affiliated Nanjing Drum Tower Hospital of Nanjing University Medical School, Nanjing 210008 (China); Qian, Bangping, E-mail: qianbangping@163.com [Spine Service, Drum Tower Hospital, Nanjing University Medical School, Nanjing 210008 (China); Li, Baoxin, E-mail: wangzhi68@163.com [Department of Radiology, The Affiliated Nanjing Drum Tower Hospital of Nanjing University Medical School, Nanjing 210008 (China); Qin, Guochu, E-mail: qgc7605@yahoo.com.cn [Department of Radiology, The Affiliated Nanjing Drum Tower Hospital of Nanjing University Medical School, Nanjing 210008 (China); Zhou, Zhengyang, E-mail: zyzhou@nju.edu.cn [Department of Radiology, The Affiliated Nanjing Drum Tower Hospital of Nanjing University Medical School, Nanjing 210008 (China); Qiu, Yong, E-mail: scoliosis2002@sina.com [Spine Service, Drum Tower Hospital, Nanjing University Medical School, Nanjing 210008 (China); Sun, Xizhao, E-mail: sunxizhaonj@163.com [Department of Radiology and Urology, The Affiliated Nanjing Drum Tower Hospital of Nanjing University Medical School, No. 321 Zhongshan Road, Nanjing 210008 (China); Zhu, Bin, E-mail: gobin10266@163.com [Department of Radiology, The Affiliated Nanjing Drum Tower Hospital of Nanjing University Medical School, Nanjing 210008 (China)

    2013-08-15

    Purpose: To evaluate the effectiveness of spectral CT in reducing metal artifacts caused by pedicle screws in patients with scoliosis. Materials and methods: Institutional review committee approval and written informed consents from patients were obtained. 18 scoliotic patients with a total of 228 pedicle screws who underwent spectral CT imaging were included in this study. Monochromatic image sets with and without the additional metal artifacts reduction software (MARS) correction were generated with photon energy at 65 keV and from 70 to 140 keV with 10 keV interval using the 80 kVp and 140 kVp projection sets. Polychromatic images corresponded to the conventional 140 kVp imaging were also generated from the same scan data as a control group. Both objective evaluation (screw width and quantitative artifacts index measurements) and subjective evaluation (depiction of pedicle screws, surrounding structures and their relationship) were performed. Results: Image quality of monochromatic images in the range from 110 to 140 keV (0.97 ± 0.28) was rated superior to the conventional polychromatic images (2.53 ± 0.54) and also better than monochromatic images with lower energy. Images of energy above 100 keV also give accurate measurement of the width of screws and relatively low artifacts index. The form of screws was slightly distorted in MARS reconstruction. Conclusions: Compared to conventional polychromatic images, monochromatic images acquired from dual-energy CT provided superior image quality with much reduced metal artifacts of pedicle screws in patients with scoliosis. Optimal energy range was found between 110 and 140 keV.

  11. Comparative Analysis of Interval, Skipped, and Key-vertebral Pedicle Screw Strategies for Correction in Patients With Lenke Type 1 Adolescent Idiopathic Scoliosis.

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    Wang, Fei; Xu, Xi-Ming; Lu, Yanghu; Wei, Xian-Zhao; Zhu, Xiao-Dong; Li, Ming

    2016-03-01

    Pedicle screw constructs have become the mainstay for surgical correction in patients with spinal deformities. To reduce or avoid the risk of pedicle screw-based complications and to decrease the costs associated with pedicle screw instrumentation, some authors have introduced interval, skipped, and key-vertebral pedicle screw strategies for correction. However, there have been no comparisons of outcomes among these 3 pedicle screw-placement strategies.The aim of this study was to compare the correlative clinical outcomes of posterior correction and fusion with pedicle screw fixation using these 3 surgical strategies.Fifty-six consecutive patients with Lenke type 1 adolescent idiopathic scoliosis were included in this study. Twenty patients were treated with the interval pedicle screw strategy (IPSS), 20 with the skipped pedicle screw strategy (SPSS), and 16 with the key-vertebral pedicle screw strategy (KVPSS). Coronal and sagittal radiographs were analyzed before surgery, at 1 week after surgery, and at the last follow-up after surgery.There were no significant differences among the 3 groups regarding preoperative radiographic parameters. No significant difference was found between the IPSS and SPSS groups in correction of the main thoracic curve (70.8% vs 70.0%; P = 0.524). However, there were statistically significant differences between the IPSS and KVPSS groups (70.8% vs 64.9%) and between the SPSS and KVPSS groups (70.0% vs 64.9%) in correction of the main thoracic curve (P SPSS group was significantly higher than those in the IPSS (P SPSS and KVPSS groups (P SPSS, it can achieve a satisfactory clinical outcome and is more cost-effective.

  12. Minimally invasive unilateral pedicle screw fixation and lumbar interbody fusion for the treatment of lumbar degenerative disease.

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    Lin, Bin; Xu, Yang; He, Yong; Zhang, Bi; Lin, Qiuyan; He, Mingchang

    2013-08-01

    Minimally invasive unilateral pedicle screw fixation for the treatment of degenerative lumbar diseases has won the support of many surgeons. However, few data are available regarding clinical research on unilateral pedicle screw fixation associated with minimally invasive techniques for the treatment of lumbar spinal diseases. The purpose of this study was to evaluate clinical outcomes in a selected series of patients with lumbar degenerative diseases treated with minimally invasive unilateral vs classic bilateral pedicle screw fixation and lumbar interbody fusion. Patients in the unilateral group (n=43) underwent minimally invasive unilateral pedicle screw fixation with the Quadrant system (Medtronic, Memphis, Tennessee). The bilateral group (n=42) underwent bilateral instrumentation via the classic approach. Visual analog scale pain scores, Oswestry Disability Index scores, fusion rate, operative time, blood loss, and complications were analyzed. Mean operative time was 75 minutes in the unilateral group and 95 minutes in the bilateral group. Mean blood loss was 220 mL in the unilateral group and 450 mL in the bilateral group. Mean postoperative visual analog scale pain score was 3.10±0.16 in the unilateral group and 3.30±1.10 in the bilateral group. Mean postoperative Oswestry Disability Index score was 15.67±2.3 in the unilateral group and 14.93±2.6 in the bilateral group. Successful fusion was achieved in 92.34% of patients in the unilateral group and 93.56% of patients in the bilateral group. Minimally invasive unilateral pedicle screw fixation is an effective and reliable option for the surgical treatment of lumbar degenerative disease. It causes less blood loss, requires less operative time, and has a fusion rate comparable with that of conventional bilateral fixation. Copyright 2013, SLACK Incorporated.

  13. Addressing Stretch Myelopathy in Multilevel Cervical Kyphosis with Posterior Surgery Using Cervical Pedicle Screws

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    Mahesh, Bijjawara; Vijay, Shekarappa; Arun, Kumar; Srinivasa, Reddy

    2016-01-01

    Study Design Technique description and retrospective data analysis. Purpose To describe the technique of cervical kyphosis correction with partial facetectomies and evaluate the outcome of single-stage posterior decompression and kyphosis correction in multilevel cervical myelopathy. Overview of Literature Kyphosis correction in multilevel cervical myelopathy involves anterior and posterior surgery. With the advent of cervical pedicle screw-rod instrumentation, single-stage posterior kyphosis correction is feasible and can address stretch myelopathy by posterior shortening. Methods Nine patients underwent single-stage posterior decompression and kyphosis correction for multilevel cervical myelopathy using cervical pedicle screw instrumentation from March 2011 to February 2014 and were evaluated preoperatively and postoperatively with modified Japanese Orthopaedic Association (mJOA) scoring and computed tomography scans for radiological measurements. Kyphosis assessment was made with Ishihara curvature index and C2–C7 Cobb's angle. The linear length of the spinal canal and the actual spinal canal length were also evaluated. The average follow-up was 40.56 months (range, 20 to 53 months). Results The average preoperative C2–7 Cobb's angle of 6.3° (1° to 12°) improved to 2° (10° to −9°). Ishihara index improved from −15.8% (−30.5% to −4.7%) to −3.66% (−14.5% to +12.6%). The actual spinal canal length decreased from 83.64 mm (range, 76.8 to 91.82 mm) to 82.68 mm (range, 75.85 to 90.78 mm). The preoperative mJOA score of 7.8 (range, 3 to 11) improved to 15.0 (range, 13 to 17). Conclusions Single-stage posterior decompression and kyphosis correction using cervical pedicle screws for multilevel cervical myelopathy may address stretch myelopathy, in addition to decompression in the transverse plane. However, cervical lordosis was not achieved with this method as predictably as by the anterior approach. The present study shows evidence of mild

  14. Treatment of dystrophic scoliosis in neurofibromatosis Type 1 with one-stage posterior pedicle screw technique.

    Science.gov (United States)

    Wang, Zhenyu; Fu, Changfeng; Leng, Jiali; Qu, Zhigang; Xu, Feng; Liu, Yi

    2015-04-01

    Corrective surgery for dystrophic scoliosis in neurofibromatosis Type 1 (NF-1) is challenging. There are various surgical methods, all with unsatisfactory outcomes. The purpose of the study was to evaluate the clinical outcomes of the treatment of dystrophic scoliosis in NF-1 with one-stage posterior pedicle screw approach. This is a retrospective clinical study. Sixteen patients with dystrophic scoliosis in NF-1 underwent one-stage posterior surgery with pedicle screw system. We used preoperative and postoperative whole-spine radiographs to determine coronal and sagittal Cobb angles (curve correction); distance between apex vertebra and central sacral vertical line (DAC), pelvic obliquity, and shoulder tilt (coronal balance improvement); and sagittal vertical axis and pelvic tilt angle (sagittal balance improvement). We assessed the fusion rate using fusion segment computed tomography scan. Patients underwent surgery with or without osteotomy according to spinal flexibility. Fusion segment selection method of fusion segments selection which mean fusing from one or two levels proximal to upper end vertebra to one or two levels distal to the lower end vertebra (EV+1 or 2) or stable vertebrae fusion. There were no study-specific conflict of interest-associated biases. The average follow-up time was 40.9 months. Mean scoliosis and kyphosis improved from 83.2° to 27.6° and 58.5° to 26.8°, respectively; at the last follow-up, it was 30.4° and 27.4°, respectively. Mean DAC, pelvic obliquity, and shoulder tilt improved from 53.0 to 23.9, 8.1 to 4.9, and 9.8 to 7.5 mm, respectively. Sagittal vertical axis and pelvic tilt angle improved from -5.8 to 1.6 mm and 17.9° to -5.8°, respectively. During follow-up, mean coronal and sagittal correction losses were 2.8° and 0.7°, respectively. Two EV+1 or 2 patients had decompensation. No pseudoarthrosis was identified. The one-stage posterior pedicle screw approach is safe and effective in the treatment of dystrophic

  15. The accuracy of the lateral vertebral notch-referred pedicle screw insertion technique in subaxial cervical spine: a human cadaver study.

    Science.gov (United States)

    Luo, Jiaquan; Wu, Chunyang; Huang, Zhongren; Pan, Zhimin; Li, Zhiyun; Zhong, Junlong; Chen, Yiwei; Han, Zhimin; Cao, Kai

    2017-04-01

    This is a cadaver specimen study to confirm new pedicle screw (PS) entry point and trajectory for subaxial cervical PS insertion. To assess the accuracy of the lateral vertebral notch-referred PS insertion technique in subaxial cervical spine in cadaver cervical spine. Reported morphometric landmarks used to guide the surgeon in PS insertion show significant variability. In the previous study, we proposed a new technique (as called "notch-referred" technique) primarily based on coronal multiplane reconstruction images (CMRI) and cortical integrity after PS insertion in cadavers. However, the PS position in cadaveric cervical segment was not confirmed radiologically. Therefore, the difference between the pedicle trajectory and the PS trajectory using the notch-referred technique needs to be illuminated. Twelve cadaveric cervical spines were conducted with PS insertion using the lateral vertebral notch-referred technique. The guideline for entry point and trajectory for each vertebra was established based on the morphometric data from our previous study. After 3.5-mm diameter screw insertion, each vertebra was dissected and inspected for pedicle trajectory by CT scan. The pedicle trajectory and PS trajectory were measured and compared in axial plane. The perforation rate was assessed radiologically and was graded from ideal to unacceptable: Grade 0 = screw in pedicle; Grade I = perforation of pedicle wall less than one-fourth of the screw diameter; Grade II = perforation more than one-fourth of the screw diameter but less than one-second; Grade III = perforation more than one-second outside of the screw diameter. In addition, pedicle width between the acceptable and unacceptable screws was compared. A total of 120 pedicle screws were inserted. The perforation rate of pedicle screws was 78.3% in grade 0 (excellent PS position), 10.0% in grade I (good PS position), 8.3% in grade II (fair PS position), and 3.3% in grade III (poor PS position). The

  16. Effect of different inner core diameters on structural strength of cannulated pedicle screws under various lumbar spine movements.

    Science.gov (United States)

    Chang, Chia-Ming; Lai, Yu-Shu; Cheng, Cheng-Kung

    2017-08-15

    Currently, cannulated pedicle screws have been widely used in minimal invasive or navigation techniques. However, the stress distribution and the strength of different core diameters of cannulated screw are not clear. This study aimed to investigate the mechanical strength of cannulated screws with different inner core diameter under various lumbar spine movements using finite element analysis. The results showed that the von-Mises stress of a cannulated screw was larger than that of a solid screw in all loading conditions, especially above 2 mm in cannulated core diameter. In lateral bending, extension, and flexion, the maximum von-Mises stress was found approximate to the proximal thread for all types of screws. In rotation condition, the maximum von-Mises stress was located at the middle of the screw. Additionally, the difference in stiffness of instrumented levels was not significant among four screws under the same loading condition. Cannulated screws could provide enough stability for the vertebral body fusion comparing to solid screws. The diameter of cannulated core is suggested not to exceed 2.0 mm.

  17. "NIMS technique" for minimally invasive spinal fixation using non-fenestrated pedicle screws: A technical note

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    Alugolu Rajesh

    2015-01-01

    Full Text Available Study Design: Case series. Objective: To reduce the cost of minimally invasive spinal fixation. Background: Minimally invasive spine (MIS surgery is an upcoming modality of managing a multitude of spinal pathologies. However, in a resource-limited situations, using fenestrated screws (FSs may prove very costly for patients with poor affordability. We here in describe the Nizam′s Institute of Medical Sciences (NIMS experience of using routine non-FSs (NFSs for transpedicular fixation by the minimally invasive way to bridge the economic gap. Materials and Methods: A total of 7 patients underwent NFS-minimally invasive spine (MIS surgery. Male to female distribution was 6:1. The average blood loss was 50 ml and the mean operating time was 2 and 1/2 h. All patients were mobilized the very next day after confirming the position of implants on X-ray/computed tomography. Results: All 7 patients are doing well in follow-up with no complaints of a backache or fresh neurological deficits. There was no case with pedicle breach or screw pullout. The average cost of a single level fixation by FS and NFS was `1, 30,000/patient and `32,000/patient respectively ($2166 and $530, respectively. At the end of 1-year follow-up, we had two cases of screw cap loosening and with a displacement of the rod cranio-caudally in one case which was revised through the same incisions. Conclusions: Transpedicular fixation by using NFS for thoracolumbar spinal pathologies is a cost-effective extension of MIS surgery. This may extend the benefits to a lower socioeconomic group who cannot afford the cost of fenestrated screw (FS.

  18. Percutaneous pedicle screw for unstable spine fractures in polytraumatized patients: A report of two cases

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    Boon Beng Tan

    2012-01-01

    Full Text Available Unstable spine fractures commonly occur in the setting of a polytraumatized patient. The aim of management is to balance the need for early operative stabilization and prevent additional trauma due to the surgery. Recent published literature has demonstrated the benefits of early stabilization of an unstable spine fracture particularly in patients with higher injury severity score (ISS. We report two cases of polytrauma with unstable spine fractures stabilized with a minimally invasive percutaneous pedicle screw instrumentation system as a form of damage control surgery. The patients had good recovery from the polytrauma injuries. These two cases illustrate the role of minimally invasive stabilization, its limitations and technical pitfalls in the management of unstable spine fractures in the polytrauma setting as a form of damage control surgery.

  19. Bone cement enhanced pedicle screw fixation combined with vertebroplasty for elderly patients with malignant spinal tumors

    Institute of Scientific and Technical Information of China (English)

    TAN Jiang-wei; SHEN Bing-hua; DU Wei; LIU Jiang-qing; LU Shi-qiao

    2013-01-01

    Background Older patients with malignant spinal tumors are difficult to treat because they have many co-morbidities including osteoporosis.The purpose of this research is to discuss the technique and clinical outcome of bone cement enhanced pedicle screw fixation combined with vertebroplasty (the Sandwich Procedure) for elderly patients with severe osteoporosis and malignant spinal tumors.Methods This study includes 28 consecutive elderly patients with malignant thoracic or lumbar spinal tumors.There were nine patients with myelomas,and 19 patients with metastatic bone tumors.The Sandwich Procedure began with curettage of the tumor and a vertebroplasty with bone cement (polymethyl methacrylate,PMMA),followed by PMMA enhanced pedicle screw fixation.Patients were evaluated with the visual analogue scale (VAS),oswestry disability index (ODI),American Spinal Cord Injury Association (ASIA) neurological function classification,and the radiographic degree of kyphosis (Cobb angle).Data were analyzed using paired t-test to compare the pre-and post-operative values.The complications,local recurrences,and the survival status were also recorded.Results There was no operative mortality,and the mean operative time was 210 minutes (range 150-250 minutes).The average blood loss was 1550 ml (range 650-3300 ml).The average amount of cement for vertebroplasty was 3.6 ml (range 3-5 ml).The VAS,ODI,and ASIA scores were significantly improved after surgery (P <0.05).However,we found no differences between the pre and post-operative Cobb angles.The shortest survival time was 3 months,and we found no evidence of local recurrence in this group of patients.Conclusion The Sandwich Procedure is a safe operation and provides symptomatic relief in these difficult patients,permitting further treatment with chemotherapy or radiotherapy.

  20. Comparison of interfaces of different pedicle screws with micro-CT technique in lumbar vertebrae with osteoporosis of sheep

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    Da LIU

    2015-07-01

    Full Text Available Objective To compare the changes in interfaces of expandable pedicle screw (EPS and polymethylmethacrylateenhanced pedicle screw (PMMA-PS after being used in osteoporotic sheep lumbar vertebrae with micro-CT technique. Methods Six lumbar vertebrae (L1-L6 in each sheep were randomly divided into three different screw-insertion groups (two vertebrae with four pedicles in each group after reproduction of osteoporosis in sheep. After making the pilot hole using the same method, CPS was inserted through the pilot hole into vertebral body in CPS group, while PMMA (1.0ml was injected into the pilot hole prior to the insertion of CPS in PMMA-PS group, and EPS was inserted through pedicle into vertebral body in EPS group. All the sheep were sacrificed, and lumbar vertebrae (L1-L6 were harvested respectively at the 6- and 12-week postoperatively. The micro-CT three dimensional reconstruction and histomorphometric analysis were performed to evaluate the interfacial conditions. Results  It was clearly demonstrated that interface was formed where the bone trabeculae was directly in contact with the screw to form "screw-bone" interface in both CPS and EPS groups both 6 weeks and 12 weeks after the operation. The screw was fully surrounded by PMMA and formed "screw-PMMA-bone" interface in PMMA-PS group. The anterior part of EPS expanded in vertebral body to form a clawlike structure, pressing against the surrounding bone trabeculae, thus significantly improved the local bone quality (amount and density of bone trabeculae. From 6 weeks to 12 weeks after the operation, there was no visual difference in bone quality around the screw in both CPS and PMMA-PS groups. There was no degradation and absorption of PMMA, and it led to form the second non-biological interface in PMMA-PS group. Nevertheless, bone quality around expanding part of EPS at 12-week post-operation was significantly improved compared with that at 6-week post-operation, thus forming a good

  1. A robot-assisted surgical system using a force-image control method for pedicle screw insertion.

    Directory of Open Access Journals (Sweden)

    Wei Tian

    Full Text Available OBJECTIVE: To introduce a robot-assisted surgical system for spinal posterior fixation that can automatically recognize the drilling state and stop potential cortical penetration with force and image information and to further evaluate the accuracy and safety of the robot for sheep vertebra pedicle screw placement. METHODS: The Robotic Spinal Surgery System (RSSS was composed of an optical tracking system, a navigation and planning system, and a surgical robot equipped with a 6-DOF force/torque sensor. The robot used the image message and force signals to sense the different operation states and to prevent potential cortical penetration in the pedicle screw insertion operation. To evaluate the accuracy and safety of the RSSS, 32 screw insertions were conducted. Furthermore, six trajectories were deliberately planned incorrectly to explore whether the robot could recognize the different drilling states and immediately prevent cortical penetration. RESULTS: All 32 pedicle screws were placed in the pedicle without any broken pedicle walls. Compared with the preoperative planning, the average deviations of the entry points in the axial and sagittal views were 0.50 ± 0.33 and 0.65 ± 0.40 mm, and the average deviations of the angles in the axial and sagittal views were 1.9 ± 0.82° and 1.48 ± 1.2°. The robot successfully recognized the different drilling states and prevented potential cortical penetration. In the deliberately incorrectly planned trajectory experiments, the robot successfully prevented the cortical penetration. CONCLUSION: These results verified the RSSS's accuracy and safety, which supported its potential use for the spinal surgery.

  2. A robot-assisted surgical system using a force-image control method for pedicle screw insertion.

    Science.gov (United States)

    Tian, Wei; Han, Xiaoguang; Liu, Bo; Liu, Yajun; Hu, Ying; Han, Xiao; Xu, Yunfeng; Fan, Mingxing; Jin, Haiyang

    2014-01-01

    To introduce a robot-assisted surgical system for spinal posterior fixation that can automatically recognize the drilling state and stop potential cortical penetration with force and image information and to further evaluate the accuracy and safety of the robot for sheep vertebra pedicle screw placement. The Robotic Spinal Surgery System (RSSS) was composed of an optical tracking system, a navigation and planning system, and a surgical robot equipped with a 6-DOF force/torque sensor. The robot used the image message and force signals to sense the different operation states and to prevent potential cortical penetration in the pedicle screw insertion operation. To evaluate the accuracy and safety of the RSSS, 32 screw insertions were conducted. Furthermore, six trajectories were deliberately planned incorrectly to explore whether the robot could recognize the different drilling states and immediately prevent cortical penetration. All 32 pedicle screws were placed in the pedicle without any broken pedicle walls. Compared with the preoperative planning, the average deviations of the entry points in the axial and sagittal views were 0.50 ± 0.33 and 0.65 ± 0.40 mm, and the average deviations of the angles in the axial and sagittal views were 1.9 ± 0.82° and 1.48 ± 1.2°. The robot successfully recognized the different drilling states and prevented potential cortical penetration. In the deliberately incorrectly planned trajectory experiments, the robot successfully prevented the cortical penetration. These results verified the RSSS's accuracy and safety, which supported its potential use for the spinal surgery.

  3. Percutaneous pedicle screw reduction and axial presacral lumbar interbody fusion for treatment of lumbosacral spondylolisthesis: A case series

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    Miller Larry E

    2011-09-01

    Full Text Available Abstract Introduction Traditional surgical management of lumbosacral spondylolisthesis is technically challenging and is associated with significant complications. The advent of minimally invasive surgical techniques offers patients treatment alternatives with lower operative morbidity risk. The combination of percutaneous pedicle screw reduction and an axial presacral approach for lumbosacral discectomy and fusion offers an alternative procedure for the surgical management of low-grade lumbosacral spondylolisthesis. Case presentation Three patients who had L5-S1 grade 2 spondylolisthesis and who presented with axial pain and lumbar radiculopathy were treated with a minimally invasive surgical technique. The patients-a 51-year-old woman and two men (ages 46 and 50-were Caucasian. Under fluoroscopic guidance, spondylolisthesis was reduced with a percutaneous pedicle screw system, resulting in interspace distraction. Then, an axial presacral approach with the AxiaLIF System (TranS1, Inc., Wilmington, NC, USA was used to perform the discectomy and anterior fixation. Once the axial rod was engaged in the L5 vertebral body, further distraction of the spinal interspace was made possible by partially loosening the pedicle screw caps, advancing the AxiaLIF rod to its final position in the vertebrae, and retightening the screw caps. The operative time ranged from 173 to 323 minutes, and blood loss was minimal (50 mL. Indirect foraminal decompression and adequate fixation were achieved in all cases. All patients were ambulatory after surgery and reported relief from pain and resolution of radicular symptoms. No perioperative complications were reported, and patients were discharged in two to three days. Fusion was demonstrated radiographically in all patients at one-year follow-up. Conclusions Percutaneous pedicle screw reduction combined with axial presacral lumbar interbody fusion offers a promising and minimally invasive alternative for the management

  4. Biomechanical comparison between C-7 lateral mass and pedicle screws in subaxial cervical constructs. Presented at the 2009 Joint Spine Meeting. Laboratory investigation.

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    Xu, Risheng; McGirt, Matthew J; Sutter, Edward G; Sciubba, Daniel M; Wolinsky, Jean-Paul; Witham, Timothy F; Gokaslan, Ziya L; Bydon, Ali

    2010-12-01

    The aim of this study was to conduct the first in vitro biomechanical comparison of immediate and postcyclical rigidities of C-7 lateral mass versus C-7 pedicle screws in posterior C4-7 constructs. Ten human cadaveric spines were treated with C4-6 lateral mass screw and C-7 lateral mass (5 specimens) versus pedicle (5 specimens) screw fixation. Spines were potted in polymethylmethacrylate bone cement and placed on a materials testing machine. Rotation about the axis of bending was measured using passive retroreflective markers and infrared motion capture cameras. The motion of C-4 relative to C-7 in flexion-extension and lateral bending was assessed uninstrumented, immediately after instrumentation, and following 40,000 cycles of 4 Nm of flexion-extension and lateral bending moments at 1 Hz. The effect of instrumentation and cyclical loading on rotational motion across C4-7 was analyzed for significance. Preinstrumented spines for the 2 cohorts were comparable in bone mineral density and range of motion in both flexion-extension (p = 0.33) and lateral bending (p = 0.16). Lateral mass and pedicle screw constructs significantly reduced motion during flexion-extension (11.3°-0.26° for lateral mass screws, p = 0.002; 10.51°-0.30° for pedicle screws, p = 0.008) and lateral bending (7.38°-0.27° for lateral mass screws, p = 0.003; 11.65°-0.49° for pedicle screws, p = 0.03). After cyclical loading in both cohorts, rotational motion over C4-7 was increased during flexion-extension (0.26°-0.68° for lateral mass screws; 0.30°-1.31° for pedicle screws) and lateral bending (0.27°-0.39° and 0.49°-0.80°, respectively), although the increase was not statistically significant (p > 0.05). There was no statistical difference in postcyclical flexion-extension (p = 0.20) and lateral bending (0.10) between lateral mass and pedicle screws. Both C-7 lateral mass and C-7 pedicle screws allow equally rigid fixation of subaxial lateral mass constructs ending at C-7

  5. Effect of Crosslinks on the Stability of the Spine and the Pedicle Screw Fixation.

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    Xiang-Yu, Zhang; Feng, S U; Shi, Yan; Zhi-Min, Zhang; Pei-Nan, Zhang

    2015-06-01

    To evaluate the effect of crosslinks on the stability of the spine and pedicle screws. Compression fracture of the L1 vertebra was produced in 30 fresh thoracic and lumbar vertebrae samples obtained from adult sheep, which were divided into 3 groups (n=10)with lot-drawing method. Four screws were fixed onto the superior and inferior pedicles of vertebral arch close to the fractured vertebrae, with different number of crosslinks (0 in Group A,1 in Group B, and 2 in Group C) on the rods. After fixation, the samples were subject to 10 000 times of fatigue test with 1.5 Hz load on the HY-3080 computer-control electronic universal test machine and HY-1000NM computer-control torsion test machine. The axial compressive stiffness, maximum pullout strength,and range of motion (ROM) of 6 directions, i.e., flexion, extension, left and right lateral bending, and left and right axial rotation of the 3 groups were measured and compared. There were no statistically significant differences in axial compressive stiffness as well as the ROM of flexion, extension, and left and right lateral bending (all P>0.05). The maximum pullout strength was significantly smaller in Group A and Group B than in Group C [(129.56±29.63)N vs.(294.67±23.25) N,P=0.000;(254.02±36.29)vs.(294.67±23.25)N, P=0.006]. The ROM of left axial rotation was the highest in Group A(13.35°±1.06°), followed by Group B(12.23°±1.06°)and Group C (11.04°±0.74°)(F=13.44, P=0.000; Group B vs. Group A, P=0.000; Group B vs. Group C, P=0.001; Group C vs. Group A,P=0.000). The ROM of right axial rotation was also the highest in Group A(13.56°±1.15°), lower in Group B (12.39°±1.01°) and the lowest in Group C (10.81°±0.51°) (F=21.91, P=0.000; Group B vs. Group A,P=0.002; Group B vs. Group C, P=0.001; Group C vs. Group A, P=0.000). Crosslinks may reinforce the pullout strength of the screws and improve the axial stability of the spine.

  6. Morphometric evaluation of subaxial cervical spine using multi-detector computerized tomography (MD-CT) scan: the consideration for cervical pedicle screws fixation

    OpenAIRE

    Chanplakorn, Pongsthorn; Kraiwattanapong, Chaiwat; Aroonjarattham, Kitti; Leelapattana, Pittavat; Keorochana, Gun; Jaovisidha, Suphaneewan; Wajanavisit, Wiwat

    2014-01-01

    Background Cervical pedicle screw (CPS) insertion is a technically demanding procedure. The quantitative understanding of cervical pedicle morphology, especially the narrowest part of cervical pedicle or isthmus, would minimize the risk of catastrophic damage to surrounding neurovascular structures and improve surgical outcome. The aim of this study was to investigate morphology and quantify cortical thickness of the cervical isthmus by using Multi-detector Computerized Tomography (MD-CT) sca...

  7. Decisive factor in increase of loading at adjacent segments after lumbar fusion: operative technique, pedicle screws, or fusion itself: biomechanical analysis using finite element

    Science.gov (United States)

    Park, Joon-Hee; Kim, Ho-Joong; Kang, Kyoung-Tak; Kim, Ka-yeon; Chun, Heoung-Jae; Moon, Seong-Hwan; Lee, Hwan-Mo

    2010-03-01

    The aim of this study is to investigate the change in biomechanical milieu following removal of pedicle screws or removal of spinous process with posterior ligament complex in instrumented single level lumbar arthrodesis. We developed and validated a finite element model (FEM) of the intact lumbar spine (L2-4). Four scenarios of L3-4 lumbar fusion were simulated: posterolateral fusion (PLF) at L3-4 using pedicle screw system with preservation of PLC (Pp WiP), L3-4 lumbar posterolateral fusion state after removal of pedicle screw system with preservation of PLC (Pp WoP), L3-4 using pedicle screw system without preservation PLC (Sp WiP), L3-4 lumbar posterolateral fusion state after removal of pedicle screw system without preservation of PLC (Sp WoP). For these models, we investigated the range of motion and maximal Von mises stress of disc in all segments under various moments. All fusion models demonstrated increase in range of motion at adjacent segments compared to the intact model.For the four fusion models, the WiP model s P had the largest increase in range of motion at each adjacent segment. This study demonstrated that removal of pedicle screw system and preservation of PLC after complete lumbar spinal fusion could reduce the stress of adjacent segments synergistically and might have beneficial effects in preventing ASD.

  8. Clinical application of pedicle screw in atlas using pedicle exposure method%寰椎椎弓根显露置钉法的临床应用

    Institute of Scientific and Technical Information of China (English)

    谭明生; 唐向盛; 移平; 杨峰

    2011-01-01

    Objective To explore the surgical feasibility and clinical outcome of pedicle screw in atlas by pedicle exposure method (PEM). Methods Forty-six patients with atlas dislocation were treated surgically with pedicle screw by a revised technique. The patients received preoperative CT, MRI and radiograph examination. The heights of posterior arch were 2.54.0 mm, with an average of 3. 1 mm. Results All the 92 screws were successfully placed in the atlas of 46 patients and obtained satisfactory fixation. Thirty-six patients were followed up for 3-42 months, with an average of 18.6 months. Bony fusion was observed in all the 36 cases within 3-6 months; there were no complications such as internal fixation failure or redislocation of atlas. Two screws penetrated into the medial rim of the vertebral artery foramen, but caused no vertebral artery injury. Neurological function was greatly improved in 31 cases, and became better in 5 cases. Conclusion Application of pedicle screw in atlas by pedicle exposure method is surgically feasible, with highly accurate and safe insertion of the screw;the method is suitable for patients with the height of posterior arch < 4 mm, especially for children.%目的 探讨寰椎椎弓根显露置钉法(pedicle exposure method,PEM)的手术可操作性和临床疗效.方法 对46例寰枢椎脱位患者应用经寰椎椎弓根螺钉内固定技术治疗.患者术前均行X线、CT和MRI等影像学检查,寰椎后弓(椎弓根)高度为2.5~4.0 mm,平均3.1 mm;术中在直视下行C1,2置钉,复位固定,椎板后弓植骨.结果 46例患者的92枚螺钉均成功置入,复位固定满意.其中36例术后获3~42个月随访,平均18.6个月,患者均在3~6个月寰枢椎骨性融合,未发现螺钉松动、断钉和寰枢椎再移位现象;其中2枚螺钉穿入椎动脉孔内缘1 mm,但无椎动脉损伤的临床表现.31例患者脊髓功能明显改善,5例好转.结论 椎弓根显露置钉法可操作性强,置钉准确

  9. Learning retention of thoracic pedicle screw placement using a high-resolution augmented reality simulator with haptic feedback1

    Science.gov (United States)

    Luciano, Cristian J.; Banerjee, P. Pat; Bellotte, Brad; Lemole, G. Michael; Oh, Michael; Charbel, Fady T.; Roitberg, Ben

    2011-01-01

    Background We evaluated the use of a part-task simulator with 3D and haptic feedback as a training tool for a common neurosurgical procedure – placement of thoracic pedicle screws. Objective To evaluate the learning retention of thoracic pedicle screw placement on a high-performance augmented reality and haptic technology workstation. Methods Fifty-one fellows and residents performed thoracic pedicle screw placement on the simulator. The virtual screws were drilled into a virtual patient’s thoracic spine derived from a computed tomography data set of a real patient. Results With a 12.5% failure rate, a two-proportion z-test yielded P= 0.08. For performance accuracy, an aggregate Euclidean distance deviation from entry landmark on the pedicle and a similar deviation from the target landmark in the vertebral body yielded P=0.04 from a two-sample t-test in which the rejected null hypothesis assumes no improvement in performance accuracy from the practice to the test sessions, and the alternative hypothesis assumes an improvement. Conclusion The performance accuracy on the simulator was comparable to the accuracy reported in literature on recent retrospective evaluation of such placements. The failure rates indicated a minor drop from practice to test sessions, and also indicated a trend (P=0.08) towards learning retention resulting in improvement from practice to test sessions. The performance accuracy showed a 15% mean score improvement and over 50% reduction in standard deviation from practice to test. It showed evidence (P=0.04) of performance accuracy improvement from practice to test session. PMID:21471846

  10. The Use of Percutaneous Lumbar Fixation Screws for Bilateral Pedicle Fractures with an Associated Dislocation of a Lumbar Disc Prosthesis

    Directory of Open Access Journals (Sweden)

    William D. Harrison

    2013-01-01

    Full Text Available Study Design. Case report. Objective. To identify a safe technique for salvage surgery following complications of total disc replacement. Summary of Background Data. Lumbar total disc replacement (TDR is considered by some as the gold standard for discogenic back pain. Revision techniques for TDR and their complications are in their infancy. This case describes a successful method of fixation for this complex presentation. Methods and Results. A 48-year-old male with lumbar degenerative disc disease and no comorbidities. Approximately two weeks postoperatively for a TDR, the patient represented with acute severe back pain and the TDR polyethylene inlay was identified as dislocated anteriorly. Subsequent revision surgery failed immediately as the polyethylene inlay redislocated intraoperatively. Further radiology identified bilateral pedicle fractures, previously unseen on the plain films. The salvage fusion of L5/S1 reutilized the anterior approach with an interbody fusion cage and bone graft. The patient was then turned intraoperatively and redraped. The percutaneous pedicle screws were used to fix L5 to the sacral body via the paracoccygeal corridor. Conclusion. The robust locking screw in the percutaneous screw allowed a complete fixation of the pedicle fractures. At 3-year followup, the patient has an excellent result and has returned to playing golf.

  11. Augmented reality surgical navigation with ultrasound-assisted registration for pedicle screw placement: a pilot study.

    Science.gov (United States)

    Ma, Longfei; Zhao, Zhe; Chen, Fang; Zhang, Boyu; Fu, Ligong; Liao, Hongen

    2017-08-05

    We present a novel augmented reality (AR) surgical navigation system based on ultrasound-assisted registration for pedicle screw placement. This system provides the clinically desired targeting accuracy and reduces radiation exposure. Ultrasound (US) is used to perform registration between preoperative computed tomography (CT) images and patient, and the registration is performed by least-squares fitting of these two three-dimensional (3D) point sets of anatomical landmarks taken from US and CT images. An integral videography overlay device is calibrated to accurately display naked-eye 3D images for surgical navigation. We use a 3.0-mm Kirschner wire (K-wire) instead of a pedicle screw in this study, and the K-wire is calibrated to obtain its orientation and tip location. Based on the above registration and calibration, naked-eye 3D images of the planning path and the spine are superimposed onto patient in situ using our AR navigation system. Simultaneously, a 3D image of the K-wire is overlaid accurately on the real one to guide the insertion procedure. The targeting accuracy is evaluated postoperatively by performing a CT scan. An agar phantom experiment was performed. Eight K-wires were inserted successfully after US-assisted registration, and the mean targeting error and angle error were 3.35 mm and [Formula: see text], respectively. Furthermore, an additional sheep cadaver experiment was performed. Four K-wires were inserted successfully. The mean targeting error was 3.79 mm and the mean angle error was [Formula: see text], and US-assisted registration yielded better targeting results than skin markers-based registration (targeting errors: 2.41 vs. 5.18 mm, angle errors: [Formula: see text] vs. [Formula: see text]. Experimental outcomes demonstrate that the proposed navigation system has acceptable targeting accuracy. In particular, the proposed navigation method reduces repeated radiation exposure to the patient and surgeons. Therefore, it has promising

  12. A 3D navigation template for guiding a unilateral lumbar pedicle screw with contralateral translaminar facet screw fixation: a study protocol for multicentre randomised controlled trials.

    Science.gov (United States)

    Shao, Zhen-Xuan; He, Wei; He, Shao-Qi; Lin, Sheng-Lei; Huang, Zhe-Yu; Tang, Hong-Chao; Ni, Wen-Fei; Wang, Xiang-Yang; Wu, Ai-Min

    2017-07-21

    The incidence of lumbar disc degeneration disease has increased in recent years. Lumbar interbody fusion using two unilateral pedicle screws and a translaminar facet screw fixation has advantages of minimal invasiveness and lower costs compared with the traditional methods. Moreover, a method guided by a three-dimensional (3D) navigation template may help us improve the surgical accuracy and the success rate. This is the first randomised study using a 3D navigation template to guide a unilateral lumbar pedicle screw with contralateral translaminar facet screw fixation. Patients who meet the criteria of the surgery will be randomly divided into experimental groups and control groups by a computer-generated randomisation schedule. We will preoperatively design an individual 3D navigation template using CATIA software and MeditoolCreate. The following primary outcomes will be collected: screw angles compared with the optimal screw trajectories in 3D digital images, length of the wound incision, operative time, intraoperative blood loss and complications. The following secondary outcomes will be collected: visual analogue scale (VAS) for back pain, VAS for leg pain and the Oswestry Disability Index. These parameters will be evaluated on day 1 and then 3, 6, 12 and 24 months postoperatively. The study has been reviewed and approved by the institutional ethics review board of the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University. The results will be presented at scientific communities and peer-reviewed journals. ChiCTR-IDR-17010466. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  13. Both unilateral and bilateral pedicle screw fixation are effective for lumbar spinal fusion—A meta-analysis-based systematic review

    Directory of Open Access Journals (Sweden)

    Jiaquan Luo

    2014-04-01

    Full Text Available A series of studies have been conducted to evaluate the effectiveness of unilateral versus bilateral pedicle screw fixation in lumbar spinal fusion, but there is still controversy about which one is more superior. We performed a meta-analysis to more accurately estimate the effectiveness of unilateral versus bilateral pedicle screw fixation in lumbar spinal fusion. Studies on the comparison between unilateral and bilateral pedicle screw fixation in lumbar spinal fusion were identified from PubMed, SpringerLink, China National Knowledge Infrastructure (CNKI, the Wanfang database and the China Biology Medical literature database (CBM and related references were searched. The included trials were screened according to the criteria of inclusion and exclusion. The quality of included trials was evaluated. Data were extracted by two reviewers independently. RevMan 5.1.1 was used for data analysis. The fixed or random effect model was selected based on the heterogeneity test among studies evaluated using the I2 statistic. A total of nine studies involving 567 patients were included in the analyses for the effectiveness of unilateral versus bilateral pedicle screw fixation in lumbar spinal fusion. Unilateral pedicle screw fixation was performed in 287 patients and bilateral pedicle screw fixation in 280 patients. The results of the meta-analysis indicated that statistically significant differences were observed between the two fixation procedures with regard to mean operation time and amount of bleeding. There were no differences in hospitalisation days, fusion rate, complication rate, and excellent and good rates. This meta-analysis suggested that both unilateral and bilateral pedicle screw fixation are effective in one or two segmental lumbar spinal fusion. In comparison with bilateral fixation, unilateral fixation can shorten the operation time, reduce the amount of bleeding, and reduce medical expenses. There were similar effects with regard to

  14. A STUDY OF FUNCTIONAL OUTCOME OF UNSTABLE THORACO LUMBAR SPINE INJURIES TREATED WITH MOSS - MIAMI (PEDICLE SCREWS INSTRUMENTATION

    Directory of Open Access Journals (Sweden)

    Chandra Sekhar Rao

    2015-10-01

    Full Text Available With the increased incidence of road traffic accidents and industrial trauma, there has been a significant increase in the number of thoraco - lumbar spinal injuries. Decompression and early fusion with instrumentation is a generally accepted treatment meth od for patients with unstable injuries and with a neurological deficit; it helps in early mobilization, and avoids the complications of prolonged recumbency. The pedicle screw - rod system is versatile in that it stabilizes the three columns of the spine. Th e pedicle is the strongest part of the vertebra and is the force nucleus of the vertebral body. Through the pedicle all forces are transmitted from posterior elements to the vertebral body. Therefore, by fixation of the vertebral body through the pedicle, significant strength of the entire vertebral complex is possible. In our study we operated on 28 patients of unstable thoraco - lumbar injuries , where we performed Moss - Miami instrumentation ( pedicular screw rod fixation. All the cases were followed up for a minimum of one year. In all these cases we had favorable results. There was a reduction of an average pre - op kyphotic angle of 15.8º to an average post - op kyphotic angle of 6.6º. W e also noted significant neurological improvement as assessed by Frankel g rading. In this study, we found that the t ranspedicular fixation with screws and rods system is effective in the treatment of unstable thoracolumbar spinal injuries. Although the prognosis of the neurological injury seems to be largely determined at the ti me of trauma, surgical decompression will definitely improve the neurologic deficit in incomplete cord injuries. Cases where there is complete neurologic deficit with no hope for recovery , will also be benefited from surgical fixation in terms of early mob ilization and rehabilitation

  15. Biomechanical evaluation of bending strength of spinal pedicle screws, including cylindrical, conical, dual core and double dual core designs using numerical simulations and mechanical tests.

    Science.gov (United States)

    Amaritsakul, Yongyut; Chao, Ching-Kong; Lin, Jinn

    2014-09-01

    Pedicle screws are used for treating several types of spinal injuries. Although several commercial versions are presently available, they are mostly either fully cylindrical or fully conical. In this study, the bending strengths of seven types of commercial pedicle screws and a newly designed double dual core screw were evaluated by finite element analyses and biomechanical tests. All the screws had an outer diameter of 7 mm, and the biomechanical test consisted of a cantilever bending test in which a vertical point load was applied using a level arm of 45 mm. The boundary and loading conditions of the biomechanical tests were applied to the model used for the finite element analyses. The results showed that only the conical screws with fixed outer diameter and the new double dual core screw could withstand 1,000,000 cycles of a 50-500 N cyclic load. The new screw, however, exhibited lower stiffness than the conical screw, indicating that it could afford patients more flexible movements. Moreover, the new screw produced a level of stability comparable to that of the conical screw, and it was also significantly stronger than the other screws. The finite element analysis further revealed that the point of maximum tensile stress in the screw model was comparable to the point at which fracture occurred during the fatigue test. Copyright © 2014 IPEM. Published by Elsevier Ltd. All rights reserved.

  16. A New Electromagnetic Navigation System for Pedicle Screws Placement: A Human Cadaver Study at the Lumbar Spine.

    Directory of Open Access Journals (Sweden)

    Patrick Hahn

    Full Text Available Technical developments for improving the safety and accuracy of pedicle screw placement play an increasingly important role in spine surgery. In addition to the standard techniques of free-hand placement and fluoroscopic navigation, the rate of complications is reduced by 3D fluoroscopy, cone-beam CT, intraoperative CT/MRI, and various other navigation techniques. Another important aspect that should be emphasized is the reduction of intraoperative radiation exposure for personnel and patient. The aim of this study was to investigate the accuracy of a new navigation system for the spine based on an electromagnetic field.Twenty pedicle screws were placed in the lumbar spine of human cadavers using EMF navigation. Navigation was based on data from a preoperative thin-slice CT scan. The cadavers were positioned on a special field generator and the system was matched using a patient tracker on the spinous process. Navigation was conducted using especially developed instruments that can be tracked in the electromagnetic field. Another thin-slice CT scan was made postoperatively to assess the result. The evaluation included the position of the screws in the direction of trajectory and any injury to the surrounding cortical bone. The results were classified in 5 groups: grade 1: ideal screw position in the center of the pedicle with no cortical bone injury; grade 2: acceptable screw position, cortical bone injury with cortical penetration ≤ 2 mm; grade 3: cortical bone injury with cortical penetration 2,1-4 mm, grad 4: cortical bone injury with cortical penetration 4,1-6 mm, grade 5: cortical bone injury with cortical penetration >6 mm.The initial evaluation of the system showed good accuracy for the lumbar spine (65% grade 1, 20% grade 2, 15% grade 3, 0% grade 4, 0% grade 5. A comparison of the initial results with other navigation techniques in literature (CT navigation, 2D fluoroscopic navigation shows that the accuracy of this system is

  17. Progress on spinal pedicle screw placement%脊柱椎弓根螺钉置钉技术研究进展

    Institute of Scientific and Technical Information of China (English)

    刘运潮; 侯树勋; 张宇鹏

    2016-01-01

    Pedicle screw technology has been increasingly common in spinal surgery due to its advantages of three-column fixation, immediate fixation to the spine, strong orthopedic force, and significant improvement in fusion rate. To improve the insertion accuracy, a variety of screw systems have been proposed. The traditional freehand insertion has a rather long learning curve, and the contribution of clinical experience to the improvement of the insertion accuracy is limited. However, guided by imaging technologies, insertion accuracy is improved signiifcantly. X-ray assisted screw insertion is the most common technology due to its lower economic cost and easier operation of the assisted equipment, but its accuracy in more complex cases like scoliosis needs to be improved. The new computer-aided screw technology can provide accurate navigation in the surgery, but it is not common now due to high costs. Combined with 3 D printing technology, the digital navigation templates assisted technology can set tailored navigation template for each patient by accurate pedicle screw placement at an inexpensive price. However, this technique has not been widely used since it costs much time for preoperative designing. In this paper, the research development of freehand ( unassisted ) fixation, fixation by computer assisted navigation, fixation assisted by X-ray, and digital navigation template technique are summarized. Evaluation standards on fixation accuracy of pedicle screws are discussed to show the whole picture of pedicle screw placement for spine fusion.

  18. Clinical effects of posterior pedicle screw fixation on spinal deformity in growing period: a report of 360 cases

    Directory of Open Access Journals (Sweden)

    Zheng-lei WANG

    2011-08-01

    Full Text Available Objective To observe the effect of a new kind of pedicle screw frame system with sliding terminus and locked middle segment on spinal deformity in growing period.Methods Three hundred and sixty patients in growing period were involved in the present study,and among them 82 were suffering from congenital scoliosis,218 idiopathic scoliosis and 60 kyphosis.All the patients were treated with the pedicle screw frame system with sliding terminus and locked middle segment.The treatment effects and postoperative complications were observed,and the Cobb angle before and after the operation was compared.Results The Cobb angle of 300 scoliosis patients was corrected from 53°±3° to 8°±2°,and the Cobb angle of 60 kyphosis patients was corrected from 60°±2° to 25°±3°,and the corrective effect was satisfactory.The correction rate of patients with Cobb angle ≤50° was 80%.Two hundred and ten patients were followed-up for 1 to 6 years,and the longitudinal growth of spine was 1.5-4.0cm.No severe complication,such as screw fracture,rod fracture or nerve injury,occurred.Conclusion The pedicle screw frame system with sliding terminus had a favorable three-dimensional correction effect,and the spine growth would not be restricted,and there was no stiffness,vertebral rotation,or distortion of shaft after operation.

  19. Comparison study of the pullout strength of conventional spinal pedicle screws and a novel design in full and backed-out insertions using mechanical tests.

    Science.gov (United States)

    Amaritsakul, Yongyut; Chao, Ching-Kong; Lin, Jinn

    2014-03-01

    Recently, new pedicle screw designs have been developed. However, these designs' performances are still unclear, especially when backed out after insertion. The objective of this study was to investigate the performances of different screw designs when backed out from full insertion. Seven conventional designs of the pedicle screw and one novel design were inserted into polyurethane foam (0.32 g/cm(3)). All screws were first fully inserted (43 mm) and were backed out 360°. Axial pullout tests were performed and the reaction force was measured. The results showed that the conical screw of type 1 with a small inner diameter provided the highest pullout strength in both full insertion and backed-out insertion (2401.85 and 2169.82 N, respectively). However, this screw's pullout strength significantly decreased (9.7%) when backed out from full insertion. There was no significant difference between the conical screw of type 1 with a small inner diameter and double duo core screw (p > 0.01) in backed-out insertion. The cylindrical screw with a small diameter, dual inner core screw and double dual core screw also provided good results in both full insertion (2115.44, 2182.99 and 2226.93 N, respectively) and backed-out conditions (2065.80, 2014.28 and 1941.29 N, respectively). The increased pullout strength of the conical design could be due to the effect of bone compaction. However, the screw exhibited less consistent pullout strength when backed out when compared with the other designs. The conical screw should be inserted to the precise position without turning back, especially in osteoporosis patients. The dual inner core screw and double dual core screw could provide greater stability in both conditions. Care should be taken when using both the cylindrical screw with a small thread depth and the dual outer core screw.

  20. Known-component 3D-2D registration for quality assurance of spine surgery pedicle screw placement

    Science.gov (United States)

    Uneri, A.; De Silva, T.; Stayman, J. W.; Kleinszig, G.; Vogt, S.; Khanna, A. J.; Gokaslan, Z. L.; Wolinsky, J.-P.; Siewerdsen, J. H.

    2015-10-01

    A 3D-2D image registration method is presented that exploits knowledge of interventional devices (e.g. K-wires or spine screws—referred to as ‘known components’) to extend the functionality of intraoperative radiography/fluoroscopy by providing quantitative measurement and quality assurance (QA) of the surgical product. The known-component registration (KC-Reg) algorithm uses robust 3D-2D registration combined with 3D component models of surgical devices known to be present in intraoperative 2D radiographs. Component models were investigated that vary in fidelity from simple parametric models (e.g. approximation of a screw as a simple cylinder, referred to as ‘parametrically-known’ component [pKC] registration) to precise models based on device-specific CAD drawings (referred to as ‘exactly-known’ component [eKC] registration). 3D-2D registration from three intraoperative radiographs was solved using the covariance matrix adaptation evolution strategy (CMA-ES) to maximize image-gradient similarity, relating device placement relative to 3D preoperative CT of the patient. Spine phantom and cadaver studies were conducted to evaluate registration accuracy and demonstrate QA of the surgical product by verification of the type of devices delivered and conformance within the ‘acceptance window’ of the spinal pedicle. Pedicle screws were successfully registered to radiographs acquired from a mobile C-arm, providing TRE 1-4 mm and  registration. Using advanced pKC models, screws that did not match the device models specified in the surgical plan were detected with an accuracy of  >99%. Visualization of registered devices relative to surgical planning and the pedicle acceptance window provided potentially valuable QA of the surgical product and reliable detection of pedicle screw breach. 3D-2D registration combined with 3D models of known surgical devices offers a novel method for intraoperative QA. The method provides a near-real-time independent

  1. Clinical efficacy of bone cement injectable pedicle screw system combined with intervertebral fusion in treatment of lumbar spondylolysis and osteoporosis

    Directory of Open Access Journals (Sweden)

    Peng-yi DAI

    2016-10-01

    Full Text Available Objective  To observe the therapeutic effect of bone cement injectable pedicle screw system combined with intervertebral fusion for lumbar spondylolysis and osteoporosis. Methods  The clinical data were analyzed retrospectively of 21 patients with lumbar spondylolysis and osteoporosis who received treatment of bone cement injectable pedicle screw system and intervertebral fusion from Aug. 2013 to Nov. 2015. The 21 patients (9 males and 12 females aged from 60 to 80 years (mean 64 years old; 6 of them presented degenerative spondylolysis, 15 with isthmic spondylolisthesis; 2 cases had I degree slippage, 13 had Ⅱdegree slippage, 6 had Ⅲdegree slippage, and all the cases were unisegmental slippage including 9 cases in L4 and 12 cases in L5. Bone mineral density of lumbar vertebrae (L2-L5 was measured with dual-energy X-ray absorptiometry, and T values conforming to the diagnostic criteria of osteoporosis were less than or equal to -2.5; All patients were operated with whole lamina resection for decompression, bone cement injectable pedicle screws system implantation, propped open reduction and fixation intervertebral fusion. The clinical outcomes were determined by the radiographic evaluation including intervertebral height, height of intervertebral foramen, slip distance, slip rate and slip angle, and Oswestry disability index (ODI on preoperative, 3 months after operation and the end of the time, and the interbody fusion were followed up. Results  Cerebrospinal fluid leakage of incision was observed in two cases after operation, compression and dressing to incision, Trendelenburg position, dehydration and other treatments were taken, and the stitches of incisions were taken out on schedule. Slips in the 21 patients were reset to different extent, and lumbar physiological curvatures were recovered. The intervertebral height and height of intervertebral foramen were obviously higher 3 months after operation than that before operation (P0

  2. Minimally invasive transforaminal lumbar interbody fusion with unilateral pedicle screw fixation: comparison between primary and revision surgery.

    Science.gov (United States)

    Kang, Moo Sung; Park, Jeong Yoon; Kim, Kyung Hyun; Kuh, Sung Uk; Chin, Dong Kyu; Kim, Keun Su; Cho, Yong Eun

    2014-01-01

    Minimally invasive surgery with a transforaminal lumbar interbody fusion (MIS TLIF) is an important minimally invasive fusion technique for the lumbar spine. Lumbar spine reoperation is challenging and is thought to have greater complication risks. The purpose of this study was to compare MIS TLIF with unilateral screw fixation perioperative results between primary and revision surgeries. This was a prospective study that included 46 patients who underwent MIS TLIF with unilateral pedicle screw. The patients were divided into two groups, primary and revision MIS TLIF, to compare perioperative results and complications. The two groups were similar in age, sex, and level of operation, and were not significantly different in the length of follow-up or clinical results. Although dural tears were more common with the revision group (primary 1; revision 4), operation time, blood loss, total perioperative complication, and fusion rates were not significantly different between the two groups. Both groups showed substantial improvements in VAS and ODI scores one year after surgical treatment. Revision MIS TLIF performed by an experienced surgeon does not necessarily increase the risk of perioperative complication compared with primary surgery. MIS TLIF with unilateral pedicle screw fixation is a valuable option for revision lumbar surgery.

  3. Minimally Invasive Transforaminal Lumbar Interbody Fusion with Unilateral Pedicle Screw Fixation: Comparison between Primary and Revision Surgery

    Directory of Open Access Journals (Sweden)

    Moo Sung Kang

    2014-01-01

    Full Text Available Minimally invasive surgery with a transforaminal lumbar interbody fusion (MIS TLIF is an important minimally invasive fusion technique for the lumbar spine. Lumbar spine reoperation is challenging and is thought to have greater complication risks. The purpose of this study was to compare MIS TLIF with unilateral screw fixation perioperative results between primary and revision surgeries. This was a prospective study that included 46 patients who underwent MIS TLIF with unilateral pedicle screw. The patients were divided into two groups, primary and revision MIS TLIF, to compare perioperative results and complications. The two groups were similar in age, sex, and level of operation, and were not significantly different in the length of follow-up or clinical results. Although dural tears were more common with the revision group (primary 1; revision 4, operation time, blood loss, total perioperative complication, and fusion rates were not significantly different between the two groups. Both groups showed substantial improvements in VAS and ODI scores one year after surgical treatment. Revision MIS TLIF performed by an experienced surgeon does not necessarily increase the risk of perioperative complication compared with primary surgery. MIS TLIF with unilateral pedicle screw fixation is a valuable option for revision lumbar surgery.

  4. Posterior spinal fusion for adolescent idiopathic scoliosis using a convex pedicle screw technique: a novel concept of deformity correction.

    Science.gov (United States)

    Tsirikos, A I; Mataliotakis, G; Bounakis, N

    2017-08-01

    We present the results of correcting a double or triple curve adolescent idiopathic scoliosis using a convex segmental pedicle screw technique. We reviewed 191 patients with a mean age at surgery of 15 years (11 to 23.3). Pedicle screws were placed at the convexity of each curve. Concave screws were inserted at one or two cephalad levels and two caudal levels. The mean operating time was 183 minutes (132 to 276) and the mean blood loss 0.22% of the total blood volume (0.08% to 0.4%). Multimodal monitoring remained stable throughout the operation. The mean hospital stay was 6.8 days (5 to 15). The mean post-operative follow-up was 5.8 years (2.5 to 9.5). There were no neurological complications, deep wound infection, obvious nonunion or need for revision surgery. Upper thoracic scoliosis was corrected by a mean 68.2% (38% to 48%, p scoliosis was corrected by a mean 71% (43.5% to 8.9%, p scoliosis was corrected by a mean 72.3% (41% to 90%, p Scoliosis Research Society Outcomes Questionnaire score improved from a mean 3.6 to 4.6 (2.4 to 4, p scoliosis, an improved thoracic kyphosis and normal global sagittal balance. Both patient satisfaction and functional outcomes were excellent. Cite this article: Bone Joint J 2017;99-B:1080-7. ©2017 The British Editorial Society of Bone & Joint Surgery.

  5. Multiobjective optimization design of spinal pedicle screws using neural networks and genetic algorithm: mathematical models and mechanical validation.

    Science.gov (United States)

    Amaritsakul, Yongyut; Chao, Ching-Kong; Lin, Jinn

    2013-01-01

    Short-segment instrumentation for spine fractures is threatened by relatively high failure rates. Failure of the spinal pedicle screws including breakage and loosening may jeopardize the fixation integrity and lead to treatment failure. Two important design objectives, bending strength and pullout strength, may conflict with each other and warrant a multiobjective optimization study. In the present study using the three-dimensional finite element (FE) analytical results based on an L25 orthogonal array, bending and pullout objective functions were developed by an artificial neural network (ANN) algorithm, and the trade-off solutions known as Pareto optima were explored by a genetic algorithm (GA). The results showed that the knee solutions of the Pareto fronts with both high bending and pullout strength ranged from 92% to 94% of their maxima, respectively. In mechanical validation, the results of mathematical analyses were closely related to those of experimental tests with a correlation coefficient of -0.91 for bending and 0.93 for pullout (P design had significantly higher fatigue life (P < 0.01) and comparable pullout strength as compared with commercial screws. Multiobjective optimization study of spinal pedicle screws using the hybrid of ANN and GA could achieve an ideal with high bending and pullout performances simultaneously.

  6. A universal pedicle screw and V-rod system for lumbar isthmic spondylolysis: a retrospective analysis of 21 cases.

    Directory of Open Access Journals (Sweden)

    Xiong-sheng Chen

    Full Text Available OBJECTIVE: To investigate the surgical outcome of a universal pedicle screw-V rod system and isthmic bone grafting for isthmic spondylolysis. METHODS: Twenty-four patients with isthmic spondylolysis at L5 and grade 0-I spondylolisthesis (Meyerding classification received isthmic bone graft and stabilization using the universal pedicle screw-V rod system. Back pain was evaluated using the visual analog scale (VAS and time to bone healing, improvement in spondylolisthesis and intervertebral space height at L5/S1 and L4/L5 were assessed. RESULTS: Twenty-one patients were followed up for 24 months and included in the analysis. Back pain was markedly improved at 3 months postoperatively with a statistical difference in VAS scores compared with preoperative VAS scores (P<0.001. The VAS scores were 0 to 3 at 6 months postoperatively in all patients and no back pain was reported in all patients except 2 patients who complained of back pain after prolonged sitting. X-ray examination showed a bone graft healing time of 3 to 12 months. Grade I spondylolisthesis improved to grade 0 in 4 patients and no noticeable change was observed in the remaining 17 cases. The intervertebral space height at L5/S1 was statistically increased (P<0.05 while no statistically significant change was seen at L4/L5. There was no statistically significant difference in the ROM of the intervertebral disks of L5/S1 and L4/5 before and after surgery. CONCLUSIONS: The universal pedicle screw-V rod system and isthmic bone grafting directly repairs isthmic spondylolysis and reduces back pain, prevents anterior displacement of the diseased segment and maintains intervertebral space height, thus offering a promising alternative to current approaches for isthmic spondylolysis.

  7. Clinical efficacy of poking reduction, bone grafting and pedicle screw implanting through injured vertebra in treatment of thoracolumbar burst fracture

    Directory of Open Access Journals (Sweden)

    Da LIU

    2016-10-01

    Full Text Available Objective  To evaluate the clinical efficacy of poking reduction, bone grafting and pedicle screw implanting through injured vertebra in treatment of thoracolumbar burst fracture. Methods  Fifty-seven patients with thoracolumbar burst fractures between January 2013 and December 2013 were treated in Chengdu Military General Hospital by poking reduction, bone grafting and pedicle screw implanting through injured vertebra. All the patients were observed and recorded for basic conditions and complications. At pre-operation, 1 week post-operation and last follow-up, pain visual analogue scale (VAS and neurological function score (ASIA were recorded and the compression ratio of anterior edge and posterior edge of fractured vertebra, compression ratio of spinal canal and Cobb angle were measured and statistically analyzed in all the patients. Results  All the patients acquired surgical success with operation time about 70-120min and blood loss about 120-280ml. There was no spinal cord or nerve injury and no dural tear during the surgery. All the patients were followed up for 12 to 36 months and the neurological function significantly recovered. X-ray and CT examination at last follow-up showed good fracture healing, good position and no loosening of internal fixation device. At 1 week post-operation and last follow-up, VAS, compression ratio of anterior edge and posterior edge of fractured vertebra, compression ratio of spinal canal and Cobb angle were significantly lower than those at pre-operation (P0.05. Conclusions  Poking reduction, bone grafting and pedicle screw implanting through injured vertebra can effectively restore height of injured vertebra and reduce the compression of spinal canal, which will help correction of spinal kyphosis and recovery of spinal cord function. This method can well maintain height of injured vertebra and significantly reduce risk of long-term vertebral collapse. DOI: 10.11855/j.issn.0577-7402.2016.09.06

  8. Effect of heparin on hemorheology and inflammatory cytokines in patients with spinal trauma after PCS pedicle screw fixation

    Institute of Scientific and Technical Information of China (English)

    Nan-Xiang Huang; Hong Lin; Wei Li

    2016-01-01

    Objective:To explore the effect of low molecular weight heparin (LMWH) on the hemorheology, inflammatory cytokines, and coagulation funtion in patients with spinal trauma after PCS pedicle screw fixation.Methods: A total of 80 patients with spinal trauma who were admitted in our hospital were included in the study and randomized into the treatment group and the control group with 40 cases in each group. The patients in the two groups were performed with PCS pedicle screw fixation. The patients in the treatment group were given subcutaneous injection of LMWH after operation. The hemorheology indicators, inflammatory cytokines levels, and coagulation function change before and after operation in the two groups were compared.Results: The difference of RBV (low shear, middle shear, and high shear) (mPa•s), PAR, and PAR (1 min) (%) before operation between the two groups was not statistically significant (P>0.05), the above indicators 24 h after operation in the two groups were significantly elevated when compared with before operation (P<0.05), and the above indicators 24 h after operation in the treatment group were significantly lower than those in the control group (P<0.05). The above indicators 48 h and 1 week after operation in the control group were significantly elevated, while those in the treatment group were significantly reduced when compared with before treatment (P<0.05). CRP, IL-6, and IL-10 levels after operation in the treatment group were significantly lower than those in the control group (P<0.05). PT, APTT, and FIB after operation in the treatment group were significantly lower than those in the control group (P<0.05).Conclusions:LMWH can effectively reduce the blood viscosity, inhibit the inflammatory reaction, and contribute to postoperative rehabilitation in patients with spinal trauma after PCS pedicle screw fixation.

  9. One-stage posterior C2 and C3 pedicle screw fixation or combined anterior C2-C3 fusion for the treatment of unstable hangman's fracture.

    Science.gov (United States)

    Liu, Jingchen; Li, Ye; Wu, Yuntao

    2013-03-01

    The present study aimed to evaluate the effect of using one-stage posterior C2 and C3 pedicle screw fixation or combined anterior C2-C3 fusion in the treatment of unstable hangman's fracture. A total of 13 patients with unstable hangman's fractures underwent C2 and C3 pedicle screw fixation, lamina interbody fusion or combined anterior C2-C3 fusion and imaging examinations to evaluate the fracture fixation and healing condition at three days and three months following surgery. Postoperative X-ray and computed tomography (CT) results showed high fracture reduction, good internal fixation position and reliable fracture fixation. The three-month postoperative CT showed good vertebral fracture healing. C2 and C3 pedicle screw fixation has a good curative effect in the treatment of unstable hangman's fracture. The direct fixation of the fracture enables early ambulation by the patients.

  10. Biomechanical comparison of bilateral pedicle screw and unilateral pedicle screw fixation%双侧钉棒及同侧单钉棒置入内固定的生物力学比较

    Institute of Scientific and Technical Information of China (English)

    陈立业; 夏虹; 王建华; 尹庆水

    2011-01-01

    BACKGROUND: Most of lumbar degenerative diseases, such as lumbar instability and lumbar spondylolisthesis, need lumbarspinal fusion for the spine stability, but the choice of internal fixation approaches is an argument.OBJECTIVE: To investigate the biomechanical difference of unilateral and bilateral minimally I nvasive transforaminal lumbarinterbody fusion (TLIF) for the treatment of lumbar degenerative diseases.METHODS: Minimally invasive TLIF with different internal fixations were performed on L4-5 segments from six fresh frozenhuman lumbar cadaveric specimens. Then, the specimens were divided into two groups according to different internal fixationmethods: bilateral pedicle screw group and unilateral pedicle screw group. Range of motion (ROM) for the lumbar function unitwas measured on the biomechanical machine and compared between the two groups.RESULTS AND CONCLUSION: Compared with the compact lumbar function unit, the ROM of the two fixation groups weresignificantly lower (P < 0.05). The ROM value of the bilateral pedicle screw group was significantly lower than that of the unilateralpedicle screw group in all working states (P < 0.05). Biomechanical experiments show that unilateral TLIF provides favorablebiomechanical effect and stiffness, which offers the dependable stability of the lumbar vertebra e. However, compared with thebilateral pedicle screw fixation, there are still gaps in the unilateral pedicle screw fixation.%背景:腰椎失稳、腰椎滑脱等腰椎退行性疾病常常需要实施腰椎融合,其目标是稳定脊柱,但究竟采取何种内固定方式仍存在争论.目的:比较单侧与双侧经椎间孔减压椎体间融合治疗腰椎退行性病变的生物力学差异.方法:人新鲜尸体腰椎标本6具,L4~5模拟微创经椎间孔减压椎体间融合,根据不同的内固定组合方式分为2组,即双侧钉棒组及同侧单钉棒组.在生物力学试验机上测量各种固定方式不同工况下的运动范围(ROM

  11. Computed tomography-based morphometric analysis of cervical pedicles in Indian population: A pilot study to assess feasibility of transpedicular screw fixation

    Directory of Open Access Journals (Sweden)

    A R Patwardhan

    2012-01-01

    Full Text Available Background: Cervical transpedicular screw fixation is safe and is probably going to be the gold standard for cervical spine fixation. However, cervical transpedicular screw use in the Asian population can be limited as the transverse diameter in this group of patients may not be adequate to accommodate the 3.5-mm pedicular screw thus injuring the vital structures located in the close proximity of the pedicles. Thus lateral mass fixation remains the mainstay of treatment. The present study evaluated the transverse cervical pedicle diameter of C2-C7 vertebrae in a pilot study in 27 Indian subjects using computed tomography (CT imaging and evaluated the feasibility of transpedicular screw fixation in them. Aims: To evaluate the feasibility of transpedicular screw fixation in the Indian population. Settings and Design: The cervical pedicle diameter size differs between the Asian and non-Asian population. The authors studied the transverse pedicle diameter of the C2-C7 of the cervical spine in the Indian population using CT measurements. This cross-sectional study was carried out at a tertiary care centre for a period of four months from October 2010 to December 2010. Material and Methods: Measurements of cervical pedicles in the subjects were performed on the CT workstation from the CT images taken at 2.5-mm interval. The transverse pedicle diameter was defined as the outermost diameter of the pedicle, taken perpendicular to the axis of the pedicle at the narrowest point and measured in millimeters±0.1 mm. Statistical Analysis: Descriptive statistics was used to represent percentage of transverse diameter of cervical pedicles less than 5 mm in male and female subjects at C2-C7 levels. Since there is no previous study done in India, we initiated the study with sample size of 27 as a pilot study. The statistical analysis was performed using SPSS software. Results: The mean transverse diameters of the cervical pedicles of C2, C3, C4, C5, C6 and C7 in

  12. Are computer numerical control (CNC)-manufactured patient-specific metal templates available for posterior thoracic pedicle screw insertion? Feasibility and accuracy evaluation.

    Science.gov (United States)

    Kong, Xiangxue; Tang, Lei; Ye, Qiang; Huang, Wenhua; Li, Jianyi

    2017-07-17

    Accurate and safe posterior thoracic pedicle insertion (PTPI) remains a challenge. Patient-specific drill templates (PDTs) created by rapid prototyping (RP) can assist in posterior thoracic pedicle insertion, but pose biocompatibility risks. The aims of this study were to develop alternative PDTs with computer numerical control (CNC) and assess their feasibility and accuracy in assisting PTPI. Preoperative CT images of 31 cadaveric thoracic vertebras were obtained and then the optimal pedicle screw trajectories were planned. The PDTs with optimal screw trajectories were randomly assigned to be designed and manufactured by CNC or RP in each vertebra. With the guide of the CNC- or RP-manufactured PDTs, the appropriate screws were inserted into the pedicles. Postoperative CT scans were performed to analyze any deviations at entry point and midpoint of the pedicles. The CNC group was found to be significant manufacture-time-shortening, and cost-decreasing, when compared with the RP group (P  0.05). The screw positions were grade 0 in 90.3% and grade 1 in 9.7% of the cases in the CNC group and grade 0 in 93.5% and grade 1 in 6.5% of the cases in the RP group (P = 0.641). CNC-manufactured PDTs are viable for assisting in PTPI with good feasibility and accuracy.

  13. A prospective, randomized, controlled trial of robot-assisted vs freehand pedicle screw fixation in spine surgery.

    Science.gov (United States)

    Kim, Ho-Joong; Jung, Whan-Ik; Chang, Bong-Soon; Lee, Choon-Ki; Kang, Kyoung-Tak; Yeom, Jin S

    2017-09-01

    The purpose of this study was to compare the accuracy and safety of an instrumented posterior lumbar interbody fusion (PLIF) using a robot-assisted minimally invasive (Robot-PLIF) or a conventional open approach (Freehand-PLIF). Patients undergoing an instrumented PLIF were randomly assigned to be treated using a Robot-PLIF (37 patients) and a Freehand-PLIF (41 patients). For intrapedicular accuracy, there was no significant difference between the groups (P = 0.534). For proximal facet joint accuracy, none of the 74 screws in the Robot-PLIF group violated the proximal facet joint, while 13 of 82 in the Freehand-PLIF group violated the proximal facet joint (P Robot-PLIF and Freehand-PLIF groups, respectively (P Robotic-assisted pedicle screw placement was associated with fewer proximal facet joint violations and better convergence orientations. Copyright © 2016 John Wiley & Sons, Ltd.

  14. Placement of thoracolumbar pedicle screws using three-dimensional image guidance: experience in a large patient cohort.

    Science.gov (United States)

    Nottmeier, Eric W; Seemer, Will; Young, Phillip M

    2009-01-01

    The goal of this study was to analyze the placement accuracy and complications of thoracolumbar pedicle screws (PSs) inserted using 3D image guidance in a large patient cohort. The authors reviewed the charts of 220 consecutive patients undergoing posterior spinal fusion using 3D image guidance for instrumentation placement. A total of 1084 thoracolumbar PSs were placed using either the BrainLAB Vector Vision (BrainLAB, Inc.) or Medtronic StealthStation Treon (Medtronic, Inc.) image guidance systems. Postoperative CT scanning was performed in 184 patients, allowing for 951 screws to be graded by an independent radiologist for bone breach. All complications resulting from instrumentation placement were noted. Using the intraoperative planning function of the image-guided system, the largest diameter screw possible in each particular case was placed. The screw diameter of instrumentation placed into the L3-S1 levels was noted. No vascular or visceral complications occurred as a result of screw placement. Two nerve root injuries occurred in 1084 screws placed, resulting in a 0.2% per screw incidence and a 0.9% patient incidence of nerve root injury. Neither nerve root injury was associated with a motor deficit. The breach rate was 7.5%. Grade 1 and minor anterolateral "tip out" breaches accounted for 90% of the total breaches. Patients undergoing revision surgery accounted for 46% of the patients in this study. Accordingly, 154 screws placed through previous fusion mass could be evaluated using postoperative CT scanning. The breach rate in this specific cohort was 7.8%. A total of 765 PSs were placed into the L3-S1 levels in this study; 546 (71%) of these screws were > or = 7.5 mm in diameter. No statistical difference in breach rate was noted in PSs placed through revision spinal levels versus nonrevision spinal levels (p = 0.499). Additionally, no increase in breach rate was noted with placement of 7.5-mm-diameter screws. Three-dimensional image guidance is a useful

  15. Posterior Selective Thoracic Fusion in Adolescent Idiopathic Scoliosis Patients: a Comparison of All Pedicle Screws versus Hybrid Instrumentation

    Institute of Scientific and Technical Information of China (English)

    Bin Yu; Jian-guo Zhang; Gui-xing Qiu; Yi-peng Wang; Yu Zhao; Jian-xiong Shen; Hong Zhao; Xin-yu Yang

    2009-01-01

    Objective To analyze the influence of segmental pedicle screws versus hybrid instrumentation on the correction results in adolescent idiopathic scoliosis patients undergoing posterior selective thoracic fusion. Methods By reviewing the medical records and roentgenograms of adolescent idiopathic scoliosis patients who underwent selective thoracic fusion from February 2000 to January 2007 in our hospital, the patients were divided into 2 groups according to different instrumentation fashions: Group A was hook-screw-rod (hybrid) internal fixation type, Group B was screw-rod (all pedicle screws) internal fixation type, and the screws were used in every segment on the concave side of the thoracic curve. The parameters of the scoliosis were measured and the correction results were analyzed. Results Totally, 48 patients (7 males, 41 females) were included, with an average age of 14.4 years old and a mean follow-up time of 12.3 months. Thirty and 18 patients were assigned to group A and group B, respectively. The mean preoperative coronal Cobb angles of the thoracic curve were 48.8° and 47.4°, respectively. After surgery, they were corrected to 13.7° and 6.8°, respectively. At final follow-up, they were 17.0° and 9.5°, with an average correction rate of 64.6% and 79.0%, respectively, and the correction rate of group B was significantly higher than that of group A (P = 0.003). The mean preoperative coronal Cobb angles of the lumbar curve were 32.6° and 35.2°, respectively. After surgery, they were corrected to 8.6° and 8.3°, respectively. At final follow-up, they were 10.3° and 11.1°, with an average correction rate of 66.8% and 69.9%, respectively, and the correction rate of group B was significantly higher than that of group A (P = 0.003). The correction loss of the thoracic curve and lumbar curve in the 2 groups were 3.1° and 1.8°, 2.4° and 2.4°, respectively. No significant difference was noted (both P > 0.05). The decompensation rate at final follow

  16. Posterior lumbar interbody fusion with cortical bone trajectory screw fixation versus posterior lumbar interbody fusion using traditional pedicle screw fixation for degenerative lumbar spondylolisthesis: a comparative study.

    Science.gov (United States)

    Sakaura, Hironobu; Miwa, Toshitada; Yamashita, Tomoya; Kuroda, Yusuke; Ohwada, Tetsuo

    2016-11-01

    OBJECTIVE Several biomechanical studies have demonstrated the favorable mechanical properties of the cortical bone trajectory (CBT) screw. However, no reports have examined surgical outcomes of posterior lumbar interbody fusion (PLIF) with CBT screw fixation for degenerative spondylolisthesis (DS) compared with those after PLIF using traditional pedicle screw (PS) fixation. The purposes of this study were thus to elucidate surgical outcomes after PLIF with CBT screw fixation for DS and to compare these results with those after PLIF using traditional PS fixation. METHODS Ninety-five consecutive patients underwent PLIF with CBT screw fixation for DS (CBT group; mean followup 35 months). A historical control group consisted of 82 consecutive patients who underwent PLIF with traditional PS fixation (PS group; mean follow-up 40 months). Clinical status was assessed using the Japanese Orthopaedic Association (JOA) scale score. Fusion status was assessed by dynamic plain radiographs and CT. The need for additional surgery and surgery-related complications was also evaluated. RESULTS The mean JOA score improved significantly from 13.7 points before surgery to 23.3 points at the latest follow-up in the CBT group (mean recovery rate 64.4%), compared with 14.4 points preoperatively to 22.7 points at final follow-up in the PS group (mean recovery rate 55.8%; p fusion was achieved in 84 patients from the CBT group (88.4%) and in 79 patients from the PS group (96.3%, p > 0.05). Symptomatic adjacent-segment disease developed in 3 patients from the CBT group (3.2%) compared with 9 patients from the PS group (11.0%, p fusion rate tended to be lower in the CBT group than in the PS group, although the difference was not statistically significant between the 2 groups.

  17. Use of next generation sequencing to detect biofilm bacteria in a patient with pedicle screw loosening after spine surgery

    DEFF Research Database (Denmark)

    Xu, Yijuan; Thomsen, Trine Rolighed; Lorenzen, Jan

    2016-01-01

    2. Center for Microbial Communities, Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Denmark 3. Otto-von-Guericke University Magdeburg, Department of Orthopedic Surgery, Magdeburg, Germany 4. Eifelklinik St. Brigida, Simmerath, Germany Aim: ”Hidden deep...... as a possible cause for implant loosening. This case report describes the use of NGS in the diagnostic work-up of a patient with pedicle screw loosening after spine surgery.” Method: ”A 60 y/o male had to undergo revision spine surgery for pedicle screw loosening and adjacent segment disease 3 years after...... identified by MALDI-TOF . For the molecular detection, DNA was extracted using MolYsis complete5 (Molzym, Germany). The V1-3 region of 16S rRNA gene was PCR-amplified with bacterial primers 27F and 534R (30 cycles) and paired-end sequenced on Miseq DNA sequencer (v3 chemistry, 2×300 bp). Paired-end reads...

  18. [Analysis of reason and strategy for the failure of posterior pedicle screw short-segment internal fixation on thoracolumbar fractures].

    Science.gov (United States)

    Xing, Jin-Ming; Peng, Wen-Ming; Shi, Chu-Yun; Xu, Lei; Pan, Qi-Huao

    2013-03-01

    To analyze the reason and strategy for failure of posterior pedicle screw short-segment internal fixation on thoracolumbar fractures. From March 2008 to December 2010,the clinical data of 18 patients with thoracolumbar fracture failed in posterior pedicle screw short-segment internal fixation were retrospectively analyzed. There were 11 males and 7 females with an average age of 37.2 years (ranged, 19 to 63). The time from the first operation to complication occurrence was from 6 to 44 months with an average of 14.3 months. Of them,fusion failure was in 7 cases (combined with screw breakage in 4 cases), the progressive neuro-dysfunction was in 5 cases,the progressive lumbodorsal pain was in 6 cases. All 18 patients with kyphosis were treated with anterior internal fixation remaining posterior fixation (9 cases) and anterior internal fixation after posterior fixation removal (9 cases). All the patients were followed up from 18 to 50 months with an average of 30.5 months. No intetnal fixation loosening and breakage were found, moreover, X-ray and lamellar CT showed bone healing well. Preoperative, postoperative at 3 months and at final follow-up, ODI score was respectively 31.6+/-5.1, 8.6+/-5.7, 8.3+/-3.2; VAS score was respectively 7.2+/-2.3, 2.3+/-0.7, 2.1+/-1.1; kyphosis angle was respectively (-21.2/-+7.8 degreeso, (-5.3+/-6.8 degrees ), (-5.8+/-7.8 )degrees. Compared with preoperative data ,above-listed items had obviously ameliorated(Pinternal fixation may result in the complications such as bone nonunion ,internal fixation breakage and progressive kyphosis. Anterior reconstruction may be a good strategy for the failure of posterior operation.

  19. A Novel Patient-Specific Drill Guide Template for Pedicle Screw Insertion into the Subaxial Cervical Spine Utilizing Stereolithographic Modelling: An In Vitro Study

    Science.gov (United States)

    Delgado, Giorgio De Guzman; Grozman, Samuel Arsenio Munoz

    2017-01-01

    Study Design Cadaveric study. Purpose The purpose of this study was to assess the accuracy and feasibility of cervical pedicle screw (CPS) insertion into the subaxial cervical spine placed using a patient-specific drill guide template constructed from a stereolithographic model. Overview of Literature CPS fixation is an invaluable tool for posterior cervical fixation because of its biomechanical advantages. The major drawback is its narrow corridor that allows very little clearance for neural and vascular injuries. Methods Fifty subaxial pedicles of the cervical vertebrae from five cadavers were scanned into thin slices using computed tomography (CT). Digital imaging and communications in medicine images of the cadaver spine were digitally processed and printed to scale as a three-dimensional (3D) model. Drill guide templates were manually moulded over the 3D-printed models incorporating pins inserted in the pedicles. The drill guide templates were used for precise placement of the drill holes in the pedicles of cadaveric specimens for pedicle screw fixation. Results The instrumented cadaveric spines were subjected to CT to assess the accuracy of our pedicle placement by an external observer. Our patient-specific drill guide template had an accuracy of 94%. Conclusions The use of a patient-specific drill guide constructed using stereolithography improved the accuracy of CPS placement in a cadaveric model.

  20. Clinical and radiological results 6 years after treatment of traumatic thoracolumbar burst fractures with pedicle screw instrumentation and balloon assisted endplate reduction

    NARCIS (Netherlands)

    Verlaan, Jorrit Jan; Somers, Inne; Dhert, Wouter J A; Oner, F. Cumhur

    2015-01-01

    Background context  When used to fixate traumatic thoracolumbar burst fractures, pedicle screw constructs may fail in the presence of severe vertebral body comminution as the intervertebral disc can creep through the fractured endplates leading to insufficient anterior column support. Balloon-assist

  1. Lumbar spine superior-level facet joint violations: percutaneous versus open pedicle screw insertion using intraoperative 3-dimensional computer-assisted navigation

    Institute of Scientific and Technical Information of China (English)

    Tian Wei; Xu Yunfeng; Liu Bo; Liu Yajun; He Da; Yuan Qiang; Lang Zhao

    2014-01-01

    Background Percutaneous pedicle screw use has a high rate of cranial facet joint violations (FVs) because of the facet joint being indirectly visualized.Computer-assisted navigation shows the anatomic structures clearly,and may help to lower the rate of FVs during pedicle screw insertion.This study used computed tomography (CT) to evaluate and compare the incidence of FVs between percutaneous and open surgeries employing computer-assisted navigation for the implantation of pedicle screw instrumentation during lumbar fusions.Methods A prospective study,including 142 patients having lumbar and lumbosacral fusion,was conducted between January 2013 and April 2014.All patients had bilateral posterior pedicle screw-rod instrumentation (top-loading screws) implanted by the same group of surgeons; intraoperative 3-dimensional computer navigation was used during the procedures.All patients underwent CT examinations within 6 months postoperation.The CT scans were independently reviewed by three reviewers blinded to the technique used.Results The cohort comprised 68 percutaneous and 74 open cases (136 and 148 superior-level pedicle screw placements,respectively).Overall,superior-level FVs occurred in 20 patients (20/142,14.1%),involving 27 top screws (27/284,9.5%).The percutaneous technique (7.4% of patients,3.7% of top screws) had a significantly lower violation rate than the open procedure (20.3% of patients,14.9% of top screws).The open group also had significantly more serious violations than did the percutaneous group.Both groups had a higher violation rate when the cranial fixation involved the L5.A 1-level open procedure had a higher violation rate than did the 2-and 3-level surgeries.Conclusions With computer-assisted navigation,the placement of top-loading percutaneous screws carries a lower risk of adjacent-FVs than does the open technique; when FVs occur,they tend to be less serious.Performing a single-level open lumbar fusion,or the fusion of the L5-S1

  2. Clinical study on minimally invasive transforaminal lumbar interbody fusion combined with percutaneous pedicle screw fixation for degenerative lumbar scoliosis

    Directory of Open Access Journals (Sweden)

    Hao WU

    2016-04-01

    Full Text Available Objective To discuss the operative essentials and therapeutic effects of minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF combined with percutaneous pedicle screw fixation for degenerative lumbar scoliosis (DLS.  Methods A total of 17 DLS patients without prior spinal diseases were treated by MIS-TLIF and percutaneous pedicle screw fixation from January 2013 to September 2015 in Xuanwu Hospital, Capital Medical University. The operation time, intraoperative blood loss, hospital stay, and postoperative complication were recorded in each patient. Visual Analogue Scale (VAS and Oswestry Disability Index (ODI were used to evaluate postoperative improvement of low back and leg pain, and clinical effects were assessed according to Medical Outcome Study 36-Item Short-Form Health Survey (SF-36. Coronal Cobb angle, sagittal lordosis angle and spinal deviation distances on coronal and sagittal plane were measured before operation, one week, 3 months after operation and in the last follow-up in spinal full-length X-ray examination. Fusion rate was calculated according to X-ray or CT scan, and the degree of decompression was evaluated by MRI.  Results Decompression and fusion levels ranged from T12-S1 vertebrae, and interbody fusion was performed in 17 patients and 56 levels were fused. Average operation time was 200 min (180-300 min, intraoperative blood loss was 320 ml (200-1000 ml and hospital stay was 8.21 d (5-12 d. All patients were followed-up for 12.13 months (5-24 months. Compared with preoperation, VAS (P = 0.000, for all and ODI scores (P = 0.000, for all decreased significantly, SF-36 score increased (P = 0.000, for all, coronal Cobb angle (P = 0.000, for all, sagittal lordosis angle (P = 0.000, for all, coronal and sagittal deviation (P = 0.000, for all decreased significantly one week and 3 months after operation and in the last follow-up. The improvement rate of ODI was (86.51 ± 6.02%, fusion rate of vertebral bodies

  3. Endoscopic transforaminal lumbar decompression, interbody fusion and pedicle screw fixation——a report of 42 cases

    Institute of Scientific and Technical Information of China (English)

    ZHOU Yue; ZHANG Chao; WANG Jian; CHU Tong-wei; LI Chang-qing; ZHANG Zheng-feng; ZHENG Wen-jie

    2008-01-01

    Objective: To evaluate the surgical procedure of endoscopic transforminal discectomy, bone grafting and Dynalok pedicle screw fixation under X-Tube operation system in the treatment of lumbar disc herniation combined with segmental instability and/or pars defected spondylolithesis. Methods: From June 2004 to May 2006, 42 patients with classic features of lumbar disc herniation combined with segmental instability and/or pars defected spondylolithesis underwent endoscopic transforminal lumbar interbody fusion TLIF. Under the guidance of fluoroscopy, a 2.8 to 3.0 cm incision with 4.5 to 5.0 cm apart from the posterior middle line was made on the symptomatic side and the working portal X-Tube was docked unilaterally on the facet joint. A total facetectomy was then performed to expose neural foramina and nerve root. Discectomy and endplate preparation were completed through the tube. A Telamon cage was placed obliquely into the intervertebral space after interbody grafting, and then the Dynalok pedicle screw fixation sys- tem was performed. This procedure was accomplished on the lateral side when it is necessary. Results: Clinical outcomes were determined using the Oswestry Disability Index ODI which revealed that 62.2% of patients got excellent results, 29.2% good and 8.6% fair. The average hospital stay was 12.5 days 5-25 days. Operation time averaged 240 min 110-320 min, blood loss averaged 140 ml 80-420 ml and incision length averaged 3 cm 2.8-3.2 cm. Five patients had complications including wound infection in 1 case, incision dehiscence and focal skin necrosis in 1, progressive radicular pain of contralat-eral leg in 1 and residual radicular numbness after transient radicular pain in 2. Conclusions: This surgical procedure of endoscopic transforminal diskectomy, bone grafting, cage placement and pedicle screw fixation can be effectively accomplished under X-Tube operation system with predominant benefits such as small incision, less stripping of paraspinal muscles

  4. Surgical treatment of the osteoporotic spine with bone cement-injectable cannulated pedicle screw fixation: technical description and preliminary application in 43 patients

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    Fei Dai

    2015-02-01

    Full Text Available OBJECTIVES: To describe a new approach for the application of polymethylmethacrylate augmentation of bone cement-injectable cannulated pedicle screws. METHODS: Between June 2010 and February 2013, 43 patients with degenerative spinal disease and osteoporosis (T-score <-2.5 underwent lumbar fusion using cement-injectable cannulated pedicle screws. Clinical outcomes were evaluated using a Visual Analog Scale and the Oswestry Disability Index. Patients were given radiographic follow-up examinations after 3, 6, and 12 months and once per year thereafter. RESULTS: All patients were followed for a mean of 15.7±5.6 months (range, 6 to 35 months. The Visual Analog Scale and Oswestry Disability Index scores showed a significant reduction in back pain (p = 0.018 and an improvement in lower extremity function (p = 0.025 in patients who underwent lumbar fusion using the novel screw. Intraoperative cement leakage occurred in four patients, but no neurological complications were observed. Radiological observation indicated no loosening or pulling out of the novel screw, and bone fusion was excellent. CONCLUSIONS: The described polymethylmethacrylate augmentation technique using bone cement-injectable cannulated pedicle screws can reduce pain and improve spinal dysfunction in osteoporotic patients undergoing osteoporotic spine surgery.

  5. Comparison of the clinical accuracy of cervical (C2-C7) pedicle screw insertion assisted by fluoroscopy, computed tomography-based navigation, and intraoperative three-dimensional C-arm navigation

    Institute of Scientific and Technical Information of China (English)

    LIU Ya-jun; TIAN Wei; LIU Bo; LI Qin; HU Lin; LI Zhi-yu; YUAN Qiang; L(U) Yan-wei; SUN Yu-zhen

    2010-01-01

    Background The complicated anatomy of the cervical spine and the variation among pedicles reduces the accuracy and increases the risk of neurovascular complications associated with screw implantation in this region. In this study, we compared the accuracy of cervical (C2-C7) pedicle screw fixation assisted by X-ray fluoroscopy, computed tomography (CT)-based navigation, or intraoperative three-dimensional (3D) C-arm navigation.Methods This prospective cohort study was performed in 82 consecutive patients who underwent cervical pedicle screw fixation. The accuracy of screw insertion was assessed by postoperative CT scan with 3D reconstruction. The accuracy of screw insertion was assessed as: excellent (screw completely within pedicle); acceptable (≤ 1 mm screw outside pedicle cortex); poor (>1 mm screw outside pedicle cortex).Results A total of 145 screws were inserted in 24 patients who underwent C-arm fluoroscopy. Of these, 96 screws (66.2%) were excellent, 37 (25.5%) were acceptable, and 12 (8.3%) were poor. One hundred and fifty-nine screws were inserted in 29 patients in the CT-based navigation group. Among these, 141 (88.7%) were excellent, 14 (8.8%) were acceptable, and 4 (2.5%) were poor. A total of 140 screws were inserted in 29 patients in the intraoperative 3D C-arm navigation group, of which 127 (90.7%) were excellent, and 13 (9.3%) were acceptable. No severe or permanent neurovascular complications associated with screw insertion were observed in any patient.Conclusione CT-based and intraoperative 3D C-arm navigation were similarly accurate, and were both significantly more accurate than C-arm fluoroscopy for guiding cervical pedicle screw fixation. They were able to accurately guide the angle and depth of screw placement using visual 3D images. These two techniques are therefore preferable for high-risk cervical pedicle screw fixation. The ease and convenience of intraoperative 3D C-arm navigation suggests that it may replace virtual

  6. Are pedicle screw perforation rates influenced by distance from the reference frame in multilevel registration using a computed tomography-based navigation system in the setting of scoliosis?

    Science.gov (United States)

    Uehara, Masashi; Takahashi, Jun; Ikegami, Shota; Kuraishi, Shugo; Shimizu, Masayuki; Futatsugi, Toshimasa; Oba, Hiroki; Kato, Hiroyuki

    2017-04-01

    Pedicle screw fixation is commonly employed for the surgical correction of scoliosis but carries a risk of serious neurovascular or visceral structure events during screw insertion. To avoid these complications, we have been using a computed tomography (CT)-based navigation system during pedicle screw placement. As this could also prolong operation time, multilevel registration for pedicle screw insertion for posterior scoliosis surgery was developed to register three consecutive vertebrae in a single time with CT-based navigation. The reference frame was set either at the caudal end of three consecutive vertebrae or at one or two vertebrae inferior to the most caudal registered vertebra, and then pedicle screws were inserted into the three consecutive registered vertebrae and into the one or two adjacent vertebrae. This study investigated the perforation rates of vertebrae at zero, one, two, three, or four or more levels above or below the vertebra at which the reference frame was set. This is a retrospective, single-center, single-surgeon study. One hundred sixty-one scoliosis patients who had undergone pedicle screw fixation were reviewed. Screw perforation rates were evaluated by postoperative CT. We evaluated 161 scoliosis patients (34 boys and 127 girls; mean±standard deviation age: 14.6±2.8 years) who underwent pedicle screw fixation guided by a CT-based navigation system between March 2006 and December 2015. A total of 2,203 pedicle screws were inserted into T2-L5 using multilevel registration with CT-based navigation. The overall perforation rates for Grade 1, 2, or 3, Grade 2 or 3 (major perforations), and Grade 3 perforations (violations) were as follows: vertebrae at which the reference frame was set: 15.9%, 6.1%, and 2.5%; one vertebra above or below the reference frame vertebra: 16.5%, 4.0%, and 1.2%; two vertebrae above or below the reference frame vertebra: 20.7%, 8.7%, and 2.3%; three vertebrae above or below the reference frame vertebra: 23

  7. A comparison of unilateral and bilateral pedicle screw fixation combined with transforaminal lumbar interbody fusion for lumbar degenerative diseases

    Institute of Scientific and Technical Information of China (English)

    Yang Xiaoming; Wang Hong; Zhao Quanlai; Xu Hongguang; Liu Ping; Jin Yuelong

    2014-01-01

    Background Bilateral transpedicular screw fixation in conjunction with interbody fusion is widely used to treat lumbar degenerative diseases; however,there are some disadvantages of using this fixation system.This study comparatively analyzes the results of unilateral and bilateral pedicle screw fixation combined with transforaminal lumbar interbody fusion (TLIF) for one-level lumbar degenerative diseases.Methods Sixty-six cases with one-level lumbar degenerative diseases were studied.The patients were divided according to surgical approach into a unilateral group (Group A) and a bilateral group (Group B).The patients were evaluated for pain by visual analog scale (VAS) and Oswestry Disability Index (ODI).Operating time,blood loss,duration of hospitalization,and complication rate were also evaluated.Patients were examined at 1,3,6,and 12 months postoperatively and every year thereafter.Results Group A patients' average preoperative VAS and ODI scores were 7.03 ± 0.98 and (64.22±6.38)%,respectively,significantly decreased to 2.91 ± 0.88 and (14.42±2.08)%,respectively,at the last follow-up (P =0.000).In Group B,the average preoperative VAS and ODI scores were 6.79±0.86 and (63.22±4.70)%,respectively,significantly decreased to 3.12±0.96 and (14.62±2.08)%,respectively,at the last follow-up (P=0.000).No significant difference in the duration of hospitalization was found between groups.Operating time and blood loss of (125.9±13.0) minutes and (211.4±28.3) ml,respectively,in Group A were significantly less than (165.2±15.3) minutes and (258.6±18.3) ml,respectively,in Group B (P=-0.000).All patients achieved good bone union and had no pseudarthrosis at the last follow-up.Conclusions There are no clinical differences between unilateral and bilateral pedicle screw fixation combined with TLIF for one-level lumbar degenerative diseases.Unilateral fixation reduces operating time,bleeding,and cost of hospitalization.

  8. Accuracy of bone SPECT/CT for identifying hardware loosening in patients who underwent lumbar fusion with pedicle screws

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    Hudyana, Hendrah; Maes, Alex [AZ Groeninge, Department of Nuclear Medicine, Kortrijk (Belgium); University Hospital Leuven, Department of Morphology and Medical Imaging, Leuven (Belgium); Vandenberghe, Thierry; Fidlers, Luc [AZ Groeninge, Department of Neurosurgery, Kortrijk (Belgium); Sathekge, Mike [University of Pretoria, Department of Nuclear Medicine, Pretoria (South Africa); Nicolai, Daniel [AZ Groeninge, Department of Nuclear Medicine, Kortrijk (Belgium); Wiele, Christophe van de [AZ Groeninge, Department of Nuclear Medicine, Kortrijk (Belgium); University Ghent, Department of Radiology and Nuclear Medicine, Ghent (Belgium)

    2016-02-15

    The aim of this retrospective study was to evaluate the accuracy of bone SPECT (single photon emission computed tomography)/CT (computed tomography) in diagnosing loosening of fixation material in patients with recurrent or persistent back pain that underwent lumbar arthrodesis with pedicle screws using surgery and clinical follow-up as gold standard A total of 48 patients (median age 49 years, range 21-81 years; 17 men) who had undergone lumbar spinal arthrodesis were included in this retrospective analysis. SPECT/CT results were compared to the gold standard of surgical evaluation or clinical follow-up. Positive SPECT/CT results were considered true positives if findings were confirmed by surgery or if clinical and other examinations were completely consistent with the positive SPECT/CT finding. They were considered false positives if surgical evaluation did not find any loose pedicle screws or if symptoms subsided with non-surgical therapy. Negative SPECT/CT scans were considered true negatives if symptoms either improved without surgical intervention or remained stable over a minimum follow-up period of 6 months. Negative SPECT/CT scans were determined to be false negatives if surgery was still required and loosening of material was found. The median length of time from primary surgery to bone SPECT/CT referral was 29.5 months (range 12-192 months). Median follow-up was 18 months (range 6-57) for subjects who did not undergo surgery. Thirteen of the 48 patients were found to be positive for loosening on bone SPECT/CT. Surgical evaluation (8 patients) and clinical follow-up (5 patients) showed that bone SPECT/CT correctly predicted loosening in 9 of 13 patients, while it falsely diagnosed loosening in 4 patients. Of 35 negative bone SPECT/CT scans, 12 were surgically confirmed. In 18 patients, bone SPECT/CT revealed lesions that could provide an alternative explanation for the symptoms of pain (active facet degeneration in 14 patients, and disc and sacroiliac

  9. Unilateral versus bilateral pedicle screw fixation of minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF): a meta-analysis of randomized controlled trials.

    Science.gov (United States)

    Wang, Liang; Wang, Yipeng; Li, Zhengyao; Yu, Bin; Li, Ye

    2014-11-06

    A few studies focused on unilateral or bilateral pedicle screw (PS) fixation of minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) to treat lumbar degenerative diseases have been published. There is still debate over whether one method is superior to another. A systematic review and meta-analysis of randomized controlled trials (RCT) was performed to compare the efficacy of the two methods. We searched the established electronic literature databases of MEDLINE, EMBASE, Web of Science and the Cochrane Central Register of Controlled Trials databases for RCTs comparing the unilateral with bilateral pedicle screw fixation of MIS-TLIF. Pooled mean differences (MD) and odds ratios (OR) and with 95% CIs were calculated for the outcomes. Three RCTs were identified and analyzed. The results showed that there is no significant difference between the two methods in terms of postoperative VAS-BP score (WMD = -0.09; 95% CI: -0.69 to 0.51; P =0.78), ODI (WMD, -0.09; 95% CI -5.85 to 5.67; P =0.98), fusion rate (OR = 2.99; 95% CI 0.55 to 16.38; P = 0.21) or complication rate (OR = 1.61, 95% CI: 0.49 to 5.37; P =0.43). Unilateral pedicle screw fixation was associated with less blood loss (WMD = -87.83; 95% CI: -160.70 to -14.96; P =0.02). The existing evidence indicate that no superiority exists between the two fixation methods of MIS-TLIF in terms of functional outcome, fusion rate and complication rate, in spite of that unilateral pedicle screw fixation can achieve less blood loss than bilateral fixation.

  10. Degenerative Change in the Adjacent Segments to the Fusion Site after Posterolateral Lumbar Fusion with Pedicle Screw Instrumentation : A Minimum 4-Year Follow-up

    OpenAIRE

    Hayashi, Tetsuo; Arizono, Takeshi; Fujimoto, Toshihiro; Morooka, Takaaki; Shida, Junichi; Tokito, Takeshi; Fukumoto, Shinichi; Masuda, Sachio

    2008-01-01

    Background. Controversy remains regarding the subsequent degeneration of adjacent segments, and little reliable information could be found in the literature regarding long-term clinical results and adjacent segment degeneration. The objective of this study is to investigate the degenerative change of adjacent segments to the fusion site and clinical outcome after posterolateral lumbar fusion with pedicle screw instrumentation and identify the risk factors in degenerative change at adjacent se...

  11. Novel pedicle screw and plate system provides superior stability in unilateral fixation for minimally invasive transforaminal lumbar interbody fusion: an in vitro biomechanical study.

    Directory of Open Access Journals (Sweden)

    Jie Li

    Full Text Available This study aims to compare the biomechanical properties of the novel pedicle screw and plate system with the traditional rod system in asymmetrical posterior stabilization for minimally invasive transforaminal lumbar interbody fusion (MI-TLIF. We compared the immediate stabilizing effects of fusion segment and the strain distribution on the vertebral body.Seven fresh calf lumbar spines (L3-L6 were tested. Flexion/extension, lateral bending, and axial rotation were induced by pure moments of ± 5.0 Nm and the range of motion (ROM was recorded. Strain gauges were instrumented at L4 and L5 vertebral body to record the strain distribution under flexion and lateral bending (LB. After intact kinematic analysis, a right sided TLIF was performed at L4-L5. Then each specimen was tested for the following constructs: unilateral pedicle screw and rod (UR; unilateral pedicle screw and plate (UP; UR and transfacet pedicle screw (TFS; UP and TFS; UP and UR.All instrumented constructs significantly reduced ROM in all motion compared with the intact specimen, except the UR construct in axial rotation. Unilateral fixation (UR or UP reduced ROM less compared with the bilateral fixation (UP/UR+TFS, UP+UR. The plate system resulted in more reduction in ROM compared with the rod system, especially in axial rotation. UP construct provided more stability in axial rotation compared with UR construct. The strain distribution on the left and right side of L4 vertebral body was significantly different from UR and UR+TFS construct under flexion motion. The strain distribution on L4 vertebral body was significantly influenced by different fixation constructs.The novel plate could provide sufficient segmental stability in axial rotation. The UR construct exhibits weak stability and asymmetrical strain distribution in fusion segment, while the UP construct is a good alternative choice for unilateral posterior fixation of MI-TLIF.

  12. Known-component 3D-2D registration for image guidance and quality assurance in spine surgery pedicle screw placement

    Science.gov (United States)

    Uneri, A.; Stayman, J. W.; De Silva, T.; Wang, A. S.; Kleinszig, G.; Vogt, S.; Khanna, A. J.; Wolinsky, J.-P.; Gokaslan, Z. L.; Siewerdsen, J. H.

    2015-03-01

    Purpose. To extend the functionality of radiographic / fluoroscopic imaging systems already within standard spine surgery workflow to: 1) provide guidance of surgical device analogous to an external tracking system; and 2) provide intraoperative quality assurance (QA) of the surgical product. Methods. Using fast, robust 3D-2D registration in combination with 3D models of known components (surgical devices), the 3D pose determination was solved to relate known components to 2D projection images and 3D preoperative CT in near-real-time. Exact and parametric models of the components were used as input to the algorithm to evaluate the effects of model fidelity. The proposed algorithm employs the covariance matrix adaptation evolution strategy (CMA-ES) to maximize gradient correlation (GC) between measured projections and simulated forward projections of components. Geometric accuracy was evaluated in a spine phantom in terms of target registration error at the tool tip (TREx), and angular deviation (TREΦ) from planned trajectory. Results. Transpedicle surgical devices (probe tool and spine screws) were successfully guided with TREx30° (easily accommodated on a mobile C-arm). QA of the surgical product based on 3D-2D registration demonstrated the detection of pedicle screw breach with TRExConclusions. 3D-2D registration combined with 3D models of known surgical components provides a novel method for near-real-time guidance and quality assurance using a mobile C-arm without external trackers or fiducial markers. Ongoing work includes determination of optimal views based on component shape and trajectory, improved robustness to anatomical deformation, and expanded preclinical testing in spine and intracranial surgeries.

  13. [Use of pedicle percutaneous cemented screws in the management of patients with poor bone stock].

    Science.gov (United States)

    Pesenti, S; Graillon, T; Mansouri, N; Adetchessi, T; Tropiano, P; Blondel, B; Fuentes, S

    2016-12-01

    Management of patients with poor bone stock remains difficult due to the risks of mechanical complications such as screws pullouts. At the same time, development of minimal invasive spinal techniques using a percutaneous approach is greatly adapted to these fragile patients with a reduction in operative time and complications. The aim of this study was to report our experience with cemented percutaneous screws in the management of patients with a poor bone stock. Thirty-five patients were included in this retrospective study. In each case, a percutaneous osteosynthesis using cemented screws was performed. Indications were osteoporotic fractures, metastasis or fractures on ankylosing spine. Depending on radiologic findings, short or long constructs (2 levels above and below) were performed and an anterior column support (kyphoplasty or anterior approach) was added. Evaluation of patients was based on pre and postoperative CT-scans associated with clinical follow-up with a minimum of 6 months. Eleven men and 24 women with a mean age of 73 years [60-87] were included in the study. Surgical indication was related to an osteoporotic fracture in 20 cases, a metastasis in 13 cases and a fracture on ankylosing spine in the last 2 cases. Most of the fractures were located between T10 and L2 and a long construct was performed in 22 cases. Percutaneous kyphoplasty was added in 24 cases and a complementary anterior approach in 3 cases. Average operative time was 86minutes [61-110] and blood loss was estimated as minor in all the cases. In the entire series, average volume of cement injected was 1.8 cc/screw. One patient underwent a major complication with a vascular leakage responsible for a cement pulmonary embolism. With a 9 months average follow-up [6-20], no cases of infection or mechanical complication was reported. Minimal invasive spinal techniques are greatly adapted to the management of fragile patients. The use of percutaneous cemented screws is, in our experience

  14. Juvenile idiopathic scoliosis treated with posterior arthrodesis and segmental pedicle screw instrumentation before the age of 9 years: a 5-year follow-up

    Directory of Open Access Journals (Sweden)

    Musaoğlu Resul

    2009-01-01

    Full Text Available Abstract Study design Retrospective study. Objective To evaluate the radiological results of fusion with segmental pedicle screw fixation in juvenile idiopathic scoliosis with a minimum 5-year follow-up. Summary of background data Progression of spinal deformity after posterior instrumentation and fusion in immature patients has been reported by several authors. Segmental pedicle screw fixation has been shown to be effective in controlling both coronal and sagittal plane deformities. However, there is no long term study of fusion with segmental pedicle screw fixation in these group of patients. Methods Seven patients with juvenile idiopathic scoliosis treated by segmental pedicle screw fixation and fusion were analyzed. The average age of the patients was 7.4 years (range 5–9 years at the time of the operation. All the patients were followed up 5 years or more (range 5–8 years and were all Risser V at the most recent follow up. Three dimensional reconstruction of the radiographs was obtained and 3DStudio Max software was used for combining, evaluating and modifying the technical data derived from both 2d and 3d scan data. Results The preoperative thoracic curve of 56 ± 15° was corrected to 24 ± 17° (57% correction at the latest follow-up. The lumbar curve of 43 ± 14° was corrected to 23 ± 6° (46% correction at the latest follow-up. The preoperative thoracic kyphosis of 37 ± 13° and the lumbar lordosis of 33 ± 13° were changed to 27 ± 13° and 42 ± 21°, respectively at the latest follow-up. None of the patients showed coronal decompensation at the latest follow-up. Four patients had no evidence of crankshaft phenomenon. In two patients slight increase in Cobb angle at the instrumented segments with a significant increase in AVR suggesting crankshaft phenomenon was seen. One patient had a curve increase in both instrumented and non instrumented segments due to incorrect strategy. Conclusion In juvenile idiopathic curves of

  15. The Effect of Concomitant Rib Deformity in Congenital Scoliosis on Spinal Curve Correction After Segmental Pedicle Screw Instrumentation.

    Science.gov (United States)

    Ameri, Ebrahim; Fouladi, Daniel F; Safari, Mir Bahram; Tari, Hossein Vahid; Ghandhari, Hassan

    2017-05-01

    A single-center, prospective study. To investigate the effect of rib anomaly on surgical curve correction outcome in congenital scoliosis. The presence of rib anomalies may complicate surgical correction of congenital scoliosis. The outcome of surgical correction, however, has not been documented in scoliotic patients with and without rib deformity. Percent Cobb angle decrease (CAD) after operation was calculated in 94 patients with congenital scoliosis. Posterior segmental pedicle screw instrumentation (posterior approach) with or without previous anterior spinal release and fusion (anterior approach) was the method of correction. The impact of vertebral anomaly and rib deformity on CAD was examined. Although the type of vertebral anomaly had no significant effect on the mean CAD, it was significantly lower in 56 patients with rib deformity compared with that in the remaining patients without rib deformity (35.14%±15.83% vs. 51.54%±17.82%, Prib abnormalities, and in those with same-level vertebral and rib deformities. Patients' sex and age at the time of operation, rib number abnormality, and the type of operation (ie, posterior-only approach vs. anterior and posterior approach) did not contribute significantly to Cobb angle change after operation. Concomitant rib deformities, particularly of complex and unilateral types, significantly compromise operative curve correction outcome in congenital scoliosis.

  16. Error Analysis and Experimental Study of a Bi-Planar Parallel Mechanism in a Pedicle Screw Robot System.

    Science.gov (United States)

    Duan, Qingjuan; Du, Zhijiang; Yu, Hongjian; Wang, Yongfeng; Dong, Wei

    2016-11-30

    Due to the urgent need for high precision surgical equipment for minimally invasive spinal surgery, a novel robot-assistant system was developed for the accurate placement of pedicle screws in lumbar spinal surgeries. The structure of the robot was based on a macro-micro mechanism, which includes a serial mechanism (macro part) and a bi-planar 5R parallel mechanism (micro part). The macro part was used to achieve a large workspace, while the micro part was used to obtain high stiffness and accuracy. Based on the transfer function of dimension errors, the factors affecting the accuracy of the end effectors were analyzed. Then the manufacturing errors and joint angle error on the position-stance of the end effectors were investigated. Eventually, the mechanism of the strain energy produced by the deformation of linkage via forced assembly and displacements of the output point were calculated. The amount of the transfer errors was quantitatively analyzed by the simulation. Experimental tests show that the error of the bi-planar 5R mechanism can be controlled no more than 1 mm for translation and 1° for rotation, which satisfies the required absolute position accuracy of the robot.

  17. Error Analysis and Experimental Study of a Bi-Planar Parallel Mechanism in a Pedicle Screw Robot System

    Directory of Open Access Journals (Sweden)

    Qingjuan Duan

    2016-11-01

    Full Text Available Due to the urgent need for high precision surgical equipment for minimally invasive spinal surgery, a novel robot-assistant system was developed for the accurate placement of pedicle screws in lumbar spinal surgeries. The structure of the robot was based on a macro-micro mechanism, which includes a serial mechanism (macro part and a bi-planar 5R parallel mechanism (micro part. The macro part was used to achieve a large workspace, while the micro part was used to obtain high stiffness and accuracy. Based on the transfer function of dimension errors, the factors affecting the accuracy of the end effectors were analyzed. Then the manufacturing errors and joint angle error on the position-stance of the end effectors were investigated. Eventually, the mechanism of the strain energy produced by the deformation of linkage via forced assembly and displacements of the output point were calculated. The amount of the transfer errors was quantitatively analyzed by the simulation. Experimental tests show that the error of the bi-planar 5R mechanism can be controlled no more than 1 mm for translation and 1° for rotation, which satisfies the required absolute position accuracy of the robot.

  18. Computer navigation-assisted spinal fusion with segmental pedicle screw instrumentation for scoliosis with rett syndrome:a case report

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    Nishida,Keiichiro

    2009-12-01

    Full Text Available Scoliosis is a common clinical manifestation of Rett syndrome, a neurodevelopmental disorder that almost exclusively affects females. The spinal curve in patients with Rett syndrome is typically a long C curve of a neuromuscular type. As the onset of the scoliosis is very early and shows rapid progression, early surgical intervention has been recommended to prevent a life-threatening collapsing spine syndrome. However, there are high perioperative risks in Rett syndrome patients who undergo spinal surgery, such as neurological compromise and respiratory dysfunction due to rigid spinal curve. We herein report the surgical result of treating severe rapid progressive thoracic scoliosis in a 16-year-old girl with Rett syndrome. Posterior segmental pedicle screw fixation was performed from T1 to L3 using a computer-assisted technique. Post-operative radiography demonstrated a good correction of the curve in both the sagittal and coronal alignment. There were no postoperative complications such as neurological compromise. The patient had maintained satisfactory spinal balance as of the 3-year follow-up examination.

  19. Percutaneous Pedicle Screw Fixation with Polymethylmethacrylate Augmentation for the Treatment of Thoracolumbar Intravertebral Pseudoarthrosis Associated with Kummell’s Osteonecrosis

    Directory of Open Access Journals (Sweden)

    Hyeun-Sung Kim

    2016-01-01

    Full Text Available Purpose. The purpose of our study is to evaluate the therapeutic efficacy of short-segment percutaneous pedicle screw fixation with polymethylmethacrylate (PMMA augmentation for the treatment of osteoporotic thoracolumbar compression fracture with osteonecrosis. Methods. Osteoporotic thoracolumbar compression fractures with avascular necrosis were treated by short-segment PPF with PMMA augmentation. Eighteen were followed up for more than 2 years. The kyphotic angle, compression ratio, visual analog scale (VAS score for back pain, and the Oswestry Disability Index (ODI were analyzed. In addition, radiologic and clinical parameters of PPF group were compared with percutaneous vertebroplasty (PVP group. Results. Vertebral height and kyphotic angle of the compressed vertebral bodies were significantly corrected after the operation (P<0.05. Further, restored vertebral height was maintained during the 2 or more years of postoperative follow-up. Compared to the PVP group the postoperative compression ratio and kyphotic angle were significantly lower in the PPF group (P<0.05. The postoperative ODI and VAS of the PVP group were significantly higher than the PPF (P<0.05. Conclusions. According to our results, short-segment PPF with PMMA augmentation may be an effective minimally invasive treatment for osteoporosis in cases of osteoporotic vertebral compression fractures with Kummell’s osteonecrosis.

  20. Accuracy and safety of intraoperative CT-assisted placement of pedicle screw%术中CT辅助下椎弓根螺钉置入的精确性和安全性评估

    Institute of Scientific and Technical Information of China (English)

    潘冬生; 宋振全; 赵明光; 张海松; 陆宇; 金振野

    2016-01-01

    Objective To assess the safety and accuracy of intraoperative CT assisted-placement of pedicle screw in the patients with spinal disorders. Methods The clinical data of 39 patients with spinal disorders, who underwent intraoperative CT-assisted placement of pedicle screws in our hospital from May, 2014 through May, 2015, were analyzed retrospectively. The accuracy of pedicle screw placement was assessed by Gertzbein-Robbins classification after the surgery. The safety of pedicle screw fixation was assessed by the postoperative complications. Results A total of 112 pedicle screws were placed in the spines in 39 patients and the placements of 38 screws of them were adjusted according to intraoperative CT findings. Of 112 screws, 105 were placed in the pedicles, 5 by grade 1 pedicle breach, and 2 by grad 2 pedicle breach according to Gertzbein-Robbins classification of pedicle screw placement accuracy. Two screws breached the medical pedicle walls, 4 breached the lateral walls and 1 breached inferolateral pedicle wall. The postoperative complications included surgical site infections in 4 patients, cerebrospinal fluid leaks in 2 and injury to the nerve in 1. No complication was directly related to the screws placement. No patient required reoperation due to the misplacement of the pedicle screws. Conclusions The accuracy and safety of pedicle screw placement can be enhanced in the patients with spinal disorders by intraoperative CT scanning which may be help the surgeon adjust the improper pedicle screw placement in time.%目的 评估术中CT辅助下椎弓根固定技术的安全性和准确性.方法 回顾性分析2014年5月至2015年5月术中CT辅助下椎弓根固定手术治疗的39例脊柱脊髓疾病患者的临床资料,其中脊柱脊髓损伤6例,颅颈交界区畸形6例,脊柱退行性变14例,脊柱脊髓肿瘤13例;术后应用Gertzbein-Robbins分级评价螺钉植入的精确性.结果 椎弓根螺钉固定总数为112枚,术中根据CT影像

  1. Evaluation of initial biomechanical stability of screw-rod fixation system with lateral mass screw and pedicle screw for cervical vertebra%颈椎侧块与颈椎弓根内固定后初始稳定性评价及实验研究

    Institute of Scientific and Technical Information of China (English)

    袁欣华; 庞清江; 许柯; 张宗凯; 祝惠敏; 叶奕; 赵卫东

    2013-01-01

    目的 评价钉棒系统分别行颈椎侧块及椎弓根固定后的初始稳定性,为临床应用提供理论依据.方法 取8具新鲜冷冻人体颈椎标本,切断C4,5棘上韧带、棘间韧带、双侧关节囊,制成C4,5后柱不稳损伤模型,每个标本分别行正常标本、双侧C4,5侧块及椎弓根固定标本三维运动范围测定.结果 两种内固定组的三维运动范围均明显小于正常组,椎弓根固定组三维运动组小于侧块螺钉固定组,两组差异有统计学意义.结论 在颈椎后柱损伤模型中,用钉棒系统分别行侧块及椎弓根固定后均能明显提高脊柱三维稳定性,椎弓根内固定稳定性优于侧块钉棒系统.%Objective To investigate the initial biomechanical stability of the screw-rod system with lateral mass screw and pedicle screw for cervical vertebra fixation, and to provide theoretical basis for clinical applications of the screw-rod system. Methods Eight fresh human cervical specimens were obtained. Each specimen received a 3-D range of movement (ROM) test (normal group). Then the model of instable posterior column of C4.5 injury was set up by transection of supraspinous, interspinous ligament and bilateral articular capsule. For each specimen, another two 3-D ROM tests were carried out after receiving a lateral mass screw fixation and a pedicle screw fixation respectively. Results The ROM of the internal fixation groups was notably smaller than the normal group. There was significant difference. Conclusion For the instable cervical posterior column injury model, the screw-rod fixation system with lateral mass screw and pedicle screw for cervical vertebra fixation would evidently improve the 3-D stability of the vertebral column. And the stability of pedicle screw fixation is superior to it of mass screw fixation. within the internal fixation groups. The ROM of the pedicle screw group is much smaller.

  2. Biomechanical changes and clinical characteristics of cervical pedicle screws internal fixation%颈椎椎弓根螺钉置入内固定的生物力学变化及其临床特性

    Institute of Scientific and Technical Information of China (English)

    王华刚; 杨飞

    2011-01-01

    背景:颈椎椎弓根钉由于其独特的三维稳定性,越来越多的学者对其进行更加广泛的研究.目的:综述颈椎椎弓根解剖特点及椎弓根螺钉置钉的安全性和临床应用.方法:应用计算机检索1994-01/2010-09 CNKI及PubMed数据库相关文章,中文检索词为"颈椎弓根螺钉",英文检索词为"cervical pedicle screws",共检索到文献292篇,最终纳入符合标准的文献43篇.结果与结论:通过文献检索获得目前一致的观点认为颈椎弓根内固定由于是三维固定,因此可以获得良好的生物力学.但是,由于颈椎弓根周围毗邻部特殊的解剖结构,潜在血管、神经根和颈髓损伤的危险性,置入内固定风险及难度大,所以临床应用要做到个体化置钉.%BACKGROUND: More and more scholars have focused on cervical pedicle screws because of their unique three-dimensional stability.OBJECTIVE: To review the anatomic characteristics of the cervical pedicle, and to investigate the safety and clinical application of cervical pedicle screws.METHODS: The literature concerning the cervical pedicle screw internal fixation in recent years were extensively searched from CNKl and PubMed databases (1994-01/2010-09) using the keywords of "cervical pedicle screws" in Chinese and English. Forty-three articles of 292 were included in the result analysis.RESULTS AND CONCLUSION: Cervical pedicle screw fixation can obtain a good biomechanics based on its three-dimensional fixation. However, due to the special anatomic structures of the cervical pedicle adjacent to the surrounding, potential risks of blood vessel, nerve root and cervical spinal cord injuries, it is difficult to the internal fixation of cervical pedicle screws with a certain risk. The clinical application of pedicle screws should be individualized.

  3. Estudo biomecânico comparativo da resistência à força de compressão entre os parafusos pediculares monoaxiais com travamento interno único e parafusos pediculares monoaxiais com travamento duplo interno e externo Estudio biomecánico comparativo de la resistencia a la fuerza de compresión entre los tornillos pediculares monoaxiales con traba interna única y tornillos pediculares monoaxiales con traba dupla interna y externa Biomechanical comparative study of compression strength between single locked monoaxial screws and double locked monoaxial screws

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    Luiz Cláudio de Moura França

    2010-06-01

    los sistemas de fijación fue elaborado de acuerdo con las normas descritas por la American Society for Testing Materials (ASTM en el ensayo F1717-04. Fueron formados dos grupos, siendo el Grupo 1 compuesto por los ensayos con tornillos fijos con sistema de duplo bloqueo, y el Grupo 2, tornillos fijos con bloqueo interno único. Fueron utilizados tres conjuntos de astas y tornillos para cada grupo. Cada conjunto fue sometido a un test biomecánico. Los componentes metálicos utilizados fueron todos producidos por la misma empresa, con mismo origen en relación a la materia prima. Los modelos experimentales fueron sometidos a testes mecánicos en la máquina universal de ensayos EMIC, modelo EMIC DL 10000. RESULTADOS: los resultados obtenidos en el ensayo de compresión en las muestras del Grupo 1 tuvieron una carga máxima promedio de 2104.15 N y una carga de declive promedio de 1882.55 N. Los resultados obtenidos en el ensayo de compresión en las muestras del Grupo 2 tuvieron una carga máxima promedio de 1420.50 N y una carga de declive promedio de 1314.37 N. CONCLUSIÓN: el sistema de tornillos fijos con duplo bloqueo (Grupo 1 presentó mayor resistencia a las fuerzas de compresión cuando comparado a los tornillos con traba interna aislada.OBJECTIVE: to compare the rigidity of a pedicle fixation system composed of fixed pedicle screws with double locked system (internal and external to one composed of fixed pedicle screws with single internal locked system, submitted to compression strengths. METHODS: the experimental model used to evaluate the fixation systems was constructed according to the standard described by the American Society for Testing Materials (ASTM in trial F1717-04. The samples were divided into two groups. Group 1 was composed of tests with fixed screws with double locked system; in Group 2 fixed screws with single internal locked system were used. Three sets of rods and screws were used for each group; these sets were submitted to a

  4. The Treatment of Sacroiliac Joint Dislocation by Fixation Using Pedicle Screws Combined with Iliac Screws%髂骨置钉联合同侧椎弓根钉复位固定治疗骶髂关节脱位

    Institute of Scientific and Technical Information of China (English)

    孙海浪; 朱国太; 郝跃东; 唐晓明

    2012-01-01

    To explore the clinical effect of the treatment of sacroiliac joint dislocation by fixation using pedicle screws combined with iliac screws, total of 9 patients (3 female, 6 male) diagnosed as sacroiliac joint dislocation treated with the fixation using pedicle screws combined with iliac screws were studied. The mean age was 36. 4 years(range 21 - 55). The reason for trauma was traffic accident in 5, fall in 4. The type was 6C1, 2C2, 1C3, according to the Tile. Of the 9 patients, 5 had femur fracture, 2 had lung contusion, 2 had separation symphysis pubis, 7 had fracture of all 4 public. All patients were followed-up for 6 ~ 30 months (average 16 months). X-rays after operation showed that all the dislocations were replaced satisfied and sacroiliac joint fused. There was no screw loose and break. No re-dislocation of sacroiliac joint happened. It was safety and perfect surgical procedure that using pedicle screws combined with iliac screws to treat sacroiliac joint dislocation.%探讨髂骨置钉联合同侧椎弓根钉复位固定治疗骶髂关节脱位方法及效果.收治9例骶髂关节脱位患者,男6例,女3例,年龄21岁~55岁,平均36.4岁.5例为交通事故伤,4例为高处坠落伤,C1型6例,C2型2例,C3型1例.其中3例患者合并有股骨干骨折,2例合并有肺挫伤,2例合并有耻骨联合分离,7例伴耻骨支骨折.结果,术后9例患者均获得随访,随访6个月~30个月,平均16月,术后X线片复查示骶髂关节脱位复位满意,骶髂关节均获融合.内固定无松动断裂,骶髂关节无再脱位.应用髂骨置钉联合同侧椎弓根钉复位固定治疗技术是治疗骶髂关节脱位的一种直接而可靠的固定方法.

  5. A meta-analysis of unilateral versus bilateral pedicle screw fixation in minimally invasive lumbar interbody fusion.

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    Zheng Liu

    Full Text Available STUDY DESIGN: Meta-analysis. BACKGROUND: Bilateral pedicle screw fixation (PS after lumbar interbody fusion is a widely accepted method of managing various spinal diseases. Recently, unilateral PS fixation has been reported as effective as bilateral PS fixation. This meta-analysis aimed to comparatively assess the efficacy and safety of unilateral PS fixation and bilateral PS fixation in the minimally invasive (MIS lumbar interbody fusion for one-level degenerative lumbar spine disease. METHODS: MEDLINE/PubMed, EMBASE, BIOSIS Previews, and Cochrane Library were searched through March 30, 2014. Randomized controlled trials (RCTs and controlled clinical trials (CCTs on unilateral versus bilateral PS fixation in MIS lumbar interbody fusion that met the inclusion criteria and the methodological quality standard were retrieved and reviewed. Data on participant characteristics, interventions, follow-up period, and outcomes were extracted from the included studies and analyzed by Review Manager 5.2. RESULTS: Six studies (5 RCTs and 1 CCT involving 298 patients were selected. There were no significant differences between unilateral and bilateral PS fixation procedures in fusion rate, complications, visual analogue score (VAS for leg pain, VAS for back pain, Oswestry disability index (ODI. Both fixation procedures had similar length of hospital stay (MD = 0.38, 95% CI = -0.83 to 1.58; P = 0.54. In contrast, bilateral PS fixation was associated with significantly more intra-operative blood loss (P = 0.002 and significantly longer operation time (P = 0.02 as compared with unilateral PS fixation. CONCLUSIONS: Unilateral PS fixation appears as effective and safe as bilateral PS fixation in MIS lumbar interbody fusion but requires less operative time and causes less blood loss, thus offering a simple alternative approach for one-level lumbar degenerative disease.

  6. Advances of pedicle screw fixation for thoracolumbar fractures%椎弓根螺钉内固定术治疗胸腰椎骨折的进展

    Institute of Scientific and Technical Information of China (English)

    丁浩洋; 柯珍勇

    2014-01-01

    0BJECTIVE:To systemic il ustrate advances of pedicle screw internal fixation in treating thoracolumbar fracture. METHODS:A computer-based online search(1993-01/2014-01) of PubMed database(http://www. ncbi.nlm.nih.gov/pubmed/) and WANFANG database (http://www.wanfangdata.com.cn/) was performed for related articles with keywords“pedicular screw,internal fixation,thoracolumbar fracture”in English and in Chinese.A total of 65 articles were col ected,and 28 were included according to inclusion and exclusion criteria. RESULTS:Pedicle screws have a good biomechanical characteristic.Cooperated with different ways of operation,pedicle screws can be used for reconstructing the stability of vertebral fracture,providing three-dimensional correction,restoring the hight of vertebral body and physiological bending of the spine,and decompressing spinal canal.With the technological development in recent years,the application of intermediate screw and percutaneous pedicle screw fixation optimized the surgical approach, reduced the trauma and postoperative adverse reactions. CONCLUSION:With the application of various kinds of techniques,pedicle screw fixation can be used for the treatment of various types of thoracolumbar fractures.%目的:系统阐述椎弓根螺钉内固定术应用于胸腰椎骨折治疗的进展。方法使用计算机及因特网检索(1993-01/2014-01) PubMed数据库(http://www.ncbi.nlm.nih.gov/pubmed/)、中国万方数据库(http://www.wanfangdata.com.cn/)中相关文章,英文关键词为“pedicular screw,internal fixation,thoracolumbar fracture”,中文关键词为“椎弓根螺钉,内固定,胸腰椎骨折”。共检索到65篇文献,根据纳入及排除标准,共纳入28篇文章。结果椎弓根螺钉具有良好生物力学特性,配合不同的手术方式,可重建骨折椎稳定性,提供三维矫正,恢复椎体高度及脊柱的生理弯曲,行椎管减压。而近年来随技术发展,伤椎内固定

  7. Analysis and Treatment of Complications Associated with Misplacement of Lumbar Pedicle Screw%腰椎椎弓根螺钉位置不佳所致并发症原因分析及应对措施

    Institute of Scientific and Technical Information of China (English)

    胡文凯; 朱一平; 姚女兆; 蔡斌

    2009-01-01

    [Objective] To explore the complications caused by misplacement of lumbar pedicle screw in the treatment of lumbar spine degenerative disease and its management. [Methods]From March 2006 to March 2008, the clinical data of 217 cases of lumbar spine degenerative disease treated with the pedicle screw fixation and laminectomy were analyzed retrospectively. Fifty eight lumbar pedicle screws in 12 patients who suffered from complications of the nerve injury after operation were observed with CT to analyze the reasons of misplacement of lumbar pedicle screw. [Results] In 12 patients, there were 14 lumbar pedicle screws which were misplaced and pressed the nerves. All of these pedicle screws were in topside and perforated the wall of lumbar pedicle. Among them, 9 screws perforated the medial wall, 3 burst the pedicle and 2 perforated the inferior wall. All had injured the nerves in disparity. These pedicle screws which pressed the nerves seriously were replaced and most of the symptoms in these cases had relieved gradually. [Conclusion]The reasons of misplacements of the lumbar pedicle screw include the limited decompression extent, lumbar congenital deformity, degenerative disease and so on, all of which result in the mutation in topography of lumbar pedicle. Overall mastering the technique of pedicle screw fixation and paying attention to the individuation of the placement of the screws can avoid the complications after operation.%[目的]分析应用椎弓根螺钉治疗腰椎退行性疾病因椎弓根置钉位置不佳所致并发症及应对措施.[方法] 回顾性分析本院2006年3月至2008年1月使用椎弓根螺钉固定,椎板减压治疗腰椎退行性疾病的患者217例的临床资料,对其中12例术后出现神经症状患者的58枚椎弓根钉进行术后CT扫描,分析其螺钉位置不佳的原因.[结果]12例患者中共有14枚螺钉位置不佳,挤压神经.均为最上位螺钉穿破椎弓根骨壁,其中9例穿破内侧壁,3

  8. One-stage posterior C2 and C3 pedicle screw fixation or combined anterior C2-C3 fusion for the treatment of unstable hangman’s fracture

    OpenAIRE

    Liu, Jingchen; Li, Ye; Wu, Yuntao

    2013-01-01

    The present study aimed to evaluate the effect of using one-stage posterior C2 and C3 pedicle screw fixation or combined anterior C2-C3 fusion in the treatment of unstable hangman’s fracture. A total of 13 patients with unstable hangman’s fractures underwent C2 and C3 pedicle screw fixation, lamina interbody fusion or combined anterior C2-C3 fusion and imaging examinations to evaluate the fracture fixation and healing condition at three days and three months following surgery. Postoperative X...

  9. An anatomic study on feasibility of pedicle screw or laminar screw implant in the axis of children%儿童枢椎椎弓根及椎板螺钉内固定的解剖学研究

    Institute of Scientific and Technical Information of China (English)

    王建华; 夏虹; 尹庆水; 吴优; 朱昌荣; 乔国庆

    2013-01-01

    Objective To investigate the feasibility for internal fixation of pedicle screw and laminar screw in the axis of children. Methods Thirty-two sets of cervical CT scan images of children (age range from 2 to 10 years old) treated in Guangzhou General Hospital of Guangzhou Military Command from 2009 to 2012 were slected, in which there were 16 sets (32 sides) in play age group (age range from 2 to 5 years old ) and other 16 sets (32 sides) in primary school-age group (age range from 5 to 10 years old). The axial pedicle width, length and introvert angle of pedicle screw trajectory, as well as the isthmus width of lamina, length and outward angle of laminar screw trajectory were measured by PACS tools respectively. Results There were 15 sides where pedicle width of pedicle screw trajectory > 3.5 mm in play age group and 26 sides in primary school-age group;while 24 sides where isthmus width of laminar screw trajectory > 3.5 mm in play age group and 31 sides in primary school-age group. Differences of average width, length of pedicle and larmina all showed statistical significance between 2 groups (P 0.05). Conclusions It is mostly feasible for axis pedicle screw and laminar screw implant for primary school-age children. For the play age children, based on preoperative accurate measurement and evaluation of relative screw implant anatomic parameters through thin slice cervical CT scan images, laminar or pedicle screw or mixed internal fixation should be chosen reasonably so as to provide safe and efficient fixation.%目的:探讨儿童枢椎椎弓根及椎板螺钉内固定的可行性。方法收集2009年至2012年广州军区广州总医院儿童颈椎薄层CT影像资料32套,其中年龄2~5岁(幼龄组)及5~10岁(学龄组)各16套32侧。测量枢椎椎弓根虚拟钉道宽度、长度、内倾角,椎板虚拟钉道峡部宽度、长度及外展角数据。结果幼龄组椎弓根虚拟钉道宽度>3.5 mm为15侧、学龄组为26侧;幼龄

  10. Biomechanical Comparison of Pedicle Screw Augmented with Different Volumes of Polymethylmethacrylate in Osteoporotic and Severely Osteoporotic Synthetic Bone Blocks in Primary Implantation: An Experimental Study

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    Da Liu

    2016-01-01

    Full Text Available This study was designed to compare screw stabilities augmented with different volumes of PMMA and analyze relationship between screw stability and volume of PMMA and optimum volume of PMMA in different bone condition. Osteoporotic and severely osteoporotic synthetic bone blocks were divided into groups A0-A5 and B0-B5, respectively. Different volumes of PMMA were injected in groups A0 to A5 and B0 to B5. Axial pullout tests were performed and Fmax was measured. Fmax in groups A1-A5 were all significantly higher than group A0. Except between groups A1 and A2, A3 and A4, and A4 and A5, there were significant differences on Fmax between any other two groups. Fmax in groups B1-B5 were all significantly higher than group B0. Except between groups B1 and B2, B2 and B3, and B4 and B5, there were significant differences on Fmax between any other two groups. There was significantly positive correlation between Fmax and volume of PMMA in osteoporotic and severely osteoporotic blocks. PMMA can significantly enhance pedicle screw stability in osteoporosis and severe osteoporosis. There were positive correlations between screw stability and volume of PMMA. In this study, injection of 3 mL and 4 mL PMMA was preferred in osteoporotic and severely osteoporotic blocks, respectively.

  11. Pedicle bone grafting with posterior pedicle screw system on thoracolumbar vertebral fractures%后路椎弓根植骨结合椎弓根钉系统治疗胸腰椎骨折

    Institute of Scientific and Technical Information of China (English)

    崔文波; 邝明业

    2011-01-01

    Objective To explore the methods and results of the combination of posterior pedicle graft and pedicle screw system for treatment of thoracolumbar fractures. Methods Sixty-two cases of thoracolumbar fracture patients were treated with pedicle screw system, at the same time, push the injection device with self-made bone graft within the vertebral body through the pedicle bone graft with posterior bone graft in the treatment of bed rest after 15 to 20 days and carryed out rehabilitation exercises back muscles, waist to protect 3 to 6 months. Results Sixty-two patients in this group were operated successfully, the fine rate was 83.87%, postoperative physiological curvature of vertebral height and satisfactory recovery without neurological symptoms have increased by 6 to 28 months follow-up of vertebral height and no obvious physiological radian lost. No broken nail, broken rod fixation loosening or vertebral compression again. Conclusions AF pedicle screw system for thoracolumbar fractures with good reduction and fixation, by pedicle bone graft in the posterior vertebral body does not increase the surgical trauma, it is able to immediately increase the capacity of vertebral bone and spine stability of anterior column in compression, so that patients can be an early activity and reduce broken nails, broken rod, complications such as vertebral compression again due to too much stress.%目的 探讨后路椎弓根植骨结合椎弓根钉系统治疗胸腰椎骨折的方法和效果.方法 62例胸腰椎骨折患者,在均采用椎弓根钉系统治疗的同时,用自制植骨推注器经椎弓根椎体内植骨结合中后路植骨治疗,术后卧床15~20 d,并进行康复背肌锻炼,腰围保护3~6个月.结果 本组62例患者手术均获得成功,优良率为83.87%,术后椎体高度及生理弧度恢复满意,未出现神经症状加重,经随访6~28个月,椎体高度和生理弧度无明显丢失,无断钉、断杆、内固定松动、椎体再压缩等并

  12. geneX®骨水泥强化椎弓根螺钉体内的实验研究%The experiment study of geneX® bone cement augmentation of pedicle screw in animal model

    Institute of Scientific and Technical Information of China (English)

    张树芳; 江建明; 陈荣春; 朱青安; 黄志平

    2015-01-01

    目的:通过动物实验,评估新型带负电荷硫酸钙/β-磷酸三钙复合骨水泥(geneX®)用于强化体内椎弓根螺钉的生物力学性质变化及可行性。方法选取6只健康山羊腰椎L1~5双侧共30个椎弓根随机分为3组:geneX®组,聚甲基丙烯酸甲酯骨水泥(Polymethylmethacrylate,PMMA)组,空白对照组,每组10个椎弓根。术后3个月处死动物取材行Mirco-CT检查、组织学检查及生物力学实验。结果轴向拔出力实验:geneX®组(803±155) N, PMMA组为(994±122) N,两者差异无统计学意义(P>0.05)。两组均明显高于对照组的(524±118) N,差异具有统计学意义(P<0.05)。组织学观察及Mirco-CT显示geneX®组中螺钉周围骨水泥已经完全降解、吸收,骨小梁排列致密,成熟骨小梁附近可见大量新生骨组织,明显优于对照组及PMMA组。结论 geneX®骨水泥可有效强化椎弓根螺钉内固定的强度,其强化作用随时间推移而增强,对防止骨质疏松症患者内固定的拔出发生率有重要意义。%Objective To evaluate the long-term in vivo biomechanical effects of a newly developed biphasic calcium composite bone cement (geneX®)with a negative surface charge augmentation of pedicle screw. Methods Bilateral pedicles of lumbar vertebrae (L1~5) of 6 female sheep were fi xed with pedicle screws. One pedicle of each vertebral body was treated with a screw augmented with either geneX®(geneX® group) or PMMA (PMMA group) and the contralateral pedicle was treated with a screw without any augmentation (control group). Three months later, the sheep were killed and biomechanical tests, micro-CT analysis and histological observation were conducted on the isolated specimen vertebrae. Results Both the axial and vertical stabilities of the pedicle screws in geneX® group were significantly enhanced compared with those in the control group (P<0.05). Micro-CT reconstruction and analysis showed that there were more bone

  13. 寰枢椎椎弓根螺钉置钉技术的临床应用%Clinical application of atlantoaxial pedicle screw system fixation

    Institute of Scientific and Technical Information of China (English)

    吴长沙; 李攀; 李恩贤; 李让贤; 夏兴平; 刘超; 涂国能

    2015-01-01

    Objective To investigate the effect of atlantoaxial pedicle screw system fixation to treat upper cervical in-juries.Methods Patients with upper cervical injuries were treated with atlantoaxial pedicle screw system fixation, which included 5 cases of Jefferson fractures,11 odontoid fractures and 9 Hangman fractures.Results No patient had the injury of spinal cord,nerve root and vertebral artery.There was 1 case with vertebral vein injury,which had been controlled by compression.1 case with Jefferson fracture showed incomplete reduction.All patients were followed up from 1 year to 2 years.All fusion bone got union from CT scan and X-ray a year after surgeries.The clinical symp-toms were improved and the screws were verified to be in a proper position without breakage or loosening.Conclusions The atlantoaxial pedicle screw system fixation is an effective method,which provide stable fixation and high fusion rate for fracture to treat upper cervical injuries.%目的:探讨寰枢椎椎弓根螺钉置钉技术在上颈椎损伤临床应用的效果。方法选择性应用寰枢椎椎弓根螺钉固定技术治疗 Jefferson 骨折5例,齿状突骨折11例,Hangman 骨折9例。结果术中无椎动脉、脊髓及神经根损伤发生。1例暴露时损伤静脉丛,予以压迫即能止血;1例寰枢椎骨折不完全复位。患者均获随访,时间1~2年。患者临床症状明显改善,术后1年行 X 线及 CT 检查,显示所有骨折均骨性愈合,螺钉位置良好,无松动、断钉。结论寰枢椎椎弓根螺钉内固定技术具有固定可靠及骨折愈合率高等特点,为上颈椎损伤提供了坚固的稳定性。

  14. 成人腰椎侧凸椎弓根螺钉误置模式%Misplacement patterns of pedicle screws in surgical correction for adult lumbar scoliosis

    Institute of Scientific and Technical Information of China (English)

    丁旗; 邱勇; 孙旭; 朱峰; 王斌; 朱泽章; 吴涛; 徐磊磊

    2011-01-01

    Objective To identify the patterns and risk factors of pedicle screw misplacement in adults with lumbar scoliosis. Methods Form August 2010 to June 2011, 49 patients with lumbar scoliosis were treated by posterior fusion with using pedicle screws. There were 14 males and 35 females with an average age of 39. 2 ± 13. 8 years. Pedicle screws were inserted by freehand technique according to the anatomic landmarks. Postoperative CT scans were conducted. Pedicle perforations were assessed after measurement, and were classified as medial, lateral or anterior. Screw malpositionwas categorized into four grades: Grade 1, ≤5 2 mm; Grade 2, 2. 1-4. Omm; Grade 3, 4. 1-6. 0 mm; and Grade 4, ≥6. 1mm. Screw perforation >2mm of either pedicular or vertebral cortex were considered at potential risk, and with > 4mm of medial pedicular cortex perforation or contour of aorta was considered at high risk. The perforation rates of different groups were compared to analyze the risk factors. Results A total of 353 screws were inserted, and the average was 7. 2 per patient 316 screws (89. 5% ) were fully contained within the cortical boundaries of the pedicle. The remaining 37 (10.5% ) screws breached pedicle walls, and there were 25 screws with Grade 1, 8 with Grade 2, 1 with Grade 3 and 3 with Grade 4 perforation. Among the penetrations of the 12 screws at potential risk, 6 were lateral, 3 were medial, and 3 were anterior. No malpostioned screws were found at high risk. The screw perforation rate was similar between patients with age >50 years and patients with ages≤50 years (9. 9% versus 10.9% , P=0. 860). More perforations were found at the apical vertebra than the other levels of lumbar spine. Moreover, there was significant difference with regard to the perforation rate between the concave side (15.6% , 26/167) and the convex side (5.9% , 11/186) of the lumbar spine (P = 0.005). Significant difference ( P 60° (20.2%, 22/109) and patients with Cobb angled60° (6.1%, 15/244). In

  15. Pedicle lag screw fixation in the treatment of Hangman's fracture%椎弓根拉力螺钉内固定治疗Hangman骨折

    Institute of Scientific and Technical Information of China (English)

    刘德宝; 张复文; 卜海富; 胡孔足; 周健

    2012-01-01

    探讨应用椎弓根拉力螺钉技术治疗Hangman骨折的临床疗效.方法 对12例Hangman骨折患者经颅骨牵引获得复位后,行C2椎弓根拉力螺钉内固定术治疗.术后行X线片检查观察骨折复位及愈合情况.结果 手术时间50~90min,失血量100~300ml.术中无脊髓神经损伤,骨折复位满意.12例均获随访,时间3~36个月.骨折完全愈合,无迟发畸形.2例脊髓神经损伤者术前Franke1分级为D级,术后3~6个月均恢复至E级.结论 C2椎弓根拉力螺钉技术治疗Hangman骨折,复位满意,固定可靠,疗效满意.%Objective To stuty the clinical outcomes of Hangman's fracture treated by using pedicle lag screw fixation. Methods 12 patients with Hangman's fracture were recruited. All patients achieved reduction by skull traction, and fixed with C2 pedicle lag screw. X-ray was performed during the follow-up to observe fracture reduction and healing process. Results The operation time was 50 ~ 90 minutes, and the blood loss was 100 ~ 300 ml. And intra-operative no spinal nerves injury the reduction of the Hangman's fracture was satisfied. No postoperative complications were confirmed. 12 cases were followed up for 3~36 months. All got healing without deformity. 2 cases of Frankel D were restored to E in 3 ~ 6 months. Conclusions Pedicle lag screw fixation provides good reduction and stability to Hangman's fracture. It is a less trauma, safe and effective method in the treatment of Hangman's fracture.

  16. A CT-Based Simulation Study to Compare the Risk of Facet Joint Violation by the Cervical Pedicle Screw Between Degenerative and Nondegenerative Cervical Spines.

    Science.gov (United States)

    Lee, Dong-Ho; Noh, Hyounmin; Hwang, Chang Ju; Lee, Choon Sung; Abumi, Kuniyoshi; Cho, Jae Hwan

    2017-02-01

    A retrospective case-control study. This study aimed (A) to compare entry points and trajectories of the cervical pedicle screw (CPS) between degenerative and nondegenerative spines, and (B) to evaluate the risk of facet joint violation by the CPS according to the degree of facet degeneration. Entry point, trajectories, and risk of misplacement of the CPS have been widely researched; however, its application to degenerative cervical spine has to be elucidated. Sixty patients who underwent cervical surgeries at our institution were classified into two groups according to cervical facet joint degeneration. A simulation program with 0.7-mm thickness axial computed tomographic images was used to evaluate facet joint violation by the CPS from C3 to C6. Horizontal and vertical offsets of entry points were measured from two different anatomical landmarks on lateral mass, namely the lateral notch and the center of the superior ridge. The transverse and sagittal angles of the screws were also measured. Facet joint violation was evaluated and classified into either "minor" (cervical spine group at all levels (P = 0.001-0.026). In addition, facet joint violation was more frequently found in severely degenerated facet joints than in mild to moderately degenerated facet joints (P = 0.011). The entry point of CPS was moved more superiorly in the degenerative cervical spine in this study, which increased the risk of facet joint violation in our patients. Thus, surgeons need to modify the insertion technique of the CPS or to insert lateral mass screw instead of the CPS when it is considered to insert screws at the uppermost vertebra in the degenerative cervical spine. 4.

  17. Accuracy of Percutaneous Pedicle Screw Insertion Technique with Conventional Dual Fluoroscopy Units and a Retrospective Comparative Study Based on Surgeon Experience.

    Science.gov (United States)

    Nakahara, Masayuki; Yasuhara, Takao; Inoue, Takafumi; Takahashi, Yuichi; Kumamoto, Shinji; Hijikata, Yasukazu; Kusumegi, Akira; Sakamoto, Yushi; Ogawa, Koichi; Nishida, Kenki

    2016-06-01

    Study Design Retrospective comparative study. Objective To evaluate the accuracy of percutaneous pedicle screw (PPS) placement and intraoperative imaging time using dual fluoroscopy units and their differences between surgeons with more versus less experience. Methods One hundred sixty-one patients who underwent lumbar fusion surgery were divided into two groups, A (n = 74) and B (n = 87), based on the performing surgeon's experience. The accuracy of PPS placement and radiation time for PPS insertion were compared. PPSs were inserted with classic technique under the assistance of dual fluoroscopy units placed in two planes. The breach definition of PPS misplacement was based on postoperative computed tomography (grade I: no breach; grade II: experience.

  18. 中青年胸腰椎骨折经皮椎弓根钉棒系统短节段内固定术后螺钉断裂浅析%Analysis on Percutaneous Pedicle Screw Rod System With Short Segment Fixation After Screw Fracture in Young Thoracolumbar Fractures

    Institute of Scientific and Technical Information of China (English)

    高飞; 阿日奔吉日嘎啦; 姜富祥; 王兴; 张弘来; 王高强

    2016-01-01

    Objective TTo explore the causes of percutaneous pedicle screw rod system with short segment ifxation after screw fracture in young thoracolumbar fractures.Methods54 cases of thoracolumbar vertebral fracture percutaneous pedicle nail stick system short segment internal fixation in young patients, 4 cases of postoperative screw fracture, the clinical data were retrospectively analyzed.Results in this group of patients appear screw breakage was 7.40%. The main cause of the fracture of the screw for pedicle screw insertion angle deviation, connecting rod camber is too large.Conclusion The mechanical stability and gravity load of the percutaneous pedicle screw rod system are important reasons for the screw breakage.%目的:探讨中青年胸腰椎骨折经皮椎弓根钉棒系统短节段内固定术后螺钉断裂的原因。方法54例行胸腰段椎体骨折经皮椎弓根钉棒系统短节段内固定术的中青年患者中,4例术后发生螺钉断裂,将其临床资料进行回顾性分析。结果本组病例出现螺钉断裂为7.40%,原因为椎弓根钉置入角度不适,连接棒弯度过大。对比剩余50例螺钉未出现断裂病例(P<0.05)。结论经皮椎弓根钉棒系统自身的力学稳定性和重力负荷是导致螺钉断裂的重要原因。

  19. Experimental study on screw insertion in lower cervical pedicle assisted by digital navigation template to lower cervical pedicle stereotaxy in child%个体化导航模板辅助儿童下颈椎椎弓根螺钉置钉准确性实验研究

    Institute of Scientific and Technical Information of China (English)

    刘瑞; 张元智; 李志军; 杨勇; 赵建民; 张少杰; 刘宏伟; 马世峰

    2012-01-01

    Objective To provide a new method in the accuracy of pedicle screw placement in lower cervical vertebraes of Child using computer-aided design. Methods A novel individual navigation template was developed by reverse engineering and rapid prototyping according to pre-operative CT data of 6 child cervical vertebraes. The templates were used for lower cervical vertebraes screw placement in the cadavers. All screws were implanted by an experienced orthopaedic surgeon in the lumbar spines but not in the cervical vertebraes. Subsequently, CT scan were performed to evaluate the screw orientation associated with the pedicle axis. Results 60 cervical pedicle screws assisted by 30 digital navigation templates were placed in lower cervical vertebras. CT scan findings showed all screws were accurately nailed into the corresponding pedicles. Conclusion Pedicle screw placement assisted by digital navigation templates is highly accurate and simple. It is a new alternative to lower cervical pedicle stereotaxy of child.%目的 利用计算机辅助设计与快速成形技术为儿童下颈椎椎弓根螺钉置入提供一种个性化、精确定位的方法.方法 对6具颈椎尸体标本进行CT扫描,根据CT扫描资料,利用逆向工程原理及快速成型技术设计制造出个体化导航模板,利用个体化导航模板在尸体标本上辅助置入胸椎椎弓根螺钉,所有螺钉的置入由同一位具有腰椎椎弓根螺钉置钉经验但无颈椎椎弓根螺钉置钉经验的骨科医师进行操作,随后根据CT扫描评价椎弓根螺钉位置.结果 共设计制作30个导航模板,辅助置入60枚颈椎椎弓根螺钉,CT扫描发现所有螺钉均准确置入相应椎弓根内.结论 数字化导航模板辅助下颈椎椎弓根螺钉置钉准确性高,操作简单,为儿童下颈椎椎弓根螺钉的准确置入提供了一种新的、可行方法.

  20. A retrospective study to validate an intraoperative robotic classification system for assessing the accuracy of kirschner wire (K-wire) placements with postoperative computed tomography classification system for assessing the accuracy of pedicle screw placements.

    Science.gov (United States)

    Tsai, Tai-Hsin; Wu, Dong-Syuan; Su, Yu-Feng; Wu, Chieh-Hsin; Lin, Chih-Lung

    2016-09-01

    This purpose of this retrospective study is validation of an intraoperative robotic grading classification system for assessing the accuracy of Kirschner-wire (K-wire) placements with the postoperative computed tomography (CT)-base classification system for assessing the accuracy of pedicle screw placements.We conducted a retrospective review of prospectively collected data from 35 consecutive patients who underwent 176 robotic assisted pedicle screws instrumentation at Kaohsiung Medical University Hospital from September 2014 to November 2015. During the operation, we used a robotic grading classification system for verifying the intraoperative accuracy of K-wire placements. Three months after surgery, we used the common CT-base classification system to assess the postoperative accuracy of pedicle screw placements. The distributions of accuracy between the intraoperative robot-assisted and various postoperative CT-based classification systems were compared using kappa statistics of agreement.The intraoperative accuracies of K-wire placements before and after repositioning were classified as excellent (131/176, 74.4% and 133/176, 75.6%, respectively), satisfactory (36/176, 20.5% and 41/176, 23.3%, respectively), and malpositioned (9/176, 5.1% and 2/176, 1.1%, respectively)In postoperative CT-base classification systems were evaluated. No screw placements were evaluated as unacceptable under any of these systems. Kappa statistics revealed no significant differences between the proposed system and the aforementioned classification systems (P system and various postoperative CT-based grading systems. The robotic grading classification system is a feasible method for evaluating the accuracy of K-wire placements. Using the intraoperative robot grading system to classify the accuracy of K-wire placements enables predicting the postoperative accuracy of pedicle screw placements.

  1. Image analysis of pedicle screw misplacement in axis/%枢椎椎弓根螺钉置钉失误的影像学分析

    Institute of Scientific and Technical Information of China (English)

    王建华; 夏虹; 尹庆水; 吴增辉

    2011-01-01

    目的:分析枢椎椎弓根螺钉置钉失误的原因,探讨提高置钉成功率的方法.方法:2002年1月~2006年12月我院因上颈椎外伤、脱位和肿瘤接受寰枢椎后路内固定手术的患者50例,共置入100枚枢椎椎弓根螺钉.根据术前CT薄层扫描结果将枢椎椎动脉孔分为Ⅰ、Ⅱ、Ⅲ、Ⅳ型;在术后颈椎侧位X线片上测量枢椎椎弓根螺钉钉道上倾角,在术后CT片上测量钉道内倾角,并根据CT结果将置钉失误分为两类,A类为钉道偏内指向椎管,B类为钉道偏外指向椎动脉孔.结果:100个枢椎椎动脉孔分为Ⅰ型76个,Ⅲ型10个,Ⅳ型14个.100枚枢椎椎弓根螺钉共发生A类失误8枚(8%),其中Ⅰ型5枚,Ⅲ型1枚,Ⅳ型2枚;B类失误2枚(2%),其中Ⅲ型、Ⅳ型各1枚.Ⅰ型、Ⅲ型、Ⅳ型的置钉失误率分别为6.6%、20%、21.4%.A类失误组的钉道上倾角为14.8°±8.5°,明显小于钉道正确组的18.3°±9.7°(P<0.05),B类失误组为17.5°±6.8°,与正确钉道组无显著性差异(P>0.05).A类失误组的钉道内倾角为21.4°±7.1°,明显小于钉道正确组的33.7°±7.3°(P<0.05);B类失误组为44.9°±8.8°,明显大于正确钉道组(P<0.05).结论:枢椎椎动脉孔的解剖变异是导致置钉失误的客观因素;而术中钉道内倾角和上倾角偏小是引起置钉失误的最常见原因.术前应根据CT扫描结果充分掌握枢椎椎动脉孔的特点,结合“宁上勿下,宁内勿外”的原则,合理把握钉道方向,以提高置钉成功率.%Objective:To investigate the causes of pedicle screw misplacement in axis and the way to ensure the accuracy.Method:From January 2002 to December 2006,50 patients suffering from upper cervical trauma and tumor and undergoing posterior surgery were included in this study .A total of 100 axis pedicle screws were placed.Based on preoperative slice CT scan results,the vertebral artery grooves were divided into 4 types ( I , II , HI , IV ).After

  2. Recent progress in pedicle screw placement in the subaxial cervical spine and clinical applications%下颈椎椎弓根螺钉的置钉技术及临床应用进展

    Institute of Scientific and Technical Information of China (English)

    陈长宝; 张晓林; 马信龙

    2015-01-01

    下颈椎椎弓根螺钉是颈椎生物力学上最稳定的内固定,能有效恢复颈椎矢状序列、提供坚强内固定及更高融合率。由于下颈椎椎弓根、椎动脉及神经根等结构存在较大的个体差异,术前评估应个体化。下颈椎椎弓根螺钉的置钉技术包括徒手置钉和近年来发展的计算机导航辅助置钉技术。尽管与椎弓根螺钉相关的神经血管并发症不能完全避免,但只要进行充分的术前个性化评估和术中精准的置钉技术,就可将神经血管并发症降至最低。下颈椎椎弓根螺钉内固定技术已经应用于治疗各种颈椎疾患,并发症少,临床疗效良好,具有广泛的临床应用价值。%Pedicle screw fixation is biomechanically most reliable for reconstruction of the cervical spine, which can ef⁃fectively restore cervical sagittal profiles, provide rigid fixation and higher fusion rate. Because of the large individual differ⁃ences in cervical pedicle, vertebral artery and nerve root, preoperative evaluation should be individualized. Cervical pedicle screw techniques include freehand technique and the computer-assisted navigation technology developed recently. Although complications associated with cervical pedicle screw fixation cannot be completely obviated, they can be minimized by com⁃bination of sufficient preoperative imaging studies of the pedicles and meticulous surgical techniques of screw placement. Cervical pedicle screw fixation techniques have been used in the treatment of various cervical disorders, with fewer complica⁃tions and good clinical efficacy, and a wide range of clinical applications.

  3. 单侧腰椎弓根螺钉及经椎板关节突螺钉固定与双侧固定的比较*☆%Clinical outcomes of unilateral lumbar pedicle screw combined with translamina facet screw fixation versus bilateral fixation

    Institute of Scientific and Technical Information of China (English)

    薛剑; 靳安民; 孙小平; 王延斌; 谢伟勇

    2013-01-01

    BACKGROUND: The translaminar facet joint screw fixation and interbody fusion in the treatment of spinal disorders is a unique fixation method which can be used for degenerative lumbar spinal fusion. OBJECTIVE: To observe the clinical effect of the minimal y invasive transforaminal lumbar interbody fusion combined with unilateral lumbar pedicle screw and translamina facet screw fixation versus conventional posterior lumbar interbody fusion combined with bilateral pedicle screw fixation for the treatment of low back pain. METHODS: Forty-nine patients had lumbar disc herniation with lumbar spinal mild instability were selected from Wu Jing Zong Dui Hospital of Guangdong Province between June 2010 and June 2012. Al the patients were treated with posterior decompression and interbody fusion and internal fixation. Among the 49 patients, 24 patients were treated with minimal y invasive transforaminal lumbar interbody fusion combined with unilateral lumbar pedicle screw and translamina facet screw fixation, and 25 patients were treated with conventional posterior lumbar interbody fusion combined with bilateral pedicle screws fixation. The clinical effects of the two methods above were compared. RESULTS AND CONCLUSION: There were no significant differences of vertebral fusion rate, Japanese Orthopedic Association score and visual analogue scale score between two groups (P > 0.05). These two approaches had similar clinical outcomes for single-level lumbar degenerative disorders with no instability. These two methods could effectively improve intervertebral fusion rate, make the smal joint stability, relieve clinical symptoms and make outpatient fol ow-up satisfaction. In addition the incision length, operative time, intraoperative blood loss, postoperative incision drainage of minimal y invasive transforaminal lumbar interbody fusion combined with unilateral lumbar pedicle screw and translamina facet screw fixation technology were significantly reduced (P 0.05)。可见对

  4. Effects of nonlinearity in the materials used for the semi-rigid pedicle screw systems on biomechanical behaviors of the lumbar spine after surgery

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun; Lee, Sung-Jae [Department of Biomedical Engineering, Inje University, Gimhae 621749 (Korea, Republic of); Lim, Do-Hyung [Korea Institute of Industrial Technology, Cheonan 331825 (Korea, Republic of); Oh, Hyun-Ju [Korea Food and Drug Administration, Seoul 363951 (Korea, Republic of); Lee, Kwon-Yong, E-mail: sjl@bme.inje.ac.kr [Department of Mechanical Engineering, Sejong University, Seoul 143747 (Korea, Republic of)

    2011-10-15

    Recently, various types of semi-rigid pedicle screw fixation systems have been developed for the surgical treatment of the lumbar spine. They were introduced to address the adverse issues commonly found in traditional rigid spinal fusion--abnormally large motion at the adjacent level and subsequent degeneration. The semi-rigid system uses more compliant materials (nitinol or polymers) and/or changes in rod design (coiled or twisted rods) as compared to the conventional rigid straight rods made of Ti alloys (E = 114 GPa, {upsilon} = 0.32). However, biomechanical studies on the semi-rigid pedicle screw systems were usually limited to linear modeling of the implant and anatomic elements, which may not be capable of reflecting realistic post-operative motions of the spine. In this study, we evaluated the effects of nonlinearity in materials used for semi-rigid pedicle screw fixation systems to evaluate the changes in biomechanical behaviors using finite element analysis. Changes in range of motion (ROM) and center of rotation (COR) were assessed at the operated and adjacent levels. Actual load-displacement results of the semi-rigid rod from mechanical test were carried out to reflect the nonlinearity of the implant. In addition, nonlinear material properties of various spinal ligaments studies were used for the finite element modeling. The post-operative models were constructed by modifying the previously validated intact model of the L1-S1 spine. Eight different post-operative models were made to address the effects of nonlinearity-with a traditional stiffness modulus rod (with linear ligaments, case 1; with nonlinear ligaments, case 5), with a rigid rod (with linear ligaments, case 2; with nonlinear ligaments, case 6), with a soft rod (with linear ligaments, case 3; with nonlinear ligaments, case 7), and with a nonlinear rod (with linear ligaments, case 4; with nonlinear ligaments, case 8). To simulate the load on the lumbar spine in a neutral posture, follower load

  5. 单侧椎弓根螺钉固定在腰椎退行性疾病的研究进展%Research advances in the fixation of unilateral pedicle screw for lumber degenerative

    Institute of Scientific and Technical Information of China (English)

    黄凯; 刘展亮; 刘少喻

    2014-01-01

    The patients with lumber degenerative spondylolisthesis often have to undergo surgical treatment. Conventional surgical approach is performed by bilateral pedicle screw fixation in lumbar interbody fusion, and this maybe accelerate segment degeneration of adjacent vertebral bodies. The recent studies indicate that unilateral pedicle screw fixation in lumbar interbody fusion can achieve the same effect on stability and interbody fusion by using conventional bilateral pedicle screw fixation in lumbar interbody fusion,.and prevent from segment degeneration of vertebral bodies. But the operation indication must be restrictedly controlled, the operation technique be skilled.%保守失败的腰椎退行性疾病常需要手术治疗,传统的双侧椎弓根螺钉腰椎融合术可能增加邻近节段退变的发生率。近年研究表明,单侧椎弓根螺钉结合椎体间融合术治疗腰椎退行性疾病可获得与传统双侧椎弓根螺钉固定相似的稳定性与融合率,并可预防固定融合节段的邻近节段退变,但应用单侧椎弓根螺钉固定需要严格掌握手术适应证。

  6. Clinical observation of posterior internal fixation with vertebral pedicle screw and rod system on thoracolumbar spine fractures%椎弓根钉棒系统在胸腰椎骨折的疗效分析

    Institute of Scientific and Technical Information of China (English)

    黎华茂; 李敬中; 向峥; 林晓岗

    2012-01-01

    Objective To observe the clinical efficacy of posterior internal fixation of vertebral pedicle screw and rod system for thoracolumbar spine fractures. Methods Totally 59 patients with thoracic or lumbar vertebral fractures were treated with internal fixation of vertebral pedicle screw and rod system. The Frankel scale combined with X ray and CT images was used for the judgment of efficacy. Results Radiographic parameters were significantly improved after the experiment, the Frankel degree of cases with nerve injury symptoms was improved 2-4 degrees after surgery. Conclusions Internal fixation of vertebral pedicle screw and rod system is efficient for thoraco lumbar spine fractures.%目的 观察椎弓根钉棒系统内固定治疗胸腰椎骨折的临床疗效.方法 应用椎弓根钉棒系统内固定治疗胸腰椎骨折59例,采用Frankel分级结合X线片、CT影像表现判断疗效.结果 术后各项影像学指标均有明显改善,患者术后神经功能Frankel分级大多数都有2~4级提高.结论 椎弓根钉棒系统内固定是治疗胸腰椎骨折的一种有效方法,值得临床推广应用.

  7. Study on the accuracy of thoracolumbar pedicle screw installation assisted by O-arm navigation%O-arm导航辅助下胸腰椎椎弓根螺钉置入精确度研究

    Institute of Scientific and Technical Information of China (English)

    蒋涛; 任先军; 王卫东; 初同伟; 李长青; 阴洪; 石泽刚

    2015-01-01

    目的 探讨O-arm导航辅助下胸腰椎椎弓根螺钉置入的准确性和可靠性.方法 回顾性分析2014年3-10月收治的75例实施胸腰椎椎弓根螺钉固定术患者,32例采用O-arm导航辅助置钉(导航组),43例采用C形臂X线机透视辅助下徒手置钉(透视组),术后行X线片、CT扫描检查,比较两组螺钉置入的准确性,评价导航组术中导航和术后CT扫描的矢状位和轴位图像中螺钉置入角度的一致性.结果 透视组共置入206枚椎弓根螺钉,一次性置钉成功率为93.2%,置钉准确率为90.8%(一类),1枚三类螺钉导致L3神经根刺激症状.导航组共置入226枚椎弓根螺钉,一次性置钉成功率为100%,置钉准确率为96.9%(一类),无三类螺钉,而在术中导航和术后CT扫描的矢状位和轴位图像中,螺钉置入角度差异无统计学意义(P>0.05).结论 O-arm导航系统可以提供高清晰度导航图像并实现高精确度导航操作,有效提高胸腰椎椎弓根螺钉置入的准确性,具有良好的可靠性.%Objective To evaluate the accuracy and reliability of O-arm-based thoracolumbar pedicle screw installation.Methods A retrospective review was conducted on 75 patients who had undergone thoracolumbar pedicle screw fixation assisted with O-arm navigation (navigation group,n =32) and C-arm fluoroscopy (fluoroscopy group,n =43) from March to October 2014.All the patients were assessed with X-ray and CT images after operation.Accuracy of screw installation in both groups was compared.In navigation group,screw directions were measured on the sagittal and axial images of intraoperative navigation and post-operative CT scanning to evaluate the concordance.Results In fluoroscopy group,a total of 206 pedicle screws were placed with the one-time success rate of 93.2% and accuracy of 90.8% for screw placement,and one misplaced screw (grade llⅢ) led to L3 nerve root symptom.In navigation group,a total of 226 pedicle screws were placed with

  8. Therapeutic efficacy of pedicle screw-rod internal fixation after one-stage posterior transforaminal lesion debridement and non-structural bone grafting for tuberculosis of lumbar vertebra

    Directory of Open Access Journals (Sweden)

    Jia-ming LIU

    2015-11-01

    Full Text Available Objective To evaluate the efficacy and safety of pedicle screw-rod internal fixation after one-stage posterior transforaminal lesion debridement and non-structural bone grafting in the treatment of tuberculosis of mono-segmental lumbar vertebra. Methods From January 2010 to April 2013, 21 patients (9 males and 12 females with an average age of 49.1 years with mono-segmental tuberculosis of lumbar vertebra underwent surgery in our hospital were included. Eight patients had neurological deficit. The focus of tuberculosis was located on one side of the vertebral body, and all the patients had obvious signs of bone destruction on CT and MRI. All the patients were given anti-tuberculosis chemotherapy for 2-3 weeks before surgery. The local bone chips and autologous iliac cancellous bone were used as the intervertebral bone graft. Postoperative plain radiographs and CT were obtained to evaluate the fusion rate and degree of lumbar lordosis. The visual analogue scale score (VAS, erythrocyte sedimentation rate (ESR, and C-reactive protein (CRP before and after operation, and at final follow-up date were recorded. Results All the patients were followed up for 25.3±4.2 months. The mean operation time was 157±39 minutes, and the average blood loss was 470±143ml. The fusion rate of the interbody bone graft was 95.2%, with an average fusion period of 6.1±2.5 months. The neurological function was improved by 100%, and no severe complication or neurological injury occured. The preoperative and postoperative lordosis angles of the lumbar spine were 21.4°±5.7° and 33.6°±3.1°, respectively, and it was 31.3°±2.7° at the final follow up. The preoperative and postoperative VAS scores were 7.8±2.6 and 2.4±1.7 respectively, and it was 0.9±0.7 at the final follow up. The ESR and CRP were significantly decreased 3 months after surgery, and they became normal at 6 months. Conclusion Pedicle screw-rod internal fixation after one-stage posterior

  9. Treatment of acute thoracolumbar burst fractures with kyphoplasty and short pedicle screw fixation: Transpedicular intracorporeal grafting with calcium phosphate: A prospective study

    Directory of Open Access Journals (Sweden)

    Korovessis Panagiotis

    2007-01-01

    Full Text Available Background: In the surgical treatment of thoracolumbar fractures, the major problem after posterior correction and transpedicular instrumentation is failure to support the anterior spinal column, leading to loss of correction and instrumentation failure with associated complaints. We conducted this prospective study to evaluate the outcome of the treatment of acute thoracolumbar burst fractures by transpedicular balloon kyphoplasty, grafting with calcium phosphate cement and short pedicle screw fixation plus fusion. Materials and Methods : Twenty-three consecutive patients of thoracolumbar (T 9 to L 4 burst fracture with or without neurologic deficit with an average age of 43 years, were included in this prospective study. Twenty-one from the 23 patients had single burst fracture while the remaining two patients had a burst fracture and additionally an adjacent A1-type fracture. On admission six (26% out of 23 patients had neurological deficit (five incomplete, one complete. Bilateral transpedicular balloon kyphoplasty with liquid calcium phosphate to reduce segmental kyphosis and restore vertebral body height and short (three vertebrae pedicle screw instrumentation with posterolateral fusion was performed. Gardner kyphosis angle, anterior and posterior vertebral body height ratio and spinal canal encroachment were calculated pre- to postoperatively. Results : All 23 patients were operated within two days after admission and were followed for at least 12 months after index surgery. Operating time and blood loss averaged 45 min and 60 cc respectively. The five patients with incomplete neurological lesions improved by at least one ASIA grade, while no neurological deterioration was observed in any case. The VAS and SF-36 (Role physical and Bodily pain domains were significantly improved postoperatively. Overall sagittal alignment was improved from an average preoperative 16° to one degree kyphosis at final follow-up observation. The anterior

  10. 骨质疏松患者椎弓根螺钉稳定性的随访☆%Stability of pedicle screw in patients with osteoporosis:Follow-up visit☆

    Institute of Scientific and Technical Information of China (English)

    殷渠东; 田小武; 郑祖根

    2013-01-01

      背景:骨质疏松患者置入椎弓根螺钉后,易发生螺钉松动和复位矫正丢失等固定不稳现象,因此,骨质疏松被认为是椎弓根螺钉的相对禁忌证。  目的:观察骨质疏松患者提高椎弓根螺钉稳定性方法的临床应用效果。  方法:34例骨质疏松患者行椎弓根螺钉内固定,术中采用了提高椎弓根螺钉稳定性方法。骨折患者14例(骨折组),骨病患者20例。20例骨病患者和5例骨折患者行脊柱后外侧或椎间植骨融合(融合组)。骨质疏松按 Jikei 分级,初级8例,Ⅰ级11例,Ⅱ级8例,Ⅲ级7例。对19例初级和Ⅰ级骨质疏松患者,采用较粗和较长螺钉,同时结合采用螺钉与连接棒强直性连接,且有两根横向连接装置,左右、上下椎弓根螺钉分别在水平面和矢状面以较大成角置入螺钉等方法提高螺钉固定相对稳定性;对15例Ⅱ级和Ⅲ级骨质疏松患者,钉道注入骨水泥以提高螺钉固定绝对稳定性。  结果与结论:随访9-26个月,平均14个月,无螺钉断裂,骨折组仅2例 JikeiⅠ级患者固定后五六个月时发生螺钉松动、部分复位矫正丢失等固定不稳,但无明显其他不良影响。骨折组复位矫正丢失平均5%,融合组植骨融合率100%。对于骨质疏松患者,根据骨质梳松程度采用不同的提高螺钉固定稳定性方法,可以减少螺钉松动和复位矫正丢失等固定不稳并发症。%BACKGROUND: Screw loosening and loss of correction are main complications in patients with osteoporosis receiving pedicle screw implantation. Therefore, osteoporosis is considered as a relative contraindication for pedicle screws. OBJECTIVE: To study the clinical results of methods for improving stability of pedicle screw in patients with osteoporosis. METHODS: Thirty-four patients with osteoporosis were treated with pedicle screw internal fixation, and the methods of improving

  11. C7 pars fracture subadjacent to C7 pedicle screw instrumentation at the caudal end of a posterior cervical instrumentation construct.

    Science.gov (United States)

    Halim, Andrea; Grauer, Jonathan

    2014-07-01

    We report a case of a C7 pars fracture subadjacent to C7 pedicle screw instrumentation at the caudal end of posterior cervical instrumentation construct. To date, posterior cervical instrumentation has been "off label"; however, the US Food and Drug Administration is considering approving label indication of such instrumentation for this common surgical practice. Complications related to the techniques are reported to be relatively low. We know of no previous reports of pars fractures occurring subadjacent to such instrumentation. A 43-year-old man underwent posterior C5-C7 instrumented fusion. Postoperatively, the patient experienced cervical spine injury after a mechanical fall down stairs. Work-up detected bilateral C7 pars fractures subadjacent to the posterior instrumentation construct. After we treated the pars fracture with distal extension of the posterior fusion to the level of T2, the patient progressed to union and marked improvement of initial clinical symptoms that was maintained 2.5 years after posterior instrumentation. To our knowledge, a C7 pars fracture subadjacent to posterior cervical instrumentation construct has not been reported. We hypothesize that the pars may have been vulnerable to fracture because of excessive bone resection during foraminotomy or decortication. This complication was successfully treated by extending the fusion caudally.

  12. A comparative study on cervical biomechanical stability of lateral fixation piece and pedicle screws of screw fixation%颈椎侧块螺钉内固定和椎弓根螺钉内固定的生力学稳定性比较研究

    Institute of Scientific and Technical Information of China (English)

    冯灿林; 黄海珊; 黎霭云; 刘庆浩; 雷明; 祝城华; 许国增

    2014-01-01

    目的 比较颈椎侧块螺钉内固定和椎弓根螺钉内固定的生物力学稳定性.方法 取12具成人尸体的颈椎作为标本,于C4~C5处切断,造成颈椎不稳定模型.对标本依次行非内固定、侧块螺钉内固定和椎弓根螺钉内固定三种方式.然后进行柔韧性以及左右旋转扭矩和刚度测试,评价两种内固定术的稳定性效果.结果 在三维运动范围方面,侧块螺钉内固定比椎弓根螺钉内固定的三维运动范围有不同程度减小(P<0.05);侧块螺钉左右旋转的刚度比椎弓根螺钉内固定强(P<0.05).结论 从生物力学稳定性的角度来看,下颈椎不稳采用侧块螺钉内固定的生物力学稳定性较好.%Objective To compare the cervical biomechanical stability of lateral fixation piece and pedicle screws of screw fixation.Methods The 12 cervical vertebras as experimental sample,and from C4 to C5 were cut off and caused cervical instability model.Three ways of non fixation,lateral mass screw fixation and pedicle screw fixation were implemented.Then flexibility and rotation torque and stiffness were tested.Stability of two kinds of internal fixation was evaluated.Results In the 3-D range of movement,lateral mass screw fixation was notably smaller than that of pedicle screws fixation (P < 0.05).The lateral mass screw fixation had more strength than pedicle screws fixation (P < 0.05).Conclusion The instability of lower cervical spine patients may use lateral mass screw fixation,and its biomechanical stability is better.

  13. Pedicle screw placement treated cervical lateral lordosis deformity in muscular dystrophy:1 case report%置钉矫形治疗肌营养不良导致的颈椎侧前凸畸形一例报告

    Institute of Scientific and Technical Information of China (English)

    胡永凯; 王宇; 李淳德; 刘洪; 李宏; 邑晓东

    2015-01-01

    Objective To present one case of lateral cervical lordosis deformity treated by surgical correction using navigated pedicle screw placement.Methods A 19-year-old male patient with Emery-Dreyfus muscular dystrophy underwent surgical correction using navigated pedicle screw placement. The MRI scanning of the spine showed no abnormalities of the spinal cord. The MRI of extremities revealed a decrease in the muscle mass, and fatty infiltration in the biceps femoris and semimembranosus muscles bilaterally, consistent with the muscle dystrophy pattern. The cardiac function of the patient was evaluated by electrocardiography and echocardiography, and the results were normal. The respiratory function was evaluated by spirometry, which showed restrictive ventilatory defects, however, the arterial O2 saturation was normal. The laminas of vertebrae C2-T5 were bilaterally exposed. Traction or detachment of the interspinous ligament had not been applied. During the exposure, the neck hyperextension was gradually neutralized due to both the muscle release and gravity. Pedicle screws were bilaterally inserted at C2, C5, and T1-5 levels under navigation guidance. Lateral mass screws were bilaterally inserted at C3, C4, and C6. A special rod on the convex side was placed, then the rod was derotated. At the same time, an assistant pressed the head to bend the neck into a neutralized position. The screw nuts were then locked on the convex side. Meanwhile, the rod on the concave side was instrumented, and all the screw nuts were locked. Routine wound closure was performed and postoperative radiographs were taken.Results The surgery took 320 minutes. Blood loss was 600 ml. No surgical complications occurred. Both the cervical hyperextension and scoliosis were signiifcantly corrected. After surgery, the patient’s trunk had been well balanced on both frontal and sagittal view. And he was able to walk in an upright position with looking straight ahead on his own accord. The scoliotic

  14. Short Segment Fixation Versus Short Segment Fixation With Pedicle Screws at the Fracture Level for Thoracolumbar Burst Fracture

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    Anghel S

    2014-04-01

    Full Text Available Objective: The most prevailing surgical procedure in the treatment of thoracolumbar burst fractures, Short Segment Fixation (SSF, is often followed by loss of correction or hardware failure which may be significant enough to require another surgical intervention. In order to take advantage of its benefits but to avoid or diminish the risk and impact of associated drawbacks, some other alternatives have been lately developed among which we refer to short segment fixation with intermediate screws (SSF+IS. This article provides a comparative picture over the effectiveness of the two above-mentioned surgical treatments, focusing on their potential to prevent the loss of correction.

  15. Insertion of lower cervical spine anterior pedicle screw in 18 cadavers%下颈椎前路椎弓根螺钉置入的实验研究

    Institute of Scientific and Technical Information of China (English)

    王远政; 刘洋; 邓忠良

    2012-01-01

    目的 探讨下颈椎前路椎弓根螺钉置入技术的可行性.方法 取18具成人尸体正常颈椎标本,剔除其周围软组织至清楚显露椎体前壁.CT扫描后,用Mimics软件重建三维模型,并测量C3~C7个体化置钉参数,包括进钉点(即椎弓根中轴线在椎体前壁投影点)、置钉方向(螺钉在横断面和矢状面上的倾斜角度)以及螺钉长度.严格按照测量结果,直视下置入椎弓根螺钉.术后作CT扫描,评价置钉效果.结果 进针点:C3、C4位于置钉椎弓根对侧,正中矢状面旁2~3 mm,距上终板6~7 mm;C5~ C7与置钉椎弓根同侧,其中C5位于正中矢状面旁1~2 mm,距上终板7.0~7.5 mm,C6、C7则为4~5 mm和7.5 ~8.5 mm.置钉方向:理想角度在C3、C4为外倾角46°~47°,头倾角-11°~-7°;在C5外倾角约48°,头倾角接近0°;C6、C7为36°~40°和8~13°.螺钉长度:可选择28、30、32 mm,其直径为3.5 mm.本组共置钉144枚.术后CT示,全部螺钉均经椎体前方置入椎弓根内抵达侧块.其中,有16枚胀破椎弓根外侧皮质,3枚穿破外侧皮质(均发生在C3、C4节段).结论 下颈椎前路椎弓根螺钉置入技术是可行的.%Objective To study the feasibility of lower cervical spine anterior pedicle screw ( APS) insertion and provide basis for its clinical application according to the preoperative APS related technological parameters. Methods Normal cervical spine specimens of 18 cadavers were carefully dissected to resect the surrounding tissue and to clearly expose the centrum antetheca. Following the CT scans, three dimensional model was reconstructed by Mimics software. The imaging data to measured key parameters of anterior transpedicular screw fixation were also produced by Mimics software. The individual screw insertion parameters including intersection point (projective point of pedicle central axis on the centrum antetheca) , insertion angle (the inclined angle of screws in cross-sectional and sagittal

  16. The study of anterior cervical pedicle screw channel in the lower cervical spine%下颈椎前路椎弓根螺钉内固定解剖学测量及临床应用

    Institute of Scientific and Technical Information of China (English)

    徐荣明; 赵刘军; 马维虎; 朱彦昭

    2011-01-01

    Objective To investigate application of the anterior cervical pedicle screw in the lower cervical spine.Methods Twenty disarticulated human vertebrae (C3-C7) were evaluated with computed tomography for pedicle morphometry Parameters included vertebral body height,vertebral body depth,vertebral body width,outer pedicle width,outer pedicle height,pedicle axis length,transverse section angle,sagittal section angle,transverse intersection point distance and sagittal intersection point distance.On the basis of these data,the screw channel was determined and the screws were inserted in the specimen.Five patients underwent surgical reconstruction using anterior pedicle screw fixation.After surgery,physical examination and roentgenograms and CT scans were performed in all patients.Results The transverse section angle increased from C3(45.7°±4.0°) to C5(52.1°±5.9° ),but decreased from C6(47.8°±6.7°) to C7(44.4°± 8.3°).The sagittal section angle gradually increased from C3 (93.4°±7.2°) to C6( 112.1°±6.2°) but decreased a little to C7(102.7°±8.5°).The distances in transverse section was about 1.97-3.98 mm and in sagittal section was 3.4-7.5 mm.Anterior pedicle screws were inserted successfully in all specimens without critical pedicle wall perforations.Patients were permitted to ambulate the next day after surgery with a cervical collar.Postoperative neurological improvement was observed in all cases.Postoperative radiographic evaluation confirmed proper insertion of anterior pedicle screws without pedicle perforaton.The average follow-up time was 10.6 months.No anterior pedicle screw breakage and loosening was observed.Conclusion The entry point in anterior pedicle screw should located in 5mm to upper endplate and near anterior median line.The transverse section angle should be 45.7°-52.1°and the sagittal section angle should be 93.4°-112.1°.The lengths of the screw should be about 32 mm.%目的 通过解剖学测量和临床应用,探讨下颈椎

  17. EVALUATION OF POSTERIOR SPINAL FUSION WITH PEDICLE SCREWS AND RODS WITH BONE SUBSTITUTES IN GRADE I AND II SPONDYLOLISTHESIS

    Directory of Open Access Journals (Sweden)

    Chaitanya Reddy

    2016-04-01

    Full Text Available BACKGROUND Low-back pain is the commonest condition encountered day in and day out of an orthopaedic practice. Incidence of spondylolisthesis in normal population is around 5-7%. No matter what the aetiology is, patient has significant functional disability. OBJECTIVES To study the efficacy of pedicular screw rod system and posterolateral fusion with bone substitutes in spondylolisthesis, and to study the complications associated with this treatment modality. METHODOLOGY From July 2012 to September 2014, a total of 30 patients operated with posterolateral fusion were followed up and evaluated based on VAS for low back pain and Japanese orthopaedic association scoring system. RESULTS The mean difference between pre-operative and post-operative VAS score is 3SD with a p value of <0.001, which is strongly significant. The pre-operative and post-operative JOA score has an improvement of 73.4% with a p value of <0.001, which is strongly significant. Rate of improvement was excellent in 16.7%, good in 53.3%, fair in 23.3% and poor in 6.3% of patients; 82% of patients had bone fusion by the end of 8 months. CONCLUSION Pedicular screw rod system with postero-lumbar fusion with bone substitute is safe, promising and appealing technique for low-grade spondylolisthesis with early post-operative pain relief.

  18. C2椎弓根 C3侧块螺钉固定治疗不稳定性 Hangman 骨折%C2 Pedicle Screw C3 Lateral Mass Screw Fixation for Treatment of Unstable Hangman Fracture

    Institute of Scientific and Technical Information of China (English)

    吴磊磊; 邱玉金; 李攀

    2012-01-01

      Objective To evaluate the clinical effect of unstable Hangman fracture treated with C 2 pedicle screw C3 lateral mass screw fixation.Methods From July 2003 to July 2011,32 cases of patients with unstable Hangman fracture were treated in our hospital . Based on Levine-Edwards classification,typeⅡ-14 cases,typeⅡA -15 cases,type Ⅲ -3 cases.All the cases were treated with C 2 pedicle screw C3 lateral mass screw fixation.Results There was no spinal cord and vertebral artery injury or other complications during the opera -tion.All the patients were followed up from 3th to 24th months,average of 13.7months and got bony fusion.The preoperative displacement of C2 ~3 vertebral bodies was (5.7 ±1.3)mm,the postoperative displacement of C 2 ~3 vertebral bodies followed up for 6 months was(2.3 ±1.7) mm,P <0.05;The preoperative angulation of C 2 ~3 vertebral bodies was 12.6°±1.4°,the postoperative angulation of C 2 ~3 vertebral bodies followed up for 6 months was 7.3°±1.7°,P <0.05;based on JOA 17 scores for assessment of spinal cord function ,the preoperative score was 6.3 ±0.3,the postoperative score followed up for 6 months was 13.5 ±1.1,the recovery rate of nervous function was 67%.Conclusion For treatment of unstable Hangman fracture ,C2 pedicle screw C3 lateral mass screw fixation is an effective method .

  19. Digital placement and clinical application of lumbar pedicle screws based on 3D printing%基于3D打印的腰椎椎弓根螺钉数字化置入及临床应用

    Institute of Scientific and Technical Information of China (English)

    陈宣煌; 许卫红; 黄文华; 林海滨; 张国栋; 吴长福; 陈旭; 余正希

    2015-01-01

    BACKGROUND:3D printing to prepare individualized navigation template-assisted screw placement can elevate screw placement accuracy of spinal pedicle screw,and have good prospects for clinical application.OBJECTIVE:To investigate the method of lumbar pedicle screw navigation placement using digital design of Mimics software combined with 3D printing module,and to explore its feasibility and accuracy.METHODS:From February 2012 to August 2013,a total of 60 patients with lumbar diseases underwent 3D printing module-assisted lumbar pedicle screw navigation placement.Al patients received continuous thin slice CT scan.We colected Dicom format images.Mimics software was used for 3D reconstruction to design screw channel and the supporting column of lumbar pedicle screw placement and to divide strippable bone surface,to design navigation module with screw channel,and then to carry out 3D printing.Navigation module was utilized for navigation screw placement during the surgery.The position and replacement of screw were observed.X-ray and CT scan were applied to assess the outcomes of screw placement.The patients were folowed up for (12.17±3.21) months.Oswestry Disability Index was employed to evaluate the improvement of lumbar function.Japanese Orthopaedic Association (low back pain) scoring system was used to assess the therapeutic effects.RESULTS AND CONCLUSION:253 navigation modules were made and 253 screws were implanted.Screw channel and postoperative bone surrounding the vertebral body were observed,and no breakage was found.Postoperative X-ray and CT scan revealed that the direction of eight pedicle screws was migrated compared with preoperative design,but their positions were stil satisfactory.The placement site,direction and length of 245 pedicle screws were consistent with the desired site,direction and length in Mimics software,with an accuracy of 96.84%.The navigation module was tightly connected to bone structure in front of the corresponding vertebral body

  20. Characteristics of lower lumbar pedicle screw angle in Chinese population using digital technology%基于数字技术的国人下腰椎椎弓根螺钉置钉角度特征

    Institute of Scientific and Technical Information of China (English)

    王海洲; 李宏伟; 王爽; 纪楠; 王帅

    2015-01-01

    背景:椎弓根螺钉内固定是目前脊柱手术的主流术式,置钉安全性的关键是使螺钉通过椎弓根中心,置钉角度是决定修复质量的关键因素,以往文献中确定置钉角度多以患者躯体作为参照物,容易被体位等因素干扰。目的:应用数字技术以椎体局部解剖标志为参照物对下腰椎椎弓根螺钉置钉角度进行测量。  方法:选取100例患者的3D-CT资料,将第4,5腰椎进行三维重建后利用数字技术进行模拟手术,实现最佳位置置钉。完成模拟置钉操作以后,对椎弓根螺钉的角度进行测量,以螺钉中线与棘突中线所在平面的夹角作为冠状位角度,以螺钉中线与椎体上表面所在平面的夹角作为矢状位角度。  结果与结论:测量结果表明,各角度均较以往文献中所介绍的角度大,考虑为选取参照标志不同所致。各角度值的标准差也较大,说明椎弓根解剖差异较大,因此应注重个体化置钉。这种以单个椎体的解剖标志作为定位参考的方法可以最大程度避免体位的干扰,与术前三维重建等数字技术相结合,更符合个体化置钉的要求,能有效提高置钉的准确性。%BACKGROUND:Pedicle screw fixation is the mainstream type of spine operation currently. The key point of the fixation is to make the screw pass through the center of pedicle. The angle of pedicle screw implantation is a key factor for repair quality. In previous literatures, angle of pedicle screw is determined according to the patient body, and is easily disturbed by factors such as position of the body. OBJECTIVE:To determine the inserting angle of pedicle screw of lower lumbar spine taking local anatomic landmark as a reference using digital technology. METHODS:3D-CT data of 100 patients were selected. The fourth and fifth lumbar vertebrae received three-dimensional reconstruction, and the operation was simulated using digital

  1. Triangular bone positioning of spondylolysis vertebral pedicle screws%峡部裂椎体椎弓根钉入点三角骨定位法

    Institute of Scientific and Technical Information of China (English)

    肖善富; 张喜善

    2015-01-01

    目的:探寻一种简单、准确、可靠的峡部裂椎体椎弓根入点定位方法。方法研究分为两个阶段:①2008年1月~2012年1月,对60例峡部裂伴椎体滑脱患者应用CT测量峡部裂椎体椎弓根中轴线至三角骨下边的距离及其至三角骨内下角顶点的距离;对其中30例患者行手术治疗,术中在C臂机下找出峡部裂椎体椎弓根标准入点,测量峡部裂椎体椎弓根中轴线至三角骨下边的距离及其至三角骨内下角顶点间的距离。②2012年2月~2014年1月,将60例峡部裂伴腰椎滑脱的患者,分别采用三角骨定位法置钉(A组,n=30)和AO法置钉(B组,n=30),两组患者术前资料比较差异无统计学意义(P>0.05)。对比两组手术时间、手术出血量及术后的疼痛评分,手术后应用X线和CT检查验证置钉效果。结果进钉点位于三角骨面内、靠下方,大约在内下角下1/3分界线上下的区域内,距离内下角顶点4~7 mm,距离下边3~6 mm,在进针方向上,入点越靠外侧,钉尾外倾角度越大,入点越靠上方,钉尾头倾角度越大。对比两种方法手术结果,A组明显优于B组(P<0.05)。结论三角骨内下角及下边无明显增生,骨面清晰明确,面积小,位置恒定。应用该定位方法置钉,操作简单、可靠、创伤小、出血少,可明显提高一次性置钉率及置钉优良率,缩短手术时间。%Objective To search for a simple, accurate and reliable positioning method of positioning spondylolysis vertebra pedicle screw, and to evaluate the effect. Methods Research methods were divided into two stages: ①Frome January 2008 to January 2012, the distance between spondylolysis vertebral pedicle axis with lower boundary of triangular bone and the distance between spondylolysis vertebral pedicle axis with annulus inferior and medial oftrian-gular bones was measured by CT for 60 paitiens. In the same period, the distance between spondylolysis vertebral pedicle axis with lower

  2. Stress analysis between“X”-shaped spine dynamic fixation and traditional pedicle screw fixation%“X”形弹性脊柱内固定与传统椎弓根内固定的应力分析

    Institute of Scientific and Technical Information of China (English)

    王宇; 梅继文; 穆尚强; 高峰; 黄锐

    2015-01-01

    背景:目前国内外许多学者研发了多种动态弹性脊柱内固定器,经过生物力学研究、动物实验及临床应用发现,尚无一种脊柱弹性内固定器得到临床上的普遍认可。  目的:比较自制“X”形弹性内固定器与传统椎弓根螺钉内固定的应力差异。  方法:根据成人脊柱影像学资料,分别建立“X”形弹性脊柱内固定器与传统椎弓根螺钉内固定系统三维有限元模型,比较两组模型在垂直压缩、屈、伸、侧屈、扭转时的力学差异。  结果与结论:两模型在垂直压缩状态应下的应力均小于屈、伸、侧屈及扭转状态下的应力;在垂直压缩、前屈、后伸、侧弯及旋转时,“X”形弹性脊柱内固定器的应力更多集中在“X”形连接棒上,而传统椎弓根螺钉内固定的应力更多集中在螺钉近棒段,且“X”形弹性脊柱内固定器螺钉所受应力明显小于传统椎弓根螺钉内固定(P<0.001)。表明“X”形弹性内固定器较传统椎弓根螺钉内固定系统更能分担螺钉应力,减少螺钉术后应力集中情况。%BACKGROUND:Many scholars have developed a variety of dynamic elastic spine fixator. After biomechanical research, animal experiments and clinical application found that no one elastic spine fixator was general y recognized clinical y. OBJECTIVE:To compare the stress difference between“X”-shaped spine dynamic fixation and traditional pedicle screw fixation. METHODS:Three-dimensional finite element models of“X”-shaped spine dynamic fixation and traditional pedicle screw fixation were established according to adult spine imaging data. Mechanical differences in vertical compression, flexion, extension, lateral bending and rotation were compared between the two groups. RESULTS AND CONCLUSION:The stress at vertical compression was lower than that at flexion, extension, lateral bending and rotation in both groups. The stress at

  3. A clinical comparative analysis of the treatment between open short-segment pedicle screw fixation and percutaneous short-segment pedicle screw fixation for thoracolumbar fractures%伤椎置钉和经皮短节段固定治疗胸腰段椎体骨折的疗效比较

    Institute of Scientific and Technical Information of China (English)

    杨晓明; 徐宏光; 刘平; 王弘

    2016-01-01

    目的:对比开放伤椎置钉和经皮微创短节段固定治疗胸腰段椎体骨折的近期临床疗效。方法回顾性分析35例胸腰段椎体骨折患者,分为开放伤椎置钉短节段固定组(A 组)和经皮微创短节段固定组(B 组),测量手术前后骨折椎体压缩程度,椎体后凸畸形角度,疼痛视觉模拟评分(VAS)以及术后腰椎功能障碍指数(ODI),统计两组患者住院时间,手术失血和手术时间,并对以上参数进行对比分析。结果两组患者一般资料,术前骨折椎体压缩程度和 VAS 评分差异无统计学意义(P >0.05)。两组患者术后骨折椎体高度均有效恢复(P <0.05),且良好维持,术后 VAS 和 ODI 评分均较术前改善(P <0.05),且 B 组术后 ODI 评分优于 A 组。B 组在手术时间,失血量和住院时间上较 A 组缩短。结论两种手术方式均能有效恢复骨折椎体高度,改善术后功能,但经皮微创短节段固定在手术时间,失血量,住院时间和功能上要优于伤椎置钉短节段固定组。%Objective To comparatively analyze the clinical efficacies of the treatment between open short-segment pedicle screw fixa-tion including the fractured vertebra and percutaneous short-segment pedicle screw fixation for thoracolumbar fractures.Methods A retrospective analysis was made of 35 cases of thoracolumbar fractures which were assigned into open short-segment pedicle screw fixa-tion including the fractured vertebra(group A)and minimally invasive percutaneous short-segment pedicle screw fixation group(group B).The compression percentage of the fractured vertebra,vertebral kyphosis angle,visual analogue scale(VAS)of back pain and Oswe-stry Disability Index(ODI)were measured before and after surgery.Hospitalized time,blood loss and surgical time were also compara-tively analyzed between the two groups.Results The demographic data,compression percentage of vertebral

  4. Application of Posture Nursing Intervention in Posterior Pedicle Screw Internal Fixation%体位护理干预在脊柱后路椎弓根钉内固定术中的应用

    Institute of Scientific and Technical Information of China (English)

    马永玲

    2016-01-01

    Objective Application of posture nursing intervention in posterior pedicle screw internal fixation. Methods From October 2014 to October 2014, 100 cases of patients with posterior pedicle screw ifxation,divided into two groups:observation group (50 cases with patients treated with posture nursing intervention) and control group (50 cases of patients treated with conventional nursing intervention), compare the application effect of the two groups. Results After the intervention, the observation group nursing satisfaction is 98.0% better than the control group 86.0%(P<0.05). Conclusion The posture nursing intervention in the application of spinal posterior pedicle screw ifxation effect is good, which can improve patients' quality of life.%目的:体位护理干预在脊柱后路椎弓根钉内固定术中的应用。方法选取我院2014年10月~2015年10月收治的后路椎弓根钉内固定术患者100例,分成两组:观察组(n=50,施以体位护理干预),对照组(n=50,施以常规护理干预),对两组应用效果进行对照。结果干预后,观察组护理满意度为98.0%优于对照组86.0%(P<0.05)。结论体位护理干预在脊柱后路椎弓根钉内固定术中的应用效果良好,能提升患者生活质量。

  5. One Case of Patient had an Allergy to Internal Fixation with Metal of Pedicle Screw System%椎弓根系统内固定金属过敏一例报道

    Institute of Scientific and Technical Information of China (English)

    王勇; 陈久毅

    2013-01-01

    Internal fixation with metal in the Department of orthopedics is a common treatment method. Metal implants allergy have been reported, but relatively rare. This paper reported a case of patient in our hospital had an allergy to internal fixation with metal of pedicle screw system.%  金属内固定在骨科为常见的治疗方法,金属内植物过敏曾有报道,但较为少见,现将我院椎弓根系统内固定过敏一例报道如下。

  6. 骨水泥并椎弓根螺钉脊柱内固定的力学效应%Biomechanics Effect of Pedicle Screw with PMMA in Internal Fixation of Spine

    Institute of Scientific and Technical Information of China (English)

    吉浩宇; 霍洪军

    2011-01-01

    Objective To evaluate the effect of the strength of pedicle screw fixation with PMMA in human spine,to observe effect of pedicle screw with PMMA and revision with PMMA so as to provide basis for clinic.Methods Thirty fresh frozen adult vertebras were used,and were randomly divided into 2 groups,each which have 15 ones, and each which have 4 sides vertebral pedicle,which was named “A” side、“B”side、“C” side、and “D” side.All vertebras were good.One track was made in each “A”and “B” vertebral pedicle,then was drilled with tap.Before pedicle screw fixation,each track of “A” side was augmented with PMMA as testing side,then,“A” and “B” sides were served as contral with the pedicle screws ,which were size of 5.5 mm/40 mm.The vertebral pedicles of “C” side,which were drilled with tap,which were size of 5.5 mm、6.25 mm、and 7.0 mm,were augmented by PMMA,and finally, the 5.5 mm/40 mm screws were implanted in it.The vertebral pedicles of “D” side weredrilled with tap,which were size of 5.5 mm、6.25 mm、and 7.0 mm、then,the 7.0 mm/55 mm screws were implanted in it.The specimens were examined,and were good.Maximum incision strength was tested on both sides of eath vertebral body through electronical borer.Finally,data obtained in experiment was analyzed.Results Maximum strength was (805±64) N in “A” side, (1 198± 122) N in “B” side, (1 175±203) N in “C” side,and (953±97) N in “D” side.The differences between “A” side and “B” side were significant(P<0.05,the differences between “C” side and “D” side were significant(P<0.05),that showed that the effect of revision with PMMA was better than with the bigger screw,and that the effect of augmentation with PMMA was better than fixation with only screw.Conclusion Inner fixation through vertebral pedicle following augmentation and restoration with PMMA were the more firm,that had the effect of preventing from screw destroying vertebras, and

  7. A STUDY OF POSTERIOR LUMBAR INTERBODY FUSION WITH LOCALLY HARVESTED SPINOLAMINECTOMY BONE GRAFT AND PEDICLE SCREW FIXATION IN SPONDYLOLISTHESIS

    Directory of Open Access Journals (Sweden)

    Pardhasaradhi M

    2017-08-01

    Full Text Available BACKGROUND Posterior Lumbar Interbody Fusion (PLIF and Transforaminal Lumbar Interbody Fusion (TLIF create intervertebral fusion by means of a posterior approach. Successful results have been reported with allograft, various cages (for interbody support, autograft and recombinant human bone morphogenetic protein‐2. Interbody fusion techniques facilitate reduction and enhance fusion. Corticocancellous laminectomy bone chips alone can be used as a means of spinal fusion in patients with single level instrumented PLIF. This has got a good fusion rate. PLIF with cage gives better fusion on radiology than PLIF with iliac bone graft, but no statistical difference in the clinical outcome. Cage use precludes complications associated with iliac bone harvesting. The reported adjacent segment degeneration was 40.5% and reoperation was 8.1% after 10 years of follow up. MATERIALS AND METHODS 30 cases of spondylolisthesis who attended the Orthopaedic Outpatient Department of Andhra Medical College, Visakhapatnam, from 2014 to 2016 were taken up for study. All the cases were examined clinically and confirmed radiologically. The patient’s age, sex, symptoms and duration were noted and were examined clinically for the status of the spine. Straight leg raising test was done and neurological examination of the lower limbs performed. All the patients were subjected to the radiological examination of the lumbosacral spine by taking anteroposterior, lateral (flexion and extension views, oblique views to demonstrate spondylolysis and spondylolisthesis. MRI and x-rays studies were done in all the cases to facilitate evaluation of the root compression disk changes and spinal cord changes. RESULTS In our study, we followed all the 30 patients after the surgery following procedure of removal of loose lamina, spinous process and fibrocartilaginous mass, PLIF with only the laminectomy bone mass and CD screw system fixation up to 2 years. 12 patients (40% had excellent

  8. Biomechanics and stability of the spine after implantation with pedicle screw and cervical vertebral screw fixation%椎弓根螺钉及颈椎体螺钉置入内固定后的生物力学及稳定性比较

    Institute of Scientific and Technical Information of China (English)

    刘淼; 尚显文; 宁旭; 庄勇; 许顺恩

    2016-01-01

    BACKGROUND:From the point of view of human anatomy, the load of the spine is more. When the body moves, the range of activities, and activity are relatively large. After screws were implanted in the spine, if biomechanical properties and stability are not up to the standard, it easily leads to lack of grip force of screw and screw loosening so as to increase the incidence of complications after treatment. OBJECTIVE:To compare biomechanical properties and stability of the spine after insertion of pedicle screw and cervical vertebral screw into the spine. METHODS:100 vertebrae under human cervical spine specimens were analyzed and randomly divided into cervical vertebral screw fixation group and pedicle screw fixation group. Cervical vertebral screws and pedicle screws were implanted in lower cervical spine specimens. Electro Force 3510 material testing machine was used to test axial pul-out force, axial pul-out strength after the fatigue loading, and fixed stability. The biomechanical properties and stability were compared after two kinds of screws were implanted in the spine. RESULTS AND CONCLUSION:(1) Instantaneous pul out force and immediate pul out stiffness were significantly higher in the pedicle screw fixation group than in the cervical vertebral screw fixation group (P  目的:对比内固定椎弓根螺钉与颈椎体螺钉置入脊柱后的生物力学性能及其稳定性。  方法:选取100个人体下颈椎椎体标本进行分析,随机分为颈椎体螺钉组与内固定椎弓根螺钉组。分别将内固定椎弓根螺钉与颈椎体螺钉置入人体下颈椎标本中,采用Electro Force 3510材料试验机对标本进行轴向拔出力、疲劳加载后轴向拔出力、固定稳定性等生物力学测试,比较2种螺钉置入脊柱后的生物力学性能及其稳定性。  结果与结论:①内固定椎弓根螺钉组即时拔出力、即时拔出刚度均显著高于颈椎体螺钉组(P<0.05);②2组虽然疲劳

  9. 三种置钉方法在下颈椎经椎弓根螺钉置入过程中的比较%A comparative study on pedicle screw internal fixation to the lower cervical vertebra by three screw place methods

    Institute of Scientific and Technical Information of China (English)

    尹华; 赵银必

    2011-01-01

    背景:目前各种下颈椎椎弓根置钉方法的准确率报道不一,特别是国内常用的椎板部分切除置钉法、Abumi法、管道疏通法缺乏比较.目的:探讨下颈椎(C3~7)经椎弓根螺钉内固定的可行性,比较椎板部分切除置钉法、Abumi法、管道疏通法在置钉满意率、出血量、置钉时间、并发症等方面的差异.方法:选择60例需颈后路经椎弓根螺钉内固定治疗的下颈椎疾患病例,随机分成3组,各置入椎弓根螺钉80枚,分别采用椎板部分切除置钉法、Abumi法及管道疏通法.术中计算各方法置钉时间、出血量;出院前观察置钉满意率及在颈椎椎弓根四壁损伤例数的构成比;比较C3~7每一节段的椎弓根外侧壁损伤发生率.结果与结论:椎板部分切除组、Abumi组及管道疏通组置钉时间依次递减(P 0.05),椎弓根损伤好发生于外壁.C4、C5节段外壁损伤发生率明显高于C3、C6、C7.提示管道疏通法在经颈后路椎弓根螺钉内固定常规置钉法中优势明显.%BACKGROUND: Nowadays there are so many screw place methods in lower cervical vertebra. But they have different accuracy.There was no comparative study on the pedicle screw internal fixation in lower cervical vertebra by three screw place methods such as vertebral plate partial resection screw place method, Abumi place screw method and pipeline dredge method.OBJECTIVE: To explore the feasibility of the pedicle screw internal fixation in lower cervical vertebra (C3-7), and to compare the differences in screw satisfaction rate, blood loss, screw placing time, complications among vertebral plate partial resection screw place method, Abumi screw place method, and pipeline dredge method.METHODS: Totally 60 patients with lower cervical spine disease who needed the pedicle screw internal fixation through cervical posterior approach were chosen and divided into three groups each with 80 pedicle screws by vertebral plate partial resection

  10. "徒手法"个体化颈椎椎弓根螺钉技术治疗上颈椎骨折脱位%Free-hand cervical pedicle screw fixation for upper cervical fracture and instability

    Institute of Scientific and Technical Information of China (English)

    韩岳; 夏群; 徐宝山; 张继东; 苗军

    2011-01-01

    目的 探讨应用颈椎椎弓根钉治疗上颈椎骨折及脱位的临床效果.方法 2006年9月-2009年1月,应用颈椎椎弓根钉治疗的上颈椎骨折或脱位的患者15例.其中男11例,女4例;年龄18~60岁,平均41.2岁.寰椎骨折脱位5例,枢椎骨折脱位3例,齿状突陈旧骨折不愈合1例,C2,3骨折脱位2例,无骨折寰枢椎失稳4例.临床主要症状为颈部疼痛或伴有四肢麻木无力、步态不稳.患者术前均行Halo架牵引试行复位.所有患者均采用颈椎椎弓根钉固定并植骨融合,根据术前X线片及CT个体化确定入钉点及置钉角度,徒手法钻出骨性通道,选用22~26 mm长的Vertex或Summit钛金属螺钉固定,并行后路椎板间自体或同种异体骨植骨融合.术后1~2 d佩戴颈托离床活动.结果 本组15例共置入颈椎椎弓根螺钉64枚,均未发生椎动脉和脊髓损伤,无脑脊液漏.术后行X线正、侧位片和CT检查证实损伤节段复位满意、螺钉位置良好.术后疼痛症状基本消失,神经症状较术前有不同程度的改善.14例患者获得随访,时间12~36个月,患者颈椎序列良好,均获得骨性融合,未发生螺钉及钛棒的松动、脱出及折断.神经损伤症状较术前明显改善.结论 颈椎椎弓根钉是颈椎后路手术中坚强的固定方法,只要掌握手术操作技巧,严格个体化置钉,颈椎椎弓根钉具有固定可靠、术后并发症少、融合率高等优势,具有良好的临床疗效.%Objective To evaluate the clinical effect of the free-hand cervical pedicle screw fixation in treatment of the upper cervical fracture and instability.Methods A retrospective review was performed on 15 patients with upper cervical fracture and instability treated with cervical pedicle screw fixation and fusion from September 2006 to January 2009.There were 11 males and 4 females,at average age of 41.2 years(range,18-60 years).Of all,there were five patients with atlas fracture and dislocation

  11. 经皮内固定术与传统后路开放内固定术治疗胸腰椎骨折不良事件比较的Me ta分析%Comparison of the adverse events of percutaneous pedicle screw fixation and traditional open pedicle screw fixation for thoracolumbar fractures:a Meta-analysis

    Institute of Scientific and Technical Information of China (English)

    孙祥耀; 海涌; 张希诺

    2016-01-01

    目的:系统评价经皮椎弓根螺钉内固定术(PPSF)与传统后路开放内固定术(TOPSF)治疗胸腰椎骨折时出现的不良事件,为胸腰椎骨折治疗方法安全性的评估提供科学依据。方法计算机检索从建库至2016年3月PubMed、EMbase、Cochrane图书馆等中英文数据库。手工检索《The Journal of Bone and Joint Surgery》、《Spine》、《European Spine Journal》等期刊。英文检索词为thoracolumbar fracture、lumbar fracture、percutaneous pedicle screw fixation、open fixation、posterior surgery、sextant、traditional fixation、conventional fixation、minimally invasive surger-y、comparative study、randomized controlled trail、clinical trail等;中文检索词为经皮内固定术、后路内固定术、胸腰段骨折等。根据纳入标准进行筛选、数据提取、质量评价。采用RevMan 5.3进行Meta分析。结果最后纳入18项研究,其中随机对照试验4项,前瞻性对比研究3项,回顾性对比研究11项,共计1034例,其中PPSF组501例, TOPSF组533例。Meta分析显示:与TOPSF组相比,PPSF组手术时间短(WMD=-0.95,95%CI:-1.33~-0.57,P<0.001)、术中出血量少(WMD =-2.97,95%CI:-3.69~-2.25,P<0.001)、术后引流量少(WMD=-2.43,95%CI:-3.04~-1.83,P<0.001)、住院时间短(WMD=-5.37,95%CI:-6.69~-4.05, P<0.001)、下床活动时间早(WMD=-2.51,95%CI:-3.66~-1.36,P<0.001)、总体术后 VAS 评分低(WMD=-1.14,95%CI:-1.62~-0.66,P<0.001)、术后ODI评分低(WMD=-1.78,95%CI:-3.00~-0.55,P=0.004)、术后Cobb角矫正度丢失低(WMD=-0.52,95%CI:-0.93~-0.11,P=0.01)、术中辐射暴露时间长(WMD=5.12,95%CI:2.89~7.34,P<0.001)、两种术式椎弓根螺钉位置

  12. Economic evaluation comparing intraoperative cone beam CT-based navigation and conventional fluoroscopy for the placement of spinal pedicle screws: a patient-level data cost-effectiveness analysis.

    Science.gov (United States)

    Dea, Nicolas; Fisher, Charles G; Batke, Juliet; Strelzow, Jason; Mendelsohn, Daniel; Paquette, Scott J; Kwon, Brian K; Boyd, Michael D; Dvorak, Marcel F S; Street, John T

    2016-01-01

    Pedicle screws are routinely used in contemporary spinal surgery. Screw misplacement may be asymptomatic but is also correlated with potential adverse events. Computer-assisted surgery (CAS) has been associated with improved screw placement accuracy rates. However, this technology has substantial acquisition and maintenance costs. Despite its increasing usage, no rigorous full economic evaluation comparing this technology to current standard of care has been reported. Medical costs are exploding in an unsustainable way. Health economic theory requires that medical equipment costs be compared with expected benefits. To answer this question for computer-assisted spinal surgery, we present an economic evaluation looking specifically at symptomatic misplaced screws leading to reoperation secondary to neurologic deficits or biomechanical concerns. The study design was an observational case-control study from prospectively collected data of consecutive patients treated with the aid of CAS (treatment group) compared with a matched historical cohort of patients treated with conventional fluoroscopy (control group). The patient sample consisted of consecutive patients treated surgically at a quaternary academic center. The primary effectiveness measure studied was the number of reoperations for misplaced screws within 1 year of the index surgery. Secondary outcome measures included were total adverse event rate and postoperative computed tomography usage for pedicle screw examination. A patient-level data cost-effectiveness analysis from the hospital perspective was conducted to determine the value of a navigation system coupled with intraoperative 3-D imaging (O-arm Imaging and the StealthStation S7 Navigation Systems, Medtronic, Louisville, CO, USA) in adult spinal surgery. The capital costs for both alternatives were reported as equivalent annual costs based on the annuitization of capital expenditures method using a 3% discount rate and a 7-year amortization period

  13. Treatment of pedicle screw rod system internal fixation on sacroiliac joint fracture and dislocation%椎弓根钉棒系统固定治疗骶髂关节骨折及脱位分析

    Institute of Scientific and Technical Information of China (English)

    唐理英

    2013-01-01

    Objective To analyze the treatment effects of the iliac screw and pedicle screw rod internal fixation on sacroiliac joint fracture and dislocation and discuss the clinical application value of the pedicle screw rod system in fixation of sacroiliac joint. Methods The double plates fixation via posterior approach was adopted for the patients with sacroiliac joint fracture and dislocation in the control group (n=24),while the iliac screw and pedicle screw rod system internal fixation was adopted for the patients with sacroiliac joint fracture and dislocation in the treatment group (n=24).The clinical effects of the surgeries and the postoperative follow-up of the two groups were compared. Results There were no significant differences (P < 0.05) of the operation time,intraoperative blood loss and fracture healing time between the two groups; All the patients were followed up for 12-18 months. The Majeed score of the treatment group was 95.8%(23/24), which was better than the control group (70.8%(17/24))with significant difference (P<0.05). Conclusion The treatment effect of the iliac screw and pedicle screw rod internal fixation on sacroiliac joint fracture and dislocation is good,which can recover the normal function of joint to the greatest degree and improve the patient’s quality of life.%  目的分析应用髂骨钉与椎弓根钉棒内固定治疗骶髂关节骨折、脱位的治疗效果,探讨椎弓根钉棒系统固定骶髂关节的临床应用价值。方法对照组(n=24)骶髂关节骨折、脱位采用后路双钢板固定治疗,治疗组(n=24)为骶髂关节骨折、脱位患者采用髂骨钉与椎弓根钉棒系统固定术治疗,对比两组的手术临床效果及术后随访情况。结果两组的手术时间、术中出血量、骨折愈合时间均无显著性差异(P<0.05);所有患者均随访12~18个月, Majeed评分治疗组优良率为95.8%(23/24),明显优于对照组的70.8%(17/24),两

  14. 单侧椎弓根螺钉内固定治疗腰椎退行性疾病的研究进展%Progress of unilateral pedicle screw internal fixation for the treatment of lumbar degenerative diseases

    Institute of Scientific and Technical Information of China (English)

    谷金(综述); 梁斌(审校)

    2015-01-01

    Unilateral pedicle screw internal fixation is one of the important means of treatment of lumbar de-generative diseases.It plays an important role on solving the postoperative immediate stability of the lumbar spine, and provide enough rigid internal fixation for intervertebral fusion.This paper expounds the research present situation, advantages, limitations and future research direction of unilateral pedicle screw internal fixation.%单侧椎弓根螺钉内固定是治疗腰椎退行性疾病的重要手段之一,其在解决腰椎术后的即刻稳定性方面起着重要作用,为椎间融合术提供足够刚性内固定。该文对单侧椎弓根螺钉内固定的研究现状、优势、局限性与未来的研究方向进行综述。

  15. Pedicle screw fixation and posterior lumbar interbody fusion in treatment of lumbar spondylolisthesis%椎弓根固定加椎间植骨治疗腰椎滑脱症

    Institute of Scientific and Technical Information of China (English)

    李源

    2008-01-01

    目的 探讨经后路椎弓根螺钉复位固定加椎体间植骨融合治疗腰椎滑脱的疗效.方法 采用椎弓根内固定系统,手术复位固定后,从两侧进入椎间隙取出椎间盘及纤维环,取髂骨块植骨融合.结果 29例患者获得随访,平均随访时间16个月(9~26个月).26例症状完全消失或缓解,优良率89.6%.结论 椎弓根固定系统加椎间植骨治疗腰椎滑脱症效果满意.%Objective To discuss the efficacy of reduction and fixation by pedicle screw system and iliac dowel graft placement in the treatment of lumbar spondylolisthesis.Methods From January 2003 to Decmber 2006.29 cases with lumbar spondylolisthesis were treated with pedicle screw system and iliac dowel graft placement.Results Twenty-nine patients were followed up from 9-26 months(16 months On average).26 cases were healed or alleviated.The excellent rate was 89.6%.Conclusion This technique has been found to be a safe,rapid effective procedure for lumbar spondylolisthesis and satisfaction.

  16. Biomechanical evaluation of connectible skills using iliac screw and lumbar-sacral spine pedicle screw in the fixation between lumbar-sacral spine and pelvis%髂骨钉与腰骶椎弓根钉连接技术在腰骶骨盆固定中的生物力学评价

    Institute of Scientific and Technical Information of China (English)

    苏汝堃; 刘兴漠; 邓颖辉; 李佛保; 潘滔

    2008-01-01

    BACKGROUND: There have been many methods of fixation between lumbar-sacral spine and pelvis. However, a safe, firm, and ideal method of internal fixation has not been found.OBJECTIVE: This study was designed to investigate the stability of the fixation between lumbar-sacral spine and pelvis with the connectible skills using iliac screw and lumbar-sacral spine pedicle screw.DESIGN, TIME AND SETTING: This study, a control experiment, was performed at the Institute of Biomechanics, Sun Yat-sen University, Guangzhou, Guangdong Province, China between January 2006 and December 2007.MATERIALS: The lumbar-sacral spine and pelvis specimens were collected from six freshly cryo-preserved male adult corpses caused by trauma. Iliac screw (8.5mm×100mm), L5 pedicle screw (6.5mm×45mm), and S1 pedicle screw (6.5mm×35mm) were provided by Sofamor Company, USA. MTS 858 Bionix Material Testing System (USA) was also used.METHODS: The lumbar and iliac vertebrae, pelvis from six fresh frozen cadaveric specimens were operated in three different ways of fixation respectively: iliac ala lag screw, L5-S1 pedicle screw rod system, iliac screw and L5 pedicle screw connecting system. Three ways of fixation as mentioned above were compared with the intact group in biomechanical stability.MAIN OUTCOME MEASURES: The mobility of whirl, lateral bending, proneness, and backward stretching among groups.RESULTS: Using iliac screw for the fixation between lumbar-sacral spine and pelvis turned out to be the best in stability. The range of motion (ROM) decreased obviously in each situation. The three-dimensional mobility in the 6.4Nm moment of force was (1.07±0.86)° for whirl, (0.95±0.47)° for lateral bending, (1.22±0.67)° for proneness, and (1.80±0.73)° for backward stretching. There was significant difference between the intact group and the group carried out by iliac screw and L5 pedicle screw for the fixation between lumbar-sacral spine and pelvis (P<0.01).CONCLUSION: The connectible skills

  17. Selection of Fusion Levels Using the Fulcrum Bending Radiograph for the Management of Adolescent Idiopathic Scoliosis Patients with Alternate Level Pedicle Screw Strategy: Clinical Decision-making and Outcomes.

    Science.gov (United States)

    Samartzis, Dino; Leung, Yee; Shigematsu, Hideki; Natarajan, Deepa; Stokes, Oliver; Mak, Kin-Cheung; Yao, Guanfeng; Luk, Keith D K; Cheung, Kenneth M C

    2015-01-01

    Selecting fusion levels based on the Luk et al criteria for operative management of thoracic adolescent idiopathic scoliosis (AIS) with hook and hybrid systems yields acceptable curve correction and balance parameters; however, it is unknown whether utilizing a purely pedicle screw strategy is effective. Utilizing the fulcrum bending radiographic (FBR) to assess curve flexibility to select fusion levels, the following study assessed the efficacy of pedicle screw fixation with alternate level screw strategy (ALSS) for thoracic AIS. A retrospective study with prospective radiographic data collection/analyses (preoperative, postoperative 1-week and minimum 2-year follow-up) of 28 operative thoracic AIS patients undergoing ALSS was performed. Standing coronal/sagittal and FBR Cobb angles, FBR flexibility, fulcrum bending correction index (FBCI), trunkal shift, radiographic shoulder height (RSH), and list were assessed on x-rays. Fusion level selection was based on the Luk et al criteria and compared to conventional techniques. In the primary curve, the mean preoperative and postoperative 1 week and last follow-up standing coronal Cobb angles were 59.9, 17.2 and 20.0 degrees, respectively. Eighteen patients (64.3%) had distal levels saved (mean: 1.6 levels) in comparison to conventional techniques. Mean immediate and last follow-up FBCIs were 122.6% and 115.0%, respectively. Sagittal alignment did not statistically differ between any assessment intervals (p>0.05). A decrease in trunkal shift was noted from preoperative to last follow-up (p = 0.003). No statistically significant difference from preoperative to last follow-up was noted in RSH and list (p>0.05). No "add-on" of other vertebra or decompensation was noted and all patients achieved fusion. This is the first report to note that using the FBR for decision-making in selecting fusion levels in thoracic AIS patients undergoing management with pedicle screw constructs (e.g. ALSS) is a cost-effective strategy that

  18. Selection of Fusion Levels Using the Fulcrum Bending Radiograph for the Management of Adolescent Idiopathic Scoliosis Patients with Alternate Level Pedicle Screw Strategy: Clinical Decision-making and Outcomes.

    Directory of Open Access Journals (Sweden)

    Dino Samartzis

    Full Text Available Selecting fusion levels based on the Luk et al criteria for operative management of thoracic adolescent idiopathic scoliosis (AIS with hook and hybrid systems yields acceptable curve correction and balance parameters; however, it is unknown whether utilizing a purely pedicle screw strategy is effective. Utilizing the fulcrum bending radiographic (FBR to assess curve flexibility to select fusion levels, the following study assessed the efficacy of pedicle screw fixation with alternate level screw strategy (ALSS for thoracic AIS.A retrospective study with prospective radiographic data collection/analyses (preoperative, postoperative 1-week and minimum 2-year follow-up of 28 operative thoracic AIS patients undergoing ALSS was performed. Standing coronal/sagittal and FBR Cobb angles, FBR flexibility, fulcrum bending correction index (FBCI, trunkal shift, radiographic shoulder height (RSH, and list were assessed on x-rays. Fusion level selection was based on the Luk et al criteria and compared to conventional techniques.In the primary curve, the mean preoperative and postoperative 1 week and last follow-up standing coronal Cobb angles were 59.9, 17.2 and 20.0 degrees, respectively. Eighteen patients (64.3% had distal levels saved (mean: 1.6 levels in comparison to conventional techniques. Mean immediate and last follow-up FBCIs were 122.6% and 115.0%, respectively. Sagittal alignment did not statistically differ between any assessment intervals (p>0.05. A decrease in trunkal shift was noted from preoperative to last follow-up (p = 0.003. No statistically significant difference from preoperative to last follow-up was noted in RSH and list (p>0.05. No "add-on" of other vertebra or decompensation was noted and all patients achieved fusion.This is the first report to note that using the FBR for decision-making in selecting fusion levels in thoracic AIS patients undergoing management with pedicle screw constructs (e.g. ALSS is a cost-effective strategy

  19. 经后路寰枢椎椎弓根螺钉固定融合术治疗寰枢椎失稳%Atlanto-axial pedicle screw fixation through posterior approach for treatment of atlanto-axial joint instability

    Institute of Scientific and Technical Information of China (English)

    左春光; 刘夏君; 王新虎; 王建顺

    2013-01-01

    Objective:To discuss the therapeutic effects of the atlantoaxial pedicle screw system fixation in treatment of atlantoaxial instability. Methods:From June 2003 to March 2010,32 patients with atlantoaxial instability were treated by atlantoaxial pedicle screw system fixation, included 21 males and 11 females wiht an average age of 42.5 years old ranging from 28 to 66 years. Among them, 18 cases were odontoid process fractures,7 were congenital dissociate odontoid process,4 were Jefferson fracture combined with odontoid fracture, 3 were rheumatic arthritis causing atlantoaxial instability. All patients suffered from the atlantoaxial subluxation and atlantoaxial instability. The JOA score ranged from 4 to 14 (means 9.1±0.3) before operation. The patients had some image examination including the X-ray of cervical vertebrae (include of dynamic position film) ,spiral CT 3D reconstruction and/or MRI. The position of pedicle screw system implantation,the angle of pedicle screw system implantation and screw length were measured. Operating skull traction. Operation undewent general anesthesia, implanted the pedicle screw, reduction and bone fusion under direct vision. The bone was fixated between posterior arch of atlas and lamina of axis by the lateral combination bended to posterior. Results:One hundred and twenty-eight atlantoaxial pedicle screws were implanted in 32 patients. No patient had the injure of spinal cord,nerve root and vertebral artery. All patients were followed-up from 6 to 48 months (averaged 16 months). After operation,the JOA score ranged from 11 to 17 (averaged 15.9± 0.2) ,improvement rate was 86.1%. The fracture of odontoid process were healing completely. All fusion bone were combinated. The internal fixation wasn't loosening and breaking. Conclussion:The atlantoaxial pedicle screw system fixation was effective method to treat atlantoaxial instability. The method had many advantages, such as provide rigid and short segment fixation, safe and simple

  20. Anterior pedicle screw insertion for low cervical spine:anatomical observation%下颈椎前路椎弓根螺钉置入相关的解剖学观察

    Institute of Scientific and Technical Information of China (English)

    王远政; 刘洋; 陈富; 陈亮; 晏铮剑; 柯珍勇; 邓忠良

    2012-01-01

    目的:观察成人下颈椎前路椎弓根螺钉(Anterior pedicle screw,APS)置入相关的径线和角度,为该术的临床应用提供相关解剖学参数.方法:成人干燥尸体下颈椎(C3~C7)标本22具,分别用手工和CT测量椎弓根最窄处的高度、宽度及内外侧皮质厚度,椎弓根中轴线全长,轴线夹角,并进行统计学分析.随机在CT室资料库中抽取100例成人活体颈椎CT图像,用Mimics 软件行三维重建,除以上参数外,还测量进钉点位置的相关数据,计算置钉参数的95%CI.结果:22具标本的相关径线及角度,其手工测量值与CT测量值间无统计学差异.成人活体下颈椎CT图像测量结果通过95%CI的计算,可以得出:C3、C4进钉点位于椎体正中矢状面受术椎弓根对侧2~3 mm,距椎体上终板平面6~7 mm,进钉角度为外倾角46°~48°,头倾角C3:-11°~-12°,C4-6°~7°.C5进钉点位于椎体正中矢状面受术椎弓根同侧旁1~2 mm,距椎体上终板平面7~8 mm,进钉角度为外倾角47°~49°,头倾角1°~2°.C6、C7进钉点位于受术椎弓根同侧,正中矢状面旁4~5 mm,距椎体上终板平面7.5~8.5 mm,进钉角度为外倾角C6:40°~42°,C7:36°~38°,头倾角C6:6°~7°,C7:11°~13°.置钉长度选择30、32、34 mm较为适宜,螺钉直径可选择3.5 mm或4.0mm.结论:本实验证实了CT测量下颈椎APS置入技术相关参数的准确性,同时在国内首次利用大样本研究对该技术置钉参数进行了探索.%Objective:To observe the pathlines and angles related to lower cervical spine anterior pedicle screw(APS)fixation in adults so as to provide anatomical parameters in clinics. Methods:A total of 22 cervical spine(C3-C7)specimens of human adult cadavers were individually measured by hand and CT scan to determine the height and width of the narrowest part in pedicle, thickness of inner and outer cortexes, pedicle axis length and included angle of axes followed by statistical methods. One

  1. Clinical results of pedicle screws with cement augmentation for treating lumbar degenerative diseases in the elderly%椎弓根螺钉骨水泥强化修复老年腰椎退变的早期效果

    Institute of Scientific and Technical Information of China (English)

    陈荣国; 代凤雷; 欧先锋; 杨超; 钱建吉; 曾怿; 任家云; 虞泽龙

    2014-01-01

    背景:老年腰椎退变患者在手术中常面临椎弓根螺钉把持力不足情况,易发生脱钉、固定不牢靠等风险,如何增加螺钉的把持力成为研究的热点。目的:探讨使用椎弓根螺钉骨水泥强化方案治疗老年腰椎退变的早期临床效果。方法:选择2012年8月至2014年4月收治的患腰椎退行性疾病行腰椎内固定治疗的患者65例,根据修复方案分为2组,椎弓根螺钉内固定骨水泥强化组24例,常规椎弓根螺钉内固定组41例。比较两组患者的一般情况,采用目测类比评分法和日本矫形科学学会腰椎功能评分表对患者腰背疼痛及下肢神经功能恢复情况进行评估。结果与结论:65例患者均完成手术,获得随访,随访时间为3-20个月,随访中均行腰椎正侧位片X射线片,未发现螺钉松动、脱落、断裂、椎间隙高度丢失等情况。椎弓根螺钉内固定骨水泥强化组患者的手术出血量、住院时间与常规椎弓根螺钉内固定组差异无显著性意义(P>0.05),椎弓根螺钉内固定骨水泥强化组术后3,6个月日本矫形科学学会腰椎功能评分及术后3个月的目测类比评分均较常规椎弓根螺钉内固定组显著改善(P 0.05)。提示将骨水泥沿椎弓根螺钉钉道注入椎弓根及椎体,可达到螺钉骨水泥强化的目的,增加螺钉的把持力,重建腰椎的稳定性,取得了满意的近期疗效。%BACKGROUND:Elderly patients with degenerative lumbar degeneration often appear insufficient holding power of pedicle screw in spine surgery, which is prone to occur de-pinning and leads to insecure fixation. How to increase the holding power of screws has become a hot research. OBJECTIVE:To observe the early clinical effect of pedicle screws with cement augmentation for treating lumbar degenerative diseases in elderly patients. METHODS:A total of 65 old patients with lumbar degenerative diseases received a treatment

  2. 腰椎内固定中两种椎弓根钉加强技术与骨水泥的应用%Two strengthening pedicle screw techniques and bone cement in lumbar internal fixation

    Institute of Scientific and Technical Information of China (English)

    江泽华; 朱如森; 袁建军; 邵高升; 张学利

    2013-01-01

    BACKGROUND:Screw loosening and shedding may occur after osteoporosis associated with lumbar degenerative disease treated with pedicle screw fixation. Application of pedicle screw enhanced with cured materials can improve the therapeutic effect. OBJECTIVE:To compare the clinical effect of pedicle screws enhanced with poly(methyl methacrylate) and injectable calcium sulfate cement in the lumbar internal fixation of osteoporosis. METHODS:Sixty-one patients diagnosed with osteoporosis combined with lumbar spondylolisthesis, lumbar spinal instability, and severe lumbar spinal stenosis were col ected. Al patients were divided into two groups according to the treatment method:poly(methyl methacrylate) bone cement enhanced pedicle screw group and calcium sulfate bone cement enhanced pedicle screw group. RESULTS AND CONCLUSION:There were no significant differences in the operation time, blood loss, preoperative and postoperative visual analog scale score, Japanese Orthopedic Association scores and the Japanese Orthopedic Association score improvement rate between two groups (P>0.05). The results showed that two patients had bone cement leakage in poly(methyl methacrylate) group which had no neurological symptoms caused by new symptoms during fol ow-up period. The bone mineral density was not improved gradual y in poly(methyl methacrylate) group with fol ow-up time prolonging;however, in calcium sulfate group, the bone mineral density was increased significantly after treatment, and the change of bone mineral density was linearly related with Japanese Orthopaedic Association score improvement rate in calcium sulfate group. No screw loosening, pul ing out or neurological dysfunction occurred in both groups. The results indicate that like poly(methyl methacrylate), balcium sulfate bone cement can increase the stability of pedicle screws.%背景:骨质疏松伴腰椎退行性病变行椎弓根钉固定骨质疏松的椎体后可能会出现螺钉的松动、脱落,使用

  3. Clinical observation of posterior internal fixation with vertebral pedicle screw and rod system on thoracolumbar spine fracture%采用后路椎弓根钉棒系统治疗胸腰椎骨折疗效观察

    Institute of Scientific and Technical Information of China (English)

    王洽君

    2013-01-01

    目的 观察后路椎弓根钉棒系统治疗胸腰椎骨折的临床疗效.方法 回顾性分析32例采用后路椎弓根钉棒系统治疗胸腰椎骨折患者的临床资料,术后最长获得2年随访,分析椎体高度、椎体序列和Cobb角的改变.结果 32例患者获得6~ 48个月随访,平均15.8个月.术后椎体前、后缘高度分别为(96.85±14.33)%、(97.44±12.38)%,明显大于术前的(46.67±11.25)%、(76.76±12.62)%(均P<0.05);术后Cobb角为(7.45±2.12)°,显著小于术前的(20.56±7.51).(P<0.05).术后患者Frankel分级均有改善.结论 应用椎弓根钉棒系统治疗胸腰椎骨折能取得良好的临床疗效.%Objective To observe the clinical effect of posterior internal fixation with vertebral pedicle screw and rod system on thoracolumbar spine fracture.Methods The clinical data of 32 patients diagnosed as thoracolumbar spine fracture in our hospital who treated with posterior internal fixation with vertebral pedicle screw and rod system were retrospectively analyzed.The Frankel scale combined with X-ray and CT images were used for the judgment of efficacy.Results The vertebral Height and Cobb angles were improved significantly after the operations (P <0.05).And the Frankel degree of cases with nerve symptoms was also improved.Conclusion Posterior internal fixation with vertebral pedicle screw and rod system is effective in treating patients with thoracolumbar spine fracture.

  4. Percutaneous C2 pedicle lag screw for treatment of Hangman's fractures%经皮C2椎弓根拉力螺钉微创治疗Hangman骨折

    Institute of Scientific and Technical Information of China (English)

    翁益民; 徐华梓; 水小龙; 林焱; 王向阳; 孔建中; 池永龙

    2008-01-01

    目的 探讨经皮C2椎弓根拉力螺钉微创治疗Hangman骨折的可行性、临床疗效及手术适应证.方法 本组男5例,女4例;年龄26-68岁,平均36岁.Levine-Edwards分型:Ⅰ型5例,Ⅱ型3例,ⅡA型1例.脊髓功能依美国脊髓损伤学会(ASIA)评分:D级2例,E级7例.所有患者先行颅骨牵引达满意复位,均在全身麻醉下行经皮C2椎弓根拉力螺钉内固定术,全过程在C形臂X线机下完成,以确保安全性与准确性.结果 本组患者术后2~3个月均获骨性愈合,无感染、神经损伤、椎动脉损伤及其他并发症.结论 经皮C2椎弓根拉力螺钉微创治疗Hangnum骨折疗效满意,属微创手术,较少影响上颈椎功能.%Objective To study the feasibility and clinical effect of percutaneous C2 pedicle lag screw in treatment of Hangman's fracture and define the indications of the technique. Methods There were 9 patients including 5 males and 4 females at average age of 36 years (26-68 years). According to a Levine and Edwards System, there were 5 patients with type Ⅰ hangman' s fracture, 3 with type Ⅱ hangman' s fracture and 1 with type Ⅱ A hangman' s fracture. According to American spinal injury association (ASIA) system, the spinal cord function was ranked at Type D in 2 patients and Type E in 7. All patients achieved anatomic reduction by skull traction. Under general anesthesia, 9 patients were fixed with percutaneons C2 pedicle lag screw. The whole procedure was done under monitoring of "C"-arm fluoroscopy for safety and accuracy. Results All patients obtained bony fusion within 2-3 months, with no infection, neurological deficits, vertebra artery injury or other complications. CondusionsThe percutaneous C2 pedicle lag screw fixation is minimally invasive and effective for treatment of Hangman's fracture. During the course of treatment, the function of upper cervical spine remains unaffected.

  5. Comparison of the effect of posterior lumbar interbody fusion with pedicle screw fixation and interspinous fixation on the stiffness of adjacent segments

    Institute of Scientific and Technical Information of China (English)

    LI Chun-de; SUN Hao-lin; LU Hong-zhang

    2013-01-01

    stiffness of the cephalic adjacent segment L3/4 after fixation in the Wallis group was significantly higher than that of the PLIF group (P <0.05).Cadaver experiments showed that the stiffness of the cephalic adjacent segment in the Wallis group was significantly higher than that of the PLIF group after L4/5 segment fixation (P <0.05); the stiffness of the L5/S1 segment showed no significant difference between PLIF surgery and Wallis implantation (P >0.05).Conclusions After interspinous (Wallis) fixation,the stiffness of the cephalic adjacent segment increased.After PLIF with pedicle screw fixation,the stiffness of the cephalic adjacent segment decreased.An interspinous fixation system (Wallis) has a protective effect for cephalic adjacent segments for the immediate post-operative state.

  6. Evaluation outcomes of pedicle screw system for atlantoaxial instability%寰枢椎椎弓根钉系统固定治疗寰枢关节不稳的疗效评估

    Institute of Scientific and Technical Information of China (English)

    王春; 林永绥; 刘成招; 刘清平; 吴李勇; 林锦; 何晓宇

    2011-01-01

    Objective To evaluate the clinical outcome of pedicle screw system for atlantoaxial instability. Methods Thirty-eight patients with atlantoaxial instability were stabilized with transpedi-cle screw fixation between June 2003 to December 2008. There were 32 males and 6 females. The mean age were 45.3 years (range 18~76 years). The transpedicle screw fixation was employed in 3 patients with atlantoaxial instability for transverse ligament rupture,in 3 patients for Jefferson fracture, in 29 patients with atlantoaxial dislocation and odontoid fracture,and in 3 patients for congenital odontoid abnormality. Results All the operations were performed successfully. All patients were followed up for 6 months to 4 years,with an average of 14 months. Postoperative complications,such as injury of the nerve structures and the vertebral artery,were not observed in 38 cases. The neural function of injured spinal cord were recoveried to some extent after operation. Flexion-extension in cervical spine was normal,and axial rotation from neutral position were 25°~60° each side. Postoperative radiograph and CT showed that all screws were positioned correctly in Cl and C2. No screws and rods were broken or loosened in all cases. Fine relationships between Cl and C2 in all cases were confirmed in postoperative radiographs and computed tomography (CT)scans. Bony fusion were observed at 3 months after the surgery in all cases. Conclusion Posterior atlantoaxial complex fusion with pedicle screw system combined bone grafting is an effective method for atlantoaxial instability. The accurate insertion of pedicle screw is of utmost importance in this technique. It is more safe,because of the space available for the transpedieular screw (SAS)in Cl showed on CT scans is enlarged,when the entry point of the pedicle screw for Cl is located 1~2 nun lateraler from the vertical line through the central point of C2 lateral mass,about 3mm under the superior rim of Clposterior arch,and when the

  7. 腰椎椎弓根螺钉内固定术三维可视化设计%Design of three-dimensional visualization based on the posterior lumbar pedicle screw fixation

    Institute of Scientific and Technical Information of China (English)

    徐凯; 陈春; 黄山东; 章莹; 尹庆水

    2011-01-01

    目的 建立腰椎椎弓根内固定术后的三维可视化数字模型.方法 选择1名腰椎间盘突出和1名腰椎压缩性骨折患者,在腰椎内固定术前及术后行多排螺旋CT扫描,观测术前椎体压缩程度、手术前后腰椎结构形态,术后钉棒的位置及椎板减压情况,利用Amira 4.1软件,经剪切、分割、表面重建及绘制等步骤,对腰椎结构及内植物进行三维重建,获得立体形态的腰椎手术前后改变及内置物位置结构.结果 借助数字化导航平台,重建了手术前后的腰椎和内置物形态结构.重建的三维结构可以多彩色、透明或任意组合显示.经不同角度观察,重建的三维结构显示清晰、实体感强.在三维表面重建的图像中可清楚地观察到内固定物的位置形态,特别是可以充分评估脊髓或神经根的减压程度及椎体骨折和压缩程度.术前重建图像可以清晰显示椎弓根的位置,为术中精确定位提供参考.结论腰椎椎弓根内固定术的三维重建对基础研究、临床试验及手术规划具有重要价值,应用Amira软件可为三维建模提供基础.%Objective To establish a three-dimensional visualization model of posterior lumbar pedicle screw fixation. Methods A patient with lumbar intervertebral disc hernia and another patient with compression fracture of lumbar vertebra were involved in the present study. Both patients underwent multi-slice spiral CT scan before and after lumbar pedicle screw fixation. The degree of preoperative vertebral compression, vertebral morphology before and after surgery, postoperative pedicle screw position, and decompression effects were observed. The original data of the multi-slice spiral CT were inputted into the computer. The three-dimensional reconstructed images of the lumbar and implanted screws were obtained using the software Amira 4.1 to show the three-dimensional shape of the lumbar vertebrae before and after surgery and the location of the

  8. Applied anatomical study on pedicle screw placement in C6 and C7%C6、C7椎弓根置钉的应用解剖学研究

    Institute of Scientific and Technical Information of China (English)

    李野; 刘景臣; 武云涛; 张云峰; 公伟权; 陈许冬; 朱庆三

    2013-01-01

    Objectives:To investigate pedicle screw placement in C6 and C7,and to design C6 and C7 pedicle placement based on the isthmus as anatomic mark.Methods:15 adult cervical specimens were used regardless of gender or age.No deformity or damage to the specimen was noted.Only the C6 and C7 specimens were used.Pedicle width(PW) and pedicle height(PH) were measured.The area below the lower edge of the superior articular process,above the upper edge of the inferior articular process,and between the medial and lateral edges of the superior articular process of the same cervical segment was defined as the isthmus respectively.The isthmus was divided into three equal parts,and two vertical lines were drawn,with the medial third as the posterior plane of the isthmus and lateral third as the posterolateral plane of the isthmus.The entry point was chosen as the intersection of the horizontal line through the midpoint of the transverse process root and the vertical line through the posterolateral plane and the posterior plane of the isthmus.The screw with a diameter of 3.5mm and suitable length was inserted to ensure the end of screw to reach the cortical bone.The axis of screws was consistent with the axis of pedicle.The angle formed by the axis of cervical pedicle screw on the horizontal plane to the posterolateral plane of isthmus was defined as the transverse angle of the inserted screw (E).The angle formed by the axis of cervical pedicle screw on the sagittal plane to the posterior plane of isthmus was defined as the vertical angle of the inserted screw (F).The two angles and the full length of pedicle screw channel(FSC) were measured.Results:There was no statistical significance as for the measurement between left side and right side at the same segment (P>0.05),therefore the bilateral data were combined.PW and PH of C6 was 6.12±0.78mm and 7.48±0.81mm respectively.PW and PH of C7 was 6.85±0.73mm and 8.03±0.38mm respectively.C6's PW and PH were less than C7's (P< 0

  9. 枢椎椎弓根螺钉区域法植入技术及临床应用%Insertion technique and clinical application of regional method axis pedicle screw

    Institute of Scientific and Technical Information of China (English)

    苗军; 夏群; 胡永成; 徐宝山; 张继东; 白剑强; 吉宁

    2012-01-01

    Objective To explore the clinical efficacies and outcomes of regional method axis pedicle screw insertion technique.Methods During the period of April 2004 to June 2010,a total of 23 cases with traumatic instability of upper cervical vertebrae were recruited.There were 19 males and 4 females with a mean age of 45.8 years.They underwent surgical operations after an excellent traction reduction of cervical vertebrae.The entry points were drawn on axial facet joint and all of them distributed in the region of upper inner 1/4 of lower articular process. So the regional method was employed to determine the entry point.All subjects underwent the reconstruction of posterior stability.Axial pedicle screws were inserted by the insertion technique of axial pedicle screw via the “regional method”.The entry region was in the upper inner 1/4 area of lower articular process.The entry angle,medial inclination and superior inclination were determined by the direction of inner wall and upper wall of isthmus.Postoperative cervical radiography and CT examination were performed to confirm the screw position.Results Forty-six axial pedicle screws were implanted.No significant complications occurred. All screws stayed in excellent positions without the invasion of vertebral artery and spinal canal.Conclusion The “regional method” insertion technique of axial pedicle screw require no memory of complex entry points and entry angle parameters.And there is no need of identifying the anatomical landmarks.Thus this approach is accurate,safe and suitable for most patients.%目的 观察区域法枢椎椎弓根钉植入技术的临床治疗效果.方法 自2004年4月至2010年6月共收治创伤性寰枢椎不稳患者23例,男19例,女4例,平均年龄45.8岁.术前给予颈椎牵引复位良好后进行手术治疗.寰枢椎椎弓根螺钉固定14例,枕颈融合5例,颈1-3椎弓根钉固定4例.术中采用区域法植入枢椎椎弓根螺钉,即进钉点在枢椎下关节突内上1

  10. Basis椎弓根螺钉固定加环形植骨融合治疗腰椎滑脱%Basis pedicle screw fixation and posterior instrumented circumferential fusion for the treatment of lumbar spondylolisthesis

    Institute of Scientific and Technical Information of China (English)

    董福龙; 申才良; 张建湘; 汤健; 杨庆国; 江曙

    2011-01-01

    Objective To summarize curative effects of the decompressive laminectomy by posterior approach, reduc tion of spondylolisthesis fixed with Basis pedicle screw and posterior instrumented circumferential fusion in the treat ment of lumbar spondylolisthesis. Methods Thirty-two patients with lumbar spondylolisthesis treated with posterior instrumented circumferential fusion were studied retrospectively. Results All the patients received follow-up for 4 ~ 25 months. Symptoms were disappeared after operations in all the patients. The postoperative X-ray films showed that 29 patients obtained complete reduction,3 partly reduction. This surgical methods produced satisfactory outcomes with the 100% osseous fusion. All the bone grafts were fusion, without screws loosening or breakage or internal fixation loosing was found. Based on Hou Shu-xun Criteria for therapeutical evalution, the efficacy was as follows: excellent in 23 cases,good in 7,and fair in 2,the rate of excellent and good was 94%. Conclusions Posterior instrumented cir cumferential fusion with Basis pedicle screw is an effective method for treating severe lumbar spondylolisthesis.%目的 探讨后路腰椎管减压、Basis椎弓根螺钉系统复位固定加环形植骨融合治疗腰椎滑脱症的疗效.方法 对32例腰椎滑脱症患者行后路腰椎管减压Basis椎弓根螺钉复位固定加环形植骨融合术.结果 32例均获随访,时间4~25个月.患者术后症状均消失,X线片示29例滑脱完全复位,3例部分复位.所有患者均达骨性融合,无椎弓根钉松动、断裂及再滑脱现象.根据侯树勋等疗效评定标准评定:优23例,良7例,可2例,优良率94%.结论 Basis椎弓根固定系统复位固定加环形植骨融合治疗腰椎滑脱症临床疗效满意,可作为治疗严重腰椎滑脱的首选方法.

  11. Multiaxial inter-vertebral and vertebral pedicle pedicle screw fixation for spinal fractures: a biomechanical comparative study%经伤椎与跨伤椎万向钉置钉固定脊柱骨折的生物力学对比研究

    Institute of Scientific and Technical Information of China (English)

    王洪伟; 周跃; 李长青; 刘涛; 赵卫东

    2010-01-01

    Objective To compare the biomechanical stability of the multiaxial inter-vertebral and vertebral pedicle screw fixation in vertebral fracture fixation of the spinal fracture model. Methods Six lumbar fracture models were made on fresh calf lumbar spine specimens at L1 -L5 to compare the stability of four transpedicular multiaxial screws and six transpedicular multiaxial screws by examining the range of motion (ROM) in flexion, extension, lateral bending and torsion. Results Biomechanical experiment found that four multiaxial screws transpedicular fixation specimen exhibited a significantly larger ROM in flexion and extension than the intact specimens; while six multiaxial transpedicular screw fixation specimen exhibited a smaller ROM than the intact specimens (t =4. 844,P <0. 01 ;t =3. 722,P <0.05 ). The ROM of six multiaxial transpedicular screw fixation specimen was significantly smaller than that of four multiaxial transpedicular screw fixation specimen in flexion, extension, lateral bending and rotation ( P < 0. 01 ). Conclusions Compared with four multiaxial transpedicular screw fixation, six multiaxial transpedicular screw fixation exhibits a significantly larger stability in flexion, extension, lateral bending and rotation, as provides theoretical basis for treatment of thoracolumbar fractures with pedicular screw fixation.%目的 对比评估经伤椎6钉与跨伤椎4钉固定脊柱骨折的生物力学稳定性.方法 6具新鲜冰冻小牛腰椎标本L1~L5节段,制备成腰椎前中柱损伤模型.比较4钉固定组与6钉固定组的三维6个方向的运动范围.结果 生物力学试验证实,4钉固定组在屈曲、后伸运动方向上的稳定性都较对照组小,但差异无统计学意义.6钉固定组在屈曲、后伸运动方向上的稳定性均较完整对照组大,且差异有统计学意义(t=4.844,P<0.01;t=3.722,P<0.05).6钉固定组在各个方向的运动范围均小于4钉固定组,且两组在屈曲、后伸、侧屈

  12. Treatment of upper cervical spine instability with posterior fusion plus atlantoaxial pedicle screw%后路寰枢椎弓根钉棒系统固定融合治疗上颈椎不稳

    Institute of Scientific and Technical Information of China (English)

    马超; 田纪伟; 吴继彬; 赵猛; 戴维享; 吴德慧; 王兆红; 冯杰; 柳超; 赵庆华

    2011-01-01

    Objective To evaluate the clinical efficacies,indications and application values of posterior fusion plus pedicle screw fixation in the treatment of upper cervical spine instability.Methods From May 2006 to December 2010,a total of 24 patients with atlantoaxial instability were treated with C1-2 pedicle screws and rod fixation under general anesthesia.There were 18 males and 6 females with a mean age of 49.8 years old ( range:17 - 69 ).Results The postoperative radiographs verified a good position of all screws with satisfactory atlantoaxial reduction.A mean follow-up period of 23 months (range:3 -45 ) showed no injury of spinal cord and vertebral artery or interfixation failure.Atlantoaxial alignment and stability were restored without instrumentation-related complications.Conclusion Posterior atlantoaxial pedicle screw and rod fixation provide immediate three-dimensional rigid fixation of atlantoaxial joint.It is a more effective technique than with previously reported techniques.%目的 探讨和评估寰枢椎椎弓根钉棒系统固定融合治疗上颈椎不稳的临床疗效、适应证及应用价值.方法 2006年5月至2010年12月,采用寰枢椎椎弓根螺钉技术治疗上颈椎不稳患者24例,男18例,女6例,其中齿突发育不良造成的寰枢椎不稳5例,顽固性寰枢椎旋转脱位4例,创伤性陈旧性寰枢关节脱位6例,椎管内肿瘤4例,陈旧性齿突骨折5例,24例均采用美国强生Depuy公司生产的后路Summit钉棒系统(万向螺钉直径3.5mm,寰椎螺钉长26 ~30 mm,平均28 mm,枢椎螺钉长24 ~28 mm,平均26 mm).回顾性分析临床疗效和并发症防治,术前、术后采用JOA进行评分,根据术后随访X线及CT评价上颈椎结构的恢复情况.结果 所有患者均获随访,随访时间3~45个月,平均23个月,全组病例未发生与置钉相关的并发症,临床症状得到不同程度的改善,术前,术后6个月JOA评分改善率为73.1% ~93.6%,平均81.2%.复查X线片、CT未

  13. 下颈椎椎板和侧块作为椎弓根置钉角度参考标志的可靠性%Reliability of subaxial vertebral lamina and lateral mass for the orientation of pedicle screw insertion

    Institute of Scientific and Technical Information of China (English)

    朱裕成; 马军; 李涛; 王冰; 杨春

    2014-01-01

    Objectives: To explore reliability of subaxial vertebral lamina and lateral mass as anatomic land-mark for the orientation of pedicle screw insertion. Methods: Pedicle screws were inserted into C3-C7 pedi-cles on 10 adult cervical vertebral specimens(5 males and 5 females). Vertebral lamina and lateral mass was regarded as anatomic landmark defined as transverse and sagittal angle of pedicle screw insertion respectively. Pedicle-lamina angle (PL angle, the transverse angle) between the central axis of each pedicle and vertebral lamina, and pedicle-lateral mass angle (PLM angle, the sagittal angle) between the central axis and lateral mass were measured preoperatively on computed tomography(CT) images. On the postoperative CT, the grade of pedicle perforation was analyzed(Grade 0 was defined when the entire screw was placed within the cortical bone of the pedicle, grade 1 was defined as less than 25% of the screw diameter violation, grade 2 was de-fined as 25% to 50% of the screw diameter violation, and grade 3 was defined as more than 50% of the screw diameter violation). Grade 0 and 1 were considered to be the correct position, whereas grade 2 and 3 were considered to be wrong positions. Correlative analysis between the grade of each pedicle screw position and the pedicle width or height was performed. From October 2011 to December 2012, 6 patients underwent pedicle screw insertion on subaxial cervical vertebra. Complications and accuracy of pedicle screw placement were evaluated. Results: Among 10 cervical spine specimens, PL angles of C3-C7 pedicles on axial CT im-ages were C3, C4>C5, C6>C7. PLM angles of C3-C7 pedicles on sagittal CT images were C3, C450%穿破椎弓根;2级和3级螺钉为误置。对颈椎标本各节段椎弓根螺钉位置的分级与椎弓根的宽度与高度进行相关性分析。2011年10月~2012年12月,用同样方法对6例患者进行下颈椎椎弓根螺钉置钉手术,评估置钉准确率和并发症情况。结果:10

  14. Understanding the H -T phase diagram of the monoaxial helimagnet

    Science.gov (United States)

    Laliena, Victor; Campo, Javier; Kousaka, Yusuke

    2016-09-01

    Some unexpected features of the phase diagram of the monoaxial helimagnet in presence of an applied magnetic field perpendicular to the chiral axis are theoretically predicted. A rather general Hamiltonian with long-range Heisenberg exchange and Dzyaloshinskii-Moriya interactions is considered. The continuum limit simplifies the free energy, which contains only a few parameters which in principle are determined by the many parameters of the Hamiltonian, although in practice they may be tuned to fit the experiments. The phase diagram contains a chiral soliton lattice phase and a forced ferromagnetic phase separated by a line of phase transitions, which are of second order at low T and of first order in the vicinity of the zero-field ordering temperature, and are separated by a tricritical point. A highly nonlinear chiral soliton lattice, in which many harmonics contribute appreciably to the spatial modulation of the local magnetic moment, develops only below the tricritical temperature, and in this case, the scaling shows a logarithmic behavior similar to that at T =0 , which is a universal feature of the chiral soliton lattice. Below the tricritical temperature, the normalized soliton density curves are found to be independent of T , in agreement with the experimental results of magnetorresistance curves, while above the tricritical temperature they show a noticeable temperature dependence. The implications in the interpretation of experimental results of CrNb3S6 are discussed.

  15. Comparative study of different insertion techniques of pedicle screw in minimally invasive transforaminal lumbar interbody fusion (TLIF) procedure%微创TLIF术中不同椎弓根螺钉置入技术的对比研究

    Institute of Scientific and Technical Information of China (English)

    李振宙; 吴闻文; 宋科冉; 商卫林; 侯树勋

    2012-01-01

    [ Objective] To prospectively compare the outcomes of minimally invasive TLIF with different pedicle screw insertion techniques in the treatment of degenerative disc disease. [ Methods] From April 2008 to April 2010, 25 minimally invasive TLIF with conventional free hand pedicle screw insertion technique through expandable retractor (mini -TLIF) were match paired with 25 minimally invasive TLIF with percutaneous pedicle screw insertion technique under X - ray fluoroscopy guidance (p -TLIF) , with each group composed of 17 cases mono - segment lumbar disk herniation combined with segmental instability and 8 cases mono - segment discogenic low back pain. Patient demographics and operative data were collected. Clinical assessment in terms of Visual Analogue Scores of low back pain and sciatica were performed before surgery, 1 week, 6 months, 12 months and 24 months after surgery. Operation time, fluoroscopic time, blood loss, total morphine use, hospital stay and Mac-Nab scores of 24 postoperative months were compared between two groups. [ Results ] VAS scores of low back pain and sciatica of 1 week, 6 months, 12 months and 24 months postoperatively are decreased significantly compared to that of preoperative in both groups (P 0. 05) . Fluoroscopic time and operative time were longer in p - TLIF cases ( P 0. 05) . Two cases in p -TLIF group complicated with chronic low back pain underwent endoscopic exploration of medial branches of spinal nerves of fusion segment. Medial branches were compressed by pedicle screws and low back pain relieved after endoscopic dorsal rhizotomy. [Conclusion] Outcomes of 2 -year follow - up showed similar effect between two pedicle screw insertion techniques. Mini -TLIF keeps the advantages of p -TLIF (low tissue damage, low blood loss and low narcotics use) while avoid the disadvantage of p - TLIF ( high radiation exposure, long operation time) . Long - term outcomes still remain to be determined.%[目的]前瞻性对照研究不同椎

  16. C2 Pedicle Screw Combined with C3 Lateral Mass Screw Fixation for Treatment of Instable Hangman's Fracture%C2椎弓根螺钉联合C3侧块螺钉固定治疗不稳定性Hangman骨折

    Institute of Scientific and Technical Information of China (English)

    杨国进; 章筛林; 石志才

    2012-01-01

    Objective To evaluate the surgical management and result of C2 pedicle screw combined with C3 lateral mass screw fixation for treatment of instable Hangman's fracture. Methods From August 2005 to December 2010,16 patients with instable Hangman's fracture were all treated with C2 pedicle screw combined with C3 lateral mass screw fixation,which involved 11 males and 5 females with an average age of 35. 4 years old (range 19- 59). According to Levine-Edwards classification ,11 cases were type Ⅰ ,5 cases were type Ⅱ a,2 cases were type Ⅲ . All the patients complained neck pain and limitation of cervical movement. There were D spinal injury in 3 cases and E in 13 cases according to Frankel scale. Results All patients were followed up for a mean time of 13. 5 months (range 9~36 months). The operative time was 95~170 min (average 114 min) and the blood loss was 290~450 mL(average 353 mL). All fractures healed at 6 months postoperatively. There was no internal fixation fracture or loosing occurred. The cervical movement was excellent. Three cases of grade D spinal injury recovered to grade E. Conclusion C2 pedicle screw combined with C3 lateral mass screw fixation is an effective method for treatment of instable Hangman's fracture.%目的 探讨C2椎弓根螺钉联合C3侧块螺钉内固定治疗不稳定性Hangman骨折的临床效果及应用价值.方法 2005年8月至2010年12月采用后路C2椎弓根螺钉联合C3侧块螺钉内固定治疗16例不稳定性Hangman骨折患者,男11例,女5例;年龄19~59岁,平均35.4岁.骨折按Levine-Edwards分类,Ⅱ型9例,Ⅱa型5例,Ⅲ型2例.脊髓损伤按Frankel分级,D级3例,E级13例.结果 所有患者均获随访,随访时间9~36个月(平均18个月).手术时间95~170 min(平均114 min),术中出血290~450 mL(平均353mL),术后6个月复查时,骨折均愈合,无断钉、断棒及螺钉松动发生,颈部活动功能恢复良好.脊髓功能D级3例均恢复至E级.结论 经后路C2

  17. Simple Technique for Removing Broken Pedicular Screws

    Directory of Open Access Journals (Sweden)

    A Agrawal

    2014-03-01

    Full Text Available The procedure for removing a broken pedicle screw should ideally be technically easy and minimally invasive, as any damage to the pedicle, during removal of the broken screw, may weaken the pedicle, thus compromising on the success of re-instrumentation. We describe the case of a 32-year old man who had undergone surgery for traumatic third lumbar vertebral body fracture three years prior to current admission and had developed the complication of pedicle screw breakage within the vertebral body. The patient underwent re-exploration and removal of the distal screws. Through a paravertebral incision and muscle separation, the screws and rods were exposed and the implants were removed.

  18. 下颈椎前路椎弓根螺钉配套钢板系统的生物力学性能研究%Biomechanical characteristics of anterior pedicle screw-plate system in the lower cervical spine

    Institute of Scientific and Technical Information of China (English)

    赵刘军; 柴波; 蒋伟宇; 徐荣明; 祁峰

    2014-01-01

    目的 探讨下颈椎前路椎弓根螺钉配套钢板系统在颈椎病患者的生物力学性能.方法 采集新鲜颈椎标本16具,分解为C3/4、C4/5、C5/6、C6/7共32个运动节段(FSU),其中C3/4、C4/5、C5/6、C6/7各8个.将其按照不同节段随机分成A、B两组,将所获标本椎间盘切除后模拟植骨、分别植入我们自行设计生产的下颈椎前路椎弓根螺钉配套钢板系统和普通颈椎前路椎体螺钉钢板系统,比较两组固定系统的生物力学性能:(1)两组下颈椎三维生理运动范围(ROM);(2)两组稳定性指数;(3)两组螺钉的抗拔出力.结果 A、B两组各有16个FSU(其中C3/4、C4/5、C5/6、C6/7节段各4个),A组植入下颈椎前路椎弓根螺钉配套钢板系统16套,B组植入普通颈椎前路椎体螺钉钢板系统16套.经生物力学测试发现:(1)A组固定的颈椎节段前屈/后伸平均运动值为(12.78±1.32)°,左右侧弯(9.25±0.94)°,左右旋转(22.82 ±2.42)°;而B组分别为(16.24±1.64)、(12.08±1.32)、(28.44± 2.78)°.A组优于B组,差异有统计学意义(P<0.05).(2)A组稳定性指数(Sf)在屈伸、侧屈、旋转时分别为111%、110%、112%,而B组分别为87%、84%和88%,两者比较差异有统计学意义(P<0.05).(3)抗拔出力测试结果显示,A组最大抗拔出力为(604.68±48.76)N,而B组为(488.24±32.42)N,A组优于B组,两者比较差异有统计学意义(P<0.05).结论 下颈椎前路椎弓根螺钉配套钢板系统在生物力学性能方面优于普通颈椎前路椎体螺钉钢板系统,适用于需要颈椎前路坚强固定的患者.%Objective To explore the biomechanical characteristics of anterior pedicle screw-plate system in the lower cervical spine,and to provide basic data for clinical application.Methods Sixteen fresh cervical cadavers were collected and dissected into 32 different FSUs (8 separately in C3/4,C4/5,C5/6,and C6/7).After disectomy and intervertebral body bone graft,the subjects were randomly

  19. Cage Pedicle Screw Fixation for the Treatment of Lumbar Spondylolisthesis%Cage加椎弓根螺钉固定治疗腰椎滑脱症的临床疗效

    Institute of Scientific and Technical Information of China (English)

    桂曙光; 袁凌伟; 李得彬; 王建; 胡小东

    2015-01-01

    Objective:To research the clinical efficacy of posterior decompression and interbody cage fusion in the treatment of lumbar spondylolisthesis.Methods:From march 2009 to june 2013,I applied interbody fusion and pedicle screw in the treatment of 22 patients with lumbar spondylolisthesis, including 13 males and 9 females, aged 41-67 years, mean 48years old, type I spondylolisthesis 14cases t,ype II spondylolisthesis 7 cases, and III spondylolisthesis patients. All patients were followed up for 3 months to 32months , with an average of 28 months.Results:All the cases slippage were reseted. ,the fusion rate was 100%, the vertebral height and symptoms after operation improved significantly, the cage remain the normal position and the pedicle screw not be loosening and fracture. The excellent rate is 95.46%, ac-cording to the Zou Dewei rating criteria. Conclusion:The fixation with cage and pedicle screw in the treatment of lumbar spondylolisthesis is one of the good methods have the advantages of more safety , interbody fusion rate fixation , without fracture and loosening.%目的:评价后路减压固定加椎间cage融合术治疗腰椎滑脱症的临床疗效。方法:自2009年3月~2013年6月应用椎间cage加椎弓根螺钉固定技术治疗腰椎滑脱症患者22例,其中男13例,女9例,年龄41~67岁,平均48岁。其中Ⅰ度滑脱14例,Ⅱ度滑脱7例,Ⅲ度滑脱1例。对所有患者术后随访3个月~32个月,平均28个月。结果:所有滑脱基本复位,融合率100%,椎体间高度恢复,症状明显改善, cage位置正常,椎弓根螺钉无松动及断裂。根据邹德威等评分标准,优良率达95.46%。结论:采用cage加椎弓根螺钉固定治疗腰椎滑脱症临床效果好、安全,椎间融合率高,内固定物无断裂、松动,是较为理想的手术方法之一。

  20. C2~3椎弓根-侧块螺钉系统治疗不稳定型Hangman骨折%Transpedicular with Pedicle Screw Fixation for the Treatment of Hangman's Fractures

    Institute of Scientific and Technical Information of China (English)

    王磊; 刘海龙; 徐卫松; 仇志学; 韩国栋

    2011-01-01

    目的 探讨C2~3椎弓根-侧块螺钉系统治疗Hangman骨折的疗效及临床效果.方法 我院2007年4月至2010年10月收治的11例Hangman骨折患者进行回顾性研究,男4例,女7例;年龄22~61岁,平均42.5岁.患者均表现为颈痛、颈部活动受限,2例单侧上肢,1例双侧上肢麻木无力.所有患者入院后均行X线、三维CT及MRI检查,并测量Cz~3椎体移位和成角,其中Levine- Edwards分型,Ⅰ型3例,Ⅰ型4例,Ⅰa型2倒,Ⅲ型2例.人院后常规行颅骨牵引,Ⅰ型患者予以halo-vest架外固定治疗,Ⅱ型、Ⅱa型、Ⅲ型患者行后路C2~3椎弓根侧块螺钉内固定术,术后用费城颈托保护6周.结果 随访2~44个月,平均20.6个月.平均6个月时骨折端愈合,颈痛、肢体麻木等症状消失,但颈部活动度较正常略有下降,无内固定失败及感染等并发症发生.结论 经后路C2~3椎弓根侧块螺钉系统是治疗Hangman骨折的良好手术方式.%Objective To determine the treatment efficacy of transpedicular with pedicle screw fixation for the treatment of Hangman's fracture. Methods A retrospective review of 11 cases,including 4 males and 7 females,with Hangman's fractures was performed. The age of the patients were 22~61 years, average 42. 5 years. All the patients complained neck pain and limitation of movement of the neck. Numbness and weakness appeard in unilateral upper limb in 2 cases, biliater upper limbs in 1 case. All patients received anterior-posterior and lateral X-rays,MRI andthree dimensional CT scans. Initial and final radiographs were measured for translation and angilation of C2~J. According to the Levine-Edwards classification,there were 3 cases for type I ,4 for type H ,2 for type JI a and 2 for type I . Skull tractions under extension position were used in all patients after admission. Halo-vest treatment option for type Ⅰ ,Then type Ⅱ ,Ⅱla, Ⅲ transpedicular with pedicle screw fixation were performed. Philadelphia collars

  1. Minimally invasive percutaneous pedicle screws osteosynthesis for treatment of thoraco-lumbar vertebra fracture%经皮微创椎根弓螺钉内固定治疗胸腰椎压缩性骨折

    Institute of Scientific and Technical Information of China (English)

    林建新; 林建民; 徐志伟

    2014-01-01

    Objective To investigate the efficacy of minimally invasive percutaneous pedicle screw fixation on thoracic vertebral compression fractures. Methods Thirty patients with thoracic vertebral compression fractures from January 2012 to November 2014 were included in the study , the data were analyzed retrospectively. Of these 30 cases, 15 underwent surgical procedure of minimally invasive percutaneous pedicle screw fixation (observation group) and 15 were treated with open surgery of traditional posterior midline longitudinal incision approach. The operation time , blood loss, hospital stay, postoperative visual analogue scale (VAS), postoperative Cobb angle correction rate, postoperative failed back surgery syndrome (FBSS) were compared between two groups. Results In observation group, the mean operation time, blood loss, hospital stay were significantly reduced when compared with control (P<0.05). VAS at 48 h was significantly lower in observation group than in control group(P<0.05). The postoperative Cobb angle correction rate in observation group was similar to that in control. FBSS patients in control group was higher than in the observation group , but the difference was not statistically significant. Conclusion Minimally invasive percutaneous pedicle screws osteosynthesis has better surgical results than the traditional posterior midline longitudinal incision approach in treatment of thoraco-lumbar vertebra fracture.%目的:探讨经皮微创行椎弓根螺钉内固定治疗单纯胸腰椎压缩性骨折的临床疗效。方法选择2012年1月至2014年11月间我院收治的30例单纯胸腰椎压缩性骨折患者,分为对照组(n=15)和观察组(n=15)。对照组患者采用传统的以伤椎为中心的后正中纵行切口开放手术,观察组患者采用经皮微创椎弓根螺钉内固定手术。比较两组患者手术相关指标、术后48 h疼痛视觉模拟评分(VAS)、手术即期效果和远期效果、术后腰椎手术

  2. 单侧椎弓根螺钉置入并椎间融合对邻近椎间盘节段退变的影响%Unilateral pedicle screw fixation with lumbar interbody infusion for adjacent segment degeneration

    Institute of Scientific and Technical Information of China (English)

    邵高海; 焦春燕; 余雨; 钟斌; 李波

    2011-01-01

    背景:坚强内固定和良好融合存在严重缺陷和不足.目前还未见临床应用单侧椎弓根螺钉固定结合椎间cage植骨融合治疗腰椎退变性疾病对邻近节段退变影响的相关报道.目的:回顾分析单侧椎弓根螺钉固定结合椎间cage植骨融合治疗部分腰椎退变性疾病后对固定融合邻近上下节段退变的影响.方法:2006-03/2009-12对收治的部分腰椎管狭窄症、腰椎失稳及腰椎间盘脱出症患者22例,进行了单侧椎弓根螺钉固定加椎间cage植骨融合,术中不显露对侧.在固定融合后3,6,12,20个月及取出内固定钉棒后3,6个月,随访X射线片及MRI.针对X射线片运用角平分线法测量固定融合邻近上位椎间隙高度变化,MRI测量椎间盘髓核退变情况.结果与结论:所有病例获得随访,患者椎管狭窄症状及神经根性症状消失,并且在随访期间内没有新的临床症状出现.固定融合前、固定融合后3,6,12,20个月邻近节段上位椎间隙高度分别为(7.420±0.035 4),(7.426 6±0.036 9),(7.453 3±0.036 9),(7.516 6±0.036 9),(7.430 8±0.036 9) mm,结果表明,腰椎单侧固定融合后邻近节段椎间隙高度无明显变化(P > 0.05).MRI测量结果显示,固定融合邻近上位椎间盘髓核信号在T2加权像无明显退变.提示单侧椎弓根螺钉固定结合椎间融合治疗部分腰椎退变性疾病能有效预防固定融合邻近上下节段退变.%BACKGROUND: There are no reports add ressing effects of unilateral pedicle screw plus cage internal fixation on adjacent segment degeneration in the treatment of lumbar degenerative disease.OBJECTIVE: To review the effects of unilateral pedicle screw plus cage internal fixation on adjacent segment degeneration in the treatment of lumbar degenerative disease.METHODS: From 2006 to 2009, 22 patients with partial lumbar spinal stenosis, lumbar instability, and lumbar intervertebral disc herniation received unilateral pedicle screw plus cage

  3. Experimental study on accurate placement of the lumbar pedicle screws assisted by 3D printing navigation module%3D打印导航模块辅助腰椎椎弓根螺钉精确植入的实验研究

    Institute of Scientific and Technical Information of China (English)

    严斌; 张国栋; 吴章林; 许靖; 杨洋; 黄文华

    2014-01-01

    目的:利用数字化设计和3D打印技术研制个体化导航模块,实现个体化的微创下腰椎椎弓根螺钉精确植入。方法建立37例正常人体腰椎(L1~5)三维模型,设计导航杆使其恰好穿过椎弓根中心。基于导航杆,通过布尔运算获得导航模块。3D打印出导航模块和腰椎标本实体,在导航模块的辅助下植入椎弓根螺钉,观察螺钉的进钉点、进钉方向和螺钉在椎弓根内的位置。结果总共应用导航模块辅助植入椎弓根螺钉228枚,全部螺钉的进钉点,进钉方向都与虚拟方案相一致,螺钉在椎弓根内位置良好,无一例螺钉穿破椎弓根皮质。结论基于数字化设计的3D打印导航模块,可以实现个体化的微创下腰椎椎弓根螺钉精确植入。%Objective To study individualized navigation module that can realize the accurate placement of the minimally invasive lumbar pedicle screws based on digital design and 3D printing technology. Methods 37 cases of the normal human lumbar (L1~L5) 3D model were reconstructed in our study. Navigation bars were designed through the pedicle center. Based on the navigation bars, navigation modules were produced by Boolean Operation. The entities of navigation modules and lumbar spine specimens were built by using 3D printing technology. Then, pedicle screws assisted by navigation modules were implanted. Finally, the anchor point,orientation and position of the screws were observed. Results Navigation modules were used in 228 cases of pedicle screws implantation. The anchor point and orientation of the screws were all consistent with virtual schemes. The position of pedicle screws were good and none of the screws worn out the pedicle cortex. Conclusion By means of digital design and 3D printing navigation module, accurate placement of individualized minimally invasive lumbar pedicle screws can be realized.

  4. Effect of expandable pedicle screw fixation on the fixation strength of osteoporotic thoracic and lumbar vertebrae%可膨胀椎弓根钉骨水泥强化与骨质疏松性胸腰椎固定强度的关系

    Institute of Scientific and Technical Information of China (English)

    周庆忠; 冯晓兰; 张戈; 贾叙锋; 雷飞; 叶飞; 冯大雄

    2017-01-01

    背景:研究表明,骨质疏松常导致椎弓根螺钉内固定失败.采用普通椎弓根螺钉固定骨质疏松椎体达不到坚强的稳定性,需要采取特殊强化措施.目的:评价骨水泥强化联合可膨胀椎弓根螺钉对骨质疏松性胸腰椎稳定性的影响.方法:将20个骨质疏松性人胸腰椎椎体标本随机分为4组,普通椎弓根钉组置入普通椎弓根螺钉,其余3组均置入可膨胀椎弓根螺钉;可膨胀椎弓根钉组不进行骨水泥强化,聚甲基丙烯酸甲酯骨水泥强化组及硫酸钙骨水泥强化组于钉道内分别注入聚甲基丙烯酸甲酯骨水泥及硫酸钙骨水泥之后再置入可膨胀椎弓根钉.选择一侧椎弓根,测试椎弓根螺钉的最大轴向拔出力及屈服能量吸收值(对螺钉的握力);选择另一侧椎弓根,测试最大旋出力矩;并观察骨水泥强化后的骨水泥渗漏情况.结果与结论:①与普通椎弓根钉组相比,其余3组的最大轴向拔出力、最大旋出力矩及屈服能量吸收值均显著增加(P0.05);②骨水泥强化后未发生骨水泥渗漏现象;③结果表明,骨水泥强化联合可膨胀椎弓根螺钉可显著增强骨质疏松胸腰椎椎体的稳定性,聚甲基丙烯酸甲酯骨水泥与硫酸钙骨水泥效果相似.%BACKGROUND: Studies have shown that osteoporosis often leads to a failure in pedicle screw fixation. Considering that the use of ordinary pedicle screw fixation cannot achieve a strong and stable fixation of the osteoporotic vertebra,special measures to strengthen the internal fixation is indispensable.OBJECTIVE: To evaluate the effect of bone cement augmentation combined with expandable pedicle screw fixation on the fixation strength of osteoporotic thoracolumbar vertebrae.METHODS: Twenty osteoporotic thoracolumbar vertebral specimens were randomly divided into four groups: conventional pedicle screw group implanted with normal pedicle screw, and the other three groups implanted with expandable

  5. Treatment of scoliosis associated with untreated syringomyelia using segmental pedicle screw system%节段性椎弓根钉系统治疗伴发脊髓空洞的脊柱侧凸

    Institute of Scientific and Technical Information of China (English)

    刘一; 张绍昆; 闫明; 付长峰; 赵松; 牛丰; 张琪

    2009-01-01

    Objective To evaluate the surgical results of scoliosis associated with untreated syringomyelia with segmental pedicle screw system. Methods Thirty-five patients of scoliosis associated with untreated syringomyelia were treated with segmental pedicle screw system. Twelve cases were associated with type I Chiari malformation. The curve patterns covered atypical curve in 18 cases and atypical curve in 17 cases. There were two groups of operations: 1) Thirty cases, older than 10 years, underwent single-stage posterior correction, pedicle screw system internal fixation and bone-graft fusion; 2) Five cases, younger than 10 year, firstly underwent posterior correction and internal fixation with growth rod, and then posterior correction, internal fixation and bone-graft fusion 4-6 years later. Results The average coronal Cobb angle measured 66.5° (range, 32°-121°) preoperatively and 22.6° (range, 0°-78°) postoperatively. The average correction rate was 69.4% (range, 31%-100%). All the 35 cases were followed up 58.4 months in average (range, 13-113 months). The average coronal Cobb angle measured 25.9° (range, 3°-78°) at the latest follow-up. Six cases experienced deformity progressive after surgery. The caudal fusion vertebra was not fixed down to the stable vertebra in five of the six cases. It was shown absence of superficial abdominal reflex in one case, and expansion of sensory deficit in another one cases. Neither of two cases needed further management. Conclusion Segmental pedicle screw instrumentation is a safe procedure in treatment of scoliosis associated with untreated syringomyelia except Chiari malformation with distended type syringomyelia. Arthrodesis should be ended at the stable vertebra in the treatment of scoliosis associated with syringomyelia.%目的 评价节段性椎弓根钉系统治疗伴发脊髓空洞的脊柱侧凸的手术疗效.方法 应用节段性椎弓根钉系统治疗伴发脊髓空洞的脊柱侧凸35例.合并Chiari

  6. Anatomic and radiographic measurement for related parameters in term of lower cervical pedicle screw fixation%下颈椎椎弓根螺钉内固定相关参数的解剖学和影像学测量

    Institute of Scientific and Technical Information of China (English)

    刘景堂; 刘兴炎; 唐天驷; 葛宝丰

    2009-01-01

    目的:测量成人下颈椎椎弓根相关径线,为临床应用下颈椎椎弓根螺钉内固定提供相关解剖参数.方法:成人干燥尸体颈椎C3~C7标本20具,分别用手工和CT测量椎弓根宽度、高度,从横断面CT图像上测量椎弓根的内部宽度、内部高度,从纵断面CT图像上测量椎弓根矢状角.随机在CT窒保存的100例成人患者的颈椎CT图像上测量椎弓根的宽度、自身长度和椎弓根通道全长、椎弓根内倾角.结果:下颈椎标本各节段椎弓根宽度、高度的手工测量值与CT测量值比较无统计学差异(P>0.05),椎弓根宽度小于高度;C3~C6节段CT测量椎弓根内部宽度平均为2.5~2.8mm,椎弓根内部高度平均为2.9~3.0mm,C7椎弓根的内部宽度和高度接近,约4.0mm;下颈椎标本CT测量椎弓根矢状角分别为C3 8.6°,C4 4.6°,C5-1.3.,C6-4.0°,C7-8.2°.100例成人下颈椎CT图像测量椎弓根宽度最小值为3.1mm(C3),最大值为9.3mm(C7),其中>3.5mm者为92.8%;椎弓根自身长度平均为19.1~20.5mm,椎弓根通道全长平均为33.2~35.0mm,椎弓根内倾角平均值C3~C5为43.2°~45.1°,C6为40.8°,C7为37.5°.结论:术前CT测量可为椎弓根准确置钉提供可靠的解剖参数,下颈椎椎弓根一般可接受直径3.5mm的螺钉同定.%Objective:To measure the dimensions of the lower cervical pedicle so as to provide anatomic da-ta for clinical application of cervical pedicle screw fixation.Method:20 human adult cadaver cervical speci-mens containing C3 to C7 vertebrae were measured by two methods,one was manual measuring using digital caliper and the other was computed tomagraphy scaning.Parameters measured manually included pedicle width (PW),pedicle height (PH).These specimens were scanned by CT scanner both perpendicular and parallel to the pedicle axis.The outer and inner pedicle width and height,cephalocaudad angulation of the pedicles in the sagittal plane were measured using automatic digital CT measurements

  7. Biomechanical evaluation on the stability of anterior cervical pedicle screw fixation for osteoporosis%生物力学评价颈椎前路椎弓根螺钉植入骨质疏松椎骨内的稳定性

    Institute of Scientific and Technical Information of China (English)

    李振伟; 向阳明

    2015-01-01

    segments, the stability of fixator and bone graft is poor due to big bone graft span, which may easily cause fusion failure and pseudarthrosis, and impact curative effects. OBJECTIVE:To investigate biomechanical stability of anterior cervical pedicle screw implantation for osteoporosis in the vertebra. METHODS:A total of 12 human cervical vertebrae were col ected, including 6 vertebrae with normal bone density and 6 vertebrae with osteoporosis. Data of 60 vertebra specimens were analyzed. 30 osteoporotic specimens implanted in anterior cervical pedicle screw were set as anterior cervical pedicle screw group. 30 normal specimens implanted in anterior cervical pedicle screw were set as anterior vertebral screw group. According to bone density, 40 vertebrae were col ected in above two groups, and were considered as normal bone mineral density group, instant osteoporosis group, fatigue normal bone mineral density group, and fatigue osteoporosis group (n=10). Bone mineral density of each vertebra was detected using dual-energy X-ray absorptiometry. Biomechanical index of two kinds of screws was detected using ElectroForce 3510 material testing machine. RESULTS AND CONCLUSION:Bone mineral content, vertebral screw pul-out strength, vertebral screw pul-out stiffness, pedicle screw pul-out strength, and pedicle screw pul-out stiffness were significantly higher in the anterior cervical pedicle screw group than in the anterior vertebral screw group (P<0.05). The maximum axial pul-out strength of normal bone mineral density group, instant osteoporosis group, fatigue normal bone mineral density group, and fatigue osteoporosis group was significantly higher than in the anterior vertebral screw group (P<0.05). The results confirmed that osteoporotic vertebral biomechanical performance is more stable in anterior pedicle screws compared with the anterior vertebral screw.

  8. Congenital hypoplasia of the lumbar pedicle with spondylolisthesis: report of 2 cases.

    Science.gov (United States)

    Hsieh, Chang-Sheng; Lee, Sang-Ho; Lee, Hyung Chang; Oh, Hyeong-Seok; Hwang, Byeong-Wook; Park, Sang-Joon; Chen, Jian-Han

    2017-04-01

    Congenital hypoplasia of the spinal pedicle is a rare condition. Previously reported cases were treated conservatively or with posterior instrumented fusion. However, the absence or hypoplasia of the lumbar pedicle may increase the difficulty of pedicle screw fixation and fusion. Herein, the authors describe 2 cases of rare adult congenital hypoplasia of the right lumbar pedicles associated with spondylolisthesis. The patients underwent anterior lumbar interbody fusion with a stand-alone cage as well as percutaneous pedicle screw fixation. This method was used to avoid the difficulties associated with pedicle screw fixation and to attain solid fusion. Both patients achieved satisfactory outcomes after a minimum of 2 years of follow-up. This method may be an alternative for patients with congenital hypoplasia of the lumbar spinal pedicle.

  9. Application of percutaneous pedicle screw fixation for lumbar degenerative disease%应用经皮椎弓根螺钉技术治疗腰椎退行性疾病

    Institute of Scientific and Technical Information of China (English)

    吴浩; 陈永杰; 张璨; 陈赞; 菅凤增

    2014-01-01

    目的:评估在X线透视下经皮椎弓根螺钉微创内固定技术治疗腰椎退行性病变的安全性和准确性。方法回顾性分析首都医科大学宣武医院2012年3月至2013年10月采用X线透视下经皮椎弓根螺钉微创内固定技术,结合显微镜下微创经椎间孔入路椎间盘摘除、椎体间融合术(TLIF)治疗64例腰椎退行性疾病患者的临床资料,随访3个月或以上,统计术中出血量、住院时间、并发症、术前与术后采用视觉模拟量表(VAS)和Oswestry功能障碍指数(ODI)进行疗效评估,计算患者症状改善率;术后生活质量调查(SF-36);术后复查X线及腰椎CT平扫及腰椎核磁,评估螺钉位置及融合率。结果手术平均时间(3.4±0.9)h,术中出血平均(193±100)ml,住院平均时间(7±2)d,并发症发生率7.8%(5/64)。随访3个月显示,VAS和ODI改变差异有统计学意义(P<0.01)。临床症状改善显著,ODI改善率为50.8%,SF-36平均86.2%;64例患者共植入316颗螺钉,术后X线显示306颗螺钉位置良好,10颗螺钉位置可接受,无螺钉松动;螺钉植入成功率达100%,融合率达96%。结论X线透视下微创内固定技术完全可以获得准确、理想的螺钉植入位置,结合显微镜下微创TLIF治疗腰椎退行性疾病是安全、有效的方法。%Objective To evaluate the accuracy and safety of mini-invasive and percutaneous pedicle screw fixation with fluoroscopy for lumbar degenerative disease.Methods For this retrospective study, 64 cases of lumbar degenerative disease underwent mini-invasive transforaminal lumbar interbody fusion ( TLIF) under microscope plus percutaneous pedicle screw fixation with fluoroscopy of lumbar spine from March 2012 to October 2013.The parameters of operative duration , intraoperative blood loss volume , hospital stay and complications were recorded and analyzed.The clinical outcomes were assessed

  10. Pedicle screw system through paraspinal approach combined preoperative manual and postural reduction for thoracolumbar fractures%椎旁肌间隙入路结合术前手法复位治疗胸腰椎骨折

    Institute of Scientific and Technical Information of China (English)

    王延国; 鲁秀国; 周忠水; 翟贵亮; 郑燕平

    2013-01-01

    Objective To compare the clinical results between paraspinal approach combined preoperative manual and postural reduction and conventional posterior midline approach for thoracolumbar fracture.Methods From June 2005 to December 2011,70 patients with thoracolumbar vertebral compression or burst fractures without neural syndromes underwent reposition and internal fixation by the screw-rod system.The patients were divided into 2 groups randomly:Group A through paraspinal approach,and Group B conventional posterior midline approach.The data between 2 groups were compared,such as operation time,blood loss and visual analog scale (VAS) scores.Results Allpatients were followed up for 18 months.The differences of postoperative correction rate of Cobb' s angle and accuracy of pedicle screw placement between 2 groups were not statistically significant (P > 0.05).The operation time,blood loss and postoperative volume of drainage of Group A were less than those of the Group B(P <0.05).The postoperative VAS score of Group A were lower than those of the Group B(P <0.05).Conclusion Pedicle screw system through paraspinal approach combined preoperative manual and postural reduction is a better way than the posterior midiine approach for thoracolumbar fractures that has no need of decompression,less trauma,less injury of paraspinal muscle and more relief of postoperative low back pain.%目的 对比观察应用后路经椎旁肌间隙入路椎弓根螺钉内固定结合手法复位治疗胸腰椎骨折的疗效.方法 2005年6月~2011年12月共收治单纯性压缩性胸腰椎骨折患者70例.随机采用椎旁肌间隙入路手术36例,传统骶棘肌剥离入路手术34例.比较2种术式的手术时间、术中出血量、术后引流量、后凸Cobb角矫正率、椎体塌陷矫正率、疼痛视觉模拟量表(visual analogue scale,VAS)评分等.结果 2组手术在手术时间、术中出血量、术后引流量方面差异有统计学意义(P<0.05),拆除内固

  11. Subaxial cervical pedicle screw placement using limited opening technique: experimental study and preliminary clinical report%下颈椎椎弓根螺钉置入有限开放技术的实验研究与初步临床应用

    Institute of Scientific and Technical Information of China (English)

    方弘伟; 王向阳; 施达; 吴增晖; 欧阳钧; 赵云珍; 王晓成; 黄晓东; 陈卓

    2009-01-01

    Objectives To evaluate the safety and accuracy of limited opening technique for traspedicular screw placement in subaxial cervical spine. Methods Twenty fresh cervical specimens (C_3-C_7) were included in this study and placed with 199 pedicle screws using limited open technique for evaluation of the location of the screws. Forty C_3-C_4 specimens (80 sides) were used to observe architec-ture of the cervical pedicle and measure parameters related with screw placement. Seven patients with cer-vical instability were treated with pedicle screw fixation (29 screws) using this limited open technique.The cancellous bone in the junction of lateral mass and medical wall of pedicle was removed to find the in-let of the pedicle. The pedicle screws were inserted according to the measurement results of CT and X-ray. The patients were then evaluated radiographically for the location of the pedicle screw. Results The key structure safely leading into the pedicle was the junction between deep cortex of C_3、C_4 lateral mass and medial wall of the pedicle, which was located at the lateral upper quadrant of the lateral mass,with hard contour surface but without nutrient foramens. The screw insertion points were distributed at lat-eral upper quadrant of the lateral mass, with mean debouchement diameter of 5.2 mm, mean inlet width of 7.5 mm, medial angle of 42°and upward angle of 10°. The accuracy rate of screw placement was 94.5% in specimens and 100% in patients. Conclusion Limited opening at lateral mass surface combined with single-blade blunt end probe is proved to be a safe and accurate technique for subaxial cer-vical pedicle screw placement.%目的 评价有限开放技术在置入下颈椎椎弓根螺钉中的安全性和准确性.方法 新鲜尸体20具,利用有限开放技术对C_3~C_7椎弓根置入199枚螺钉,评价螺钉的位置;解剖观察C_3、C_4共40椎、80侧椎弓根管入口形状结构,并测量与钉道位置相关的参数.临床应用7

  12. Calcium sulfate cement augments transient stability of pedicle screw in osteoporotic vertebral body%硫酸钙骨水泥增强椎弓根螺钉置入骨质疏松椎体的瞬时稳定性

    Institute of Scientific and Technical Information of China (English)

    朱爱国; 张烽; 葛勇; 曹涌; 张弛; 陈云

    2014-01-01

    BACKGROUND:Poor implant anchorage in osteoporotic bone impacts its stability and requires the new solutions for the treatment. The augmentation technique with bone cements or bone substitutes is one strategy for the solutions. OBJECTIVE:To evaluate the transient stability of pedicle screw augmented using calcium sulfate cement in osteoporotic vertebral body. METHODS:Fresh calf lumbar vertebrae were selected to measure bone density, and then classified into four groups:the group by pedicle screw in normal vertebral body;the group by pedicle screw augmented using calcium sulfate cement in normal vertebral body;the group by pedicle screw in osteoporotic vertebral body;the group by pedicle screw augmented using calcium sulfate cement in osteoporotic vertebral body. Pedicle screw of equal specification was twisted into the tested pedicle of vertebral arch. The maximum axial screw pul-out strength and the maximum energy required to failure were recorded so as to assess the transient stability of pedicle screw augmented using calcium sulfate cement. RESULTS AND CONCLUSION:The maximum screw pul-out strength and the maximum energy required to failure were significantly less in osteoporotic vertebral body compared with normal vertebral body (P<0.05). The maximum screw pul-out strength and the maximum energy required to failure after augmentation using calcium sulfate cement were significantly increased (P<0.05). The maximum screw pul-out strength and the maximum energy required to failure after augmentation using calcium sulfate cement were identical between normal group and osteoporosis group. These results suggested that calcium sulfate cement could effectively increase the transient stability of pedicle screw. Calcium sulfate cement is effective in augmenting fixation in osteoporotic bone, and has potential in clinical application.%背景:由于内固定在骨质疏松骨上锚着力较差影响了其稳定性,因此需要新的固定方法,使用骨水泥或骨

  13. Posterior osteosynthesis of a spontaneous bilateral pedicle fracture of the lumbar spine.

    Science.gov (United States)

    Han, Sang-Hyun; Hyun, Seung-Jae; Jahng, Tae-Ahn; Kim, Ki-Jeong

    2016-03-01

    Spontaneous bilateral pedicle fractures of the lumbar spine are rare, and an optimal surgical treatment has not been suggested. The authors report the case of a 50-year-old woman who presented with low-back pain and right leg radiating pain of 1 year's duration. Radiological studies revealed a spontaneous bilateral pedicle fracture of L-5. All efforts at conservative treatment failed, and the patient underwent surgery for osteosynthesis of the fractured pedicle using bilateral pedicle screws connected with a bent rod. Her low-back and right leg pain were relieved postoperatively. A CT scan performed 3 months postoperatively revealed the disappearance of the pedicle fracture gap and presence of newly formed bony trabeculation. In rare cases of spontaneous bilateral pedicle fracture of the lumbar spine, osteosynthesis of the fractured pedicle using bilateral pedicle screws and a bent rod is a motion-preserving technique that may be an effective option when conservative management has failed.

  14. Computed tomographic morphometry of thoracic pedicles: safety pedicle parameter measurement of the Chinese immature thoracic spine.

    Science.gov (United States)

    Zheng, Changkun; Huang, Qishan; Hu, Yuezheng; Wang, Xiangyang; Chen, Wei

    2009-12-01

    Our objective was to quantify the morphometric characteristics of the pedicles of the Chinese immature thoracic spine. A total of 120 patients aged 5-14 years underwent standard thoracic computed tomography (CT). The patients were grouped according to age: group 1 (5-8 years of age), group 2 (9-11 years of age) and group 3 (12-14 years of age). Images were reformatted, and multiplanar reconstructions were used to attain images of thoracic pedicles on sagittal, coronal and transverse planes. The measurements included the inner and outer pedicle diameters on the transverse plane, pedicle sagittal diameter, pedicle length and the pedicle angle on the transverse. (1) Pedicle diameters on the transverse plane decreased gradually from T1 to T4 and increased gradually from T5 to T12. The shortest transverse diameter of the thoracic pedicle was T4 or T5. (2) The sagittal diameter was significantly larger than the transverse diameter except at T1. (3) The length of the pedicle from the posterior cortex to the anterior cortex of the vertebra increased from T1 to T12. (4) The pedicle angle decreased gradually from T1 to T8 and became negative below the level of T10. The length of the pedicle changed with age significantly, but the pedicle angle changed with age insignificantly. The success of transpedicular fixation requires a better understanding of morphological features at different ages and reasonable selection of the diameter, length and direction of the pedicle screws based on X-ray and CT films.

  15. 后路寰椎钉板系统内固定治疗不稳定型Jefferson骨折%Posterior pedicle screw-plate system for unstable Jefferson fracture

    Institute of Scientific and Technical Information of China (English)

    覃海飚; 韦蒙; 刘义斌; 刘智; 曾明义; 朱耿贇; 肖增明

    2012-01-01

    目的:探讨后路钉板系统单纯寰椎内固定治疗不稳定型Jefferson骨折的可行性及临床疗效.方法:2005年2月~2009年10月共收治外伤后不稳定型Jefferson骨折患者10例,男7例,女3例,均有枕颈部疼痛及活动受限,术前VAS评分平均7.5分,4例伴随脊髓功能损伤表现,Frankel分级C级1例,D级3例.均采用后路钉板系统单纯经寰椎椎弓根固定治疗,随访观察临床疗效、骨折复位及稳定性、手术并发症等情况.结果:手术时间70~120min,平均90min;术中出血110~300ml,平均200ml,无脊髓损伤、硬膜破裂及椎动脉损伤等并发症.患者枕颈部疼痛均明显减轻,术后VAS评分平均2.1分;伴脊髓损伤患者神经功能均恢复正常;影像学复查示所有患者达解剖复位,螺钉位置良好.随访8 ~48个月,平均25个月,患者寰椎骨折均骨性愈合,平均愈合时间为6个月.患者颈部的前屈与后伸35°~42°,平均38°;左右旋转60°~73°,平均66°;左右侧屈40°~45°,平均42°,颈椎活动度接近正常.结论:后路钉板系统单纯寰椎椎弓根内固定治疗不稳定型Jefferson骨折具有复位效果好、融合率高、寰枢椎活动度保留完整、手术并发症少等特点,为Jefferson骨折的治疗提供了一种新的术式.%Objectives: To investigate the feasibility and the clinical outcome of posterior pedicle screw-plate system for unstable Jefferson fracture. Methods: From February 2005 to October 2009, 10 patients suffering from traumatic unstable Jefferson fracture underwent posterior instrumentation by pedicle screw-plate system. Among them there were 7 males and 3 females, all cases presented with neck pain and limit of cervical range of motion(ROM), the preoperative average visual analogue score(VAS) was 7.5. 4 cases suffered from neurological deficit, including 1 Frankel C and 3 Frankel D. After surgery, the clinical efficacy, reduction and stability, surgical complications were reviewed

  16. 后路椎弓根螺钉内固定融合术治疗创伤性寰枢椎不稳%Treatment of traumatic atlantoaxial instability via posterior internal fixation and fusion plus atlantoaxial pedicle screw

    Institute of Scientific and Technical Information of China (English)

    王守国; 徐用亿; 谢跃; 费昊东; 季峰; 赵庆华; 田纪伟

    2011-01-01

    [ Objective ] To study the therapeutic effect of posterior fixation and fusion plus pedicle screw in treatment of traumatic atlantoaxial instability. [ Method] A retrospective analysis was done on twenty patients (14 male and 6 female,mean age of 39.6 years old) with traumatic atlantoaxial instability treated via atlantoaxial pedicle screw system from March 2008 to October 2010,included 4 cases with Jefferson fracture,5 cases with type- II Dens fracture,3 cases with Dens fracture combined with atlantoaxial dislocation, 1 case with Jefferson fracture combined with Dens fracture,7 cases with atlantoaxial dislocation. The post-operative effect was evaluated with JOA (Japanese Orthopaedic Association)scores and VAS( visual analogue scale). [ Result]Operative time were 138.75 ±20.06 min,and blood loss were 338. 80 ± 100. 10 ml. All patients received the follow-up( range from 12 to 25 months,mean 15.6 months). All atlantoaxial joint came to bony fusion by the last follow-up without complication due to instrumentation. There was significant difference on VAS scores between pre-operation(7. 25 ± 1. 52) and post-operation (2. 13 ± 1.75) (P<0.01). There was significant difference on JOA scores between pre-operation( 8.65 ±3.49) and post-operation (13. 05 ±4. 88) (P <0. 01), and improvement rate was 58. 01 ± 20. 15%. [ Conclusion] Posterior fixation and fusion plus pedicle screw has the advantages of strong fixation,direct screw placement,and high fusion rate in traumatic atlantoaxial instability. So it is a better alternative for traumatic atlantoaxial instability.%[目的]探讨经后路椎弓根螺钉系统内固定融合术治疗创伤性寰枢椎不稳的临床疗效.[方法]回顾2008年3月~2010年10月,采用后路椎弓根钉系统固定融合治疗创伤性寰枢椎不稳20例,男14例,女6例;平均年龄39.6岁;Jefferson骨折4例,Ⅱ型齿状突骨折5例,齿状突骨折合并寰枢椎脱位3例,Jefferson骨折合并齿状突骨折1例,寰枢椎脱位7

  17. Clinical application of C1C2 pedicle screw in atlantoaxial dislocation%椎弓根钉棒系统治疗寰枢椎脱位的临床应用

    Institute of Scientific and Technical Information of China (English)

    孟志斌; 黄涛; 李洪潮; 谭海涛; 王挺锐; 贾丙申

    2012-01-01

    Objective To explore the clinic accuracy and mechanism of C1C2 pedicle screw reduction, fixation and fusion technique in atlantoaxial dislocation. Methods A total of 16 patients with atlantoaxial dislocation were enrolled, male 10, female 6, aged 26 - 55 years old, mean age 31.4 years old. All of them were treated with C,C2 pedicle screw reduction, fixation and bone graft fusion. The pre-operation and post-operation visual analogue scale (V AS) were evaluated, the axial neck pain and neural function improvement were evaluated by using Frankel classification. Results All of 16 cases were followed up 6 - 36 months, mean 23-month. The clinic symptoms improved in different level, the cervical pain disappeared, somatic and limbs sensory recovered, strength and tension of the muscle improved, and without vascular or neural injury. The pre-operation axial neck pain VAS score was 6.14 ± 1.76, post-operation improved to 4.82 ± 1.45 (I = 2.315, P < 0.05), preoperative Frankel classification was E 9, D 2, C 4, B 1, postoperative improved to E 9, D 5, C 2. The postoperative X-ray and three-dimension CT scans showed all of C1C2 screws were implanted in proper position. In 6-month after surgery, no case of implantation failure was observed, and all patients had a stable bone fusion on atlantoaxial joint. Conclusion It is demonstrated that clinic result of C|C2 pedicle screw reduction and fixation is satisfactory, and correspond with the biomechanics for reduction and fixation of atlantoaxial joint dislocation.%目的 探讨寰枢椎脱位椎弓根钉棒系统的临床复位效果.方法 选择16例寰枢脱位患者,其中男性10例,女性6例;年龄26~ 55岁,平均年龄31.4岁.采用寰枢椎椎弓根钉棒系统进行复位内固定术,并行自体髂骨植骨.手术前后对颈后部轴性疼痛采用视觉模拟评分法(VAS)评价,对神经功能改善采用Frankel分级进行评价.结果 全组16例均获得随访,随访时间6 ~ 36个月,平均随访时间23

  18. ACCURACY OF RELATED PARAMETERS TO SCREW PLACEMENT IN LOWER CERVICAL PEDICLE MEASURED BY SPINAL VIRTUAL SURGERY SYSTEM%脊柱虚拟手术系统测量下颈椎椎弓根固定相关参数精确性的实验研究

    Institute of Scientific and Technical Information of China (English)

    曹珺; 何飞; 李超; 梁祁枫; 李中心; 蒋振营

    2011-01-01

    Objective To evaluate the accuracy of the related parameters measured by spinal virtual surgery system (SVSS) three-dimensional (3D) techniques by comparing with the parameters measured by multi-spiral CT (MSCT) workstation. Methods Seven vertebrae specimens of adult men were scanned with MSCT, and the messages were sent to MSCT workstation and SVSS. The 3D image of spine was reconstructed by using volume rendering and multi-planar reformation;based on the parameter requirement of lower cervical pedicle fixation, 10 related parameters were measured. Then SPSS11.0 analyzer software was used to analyze the parameters measured by 2 systems. Between June 2009 and March 2010, 6 patients who received screw insertion in lower cervical spines were given MSCT scanning, then the messages were sent to SVSS 3D reconstruction to evaluate the situation and to collect the parameters of pedicle screw insertion. Results SVSS measurement showed that 1 pedicle was clausura (C3) and the diameters of 4 pedicles in coronal view were lee than 3 mm (C4 in 1, C5 in 2, C6 in 1), which did not fit for screw insertion; the results were similar to those by MSCT measurement. A total of 66 lower cervical pedicle were measured successfully. Significant differences were found in 14 parameters as follows between 2 systems (P < 0.05):the left pedicle height of C3, the both sides pedicle width of C4, the right pedicle spongy width of C4, the left X-direction entrance of C6, the both sides Y-direction entrance of C3, total pedicle length of sagittal view in both sides pedicle of C3 and the left pedicle of C5, total pedicle length of axial view in C3 pedicles, the left pedicle of C5, and the right pedicle of C6. There was no significant difference in the other parameters (P > 0.05). In 6 clinical cases, 34 screws were inserted, the postoperative MSCT scanning showed.that 30 screws were placed successfully. The rate of accuracy was 88.24%. According to the Richter's perforation classification

  19. 经伤椎椎弓根植骨结合后路钉棒内固定治疗胸腰椎骨折的临床观察%Clinical Observation of Pedicle Graft by Damaged Vertebral Combined with Posterior Pedicle Screw Fixation in Treating Thoracolumbar Fractures

    Institute of Scientific and Technical Information of China (English)

    黄河; 李保华; 陈旭东; 舒春

    2014-01-01

    目的:探讨经伤椎椎弓根行椎体植骨在胸腰椎骨折中的治疗效果。方法治疗组胸腰椎爆裂性骨折76例,经后路行胸腰椎骨折复位内固定,并通过伤椎椎弓根行椎体植骨;对照组72例,为早期及同期(2008年以前)未通过椎弓根行椎体植骨的胸腰椎爆裂性骨折。两组均在术前、术后行DR及CT断层扫描检查,观察椎体高度的恢复、Cobb角的丢失情况及内固定有无松动断裂、弯曲等情况,进行比较、分析。结果治疗组的所有病例均得到随访,对照组54例获得随访,治疗组与对照组在远期丢失率,后凸畸形Cobb角度丢失率方面差异均有统计学意义。结论经伤椎椎弓根行伤椎椎体植骨、钉棒系统内固定治疗胸腰椎爆裂性骨折,术后可有效恢复伤椎椎体高度,重建前、中柱的稳定性,减少后期椎体高度的丢失,防止后凸畸形的加重及内固定的松动、断裂。%Objective To investigate Pedicle graft by damaged Vertebral the treatment of thoracolumbar fractures. Meth-ods Treatment group 76 cases, the posterior thoracic spine fracture fixation, and through the vertebral pedicle vertebral body bone;Control group, 72 cases of early and earlier(before 2008)did not undergo pedicle bone graft thoracolumbar burst fractures. Both groups were in the preoperative, postoperative DR and CT tomography examination, observation vertebral height restoration, Cobb angle of the circumstances and the loss of fracture fixation without loosening, bending, etc. , are compared and analyzed. Re-sults All the cases were followed up in treatment group,The treatment group and the control group with loss rate in the long term, kyphosis Cobb angle loss rate were significantly different. Conclusion The way of bone grafting through the vertebral pedicle and screw rod system internal fixation for the treatment of thoracolumbar burst fractures may effectively restore vertebralheight and re

  20. Research on the screws implanting in vertebral pedicle with scoliosis under the intraoperative guide of three-dimensional navigation%术中三维导航引导下脊柱侧凸的椎弓根螺钉置入研究

    Institute of Scientific and Technical Information of China (English)

    黄彦; 吕浩然; 杨进顺; 吴登将

    2012-01-01

    [Objective] To discuss the application research of intraoperative three-dimensional navigation in the vertebral pedicle screws implanting of patients with scoliosis. [ Method] Sixteen patients with scoliosis were treated with pedicle screw fixation under the 3D navigation,among which, 18 cases with adolescent idiopathic scoliosis,20 cases with senile degenerated scoliosis. The patients' spines reveived CT 3D scanning during the operation,and then the information and data of scanning were input into the navigation system,and the navigation stick stereoscopically and dynamically implanted pedicle screws into the best location, diameter and length under the guide of navigation system. [ Result] Total 236 pieces of pedicle screws were successfully implanted into 38 patients with scoliosis under the guide of 3D navigation system,the review of X-ray and CT found no loosened screw and cracking screw,according to the classification, these screws included;227 pieces in level A,7 pieces in level B,2 piece in level C,zero in level D. The radiographs taken from standing posteroanterior position and lateral side showed that the mean Cobb angle of scoliosis was corrected from preoperative 67° to post-operative 26°(21° -118°) with a correction rate of 61%. Postoperatively the angle of kyphosis was improved from the preoperative 23° to 14° (5° -29°) with a correction rate of 39%.Thirty-eight cases were received 18 months of follow-up visits on average (12-25 months) ,and there was no tardive spinal cord or nerve root lesion. [ Conclusion] The implanting approach of screws in vertebral pedicle with scoliosis is precise and reliable under the guide of 3D navigation.%[目的]探讨术中实施三维导航在脊柱侧凸病人椎弓根螺钉置入的应用价值.[方法] 38例脊柱侧凸病人行三维导航引导下椎弓根螺钉固定术,其中青少年特发性脊柱侧凸18例,老年退行性脊柱侧凸20例.手术中脊柱CT三维扫描后向导航系统输入患者

  1. Application of Patient-Specific Drill Template in the Thoracic and Cervical Pedicle Screw Implanta-tion:a Clinical Study%3D 打印个体化导航模板在胸椎和颈椎椎弓根螺钉植入的临床应用

    Institute of Scientific and Technical Information of China (English)

    宁金沛; 吴卫东; 覃求; 梁柱德; 韦武; 何恩谋; 潘式新

    2015-01-01

    Objective To investigate the accuracy and safety of patient-specific drill template in the thoracic and cervical pedi-cle screw implantation. Methods From July 2014 to November 2014,7 patients needed cervical and thoracic pedicle screw placements underwent CT scan,then Mimics 15. 0 was used to reconstruct 3D model of cervical and thoracic spine. The best drilling tracts and 3D model of patient-specific drill template were designed by Geomagic software. The 3D models above were used to print out with a rapid prototyping(RP)machine and the real drill templates were used to guide screws placement. 24 transpedicular screws were implanted into cervical and thoracic pedicle. The complications related to screws placement were re-corded. Results 23 of the 24 screws implanted by drill plate guidance were completed located in the pedicle. Just 1 screw vio-lation was observed,but the violation distance was less than 1. 2 mm. The placement accurate rate was 96% . The accuracy ac-ceptance rate was 100% . No neurovascular and visceral injury related-complications was noted. Conclusion Patient-specific biocompatible drill template is reliable and safe in the thoracic and cervical pedicle screw implantation.%目的:研究数字化(3D)打印技术的个性化导航模板设计在胸椎和颈椎手术个性化置钉应用的准确性和安全性。方法2014年7月至2014年11月,对7例需要行胸椎、颈椎椎弓根螺钉植入手术的患者术前通过 CT 扫描、Mimics 软件三维重建建立三维仿真模型。并使用 Geomagic 软件设计最佳的内固定钉道,然后根据钉道设计导航模板,用3D 打印机打印导航模板,用于手术时辅助置钉;术中辅助植入胸椎、颈椎椎弓根螺钉共24枚,术后 CT 扫描评价螺钉位置,记录有无与螺钉植入的相关并发症。结果通过导航模板辅助植入的24枚椎弓根螺钉,23枚完全在椎弓根内,1枚穿破椎弓根外壁,穿出距离均小于1.2 mm

  2. Clinical application of ployaxial pedicle screw in severe scoliosis%万向椎弓根螺钉在重度脊柱侧后凸中的应用

    Institute of Scientific and Technical Information of China (English)

    雍明; 吴继功; 马华松; 邹德威; 白克文; 张乐乐; 姬勇; 陶有平; 曾辉

    2011-01-01

    [Objective] To evaluate the clinical result of ployaxial pedicle screw for the treatment of severe scoliosis. [ Methods] From March 2008 to April 2009, there were 66 severe scoliosis patients with the average Cobb angle of scoliosis of more than 100°, which included 25 males and 41 females with an average age of 18. 2 years. The average Cobb angle of scoliosis was 113.4° (80°~165°), the average Cobb angle of kyphosis was 90. 5° (49°~165°) . [Results] The operation time was 3. 5 - 6. 5 h (average, 5.6 h) , the blood loss was 450 ~ 3 300 ml (average, 1 577 ml) . Patients had transient unilateral lower limb paralysis incompletely in one case, completely recovery after three months. The average postoperative Cobb angle in coronal plane was 42. 88°with a correction rate of 62. 1%. The average postoperative Cobb angle of in sagittal plane was 32. 3°with a correction rate of 64. 3%. The follow - up period was from 15 months to 28 months (average, 18 months) . No pseudoarthrosis and obvious correction loss either in coronal or sagittal plane was noted. [ Conclusion] Ployaxial pedicle screws treatment of severe scoliosis is a safe and effective method with well correction rate.%[目的]分析和总结万向椎弓根螺钉在治疗重度脊柱侧凸患者手术矫形中的疗效.[方法]回顾性分析了2008年3月~2009年4月期间本科使用万向椎弓根内手术矫形的66例重度脊柱侧凸病人的临床资料,其中男性25例,女性41例;平均18.2岁.侧凸主弯Cobb角平均113.4°(80°~165°),后凸角度平均90.5°(49°~165°),旋转Ⅱ-Ⅳ度.手术行后路矫形38例,截骨矫形28例,其中二期手术矫形13例.[结果]全部病例均安全完成矫形手术,手术时间3.5~6.5 h,平均5.6 h,出血450~3 300 ml,平均1 577 ml.术后出现一过性单侧下肢不全瘫1例,给予甲强龙冲击、神经营养治疗3个月后完全恢复.术后侧凸Cobb角平均42.9°,矫形率62.1%,后凸角度平均32.3°,矫形率64.3%,

  3. The main cause and countermeasure of internal fixation loosening and disruption in the treatment of thoracolumbar fracture with vertebra pedicle screw-rod system%椎弓根钉棒系统治疗胸腰段椎体骨折术后松动断裂的原因及防治

    Institute of Scientific and Technical Information of China (English)

    蒲川成; 冉学军; 邓长青; 覃勇志; 周勇

    2012-01-01

    目的 分析脊柱后路椎弓根钉棒系统内固定治疗胸腰段椎体骨折术后松动、断裂的原因,探讨防治对策.方法 426例行后路椎弓根钉棒系统内固定治疗的胸腰椎骨折患者中,术后21例发生内固定松动、断裂,其中11例进行手术翻修,10例采取保守观察治疗.结果 21例均获随访,时间8~36个月.患者均骨性愈合,未再次发生内固定物松动及断钉、断棒.结论 经后路椎弓根钉棒系统内固定术治疗胸腰段椎体骨折,撑开复位后致骨折椎体"蛋壳样"变,未植骨填充所导致的前柱不实、后柱植骨融合不良、椎弓根钉棒系统安置不当内部自身产生较大的应力及术后脊柱负重过早是钉棒松动、断裂的主要原因.通过对伤椎前后柱进行充分植骨,提高椎体的骨性愈合速度和质量,及尽可能保留后柱小关节结构,增加脊柱稳定性,可明显降低内固定物松动、断裂的发生率.%Objective To explore the main cause and countenneasure of internal fixation loosening and disruption in the treatment of thoracolumbar fracture with pedicle screw-rod system. Methods A retrospective review was made in 426 patients with thoracolumbar fractures who fixed with pedicle screw-rod system. There were 2f cases with internal fixation loosening and disruption, f f cases were undergone revisions and the other fO cases were treated conservatively. Results 2f cases were followed up for 8~36 months. All of these cases recovered without fixation loosening and disruption. Conclusions The " shell-like change after vertebral fractures distraction reduction without bone graft leads to anterior column weakness. No posterior bone graft, and wrong pedicle screw-rod system insertion leads to excessive stress force on internal fixator itself, and premature vertebral column weight-bearing were the main reasons of pedicle screw-rod system loosening and disruption in the treatment of thoracolumbar vertebral fracture with the

  4. Surgical treatment of thoracolumbar fractures by using the posterior short segment pedicle screw fixation%后路短节段固定联合伤椎置钉治疗胸腰椎骨折

    Institute of Scientific and Technical Information of China (English)

    胡力丰; 张志成; 王晓凯; 孙天胜

    2012-01-01

    Objective To evaluate the efficacy,indications and clinical outcomes of the treatment of thoracolumbar fractures by short segmental pedicle screws fixation at the level of the fracture.Methods Thirtytwo patients with thoracolumbar fracture,who underwent surgical procedure of short segmental pedicle screws fixation at the level of the fracture from 2007 to 2010,were followed up.X rays were performed preoperatively and postoperatively to locate the injured vertebral segment height and fractured kyphosis vertebral (Cobb angle).Frankel standard was used to assess the spinal cord function.Results All patients were followed up for 12 to 20 months and were in satisfying condition in the reduction of fracture.After surgery,the height of fractured vertebral body leading edge recovered from preoperative (32.4% ~69.3%,averaged (51.6 ± 17.8)% ) to (85.6% ~99.2%,averaged (92.8 ±6.2)% ) after two weeks and (90.6% ~97.8%,averaged (93.8 ±3.6)% ) at the last follow-up.Fractured vertebral Cobb angle was recovered from the preoperative ( 12.8 ° ~ 30.5 °,averaged [20.8±9.1] °) to (0° ~7.8 °,averaged [4.9 ±3.2] °) two weeks later and (2.0° ~ 12.0°,averaged [ 6.2 ± 4.6 ] o at the last follow-up.Cobb angle of the injured vertebral segment and the extend of vertebral compression were significantly improved after the angle was corrected ( P <0.01 ).Conclusion Using reduction and short segment pedicle screw fixation at the fracture level would be helpful to correct kyphotic vertebral compression and restore the height of injured vertebrate,which was also of benefit to increase the stability of short-segment posterior fixation system and reduce the loss of correction in a long run.%目的 观察经伤椎椎弓根置钉复位固定治疗胸腰椎骨折的可行性、适应证及临床疗效.方法 我院2007年1月至2010年1月收治的胸腰椎骨折采用经伤椎椎弓根置钉复位固定治疗,共随访32例,对患者术前及术后伤椎

  5. Efficacy of pedicle screw technique in treatment of os odontoideum combined with atlantoaxial dislocation%椎弓根螺钉技术治疗游离齿状突并寰枢椎脱位的疗效观察

    Institute of Scientific and Technical Information of China (English)

    王玉强; 王利民; 张玮; 刘屹林; 王卫东; 谭洪宇; 陈豪

    2012-01-01

    Objective To evaluate the efficacy and radiological variation of pedicle screw technique in the treatment of os odontoideum combined with atlantoaxial dislocation. Methods Fifteen patients with os odontoideum combined with atlantoaxial dislocation were treated with occipitocervical fusion or atlantoaxial fixation.Two patients with irreducible atlantoaxial dislocation were treated surgically with transoral anterior atlantoaxial release and one treated with posterior arch removal plus occipitocervical fusion.Two patients with atlas deformity and one infant were treated with occipitocervical fusion.The rest patients were treated with posterior reduction and pedicle screw internal fixation.Clinical manifestations and imaging changes were followed up to evaluate the clinical efficacy. Results All patients were followed-up for average 26 months (range,7-47 months).Neurological recovery was significantly improved in 13 patients and took a turn for the better in two.The average JOA scores was increased from average preoperative 8.27 to postoperative 15. According to Hirabayashi,the average improvement rate was77%,including 10 patients with excellent outcomes and five with good outcomes,with excellence rate of100%.The cervical-medullary angle was increased from average preoperative 130.3° to postoperative151.7°.Postoperative X-rays and CT showed good atlantoaxial alignment and solid bony fusion in all pa-tients,with no shedding or breakage of the fixators. Conclusion Occipitocervical fusion or adantoaxial fixation through pedicle screw technique is an effective method for treatment of os odontoideum combined with irreducible atlantoaxial dislocation.%目的 评估椎弓根螺钉技术治疗游离齿状突并寰枢椎脱位的疗效和影像学变化.方法 对15例游离齿状突并寰枢椎脱位患者利用椎弓根螺钉技术行枕颈融合术或寰枢椎固定术,其中2例难复型脱位者先行经口入路寰枢关节松解术、1例行后

  6. 椎动脉CT血管造影多平面重组在枢椎椎弓根置钉中的价值%The significance of CT multi-planar reconstruction of vertebral artery CT angiography in C2 pedicle screw placement

    Institute of Scientific and Technical Information of China (English)

    张艳; 刘溢; 王晓华

    2014-01-01

    Objectives: To investigate the significance of CT multi-planar reconstruction of vertebral artery CT angiography(CTA) in C2 pedicle screw placement. Methods: The vertebral artery CTA images of 77 pa-tients were reviewed retrospectively by CT multi-planar reconstruction. The positions in three dimensions were adjusted according to the screw′s ideal direction, and the cross section of the screw passing through the pedicle was displayed based on CT multi-planar reconstruction. A circle was demarcated on the former plane to simulate the cross section of the screw. The diameter of the circle, the accommodation of screw in C2 pedicle, and the positions of the screw related to the vertebral artery were taken into account to assess the feasibility of pedicle screw placement. And meanwhile, the feasibility was assessed by measuring the inner di-ameters of pedicle complex. The results of the two methods were compared. Results: The simulation of place-ment of C2 pedicle screw basing on CT multi-planar reconstruction illustrated the accommodation of screw in C2 and its relationship with surrounding structures. According to this method, 10(13%) cases of left side and 19 (25%) cases of right side could not accommodate the circle with the diameter of 4mm and could not be placed pedicle screw, while operation was unavailable for 12(16%) cases of left side and 20(26%) cases of right side by measurement of inner diameters. The P value of McNamara test was 0.5 in the left and 1 in the right. There was no significant differences between the results of two methods(P>0.05). The result of Kap-pa test was 0.770 in the left and 0.732 in the right, and the P value of the Kappa test in the both sides was 0, which showed good consistency. Conclusions: The simulation of placing pedicle screw in axis basing on CT multi-planar reconstruction can illustrate the screw accommodation in C2 and its relationship with sur-rounding structures, which can provide good reference for the operation.%目

  7. 探讨后路椎间盘摘除椎弓根钉内固定结合Cage植骨治疗腰椎间盘突出症的临床效果%Clinical Effect of Posterior Lumbar Interbody Fusion and Pedicle Screw Fixation Combined With Cage Bone Graft in the Treatment of Lumbar Disc Herniation

    Institute of Scientific and Technical Information of China (English)

    梁涛

    2016-01-01

    Objective To explore the feasibility of posterior lumbar interbody fusion and pedicle screw fixation combined with Cage bone graft in the treatment of lumbar disc herniation. Methods 86 patients with lumbar disc herniation were col ected. The patients in the study group were treated with posterior lumbar interbody fusion and pedicle screw fixation combined with Cage bone graft. The control group was treated with simple bone graft. Results There were significant differences in the treatment effect of the two groups after 6 months. Conclusion The treatment of lumbar disc herniation by posterior lumbar interbody fusion with pedicle screw fixation combined with Cage bone graft is effective and safe.%目的:探究腰椎间盘突出症使用后路椎间盘摘除椎弓根钉内固定结合 Cage 植骨治疗的可行性。方法收集腰椎间盘突出症患者86名,研究组使用后路椎间盘摘除椎弓根钉内固定结合 Cage 植骨治疗方案,对照组使用单纯植骨治疗方案。结果术后6个月两组患者治疗效果的差异具有统计学意义。结论腰椎间盘突出症使用后路椎间盘摘除椎弓根钉内固定结合 Cage 植骨治疗,具有较高的有效率和安全性。

  8. One stage atlantoaxial pedicle screw fixation for unstable atlas burst fracture%一期后路寰枢椎固定治疗不稳定寰椎爆裂性骨折

    Institute of Scientific and Technical Information of China (English)

    蒋伟宇; 马维虎; 赵刘军; 顾勇杰; 胡旭栋; 于亮; 李国庆; 阮超越; 洪锦炯

    2015-01-01

    Objective To assess the clinical results of one stage posterior atlanloaxial pedicle screw fixation and fusion for unstable atlas burst fracture.Methods A retrospective analysis of clinical data including 32 cases,which were admitted according to the inclusion and exclusion criteria between May 2010 and December 2013.There were 11 females and 21 males whose age ranged from 22 to 59 years (mean 41.8 years).X-ray,CT scan reconstruction and MRI were done before operation to evaluate the injury of ligament and fracture.There were 17 cases of unstable atlas burst fracture,including 5 cases Jefferson fracture,8 cases untypical Jefferson fracture,and 4 cases lateral mass fracture combined with anterior arch or posterior arch fracture.There were 15 cases combined with axial fracture,9 cases combined with dens fracture,4 cases with axial body fracture,and 2 cases with Hangman fracture.The patients had various degrees of occipital neck pain,limited mobility and neurological dysfunction.Degree C in 1 case and degree D in 5 cases were assessed by the American Spinal Cord Injury Association (ASIA) impairment scale.All patients were treated with one stage posterior atlantoaxial pedicle screw fixation and fusion.All patients were assessed clinically by neurologic recovery,atlantoaxial reduction and bone graft fusion.The preoperative and postoperative atlanto-dens interval (ADI),lateral mass distance (LMD) and VAS were measured and statistically analyzed.Complications were observed.Clinical outcome of last follow-up was evaluated by dynamic X-ray and CT scan.Results All patients were followed up.The follow-up time ranged from 10 to 24 months (mean 15.6 months).The healing time of bone fusion ranged from 5 to 10 months with an average follow-up time of 6.9 months.The average preoperative VAS score was 5.0± 1.4 while the score of last follow-up was 1.0±0.7,with statistically significant differences.Neurological status improved in all patients but one.Four cases with grade D

  9. 实时三维导航技术应用于先天性脊柱侧凸矫形的近期疗效%SHORT-TERM EFFECTIVENESS OF SPINAL NAVIGATION WITH INTRA-OPERATIVE THREE-DIMENSIONAL-IMAGING MODALITY IN PEDICLE SCREW FIXATION FOR CONGENITAL SCOLIOSIS

    Institute of Scientific and Technical Information of China (English)

    孙麟; 宋跃明; 龚全; 刘立岷; 周春光; 周忠杰

    2013-01-01

    Objective To investigate short-term effectiveness of spinal navigation with the intra-operative three-dimensional (3D)-imaging modality in pedicle screw fixation for congenital scoliosis (CS). Methods Between July 2010 and December 2011, 26 patients with CS were treated. Of 26 patients, 13 patients underwent pedicle screw fixation using the spinal navigation with the intra-operative 3D-imaging modality (navigation group), while 13 patients underwent the conventional technique with C-arm X-ray machine (control group). There was no significant difference in gender, age, hemivertebra number and location, major curve Cobb angle, and Risser grade between 2 groups (P > 0.05). Operation time, operative blood loss, frequency of the screw re-insertion, and postoperative complication were observed. The pedicle screw position was assessed by CT postoperatively with the Richter's standard and the correction of Cobb angle was assessed by X-ray films. Results All patients underwent the surgery successfully without major neurovascular complication. There was no significant difference in operation time, operative blood loss, and pedicle screw location between 2 groups (P > 0.05). A total of 58 screws were inserted in navigation group, and 3 screws (5.2%) were re-inserted. A total of 60 screws were inserted in control group, and 10 screws (16.7%) were re-inserted. There was significant difference in the rate of pedicle screw re-insertion between 2 groups (χ2 =3.975, P=0.046). Patients of navigation group were followed up 6-24 months, and 6-23 months in control group. According to Richter's standard, the results were excellent in 52 screws and good in 6 screws in navigation group; the results were excellent in 51 screws, good in 5 screws, and poor in 4 screws in control group. Significant difference was found in the pedicle screw position between 2 groups (Z=-1.992, P=0.046). The major curve Cobb angle of 2 groups at 1 week and last follow-up were significantly improved when

  10. 椎弓根螺钉置入内固定与单纯椎管减压治疗退行性腰椎滑脱的比较%Comparison of pedicle screw fixation and simple vertebral canal decompression in the treatment of lumbar degenerative spondylolisthesis

    Institute of Scientific and Technical Information of China (English)

    刘保华; 王沛; 夏群; 冯世庆; 郑永发; 李冰

    2011-01-01

    of pedicle screw fixation and fusion in treatment of degenerative spondylolisthesis, and to compare with simple vertebral canal compression.METHODS: A total of 38 patients with lumbar degenerative spondylolisthesis received treatment at the Department of Orthopaedics, General Hospital of Tianjin Medical University were selected, and 3 patients were lost in follow-up. Of the remaining 35 cases, 21 cases underwent pedicle screw fixation posterolateral fusion and 14 cases underwent simple vertebral canal decompression. Simple vertebral canal compression group treated with the rongeur bite yellow ligament and lamina to relieve nerve root compression, forward vertebral slippage of adjacent vertebral body with posterior inferior formation relative prominence was chiseled with osteotome. According to Wein-stein method pedicle screw into the needle localization, then screw into the pedicle screw and undergo vertebral plate decompression on the basis of compression condition in pedicle screw fixation and fusion group. The clinical effect underwent comprehensive evaluation of oswestry dysfunction index; horizontal displacement and angular displacement were observed at hyperextension and flexion time. Degenerative condition of adjacent segment was evaluated by UCLA system.RESULTS AN D CONCLUSION : A total of 35 patients were followed up for 1 year. The excellent rate in pedicle screw fixation and fusion group was significantly higher than that in simple vertebral canal compression group (P < 0.05). Pedicle screw fixation and fusion has little effect on the stability of lumbar. There was no significant change in adjacent segment before degenerative insertion and 1 year after insertion. Simple vertebral canal compression had a significant effect on the stability of lumbar, and there was no significant change in adjacent segment degeneration before treatment and 1 year after treatment. It is indicated that pedicle screw fixation and fusion has satisfying effects in treatment of

  11. 生物活性玻璃提高骨质疏松绵羊椎弓根螺钉稳定性的体内实验研究%In Vivo Study of Bioactive Glass in Improvement of Pedicle Screw Fixation in Osteoporosis Sheep

    Institute of Scientific and Technical Information of China (English)

    程欢; 雷伟; 吴子祥; 万世勇; 刘达; 曹鹏冲; 王征

    2011-01-01

    Objective: To investigate the effect of pedicle screw augmentation using bioactive glass (BG) in osteoporosis sheep and observe the absorption of BG and the interface between bone and screw. Methods: Osteoporosis animal models were established by ovariectomy combined with methylprednisolone injection in four adult female sheep. L2-L5 unilateral pedicles were randomly selected in each sheep which were only implanted with pedicle screw and the contralateral pedicles were implant with pedicle screw after the augmentation with BG. 3 months later, six vertebraes (12 screws) were randomly collected from all samples and the interface between screw and bone was analyzed by MicroCT. The augmentation of the screws were evaluated by Axial pull-out-test. Results: The bone mineral density (BMD) of the lumbar of the sheep decreased by 22.38%, and significant difference was found (P<0,05). The trabecular thickness (Tb. Th) and the trabecular number (Tb. N) of the interface in experiment group increased by 143.60% and 33.56% compared with the control group respectively. Significant differences of Tb. Th and Tb. N were found between experiment group and control group (P<0.05). Most of the BG around the screw channel had been degraded and much newly formed bone tissue wrapped the screws tightly in experiment group. In control group, the bone mass was much lower and the bone-screw junction was defectively tight. The junction of the interface between bone and screw in experiment group was better than that in control group. The maximal axial pullout strength in experiment group increased by 25.26% compared with that in control group (P<0.05). Conclusion: Bioactive glass can significantly improve bone microstructure of the interface in osteoporosis condition and increase the hold-strength of the pedicle screw.%目的:研究生物活性玻璃(Bioactive Glass,BG)在骨质疏松绵羊体内强化榷弓根螺钉固定的力学效果,并观察钉道界面及

  12. Applied anatomy of the lower cervical pedicle screw placement%下颈椎经椎弓根螺钉置入的应用解剖学研究

    Institute of Scientific and Technical Information of China (English)

    周树成; 张鹏

    2015-01-01

    Objective:To research on the corresponding vertebral pedicle screw insertion angle and the anchor point of the site, analyzing the relationship between the structure of inquiry pedicle and adjacent nerve,spinal cord.Methods:32 people were selected,with their C3~7 cervical as specimens,using a protractor and vernier caliper measuring angles and lengths,and into nail indicators of the specimens were compared.Results:After operation of cervical specimens were positioned in different degree, pedicle specimens on the lower half of the pedicle height as the horizontal plane,ordinate C3 to the outer edge of the inner side of the block(2.4±0.9)mm,C5 is the inside of the outer edge(2.8±0.7)mm,C6 is the inside of the outer edge(3.7±0.7)mm,C7 is the inside of the outer edge(5.5±1.3)mm,there is no significant difference of each side block edge distance,there is no statistically significant(P>0.05).Conclusion:Clinically,all parts of the lower cervical spine in the patient,tubercle of transverse process and the highest point of the notch facet and the outer side block dissection in anatomical position is the most significant symbol,there is a great clinical significance,in the surgical process is more likely to be found,it is possible to improve the safety of the surgical procedure,it is worth promoting.%目的:对椎弓根在相应椎体上的进钉角度以及进钉点的部位进行研究,同时对椎弓根的结构和与之相邻的神经、脊髓之间存在的关系进行分析探究。方法:选取32个成年人,以其C3~7段颈椎作为标本,采用量角器及游标卡尺测量相应角度及长度,并且对标本的相应进钉指标进行对比。结果:在术者对颈椎的标本进行不同程度的定位之后,以椎弓根标本中下平面上1/2椎弓根高处作为横坐标,纵坐标 C3为侧块外缘内(2.4±0.9)mm,C5为侧块外缘内(2.8±0.7)mm,C6为侧块外缘内(3.7±0.7)mm,C7为侧块外缘内(5.5±1.3)mm,各个侧块外

  13. 改良MI-TLIF联合经皮椎弓根钉固定治疗退行性腰椎侧弯%Treatment of degenerative lumbar scoliosis by using modified MI-TLIF and percutaneous pedicle screw fixation

    Institute of Scientific and Technical Information of China (English)

    尹知训; 何二兴; 崔基浩; 吴梅祥; 石中玉; 刘超杰

    2014-01-01

    治疗的有效方法。%Objective To discuss the operative essentials and therapeutic effects of modified minimally invasive-transforaminal lumbar interbody fusion (MI-TLIF) combined with percutaneous pedicle screw fixation for degenerative lumbar scoliosis (DLS). Methods From march 2012 to march 2014, 32 DLS patients were treated by modified MI-TLIF (concave-side distraction step by step, cage insertion into the curved side of intervertebral space, and bone graft fusion) and percutaneous pedicle screw fixation in the First and Fouth Affiliated Hospital of Guangzhou Medical College. Incision length, operative time, intraoperative estimate blood loss and hospital stay were recorded, Cobb's angle, lordosis angle and spinal imbalance distances on coronal and sagittal plane were measured according to preoperative and postoperative spinal full-length radiographs, postoperative improvement of low back and leg pain were evaluated by visual analogue scale (VAS) and Oswestry disability index (ODI) scoring, clinical effects were assessed according to Nakai standard. Results Incision length was 4.2-5.3 cm with the average of 4.5 cm, operative time was 85-165 min with the average of 110 min, intraoperative estimate blood loss was 120 mL (90-300 mL) and the hospital stay was 14.5 d (11-17 d). Thirty patients were followed-up for 12.5 months (4-23 months). No pedicle screw-rod breakage or cage displacement were found. Compared with preoperative and the last follow-up, the following results had statistical differences (P<0.05):VAS of low back pain and leg pain decreased from (6.8 ± 2.3), (7.5 ± 2.2) to (1.9 ± 1.3), (2.4 ± 1.5) respectively, ODI improved from (41.4 ± 2.7)% to (13.6 ± 2.5)%; Cobb's angle decreased from (33.7 ± 3.5)° to (10.1 ± 2.3)°, lordosis angle deviation decreased from (22.6 ± 8.0)° to (3.3 ± 1.4)°; Imbalance distance on sagittal plane and coronal plane improved from (46.8 ± 9.8), (29.3 ± 7.8) mm to (19.7 ± 7.6), (10.7 ± 6.3) mm respectively. According to Macnab standard, there

  14. Posterior pedicle screw fixation and interbody fusion in the treatment of recurrent lumbar disc herniation:an evaluation of vertebral stability%后路钉棒内固定椎间融合治疗复发性腰椎间盘突出症:椎体稳定性评价

    Institute of Scientific and Technical Information of China (English)

    刘凤松; 王凯; 景成伟; 张亮; 刘宾; 杨亚林

    2014-01-01

    BACKGROUND:Discectomy is an important therapy for lumbar disc herniation, but a smal number of patients undergoing discectomy wil relapse. OBJECTIVE:To investigate the spinal stability fol owing posterior pedicle screw fixation combined with interbody fusion cage for treatment of recurrent lumbar disc herniation. METHODS:Twenty-six patients with recurrent lumbar disc herniation from January 2007 to December 2011 were enrol ed and subjected to posterior pedicle screw fixation combined with interbody fusion cage. Pain relief and lumbar stability were observed postoperatively. We analyzed the spinal stability in recurrent lumbar disc herniation patients after posterior pedicle screw fixation combined with interbody fusion cage depending on literature search. RESULTS AND CONCLUSION:Al the 26 patients were fol owed up for 12-36 months. After treatment, al patients effectively al eviated the symptoms of low back pain, and lumbar interbody fusion was good, with a good rate of 96.2%. There was no pedicle screw loosening, broken, non-fusion phenomenon. Posterior decompression and interbody fusion cage combined with posterior pedicle screw fixation for recurrent lumbar disc herniation, characterized as fast symptom relief, strong fixation, exact interbody fusion exact, is an ideal treatment for recurrent lumbar disc herniation.%背景:腰椎间盘突出症治疗的重要方法是椎间盘切除,但有少部分患者会出现复发现象。  目的:探讨后路椎弓根钉棒内固定联合cage植入椎间融合治疗复发性腰椎间盘突出症后的脊柱稳定性。  方法:选择2007年1月至2011年12月复发性腰椎间盘突出症患者26例,应用后路减压cage植入椎间融合加钉棒系统内固定治疗复发性腰椎间盘突出症进行再手术治疗,观察患者治疗后疼痛症状缓解情况以及腰椎稳定性。通过数据库文献检索的方法分析后路钉棒内固定椎间融合治疗复发性腰椎间盘突出症的椎

  15. The Curative Effect of Pedicle Screw Fixation by Wiltse Approach on Lumbar Disc Herniation%Wiltse入路椎弓根螺钉固定治疗腰椎间盘突出症的疗效观察

    Institute of Scientific and Technical Information of China (English)

    杨剑; 康建平; 王松; 雷飞

    2014-01-01

    Objective To compare the clinical curative effect of pedicle screw fixation by Wiltse approach with that of traditional lumbar interbody fusion by posterior median approachon lumbar disc herniation(LDH). Methods 285 cases with lumbar disc hernia-tion received surgical treatment and were randomly divided into 2 groups:group A(Wiltse approach)(n=120)and group B(posterior median approach)(n=165); a comparative study was made between the 2 groups in bleeding in operation, time length of operation, postoperative complications, postoperative time in bed,the fusion rate;Visual Analogue Pain Score(VAS), Oswestry Disability Index (ODI)and Japanese Orthopaedic Association(JOA)were applied in the follow-up before and after operation and the results were statis-tically analyzed. Results Group A was superior to group B in bleeding in operation, time length of operation, postoperative complica-tions, postoperative time in bed,the scores of VAS and ODI in the last follow-up(P0.05);the VAS scores, ODI scores and JOA scores of both group in the last follow-up were more improved than those before operation. Conclusions Pedicle screw fixation by Wiltse approach and tradi-tional lumbar interbody fusion by posterior median approach both are effective on LDH while the former is of such advantages as less bleeding, small wound, shorter operation time, lower occurrence of complications and lower residual rate of low back pain.%目的:比较Wiltse入路(肌间隙入路)椎弓根螺钉固定融合术(A组)与传统腰椎后正中入路椎间融合术(B组)治疗腰椎间盘突出症(Lumbar disc herniation, LDH)的临床疗效。方法285例腰椎间盘突出症接受手术治疗的患者分为两组,A组120例,B组165例。比较两种手术入路术中出血量、手术时间、术后并发症,术后卧床时间、融合率,术前、术后随访均应用腰痛和腿痛视觉模拟(Visual analogue pain score,VAS)评

  16. Applied Anatomy Measurement of Safe Screw Placement Angle from the Pedicle of Vertebral Arch-Frame Structure Unit Way%经椎弓根-肋骨结构单元途径置入螺钉安全角度的应用解剖学测量

    Institute of Scientific and Technical Information of China (English)

    马云兵; 夏云祥; 杨庆秋; 王俊波; 唐桦; 李跃敏

    2013-01-01

    目的 在尸体标本上测量T1 ~T10胸椎经椎弓根-肋骨结构单元途径置入螺钉的安全角度及变化规律,为临床安全置入螺钉提供解剖学依据.方法 选取15例正常成人尸体标本,其中男9例,女6例,年龄18~60岁,平均40岁.将标本T1~T10胸椎分别沿椎弓根-肋骨平面横切,并测量T1 ~ T10各椎弓根-肋骨结构单元的横径、经椎弓根-肋骨结构单元途径置入的螺钉与矢状面的最小与最大安全成角及安全角度范围.结果 椎弓根-肋骨结构单元的横径变化规律为T1 ~T4逐渐变小,T5 ~ T10又逐渐变大;置钉安全角度范围为T1、T2最大,T5 ~T10次之,T3、T4最小;T1~T2及T5~ T10比较差异无统计学意义(P>0.05),而T2~ T5比较差异均有统计学意义(P<0.05),男性与女性比较无统计学意义(P>0.05).结论 临床经椎弓根-肋骨结构单元置入螺钉时,应根据不同节段椎弓根-肋骨结构单元置钉安全角度的大小相应调整螺钉置入角度.%Objective To provide the anatomical basis for clinical safe screw placement by measuring the safe screw placement angle from T1 - T10 thoracic pedicle-frame structure unit way in adult body specimen. Methods 15 cases of normal adult body specimens, including 9 cases of male, and 6 cases of female, aged 18 ~ 60 years old, average age was 40. The T1 - T10 thoracic vertebras of the body specimen were transected along the pedicle of vertebral arch-frame plane, and we measured the transverse diameter of the T1 - T10 the pedicle of vertebral arch-frame structure unit, and the minimum and maximum safe angle between the sagittal plane and the screw placed from the pedicle of vertebral arch - frame structure unit way. Results The transverse diameter of pedicle of vertebral arch-frame structure unit decreased gradually from T1to T4, and increased gradually from T5 to T10. The range of safe screw placement angle was widest at T1 and T2, followed by T5 - T10, and was

  17. Transpedicular screw fixation in the thoracic and lumbar spine with a novel cannulated polyaxial screw system

    Directory of Open Access Journals (Sweden)

    Lutz Weise

    2008-10-01

    Full Text Available Lutz Weise, Olaf Suess, Thomas Picht, Theodoros KombosNeurochirurgische Klinik, Charité – Universitätsmedizin Berlin, Berlin, GermanyObjective: Transpedicular screws are commonly and successfully used for posterior fixation in spinal instability, but their insertion remains challenging. Even using navigation techniques, there is a misplacement rate of up to 11%. The aim of this study was to assess the accuracy of a novel pedicle screw system.Methods: Thoracic and lumbar fusions were performed on 67 consecutive patients for tumor, trauma, degenerative disease or infection. A total of 326 pedicular screws were placed using a novel wire-guided, cannulated, polyaxial screw system (XIA Precision®, Stryker. The accuracy of placement was assessed post operatively by CT scan, and the patients were followed-up clinically for a mean of 16 months.Results: The total medio-caudal pedicle wall perforation rate was 9.2% (30/326. In 19 of these 30 cases a cortical breakthrough of less than 2 mm occurred. The misplacement rate (defined as a perforation of 2 mm or more was 3.37% (11/326. Three of these 11 screws needed surgical revision due to neurological symptoms or CSF leakage. There have been no screw breakages or dislocations over the follow up-period.Conclusion: We conclude that the use of this cannulated screw system for the placement of pedicle screws in the thoracic and lumbar spine is accurate and safe. The advantages of this technique include easy handling without a time-consuming set up. Considering the incidence of long-term screw breakage, further investigation with a longer follow-up period is necessary.Keywords: spinal instrumentation, pedicle screws, misplacement, pedicle wall perforation

  18. 椎弓根钉棒系统治疗不稳定性Jefferson骨折的生物力学分析%Instable Jefferson fracture fixed with the single or double side atlantoaxial pedicle screw-rod system: A biomechanical study

    Institute of Scientific and Technical Information of China (English)

    蒋小红; 肖增明; 温洁明; 唐林; 蒋雄健

    2011-01-01

    BACKGROUND: At present, posterior atlanto-axial pedicle screws have a trend to replace Magerl technology, and become the new standard operation for vertebral instability.OBJECTIVE: To evaluate the mechanical stability of the single or double side atlantoaxial pedicle screw-rod system for treatment of instable Jefferson fracture, in order to provide the basis for clinical application.METHODS: After gross observation and X-radiography confirmation of the specimen's integrity and no osseous abnormality, six adult wet-cadvaveric spinal (C0-4) specimens were used to test the biomechanical stability. The specimens were intact, after instable Jefferson fracture and transverse ligament section, and after stabilization fellow the two techniques: the single or double side atlantoaxial pedicle screw-rod system. The three dimensional movements of C1-2 were recorded though photogrametry with a pure moment of 1.53 N . m. The range of motion (ROM) of each specimen in two fixations was calculated. Statistical analysis was performed with one-way analysis of variance, Fish's least significant difference test to evaluate the immediate stability of the fixation with the two methods.RESULTS AND CONCLUSION: In flexion, lateral flexion and axial rotation of sports, the ROM in the single side atlantoaxial pedicle screw-rod system group was significantly more than that in the double side atlantoaxial pedicle screw-rod system group (P < 0.05). In the treatment of instable Jefferson fracture, the double side atlantoaxial pedicle screw-rod system can provide excellent stability; Fixed effect of the single side atlantoaxial pedicle screw-rod system is not good, and its anti-rotation ability is poor and cannot satisfy the demands of the strengthen stability, graft fusion, which should avoid to be used alone.%背景:目前后路寰枢椎椎弓根螺钉有取代Magerl技术趋势,成为治疗寰枢椎不稳的新标准术式.目的:评价单、双侧椎弓根钉棒系统治疗不稳定

  19. Free-hand placement of high thoracic pedicle screws with the aid of fluoroscopy: evaluation of positioning by CT scans in a four-year consecutive series Colocação de parafusos pediculares na coluna torácica alta utilizando fluoroscopia: avaliação do posicionamento dos parafusos por tomografia computadorizada em uma série de casos durante quatro anos

    Directory of Open Access Journals (Sweden)

    Bruno Perocco Braga

    2010-06-01

    Full Text Available OBJECTIVE: To evaluate the feasibility, safety and accuracy of pedicle screw placement in the upper thoracic spine using the free-hand technique with the aid of fluoroscopy; to analyze the methods used to verify correct screw positioning intra and postoperatively. METHOD: All patients with instability of the cervicothoracic or upper thoracic spine and at least one screw placed in the segment T1-T6 as part of a posterior construct entered the study. Only C-arm intraoperative fluoroscopy was used to guide screw placement. RESULTS: We obtained excellent positioning in 98.07% of the screws. CT scans precisely demonstrated pedicle wall and anterolateral body violations. There was no hardware failure, no neurological or vascular injury and no loss of alignment during the follow-up period. CONCLUSION: Pedicle screws can be safely placed in the upper thoracic spine when strict technical principles are followed. Only a CT scan can precisely demonstrate vertebral body and medial pedicle cortical violations.OBJETIVO: Avaliar a factibilidade, segurança e eficácia da colocação de parafusos pediculares na coluna torácia alta utilizando apenas a fluoroscopia; analisar os métodos intra e pós-operatórios de verficação do posicionamento de parafusos. MÉTODO: Todos os pacientes com instabilidade da coluna cervico-torácica ou torácica alta e pelo menos um parafuso colocado no segmento T1-T6 foram incluídos no estudo. Apenas fluoroscopia intra-operatória foi utilizada para guiar a colocação dos parafusos. RESULTADOS: Obtivemos excelente posicionamento em 98,07% dos parafusos. TC axial mostrou precisamente violações pediculares e da parede anterolateral do corpo vertebral. Não houve falência do instrumental, lesões neurológicas ou vasculares, ou perda do alinhamento sagital no período de seguimento. CONCLUSÃO: Os parafusos pediculares podem ser colocados com segurança na coluna torácica alta desde que técnicas operatórias precisas sejam

  20. 顶椎置钉与否对Lenke 1型青少年特发性脊柱侧凸矫形效果的影响%Effect of apical pedicle screw placement on the surgical correction of Lenke 1 adolescent idiopathic scoliosis

    Institute of Scientific and Technical Information of China (English)

    郑欣; 王渭君; 钱邦平; 江华; 王斌; 朱泽章; 俞扬; 邱勇

    2012-01-01

    Objectives: To investigate the effect of apical pedicle screw instrumentation on the correction of thoracic adolescent idiopathic scoliosis(AIS). Methods: From June 2009 to January 2010, 69 Lenke 1 type AIS patients treated with exclusive pedicle screw instrumentation were reviewed. The mean age at the time of surgery was 15.0 years old(range, 12-20 years), and the Cobb angle was 53.7° on average (range, 50°-70°). According to whether pedicle screws were inserted in the apical vertebrae, all cases were divided into two groups: group A (without apical instrumentation, 35 cases) and group B (instrumented with screws, 34 cases). The preoperative chronological age, sex, the Cobb angle of the major curve, and rotation degree of the apex were compared between two groups. The implant density, postoperative Cobb angle, the correction rate in Cobb angle, and derotation degree of the apical vertebra were also recorded and compared between two groups. While in group B, misplacement of the apical screws was calculated on CT scans. Results: There was no statistical difference with respect to the chronological age, gender distribution, the preoperative Cobb angle, curve flexibility and rotation degree of the apex between the two groups. No case suffered from coronal or sagittal imbalance postoperatively. The loss of correction was also not significant in both groups. The implant density averaged 63.4% in group A and 65.3% in group B. The fusion levels were 11.3 in group A and 11.6 in group B. The correction rate in Cobb angle was 73.9% in group A and 72.6% in group B. There was no statistical difference in terms of implant density, number of fused vertebrae or the Cobb angle correction rate between the two groups. However, as for the derotation degree of the apical vertebrae, group A had a significantly lower degree(18.4%) than group B(34.8%)(P<0.05). In the 41 pedicle screws instrumented in the apical vertebrae in group B, 5(12.2%) were identified as misplacement

  1. 后路椎间融合加椎弓根螺钉固定术治疗退行性腰椎间盘病变%Posterior lumbar interbody fusion combined with pedicle screw fixation in treatment of degenerative diseases of lumbar intervertebral disc

    Institute of Scientific and Technical Information of China (English)

    黄占柱; 仇小华; 张如意

    2011-01-01

    Objective To investigate the clinical effect of treating the patients suffering from degenerative diseases of lumbar intervertebral disc with posterior lumbar interbody fusion (PLIF) combined with pedicle screw fixation.Methods This study was based on 100 cases suffering from degenerative diseases of lumbar intervertebral disc who underwent PLIF combined with pedicle screw fixation.All the patients were followed by 1 - 2 years.The shape and the function of spinal column were both estimated before and after the operation,and they were also estimated during the following of the patients after the operation.The datas in the formal 3 stages were multiply compared.Results Between the preoperative and postoperative datas,there were statistically significant differences in the JOA scores and the angle of scoliosis and kyphosis (P < 0.05 ).And so do the preoperative datas and the datas during the following (P <0.05).But no similar result was detected between the postoperative data and the data during the following (P > 0.05).Conclusions Posterior lumbar interbody fusion (PLIF) combined with pedicle screw fixation has a significant effect in treating degenerative diseases of lumbar intervertebral disc,deserving further study and clinical popularization.%目的 探讨后路椎间融合加椎弓根螺钉固定术治疗退行性腰椎间盘病变的临床疗效.方法 对100例退行性腰椎间盘病变患者采取后路椎间融合加椎弓根螺钉固定术,术后予1~2年随访,并比较术前、术后及随访时脊柱形态、功能恢复情况(JOA评分).结果 术后与术前患者脊柱后凸、侧凸角度和JOA评分比较差异均有统计学意义(P均<0.05),随访时与术前比较差异也有统计学意义(P<0.05),随访时与术后比较差异无统计学意义(P>0.05).结论 后路椎体间融合术治疗退行性腰椎间盘病变效果显著,有进一步研究和推广价值.

  2. Clinical Application of Single-side Pedicle Screw Fixation for Lumbar Posterior Fusion under Quad-rant System%可扩张通道单侧椎弓根内固定在腰椎融合术中的临床应用

    Institute of Scientific and Technical Information of China (English)

    张帅; 徐皓; 尹承慧; 黄小金

    2016-01-01

    目的:探讨经肌间隙可扩张通道单侧椎弓根内固定在单节段腰椎融合术中的临床应用价值。方法2012年8月至2014年6月,随机选取我院具有完整临床资料和随访信息的经肌间隙可扩张通道单侧椎弓根螺钉固定的患者45例。观察末次随访 Oswestry 功能障碍指数评分(oswestry disability index,ODI)和腰腿痛视觉模拟评分(visual an-alogue scale,VAS),术后1年 X 线片/ CT 观察测量椎间隙高度及观察椎间融合情况。结果术后末次随访 ODI、VAS评分及椎间隙高度较术前差异均有统计学意义(P <0.05),末次随访植骨融合率为100%。结论可扩张通道单侧椎弓根内固定在腰椎融合术中具有创伤小的优点,且疗效肯定,为腰椎退行性疾病的患者提供了一种简单、有效的治疗方法。%Objective To assess the clinical value of minimally invasive single-side pedicle screw fixation for lumbar pos-terior fusion. Methods A consecutive series of 45 patients who had undergone lumbar spinal fusion of 1 segment to treat de-generative lumbar disease was analyzed,which underwent TLIF with unilateral pedicle screw fixation under Quadrant system. More than 1 year all the patients were followed up with VAS scores and Oswestry disability questionnaire. All the patients ac-cepted X-line/ CT evaluation to compare the intervertebral height/ fusion rates at the operative level pre-operation with post-op-eration. Results The ODI score,VAS score and intervertebral height were significantly improved when compared with preop-erative one. The fusion rate were 100% . Conclusion Single-side pedicle screw fixation assisted by under Quadrant system caused less iatrogenic injury and had positive efforts post-operation. It can provide a simple and reliable choice in degenerative lumbar disease.

  3. 术前计划在脊柱微创手术机器人椎弓根螺钉置入操作中的价值探讨%Clinical value of preoperative plan in spinal minimal invasive robot system assisted drilling for pedicle screw placement on cattle lumbar spine

    Institute of Scientific and Technical Information of China (English)

    王洪伟; 张鹤; 李长青; 赵忆文; 韩建达; 周跃

    2013-01-01

    [Objective] To evaluate and investigate the clinical value of the drilling for pedicle screw placement on cattle lumbar spine through preoperative plan by using spinal minimal invasive robot system, summarize the experience, optimize the design of the system. [ Methods] Sixteen cattle lumbar spines were randomly divided into two groups. Preoperative computed to-mographic ( CT) scan of 8 lumbar spines in experimental group (EG) in axial plane were captured for each vertebra from the CT film, the surgeon planed the entry point and trajectory of the screws. Intraoperative fluoroscopic X - rays was used to locate the relative position of the robotic arm and the speciman. On the basis of preoperative CT scan and introoperative fluoroscopic data, we aligned the robot to the desired entry point and trajectory, as dictated by the surgeons preoperative plan. The other 8 cattle lumbar spines in contral group (CG) were drilled the pedicle hole in operation under the guidance of introperative C - arm fluo-roscopy. Sixteen cattle lumbar spines were inserted 160 K -wires by using the spinal minimal invasive robot system. The time for system registration and pedicle drilling, fluoroscopic times and the radiation exposure time were measured and recorded. Postoperative CT scans were used to assess the position of the K - wires. [ Results] Assisted by spinal minimal invasive robot system, the average time for system registration was (351. 7 ±24. 9) s, the time for procedure of drilling one K - wire in EG and CG was respectively (89. 5 ± 6. 1) s and (447. 5 ± 90. 7) s , fluoroscopic for the procesure was respectively (2. 9 ±0. 8) times and ( 11. 5 ± 3. 8) times, the radiation exposure time was respectively (2. 9 ± 1.0) s and (11.1 ±3.2) s , there were significant difference between the two groups (P =0.000, t = - 11. 143; P =0. 000, t= -6. 243; P =0.000, t = -7.002) . Overall, only twelve (15. 0% ) of the 80 screws in EG violated the pedicle wall. Four screws (5.0% ) were

  4. Polymethylmethacrylate augmentation of a cannulated and fenestrated pedicle screw for lumbar degenerative disease accompanied with osteoporosis:strengthening technical points%骨水泥注入中空侧孔椎弓根螺钉内固定骨质疏松性腰椎退变:强化技术要点

    Institute of Scientific and Technical Information of China (English)

    荆丹峰; 许艺荠; 孙太存; 田进; 鲁彪; 崔学文

    2014-01-01

    BACKGROUND:Once lumbar degenerative diseases merge with lumbar spinal stenosis, lumbar instability and degenerative scoliosis, surgical therapy is required for corresponding clinical symptoms, and the usage of internal fixators cannot be inevitable. Osteoporosis is rather common in the elderly. Therefore, how to implant stable pedicle screw fixation system in serious osteoporosis patients wil be a big difficulty. In recent years, some studies have proven the biomechanical stability of polymethylmethacrylate augmentation of a cannulated and fenestrated pedicle screw in the vertebral body, so it becomes very hot in the spine surgery. OBJECTIVE: To explore the clinical efficacy of the use of polymethylmethacrylate augmentation of a cannulated and fenestrated pedicle screw fixation for the treatment of lumbar degenerative disease accompanied with osteoporosis. METHODS:Thirty-one patients with lumbar degenerative disease accompanied with osteoporosis from Jun 2008 to Jan 2013 were selected, including 11 males and 20 females with an average age of 73.5 years (range, 65-86 years). There were 14 cases of lumbar degenerative stenosis, 9 of lumbar intervertebral disc herniation combined with segmental instability, 6 of lumbar degenerative spondylolisthesis, and 2 of lumbar degenerative scoliosis. The patients were treated with lumbar canal decompression, fusion and polymethylmethacrylate augmentation of a cannulated and fenestrated pedicle screw fixation according to their clinical features and imaging data. Visual analog scale for pain evaluation was used before and after fixation, the Japanese Orthopaedic Association (JOA) scale was used for assessment of neurological function and life skils before internal fixation and during folow-up. RESULTS AND CONCLUSION:Al cases were folowed up for 40 months (range, 36-48months). No screw breakage, rod breakage, screw extraction, loosening, pseudoarticulation formation, or incision infection was found. The postoperative visual

  5. Estimation of residual microaccelerations on board an artificial earth satellite in the monoaxial solar orientation mode

    Science.gov (United States)

    Ignatov, A. I.; Sazonov, V. V.

    2013-09-01

    The mode of monoaxial solar orientation of a designed artificial Earth satellite (AES), intended for microgravitational investigations, is studied. In this mode the normal line to the plane of satellite’s solar batteries is permanently directed at the Sun, the absolute angular velocity of a satellite is virtually equal to zero. The mode is implemented by means of an electromechanical system of powered flywheels or gyrodynes. The calculation of the level of microaccelerations arising on board in such a mode, was carried out by mathematical modeling of satellite motion with respect to the center of masses under an effect of gravitational and restoring aerodynamic moments, as well as of the moment produced by the gyrosystem. Two versions of a law for controlling the characteristic angular momentum of a gyrosystem are considered. The first version provides only attenuation of satellite’s perturbed motion in the vicinity of the position of rest with the required velocity. The second version restricts, in addition, the increase in the accumulated angular momentum of a gyrosystem by controlling the angle of rotation of the satellite around the normal to the light-sensitive side of the solar batteries. Both control law versions are shown to maintain the monoaxial orientation mode to a required accuracy and provide a very low level of quasistatic microaccelerations on board the satellite.

  6. Screw in the aorta: minimally invasive graft replacement for chronic aortic erosion by spinal instrument.

    Science.gov (United States)

    Fukuda, Wakako; Aoki, Chikashi; Daitoku, Kazuyuki; Taniguchi, Satoshi; Fukuda, Ikuo

    2013-01-01

    Intra-and early post-operative aortic injury by pedicle screw is not a rare complication in orthopedic surgery, but aortic penetration by a screw head over a long time period is considered as an uncommon case. There are various surgical management options for thoracic aortic injury caused by malpositioned spinal instruments. We report a case of a patient who underwent minimally invasive graft replacement of the descending thoracic artery for pedicle screw penetration.

  7. The accuracy and the safety of individualized 3D printing screws insertion templates for cervical screw insertion.

    Science.gov (United States)

    Deng, Ting; Jiang, Minghui; Lei, Qing; Cai, Lihong; Chen, Li

    2016-12-01

    Clinical trial for cervical screw insertion by using individualized 3-dimensional (3D) printing screw insertion templates device. The objective of this study is to evaluate the safety and accuracy of the individualized 3D printing screw insertion template in the cervical spine. Ten patients who underwent posterior cervical fusion surgery with cervical pedicle screws, laminar screws or lateral mass screws between December 2014 and December 2015 were involved in this study. The patients were examined by CT scan before operation. The individualized 3D printing templates were made with photosensitive resin by a 3D printing system to ensure the screw shafts entered the vertebral body without breaking the pedicle or lamina cortex. The templates were sterilized by a plasma sterilizer and used during the operation. The accuracy and the safety of the templates were evaluated by CT scans at the screw insertion levels after operation. The accuracy of this patient-specific template technique was demonstrated. Only one screw axis greatly deviated from the planned track and breached the cortex of the pedicle because the template was split by rough handling and then we inserted the screws under the fluoroscopy. The remaining screws were inserted in the track as preoperative design and the screw axis deviated by less than 2 mm. Vascular or neurologic complications or injuries did not happen. And no infection, broken nails, fracture of bone structure, or screw pullout occurred. This study verified the safety and the accuracy of the individualized 3D printing screw insertion templates in the cervical spine as a kind of intraoperative screw navigation. This individualized 3D printing screw insertion template was user-friendly, moderate cost, and enabled a radiation-free cervical screw insertion.

  8. Transforaminal lumbar interbody fusion combined unilateral pedicle screw fixation for upper lumbar disc herniation%经椎间孔融合联合单侧椎弓根钉内固定治疗高位腰椎椎间盘突出症

    Institute of Scientific and Technical Information of China (English)

    付松; 邵诗泽; 荣晓玲; 侯海涛; 孙秀琛; 刘海军; 王龙强; 王欢; 黄相鹏

    2013-01-01

    Objective To evaluate the clinical effect of unilateral transforaminal lumbar interbody fusion (TLIF) combined unilateral pedicle screw fixation for the treatment of upper lumbar disc herniation.Methods From Mar 2006 to December 2008,23 cases with upper lumbar disc herniation undewent laminectomy,transforamina discectomy and lumbar interbody fusion were reviewed retrospectively.The involved level included L1/L2 in 5 cases,L2/L3 in 8 cases and L3/L4 in 10 cases.All cases were treated by single cage combined unilateral pedicle screw placement.Japanese Orthopaedic Association (JOA) scores (29 scores) were used to assesse the clinical outcome and the excellent rate,improve rate and fusion status were reviewed retrospectively.Results Complications included dural tear(1 cases) and pedicle screw deviating(1 cases).The mean follow-up time was 40.2 months(24 ~ 52 months).The preoperative JOA score was 10.04 ± 2.12,and 24.13 ± 3.39 at 23 months postoperative.excellent rate was 91.3%.Bone fusion rate was 95.8%.Conclusion Unilateral transforaminal lumbar interbody fusion combined unilateral pedicle screw fixation has the advantages of small incision,little bleeding,no destruction of the contralateral structure,short operating time or hospital stay,low medical device expenses and good recovery.%目的 观察经椎间孔融合(transforaminal lumbar interbody fusion,TLIF)联合单侧椎弓根钉内固定治疗高位腰椎椎间盘突出症的临床疗效.方法 2006年3月~2008年12月收治且获得随访的单间隙高位腰椎椎间盘突出症患者23例,其中L1/L2 5例,L2/L3 8例,L3/L4 10例.均采用经椎间孔单枚Cage植骨融合并单侧椎弓根螺钉内固定术治疗.根据日本骨科学会(Japanese Orthopaedic Association,JOA)(29分)评分法评估术后疗效,计算改善率和优良率,观察植骨融合情况.结果 1例硬脊膜撕裂,1例椎弓根螺钉位置偏斜.随访23~52个月,平均40.2个月,JOA评分由术前10.04±2.12提高到随访23

  9. 后路漂浮法减压内固定治疗严重黄韧带骨化型胸椎管狭窄症%Treatment of Thoracic Spine Stenosis by Laminectomy Using “Lamina Floating” Technique and Internal Fixation with Severe Ossification of the Ligamentum Flavum by Pedicle Screw

    Institute of Scientific and Technical Information of China (English)

    陈建梅; 姚晓东; 黄丽花; 李金泉; 徐皓

    2012-01-01

    Objective To evaluate the effect of laminectomy using "lamina floating" technique and internal fixation by pedicle screw to thoracic spine stenosis with severe ossification of the ligamentum flavum (OLF-TSS). Methods From January 2007 to October 2010,15 patients of OLF-TSS in the hospital treated with laminectomy using "lamina floating" technique and internal fixation by pedicle screw were retrospectively analyzed according to Japanese Orthopaedic Association (JOA) scoring system and complications. Results The mean follow-up period was 10. 3 months (ranging from 5 months to 3 years). According to the JOA scoring system,excellent in 10 cases,good in 3 cases, the excellent and good rate was 86. 7%. 2 cases with cerebrospinal fluid leakage were recovered after repaired with back fascia. Conclusion Laminectomy using "lamina floating" technique is a safe and effective method for decompression of OLF-TSS, and internal fixation by pedicle screw can effectively rebuild spinal stability post-operation. So laminectomy using "lamina floating" technique and internal fixation by pedicle screw is a good choice for severe ossification of the ligamentum flavum thoracic spine stenosis.%目的 探讨经后路漂浮法减压及内固定术治疗严重黄韧带骨化型胸椎管狭窄症的疗效.方法 2007年1月至2010年10月,我科收治严重黄韧带骨化型胸椎管狭窄症15例,根据Miyakoshit分型均为融合型,其中男7例,女8例;年龄40~67岁,平均56岁.所有患者术前均行X线、CT、MRI检查,并采用后路漂浮法减压+椎弓根钉内固定术.通过JOA评分、并发症发生情况评估疗效.结果 术后15例均获得随访,随访5个月~3年,平均10.3个月.根据JOA评分进行疗效评价,优10例,良3例,可2例,优良率86.7%.其中2例出现硬脊膜撕裂,经腰背筋膜修复后痊愈.结论 后路漂浮法可以安全有效地对受压胸髓实现减压,椎弓根钉内固定可以提供脊柱稳定,是治疗黄韧带骨化型胸椎管狭窄症的良好术式.

  10. Preliminary report of C1-C2 pedicle screw fixation for pediatric atlantoaxial dislocation%寰枢椎椎弓根螺钉内固定术治疗儿童寰枢椎脱位的初步报告

    Institute of Scientific and Technical Information of China (English)

    谭明生; 唐向盛; 王文军; 张恩中; 移平; 杨峰; 蒋欣; 郝庆英

    2012-01-01

    Objectives: To investigate the surgical feasibility and short-term clinical outcome of C1-C2 pedicle screw fixation for pediatric atlantoaxial dislocation. Methods: Between September 2005 and March 2011, 16 cases suffering from pediatric atlantoaxial dislocation undergoing atlantoaxial pedicle screw instrumentation were reviewed retrospectively. There were 9 males and 7 females with the age at time of surgery ranging from 5 to 13 years (mean, 9.1 years). All patients presented with pain at craniocervical junction and neck stiffness. 3 cases were complicated with medulla compression, and according to ASIA classification, there were 2 grade D and 1 grade C. Standard anterior-posterior, lateral and flexion-extension radiographs, computed tomography and MRI of cervical spine were obtained in all patients before operation. All patients presented with atlantoaxial dislocation, and the pathogenesis included disruption of transverse ligament(n=l), atlantoaxial fracture and dislocation(n=l), congenital odontoid malfromation(n=12), atlantoaxial rotatory subluxation(n=2). Cervical spinal cord compression was identified in 5 cases. The height of Cl posterior arch was 2.5-3.8mm (average, 3.0mm). The atlanto-dental interval(ADI) was 6-14mm(average, 9mm). Preoperative skull traction wasperformed rou-tinely on all cases for 1-2 weeks, and complete reduction was achieved in 7 cases, incomplete reduction in 5 cases, and no reduction in 4 cases. All patients had Cl pedicle screws placed as part of a fixation construct with pedicle exposure method(PEM). C1-C2 pedicle screw placement under direct vision in-traoperativeiy, reduction and fixation, bone graft and fusion were administered in all cases. The neurological function and CT scan were used to evaluate the surgical outcome. Results: All 16 patients underwent bilateral atlantoaxial pedicle screw fixation. All operations were completed successfully. A total of 64 screws were successfully placed. Reduction and fixation were

  11. 腰椎皮质骨钉道螺钉在骨质疏松症患者中应用的三维有限元分析%Biomechanical evaluation of lumbar pedicle screws using cortical bone trajectory in osteoporosis:a finite element study

    Institute of Scientific and Technical Information of China (English)

    邵明昊; 吕飞舟; 马晓生; 夏新雷; 王洪立; 郑超君; 张帆; 姜建元

    2015-01-01

    Huashan Hospital of Fudan University from March to September 2015. All of these patients were female with T value of bone mineral density less than -2.5 SD. Pedicle screws were placed using TT screw (6.5 mm diameter, length of 45 mm) or CBT screw (diameter of 5.0 mm, length of 35 mm). Carefully compare the two models in terms of the axial pull-out strength, the screw stability and the vertebral construct stability.Results The pull-out strength of CBT screw group (1 277.1±331.3) N was 26.04% higher compared with that of the TT screw group [(1 013.2±279.1) N, (t=3.128,P=0.024)]. The load stress-displacement ratio of CBT screw group is significantly higher than that of TT screw group (P<0.05). The CBT construct had superior resistance to flexion and extension loading and inferior resistance to lateral bending and axial rotation (P<0.05). The load-displacement ratio of axial direction, lateral bending, and rotation in TT screw group were higher compared to CBT screw group (P<0.05). Conclusion The three-dimensional finite element can effectively simulate lumbar structure of patients with osteoporosis. CBT screw group is demonstrated to have superior fixation strength for each individual screw and sufficient stiffness in flexion and extension within a construct. Compared with TT screw, CBT screw may be more beneficial for osteoporotic patients.

  12. 固定角度侧块与椎弓根钉棒系统治疗无神经损伤胸腰椎骨折%The fixed-angle lateral masses and pedicle screw and rod system for thoracolumbar fractures without nerve injuries

    Institute of Scientific and Technical Information of China (English)

    滕勇; 季明华; 李强; 向阳; 张文举; 戎帅; 郭树章; 谷长增

    2013-01-01

    Objective To investigate the curative results of fixed-angle lateral masses in the posterior approach and the pedicle screw and rod system in the treatment of thoracolumbar fractures without nerve injuries. Methods From October 2008 to February 2012, 38 patients who had thoracolumbar burst fractures without neurological symptoms or decompression and with mechanical instability were included in the study. They were treated by the ifxed-angle lateral masses in the posterior approach (-100,-50, 00, 50 and 100 ) and reduction and ifxation of the pedicle screw and rod system. Single short-segment ifxation was performed on the patients without posterior ligamentous complex injuries. Pedicle screw ifxation at the injured level was performed on the patients with posterior ligamentous complex injuries and complete pedicle at the injured level. The patients with combined pedicle injuries at the injured level underwent ifxation of 2 vertebral bodies up and down. Posterolateral fusion was achieved in all patients with posterior ligamentous complex injuries. Wearing a brace, all patients were able to walk at 1-3 days after the operation. The preoperative and postoperative X-ray, CT and MRI data of all patients were reviewed. Results All patients were followed up thoroughly for a mean period of 28.2 months ( range;4-40 months ). No breakage of screws or rods or the failure of internal ifxation occurred. The mean operation time was 92 ( 82.6±19.2 ) minutes. The mean height of injured vertebral bodies was 41.6% preoperatively, which was increased to 91.2% postoperatively. The mean Cobb’s angle was 35.3° preoperatively, which was decreased to 7.8° postoperatively. The mean sagittal plane displacement was ( 32.7±7.6 )%preoperatively, which was decreased to ( 8.7±4.9 )%postoperatively ( P<0.05 ). Conclusions It is an ideal treatment method of the fixed-angle lateral masses and pedicle screw and rod system for thoracolumbar burst fractures without nerve injuries and with

  13. Real-Time Monitoring Method for Pedicle Screw Fixation Surgery Based on Near-Inf rared Spectrum and Computer Tomography Images%联合近红外参数与CT影像的椎弓根螺钉监测方法

    Institute of Scientific and Technical Information of China (English)

    刘洋洋; 王钰妍; 高慧; 钱志余; 谢捷如; 李韪韬

    2016-01-01

    Spine is one of the most important organs in the human body .One of the most commonly used method for the treat‐ment of spinal diseases is the internal fixation and accurate placement of pedicle screw ,which is a key factor of spinal surgery . However ,due to the large differences as to the appearance of pedicles ,it is hard to place the pedicle screw precisely ,which will cause complication .Therefore ,to find a new real‐time intra‐operative monitoring method with navigation is the direction of clini‐cal application research .In this paper ,a new method was firstly proposed .This method combined computer tomography (CT ) values and near‐infrared spectroscopy (NIRs) measurement data to guide the PS placement ,and the relationship between NIRs parameters and CT values along the PS trajectory in vertebrae was investigated .First ,we took pig vertebrae as samples and dif‐ferent puncture paths were planned .Second ,a near‐infrared monitoring device was utilized in experiments of fresh pig vertebrae to acquire the best NIRs monitoring pattern factors .Finally ,the correlation function between NIRs data and CT values pattern factors was obtained .The results showed that CT values have a linear relationship with NIRs monitoring pattern factors ,which provide references for real‐time monitoring method in pedicle screw fixation surgery .This model can be applied in monitoring the pedicle screw implantation and alarming .The proposed method will be potential in improving the accuracy of PS placement and reduce the risk caused by the misplacement of pedicle screw .%脊柱的治疗非常重要,其中螺钉的准确植入是其内固定术的一个重要影响因素。但由于椎骨外形差异较大,很容易在螺钉植入过程中出现误植,从而引起并发症。因此,需要寻找一种准确的椎弓根螺钉植入检测与监测方法。提出了一种联合近红外参数和CT 影像方法,该方法可应用于椎弓根螺钉的植入过

  14. Investigation of conductivity switching upon action of monoaxial pressure on plasticized PVC films

    CERN Document Server

    Vlasov, D V; Krystob, V I; Vlasova, T V

    2010-01-01

    The effect of conductivity switching of wideband polymers -plasticized PVC films under the influence of mono axial pressure is experimentally investigated. For various plasticizers the value of monoaxial pressure, causing jumps of conductivity on four and more orders, changes from units to hundreds bars, and the effect remains at a thickness of films of an order of hundreds micron, that is on two orders more than critical thickness for others wideband polymers. In addition to the reasons stated earlier on the interpretation of anomalies of plastic compounds conductivity, the phenomenological electron-molecular model of dynamic traps is considered, in which local transfer of charges is carried out by mobile segments of the plasticized polymer molecules.

  15. 寰枢椎椎弓根螺钉术中复位固定融合术治疗陈旧性齿状突骨折并寰枢椎脱位%Surgical treatment with atlantoaxial pedicle screws for reduction of atlantoaxial dislocation caused by old odontold fracture

    Institute of Scientific and Technical Information of China (English)

    杨军; 倪斌; 谢宁; 王新伟; 周许辉; 卢旭华; 郭翔; 陈飞

    2012-01-01

    Objectives: To summarize the clinical results of the posterior atlantoaxial pedicle screw-rod internal fixation with its intraoperalive reduction and fusion in treatment of old odontoid fracture combined with unreducible atlanloaxial dislocation. Methods: Twenty-one(8 females, 13 males) patients with an average age of 38.5 (13-68) years at the time of injury between January 2007 and January 2010 were studied. The patients had various degrees of occipital neck pain, limited mobility and associated with neurological dysfunction. Degree B in 2 cases, degree C in 13 cases and degree D in 6 cases were assessed by the ASIA impairment scale. Japanese Orthopaedic Association (JOA) scores before operation were recorded from 4 to 14 (mean, 8.3). Cervical spinal cord compression was showed by MRI examination in 18 patients, and in-tramedullary T2-weighted high signal change was found by MRI in 7 patients. All patients had anterior atlantoaxial dislocation, and underwent skull traction before operation. Fifteen cases were partially reduced (71.4%), and 6 not reduced at all (28.6%). The preoperative atlanlo-dens interval (ADI) was from 9mm to 15mm (average 12.3mm). Patients were treated with posterior atlanloaxial pedicle screw-rod internal fixation with its intraoperative reduction and fusion. All patients were assessed clinically for neurologic recovery, at-lantoaxial reduction and bone graft fusion. Results: No intraoperative vertebral artery injury and spinal cord injury were noted. A total of 84 pedicle screws was inserted. Postoperative CT reconstruction showed that 4 screw malpositions were noted, 3 of which penetrated lateral pedicle cortex but no vertebral artery injury confirmed by vertebral angiography, 1 penetrated medial pedicle cortex but no symptom of nerve root injury was found. 80 screws were sited completely in pedicle. All 21 patients were followed up for an average of 20 months(range, 6-36 months). Postoperative cervical spine CT and MRI showed that the

  16. Study of Bone-screw Surface Fixation in Lumbar Dynamic Stabilization

    Directory of Open Access Journals (Sweden)

    Yun-Gang Luo

    2015-01-01

    Full Text Available Background: We aimed to use the animal model of dynamic fixation to examine the interaction of the pedicle screw surface with surrounding bone, and determine whether pedicle screws achieve good mechanical stability in the vertebrae. Methods: Twenty-four goats aged 2-3 years had Cosmic ® pedicle screws implanted into both sides of the L2-L5 pedicles. Twelve goats in the bilateral dynamic fixation group had fixation rods implanted in L2-L3 and L4-L5. Twelve goats in the unilateral dynamic fixation group had fixation rods randomly fixed on one side of the lumbar spine. The side that was not implanted with fixation rods was used as a static control group. Results: In the static control group, new bone was formed around the pedicle screw and on the screw surface. In the unilateral and bilateral dynamic fixation groups, large amounts of connective tissue formed between and around the screw threads, with no new bone formation on the screw surface; the pedicle screws were loose after the fixed rods were removed. The bone mineral density and morphological parameters of the region of interest (ROI in the unilateral and bilateral dynamic fixation group were not significantly different (P > 0.05, but were lower in the fixed groups than the static control group (P 0.05; however the maximum pull force of the fixation groups was significantly less than the static control group (P < 0.01. Conclusions: Fibrous connective tissue formed at the bone-screw interface under unilateral and bilateral pedicle dynamic fixation, and the pedicle screws lost mechanical stability in the vertebrae.

  17. Pedicale screw system plus ACPC perfusion to treat fractures of thoracolumbar vertebrae

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@In recent years the pedicle screw system has been widely used in treating thoracolumbar vertebral fractures. The effect to recover the injured vertebrae height, the spinal physiological curve and to decompress vertebral canal has been confirmed. But the problems of internal fixation bending, loosening and breaking, which result in the loss of the vertebral height and spinal angulation deformity, are quite common and cause a lot of difficulties for surgeons. To solve these problems and decrease the sequelae from treating thoracolumbar vertebrae fractures with vertebral pedicle screw system, we have tried using vertebral pedicle screw system plus ACPC perfusion to treat 18patients with thoracolumbar vertebral fractures.Satisfactory results have been obtained.

  18. Biomechanical comparison of reconstruction plate versus pedicle screw-rod system in fixation of the models of Tile B1 pelvic injury%钢板与钉棒系统固定骨盆Tile B1型损伤模型的生物力学比较

    Institute of Scientific and Technical Information of China (English)

    李尚政; 苏伟; 庄小强; 白宇; 陆生林

    2014-01-01

    Objective To compare the biomechanical properties of reconstruction plate and pedicle screw-rod system in fixation of the models of Tile B1 pelvic injury.Methods We used 7 cadaveric specimens of normal adult pelvis from 2 males and 5 females with an average death age of 42.1 years.The cadaveric pelvis preserved an intact spine from the fifth lumbar vertebra to 20 centimeters above the proximal ends of both femurs,intact pubic symphysis,bilateral hip joints,bilateral sacroiliac joints,and major pelvic ligaments.After the pelvic specimens were put in an AGS-X biomechanical testing machine at a simulated standing neutral posture,they were subjected to a vertical load of up to 500 N downward from the L5 vertebral body.The displacements of the symphysis pubis were recorded sequentially in the following 4 conditions:1.intact pelvis (the intact group); 2.models of Tile B1 pelvic injury simulating rotatory unstable injury of the pelvis in which the symphysis pubis was cut apart in combination with ruptures of ipsilateral sacrospinous and sacrotuberous ligaments (the injury group); 3.Tile B1 pelvic injury fixated with a reconstruction plate (the plate group).4.Tile B1 pelvic injury fixated with the pedicle screw-rod system (the screw-rod group).Results Under the vertical load of 500 N,the displacements of the symphysis pubis in the intact,injury,plate and screw-rod groups were respectively 0.121 ±0.025 mm,4.512 ±0.391 mm,0.358 ±0.051 mm,and 0.656 ±0.103 mm.There were significant differences between the 4 groups (F =725.707,P =0.000).The displacement increased from the intact group,the plate group,the screw-rod group to the injury group.The differences between any 2 groups were significant (P < 0.05).Conclusions In fixation of the models of Tile B1 pelvic injury,the reconstruction plate and the pedicle screw-rod system can both effectively restore the biomechanical stability of the injured pelvis.However,internal fixation with the reconstruction plate may yield better

  19. RISK FACTORS OF PEDICLE FIXATION INSTABILITY AT PATIENTS WITH DEGENERATIVE LUMBAR SPINE PATHOLOGY

    Directory of Open Access Journals (Sweden)

    A. E. Bokov

    2016-01-01

    Full Text Available Objective. To assess risk factors оf pedicle screw instability after decompression and fusion in patients with degenerative lumbar spine disease.Materials and methods. This is a prospective non-randomized study, the results of 130 surgical interventions with pedicle instrumentation in patients with degenerative lumbar spine diseases were studied. Minimal follow up period accounts for 18 months. Before intervention computed tomography (CT was applied and cancellous bone radiodensity was measured.Patients were treated with nerve root decompression and pedicle screw fixation stand-alone or with lumbar interbody fusion. During follow-up period computed tomography was applied and cases with evidence of pedicle screw loosening were detected. Radiodensity of cancellous bone, extension of fixation, extensiveness of decompression, application of interbody fusion, incomplete vertebra body reduction and heterogeneity of studied group were taken into account as potential risk factors of implant instability development. The correlation between pedicle screws loosening rate and mentioned predictors was estimated using logistic regression analysis.Results. Radiodensity of vertebra body cancellous bone getting decreased, the increase number of fixed levels and extensiveness of facet joints and ligaments resection are associated with the increased risk of a screw loosening development. Laminectomy, interbody fusion, altered biomechanics associated with incomplete vertebra body reduction and L5–S1 segment included into fixed zone did not have a significant influence on pedicle screws loosening rate. Bias related to heterogeneity of studied group was also insignificant. Goodness-of-fit of estimated general logistic regression model: № 2 = 67,57851; p < 0,0001. This model classified correctly 81,5% cases with sensitivity and specificity of 77,4% and 85,3% respectively.Conclusion. Radiodensity of a vertebra cancellous bone, number of fixed levels and

  20. Is There Asymmetry Between the Concave and Convex Pedicles in Adolescent Idiopathic Scoliosis? A CT Investigation.

    Science.gov (United States)

    Davis, Colin M; Grant, Caroline A; Pearcy, Mark J; Askin, Geoffrey N; Labrom, Robert D; Izatt, Maree T; Adam, Clayton J; Little, J Paige

    2017-03-01

    Adolescent idiopathic scoliosis is a complex three-dimensional deformity of the spine characterized by deformities in the sagittal, coronal, and axial planes. Spinal fusion using pedicle screw instrumentation is a widely used method for surgical correction in severe (coronal deformity, Cobb angle > 45°) adolescent idiopathic scoliosis curves. Understanding the anatomic difference in the pedicles of patients with adolescent idiopathic scoliosis is essential to reduce the risk of neurovascular or visceral injury through pedicle screw misplacement. To use CT scans (1) to analyze pedicle anatomy in the adolescent thoracic scoliotic spine comparing concave and convex pedicles and (2) to assess the intra- and interobserver reliability of these measurements to provide critical information to spine surgeons regarding size, length, and angle of projection. Between 2007 and 2009, 27 patients with adolescent idiopathic scoliosis underwent thoracoscopic anterior correction surgery by two experienced spinal surgeons. Preoperatively, each patient underwent a CT scan as was their standard of care at that time. Twenty-two patients (mean age, 15.7 years; SD, 2.4 years; range, 11.6-22 years) (mean Cobb angle, 53°; SD, 5.3°; range, 42°-63°) were selected. Inclusion criteria were a clinical diagnosis of adolescent idiopathic scoliosis, female, and Lenke type 1 adolescent idiopathic scoliosis with the major curve confined to the thoracic spine. Using three-dimensional image analysis software, the pedicle width, inner cortical pedicle width, pedicle height, inner cortical pedicle height, pedicle length, chord length, transverse pedicle angle, and sagittal pedicle angles were measured. Randomly selected scans were remeasured by two of the authors and the reproducibility of the measurement definitions was validated through limit of agreement analysis. The concave pedicle widths were smaller compared with the convex pedicle widths at T7, T8, and T9 by 37% (3.44 mm ± 1.16 mm vs 4

  1. Radiological studies on the best entry point and trajectory of anterior cervical pedicle screw in the lower cervical spine%下颈椎前路椎弓根螺钉最佳进钉点和进钉方向的影像学研究及其临床运用

    Institute of Scientific and Technical Information of China (English)

    赵刘军; 徐荣明; 华群; 马维虎; 蒋伟宇; 朱彦召

    2012-01-01

    Objective:To explore the best entry point and trajectory of anterior cervical screw in the cervical screw by radiological studies,and provide reference for clincal application. Methods:From January 2008 to December 2010,50 patients were scanned by cervical CT and confirmed no obvious defect of lower cervical spine. Of them, 27 cases were males and 23 were females,ranged the age from 38 to 83 years ( mean 58.5 years). On horizontal axis,the camber angle of C3-C7 anterior lower cervical pedicle of vertebral arch axis (α) and distance between (axial length, AL) of anterior cervical pedicle axial line was measured from C3 to C7- Vertebral were divided into four areas, and from measured side of pedicle of vertebral began to record, orderly 1 to 4, the area of pedicle vertebral arch intersert into vertebral were recorded. On sagittal view, the head or tail angle(β)and length (sagittal length,SL)of anterior cervical pedicle axial line was also measured from C3 to C7- Vertebral were divided into four areas,and from measured side of pedicle of vertebral began to record, orderly 1 to 4, the area of pedicle verte-bralarch arch intersert into vertebral were recorded. The above data were statistically analyzed to find the best entry point and trajectory of anterior cervical screw in the cervical screw and insert pedicle screw. Results:The lateral angle of lower cervical spine was 38° to 45° on transverse plane,C3 to C5 increasing gradually,C5 to C7 decreasing. On sagittal view,C3,C4 pedicle were head tulting, C5 were basic level, C6, C7 were tail. C3 to C5 decreasing gradually, C5 to C7 increasing gradually. C3 to C7 in AL and SL increased gradually. On horizontal axis, the intersection of C3, C4 and C5 were in the second area, the number of C6 in the second and third area were the same,but C7 were in the third area. The intersection in the first and forth area were less. On sagittal view, the intersection of C3, C4 and C5 were in the first area, the number of C6 in third

  2. 单侧椎弓根钉固定加单枚Cage植骨融合治疗腰椎退行性疾病的临床观察%Unilateral Pedicle Screw Fixation with Single Cage Interbody Fusion Clinical Observation on the Treatment of Lumbar De-generative Disease

    Institute of Scientific and Technical Information of China (English)

    李辉

    2015-01-01

    Objective:To investigate the unilateral pedicle screw fixation with single Cage implantation clinical curative effect of the treatment of degenerative disease of lumbar spine bone fusion .Methods:From March 2007 to March 2011 hospitalized in department of orthopedics in our hospital treatment of 48 cases of lesions caused by degenerative lumbar disease were randomly divided into 2 groups ,respectively using unilateral pedicle screw fixation with single Cage inter‐body fusion in the treatment of 22 cases of the treatment group is unilateral ,bilateral pedicle screw fixation and inter‐body fusion in the treatment of single Cage 26 cases were bilateral treatment group .Comparative analysis of 2 groups of patients before and after operation of Japanese Orthopedic Association (JOA ) score and visual analogue scale (VAS) ,improvement rate ,operation time ,amount of bleeding ,hospitalization days ,cost of hospitalization and postop‐erative follow‐up of Cage bone graft fusion .Results:48 patients were followed up ,followed up for 12~24 months ,aver‐age 18 months ,two groups of patients with JOA score of VAS and compares their differences had no statistical signifi‐cance (P>0 .05)before operation ,no statistical significance at the end of the follow‐up JOA score of VAS and compares their differences (P>0 .05) ,but the patients in the 2 groups compared with the preoperative JOA score of VAS and the comparison was statistically significant (P<0 .01) .The operation time ,hemorrhage volume ,length of hospitalization , cost of hospitalization ,unilateral treatment group was significantly better than the bilateral treatment group (P<0.01) .Conclusion:Unilateral pedicle screw fixation and bone grafting with single cage spine surgery is effective opera‐tion technology ,and achieve the same clinical efficacy of bilateral pedicle screw fixation of the same in the treatment of lumbar degenerative disease .And this technique has short operation time ,intraoperative

  3. 三种单纯腰椎椎间融合并双侧椎弓根螺钉内固定后即刻稳定性的比较%Initial stability of lumbar spine following three types of interbody fusion and bilateral pedicle screw fixation

    Institute of Scientific and Technical Information of China (English)

    张烽; 陈兵乾; 居建文; 王素春; 段广超; 王以进

    2008-01-01

    BACKGROUND:Operative approaches of lumbar interbody fusion include anterior (ALIF),posterior (PLIF) and transforaminal lumbar interbody fusion (TLIF).The resected structures and cage implantation sites are different,and the initial stability of lumbar spine is varied.OBJECTIVE:To compare the initial stability of lumbar spine following ALIF,PLIF or TLIF in combination with bilateral pedicle screw fixation.DESIGN:Comparative observation.MATERIALS:Fifteen samples of fresh calf lumbar spine were used.METHODS:Models ofALIE PLIF and TLIF were simulated.After examination as normal group,the samples were randomly divided into three groups (n=5).Besides anterior,posterior and transforaminal lumbar interbody fusion include anterior,bilateral pedicle screw fixation was performed.MAIN OUTCOME MEASURES:Biomechanical characteristics of the lumbar spine before and after ALIF,PLIF or TLIF in combination with bilateral pedicle screw fixation.RESULTS:Following three approaches of lumbar interbody fusion,the stability of lumbar spine was significantly reduced,which was enhanced after bilateral pedicle screw fixation (torsion indexes were also increased).In addition,rigidity of the lumbar spine was enhanced.The stability indexes of lumbar spine following TLIF were significantly greater than the other approaches,indicating the initial stability of TLIF was the best.The rigidity,stress,and swain of lumbar spine following PLIF were greater than ALIE but torsion indexes were smaller than ALIE CONCLUSION:The stability of lumbar spine following lumbar interbody fusion was significantly reduced compared with normal sample.But bilateral pedicle screw fixation greatly increases the stability.Among three types of lumbar interbody fusion,the initial stability of lumbar spine following TLIF is the best.%背景:椎间融合术按照手术入路主要有前路椎间融合术、后路椎间融合术和椎间孔入路椎问融合术.3种融合术术中切除的结构不同,融合器置入的部位

  4. 骨盆Ⅰ-Ⅱ-Ⅳ区肉瘤整块切除后腰盆钉棒重建系统%Enbloc resection of pelvic sarcoma involving region Ⅰ , Ⅱ, IV and reconstruction with the prosthetic acetabulum pedicle screw and rod system

    Institute of Scientific and Technical Information of China (English)

    沈靖南; 王晋; 尹军强; 黄纲; 雍碧城; 李浩淼; 邹昌业

    2012-01-01

    目的 探讨骨盆Ⅰ-Ⅱ-Ⅳ区肉瘤整块切除后新设计的腰盆钉棒重建系统的临床应用.方法 回顾性研究中山大学附属第一医院骨肿瘤科,2009年6月到2010年12月期间,行骨盆Ⅰ区、Ⅱ区和Ⅳ区肉瘤整块切除和腰盆钉棒系统重建术的病例资料,评价该术式的治疗效果及术后并发症.入选条件:穿刺活检证实骨盆原发性肉瘤:肺部CT未见转移灶,Eneking分期为ⅡB期;患者能完成规范的新辅助化疗;术前MRI评估证实肉瘤未侵犯髂外动静脉、坐骨神经和盆腔脏器,确认肉瘤累及骨盆Ⅰ-Ⅱ-Ⅳ三个区域.结果 4例累及骨盆Ⅰ区、Ⅱ区和Ⅳ区的原发性肉瘤患者接受肿瘤整块切除后腰盆钉棒系统重建.患者男3例,女1例;平均年龄29.75岁(18 ~45岁).病理类型包括:尤文肉瘤2例,软骨肉瘤1例和骨肉瘤1例,尤文肉瘤和骨肉瘤完成新辅助化疗.肉瘤整块切除范围包括骨盆Ⅰ区、Ⅱ区和Ⅳ区肿瘤、肿瘤累及的髂肌、臀中小肌和部分臀大肌,同时采用骨盆髋臼和腰椎椎弓根钉棒系统重建髋臼、骨盆环和腰骶连接.术后3周患者开始进行康复治疗,术后3个月可扶拐行走.术后平均隧访14个月(9~19个月),目前尚未发现复发和转移.MSTS功能评分平均为66.67% (63% ~73%);Harris髋关节评分良2例,差2例.结论 骨盆原发性肉瘤治疗的主要目标是通过广泛切除而获得治愈,通过骨盆环重建挽救下肢的主要功能.骨盆Ⅰ区、Ⅱ区和Ⅳ区肉瘤整块切除和腰盆钉棒系统既能完整的切除肿瘤,又能有效重建骨盆和腰骶连接功能.这种重建方式近期疗效观察能够达到患者及骨肿瘤专科医生的功能期望.%Objective This study is to evaluate the effect of en bloc resection of pelvic sarcoma involving region Ⅰ, Ⅱ , Ⅳ and reconstruction with the prosthetic acetabulum pedicle screw and rod system. Methods A continuous and retrospective analysis was

  5. Clinical Analysis of Enhanced Pedicle Screw Fixation for Spinal Stenosis Caused by Osteoporosis%椎体强化椎弓根螺钉固定治疗骨质疏松性椎管狭窄的临床分析

    Institute of Scientific and Technical Information of China (English)

    官建中; 王照东; 吴敏; 周建生; 肖玉周

    2012-01-01

    目的 观察探讨老年骨质疏松性椎管狭窄行后路椎管减压、椎体强化推弓根螺钉内固定并椎间后外侧植骨的治疗效果.方法 对15例老年骨质疏松性椎管狭窄患者行经后路椎管探查减压植骨椎体强化椎弓根螺钉内固定术治疗,患者年龄为55 -75岁,平均66.5岁,术后随访12个月,观察术后并发症及症状缓解情况,回顾性分析临床资料,按照Oswesty功能障碍指数(Oswestry disabilityindex,ODI)设计问卷调查随访,对临床治疗效果进行评分并行统计学分析(P<0.05).结果 15例患者术后间歇性跛行、腰腿痛等相关神经压迫症状均有明显缓解,该术式总体优良率100%.结论 老年骨质疏松性腰椎椎管狭窄患者非手术治疗无效,经过术前相关检查及身体状况的严格评估后,无手术禁忌证者可以考虑手术治疗.经后路椎管探查减压植骨椎体强化椎弓根螺钉内固定术能有效缓解患者临床症状,提高临床疗效,是治疗老年骨质疏松性椎管狭窄的一种安全、有效的方法.%Objective To observe and investigate the effects of posterior spinal canal decompression,vertebral strengthening, pedicle screws fixation and poslerolaleral grafting in elderly patients with spinal stenosis caused by osteoporosis. Methods All 15 aged patients aged between 55 to 75 years old (average 66.5 ) with spinal stenosis caused by osteoporosis were treated with posterior spinal canal decompression,vertebral strengthening and pedicle screws fixation. A questionnaire survey was conducted to follow up the complications and conditions of the patients after surgery according to Oawestry disability index. The clinical date and scoTe of the effect were analyzed after the survey. Results The sign of neurotbltpsis such as internment ciaudicaiion, lumbago and scelalgia pain were apparently eased and the total rate of excellent or good was 100%. Conclusion The physical therapy is invalid in elderly patients with

  6. Minimally Invasive Percutaneous Injured Vertebra Pedicle Screw Fixation for Treatment of Thoracolumbar Fracture:15 Cases for Clinical Effect Observation%经皮后路单节段椎弓根钉内固定治疗胸腰椎骨折15例临床疗效观察

    Institute of Scientific and Technical Information of China (English)

    杨文宇; 卢光辉

    2015-01-01

    Objective To evaluate the clinical outcome of percutaneous injured vertebra pedicle screw fixation for thoracolumbar fracture. Methods 15 compression fracture and mild burst fracture patients treated by minimal yInvasive percutaneous injured vertebra pedicle screw fixation were fol owed up for 6to 24 months (average 16 months). The Denis pain scale, anterior vertebral height cor ection rate, kyphosis Cobb's angle cor ection rate and patients' satisfaction were recorded.Results Al patients were fol owed up and had a high level of satisfaction with surgery. According to Denis pain grading, 12 patients had no pain, 3 patients with occasional pain but no medication. X-ray evaluation revealed satisfactory recovery of vertebral body height, the anterior vertebral height cor ection rate was 95%, and the kyphosis Cobb's angle correction rate was 98%. No implant break, and no signs of pseudoarthrosis were observed.Conclusion The treatment for thoracolumbar fracture by percutaneous injured vertebra pedicle screw fixation isef ective with a proper indication.%目的:探讨胸腰椎骨折应用经皮后路单节段椎弓根钉内固定治疗的临床效果。方法对15例压缩性骨折和轻度暴力骨折采用经皮后路单节段椎弓根钉内固定。患者随访6~24(平均16)个月,进行临床Denis疼痛评分、椎体前缘高度矫正率、后凸Cobb's角矫正率,调查患者手术满意度。结果所有患者均得到随访,所有患者均对手术表示满意。按照Denis疼痛分级,P1级有12例患者无疼痛,P2级有3例患者有轻微疼痛,无需服药治疗,神经功能均恢复至正常;X线检查术后椎体高度恢复满意,术后伤椎高度矫正率为95%、后凸Cobb's角矫正率为98%。无内固定物断裂、松动、脱出,所有病例均获得骨性愈合。结论选择好适应证,经皮后路单节段椎弓根钉内固定治疗胸腰段骨折能达到理想的疗效。

  7. 单侧椎弓根螺钉内固定椎间融合治疗腰椎退行性病变临床研究%Unilateral pedicle screw fixation with transforaminal lumbar interbody fusion for the treatment of lumbar degenerative disease

    Institute of Scientific and Technical Information of China (English)

    徐海栋; 陈勇; 许斌; 赵建宁

    2011-01-01

    Objective This study aimed to investigate the clinical outcome of unilateral pedicle screw (Ups) fixation and transforaminal lumbar interbody fusion (TLJF) in the treatment of lumbar degenerative disease. Methods Forty-two patients with lumbar degenerative disease were assigned to two groups on a voluntary basis to receive Ups + TLJF ( n = 24 ) and bilateral pedicle screw fixation combined with fusion between vertebra (n = 18). Pre-and post-operative back pains were compared using the visual analog scale (VAS) system, the clinical outcomes assessed by the Kim method, and the fusion status evaluated by the Schulte method. Results The clinical symptoms of all the patients were improved post-operatively, with no complications. The Ups + TL1F group showed higher VAS and Kim scores than the bilateral fixation group, but no significant differences were observed in the bone graft fusion between the two groups. The patients were followed up for6 to 18 (mean 12.8) months. Conclusion Ups + TLJF, characterized by minimal invasiveness, is a reliable and effective option for the management of lumbar degenerative disease. However, its indications should be well considered.%目的 评估单侧椎弓根螺钉内固定(unilateral pedicle screw fixation,Ups)结合经椎间孔椎间融合(transforaminallumbar interbody fusio,TLIE)治疗腰椎退行性疾病的临床疗效. 方法 2009年12月至2010年12月,共收治不同类型腰椎退行性疾病患者42例,按照自愿的原则,采用Ups结合TLIF治疗24例和双侧椎弓根螺钉内固定术结合椎间融合术治疗18例.应用视觉模拟评分系统(Visual Analog Scale,VAS)评估患者术前、术后疼痛情况,应用Kim方法评价临床效果,应用Schulte方法观察植骨融合情况. 结果 所有患者术后临床症状较术前明显改善、临床疗效良好,无并发症的发生.VAS评分、Kim评分单侧固定优于双侧固定,Schulte方法观察植骨融合2组无显著差异.随访时间6~18个月,平均12

  8. Merits Difference of Percutaneous Pedicle Screw Internal Fixation and Tra-ditional Surgery in Treatment of Thoracolumbar Fracture%经皮椎弓根螺钉内固定术和传统手术治疗胸腰椎骨折的优劣差异

    Institute of Scientific and Technical Information of China (English)

    刘军; 张陆; 高松明

    2016-01-01

    目的:研究比较经皮微创椎弓根螺钉内固定和传统的开放手术治疗胸腰椎骨折临床优劣差异。方法整群选取2012年12月—2015年6月期间在该院治疗的胸腰椎骨折患者44例,采用随机分组将其均分成微创组和开放组,每组患者22例。开放组采用传统的开放性椎弓根螺钉内固定手术治疗;微创组实施Sextant系统下经皮微创内固定手术治疗。记录两组患者的围手术期相关指标、胸腰椎术后矫正情况,并随访观察并发症情况。结果微创组在手术时间、切口大小、出血量等围手术期指标均要明显优于开放组(P﹤0.05);治疗后,两组在椎前缘高度差异有统计学意义(P﹤0.05)。开放组并发症发生例数明显高于微创组(P﹤0.05)。结论经皮椎弓根螺钉内固定术治疗胸腰椎骨折具有出血少、安全性高、临床效果好等优点。%Objective To research and compare the merits difference of percutaneous pedicle screw fixation and traditional surgery in treatment of thoracolumbar fracture. Methods 44 cases of patients with thoracolumbar fracture treated in our hos-pital from December 2012 to June 2015 were selected and randomly divided into the mini-invasive group and the open group with 22 cases in each, the open group were treated with traditional open?pedicle screw internal fixation, the mini-in-vasive group were treated with minimally invasive percutaneous internal fixation under the Sextant system, the related index-es in the perioperative period and rectification condition after thoracolumbar surgery of the two groups were recorded , the complication condition was followed up and observed. Results The indexes in the perioperative period such as operation time, cut size and blood loss were obviously higher than those in the open group, (P﹤0.05), after treatment, the difference in the anterior vertebral body height between the two groups was statistically significant (P﹤0.05), the

  9. Analysis of posterior pedicle screw-only constructs in surgical treatment of adolescent idiopathic scoliosis with a minimum three-year follow-up%后路全椎弓根螺钉系统治疗青少年特发性脊柱侧凸疗效分析

    Institute of Scientific and Technical Information of China (English)

    李明; 赵颖川; 朱晓东; 贺石生; 王传锋; 杨长伟

    2010-01-01

    Objective To evaluate clinical outcomes of a group of adolescent idiopathic scoliosis ( AIS) patients undergoing posterior pedicle screw-only instrumentations. Methods Between April 2002 and July 2006,121 AIS patients (93 female and 28 male, average age at operation was 15.5 years which ranged from 10 to 20 years) received posterior pedicle screw-only instrumentation and fusion. All the patients were evaluated by the various-parameters measured in X-ray films before and after surgery, including Cobb angle on coronal plane, Cobb angle on sagittal plane, clavicle angle and shoulder height difference, lowest instrumented vertebrae (LIV) angulation, proximal junction kyphotic angle, the distances of central scaral vertical line (CSV!.) to the LIV,to the apical vertebra and to the C_7 plumb line respectively. Complications were followed. Results An average of (11.0 ± 1.5) levels was fused. An average coronal correction of proximal thoracic curve was 41. 8% , of thoracic curve was 70. 8% , of thoracolumbar/lumbar curves was 74. 0%. No significant change was found in sagittal alignment. Shoulder balance and apex vertebral to central sacral line were restored well. There were no pseudoarthroses and loss of correction during the follow-ups. One adding-on, 4 proximal thoracic decompensation and 15 proximal junction kyphosis were found during the follow-ups. Conclusion Posterior pedicle screw-only instrumentation and fusion has excellent radiographic and clinical results with minimal complications in the surgical treatment of AIS.%目的 探讨采用单纯后路全椎弓根螺钉系统治疗青少年特发性脊柱侧凸(AIS)的疗效.方法 2002年4月至2006年7月,连续收治121例AIS患者,其中男性28例,女性93例;年龄10~20岁,平均15.5岁.全部患者采用后路全椎弓根螺钉系统治疗.手术前后在脊柱X线片上测量冠状位Cobb角,矢状面胸椎后凸和腰椎前凸角,最下端融合椎冠状面成角,锁骨角及双肩高度差.骶骨中

  10. Effect of Salmon calcitonin combined with expandable pedicle screw internal fixation system in the treatment of senile osteoporotic thoracolumbar fractures%鲑鱼降钙素联合EPS治疗骨质疏松性胸腰椎骨折的疗效

    Institute of Scientific and Technical Information of China (English)

    樊勇; 桑宏勋; 漆伟; 贺伍儿; 张扬; 雷伟

    2013-01-01

    Objective To investigate the clinical effect of salmon calcitonin combined with expandable pedicle screw ( EPS) internal fixation system in the treatment of senile osteoporotic thoracolumbar fractures. Methods A retrospective analysis was earned out in 78 cases of senile osteoporotic thoracolumbar fractures treating with salmon calcitonin combined expandable pedicle screw internal fixation system from January 2008 to January 2010. Patients were observed before and after treatment. Results The anterior and posterior height of vertebral body after operation were significantly higher than the preoperative ones, respectively ( P < 0. 05 ). The postoperative Cobb ' s angle was significantly lower than the preoperative one ( P < 0. 05 ). Postoperative VAS score and JOA score and BMD were significantly better than preoperative ones (P < 0. 05 ). Conclusion For senile osteoporotic thoracolumbar fractures, the salmon calcitonin combined with expandable pedicle screw internal fixation system has a good clinical effect. The method has the advantages of simple operation, rapid postoperative recovery, high stability, promote bone healing, and the clinical application.%目的 探讨鲑鱼降钙素联合膨胀式椎弓根螺钉(EPS)内固定系统治疗老年骨质疏松性胸腰椎骨折的临床疗效.方法 2008年1月~2010年1月,78例老年骨质疏松性胸腰椎骨折患者在我院采用鲑鱼降钙素联合膨胀式椎弓根螺钉内固定系统进行治疗.观察治疗前后的患者情况.结果 通过治疗后的分析,患者术后的椎体前缘高度和椎体后缘高度均明显的高于术前的患者的椎体前缘高度和椎体后缘高度,数据比较具有显著的差异(P<0.05);术后的Cobb's角度明显的低于术前的Cobb's角度,数据的比较具有显著性的差异(P<0.05).术后的VAS评分和JOA评分以及BMD均明显的优于手术治疗前,数据比较具有显著的差异(P<0.05).结论 对于老年骨质疏松性胸腰椎骨折

  11. Treatment of lumbar spondylolisthesis with posterior interbody fusion and RF pedicle screw spinal system%RF椎弓根螺钉系统复位内固定并椎间植骨融合术治疗腰椎滑脱症

    Institute of Scientific and Technical Information of China (English)

    陈治权; 王义生

    2010-01-01

    Objective To evaluate the clinical effect of lumbar spondylolisthesis treated by posterior lumbar interbody fusion and RF pedicle screw spinal system. Methods From February 2000 to February 2008,37 cases of lumbar spondylolisthesis were included in this study according to Meyerding classification,roentgengram showed that there were 6 cases of grade Ⅰ,27 cases of grade Ⅱ,4 cases of grade Ⅲ. All patients obtained followed up, were treated with posterior decompression of total laminectomy and bilateral nerve canal, lumbar interbody fusion was done with RF pedicle screw spinal system. Results All the patients were followed up from 12-38 months with an average of 32.7 months. According to standard of Hou Shu-xun and fusion rate after operation,the therapeutic effect was excellent in 31 cases,good in 4 cases, fair in 2 cases,the satisfactory rate was 94.6%. During operation complication occurred in 1 case with the incidence rate of 2.7%. Surgical reduction rate was 88.9%. The bony fusion was seen in all patients. Conclusions Posterior lumbar interbody fusion and RF pedicle screw spinal system provide fixation with satisfactory clinical results and relatively high fusion rate.%目的 探讨RF椎弓根螺钉系统复位内固定并椎间植骨融合术治疗腰椎滑脱症的效果.方法 自2000年2月至2008年2月,采用RF椎弓根螺钉系统复位内固定并椎间植骨融合术治疗并获得随访的真性腰椎滑脱症37例,其中Ⅰ度滑脱6例,Ⅱ度滑脱27例,Ⅲ度滑脱4例.滑脱节段:第3腰椎(L3)滑脱3例,L4滑脱9例,L5滑脱25例.结果 所有患者术后随访12~38个月,平均32.7个月.根据侯树勋等制定的疗效评定标准及融合率:优31例,良4例,可2例,优良率94.6%.术中并发症1例,发生率为2.7%.手术完全复位率88.9%,椎间融合率100%.结论 RF椎弓根螺钉系统复位内固定并椎间植骨融合术能使腰椎滑脱得到较为确实的复位和固定,脊柱融合率高,临床效果满意.

  12. 钉棒置入与椎间融合修复极外侧型腰椎间盘突出症:远期腰椎稳定性随访%Extreme lateral lumbar disc herniation after pedicle screw fixation and interbody fusion cage:lumbar stability at long-tem follow-up

    Institute of Scientific and Technical Information of China (English)

    史瑞明; 李国胜; 张义峰; 黄震源; 孙利; 王存

    2014-01-01

    BACKGROUND:Extreme lateral lumbar disc herniation is a rare type of lumbar disc herniation, there are a variety of treatment methods, but the therapeutic efficacy and recurrence rate are controversial. OBJECTIVE:To investigate the availability of lumbar pedicle screw fixation combined with interbody fusion cage for treating extreme lateral lumbar disc herniation. METHODWe retrospectively analyzed 19 patients with extreme lateral lumbar disc herniation after treatment with lumbar pedicle screw fixation combining with interbody fusion cage from March 2006 to January 2009. The outcomes were evaluated depending on VAS scoring standard and Macnab scoring standard, lumbar stability were observed postoperatively. We analyzed the spinal stability in recurrent lumbar disc herniation patients after lumbar pedicle screw fixation combined with interbody fusion cage depending on literature search. RESULTS AND CONCLUSION:Al the 19 patients were fol owed up for 13 months to 3 years, the leg and lumbar pain of al the patients were relieved to varying degrees. Preoperative VAS score was 7.3±1.28 points and postoperative VAS score was 2.1±0.8 points, showing significant difference between two groups (P  目的:探讨应用腰椎椎弓根钉棒内固定联合椎间融合器置入椎间融合修复极外侧型腰椎间盘突出症的临床效果。  方法:回顾性分析2006年3月至2009年1月行腰椎椎弓根钉棒系统联合椎间融合器置入椎间融合治疗的19例极外侧型腰椎间盘突出症患者的临床资料,根据目测类比评分标准及Macnab评价标准进行疗效判定,观察治疗后腰椎稳定性,通过数据库文献检索方法评估腰椎椎弓根钉棒内固定联合椎间融合器置入椎间融合修复极外侧型腰椎间盘突出症的效果。  结果与结论:19例患者均得到随访,随访时间13个月-3年。所有患者治疗后即有下肢及腰部疼痛不同程度的缓解,治

  13. Parafusos pediculares: estruturas anatômicas em risco no tratamento da escoliose idiopática Tornillos pediculares: las estructuras anatómicas en riesgo en el tratamiento de escoliosis idiopática Pedicle screws: anatomic structures at risk in idiopathic scoliosis treatment

    Directory of Open Access Journals (Sweden)

    Herton Rodrigo Tavares Costa

    2012-12-01

    Full Text Available OBJETIVO: Avaliar a posição das estruturas anatômicas em risco durante a inserção de parafusos pediculares na coluna torácica e sua relação com a variação do ângulo de Cobb. MÉTODOS: Os parâmetros estudados foram: a medida do ângulo de Cobb nas radiografias e a posição da medula espinhal, da cavidade pleural e aorta na ressonância nuclear magnética em relação a uma linha de 40mm criada para simular o parafuso pedicular nas cinco vértebras apicais. RESULTADOS: A distância da aorta ao corpo vertebral e o ângulo de segurança do lado convexo apresentaram diferença estatística quando relacionados com a variação do ângulo de Cobb medido. CONCLUSÃO: Os resultados apresentados sugerem maior risco de lesão da artéria aorta com o aumento do ângulo de Cobb e aumento do risco na inserção de parafusos pediculares no lado convexo da curvatura, quando se considera o ângulo de segurança.OBJETIVO: Evaluar la posición de las estructuras anatómicas en situación de riesgo durante la inserción de tornillos pediculares en la columna torácica y su relación con la variación del ángulo de Cobb. MÉTODOS: Los parámetros estudiados fueron: la medida del ángulo de Cobb en las radiografías y la posición de la médula espinal, la cavidad pleural y la aorta en la RM en relación con una línea de 40mm, diseñada para simular el tornillo pedicular en el plano de las cinco vértebras apicales. RESULTADOS: La distancia desde la aorta hacia el cuerpo vertebral y el ángulo de seguridad en el lado convexo mostraron diferencia estadística relacionada con la variación del ángulo de Cobb medido. CONCLUSIÓN: Los resultados sugieren un mayor riesgo de daño a la aorta con el aumento del ángulo de Cobb e incremento del riesgo en la inserción de tornillos pediculares en el lado convexo cuando se considera el ángulo de seguridad.OBJECTIVE: To evaluate the position of anatomical structures at risk during insertion of pedicle screws in

  14. Effects of C arm X-ray perspective computer auxiliary surgery navigation system on screw fixation in the elderly lumbar vertebrae pedicle%C臂透视计算机辅助导航对老年人腰椎椎弓根螺钉置入术及手术疗效的影响

    Institute of Scientific and Technical Information of China (English)

    张良; 孙常太; 徐宏兵; 张华俦; 王英民

    2012-01-01

    Objective To investigate the influence of C arm X- ray perspective computer auxiliary surgery navigation system on lumbar vertebral pedicle screw fixation in the elderly.Methods 286 patients(aged≥65 years) treated by lumbar spine post decompress and pedicle screw fixation for lumbar vertebral degeneration were divided into navigation (n=153) or non-navigation (n=133) groups.The amount of blood loss,surgery duration and time of beginning to walk after surgery were measured and compared, the improvement grading was determined by Oswestry disability index (ODI) before surgery and at the last follow-up. Results The surgery duration [(27.6+6.3)ain vs.(33.8±9.9)min],the volume of blood loss[(135.7±21.1)ml vs.(165.4±32.1)ml] and the time of beginning to walk after surgery[(134.6± 12.3)h vs.(169.0±23.9)h] were obviously reduced in navigation group as compared with non-navigation group (P < 0.05). The grading improvement rate by ODI[(76.6±±3.7)%vs.(69.8+6.6)%] was higher in navigation group than in non navigation group (P<0.05). Conclusions Using C arm X-ray perspective computer auxiliary surgery navigation system to lumbar pedicle screws fixation is helpful in the elderly for improving clinical efficacy.%目的 探讨C型臂透视计算机辅助手术导航系统对于老年人腰椎椎弓根螺钉置入术的影响. 方法 对286例65岁及以上行腰椎后路减压内固定的腰椎退行性疾病患者分为导航(153例)和未导航(133例)两组,比较两组患者的术中失血量、手术时问和术后下地时间.应用Oswestry功能障碍指数问卷表(ODI)对所有患者的术前和末次随访评分,计算2次评分的ODI评分改善率. 结果 导航组与未导航组相比,椎弓根手术时间[ (27.6±6.3)min、(33.8±9.9)min]和出血量[(135.7±21.1)ml、(165.4±32.1)ml]减少,术后下地时间[(134.6±12.3)h、(169.0=23.9)h]缩短;ODI评分改善率[(76.6±3.7)%、(69.8±6.6)%]提高. 结论 C型臂透视计算机辅助手术导

  15. Transforaminal lumbar interbody fusion combined with unilateral pedicle screw fixation for upper lumbar disc hernia-tion%经椎间孔行腰椎间融合联合单侧椎弓根螺钉固定术治疗高位腰椎间盘突出症疗效分析

    Institute of Scientific and Technical Information of China (English)

    谭健; 李平元; 欧军; 苏小桃; 卢政好

    2014-01-01

    Objective To investigate the clinical effect of transforaminal lumbar interbody fusion (TLIF) combined with unilateral pedicle screw fixation for upper lumbar disc herniation. Methods Retrospectively analysed the clinical data of 16 patients with upper lumbar disc herniation from Jun 2009 to Feb 2013 in our hospital, who were treated with transforaminal lumbar interbody fusion combined with unilateral pedicle screw fixation;using the visual analogue scale assessed the pain degree of patients at admission and after operation; assessed the clinical efficacy at last follow-up according to the modified MacNab criteria and observed intervertebral fusion. Results 16 patients were followed up 12 to 52 months (average 24.2 months) after surgery. All the patients had no nerve damage and leakage of cerebrospinal fluid complications. VAS score at different postopera-tive periods had significant difference compared with the VAS score before operation (P<0.01). According to the modified Mac-Nab criteria,the excellent and good rate was 93.75%. X-ray examination showed that there were no internal fixation failure and lumbar interbody non-fusion at the last follow-up. Conclusion Transforaminal lumbar interbody fusion combined with uni-lateral pedicle screw fixation has satisfied effect in the treatment of upper lumbar disc herniation,and has the advantages of small trauma,less complications,low cost.%目的:探讨经椎间孔行腰椎间融合(transforaminal lumbar interbody fusion,TLIF)联合单侧椎弓根螺钉固定术治疗高位腰椎间盘突出症的临床疗效。方法回顾性分析2009年6月~2013年2月本院16例高位腰椎间盘突出症患者临床资料,均采用TLIF联合单侧椎弓根螺钉固定术治疗;采用腰腿痛视觉模拟评分测评入院时和TLIF联合单侧椎弓根螺钉固定术后(术后1周、1个月、3个月及末次随访)患者疼痛情况,末次随访采用改良MacNab标准评定临床疗效,并了解椎间融合

  16. Variant lumbar pedicle

    Energy Technology Data Exchange (ETDEWEB)

    Whelan, M.A.; Feldman, F.

    1982-01-01

    Three cases of aplastic and/or hypoplastic lumbar pedicle are presented and discussed. The importance of plain films, especially the 45/sup 0/ posterior oblique, for making the diagnosis is emphasized. The incidence and embryology of abnormalities of the pedicle are reviewed and the radiological features used to differentiate these congenital abnormalities from neoplasm and trauma are described.

  17. Accuracy and complications of transpedicular C2 screw placement without the use of spinal navigation.

    Science.gov (United States)

    Mueller, Christian-Andreas; Roesseler, Lukas; Podlogar, Martin; Kovacs, Attlila; Kristof, Rudolf Andreas

    2010-05-01

    The objective of the study was to describe the technique, accuracy of placement and complications of transpedicular C2 screw fixation without spinal navigation. Patients treated by C2 pedicle screw fixations were identified from the surgical log book of the department. Clinical data were extracted retrospectively from the patients' charts. Pedicle screw placement accuracy was assessed on postoperative CT scans according to Gertzbein and Robbins (GRGr). A total of 27 patients were included in the study. The mean age of the patients was 56 +/- 22.0 years; 51.9% of them were female. As much as 17 patients suffered from trauma, 5 of degenerative disease, 3 of inflammations and 2 of metastatic disease. A total of 47 C2 transpedicular screw fixations were performed. The canulated screws were inserted under visual control following the preparation of the superior surface of the isthmus and of the medial surface of the pedicles of the C2. Intraoperative fluoroscopy was additionally used. The postoperative CT findings showed in 55.3% GRGr 1, in 27.7% GRGr 2, in 10.6% GRGr 3, and in 6.3% GRGr 4 pedicle screw insertion accuracy. Screw insertions GRGr 5 were not observed. Screw malpositioning (i.e., GRGr 3 and 4) was significantly associated with thin (C2 fractures. In the three patients with screw insertions GRGr 4, postoperative angiographies were performed to exclude vertebral artery affections. In one of these three cases, the screw caused a clinically asymptomatic vertebral artery compression. Hardware failures did not occur. In one patient, postoperative pneumonia resulted in the death of the patient. Careful patient selection and surgical technique is necessary to avoid vertebral artery injury in C2 pedicle screw fixation without spinal navigation. A slight opening of the vertebral artery canal (Gertzbein and Robbins grade C2 pedicle screw insertions.

  18. 腰椎经后路椎体间融合后单边或双边固定对邻近节段退变的影响%Comparative study of adjacent segment degeneration after posterior lumbar interbody fusion with unilateral or bilateral pedicle screw instrumentation

    Institute of Scientific and Technical Information of China (English)

    林斌; 张文彬; 周琴; 张峰; 敖庆芳; 俞辉; 陆成武

    2014-01-01

    背景:在行后路椎体融合内固定术中,椎弓根钉置入不可避免会损伤邻近关节突关节。目前一致认为单边固定因保留一侧关节突关节可明显降低邻近节段退变的发生率,但仍缺乏对邻近节段退变的影响因素及不同节段退变发生率的长期随访研究。  目的:对比经后路椎体间融合术(posterior lumbar interbody fusion,PLIF)后单边或双边椎弓根螺钉固定对邻近节段退变的影响。  方法:2006年2月至2007年12月,101例行PLIF手术的L4-L5椎间盘突出症患者纳入本研究。采用单边固定42例,双边固定59例。所有患者术后随访时间均超过5年。邻近节段分为三个节段:第1个近端邻近节段、第2个近端邻近节段及远端邻近节段。依据末次随访的影像学资料评估邻近节段退变的情况,并记录末次随访时的ODI评分评价腰椎功能。  结果:单边固定组第1个近端邻近节段、第2个近端邻近节段及远端邻近节段退变的发生率分别为57.1%(24/42)、45.2%(19/42)、38.1%(16/42);双边固定组第1个近端邻近节段、第2个近端邻近节段及远端邻近节段退变的发生率分别为72.9%(43/59)、68.0%(40/59)、50.8%(30/59)。两组第1个近端邻近节段和远端邻近节段退变发生率无统计学差异,而第2个近端邻近节段退变发生率具有统计学差异。末次随访时单边固定组和双边固定组的ODI评分分别为25.6±5.9、28.4±5.2,两组具有显著统计学差异(t=-2.503,P=0.014)。  结论:对于行腰椎后路减压融合术的单节段腰椎间盘突出症患者,单边固定者邻近节段退变发生率低于双边固定者,尤其对于第2个近端邻近退变节段的患者。%Background: In the instrumented fusion, adjacent facet joint violation or impingement by pedicle screws is unavoidable. Unilateral pedicle screw instrumentation is thought to reduce

  19. Pedicled perforator flaps

    DEFF Research Database (Denmark)

    Demirtas, Yener; Ozturk, Nuray; Kelahmetoglu, Osman;

    2009-01-01

    Described in this study is a surgical concept that supports the "consider and use a pedicled perforator flap whenever possible and indicated" approach to reconstruct a particular skin defect. The operation is entirely free-style; the only principle is to obtain a pedicled perforator flap to recon......Described in this study is a surgical concept that supports the "consider and use a pedicled perforator flap whenever possible and indicated" approach to reconstruct a particular skin defect. The operation is entirely free-style; the only principle is to obtain a pedicled perforator flap...... more practical and creative to use a free-style manner during pedicled perforator flap surgery, instead of being obliged to predefined templates for this type of procedure....

  20. Anatomic considerations for C2 pedicle screw placement: the use of computerized tomography measurements Consideraciones anatómicas de la cocalización de los tornillos pediculares en C2: uitlización de las medidas de la tomografia computadorizada Considerações anatômicas sobre a localização dos parafusos pediculares em C2: utilização das medidas da tomografia computadorizada

    Directory of Open Access Journals (Sweden)

    Adebukoa Onibokun

    2009-03-01

    Full Text Available OBJECTIVE: more detailed anatomical knowledge of the C2 pedicle is required to optimize and minimize the risk of screw placement. The aim of this study was to evaluate the linear and angular dimensions of the true C2 pedicle using axial CT. METHODS: ninety three patients (47 males, 46 females mean age 48 years who had cervical spinal CT imaging performed were evaluated for this study. Axial images of the C2 pedicle were selected and the following pedicle parameters were determined: pedicle width (PW, the mediolateral diameter of the pedicle isthmus, perpendicular to the pedicle axis and pedicle transverse angle (PTA, that is, the angle between the pedicle axis and the midline of the vertebral body. RESULTS: the overall mean pedicle width was 5.8 1.2mm. The mean pedicle width in males (6.01.3mm was greater than that in the female subjects (5.6 1.1mm. This difference was not found to be statistically significant (p=.6790. The overall mean pedicle transverse angle was 43.93.9 degrees. The mean PTA in males was 43.23.8 degrees, while that in females was 44.73.7 degrees. CONCLUSION: preoperative planning is absolutely mandatory, particularly in determining not only screw trajectory, but in analyzing individual patient anatomy and reception to a C2 pedicle screw.OBJETIVO: el conocimiento detallado de las características anatómicas del pedículo de C2 es necesario para minimizar los riesgos relacionados con la colocación de los tornillos. El objetivo del estudio fue evaluar las medidas lineares y angulares del eje axial verdadero del pedículo de C2 utilizando la tomografía computadorizada. MÉTODOS: fueron utilizadas tomografías computadorizadas axiales de 93 pacientes (47 del sexo masculino y 46 del sexo femenino con promedio de edad de 48 años. Las imágenes axiales del pedículo de C2 fueron seleccionadas para el estudio y los parámetros estudiados fueron: Ancho del pedículo (diámetro mediolateral del istmo del pedículo perpendicular al

  1. 以枢椎椎弓峡部内上壁为解剖标志行枢椎椎弓根置钉的CT测量及临床应用%The CT scanning and clinical application of axis pedicle screw placement guided by the morphology of C2 interarticularis

    Institute of Scientific and Technical Information of China (English)

    张金明; 豆贲; 刘晓岚; 石明国; 杨占辉; 吴海龙; 王伟; 王军辉

    2012-01-01

    Objectives: To evaluate the feasibility and reliability of axis pedicle screw placement guided by the morphology of inlerarticularis. Methods: C2 three-dimensional CT reconstruction was performed in 57 normal adults. The cross-sectional images were used for study. The width of the central(Ll) and the height (L2) at left and right side were measured. The distances from the interarticularis to the outer anchoring point B and the most medial point A were used as anatomical sign in C2 interarticularis.Tilt- distances from the interarticularis to the best anchoring point S (the intersection between vertebral pedicle central line and interarticularis rear cortex), and the maximum safety for screw placement at cross-sectional plane through A, B and S point respectively were measured. The distance from the interarticularis to the best point S at coronal plane was measured, and the best introversion and uplroversion angle at point S was measured. From October 2007 to July 2011, 33 cases underwent posterior atlantoaxial pedicle screw fixation guided by this method. Of these, there were 13 with new odontoid fracture, 10 with old odontoid process fracture, 7 with transverse lig-ment rupture and 3 with Jefferson fractrue. Intraoperative and postoperative complications associated with instrumentation were evaluated. Screw position was also determined under three-dimensional CT scan after operation. Results: The distance between point A, B, S to interarticularis on CT coronal plane was 1.75mm, 9.01±0.62mm, 5.77±0.53mm respectively. There were statistical differences between piont S and A, B with respect to safety instrumentation (P<0.05). The distance from point S to the superomedial part of C2 interarticularis at coronal plane was 4.30±0.49mm, with an introversion of 30g and uptroversion of 26°. A lotal of 66 C2 pedicle screws was planed. There was no neurovascular complication noted. Postoperative three-dimensional CT scan showed no screw into spine canal and transverse

  2. SURVEY SUBAXIAL CERVICAL VERTEBRAE FOR TRANSPEDICULAR SCREW FIXATION

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Objective In this study, the pedicles of subaxial vertebrae from C3 to C7 were measured to provide some morphometric data for cervical transpedicular screw fixation. Methods 20 dried bone cervical spinal columns (C3-C7), pedicle dimensions (pedicle height, width, length), and transverse and sagittal angles of the pedicles were performed with vernier in linear and angular measurements. Results The obtained data revealed that the mean values were approximately ranging from 6.7 to 7.2 mm for pedicle height, 4.4 to 4.9 mm for pedicle width, 22.2 to 27.7 mm for pedicle axis length, 42.3° to 51.5° for transverse angle, and 5.2° to 14.1° for sagittal angle. Conclusion Linear measurements of pedicle dimensions and also axial angles from horizontal and vertical planes may provide some anatomic limitations for subaxial cervical transpedicular screw fixation, and also contribute to the safety of the surgical procedure.

  3. 后路单侧椎弓根钉固定联合椎间融合术治疗退行性腰椎失稳%POSTERIOR UNILATERAL PEDICLE SCREW FIXATION PLUS LUMBAR INTERBODY FUSION FOR TREATMENT OF DEGENERATIVE LUMBAR INSTABILITY

    Institute of Scientific and Technical Information of China (English)

    魏富鑫; 刘少喻; 崔尚斌; 王乐; 梁春祥; 龙厚清; 黄阳亮

    2013-01-01

    Objective To evaluate the effectiveness of posterior unilateral pedicle screw fixation plus lumbar interbody fusion in treatment of degenerative lumbar instability.Methods Between February 2008 and December 2011,33 patients with degenerative lumbar instability were treated with posterior unilateral pedicle screw fixation plus lumbar interbody fusion,including 14 cases of lumbar disc protrusion with instability,15 cases of lumbar spinal stenosis with instability,3 recurrent cases of lumbar disc protrusion at 1 year after discectomy,and 1 case of extreme lateral lumbar disc protrusion.There were 20 males and 13 females with an average age of 47.2 years (range,39-75 years).The average disease duration was 12.8 months (range,6-25 months).Single-segment-fixation was performed in 28 cases (L4,5 in 21 cases,L5,S1 in 6 cases,and L5,6 in 1 case),and double-segment-fixation was performed in 5 cases (L3.4 and L4,5).The clinical results were evaluated by using Oswestry disability index (ODI) and modified Japanese Orthopaedic Association (JOA) score for low back pain.Results Infection occurred in 1 case,and was cured after dressing change; primary healing was obtained in the other patients.Thirty-one patients were followed up 32.3 months on average (range,15-53 months).Cage displacement occurred in 1 case who received bilateral pedicle screw fixation plus lumbar interbody fusion; no screw breaking,Cage displacement,or pseudoarthrosis was observed in the others.X-ray films showed bone fusion in the other patients except 1 case of bone fusion failure.ODI and JOA score at last follow-up were significantly improved when compared with the ones before operation and at 2 weeks after operation (P <0.05); the improvement rates were 74.0% ± 10.1% and 83.6% ± 9.4%,respectively.Conclusion Posterior unilateral pedicle screw fixation plus lumbar interbody fusion is an effective and reliable method for patients with degenerative lumbar instability because it has the advantages of

  4. Role of rod diameter in comparison between only screws versus hooks and screws in posterior instrumentation of thoracic curve in idiopathic scoliosis.

    Science.gov (United States)

    Lamartina, Claudio; Petruzzi, Maria; Macchia, Marcello; Stradiotti, Paola; Zerbi, Alberto

    2011-05-01

    Since the introduction of Cotrel-Dubousset instrumentation in 1984, the correction techniques in scoliosis surgery have changed from Harrington principles of concave distraction to segmental realignment to a variety of possibilities including the rod rotation manoeuvres, and to segmental approximation via cantilever methods. Additionally, pedicle screw utilization in lumbar curves enhanced correction and stabilization of various deformities, and various studies have strongly supported the clinical advantages of lumbar pedicle screws versus conventional hook instrumentation. Pedicle screw constructs have become increasingly popular in the treatment of patients with spinal deformity. When applied to adolescent idiopathic scoliosis patients, pedicle screw fixation has demonstrated increased corrective ability compared with traditional hook/hybrid instrumentation. In our study, we do a retrospective review of idiopathic scoliosis patients (King 2-Lenke 1 B/C) treated with a selective thoracic posterior fusion using an all-screw construct versus a hybrid (pedicle screws and hooks) construct and, compare the percentage of correction of the scoliotic curves obtained with screws alone and screws and hooks. Special attention was given to the rod diameter and correction technique. Our results show that the percentage of correction of idiopathic thoracic scoliosis is similar when treating the scoliosis with rods and screws alone or with rods, screws and hooks; therefore, we and the majority of authors in the literature do not consider the rod section. This can be an important parameter in the evaluation of the superiority of treatment with screws only or screws and hooks. In our study, even if not of statistical significance, the better thoracic curve correction obtained with the hybrid group should be ascribed to the fact that in this group mostly 6 mm rods were used.

  5. Posterior cervical spine arthrodesis with laminar screws: a report of two cases

    Directory of Open Access Journals (Sweden)

    Sugimoto,Yoshihisa

    2007-04-01

    Full Text Available We performed fixation using laminar screws in 2 patients in whom lateral mass screws, pedicle screws or transarticular screws could not be inserted. One was a 56-year-old woman who had anterior atlantoaxial subluxation (AAS. When a guide wire was inserted using an imaging guide, the hole bled massively. We thought the re-insertion of a guide wire or screw would thus increase the risk of vascular injury, so we used laminar screws. The other case was an 18-year-old man who had a hangman fracture. Preoperative magnetic resonance angiography showed occlusion of the left vertebral artery. A laminar screw was inserted into the patent side (i.e., the right side of C2. Cervical pedicle screws are the most biomechanically stable screws. However, their use carries a high risk of neurovascular complications during screw insertion, because the cervical pedicle is small and is adjacent laterally to the vertebral artery, medially to the spinal cord, and vertically to the nerve roots. Lateral mass screws are also reported to involve a risk of neurovascular injuries. The laminar screw method was thus thought to be useful, since arterial injuries could thus be avoided and it could also be used as a salvage modality for the previous misinsertion.

  6. Coupled fluid-dynamical and structural analysis of a mono-axial mems accelerometer

    Directory of Open Access Journals (Sweden)

    A Cammarata

    2016-09-01

    Full Text Available This study is aimed to numerically investigate the elastodynamics of a mono-axial MEMS accelerometer. The vibrating part of the device is dipped into a fluid micro-channel and made of a proof mass connected to the frame by two flexible legs. The adopted mathematical model lies on a linearized motion equations system, where the mass matrix is obtained by means of both lumped and distributed approach. The stiffness matrix is otherwise derived through FEA, in which the proof mass and the compliant legs are modeled as rigid and flexible bodies, respectively. The squeezed-film damping effect is evaluated by a fluid-dynamical FE model based on a modified Reynolds formulation. The ensuing analyses are carried-out for three pressure levels of the narrow gas film surrounding the device, by applying the logarithmic decrement method for evaluating the damping ratio. Numerical results, in terms of acceleration, frequency range and noise disturbance, are successfully compared to analytical and experimental ones previously published in literature. Our model characterizes the accelerometer dynamics in space, allowing, in addition, to assess translational motion errors along directions apart the working one.

  7. PIPELINE微创通道结合VIPER2经皮椎弓根螺钉技术治疗腰椎退变性疾病%Treatment of lumbar degenerative diseases by pIPELINE minimally invasive access in combination with VIPER2 Percu-taneous Pedicle Screw Fixation

    Institute of Scientific and Technical Information of China (English)

    李宇旭; 陈钢; 龚飞鹏; 龙智生; 肖裕华; 李建飞

    2015-01-01

    Objective To study the curative effects of PIPELINE Expandable Access System in combination with VIPER2 percutaneous pedicle screw fixation on lumbar degenerative diseases. Methods The clinical data of 32 patients with lumbar de-generative diseases were collected,who received PIPELINE minimally invasive access decompression and fusion in combination with VIPER2 percutaneous pedicle screw fixation for treatment from February 2012 to December 2013 ,and follow-up was per-formed for all the patients. Posterior paramedian transmultifidus approach was adopted for all the patients ,spinal decompression and interbody fusion by PIPELINE Expandable Access System in combination with VIPER2 percutaneous pedicle screw fixation were performed. The visual analogue scale (VAS) pain score and Oswestry disability index (ODI) were adopted for the assessment of clinical effects. Complications as well as preoperative and postoperative indicators were observed. Results The average follow-up time of all the patients was 8.3 months. Statistical analysis showed that the VAS score for lumbocrural pain and ODI score at 1 week after operation and the last follow-up visit were remarkably improved compared with those before operation ,and the differ-ence was statistically significant(P<0.05). The improvement rate of the quality of life at the last follow-up visit was 85%. The aver-age duration of operation was 122 minutes. The average length of incision was 5.3cm. The average intraoperative bleeding volume was 0.18L and the average postoperative drainage volume was 0.085L. As for the postoperative complications ,epidermal necrosis of incision was observed in 3 cases,which achieved healing by primary intention after dressing change. Conclusion PIPELINE mini-mally invasive access in combination with VIPER2 percutaneous pedicle screw fixation has advantages such as mild tissue dam-age,less bleeding,fast postoperative recovery and definite short-term effects in the treatment of lumbar degenerative

  8. Treatment of Lumbar Degenerative Disease with Unilateral Decompression,Bone Graft Fusion and Unilateral Pedicle Screw Fixation%经单侧减压融合、单边椎弓根螺钉内固定治疗腰椎退变性疾病

    Institute of Scientific and Technical Information of China (English)

    宋晋刚; 崔易坤; 苗艳; 尹振宇; 羊刚毅; 黄海锋

    2016-01-01

    目的:探讨经单侧行病变节段椎管减压、椎间植骨融合、单边椎弓根螺钉内固定治疗腰椎退变性疾病的临床疗效。方法我院2010年1月~2013年12月对35例腰椎退变性疾病采用经单侧减压、椎间植骨融合、单边椎弓根螺钉固定手术治疗。根据 JOA 评分法评估术后腰椎功能改善情况,采用视觉模拟评分(visual analog scale,VAS)评估术后疼痛缓解情况,腰椎正侧位 X 线片及 CT 扫描了解植骨融合情况。结果随访12~18个月,平均15个月。术前 JOA 评分(8.2±2.1)分,显著低于术后3个月(20.8±3.8)分(q =22.123,P <0.05)和术后12个月(21.7±3.9)分(q =23.703,P <0.05);VAS 评分术前(7.9±2.1)分,显著高于术后3个月(2.4±0.4)分(q =26.107,P <0.05)和12个月(2.3±0.3)分(q =26.582,P <0.05);JOA 评分和 VAS 评分随访期间无显著变化(P >0.05)。1年后椎间植骨融合率100%,未发现椎弓根螺钉松动、断裂、拔钉等异常。结论经单侧减压、椎间植骨融合联合单边椎弓根螺钉内固定治疗腰椎退变性疾病疗效满意,可在合适病例中推广应用。%Objective To investigate the clinical effects of unilateral vertebral canal decompression,intervertebral bone graft fusion,and unilateral pedicle screw fixation in the treatment of lumbar degenerative disease. Methods From January 2010 to December 2013,a total of 35 cases of lumbar degenerative disease were treated with unilateral decompression,intervertebral bone graft fusion,and unilateral pedicle screw fixation.The postoperative spine functions were evaluated with the JOA scores,the postoperative pain relief was evaluated with the VAS scores,and bone graft fusion was reviewed with lumbar X-ray and CT scanning. Results The patients were followed up for 12 -18 months (mean,15 months).The preoperative JOA scores (8.2 ±2

  9. 经寰枢椎椎弓根螺钉固定治疗Jefferson 骨折合并寰枢椎不稳%Treatment of Jefferson fracture combined with atlantoaxial instability with C1-C2 pedicle screw fixation

    Institute of Scientific and Technical Information of China (English)

    陈建明; 张成程; 许天明; 文景; 李勇; 周艳

    2011-01-01

    Objective To discuss the clinical outcomes of C1-C2 pedicle screw fixation in treatment of Jefferson fracture combined with aflantoaxial instability.Methods Eleven adult patients with Jefferson fracture combined with atlantoaxial instability were treated with C1-C2 pedicle screw fixation in our department from January 2006 to December 2009.There were eight males and three females at age range of 20-52 years(mean 36 years).There were eight patients with fresh fractures,three with old fracture and three complicated with odontoid process fracture.The main preoperative clinical symptoms were the limitation of head torsion and pain in the occiput and neck,with no spinal dysfunction in all patients.X-ray,CT scan,three-dimensional reconstruction,MRI scan and skull traction were performed in all patients before operation.Then,the patients were treated with C1-C2 pedicle screw fixation without fusion between C1-C2 under general anesthesia.Results The atlantoaxial dislocation was reduced completely and the patients could move from bed,wearing the neck collar.There was no injury of vertebral artery,spinal cord or nerve roots during operation,but one patient suffered the venous plexus bleeding which was packed with the hemostatic gauze.Eleven patients were followed up for 6-24 months(average 15 months),which showed bone union,with no internal fixation breakage,loosening or dislocation.The internal fixation was removed from seven patients 15 months after operation,with mild limitation of the cervical vertebra torsion(90°-135°,average 115°)but with no limitation of obvious extension-flexion motion.Conclusion C1-C2 pedicle screw fixation has features of simple operation,short segment fixation,solid fixation and high rate of bone healing for treatment of Jefferson fracture combined with atlantoaxial instability.%目的 探讨经寰枢椎椎弓根螺钉内固定治疗Jefferson骨折合并寰枢椎不稳的临床疗效.方法 选择2006年1月-2009年12月采用经寰枢椎椎

  10. 18例先天性脊柱侧凸患儿行后路半椎体切除加椎弓根系统内固定手术的护理%Perioperative nursing of 18 children undergoing posterior hemivertebrae excision and pedicle screw fixation for the congenital scoliosis

    Institute of Scientific and Technical Information of China (English)

    李燕晖; 鲁秀平; 郑艳红; 李卫平; 郭书姣; 陈晓颖

    2011-01-01

    This paper summarizes the perioperative nursing of 18 congenital scoliosis children treated by posterior hemiver-tebrae excision and pedicle screw fixation. Preoperative care focused on psychological nursing,traction nursing and pulmonary function training. After operation,the key points in nursing were vital signs monitoring,observation of patients' status,posture and skin care,prevention and control of postoperative complications,and functional exercises. All the patients were cured and discharged. The outcome within follow-up was satisfactory.%总结了18例后路半椎体切除加椎弓根系统内固定治疗先天性脊柱侧凸患儿的围手术期护理,术前重点做好心理护理、牵引护理、肺功能训练等,术后注意做好生命体征监测、病情观察、体位及皮肤护理、并发症护理、功能锻炼等。18例手术患儿均痊愈出院,随访效果良好。

  11. Clinical effect of posterior pedicle screw fixation combined with total laminectomy decompression on cervical spinal fracture and dislocation%后路椎弓根内固定联合全椎板减压治疗颈椎骨折脱位的临床效果

    Institute of Scientific and Technical Information of China (English)

    吕乔; 刘卫华; 杨会武; 程微; 杨子斌

    2016-01-01

    目的 探讨后路椎弓根内固定联合全椎板减压治疗颈椎骨折脱位的临床效果.方法 选择2010年1月至2014年7月云南省大理白族自治州人民医院收治的颈椎骨折脱位患者87例,术前美国脊髓损伤学会(ASIA)神经病损分级:A级18例,B级34例,C级21例,D级10例,E级4例.所有患者均采用单纯后路椎弓根内固定联合全椎板减压治疗,记录手术时间、术中出血量、术后引流量、并发症发生情况、置钉情况和随访情况,采用ASIA分级评定术后脊髓神经功能恢复情况.结果 87例患者均顺利完成手术,置钉成功率92.5%(285/308),手术时间40 ~ 96 min,平均(63±15)min;术中出血量100~400 ml,平均(260 ±44) ml;术后引流量230 ~3000ml,平均(320 ±46) ml.术后发生脑脊液漏6例,切口表层感染2例,肺不张3例,下肢静脉血栓形成3例,肺栓塞1例,顽固性低钠低氯血症2例,酸中毒、高钾血症1例,经对症治疗后均好转或痊愈术后13例(ASIA分级A级6例、B级7例)死亡,19例(ASIA分级B级12例、C级5例、D级2例)失访,余55例患者中完全解剖复位38例(69.1%),基本复位17例(30.9%),末次随访时无再脱位及断钉、断棒情况;末次随访时ASIA分级:A级12例,均无脊髓神经功能恢复;B级15例,1例恢复至C-级,6例恢复至B+级,8例无恢复;C级16例,8例恢复至D级,5例恢复至E-级,3例无恢复;D级8例,7例恢复至E级,1例无恢复.结论 后路椎弓根内固定联合全椎板减压治疗颈椎骨折脱位安全、有效.%Objective To evaluate the clinical effect of posterior pedicle screw fixation combined with total laminectomy decompression on cervical spinal fracture and dislocation.Methods Totally 87 patients with cervical spinal fracture and dislocation from January 2010 to July 2014 in Dali Bai Autonomous Prefecture People's Hospital were enrolled;preoperative American Spinal Injury Association(ASIS) grades were as follows:18 cases of grade A,34 cases of grade B

  12. 瞄准器辅助下椎弓根螺钉技术治疗下颈椎骨折合并强直性脊柱炎%Treatment of cervical spine fractures associated with ankylosing spondylitis using posterior pedicle screwing aided by a self-designed aiming device

    Institute of Scientific and Technical Information of China (English)

    徐兆万; 刘大勇; 冀旭斌; 伦登兴; 王炳武; 隋国侠; 钟军; 厉峰; 刘伟强

    2014-01-01

    Objective To evaluate the clinical efficacy of a self-designed aiming device used in posterior pedicle screwing for cervical spine fractures associated with ankylosing spondylitis.Methods A retrospective analysis was performed of 8 patients with cervical spine fracture associated with ankylosing spondylitis who had received cervical posterior surgery between January 2006 and December 2012 in our department.They were 7 men and one woman,from 35 to 66 years of age (mean,39.0 years).The fracture affected C5-6 in 2 cases,C6-7 in 3,C6 in one,and C7 in 2.Preoperatively Halo-vest external fixation was installed to ensure the cervical sequence.During the operation,all the 8 patients were fixated with short cervical posterior segmental pedicle screws with the help of the self-designed aiming device.The Halo-vest external fixation was removed after postoperative radiographic data revealed fracture healing.Results The 8 cases were followed up for 12 to 87 months (mean,45 months).No such complications as injuries to spinal cord,vertebral artery or nerve root happened.Imaging data showed satisfactory position of internal fixation by one week after operation.At 3 and 6 months and the last follow-up postoperatively,imaging information showed the fractures healed and bone grafts were fused with no pedicle screw loosening,emergence or fracture.Conclusion Treatment of cervical spine fractures associated with ankylosing spondylitis can be effectively and safely treated using posterior pedicle screws with the help of our self-designed aiming device.%目的 评价在自行设计的瞄准器辅助下椎弓根螺钉技术治疗下颈椎骨折合并强直性脊柱炎(AS)的疗效.方法 回顾性分析自2006年1月至2012年12月收治的8例下颈椎骨折合并AS患者资料,男7例,女1例;年龄35 ~ 66岁,平均39.0岁;骨折部位:经C5-6椎间隙2例,经C6-7椎间隙3例,经C6椎体1例,经C7椎体2例.患者术前行Halo-vest外固定支架固定,术中在自行设计的瞄准

  13. Morphological character of cervical spine for anterior transpedicular screw fixation

    Directory of Open Access Journals (Sweden)

    Rong-Ping Zhou

    2013-01-01

    Full Text Available Background: Anterior cervical interbody grafts/cages combined with a plate were frequently used in multilevel discectomies/corpectomies. In order to avoid additional posterior stabilization in patients who undergo anterior reconstructive surgery, an anterior cervical transpedicular screw fixation, which offers higher stability is desirable. We investigated in this study the anatomical (morphologic characters for cervical anterior transpedicular screw fixation. Materials and Methods: Left pedicle parameters were measured on computed tomography (CT images based on 36 cervical spine CT scans from healthy subjects. The parameters included outer pedicle width (Distance from lateral to medial pedicle surface in the coronal plane, outer pedicle height (OPH (Distance from upper to lower pedicle surface in the sagittal plane, maximal pedicle axis length (MPAL, distance transverse insertion point (DIP, distance of the insertion point to the upper end plate (DIUP, pedicle sagittal transverse angle (PSTA and pedicle transverse angle (PTA at C3 to C7. Results: The values of outer pedicle width and MPAL in males were larger than in females from C3 to C7. The OPH in males was larger than in females at C3 to C6, but there was no difference at C7. The DIP and PTA were significantly greater in males than in females at C3, but there was no difference in the angle at C4-7. The PSTA was not statistically different between genders at C3, 4, 7, but this value in males was larger than females at C5, 6. The DIUP was significantly greater in males at C3, 4, 6, 7 but was non significant at C5. Conclusions: The placement of cervical anterior transpedicular screws should be individualized for each patient and based on a detailed preoperative planning.

  14. 腰椎滑脱椎弓根螺钉内固定融合术后邻近节段椎间隙变化的相关研究%Related study on adjacent segments intervertebral space change after spondylolishesis pedicle screw internal fixation and fusion operation

    Institute of Scientific and Technical Information of China (English)

    贾鹏; 赵文国; 王勇贵

    2013-01-01

    目的 探讨腰椎内固定融合术后邻近椎间隙高度的变化及其与螺钉角度的关系.方法 回顾性分析31例行腰椎内固定融合术的腰椎滑脱患者的临床资料,观察术后固定融合区邻近椎间隙的变化;对是否“悬浮固定”对邻近椎间隙高度变化的影响及不同邻近节段椎间隙高度变化进行对比;分析邻近椎间隙高度变化与螺钉角度的关系.结果 L5~S1固定组其上方的L4/L5椎间隙术后1 a高度与术后即时比较虽有一定程度的降低,但差异无统计学意义(P>0.05);L4~L5固定组其上方的L3/L4椎间隙及下方的L5/S1椎间隙术后1 a高度与术后即时比较虽有一定程度的降低,但差异亦无统计学意义(P>0.05);L5~S1固定组其上方的L4/L5椎间隙高度变化与L4~L5固定组其上方的L3/L4椎间隙高度变化比较,差异无统计学意义(P>0.05);L4~L5固定后,固定融合区上方邻近椎间隙(L3/L4)高度变化与下方邻近椎间隙(L5/S1)高度变化比较,差异无统计学意义(P>0.05);螺钉角度<6°组与螺钉角度≥6.组比较,固定融合区上方邻近椎间隙高度变化差异无统计学意义(P>0.05);固定融合区上方椎间隙高度变化与螺钉角度呈正线性相关关系(r =0.373,P=0.039).结论 是否“悬浮固定”对固定融合区邻近节段椎间隙无影响,固定融合区上、下方邻近节段椎间隙变化无差异;螺钉角度的大小与固定融合区上方邻近节段椎间隙存在正相关关系,即螺钉角度越大,椎间隙变小越明显.%Objective To observe the change of the height of the adjacent segments intervertebral space after internal fixation and fusion operation of lumbar vertebrae and the relation between the change of height of intervetebral space in the adjacent segments and the angle of the pedicle screw.Methods Thirty-one patients who had undergone an internal fixation and fusion operation of lumbar vertebrae were analyzed

  15. Study of adjacent segment degeneration after internal fixation lumbar fusion with pedicle screw%腰椎滑脱椎弓根螺钉内固定融合术后邻近节段退变的相关研究

    Institute of Scientific and Technical Information of China (English)

    赵文国; 沈冰; 张柳; 王勇贵; 贾鹏

    2008-01-01

    Objective To observe the changes of the height of intervertebral discs of the segments adjacent to the fusional and instrumental area after the operation and the relation between the changes of height of intervetebral discs in the adjacent segments and the angle of the pedicle screw.Methods Thirty-one patients who underwent internal fixation from September 2004 to March 2006 were retrospectively analyzed.The intervertebral discs height of adjacent segment was studied.The influence of"Suspensory fixation"on the changes of height of adjacent intervertebral discs was compared.The relation between the changes of the height of the upper adjacent intervertebral discs and the angle of pedicle screw was analyzed.Results The mean follow-up period for the patients was 13.5 months(10-16 months).In the operating-group,the height of the adjacent intervertebral disc decreased slightly,but the changes had no statistical significance(P>0.05).Between the group fixed between L5 and S1 and group fixed between L4and L5,the changes of the height of the upper adjacent intervertebral discs had no obvious difference(P>0.05).In the group fixed between L4 and L5,there had no obvious difference between the changes of the height of the upper adjacent intervertebral discs and the changes of the height of the lower one(P>0.05).When the operating-group were divided into two groups according to the angle of pedicle screw (<6°or>6°),the changes of the height of the upper adjacent intervertebral discs had no obvious difference(P>0.05).But there had positive and correlative relation between changes of the height of the adjacent intervertebral discs and the angle of pedicle screw(r=0.373,P=0.039).Conclusion "Suspensory fixation"has no different influence on the changes of height of adjacent intervertebral discs.There has no difference on the risk of degeneration between upper and lower segment adjacent to the fusional area.There has positive and correlative relation between the changes

  16. 腰椎短节段椎弓根螺钉固定术后近端邻近节段前凸原因分析%Pathogenesis analysis of proximal junctional lordosis after short-level posterior pedicle screw fixation in lumbar spine

    Institute of Scientific and Technical Information of China (English)

    刘海鹰; 王波; 王会民; 缪克难; 金朝晖

    2008-01-01

    Objective To analyze the possible reasons for proximal junctional lordosis(PJL)after short-segment posterior pedicle screw fixation in lumbar spine and discuss its proper management.Methods From December 2001 to August 2005,345 patients were treated by short-segment pedicle screw fixation and these patients were reviewed.Clinical outcome was evaluated according to Oswestry Disability Index(ODI).Proximal junctional lordosis was assessed evaluated on radiographs,by measuring lumbar lordosis angle,segmental angle at proximal level and lumbar-sacral angle.Risk factors of proximal junctional lordosis were analyzed.Resuits All patients were followed-up for 2 to 6 years(average 3.8 years).ODI after lumbar surgery was 9.7-46.2(average 19.6±10.7).PJL was noted in 78 patients(22.6%),37(10.7%)of whom were symptomatic and 21(6.1%)received revision surgery.PJL was more commonly occurred in patients over 60 years old,with reduced lumbar lordosis or veaical sacrum.The number of fusion-segment was not correlated to the occurrence of PJL.Conclusions Short-segment posterior pediele screw fixation can not improve lumbar sagittal alignment.Age over of 60 years,reduced lumbar lordosis and vertical sacrum are possible risk factors of PJL sacrum.%目的 分析腰椎后路椎弓根螺钉固定术后近端邻近节段前凸的可能原因,探讨合理的应对措施.方法 回顾分析2001年12月至2005年8月345例进行腰椎后路椎弓根螺钉患者,根据Oswestry功能障碍指数评价患者的临床效果,影像学检查观察近端邻近节段前凸情况,测量邻近节段椎间角、腰前凸角、腰骶角,并分析年龄、融合节段范围、腰骶力线对近端邻近节段前凸形成的影响.结果 全部患者随访2~6年(平均3.8年),术后Oswestry功能障碍指数为9.7~46.2(平均19.6±10.7).78例(22.6%)术后出现近端邻近节段前凸,37例(10.7%)出现临床症状,21例(6.1%)接受再次手术.年龄大于60岁、术后腰前凸减小、垂直骶骨的

  17. 骨水泥强化椎弓根螺钉技术应用于脊柱肿瘤外科治疗的临床疗效探究%Effects of pedicle screw cement augmentation on spine tumor surgery

    Institute of Scientific and Technical Information of China (English)

    钟南哲; 严望军; 魏海峰; 刘铁龙; 肖建如; 杨兴海

    2016-01-01

    固定方法成功操作的关键在于获得合理的骨水泥弥散分布方式。%Objective To evaluate the effectiveness and safety of cement-augmented pedicle screw ifxation on spine tumor with osteoporotic adjacent vertebrae.Methods The medical records of 35 patients ( 22 males, 13 females ) with spine tumors combined with adjacent vertebral osteoporosis were retrospectively analyzed. All underwent operation and were reconstructed by cement-augmented pedicle screw fixation from December 2012 to November 2014. The mean age was ( 58.1 ± 8.5 ) years ( range: 40 - 76 years ). Characteristics of cement distribution, and the location of cement in the vertebrae and with screws were investigated.Results The mean follow-up time was ( 28.3 ± 4.6 ) months ( range: 14 - 37 months ). Scores of American spinal cord injury association ( ASIA ) and visual analogue scale ( VAS ) were all improved signiifcantly at the last follow-up. The mean correction rate of kyphosis and scoliosis were 54.8% and 71% respectively with the average loss of angle 0.6° and 0.3° respectively. Preoperative and postoperative coronal Cobb’s angles were ( 6.0 ± 6.4 ) ° and ( 1.5 ± 2.3 ) °, and preoperative and postoperative sagittal Cobb’s angles were ( 14.1 ± 12.8 ) ° and ( 11.2 ± 8.1 ) °, with statistical signiifcance. Coronal and sagittal Cobb’s angles showed no signiifcant changes 3 months postoperatively and in the latest follow-up. No operative complications, non-union or instrumental failure were detected during the follow-up. 73.4% of cement distributed in the anterior column and the rest 26.6% in the anterior column and the anterior part of the medial column. 95% conifdential interval (CI )of the ratio between the diameter of cement distribution and screw: ( 1.80 - 3.14 ); the depth of cement distribution and screw: ( 64.6% - 92.2% ); the volume of screw and cement distribution: ( 10.1% - 40.6% ); the volume of cement distribution and vertebrae: ( 2.0% - 20.2% ); the depth

  18. Pedicle morphology of the thoracic spine in preadolescent idiopathic scoliosis: magnetic resonance supported analysis.

    Science.gov (United States)

    Catan, Hüseyin; Buluç, Levent; Anik, Yonca; Ayyildiz, Erhan; Sarlak, Ahmet Yilmaz

    2007-08-01

    Although several studies have been reported on the adult vertebral pedicle morphology, little is known about immature thoracic pedicles in patients with idiopathic scoliosis. A total of 310 pedicles (155 vertebrae) from T1 to T12 in 10-14 years age group were analyzed with the use of magnetic resonance imaging and digital measurement program in 13 patients with right-sided thoracic idiopathic scoliosis. Each pedicle was measured in the axial and sagittal planes including transverse and sagittal pedicle width and angles, chord length, interpedicular distance and epidural space width on convex and concave sides of the curve. The smallest transverse pedicle widths were in the periapical region and the largest were in the caudal region. No statistically significant difference in transverse pedicle widths was detected between the convex and concave sides. The transverse pedicle angle measured 15.56 degrees at T1 and decreased to 6.32 degrees at T12. Chord length increased gradually from the cephalad part of the thoracic spine to the caudad part as the shortest length was seen at T1 convex level with a mean of 30.45 mm and the largest length was seen at T12 concave level with a mean of 41.73 mm. The width of epidural space on the concave side was significantly smaller than that on the convex side in most levels of the curve. Based on the anatomic measurements, it may be reasonable to consider thoracic pedicle screws in preadolescent idiopathic scoliosis.

  19. Electrical conductivity measurement: a new technique to detect iatrogenic initial pedicle perforation.

    Science.gov (United States)

    Bolger, Ciaran; Kelleher, Michael O; McEvoy, Linda; Brayda-Bruno, M; Kaelin, A; Lazennec, J-Y; Le Huec, J-C; Logroscino, C; Mata, P; Moreta, P; Saillant, G; Zeller, R

    2007-11-01

    Pedicle screw fixation has achieved significant popularity amongst spinal surgeons for both single and multi-level spinal fusion. Misplacement and pedicle cortical violation occurs in over 20% of screw placement and can result in potential complications such as dysthesia, paraparesis or paraplegia. There have been many advances in techniques available for navigating through the pedicle; however, these techniques are not without drawbacks. A new electrical conductivity-measuring device, previously evaluated on the porcine model to detect the pedicle violation, was evaluated amongst nine European Hospitals to be used in conjunction with the methods currently used in that centre. This new device is based on two original principles; the device is integrated in the drilling or screwing tool. The technology allows real-time detection of perforation through two independent parameters, impedance variation and evoked muscle contractions. Data was collected twofold. Initially, the surgeon was given the device and a comparison was made between the devices ability to detect a breech and the surgeon's ability to detect one using his traditional methods of pedicle preparation. In the second module of the study, the surgeon was limited to using the electrical conductivity detection device as their sole guide to detect pedicle breaches. A comparison was made between the detection ability of the device and the other detection possibilities. Post-operative fine cut CT scanning was used to detect the pedicle breaches. Overall, the 11 trial surgeons performed a total of 521 pedicle drillings on 97 patients. Initially there were 147 drillings with 23 breaches detected. The detection rate of these breaches were 22/23 for the device compared to 10/23 by the surgeon. Over both parts of the study 64 breaches (12.3%) were confirmed on post-operative CT imaging. The electrical conductivity detection device detected 63 of the 64 breaches (98.4%). There was one false negative and four false

  20. RHEOLOGICAL DEFORMATION BEHAVIOR MODEL OF SUGAR DOUGH IN THE CONDITIONS OF MONOAXIAL COMPRESSION

    Directory of Open Access Journals (Sweden)

    G. O. Magomedov

    2014-01-01

    Full Text Available Summary. The knowledge of regularities of deformation behavior of the processed confectionery masses with certain rheological properties allows to calculate parameters of shaping process and to select processing equipment for its carrying out. The article studies the obtaining of the rheological equation of deformation behavior of sugar dough in the conditions of monoaxial compression which is realized in sugar cookies dough pieces formation processes. The results of the pilot studies confirming adequacy of the offered rheological equation are presented. The behavior of an elastic-, viscous- and plastic body in the conditions of quasistatic test for creeping during which the set size is tension, and the measured one is relative deformation is considered. The main rheological properties of sugar dough received experimentally are given. Values of rheological constants are received and it is revealed that at 95% confidential probability, the rheological equation for the general deformation of an elastic-, viscous- and plastic body adequately describes experimental data. The maximum fault thus makes 2,3%. It is established that dough pieces shaping processes from the sugar dough possessing visco- and plastic properties should be realized at an external tension (power impact from the forming body which exceeds a limit of fluidity of the dough formed. The level of external tension, as well as the duration of its influence (that is formation duration should be chosen taking into account the residual deformations in the processed mass which guarantee giving of a certain geometrical form and drawing on a surface of dough pieces. The rheological model of sugar dough allows to predict its deformation behavior in the formation conditions, and to calculate the parameters of sugar dough formation process.

  1. Atlantoaxial Pedicle Screw via Posterior Fixation and Fusion for the Treatment of Jefferson Fracture%寰枢椎椎弓根螺钉经后路固定融合治疗 Jefferson 骨折伴齿状突骨折

    Institute of Scientific and Technical Information of China (English)

    洪波; 向铁城; 黄象望; 刘向阳; 盛斌; 邓化龙; 熊伟

    2014-01-01

    [Objective] To explore clinical outcome of atlantoaxial pedicle screw via posterior fixation and infusion for the treatment of Jefferson fracture associated with odontoid fracture .[Methods] A total of 12 pa-tients with Jefferson fracture and odontoid fracture from March 2009 to May 2012 underwent atlantoaxial pedi-cle screw via posterior fixation and infusion .All patients were 8 males and 4 females with a mean age of 40 .3 years old(ranged 25 to 62 years old) .According to Anderson classification ,there were 9 patients with type II odontoid fracture and 3 patients with type III odontoid fracture .Preoperative JOA score of neurological func-tion were from 5~13(means 9 .6 ± 0 .2) .Before the operation ,the imaging examinations such as X-ray ,spiral 3-dimension CT and MRI and skull traction were performed .JOA scores were compared between before and one year after operation .The improvement rate was calculated .[Results]Atlantoaxial fracture dislocation a-chieved basic reduction .No vertebral artery injury ,spinal and nerve root injury occurred during the operation . No deterioration of spinal cord injury was observed after operation .All patients were followed up for 6~18 months(mean 13 months) .Clinical symptoms were improved significantly .Reexamination of X-ray and spiral CT 6 months after operation showed that all fractures were bone union .The screw position was good .No loosening ,defluxion and breaking occurred .JOA scores of neurological function one year after operation were 14~17(mean 16 .1 ± 0 .2) .The average improvement rate was 85 .8% .[Conclusion]Atlantoaxial pedicle screw via posterior fixation and infusion for the treatment of Jefferson fracture associated with odontoid fracture has significant efficacy .It is advantages such as stable fixation and high bone union rate .%[目的]探讨寰枢椎椎弓根螺钉经后路固定融合治疗 Jefferson 骨折伴齿状突骨折的临床疗效。[方法]自2009年3月至2012年5月对12例Jefferson骨折

  2. Preliminary clinical application of the new instrumentation growing rods of sliding pedicle screw system for scoliosis in children%新型滑槽钉生长棒内固定系统治疗儿童脊柱侧凸的初步报告

    Institute of Scientific and Technical Information of China (English)

    王文军; 薛静波; 晏怡果; 左建宏; 姚女兆; 王程; 王麓山; 李学林; 欧阳智华

    2013-01-01

    目的 评价新型滑槽钉生长棒内固定系统在儿童脊柱侧凸治疗中的初步临床疗效.方法 自2009年1月至2011年7月,使用滑槽钉生长棒内固定系统治疗脊柱侧凸患儿10例,男3例,女7例;年龄4~12岁,平均7.8岁.Risser征均为0级.均为特发性脊柱侧凸.单胸弯3例,单胸腰弯或腰弯6例,双胸弯1例.入院时冠状位Cobb角38°~85°,平均66.8°;矢状位Cobb角38°~66°,平均45.5°;坐高36~64 cm,平均48.6 cm.疗效评价指标包括冠状位、矢状位Cobb角及其矫正率、坐高、躯干偏移、双肩高度差、植骨融合情况、矫正丢失率和并发症,重点在身高和发育情况.结果 术后即刻冠状位Cobb角17°~39°,平均28°,矫正率为48%~65%,平均为52%.术后矢状位Cobb角25°~39°,平均31°,坐高46~70 cm,平均56.8 cm.全部病例随访12~44个月,平均26.5个月.随访期间矫正角度丢失率<5%,坐高平均增加2 cm,3例出现矫形棒尾端皮肤感染,均予以局部换药后痊愈,1例术后出现肩部失平衡,余未出现断钉、断棒等内固定相关并发症.结论 新型滑槽钉生长棒内固定系统治疗儿童脊柱侧凸的初步临床疗效证实该系统的有效性和安全性.%Objective To evaluate the primary clinical outcome of the new instrumentation growing rods of sliding pedicle screw system in the treatment of scoliosis in children.Methods From January 2009 to July 2011,10 patients with idiopathic scoliosis were treated using a new instrumentation growing rods of sliding pedicle screw system.There were 3 males and 7 females,aged from 4 to 12 years (average,7.8 years).Risser sign was grade 0 in all patients.There were 3 cases of single thoracic curve,6 cases of single thoracolumbar or lumbar curve,and 1 case of double thoracic curve.Before operation,the average coronal Cobb angle was 66.8°(range,38° to 85°),the average sagittal Cobb angle was 45.5°(range,38° to 66°),and the average sitting height

  3. Study of Bone-screw Surface Fixation in Lumbar Dynamic Stabilization

    Institute of Scientific and Technical Information of China (English)

    Yun-Gang Luo; Tao Yu; Guo-Min Liu; Nan Yang

    2015-01-01

    Background:We aimed to use the animal model of dynamic fixation to examine the interaction of the pedicle screw surface with surrounding bone,and determine whether pedicle screws achieve good mechanical stability in the vertebrae.Methods:Twenty-four goats aged 2-3 years had Cosmic(R) pedicle screws implanted into both sides of the L2-L5 pedicles.Twelve goats in the bilateral dynamic fixation group had fixation rods implanted in L2-L3 and L4-L5.Twelve goats in the unilateral dynamic fixation group had fixation rods randomly fixed on one side of the lumbar spine.The side that was not implanted with fixation rods was used as a static control group.Results:In the static control group,new bone was formed around the pedicle screw and on the screw surface.In the unilateral and bilateral dynamic fixation groups,large amounts of connective tissue formed between and around the screw threads,with no new bone formation on the screw surface; the pedicle screws were loose after the fixed rods were removed.The bone mineral density and morphological parameters of the region of interest (ROI) in the unilateral and bilateral dynamic fixation group were not significantly different (P > 0.05),but were lower in the fixed groups than the static control group (P < 0.05).This showed the description bone of the ROI in the static control group was greater than in the fixation groups.Under loading conditions,the pedicle screw maximum pull force was not significantly different between the bilateral and unilateral dynamic fixation groups (P > 0.05); however the maximum pull force of the fixation groups was significantly less than the static control group (P < 0.01).Conclusions:Fibrous connective tissue formed at the bone-screw interface under unilateral and bilateral pedicle dynamic fixation,and the pedicle screws lost mechanical stability in the vertebrae.

  4. A finite element modeling of posterior atlantoaxial fixation and biomechanical analysis of C2 intralaminar screw fixation

    Institute of Scientific and Technical Information of China (English)

    Ma Xuexiao; Peng Xianbo; Xiang Hongfei; Zhang Yan; Zhang Guoqing; Chen Bohua

    2014-01-01

    Background The objective of this study was to use three-dimensional finite element (FE) models to analyze the stability and the biomechanics of two upper cervical fixation methods:the C2 intralaminar screw method and the C2 pedicle screw method.Methods From computed tomography images,a nonlinear three-dimensional FE model from C0 (occiput) to C3 was developed with anatomic detail.The C2 intralaminar screw and the C2 pedicle screw systems were added to the model,in parallel to establish the interlaminar model and the pedicle model.The two models were operated with all possible states of motion and physiological loads to simulate normal movement.Results Both the C2 intralaminar screw method and the C2 pedicle screw method significantly reduced motion compared with the intact model.There were no statistically significant differences between the two methods.The Von Mises stresses of the internal and external laminar walls were similar between the two methods.Stability was also similar.Conclusions The C2 intralaminar screw method can complement but cannot completely replace the C2 pedicle screw method.Clinicians would need to assess and decide which approach to adopt for the best therapeutic effect.

  5. 长节段椎弓根钉系统内固定与个性化截骨方法治疗强直性脊柱炎后凸畸形%Long-segment pedicle screw fixation and individual osteotomy in the treatment of ankylosing spondylitis with kyphosis

    Institute of Scientific and Technical Information of China (English)

    王晓平; 郑蕊; 张敬; 陆明; 马华松; 周建伟; 袁伟; 陈阳; 牛晶; 任冬云; 秦柳花

    2013-01-01

    BACKGROUND:Orthopedic osteotomy at the apex of kyphosis is best for treatment of ankylosing spondylitis from a biomechanical aspect, but there is a high risk for intraoperative spinal cord injury. OBJECTIVE:To explore the clinical efficacy of vertebral plate osteotomy+vertebra osteotomy+long-segment pedicle screw fixation in the treatment of ankylosing spondylitis with kyphotic deformity. METHODS:Thirty-six patients with ankylosing spondylitis were subjected to pedicle subtraction osteotomy and Smith-Peterson osteotomy, and then fol owed up for 3 months to 2 years. RESULTS AND CONCLUSION:After implantation, sagittal imbalance did not occur in 36 patients, and the improvement rate of sagittal imbalance was 64%. The improvement rates of thoracolumbar kyphosis and chin-brow vertical angle were 60%and 98%, respectively. The pain relief rate was 64%, and the Oswestry Disability Index was 95%. There were no pul ed nails, broken nails and broken robs after implantation. These findings indicate that the combination of selective osteotomy technique and long-segment internal fixation can achieve stable fixation effects, prevent sagittal imbalance, and avoid the occurrence of pul ing nails, breaking nails and breaking robs caused by osteoporosis.%背景:生物力学的观点认为:强直性脊柱炎的矫形在后凸的顶点处截骨最佳,但术中脊髓损伤的风险大。  目的:分析联合应用椎板间截骨+椎体截骨+长节段椎弓根钉系统内固定治疗强直性脊柱炎后凸畸形的临床效果。  方法:强直性脊柱炎患者共36例,均采用PSO(Pedicle Subtraction Osteotomy)截骨+SPO(Smith-Peterson Osteotomy)联合截骨治疗。随访时间3个月至2年。  结果与结论:36例患者未发现植入物修复后矢状位失平衡者,矢状位失衡的改善率为64%。患者植入物修复后胸腰椎后凸角的到恢复,改善率为60%;颌眉角的改善率为98%,疼痛症状缓解程度为64%,ODI 指数95%

  6. The evaluation of curative effect for lumbar spondylolisthesis by posterior lumbar intervertebral compression bone graft fusion and pedicle screw internal fixation%椎间打压植骨融合椎弓根钉内固定术治疗腰椎滑脱症疗效评价

    Institute of Scientific and Technical Information of China (English)

    黄久勤; 王传文

    2009-01-01

    Objective To investigate the curative effect for lumbar spondylolisthesis by posterior lumbar intervertebral compression bone graft fusion and pedicle screw internal fixation.Method All 39 cases with lumbar spondylolisthesis accepted treatment during January 2003 to October 2007.There were cataplasia spondylolisthesis in 14 cases and isthmic spondylolisthesis in 25 cases.Twenty-two cases had spondylolisthesis in L4 and 17 cases had spondylolisthesis in L5.According to Meyerding grading,11 patients were classified as degree Ⅰ lesion.27 patients as degree Ⅱ lesion and 1 patient as degree Ⅲ lesion.By the help of X-ray machine,pedicle screw Was embedded in the vertebral spondylolisthesis and it Was lower vertebra.Laminectomy decompress was administered in vertebral spondylolisthesis and hold-down bars was placed to open intervertebral space.Then restored the vertebral spondylolisthesis and fixed it temporary.Next,intervertebral compression bone graft fusion was finished and was adjusted.Results Follow-up period was 5 months to 4 years.Clinical outcomes were measured with Prolo evaluation scale,35 cases were cured,4 cases were good effect.Conclusions This operation has been found to be asafe,rapid and effective method for lumbar spondylolisthesis and it produces a high fusion rate and lower expense.%目的 评价椎间打压植骨融合椎弓根钉内固定术治疗腰椎滑脱症的临床疗效.方法 2003年1月至2007年10月收治的腰椎滑脱症患者39例,其中退变性滑脱14例,峡部裂性滑脱25例.L4椎体滑脱22例,L5k椎体滑脱17例.按Meyerding滑脱程度分级标准:Ⅰ度滑脱11例,Ⅱ度滑脱27例,Ⅲ度滑脱1例.C型臂X线机透视定位下在滑脱椎体及其下位椎体间植入椎弓根螺钉,行滑脱椎体全椎板减压术,安放固定棒并撑开椎间隙,进行滑脱椎体复位及临时固定,处理椎间隙,行椎间打压植骨融合术,调整钉棒进行椎间适度加压,以植骨块稳定为度.结果 本组患者

  7. Quadrant 单侧固定椎间融合治疗不稳定型腰椎间盘突出症%Unilateral Pedicle Screw Fixation and Interbody Fusion for the Treatment of Lumbar Disc Hernia-tion with Lumbar Spinal Instability under Mast Quadrant System

    Institute of Scientific and Technical Information of China (English)

    李青; 姚海燕; 梁道臣; 赵成毅; 张爱明; 梅治; 陈应超; 张非

    2014-01-01

    Objective To explore the clinical outcome of the minimally invasive surgical approach by mast Quadrant sys-tem in the treatment of lumbar disc herniation with lumbar spinal instability. Methods For 31 patients with single level lum-bar disc herniation with lumbar spinal instability which diagnosed by magnetic resonance imaging and dynamic X-rays. This group included 20 males and 11 females. All patients were managed by unilateral pedicle