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1

Injection of Bupivacaine into Disc Space to Detect Painful Nonunion after Anterior Lumbar Interbody Fusion (ALIF) Surgery in Patients with Discogenic Low Back Pain  

PubMed Central

Purpose Bupivacaine is commonly used for the treatment of back pain and the diagnosis of its origin. Nonunion is sometimes observed after spinal fusion surgery; however, whether the nonunion causes pain is controversial. In the current study, we aimed to detect painful nonunion by injecting bupivacaine into the disc space of patients with nonunion after anterior lumbar interbody fusion (ALIF) surgery for discogenic low back pain. Materials and Methods From 52 patients with low back pain, we selected 42 who showed disc degeneration at only one level (L4-L5 or L5-S1) on magnetic resonance imaging and were diagnosed by pain provocation on discography and pain relief by discoblock (the injection of bupivacaine). They underwent ALIF surgery. If the patients showed low back pain and nonunion 2 years after surgery, we injected bupivacaine into the nonunion disc space. Patients showing pain relief after injection of bupivacaine underwent additional posterior fixation using pedicle screws. These patients were followed up 2 years after the revision surgery. Results Of the 42 patient subjects, 7 showed nonunion. Four of them did not show low back pain; whereas 3 showed moderate or severe low back pain. These 3 patients showed pain reduction after injection of bupivacaine into their nonunion disc space and underwent additional posterior fixation. They showed bony union and pain relief 2 years after the revision surgery. Conclusion Injection of bupivacaine into the nonunion disc space after ALIF surgery for discogenic low back pain is useful for diagnosis of the origin of pain. PMID:24532522

Kimura, Seiji; Orita, Sumihisa; Inoue, Gen; Eguchi, Yawara; Takaso, Masashi; Ochiai, Nobuyasu; Kuniyoshi, Kazuki; Aoki, Yasuchika; Ishikawa, Tetsuhiro; Miyagi, Masayuki; Kamoda, Hiroto; Suzuki, Miyako; Sakuma, Yoshihiro; Kubota, Gou; Oikawa, Yasuhiro; Inage, Kazuhide; Sainoh, Takeshi; Yamauchi, Kazuyo; Toyone, Tomoaki; Nakamura, Junichi; Kishida, Shunji; Sato, Jun; Takahashi, Kazuhisa

2014-01-01

2

Coblation of spinal endplates in preparation for interbody spinal fusion  

Microsoft Academic Search

Posterior lumbar interbody fusion (PLIF) and anterior lumbar interbody fusion (ALIF) have become routine alternatives to intertransverse process fusion. The use of Coblation® (ArthroCare Corporation, Sunnyvale, CA) allows for routine and reproducible removal of cartilaginous endplate down to the bony endplate. Our experience with this new technology is reviewed. The authors used Coblation® to prepare endplates of 10 consecutive patients

Henry E. Aryan; Christopher P. Ames; Bartek Szandera; Andrew D. Nguyen; Frank L. Acosta; William R. Taylor

2006-01-01

3

Failed anterior lumbar interbody fusion due to incomplete foraminal decompression  

Microsoft Academic Search

Background  Anterior lumbar interbody fusion (ALIF) has gained widespread popularity for spinal disorders requiring fusion. The purpose\\u000a of this study was to analyze ALIF failures.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  The medical records of 223 patients treated with ALIF between January 2007 and June 2008 were retrospectively reviewed. Patients\\u000a with unfavorable outcomes, including subsequent posterior decompression at the index level or poor outcomes after ALIF were

Kyung-Chul Choi; Yong Ahn; Byung-Uk Kang; Joo-Hee Jang; Kyeong-Ki Kim; Yong Hwan Shin; Jong-Oh Choi; Sang-Ho Lee

2011-01-01

4

Anterior Lumbar Interbody Fusion: Two-Year Results with a Modular Interbody Device  

PubMed Central

Study Design Retrospective case series. Purpose To present radiographic outcomes following anterior lumbar interbody fusion (ALIF) utilizing a modular interbody device. Overview of Literature Though multiple anterior lumbar interbody techniques have proven successful in promoting bony fusion, postoperative subsidence remains a frequently reported phenomenon. Methods Forty-three consecutive patients underwent ALIF with (n=30) or without (n=11) supplemental instrumentation. Two patients underwent ALIF to treat failed posterior instrumented fusion. The primary outcome measure was presence of fusion as assessed by computed tomography. Secondary outcome measures were lordosis, intervertebral lordotic angle (ILA), disc height, subsidence, Bridwell fusion grade, technical complications and pain score. Interobserver reliability of radiographic outcome measures was calculated. Results Forty-three patients underwent ALIF of 73 motion segments. ILA and disc height increased over baseline, and this persisted through final follow-up (p<0.01). Solid anterior interbody fusion was present in 71 of 73 motion segments (97%). The amount of new bone formation in the interbody space increased over serial imaging. Subsidence >4 mm occurred in 12% of patients. There were eight surgical complications (19%): one major (reoperation for nonunion/progressive subsidence) and seven minor (five subsidence, two malposition). Conclusions The use of a modular interbody device for ALIF resulted in a high rate of radiographic fusion and a low rate of subsidence. The large endplate and modular design of the device may contribute to a low rate of subsidence as well as maintenance of ILA and lordosis. Previously reported quantitative radiographic outcome measures were found to be more reliable than qualitative or categorical measures. PMID:25346811

Yeoman, Chevas; Chung, Woosik M.; Chappuis, James L; Freedman, Brett

2014-01-01

5

Indications for anterior lumbar interbody fusion.  

PubMed

Anterior lumbar interbody fusion (ALIF) has become a widely recognized surgical technique for degenerative pathology of the lumbar spine. Spinal fusion has evolved dramatically ever since the first successful internal fixation by Hadra in 1891 who used a posterior approach to wire adjacent cervical vertebrae in the treatment of fracture-dislocation. Advancements were made to reduce morbidity including bone grafting substitutes, metallic hardware instrumentation and improved surgical technique. The controversy regarding which surgical approach is best for treating various pathologies of the lumbar spine still exists. Despite being an established treatment modality, current indications of ALIF are yet to be clearly defined in the literature. This article discusses the current literature on indications on ALIF surgery. PMID:24002831

Mobbs, Ralph J; Loganathan, Aji; Yeung, Vivian; Rao, Prashanth J

2013-08-01

6

Fusion after minimally disruptive anterior lumbar interbody fusion: Analysis of extreme lateral interbody fusion by computed tomography  

PubMed Central

Background Less invasive fusion approaches, such as extreme lateral interbody fusion (XLIF), have proliferated, but few reports have critically assessed fusion rates. To date, no studies have reported computed tomography (CT) documented fusion rates following XLIF. Methods An institutional review board-approved prospective radiographic and CT assessment of minimally disruptive anterior lumbar interbody fusion (mini-ALIF) fusions performed through the XLIF approach. Sixty-six patients (88 operative levels) were examined 12 months after XLIF to determine the rate and quality of anterior lumbar fusion. Results Eighty five of the 88 levels (96.6%) were judged fused by CT. Sixty-four of the 66 patients (97.0%) were judged fused by CT. Patient satisfaction at 12 months after surgery was high, with 89.4% reportedly “satisfied or very satisfied” with their results. No revisions were necessary for pseudarthrosis. Conclusion Mini-ALIF using an XLIF approach reliably results in anterior lumbar fusion.

Rodgers, W. B.; Gerber, Edward J.; Patterson, Jamie R.

2010-01-01

7

Current status of bone graft options for anterior interbody fusion of the cervical and lumbar spine.  

PubMed

Anterior cervical discectomy and fusion (ACDF) and anterior lumbar interbody fusion (ALIF) are common surgical procedures for degenerative disc disease of the cervical and lumbar spine. Over the years, many bone graft options have been developed and investigated aimed at complimenting or substituting autograft bone, the traditional fusion substrate. Here, we summarise the historical context, biological basis and current best evidence for these bone graft options in ACDF and ALIF. PMID:23743981

Chau, Anthony Minh Tien; Xu, Lileane Liang; Wong, Johnny Ho-Yin; Mobbs, Ralph Jasper

2014-01-01

8

Presacral retroperitoneal approach to axial lumbar interbody fusion: a new, minimally invasive technique at L5-S1: Clinical outcomes, complications, and fusion rates in 50 patients at 1-year follow-up  

PubMed Central

Background The presacral retroperitoneal approach to an axial lumbar interbody fusion (ALIF) is a percutaneous, minimally invasive technique for interbody fusion at L5-S1 that has not been extensively studied, particularly with respect to long-term outcomes. Objective The authors describe clinical and radiographic outcomes at 1-year follow-up for 50 consecutive patients who underwent the presacral ALIF. Methods Our patients included 24 males and 26 females who underwent the presacral ALIF procedure for interbody fusion at L5-S1. Indications included mechanical back pain and radiculopathy. Thirty-seven patients had disc degeneration at L5-S1, 7 had previously undergone a discectomy, and 6 had spondylolisthesis. A 2-level L4-S1 fusion was performed with a transforaminal lumbar interbody fusion at L4-5 in 15 patients. AxiaLIF was performed as a stand-alone procedure in 5 patients and supplemented with pedicle screws in 45 patients. Pre- and postoperative visual analog scale (VAS) and Oswestry Disability Index (ODI) scores were evaluated and complications were tracked. Fusion was evaluated by an independent neuro-radiologist. Results At 1-year follow-up, VAS and ODI scores had significantly improved by 49% and 50%, respectively, versus preoperative scores. By high-resolution computer tomography (CT) scans, fusion was achieved in 44 (88%) patients, developing bone occurred in 5 (10%), and 1 (2%) patient had pseudoarthrosis. One patient suffered a major operative complication–a bowel perforation with a pre-sacral abscess that resolved with treatment. Conclusion Our initial 50 patients who underwent presacral ALIF showed clinical improvement and fusion rates comparable with other interbody fusion techniques; its safety was reflected by low complication rates. Its efficacy in future patients will continue to be monitored, and will be reported in a 2-year follow-up study of fusion.

Bohinski, Robert J.; Jain, Viral V.; Tobler, William D.

2010-01-01

9

Endoscopic Foraminal Decompression Preceding Oblique Lateral Lumbar Interbody Fusion To Decrease The Incidence Of Post Operative Dysaesthesia  

PubMed Central

Background Lumbar interbody fusion has become a well established method to diminish axial back pain as well as radiculopathy in patients with degenerative disc disease, stenosis, and instability. The concept of indirect decompression of the neural foramen and spinal canal while performing fusion became popular in the mid 1990’s with description of ALIF techniques. Morphometric analysis confirmed the extent of decompression of posterior elements with interbody height restoration. In an attempt to diminish potential complications associated with anterior or posterior approaches to the spine for interbody fusion, and with the hope of accomplishing fusion in a less invasive manner, lateral lumbar interbody fusion has become quite popular. This transpsoas approach to the disc space has been associated with a high incidence of neurologic complications. Even though this is the first technique to routinely recommend EMG monitoring to increase safety in the approach, neurologic injuries still occur. A newer oblique lateral lumbar interbody (OLLIF) approach has recently been described to lessen the incidence of neurologic injury. This technique also advocates use of EMG testing to lessen neurologic trauma. In spite of this precaution, neurologic insult has not been eliminated. In fact, even in patients whose electrical stimulation thresholds suggested a safe entry space into the disc, transient dysaesthesia continues to occur in 20-25 percent of cases. Purpose This pilot study reflects data and observations of a subset of patients treated with endoscopic foraminotomy preceding oblique lateral lumbar interbody fusion (OLLIF) to assess specifically potential improvements in dysaesthesia rates. Methods A select subset of patients undergoing OLLIF failed to meet electrodiagnostic criteria for safe disc access through Kambin’s triangle. These patients underwent an endoscopic foraminotomy and exiting nerve decompression prior to discectomy, endplate preparation and cage insertion. Results Dysaesthesia did not occur in these patients whom otherwise would have likely been at risk for neurologic deficit. Conclusions These findings suggest that patients at risk for neurologic insult during oblique lateral lumbar interbody fusion can be protected by foraminoplasty. PMID:25694923

Katzell, Jeffrey

2014-01-01

10

PEEK Versus Ti Interbody Fusion Devices: Resultant Fusion, Bone Apposition, Initial and 26 Week Biomechanics.  

PubMed

STUDY DESIGN:: Comparative evaluation of in vitro and in vivo biomechanics, resulting fusion and histomorphometric aspects of Polyetheretherketone (PEEK) versus Titanium (Ti) interbody fusion devices in an animal model with similar volumes of bone graft. OBJECTIVE:: Identify differences in the characteristics of fusion and biomechanics immediately following implantation (time zero) and at 26 weeks with each interbody implant. SUMMARY OF BACKGROUND DATA:: PEEK has been well accepted in spinal surgery, it provides a closer match to the mechanical properties of bone than metallic implants such as titanium. This is thought to reduce graft stress shielding and subsidence of interbody fusion devices. There remains controversy as to the overall influence of this as a factor influencing resultant fusion and initial stability. While material modulus is one factor of importance, other design factors are likely to play a large role determining overall performance of an interbody implant. METHODS:: A Ti and PEEK device of similar size with a central void to accommodate graft material were compared. The PEEK device had a ridged surface on the caudal and cephalad surfaces, while Ti device allowed axial compliance and had bone ingrowth endplates and polished internal surfaces. A two level ALIF was performed in 9 sheep and fusion, biomechanics, and bone apposition were evaluated at 26 weeks. Time zero in vitro biomechanical tests were performed to establish initial stability immediately following implantation. RESULTS:: No differences were detected in the biomechanical measures of each of the devices in in vitro time zero tests. All levels were fused by 26 weeks with considerably lower Range of Motion (ROM) when compared to in vitro tests. ROM in all modes of bending was reduced by over 70% when compared to intact values for Axial Rotation (Ti-74%, PEEK-71%), Lateral Bending (Ti-90%, PEEK-88%) and Flexion/Extension (Ti-92%, PEEK-91%). Mechanical properties of fusions formed with each implant did not differ, however bone apposition was variable with polished internal Ti surfaces being lower than PEEK and treated Ti endplates showing the greatest levels. Graft material displayed axial trabecular alignment with both implants. CONCLUSIONS:: Although material properties and surface characteristics resulted in differing amounts of biological integration from the host, both implants were capable of producing excellent fusion results using similar volumes of bone graft. PMID:22801456

Pelletier, Matthew; Cordaro, Nicholas; Lau, Abe; Walsh, William R

2012-07-13

11

Comparison of low back fusion techniques: transforaminal lumbar interbody fusion (TLIF) or posterior lumbar interbody fusion (PLIF) approaches  

Microsoft Academic Search

The authors review and compare posterior lumbar interbody fusion (PLIF) with transforaminal lumbar interbody fusion (TLIF).\\u000a A review of the literature is performed wherein the history, indications for surgery, surgical procedures with their respective\\u000a biomechanical advantages, potential complications, and grafting substances are presented. Along with the technical advancements\\u000a and improvements in grafting substances, the indications and use of PLIF and

Chad D. Cole; Todd D. McCall; Meic H. Schmidt; Andrew T. Dailey

2009-01-01

12

Analysis of spinal lumbar interbody fusion cage subsidence using Taguchi method, finite element analysis, and artificial neural network  

NASA Astrophysics Data System (ADS)

Subsidence, when implant penetration induces failure of the vertebral body, occurs commonly after spinal reconstruction. Anterior lumbar interbody fusion (ALIF) cages may subside into the vertebral body and lead to kyphotic deformity. No previous studies have utilized an artificial neural network (ANN) for the design of a spinal interbody fusion cage. In this study, the neural network was applied after initiation from a Taguchi L 18 orthogonal design array. Three-dimensional finite element analysis (FEA) was performed to address the resistance to subsidence based on the design changes of the material and cage contact region, including design of the ridges and size of the graft area. The calculated subsidence is derived from the ANN objective function which is defined as the resulting maximum von Mises stress (VMS) on the surface of a simulated bone body after axial compressive loading. The ANN was found to have minimized the bone surface VMS, thereby optimizing the ALIF cage given the design space. Therefore, the Taguchi-FEA-ANN approach can serve as an effective procedure for designing a spinal fusion cage and improving the biomechanical properties.

Nassau, Christopher John; Litofsky, N. Scott; Lin, Yuyi

2012-09-01

13

Minimally invasive transforaminal lumbar interbody fusion  

PubMed Central

Background: The use of minimally invasive surgical (MIS) techniques represents the most recent modification of methods used to achieve lumbar interbody fusion. The advantages of minimally invasive spinal instrumentation techniques are less soft tissue injury, reduced blood loss, less postoperative pain and shorter hospital stay while achieving clinical outcomes comparable with equivalent open procedure. The aim was to study the clinicoradiological outcome of minimally invasive transforaminal lumbar interbody fusion. Materials and Methods: This prospective study was conducted on 23 patients, 17 females and 6 males, who underwent MIS-transforaminal lumbar interbody fusion (TLIF) followed up for a mean 15 months. The subjects were evaluated for clinical and radiological outcome who were manifested by back pain alone (n = 4) or back pain with leg pain (n = 19) associated with a primary diagnosis of degenerative spondylolisthesis, massive disc herniation, lumbar stenosis, recurrent disc herniation or degenerative disc disease. Paraspinal approach was used in all patients. The clinical outcome was assessed using the revised Oswestry disability index and Macnab criteria. Results: The mean age of subjects was 55.45 years. L4-L5 level was operated in 14 subjects, L5-S1 in 7 subjects; L3-L4 and double level was fixed in 1 patient each. L4-L5 degenerative listhesis was the most common indication (n = 12). Average operative time was 3 h. Fourteen patients had excellent results, a good result in 5 subjects, 2 subjects had fair results and 2 had poor results. Three patients had persistent back pain, 4 patients had residual numbness or radiculopathy. All patients had a radiological union except for 1 patient. Conclusion: The study demonstrates a good clinicoradiological outcome of minimally invasive TLIF. It is also superior in terms of postoperative back pain, blood loss, hospital stay, recovery time as well as medication use. PMID:25404767

Jhala, Amit; Singh, Damandeep; Mistry, MS

2014-01-01

14

Comparison of Transforaminal Lumbar Interbody Fusion with Direct Lumbar Interbody Fusion: Clinical and Radiological Results  

PubMed Central

Objective The use of direct lumbar interbody fusion (DLIF) has gradually increased; however, no studies have directly compared DLIF and transforaminal lumbar interbody fusion (TLIF). We compared DLIF and TLIF on the basis of clinical and radiological outcomes. Methods A retrospective review was performed on the medical records and radiographs of 98 and 81 patients who underwent TLIF and DLIF between January 2011 and December 2012. Clinical outcomes were compared with a visual analog scale (VAS) and the Oswestry disability index (ODI). The preoperative and postoperative disc heights, segmental sagittal/coronal angles, and lumbar lordosis were measured on radiographs. Fusion rates, operative time, estimated blood loss (EBL), length of hospital stay, and complications were assessed. Results DLIF was superior to TLIF regarding its ability to restore disc height, foraminal height, and coronal balance (p<0.001). As the extent of surgical level increased, DLIF displayed significant advantages over TLIF considering the operative time and EBL. However, fusion rates at 12 months post-operation were lower for DLIF (87.8%) than for TLIF (98.1%) (p=0.007). The changes of VAS and ODI between the TLIF and DLIF were not significantly different (p>0.05). Conclusion Both DLIF and TLIF are less invasive and thus good surgical options for treating degenerative lumber diseases. DLIF has higher potential in increasing neural foramina and correcting coronal balance, and involves a shorter operative time and reduced EBL, in comparison with TLIF. However, DLIF displayed a lower fusion rate than TLIF, and caused complications related to the transpsoas approach. PMID:25628805

Lee, Young Seok; Park, Seung Won; Chung, Chan

2014-01-01

15

Comparison of the different surgical approaches for lumbar interbody fusion.  

PubMed

This review will outline the history of spinal fusion. It will compare the different approaches currently in use for interbody fusion. A comparison of the techniques, including minimally invasive surgery and graft options will be included. Lumbar interbody fusion is a commonly performed surgical procedure for a variety of spinal disorders, especially degenerative disease. Currently this procedure is performed using anterior, lateral, transforaminal and posterior approaches. Minimally invasive techniques have been increasing in popularity in recent years. A posterior approach is frequently used and has good fusion rates and low complication rates but is limited by the thecal and nerve root retraction. The transforaminal interbody fusion avoids some of these complications and is therefore preferable in some situations, especially revision surgery. An anterior approach avoids the spinal cord and cauda equina all together, but has issues with visceral exposure complications. Lateral lumbar interbody fusion has a risk of lumbar plexus injury with dissection through the psoas muscle. Studies show less intraoperative blood loss for minimally invasive techniques, but there is no long-term data. Iliac crest is the gold standard for bone graft, although adjuncts such as bone morphogenetic proteins are being used more frequently, despite their controversial history. More high-level studies are needed to make generalisations regarding the outcomes of one technique compared with another. PMID:25439753

Talia, Adrian J; Wong, Michael L; Lau, Hui C; Kaye, Andrew H

2015-02-01

16

Radiological and functional outcome after anterior lumbar interbody spinal fusion  

Microsoft Academic Search

Outcome after anterior spinal fusion has mainly been studied radiologically and reported fusion rates vary greatly. The aim of this study was to investigate radiological and long-term clinical outcome. The study comprised 120 consecutive patients, operated on during the period 1979–1987, with single-or two-level anterior interbody spinal fusion due to disc degeneration or isthmic spondylolisthesis with lumbar instability. In 64

F. B. Christensen; B. Karlsmose; E. S. Hansen; C. E. Bringer

1996-01-01

17

Finite element biomechanics of cervical spine interbody fusion  

Microsoft Academic Search

The biomechanical responses of cervical discectomy coupled with fusion using five types of interbody fusion materials were determined. Titanium core, titanium cage, tricortical iliac crest, tantalum core, and tantalum cage fusion materials were used. Smith-Robinson and Bailey-Badgley procedures were analyzed. A validated three-dimensional anatomically accurate three-segment C4-C5-C6 finite element model of the spine was developed using close-up computed tomography images

Srirangak Kumaresan; Narayan Yoganandan; Frank A. Pintar

1997-01-01

18

Double-segment Wilhelm Tell technique for anterior lumbar interbody fusion in unstable isthmic spondylolisthesis and adjacent segment discopathy.  

PubMed

The Wilhelm Tell technique is a novel instrumented anterior lumbar interbody fusion (ALIF) procedure using a specially designed composite carbon fibre cage and a single short-threaded cancellous screw that obliquely passes through the upper adjacent vertebral body, the interbody cage itself and through the lower adjacent vertebral body. This single-stage fusion method, which is in principle a combination of the Louis technique and modern cage surgery, is reported to have a lower rate of pseudoarthrosis formation than stand-alone cage techniques. In addition, it eliminates both the surgical trauma of paravertebral muscle retraction and the risk of neural damage by poorly located pedicular screws. This anterior approach allows decompression of neural structures within the anterior part of the spinal canal and the foraminal region. It is the purpose of this case report, to present the successful application of this novel technique in a 32-year-old woman who concurrently suffered from severe instability-related back pain from L4/5 isthmic spondylolisthesis and marked L5/S1 degenerative disc disease. PMID:16459090

Wenger, Markus; Vogt, Emanuel; Markwalder, Thomas-Marc

2006-02-01

19

Finite element analysis of minimal invasive transforaminal lumbar interbody fusion.  

PubMed

The purpose of our study is to develop and validate three-dimensional finite element models of transforaminal lumbar interbody fusion, and explore the most appropriate method of fixation and fusion by comparing biomechanical characteristics of different fixation method. We developed four fusion models: bilateral pedicle screws fixation with a single cage insertion model (A), bilateral pedicle screws fixation with two cages insertion model (B), unilateral pedicle screws fixation with a single cage insertion model (C), and unilateral pedicle screws fixation with two cages insertion model (D); the models were subjected to different forces including anterior bending, posterior extension, left bending, right bending, rotation, and axial compressive. The von Mises stress of the fusion segments on the pedicle screw and cages was recorded. Angular variation and stress of pedicle screw and cage were compared. There were differences of Von Mises peak stress among four models, but were within the range of maximum force. The angular variation in A, B, C, and D decreased significantly compared with normal. There was no significant difference of angular variation between A and B, and C and D. Bilateral pedicle screws fixation had more superior biomechanics than unilateral pedicle screws fixation. In conclusion, the lumbar interbody fusion models were established using varying fixation methods, and the results verified that unilateral pedicle screws fixation with a single cage could meet the stability demand in minimal invasive transforaminal interbody fusion. PMID:24782059

Zhao, Chuncheng; Wang, Xinhu; Chen, Changchun; Kang, Yanzhong

2014-09-01

20

Biomechanical Characteristics of an Integrated Lumbar Interbody Fusion Device  

PubMed Central

Introduction We hypothesized that an Integrated Lumbar Interbody Fusion Device (PILLAR SA, Orthofix, Lewisville, TX) will function biomechanically similar to a traditional anterior interbody spacer (PILLAR AL, Orthofix, Lewisville, TX) plus posterior instrumentation (FIREBIRD, Orthofix, Lewisville, TX). Purpose of this study was to determine if an Integrated Interbody Fusion Device (PILLAR SA) can stabilize single motion segments as well as an anterior interbody spacer (PILLAR AL) + pedicle screw construct (FIREBIRD). Methods Eight cadaveric lumbar spines (age: 43.9±4.3 years) were used. Each specimen's range of motion was tested in flexion-extension (FE), lateral bending (LB), and axial rotation (AR) under intact condition, after L4-L5 PILLAR SA with intervertebral screws and after L4-L5 360° fusion (PILLAR AL + Pedicle Screws and rods (FIREBIRD). Each specimen was tested in flexion (8Nm) and extension (6Nm) without preload (0 N) and under 400N of preload, in lateral bending (±6 Nm) and axial rotation (±5 Nm) without preload. Results Integrated fusion using the PILLAR SA device demonstrated statistically significant reductions in range of motion of the L4-L5 motion segment as compared to the intact condition for each test direction. PILLAR SA reduced ROM from 8.9±1.9 to 2.9±1.1° in FE with 400N follower preload (67.4%), 8.0±1.7 to 2.5±1.1° in LB, and 2.2±1.2 to 0.7±0.3° in AR. A comparison between the PILLAR SA integrated fusion device versus 360° fusion construct with spacer and bilateral pedicle screws was statistically significant in FE and LB. The 360° fusion yielded motion of 1.0±0.5° in FE, 1.0±0.8° in LB (p0.05). Conclusions The PILLAR SA resulted in motions of less than 3° in all modes of motion and was not as motion restricting as the traditional 360° using bilateral pedicle screws. The residual segmental motions compare very favorably with published biomechanical studies of other interbody integrated fusion devices. PMID:25694931

Voronov, Leonard I.; Vastardis, Georgios; Zelenakova, Julia; Carandang, Gerard; Havey, Robert M.; Waldorff, Erik I.; Zindrick, Michael R.

2014-01-01

21

Single or double-level anterior interbody fusion techniques for cervical degenerative disc disease  

Microsoft Academic Search

BACKGROUND: The number of surgical techniques for decompression and solid interbody fusion as treatment for cervical spondylosis has increased rapidly, but the rationale for the choice between different techniques remains unclear. OBJECTIVES: To determine which technique of anterior interbody fusion gives the best clinical and radiological outcomes in patients with single- or double-level degenerative disc disease of the cervical spine.

W. Jacobs; P. C. P. H. Willems; J. van Limbeek; R. H. M. A. Bartels; P. Pavlov; P. G. Anderson; C. Oner

2011-01-01

22

A carbon fiber implant to aid interbody lumbar fusion. Mechanical testing.  

PubMed

A carbon-fiber-reinforced polymer implant has been designed to aid interbody lumbar fusion. The cage-like implant has ridges or teeth to resist pullout or retropulsion, struts to support weight bearing, and a hollow center for packing of autologous bone graft. Because carbon is radiolucent, bony healing can be imaged by standard radiographic techniques. The device has been mechanically tested in cadaver spines and compared with posterior lumbar interbody fusion performed with donor bone. The carbon device required a pullout force of 353 N compared with 126 N for donor bone. In compression testing, posterior lumbar interbody fusion performed with the carbon device bore a load of 5,288 N before failure of the vertebral bone. Posterior lumbar interbody fusion performed with donor bone failed at 4,628 N, and unmodified motion segments failed at 6,043 N. The carbon fiber implant separates the mechanical and biologic functions of posterior lumbar interbody fusion. PMID:1862425

Brantigan, J W; Steffee, A D; Geiger, J M

1991-06-01

23

Treating Traumatic Lumbosacral Spondylolisthesis Using Posterior Lumbar Interbody Fusion with three years follow up  

PubMed Central

Objective: To analyze the surgical outcome of traumatic lumbosacral spondylolisthesis treated using posterior lumbar interbody fusion, and help spine surgeons to determine the treatment strategy. Methods: We reviewed retrospectively five cases of traumatic lumbosacral spondylolisthesis treated in our hospital from May 2005 to May 2010. There were four male and one female patient, treated surgically using posterior lumbar interbody fusion. The patients’ data including age, neurological status, operation time, blood loss, follow-up periods, X- radiographs and fusion status were collected. Results: All the cases were treated using posterior lumbar interbody fusion to realize decompression, reduction and fusion. Solid arthrodesis was found at the 12-month follow-up. No shift or breakage of the instrumentation was found, and all the patients were symptom-free at the last follow-up. Conclusion: Traumatic lumbosacral spondylolisthesis can be treated using posterior lumbar interbody fusion to realize the perfect reduction, decompression, fixation and fusion. PMID:25225542

Tang, Shujie

2014-01-01

24

Finite element analysis of anterior cervical spine interbody fusion.  

PubMed

The present study investigated the external and the internal biomechanical responses of anterior cervical discectomy coupled with fusion. Five different types of interbody fusion materials were used: titanium core, titanium cage, tricortical iliac crest, tantalum core, and tantalum cage. Two different types of surgical procedures were analyzed: Smith-Robinson and Bailey-Badgley. A validated three-dimensional anatomically accurate finite element model of the human cervical spine was used in the study. The finite element model was exercised in compression, flexion, extension, and lateral bending for the intact case and for the two surgical procedures with five implant materials. The external response in terms of the stiffness and angular rotation, and the internal response in terms of the disc and the vertebral stresses were determined. The Smith-Robinson technique resulted in the highest increase in external response under all modes of loading for all implant materials. In contrast, the Bailey-Badgley technique produced a higher increase in the disc and the vertebral body stresses than the Smith-Robinson technique. As experimental human cadaver tests can only determine the external response of the non-fused spine simulating immediate post-operative structure, the present finite element studies assist in the understanding of biomechanics of interbody fusion by delineating the changes in the extrinsic and intrinsic characteristics of the cervical spine components due to surgery. PMID:9408574

Kumaresan, S; Yoganandan, N; Pintar, F A

1997-01-01

25

Fusion rate after posterior lumbar interbody fusion with carbon fiber implant: 1-year follow-up of 51 patients  

Microsoft Academic Search

Problems associated with posterior lumbar interbody fusion (PLIF) have traditionally included the need for donor bone, prolonged healing time of donor bone, the difficulty of cutting precise bony channels, the risk of retropulsion of graft, postoperative collapse of the bone graft, and pseudarthrosis. To avoid these problems a carbon fiber reinforced polymer implant cage has been developed to facilitate interbody

T. Tullberg; B. Brandt; J. Rydberg; P. Fritzell

1996-01-01

26

Bilateral implantation of low-profile interbody fusion cages: subsidence, lordosis, and fusion analysis  

Microsoft Academic Search

BACKGROUND CONTEXT: The use of interbody fusion cages as a treatment for degenerative disc disease has become widespread. Low-profile cages have been developed to allow a closer fit when implanting bilateral cages in patients with smaller vertebral bodies. Some surgeons feel the open design also allows better bone contact and visualization. This is particularly true when two low-profile cages are

Michael Schiffman; Salvador A Brau; Robin Henderson; Gwen Gimmestad

2003-01-01

27

Biological performance of a polycaprolactone-based scaffold used as fusion cage device in a large animal model of spinal reconstructive surgery  

Microsoft Academic Search

A bioactive and bioresorbable scaffold fabricated from medical grade poly (epsilon-caprolactone) and incorporating 20% beta-tricalcium phosphate (mPCL–TCP) was recently developed for bone regeneration at load bearing sites. In the present study, we aimed to evaluate bone ingrowth into mPCL–TCP in a large animal model of lumbar interbody fusion. Six pigs underwent a 2-level (L3\\/4; L5\\/6) anterior lumbar interbody fusion (ALIF)

Sunny A. Abbah; Christopher X. L. Lam; Dietmar W. Hutmacher; James C. H. Goh; Hee-Kit Wong

2009-01-01

28

Combined anterior interbody fusion and posterior pedicle screw fixation in patients with degenerative lumbar disc disease  

Microsoft Academic Search

We reviewed 47 consecutive patients with degenerative lumbar disc disease. All patients were treated by anterior interbody fusion using an autogenous iliac bone graft in combination with posterior pedicle fixation but without a posterior fusion. There were 32 men and 15 women with a mean age of 44 (range 23–56) years. One third ( n=15) of the patients had previous

M. A. El Masry; W. S. Badawy; P. Rajendran; D Chan

2004-01-01

29

Clinical and Radiological Outcomes of Segmental Spinal Fusion in Transforaminal Lumbar Interbody Fusion with Spinous Process Tricortical Autograft  

PubMed Central

Study Design A retrospective study. Purpose To investigate clinical and radiological outcomes when using spinous process as a tricortical autograft for segmental spinal fusion in transforaminal lumbar interbody fusion (TLIF). Overview of Literature Interbody spinal fusion is one of the important procedures in spinal surgery. Many types of autografts are harvested at the expense of complications. Clinical and radiographic results of patients who underwent TLIF with intraoperative harvested spinous process autograft in Prasat Neurological Institue, Bangkok, Thailand, were assessed as new technical innovation. Methods Between October 2005 to July 2009, 30 cases of patients who underwent TLIF with spinous process tricortical autograft were included. Clinical evaluations were assessed by visual analog scales (VAS) and Prolo functional and economic scores at the preoperation and postoperation and at 2 years postoperation. Static and dynamic plain radiograph of lumbar spine were reviewed for achievement of fusion. Results Initial successful fusion time in lumbar interbody fusion with spinous process tricortical autograft was 4.72 months (range, 3.8-6.1 months) postoperation and 100% fusion rate was reported at 2 years. Our initial successful fusion time in lumbar interbody fusion was compared to the other types of grafts in previous literatures. Conclusions The use of intraoperative harvested spinous process tricortical autograft has overcome many disadvantages of harvesting autograft with better initial successful fusion time (4.72 months). VAS and Prolo scores showed some improvement in the outcomes between the preoperative and postoperative periods. PMID:24761199

Tangviriyapaiboon, Teera

2014-01-01

30

Minimally invasive versus open transforaminal lumbar interbody fusion  

PubMed Central

Background Available clinical data are insufficient for comparing minimally invasive (MI) and open approaches for transforaminal lumbar interbody fusion (TLIF). To date, a paucity of literature exists directly comparing minimally invasive (MI) and open approaches for transforaminal lumbar interbody fusion (TLIF). The purpose of this study was to directly compare safety and effectiveness for these two surgical approaches. Materials and Methods Open or minimally invasive TLIF was performed in 63 and 76 patients, respectively. All consecutive minimally invasive TLIF cases were matched with a comparable cohort of open TLIF cases using three variables: diagnosis, number of spinal levels, and history of previous lumbar surgery. Patients were treated for painful degenerative disc disease with or without disc herniation, spondylolisthesis, and/or stenosis at one or two spinal levels. Clinical outcome (self-report measures, e.g., visual analog scale (VAS), patient satisfaction, and MacNab's criteria), operative data (operative time, estimated blood loss), length of hospitalization, and complications were assessed. Average follow-up for patients was 37.5 months. Results: The mean change in VAS scores postoperatively was greater (5.2 vs. 4.1) in theopen TLIF patient group (P = 0.3). MacNab's criteria score was excellent/good in 67% and 70% (P = 0.8) of patients in open and minimally invasive TLIF groups, respectively. The overall patient satisfaction was 72.1% and 64.5% (P = 0.4) in open and minimally invasive TLIF groups, respectively. The total mean operative time was 214.9 min for open and 222.5 min for minimally invasive TLIF procedures (P = 0.5). The mean estimated blood loss for minimally invasive TLIF (163.0 ml) was significantly lower (P < 0.0001) than the open approach (366.8 ml). The mean duration of hospitalization in the minimally invasive TLIF (3 days) was significantly shorter (P = 0.02) than the open group (4.2 days). The total rate of neurological deficit was 10.5% in the minimally invasive TLIF group compared to 1.6% in the open group (P = 0.02). Conclusions: Minimally invasive TLIF technique may provide equivalent long-term clinical outcomes compared to open TLIF approach in select population of patients. The potential benefit of minimized tissue disruption, reduced blood loss, and length of hospitalization must be weighted against the increased rate of neural injury-related complications associated with a learning curve. PMID:20657693

Villavicencio, Alan T.; Roeca, Cassandra M.; Nelson, E. Lee; Mason, Alexander

2010-01-01

31

Assessment of Bioplex Interbody Fusion Device in a Sheep Lumbar Fusion Model  

PubMed Central

Objective The purpose of this study was to evaluate the bioPlex bioresorbable interbody device in a sheep lumbar fusion model and compare it to the concorde®, a standard carbon fiber interbody cage. Background Lumbar interbody fusion devices are made from a variety of materials, including titanium alloys, carbon-fiber, and PEEK. The BioPlex Continuous Phase Composite (CPC) is a unique bioresorbable material comprised of Pro Osteon 500R and 70:30 Poly (L/D, L-lactic acid). The BioPlex device is radiolucent, resorbable and due to its bulk nanoporosity of 8%, has a more consistent degradation profile as compared to a polymer alone. Methods A total of twenty five male Suffolk sheep were used in this study; nineteen of which were implanted with a bioPlex or concorde device at the L3-L4 and L5-L6 levels using a modified transforaminal/lateral approach. A discectomy was performed and each implant (filled with autologous bone) was placed within the disc space. The sheep were sacrificed at 6, 12, 24 months postimplantation. Fusion was assessed via motion, radiographic and histological data. Results The BioPlex and Concorde implanted levels had significantly less motion (p<0.05) than the normal controls in flexion/extension and lateral bending at 6, 12, and 24 months. No significant difference in motion was detected between the bioPlex and concorde implants. CT fusion scores correlated with the motion analysis in all the three cases. Conclusion In comparison to the concorde device, the bioPlex implant appears to have equivalent radiographic and biomechanical fusion success. PMID:24027458

Fredericks, Douglas C.; Gandhi, Anup A.; Grosland, Nicole M.; Smucker, Joseph D.

2013-01-01

32

Biomechanical analysis of cages for posterior lumbar interbody fusion.  

PubMed

Interbody fusions using intervertebral cages have become increasingly common in spinal surgery. Computational simulations were conducted in order to compare different cage designs in terms of their biomechanical interaction with the spinal structures. Differences in cage design and surgical technique may significantly affect the biomechanics of the fused spine segment, but little knowledge is available on this topic. In the present study, four 3D finite element models were developed, reproducing the human L4-L5 spinal unit in intact condition and after implantation of three different cage models. The intact model consisted of two vertebral bodies and relevant laminae, facet joints, main ligaments and disc. The instrumented models reproduced the post-operative conditions resulting after implant of the different cages. The three considered devices were hollow threaded titanium cages, the BAK (Zimmer Centerpulse, Warsaw, IN, USA), the Interfix and the Interfix Fly (both by Medtronic Sofamor Danek, Memphis, TN, USA). Simulations were run imposing various loading conditions, under a constant compressive preload. A great increase in the stiffness induced on the spinal segment by all cages was observed in all the considered loading cases. Stress distributions on the bony surface were evaluated and discussed. The differences observed between the biomechanics of the instrumented models were associated with the geometrical and surgical features of the devices. PMID:16563847

Fantigrossi, Alfonso; Galbusera, Fabio; Raimondi, Manuela Teresa; Sassi, Marco; Fornari, Maurizio

2007-01-01

33

Posterior interbody fusion using a diagonal cage with unilateral transpedicular screw fixation for lumbar stenosis.  

PubMed

Few reports have described the combined use of unilateral pedicle screw fixation and interbody fusion for lumbar stenosis. We retrospectively reviewed 79 patients with lumbar stenosis. The rationale and effectiveness of unilateral pedicle screw fixation were studied from biomechanical and clinical perspectives, aiming to reduce stiffness of the implant. All patients were operated with posterior interbody fusion using a diagonal cage in combination with unilateral transpedicular screw fixation and had reached the 3-year follow-up interval after operation. The mean operating time was 115 minutes (range=95-150 min) and the mean estimated blood loss was 150 mL (range=100-200 mL). The mean duration of hospital stay was 10 days (range=7-15 days). Clinical outcomes were assessed prior to surgery and reassessed at intervals using Denis' pain and work scales. Fusion status was determined from X-rays and CT scans. At the final follow-up, the clinical results were satisfactory and patients showed significantly improved scores (p<0.01) either on the pain or the work scale. Successful fusion was achieved in all patients. There were no new postoperative radiculopathies, or instances of malpositioned or fractured hardware. Posterior interbody fusion using a diagonal cage with unilateral transpedicular fixation is an effective treatment for decompressive surgery for lumbar stenosis. PMID:21237659

Zhao, Jian; Zhang, Feng; Chen, Xiaoqing; Yao, Yu

2011-03-01

34

Lateral Interbody Fusion for Treatment of Discogenic Low Back Pain: Minimally Invasive Surgical Techniques  

PubMed Central

Low back pain is one of the most common ailments in the general population, which tends to increase in severity along with aging. While few patients have severe enough symptoms or underlying pathology to warrant surgical intervention, in those select cases treatment choices remain controversial and reimbursement is a substancial barrier to surgery. The object of this study was to examine outcomes of discogenic back pain without radiculopathy following minimally-invasive lateral interbody fusion. Twenty-two patients were treated at either one or two levels (28 total) between L2 and 5. Discectomy and interbody fusion were performed using a minimallyinvasive retroperitoneal lateral transpsoas approach. Clinical and radiographic parameters were analyzed at standard pre- and postoperative intervals up to 24 months. Mean surgical duration was 72.1 minutes. Three patients underwent supplemental percutaneous pedicle screw instrumentation. Four (14.3%) stand-alone levels experienced cage subsidence. Pain (VAS) and disability (ODI) improved markedly postoperatively and were maintained through 24 months. Segmental lordosis increased significantly and fusion was achieved in 93% of levels. In this series, isolated axial low back pain arising from degenerative disc disease was treated with minimally-invasive lateral interbody fusion in significant radiographic and clinical improvements, which were maintained through 24 months. PMID:22548181

Marchi, Luis; Oliveira, Leonardo; Amaral, Rodrigo; Castro, Carlos; Coutinho, Thiago; Coutinho, Etevaldo; Pimenta, Luiz

2012-01-01

35

Vertebral osteolytic defect due to cellulose particles derived from gauze fibers after posterior lumbar interbody fusion.  

PubMed

Vertebral cystic lesions may be observed in pseudarthroses after lumbar fusion surgery. The authors report a rare case of pseudarthrosis after spinal fusion, accompanied by an expanding vertebral osteolytic defect induced by cellulose particles. A male patient originally presented at the age of 69 years with leg and low-back pain caused by a lumbar isthmic spondylolisthesis. He underwent a posterior lumbar interbody fusion, and his neurological symptoms and pain resolved within a year but recurred 14 months after surgery. Radiological imaging demonstrated a cystic lesion on the inferior endplate of L-5 and the superior endplate of S-1, which rapidly enlarged into a vertebral osteolytic defect. The patient underwent revision surgery, and his low-back pain resolved. A histopathological examination demonstrated foreign body-type multinucleated giant cells, containing 10-?m particles, in the sample collected just below the defect. Micro-Fourier transform infrared spectroscopy revealed that the foreign particles were cellulosic, presumably originating from cotton gauze fibers that had contaminated the interbody cages used during the initial surgery. Vertebral osteolytic defects that occur after interbody fusion are generally presumed to be the result of infection. This case suggests that some instances of vertebral osteolytic defects may be aseptically induced by foreign particles. Hence, this possibility should be carefully considered in such cases, to help prevent contamination of the morselized bone used for autologous grafts by foreign materials, such as gauze fibers. PMID:25259557

Takenaka, Shota; Mukai, Yoshihiro; Hosono, Noboru; Tateishi, Kosuke; Fuji, Takeshi

2014-12-01

36

Perioperative thrombotic occlusion of left external iliac artery during anterior lumbar interbody fusion  

Microsoft Academic Search

We report a case of thrombotic occlusion of left external iliac artery during the procedure of anterior lumbar interbody fusion.\\u000a The diagnosis was confirmed by computed tomography angiography. The patient also developed severe rhabdomyolysis postoperatively.\\u000a In spite of receiving emergent thromboendarterectomy, the patient expired on postoperative day 3. This report attempts to\\u000a remind spinal surgeons and anesthesiologists of this rare but

Jen-Hsuan Huang; Cheng-Hung Lee; Tzung-chieh Tsai; Shih-Yen Peng

2008-01-01

37

Segmental and global lordosis changes with two-level axial lumbar interbody fusion and posterior instrumentation  

PubMed Central

Background Loss of lumbar lordosis has been reported after lumbar interbody fusion surgery and may portend poor clinical and radiographic outcome. The objective of this research was to measure changes in segmental and global lumbar lordosis in patients treated with presacral axial L4-S1 interbody fusion and posterior instrumentation and to determine if these changes influenced patient outcomes. Methods We performed a retrospective, multi-center review of prospectively collected data in 58 consecutive patients with disabling lumbar pain and radiculopathy unresponsive to nonsurgical treatment who underwent L4-S1 interbody fusion with the AxiaLIF two-level system (Baxano Surgical, Raleigh NC). Main outcomes included back pain severity, Oswestry Disability Index (ODI), Odom's outcome criteria, and fusion status using flexion and extension radiographs and computed tomography scans. Segmental (L4-S1) and global (L1-S1) lumbar lordosis measurements were made using standing lateral radiographs. All patients were followed for at least 24 months (mean: 29 months, range 24-56 months). Results There was no bowel injury, vascular injury, deep infection, neurologic complication or implant failure. Mean back pain severity improved from 7.8±1.7 at baseline to 3.3±2.6 at 2 years (p < 0.001). Mean ODI scores improved from 60±15% at baseline to 34±27% at 2 years (p < 0.001). At final follow-up, 83% of patients were rated as good or excellent using Odom's criteria. Interbody fusion was observed in 111 (96%) of 116 treated interspaces. Maintenance of lordosis, defined as a change in Cobb angle ? 5°, was identified in 84% of patients at L4-S1 and 81% of patients at L1-S1. Patients with loss or gain in segmental or global lordosis experienced similar 2-year outcomes versus those with less than a 5° change. Conclusions/Clinical Relevance Two-level axial interbody fusion supplemented with posterior fixation does not alter segmental or global lordosis in most patients. Patients with postoperative change in lordosis greater than 5° have similarly favorable long-term clinical outcomes and fusion rates compared to patients with less than 5° lordosis change. PMID:25694920

Melgar, Miguel A; Tobler, William D; Ernst, Robert J; Raley, Thomas J; Anand, Neel; Miller, Larry E; Nasca, Richard J

2014-01-01

38

Complications with axial presacral lumbar interbody fusion: A 5-year postmarketing surveillance experience  

PubMed Central

Background Open and minimally invasive lumbar fusion procedures have inherent procedural risks, with posterior and transforaminal approaches resulting in significant soft-tissue injury and the anterior approach endangering organs and major blood vessels. An alternative lumbar fusion technique uses a small paracoccygeal incision and a presacral approach to the L5-S1 intervertebral space, which avoids critical structures and may result in a favorable safety profile versus open and other minimally invasive fusion techniques. The purpose of this study was to evaluate complications associated with axial interbody lumbar fusion procedures using the Axial Lumbar Interbody Fusion (AxiaLIF) System (TranS1, Wilmington, North Carolina) in the postmarketing period. Methods Between March 2005 and March 2010, 9,152 patients underwent interbody fusion with the AxiaLIF System through an axial presacral approach. A single-level L5-S1 fusion was performed in 8,034 patients (88%), and a 2-level (L4-S1) fusion was used in 1,118 (12%). A predefined database was designed to record device- or procedure-related complaints via spontaneous reporting. The complications that were recorded included bowel injury, superficial wound and systemic infections, transient intraoperative hypotension, migration, subsidence, presacral hematoma, sacral fracture, vascular injury, nerve injury, and ureter injury. Results Complications were reported in 120 of 9,152 patients (1.3%). The most commonly reported complications were bowel injury (n = 59, 0.6%) and transient intraoperative hypotension (n = 20, 0.2%). The overall complication rate was similar between single-level (n = 102, 1.3%) and 2-level (n = 18, 1.6%) fusion procedures, with no significant differences noted for any single complication. Conclusions The 5-year postmarketing surveillance experience with the AxiaLIF System suggests that axial interbody lumbar fusion through the presacral approach is associated with a low incidence of complications. The overall complication rates observed in our evaluation compare favorably with those reported in trials of open and minimally invasive lumbar fusion surgery.

Gundanna, Mukund I.; Miller, Larry E.; Block, Jon E.

2011-01-01

39

Transforaminal lumbar interbody fusion using unilateral pedicle screws and a translaminar screw.  

PubMed

Lumbar spinal fusion is advancing with minimally invasive techniques, bone graft alternatives, and new implants. This has resulted in significant reductions of operative time, duration of hospitalization, and higher success in fusion rates. However, costs have increased as many new technologies are expensive. This study was carried out to investigate the clinical outcomes and fusion rates of a low implant load construct of unilateral pedicle screws and a translaminar screw in transforaminal lumbar interbody fusion (TLIF) which reduced the cost of the posterior implants by almost 50%. Nineteen consecutive patients who underwent single level TLIF with this construct were included in the study. Sixteen patients had a TLIF allograft interbody spacer placed, while in three a polyetheretherketone (PEEK) cage was used. Follow-up ranged from 15 to 54 months with a mean of 32 months. A clinical and radiographic evaluation was carried out preoperatively and at multiple time points following surgery. An overall improvement in Oswestry scores and visual analogue scales for leg and back pain (VAS) was observed. Three patients underwent revision surgery due to recurrence of back pain. All patients showed radiographic evidence of fusion from 9 to 26 months (mean 19) following surgery. This study suggests that unilateral pedicle screws and a contralateral translaminar screw are a cheaper and viable option for single level lumbar fusion. PMID:19015896

Sethi, Anil; Lee, Sandra; Vaidya, Rahul

2009-03-01

40

Transforaminal lumbar interbody fusion using unilateral pedicle screws and a translaminar screw  

PubMed Central

Lumbar spinal fusion is advancing with minimally invasive techniques, bone graft alternatives, and new implants. This has resulted in significant reductions of operative time, duration of hospitalization, and higher success in fusion rates. However, costs have increased as many new technologies are expensive. This study was carried out to investigate the clinical outcomes and fusion rates of a low implant load construct of unilateral pedicle screws and a translaminar screw in transforaminal lumbar interbody fusion (TLIF) which reduced the cost of the posterior implants by almost 50%. Nineteen consecutive patients who underwent single level TLIF with this construct were included in the study. Sixteen patients had a TLIF allograft interbody spacer placed, while in three a polyetheretherketone (PEEK) cage was used. Follow-up ranged from 15 to 54 months with a mean of 32 months. A clinical and radiographic evaluation was carried out preoperatively and at multiple time points following surgery. An overall improvement in Oswestry scores and visual analogue scales for leg and back pain (VAS) was observed. Three patients underwent revision surgery due to recurrence of back pain. All patients showed radiographic evidence of fusion from 9 to 26 months (mean 19) following surgery. This study suggests that unilateral pedicle screws and a contralateral translaminar screw are a cheaper and viable option for single level lumbar fusion. PMID:19015896

Lee, Sandra; Vaidya, Rahul

2008-01-01

41

Complete cage migration/subsidence into the adjacent vertebral body after posterior lumbar interbody fusion.  

PubMed

A variety of implant-related short and long-term complications after lumbar fusion surgery are recognized. Mid to long-term complications due to cage migration and/or cage subsidence are less frequently reported. Here, we report a patient with a complete cage migration into the superior adjacent vertebral body almost 20years after the initial posterior lumbar interbody fusion procedure. In this patient, the cage migration/subsidence was clinically silent, but a selective decompression for adjacent segment degenerative lumbar spinal stenosis was performed. We discuss the risk factors for cage migration/subsidence in view of the current literature. PMID:25455736

Corniola, Marco V; Jägersberg, Max; Stienen, Martin N; Gautschi, Oliver P

2015-03-01

42

Does Transforaminal Lumbar Interbody Fusion Have Advantages over Posterolateral Lumbar Fusion for Degenerative Spondylolisthesis?  

PubMed Central

Study Design?Retrospective cohort study. Objective?To compare the clinical and radiographic outcomes of transforaminal lumbar interbody fusion (TLIF) and posterolateral lumbar fusion (PLF) in the treatment of degenerative spondylolisthesis. Methods?This study compared 24 patients undergoing TLIF and 32 patients undergoing PLF with instrumentation. The clinical outcomes were assessed by visual analog scale (VAS) for low back pain and leg pain, physical component summary (PCS) of the 12-item Short-Form Health Survey, and the Oswestry Disability Index (ODI). Radiographic parameters included slippage of the vertebra, local disk lordosis, the anterior and posterior disk height, lumbar lordosis, and pelvic parameters. Results?The improvement of VAS of leg pain was significantly greater in TLIF than in PLF unilaterally (3.4 versus 1.0; p?=?0.02). The improvement of VAS of low back pain was significantly greater in TLIF than in PLF (3.8 versus 2.2; p?=?0.02). However, there was no significant difference in improvement of ODI or PCS between TLIF and PLF. Reduction of slippage and the postoperative disk height was significantly greater in TLIF than in PLF. There was no significant difference in local disk lordosis, lumbar lordosis, or pelvic parameters. The fusion rate was 96% in TLIF and 84% in PLF (p?=?0.3). There was no significant difference in fusion rate, estimated blood loss, adjacent segmental degeneration, or complication rate. Conclusions?TLIF was superior to PLF in reduction of slippage and restoring disk height and might provide better improvement of leg pain. However, the health-related outcomes were not significantly different between the two procedures. PMID:25844282

Fujimori, Takahito; Le, Hai; Schairer, William W.; Berven, Sigurd H.; Qamirani, Erion; Hu, Serena S.

2014-01-01

43

A randomized double-blind prospective study of the efficacy of pulsed electromagnetic fields for interbody lumbar fusions  

SciTech Connect

A randomized double-blind prospective study of pulsed electromagnetic fields for lumbar interbody fusions was performed on 195 subjects. There were 98 subjects in the active group and 97 subjects in the placebo group. A brace containing equipment to induce an electromagnetic field was applied to patients undergoing interbody fusion in the active group, and a sham brace was used in the control group. In the active group there was a 92% success rate, while the control group had a 65% success rate (P greater than 0.005). The effectiveness of bone graft stimulation with the device is thus established.

Mooney, V. (Univ. of California, Irvine (USA))

1990-07-01

44

Circumferential fusion of the lumbar and lumbosacral spine using a carbon fiber ALIF cage implant versus autogenous bone graft: a comparative study.  

PubMed

This study reports on 92 patients treated with circumferential lumbar fusions for degenerative conditions. The elected procedure was a circumferential fusion using transpedicular stabilization. Two groups were examined depending on whether they were stabilized anteriorly with autogenous bicortical iliac crest graft (n = 38) or with an ALIF carbon fiber cage implant (n = 54). The patients were evaluated for clinical and radiographic outcome. The minimum follow-up interval was at least 12 months. Fusion rates, postoperative loss of correction, and clinical results, including pain at the bone donor site, neurologic function, satisfaction, depression, and consumption of analgesics, were not significantly different between patients with autogenous bone graft and patients with carbon cage. This study failed to prove major advantages of the carbon cages in the clinical and radiologic outcome. PMID:12394660

Zelle, Boris; Konig, Friedhelm; Enderle, Alfred; Bertagnoli, Rudolf; Dorner, Jochen

2002-10-01

45

Single-level transforaminal interbody fusion for traumatic lumbosacral fracture-dislocation: a case report.  

PubMed

L5S1 fracture-dislocations are rare three-column injuries. The infrequency of this injury has led to a lack of a universally accepted treatment strategy. Transforaminal lumbar interbody fusion (TLIF) has been shown to be an effective approach for interbody fusion in degenerative indications, but has not been previously reported in the operative management of traumatic lumbosacral dislocation. The authors report a case of traumatic L5S1 fracture-dislocation in a 30-year-old male, presenting with a right-sided L5 neurologic deficit, following a street sweeper accident. Imaging revealed an L5S1 fracture-dislocation with fracture of the S1 body. Open reduction with TLIF and L5S1 posterolateral instrumented fusion was carried out within 24 hours of injury. Excellent reduction was obtained, and maintained at long-term follow-up, with complete resolution of pain and neurologic deficit. In this patient, L5S1 fracture-dislocation was treated successfully, with an excellent outcome, with a single level TLIF and instrumented posterolateral fusion at L5S1. PMID:23547528

Herrera, Anthony J; Berry, Chirag A; Rao, Raj D

2013-02-01

46

Agents & ALifeAgents & ALife Artificial LifeArtificial Life  

E-print Network

-state phase space systems thatCannot (?) pre-state phase space systems that include life?include life? HowAgents & ALifeAgents & ALife Artificial LifeArtificial Life Thumbing its Nose atThumbing its NoseMassey University #12;Agents & ALifeAgents & ALife QuestionsQuestions Philosophy and Life - what is it

Hawick, Ken

47

Systematic review of anterior interbody fusion techniques for single- and double-level cervical degenerative disc disease  

Microsoft Academic Search

STUDY DESIGN: A systematic review of randomized controlled trials. OBJECTIVE: To determine which technique of anterior cervical interbody fusion (ACIF) gives the best outcome in patients with cervical degenerative disc disease. SUMMARY OF BACKGROUND DATA: The number of surgical techniques for decompression and ACIF as treatment for cervical degenerative disc disease has increased rapidly, but the rationale for the choice

W. Jacobs; P. C. P. H. Willems; M. Kruyt; J. van Limbeek; P. G. Anderson; P. Pavlov; R. H. M. A. Bartels; C. Oner

2011-01-01

48

Time-sequential changes of differentially expressed miRNAs during the process of anterior lumbar interbody fusion using equine bone protein extract, rhBMP-2 and autograft  

NASA Astrophysics Data System (ADS)

The precise mechanism of bone regeneration in different bone graft substitutes has been well studied in recent researches. However, miRNAs regulation of the bone formation has been always mysterious. We developed the anterior lumbar interbody fusion (ALIF) model in pigs using equine bone protein extract (BPE), recombinant human bone morphogenetic protein-2 (rhBMP-2) on an absorbable collagen sponge (ACS), and autograft as bone graft substitute, respectively. The miRNA and gene expression profiles of different bone graft materials were examined using microarray technology and data analysis, including self-organizing maps, KEGG pathway and Biological process GO analyses. We then jointly analyzed miRNA and mRNA profiles of the bone fusion tissue at different time points respectively. Results showed that miRNAs, including let-7, miR-129, miR-21, miR-133, miR-140, miR-146, miR-184, and miR-224, were involved in the regulation of the immune and inflammation response, which provided suitable inflammatory microenvironment for bone formation. At late stage, several miRNAs directly regulate SMAD4, Estrogen receptor 1 and 5-hydroxytryptamine (serotonin) receptor 2C for bone formation. It can be concluded that miRNAs play important roles in balancing the inflammation and bone formation.

Chen, Da-Fu; Zhou, Zhi-Yu; Dai, Xue-Jun; Gao, Man-Man; Huang, Bao-Ding; Liang, Tang-Zhao; Shi, Rui; Zou, Li-Jin; Li, Hai-Sheng; Bünger, Cody; Tian, Wei; Zou, Xue-Nong

2014-03-01

49

Protecting the genitofemoral nerve during direct/extreme lateral interbody fusion (DLIF/XLIF) procedures.  

PubMed

A 77-year-old male presented with a history of severe lower back pain for 10 years with radiculopathy, positive claudication type symptoms in his calf with walking, and severe "burning" in his legs bilaterally with walking. Magnetic resonance imaging (MRI) revealed lumbar stenosis at the L3-L4 and L4-L5 levels. During the direct or extreme lateral interbody fusion (DLIF/XLIF) procedure, bilateral posterior tibial, femoral, and ulnar nerve somatosensory evoked potentials (SSEPs) were recorded with good morphology of waveforms observed. Spontaneous electromyography (S-EMG) and triggered electromyography (T-EMG) were recorded from cremaster and ipsilateral leg muscles. A left lateral retroperitoneal transpsoas approach was used to access the anterior disc space for complete discectomy, distraction, and interbody fusion. T-EMG ranging from 0.05 to 55.0 mA with duration of 200 microsec was used for identification of the genitofemoral nerve using a monopolar stimulator during the approach. The genitofemoral nerve (L1-L2) was identified, and the guidewire was redirected away from the nerve. Post-operatively, the patient reported complete pain relief and displayed no complications from the procedure. Intraoperative SSEPs, S-EMG, and T-EMG were utilized effectively to guide the surgeon's approach in this DLIF thereby preventing any post-operative neurological deficits such as damage to the genitofemoral nerve that could lead to groin pain. PMID:21313792

Jahangiri, Faisal R; Sherman, Jonathan H; Holmberg, Andrea; Louis, Robert; Elias, Jeff; Vega-Bermudez, Francisco

2010-12-01

50

Influence of Alendronate and Endplate Degeneration to Single Level Posterior Lumbar Spinal Interbody Fusion  

PubMed Central

Objective Using alendronate after spinal fusion is a controversial issue due to the inhibition of osteoclast mediated bone resorption. In addition, there are an increasing number of reports that the endplate degeneration influences the lumbar spinal fusion. The object of this retrospective controlled study was to evaluate how the endplate degeneration and the bisphosphonate medication influence the spinal fusion through radiographic evaluation. Methods In this study, 44 patients who underwent single-level posterior lumbar interbody fusion (PLIF) using cage were examined from April 2007 to March 2009. All patients had been diagnosed as osteoporosis and would be recommended for alendronate medication. Endplate degeneration is categorized by the Modic changes. The solid fusion is defined if there was bridging bone between the vertebral bodies, either within or external to the cage on the plain X-ray and if there is less than 5° of angular difference in dynamic X-ray. Results In alendronate group, fusion was achieved in 66.7% compared to 73.9% in control group (no medication). Alendronate did not influence the fusion rate of PLIF. However, there was the statistical difference of fusion rate between the endplate degeneration group and the group without endplate degeneration. A total of 52.4% of fusion rate was seen in the endplate degeneration group compared to 91.3% in the group without endplate degeneration. The endplate degeneration suppresses the fusion process of PLIF. Conclusion Alendronate does not influence the fusion process in osteoporotic patients. The endplate degeneration decreases the fusion rate. PMID:25620981

Rhee, Wootack; Ha, Seongil; Lim, Jae Hyeon; Jang, Il Tae

2014-01-01

51

Anterior lumbar fusion using a hybrid interbody graft. A preliminary radiographic report.  

PubMed

This is a radiographic report of 40 patients (20 men, 20 women) who underwent anterior lumbar interbody fusions (73 levels) utilizing a "hybrid" interbody graft composed of femoral cortical allograft (FCA) bone and iliac crest cancellous autograft bone. The average age at surgery was 38 years (range 17-64 years), and follow-up averaged 1.4 years (range 1.0-2.4 years). Nineteen of the patients had undergone previous lumbar surgery. Thirty-two patients (63 levels) underwent anterior fusion combined with some type of posterior fixation, and eight patients (10 levels) had no posterior fixation. Types of posterior fixation included: for 20 patients (36 levels) Steffee variable screw placement fixation, for 10 patients (23 levels) translaminar facet screws (TFS), for 1 patient (3 levels) Knodt rods and for 1 patient (1 level) facet screws. Based on the persistence of lucent lines at the graft-host interface, three patients (one level each) were felt to have non-unions at their latest follow-ups at 1.4, 1.5 and 2.0 years, respectively. Two of these patients had no posterior fixation, and the other had TFS fixation. The overall fusion rate was 96% (70 of 73 levels). The fusion rate for all levels treated with posterior fixation was 98% compared with 75% for those without fixation. Intervertebral disc heights (IVDH) were measured on all films and corrected for magnification with computer assistance. On average, the IVDH was increased postoperatively but returned to preoperative values at follow-up. IVDH loss was independent of the type of instrumentation used. No complications arose from the use of the hybrid graft.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7874539

Holte, D C; O'Brien, J P; Renton, P

1994-01-01

52

CT Evaluation of Lumbar Interbody Fusion: Current Concepts  

Microsoft Academic Search

Operative techniques for fusing an unstable por- tion of the lumbar spine or immobilizing a painful vertebral motion segment have been in use for many years. Lumbar fusion procedures initially were used to treat patients with infections (tuberculous spondy- litis) or misaligned spines (isthmic spondylolisthesis) (1-8). Early techniques involving the use of harvested autogenous bone graft without instrumentation were largely

Alan L. Williams; Matthew F. Gornet; J. Kenneth Burkus

53

Postoperative Flat Back: Contribution of Posterior Accessed Lumbar Interbody Fusion and Spinopelvic Parameters  

PubMed Central

Objective Posterior accessed lumbar interbody fusion (PALIF) has a clear objective to restore disc height and spinal alignment but surgeons may occasionally face the converse situation and lose lumbar lordosis. We analyzed retrospective data for factors contributing to a postoperative flat back. Methods A total of 105 patients who underwent PALIF for spondylolisthesis and stenosis were enrolled. The patients were divided according to surgical type [posterior lumbar inter body fusion (PLIF) vs. unilateral transforaminal lumbar interbody fusion (TLIF)], number of levels (single vs. multiple), and diagnosis (spondylolisthesis vs. stenosis). We measured perioperative index level lordosis, lumbar lordosis, pelvic tilt, sacral slope, pelvic incidence, and disc height in standing lateral radiographs. The change and variance in each parameter and comparative group were analyzed with the paired and Student t-test (p<0.05), correlation coefficient, and regression analysis. Results A significant perioperative reduction was observed in index-level lordosis following TLIF at the single level and in patients with spondylolisthesis (p=0.002, p=0.005). Pelvic tilt and sacral slope were significantly restored following PLIF multilevel surgery (p=0.009, p=0.003). Sacral slope variance was highly sensitive to perioperative variance of index level lordosis in high sacral sloped pelvis. Perioperative variance of index level lordosis was positively correlated with disc height variance (R2=0.286, p=0.0005). Conclusion Unilateral TLIF has the potential to cause postoperative flat back. PLIF is more reliable than unilateral TLIF to restore spinopelvic parameters following multilevel surgery and spondylolisthesis. A high sacral sloped pelvis is more vulnerable to PALIF in terms of a postoperative flat back. PMID:25371781

Kim, Jin Kwon; Kim, Deok Ryeng; Kim, Joo Seung

2014-01-01

54

Multilevel extreme lateral interbody fusion (XLIF) and osteotomies for 3-dimensional severe deformity: 25 consecutive cases  

PubMed Central

Background This is a retrospective review of 25 patients with severe lumbar nerve root compression undergoing multilevel anterior retroperitoneal lumbar interbody fusion and posterior instrumentation for deformity. The objective is to analyze the outcomes and clinical results from anterior interbody fusions performed through a lateral approach and compare these with traditional surgical procedures. Methods A consecutive series of 25 patients (78 extreme lateral interbody fusion [XLIF] levels) was identified to illustrate the primary advantages of XLIF in correcting the most extreme of the 3-dimensional deformities that fulfilled the following criteria: (1) a minimum of 40° of scoliosis; (2) 2 or more levels of translation, anterior spondylolisthesis, and lateral subluxation (subluxation in 2 planes), causing symptomatic neurogenic claudication and severe spinal stenosis; and (3) lumbar hypokyphosis or flat-back syndrome. In addition, the majority had trunks that were out of balance (central sacral vertical line ?2 cm from vertical plumb line) or had sagittal imbalance, defined by a distance between the sagittal vertical line and S1 of greater than 3 cm. There were 25 patients who had severe enough deformities fulfilling these criteria that required supplementation of the lateral XLIF with posterior osteotomies and pedicle screw instrumentation. Results In our database, with a mean follow-up of 24 months, 85% of patients showed evidence of solid arthrodesis and no subsidence on computed tomography and flexion/extension radiographs. The complication rate remained low, with a perioperative rate of 2.4% and postoperative rate of 12.2%. The lateral listhesis and anterior spondylolisthetic subluxation were anatomically reduced with minimally invasive XLIF. The main finding in these 25 cases was our isolation of the major indication for supplemental posterior surgery: truncal decompensation in patients who are out of balance by 2 cm or more, in whom posterior spinal osteotomies and segmental pedicle screw instrumentation were required at follow up. No patients were out of sagittal balance (sagittal vertical line <3 cm from S1) postoperatively. Segmental instrumentation with osteotomies was also more effective for restoration of physiologic lumbar lordosis compared with anterior stand-alone procedures. Conclusions This retrospective study supports the finding that clinical outcomes (coronal/sagittal alignment) improve postoperatively after minimally invasive surgery with multilevel XLIF procedures and are improved compared with larger extensile thoracoabdominal anterior scoliosis procedures. PMID:25694908

McAfee, Paul C.; Shucosky, Erin; Chotikul, Liana; Salari, Ben; Chen, Lun; Jerrems, Dan

2013-01-01

55

A Meta-Analysis of Unilateral versus Bilateral Pedicle Screw Fixation in Minimally Invasive Lumbar Interbody Fusion  

PubMed Central

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. PMID:25375315

Liu, Zheng; Fei, Qi; Wang, Bingqiang; Lv, Pengfei; Chi, Cheng; Yang, Yong; Zhao, Fan; Lin, Jisheng; Ma, Zhao

2014-01-01

56

Navigation-assisted fluoroscopy in minimally invasive direct lateral interbody fusion: a cadaveric study  

PubMed Central

Background Minimally invasive surgery (MIS) is dependent on intraoperative fluoroscopic imaging for visualization, which significantly increases exposure to radiation. Navigation-assisted fluoroscopy (NAV) can potentially decrease radiation exposure and improve the operating room environment by reducing the need for real-time fluoroscopy. The direct lateral interbody fusion (DLIF) procedure is a technique for MIS intervertebral lumbar and thoracic interbody fusions. This study assesses the use of navigation for the DLIF procedure in comparison to standard fluoroscopy (FLUORO), as well as the accuracy of the NAV MIS DLIF procedure. Methods Three fresh whole-body cadavers underwent multiple DLIF procedures at the T10-L5 levels via either NAV or FLUORO. Radiation exposure and surgical times were recorded and compared between groups. An additional cadaver was used to evaluate the accuracy of the NAV system for the DLIF procedure by measuring the deviation error as the surgeon worked further from the anterior superior iliac spine tracker. Results Approach, discectomy, and total fluoroscopy times for FLUORO were longer than NAV (P < .05). In contrast, the setup time was longer in NAV (P = .005). Cage insertion and total operating times were similar for both. Radiation exposure to the surgeon for NAV was significantly less than FLUORO (P < .05). Accuracy of the NAV system was within 1 mm for L2-5. Conclusion Navigation for the DLIF procedure is feasible. Accuracy for this procedure over the most common levels (L2-5) is likely sufficient for safe clinical application. Although initial setup times were longer with NAV, simultaneous anteroposterior and lateral imaging with the NAV system resulted in overall surgery times similar to FLUORO. Navigation minimizes fluoroscopic radiation exposure. Clinical significance Navigation for the DLIF procedure is accurate and decreases radiation exposure without increasing the overall surgical time.

Webb, Jonathan E.; Regev, Gilad J.; Garfin, Steven R.; Kim, Choll W.

2010-01-01

57

Percutaneous posterior-lateral lumbar interbody fusion for degenerative disc disease using a B-Twin expandable spinal spacer  

Microsoft Academic Search

Degenerative disc disease (DDD) causes gradual intervertebral space collapse, concurrent discogenic or facet-induced pain,\\u000a and possible compression radiculopathy. A new minimal invasion procedure of percutaneous posterior-lateral lumbar interbody\\u000a fusion (PPLIF) using a B-Twin stand-alone expandable spinal spacer (ESS) was designed to treat this disease and evaluated\\u000a by follow-up more than 1 year. 12 cases with chronic low back pain and compressive

Lizu Xiao; Donglin Xiong; Qiang Zhang; Jin Jian; Husan Zheng; Yuhui Luo; Juanli Dai; Deren Zhang

2010-01-01

58

Posterior Lumbar Interbody Fusion Using an Unilateral Cage: A Prospective Study of Clinical Outcome and Stability  

PubMed Central

Objective The purpose of this study was to evaluate the clinical and radiological results of instrumented posterior lumbar interbody fusion (PLIF) using an unilateral cage. Methods Seventeen patients with unilateral radiculopathy who underwent bilateral percutaneous screw fixation with a single fusion cage inserted on the symptomatic side for treatment of focal degenerative lumbar spine disease were prospectively enrolled in this study. Their clinical results, radiological parameters, and related complications were assessed 10 days, 3 months, and 12 months postoperatively. Results There was no pseudarthrosis, instrumented fusion failure, significant cage subsidence, or retropulsion in any patient. The surgery restored the disc space height and maintained it as of 12 months postoperatively and did not exacerbate the lumbar lordotic and scoliotic angles. All patients had excellent or good outcomes according to the modified MacNab's criteria. The mean pain score according to the visual analogue scale was 7.5 preoperatively but had improved to 2.5 when reassessed 3 months postoperatively. The improvement was maintained as of 12 months postoperatively. Conclusion In cases of uncomplicated unilateral radiculopathy, PLIF using a single cage can be an effective and safe procedure with the advantage of preserving the posterior elements of the contralateral side. A shorter operative time and greater cost-effectiveness than for PLIF using bilateral cages can be expected. PMID:25110483

Lee, Seok Ki; Kim, Seok Won; Ju, Chang Il; Lee, Sung Myung

2014-01-01

59

Digitalized Design of Extraforaminal Lumbar Interbody Fusion: A Computer-Based Simulation and Cadaveric Study  

PubMed Central

Purpose This study aims to investigate the feasibility of a novel lumbar approach named extraforaminal lumbar interbody fusion (ELIF), a newly emerging minimally invasive technique for treating degenerative lumbar disorders, using a digitalized simulation and a cadaveric study. Methods The ELIF surgical procedure was simulated using the Mimics surgical simulator and included dissection of the superior articular process, dilation of the vertebral foramen, and placement of pedicle screws and a cage. ELIF anatomical measures were documented using a digitalized technique and subsequently validated on fresh cadavers. Results The use of the Mimics allowed for the vivid simulation of ELIF surgical procedures, while the cadaveric study proved the feasibility of this novel approach. ELIF had a relatively lateral access approach that was located 8–9 cm lateral to the median line with an access depth of approximately 9 cm through the intermuscular space. Dissection of the superior articular processes could fully expose the target intervertebral discs and facilitate a more inclined placement of the pedicle screws and cage with robust enhancement. Conclusions According to the computer-based simulation and cadaveric study, it is feasible to perform ELIF. Further research including biomechanical study is needed to prove ELIF has a superior ability to preserve the posterior tension bands of the spinal column, with similar effects on spinal decompression, fixation, and fusion, and if it can enhance post-fusion spinal stability and expedites postoperative recovery. PMID:25157907

Yang, Mingjie; Zeng, Cheng; Guo, Song; Pan, Jie; Han, Yingchao; Li, Zeqing; Li, Lijun; Tan, Jun

2014-01-01

60

Posterior lumbar interbody fusion and posterolateral fusion: Analogous procedures in decreasing the index of disability in patients with spondylolisthesis  

PubMed Central

Objective: The purpose of this study was to evaluate the disability in patients with spondylolisthesis who assigned either to posterolateral fusion (PLF) or posterior lumbar interbody fusion (PLIF) and to compare it between two groups. Methods: In a prospective observational study, 102 surgical candidates with low-grade degenerative and isthmic spondylolisthesis enrolled from 2012 to 2014, and randomly assigned into two groups: PLF and PLIF. Evaluation of disability has been done by a questionnaire using Oswestry Disability Index (ODI). The questionnaire was completed by all patients before the surgery, the day after surgery, after 6 months and after 1-year. Results: There were no statistically significant differences in terms of age and sex distribution and pre-operation ODI between groups (P > 0.05). Comparison of the mean ODI scores of two groups over the whole study period showed no significant statistical difference (P = 0.074). ODIs also showed no significant differences between two groups the day after surgery, 6th months and 1-year after surgery (P = 0.385, P = 0.093, P = 0.122 and P = 433) respectively. Analyzing the course of ODI over the study period, showed a significant descending pattern for either of groups (P < 0.0001). Conclusion: Both surgical fusion techniques (PLF and PLIF) were efficient to lessen the disability of patients with spondylolisthesis, and none of the fusion techniques were related to a better outcome in terms of disability.

Alijani, Babak; Emamhadi, Mohamahreza; Behzadnia, Hamid; Aramnia, Ali; Chabok, Shahrokh Yousefzadeh; Ramtinfar, Sara; Leili, Ehsan Kazemnejad; Golmohamadi, Shabnam

2015-01-01

61

Autologous clavicle bone graft for anterior cervical discectomy and fusion with titanium interbody cage.  

PubMed

A variety of donor-site complications have been reported for anterior cervical discectomy and fusion (ACDF) using autologous iliac bone graft. To minimize such morbidities and to obtain optimal bony fusion at the ACDF surgery, a novel technique was used to harvest cancellous bone from the autologous clavicle instead of the popular iliac crest graft. After a routine cervical discectomy of the affected level, a 1.5-cm linear skin incision was made over the clavicle within 2.5 cm of the sternoclavicular joint on the medial one-third portion. This portion is known as an anatomically safe zone, with no subcutaneous distribution of the supraclavicular nerve. Then, cancellous bone was harvested through a small cortical window developed on the clavicle. Care was taken not to injure the subclavian major vessels and the lung below the clavicle. A box-type titanium cage was packed with the harvested cancellous bone and then inserted into the discectomy-treated space for cervical interbody fusion. From 2009 to 2013, 16 patients with cervical radiculopathy and/or myelopathy underwent single-level ACDF with this method. All but 1 patient experienced significant improvement of clinical symptoms after the surgery and showed radiographic evidence of solid bony fusion and spinal stabilization within 6 months. Further, no peri- and postoperative complications at the clavicular donor site were noted. The mean visual analog scale pain score (range 0 [no pain to 10 [maximum pain]) at 1 year after the surgery was 0.1, and 13 of 14 patients with data at 1-year follow-up were highly satisfied with their donor-site cosmetic outcome. The clavicle is a safe, reliable, and technically easy source of autologous bone graft that yields optimal fusion rates and patient satisfaction with ACDF surgery. PMID:25170654

Iwasaki, Koichi; Ikedo, Taichi; Hashikata, Hirokuni; Toda, Hiroki

2014-11-01

62

Decompression, correction, and interbody fusion for lumbar burst fractures using a single posterior approach.  

PubMed

Burst fractures of the lumbar spine with instability or severe kyphosis are best served by surgical treatment. The question as to how these fractures should be approached and stabilized (anteriorly, posteriorly, or combined anteroposteriorly) is controversial. We performed decompression, correction, and interbody fusion using a single posterior approach for Denis type B or C lumbar burst fractures with severe kyphosis. The operative technique is as follows: after partial laminectomy, the bone fragment, which had migrated into the spinal canal, is impacted into the posterior wall of the vertebral body. After curetting the injured disk, bone chips and adapted lamina are inserted into the disk space for anterior support. Five Denis type B or C burst fractures demanding >20 degrees kyphosis correction were treated by this procedure. Mean follow-up was 41 months. We evaluated neurologic assessment and localized kyphotic angle. The neurologic function of all 5 patients improved by at least 1 grade, as measured by the Frankel grading scale. Mean values of localized kyphosis improved from a mean 23.0. before surgery to -3.0 degrees after surgery. At follow-up examination, average regional kyphosis was -2.4 degrees . No implant failure was observed at follow-up. Bony fusion was achieved in all patients. The advantages of this operative procedure are it is safe for the neural structures and complete spinal canal decompression and kyphosis correction are achieved, while providing anterior support and posterior stabilization. PMID:19824611

Sasagawa, Takeshi; Kawahara, Norio; Murakami, Hideki; Demura, Satoru; Tomita, Katsuro

2009-10-01

63

Comparing Miniopen and Minimally Invasive Transforaminal Interbody Fusion in Single-Level Lumbar Degeneration  

PubMed Central

Degenerative diseases of the lumbar spine, which are common among elderly people, cause back pain and radicular symptoms and lead to a poor quality of life. Lumbar spinal fusion is a standardized and widely accepted surgical procedure used for treating degenerative lumbar diseases; however, the classical posterior approach used in this procedure is recognized to cause vascular and neurologic damage of the lumbar muscles. Various studies have suggested that using the minimally invasive transforaminal interbody fusion (TLIF) technique provides long-term clinical outcomes comparable to those of open TLIF approaches in selected patients. In this study, we compared the perioperative and short-term advantages of miniopen, MI, and open TLIF. Compared with open TLIF, MI-TLIF and miniopen TLIF were associated with less blood loss, shorter hospital stays, and longer operative times; however, following the use of these procedures, no difference in quality of life was measured at 6 months or 1 year. Whether miniopen TLIF or MI-TLIF can replace traditional TLIF as the surgery of choice for treating degenerative lumbar deformity remains unclear, and additional studies are required for validating the safety and efficiency of these procedures. PMID:25629037

Lo, Wei-Lun; Lin, Chien-Min; Yeh, Yi-Shian; Tseng, Yuan-Yun; Yang, Shun-Tai

2015-01-01

64

Comparing miniopen and minimally invasive transforaminal interbody fusion in single-level lumbar degeneration.  

PubMed

Degenerative diseases of the lumbar spine, which are common among elderly people, cause back pain and radicular symptoms and lead to a poor quality of life. Lumbar spinal fusion is a standardized and widely accepted surgical procedure used for treating degenerative lumbar diseases; however, the classical posterior approach used in this procedure is recognized to cause vascular and neurologic damage of the lumbar muscles. Various studies have suggested that using the minimally invasive transforaminal interbody fusion (TLIF) technique provides long-term clinical outcomes comparable to those of open TLIF approaches in selected patients. In this study, we compared the perioperative and short-term advantages of miniopen, MI, and open TLIF. Compared with open TLIF, MI-TLIF and miniopen TLIF were associated with less blood loss, shorter hospital stays, and longer operative times; however, following the use of these procedures, no difference in quality of life was measured at 6 months or 1 year. Whether miniopen TLIF or MI-TLIF can replace traditional TLIF as the surgery of choice for treating degenerative lumbar deformity remains unclear, and additional studies are required for validating the safety and efficiency of these procedures. PMID:25629037

Lo, Wei-Lun; Lin, Chien-Min; Yeh, Yi-Shian; Su, Yu-Kai; Tseng, Yuan-Yun; Yang, Shun-Tai; Lin, Jai-Wei

2015-01-01

65

Clinical and radiographic outcomes after minimally invasive transforaminal lumbar interbody fusion  

PubMed Central

Objective To evaluate outcomes after minimally invasive transforaminal lumbar interbody fusion (MI-TLIF). Background MI-TLIF is a relatively novel technique for treating symptomatic spondylolisthesis and degenerative disc disease of the lumbar spine. It has become a popular option for lumbar arthrodesis largely because of its potential to minimize iatrogenic trauma to the soft tissue, paraspinous muscles as well as to neural elements. Methods Literature search using PubMed database. Results Eight retrospective clinical studies and 1 prospective clinical study were identified. No randomized studies were found. The indications for surgery were low-back pain and/or radicular symptoms secondary to spondylolisthesis and/or degenerative disc disease. Analysis of radiographic outcomes demonstrated a fusion rate greater than 90% in the vast majority of patients. Patients also experienced a significant improvement in functional outcome parameters at a mean follow-up of 20 months. Comparison of functional outcomes of MI-TLIF patients to a similar matched cohort of patients who underwent conventional open TLIF did not demonstrate any statistically significant difference between both cohorts. Conclusion For carefully selected patients, MI-TLIF has a very favorable long term outcome that is comparable to conventional open TLIF, with the added benefit of decreased adjacent tissue injury.

Etame, Arnold B.; Wang, Anthony C.; Than, Khoi D.; Park, Paul

2010-01-01

66

Unilateral versus bilateral pedicle screw instrumentation for single-level minimally invasive transforaminal lumbar interbody fusion.  

PubMed

Minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) has become an increasingly popular method of lumbar arthrodesis. However, there are few published studies comparing the clinical outcomes between unilateral and bilateral instrumented MIS TLIF. Sixty-five patients with degenerative lumbar spine disease were enrolled in this study. Thirty-one patients were randomized to the unilateral group and 34 to the bilateral group. Recorded demographic data included sex, age, preoperative diagnosis, and degenerated segment. Operative time, blood loss, hospital stay length, complication rates, and fusion rates were also evaluated. The Oswestry Disability Index (ODI) score and Visual Analog Scale (VAS) pain score data were obtained. All patients were asked to follow-up at 3 and 6 months after surgery, and once every 6 months thereafter. The mean follow-up was 26.6 months (range 18-36 months). The two groups were similar in sex, age, preoperative diagnosis, and operated level. The unilateral group had significantly shorter operative time, lower blood loss, and shorter hospital time than the bilateral group. The average postoperative ODI and VAS scores improved significantly in each group. No significant differences were found between the two groups in relation to ODI and VAS. All patients showed evidence of fusion at 12 months postoperatively. The total fusion rate, screw failure, and general complication rate were not significantly different. Results showed that single-level MIS TLIF with unilateral pedicle screw fixation would be sufficient in the management of preoperatively stable patients with lumbar degenerative disease. It seems that MIS TLIF with unilateral pedicle screw instrumentation is a better choice for single-level degenerative lumbar spine disease. PMID:24814852

Shen, Xiaolong; Zhang, Hailong; Gu, Xin; Gu, Guangfei; Zhou, Xu; He, Shisheng

2014-09-01

67

Porous biodegradable lumbar interbody fusion cage design and fabrication using integrated global-local topology optimization with laser sintering.  

PubMed

Biodegradable cages have received increasing attention for their use in spinal procedures involving interbody fusion to resolve complications associated with the use of nondegradable cages, such as stress shielding and long-term foreign body reaction. However, the relatively weak initial material strength compared to permanent materials and subsequent reduction due to degradation may be problematic. To design a porous biodegradable interbody fusion cage for a preclinical large animal study that can withstand physiological loads while possessing sufficient interconnected porosity for bony bridging and fusion, we developed a multiscale topology optimization technique. Topology optimization at the macroscopic scale provides optimal structural layout that ensures mechanical strength, while optimally designed microstructures, which replace the macroscopic material layout, ensure maximum permeability. Optimally designed cages were fabricated using solid, freeform fabrication of poly(?-caprolactone) mixed with hydroxyapatite. Compression tests revealed that the yield strength of optimized fusion cages was two times that of typical human lumbar spine loads. Computational analysis further confirmed the mechanical integrity within the human lumbar spine, although the pore structure locally underwent higher stress than yield stress. This optimization technique may be utilized to balance the complex requirements of load-bearing, stress shielding, and interconnected porosity when using biodegradable materials for fusion cages. PMID:23897113

Kang, Heesuk; Hollister, Scott J; La Marca, Frank; Park, Paul; Lin, Chia-Ying

2013-10-01

68

Anterior Dislodgement of a Fusion Cage after Transforaminal Lumbar Interbody Fusion for the Treatment of Isthmic Spondylolisthesis  

PubMed Central

Transforaminal lumbar interbody fusion (TLIF) is commonly used procedure for spinal fusion. However, there are no reports describing anterior cage dislodgement after surgery. This report is a rare case of anterior dislodgement of fusion cage after TLIF for the treatment of isthmic spondylolisthesis with lumbosacral transitional vertebra (LSTV). A 51-year-old man underwent TLIF at L4-5 with posterior instrumentation for the treatment of grade 1 isthmic spondylolisthesis with LSTV. At 7 weeks postoperatively, imaging studies demonstrated that banana-shaped cage migrated anteriorly and anterolisthesis recurred at the index level with pseudoarthrosis. The cage was removed and exchanged by new cage through anterior approach, and screws were replaced with larger size ones and cement augmentation was added. At postoperative 2 days of revision surgery, computed tomography (CT) showed fracture on lateral pedicle and body wall of L5 vertebra. He underwent surgery again for paraspinal decompression at L4-5 and extension of instrumentation to S1 vertebra. His back and leg pains improved significantly after final revision surgery and symptom relief was maintained during follow-up period. At 6 months follow-up, CT images showed solid fusion at L4-5 level. Careful cage selection for TLIF must be done for treatment of spondylolisthesis accompanied with deformed LSTV, especially when reduction will be attempted. Banana-shaped cage should be positioned anteriorly, but anterior dislodgement of cage and reduction failure may occur in case of a highly unstable spine. Revision surgery for the treatment of an anteriorly dislodged cage may be effectively performed using an anterior approach. PMID:24175028

Oh, Hyeong Seok; Lee, Sang-Ho

2013-01-01

69

Open and Minimally Invasive Transforaminal Lumbar Interbody Fusion: Comparison of Intermediate Results and Complications  

PubMed Central

Study Design Prospective study. Purpose To compare clinical and radiological outcomes of open vs. minimally invasive transforaminal lumbar interbody fusion (MI-TLIF). Overview of Literature MI-TLIF promises smaller incisions and less soft tissue dissection resulting in lower morbidity and faster recovery; however, it is technically challenging. Methods Twenty-five patients with MI-TLIF were compared with 25 matched open TLIF controls. A minimum 2 year follow-up and a statistical analysis of perioperative and long-term outcomes were performed. Potential complications were recorded. Results The mean ages for the open and MI-TLIF cases were 44.4 years (range, 19-69 years) and 43.6 years (range, 20-69 years), respectively. The male:female ratio was 13:12 for both groups. Average follow-up was 26.9 months for the MI-TLIF group and 29.3 months for the open group. Operative duration was significantly longer in the MI-TLIF group than that in the open group (p<0.05). No differences in estimated blood loss, duration to ambulation, or length of stay were found. Significant improvements in the Oswestry disability index and EQ-5D functional scores were observed at 6-, 12-, and 24-months in both groups, but no significant difference was detected between the groups. Fusion rates were comparable. Cage sizes were significantly smaller in the MI-TLIF group at the L5/S1 level (p<0.05). One patient had residual spinal stenosis at the MI-TLIF level, and one patient who underwent two-level MI-TLIF developed a deep vein thrombosis resulting in a pulmonary embolism. Conclusions MI-TLIF and open TLIF had comparable long-term benefits. Due to technical constraints, patients should be advised on the longer operative time and potential undersizing of cages at the L5S1 level.

Hee, Hwan Tak

2015-01-01

70

Clinical and Radiological Outcomes of a New Cage for Direct Lateral Lumbar Interbody Fusion  

PubMed Central

Objective In Korea, direct lateral interbody fusion (DLIF) was started since 2011, using standard cage (6° lordotic angle, 18mm width). Recently, a new wider cage with higher lordotic angle (12°, 22mm) was introduced. The aim of our study is to compare the clinical and radiologic outcomes of the two cage types. Methods We selected patients underwent DLIF, 125 cases used standard cages (standard group) and 38 cases used new cages (wide group). We followed them up for more than 6 months, and their radiological and clinical outcomes were analyzed retrospectively. For radiologic outcomes, lumbar lordotic angle (LLA), segmental lordoic angle (SLA), disc angle (DA), foraminal height change (FH), subsidence and intraoperative endplate destruction (iED) were checked. Clinical outcomes were compared using visual analog scale (VAS) score, Oswestry disability index (ODI) score and complications. Results LLA and SLA showed no significant changes postoperatively in both groups. DA showed significant increase after surgery in the wide group (p<0.05), but not in the standard group. Subsidence was significantly lower in the wide group (p<0.05). There was no difference in clinical outcomes between the two groups. Additional posterior decompression was done more frequently in the wide group. Postoperative change of foraminal height was significantly lower in the wide group (p<0.05). The iED was observed more frequently in the wide group (p<0.05) especially at the anterior edge of cage. Conclusion The new type of cage seems to result in more DA and less subsidence. But indirect foraminal decompression seems to be less effective than standard cage. Intraoperative endplate destruction occurs more frequently due to a steeper lordotic angle of the new cage. PMID:25346760

Kim, Shin Jae; Lee, Young Seok; Kim, Young Baeg; Hung, Vo Tan

2014-01-01

71

Usefulness of Contralateral Indirect Decompression through Minimally Invasive Unilateral Transforaminal Lumbar Interbody Fusion  

PubMed Central

Study Design Retrospective study. Purpose This study aims to investigate the clinical and radiological results of contralateral indirect decompression through minimally invasive unilateral transforaminal lumbar interbody fusion (MI-TLIF). Overview of Literature Several studies have proposed that blood loss and operation time could be reduced through a unilateral approach, although many surgeons have forecast that satisfactory foraminal decompression is difficult to achieve through a unilateral approach. Methods The study included 30 subjects who had undergone single-level MI-TLIF. Visual analogue scale (VAS) and Oswestry disability index (ODI) were analyzed for clinical assessment. Disc height, segmental lordosis, and lumbar lordosis angle were examined for radiological assessment. The degree of contralateral indirect decompression was evaluated through a comparative analysis, with a magnetic resonance imaging (MRI) performed preoperatively and at one year postoperatively. Results Intraoperative blood loss volume was 308.75 mL in the unilateral approach group (UAP), and 575.00 mL in the bilateral approach group (BAP), showing a statistically significant difference. Operation time was 139.50 minutes in the UAP group, and 189.00 minutes in the BAP group, exhibiting a statistically significant difference (p<0.05). On the other hand, no significant difference was found in VAS, ODI, disc height, lordosis angles and the degree of nerve decompression in the vertebral foramen, using MRI, between the two groups (p>0.05). Conclusions Satisfactory results were acquired with MI-TLIF conducted through the unilateral approach of contralateral indirect decompression, in alignment with the bilateral approach. Therefore, contralateral indirect decompression is thought to be a useful procedure in reducing the operation time and volume of blood loss. PMID:25187862

Yoo, Jae-Sung; Lee, Jun-Yeul

2014-01-01

72

A minimally invasive posterior lumbar interbody fusion using percutaneous long arm pedicle screw system for degenerative lumbar disease  

PubMed Central

The aim of this study is to evaluate the therapeutic efficacy of patients with lumbar degeneration and instability treated with percutaneous pedicle screw fixation and minimally invasive lumbar interbody fusion. Twenty-one patients were selected in our hospital from November, 2012 to March, 2013. The patients with an average age 55.62 years, including 8 vertebral spondylolisthesis, 4 lumbar intervertebral disc herniation, and 9 lumbar spinal canal stenosis cases. All the patients were managed to take the lumbar MRI and radiographs. The comparison of preoperative and postoperative (3 days, 2 weeks, 3 months) VAS and ODI score were analyzed. The results indicated that VAS scores were 7.14 ± 0.79 before operation, and 5.19 ± 0.81 in 3 days after operation, 4 ± 0.84 after 2 weeks, and 2.67 ± 0.66 after 3 months. The pain was relieved, and the postoperative VAS score was lower than that before treatment (P < 0.05). ODI score was 55.8 ± 11.4 before operation, 47.38 ± 9.38 after 3 days, 41.38 ± 8.09 after 2 weeks, 35.76 ± 4.50 after 3 months. ODI score was obviously decreased (P < 0.05). In conclusion, percutaneous pedicle screw fixation combined with minimally invasive interbody fusion is a safe, effective, feasible minimally invasive spine operation, with worthy for spreading. PMID:25550904

He, Er-Xing; Cui, Ji-Hao; Yin, Zhi-Xun; Li, Chuang; Tang, Cheng; He, Yi-Qian; Liu, Cheng-Wei

2014-01-01

73

Transforaminal lumbar interbody fusion rates in patients using a novel titanium implant and demineralized cancellous allograft bone sponge  

PubMed Central

Background Transforaminal lumbar interbody fusion (TLIF) with grafting and implant options like iliac crest bone graft (ICBG), recombinant bone morphogenetic protein (rhBMP), and polyetheretherketone (PEEK) cages have been reported to achieve extremely high fusion rates. Unfortunately, these options have also been frequently cited in the literature as causing postoperative morbidity and complications at a high cost. Knowing this, we sought to investigate TLIF using an acid-etched, roughened titanium cage that upregulates osteogenesis to see if similar fusion rates to those cited for ICBG, rhBMP, and PEEK cages could be safely achieved with minimal morbidity and complications. Materials and methods A radiographic fusion study of 82 patients who underwent TLIF using an acid-etched, roughened titanium cage with demineralized cancellous bone graft was conducted. Fusion was assessed and graded by an independent radiologist using computed tomography scan with sagittal and coronal reconstructions. Results Fusion rates at 6 months were 41 of 44 (93.2%) and at 12 months were 37 of 38 (97.4%). There were no radiographic device-related complications. Conclusions TLIF with an acid-etched, roughened titanium cage filled with a decalcified bone graft achieved similar fusion rates to historical controls using ICBG, rhBMP, and PEEK. PMID:25580378

Girasole, Gerard; Muro, Gerard; Mintz, Abraham; Chertoff, Jason

2013-01-01

74

Posterior lumbar interbody fusion (PLIF) with cages and local bone graft in the treatment of spinal stenosis.  

PubMed

Posterior lumbar interbody fusion (PLIF) implants are increasingly being used for 360 degrees fusion after decompression of lumbar spinal stenosis combined with degenerative instability. Both titanium and PEEK (PolyEtherEtherKetone) implants are commonly used. Assessing the clinical and radiological results as well as typical complications, such as migration of the cages, is important. In addition, questions such as which radiological parameters can be used to assess successful fusion, and whether the exclusive use of local bone graft is sufficient, are frequently debated. We prospectively evaluated 30 patients after PLIF instrumentation for degenerative lumbar spinal canal stenosis, over a course of 42 months. In all cases, titanium cages and local bone graft were used for spondylodesis. The follow-up protocol of these 30 cases included standardised clinical and radiological evaluation at 3, 6, 12 and 42 months after surgery. Overall satisfactory results were achieved. With one exception, a stable result was achieved with restoration of the intervertebral space in the anterior column. After 42 months of follow-up in most cases, a radiologically visible loss of disc space height can be demonstrated. Clinically relevant migration of the cage in the dorsal direction was detected in one case. Based on our experience, posterior lumbar interbody fusion (PLIF) can be recommended for the treatment of monosegmental and bisegmental spinal stenosis, with or without segmental instability. Postoperative evaluation is mainly based on clinical parameters since the titanium implant affects the diagnostic value of imaging studies and is responsible for artefacts. The results observed in our group of patients suggest that local autologous bone graft procured from the posterior elements after decompression is an adequate material for bone grafting in this procedure. PMID:17009828

Trouillier, Hans; Birkenmaier, Christof; Rauch, Alexander; Weiler, Christoph; Kauschke, Thomas; Refior, Hans Jürgen

2006-08-01

75

Perioperative complications with rhBMP-2 in transforaminal lumbar interbody fusion.  

PubMed

Bone morphogenetic protein (BMP) is commonly used as an ICBG substitute for transforaminal lumbar interbody spine fusion (TLIF). However, multiple recent reports have raised concerns regarding a substantial incidence of perioperative radiculopathy. Also, given the serious complications reported with anterior cervical BMP use, risks related to swelling and edema with TLIF need to be clarified. As TLIF related complications with rhBMP-2 have generally been reported in small series or isolated cases, without a clear denominator, actual complication rates are largely unknown. The purpose this study is to characterize perioperative complications and complication rates in a large consecutive series of TLIF procedures with rhBMP-2. We reviewed inpatient and outpatient medical records for a consecutive series of 204 patients [113 females, 91 males, mean age 49.3 (22-79) years] who underwent TLIF using rhBMP-2 between 2003 and 2007. Complications observed within a 3-month perioperative interval were categorized as to etiology and severity. Wound problems were delineated as wound infection, hematoma/seroma or persistent drainage/superficial dehiscence. Neurologic deficits and radiculopathies were analyzed to determine the presence of a clear etiology (screw misplacement) and identify any potential relationship to rhBMP-2 usage. Complications were observed in 47 of 204 patients (21.6%) during the 3-month perioperative period. Major complications occurred in 13 patients (6.4%) and minor complications in 34 patients (16.7%). New or more severe postoperative neurologic complaints were noted in 13 patients (6.4%), 6 of whom required additional surgery. These cases included one malpositioned pedicle screw and one epidural hematoma. In four patients (2.0%), localized seroma/hematoma in the area of the foramen caused neural compression, and required revision. In one additional patient, vertebral osteolysis caused foraminal narrowing and radiculopathy, but resolved without further surgery. Persistent radiculopathy without clear etiology on imaging studies was seen in six patients. Wound related problems were seen in six patients (2.9%), distributed as wound infection (3), hematoma/seroma (1) and persistent drainage/dehiscence (2). Overall, this study demonstrates a modest complication rate for TLIF using rhBMP-2. While perioperative complications which appeared specific to BMP usage were noted, they occurred infrequently. It will be necessary to weigh this incidence of complications against the complication rate associated with ICBG harvest and any differential benefit in obtaining a solid arthrodesis. PMID:20582554

Owens, Kirk; Glassman, Steven D; Howard, Jennifer M; Djurasovic, Mladen; Witten, Jonathan L; Carreon, Leah Y

2011-04-01

76

Lateral Lumbar Interbody Fusion for the Correction of Spondylolisthesis and Adult Degenerative Scoliosis in High-Risk Patients: Early Radiographic Results and Complications  

PubMed Central

Background Lateral lumbar interbody fusion (LLIF) is not associated with many of the complications seen in other interbody fusion techniques. This study used computed tomography (CT) scans, the radiographic gold standard, to assess interbody fusion rates achieved utilizing the LLIF technique in high-risk patients. Methods We performed a retrospective review of patients who underwent LLIF between January 2008 and July 2013. Forty-nine patients underwent nonstaged or staged LLIF on 119 levels with posterior correction and augmentation. Per protocol, patients received CT scans at their 1-year follow-up. Of the 49 patients, 21 patients with LLIF intervention on 54 levels met inclusion criteria. Two board-certified musculoskeletal radiologists and the senior surgeon (JZ) assessed fusion. Results Of the 21 patients, 6 patients had had previous lumbar surgery, and the cohort's comorbidities included osteoporosis, diabetes, obesity, and smoking, among others. Postoperative complications occurred in 12 (57.1%) patients and included anterior thigh pain and weakness in 6 patients, all of which resolved by 6 months. Two cases of proximal junctional kyphosis occurred, along with 1 case of hardware pullout. Two cases of abdominal atonia occurred. By CT scan assessment, each radiologist found fusion was achieved in 53 of 54 levels (98%). The radiologists' findings were in agreement with the senior surgeon. Conclusion Several studies have evaluated LLIF fusion and reported fusion rates between 88%-96%. Our results demonstrate high fusion rates using this technique, despite multiple comorbidities in the patient population. Spanning the ring apophysis with large LLIF cages along with supplemental posterior pedicle screw augmentation can enhance stability of the fusion segment and increase fusion rates. PMID:24688329

Waddell, Brad; Briski, David; Qadir, Rabah; Godoy, Gustavo; Houston, Allison Howard; Rudman, Ernest; Zavatsky, Joseph

2014-01-01

77

TranS1 VEO system: a novel psoas-sparing device for transpsoas lumbar interbody fusion  

PubMed Central

Minimally invasive approaches for lumbar interbody fusion have been popularized in recent years. The retroperitoneal transpsoas approach to the lumbar spine is a technique that allows direct lateral access to the intervertebral disc space while mitigating the complications associated with traditional anterior or posterior approaches. However, a common complication of this procedure is iatrogenic injury to the psoas muscle and surrounding nerves, resulting in postsurgical motor and sensory deficits. The TranS1 VEO system (TranS1 Inc, Raleigh, NC, USA) utilizes a novel, minimally invasive transpsoas approach to the lumbar spine that allows direct visualization of the psoas and proximal nerves, potentially minimizing iatrogenic injury risk and resulting clinical morbidity. This paper describes the clinical uses, procedural details, and indications for use of the TranS1 VEO system. PMID:23766663

Hardenbrook, Mitchell A; Miller, Larry E; Block, Jon E

2013-01-01

78

Effects of autogenous bone graft impaction and tricalcium phosphate on anterior interbody fusion in the porcine lumbar spine.  

PubMed

Background Impaction grafting can be achieved inside the spinal fusion cages, but its effect on bone graft incorporation and spinal fusion has not been studied. Animals and methods We investigated the effect of impaction grafting on the bone graft healing and fusion potential of beta-tricalcium phosphate (beta-TCP) inside the carbon fiber reinforced spinal fusion device (Brantigan cage) in 10 Danish landrace pigs. Lumbar spine interbody fusion of L2/3, L4/5 and L6/7 using carbon fiber cages was performed on each pig. Cages filled with either loosely-packed autologous iliac bone graft, rod-impacted autologous bone graft or beta-TCP were randomly distributed to the three fusion levels. Half of the animals were followed for 8 weeks, and the other half for 16 weeks. Results Radiographs and CT evaluations showed that autograft levels had significantly better results than beta-TCP levels (p<0.001 Fisher's Exact Test). However, the difference between impacted and loosely-packed levels was not significant. Histomorphometric analysis showed no difference between the loosely-packed and impacted cages with regard to bone volume, bone marrow volume, cartilage and fibrous tissue volume, while both of the autograft levels differed from the beta-TCP levels in all of the aforementioned parameters. Fluorochrome studies demonstrated that bone mineral apposition rate was significantly higher in the impacted cages than in the loosely-packed cages at 16 weeks. Interpretation Manual impaction of autologous bone graft into the carbon fiber cages resulted in a faster mineral apposition rate by 16 weeks. Bone ingrowth and spinal fusion were not influenced by impaction grafting. PMID:15370591

Li, Haisheng; Zou, Xuenong; Xue, Qingyun; Egund, Niels; Lind, Martin; Bünger, Cody

2004-08-01

79

Good Functional Outcome and Adjacent Segment Disc Quality 10 Years after Single-Level Anterior Lumbar Interbody Fusion with Posterior Fixation  

PubMed Central

We reviewed the records of a prospective consecutive cohort to evaluate the clinical performance of anterior lumbar interbody fusion with a titanium box cage and posterior fixation, with emphasis on long-term functional outcome. Thirty-two patients with chronic low back pain underwent anterior lumbar interbody fusion and posterior fixation. Radiological and functional results (visual analogue scale [VAS] and Oswestry score) were evaluated. Adjacent segment degeneration (ASD) was evaluated radiologically and by magnetic resonance imaging (MRI). Twenty-five patients (78%) were available for follow-up. Functional scores showed significant improvement in pain and function up to the 2-year follow-up observation. At 4 years, there was some deterioration of the clinical results. At 10-year follow-up, results remained stable compared with 4-year results. MRI showed ASD in 3/25 (12%) above and 2/10 (20%) below index level (compared with absent preoperatively). ASD could not be related to clinical outcome in this study. Anterior lumbar interbody fusion and posterior fixation is safe and effective. Initial improvement in VAS and Oswestry scores is partly lost at the 4-year follow-up. Good clinical results are maintained at 10-year follow-up and are not related to adjacent segment degeneration. PMID:24353942

Horsting, Philip P.; Pavlov, Paul W.; Jacobs, Wilco C.H.; Obradov-Rajic, Marina; de Kleuver, Marinus

2012-01-01

80

Anterior cervical interbody fusion using polyetheretherketone cage filled with autologous and synthetic bone graft substrates for cervical spondylosis: comparative analysis between PolyBone® and iliac bone.  

PubMed

Clinical and radiological outcomes of cervical interbody fusion using a polyetheretherketone cage filled with PolyBone(®) (Kyungwon Medical Co., Ltd., Seoul, Korea), beta-tricalcium phosphate material, and autologous iliac bone were retrospectively compared in 47 patients who underwent anterior cervical discectomy and fusion (ACDF) between January 2007 and April 2008. Of these, 23 received iliac bone grafts and 24 received PolyBone. Numeric rating scale and neck disability index were used for clinical outcome assessments. Cervical radiography was performed immediately postoperatively, and at 1, 3, 6, 12, and 24 months postoperatively. Computed tomography (CT) was performed at 12 and 24 months postoperatively. Change in segmental lordosis, disk height, and fusion were compared at 12 and 24 months postoperatively. Clinical outcomes were similar between both groups. CT and radiography at 12 months showed that fusion had occurred in 22 patients in the iliac bone group and in 19 in the PolyBone recipients. Fusion was also identified in 22 patients in both iliac bone and PolyBone groups at 24 months postoperatively. The clinical outcomes of ACDF using PolyBone and iliac bone were similar, with similar cervical interbody fusion rates at 24 months postoperatively. However, the time taken for fusion was apparently longer in the PolyBone group. PMID:23438658

Park, Jin Hoon; Roh, Sung Woo

2013-01-01

81

Intraspinal metalloma causing lumbar stenosis after interbody fusion with cylindrical titanium cages.  

PubMed

Intraspinal metallomas are rare. The authors present a case after implantation of two titanium threaded interbody cages at the L4L5 level, without posterior instrumentation. To their knowledge this is the first case due to intervertebral cages. The lack of additional instrumentation had probably allowed the cages to make contact. Subsequently, friction generated wear debris, which led to the formation of a granuloma, responsible for compression of the dural sac. Intraspinal metallosis should be kept in mind as an infrequent cause of delayed neurological symptoms after spinal surgery with metallic instrumentation. PMID:23409582

Fernández-Baíllo, Nicomedes; Sánchez Marquez, José Miguel; Conde Gallego, Esther; Martín Esteban, Ana

2012-12-01

82

The use of a stand-alone interbody fusion cage in subaxial cervical spine trauma: a preliminary report.  

PubMed

Background?Anterior spinal surgery has a predominant role in the treatment of traumatic lesions of the subaxial cervical spine. Plating is considered indispensable to achieve stability but may cause dysphagia, dysphonia, and adjacent-level ossification. Zero-P (Synthes GmbH, Oberdorf, Switzerland), an anchored interdisc spacer, can be used without an associated plate. The present study aimed to test if this new implant would be associated with a low rate of dysphagia and other short-term complications compared with the standard for anterior spinal fusion surgery and would be able to achieve a solid fusion and maintain correct metamere alignment. Material and Methods?This is a preliminary presentation of a clinical case series of patients with subaxial cervical injuries who underwent anterior interbody fusion. From July 2009 until September 2011, 12 patients were treated with a Zero-P cage. The data for analysis included operating time compared with the standard for spinal fusion surgery with a cage plus plate construct, intraoperative blood loss, clinical and radiographic results, and complications. Results?In the postoperative period no patient had neurologic worsening. One patient experienced transient dysphonia and moderate dysphagia. All the patients were followed up for a minimum of 6 months (mean: 13 months; range: 6-27 months). Stability and fusion were obtained in all patients together with correct metamere alignment. Conclusion?We presented the preliminary results of a clinical case series. Our results support the initiation of prospective randomized trials with more patients and longer follow-up. PMID:24682927

Brembilla, Carlo; Lanterna, Luigi Andrea; Gritti, Paolo; Signorelli, Antonio; Biroli, Francesco

2015-01-01

83

Lateral retroperitoneal transpsoas interbody fusion in a patient with achondroplastic dwarfism.  

PubMed

The authors present the first reported use of the lateral retroperitoneal transpsoas approach for interbody arthrodesis in a patient with achondroplastic dwarfism. The inherent anatomical abnormalities of the spine present in achondroplastic dwarfism predispose these patients to an increased incidence of spinal deformity as well as neurogenic claudication and potential radicular symptoms. The risks associated with prolonged general anesthesia and intolerance of significant blood loss in these patients makes them ideal candidates for minimally invasive spinal surgery. The patient in this case was a 51-year-old man with achondroplastic dwarfism who had a history of progressive claudication and radicular pain despite previous extensive lumbar laminectomies. The lateral retroperitoneal transpsoas approach was used for placement of interbody cages at L1/2, L2/3, L3/4, and L4/5, followed by posterior decompression and pedicle screw instrumentation. The patient tolerated the procedure well with no complications. Postoperatively his claudicatory and radicular symptoms resolved and a CT scan revealed solid arthrodesis with no periimplant lucencies. PMID:25415482

Staub, Blake N; Holman, Paul J

2015-02-01

84

Structural and mechanical evaluations of a topology optimized titanium interbody fusion cage fabricated by selective laser melting process.  

PubMed

A topology optimized lumbar interbody fusion cage was made of Ti-Al6-V4 alloy by the rapid prototyping process of selective laser melting (SLM) to reproduce designed microstructure features. Radiographic characterizations and the mechanical properties were investigated to determine how the structural characteristics of the fabricated cage were reproduced from design characteristics using micro-computed tomography scanning. The mechanical modulus of the designed cage was also measured to compare with tantalum, a widely used porous metal. The designed microstructures can be clearly seen in the micrographs of the micro-CT and scanning electron microscopy examinations, showing the SLM process can reproduce intricate microscopic features from the original designs. No imaging artifacts from micro-CT were found. The average compressive modulus of the tested caged was 2.97+/-0.90 GPa, which is comparable with the reported porous tantalum modulus of 3 GPa and falls between that of cortical bone (15 GPa) and trabecular bone (0.1-0.5 GPa). The new porous Ti-6Al-4V optimal-structure cage fabricated by SLM process gave consistent mechanical properties without artifactual distortion in the imaging modalities and thus it can be a promising alternative as a porous implant for spine fusion. PMID:17415762

Lin, Chia-Ying; Wirtz, Tobias; LaMarca, Frank; Hollister, Scott J

2007-11-01

85

Screw Placement Accuracy for Minimally Invasive Transforaminal Lumbar Interbody Fusion Surgery: A Study on 3-D Neuronavigation-Guided Surgery  

PubMed Central

Purpose?The aim of this study was to assess the impact of 3-D navigation for pedicle screw placement accuracy in minimally invasive transverse lumbar interbody fusion (MIS-TLIF). Methods?A retrospective review of 52 patients who had MIS-TLIF assisted with 3D navigation is presented. Clinical outcomes were assessed with the Oswestry Disability Index (ODI), Visual Analog Scales (VAS), and MacNab scores. Radiographic outcomes were assessed using X-rays and thin-slice computed tomography. Result?The mean age was 56.5 years, and 172 screws were implanted with 16 pedicle breaches (91.0% accuracy rate). Radiographic fusion rate at a mean follow-up of 15.6 months was 87.23%. No revision surgeries were required. The mean improvement in the VAS back pain, VAS leg pain, and ODI at 11.3 months follow-up was 4.3, 4.5, and 26.8 points, respectively. At last follow-up the mean postoperative disc height gain was 4.92?mm and the mean postoperative disc angle gain was 2.79 degrees. At L5–S1 level, there was a significant correlation between a greater disc space height gain and a lower VAS leg score. Conclusion?Our data support that application of 3-D navigation in MIS-TLIF is associated with a high level of accuracy in the pedicle screw placement. PMID:24353961

Torres, Jorge; James, Andrew R.; Alimi, Marjan; Tsiouris, Apostolos John; Geannette, Christian; Härtl, Roger

2012-01-01

86

Differences in the outcomes of anterior versus posterior interbody fusion surgery of the lumbar spine: A propensity score-controlled cohort analysis of 10,941 patients.  

PubMed

Few studies have measured outcome differences between the various available spinal fusion techniques. We compare long-term outcomes of anterior versus posterior lumbar interbody fusion. Using the MarketScan database (Truven Health Analytics, Ann Arbor, MI, USA) we selected patients ?18years old who underwent lumbar fusion surgery from 2000-2009 using either approach. Exclusion criteria included circumferential fusion, and having less than 1year of preoperative or less than 2years of postoperative follow-up. Using an inverse probability-weighted propensity-score model we compared reoperation and 90day complication rates, and postoperative health resource utilization of both approaches. A total of 10,941 patients were identified. Of these, 7460 (68.2%) and 3481 (31.8%) underwent posterior and anterior interbody fusion, respectively. Anterior fusion patients had a higher 2year reoperation rate (odds ratio 1.43, 95% confidence interval [CI]: 1.21-1.70, p<0.0001), although differences became non-significant at maximum follow-up (p=0.0877). The 90day complication rate was 15.7%, with anterior fusion patients being more likely to experience complications (relative risk 1.24, 95%CI: 1.13-1.36, p<0.0001). Anterior fusion patients also had greater levels of postoperative health utilization, surpassing posterior fusion patients by an average of $US7450 in total charges (95% CI: $4670-$10,220, p<0.0001). As currently practiced in the USA, anterior lumbar surgical approaches may be associated with higher postoperative morbidity and reoperation rates than posterior fusion approaches. PMID:25691076

Huang, Kevin T; Hazzard, Matthew; Thomas, Steven; Chagoya, Gustavo; Berg, Rand Wilcox Vanden; Adogwa, Owoicho; Bagley, Carlos A; Isaacs, Robert; Gottfried, Oren N; Lad, Shivanand P

2015-05-01

87

Comparison of one-level minimally invasive and open transforaminal lumbar interbody fusion in degenerative and isthmic spondylolisthesis grades 1 and 2  

PubMed Central

Minimally invasive lumbar fusion techniques have only recently been developed. The goals of these procedures are to reduce approach-related soft tissue injury, postoperative pain and disability while allowing the surgery to be conducted in an effective manner. There have been no prospective clinical reports published on the comparison of one-level transforaminal lumbar interbody fusion in low-grade spondylolisthesis performed with an independent blade retractor system or a traditional open approach. A prospective clinical study of 85 consecutive cases of degenerative and isthmic lower grade spondylolisthesis treated by minimally invasive transforaminal lumbar interbody fusion (MiTLIF) or open transforaminal lumbar interbody fusion (OTLIF) was done. A total of 85 patients suffering from degenerative spondylolisthesis (n = 46) and isthmic spondylolisthesis (n = 39) underwent one-level MiTLIF (n = 42) and OTLIF (n = 43) by two experienced surgeons at one hospital, from June 2006 to March 2008 (minimum 13-month follow-up). The following data were compared between the two groups: the clinical and radiographic results, operative time, blood loss, transfusion needs, X-ray exposure time, postoperative back pain, length of hospital stay, and complications. Clinical outcome was assessed using the visual analog scale (VAS) and the Oswestry disability index. The operative time, clinical and radiographic results were basically identical in both groups. Comparing with the OTLIF group, the MiTLIF group had significantly lesser blood loss, lesser need for transfusion, lesser postoperative back pain, and shorter length of hospital stay. The radiation time was significantly longer in MiTLIF group. One case of nonunion was observed from each group. Minimally invasive TLIF has similar surgical efficacy with the traditional open TLIF in treating one-level lower grade degenerative or isthmic spondylolisthesis. The minimally invasive technique offers several potential advantages including smaller incisions, less tissue trauma and quicker recovery. However, this technique needs longer X-ray exposure time. PMID:20411281

Zhou, Yue; Zhang, Zheng Feng; Li, Chang Qing; Zheng, Wen Jie; Liu, Jie

2010-01-01

88

Demineralized Bone Matrix, as a Graft Enhancer of Auto-Local Bone in Posterior Lumbar Interbody Fusion  

PubMed Central

Study Design A case controlled study with prospective data collection. Purpose To evaluate the early influence and the final consequence of demineralized bone matrix (DBM) on auto-local bone as a graft enhancer in posterior lumbar interbody fusion (PLIF). Overview of Literature DBM is known as an osteoinductive material; however, it has not been clearly recognized to enhance auto-local bone with a small amount. Methods Patients who had a PLIF were allocated into two groups. Group I (70 cases) used auto-local bone chips and group II (44 cases) used DBM as an additive to auto-local bone, 1 mL per a segment. Group selection was alternated. Early assessment was performed by computed tomography at 6 months and final assessment was done by simple radiography after 24 months at least. The degree of bone formation was assessed by 4 grade scale. Results The subjects of both groups were homogenous and had similar Oswestry Disability Index at final assessment. The ratio of auto-local bone chips and DBM was 6:1. The degree of bone formation at 6 months after surgery was superior in group II. However, there was no significant difference between the two groups at the final assessment. Conclusions DBM was not recognized to enhance auto-local bone with small amount. PMID:24761193

Moon, Sang Ho; Kim, Tae Woo; Boo, Kyung Hwan; Hong, Sung Won

2014-01-01

89

Prospective Randomized Controlled Trial of The Stabilis Stand Alone Cage (SAC) Versus Bagby and Kuslich (BAK) Implants for Anterior Lumbar Interbody Fusion  

PubMed Central

Background Degenerative disc disease is common and debilitating for many patients. If conservative extensive care fails, anterior lumbar interbody fusion has proven to be an alternative form of surgical management. The Stabilis Stand Alone Cage(SAC) was introduced as a method to obtain stability and fusion. The purpose of this study was to determine whether the Stabilis Stand Alone Cage (SAC) is comparable in safety and efficacy to the Bagby and Kuslich (BAK) device. Methods As part of a prospective, randomized, controlled FDA trial, 73 patients underwent anterior interbody fusion using either the SAC(56%) or the BAK device (44%). Results Background characteristics were similar between the two groups. There was no significant difference between the SAC and BAK groups in mean operative time or mean blood loss during surgery. Adverse event rates did not differ between the groups. Assessment of plain radiographs could not confirm solid fusion in 63% of control and 71% of study patients. Functional scores from Owestry and SF-36 improved in both groups by the two-year follow-up. There were no significant differences between the SAC and BAK patients with respect to outcome. Conclusions Both the Stabilis Stand Alone Cage and the BAK Cage provided satisfactory improvement in function and pain relief, despite less than expected radiographic fusion rates. The apparent incongruency between fusion rates and functional outcomes suggests that either radiographs underestimate the true incidence of fusion, or that patients are obtaining good pain relief and improved function despite a lower rate of fusion than previously reported. This was a Level III study. PMID:25694930

Lavelle, William; McLain, Robert F.; Rufo-Smith, Candace; Gurd, David P.

2014-01-01

90

Modified Posterior Lumbar Interbody Fusion for Radiculopathy Following Healed Vertebral Collapse of the Middle-Lower Lumbar Spine  

PubMed Central

Study Design?Retrospective study. Objectives?Lumbar radiculopathy is rarely observed in patients who have achieved bony healing of vertebral fractures in the middle-lower lumbar spine. The objectives of the study were to clarify the clinical features of such radiculopathy and to evaluate the preliminary outcomes of treatment using a modified posterior lumbar interbody fusion (PLIF) procedure. Methods?Fourteen patients with at least 2-year follow-up were enrolled in this study. The radiologic and clinical features of radiculopathy were retrospectively reviewed. As part of our modified PLIF procedure, a bone block was laid on chipped bone to fill the cavity of the fractured end plate and to flatten the cage–bone interface. Results?The morphologic features of spinal deformity in our patients typically consisted of the intradiscal vacuum phenomenon, spondylolisthesis, and a retropulsed intervertebral disk with a vertebral rim in the damaged segment. Cranial end plate fracture resulted in radiculopathy of the traversing nerve roots due to lateral recess stenosis. On the other hand, caudal end plate fracture led to unilateral radiculopathy of the exiting nerve root due to foraminal stenosis. The mean recovery rate based on the Japanese Orthopaedic Association score was 65.0%. Solid fusion was achieved in all but one case. Conclusions?Because of severe deterioration of the anterior column following end plate fracture, the foraminal zone must be decompressed in caudal end plate fractures. The modified PLIF procedure yielded satisfactory clinical outcomes due to anterior reconstruction and full decompression for both foraminal and lateral recess stenoses. PMID:25396106

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

2014-01-01

91

Modified posterior lumbar interbody fusion for radiculopathy following healed vertebral collapse of the middle-lower lumbar spine.  

PubMed

Study Design?Retrospective study. Objectives?Lumbar radiculopathy is rarely observed in patients who have achieved bony healing of vertebral fractures in the middle-lower lumbar spine. The objectives of the study were to clarify the clinical features of such radiculopathy and to evaluate the preliminary outcomes of treatment using a modified posterior lumbar interbody fusion (PLIF) procedure. Methods?Fourteen patients with at least 2-year follow-up were enrolled in this study. The radiologic and clinical features of radiculopathy were retrospectively reviewed. As part of our modified PLIF procedure, a bone block was laid on chipped bone to fill the cavity of the fractured end plate and to flatten the cage-bone interface. Results?The morphologic features of spinal deformity in our patients typically consisted of the intradiscal vacuum phenomenon, spondylolisthesis, and a retropulsed intervertebral disk with a vertebral rim in the damaged segment. Cranial end plate fracture resulted in radiculopathy of the traversing nerve roots due to lateral recess stenosis. On the other hand, caudal end plate fracture led to unilateral radiculopathy of the exiting nerve root due to foraminal stenosis. The mean recovery rate based on the Japanese Orthopaedic Association score was 65.0%. Solid fusion was achieved in all but one case. Conclusions?Because of severe deterioration of the anterior column following end plate fracture, the foraminal zone must be decompressed in caudal end plate fractures. The modified PLIF procedure yielded satisfactory clinical outcomes due to anterior reconstruction and full decompression for both foraminal and lateral recess stenoses. PMID:25396106

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

2014-12-01

92

A Systematic Review and Meta-Analysis of Unilateral versus Bilateral Pedicle Screw Fixation in Transforaminal Lumbar Interbody Fusion  

PubMed Central

Background Transforaminal lumbar interbody fusion (TLIF) has become one of the most widely used procedures for lumbar spinal disorders. However, it is still unclear whether TLIF with unilateral pedicle screw (PS) fixation is as effective as that with bilateral PS fixation. We performed a meta-analysis of the literatures and aimed to gain a better understanding of whether TLIF with unilateral PS fixation was safe and effective for lumbar diseases. Methodology/Principal Findings We systematically searched Ovid, Springer, and Medline databases for relevant randomized controlled trials (RCTs) that compared the clinical and radiological outcomes of unilateral versus bilateral PS fixation in TLIF. Risk of bias in included studies was assessed using the Cochrane Risk of Bias tool. We generated pooled risk ratios or weighted mean differences across studies. According to our predefined inclusion criteria, seven RCTs with a total of 441 patients were included in this study. Baseline characteristics were similar between the unilateral and bilateral groups. Our meta-analysis showed that no significant difference was detected between the two groups in terms of postoperative clinical function, fusion status, reoperation rate, complication rate, and hospital stay (p>0.05). Pooled estimates revealed that the unilateral group was associated with significantly reduced implant cost, operative time and blood loss (p<0.05). Conclusions/Significances Our meta-analysis suggested TLIF with unilateral PS fixation was as safe and effective as that with bilateral PS fixation for lumbar diseases in selected patients. Despite these findings, our meta-analysis was based on studies with small sample size and different study characteristics that might lead to the inconsistent results such as various functional outcomes among the included studies. Therefore, high-quality randomized controlled trials with larger sample size are also needed to further clarify these issues and to provide the long-term outcomes. PMID:24489929

Hu, Xu-Qi; Wu, Xin-Lei; Xu, Cong; Zheng, Xu-Hao; Jin, Yong-Long; Wu, Li-Jun; Wang, Xiang-Yang; Xu, Hua-Zi; Tian, Nai-Feng

2014-01-01

93

Biomechanical Analysis of a Newly Developed Shape Memory Alloy Hook in a Transforaminal Lumbar Interbody Fusion (TLIF) In Vitro Model  

PubMed Central

Objective The objective of this biomechanical study was to evaluate the stability provided by a newly developed shape memory alloy hook (SMAH) in a cadaveric transforaminal lumbar interbody fusion (TLIF) model. Methods Six human cadaveric spines (L1-S2) were tested in an in vitro flexibility experiment by applying pure moments of ±8 Nm in flexion/extension, left/right lateral bending, and left/right axial rotation. After intact testing, a TLIF was performed at L4-5. Each specimen was tested for the following constructs: unilateral SMAH (USMAH); bilateral SMAH (BSMAH); unilateral pedicle screws and rods (UPS); and bilateral pedicle screws and rods (BPS). The L3–L4, L4–L5, and L5-S1 range of motion (ROM) were recorded by a Motion Analysis System. Results Compared to the other constructs, the BPS provided the most stability. The UPS significantly reduced the ROM in extension/flexion and lateral bending; the BSMAH significantly reduced the ROM in extension/flexion, lateral bending, and axial rotation; and the USMAH significantly reduced the ROM in flexion and left lateral bending compared with the intact spine (p<0.05). The USMAH slightly reduced the ROM in extension, right lateral bending and axial rotation (p>0.05). Stability provided by the USMAH compared with the UPS was not significantly different. ROMs of adjacent segments increased in all fixed constructs (p>0.05). Conclusions Bilateral SMAH fixation can achieve immediate stability after L4–5 TLIF in vitro. Further studies are required to determine whether the SMAH can achieve fusion in vivo and alleviate adjacent segment degeneration. PMID:25474112

Wang, Xi; Xu, Jing; Zhu, Yuexing; Li, Jiukun; Zhou, Si; Tian, Shunliang; Xiang, Yucheng; Liu, Xingmo; Zheng, Ying; Pan, Tao

2014-01-01

94

Continuous somatosensory evoked potentials monitoring is highly sensitive to intraoperative occlusion of iliac artery during anterior lumbar interbody fusion: case report.  

PubMed

We report a case of thrombotic occlusion of the left common iliac artery during an L5-S1 anterior interbody fusion exposed via a retroperitoneal approach. The loss of distal blood flow was detected by loss of cortical and peripheral somatosensory evoked potentials on the left lower extremity. Restoration of the blood flow resulted in gradual return of evoked potentials of the involved extremity. The neurophysiological and pulse oximetry monitoring of the lower extremities are extremely sensitive for an early detection of thrombotic occlusions and vascular complications. PMID:19694209

Haghighi, S S; Zhang, R; Raiszadeh, R; Chammas, J; Bench, G; Raiszadeh, K; Terramanis, T T

2009-01-01

95

The European multicenter trial on the safety and efficacy of guided oblique lumbar interbody fusion (GO-LIF)  

PubMed Central

Background Because of the implant-related problems with pedicle screw-based spinal instrumentations, other types of fixation have been tried in spinal arthrodesis. One such technique is the direct trans-pedicular, trans-discal screw fixation, pioneered by Grob for spondylolisthesis. The newly developed GO-LIF procedure expands the scope of the Grob technique in several important ways and adds security by means of robotic-assisted navigation. This is the first clinical trial on the GO-LIF procedure and it will assess safety and efficacy. Methods/Design Multicentric prospective study with n = 40 patients to undergo single level instrumented spinal arthrodesis of the lumbar or the lumbosacral spine, based on a diagnosis of: painful disc degeneration, painful erosive osteochondrosis, segmental instability, recurrent disc herniation, spinal canal stenosis or foraminal stenosis. The primary target criteria with regards to safety are: The number, severity and cause of intra- and perioperative complications. The number of significant penetrations of the cortical layer of the vertebral body by the implant as recognized on postoperative CT. The primary target parameters with regards to feasibility are: Performance of the procedure according to the preoperative plan. The planned follow-up is 12 months and the following scores will be evaluated as secondary target parameters with regards to clinical improvement: VAS back pain, VAS leg pain, Oswestry Disability Index, short form - 12 health questionnaire and the Swiss spinal stenosis questionnaire for patients with spinal claudication. The secondary parameters with regards to construct stability are visible fusion or lack thereof and signs of implant loosening, implant migration or pseudarthrosis on plain and functional radiographs. Discussion This trial will for the first time assess the safety and efficacy of guided oblique lumbar interbody fusion. There is no control group, but the results, the outcome and the rate of any complications will be analyzed on the background of the literature on instrumented spinal fusion. Despite its limitations, we expect that this study will serve as the key step in deciding whether a direct comparative trial with another fusion technique is warranted. Trial Registration Clinical Trials NCT00810433 PMID:20819219

2010-01-01

96

Transforaminal lumbar interbody fusion using unilateral pedicle screw fixation plus contralateral translaminar facet screw fixation in lumbar degenerative diseases  

PubMed Central

Background: Transforaminal lumbar interbody fusion (TLIF) has been used in lumbar degenerative diseases. Some researchers have applied unilateral fixation in TLIF to reduce operational trauma without compromising the clinical outcome, but it is always suspected biomechanically unstable. The supplementary contralateral translaminar facet screw (cTLFS) seemed to be able to overcome the inherent drawbacks of unilateral pedicle screw (uPS) fixation theoretically. This study evaluates the safety, feasibility and efficacy of TLIF using uPS with cTLFS fixation in the treatment of lumbar degenerative diseases (LDD). Materials and Methods: 50 patients (29 male) underwent the aforementioned surgical technique for their LDD between December 2009 and April 2012. The results were evaluated based on visual analogue scale (VAS) of the leg and back, Japanese Orthopedic Association (JOA) score and Oswestry Disability Index (ODI) were recorded. The radiographic examinations in form of X-ray, computed tomography (CT) or magnetic resonance imaging was done preoperatively and 1 week, 3 months, 6 months, 12 months and 24 months postoperatively. The student t-test was used for comparison between the preoperative values and postoperative counterparts. P < 0.05 was considered to be statistically significant. Results: Among 50 patients, 22 received one level fusion and 28 two level's, with corresponding operation time and estimated blood loss being approximately 90 min, 150 ml and 120 min, 200 ml, respectively. No severe complications happened perioperatively. The mean VAS (back, leg) scores dropped from (7.6, 7.5) preoperatively to (2.1, 0.6) at 12 months’ followup, ODI from 49.1 preoperatively to 5.6 and JOA score raised from 10.6 preoperatively to 28.5, all P < 0.001, suggesting of good clinical outcome. From the three-dimensional reconstructed CT, 62 out of 70 segments displayed solid fusion with fusion rate of 88.6% at 12 months postoperatively. Conclusions: TLIF using uPS fixation plus cTLFS fixation is a safe, feasible and effective technique in the treatment of one or two level lumbar degenerative diseases short termly. PMID:25143640

Liu, Fubing; Jiang, Chun; Cao, Yuanwu; Jiang, Xiaoxing; Feng, Zhenzhou

2014-01-01

97

Osteoinductive activity of ErhBMP-2 after anterior cervical diskectomy and fusion with a ß-TCP interbody cage in a goat model.  

PubMed

Bone morphogenetic protein (BMP)-2 induces bone and cartilage tissue formation. Large amounts of BMP-2 are difficult to purify or to produce in vitro using eukaryotic cells. The goal of the present study was to assess the clinical use of Escherichia coli-derived recombinant human BMP-2 (ErhBMP-2) on bone fusion after cervical and lumbar spine surgery in a goat model, compared with the standard autogenous iliac bone grafting. Thirty-six goats were randomized to 3 groups: (A) autogenous iliac bone grafting, (B) cervical interbody fusion cage containing ß-tricalcium phosphate (ß-TCP), or (C) cervical interbody fusion cage containing ß-TCP+ErhBMP-2 (2.5 mg). Cervical bone repair was evaluated using radiographs and computed tomography scans at 0, 3, and 6 months. Histological analyses were performed on cervical samples. Two goats died from infection. The differences in intervertebral height among the groups were not significant 3 months postoperatively but became significant after 6 months between groups A vs B and C (P=.04); there was no difference between groups B and C at 6 months. Adding ErhBMP-2 significantly increased cervical fusion at 6 months (P=.04). Histological examinations showed that ß-TCP+ErhBMP-2 increased new bone area, material degradation rate, and depth of tissue penetration and decreased residual material area, all in a time-dependent manner. Escherichia coli-derived rhBMP-2 combined with an enhanced fusion cage containing ß-TCP induced bone formation in a goat model. Furthermore, its ability to promote bone fusion was similar to autogenous iliac bone grafting. PMID:24679197

Wang, Hongli; Zhang, Fan; Lv, Feizhou; Jiang, Jianyuan; Liu, Dayong; Xia, Xinlei

2014-02-01

98

Perioperative Surgical Complications and Learning Curve Associated with Minimally Invasive Transforaminal Lumbar Interbody Fusion: A Single-Institute Experience  

PubMed Central

Background As surgical complications tend to occur more frequently in the beginning stages of a surgeon's career, knowledge of perioperative complications is important to perform a safe procedure, especially if the surgeon is a novice. We sought to identify and describe perioperative complications and their management in connection with minimally invasive transforaminal lumbar interbody fusion (TLIF). Methods We performed a retrospective chart review of our first 124 patients who underwent minimally invasive TLIF. The primary outcome measure was adverse events during the perioperative period, including neurovascular injury, implant-related complications, and wound infection. Pseudarthroses and adjacent segment pathologies were not included in this review. Adverse events that were not specifically related to spinal surgery and did not affect recovery were also excluded. Results Perioperative complications occurred in 9% of patients (11/124); including three cases of temporary postoperative neuralgia, two deep wound infections, two pedicle screw misplacements, two cage migrations, one dural tear, and one grafted bone extrusion. No neurologic deficits were reported. Eight complications occurred in the first one-third of the series and only 3 complications occurred in the last two-thirds of the series. Additional surgeries were performed in 6% of patients (7/124); including four reoperations (two for cage migrations, one for a misplaced screw, and one for an extruded graft bone fragment) and three hardware removals (one for a misplaced screw and two for infected cages). Conclusions We found perioperative complications occurred more often in the early period of a surgeon's experience with minimally invasive TLIF. Implant-related complications were common and successfully managed by additional surgeries in this series. We suggest greater caution should be exercised to avoid the potential complications, especially when surgeon is a novice to this procedure. PMID:25729524

Lee, Soo Bin; Seok, Sang Ok; Jo, Byung Woo; Ha, Joong Won

2015-01-01

99

Soft Stabilization With an Artificial Intervertebral Ligament in Grade I Degenerative Spondylolisthesis: Comparison With Instrumented Posterior Lumbar Interbody Fusion  

PubMed Central

Background The purpose of this retrospective study was to evaluate the efficacy of soft stabilization with an artificial intervertebral ligament after microdecompression for the treatment of grade I degenerative spondylolisthesis. Methods From a total of 54 patients with degenerative spondylolisthesis who were treated surgically from May 2000 to April 2003, 36 patients who showed grade I spondylolisthesis without evidence of concomitant disc herniation necessitating discectomy were enrolled in the study. After decompression, the patients had undergone either soft stabilization with an artificial intervertebral ligament (n = 17) or instrumented posterior lumbar interbody fusion (PLIF; n = 19). Results The average follow-up period was 24 months for the PLIF group and 16 months for the soft stabilization group. In the PLIF group, preoperative mean scores of 60% on the Oswestry Disability Index, 8.8 on the visual analog scale (VAS) for low-back pain, and 9.3 on the VAS for leg pain improved to 28%, 4.1, and 2.6, respectively, after surgery. Corresponding scores in the soft stabilization group were 55%, 8.4, and 8.9, improving to 25%, 4.1, and 2.2 after surgery. There were no significant differences between the 2 groups in any of these clinical parameters. Patients’ subjective improvement rates and satisfaction with the surgical procedure were higher in the soft stabilization group, but the differences were not significant. Mean operation time and mean blood loss were significantly lower in the soft stabilization group than in the PLIF group. In the soft stabilization group, there were 3 cases of progression of slippage in patients who had had preoperative slippage of more than 20%; there was 1 dural tear in the PLIF group. Conclusions Patients with grade I degenerative spondylolisthesis who received soft stabilization with an artificial intervertebral ligament after microdecompression had clinical outcomes similar to those of patients who received PLIF. Since soft stabilization can be done in a much less invasive way than fusion, if slippage is 20% or less, soft stabilization with an artificial ligament is a viable alternative to fusion for patients who are elderly or who have significant comorbidities that make a prolonged operation inadvisable. Level of Evidence This study was a retrospective comparative study with a very limited population (level III evidence).

Lee, Sang-Ho; Park, Sun-Hee; Whang, Ji-Hee

2007-01-01

100

The use of RhBMP-2 in single-level transforaminal lumbar interbody fusion: a clinical and radiographic analysis  

PubMed Central

The “off label” use of rhBMP-2 in the transforaminal lumbar interbody fusion (TLIF) procedure has become increasingly popular. Although several studies have demonstrated the successful use of rhBMP-2 for this indication, uncertainties remain regarding its safety and efficacy. The purpose of this study is to evaluate the clinical and radiographic outcomes of the single-level TLIF procedure using rhBMP-2. Patients who underwent a single-level TLIF between January 2004 and May 2006 with rhBMP-2 were identified. A retrospective evaluation of these patients included operative report(s), pre- and postoperative medical records, and dynamic and static lumbar radiographs. Patient-reported clinical outcome measures were obtained from a telephone questionnaire and included a modification of the Odom’s criteria, a patient satisfaction score, and back and leg pain numeric rating scale scores. Forty-eight patients met the study criteria and were available for follow-up (avg. radiographic and clinical follow-up of 19.4 and 27.4 months, respectively). Radiographic fusion was achieved in 95.8% of patients. Good to excellent results were achieved in 71% of patients. On most recent clinical follow-up, 83% of patients reported improvement in their symptoms and 84% reported satisfaction with their surgery. Twenty-nine patients (60.4%) reported that they still had some back pain, with an average back pain numeric rating score of 2.8. Twenty patients (41.7%) reported that they still had some leg pain, with an average leg pain numeric rating score was 2.4. Thirteen patients (27.1%) had one or more complications, including transient postoperative radiculitis (8/48), vertebral osteolysis (3/48), nonunion (2/48), and symptomatic ectopic bone formation (1/48). The use of rhBMP-2 in the TLIF procedure produces a high rate of fusion, symptomatic improvement and patient satisfaction. Although its use eliminates the risk of harvesting autograft, rhBMP-2 is associated with other complications that raise concern, including a high rate of postoperative radiculitis. PMID:19475434

Makda, Junaid; Hong, Joseph; Patel, Ravi; Hilibrand, Alan S.; Anderson, David G.; Vaccaro, Alexander R.; Albert, Todd J.

2009-01-01

101

A prospective study of Autologous Growth Factors (AGF) in lumbar interbody fusion  

Microsoft Academic Search

BackgroundNumerous preclinical and clinical studies have reported on the use of platelet concentrates to promote tissue healing. The results in spinal fusion applications are limited and controversial.

Louis G. Jenis; Robert J. Banco; Brian Kwon

2006-01-01

102

Interbody Fusion Using VITOSS ® Bone Graft Substitute with Autogenous Bone Marrow Aspirate - One Year Interim Results  

Microsoft Academic Search

Autologous cancellous bone is generally considered the gold standard for promoting spinal fusion. However, harvesting the autograft is associated with increased length of surgery and blood loss, as well as significant morbidity at the donor site and other complications. In addition, the availability of quality autologous graft may be limited. Synthetic calcium-based bone void fillers have been used successfully in

Peter F. Ullrich

103

Anterior lumbar interbody fusion with carbon fiber cage loaded with bioceramics and platelet-rich plasma. An experimental study on pigs.  

PubMed

Platelet-rich plasma (PRP) is an autogenous source of growth factor and has been shown to enhance bone healing both in clinical and experimental studies. PRP in combination with porous hydroxyapatite has been shown to increase the bone ingrowth in a bone chamber rat model. The present study investigated whether the combination of beta tricalcium phosphate (beta-TCP) and PRP may enhance spinal fusion in a controlled animal study. Ten Danish Landrace pigs were used as a spinal fusion model. Immediately prior to the surgery, 55 ml blood was collected from each pig for processing PRP. Three-level anterior lumbar interbody fusion was performed with carbon fiber cages and staples on each pig. Autogenous bone graft, beta-TCP, and beta-TCP loaded with PRP were randomly assigned to each level. Pigs were killed at the end of the third month. Fusion was evaluated by radiographs, CT scanning, and histomorphometric analysis. All ten pigs survived the surgery. Platelet concentration increased 4.4-fold after processing. Radiograph examination showed 70% (7/10) fusion rate in the autograft level. All the levels with beta-TCP+PRP showed partial fusion, while beta-TCP alone levels had six partial fusions and four non-fusions ( P=0.08). CT evaluation of fusion rate demonstrated fusion in 50% (5/10) of the autograft levels. Only partial fusion was seen at beta-TCP levels and beta-TCP+PRP levels. Histomorphometric evaluation found no difference between beta-TCP and beta-TCP+PRP levels on new bone volume, remaining beta-TCP particles, and bone marrow and fibrous tissue volume, while the same parameters differ significantly when compared with autogenous bone graft levels. We concluded from our results in pigs that the PRP of the concentration we used did not improve the bone-forming capacity of beta-TCP biomaterial in anterior spine fusion. Both beta-TCP and beta-TCP+PRP had poorer radiological and histological outcomes than that of autograft after 3 months. PMID:14730438

Li, Haisheng; Zou, Xuenong; Xue, Qingyun; Egund, Niels; Lind, Martin; Bünger, Cody

2004-07-01

104

Is there a need for cervical collar usage post anterior cervical decompression and fusion using interbody cages? A randomized controlled pilot trial.  

PubMed

Anterior cervical discectomy and fusion (ACDF) is a common surgical intervention for radiculopathy resulting from degenerative cervical spine conditions. Post-surgical cervical collar use is believed to reduce post-operative pain, provide the patient with a sense of security during activities of daily living and even reduce rates of non-fusion. This prospective randomized controlled pilot trial investigates trial design feasibility in relation to prospective physical, functional, and quality of life-related outcomes of patients undergoing ACDF with interbody cage, with (n?=?17) and without (n?=?16) post-operative cervical collar usage. Results show that the sample provides sufficient statistical power to show that the use of a rigid cervical collar during 6 post-operative weeks is associated with significantly lower levels of neck disability index after 6 weeks and significantly lower levels of prospective neck pain. To investigate causal quality of life or fusion rate outcomes, sample size needs to be increased at least fourfold and optimally sixfold when accounting for data loss in prospective follow-up. The study suggests that post-surgical cervical collar usage may help certain patients cope with initial post-operative pain and disability. PMID:23074995

Abbott, Allan; Halvorsen, Marie; Dedering, Asa

2013-05-01

105

Prospective Analysis of a New Bone Graft in Lumbar Interbody Fusion: Results of a 2- Year Prospective Clinical and Radiological Study  

PubMed Central

Background This study examined the efficacy and safety of bone graft material ABM/P-15 (iFACTOR) for use in posterior lumbar interbody fusion. ABM/P-15 has been used safely for more than a decade in dental applications. Methods Forty patients underwent PLIF surgery, with each patient as control. Assessments up to 24 months included radiographs, CT scan, VAS, and ODI. Primary success criteria were fusion and safety. Results Intra-cage bridging bone occurred earlier with ABM/P-15 than autograft (97.73% vs. 59.09% at 6 months). On average pain decreased 29 points and function improved 43 points. Radio dense material outside the disk space occurred more frequently with ABM/P-15 than autograft, without clinical consequence. Conclusions This study suggests that ABM/P-15 has equal or greater efficacy at 6 and 12 months. Pain improvements exceeded success criteria at all time points. Functional improvement exceeded success criteria at all time points. Clinical Relevance This study explores the safety and efficacy of an osteobiologic peptide enhanced bone graft material as a viable alternative to autograft and its attendant risks. PMID:25709887

Raskin, Yannic

2015-01-01

106

Assessment of bone graft incorporation by 18?F-fluoride positron-emission tomography/computed tomography in patients with persisting symptoms after posterior lumbar interbody fusion  

PubMed Central

Background Posterior lumbar interbody fusion (PLIF) is a method that allows decompression of the spinal canal and nerve roots by laminectomy combined with fusion by means of intervertebral cages filled with bone graft and pedicle screw fixation. Conventional imaging techniques, such as plain radiography and computed tomography (CT), have limitations to assess bony fusion dynamics. Methods In 16 PLIFs of 15 patients with persisting symptoms, positron-emission tomography (PET)/CT scans were made 60?min after intravenous administration of 156 to 263?MBq of 18?F-fluoride, including 1-mm sliced, high-dose, non-contrast-enhanced CT scanning. Maximal standard uptake values (SUVmax) of various regions were calculated and correlated with abnormalities on CT. Results Subsidence of the cages into the vertebral endplates was the most frequently observed abnormality on CT (in 16 of 27 or 59% of evaluable endplates). Endplate SUVmax values were significantly higher for those patients with pronounced (p?fusion was seen on CT in 63% but showed no correlation to intercorporal SUVmax values. Conclusions With the use of 18?F-fluoride PET/CT, intervertebral cage subsidence appeared to be a prominent finding in this patient group with persisting symptoms, and highly correlating with the degree of PET hyperactivity at the vertebral endplates and pedicle screw entry points. Further study using 18?F-fluoride PET/CT should specifically assess the role of metabolically active subsidence in a prospective patient group, to address its role in nonunion and as a cause of persisting pain. PMID:22846374

2012-01-01

107

Surgical Data and Early Postoperative Outcomes after Minimally Invasive Lumbar Interbody Fusion: Results of a Prospective, Multicenter, Observational Data-Monitored Study  

PubMed Central

Minimally invasive lumbar interbody fusion (MILIF) offers potential for reduced operative morbidity and earlier recovery compared with open procedures for patients with degenerative lumbar disorders (DLD). Firm conclusions about advantages of MILIF over open procedures cannot be made because of limited number of large studies of MILIF in a real-world setting. Clinical effectiveness of MILIF in a large, unselected real-world patient population was assessed in this Prospective, monitored, international, multicenter, observational study. Objective: To observe and document short-term recovery after minimally invasive interbody fusion for DLD. Materials and Methods: In a predefined 4-week analysis from this study, experienced surgeons (?30 MILIF surgeries pre-study) treated patients with DLD by one- or two-level MILIF. The primary study objective was to document patients’ short-term post-interventional recovery (primary objective) including back/leg pain (visual analog scale [VAS]), disability (Oswestry Disability Index [ODI]), health status (EQ-5D) and Patient satisfaction. Results: At 4 weeks, 249 of 252 patients were remaining in the study; the majority received one-level MILIF (83%) and TLIF was the preferred approach (94.8%). For one-level (and two-level) procedures, surgery duration was 128 (182) min, fluoroscopy time 115 (154) sec, and blood-loss 164 (233) mL. Time to first ambulation was 1.3 days and time to study-defined surgery recovery was 3.2 days. Patients reported significantly (P < 0.0001) reduced back pain (VAS: 2.9 vs 6.2), leg pain (VAS: 2.5 vs 5.9), and disability (ODI: 34.5% vs 45.5%), and a significantly (P < 0.0001) improved health status (EQ-5D index: 0.61 vs 0.34; EQ VAS: 65.4 vs 52.9) 4 weeks postoperatively. One adverse event was classified as related to the minimally invasive surgical approach. No deep site infections or deaths were reported. Conclusions: For experienced surgeons, MILIF for DLD demonstrated early benefits (short time to first ambulation, early recovery, high patient satisfaction and improved patient-reported outcomes) and low major perioperative morbidity at 4 weeks postoperatively. PMID:25811615

Pereira, Paulo; Buzek, David; Franke, Jörg; Senker, Wolfgang; Kosmala, Arkadiusz; Hubbe, Ulrich; Manson, Neil; Rosenberg, Wout; Assietti, Roberto; Martens, Frederic; Barbanti Brodano, Giovanni; Scheufler, Kai-Michael

2015-01-01

108

Novel Pedicle Screw and Plate System Provides Superior Stability in Unilateral Fixation for Minimally Invasive Transforaminal Lumbar Interbody Fusion: An In Vitro Biomechanical Study  

PubMed Central

Purpose 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. Methods 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. Results 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. Conclusions 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. PMID:25807513

Zhu, Qingan; Zhou, Yue; Li, Changqing; Liu, Huan; Huang, Zhiping; Shang, Jin

2015-01-01

109

Four-year follow-up results of transforaminal lumbar interbody fusion as revision surgery for recurrent lumbar disc herniation after conventional discectomy.  

PubMed

This study investigated the safety, effectiveness, and clinical and radiological outcomes of transforaminal lumbar interbody fusion (TLIF) for recurrent lumbar disc herniation (rLDH) following previous lumbar spine surgery. Seventy-three consecutive patients treated for rLDH between June 2005 and May 2012 were included in the study. The previous surgical procedures included percutaneous discectomy, discectomy with laminotomy, discectomy with unilateral laminectomy, and discectomy with bilateral laminectomy. The level of rLDH was L4-L5 in 51 patients, L5-S1 in 19 patients, and L3-L4 in three patients. All patients underwent reoperation using the TLIF technique. Outcomes were evaluated using the Oswestry disability index (ODI), visual analogue scale (VAS) scores for low back pain and leg pain, and the Japanese Orthopaedic Association (JOA) score, based on the results of physical examinations and questionnaires. The range of motion and disc height index of the operative segment were compared between preoperative and postoperative radiographs. The mean follow-up period was 4.1 years. The VAS scores for low back pain and leg pain, ODI, and JOA score improved significantly between the preoperative and final follow-up evaluations. The mean recovery rate of the JOA score was 89.0%. The disc space height and stability at the fused level were significantly improved after surgery. The fusion rate at the final follow-up was 93.2%. There were no major complications. These results indicate that TLIF can be considered an effective, reliable, and safe alternative procedure for the treatment of rLDH. PMID:25443080

Li, Zhonghai; Tang, Jiaguang; Hou, Shuxun; Ren, Dongfeng; Li, Li; Lu, Xiang; Hou, Tiesheng

2015-02-01

110

A unique modular implant system enhances load sharing in anterior cervical interbody fusion: a finite element study  

PubMed Central

Background The efficacy of dynamic anterior cervical plates is somewhat controversial. Screws in static-plate designs have a smaller diameter and can cut through bone under load. While not ideal, this unintended loosening can help mitigate stress shielding. Stand-alone interbody devices with integral fixation have large endplate contact areas that may inhibit or prevent loosening of the fixation. This study investigates the load sharing ability of a novel dynamic plate design in preventing the stress shielding of the graft material compared to the non-dynamic devices. Methods An experimentally validated intact C5-C6 finite element model was modified to simulate discectomy and accommodate implant-graft assembly. Four implant iterations were modeled; InterPlate titanium device with dynamic surface features (springs), InterPlate titanium non-dynamic device, InterPlate titanium design having a fully enclosed graft chamber, and the InterPlate design in unfilled PEEK having a fully enclosed graft chamber. All the models were fixed at the inferior-most surface of C6 and the axial displacement required to completely embed the dynamic surface features was applied to the model. Results InterPlate device with dynamic surface features induced higher graft stresses compared to the other design iterations resulting in uniform load sharing. The distribution of these graft stresses were more uniform for the InterPlate dynamic design. Conclusions These results indicate that the dynamic design decreases the stress shielding by increasing and more uniformly distributing the graft stress. Fully enclosed graft chambers increase stress shielding. Lower implant material modulus of elasticity does not reduce stress shielding significantly. PMID:24618205

2014-01-01

111

Evaluation of Functional Outcomes in Individuals 10 Years after Posterior Lumbar Interbody Fusion with Corundum Implants and Decompression: A Comparison of 2 Surgical Techniques  

PubMed Central

Background The purpose of this study was to evaluate lumbar spine-related functional disability in individuals 10 years after lumbar decompression and lumbar decompression with posterior lumbar interbody fusion (PLIF) with corundum implants surgery for degenerative stenosis and to compare the long-term outcome of these 2 surgical techniques. Material/Methods From 1998 to 2002, 100 patients with single-level lumbar stenosis were surgically treated. The patients were randomly divided into 2 groups that did not differ in terms of clinical or neurological symptoms. Group A consisted of 50 patients who were treated with PLIF and the use of porous ceramic corundum implants; the mean age was 57.74 and BMI was 27.34. Group B consisted of 50 patients treated with decompression by fenestration; mean age was 51.28 and the mean BMI was 28.84. Results There was no statistical significance regarding age, BMI, and sex. Both treatments revealed significant improvements. In group A, ODI decreased from 41.01% to 14.3% at 1 year and 16.3 at 10 years. In group B, ODI decreased from 63.8% to 18.36% at 1 year and 22.36% at 10 years. The difference between groups was statistically significant. There were no differences between the groups regarding the Rolland-Morris disability questionnaire and VAS at 1 and 10 years after surgery. Conclusions Long-term results evaluated according to the ODI, the Rolland-Morris disability questionnaire, and the VAS showed that the both methods significantly reduce patient disability, and this was maintained during next 10 years. The less invasive fenestration procedure was only slightly less favorable than surgical treatment of stenosis by both PLIF with corundum implants and decompression. PMID:25106708

Truszczy?ska, Aleksandra; R?pa?a, Kazimierz; ?ukawski, Stanislaw; Trzaskoma, Zbigniew; Tarnowski, Adam; Drzal-Grabiec, Justyna; Cabak, Anna

2014-01-01

112

Minimally Invasive Versus Open Transforaminal Lumbar Interbody Fusion for Degenerative Spondylolisthesis Grades 1-2: Patient-Reported Clinical Outcomes and Cost-Utility Analysis  

PubMed Central

Background Transforaminal lumbar interbody fusion (TLIF) is the standard surgical treatment for patients with lumbar degenerative spondylolisthesis who do not respond to a 6-week course of conservative therapy. A number of morbidities are associated with the conventional open-TLIF method, so minimally invasive surgery (MIS) techniques for TLIF (MIS-TLIF) have been introduced to reduce the trauma to paraspinal muscles and hasten postoperative recovery. Because providing cost-effective medical treatment is a core initiative of healthcare reforms, a comparison of open-TLIF and MIS-TLIF must include a cost-utility analysis in addition to an analysis of clinical effectiveness. Methods We compared patient-reported clinical functional outcomes and hospital direct costs in age-matched patients treated surgically with either open-TLIF or MIS-TLIF. Patients were followed for at least 1 year, and patient scores on the Oswestry Disability Index (ODI) and visual analog scale (VAS) were analyzed at 6 weeks, 6 months, and ?1 year postoperatively in the 2 treatment groups. Results Compared to their preoperative scores, patients in both the open-TLIF and MIS-TLIF groups had significant improvements in the ODI and VAS scores at each follow-up point, but no significant difference in functional outcome occurred between the open-TLIF and MIS-TLIF groups (P=0.46). However, open-TLIF is significantly more costly compared to MIS-TLIF (P=0.0002). Conclusion MIS-TLIF is a more cost-effective treatment than open-TLIF for patients with degenerative spondylolisthesis and is equally effective as the conventional open-TLIF procedure, although further financial analysis—including an analysis of indirect costs—is needed to better understand the full benefit of MIS-TLIF. PMID:24688330

Sulaiman, Wale A. R.; Singh, Manish

2014-01-01

113

Harvesting local cylinder autograft from adjacent vertebral body for anterior lumbar interbody fusion: surgical technique, operative feasibility and preliminary clinical results  

PubMed Central

Autogenous iliac crest has long served as the gold standard for anterior lumbar arthrodesis although added morbidity results from the bone graft harvest. Therefore, femoral ring allograft, or cages, have been used to decrease the morbidity of iliac crest bone harvesting. More recently, an experimental study in the animal showed that harvesting local bone from the anterior vertebral body and replacing the void by a radio-opaque ?-tricalcium phosphate plug was a valid concept. However, such a concept precludes theoretically the use of posterior pedicle screw fixation. At one institution a consecutive series of 21 patients underwent single- or multiple-level circumferential lumbar fusion with anterior cages and posterior pedicle screws. All cages were filled with cancellous bone harvested from the adjacent vertebral body, and the vertebral body defect was filled with a ?-tricalcium phosphate plug. The indications for surgery were failed conservative treatment of a lumbar degenerative disc disease or spondylolisthesis. The purpose of this study, therefore, was to report on the surgical technique, operative feasibility, safety, benefits, and drawbacks of this technique with our primary clinical experience. An independent researcher reviewed all data that had been collected prospectively from the onset of the study. The average age of the patients was 39.9 (26–57) years. Bone grafts were successfully harvested from 28 vertebral bodies in all but one patient whose anterior procedure was aborted due to difficulty in freeing the left common iliac vein. This case was converted to a transforaminal interbody fusion (TLIF). There was no major vascular injury. Blood loss of the anterior procedure averaged 250 ml (50–350 ml). One tricalcium phosphate bone plug was broken during its insertion, and one endplate was broken because of wrong surgical technique, which did not affect the final outcome. One patient had a right lumbar plexopathy that was not related to this special technique. There was no retrograde ejaculation, infection or pseudoarthrosis. One patient experienced a deep venous thrombosis. At the last follow up (mean 28 months) all patients had a solid lumbar spine fusion. At the 6-month follow up, the pain as assessed on the visual analog scale (VAS) decreased from 6.9 to 4.5 (33% decrease), and the Oswestry disability index (ODI) reduced from 48.0 to 31.7 with a 34% reduction. However, at 2 years follow up there was a trend for increase in the ODI (35) and VAS (5). The data in this study suggest that harvesting a cylinder of autograft from the adjacent vertebral body is safe and efficient. Filling of the void defect with a ?-tricalcium phosphate plug does not preclude the use of posterior pedicle screw stabilization. PMID:16598484

Jiang, Liang; Steffen, Thomas; Ouellet, Jean; Reindl, Rudy; Aebi, Max

2006-01-01

114

In Vivo Assessment of Bone Graft/Endplate Contact Pressure in a Caprine Interbody Pseudarthrosis Model: A Preliminary Biomechanical Characterization of the Fusion Process for the Development of a Microelectromechanical Systems (MEMS) Biosensor  

PubMed Central

Background In this preliminary study we used a goat model to quantify pressure at an interbody bone graft interface. Although the study was designed to assess fusion status, the concept behind the technology could lead to early detection of implant failure and potential hazardous complications related to motion-preservation devices. The purpose of this study was to investigate the feasibility of in vivo pressure monitoring as a strategy to determine fusion status. Methods Telemetric pressure transducers were implanted, and pressure at the bone graft interfaces of cervical interbody fusion autografts placed into living goats (Groups A and B) was evaluated. Group A constituted the 4-month survival group and Group B the 6-month survival group. One goat served as the study control (Group C) and was not implanted with a pressure transducer. An additional six cadaveric goat cervical spines (Group D) were obtained from a local slaughterhouse and implanted with bone grafts and ventral plates and used for in vitro biomechanical comparison to the specimens from Groups A and B. Results All goats demonstrated an increase in interface pressure within the first 10 days postoperatively, with the largest relative change in pressure occurring between the sixth and ninth days. The goats from Groups A and B had a 200% to 400% increase in relative pressure. Conclusions Although this was a pilot study to assess pressure as an indicator for a fusion or pseudarthrosis, the preliminary data suggest that early bone healing is detectable by an increase in pressure. Thus, pressure may serve as an indicator of fusion status by detecting altered biomechanical parameters.

Gordon, Ilya; Schlenk, Richard; Coquillette, Madeline; Fleischman, Aaron J.; Roy, Shuvo; Togawa, Daisuke; Bauer, Thomas W.; Benzel, Edward C.

2008-01-01

115

[Application of a stand-alone interbody fusion cage based on a novel porous TiO2/glass ceramic--2: Biomechanical evaluation after implantation in the sheep cervical spine].  

PubMed

Animals are becoming more and more common as in vivo models for the human spine. Especially the sheep cervical spine is stated to be of good comparability and usefulness in the evaluation of in vivo radiological, biomechanical and histological behaviour of new bone replacement materials, implants and cages for cervical spine interbody fusion. In preceding biomechanical in vitro examinations human cervical spine specimens were tested after fusion with either a cubical stand-alone interbody fusion cage manufactured from a new porous TiO2/glass composite (Ecopore) or polymethylmethacrylate (PMMA) after discectomy. Following our first experience with the use of the new material and its influence on the primary stability after in vitro application we carried out fusions of 20 sheep cervical spines levels with either PMMA or an Ecopore-cage, and performed radiological examinations during the following 2-4 months. In this second part of the study we intended the biomechanical evaluation of the spine segments with reference to the previously determined morphological findings, like subsidence of the implants, significant increase of the kyphosis angle and degree of the bony fusion along with the interpretation of the results. 20 sheep cervical spines segments with either PMMA- or Ecopore-fusion in the levels C2/3 and C4/5 were tested, in comparison to 10 native corresponding sheep cervical spine segments. Non-destructive biomechanical testing was performed, including flexion/extension, lateral bending and axial rotation using a spine testing apparatus. Three-dimensional range of motion (ROM) was evaluated using an ultrasound measurement system. In the native spine segments C2/3 and C4/5 the ROM increased in cranio-caudal direction particulary in flexion/extension, less pronounced in lateral flexion and axial rotation (p < 0.05). The overall ROM of both tested segments was greatest in lateral flexion, reduced to 52% in flexion/extension and to 16% in axial rotation. After 2 months C2/3- and C4/5-segments with PMMA-fusion and C2/3-segments with Ecopore-interposition showed decrease of ROM in lateral flexion in comparison to the native segments, indicating increasing stiffening. However, after 4 months all operated segments, independent from level or implanted material, were stiffer than the comparable native segments. The decrease of the ROM correlated with the radiological-morphological degree of fusion. Our evaluation of the new porous TiO2/glass composite as interbody fusion cage has shown satisfactory radiological results as well as distinct biomechanical stability and fusion of the segments after 4 months in comparison to PMMA. After histological analysis of the bone-biomaterial-interface, further examinations of this biomaterial previous to an application as alternative to other customary cages in humans are necessary. PMID:15884708

Korinth, M C; Hero, T; Pandorf, T; Zell, D

2005-04-01

116

A-Life for Music: Music and Computer Models of Living Systems  

E-print Network

, and includes a CD with various examples music related to A-Life. #12;A-Life for Music: Music and Computer Models of Living Systems Edited by Eduardo Reck Miranda DAS 24://www.areditions.com Order Your Copy NOW! ALife for Music: Music and Computer Models of Living Systems Edited by Eduardo

Miranda, Eduardo Reck

117

ISASS Policy Statement - Cervical Interbody  

PubMed Central

Morgan Lorio, MD, FACS, Chair, ISASS Task Force on Coding & Reimbursement In 2011, CPT code 22551 was revised to combine or bundle CPT codes 63075 and 22554 when both procedures were performed at the same site/same surgical session. The add on code +22552 is used to report each additional interspace. 2014 heralded a downward pressure on this now prime target code (for non-coverage?) 22551 through an egregious insurer attempt to redefine cervical arthrodesis, effectively removing spine surgeon choice and altering best practice without clinical evidence. Currently, spine surgeons are equally split on the use of allograft versus cages for cervical arthrodesis. Structural allograft, CPT code 20931, is reported once per same surgical session, regardless of the number of allografts used. CPT code 22851 which is designated solely for cage use, has a higher reimbursement than structural allograft, and may be reported for each inner space. Hence, the rationale behind why some payers wrongly consider “spine cages NOT medically necessary for cervical fusion.” A timely consensus paper summarizing spine surgeon purview on the logical progressive evolution of cervical interbody fusion for ISASS/IASP membership was strategically identified as an advocacy focus by the ISASS Task Force. ISASS appreciates the authors’ charge with gratitude. This article has both teeth and transparent clinical real-world merit. PMID:25694945

Singh, Kern; Qureshi, Sheeraz

2014-01-01

118

ISASS Policy Statement - cervical interbody.  

PubMed

Morgan Lorio, MD, FACS, Chair, ISASS Task Force on Coding & Reimbursement In 2011, CPT code 22551 was revised to combine or bundle CPT codes 63075 and 22554 when both procedures were performed at the same site/same surgical session. The add on code +22552 is used to report each additional interspace. 2014 heralded a downward pressure on this now prime target code (for non-coverage?) 22551 through an egregious insurer attempt to redefine cervical arthrodesis, effectively removing spine surgeon choice and altering best practice without clinical evidence. Currently, spine surgeons are equally split on the use of allograft versus cages for cervical arthrodesis. Structural allograft, CPT code 20931, is reported once per same surgical session, regardless of the number of allografts used. CPT code 22851 which is designated solely for cage use, has a higher reimbursement than structural allograft, and may be reported for each inner space. Hence, the rationale behind why some payers wrongly consider "spine cages NOT medically necessary for cervical fusion." A timely consensus paper summarizing spine surgeon purview on the logical progressive evolution of cervical interbody fusion for ISASS/IASP membership was strategically identified as an advocacy focus by the ISASS Task Force. ISASS appreciates the authors' charge with gratitude. This article has both teeth and transparent clinical real-world merit. PMID:25694945

Singh, Kern; Qureshi, Sheeraz

2014-01-01

119

Biomechanics of Lateral Interbody Spacers: Going Wider for Going Stiffer  

PubMed Central

This study investigates the biomechanical stability of a large interbody spacer inserted by a lateral approach and compares the biomechanical differences with the more conventional transforaminal interbody fusion (TLIF), with and without supplemental pedicle screw (PS) fixation. Twenty-four L2-L3 functional spinal units (FSUs) were tested with three interbody cage options: (i) 18?mm XLIF cage, (ii) 26?mm XLIF cage, and (iii) 11?mm TLIF cage. Each spacer was tested without supplemental fixation, and with unilateral and bilateral PS fixation. Specimens were subjected to multidirectional nondestructive flexibility tests to 7.5?N·m. The range of motion (ROM) differences were first examined within the same group (per cage) using repeated-measures ANOVA, and then compared between cage groups. The 26?mm XLIF cage provided greater stability than the 18?mm XLIF cage with unilateral PS and 11?mm TLIF cage with bilateral PS. The 18?mm XLIF cage with unilateral PS provided greater stability than the 11?mm TLIF cage with bilateral PS. This study suggests that wider lateral spacers are biomechanically stable and offer the option to be used with less or even no supplemental fixation for interbody lumbar fusion. PMID:23213284

Pimenta, Luiz; Turner, Alexander W. L.; Dooley, Zachary A.; Parikh, Rachit D.; Peterson, Mark D.

2012-01-01

120

The SNAP trial: a double blind multi-center randomized controlled trial of a silicon nitride versus a PEEK cage in transforaminal lumbar interbody fusion in patients with symptomatic degenerative lumbar disc disorders: study protocol  

PubMed Central

Background Polyetheretherketone (PEEK) cages have been widely used in the treatment of lumbar degenerative disc disorders, and show good clinical results. Still, complications such as subsidence and migration of the cage are frequently seen. A lack of osteointegration and fibrous tissues surrounding PEEK cages are held responsible. Ceramic implants made of silicon nitride show better biocompatible and osteoconductive qualities, and therefore are expected to lower complication rates and allow for better fusion. Purpose of this study is to show that fusion with the silicon nitride cage produces non-inferior results in outcome of the Roland Morris Disability Questionnaire at all follow-up time points as compared to the same procedure with PEEK cages. Methods/Design This study is designed as a double blind multi-center randomized controlled trial with repeated measures analysis. 100 patients (18–75 years) presenting with symptomatic lumbar degenerative disorders unresponsive to at least 6 months of conservative treatment are included. Patients will be randomly assigned to a PEEK cage or a silicon nitride cage, and will undergo a transforaminal lumbar interbody fusion with pedicle screw fixation. Primary outcome measure is the functional improvement measured by the Roland Morris Disability Questionnaire. Secondary outcome parameters are the VAS leg, VAS back, SF-36, Likert scale, neurological outcome and radiographic assessment of fusion. After 1 year the fusion rate will be measured by radiograms and CT. Follow-up will be continued for 2 years. Patients and clinical observers who will perform the follow-up visits will be blinded for type of cage used during follow-up. Analyses of radiograms and CT will be performed independently by two experienced radiologists. Discussion In this study a PEEK cage will be compared with a silicon nitride cage in the treatment of symptomatic degenerative lumbar disc disorders. To our knowledge, this is the first randomized controlled trial in which the silicon nitride cage is compared with the PEEK cage in patients with symptomatic degenerative lumbar disc disorders. Trial registration NCT01557829 PMID:24568365

2014-01-01

121

Complications of Lumbar Artificial Disc Replacement Compared to Fusion: Results From the Prospective, Randomized, Multicenter US Food and Drug Administration Investigational Device Exemption Study of the Charité Artificial Disc  

PubMed Central

Background Previous reports of lumbar total disc replacement (TDR) have described significant complications. The US Food and Drug Administration (FDA) investigational device exemption (IDE) study of the Charité artificial disc represents the first level I data comparison of TDR to fusion. Methods In the prospective, randomized, multicenter IDE study, patients were randomized in a 2:1 ratio, with 205 patients in the Charité group and 99 patients in the control group (anterior lumbar interbody fusion [ALIF] with BAK cages). Inclusion criteria included confirmed single-level degenerative disc disease at L4-5 or L5-S1 and failure of nonoperative treatment for at least 6 months. Complications were reported throughout the study. Results The rate of approach-related complications was 9.8% in the investigational group and 10.1% in the control group. The rate of major neurological complications was similar between the 2 groups (investigational = 4.4%, control = 4.0%). There was a higher rate of superficial wound infection in the investigational group but no deep wound infections in either group. Pseudarthrosis occurred in 9.1% of control group patients. The rate of subsidence in the investigational group was 3.4%. The reoperation rate was 5.4% in the investigational group and 9.1% in the control group. Conclusions The incidence of perioperative and postoperative complications for lumbar TDR was similar to that of ALIF. Vigilance is necessary with respect to patient indications, training, and correct surgical technique to maintain TDR complications at the levels experienced in the IDE study.

Majd, Mohammed E.; Isaza, Jorge E.; Blumenthal, Scott L.; McAfee, Paul C.; Guyer, Richard D.; Hochschuler, Stephen H.; Geisler, Fred H.; Garcia, Rolando; Regan, John J.

2007-01-01

122

Comparison between Two Different Cervical Interbody Fusion Cages in One Level Stand-alone ACDF: Carbon Fiber Composite Frame Cage Versus Polyetheretherketone Cage  

PubMed Central

Objective The authors conducted a retrospective study to compare the implantation of carbon fiber composite frame cages (CFCFCs) to the implantation of polyetheretherketone (PEEK) cages after anterior cervical discectomy for cervical degenerative disc disease. In addition, the predictive factors that influenced fusion or subsidence were investigated. Methods A total of 58 patients with single-level degenerative disc disease were treated with anterior cervical discectomy and implantation of stand-alone cages; CFCFCs were used in 35 patients, and PEEK cages were used in 23 patients. Preoperative and postoperative radiological and clinical assessments were performed. Results During the mean follow-up period of 41 months, fusion occurred in 43 patients (74.1%), and subsidence developed in 18 patients (31.0%). Pain decreased in all patients, and the patients' satisfaction rate was 75.9%. Neither fusion nor subsidence was related to the clinical outcome. There were no significant differences in the clinical and radiological outcomes between the CFCFC and the PEEK cage groups. Smoking history (p=0.023) was significantly associated with pseudarthrosis, and cage height (?7mm) (p=0.037) were significantly associated with subsidence. Conclusion The clinical and radiological results were similar between the CFCFC and the PEEK cage groups. Fusion or subsidence did not affect the clinical outcomes. Smoking history and cage height (?7mm) were predictive factors for pseudarthrosis or subsidence in anterior cervical discectomy and fusion with stand-alone cages. PMID:25346758

Yoo, Minwook; Kim, Wook-Ha; Hyun, Seung-Jae; Jahng, Tae-Ahn; Kim, Hyun-Jib

2014-01-01

123

Lumbar interbody fusion with porous biphasic calcium phosphate enhanced by recombinant bone morphogenetic protein-2/silk fibroin sustained-released microsphere: an experimental study on sheep model.  

PubMed

Biphasic calcium phosphate (BCP) has been investigated extensively as a bone substitute nowadays. However, the bone formation capacity of BCP is limited owing to lack of osteoinduction. Silk fibroin (SF) has a structure similar to type I collagen, and could be developed to a microsphere for the sustained-release of rhBMP-2. In our previous report, bioactivity of BCP could be enhanced by rhBMP-2/SF microsphere (containing 0.5 µg rhBMP-2) in vitro. However, the bone regeneration performance of the composite in vivo was not investigated. Thus, the purpose of this study was to evaluate the efficacy of BCP/rhBMP-2/SF in a sheep lumbar fusion model. A BCP and rhBMP-2/SF microsphere was developed, and then was integrated into a BCP/rhBMP-2/SF composite. BCP, BCP/rhBMP-2 and BCP/rhBMP-2/SF were implanted randomly into the disc spaces of 30 sheep at the levels of L1/2, L3/4 and L5/6. After sacrificed, the fusion segments were evaluated by manual palpation, CT scan, biomechanical testing and histology at 3 and 6 months, respectively. The composite demonstrated a burst-release of rhBMP-2 (39.1 ± 2.8 %) on the initial 4 days and a sustained-release (accumulative 81.3 ± 4.9 %) for more than 28 days. The fusion rates, semi-quantitative CT scores, fusion stiffness in bending in all directions and histologic scores of BCP/rhBMP-2/SF were significantly greater than BCP and BCP/rhBMP-2 at each time point, respectively (P < 0.05). These findings indicate that the SF microspheres containing a very low dose of rhBMP-2 improve fusion in sheep using BCP constructs. PMID:25690620

Chen, Liang; Liu, Hai-Long; Gu, Yong; Feng, Yu; Yang, Hui-Lin

2015-03-01

124

Sequential Changes of Plasma C-Reactive Protein, Erythrocyte Sedimentation Rate and White Blood Cell Count in Spine Surgery : Comparison between Lumbar Open Discectomy and Posterior Lumbar Interbody Fusion  

PubMed Central

Objective C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) are often utilized to evaluate for postoperative infection. Abnormal values may be detected after surgery even in case of non-infection because of muscle injury, transfusion, which disturbed prompt perioperative management. The purpose of this study was to evaluate and compare the perioperative CRP, ESR, and white blood cell (WBC) counts after spine surgery, which was proved to be non-infection. Methods Twenty patients of lumbar open discectomy (LOD) and 20 patients of posterior lumbar interbody fusion (PLIF) were enrolled in this study. Preoperative and postoperative prophylactic antibiotics were administered routinely for 7 days. Blood samples were obtained one day before surgery and postoperative day (POD) 1, POD3, and POD7. Using repeated measures ANOVA, changes in effect measures over time and between groups over time were assessed. All data analysis was conducted using SAS v.9.1. Results Changes in CRP, within treatment groups over time and between treatment groups over time were both statistically significant F(3,120)=5.05, p=0.003 and F(1,39)=7.46, p=0.01, respectively. Most dramatic changes were decreases in the LOD group on POD3 and POD7. Changes in ESR, within treatment groups over time and between treatment groups over time were also found to be statistically significant, F(3,120)=6.67, p=0.0003 and F(1,39)=3.99, p=0.01, respectively. Changes in WBC values also were be statistically significant within groups over time, F(3,120)=40.52, p<0.001, however, no significant difference was found in between groups WBC levels over time, F(1,39)=0.02, p=0.89. Conclusion We found that, dramatic decrease of CRP was detected on POD3 and POD7 in LOD group of non-infection and dramatic increase of ESR on POD3 and POD7 in PLIF group of non-infection. We also assumed that CRP would be more effective and sensitive parameter especially in LOD than PLIF for early detection of infectious complications. Awareness of the typical pattern of CRP, ESR, and WBC may help to evaluate the early postoperative course. PMID:25368764

Choi, Man Kyu; Kim, Kee D; Ament, Jared D.

2014-01-01

125

Laparoscopic anterior spinal arthrodesis with rhBMP-2 in a titanium interbody threaded cage.  

PubMed

Anterior lumbar interbody arthrodesis is commonly performed for conditions involving infection, deformity, and instability. The purpose of this investigation was to determine the effective dose of recombinant human bone morphogenetic protein-2 (rhBMP-2) as a bone graft substitute inside a titanium threaded interbody fusion cage using a nonhuman primate model of laparoscopic anterior lumbar interbody arthrodesis. Eight adult rhesus monkeys underwent laparoscopic exposure of the lumbosacral spine followed by insertion of a hollow titanium threaded cylindrical cage (Sofamor-Danek, Memphis, TN, U.S.A.). Before insertion, the chamber of the cage was filled with a collagen sponge delivery vehicle soaked with either 0 mg/ml (sham, buffer only), 0.75 mg/ml (low dose), or 1.5 mg/ml (high dose) of rhBMP-2 (Genetics Institute, Cambridge, MA, U.S.A.). Fusions were evaluated in a blinded fashion with plain radiographs and computed tomography (CT) scans 12 and 24 weeks after surgery, and by manual palpation and histology after euthanasia 24 weeks after surgery. All five monkeys treated with a cage filled with rhBMP-2 obtained a solid fusion as assessed by manual palpation. The two monkeys that received no growth factor did not achieve solid fusions. Plain radiographs were of limited value, with fusions best assessed on sagittally reconstructed CT scans. Scans from the two animals treated without growth factor showed ingrowth of bone only into the outer edges of the cage, but not through the center. Scans from the rhBMP-2-treated animals demonstrated arthrodesis with continuous bone growth through the cage. Histologic analysis demonstrated normal mature trabecular bone surrounding and growing through the cages, which correlated with the CT scan findings. We conclude that rhBMP-2 delivered in a threaded titanium interbody cage can serve as a bone graft substitute in a nonhuman primate model. Sagittal reconstructed CT may be a better method to assess for fusion with this device. PMID:9588464

Boden, S D; Martin, G J; Horton, W C; Truss, T L; Sandhu, H S

1998-04-01

126

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

Microsoft Academic Search

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

Shih-Hao Chen; Ruey Mo Lin; Hsiang-Ho Chen; Kai-Jow Tsai

2007-01-01

127

Lumbar Laminectomy and Transforaminal Lumbar Interbody Fusion  

MedlinePLUS Videos and Cool Tools

... sponge and bone marrow, or sometimes bone morphogenic protein, which is not really approved for use in ... we’re using a material called bone morphogenic protein. Now, I should spend a moment speaking about ...

128

Mid-range outcomes in 64 consecutive cases of multilevel fusion for degenerative diseases of the lumbar spine  

PubMed Central

In the treatment of multilevel degenerative disorders of the lumbar spine, spondylodesis plays a controversial role. Most patients can be treated conservatively with success. Multilevel lumbar fusion with instrumentation is associated with severe complications like failed back surgery syndrome, implant failure, and adjacent segment disease (ASD). This retrospective study examines the records of 70 elderly patients with degenerative changes or instability of the lumbar spine treated between 2002 and 2007 with spondylodesis of more than two segments. Sixty-four patients were included; 5 patients had died and one patient was lost to follow-up. We evaluated complications, clinical/radiological outcomes, and success of fusion. Flexion-extension and standing X-rays in two planes, MRI, and/or CT scans were obtained pre-operatively. Patients were assessed clinically using the Oswestry disability index (ODI) and a Visual Analogue Scale (VAS). Surgery performed was dorsolateral fusion (46.9%) or dorsal fusion with anterior lumbar interbody fusion (ALIF; 53.1%). Additional decompression was carried out in 37.5% of patients. Mean follow-up was 29.4±5.4 months. Average patient age was 64.7±4.3 years. Clinical outcomes were not satisfactory for all patients. VAS scores improved from 8.6±1.3 to 5.6±3.0 pre- to post-operatively, without statistical significance. ODI was also not significantly improved (56.1±22.3 pre- and 45.1±26.4 post-operatively). Successful fusion, defined as adequate bone mass with trabeculation at the facets and transverse processes or in the intervertebral segments, did not correlate with good clinical outcomes. Thirty-five of 64 patients (54%) showed signs of pedicle screw loosening, especially of the screws at S1. However, only 7 of these 35 (20%) complained of corresponding back pain. Revision surgery was required in 24 of 64 patients (38%). Of these, indications were adjacent segment disease (16 cases), pedicle screw loosening (7 cases), and infection (one case). At follow-up of 29.4 months, patients with radiographic ASD had worse ODI scores than patients without (54.7 vs. 36.6; P<0.001). Multilevel fusion for degenerative disease still has a high rate of complications, up to 50%. The problem of adjacent segment disease after fusion surgery has not yet been solved. This study underscores the need for strict indication guidelines to perform lumbar spine fusion of more than two levels. PMID:21808698

Röllinghoff, Marc; Schlüter-Brust, Klaus; Groos, Daniel; Sobottke, Rolf; Michael, Joern William-Patrick; Eysel, Peer; Delank, Karl Stefan

2010-01-01

129

Dissection of left iliac artery during anterior lumbar interspace fusion: Report of a case.  

PubMed

Vascular injury is an uncommon complication of spine surgery. Among the different approaches, anterior lumbar interbody fusion has increased potential for vascular injuries, since the great vessels and their branches overly the disc spaces to be operated on, and retraction of these vessels is necessary to gain adequate surgical exposure. The reported incidence for anterior lumbar interbody fusion-associated vascular injuries ranges from 0% to 18.1%, with venous laceration as the most common type. We report a case of anterior lumbar interbody fusion-associated left common iliac artery dissection leading to delayed acute limb ischemia developing in early post-operative period. PMID:24848500

Fischer, Uwe M; Davies, Mark G; Sayed, Hosam El

2015-04-01

130

Biomechanical stability of a bioabsorbable self-retaining polylactic acid/nano-sized ?-tricalcium phosphate cervical spine interbody fusion device in single-level anterior cervical discectomy and fusion sheep models  

PubMed Central

Purpose The aim of this study was to investigate the biomechanical stability provided by a novel, polylactic acid/nano-sized, ?-tricalcium phosphate, bioabsorbable, self-retaining cervical fusion cage (BCFC). Methods Quasistatic nonconstraining torques (maximum 1.5 NM) induced flexion, extension, lateral bending (±1.5 NM), and axial rotation (±1.5 NM) on 32 sheep cervical spines (C2–C5). The motion segment C3–C4 was first tested intact; the following groups were tested after complete discectomy: autologous tricortical iliac crest bone graft, Medtronic–Wego polyetheretherketone (PEEK) cage, Solis PEEK cage, and BCFC. The autologous bone graft group was tested with an anterior plate. The mean range of motion (ROM) was calculated from the load-displacement curves. Results BCFC significantly decreased ROM in lateral bending and axial rotation compared to other implants, and no significant difference in ROM between two types of PEEK cages and BCFC could be observed in flexion and extension. Anterior cervical plate (ACP) significantly decreased ROM in flexion and extension, but no significant difference in ROM between BCFC and bone graft plus ACP could be determined in lateral bending and axial rotation. Conclusion The BCFC device showed better stability to autologous tricortical iliac crest bone graft and PEEK cages in single-level anterior cervical discectomy and fusion models and thus may be a potential alternative to the current PEEK cages. PMID:23226018

Cao, Lu; Duan, Ping-Guo; Li, Xi-Lei; Yuan, Feng-Lai; Zhao, Ming-Dong; Che, Wu; Wang, Hui-Ren; Dong, Jian

2012-01-01

131

An Ecology of Text: Using Text Retrieval to Study Alife on the Net  

Microsoft Academic Search

I introduce a new alife model, an ecology based on a corpus of text, and apply it to the analysis of posts to USENET News. In this corporal ecology posts are organisms, the newsgroups of NetNews define an environment, and human posters situated in their wider context make up a scarce resource. I apply latent semantic indexing (LSI), a text

Michael L. Best

1997-01-01

132

An Ecology of Text: Using Text Retrieval to Study Alife on the Net  

Microsoft Academic Search

I introduce a new alife model, an ecology based on a corpus of text, and apply it to the analysis of posts to USENET News. In this corporal ecology posts are organisms, the newsgroups of NetNews define an environment, and human posters situated in their wider context make up a scarce resource. I apply latent semantic indexing (LSI), a text

Michael L Best

1998-01-01

133

esearchers in artificial intelligence (AI) and artificial life (Alife) are interested  

E-print Network

R esearchers in artificial intelligence (AI) and artificial life (Alife) are interested feature The relationship between matter and life Rodney Brooks Moore's law states that computational the world chess champion is a good example. The essential ideas were in place in Greenblatt's 1965 program

Brooks, Rodney

134

Construct Rigidity after Fatigue Loading in Pedicle Subtraction Osteotomy with or without Adjacent Interbody Structural Cages  

PubMed Central

Introduction?Studies document rod fracture in pedicle subtraction osteotomy (PSO) settings where disk spaces were preserved above or adjacent to the PSO. This study compares the multidirectional bending rigidity and fatigue life of PSO segments with or without interbody support. Methods?Twelve specimens received bilateral T12–S1 posterior fixation and L3 PSO. Six received extreme lateral interbody fusion (XLIF) cages in addition to PSO at L2–L3 and L3–L4; six had PSO only. Flexion-extension, lateral bending, and axial rotation (AR) tests were conducted up to 7.5 Newton-meters (Nm) for groups: (1) posterior fixation, (2) L3 PSO, (3) addition of cages (six specimens). Relative motion across the osteotomy (L2–L4) and entire fixation site (T12–S1) was measured. All specimens were then fatigue tested for 35K cycles. Results?Regardingmultiaxial bending, there was a significant 25.7% reduction in AR range of motion across L2–L4 following addition of cages. Regarding fatigue bending, dynamic stiffness, though not significant (p?=?0.095), was 22.2% greater in the PSO?+?XLIF group than in the PSO-only group. Conclusions?Results suggest that placement of interbody cages in PSO settings has a potential stabilizing effect, which is modestly evident in the acute setting. Inserting cages in a second-stage surgery remains a viable option and may benefit patients in terms of recovery but additional clinical studies are necessary to confirm this. PMID:24353970

Deviren, Vedat; Tang, Jessica A.; Scheer, Justin K.; Buckley, Jenni M.; Pekmezci, Murat; McClellan, R. Trigg; Ames, Christopher P.

2012-01-01

135

Stand-alone cage for posterior lumbar interbody fusion in the treatment of high-degree degenerative disc disease: design of a new device for an “old” technique. A prospective study on a series of 116 patients  

Microsoft Academic Search

Chronic lumbar pain due to degenerative disc disease affects a large number of people, including those of fully active age.\\u000a The usual self-repair system observed in nature is a spontaneous attempt at arthrodesis, which in most cases leads to pseudoarthrosis.\\u000a In recent years, many possible surgical fusion techniques have been introduced; PLIF is one of these. Because of the growing

Francesco Costa; Marco Sassi; Alessandro Ortolina; Andrea Cardia; Roberto Assietti; Alberto Zerbi; Martin Lorenzetti; Fabio Galbusera; Maurizio Fornari

2011-01-01

136

Proc. of the Alife XII Conference, Odense, Denmark, 2010 257 Body/Brain Co-Evolution in Soft Robots  

E-print Network

and rescue robots. Imagine, for instance, a machine that can squeeze through holes, climb up walls, and flowProc. of the Alife XII Conference, Odense, Denmark, 2010 257 Body/Brain Co-Evolution in Soft Robots 02155 rieffelj@union.edu Extended Abstract Autonomous Robots have achieved considerable results

Rieffel, John

137

Anterolateral radical debridement and interbody bone grafting combined with transpedicle fixation in the treatment of thoracolumbar spinal tuberculosis.  

PubMed

This retrospective cohort study was conducted to evaluate the clinical outcomes of radical anterolateral debridement and autogenous ilium with rib or titanium cage interbody autografting with transpedicle fixation for the treatment of thoracolumbar tuberculosis.Spinal tuberculosis operation aims to remove the lesions and necrotic tissues, remove spinal cord compression, and reconstruct spinal stability. However, traditional operation methods cannot effectively correct cyrtosis or stabilize the spine. In addition, the patient needs to stay in bed for a long time and may have many complications. So far, the best surgical method and fixation method for spinal tuberculosis remain controversial.There were a total of 43 patients, 16 involving spinal cord injury, from January 2004 to January 2011. The patients were surgically treated for radical anterolateral debridement via posterolateral incision and autogenous ilium with rib or titanium cage interbody autografting and single-stage transpedicle fixation. All the patients were followed up to determine the stages of intervertebral bone fusion and the corrections of spinal kyphosis with the restoration of neurological deficit.The erythrocyte sedimentation rate (ESR) of these patients decreased to normal levels for a mean of 2.8 months. The function of feeling, motion, and sphincter in 16 paraplegia cases gradually recovered after 1 week to 3 months postoperatively, and the American Spinal Injury Association scores significantly increased at the final follow-up. Intervertebral bone fusions were all achieved postoperatively. No internal fixation devices were loose, extracted, or broken. There was no correction degree loss during the follow-up.The method of radical anterolateral debridement and autogenous ilium with rib or titanium cage interbody autografting and single-stage transpedicle fixation was effective for the treatment of thoracolumbar tuberculosis, correcting kyphotic deformity, and reconstructing spinal stability, obtaining successful intervertebral bony fusion and promoting the recovery of paraplegia. These results showed satisfactory clinical outcomes. PMID:25860219

Cheng, Zhaohui; Wang, Jian; Zheng, Qixin; Wu, Yongchao; Guo, Xiaodong

2015-04-01

138

Fusion  

NASA Astrophysics Data System (ADS)

The book abounds with fascinating anecdotes about fusion's rocky path: the spurious claim by Argentine dictator Juan Peron in 1951 that his country had built a working fusion reactor, the rush by the United States to drop secrecy and publicize its fusion work as a propaganda offensive after the Russian success with Sputnik; the fortune Penthouse magazine publisher Bob Guccione sank into an unconventional fusion device, the skepticism that met an assertion by two University of Utah chemists in 1989 that they had created "cold fusion" in a bottle. Aimed at a general audience, the book describes the scientific basis of controlled fusion--the fusing of atomic nuclei, under conditions hotter than the sun, to release energy. Using personal recollections of scientists involved, it traces the history of this little-known international race that began during the Cold War in secret laboratories in the United States, Great Britain and the Soviet Union, and evolved into an astonishingly open collaboration between East and West.

Herman, Robin

1990-10-01

139

Fusion  

NASA Astrophysics Data System (ADS)

The process in which two lighter atomic nuclei are combined to form a heavier atomic nucleus. Very high temperatures are normally required in order for atomic nuclei to collide with sufficient energy to overcome their mutual electrostatic repulsions (each atomic nucleus has a positive charge, the magnitude of which depends on the number of protons it contains). Fusion that occurs under high-tempe...

Murdin, P.

2000-11-01

140

Instrumentation in lumbar fusion improves back pain but not quality of life 2 years after surgery  

PubMed Central

Background and purpose Instrumented and non-instrumented methods of fusion have been compared in several studies, but the results are often inconsistent and conflicting. We compared the 2-year results of 3 methods of lumbar fusion when used in degenerative disc disease (DDD), using the Swedish Spine Register (SWESPINE). Methods All patients registered in SWESPINE for surgical treatment of DDD between January 1, 2000 and October 1, 2007 were eligible for the study. Patients who had completed the 2-year follow-up were included in the analysis. The outcomes of 3 methods of surgical fusion were assessed. Results Of 1,310 patients enrolled, 115 had undergone uninstrumented fusion, 620 instrumented posterolateral fusion, and 575 instrumented interbody fusion. Irrespective of the surgical procedure, quality of life (QoL) improved and back pain diminished. Change in QoL and functional disability and return to work was similar in the 3 groups. Patients who had undergone uninstrumented fusion had more back pain than the patients with instrumented interbody fusion at the 2-year follow-up (p = 0.02), although the difference was only 7 visual analog scale (VAS) units (95% CI: 1–13) on a 100-point scale. Moreover, 83% of the patients with uninstrumented fusion used analgesics at the end of follow-up as compared to 68% of the patients who had undergone surgery with one of the 2 instrumented fusion techniques. Interpretation In comparison with instrumented interbody fusion, uninstrumented fusion was associated with higher levels of back pain 2 years after surgery. We found no evidence for differences in QoL between uninstrumented fusion and instrumented interbody fusion. PMID:23368746

2013-01-01

141

An ecology of text: using text retrieval to study alife on the net.  

PubMed

I introduce a new alife model, an ecology based on a corpus of text, and apply it to the analysis of posts to USENET News. In this corporal ecology posts are organisms, the newsgroups of NetNews define an environment, and human posters situated in their wider context make up a scarce resource. I apply latent semantic indexing (LSI), a text retrieval method based on principal component analysis, to distill from the corpus those replicating units of text. LSI arrives at suitable replicators because it discovers word co-occurrences that segregate and recombine with appreciable frequency. I argue that natural selection is necessarily in operation because sufficient conditions for its occurrence are met: replication, mutagenicity, and trait/fitness covariance. I describe a set of experiments performed on a static corpus of over 10,000 posts. In these experiments I study average population fitness, a fundamental element of population ecology. My study of fitness arrives at the unhappy discovery that a flame-war, centered around an overly prolific poster, is the king of the jungle. PMID:9654782

Best, M L

1997-01-01

142

Midline lumbar fusion with cortical bone trajectory screw.  

PubMed

A novel cortical bone trajectory (CBT) screw technique provides an alternative fixation technique for lumbar spine. Trajectory of CBT screw creates a caudo-cephalad path in sagittal plane and a medio-lateral path in axial plane, and engages cortical bone in the pedicle. The theoretical advantage is that it provides enhanced screw grip and interface strength. Midline lumbar fusion (MIDLF) is composed of posterior midline approach, microsurgical laminectomy, and CBT screw fixation. We adopted the MIDLF technique for lumbar spondylolisthesis. Advantages of this technique include that decompression and fusion are available in the same field, and it minimizes approach-related damages. To determine whether MIDLF with CBT screw is as effective as traditional approach and it is minimum invasive technique, we studied the clinical and radiological outcomes of MIDLF. Our results indicate that MIDLF is effective and minimum invasive technique. Evidence of effectiveness of MIDLF is that patients had good recovery score, and that CBT screw technique was safety in clinical and stable in radiological. MIDLF with CBT screw provides the surgeon with additional options for fixation. This technique is most likely to be useful for treating lumbar spondylolisthesis in combination with midline decompression and insertion of an interbody graft, such as the transforaminal lumbar interbody fusion or posterior lumbar interbody fusion techniques. PMID:25169139

Mizuno, Masaki; Kuraishi, Keita; Umeda, Yasuyuki; Sano, Takanori; Tsuji, Masanori; Suzuki, Hidenori

2014-01-01

143

Injury of the right and left inferior epigastric artery during the implantation of a stand-alone ALIF cage through a left retroperitoneal approach: a case report  

Microsoft Academic Search

Various perioperative vascular complications of anterior lumbar spine procedures have been described in orthopaedic literature.\\u000a We report the unusual case of a perioperative bleeding from the right and left epigastric inferior artery occurring when using\\u000a a stand-alone ALIF device (Synfix, Synthes, Oberdorf, Switzerland) at the L5\\/S1 level through an anterior left retroperitoneal\\u000a approach. The primary stability of the Synfix is

Martin Thaler; E. Mayr; M. Liebensteiner; C. M. Bach

2010-01-01

144

Biomechanical evaluation of a spherical lumbar interbody device at varying levels of subsidence  

PubMed Central

Background Ulf Fernström implanted stainless steel ball bearings following discectomy, or for painful disc disease, and termed this procedure disc arthroplasty. Today, spherical interbody spacers are clinically available, but there is a paucity of associated biomechanical testing. The primary objective of the current study was to evaluate the biomechanics of a spherical interbody implant. It was hypothesized that implantation of a spherical interbody implant, with combined subsidence into the vertebral bodies, would result in similar ranges of motion (RoM) and facet contact forces (FCFs) when compared with an intact condition. A secondary objective of this study was to determine the effect of using a polyetheretherketone (PEEK) versus a cobalt chrome (CoCr) implant on vertebral body strains. We hypothesized that the material selection would have a negligible effect on vertebral body strains since both materials have elastic moduli substantially greater than the annulus. Methods A finite element model of L3-L4 was created and validated by use of ROM, disc pressure, and bony strain from previously published data. Virtual implantation of a spherical interbody device was performed with 0, 2, and 4 mm of subsidence. The model was exercised in compression, flexion, extension, axial rotation, and lateral bending. The ROM, vertebral body effective (von Mises) strain, and FCFs were reported. Results Implantation of a PEEK implant resulted in slightly lower strain maxima when compared with a CoCr implant. For both materials, the peak strain experienced by the underlying bone was reduced with increasing subsidence. All levels of subsidence resulted in ROM and FCFs similar to the intact model. Conclusions The results suggest that a simple spherical implant design is able to maintain segmental ROM and provide minimal differences in FCFs. Large areas of von Mises strain maxima were generated in the bone adjacent to the implant regardless of whether the implant was PEEK or CoCr.

Rundell, Steven A.; Isaza, Jorge E.; Kurtz, Steven M.

2011-01-01

145

Biomechanical effect of anterior cervical spine fusion on adjacent segments.  

PubMed

The biomechanical effects of superior (C4-C5) and inferior (C5-C6) level fusions with different graft materials on the adjacent unaltered components were quantified using an anatomically accurate and experimentally validated C4-C5-C6 finite element model. Smith-Robinson and Bailey-Badgley fusion procedures were analyzed with five different types of inter-body fusion materials with varying stiffnesses. Intact and surgically altered finite element models were subjected to physiologic compression, flexion, extension and lateral bending. The external axial and angular stiffness, and the internal unaltered intervertebral disc (C5-C6 for the superior and C4-C5 for inferior fusion) and C5 vertebral body stresses were determined. The superior level fusion resulted in the highest increase in external response in lateral bending for all implant materials in both surgical procedures. In contrast, the inferior level fusion produced a higher increase in the C4-C5 disc and C5 vertebral body stresses in compression than the superior level fusion in both surgical procedures. The increased internal stress responses reflecting the changes in the load-sharing following inferior level fusion may explain clinical observations such as enhanced degeneration subsequent to surgery. Because of the inclusion of three levels in the present multi-segment finite element model, it was possible to determine these responses in the unaltered adjacent components of the cervical spine. PMID:10436851

Maiman, D J; Kumaresan, S; Yoganandan, N; Pintar, F A

1999-01-01

146

Transforaminal Lumbar Interbody Fusion Using a Modified Distractor Handle: A Midterm Clinicoradiological Follow-Up Study  

PubMed Central

In current TLIF practice, the choice of the cage size is empirical and primarily depends on the case volume and experience of the surgeon. We used a self-made modified distractor handle in TLIF procedure with the goal of standardizing the intervertebral space tension and determining the proper cage size. PMID:24089692

Rewuti, Abuduaini; Chen, Zixian; Feng, Zhenzhou; Cao, Yuanwu; Jiang, Xiaoxing; Jiang, Chun

2013-01-01

147

Adjacent Lumbar Disc Herniation after Lumbar Short Spinal Fusion  

PubMed Central

A 70-year-old outpatient presented with a chief complaint of sudden left leg motor weakness and sensory disturbance. He had undergone L4/5 posterior interbody fusion with L3–5 posterior fusions for spondylolisthesis 3 years prior, and the screws were removed 1 year later. He has been followed up for 3 years, and there had been no adjacent segment problems before this presentation. Lumbar magnetic resonance imaging (MRI) showed a large L2/3 disc hernia descending to the L3/4 level. Compared to the initial MRI, this hernia occurred in an “intact” disc among multilevel severely degenerated discs. Right leg paresis and bladder dysfunction appeared a few days after admission. Microscopic lumbar disc herniotomy was performed. The right leg motor weakness improved just after the operation, but the moderate left leg motor weakness and difficulty in urination persisted. PMID:25276453

Iwatsuki, Koichi; Ohnishi, Yu-ichiro; Yoshimine, Toshiki

2014-01-01

148

Adjacent lumbar disc herniation after lumbar short spinal fusion.  

PubMed

A 70-year-old outpatient presented with a chief complaint of sudden left leg motor weakness and sensory disturbance. He had undergone L4/5 posterior interbody fusion with L3-5 posterior fusions for spondylolisthesis 3 years prior, and the screws were removed 1 year later. He has been followed up for 3 years, and there had been no adjacent segment problems before this presentation. Lumbar magnetic resonance imaging (MRI) showed a large L2/3 disc hernia descending to the L3/4 level. Compared to the initial MRI, this hernia occurred in an "intact" disc among multilevel severely degenerated discs. Right leg paresis and bladder dysfunction appeared a few days after admission. Microscopic lumbar disc herniotomy was performed. The right leg motor weakness improved just after the operation, but the moderate left leg motor weakness and difficulty in urination persisted. PMID:25276453

Ninomiya, Koshi; Iwatsuki, Koichi; Ohnishi, Yu-Ichiro; Ohkawa, Toshika; Yoshimine, Toshiki

2014-01-01

149

National trends in revision spinal fusion in the USA: patient characteristics and complications.  

PubMed

Using the United States Nationwide Inpatient Sample, we identified national trends in revision spinal fusion along with a comprehensive comparison of comorbidities, inpatient complications and surgical factors of revision spinal fusion compared to primary spinal fusion. In 2009, there were 410 158 primary spinal fusion discharges and 22 128 revision spinal fusion discharges. Between 2002 and 2009, primary fusion increased at a higher rate compared with revision fusion (56.4% vs 51.0%; p < 0.001). In 2009, the mean length of stay and hospital charges were higher for revision fusion discharges than for primary fusion discharges (4.2 days vs 3.8 days, p < 0.001; USD $91 909 vs. $87 161, p < 0.001). In 2009, recombinant human bone morphogenetic protein (BMP) was used more in revision fusion than in primary fusion (39.6% vs 27.6%, p < 0.001), whereas interbody devices were used less in revision fusion (41.8% vs 56.6%, p < 0.001). In the multivariable logistic regression model for all spinal fusions, depression (odds ratio (OR) 1.53, p < 0.001), psychotic disorders (OR 1.49, p < 0.001), deficiency anaemias (OR 1.35, p < 0.001) and smoking (OR 1.10, p = 0.006) had a greater chance of occurrence in revision spinal fusion discharges than in primary fusion discharges, adjusting for other variables. In terms of complications, after adjusting for all significant comorbidities, this study found that dural tears (OR 1.41; p < 0.001) and surgical site infections (OR 3.40; p < 0.001) had a greater chance of occurrence in revision spinal fusion discharges than in primary fusion discharges (p < 0.001). A p-value < 0.01 was considered significant in all final analyses. PMID:24891583

Rajaee, S S; Kanim, L E A; Bae, H W

2014-06-01

150

Epidemiologic trends in the utilization, demographics, and cost of bone morphogenetic protein in spinal fusions.  

PubMed

Bone morphogenetic protein (BMP) utilization as an adjunct for spinal arthrodesis has gained considerable momentum among spine surgeons. Despite carrying Food and Drug Administration approval for only single level anterior lumbar interbody fusion from L4-S1, the majority of BMP administration is in "off label" settings. Over the last decade, BMP utilization has increased in all facets of spine surgery with the only exception being the anterior cervical spine, in which a downward trend resulted following the 2008 Food and Drug Administration warnings. The future application of BMP in spinal fusion, especially in anterior cervical fusions, will need to be further clarified in terms of efficacy, complications, and cost-effectiveness. PMID:24903375

Louie, Philip K; Hassanzadeh, Hamid; Singh, Kern

2014-09-01

151

Delayed perforation of posterior pharyngeal wall caused by dislodged bioresorbable interbody cage. Case report.  

PubMed

A 48-year-old man was admitted for the management of congenital anomalies: Arnold-Chiari type I malformation combined with odontoid upward migration. He also had degenerative stenosis of the spinal canal by spurs at C2/C3 and C3/C4 levels. Osseous deformities caused ischaemic changes of the brainstem as well as spinal cord compression. Authors used the Biocage - interbody cage covered by bioresorbable layer to fill the surgically created gap after removal of the right part of C3 vertebral body. Twenty-seven months after implantation, the implant was extruded through posterior pharyngeal wall. Authors describe this unusual case and discuss possible causes of Biocage extrusion. PMID:24821644

Zapa?owicz, Krzysztof; Radek, Maciej; Wojdyn, Maciej; Pietkiewicz, Piotr; Olszewski, Jurek

2014-01-01

152

Nuclear fusion  

Microsoft Academic Search

The advantages of nuclear fusion as an energy source and research progress in this area are summarized. The current state of the art is described. Laser fusion, inertial confinement fusion, and magnetic fusion (the tokamak) are explained, the latter in some detail. Remaining problems and planned future reactors are considered. They are the Compact Ignition Tokamak (CIT), the International Thermonuclear

T. K. Fowler

1989-01-01

153

Extreme multi-level anterior cervical discectomy and fusion.  

PubMed

The use of anterior cervical discectomy and fusion (ACDF) is a common procedure used to treat those who suffer from degenerative disc disease (DDD) of the cervical spine which may result in spondylolisthesis, spinal stenosis, disc herniation, nerve root and/or cord compression. ACDF is regularly used for the fusion of one to four cervical spine levels; however, the literature documenting the fusion of 5 or 6 levels is surprisingly lacking. In this retrospective review of our case series, we document two 5-level and two 6-level ACDF in elderly patients using custom made titanium fusion plates and patellar allograft bone for interbody placement without posterior fixation. The documentation of these long anterior constructs without supplemental posterior fixation or the use of a halo vest apparatus, but a simple neck collar for three months, is an important contribution to the literature illustrating that with utilization of appropriate technique, a high number of levels can be safely fused in the elderly patients necessitating this particular procedure. PMID:23957113

Morgan, Jeremy P; Asfora, Wilson T

2013-07-01

154

Complication with Removal of a Lumbar Spinal Locking Plate  

PubMed Central

Introduction. The use of locking plate technology for anterior lumbar spinal fusion has increased stability of the vertebral fusion mass over traditional nonconstrained screw and plate systems. This case report outlines a complication due to the use of this construct. Case. A patient with a history of L2 corpectomy and anterior spinal fusion presented with discitis at the L4/5 level and underwent an anterior lumbar interbody fusion (ALIF) supplemented with a locking plate placed anterolaterally for stability. Fifteen months after the ALIF procedure, he returned with a hardware infection. He underwent debridement of the infection site and removal of hardware. Results. Once hardware was exposed, removal of the locking plate screws was only successful in one out of four screws using a reverse thread screw removal device. Three of the reverse thread screw removal devices broke in attempt to remove the subsequent screws. A metal cutting drill was then used to break hoop stresses associated with the locking device and the plate was removed. Conclusion. Anterior locking plates add significant stability to an anterior spinal fusion mass. However, removal of this hardware can be complicated by the inherent properties of the design with significant risk of major vascular injury. PMID:25838956

Crawford, Brooke; Lenarz, Christopher; Watson, J. Tracy; Alander, Dirk

2015-01-01

155

Complication with removal of a lumbar spinal locking plate.  

PubMed

Introduction. The use of locking plate technology for anterior lumbar spinal fusion has increased stability of the vertebral fusion mass over traditional nonconstrained screw and plate systems. This case report outlines a complication due to the use of this construct. Case. A patient with a history of L2 corpectomy and anterior spinal fusion presented with discitis at the L4/5 level and underwent an anterior lumbar interbody fusion (ALIF) supplemented with a locking plate placed anterolaterally for stability. Fifteen months after the ALIF procedure, he returned with a hardware infection. He underwent debridement of the infection site and removal of hardware. Results. Once hardware was exposed, removal of the locking plate screws was only successful in one out of four screws using a reverse thread screw removal device. Three of the reverse thread screw removal devices broke in attempt to remove the subsequent screws. A metal cutting drill was then used to break hoop stresses associated with the locking device and the plate was removed. Conclusion. Anterior locking plates add significant stability to an anterior spinal fusion mass. However, removal of this hardware can be complicated by the inherent properties of the design with significant risk of major vascular injury. PMID:25838956

Crawford, Brooke; Lenarz, Christopher; Watson, J Tracy; Alander, Dirk

2015-01-01

156

Fusion Basics  

NSDL National Science Digital Library

This website from the Princeton Plasma Physics Laboratory provides background information about fusion. Different sections cover fusion reactions, plasma heating, and how a fusion power plant would work. In addition, the site offers links to research projects at the Princeton Plasma Physics Laboratory.

157

Anterior cervical interbody constructs: effect of a repetitive compressive force on the endplate.  

PubMed

Graft subsidence following anterior cervical reconstruction can result in the loss of sagittal balance and recurring foraminal stenosis. This study examined the implant-endplate interface using a cyclic fatigue loading protocol in an attempt to model the subsidence seen in vivo. The superior endplate from 30 cervical vertebrae (C3 to T1) were harvested and biomechanically tested in axial compression with one of three implants: Fibular allograft; titanium mesh cage packed with cancellous chips; and trabecular metal. Each construct was cyclically loaded from 50 to 250?N for 10,000 cycles. Nondestructive cyclic loading of the cervical endplate-implant construct resulted in a stiffer construct independent of the type of the interbody implant tested. The trabecular metal construct demonstrated significantly more axial stability and significantly less subsidence in comparison to the titanium mesh construct. Although the allograft construct resulted in more subsidence than the trabecular metal construct, the difference was not significant and no difference was found when comparing axial stability. For all constructs, the majority of the subsidence during the cyclic testing occurred during the first 500 cycles and was followed by a more gradual settling in the remaining 9,500 cycles. PMID:22002745

Ordway, Nathaniel R; Rim, Byeong Cheol; Tan, Rong; Hickman, Rebecca; Fayyazi, Amir H

2012-04-01

158

Single level Lumbar Fusion for Degenerative Disc Disease is Associated with Worse outcomes compared to Fusion for Spondylolisthesis in a Workers' Compensation Setting.  

PubMed

Study Design. Retrospective cohort studyObjective. Compare lumbar fusion outcomes, return to work (RTW) status in particular, between workers' compensation (WC) subjects undergoing single level posterolateral fusion for either spondylolisthesis or degenerative disc disease (DDD)Summary of Background Data. Lumbar fusion for spondylolisthesis tends to yield more consistent outcomes than fusion for DDD and discogenic low back pain. Within the clinically distinct WC population, relatively few studies exist which evaluate lumbar fusion outcomes.Methods. 869 Ohio WC subjects were identified that underwent single level posterolateral lumbar fusion with or without posterior interbody fusion between 1993-2010 using CPT procedural and ICD-9 diagnostic codes. 269 underwent fusion for spondylolisthesis, and 620 of underwent fusion for DDD.Subjects were considered returned to work within a reasonable timeline if they made a stable RTW within 2 years of fusion and remained working for greater than 6 months of the following year. To determine predictors of RTW status, we performed a multivariate logistic regression analysis. We measured a number of secondary outcomes.Results. Fusion for spondylolisthesis was positively associated with RTW status (p = 0.050; OR 1.42,CI 1.00-2.00). 36.4% of the spondylolisthesis cohort and 24.4% of the DDD cohort returned to work in a reasonable timeline postoperatively.Other negative predictors included: age >50 at fusion (OR 0.66,CI 0.45-0.95), >2 years between injury and index fusion (OR 0.59,CI 0.41-0.84), permanent disability (OR 0.61,CI 0.43-0.86), legal representation (OR 0.67,CI 0.46-0.97), and psychological comorbidity before fusion (OR 0.30,CI 0.14-0.62).Subjects in the DDD cohort were prescribed opioid analgesics for an average of 294 of additional days postoperatively (p<0.001), which equated to 24,759 additional milligrams of morphine equivalents (p<0.001).Conclusions. Our study is supportive of the conclusion that DDD is a questionable indication for spinal fusion. Given the generally poor outcomes of this study, future studies should determine if lumbar fusion surgery is an effective treatment modality in similar WC patients. PMID:25494321

Anderson, Joshua T; Haas, Arnold R; Percy, Rick; Woods, Stephen T; Ahn, Uri M; Ahn, Nicholas U

2014-12-01

159

Structural analysis of the intervertebral discs adjacent to an interbody fusion using multibody dynamics and finite element cosimulation  

Microsoft Academic Search

This work describes a methodology for the dynamic and structural analysis of complex (bio)mechanical systems that joins both\\u000a multibody dynamics and finite element domains, in a synergetic way, through a cosimulation procedure that takes benefit of\\u000a the advantages of each numerical formulation. To accomplish this goal, a cosimulation module is developed based on the gluing\\u000a algorithm X-X, which is the

Nuno Miguel Barroso Monteiro; Miguel Pedro Tavares da Silva; João Orlando Marques Gameiro Folgado; João Pedro Levy Melancia

2011-01-01

160

Changes in Neuroforaminal Height with 2 Level Axial Presacral Lumbar Interbody Fusion at L4-S1  

PubMed Central

Background The objective was to examine the changes in neuroforaminal height at L4-L5 and L5-S1 after insertion and graduated foraminal distraction using the 2 level transsacral implant in a cadaveric model. Methods Discectomy and transsacral instrumentation was performed in six fresh human cadavers at L4-S1. The neuroforaminal height was measured at L4-L5 and L5-S1 before and after insertion of the implant and then at each stage of manual distraction. Results Mean L4-5 neuroforaminal height increased from 18.2 ± 3.1mm to 20.3± 2.9mm (11%) on the left and from 18.8±2.8mm to 20.6± 2.3mm (12%) on the right (P<0.05). Mean L5-S1 neuroforaminal height increased from 15.7±3.0mm to 18.4 ±2.8mm (17%) on the left and from 15.6 ±2.1mm to 18.3 ±1.8mm (17%) on the right (P<0.05). When the neuroforaminal height was plotted against amount of rotation of the screw driver it was found that the neuroforaminal height at L5-S1 increased by 1mm on average for every complete revolution of the screw driver. At least 2 full rotations of the screw driver were achieved in all cadavers. Conclusions The transsacral screw construct distracted the disc space and neuroforaminal height in a cadaveric spine model without soft tissue envelope. During the initial process, manual control of disc space distraction predictably correlated with the increase in the neuroforaminal height to a maximum. However, further research is needed to look at variables affecting disc space pliability, implant subsidence, in vivo application, and clinical benefit of this procedure. PMID:25694937

Marawar, Satyajit; Jung, Jin; Sun, Mike

2014-01-01

161

Fusion breeder  

SciTech Connect

The fusion breeder is a fusion reactor designed with special blankets to maximize the transmutation by 14 MeV neutrons of uranium-238 to plutonium or thorium to uranium-233 for use as a fuel for fission reactors. Breeding fissile fuels has not been a goal of the US fusion energy program. This paper suggests it is time for a policy change to make the fusion breeder a goal of the US fusion program and the US nuclear energy program. The purpose of this paper is to suggest this policy change be made and tell why it should be made, and to outline specific research and development goals so that the fusion breeder will be developed in time to meet fissile fuel needs.

Moir, R.W.

1982-02-22

162

Fusion breeder  

SciTech Connect

The fusion breeder is a fusion reactor designed with special blankets to maximize the transmutation by 14 MeV neutrons of uranium-238 to plutonium or thorium to uranium-233 for use as a fuel for fission reactors. Breeding fissile fuels has not been a goal of the US fusion energy program. This paper suggests it is time for a policy change to make the fusion breeder a goal of the US fusion program and the US nuclear energy program. The purpose of this paper is to suggest this policy change be made and tell why it should be made, and to outline specific research and development goals so that the fusion breeder will be developed in time to meet fissile fuel needs.

Moir, R.W.

1982-04-20

163

Fusion Implementation  

SciTech Connect

If a fusion DEMO reactor can be brought into operation during the first half of this century, fusion power production can have a significant impact on carbon dioxide production during the latter half of the century. An assessment of fusion implementation scenarios shows that the resource demands and waste production associated with these scenarios are manageable factors. If fusion is implemented during the latter half of this century it will be one element of a portfolio of (hopefully) carbon dioxide limiting sources of electrical power. It is time to assess the regional implications of fusion power implementation. An important attribute of fusion power is the wide range of possible regions of the country, or countries in the world, where power plants can be located. Unlike most renewable energy options, fusion energy will function within a local distribution system and not require costly, and difficult, long distance transmission systems. For example, the East Coast of the United States is a prime candidate for fusion power deployment by virtue of its distance from renewable energy sources. As fossil fuels become less and less available as an energy option, the transmission of energy across bodies of water will become very expensive. On a global scale, fusion power will be particularly attractive for regions separated from sources of renewable energy by oceans.

J.A. Schmidt

2002-02-20

164

Technology Fusion  

Microsoft Academic Search

Technology fusion involves the combination and transformation of a number of different core technologies in order to create new product markets. The key element of technology fusion is that it is both complementary and cooperative. Typically, it is the result of reciprocal and substantial R&D expenditure by companies from a range of industries and with different technological competences. For example,

J. Tidd; T. Sammut-Bonnici

2014-01-01

165

Laser fusion  

Microsoft Academic Search

Unrestricted laser fusion offers nations an opportunity to circumvent arms control agreements and develop thermonuclear weapons. Early laser weapons research sought a clean radiation-free bomb to replace the fission bomb, but this was deceptive because a fission bomb was needed to trigger the fusion reaction and additional radioactivity was induced by generating fast neutrons. As laser-implosion experiments focused on weapons

W. A. Smit; P. Boskma

1980-01-01

166

Fusion Power.  

ERIC Educational Resources Information Center

Discusses the extraordinary potential, the technical difficulties, and the financial problems that are associated with research and development of fusion power plants as a major source of energy. (GA)

Dingee, David A.

1979-01-01

167

Fusion Simulation  

NSDL National Science Digital Library

In this activity, kids are able to see with their own eyes how fusion works. The simple experiment requires only Velcro and two strong magnets.The activity begins with a brief overview that introduces students to the science they are about to see. Then, the procedure is laid out in simple step-by-step directions. The activity ends with an explanation that gives students a deeper understanding of how what they've just witnessed relates to fusion.

168

Cell fusion.  

PubMed

Selective cell fusion is a natural part of development. It is found in sexually reproducing organisms that require fertilization to propagate and in muscles, placenta, bones, lens of the eye and stem cells. Cell fusion is particularly important in the development of C. elegans: in addition to 300 sperm and oocytes that fuse during fertilization, 300 of the 1090 somatic cells born, fuse throughout development. Studies of cell fusion in C. elegans have shown that although different types of cells fuse, cell membrane merger is initiated through a common mechanism involving the action of one gene, eff-1. In worms with mutations that inactivate eff-1, almost none of the 300 somatic cells that normally fuse do so, but appear to differentiate, attach and behave in the same way as fusing cells. Such worms develop and survive but have numerous morphological, behavioral and fertility defects associated to cell fusion failure in the epidermis, pharynx, male tail, vulva and uterus. Cell fusion in embryonic dorsal epithelial cells has been analyzed in great detail by confocal microscopy using membrane fluorescent probes, apical junction markers and cytoplasmic aqueous fluorescent probes allowing the direct observation of membrane disappearance, pore expansion and cytoplasmic content mixing. The complete elimination of the membranes between two fusing cells takes about 30 min and involves vesiculation of the fusing membranes. Genetic and cell biological evidence indicates that eff-1 activity is both necessary and sufficient to fuse epithelial and myoepithelial cells in vivo. Based on electron microscopic analyses of intermediates of cell fusion in eff-1 mutants, it appears that eff-1 is required for both initiation and expansion of fusion pores, similar to the fusogen of Influenza virus. While only one gene encoding a novel candidate component of the cell membrane fusion machinery has been found, the nematode's cell fusion program is under the control of many cell-specific transcriptional regulators. A large number of these conserved regulators prevent cell fusion by repressing eff-1 activity. For example, if either ceh-16/engrailed or the GATA factor EGL-18/ELT-5 is inactivated, the lateral epidermal cells that normally do not fuse in the embryo will fuse causing embryonic lethality. And if either the Hox protein lin-39/Deformed or its cofactor ceh-20/Extradenticle is inactivated, the ventral epidermal vulval precursor cells that normally do not fuse in the larvae will fuse and the hermaphrodite will have no vulva. In addition, there is evidence for coordinated and complex regulation of lin-39 in the ventral epidermis by Ras, Wnt, Rb/E2F, NuRD and lin-15 pathways. It appears that in many cells that normally do not fuse, specific transcription complexes repress eff-1 expression preventing cell fusion. ref-2 (REgulator of Fusion-2) encodes a Zn-finger protein that is required to generate ventral Pn.p cells and to keep them unfused both in males and hermaphrodites. ref-2 is necessary, but not sufficient, to maintain Pn.p cells unfused. This review shows that far from cell fusion being an unusual phenomenon, there is the clear prospect that animal cells in all tissues are intrinsically programmed to fuse, and are only prevented from fusing by transcriptional and post-transcriptional control mechanisms. There are three major questions that remain open for future research: (1) How does eff-1 fuse cells? (2) How do Ras, Wnt, Rb, NuRD, E2F, heterochronic and other pathways control cell fusion? (3) What are the implications of cell fusion beyond worms? PMID:18050486

Podbilewicz, Benjamin

2006-01-01

169

Pedicle-Screw-Based Dynamic Systems and Degenerative Lumbar Diseases: Biomechanical and Clinical Experiences of Dynamic Fusion with Isobar TTL  

PubMed Central

Dynamic systems in the lumbar spine are believed to reduce main fusion drawbacks such as pseudarthrosis, bone rarefaction, and mechanical failure. Compared to fusion achieved with rigid constructs, biomechanical studies underlined some advantages of dynamic instrumentation including increased load sharing between the instrumentation and interbody bone graft and stresses reduction at bone-to-screw interface. These advantages may result in increased fusion rates, limitation of bone rarefaction, and reduction of mechanical complications with the ultimate objective to reduce reoperations rates. However published clinical evidence for dynamic systems remains limited. In addition to providing biomechanical evaluation of a pedicle-screw-based dynamic system, the present study offers a long-term (average 10.2 years) insight view of the clinical outcomes of 18 patients treated by fusion with dynamic systems for degenerative lumbar spine diseases. The findings outline significant and stable symptoms relief, absence of implant-related complications, no revision surgery, and few adjacent segment degenerative changes. In spite of sample limitations, this is the first long-term report of outcomes of dynamic fusion that opens an interesting perspective for clinical outcomes of dynamic systems that need to be explored at larger scale. PMID:25031874

Barrey, Cédric; Perrin, Gilles; Champain, Sabina

2013-01-01

170

Characteristics of Back Muscle Strength in Patients with Scheduled for Lumbar Fusion Surgery due to Symptomatic Lumbar Degenerative Diseases  

PubMed Central

Study Design Cross sectional study. Purpose To evaluate characteristics of back muscle strength in patients scheduled for lumbar fusion surgery. Overview of Literature Little is known regarding muscle strength in patients with symptomatic lumbar degenerative diseases who require fusion surgery. Methods Consecutive 354 patients scheduled for posterior lumbar interbody fusion due to symptomatic degenerative diseases were approached for participation. 316 patients were enrolled. Before surgery, muscle strength was assessed by measuring maximal isometric extension strength at seven angular positions (0°, 12°, 24°, 36°, 48°, 60°, and 72°) and mean isometric strength was calculated. The Oswestry Disability Index (0-100) and visual analogue scale (0-100) for back pain were recorded. Muscle strength was compared according to gender, age (<60, 60-70, and ?70 years) and scheduled fusion level (short, <3; long, ?3). Results Isometric strength was significantly decreased compared with previously reported results of healthy individuals, particularly at extension positions (0°-48°, p<0.05). Mean isometric strength was significantly lower in females (p<0.001) and older patients (p<0.05). Differences of isometric strength between short and long level fusion were not significantly different (p>0.05). Isometric strengths showed significant, but weak, inverse correlations with age and Oswestry Disability Index (r<0.4, p<0.05). Conclusions In patients with symptomatic lumbar degenerative diseases, back muscle strength significantly decreased, particularly at lumbar extension positions, and in females and older patients. PMID:25346820

Park, Won Hah; Lee, Chong Suh; Kang, Kyung Chung

2014-01-01

171

Cost-utility analysis of posterior minimally invasive fusion compared with conventional open fusion for lumbar spondylolisthesis  

PubMed Central

Background The utility and cost of minimally invasive surgical (MIS) fusion remain controversial. The primary objective of this study was to compare the direct economic impact of 1- and 2-level fusion for grade I or II degenerative or isthmic spondylolisthesis via an MIS technique compared with conventional open posterior decompression and fusion. Methods A retrospective cohort study was performed by use of prospective data from 78 consecutive patients (37 with MIS technique by 1 surgeon and 41 with open technique by 3 surgeons). Independent review of demographic, intraoperative, and acute postoperative data was performed. Oswestry disability index (ODI) and Short Form 36 (SF-36) values were prospectively collected preoperatively and at 1 year postoperatively. Cost-utility analysis was performed by use of in-hospital micro-costing data (operating room, nursing, imaging, laboratories, pharmacy, and allied health cost) and change in health utility index (SF-6D) at 1 year. Results The groups were comparable in terms of age, sex, preoperative hemoglobin, comorbidities, and body mass index. Groups significantly differed (P < .01) regarding baseline ODI and SF-6D scores, as well as number of 2-level fusions (MIS, 12; open, 20) and number of interbody cages (MIS, 45; open, 14). Blood loss (200 mL vs 798 mL), transfusions (0% vs 17%), and length of stay (LOS) (6.1 days vs 8.4 days) were significantly (P < .01) lower in the MIS group. Complications were also fewer in the MIS group (4 vs 12, P < .02). The mean cost of an open fusion was 1.28 times greater than that of an MIS fusion (P = .001). Both groups had significant improvement in 1-year outcome. The changes in ODI and SF-6D scores were not statistically different between groups. Multivariate regression analysis showed that LOS and number of levels fused were independent predictors of cost. Age and MIS were the only predictors of LOS. Baseline outcomes and MIS were predictors of 1-year outcome. Conclusion MIS posterior fusion for spondylolisthesis does reduce blood loss, transfusion requirements, and LOS. Both techniques provided substantial clinical improvements at 1 year. The cost utility of the MIS technique was considered comparable to that of the open technique. Level of Evidence Level III.

Rampersaud, Y. Raja; Gray, Randolph; Lewis, Steven J.; Massicotte, Eric M.; Fehlings, Michael G.

2011-01-01

172

Current strategies for the restoration of adequate lordosis during lumbar fusion  

PubMed Central

Not restoring the adequate lumbar lordosis during lumbar fusion surgery may result in mechanical low back pain, sagittal unbalance and adjacent segment degeneration. The objective of this work is to describe the current strategies and concepts for restoration of adequate lordosis during fusion surgery. Theoretical lordosis can be evaluated from the measurement of the pelvic incidence and from the analysis of spatial organization of the lumbar spine with 2/3 of the lordosis given by the L4-S1 segment and 85% by the L3-S1 segment. Technical aspects involve patient positioning on the operating table, release maneuvers, type of instrumentation used (rod, screw-rod connection, interbody cages), surgical sequence and the overall surgical strategy. Spinal osteotomies may be required in case of fixed kyphotic spine. AP combined surgery is particularly efficient in restoring lordosis at L5-S1 level and should be recommended. Finally, not one but several strategies may be used to achieve the need for restoration of adequate lordosis during fusion surgery. PMID:25621216

Barrey, Cédric; Darnis, Alice

2015-01-01

173

Cervical spondylodiscitis associated with oesophageal perforation: a rare complication after anterior cervical fusion.  

PubMed

Anterior cervical instrumented fusion is a commonly performed spinal surgery with relatively low complication rate. Especially, spinal infections are very rare and often associated with oesophageal perforation secondary to hardware migration. We present a rare complication of cervical spondylodiscitis in a 24-year-old man after an anterior cervical fusion. He had sustained a C5/C6 fracture dislocation associated with incomplete tetraplegia and he was treated by a combined staged posterior (lateral mass screws) and anterior (plate, PEEK) cervical fusion with an uneventful postoperative course with exception of light dysphagia for liquids. Three months after surgery, the patient developed fever and severe dysphagia. A barium-swallow study was indicative for oesophageal perforation, while MRI of the neck demonstrated spondylodiscitis C5/C6 accompanied by a prevertebral and epidural abscess. The treatment consisted of surgical debridement and evacuation of the abscesses, removal of the anterior spinal implants and insertion of a mesh cage with iliac bone graft. The weakened oesophagus posterior wall was enhanced with resorbable interrupted sutures and a 6-week course of antibiotics was administered. Dysphagia improved significantly while interbody fusion occurred 5 months following revision surgery. Five years postoperatively motor and sensor function had returned to normal limits. Dysphagia or deterioration of preexisted dysphagia in the late postoperative setting should be considered carefully and evaluated for oesophageal perforation and complicated spinal infection. In the case of not completed fusion, removal of the implants followed by meticulous debridement and insertion of titanium mesh cage, filled with autogenous bone graft lead to successful fusion and infection eradication. PMID:23412223

Korovessis, Panagiotis; Repantis, Thomas; Vitsas, Vasilis; Vardakastanis, Konstantinos

2013-11-01

174

Cold fusion, Alchemist's dream  

SciTech Connect

In this report the following topics relating to cold fusion are discussed: muon catalysed cold fusion; piezonuclear fusion; sundry explanations pertaining to cold fusion; cosmic ray muon catalysed cold fusion; vibrational mechanisms in excited states of D{sub 2} molecules; barrier penetration probabilities within the hydrogenated metal lattice/piezonuclear fusion; branching ratios of D{sub 2} fusion at low energies; fusion of deuterons into {sup 4}He; secondary D+T fusion within the hydrogenated metal lattice; {sup 3}He to {sup 4}He ratio within the metal lattice; shock induced fusion; and anomalously high isotopic ratios of {sup 3}He/{sup 4}He.

Clayton, E.D.

1989-09-01

175

Osteoconductive hydroxyapatite coated PEEK for spinal fusion surgery  

NASA Astrophysics Data System (ADS)

Polyetheretherketone (PEEK) has attracted much interest as biomaterial for interbody fusion cages due to its similar stiffness to bone and good radio-transparency for post-op visualization. Hydroxyapatite (HA) coating stimulates bone growth to the medical implant. The objective of this work is to make an implant consisting of biocompatible PEEK with an osteoconductive HA surface for spinal or orthopedic applications. Highly dense and well-adhered HA coating was developed on medical-grade PEEK using aerosol deposition (AD) without thermal degradation of the PEEK. The HA coating had a dense microstructure with no cracks or pores, and showed good adhesion to PEEK at adhesion strengths above 14.3 MPa. The crystallinity of the HA coating was remarkably enhanced by hydrothermal annealing as post-deposition heat-treatment. In addition, in vitro and in vivo biocompatibility of PEEK, in terms of cell adhesion morphology, cell proliferation, differentiation, and bone-to-implant contact ratio, were remarkably enhanced by the HA coating through AD.

Hahn, Byung-Dong; Park, Dong-Soo; Choi, Jong-Jin; Ryu, Jungho; Yoon, Woon-Ha; Choi, Joon-Hwan; Kim, Jong-Woo; Ahn, Cheol-Woo; Kim, Hyoun-Ee; Yoon, Byung-Ho; Jung, In-Kwon

2013-10-01

176

RSNA 2002: Image Fusion Image Fusion  

E-print Network

of anatomical feature #12;RSNA 2002: Image Fusion Types of Data to be Registered Anatomic CT, MRI, US Digitized; markers for repositioning Hybrid scanners, e.g. PET/CT #12;RSNA 2002: Image Fusion Classification of imageRSNA 2002: Image Fusion Image Fusion: Introduction to the Technology Charles A. Pelizzari, Ph

Pelizzari, Charles A.

177

Nuclear Fusion  

NSDL National Science Digital Library

This simple and engaging astronomy activity explains nuclear fusion and how radiation is generated by stars, using marshmallows as a model. Learners will explore what cosmic radiation is and where it comes from, and how the elements in the universe are generated. The PDF contains step-by-step instructions, photos, presentation tips, links to background information, and a printable Periodic Table of the Elements.

2012-12-26

178

Guideline update for the performance of fusion procedures for degenerative disease of the lumbar spine. Part 3: assessment of economic outcome.  

PubMed

A comprehensive economic analysis generally involves the calculation of indirect and direct health costs from a societal perspective as opposed to simply reporting costs from a hospital or payer perspective. Hospital charges for a surgical procedure must be converted to cost data when performing a cost-effectiveness analysis. Once cost data has been calculated, quality-adjusted life year data from a surgical treatment are calculated by using a preference-based health-related quality-of-life instrument such as the EQ-5D. A recent cost-utility analysis from a single study has demonstrated the long-term (over an 8-year time period) benefits of circumferential fusions over stand-alone posterolateral fusions. In addition, economic analysis from a single study has found that lumbar fusion for selected patients with low-back pain can be recommended from an economic perspective. Recent economic analysis, from a single study, finds that femoral ring allograft might be more cost-effective compared with a specific titanium cage when performing an anterior lumbar interbody fusion plus posterolateral fusion. PMID:24980580

Ghogawala, Zoher; Whitmore, Robert G; Watters, William C; Sharan, Alok; Mummaneni, Praveen V; Dailey, Andrew T; Choudhri, Tanvir F; Eck, Jason C; Groff, Michael W; Wang, Jeffrey C; Resnick, Daniel K; Dhall, Sanjay S; Kaiser, Michael G

2014-07-01

179

Recombinant human Bone Morphogenetic Protein-2 (rhBMP-2) in posterolateral lumbar spine fusion: complications in the elderly  

PubMed Central

Study design Retrospective cohort study of 1430 patients undergoing lumbar spinal fusion from 2002 - 2009. Objective: The goal of this study was to compare and evaluate the number of complications requiring reoperation in elderly versus younger patients. Summary of background data rhBMP-2 has been utilized off label for instrumented lumbar posterolateral fusions for many years. Many series have demonstrated predictable healing rates and reoperations. Varying complication rates in elderly patients have been reported. Materials and methods All patients undergoing instrumented lumbar posterolateral fusion of ??3 levels consenting to utilization of rhBMP-2 were retrospectively evaluated. Patient demographics, body mass index, comorbidities, number of levels, associated interbody fusion, and types of bone void filler were analyzed. The age of patients were divided into less than 65 and greater than or equal to 65 years. Complications related to the performed procedure were recorded. Results After exclusions, 482 consecutive patients were evaluated with 42.1% males and 57.9% females. Average age was 62 years with 250 (51.9%) < 65 and 232 (48.1%) ??65 years. Patients ??65 years of age stayed longer (5.0 days) in the hospital than younger patients (4.5 days) (p=0.005). Complications requiring reoperation were: acute seroma formation requiring decompression 15/482, 3.1%, bone overgrowth 4/482, 0.8%, infection requiring debridement 11/482, 2.3%, and revision fusion for symptomatic nonunion 18/482, 3.7%. No significant differences in complications were diagnosed between the two age groups. Statistical differences were noted between the age groups for medical comorbidities and surgical procedures. Patients older than 65 years underwent longer fusions (2.1 versus 1.7 levels, p=0.001). Discussion Despite being older and having more comorbidities, elderly patients have similar complication and reoperation rates compared to younger healthier patients undergoing instrumented lumbar decompression fusions with rhBMP-2. PMID:23317417

2013-01-01

180

Hybrid dynamic stabilization with posterior spinal fusion in the lumbar spine  

PubMed Central

Background Instrumented lumbar arthrodesis has been established as the gold standard in the care of patients with degenerative disc disease. However, spinal fusion results in the elimination of motion of the functional spinal unit and has been implicated in the development of adjacent-level degeneration. Motion-preserving devices such as the dynamic rod allow for stabilization of a pathologic motion segment above a fused segment and create a transitional zone (index level) that decreases the loads applied to the supra-adjacent normal segment. Methods After institutional review board approval, 28 patients were included in this prospective, consecutive, nonrandomized clinical trial. Each subject was consented for dynamic stabilization. There was no attempt at fusion at the dynamic level. The cohort underwent a posterior lateral spinal fusion with single- or 2-level transforaminal lumbar interbody fusion by use of a cage, with superior-level posterior dynamic instrumentation. Functional clinical outcomes were measured with a 100-point visual analog scale, Oswestry Disability Index, and Short Form 36 questionnaire. Radiographic measurements, fusion evaluation, complications, and screw loosening were recorded. Results A minimum of 24 months’ follow-up data included 22 patients. No device failure or screw breakage was identified. Postoperative range of motion averaged 2.5° at the index level, and the superior adjacent-level range of motion remained unchanged (P > .05). Disc height was preserved at all levels (P > .05). Of 180 screws, 6 (3%) showed radiographic loosening. Functional outcomes showed significant improvement in mean postoperative visual analog scale score by 24.7 points (P < .01) and Oswestry Disability Index by 27.6 points (P < .01), as well as the Short Form 36 physical (P < .01) and mental (P < .05) components from baseline to 2-year follow-up. Conclusions Our preliminary results at 2 years are satisfactory. Clinical Relevance Ultimately, further follow-up will assess the potential for this treatment to delay adjacent-level changes in the long term.

Hudson, William R. S.; Gee, John Eric; Billys, James B.; Castellvi, Antonio E.

2011-01-01

181

Nell-1 Protein Promotes Bone Formation in a Sheep Spinal Fusion Model  

PubMed Central

Bone morphogenetic proteins (BMPs) are widely used as bone graft substitutes in spinal fusion, but are associated with numerous adverse effects. The growth factor Nel-like molecule-1 (Nell-1) is mechanistically distinct from BMPs and can minimize complications associated with BMP therapies. This study evaluates the efficacy of Nell-1 combined with demineralized bone matrix (DBM) as a novel bone graft material for interbody spine fusion using sheep, a phylogenetically advanced animal with biomechanical similarities to human spine. Nell-1+sheep DBM or Nell-1+heat-inactivated DBM (inDBM) (to determine the osteogenic effect of residual growth factors in DBM) were implanted in surgical sites as follows: (1) DBM only (control) (n=8); (2) DBM+0.3?mg/mL Nell-1 (n=8); (3) DBM+0.6?mg/mL Nell-1 (n=8); (4) inDBM only (control) (n=4); (5) inDBM+0.3?mg/mL Nell-1 (n=4); (6) inDBM+0.6?mg/mL Nell-1 (n=4). Fusion was assessed by computed tomography, microcomputed tomography, and histology. One hundred percent fusion was achieved by 3 months in the DBM+0.6?mg/mL Nell-1 group and by 4 months in the inDBM+0.6?mg/mL Nell-1 group; bone volume and mineral density were increased by 58% and 47%, respectively. These fusion rates are comparable to published reports on BMP-2 or autograft bone efficacy in sheep. Nell-1 is an independently potent osteogenic molecule that is efficacious and easily applied when combined with DBM. PMID:21128865

Siu, Ronald K.; Lu, Steven S.; Li, Weiming; Whang, Julie; McNeill, Gabriel; Zhang, Xinli; Wu, Benjamin M.; Turner, A. Simon; Seim, Howard B.; Hoang, Paul; Wang, Jeffrey C.; Gertzman, Arthur A.; Ting, Kang

2011-01-01

182

MIT Plasma Science and Fusion Center Fusion Technology & Engineering Division  

E-print Network

MIT Plasma Science and Fusion Center Fusion Technology & Engineering Division Fusion Magnets Peer Technology & Engineering Division Fusion Magnets Peer Review, MIT Plasma Science and Fusion Center; April 10 Science and Fusion Center Fusion Technology & Engineering Division Fusion Magnets Peer Review, MIT Plasma

183

The First Clinical Trial of Beta-Calcium Pyrophosphate as a Novel Bone Graft Extender in Instrumented Posterolateral Lumbar Fusion  

PubMed Central

Background Porous ?-calcium pyrophosphate (?-CPP) was developed to improve the fusion success of posterolateral lumbar fusion (PLF). The possibility of accomplishing PLF using a mixture of porous ?-CPP and iliac bone was studied. This paper reports the radiologic results of PLF using the ?-CPP plus autograft for lumbar degenerative disease as a bone graft extender. Methods A prospective, case-matched, radiographic study evaluating the results of short segment lumbar fusion using a ?-CPP plus autograft was performed to compare the efficacy of ?-CPP plus autograft with that of an autograft alone for short segment lumbar fusion. Thirty one consecutive patients (46 levels) underwent posterolateral fusion with pedicle screw fixation and additional posterior lumbar interbody fusion. In all patients, 3 mL of ?-CPP plus 3 mL of autogenous bone graft was placed randomly in one side of a posterolateral gutter, and 6 mL of autogenous iliac bone graft was placed on the other. The fusion rates, volumes of fusion masses, and bone absorption percentage were evaluated postoperatively using simple radiographs and 3 dimensional computed tomography (3D-CT) scans. Results The control sides treated with an autograft showed significantly better Lenke scores than the study sides treated with ?-CPP at 3 and 6 months postoperatively, but there was no difference between the two sides at 12 months. The fusion rates (confirmed by 3D-CT) were 87.0% in the ?-CPP group and 89.1% in the autograft group, which were not significantly different. The fusion mass volumes and bone absorption percentage at 12 months postoperatively were 2.49 mL (58.4%) and 1.89 mL (69.5%) for the ?-CPP and autograft groups, respectively, and mean fusion mass volume was significantly higher in the ?-CPP group. Conclusions ?-CPP combined with an autograft is as effective as autologous bone for grafting during instrumented posterolateral spinal fusion. These findings suggest that ?-CPP bone chips can be used as a novel bone graft extender for short-segment posterolateral spinal fusion. PMID:21909472

Lee, Jae Hyup; Jeung, Ul-Oh; Park, Kun-Woo; Kim, Min-Seok; Lee, Choon-Ki

2011-01-01

184

Complications of anterior cervical discectomy and fusion using recombinant human bone morphogenetic protein-2.  

PubMed

The use of bone morphogenetic protein-2 (rhBMP-2) in spinal fusion has increased dramatically since an FDA approval for its use in anterior lumbar fusion with the LT cage. There are several reports of its use in transforaminal lumbar interbody fusion, posterolateral fusion, and anterior cervical fusion. Reports on adverse effects of rhBMP-2 when used in spinal fusion are scarce in literature. An Institutional Review Board approved retrospective study was conducted in patients undergoing anterior spinal fusion and instrumentation following diskectomy at a single center. Forty-six consecutive patients were included. Twenty-two patients treated with rhBMP-2 and PEEK cages were compared to 24 in whom allograft spacers and demineralized bone matrix was used. Patients filled out Cervical Oswestry Scores, VAS for arm pain, neck pain, and had radiographs preoperatively as well at every follow up visit. Radiographic examination following surgery revealed end plate resorption in all patients in whom rhBMP-2 was used. This was followed by a period of new bone formation commencing at 6 weeks. In contrast, allograft patients showed a progressive blurring of end plate-allograft junction. Dysphagia was a common complication and it was significantly more frequent and more severe in patients in whom rhBMP-2 was used. Post operative swelling anterior to the vertebral body on lateral cervical spine X-ray was significantly larger in the rhBMP-2 group when measured from 1 to 6 weeks after which it was similar. These effects are possibly due to an early inflammatory response to rhBMP-2 and were observed to be dose related. With the parameters we used, there was no significant difference in the clinical outcome of patients in the two groups at 2 years. The cost of implants in patients treated with rhBMP-2 and PEEK spacers was more than three times the cost of allograft spacers and demineralized bone matrix in 1, 2, and 3-level cases. Despite providing consistently good fusion rates, we have abandoned using rhBMP-2 and PEEK cages for anterior cervical fusion, due to the side effects, high cost, and the availability of a suitable alternative. PMID:17387522

Vaidya, Rahul; Carp, Julia; Sethi, Anil; Bartol, Stephen; Craig, Joseph; Les, Clifford M

2007-08-01

185

About sponsorship Fusion power  

E-print Network

About sponsorship Fusion power Nuclear ambitions Jun 30th 2005 From The Economist print edition project to build a nuclear-fusion reactor came a step closer to reality when politicians agreed it should century, fusion advocates have claimed that achieving commercial nuclear fusion is 30 years away

186

Fusion Energy 101 Jeff Freidberg  

E-print Network

Fusion Cons: · It doesn't work yet 8 #12;How does fusion work? Science · Nuclear physics · Plasma physicsFusion Energy 101 Jeff Freidberg PSFC & NSE January 2012 1 #12;Outline 1. What is fusion's role in energy production 2. How does fusion work? 3. Where is fusion research now? 4. Where might fusion

187

Bemerkungen zur "kalten Fusion"  

E-print Network

Steven Jones et al. reported to have observed nuclear fusion at room temperature. They observed this "cold fusion" by electrolyzing heavy water. Later experiments confirmed these observations. These experiments confirmed the generation of strong electric fields within the deuterided metals. These electric fields accelerate the deuterons to keV energies and allow the observed nuclear fusion. Roman Sioda and I suggested a theoretical description of this nuclear fusion. Our "extended micro hot fusion" scenario explains how nuclear fusion can be generated over a long time within deuterided metals. Moreover we predicted the explosion of large pieces of deuterided metals. This article reviews the "cold fusion" work of Steven Jones et al. and discusses the fracto-fusion scenario. I show that the extended micro hot fusion scenario can explain the observed neutron emissions, neutron bursts, and heat bursts.

Rainer W. Kuehne

2006-04-14

188

MIT Plasma Science and Fusion Center Fusion Technology & Engineering Division  

E-print Network

MIT Plasma Science and Fusion Center Fusion Technology & Engineering Division J.H. Schultz, P close #12;MIT Plasma Science and Fusion Center Fusion Technology & Engineering Division Dimensionally No , Yes No #12;MIT Plasma Science and Fusion Center Fusion Technology & Engineering Division Ip

189

MIT Plasma Science and Fusion Center Fusion Technology & Engineering Division  

E-print Network

MIT Plasma Science and Fusion Center Fusion Technology & Engineering Division J.H. Schultz M Point Studies #12;MIT Plasma Science and Fusion Center Fusion Technology & Engineering Division A New on assumed p*/E #12;MIT Plasma Science and Fusion Center Fusion Technology & Engineering Division Calibration

190

ChemTeacher: Fusion  

NSDL National Science Digital Library

ChemTeacher compiles background information, videos, articles, demonstrations, worksheets and activities for high school teachers to use in their classrooms. The Fusion page includes resources for teaching students about the discovery and applications of fusion.

2012-07-24

191

Slow liner fusion  

SciTech Connect

{open_quotes}Slow{close_quotes} liner fusion ({approximately}10 ms compression time) implosions are nondestructive and make repetitive ({approximately} 1 Hz) pulsed liner fusion reactors possible. This paper summarizes a General Atomics physics-based fusion reactor study that showed slow liner feasibility, even with conservative open-line axial magnetic field confinement and Bohm radial transport.

Shaffer, M.J.

1997-08-01

192

Development and Testing of Manufacturing Methods for a Piezoelectric Composite Stacked Generator to Improve the Success Rate of Interbody Spinal Fusion  

E-print Network

method using silver epoxy. Furthermore, this work investigates potential modes of failure and the ability of the specimen to provide an adequate amount of power for electrical stimulation. Three testing stages were conducted to determine potential failure...

Tobaben, Eric

2014-08-31

193

Anterior lumbar interbody fusion with carbon fiber cage loaded with bioceramics and platelet-rich plasma. An experimental study on pigs  

Microsoft Academic Search

Platelet-rich plasma (PRP) is an autogenous source of growth factor and has been shown to enhance bone healing both in clinical and experimental studies. PRP in combination with porous hydroxyapatite has been shown to increase the bone ingrowth in a bone chamber rat model. The present study investigated whether the combination of beta tricalcium phosphate (?-TCP) and PRP may enhance

Haisheng Li; Xuenong Zou; Qingyun Xue; Niels Egund; Martin Lind; Cody Bünger

2004-01-01

194

Porous titanium-6 aluminum-4 vanadium cage has better osseointegration and less micromotion than a poly-ether-ether-ketone cage in sheep vertebral fusion.  

PubMed

Interbody fusion cages made of poly-ether-ether-ketone (PEEK) have been widely used in clinics for spinal disorders treatment; however, they do not integrate well with surrounding bone tissue. Ti-6Al-4V (Ti) has demonstrated greater osteoconductivity than PEEK, but the traditional Ti cage is generally limited by its much greater elastic modulus (110?GPa) than natural bone (0.05-30?GPa). In this study, we developed a porous Ti cage using electron beam melting (EBM) technique to reduce its elastic modulus and compared its spinal fusion efficacy with a PEEK cage in a preclinical sheep anterior cervical fusion model. A porous Ti cage possesses a fully interconnected porous structure (porosity: 68?±?5.3%; pore size: 710?±?42??m) and a similar Young's modulus as natural bone (2.5?±?0.2?GPa). When implanted in vivo, the porous Ti cage promoted fast bone ingrowth, achieving similar bone volume fraction at 6 months as the PEEK cage without autograft transplantation. Moreover, it promoted better osteointegration with higher degree (2-10x) of bone-material binding, demonstrated by histomorphometrical analysis, and significantly higher mechanical stability (P?

Wu, Su-Hua; Li, Yi; Zhang, Yong-Quan; Li, Xiao-Kang; Yuan, Chao-Fan; Hao, Yu-Lin; Zhang, Zhi-Yong; Guo, Zheng

2013-12-01

195

The fusion breeder  

NASA Astrophysics Data System (ADS)

The fusion breeder is a fusion reactor designed with special blankets to maximize the transmutation by 14 MeV neutrons of uranium-238 to plutonium or thorium to uranium-233 for use as a fuel for fission reactors. Breeding fissile fuels has not been a goal of the U.S. fusion energy program. This paper suggests it is time for a policy change to make the fusion breeder a goal of the U.S. fusion program and the U.S. nuclear energy program. There is wide agreement that many approaches will work and will produce fuel for five equal-sized LWRs, and some approach as many as 20 LWRs at electricity costs within 20% of those at today's price of uranium (30/lb of U3O8). The blankets designed to suppress fissioning, called symbiotes, fusion fuel factories, or just fusion breeders, will have safety characteristics more like pure fusion reactors and will support as many as 15 equal power LWRs. The blankets designed to maximize fast fission of fertile material will have safety characteristics more like fission reactors and will support 5 LWRs. This author strongly recommends development of the fission suppressed blanket type, a point of view not agreed upon by everyone. There is, however, wide agreement that, to meet the market price for uranium which would result in LWR electricity within 20% of today's cost with either blanket type, fusion components can cost severalfold more than would be allowed for pure fusion to meet the goal of making electricity alone at 20% over today's fission costs. Also widely agreed is that the critical-path-item for the fusion breeder is fusion development itself; however, development of fusion breeder specific items (blankets, fuel cycle) should be started now in order to have the fusion breeder by the time the rise in uranium prices forces other more costly choices.

Moir, Ralph W.

1982-10-01

196

FUSION NUCLEAR SCIENCE PROGRAM & SUPPORTING FUSION NUCLEAR SCIENCE FACILITY (FNSF)  

E-print Network

FUSION NUCLEAR SCIENCE PROGRAM & SUPPORTING FUSION NUCLEAR SCIENCE FACILITY (FNSF): UPDATE in order to apply the knowledge we gained about burning plasma state #12;FUSION NUCLEAR SCIENCE PROGRAM #12;FUSION NUCLEAR SCIENCE PROGRAM DEVELOPMENT OF ELEMENTS OF THE FUSION NUCLEAR SCIENCE PROGRAM

197

Limited access surgery for 360 degrees in-situ fusion in a dysraphic patient with high-grade spondylolisthesis.  

PubMed

Progressive high-grade spondylolisthesis can lead to spinal imbalance. High-grade spondylolisthesis is often reduced and fused in unbalanced pelvises, whereas in-situ fusion is used more often in balanced patients. The surgical goal is to recreate or maintain sagittal balance but if anatomical reduction is necessary, the risk of nerval damage with nerve root disruption in worst cases is increased. Spinal dysraphism like spina bifida or tethered cord syndrome make it very difficult to achieve reduction and posterior fusion due to altered anatomy putting the focus on anterior column support. Intensive neural structure manipulation should be avoided to reduce neurological complications and re-tethering in these cases. A 26-year-old patient with a history of diastematomyelia, occult spina bifida and tethered cord syndrome presented with new onset of severe low back pain, and bilateral L5/S1 sciatica after a fall. The X-ray demonstrated a grade III spondylolisthesis with spina bifida and the MRI scan revealed bilateral severely narrowed exit foramina L5 due to the listhesis. Because she was well balanced sagittally, the decision for in-situ fusion was made to minimise the risk of neurological disturbance through reduction. Anterior fusion was favoured to minimise manipulation of the dysraphic neural structures. Fusion was achieved via isolated access to the L4/L5 disc space. A L5 transvertebral hollow modular anchorage (HMA) screw was passed into the sacrum from the L4/L5 disc space and interbody fusion of L4/L5 was performed with a cage. The construct was augmented with pedicle screw fixation L4-S1 via a less invasive bilateral muscle split for better anterior biomechanical support. The postoperative course was uneventful and fusion was CT confirmed at the 6-month follow-up. At the last follow-up, she worked full time, was completely pain free and not limited in her free-time activities. The simultaneous presence of high-grade spondylolisthesis and spinal dysraphism make it very difficult to find a decisive treatment plan because both posterior and anterior treatment strategies have advantages and disadvantages in these challenging cases. The described technique combines several surgical options to achieve 360° fusion with limited access, reducing the risk of neurological sequelae. PMID:22008862

König, M A; Boszczyk, B M

2012-03-01

198

Fusion Energy Education  

NSDL National Science Digital Library

The basics of fusion are deceptively simple: the process powers the sun and other stars, and it all takes place when atomic nuclei collide at high speed. But many questions remain. How can humans develop and exploit fusion energy? Is there a way to convert it more efficiently into useful mechanical, electrical, or thermal energy? This intriguing site, created by the Lawrence Livermore National Laboratory and the Princeton Plasma Physics Laboratory, presents an online fusion course designed to teach students and others about how fusion works and how it might be harnessed in the future. Visitors can try out The Guided Tour to get started, or they can click on one of the Main Topics. These include Energy Sources and Conversions, Two Key Fusion Reactions, and Creating the Conditions for Fusion. Each section contains graphics, explanatory text, and various diagrams. The site also includes charts which can be printed out for classroom use.

199

Viral membrane fusion  

Microsoft Academic Search

Infection by viruses having lipid-bilayer envelopes proceeds through fusion of the viral membrane with a membrane of the target cell. Viral 'fusion proteins' facilitate this process. They vary greatly in structure, but all seem to have a common mechanism of action, in which a ligand-triggered, large-scale conformational change in the fusion protein is coupled to apposition and merger of the

Stephen C Harrison

2008-01-01

200

Status of fusion maintenance  

SciTech Connect

Effective maintenance will be an essential ingredient in determining fusion system productivity. This level of productivity will result only after close attention is paid to the entire system as an entity and appropriate integration of the elements is made. The status of fusion maintenance is reviewed in the context of the entire system. While there are many challenging developmental tasks ahead in fusion maintenance, the required technologies are available in several high-technology industries, including nuclear fission.

Fuller, G.M.

1984-01-01

201

Fusion propulsion systems  

Microsoft Academic Search

The results of a US Air Force Astronautics Laboratory (AFAL)-sponsored study of fusion propulsion are summarized. The study explored the potential of fusion propulsion for Air Force missions. Fusion fuels and existing confinement concepts were evaluated according to elaborate criteria. Two fuels, deuterium-tritium and deuterium-helium 3 (D-3He), were considered worthy of further consideration. D-3He was selected as the most attractive

V. E. Haloulakos

1989-01-01

202

Intense fusion neutron sources  

Microsoft Academic Search

The review describes physical principles underlying efficient production of free neutrons, up-to-date possibilities and prospects of creating fission and fusion neutron sources with intensities of 1015-1021 neutrons\\/s, and schemes of production and application of neutrons in fusion-fission hybrid systems. The physical processes and parameters of high-temperature plasmas are considered at which optimal conditions for producing the largest number of fusion

B. V. Kuteev; P. R. Goncharov; V. Yu. Sergeev; V. I. Khripunov

2010-01-01

203

Intense fusion neutron sources  

Microsoft Academic Search

The review describes physical principles underlying efficient production of free neutrons, up-to-date possibilities and prospects\\u000a of creating fission and fusion neutron sources with intensities of 1015–1021 neutrons\\/s, and schemes of production and application of neutrons in fusion-fission hybrid systems. The physical processes\\u000a and parameters of high-temperature plasmas are considered at which optimal conditions for producing the largest number of\\u000a fusion

B. V. Kuteev; P. R. Goncharov; V. Yu. Sergeev; V. I. Khripunov

2010-01-01

204

Magnetic fusion reactor economics  

SciTech Connect

An almost primordial trend in the conversion and use of energy is an increased complexity and cost of conversion systems designed to utilize cheaper and more-abundant fuels; this trend is exemplified by the progression fossil fission {yields} fusion. The present projections of the latter indicate that capital costs of the fusion ``burner`` far exceed any commensurate savings associated with the cheapest and most-abundant of fuels. These projections suggest competitive fusion power only if internal costs associate with the use of fossil or fission fuels emerge to make them either uneconomic, unacceptable, or both with respect to expensive fusion systems. This ``implementation-by-default`` plan for fusion is re-examined by identifying in general terms fusion power-plant embodiments that might compete favorably under conditions where internal costs (both economic and environmental) of fossil and/or fission are not as great as is needed to justify the contemporary vision for fusion power. Competitive fusion power in this context will require a significant broadening of an overly focused program to explore the physics and simbiotic technologies leading to more compact, simplified, and efficient plasma-confinement configurations that reside at the heart of an attractive fusion power plant.

Krakowski, R.A.

1995-12-01

205

Complications due to the use of BMP/INFUSE in spine surgery: The evidence continues to mount.  

PubMed

Increasingly, adverse events (AE) attributed to utilizing BMP/INFUSE (Bone Morphogenetic Protein, Medtronic, Memphis, TN, USA) "off-label" in spine surgery are being reported. In 2008, the Food and Drug Administration (FDA) issued a warning that in anterior cervical spine surgery, the "off-label" use of BMP/INFUSE contributed to marked dysphagia, hematoma, seroma, swelling, and/or the need for intubation/tracheostomy. Subsequent studies have cited the following AE; heterotopic ossification (HO), osteolysis, infection, arachnoiditis, increased neurological deficits, retrograde ejaculation, and cancer. Furthermore, in 2011, Carragee et al. noted that 13 of the original industry-sponsored BMP/INFUSE spinal surgery studies failed to acknowledge multiple AE. Additionally, in 2012, Comer et al. observed that the frequency of retrograde ejaculation reported for BMP/INFUSE used "on-label" to perform Anterior Lumbar Interbody Fusion/Lumbar Tapered Fusion-Cage Device (ALIF/LT-Cage) was also largely "under-reported." To summarize, there is mounting evidence in the spinal literature that utilizing BMP/INFUSE in spinal fusions contributes to major perioperative and postoperative morbidity. PMID:23878769

Epstein, Nancy E

2013-01-01

206

A polycaprolactone-tricalcium phosphate composite scaffold as an autograft-free spinal fusion cage in a sheep model.  

PubMed

Titanium (Ti) based spinal fusion cages are frequently used in the clinics for the treatment of spinal degeneration and related diseases, however, their further clinical application is generally harassed by several drawbacks such as stress shielding, non-biodegradability and additional bone grafting procedure. Our earlier work has demonstrated the efficacy of a biodegradable macro-porous polycaprolactone-tricalcium phosphate (PCL-TCP) composite scaffold in promoting bony tissue ingrowth as well as its ability to sustain mechanical loads upon implantation into an orthotopic defect site. In this study, we investigated the use of PCL-TCP scaffold as an autograft-free spinal fusion cage in a preclinical sheep model over 12 months, and compared the fusion efficacy against Ti cages incorporated with autografts. Results showed that despite PCL-TCP scaffold as an autograft-free cage attaining a slower fusion rate at early stage (6 month), it achieved similar degree of spinal fusion efficacy as Ti cages aided with autograft at 12 month post-operation as evidenced by the radiographic and histological evaluation. PCL-TCP cages alone demonstrated better bone ingrowth with 2.6 fold higher bone/interspace ratio (B/I) and more homogeneous bone tissue distribution compared with that of the Ti cages (88.10  ±  3.63% vs. 33.74  ±  2.78%, p < 0.05) as seen from the histological and micro-CT analysis. Moreover, besides the bone tissue ingrowth, a quantitative approach was illustrated to accurately evaluate the osteointegration of fusion cage with surrounding bone tissue, and showed a 1.36 fold higher degree of osteointegration occurred in PCL-TCP cage group than Ti cage group (CS/PC: 79.31  ±  3.15% vs 58.44  ±  2.43%, p < 0.05). Furthermore, biomechanical analysis showed comparable mechanical strength of fused segments in both groups in terms of the range of motion and stiffness at 12 month (p > 0.05). The degradation profile of the PCL-TCP cages was noted to increase in tandem with new bone ingrowth into the pores, while maintaining good structural integrity necessary for supporting the spinal interbody segments. Therefore, with the better osteointegration, more bone tissue ingrowth as well as its favorable biodegradable and radiolucent properties, PCL-TCP cage has been demonstrated to be a promising candidate as an autograft-free fusion cage for clinical application. PMID:24743032

Li, Yi; Wu, Zhi-gang; Li, Xiao-kang; Guo, Zheng; Wu, Su-hua; Zhang, Yong-quan; Shi, Lei; Teoh, Swee-hin; Liu, Yu-chun; Zhang, Zhi-yong

2014-07-01

207

Controlled Nuclear Fusion.  

ERIC Educational Resources Information Center

This publication is one of a series of information booklets for the general public published by The United States Atomic Energy Commission. Among the topics discussed are: Importance of Fusion Energy; Conditions for Nuclear Fusion; Thermonuclear Reactions in Plasmas; Plasma Confinement by Magnetic Fields; Experiments With Plasmas; High-Temperature…

Glasstone, Samuel

208

Mars manned fusion spaceship  

Microsoft Academic Search

Fusion Propulsion has an enormous potential for space exploration in the near future. In the twenty-first century, a usable and efficient fusion rocket will be developed and in use. Because of the great distance between other planets and Earth, efficient use of time, fuel, and payload is essential. A nuclear spaceship would provide greater fuel efficiency, less travel time, and

J. Hedrick; B. Buchholtz; P. Ward; J. Freuh; E. Jensen

1991-01-01

209

FEL amplifiers for fusion  

Microsoft Academic Search

Potential advantages of the free electron laser (FEL) as a fusion driver are noted and proposed high power FEL systems are described. Advantages for fusion of a pulsed multipass FEL system, in which the optical pulses are built up inside a long (approx. 400 m) resonator cavity and a storage ring provides the electron beam, are described. In one possible

S. B. Segall; H. R. Hiddleston; G. C. Catella

1980-01-01

210

Decomposition of incomplete fusion  

SciTech Connect

The velocity distribution of fusion-like products formed in the reaction 701 MeV /sup 28/Si+/sup 100/Mo is decomposed into 26 incomplete fusion channels. The momentum deficit of the residue per nonevaporative mass unit is approximately equal to the beam momentum per nucleon. The yields of the incomplete fusion channels correlate with the Q-value for projectile fragmentation rather than that for incomplete fusion. The backward angle multiplicities of light particles and heavy ions increase with momentum transfer, however, the heavy ion multiplicities also depend on the extent of the fragmentation of the incomplete fusion channel. These data indicate that at fixed linear momentum transfer, increased fragmentation of the unfused component is related to a reduced transferred angular momentum. 22 refs., 6 figs., 1 tab.

Sobotka, L.B.; Sarantities, D.G.; Stracener, D.W.; Majka, Z.; Abenante, V.; Semkow, T.M.; Hensley, D.C.; Beene, J.R.; Halbert, M.L.

1989-01-01

211

Investigation into Fusion Feasibility of a Magnetized Target Fusion Reactor  

E-print Network

conditions suitable for nuclear fusion on earth have made significant leaps and bounds in re- cent years due;1.1 Fusion Challenges and Requirements There are a number of ongoing large-scale efforts to acheive nuclear fusion, including NIF[15] and ITER. This paper reports on an effort by a Canadian nuclear fusion research

Wetton, Brian

212

Particle beam fusion  

SciTech Connect

Today, in keeping with Sandia Laboratories` designation by the Department of Energy as the lead laboratory for the pulsed power approach to fusion, its efforts include major research activities and the construction of new facilities at its Albuquerque site. Additionally, in its capacity as lead laboratory, Sandia coordinates DOE-supported pulsed power fusion work at other government operated laboratories, with industrial contractors, and universities. The beginning of Sandia`s involvement in developing fusion power was an outgrowth of its contributions to the nation`s nuclear weapon program. The Laboratories` work in the early 1960`s emphasized the use of pulsed radiation environments to test the resistance of US nuclear weapons to enemy nuclear bursts. A careful study of options for fusion power indicated that Sandia`s expertise in the pulsed power field could provide a powerful match to ignite fusion fuel. Although creating test environments is an achieved goal of Sandia`s overall program, this work and other military tasks protected by appropriate security regulations will continue, making full use of the same pulsed power technology and accelerators as the fusion-for-energy program. Major goals of Sandia`s fusion program including the following: (1) complete a particle accelerator to deliver sufficient beam energy for igniting fusion targets; (2) obtain net energy gain, this goal would provide fusion energy output in excess of energy stored in the accelerator; (3) develop a technology base for the repetitive ignition of pellets in a power reactor. After accomplishing these goals, the technology will be introduced to the nation`s commercial sector.

NONE

1980-12-31

213

RESEARCH HIGHLIGHTS State of fusion  

E-print Network

RESEARCH HIGHLIGHTS State of fusion In the 1950s,the promise of controlled nuclear fusion for continued optimism. Nuclear fusion power relies on the energy released when two light atomic nuclei fuse, although there is still some way to go to realize the dream,the latest status report on fusion research

Loss, Daniel

214

Spherical torus fusion reactor  

DOEpatents

The object of this invention is to provide a compact torus fusion reactor with dramatic simplification of plasma confinement design. Another object of this invention is to provide a compact torus fusion reactor with low magnetic field and small aspect ratio stable plasma confinement. In accordance with the principles of this invention there is provided a compact toroidal-type plasma confinement fusion reactor in which only the indispensable components inboard of a tokamak type of plasma confinement region, mainly a current conducting medium which carries electrical current for producing a toroidal magnet confinement field about the toroidal plasma region, are retained.

Martin Peng, Y.K.M.

1985-10-03

215

Fusion for Space Propulsion  

NASA Technical Reports Server (NTRS)

There is little doubt that humans will attempt to explore and develop the solar system in this century. A large amount of energy will be required for accomplishing this. The need for fusion propulsion is discussed. For a propulsion system, there are three important thermodynamical attributes: (1) The absolute amount of energy available, (2) the propellant exhaust velocity, and (3) the jet power per unit mass of the propulsion system (specific power). For human exploration and development of the solar system, propellant exhaust velocity in excess of 100 km/s and specific power in excess of 10 kW/kg are required. Chemical combustion can produce exhaust velocity up to about 5 km/s. Nuclear fission processes typically result in producing energy in the form of heat that needs to be manipulated at temperatures limited by materials to about 2,800 K. Using the energy to heat a hydrogen propellant increases the exhaust velocity by only a factor of about two. Alternatively the energy can be converted into electricity which is then used to accelerate particles to high exhaust velocity. The necessary power conversion and conditioning equipment, however, increases the mass of the propulsion system for the same jet power by more than two orders of magnitude over chemical system, thus greatly limits the thrust-to-weight ratio attainable. The principal advantage of the fission process is that its development is relatively mature and is available right now. If fusion can be developed, fusion appears to have the best of all worlds in terms of propulsion - it can provide the absolute amount, the propellant exhaust velocity, and the high specific jet power. An intermediate step towards pure fusion propulsion is a bimodal system in which a fission reactor is used to provide some of the energy to drive a fusion propulsion unit. The technical issues related to fusion for space propulsion are discussed. The technical priorities for developing and applying fusion for propulsion are somewhat different from those for terrestrial electrical power generation. Thus fusion schemes that are initially attractive for electrical power generation might not necessarily be attractive also for propulsion and vice versa, though the underlying fusion science and engineering enjoy much overlap. Parallel efforts to develop these qualitatively differently fusion schemes for the two applications could benefit greatly from each other due to the synergy in the underlying physics and engineering. Pulsed approaches to fusion have not been explored to the same degree as steady-state or long-pulse approaches to fusion in the fusion power research program. The concerns early on were several. One was that the pulsed power components might not have the service lifetimes meeting the requirements of a practical power generating plant. Another was that, for many pulsed fusion schemes, it was not clear whether the destruction of hardware per pulse could be minimized or eliminated or recycled to such an extent as to make economical electrical power generation feasible, Significant development of the underlying pulsed power component technologies have occurred in the last two decades because of defense and other energy requirements. The state of development of the pulsed power technologies are sufficiently advanced now to make it compelling to visit or re-visit pulsed fusion approaches for application to propulsion where the cost of energy is not so demanding a factor as in the case of terrestrial power application. For propulsion application, the overall mass of the fusion system is the critical factor. Producing fusion reactions require extreme states of matter. Conceptually, these extreme states of matter are more readily realizable in the pulsed states, at least within appropriate bounds, than in the steady states. Significant saving in system mass may result in such systems. Magnetic fields are effective in confining plasma energy, whereas inertial compression is an effective way of heating and containing the plasma. Intensive research in developing magnetic energy containme

Thio, Y. C. Francis; Schafer, Charles (Technical Monitor)

2001-01-01

216

Biomechanical comparison of three stand-alone lumbar cages — a three-dimensional finite element analysis  

PubMed Central

Background For anterior lumbar interbody fusion (ALIF), stand-alone cages can be supplemented with vertebral plate, locking screws, or threaded cylinder to avoid the use of posterior fixation. Intuitively, the plate, screw, and cylinder aim to be embedded into the vertebral bodies to effectively immobilize the cage itself. The kinematic and mechanical effects of these integrated components on the lumbar construct have not been extensively studied. A nonlinearly lumbar finite-element model was developed and validated to investigate the biomechanical differences between three stand-alone (Latero, SynFix, and Stabilis) and SynCage-Open plus transpedicular fixation. All four cages were instrumented at the L3-4 level. Methods The lumbar models were subjected to the follower load along the lumbar column and the moment at the lumbar top to produce flexion (FL), extension (EX), left/right lateral bending (LLB, RLB), and left/right axial rotation (LAR, RAR). A 10 Nm moment was applied to obtain the six physiological motions in all models. The comparison indices included disc range of motion (ROM), facet contact force, and stresses of the annulus and implants. Results At the surgical level, the SynCage-open model supplemented with transpedicular fixation decreased ROM (>76%) greatly; while the SynFix model decreased ROM 56-72%, the Latero model decreased ROM 36-91%, in all motions as compared with the INT model. However, the Stabilis model decreased ROM slightly in extension (11%), lateral bending (21%), and axial rotation (34%). At the adjacent levels, there were no obvious differences in ROM and annulus stress among all instrumented models. Conclusions ALIF instrumentation with the Latero or SynFix cage provides an acceptable stability for clinical use without the requirement of additional posterior fixation. However, the Stabilis cage is not favored in extension and lateral bending because of insufficient stabilization. PMID:24088294

2013-01-01

217

Fusion Chamber Technology Publications  

E-print Network

.N. Ruzic, and J.P. Allain, "Erosion/deposition analysis of lithium- based liquid surface divertors," J. 981-985, March (2001).. 16. E.T. Cheng, "Study of a Lead-Bismuth Cooled Fusion Blanket for Burning

California at Los Angeles, University of

218

Fusion: The Hydrogen Bomb  

NSDL National Science Digital Library

Just after World War II, nuclear scientists turned their attention from fission to fusion. This video segment adapted from AMERICAN EXPERIENCE looks at the beginnings of thermonuclear power generation.

WGBH Educational Foundation

2004-02-20

219

Cold nuclear fusion  

Microsoft Academic Search

The possibility that negative muons could catalyze nuclear fusion was suggested on theoretical grounds by F.C. Frank and A.D. Sakharov in the late 1940s; the first experimental observations of the process followed serendipitously a decade later, in experiments at Berkeley by L.W. Alvarez. The fastest mechanism for muon-catalyzed, or 'cold' fusion, was suggested by Vesman (1967); it depends on a

Johann Rafelski; Steven E. Jones

1987-01-01

220

Fusion ignition research experiment  

SciTech Connect

Understanding the properties of high gain (alpha-dominated) fusion plasmas in an advanced toroidal configuration is the largest remaining open issue that must be addressed to provide the scientific foundation for an attractive magnetic fusion reactor. The critical parts of this science can be obtained in a compact high field tokamak which is also likely to provide the fastest and least expensive path to understanding alpha-dominated plasmas in advanced toroidal systems.

Dale Meade

2000-07-18

221

Magnetized Target Fusion  

NASA Technical Reports Server (NTRS)

Magnetized target fusion (MTF) is under consideration as a means of building a low mass, high specific impulse, and high thrust propulsion system for interplanetary travel. This unique combination is the result of the generation of a high temperature plasma by the nuclear fusion process. This plasma can then be deflected by magnetic fields to provide thrust. Fusion is initiated by a small traction of the energy generated in the magnetic coils due to the plasma's compression of the magnetic field. The power gain from a fusion reaction is such that inefficiencies due to thermal neutrons and coil losses can be overcome. Since the fusion reaction products are directly used for propulsion and the power to initiate the reaction is directly obtained from the thrust generation, no massive power supply for energy conversion is required. The result should be a low engine mass, high specific impulse and high thrust system. The key is to successfully initiate fusion as a proof-of-principle for this application. Currently MSFC is implementing MTF proof-of-principle experiments. This involves many technical details and ancillary investigations. Of these, selected pertinent issues include the properties, orientation and timing of the plasma guns and the convergence and interface development of the "pusher" plasma. Computer simulations of the target plasma's behavior under compression and the convergence and mixing of the gun plasma are under investigation. This work is to focus on the gun characterization and development as it relates to plasma initiation and repeatability.

Griffin, Steven T.

2002-01-01

222

ITER Fusion Energy  

ScienceCinema

ITER (in Latin ?the way?) is designed to demonstrate the scientific and technological feasibility of fusion energy. Fusion is the process by which two light atomic nuclei combine to form a heavier over one and thus release energy. In the fusion process two isotopes of hydrogen ? deuterium and tritium ? fuse together to form a helium atom and a neutron. Thus fusion could provide large scale energy production without greenhouse effects; essentially limitless fuel would be available all over the world. The principal goals of ITER are to generate 500 megawatts of fusion power for periods of 300 to 500 seconds with a fusion power multiplication factor, Q, of at least 10. Q ? 10 (input power 50 MW / output power 500 MW). The ITER Organization was officially established in Cadarache, France, on 24 October 2007. The seven members engaged in the project ? China, the European Union, India, Japan, Korea, Russia and the United States ? represent more than half the world?s population. The costs for ITER are shared by the seven members. The cost for the construction will be approximately 5.5 billion Euros, a similar amount is foreseen for the twenty-year phase of operation and the subsequent decommissioning.

Dr. Norbert Holtkamp

2010-01-08

223

Improvements of image fusion methods  

NASA Astrophysics Data System (ADS)

Fusion of images from different imaging modalities, obtained by conventional fusion methods, may cause artifacts, including destructive superposition and brightness irregularities, in certain cases. This paper proposes two methods for improving image multimodal fusion quality. Based on the finding that a better fusion can be achieved when the images have a more positive correlation, the first method is a decision algorithm that runs at the preprocessing fusion stage and determines whether a complementary gray level of one of the input images should be used instead of the original one. The second method is suitable for multiresolution fusion, and it suggests choosing only one image from the lowest-frequency sub-bands in the pyramids, instead of combining values from both sub-bands. Experimental results indicate that the proposed fusion enhancement can reduce fusion artifacts. Quantitative fusion quality measures that support this conclusion are shown.

Ben-Shoshan, Yotam; Yitzhaky, Yitzhak

2014-03-01

224

50 Years of Fusion Research Fusion Innovation Research and Energy  

E-print Network

· Theory of Fusion Plasmas ­ Energy Principle developed in mid-50s became a powerful tool for assessing · Theory of Fusion Plasmas ­ Energy Principle developed in mid-50s became a powerful tool for assessing

225

STATs and macrophage fusion  

PubMed Central

Macrophages play a pivotal role in host defense against multiple foreign materials such as bacteria, parasites and artificial devices. Some macrophage lineage cells, namely osteoclasts and foreign body giant cells (FBGCs), form multi-nuclear giant cells by the cell–cell fusion of mono-nuclear cells. Osteoclasts are bone-resorbing cells, and are formed in the presence of RANKL on the surface of bones, while FBGCs are formed in the presence of IL-4 or IL-13 on foreign materials such as artificial joints, catheters and parasites. Recently, fusiogenic mechanisms and the molecules required for the cell–cell fusion of these macrophage lineage cells were, at least in part, clarified. Dendritic cell specific transmembrane protein (DC-STAMP) and osteoclast stimulatory transmembrane protein (OC-STAMP), both of which comprise seven transmembrane domains, are required for both osteoclast and FBGC cell–cell fusion. STAT6 was demonstrated to be required for the cell–cell fusion of FBGCs but not osteoclasts. In this review, advances in macrophage cell–cell fusion are discussed. PMID:24069561

2013-01-01

226

Myoblast fusion in Drosophila  

SciTech Connect

The body wall musculature of a Drosophila larva is composed of an intricate pattern of 30 segmentally repeated muscle fibers in each abdominal hemisegment. Each muscle fiber has unique spatial and behavioral characteristics that include its location, orientation, epidermal attachment, size and pattern of innervation. Many, if not all, of these properties are dictated by founder cells, which determine the muscle pattern and seed the fusion process. Myofibers are then derived from fusion between a specific founder cell and several fusion competent myoblasts (FCMs) fusing with as few as 3-5 FCMs in the small muscles on the most ventral side of the embryo and as many as 30 FCMs in the larger muscles on the dorsal side of the embryo. The focus of the present review is the formation of the larval muscles in the developing embryo, summarizing the major issues and players in this process. We have attempted to emphasize experimentally-validated details of the mechanism of myoblast fusion and distinguish these from the theoretically possible details that have not yet been confirmed experimentally. We also direct the interested reader to other recent reviews that discuss myoblast fusion in Drosophila, each with their own perspective on the process . With apologies, we use gene nomenclature as specified by Flybase (http://flybase.org) but provide Table 1 with alternative names and references.

Haralalka, Shruti [Stowers Institute for Medical Research, Kansas City, MO 64110 (United States)] [Stowers Institute for Medical Research, Kansas City, MO 64110 (United States); Abmayr, Susan M., E-mail: sma@stowers.org [Stowers Institute for Medical Research, Kansas City, MO 64110 (United States); Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, MO 66160 (United States)

2010-11-01

227

Fusion, magnetic confinement  

SciTech Connect

An overview is presented of the principles of magnetic confinement of plasmas for the purpose of achieving controlled fusion conditions. Sec. 1 discusses the different nuclear fusion reactions which can be exploited in prospective fusion reactors and explains why special technologies need to be developed for the supply of tritium or {sup 3}He, the probable fuels. In Sec. 2 the Lawson condition, a criterion that is a measure of the quality of confinement relative to achieving fusion conditions, is explained. In Sec. 3 fluid equations are used to describe plasma confinement. Specific confinement configurations are considered. In Sec. 4 the orbits of particle sin magneti and electric fields are discussed. In Sec. 5 stability considerations are discussed. It is noted that confinement systems usually need to satisfy stability constraints imposed by ideal magnetohydrodynamic (MHD) theory. The paper culminates with a summary of experimental progress in magnetic confinement. Present experiments in tokamaks have reached the point that the conditions necessary to achieve fusion are being satisfied.

Berk, H.L.

1992-08-06

228

Realization of Fusion Energy: An alternative fusion roadmap  

E-print Network

Realization of Fusion Energy: An alternative fusion roadmap Farrokh Najmabadi Professor of Electrical & Computer Engineering Director, Center for Energy Research UC San Diego International Fusion Road of emerging nations, energy use is expected to grow ~ 4 fold in this century (average 1.6% annual growth rate

229

Culham Centre for Fusion Energy Fusion -A clean future  

E-print Network

supplies of fossil fuels mean that we need to find new, cleaner ways of powering the planet. Nuclear fusion sources will not be enough by themselves to meet the demand. Nuclear fusion can be an important long from fossil fuels or nuclear fission. Why we need fusion energy The amount of lithium contained

230

Osteoclast fusion is based on heterogeneity between fusion partners.  

PubMed

Bone-resorbing osteoclasts are formed through fusion of mononucleated precursors. Their choice of partners during the fusion process remains unclear. We hypothesized that osteoclasts are selective in their choice of fusion partner and that this selectivity is based on heterogeneity among the cells with respect to their maturation stage and their expression and cellular organization of fusion factors. Support for this hypothesis was found from immunofluorescence staining of the osteoclast fusion factors CD47, dendritic cell-specific transmembrane protein (DC-STAMP), and syncytin-1. These stainings revealed heterogeneous localization patterns of all three factors within a given culture of osteoclasts. CD47 was found to be localized primarily in small osteoclasts and preosteoclasts, which were also positive for DC-STAMP but negative for cathepsin K expression. A role of CD47 in the early osteoclast fusion steps was also suggested from experiments with a CD47 blocking antibody, which resulted in an inhibition of the fusion of small osteoclasts. Conversely, blocking of connexin 43 affected the fusion of larger osteoclasts with four or more nuclei. The suggestion that different fusion factors function at different stages of osteoclast fusion supports the idea of heterogeneity in the osteoclast population; our results suggest that osteoclast fusion is indeed based on heterogeneity. Considering the in vivo environment in which osteoclasts develop and fuse, our findings seem very applicable and provide novel, important insight into key issues in bone and fusion research. PMID:24862648

Hobolt-Pedersen, Anne-Sofie; Delaissé, Jean-Marie; Søe, Kent

2014-07-01

231

Simulation of Fusion Plasmas  

ScienceCinema

The upcoming ITER experiment (www.iter.org) represents the next major milestone in realizing the promise of using nuclear fusion as a commercial energy source, by moving into the ?burning plasma? regime where the dominant heat source is the internal fusion reactions. As part of its support for the ITER mission, the US fusion community is actively developing validated predictive models of the behavior of magnetically confined plasmas. In this talk, I will describe how the plasma community is using the latest high performance computing facilities to develop and refine our models of the nonlinear, multiscale plasma dynamics, and how recent advances in experimental diagnostics are allowing us to directly test and validate these models at an unprecedented level.

Chris Holland

2010-01-08

232

Simulation of Fusion Plasmas  

SciTech Connect

The upcoming ITER experiment represents the next major milestone in realizing the promise of using nuclear fusion as a commercial energy source, by moving into the 'burning plasma' regime where the dominant heat source is the internal fusion reactions. As part of its support for the ITER mission, the US fusion community is actively developing validated predictive models of the behavior of magnetically confined plasmas. In this talk, I will describe how the plasma community is using the latest high performance computing facilities to develop and refine our models of the nonlinear, multiscale plasma dynamics, and how recent advances in experimental diagnostics are allowing us to directly test and validate these models at an unprecedented level.

Holland, Chris (UC San Diego) [UC San Diego

2008-12-17

233

Simulation of Fusion Plasmas  

SciTech Connect

The upcoming ITER experiment (www.iter.org) represents the next major milestone in realizing the promise of using nuclear fusion as a commercial energy source, by moving into the “burning plasma” regime where the dominant heat source is the internal fusion reactions. As part of its support for the ITER mission, the US fusion community is actively developing validated predictive models of the behavior of magnetically confined plasmas. In this talk, I will describe how the plasma community is using the latest high performance computing facilities to develop and refine our models of the nonlinear, multiscale plasma dynamics, and how recent advances in experimental diagnostics are allowing us to directly test and validate these models at an unprecedented level.

Chris Holland

2008-12-17

234

HEAVY ION INERTIAL FUSION  

SciTech Connect

Inertial fusion has not yet been as well explored as magnetic fusion but can offer certain advantages as an alternative source of electric energy for the future. Present experiments use high-power beams from lasers and light-ion diodes to compress the deuterium-tritium (D-T) pellets but these will probably be unsuitable for a power plant. A more promising method is to use intense heavy-ion beams from accelerator systems similar to those used for nuclear and high-energy physics; the present paper addresses itself to this alternative. As will be demonstrated the very high beam power needed poses new design questions, from the ion source through the accelerating system, the beam transport system, to the final focus. These problems will require extensive study, both theoretically and experimentally, over the next several years before an optimum design for an inertial fusion driver can be arrived at.

Keefe, D.; Sessler, A.M.

1980-07-01

235

Spherical torus fusion reactor  

DOEpatents

A fusion reactor is provided having a near spherical-shaped plasma with a modest central opening through which straight segments of toroidal field coils extend that carry electrical current for generating a toroidal magnet plasma confinement fields. By retaining only the indispensable components inboard of the plasma torus, principally the cooled toroidal field conductors and in some cases a vacuum containment vessel wall, the fusion reactor features an exceptionally small aspect ratio (typically about 1.5), a naturally elongated plasma cross section without extensive field shaping, requires low strength magnetic containment fields, small size and high beta. These features combine to produce a spherical torus plasma in a unique physics regime which permits compact fusion at low field and modest cost.

Peng, Yueng-Kay M. (Oak Ridge, TN)

1989-01-01

236

Intense fusion neutron sources  

NASA Astrophysics Data System (ADS)

The review describes physical principles underlying efficient production of free neutrons, up-to-date possibilities and prospects of creating fission and fusion neutron sources with intensities of 1015-1021 neutrons/s, and schemes of production and application of neutrons in fusion-fission hybrid systems. The physical processes and parameters of high-temperature plasmas are considered at which optimal conditions for producing the largest number of fusion neutrons in systems with magnetic and inertial plasma confinement are achieved. The proposed plasma methods for neutron production are compared with other methods based on fusion reactions in nonplasma media, fission reactions, spallation, and muon catalysis. At present, intense neutron fluxes are mainly used in nanotechnology, biotechnology, material science, and military and fundamental research. In the near future (10-20 years), it will be possible to apply high-power neutron sources in fusion-fission hybrid systems for producing hydrogen, electric power, and technological heat, as well as for manufacturing synthetic nuclear fuel and closing the nuclear fuel cycle. Neutron sources with intensities approaching 1020 neutrons/s may radically change the structure of power industry and considerably influence the fundamental and applied science and innovation technologies. Along with utilizing the energy produced in fusion reactions, the achievement of such high neutron intensities may stimulate wide application of subcritical fast nuclear reactors controlled by neutron sources. Superpower neutron sources will allow one to solve many problems of neutron diagnostics, monitor nano-and biological objects, and carry out radiation testing and modification of volumetric properties of materials at the industrial level. Such sources will considerably (up to 100 times) improve the accuracy of neutron physics experiments and will provide a better understanding of the structure of matter, including that of the neutron itself.

Kuteev, B. V.; Goncharov, P. R.; Sergeev, V. Yu.; Khripunov, V. I.

2010-04-01

237

Intense fusion neutron sources  

SciTech Connect

The review describes physical principles underlying efficient production of free neutrons, up-to-date possibilities and prospects of creating fission and fusion neutron sources with intensities of 10{sup 15}-10{sup 21} neutrons/s, and schemes of production and application of neutrons in fusion-fission hybrid systems. The physical processes and parameters of high-temperature plasmas are considered at which optimal conditions for producing the largest number of fusion neutrons in systems with magnetic and inertial plasma confinement are achieved. The proposed plasma methods for neutron production are compared with other methods based on fusion reactions in nonplasma media, fission reactions, spallation, and muon catalysis. At present, intense neutron fluxes are mainly used in nanotechnology, biotechnology, material science, and military and fundamental research. In the near future (10-20 years), it will be possible to apply high-power neutron sources in fusion-fission hybrid systems for producing hydrogen, electric power, and technological heat, as well as for manufacturing synthetic nuclear fuel and closing the nuclear fuel cycle. Neutron sources with intensities approaching 10{sup 20} neutrons/s may radically change the structure of power industry and considerably influence the fundamental and applied science and innovation technologies. Along with utilizing the energy produced in fusion reactions, the achievement of such high neutron intensities may stimulate wide application of subcritical fast nuclear reactors controlled by neutron sources. Superpower neutron sources will allow one to solve many problems of neutron diagnostics, monitor nano-and biological objects, and carry out radiation testing and modification of volumetric properties of materials at the industrial level. Such sources will considerably (up to 100 times) improve the accuracy of neutron physics experiments and will provide a better understanding of the structure of matter, including that of the neutron itself.

Kuteev, B. V. [Russian Research Centre Kurchatov Institute (Russian Federation); Goncharov, P. R.; Sergeev, V. Yu. [St. Petersburg State Polytechnic University (Russian Federation); Khripunov, V. I. [Russian Research Centre Kurchatov Institute (Russian Federation)

2010-04-15

238

Workmanship standards for fusion welding  

NASA Technical Reports Server (NTRS)

Workmanship standards manual defines practices, that adhere to rigid codes and specifications, for fusion welding of component piping, assemblies, and systems. With written and pictorial presentations, it is part of the operating procedure for fusion welding.

Phillips, M. D.

1967-01-01

239

Multisensor data fusion algorithm development  

SciTech Connect

This report presents a two-year LDRD research effort into multisensor data fusion. We approached the problem by addressing the available types of data, preprocessing that data, and developing fusion algorithms using that data. The report reflects these three distinct areas. First, the possible data sets for fusion are identified. Second, automated registration techniques for imagery data are analyzed. Third, two fusion techniques are presented. The first fusion algorithm is based on the two-dimensional discrete wavelet transform. Using test images, the wavelet algorithm is compared against intensity modulation and intensity-hue-saturation image fusion algorithms that are available in commercial software. The wavelet approach outperforms the other two fusion techniques by preserving spectral/spatial information more precisely. The wavelet fusion algorithm was also applied to Landsat Thematic Mapper and SPOT panchromatic imagery data. The second algorithm is based on a linear-regression technique. We analyzed the technique using the same Landsat and SPOT data.

Yocky, D.A.; Chadwick, M.D.; Goudy, S.P.; Johnson, D.K.

1995-12-01

240

Fusion for Space Propulsion  

NASA Technical Reports Server (NTRS)

The need for fusion propulsion for interplanetary flights is discussed. For a propulsion system, there are three important system attributes: (1) The absolute amount of energy available, (2) the propellant exhaust velocity, and (3) the jet power per unit mass of the propulsion system (specific power). For efficient and affordable human exploration of the solar system, propellant exhaust velocity in excess of 100 km/s and specific power in excess of 10 kW/kg are required. Chemical combustion obviously cannot meet the requirement in propellant exhaust velocity. Nuclear fission processes typically result in producing energy in the form of heat that needs to be manipulated at temperatures limited by materials to about 2,800 K. Using the fission energy to heat a low atomic weight propellant produces propellant velocity of the order of 10 kinds. Alternatively the fission energy can be converted into electricity that is used to accelerate particles to high exhaust velocity. However, the necessary power conversion and conditioning equipment greatly increases the mass of the propulsion system. Fundamental considerations in waste heat rejection and power conditioning in a fission electric propulsion system place a limit on its jet specific power to the order of about 0.2 kW/kg. If fusion can be developed for propulsion, it appears to have the best of all worlds - it can provide the largest absolute amount of energy, the propellant exhaust velocity (> 100 km/s), and the high specific jet power (> 10 kW/kg). An intermediate step towards fusion propulsion might be a bimodal system in which a fission reactor is used to provide some of the energy to drive a fusion propulsion unit. There are similarities as well as differences between applying fusion to propulsion and to terrestrial electrical power generation. The similarities are the underlying plasma and fusion physics, the enabling component technologies, the computational and the diagnostics capabilities. These physics and engineering capabilities have been demonstrated for a fusion reactor gain (Q) of the order of unity (TFTR: 0.25, JET: 0.65, JT-60: Q(sub eq) approx. 1.25). These technological advances made it compelling for considering fusion for propulsion.

Thio, Y. C. Francis; Schmidt, George R.; Santarius, John F.; Turchi, Peter J.; Siemon, Richard E.; Rodgers, Stephen L. (Technical Monitor)

2002-01-01

241

Atomic data for fusion  

SciTech Connect

This report provides a handbook of recommended cross-section and rate-coefficient data for inelastic collisions between hydrogen, helium and lithium atoms, molecules and ions, and encompasses more than 400 different reactions of primary interest in fusion research. Published experimental and theoretical data have been collected and evaluated, and the recommended data are presented in tabular, graphical and parametrized form. Processes include excitation and spectral line emission, charge exchange, ionization, stripping, dissociation and particle interchange reactions. The range of collision energies is appropriate to applications in fusion-energy research.

Hunter, H.T.; Kirkpatrick, M.I.; Alvarez, I.; Cisneros, C.; Phaneuf, R.A. (eds.) [eds.; Barnett, C.F.

1990-07-01

242

Fusion reactors as a future energy source  

Microsoft Academic Search

A detailed update of fusion research concepts is given. Discussions are given for the following areas: (1) the magnetic confinement principle, (2) UWMAK I: conceptual design for a fusion reactor, (3) the inertial confinement principle, (4) the laser fusion power plant, (5) electron-induced fusion, (6) the long-term development potential of fusion reactors, (7) the symbiosis between fusion and fission reactors,

W. Seifritz

1975-01-01

243

Cell Fusion and Stem Cells  

Microsoft Academic Search

\\u000a Differentiation, self-renewal and the ability to readily undergo cell fusion are properties of adult and embryonic stem cells.\\u000a Spontaneous fusion between stem cells, and fusion of stem cells with various differentiated cell types, has been observed\\u000a in many in vitro and in vivo contexts. Stem cell fusion is implicated in many crucial functions during normal development\\u000a and is increasingly being

Alain Silk; Anne E. Powell; Paige S. Davies; Melissa H. Wong

244

Human-Centered Fusion Framework  

SciTech Connect

In recent years the benefits of fusing signatures extracted from large amounts of distributed and/or heterogeneous data sources have been largely documented in various problems ranging from biological protein function prediction to cyberspace monitoring. In spite of significant progress in information fusion research, there is still no formal theoretical framework for defining various types of information fusion systems, defining and analyzing relations among such types, and designing information fusion systems using a formal method approach. Consequently, fusion systems are often poorly understood, are less than optimal, and/or do not suit user needs. To start addressing these issues, we outline a formal humancentered fusion framework for reasoning about fusion strategies. Our approach relies on a new taxonomy for fusion strategies, an alternative definition of information fusion in terms of parameterized paths in signature related spaces, an algorithmic formalization of fusion strategies and a library of numeric and dynamic visual tools measuring the impact as well as the impact behavior of fusion strategies. Using a real case of intelligence analysis we demonstrate that the proposed framework enables end users to rapidly 1) develop and implement alternative fusion strategies, 2) understand the impact of each strategy, 3) compare the various strategies, and 4) perform the above steps without having to know the mathematical foundations of the framework. We also demonstrate that the human impact on a fusion system is critical in the sense that small changes in strategies do not necessarily correspond to small changes in results.

Posse, Christian; White, Amanda M.; Beagley, Nathaniel

2007-05-16

245

Laser Inertial Fusion-based  

E-print Network

pure fusion system #12;5 #12;6 #12;Moses, 24th Annual ASPE Meeting 7 Laser diodes and He gas cooling have been developed as part of the Mercury Project and allows ultra-compact laser architectures HighLIFE: Laser Inertial Fusion-based Energy Presented by Jeff Latkowski LIFE Chief Engineer Fusion

246

Gasdynamic Mirror Fusion Propulsion Experiment  

Microsoft Academic Search

A gasdynamic mirror (GDM) fusion propulsion experiment is currently being constructed at the NASA Marshall Space Flight Center (MSFC) to test the feasibility of this particular type of fusion device. Because of the open magnetic field line configuration of mirror fusion devices, they are particularly well suited for propulsion system applications since they allow for the easy ejection of thrust

Bill Emrich

2000-01-01

247

The fusion applications study - FAME  

Microsoft Academic Search

The Fusion Applications and Market Evaluation (''FAME'') study, being conducted by GA Technologies for Lawrence Livermore National Laboratory (LLNL) and US Department of Energy, Office of Fusion Energy, (US DOE) is described. This two-year program has a FY86 objective of Evaluating Alternative Applications of Fusion, and a FY87 goal of Exploring Innovative Applications. Applications are being reviewed and categorized into

K. R. Schultz; B. A. Engholm; R. F. Bourque; E. T. Cheng; M. J. Schaffer; C. P. C. Wong

1986-01-01

248

Fusion Energy Sciences Program Mission  

E-print Network

research effort to advance plasma science, fusion science, and fusion technology--the knowledge base needed of energy is released. Fusion science research is organized around the two leading methods of confining the ongoing negotiations to construct the international burning plasma experiment, ITER. The National Research

249

Cell fusion: an EFFicient sculptor.  

PubMed

Mutations in the eff-1 gene of Caenorhabditis elegans, which prevent all cell-cell fusions in the nematode's epidermis, have revealed developmental roles for cell fusion. An extracellular fusogen-like domain in EFF-1 suggests it might direct the fusion of lipid bilayers. PMID:12121640

Witze, Eric; Rothman, Joel H

2002-07-01

250

V-fusion: a convenient, nontoxic method for cell fusion.  

PubMed

Cell-to-cell fusion (cell fusion) is a fundamental biological process that also has been used as a versatile experimental tool to dissect a variety of cellular mechanisms, including the consequences of cell fusion itself, and to produce cells with desired properties, such as hybridomas and reprogrammed progenitors. However, current methods of cell fusion are not satisfactory because of their toxicity, inefficiency, or lack of flexibility. We describe a simple, versatile, scalable, and nontoxic approach that we call V-fusion, as it is based on the ability of the vesicular stomatitis virus G protein (VSV-G), a viral fusogen of broad tropism, to become rapidly and reversibly activated. We suggest that this approach will benefit a broad array of studies that investigate consequences of cell fusion or use cell fusion as an experimental tool. PMID:20964635

Gottesman, Amy; Milazzo, Joseph; Lazebnik, Yuri

2010-10-01

251

Fusion power Bouillabaisse sushi  

E-print Network

to be joining America, China, Russia and South Korea in a project called , which aims to build a fusion reactor and Rokkasho in Japan. America is siding with Japan, while the French have the backing of the Chinese on Iraq. America is commonly thought to be supporting Rokkasho in return for Japan's support in Iraq

252

Mars manned fusion spaceship  

NASA Technical Reports Server (NTRS)

Fusion Propulsion has an enormous potential for space exploration in the near future. In the twenty-first century, a usable and efficient fusion rocket will be developed and in use. Because of the great distance between other planets and Earth, efficient use of time, fuel, and payload is essential. A nuclear spaceship would provide greater fuel efficiency, less travel time, and a larger payload. Extended missions would give more time for research, experiments, and data acquisition. With the extended mission time, a need for an artificial environment exists. The topics of magnetic fusion propulsion, living modules, artificial gravity, mass distribution, space connection, and orbital transfer to Mars are discussed. The propulsion system is a magnetic fusion reactor based on a tandem mirror design. This allows a faster, shorter trip time and a large thrust to weight ratio. The fuel proposed is a mixture of deuterium and helium-3. Helium-3 can be obtained from lunar mining. There will be minimal external radiation from the reactor resulting in a safe, efficient propulsion system.

Hedrick, James; Buchholtz, Brent; Ward, Paul; Freuh, Jim; Jensen, Eric

1991-01-01

253

Bubble fusion: Preliminary estimates  

SciTech Connect

The collapse of a gas-filled bubble in disequilibrium (i.e., internal pressure {much_lt} external pressure) can occur with a significant focusing of energy onto the entrapped gas in the form of pressure-volume work and/or acoustical shocks; the resulting heating can be sufficient to cause ionization and the emission of atomic radiations. The suggestion that extreme conditions necessary for thermonuclear fusion to occur may be possible has been examined parametrically in terms of the ratio of initial bubble pressure relative to that required for equilibrium. In this sense, the disequilibrium bubble is viewed as a three-dimensional ``sling shot`` that is ``loaded`` to an extent allowed by the maximum level of disequilibrium that can stably be achieved. Values of this disequilibrium ratio in the range 10{sup {minus}5}--10{sup {minus}6} are predicted by an idealized bubble-dynamics model as necessary to achieve conditions where nuclear fusion of deuterium-tritium might be observed. Harmonic and aharmonic pressurizations/decompressions are examined as means to achieve the required levels of disequilibrium required to create fusion conditions. A number of phenomena not included in the analysis reported herein could enhance or reduce the small levels of nuclear fusions predicted.

Krakowski, R.A.

1995-02-01

254

Fusion Ignition Research Experiment (FIRE)  

NSDL National Science Digital Library

A division of the Princeton Plasma Research Laboratory (described in the July 1, 1994 Scout Report for Science & Engineering), the Fusion Ignition Research Experiment (FIRE) aims "to attain, explore, understand and optimize alpha-dominated plasmas to provide knowledge for the design of attractive Magnetic Fusion systems." Up-to-date, downloadable reports (.pdf and MS Word formats) contain background information and reviews of US fusion policy, Snowmass Fusion Summer Study working group summaries, FIRE reports on physics and engineering design considerations, and an engineering appendix. Clearly displayed, this site harbors a wealth of dense information for researchers interested in the design of magnetic fusion systems.

255

Stau-catalyzed Nuclear Fusion  

E-print Network

We point out that the stau may play a role of a catalyst for nuclear fusions if the stau is a long-lived particle as in the scenario of gravitino dark matter. In this letter, we consider d d fusion under the influence of stau where the fusion is enhanced because of a short distance between the two deuterons. We find that one chain of the d d fusion may release an energy of O(10) GeV per stau. We discuss problems of making the stau-catalyzed nuclear fusion of practical use with the present technology of producing stau.

K. Hamaguchi; T. Hatsuda; T. T. Yanagida

2006-10-06

256

Accelerators for heavy ion fusion  

SciTech Connect

Large fusion devices will almost certainly produce net energy. However, a successful commercial fusion energy system must also satisfy important engineering and economic constraints. Inertial confinement fusion power plants driven by multi-stage, heavy-ion accelerators appear capable of meeting these constraints. The reasons behind this promising outlook for heavy-ion fusion are given in this report. This report is based on the transcript of a talk presented at the Symposium on Lasers and Particle Beams for Fusion and Strategic Defense at the University of Rochester on April 17-19, 1985.

Bangerter, R.O.

1985-10-01

257

Research on fusion neutron sources  

NASA Astrophysics Data System (ADS)

The use of fusion devices as powerful neutron sources has been discussed for decades. Whereas the successful route to a commercial fusion power reactor demands steady state stable operation combined with the high efficiency required to make electricity production economic, the alternative approach to advancing the use of fusion is free of many of complications connected with the requirements for economic power generation and uses the already achieved knowledge of Fusion physics and developed Fusion technologies. "Fusion for Neutrons" (F4N), has now been re-visited, inspired by recent progress achieved on comparably compact fusion devices, based on the Spherical Tokamak (ST) concept. Freed from the requirement to produce much more electricity than used to drive it, a fusion neutron source could be efficiently used for many commercial applications, and also to support the goal of producing energy by nuclear power. The possibility to use a small or medium size ST as a powerful or intense steady-state fusion neutron source (FNS) is discussed in this paper in comparison with the use of traditional high aspect ratio tokamaks. An overview of various conceptual designs of compact fusion neutron sources based on the ST concept is given and they are compared with a recently proposed Super Compact Fusion Neutron Source (SCFNS), with major radius as low as 0.5 metres but still able to produce several MW of neutrons in a steady-state regime.

Gryaznevich, M. P.

2012-06-01

258

Physics of magnetic confinement fusion  

NASA Astrophysics Data System (ADS)

Fusion is the energy source of the universe. The local conditions in the core of the Sun allow the transfer of mass into energy, which is finally released in the form of radiation. Technical fusion melts deuterons and tritons to helium releasing large amounts of energy per fusion process. Because of the conditions for fusion, which will be deduced, the fusion fuel is in the plasma state. Here we report on the confinement of fusion plasmas by magnetic fields. Different confinement concepts — tokamaks and stellarators — will be introduced and described. The first fusion reactor, ITER, and the most modern stellarator, Wendelstein 7-X, are under construction. Their basic features and objectives will be presented.

Wagner, F.

2013-06-01

259

Twelve-month results of a multicenter, blinded, pilot study of a novel peptide (B2A) in promoting lumbar spine fusion.  

PubMed

OBJECT Failure of fusion after a transforaminal lumbar interbody fusion (TLIF) procedure is a challenging problem that can lead to ongoing low-back pain, dependence on pain medication, and inability to return to work. B2A is a synthetic peptide that has proven efficacy in achieving fusion in animal models and may have a better safety profile than bone morphogenetic protein. The authors undertook this study to evaluate the safety and efficacy of B2A peptide-enhanced ceramic granules (Prefix) in comparison with autogenous iliac crest bone graft (ICBG, control) in patients undergoing single-level TLIF. METHODS Twenty-four patients with single-level degenerative disorders of the lumbar spine at L2-S1 requiring TLIF were enrolled between 2009 and 2010. They were randomly assigned to 3 groups: a control group (treated with ICBG, n = 9), a Prefix 150 group (treated with Prefix 150 ?g/cm(3) granules, n = 8), and a Prefix 750 group (treated with Prefix 750 ?g/cm(3) granules, n = 7). Outcome measures included the Oswestry Disability Index (ODI), visual analog pain scale, and radiographic fusion as assessed by CT and dynamic flexion/extension lumbar plain radiographs. RESULTS At 12 months after surgery, the radiographic fusion rate was 100% in the Prefix 750 group, 78% in the control group, and 50% in the Prefix 150 group, although the difference was not statistically significant (p = 0.08). At 6 weeks the mean ODI score was 41.0 for the control group, 27.7 for the Prefix 750 group, and 32.2 for the Prefix 150 group, whereas at 12 months the mean ODI was 24.4 for control, 31.1 for Prefix 750, and 29.7 for Prefix 150 groups. Complications were evenly distributed among the groups. CONCLUSIONS Prefix appears to provide a safe alternative to autogenous ICBG. Prefix 750 appears to show superior radiographic fusion when compared with autograft at 12 months after TLIF, although no statistically significant difference was demonstrated in this small study. Prefix and control groups both appeared to demonstrate comparable improvements to ODI at 12 months. PMID:25615629

Sardar, Zeeshan; Alexander, David; Oxner, William; Plessis, Stephan du; Yee, Albert; Wai, Eugene K; Anderson, D Greg; Jarzem, Peter

2015-04-01

260

Update review and clinical presentation on chronic low back pain treated by AxiaLIF  

Microsoft Academic Search

Paracoccygeal approach to the L5–S1 junction with transsacral instrumentation was described recently as an alternative method\\u000a to transforaminal lumbar interbody fusion or posterior lumbar interbody fusion. A percutaneous L5–S1 discectomy, interbody\\u000a distraction, and fixation could be achieved while preserving the integrity of the muscles, ligaments, and disc anulus. Retroperitoneal\\u000a viscera and dorsal neural elements are avoided via the presacral safe

Samo K. Fokter

2011-01-01

261

Fusion pumped laser  

DOEpatents

The apparatus of this invention may comprise a system for generating laser radiation from a high-energy neutron source. The neutron source is a tokamak fusion reactor generating a long pulse of high-energy neutrons and having a temperature and magnetic field effective to generate a neutron flux of at least 10/sup 15/ neutrons/cm/sup 2//center dot/s. Conversion means are provided adjacent the fusion reactor at a location operable for converting the high-energy neutrons to an energy source with an intensity and energy effective to excite a preselected lasing medium. A lasing medium is spaced about and responsive to the energy source to generate a population inversion effective to support laser oscillations for generating output radiation. 2 figs., 2 tabs.

Pappas, D.S.

1987-07-31

262

Spectral label fusion.  

PubMed

We present a new segmentation approach that combines the strengths of label fusion and spectral clustering. The result is an atlas-based segmentation method guided by contour and texture cues in the test image. This offers advantages for datasets with high variability, making the segmentation less prone to registration errors. We achieve the integration by letting the weights of the graph Laplacian depend on image data, as well as atlas-based label priors. The extracted contours are converted to regions, arranged in a hierarchy depending on the strength of the separating boundary. Finally, we construct the segmentation by a region-wise, instead of voxel-wise, voting, increasing the robustness. Our experiments on cardiac MRI show a clear improvement over majority voting and intensity-weighted label fusion. PMID:23286157

Wachinger, Christian; Golland, Polina

2012-01-01

263

ProFusion  

NSDL National Science Digital Library

Originally developed by the University of Kansas Information Telecommunication and Technology Center, and School of Engineering DesignLab (see the July 25, 1997 Scout Report), ProFusion is a meta-search and "deep Web" search engine. Purchased by Intelliseek and fitted with a new interface, ProFusion allows users to search over 1,000 search sites, "including search engines, Web directories, discussion groups, news sources, online publications, and archives." Visitors can also perform targeted searches of vertical search sources, selecting which databases to query. Two other new features include an alert service that tracks changes to selected pages and notifies users by email and a Search Assistant that suggests results from search engine groups relevant to a query in addition to the general Web results. Worth a spin around the block.

264

Laser fusion program  

Microsoft Academic Search

Progress in the development of high-energy short-pulse CO2 laser systems for fusion research is reported. The single beam system was used for target experimentation, and its optical train was improved. The initiation of two-beam target experiments on the two-beam system is described. Progress in construction checkout of the eight-beam system is continuing. The prototype program and HEGLF system design are

E. Stark; F. Skoberne

1977-01-01

265

(Fusion energy research)  

SciTech Connect

This report discusses the following topics: principal parameters achieved in experimental devices (FY88); tokamak fusion test reactor; Princeton beta Experiment-Modification; S-1 Spheromak; current drive experiment; x-ray laser studies; spacecraft glow experiment; plasma deposition and etching of thin films; theoretical plasma; tokamak modeling; compact ignition tokamak; international thermonuclear experimental reactor; Engineering Department; Project Planning and Safety Office; quality assurance and reliability; and technology transfer.

Phillips, C.A. (ed.)

1988-01-01

266

Modular Aneutronic Fusion Engine  

SciTech Connect

NASA's JUNO mission will arrive at Jupiter in July 2016, after nearly five years in space. Since operational costs tend to rise with mission time, minimizing such times becomes a top priority. We present the conceptual design for a 10MW aneutronic fusion engine with high exhaust velocities that would reduce transit time for a Jupiter mission to eighteen months and enable more challenging exploration missions in the solar system and beyond. __________________________________________________

Gary Pajer, Yosef Razin, Michael Paluszek, A.H. Glasser and Samuel Cohen

2012-05-11

267

Europe: tilting toward fusion  

Microsoft Academic Search

Nuclear reactor technology, which has been developing in Europe since World War II, has progressed to the breeder, and is now developing fusion programs. In spite of some safety concerns, Britain is likely to shift its next nuclear effort to the pressurized-water reactor (PWR) after a period of emphasizing the advanced gas-cooled reactors (AGRs). France began in 1959 with gas-cooled

1976-01-01

268

High Level Information Fusion (HLIF) with nested fusion loops  

NASA Astrophysics Data System (ADS)

Situation modeling and threat prediction require higher levels of data fusion in order to provide actionable information. Beyond the sensor data and sources the analyst has access to, the use of out-sourced and re-sourced data is becoming common. Through the years, some common frameworks have emerged for dealing with information fusion—perhaps the most ubiquitous being the JDL Data Fusion Group and their initial 4-level data fusion model. Since these initial developments, numerous models of information fusion have emerged, hoping to better capture the human-centric process of data analyses within a machine-centric framework. 21st Century Systems, Inc. has developed Fusion with Uncertainty Reasoning using Nested Assessment Characterizer Elements (FURNACE) to address challenges of high level information fusion and handle bias, ambiguity, and uncertainty (BAU) for Situation Modeling, Threat Modeling, and Threat Prediction. It combines JDL fusion levels with nested fusion loops and state-of-the-art data reasoning. Initial research has shown that FURNACE is able to reduce BAU and improve the fusion process by allowing high level information fusion (HLIF) to affect lower levels without the double counting of information or other biasing issues. The initial FURNACE project was focused on the underlying algorithms to produce a fusion system able to handle BAU and repurposed data in a cohesive manner. FURNACE supports analyst's efforts to develop situation models, threat models, and threat predictions to increase situational awareness of the battlespace. FURNACE will not only revolutionize the military intelligence realm, but also benefit the larger homeland defense, law enforcement, and business intelligence markets.

Woodley, Robert; Gosnell, Michael; Fischer, Amber

2013-05-01

269

COLLABORATIVE: FUSION SIMULATION PROGRAM  

SciTech Connect

New York University, Courant Institute of Mathematical Sciences, participated in the ���¢��������Fusion Simulation Program (FSP) Planning Activities���¢������� [http://www.pppl.gov/fsp], with C.S. Chang as the institutional PI. FSP���¢��������s mission was to enable scientific discovery of important new plasma phenomena with associated understanding that emerges only upon integration. This requires developing a predictive integrated simulation capability for magnetically-confined fusion plasmas that are properly validated against experiments in regimes relevant for producing practical fusion energy. Specific institutional goal of the New York University was to participate in the planning of the edge integrated simulation, with emphasis on the usage of large scale HPCs, in connection with the SciDAC CPES project which the PI was leading. New York University successfully completed its mission by participating in the various planning activities, including the edge physics integration, the edge science drivers, and the mathematical verification. The activity resulted in the combined report that can be found in http://www.pppl.gov/fsp/Overview.html. Participation and presentations as part of this project are listed in a separation file.

Chang, Choong Seock

2012-06-05

270

Intitutional constraints to fusion commercialization  

SciTech Connect

The major thrust of this report is that the long time frame associated with the development of commercial fusion systems in the context of the commercialization and institutional history of an allied technology, fission-power, suggests that fusion commercialization will not occur without active and broad-based support on the part of the Nation's political leaders. Its key recommendation is that DOE fusion planners devote considerable resources to analytical efforts aimed at determining the need for fusion and the timing of that need, in order to convince policymakers that they need do more than preserve fusion as an option for application at some indefinite point in the future. It is the thesis of the report that, in fact, an act of political vision on the part of the Nation's leaders will be required to accomplish fusion commercialization.

Not Available

1979-10-01

271

Stockpile tritium production from fusion  

SciTech Connect

A fusion breeder holds the promise of a new capability - ''dialable'' reserve capacity at little additional cost - that offers stockpile planners a new way to deal with today's uncertainties in forecasting long range needs. Though still in the research stage, fusion can be developed in time to meet future military requirements. Much of the necessary technology will be developed by the ongoing magnetic fusion energy program. However, a specific program to develop the nuclear technology required for materials production is needed if fusion is to become a viable option for a new production complex around the turn of the century.

Lokke, W.A.; Fowler, T.K.

1986-03-21

272

Economic potential of inertial fusion  

SciTech Connect

Beyond the achievement of scientific feasibility, the key question for fusion energy is: does it have the economic potential to be significantly cheaper than fission and coal energy. If fusion has this high economic potential then there are compelling commercial and geopolitical incentives to accelerate the pace of the fusion program in the near term, and to install a global fusion energy system in the long term. Without this high economic potential, fusion's success depends on the failure of all alternatives, and there is no real incentive to accelerate the program. If my conjectures on the economic potential of inertial fusion are approximately correct, then inertial fusion energy's ultimate costs may be only half to two-thirds those of advanced fission and coal energy systems. Relative cost escalation is not assumed and could increase this advantage. Both magnetic and inertial approaches to fusion potentially have a two-fold economic advantage which derives from two fundamental properties: negligible fuel costs and high quality energy which makes possible more efficient generation of electricity. The wining approach to fusion may excel in three areas: electrical generating efficiency, minimum material costs, and adaptability to manufacture in automated factories. The winning approach must also rate highly in environmental potential, safety, availability factor, lifetime, small 0 and M costs, and no possibility of utility-disabling accidents.

Nuckolls, J.H.

1984-04-01

273

The path to fusion power†  

PubMed Central

The promise, status and challenges of developing fusion power are outlined. The key physics and engineering principles are described and recent progress quantified. As the successful demonstration of 16?MW of fusion in 1997 in the Joint European Torus showed, fusion works. The central issue is therefore to make it work reliably and economically on the scale of a power station. We argue that to meet this challenge in 30 years we must follow the aggressive programme known as the ‘Fast Track to Fusion’. This programme is described in some detail. PMID:20123748

Smith, Chris Llewellyn; Cowley, Steve

2010-01-01

274

Helium Find Thaws the Cold Fusion Trail.  

ERIC Educational Resources Information Center

Reported is a study of cold fusion in which trace amounts of helium, possible evidence of an actual fusion reaction, were found. Research methodology is detailed. The controversy over the validity of experimental results with cold fusion are reviewed. (CW)

Pennisi, E.

1991-01-01

275

Weapons Activities/ Inertial Confinement Fusion Ignition  

E-print Network

Weapons Activities/ Inertial Confinement Fusion Ignition and High Yield Campaign FY 2012 Congressional Budget Inertial Confinement Fusion Ignition and High Yield Campaign Funding Profile by Subprogram FY 2010 Actual Appropriation FY 2011 Request FY 2012 Request Inertial Confinement Fusion Ignition

276

Fusion project decision delayed ITER -NUCLEAR FUSION PROJECT  

E-print Network

and Technology ministry. Self-sustaining Iter is the boldest nuclear initiative since the Manhattan ProjectFusion project decision delayed ITER - NUCLEAR FUSION PROJECT The project is estimated to cost $5bn or Japan for the multi-billion dollar project. The US has been against the French option because of France

277

Muon-catalyzed fusion: a new direction in fusion research  

SciTech Connect

In four years of intensive research, muon-catalyzed fusion has been raised from the level of a scientific curiosity to a potential means of achieving clean fusion energy. This novel approach to fusion is based on the fact that a sub-atomic particle known as a ''muon'' can induce numerous energy-releasing fusion reactions without the need for high temperatures or plasmas. Thus, the muon serves as a catalyst to facilitate production for fusion energy. The success of the research effort stems from the recent discovery of resonances in the reaction cycle which make the muon-induced fusion process extremely efficient. Prior estimates were pessimistic in that only one fusion per muon was expected. In that case energy balance would be impossible since energy must be invested to generate the muons. However, recent work has gone approximately half-way to energy balance and further improvements are being worked on. There has been little time to assess the full implications of these discoveries. However, various ways to use muon-catalyzed fusion for electrical power production are now being explored.

Jones, S.E.

1986-01-01

278

Laser Fusion Research at NRL Fusion Power Associates Meeting  

E-print Network

are conducted on the Nike KrF facility Nike is operated by 3 technicians Nike's angularly multiplexed opticalLaser Fusion Research at NRL Fusion Power Associates Meeting Washington DC 5 December 2012 Presented by Steve Obenschain Laser Plasma Branch Plasma Physics Division U.S. Naval Research Laboratory

279

Microwave superheaters for fusion  

NASA Astrophysics Data System (ADS)

The microwave superheater uses the synchrotron radiation from a thermonuclear plasma to heat gas seeded with an alkali metal to temperatures far above the temperature of material walls. It can improve the efficiency of the Compact Fusion Advanced Rankine (CFAR) cycle described elsewhere in these proceedings. For a proof-of-principle experiment using helium, calculations show that a gas superheat delta T of 2000 K is possible when the wall temperature is maintained at 1000 K. The concept can be scaled to reactor grade systems. Because of the need for synchrotron radiation, the microwave superheater is best suited for use with plasmas burning an advanced fuel such as D He-3.

Campbell, R. B.; Hoffman, M. A.; Logan, B. G.

1987-10-01

280

Fission and Fusion Game  

NSDL National Science Digital Library

In this activity, students play a board game where they learn the characteristics of and differences between fission and fusion, as well as the real world applications of these energy-releasing reactions. Reproducible game cards and and game board are included in the resource. The investigation supports material presented in chapter 3, "What Heats the Earth's Interior?" in the textbook, Energy flow, part of the Global System Science, an interdisciplinary course for high school students that emphasizes how scientists from a wide variety of fields work together to understand significant problems of global impact.

281

Fusion reactor pumped laser  

DOEpatents

A nuclear pumped laser capable of producing long pulses of very high power laser radiation is provided. A toroidal fusion reactor provides energetic neutrons which are slowed down by a moderator. The moderated neutrons are converted to energetic particles capable of pumping a lasing medium. The lasing medium is housed in an annular cell surrounding the reactor. The cell includes an annular reflecting mirror at the bottom and an annular output window at the top. A neutron reflector is disposed around the cell to reflect escaping neutrons back into the cell. The laser radiation from the annular window is focused onto a beam compactor which generates a single coherent output laser beam.

Jassby, Daniel L. (Princeton, NJ)

1988-01-01

282

The future of fusion  

NASA Astrophysics Data System (ADS)

The population of the world is increasing, mainly in the developing world, and is projected to saturate within about 100 years at up to twice the present population of 6 billion people (Bos et al., World Population Projections: 1994-95 Edition, Published for the World Bank). Studies (Goldemberg and Johansson (Eds.), Energy as an Instrument for Socio-Economic Development United Nations Development Programme, New York, 1995, p. 9; United Nations Statistical Yearbooks, 10th issue; 1965; 20th issue; 1975, 22nd issue, 1977; 32nd issue, 1987; and 39th issue 1994, United Nations Publications; Sheffield, J. Technol. Forecasting Social Change 59 (1998) 55.) show that, historically, the population growth rate has varied inversely as the annual per capita energy use in most parts of the developing world, where per capita energy use is typically less than 1 t of oil equivalent energy per year. However, in areas with more than 2-3 t of oil equivalent of energy use per year per person, the growth rate is around zero. If this trend continues, a stable world population will require, allowing for energy efficiency improvements, some 2-3 times the present annual energy use. There is an abundance of energy in the world both exploited and potential to meet this need - fossil, fission, and renewables - but it is not evenly distributed, some are costly, and there are issues of environmental pollution in present use, that may limit use. Fusion energy is a potential longer-term source with attractive environmental features. It is the least-developed energy option and still faces a challenging development path, but there are many areas of the world that would benefit hugely from its deployment from the later part of the 21st century onward, and it is important to consider how it might be deployed. Most fusion power plant options considered today show an economy of scale, owing to the fixed distance needed for shielding fusion neutrons, tritium breeding and handling the heat loads. One interesting approach is to use the power plant to co-produce electricity and hydrogen to facilitate the introduction of lower cost of electricity, multi-gigawatt power plants (Sheffield et al., A study of options for the deployment of large fusion power plants, 2000, to be published).

Sheffield, John

2001-05-01

283

The modified Lapidus fusion.  

PubMed

Due to its proximal correction site and long lever arm, the Lapidus fusion, modified or not, is a powerful technique to correct hallux valgus deformities. The disadvantages are a high complication rate and a long postoperative rehabilitation period. It is only performed in 5% to 10% of all hallux valgus deformity corrections but remains, however, an important procedure, especially in moderate to severe deformities with intermetatarsal angles more than 14°, hypermobility of the first ray, arthritis of the first tarsometatarsal joint, and recurrent deformities. This article provides an overview of the procedure with special focus on the surgical technique. PMID:24878411

Schmid, Timo; Krause, Fabian

2014-06-01

284

Entry states in subbarrier fusion  

Microsoft Academic Search

The cross section for fusion of heavy ions below the Coulomb barrier can be orders of magnitude larger than the predictions of models that are quite successful above the barrier. Recent studies of ..gamma..-ray multiplicity have shown that the average l of the partial waves participating in subbarrier fusion is much higher than expected. The discrepancies become larger as the

M. L. Halbert; J. R. Beene; D. C. Hensley; K. Honkanen; T. Semkow; V. Abenante; D. G. Sarantites

1986-01-01

285

Plasma Physics for Nuclear Fusion  

Microsoft Academic Search

The book focuses on the properties of gaseous plasmas needed in the attainment of controlled fusion reactions. The first five chapters develop the fundamentals of plasma physics and present the conditions of nuclear fusion reactions. The next four provide a magnetohydrodynamic description of plasmas, followed by four chapters that explain wave phenomena and instabilities by means of a kinetic model.

K. Miyamoto; Robert L. Dewar

1980-01-01

286

Cellulose binding domain fusion proteins  

SciTech Connect

A cellulose binding domain (CBD) having a high affinity for crystalline cellulose and chitin is disclosed, along with methods for the molecular cloning and recombinant production thereof. Fusion products comprising the CBD and a second protein are likewise described. A wide range of applications are contemplated for both the CBD and the fusion products, including drug delivery, affinity separations, and diagnostic techniques.

Shoseyov, Oded (Karmey Yosef, IL); Shpiegl, Itai (Rehovot, IL); Goldstein, Marc A. (Davis, CA); Doi, Roy H. (Davis, CA)

1998-01-01

287

Cellulose binding domain fusion proteins  

SciTech Connect

A cellulose binding domain (CBD) having a high affinity for crystalline cellulose and chitin is disclosed, along with methods for the molecular cloning and recombinant production. Fusion products comprising the CBD and a second protein are likewise described. A wide range of applications are contemplated for both the CBD and the fusion products, including drug delivery, affinity separations, and diagnostic techniques. 16 figs.

Shoseyov, O.; Yosef, K.; Shpiegl, I.; Goldstein, M.A.; Doi, R.H.

1998-02-17

288

Pulsed power fusion program update  

Microsoft Academic Search

The US Department of Energy has supported a substantial research program in Inertial Confinement Fusion (ICF) since the early 1970s. Over the ensuing 25 years, pulsed power approaches to inertial fusion have remained of interest primarily because of the high energy, efficiency, and relatively low cost of the technology when compared to the mainline ICF approach involving large glass lasers.

J. P. Quintenz; R. G. Adams; G. O. Allshouse; J. E. Bailey; D. D. Bloomquist; G. A. Chandler; R. S. Coats; D. L. Cook; M. E. Cuneo; C. Deeney; M. S. Derzon; M. P. Desjarlais; M. R. Douglas; D. L. Fehl; A. B. Filuk; T. A. Haill; D. L. Hanson; D. J. Johnson; M. L. Kiefer; J. S. Lash; R. J. Leeper; B. M. Marder; M. K. Matzen; D. H. McDaniel; E. J. McGuire; T. A. Mehlhorn; L. P. Mix; A. R. Moats; T. J. Nash; C. L. Olson; R. E. Olson; T. D. Pointon; J. L. Porter; C. L. Ruiz; T. W. L. Sanford; J. F. Seamen; D. B. Seidel; S. A. Slutz; R. B. Spielman; W. A. Stygar; M. A. Sweeney; R. A. Vesey; D. F. Wenger

1998-01-01

289

The status of cold fusion  

Microsoft Academic Search

This report attempts to update the status of the phenomenon of cold fusion. The new field is continuing to grow as a variety of nuclear reactions are discovered to occur in a variety of chemical environments at modest temperatures. However, it must be cautioned that most scientists consider cold fusion as something akin to UFO's, ESP, and numerology.

E. Storms

1993-01-01

290

Nuclear Fusion Technology In Japan  

Microsoft Academic Search

This is a technological assessment of the status of nuclear fusion researah and development technology in Japan. The Japanese nuclear policy, vision, goals, and supporting organizational structure are reviewed. The supporting facilities of the Japanese Atomic Energy Re- search Institute (JAERI) are illustrated and described. Specific emphasis is placed on the JAERI Naka Fusion Research Establishment near Mito. New photographic

Floyd A Wyczalek

1990-01-01

291

ITER activities and fusion technology  

Microsoft Academic Search

At the 21st IAEA Fusion Energy Conference, 68 and 67 papers were presented in the categories of ITER activities and fusion technology, respectively. ITER performance prediction, results of technology R&D and the construction preparation provide good confidence in ITER realization. The superconducting tokamak EAST achieved the first plasma just before the conference. The construction of other new experimental machines has

M. Seki

2007-01-01

292

Docking and fusion in neurosecretion  

Microsoft Academic Search

A central issue in neurobiology concerns the mechanisms of membrane fusion that are essential for the rapid regulated delivery of neurotransmitters into the synapse. While many gene products are required for neurosecretion, recent research has focused on defining the core exocytotic machinery that is responsible for the docking of synaptic vesicles (SVs) and their fusion with the plasma membrane. N-ethylmaleimide-sensitive

Linda J Robinson; Thomas FJ Martin

1998-01-01

293

Fusion Policy Advisory Committee (FPAC)  

SciTech Connect

This document is the final report of the Fusion Policy Advisory Committee. The report conveys the Committee's views on the matters specified by the Secretary in his charge and subsequent letters to the Committee, and also satisfies the provisions of Section 7 of the Magnetic Fusion Energy Engineering Act of 1980, Public Law 96-386, which require a triennial review of the conduct of the national Magnetic Fusion Energy program. Three sub-Committee's were established to address the large number of topics associated with fusion research and development. One considered magnetic fusion energy, a second considered inertial fusion energy, and the third considered issues common to both. For many reasons, the promise of nuclear fusion as a safe, environmentally benign, and affordable source of energy is bright. At the present state of knowledge, however, it is uncertain that this promise will become reality. Only a vigorous, well planned and well executed program of research and development will yield the needed information. The Committee recommends that the US commit to a plan that will resolve this critically important issue. It also outlines the first steps in a development process that will lead to a fusion Demonstration Power Plant by 2025. The recommended program is aggressive, but we believe the goal is reasonable and attainable. International collaboration at a significant level is an important element in the plan.

Not Available

1990-09-01

294

Operationally confined nuclear fusion system  

Microsoft Academic Search

This invention consists of a system for generating clean controllable inexpensive electrical power by nuclear fusion (Not fission) of light weight atoms and\\/or isotopes of hydrogen such as deuterium. Fusionable ions are accelerated head-on from many directions through the middle of a reaction chamber. Such ions are produced by especially designed cyclotrons aimed at one another. Since the orbital motion

Jarnagin

1980-01-01

295

Overview of fusion reactor safety  

Microsoft Academic Search

Use of deuterium-tritium fusion reactors requires examination of several major safety and environmental issues: (1) tritium inventory control; (2) neutron activation of structural materials, fluid streams and reactor hall environment; (3) release of radioactivity from energy sources including lithium spill reactions, superconducting magnet stored energy release, and plasma disruptions; (4) high magnetic and electromagnetic fields associated with fusion reactor superconducting

S. Cohen; J. G. Crocker

1981-01-01

296

The status of cold fusion  

NASA Astrophysics Data System (ADS)

This report attempts to update the status of the phenomenon of cold fusion. The new field is continuing to grow as a variety of nuclear reactions are discovered to occur in a variety of chemical environments at modest temperatures. However, it must be cautioned that most scientists consider cold fusion as something akin to UFO's, ESP, and numerology.

Storms, E.

297

Carrier materials for spinal fusion  

Microsoft Academic Search

Background contextThe rise in spinal fusion procedures has led to an increase in the available number and variety of bone graft substitutes. As our understanding of the biologic processes that influence bony fusion has improved, appreciation for the role of the carrier material involved in bone grafts has also increased.

Brian Kwon; Louis G. Jenis

2005-01-01

298

Fusion algebra of critical percolation  

E-print Network

We present an explicit conjecture for the chiral fusion algebra of critical percolation considering Virasoro representations with no enlarged or extended symmetry algebra. The representations we take to generate fusion are countably infinite in number. The ensuing fusion rules are quasi-rational in the sense that the fusion of a finite number of these representations decomposes into a finite direct sum of these representations. The fusion rules are commutative, associative and exhibit an sl(2) structure. They involve representations which we call Kac representations of which some are reducible yet indecomposable representations of rank 1. In particular, the identity of the fusion algebra is a reducible yet indecomposable Kac representation of rank 1. We make detailed comparisons of our fusion rules with the recent results of Eberle-Flohr and Read-Saleur. Notably, in agreement with Eberle-Flohr, we find the appearance of indecomposable representations of rank 3. Our fusion rules are supported by extensive numerical studies of an integrable lattice model of critical percolation. Details of our lattice findings and numerical results will be presented elsewhere.

Jorgen Rasmussen; Paul A. Pearce

2007-08-08

299

Cell fusion: EFF is enough.  

PubMed

Developmentally programmed cell-cell fusion in Caenorhabditis elegans requires the EFF-1 protein, which is sufficient to cause normally non-fusing cells to fuse. EFF-1 localizes to fusion-fated membranes, implicating it as a direct fusogen. PMID:15823525

Kontani, Kenji; Rothman, Joel H

2005-04-12

300

Activity : Fusion Reactions  

NSDL National Science Digital Library

This activity gives students an opportunity to learn about the elements created in the cores of high-mass stars by fusion reactions. They will discover that all stars start by burning hydrogen and end up creating many heavier elements inside their cores, elements that will be released into space when it dies in a supernova explosion. Students associate a layer with an element that is being produced by the high-mass star. This will illustrate that as the temperature of the star increases with depth, the ash of each burning stage becomes the fuel for the next stage. Surrounding the core of iron nuclei is a layer of silicon fusion, then magnesium, then neon, then oxygen, then carbon, then helium, and lastly, in the relatively cool periphery of the core, hydrogen fuses into helium. Students will draw their own version of the onion-like nature of the core of a star based on the model and explain the process that occurs at each layer.

2007-12-12

301

Statistics in fusion experiments  

NASA Astrophysics Data System (ADS)

Since the reasons for the variability in data from plasma experiments are often unknown or uncontrollable, statistical methods must be applied. Reliable interpretation and public accountability require full data sets. Two examples of data misrepresentation at PPPL are analyzed: Te >100 eV on S-1 spheromak.(M. Yamada, Nucl. Fusion 25, 1327 (1985); reports to DoE; etc.) The reported high values (statistical artifacts of Thomson scattering measurements) were selected from a mass of data with an average of 40 eV or less. ``Correlated'' spectroscopic data were meaningless. (2) Extrapolation to Q >=0.5 for DT in TFTR.(D. Meade et al., IAEA Baltimore (1990), V. 1, p. 9; H. P. Furth, Statements to U. S. Congress (1989).) The DD yield used there was the highest through 1990 (>= 50% above average) and the DT to DD power ratio used was about twice any published value. Average DD yields and published yield ratios scale to Q<0.15 for DT, in accord with the observed performance over the last 3 1/2 years. Press reports of outlier data from TFTR have obscured the fact that the DT behavior follows from trivial scaling of the DD data. Good practice in future fusion research would have confidence intervals and other descriptive statistics accompanying reported numerical values (cf. JAMA).

McNeill, D. H.

1997-11-01

302

Inertial confinement fusion  

SciTech Connect

This issue of the ICF Quarterly contains seven articles that describe recent progress in Lawrence Livermore National Laboratory's ICF program. The Department of Energy recently initiated an effort to design a 1--2 MJ glass laser, the proposed National Ignition Facility (NIF). These articles span various aspects of a program which is aimed at moving forward toward such a facility by continuing to use the Nova laser to gain understanding of NIF-relevant target physics, by developing concepts for an NIF laser driver, and by envisioning a variety of applications for larger ICF facilities. This report discusses research on the following topics: Stimulated Rotational Raman Scattering in Nitrogen; A Maxwell Equation Solver in LASNEX for the Simulation of Moderately Intense Ultrashort Pulse Experiments; Measurements of Radial Heat-Wave Propagation in Laser-Produced Plasmas; Laser-Seeded Modulation Growth on Directly Driven Foils; Stimulated Raman Scattering in Large-Aperture, High-Fluence Frequency-Conversion Crystals; Fission Product Hazard Reduction Using Inertial Fusion Energy; Use of Inertial Confinement Fusion for Nuclear Weapons Effects Simulations.

Powers, L.; Condouris, R.; Kotowski, M.; Murphy, P.W. (eds.)

1992-01-01

303

Utility requirements for fusion  

SciTech Connect

This report describes work done and results obtained during performance of Task 1 of a study of Utility Requirements and Criteria for Fusion Options. The work consisted of developing a list of utility requirements for fusion optics containing definition of the requirements and showing their relative importance to the utility industry. The project team members developed a preliminary list which was refined by discussions and literature searches. The refined list was recast as a questionnaire which was sent to a substantial portion of the utility industry in this country. Forty-three questionnaire recipients responded including thirty-two utilities. A workshop was held to develop a revised requirements list using the survey responses as a major input. The list prepared by the workshop was further refined by a panel consisting of vice presidents of the three project team firms. The results of the study indicate that in addition to considering the cost of energy for a power plant, utilities consider twenty-three other requirements. Four of the requirements were judged to be vital to plant acceptability: Plant Capital Cost, Financial Liability, Plant Safety and Licensability.

Vondrasek, R.J.

1982-02-01

304

Information integration for data fusion  

SciTech Connect

Data fusion has been identified by the Department of Defense as a critical technology for the U.S. defense industry. Data fusion requires combining expertise in two areas - sensors and information integration. Although data fusion is a rapidly growing area, there is little synergy and use of common, reusable, and/or tailorable objects and models, especially across different disciplines. The Laboratory-Directed Research and Development project had two purposes: to see if a natural language-based information modeling methodology could be used for data fusion problems, and if so, to determine whether this methodology would help identify commonalities across areas and achieve greater synergy. The project confirmed both of the initial hypotheses: that the natural language-based information modeling methodology could be used effectively in data fusion areas and that commonalities could be found that would allow synergy across various data fusion areas. The project found five common objects that are the basis for all of the data fusion areas examined: targets, behaviors, environments, signatures, and sensors. Many of the objects and the specific facts related to these objects were common across several areas and could easily be reused. In some cases, even the terminology remained the same. In other cases, different areas had their own terminology, but the concepts were the same. This commonality is important with the growing use of multisensor data fusion. Data fusion is much more difficult if each type of sensor uses its own objects and models rather than building on a common set. This report introduces data fusion, discusses how the synergy generated by this LDRD would have benefited an earlier successful project and contains a summary information model from that project, describes a preliminary management information model, and explains how information integration can facilitate cross-treaty synergy for various arms control treaties.

Bray, O.H.

1997-01-01

305

LiWall Fusion - The New Concept of Magnetic Fusion  

SciTech Connect

Utilization of the outstanding abilities of a liquid lithium layer in pumping hydrogen isotopes leads to a new approach to magnetic fusion, called the LiWall Fusion. It relies on innovative plasma regimes with low edge density and high temperature. The approach combines fueling the plasma by neutral injection beams with the best possible elimination of outside neutral gas sources, which cools down the plasma edge. Prevention of cooling the plasma edge suppresses the dominant, temperature gradient related turbulence in the core. Such an approach is much more suitable for controlled fusion than the present practice, relying on high heating power for compensating essentially unlimited turbulent energy losses.

L.E. Zakharov

2011-01-12

306

Modern magnetic fusion  

NASA Astrophysics Data System (ADS)

Adiabatic orbit theories are found inapplicable to fusion reactors because (a) zero-energy ions are incompatible with the Lawson Criterion; (b) adiabatic orbits are incompatible with orbit focusing which is crucial to modern magnetic confinement. They are replaced by exact cyclic accelerator orbit theory of single particle confinement using the ``field index'' in strong focusing mirror (SFM) and nonlinear, non-feedback stable neutralization by oscillating electrons. SFM is an axisymmetric, completely closed mirror, with min-B confinement in both r and z, i.e., infinite (zero loss cone) or negative mirror ratio (field reversed in center). It can be bult by 3 or more pairs of coils, or by diamagnetism. Axial mirror losses, previously interpreted as ``collective'' instabilities, are compatible with being caused by single particle instabilities. Synchrotron radiation losses, Ps, are greatly reduced by the Burkhardt effect that makes Ps independent of B for ??1. Effects of E, B, grad B, and grad E, E×B etc. on electron motions may become dominant. Large orbits show absence of anomalous diffusion, which defies the tenet that fusion reactors must be large. An elaborae 2 1/2 dimensional Fokker-Planck simulation on CRAY-2 indicates that D+3He high-beta migma in SFM will be ignited with ``cold'' fuel injection when 30% of the p's from D+3He??+p+18.35 MeV are trapped to cause population inversion of protons (negative proton temperature, i.e, maximum ``free energy''). The reactor is started by the injection of accelerated D+ and 3He+ (100's of keV); thereafter, only cold D, 3He and electrons (10 eV) are injected, and are collisionally accelerated by protons. With nion=6×1014cm-3, ?pL=0.9, the D+3He migma ignites with Q˜105 to generate 60 MWth m-3 of fusion power with 1% of power in neutrons, which meets the definition of ``aneutronic.'' Calculations of relaxation times using test particle-field particle formulas, which are non-physical in a negative temperature plasma, are replaced by Coulomb interactions of all ions with all ions. Multiple scattering effects are suppressed in focusing fields. The Rostoker effect of the internal currents acting on the ions further increase relaxation times.

Maglich, B. C.; Chuang, T.-F.; Powell, C.; Nering, J.; Wilmerding, A.

1994-07-01

307

Muon catalyzed fusion  

SciTech Connect

This paper presents an overview of the program and results of our experiment performed by a European-American collatoration at the Swiss Institute of Nuclear Research. Systematic investigations of the low temperature region (23K to 300K) reveal a surprisingly rich physics of mesoatomic and mesomolecular processes, unparalleled in other systems of isotopic hydrogen mixtures. A dramatic density dependence of the reaction rates is found. The rich structure in the time spectra of the fusion neutrons observed at low gas density yields first evidence for new effects, most likely strong contributions from reactions of hot muonic atoms. The important question of muon losses due to He sticking is investigated by different methods and over a wide range of tritium concentrations.

Breunlich, W.H.; Cargnelli, M.; Marton, J.; Naegele, N.; Pawlek, P.; Scrinzi, A.; Werner, J.; Zmeskal, J.; Bistirlich, J.; Crowe, K.M.

1986-01-01

308

Fusion reactor pumped laser  

DOEpatents

A nuclear pumped laser capable of producing long pulses of very high power laser radiation is provided. A toroidal fusion reactor provides energetic neutrons which are slowed down by a moderator. The moderated neutrons are converted to energetic particles capable of pumping a lasing medium. The lasing medium is housed in an annular cell surrounding the reactor. The cell includes an annular reflecting mirror at the bottom and an annular output window at the top. A neutron reflector is disposed around the cell to reflect escaping neutrons back into the cell. The laser radiation from the annular window is focused onto a beam compactor which generates a single coherent output laser beam. 10 figs.

Jassby, D.L.

1987-09-04

309

Fusion pumped laser  

DOEpatents

Apparatus is provided for generating energy in the form of laser radiation. A tokamak fusion reactor is provided for generating a long, or continuous, pulse of high-energy neutrons. The tokamak design provides a temperature and a magnetic field which is effective to generate a neutron flux of at least 10.sup.15 neutrons/cm.sup.2.s. A conversion medium receives neutrons from the tokamak and converts the high-energy neutrons to an energy source with an intensity and an energy effective to excite a preselected lasing medium. The energy source typically comprises fission fragments, alpha particles, and radiation from a fission event. A lasing medium is provided which is responsive to the energy source to generate a population inversion which is effective to support laser oscillations for generating output radiation.

Pappas, Daniel S. (Los Alamos, NM)

1989-01-01

310

Fusion Power Demonstration III  

SciTech Connect

This is the third in the series of reports covering the Fusion Power Demonstration (FPD) design study. This volume considers the FPD-III configuration that incorporates an octopole end plug. As compared with the quadrupole end-plugged designs of FPD-I and FPD-II, this octopole configuration reduces the number of end cell magnets and shortens the minimum ignition length of the central cell. The end-cell plasma length is also reduced, which in turn reduces the size and cost of the end cell magnets and shielding. As a contiuation in the series of documents covering the FPD, this report does not stand alone as a design description of FPD-III. Design details of FPD-III subsystems that do not differ significantly from those of the FPD-II configuration are not duplicated in this report.

Lee, J.D. (ed.)

1985-07-01

311

Fusion pumped light source  

DOEpatents

Apparatus is provided for generating energy in the form of light radiation. A fusion reactor is provided for generating a long, or continuous, pulse of high-energy neutrons. The neutron flux is coupled directly with the lasing medium. The lasing medium includes a first component selected from Group O of the periodic table of the elements and having a high inelastic scattering cross section. Gamma radiation from the inelastic scattering reactions interacts with the first component to excite the first component, which decays by photon emission at a first output wavelength. The first output wavelength may be shifted to a second output wavelength using a second liquid component responsive to the first output wavelength. The light outputs may be converted to a coherent laser output by incorporating conventional optics adjacent the laser medium.

Pappas, Daniel S. (Los Alamos, NM)

1989-01-01

312

Prospects for bubble fusion  

SciTech Connect

In this paper a new method for the realization of fusion energy is presented. This method is based on the superhigh compression of a gas bubble (deuterium or deuterium/thritium) in heavy water or another liquid. The superhigh compression of a gas bubble in a liquid is achieved through forced non-linear, non-periodic resonance oscillations using moderate amplitudes of forcing pressure. The key feature of this new method is a coordination of the forced liquid pressure change with the change of bubble volume. The corresponding regime of the bubble oscillation has been called {open_quotes}basketball dribbling (BD) regime{close_quotes}. The analytical solution describing this process for spherically symmetric bubble oscillations, neglecting dissipation and compressibility of the liquid, has been obtained. This solution shown no limitation on the supercompression of the bubble and the corresponding maximum temperature. The various dissipation mechanisms, including viscous, conductive and radiation heat losses have been considered. It is shown that in spite of these losses it is possible to achieve very high gas bubble temperatures. This because the time duration of the gas bubble supercompression becomes very short when increasing the intensity of compression, thus limiting the energy losses. Significantly, the calculated maximum gas temperatures have shown that nuclear fusion may be possible. First estimations of the affect of liquid compressibility have been made to determine possible limitations on gas bubble compression. The next step will be to investigate the role of interfacial instability and breaking down of the bubble, shock wave phenomena around and in the bubble and mutual diffusion of the gas and the liquid.

Nigmatulin, R.I. [Tyumen Institute of Mechanics of Multiphase Systems (TIMMS), Marx (Russian Federation); Lahey, R.T. Jr. [Rensselaer Polytechnic Institute, Troy, NY (United States)

1995-09-01

313

Soldier systems sensor fusion  

NASA Astrophysics Data System (ADS)

This paper addresses sensor fusion and its applications in emerging Soldier Systems integration and the unique challenges associated with the human platform. Technology that,provides the highest operational payoff in a lightweight warrior system must not only have enhanced capabilities, but have low power components resulting in order of magnitude reductions coupled with significant cost reductions. These reductions in power and cost will be achieved through partnership with industry and leveraging of commercial state of the art advancements in microelectronics and power sources. As new generation of full solution fire control systems (to include temperature, wind and range sensors) and target acquisition systems will accompany a new generation of individual combat weapons and upgrade existing weapon systems. Advanced lightweight thermal, IR, laser and video senors will be used for surveillance, target acquisition, imaging and combat identification applications. Multifunctional sensors will provide embedded training features in combat configurations allowing the soldier to 'train as he fights' without the traditional cost and weight penalties associated with separate systems. Personal status monitors (detecting pulse, respiration rate, muscle fatigue, core temperature, etc.) will provide commanders and highest echelons instantaneous medical data. Seamless integration of GPS and dead reckoning (compass and pedometer) and/or inertial sensors will aid navigation and increase position accuracy. Improved sensors and processing capability will provide earlier detection of battlefield hazards such as mines, enemy lasers and NBC (nuclear, biological, chemical) agents. Via the digitized network the situational awareness database will automatically be updated with weapon, medical, position and battlefield hazard data. Soldier Systems Sensor Fusion will ultimately establish each individual soldier as an individual sensor on the battlefield.

Brubaker, Kathryne M.

1998-08-01

314

EDITORIAL: Safety aspects of fusion power plants  

Microsoft Academic Search

This special issue of Nuclear Fusion contains 13 informative papers that were initially presented at the 8th IAEA Technical Meeting on Fusion Power Plant Safety held in Vienna, Austria, 10-13 July 2006. Following recommendation from the International Fusion Research Council, the IAEA organizes Technical Meetings on Fusion Safety with the aim to bring together experts to discuss the ongoing work,

B. N. Kolbasov

2007-01-01

315

Safety aspects of fusion power plants  

Microsoft Academic Search

This special issue of Nuclear Fusion contains 13 informative papers that were initially presented at the 8th IAEA Technical Meeting on Fusion Power Plant Safety held in Vienna, Austria, 10–13 July 2006.Following recommendation from the International Fusion Research Council, the IAEA organizes Technical Meetings on Fusion Safety with the aim to bring together experts to discuss the ongoing work, share

B. N. Kolbasov

2007-01-01

316

Fusion Rules in Conformal Field Theory  

Microsoft Academic Search

Several aspects of fusion rings and fusion rule algebras, and of their manifestations in twodimensional (conformal) field theory, are described: diagonalization and the connection with modular invariance; the presentation in terms of quotients of polynomial rings; fusion graphs; various strategies that allow for a partial classification; and the role of the fusion rules in the conformal bootstrap programme.

Jürgen Fuchs

1994-01-01

317

Temperature & Nuclear Fusion 4 October 2011  

E-print Network

Temperature & Nuclear Fusion 4 October 2011 Goals · Review temperature in stars · Practice using the important energy scales for nuclear fusion Temperature 1. For each relation we regularly use in class temperature. #12;temperature & nuclear fusion 2 Nuclear Fusion 2. There are a few different energy scales

Militzer, Burkhard

318

Temperature & Nuclear Fusion 4 October 2011  

E-print Network

Temperature & Nuclear Fusion 4 October 2011 Goals · Review temperature in stars · Practice using the important energy scales for nuclear fusion Temperature 1. For each relation we regularly use in class-Boltzmann equation: L = 4R2 T4 . (d) In fusion energy generation: T . #12;temperature & nuclear fusion 2 Nuclear

Militzer, Burkhard

319

The Case for Magnetized Target Fusion (MTF)  

E-print Network

of Sciences Committee on the Prospects for Inertial Confinement Fusion Energy Systems Albuquerque NM, March 31IL-3_11-1 The Case for Magnetized Target Fusion (MTF) a.k.a Magneto-Inertial Fusion (MIF) Irvin R of conventional unmagnetized targets by orders of magnitude; (b) makes fusion "easier" for any driver; (c) makes

320

Fusion -Aclean future Research at Culham Centre  

E-print Network

alternative ways of producing energy. Nuclear fusion can be an important long-term energy sourceFusion -Aclean future Research at Culham Centre for Fusion Energy #12;Increasing energy demands, cleaner ways of powering itself. Nuclear fusion ­ the process that provides the sun's energy ­ can play

321

CONFERENCES AND SYMPOSIA FUSION REACTOR DESIGN IV  

E-print Network

of its Fusion Technology and Engineering Programme, the 4th Technical Committee and Workshop on Fusion of fusion power reactor development is to bring to the world a new source of unlimited energy. While and Technology in Yalta in order to -- review and assess the current status and recent progress made in fusion

Abdou, Mohamed

322

The age of fusion - On the brink  

Microsoft Academic Search

The state of the art on magnetic fusion energy reactors is discussed in detail, and extensive diagrams of the different reactor designs as well as projected timetables for future advances in fusion capabilities are presented. During the 1980s, the scientific feasibility of fusion power will be tested in the US at the Tokamak Fusion Test Reactor (TFTR), and while the

S. Walters

1982-01-01

323

Summary of Topic1 Fusion Power Extraction  

E-print Network

and design concepts for fusion nuclear components worldwide (focus on power extraction and tritium fuel cycle)? · What are the key fusion nuclear science and technology (FNST) issues and challenges? · What issues can be resolved in non-fusion facilities? · What issues require experiments in integrated fusion nuclear

Abdou, Mohamed

324

Fusion Policy Advisory Committee FINAL REPORT  

E-print Network

energy source. Fusion's urgency will be further increased if fossil fuel and nuclear fission becomeFusion Policy Advisory Committee (FPAC) FINAL REPORT September 1990 Report of the Technical Panel on Magnetic Fusion of the Energy Research Advisory Board Washington, D .C. 20585 #12;#12;Fusion Policy

325

Criteria for Practical Fusion Power Systems  

E-print Network

to the successful deployment of fusion power plants. The following sections discuss the criteria and parameters and executive oKcers to identify the key crite- ria that must be met by fusion plants in order to be acceptable financial, public, and regulatory approvals of fusion power plant technology. Journal of Fusion Energy

326

Influenza Virus-Membrane Fusion Triggered by Proton Uncaging for Single Particle Studies of Fusion Kinetics  

E-print Network

Influenza Virus-Membrane Fusion Triggered by Proton Uncaging for Single Particle Studies of Fusion for studying membrane fusion, focusing on influenza virus fusion to lipid bilayers, which provides high temporal resolution through the rapid and coordinated initiation of individual virus fusion events. Each

Daniel, Susan

327

Detecting Sensor Failures in a Multi-Sensor Data Fusion SystemData Fusion System  

E-print Network

Detecting Sensor Failures in a Multi-Sensor Data Fusion SystemData Fusion System Thomas Pfister 21 · Introduction · Realization sensor fusion · Failure detection methods · Simulation results Detecting Sensor Failures in a Multi-Sensor Data Fusion System #12;Introduction Multi-Sensor Data Fusion · Problem

Berns, Karsten

328

Pubertal growth and epiphyseal fusion  

PubMed Central

The complex networks of nutritional, cellular, paracrine, and endocrine factors are closely related with pubertal growth and epiphyseal fusion. Important influencing factors include chondrocyte differentiation capacity, multiple molecular pathways active in the growth plate, and growth hormone-insulin-like growth factor-I axis activation and epiphyseal fusion through estrogen and its receptors. However, the exact mechanisms of these phenomena are still unclear. A better understanding of the detailed processes involved in the pubertal growth spurt and growth plate closure in longitudinal bone growth will help us develop methods to efficiently promote pubertal growth and delay epiphyseal fusion with fewer adverse effects.

2015-01-01

329

Image fusion with guided filtering.  

PubMed

A fast and effective image fusion method is proposed for creating a highly informative fused image through merging multiple images. The proposed method is based on a two-scale decomposition of an image into a base layer containing large scale variations in intensity, and a detail layer capturing small scale details. A novel guided filtering-based weighted average technique is proposed to make full use of spatial consistency for fusion of the base and detail layers. Experimental results demonstrate that the proposed method can obtain state-of-the-art performance for fusion of multispectral, multifocus, multimodal, and multiexposure images. PMID:23372084

Li, Shutao; Kang, Xudong; Hu, Jianwen

2013-07-01

330

Advanced fusion concepts: project summaries  

SciTech Connect

This report contains descriptions of the activities of all the projects supported by the Advanced Fusion Concepts Branch of the Office of Fusion Energy, US Department of Energy. These descriptions are project summaries of each of the individual projects, and contain the following: title, principle investigators, funding levels, purpose, approach, progress, plans, milestones, graduate students, graduates, other professional staff, and recent publications. Information is given for each of the following programs: (1) reverse-field pinch, (2) compact toroid, (3) alternate fuel/multipoles, (4) stellarator/torsatron, (5) linear magnetic fusion, (6) liners, and (7) Tormac. (MOW)

None

1980-12-01

331

Nuclear fusion: Fast heating scalable to laser fusion ignition  

Microsoft Academic Search

Rapid heating of a compressed fusion fuel by a short-duration laser pulse is a promising route to generating energy by nuclear fusion, and has been demonstrated on an experimental scale using a novel fast-ignitor geometry. Here we describe a refinement of this system in which a much more powerful, pulsed petawatt (1015 watts) laser creates a fast-heated core plasma that

R. Kodama; H. Shiraga; K. Shigemori; Y. Toyama; S. Fujioka; H. Azechi; H. Fujita; H. Habara; T. Hall; Y. Izawa; T. Jitsuno; Y. Kitagawa; K. M. Krushelnick; K. L. Lancaster; K. Mima; K. Nagai; M. Nakai; H. Nishimura; T. Norimatsu; P. A. Norreys; S. Sakabe; K. A. Tanaka; A. Youssef; M. Zepf; T. Yamanaka

2002-01-01

332

Fusion materials irradiations at MaRIE's fission fusion facility  

SciTech Connect

Los Alamos National Laboratory's proposed signature facility, MaRIE, will provide scientists and engineers with new capabilities for modeling, synthesizing, examining, and testing materials of the future that will enhance the USA's energy security and national security. In the area of fusion power, the development of new structural alloys with better tolerance to the harsh radiation environments expected in fusion reactors will lead to improved safety and lower operating costs. The Fission and Fusion Materials Facility (F{sup 3}), one of three pillars of the proposed MaRIE facility, will offer researchers unprecedented access to a neutron radiation environment so that the effects of radiation damage on materials can be measured in-situ, during irradiation. The calculated radiation damage conditions within the F{sup 3} match, in many respects, that of a fusion reactor first wall, making it well suited for testing fusion materials. Here we report in particular on two important characteristics of the radiation environment with relevancy to radiation damage: the primary knock-on atom spectrum and the impact of the pulse structure of the proton beam on temporal characteristics of the atomic displacement rate. With respect to both of these, analyses show the F{sup 3} has conditions that are consistent with those of a steady-state fusion reactor first wall.

Pitcher, Eric J [Los Alamos National Laboratory

2010-10-06

333

Seminar -1. letnik bolonjske magistrske stopnje Inertial confinement fusion  

E-print Network

the principles of nuclear fusion. I will describe two different approaches to fusion, which are the magnetic fusion is and two different paths to achieve the final goal, nuclear fusion. [1] Fusion FusionSeminar - 1. letnik bolonjske magistrske stopnje Inertial confinement fusion Author: Matic Kunsek

Â?umer, Slobodan

334

Fusion of the ear bones  

MedlinePLUS

Fusion of the ear bones is the joining of the bones of the inner ear. These are the incus, malleus, and stapes bones. Related topics include: Chronic ear infection Otosclerosis Middle ear malformations

335

Image fusion for tactical applications  

NASA Astrophysics Data System (ADS)

Multispectral sensors are increasingly being employed in military applications. Just as in satellite imagery of the earth, multispectral data is required in order to extract the maximum amount of information from a scene. The advantages of image fusion have been postulated for navigation, surveillance, fire control, and missile guidance to improve accuracy and contribute to mission success. The fusion process is a critical element of each of these applications. Imagery from various sensors must be calibrated, enhanced and spatially registered in order to achieve the desired 'fusion' of information into a single 'picture' for rapid assessment. In a tactical military environment this fusion of data must be presented to the end user in a timely and ergonomical fashion. The end user (e.g., a combat pilot) may already be operating at maximum sensory input capacity. Does he or she really need another cockpit display?

McDaniel, Robert V.; Scribner, Dean A.; Krebs, William K.; Warren, Penny R.; Ockman, Norman; McCarley, Jason

1998-10-01

336

Magnetic fusion 1985: what next  

SciTech Connect

Recent budget reductions for magnetic fusion have led to a re-examination of program schedules and objectives. Faced with delays and postponement of major facilities as previously planned, some have called for a near-term focus on science, others have stressed technology. This talk will suggest a different focus as the keynote for this conference, namely, the applications of fusion. There is no doubt that plasma science is by now mature and fusion technology is at the forefront. This has and will continue to benefit many fields of endeavor, both in actual new discoveries and techniques and in attracting and training scientists and engineers who move on to make significant contributions in science, defense and industry. Nonetheless, however superb the science or how challenging the technology, these are means, not ends. To maintain its support, the magnetic fusion program must also offer the promise of power reactors that could be competitive in the future. At this conference, several new reactor designs will be described that claim to be smaller and economically competitive with fission reactors while retaining the environmental and safety characteristics that are the hallmark of fusion. The American Nuclear Society is an appropriate forum in which to examine these new designs critically, and to stimulate better ideas and improvements. As a preview, this talk will include brief discussions of new tokamak, tandem mirror and reversed field pinch reactor designs to be presented in later sessions. Finally, as a preview of the session on fusion breeders, the talk will explore once again the economic implications of a new nuclear age, beginning with improved fission reactors fueled by fusion breeders, then ultimately evolving to reactors based solely on fusion.

Fowler, T.K.

1985-03-01

337

TRITIUM ACCOUNTANCY IN FUSION SYSTEMS  

SciTech Connect

The US Department of Energy (DOE) has clearly defined requirements for nuclear material control and accountability (MC&A) of tritium whereas the International Atomic Energy Agency (IAEA) does not since tritium is not a fissile material. MC&A requirements are expected for tritium fusion machines and will be dictated by the host country or regulatory body where the machine is operated. Material Balance Areas (MBAs) are defined to aid in the tracking and reporting of nuclear material movements and inventories. Material subaccounts (MSAs) are established along with key measurement points (KMPs) to further subdivide a MBA to localize and minimize uncertainties in the inventory difference (ID) calculations for tritium accountancy. Fusion systems try to minimize tritium inventory which may require continuous movement of material through the MSAs. The ability of making meaningful measurements of these material transfers is described in terms of establishing the MSA structure to perform and reconcile ID calculations. For fusion machines, changes to the traditional ID equation will be discussed which includes breading, burn-up, and retention of tritium in the fusion device. The concept of “net” tritium quantities consumed or lost in fusion devices is described in terms of inventory taking strategies and how it is used to track the accumulation of tritium in components or fusion machines.

Klein, J. E.; Farmer, D. A.; Moore, M. L.; Tovo, L. L.; Poore, A. S.; Clark, E. A.; Harvel, C. D.

2014-03-06

338

Robust Match Fusion Using Optimization.  

PubMed

In this paper, we present a novel patch-based match and fusion algorithm by taking account of moving scene in a multiple exposure image sequence using optimization. A uniform iterative approach is developed to match and find the corresponding patches in different exposure images, which are then fused in each iteration. Our approach does not need to align the input multiple exposure images before the fusion process. Considering that the pixel values are affected by various exposure time, we design a new patch-based energy function that will be optimized to improve the matching accuracy. An efficient patch-based exposure fusion approach using the random walker algorithm is developed to preserve the moving objects from the input multiple exposure images. To the best of our knowledge, our algorithm is the first patch-based exposure fusion work to preserve the moving objects of dynamic scenes that does not need the registration process of different exposure images. Experimental results of moving scenes demonstrate that our algorithm achieves visually pleasing fusion results without ghosting artifacts, while the results produced by the state-of-the-art exposure fusion and tone mapping algorithms exhibit different levels of ghosting artifacts. PMID:25248209

Qin, Xiameng; Shen, Jianbing; Mao, Xiaoyang; Li, Xuelong; Jia, Yunde

2014-09-16

339

Prospects for Tokamak Fusion Reactors  

SciTech Connect

This paper first reviews briefly the status and plans for research in magnetic fusion energy and discusses the prospects for the tokamak magnetic configuration to be the basis for a fusion power plant. Good progress has been made in achieving fusion reactor-level, deuterium-tritium (D-T) plasmas with the production of significant fusion power in the Joint European Torus (up to 2 MW) and the Tokamak Fusion Test Reactor (up to 10 MW) tokamaks. Advances on the technologies of heating, fueling, diagnostics, and materials supported these achievements. The successes have led to the initiation of the design phases of two tokamaks, the International Thermonuclear Experimental Reactor (ITER) and the US Toroidal Physics Experiment (TPX). ITER will demonstrate the controlled ignition and extended bum of D-T plasmas with steady state as an ultimate goal. ITER will further demonstrate technologies essential to a power plant in an integrated system and perform integrated testing of the high heat flux and nuclear components required to use fusion energy for practical purposes. TPX will complement ITER by testing advanced modes of steady-state plasma operation that, coupled with the developments in ITER, will lead to an optimized demonstration power plant.

Sheffield, J.; Galambos, J.

1995-04-01

340

../fusion/templates/mapguide/maroon/css/maroon_fusion.css background-image: url(../images/background.gif);  

E-print Network

../fusion/templates/mapguide/maroon/css/maroon_fusion.css body { background-image: url(../images/background.gif); ../fusion/templates/mapguide/maroon/css/ maroon_fusion.css body { background-color: #3e5c5f; ../fusion: #500000; ../fusion/templates/mapguide/maroon/css/maroon_fusion.css #FileMenu { background-image: url(../images

Ahmad, Sajjad

341

Kinetic advantage of controlled intermediate nuclear fusion  

SciTech Connect

The dominated process of controlled fusion is to let nuclei gain enough kinetic energy to overcome Coulomb barrier. As a result, a fusion scheme can consider two factors in its design: to increase kinetic energy of nuclei and to alter the Coulomb barrier. Cold Fusion and Hot fusion are all one-factor schemes while Intermediate Fusion is a twofactors scheme. This made CINF kinetically superior. Cold Fusion reduces deuteron-deuteron distance, addressing Coulomb barrier, and Hot Fusion heat up plasma into extreme high temperature, addressing kinetic energy. Without enough kinetic energy made Cold Fusion skeptical. Extreme high temperature made Hot Fusion very difficult to engineer. Because CIFN addresses both factors, CIFN is a more promising technique to be industrialized.

Guo Xiaoming [Physics and Computer Science Department, Wilfrid Laurier University, Waterloo, Ontario, N2L 3C5 (Canada)

2012-09-26

342

Fusion Plasma Theory project summaries  

SciTech Connect

This Project Summary book is a published compilation consisting of short descriptions of each project supported by the Fusion Plasma Theory and Computing Group of the Advanced Physics and Technology Division of the Department of Energy, Office of Fusion Energy. The summaries contained in this volume were written by the individual contractors with minimal editing by the Office of Fusion Energy. Previous summaries were published in February of 1982 and December of 1987. The Plasma Theory program is responsible for the development of concepts and models that describe and predict the behavior of a magnetically confined plasma. Emphasis is given to the modelling and understanding of the processes controlling transport of energy and particles in a toroidal plasma and supporting the design of the International Thermonuclear Experimental Reactor (ITER). A tokamak transport initiative was begun in 1989 to improve understanding of how energy and particles are lost from the plasma by mechanisms that transport them across field lines. The Plasma Theory program has actively-participated in this initiative. Recently, increased attention has been given to issues of importance to the proposed Tokamak Physics Experiment (TPX). Particular attention has been paid to containment and thermalization of fast alpha particles produced in a burning fusion plasma as well as control of sawteeth, current drive, impurity control, and design of improved auxiliary heating. In addition, general models of plasma behavior are developed from physics features common to different confinement geometries. This work uses both analytical and numerical techniques. The Fusion Theory program supports research projects at US government laboratories, universities and industrial contractors. Its support of theoretical work at universities contributes to the office of Fusion Energy mission of training scientific manpower for the US Fusion Energy Program.

Not Available

1993-10-01

343

The Path to Magnetic Fusion Energy  

SciTech Connect

When the possibility of fusion as an energy source for electricity generation was realized in the 1950s, understanding of the plasma state was primitive. The fusion goal has been paced by, and has stimulated, the development of plasma physics. Our understanding of complex, nonlinear processes in plasmas is now mature. We can routinely produce and manipulate 100 million degree plasmas with remarkable finesse, and we can identify a path to commercial fusion power. The international experiment, ITER, will create a burning (self-sustained) plasma and produce 500 MW of thermal fusion power. This talk will summarize the progress in fusion research to date, and the remaining steps to fusion power.

Prager, Stewart (PPPL) [PPPL

2011-05-04

344

A Model for Membrane Fusion  

NASA Astrophysics Data System (ADS)

Pheochromocytoma is a tumor of the adrenal gland which originates from chromaffin cells and is characterized by the secretion of excessive amounts of neurotransmitter which lead to high blood pressure and palpitations. Pheochromocytoma contain membrane bound granules that store neurotransmitter. The release of these stored molecules into the extracellular space occurs by fusion of the granule membrane with the cell plasma membrane, a process called exocytosis. The molecular mechanism of this membrane fusion is not well understood. It is proposed that the so called SNARE proteins [1] are the pillar of vesicle fusion as their cleavage by clostridial toxin notably, Botulinum neurotoxin and Tetanus toxin abrogate the secretion of neurotransmitter [2]. Here, I describe how physical principles are applied to a biological cell to explore the role of the vesicle SNARE protein synaptobrevin-2 in easing granule fusion. The data presented here suggest a paradigm according to which the movement of the C-terminal of synaptobrevin-2 disrupts the lipid bilayer to form a fusion pore through which molecules can exit.

Ngatchou, Annita

2010-01-01

345

Adaptive multistrategy image fusion method  

NASA Astrophysics Data System (ADS)

Design of fusion rule is an important step in fusion process. Traditional single fusion rules are inflexible when they are being used to fuse feature-rich images. To address this problem, an adaptive multistrategy image fusion method is proposed. Its flexibility lies in the combination of a choose-max strategy and a weighted average strategy. Moreover, the region-based characteristics and the shift-invariant shearlet transform (SIST)-based activity measures are proposed to guide the selection of strategies. The key points of our method are: (1) Window-based features are extracted from the source images. (2) Use of the fuzzy c-means clustering algorithm to construct a region map in the feature difference space. (3) The dissimilarity between corresponding regions is employed to quantify the characteristic of regions and the local average variance of the SIST coefficients are considered as activity measures to evaluate the salience of the related coefficient. (4) The adaptive multistrategy selection scheme is achieved by a sigmoid function. Experimental results show that the proposed method is superior to the conventional image fusion methods both in subjective and objective evaluations.

Luo, Xiao-qing; Zhang, Zhan-cheng; Wu, Xiao-jun

2014-09-01

346

Virus and cell fusion mechanisms.  

PubMed

In biomembrane fusion pathways, membranes are destabilized through insertions of amphipathic protein segments, lipid reorganization via hemifusion, protein restructuring, and dimpling of the membranes. Four classes of membrane proteins are known in virus and cell fusion. Class I virus-cell fusion proteins (fusogens) are ?-helix-rich prefusion trimers that form coiled-coil structures that insert hydrophobic fusion peptides or loops (FPs or FLs) into membranes and refold into postfusion trimers. Class II virus-cell fusogens are ?-sheet-rich prefusion homo- or heterodimers that insert FLs into membranes, ending in postfusion trimers. Class III virus-cell fusogens are trimers with both ?-helices and ?-sheets that dissociate into monomers, insert FLs into membranes, and oligomerize into postfusion trimers. Class IV reoviral cell-cell fusogens are small proteins with FLs that oligomerize to fuse membranes. Class I cell-cell fusogens (Syncytins) were captured by mammals from retroviruses, and class II cell-cell fusogens (EFF-1/AFF-1) fuse membranes via homotypic zippering. Mechanisms and fusogens for most cell fusion events are unknown. PMID:25000995

Podbilewicz, Benjamin

2014-01-01

347

76 FR 49757 - Fusion Energy Sciences Advisory Committee  

Federal Register 2010, 2011, 2012, 2013, 2014

...plasma science, fusion science, and fusion technology related to the Fusion Energy Sciences program. Additionally...renewal of the Fusion Energy Sciences Advisory Committee has...and to be in the public interest in connection with...

2011-08-11

348

Polyetheretherketone as a biomaterial for spinal applications.  

PubMed

Threaded lumbar interbody spinal fusion devices (TIBFD) made from titanium have been reported to be 90% effective for single-level lumbar interbody fusion, although radiographic determination of fusion has been intensely debated in the literature. Using blinded radiographic, biomechanic, histologic, and statistical measures, we evaluated a radiolucent polyetheretherketone (PEEK)-threaded interbody fusion device packed with autograft or rhBMP-2 on an absorbable collagen sponge in 13 sheep at 6 months. Radiographic fusion, increased spinal level biomechanical stiffness, and histologic fusion were demonstrated for the PEEK cages filled with autograft or rhBMP-2 on a collagen sponge. No device degradation or wear debris was observed. Only mild chronic inflammation consisting of a few macrophages was observed in peri-implant tissues. Based on these results, the polymeric biomaterial PEEK may be a useful biomaterial for interbody fusion cages due to the polymer's increased radiolucency and decreased stiffness. PMID:16115677

Toth, Jeffrey M; Wang, Mei; Estes, Bradley T; Scifert, Jeffrey L; Seim, Howard B; Turner, A Simon

2006-01-01

349

Superconducting magnets for fusion applications  

SciTech Connect

Fusion magnet technology has made spectacular advances in the past decade; to wit, the Mirror Fusion Test Facility and the Large Coil Project. However, further advances are still required for advanced economical fusion reactors. Higher fields to 14 T and radiation-hardened superconductors and insulators will be necessary. Coupled with high rates of nuclear heating and pulsed losses, the next-generation magnets will need still higher current density, better stability and quench protection. Cable-in-conduit conductors coupled with polyimide insulations and better steels seem to be the appropriate path. Neutron fluences up to 10/sup 19/ neutrons/cm/sup 2/ in niobium tin are achievable. In the future, other amorphous superconductors could raise these limits further to extend reactor life or decrease the neutron shielding and corresponding reactor size.

Henning, C.D.

1987-07-02

350

Laser fusion experiments at LLL  

SciTech Connect

These notes present the experimental basis and status for laser fusion as developed at LLL. Two other chapters, one authored by K.A. Brueckner and the other by C. Max, present the theoretical implosion physics and laser plasma interaction physics. The notes consist of six sections. The first is an introductory section which provides some of the history of inertial fusion and a simple explanation of the concepts involved. The second section presents an extensive discussion of diagnostic instrumentation used in the LLL Laser Fusion Program. The third section is a presentation of laser facilities and capabilities at LLL. The purpose here is to define capability, not to derive how it was obtained. The fourth and fifth sections present the experimental data on laser-plasma interaction and implosion physics. The last chapter is a short projection of the future.

Ahlstrom, H.G.

1980-06-16

351

Fusion power for space propulsion.  

NASA Technical Reports Server (NTRS)

Principles of operation, interplanetary orbit-to-orbit mission capabilities, technical problems, and environmental safeguards are examined for thermonuclear fusion propulsion systems. Two systems examined include (1) a fusion-electric concept in which kinetic energy of charged particles from the plasma is converted into electric power (for accelerating the propellant in an electrostatic thrustor) by the van de Graaf generator principle and (2) the direct fusion rocket in which energetic plasma lost from the reactor has a suitable amount of added propellant to obtain the optimum exhaust velocity. The deuterium-tritium and the deuterium/helium-3 reactions are considered as suitable candidates, and attention is given to problems of cryogenic refrigeration systems, magnet shielding, and high-energy particle extraction and guidance.

Roth, R.; Rayle, W.; Reinmann, J.

1972-01-01

352

Fusion: Power for the future  

NASA Astrophysics Data System (ADS)

There is a growing recognition that we need an alternative to conventional fossil fuels. Shortages of oil and gas have the potential to cause economic and political instability, and burning fossil fuels can cause environmental damage, as well as being the likeliest cause of global warming. Fusion - the process that powers the sun and stars, has the potential to provide large-scale, safe energy production, without adding to global warming and without the long-term radioactive waste associated with conventional fission power stations. More importantly, within the next 20 years large-scale fusion power production is planned to be demonstrated by the multinational experiment ITER, and a proposed `fast track' to fusion envisages a time-scale of roughly 30 years for a prototype power plant PROTO to be built.

Webster, Anthony J.

2003-03-01

353

(Meeting on fusion reactor materials)  

SciTech Connect

During his visit to the KfK, Karlsruhe, F. W. Wiffen attended the IEA 12th Working Group Meeting on Fusion Reactor Materials. Plans were made for a low-activation materials workshop at Culham, UK, for April 1991, a data base workshop in Europe for June 1991, and a molecular dynamics workshop in the United States in 1991. At the 11th IEA Executive Committee on Fusion Materials, discussions centered on the recent FPAC and Colombo panel review in the United States and EC, respectively. The Committee also reviewed recent progress toward a neutron source in the United States (CWDD) and in Japan (ESNIT). A meeting with D. R. Harries (consultant to J. Darvas) yielded a useful overview of the EC technology program for fusion. Of particular interest to the US program is a strong effort on a conventional ferritic/martensitic steel for fist wall/blanket operation beyond NET/ITER.

Jones, R.H. (Pacific Northwest Lab., Richland, WA (USA)); Klueh, R.L.; Rowcliffe, A.F.; Wiffen, F.W. (Oak Ridge National Lab., TN (USA)); Loomis, B.A. (Argonne National Lab., IL (USA))

1990-11-01

354

2005 7th International Conference on Information Fusion (FUSION) Construction of a Geospatial Predictor by Fusion of  

E-print Network

2005 7th International Conference on Information Fusion (FUSION) Construction of a Geospatial Predictor by Fusion of Global and Local Models 1~ ~ ~~ 121 Bo Han1, Slobodan Vucetic', Amy Braverman , Zoran Obradovic' 'Center for Information Science and Technology 2Jet Propulsion Laboratory Temple University

Obradovic, Zoran

355

Advanced Concepts: Aneutronic Fusion Power and Propulsion  

NASA Technical Reports Server (NTRS)

Aneutronic Fusion for In-Space thrust, power. Clean energy & potential nuclear gains. Fusion plant concepts, potential to use advanced fuels. Methods to harness ionic momentum for high Isp thrust plus direct power conversion into electricity will be presented.

Chapman, John J.

2012-01-01

356

Role of atomic collisions in fusion  

SciTech Connect

Atomic physics issues have played a large role in controlled fusion research. A general discussion of the present role of atomic processes in both magnetic and inertial controlled fusion work is presented.

Post, D.E.

1982-04-01

357

Fusion Nuclear Science and Technology (FNST)Fusion Nuclear Science and Technology (FNST) Challenges and Facilities  

E-print Network

Fusion Nuclear Science and Technology (FNST)Fusion Nuclear Science and Technology (FNST) Challenges these issues. 2 #12;FNST is the science, engineering, technology and materials Fusion Nuclear Science & Technology (FNST) FNST is the science, engineering, technology and materials for the fusion nuclear

Abdou, Mohamed

358

Report ofReport of Nuclear Fusion Section,Nuclear Fusion Section,  

E-print Network

Report ofReport of Nuclear Fusion Section,Nuclear Fusion Section, National Committee for NuclearJapan Atomic Energy Research Institute On the New Way of Nuclear Fusion ResearchOn the New Way of Nuclear on the new way of developing nuclear fusion under the new circumstances (chair: Prof. A. Koyama) under

359

Fusion Nuclear Science and Technology (FNST)Fusion Nuclear Science and Technology (FNST) Challenges and Facilities  

E-print Network

Fusion Nuclear Science and Technology (FNST)Fusion Nuclear Science and Technology (FNST) Challenges on MFE Roadmapping in the ITER Era Princeton, NJ 7-10 September 2011 1 #12;Fusion Nuclear Science never done any experiments on FNST in a real fusion nuclear environment we must be realistic on what

Abdou, Mohamed

360

FUSION-3792; No.of Pages15 Fusion Engineering and Design xxx (2006) xxxxxx  

E-print Network

FUSION-3792; No.of Pages15 Fusion Engineering and Design xxx (2006) xxx­xxx Recent progress.07.087 #12;FUSION-3792; No.of Pages15 2 F. Najmabadi, A.R. Raffray / Fusion Engineering and Design xxx (2006) xxx­xxx of any stellarator configuration represents a large number of trade-offs among physics

Raffray, A. René

361

Science/Fusion Energy Sciences FY 2011 Congressional Budget Fusion Energy Sciences  

E-print Network

Science/Fusion Energy Sciences FY 2011 Congressional Budget Fusion Energy Sciences Funding Profile FY 2010 Current Appropriation FY 2011 Request Fusion Energy Sciences Science 163,479 +57,399 182, Fusion Energy Sciences 394,518b +91,023 426,000 380,000 Public Law Authorizations: Public Law 95

362

Stochastic Fusion Simulations and Experiments Suggest Passive and Active Roles of Hemagglutinin during Membrane Fusion  

E-print Network

from fusion data. One approach correlates the fusion rate with the fraction of fusogenic HA trimers the fusion rate with the total concentration of fusogenic HA trimers and indicates that more than one HA participates in fusion through interactions with a fusogenic HA. Our results, based on H3 and H1 serotypes

Daniel, Susan

363

Z-Pinch Fusion Propulsion  

NASA Technical Reports Server (NTRS)

Fusion-based nuclear propulsion has the potential to enable fast interplanetary transportation. Shorter trips are better for humans in the harmful radiation environment of deep space. Nuclear propulsion and power plants can enable high Ispand payload mass fractions because they require less fuel mass. Fusion energy research has characterized the Z-Pinch dense plasma focus method. (1) Lightning is form of pinched plasma electrical discharge phenomena. (2) Wire array Z-Pinch experiments are commonly studied and nuclear power plant configurations have been proposed. (3) Used in the field of Nuclear Weapons Effects (NWE) testing in the defense industry, nuclear weapon x-rays are simulated through Z-Pinch phenomena.

Miernik, Janie

2011-01-01

364

Fusion Breeder Program interim report  

SciTech Connect

This interim report for the FY82 Fusion Breeder Program covers work performed during the scoping phase of the study, December, 1981-February 1982. The goals for the FY82 study are the identification and development of a reference blanket concept using the fission suppression concept and the definition of a development plan to further the fusion breeder application. The context of the study is the tandem mirror reactor, but emphasis is placed upon blanket engineering. A tokamak driver and blanket concept will be selected and studied in more detail during FY83.

Moir, R.; Lee, J.D.; Neef, W.

1982-06-11

365

Method for vacuum fusion bonding  

DOEpatents

An improved vacuum fusion bonding structure and process for aligned bonding of large area glass plates, patterned with microchannels and access holes and slots, for elevated glass fusion temperatures. Vacuum pumpout of all components is through the bottom platform which yields an untouched, defect free top surface which greatly improves optical access through this smooth surface. Also, a completely non-adherent interlayer, such as graphite, with alignment and location features is located between the main steel platform and the glass plate pair, which makes large improvements in quality, yield, and ease of use, and enables aligned bonding of very large glass structures.

Ackler, Harold D. (Sunnyvale, CA); Swierkowski, Stefan P. (Livermore, CA); Tarte, Lisa A. (Livermore, CA); Hicks, Randall K. (Stockton, CA)

2001-01-01

366

Fusion bonding and alignment fixture  

DOEpatents

An improved vacuum fusion bonding structure and process for aligned bonding of large area glass plates, patterned with microchannels and access holes and slots, for elevated glass fusion temperatures. Vacuum pumpout of all the components is through the bottom platform which yields an untouched, defect free top surface which greatly improves optical access through this smooth surface. Also, a completely non-adherent interlayer, such as graphite, with alignment and location features is located between the main steel platform and the glass plate pair, which makes large improvements in quality, yield, and ease of use, and enables aligned bonding of very large glass structures.

Ackler, Harold D. (Sunnyvale, CA); Swierkowski, Stefan P. (Livermore, CA); Tarte, Lisa A. (Livermore, CA); Hicks, Randall K. (Stockton, CA)

2000-01-01

367

Exo-endo cellulase fusion protein  

DOEpatents

The present invention relates to a heterologous exo-endo cellulase fusion construct, which encodes a fusion protein having cellulolytic activity comprising a catalytic domain derived from a fungal exo-cellobiohydrolase and a catalytic domain derived from an endoglucanase. The invention also relates to vectors and fungal host cells comprising the heterologous exo-endo cellulase fusion construct as well as methods for producing a cellulase fusion protein and enzymatic cellulase compositions.

Bower, Benjamin S. (Palo Alto, CA); Larenas, Edmund A. (Palo Alto, CA); Mitchinson, Colin (Palo Alto, CA)

2012-01-17

368

A Review of Data Fusion Techniques  

PubMed Central

The integration of data and knowledge from several sources is known as data fusion. This paper summarizes the state of the data fusion field and describes the most relevant studies. We first enumerate and explain different classification schemes for data fusion. Then, the most common algorithms are reviewed. These methods and algorithms are presented using three different categories: (i) data association, (ii) state estimation, and (iii) decision fusion. PMID:24288502

2013-01-01

369

Fusion R&D strategy for Japan  

NASA Astrophysics Data System (ADS)

The present status and the strategy of fusion R&D in Japan are outlined. Although the past fusion research subjects in Japan were strongly oriented to plasma confinement and related device technologies, activity in fusion engineering, especially materials engineering, is now growing. It is recognized that the development of radiation-resistant low activation materials is the key to the realization of fusion reactors. It is of vital importance to establish the sound research plan for materials development.

Iiyoshi, A.

1998-10-01

370

Heavy Ion Fusion Systems Assessment study  

SciTech Connect

The Heavy Ion Fusion Systems Assessment (HIFSA) study was conducted with the specific objective of evaluating the prospects of using induction linac drivers to generate economical electrical power from inertial confinement fusion. The study used algorithmic models of representative components of a fusion system to identify favored areas in the multidimensional parameter space. The resulting cost-of-electricity (COE) projections are comparable to those from other (magnetic) fusion scenarios, at a plant size of 100 MWe.

Dudziak, D.J.; Herrmannsfeldt, W.B.

1986-07-01

371

Fusion or confusion: knowledge or nonsense?  

Microsoft Academic Search

The terms 'data fusion,' 'sensor fusion,' multi-sensor integration,' and 'multi-source integration' have been used widely in the technical literature to refer to a variety of techniques, technologies, systems, and applications which employ and\\/or combine data derived from multiple information sources. Applications of data fusion range from real-time fusion of sensor information for the navigation of mobile robots to the off-line

Peter L. Rothman; Richard V. Denton

1991-01-01

372

Z-Pinch Fusion for Energy Applications  

SciTech Connect

Z pinches, the oldest fusion concept, have recently been revisited in light of significant advances in the fields of plasma physics and pulsed power engineering. The possibility exists for z-pinch fusion to play a role in commercial energy applications. We report on work to develop z-pinch fusion concepts, the result of an extensive literature search, and the output for a congressionally-mandated workshop on fusion energy held in Snowmass, Co July 11-23,1999.

SPIELMAN,RICK B.

2000-01-01

373

Magneto-Inertial Fusion (Magnetized Target Fusion)( g g )  

E-print Network

. In this Talk: ·Magnetized Target Fusion (MTF) demonstration, FRCHX at AFRL in Albuquerque ·Some MIF-IFE reactor/Target Combinations are possible Los Alamos / AFRL Field Reversed Configuration Shiva Star FRCHX U. Rochester LLE. White, H. Wood Air Force Research Laboratory, Directed Energy Directorate, Kirtland AFB, NM 87117, USA D

374

Z-Pinch Inertial Fusion Energy Fusion Power Associates Annual  

E-print Network

· Linear Transformer Driver technology · Pulsed power IFE #12;3 We were required to demonstrate 3-pinch IFE #12;8 The goal of the pulsed power fusion program is to validate a target design and a machine Transformer Driver cavity #12;11 · rise time 70 nsec · timing jitter = 2 ns (1) · voltage and current

375

Calculation of fusion product angular correlation coefficients for fusion plasmas  

SciTech Connect

The angular correlation coefficients for fusion products are calculated in the cases of Maxwellian and beam-target plasmas. Measurement of these coefficients as a localized ion temperature or fast-ion diagnostic is discussed. 8 refs., 7 figs., 1 tab.

Murphy, T.J.

1987-08-01

376

LIFE Power Plant Fusion Power Associates  

E-print Network

LIFE Power Plant Fusion Power Associates December 14, 2011 Mike Dunne LLNL #12;NIf-1111-23714.ppt LIFE power plant 2 #12;LIFE delivery timescale NIf-1111-23714.ppt 3 #12;Timely delivery is enabled fusion options exist. NIF/LIFE allows timely integrated demonstration. · Fusion performance based

377

Nuclear Fusion Energy Research Ghassan Antar  

E-print Network

Nuclear Fusion Energy Research at AUB Ghassan Antar Physics Department American University: http://aub.edu.lb/physics/lpfd #12;Dr. G. Antar 3 Outline 1. A brief introduction to Magnetic Fusion: Disruptions, Plasma Facing Components #12;Dr. G. Antar 4 Fusion Occurs when Two Nuclei Unite to Form One

Shihadeh, Alan

378

Study of Nuclear Physics for Nuclear Fusion  

Microsoft Academic Search

Based on the concept of “damp matching” [1] and the famous d + t fusion data, a conventional quantum mechanics calculation shows that the plasma fusion, muon-catalyzed fusion, and the low-energy nuclear reaction are essentially same in the sense of resonant tunneling through the Coulomb barrier. The good agreement between theory and experimental data justifies the selectivity in resonant tunneling,

Xing Z. Li; Bing Liu; Xian Z. Ren; Jian Tian; Wei Z. Yu; Dong X. Cao

2000-01-01

379

Nuclear fusion in cultured microspores of barley  

Microsoft Academic Search

Fusion of the generative and vegetative nuclei physically separated by a wall has been observed in cultured microspores of barley. The generative cell appears to play an active role in fusion as it elongates toward the vegetative nucleus, becomes detached from the microspore wall, and finally completely encloses the vegetative nucleus. The generative cell wall disappears before nuclear fusion takes

Feng-Ming Lee; Chi-Chang Chen

1987-01-01

380

Fusion of FLIR automatic target recognition algorithms  

Microsoft Academic Search

In this paper, we investigate several fusion techniques for designing a composite classifier to improve the performance (probability of correct classification) of forward-looking infrared (FLIR) automatic target recognition (ATR). The motivation behind the fusion of ATR algorithms is that if each contributing technique in a fusion algorithm (composite classifier) emphasizes on learning at least some features of the targets that

Syed A. Rizvi; Nasser M. Nasrabadi

2003-01-01

381

Myoblast fusion: playing hard to get.  

PubMed

In Drosophila myoblast fusion, the fusing cell invades another by actin-enriched protrusion. In this issue of Developmental Cell, Kim et al. (2015) examine the myoblast fusion mechanism from the perspective of the "receiving" cell and report that fusion depends on the ability of this cell to stiffen its actomyosin cortex. PMID:25758859

Chernomordik, Leonid V; Kozlov, Michael M

2015-03-01

382

Fusion Lecture Summary Eugene S. Evans  

E-print Network

Fusion Lecture Summary Eugene S. Evans Physics H190, University of California, Berkeley March 31" by Edward I. Moses (Principle Associate Director, National Ignition Facility and Photon Science) Eugene S Fusion Engine (LIFE) Final Thoughts 5 Acknowledgements Eugene S. Evans (2010) Fusion Lecture Summary

Budker, Dmitry

383

FUSION POWER PLANTS GOALS AND TECHNOLOGICAL CHALLENGES  

E-print Network

FUSION POWER PLANTS ­ GOALS AND TECHNOLOGICAL CHALLENGES Farrokh Najmabadi Dept. of Electrical for fusion power plants is given and their economic, safety, and environmental features are explored. Concep- tual design studies predict that fusion power plants will be capital intensive and will be used

Najmabadi, Farrokh

384

Recurrent gene fusions in prostate cancer  

Microsoft Academic Search

The discovery of recurrent gene fusions in a majority of prostate cancers has important clinical and biological implications in the study of common epithelial tumours. Gene fusion and chromosomal rearrangements were previously thought to be primarily the oncogenic mechanism of haematological malignancies and sarcomas. The prostate cancer gene fusions that have been identified thus far are characterized by 5? genomic

Chandan Kumar-Sinha; Scott A. Tomlins; Arul M. Chinnaiyan

2008-01-01

385

Antimatter Driven PB11 Fusion Propulsion System  

Microsoft Academic Search

One of the major advantages of using P-B11 fusion fuel is that the reaction produces only charged particles in the form of three alpha particles and no neutrons. A fusion concept that lends itself to this fuel cycle is the Magnetically Insulated Inertial Confinement Fusion (MICF) reactor whose distinct advantage lies in the very strong magnetic field that is created

Terry Kammash; James Martin; Thomas Godfroy

2003-01-01

386

Fusion-electric propulsion for hypersonic flight  

Microsoft Academic Search

Recent studies by Bussard (1986-1991) have shown that charged nuclei of certain light element isotopes can be electrostatically compressed to sufficient density for nuclear fusions to occur. And the resulting fusion reactions involving such nuclei emit no neutrons and induce no radioactivity at all. Such 'clean' fusion reactions can develop 4 to 8 times more engine thrust per fuel flow

H. D. Froning Jr.; R. W. Bussard

1993-01-01

387

Laser Fusion Energy The High Average Power  

E-print Network

Laser Fusion Energy and The High Average Power Program John Sethian Naval Research Laboratory Dec for Inertial Fusion Energy with lasers, direct drive targets and solid wall chambers Lasers DPPSL (LLNL) Kr posters Snead Payne #12;Laser(s) Goals 1. Develop technologies that can meet the fusion energy

388

Status and problems of fusion reactor development  

Microsoft Academic Search

Thermonuclear fusion of deuterium and tritium constitutes an enormous potential for a safe, environmentally compatible and sustainable energy supply. The fuel source is practically inexhaustible. Further, the safety prospects of a fusion reactor are quite favourable due to the inherently self-limiting fusion process, the limited radiologic toxicity and the passive cooling property. Among a small number of approaches, the concept

Uwe Schumacher

2001-01-01

389

Fusion reactors-high temperature electrolysis (HTE)  

Microsoft Academic Search

Results of a study to identify and develop a reference design for synfuel production based on fusion reactors are given. The most promising option for hydrogen production was high-temperature electrolysis (HTE). The main findings of this study are: 1. HTE has the highest potential efficiency for production of synfuels from fusion; a fusion to hydrogen energy efficiency of about 70%

Fillo

1978-01-01

390

A wavelet-based image fusion tutorial  

Microsoft Academic Search

The objective of image fusion is to combine information from multiple images of the same scene. The result of image fusion is a new image which is more suitable for human and machine perception or further image-processing tasks such as segmentation, feature extraction and object recognition. Di4erent fusion methods have been proposed in literature, including multiresolution analysis. This paper is

Gonzalo Pajares; Jesús Manuel De La Cruz

2004-01-01

391

EPRI Fusion Energy Assessment July 19, 2011  

E-print Network

· Requires two major changes to the MFE enterprise ­ An accelerated fusion nuclear science and engineering research program RJF EPRI 2011 #12;ACCELERATE MFE VIA FUSION NUCLEAR S&T PROGRAM IN ITER TIMEFRAME #12;THE & Opportunities + ReNew ­ 2010: Fusion Nuclear Science Program (FNSP) White Paper ­ 2010: Pilot Plant concept

392

the fusion trend line Stan Milora (ORNL)  

E-print Network

: Greenwald report on Priorities, Gaps and Opportunities identifies glaring gaps in materials, fusion nuclear ­materials and fusion nuclear science and technology ReNeW findings VLT Virtual Laboratory for Technology need to move." ­ High level goal 2 "Materials in a fusion environment " includes PMI effects, nuclear

393

Weapons Activities/ Inertial Confinement Fusion Ignition  

E-print Network

Weapons Activities/ Inertial Confinement Fusion Ignition and High Yield Campaign FY 2011 Congressional Budget Inertial Confinement Fusion Ignition and High Yield Campaign Funding Profile by Subprogram Fusion Ignition and High Yield Campaign Ignition 100,535 106,734 109,506 NIF Diagnostics, Cryogenics

394

THE REQUIREMENTS OF A FUSION DEMONSTRATION  

E-print Network

Institute of Plasma and Fusion Research University of California, Los Angeles Los Angeles, CA 90024 of Plasma and Fusion Research, University of California, Los Angeles Los Angeles, CA 90024-1597. Kenneth R#12;THE REQUIREMENTS OF A FUSION DEMONSTRATION REACTOR AND THE STARLITE STUDY Robert W. Conn

Najmabadi, Farrokh

395

Remote computing using the National Fusion Grid  

Microsoft Academic Search

The National Fusion Collaboratory (http:\\/\\/www.fusiongrid.org) uses grid technology to implement remote computing on the National Fusion Grid. The motivations are to reduce the cost of computing resources, shorten the software deployment cycle, and simplify remote computing for the user community. The National Fusion Collaboratory has successfully demonstrated remote access as a grid service to the TRANSP transport analysis code for

J. R. Burruss; S Flanagan; K Keahey; C Ludescher; D. C McCune; Q Peng; L Randerson; D. P Schissel; M Thompson

2004-01-01

396

Tritium breeding in fusion reactors  

SciTech Connect

Key technological problems that influence tritium breeding in fusion blankets are reviewed. The breeding potential of candidate materials is evaluated and compared to the tritium breeding requirements. The sensitivity of tritium breeding to design and nuclear data parameters is reviewed. A framework for an integrated approach to improve tritium breeding prediction is discussed with emphasis on nuclear data requirements.

Abdou, M.A.

1982-10-01

397

Tungsten Spectroscopy for Fusion Plasmas  

SciTech Connect

Tungsten is one of very few candidate materials for plasma facing components in future fusion devices. Therefore, investigations have been started at fusion devices and EBITs to provide atomic data for W in fusion plasmas. Usually the influx of impurities is deduced from the intensity of spectral lines from neutrals or ions in a low ionisation state. For this purpose the appropriate ionisation rates and excitation rates have to be known. At the moment, a WI transition (7S-7P) at 400.9 nm is used, but an extension of the method to other lines is under investigation. In the core of present day plasmas ionisation states up to W56+ can be reached and in a reactor states up to around W68+ will be present. In order to extract information on the local W concentrations over the whole plasma radius atomic data (wavelength, excitation, ionisation, recombination) for all the charge states up to the maximum ionisation state are necessary. Similarly, a high sensitivity has to be achieved since the central W concentrations should stay below 10-4. For an unambiguous identification of the transitions EBIT measurements are of great advantage, but due to the lower electron density compared to fusion plasmas, investigations there are indispensable.

Neu, R.; Puetterich, T.; Dux, R. [Max-Planck-Institut fuer Plasmaphysik, Euratom Association, Boltzmannstr.2, 85748 Garching (Germany); Pospieszczyk, A.; Sergienko, G. [Institut fuer Plasmaphysik, Euratom Association, Forschungszentrum Juelich GmbH, 52425 Juelich (Germany)

2007-04-06

398

Quantum tunneling in nuclear fusion  

Microsoft Academic Search

Recent theoretical advances in the study of heavy-ion fusion reactions below the Coulomb barrier are reviewed. Particular emphasis is given to new ways of analyzing data (such as studying barrier distributions), new approaches to channel coupling (such as the path-integral and Green's function formalisms), and alternative methods to describe nuclear structure effects (such as those using the interacting boson model).

A. B. Balantekin; N. Takigawa

1998-01-01

399

From fusion hindrance to oscillations  

NASA Astrophysics Data System (ADS)

This paper is devoted mainly to the fusion hindrance phenomenon, in its various aspects. Recent experimental results on medium-light systems where the fusion Q-value is positive are discussed. The application of the coupled-channels model using a shallow ion-ion potential is illustrated for 32,36S + 48Ca. The detailed influence of nuclear structure on the low-energy fusion cross sections is shown for the pair of systems 48Ti + 58Fe and 58Ni + 54Fe, where the low-lying quadrupole modes have a different degree of collectivity. The sub-barrier excitation function of 48Ti + 58Fe is much larger than for 58Ni + 54Fe. The lighter symmetric system 28Si +28Si has been the object of recent experimental investigations. Its fusion cross sections have been measured in a wide energy range down to ?1µb. Above the barrier, we have a clear indication of oscillations in the excitation function, probably due to the penetration of successive centrifugal barriers, that are in rather good agreement with previous calculations. The CC model using the shallow M3Y+ repulsion potential is able to reproduce also the sub-barrier part of the excitation function of 28Si +28Si.

Montagnoli, G.

2015-01-01

400

Model Fusion and Joint Inversion  

NASA Astrophysics Data System (ADS)

Inverse problems are inherently non-unique, and regularization is needed to obtain stable and reasonable solutions. The regularization adds information to the problem and determines which solution, out of the infinitely many, is obtained. In this paper, we review and discuss the case when a priori information exists in the form of either known structure or in the form of another inverse problem for a different property. The challenge is to include such information in the inversion process. To use existing known structure, we review the concept of model fusion, where we build a regularization functional that fuses the inverted model to a known one. The fusion is achieved by four different techniques. Joint inversion of two data sets is achieved by using iterative data fusion. The paper discusses four different methods for joint inversion. We discuss the use of correspondence maps or the petrophysics of the rocks, as well as structure. In particular, we suggest to further stabilize the well-known gradient cross product and suggest a new technique, Joint Total Variation, to solve the problem. The Joint Total Variation is a convex functional for joint inversion and, as such, has favorable optimization properties. We experiment with the techniques on the DC resistivity problem and the borehole tomography and show how model fusion and joint inversion can significantly improve over existing techniques.

Haber, Eldad; Holtzman Gazit, Michal

2013-09-01

401

Inertial confinement fusion (ICF) review  

SciTech Connect

During its 1996 winter study JASON reviewed the DOE Inertial Confinement Fusion (ICF) program. This included the National Ignition Facility (NIF) and proposed studies. The result of the review was to comment on the role of the ICF program in support of the DOE Science Based Stockpile Stewardship program.

Hammer, D.; Dyson, F.; Fortson, N.; Novick, B.; Panofsky, W.; Rosenbluth, M.; Treiman, S.; York, H.

1996-03-01

402

Magnetic fusion and project ITER  

SciTech Connect

It has already been demonstrated that our economics and international relationship are impacted by an energy crisis. For the continuing prosperity of the human race, a new and viable energy source must be developed within the next century. It is evident that the cost will be high and will require a long term commitment to achieve this goal due to a high degree of technological and scientific knowledge. Energy from the controlled nuclear fusion is a safe, competitive, and environmentally attractive but has not yet been completely conquered. Magnetic fusion is one of the most difficult technological challenges. In modem magnetic fusion devices, temperatures that are significantly higher than the temperatures of the sun have been achieved routinely and the successful generation of tens of million watts as a result of scientific break-even is expected from the deuterium and tritium experiment within the next few years. For the practical future fusion reactor, we need to develop reactor relevant materials and technologies. The international project called ``International Thermonuclear Experimental Reactor (ITER)`` will fulfill this need and the success of this project will provide the most attractive long-term energy source for mankind.

Park, H.K.

1992-09-01

403

Magnetic fusion and project ITER  

SciTech Connect

It has already been demonstrated that our economics and international relationship are impacted by an energy crisis. For the continuing prosperity of the human race, a new and viable energy source must be developed within the next century. It is evident that the cost will be high and will require a long term commitment to achieve this goal due to a high degree of technological and scientific knowledge. Energy from the controlled nuclear fusion is a safe, competitive, and environmentally attractive but has not yet been completely conquered. Magnetic fusion is one of the most difficult technological challenges. In modem magnetic fusion devices, temperatures that are significantly higher than the temperatures of the sun have been achieved routinely and the successful generation of tens of million watts as a result of scientific break-even is expected from the deuterium and tritium experiment within the next few years. For the practical future fusion reactor, we need to develop reactor relevant materials and technologies. The international project called International Thermonuclear Experimental Reactor (ITER)'' will fulfill this need and the success of this project will provide the most attractive long-term energy source for mankind.

Park, H.K.

1992-01-01

404

Frontiers of Fusion Materials Science  

E-print Network

for the development of innovative materials and fabrication methods that will establish the technological viability (alloys and ceramic composites), insulators, etc. ¥TodayÕs presentation: Materials science highlights and Compatibility Phenomena Fabrication and Joining Science Materials for Attractive Fusion Energy · Structural

405

Progress in pulsed power fusion  

SciTech Connect

Pulsed power offers and efficient, high energy, economical source of x-rays for inertial confinement fusion (ICF) research. We are pursuing two main approaches to ICF driven with pulsed power accelerators: intense light ion beams and z-pinches. This paper describes recent progress in each approach and plans for future development.

Quintenz, J.P.; Adams, R.G.; Bailey, J.E. [and others

1996-07-01

406

Magnetic fusion: progress -> stagnation -> degradation  

NASA Astrophysics Data System (ADS)

``The theory of the failure of magnetic fusion,'' created in 2004 and presented to APS-2007 introduced the notion of the ``difficult'' and ``complicated'' stages of the program and described them details. At the first phase the emerging fusion science was created under strong leadership. Progress was visible on year to year basis, and the program was easy to manage. The complicated phase started in the late 1980s, when the plasma physics appeared to be incapable to implement the mission of ITER to test nuclear components of a fusion reactor. Then, the failure of TFTR (PPPL, USA) and JET (Culham, UK) in the mid 1990 to demonstrate QDT=1 and the blindness of their leaders to already visible means to resolve the problem, were a clear indication of an irreversible stagnation. In fact, right after 2007, it became clear that in the case of a large system of human ``particles'' (scientists) two phases have a continuation. The internal degrees of freedom, otherwise protected from external perturbations by a strong dedication to the scientific method, are now eroding and collapsing. The loss of science in addressing confinement, stability, power extraction, fueling, stationary regimes issues makes the current program irrelevant to fusion energy. A fresh approach should be taken.

Zakharov, Leonid

2012-10-01

407

Antiproton Driven Fusion Propulsion System  

Microsoft Academic Search

A fusion propulsion system in which the plasma is heated to thermonuclear temperature by antiproton annihilation reactions is proposed. It makes use of an open-ended magnetic confinement device known as the gasdynamic mirror (GDM) in which the plasma - such as deuteriumtritium (DT) - is confined long enough to be heated before being ejected through one mirror (serving as a

Ricky Tang; Terry Kammash; Alec Gallimore

2008-01-01

408

Nuclear data for fusion calculations  

SciTech Connect

The European Activation System for calculations of activation of fusion devices is described, concentrating on recent innovations such as uncertainty estimation and the modelling of pulsed exposures. A comparison of measurements and calculational results is reviewed as a means of improving the data libraries.

Forrest, R.A. [UKAEA Government Division, Culham (United Kingdom)

1994-12-31

409

Fusion - A potential power source  

Microsoft Academic Search

Duplicating the fusion process of the sun and the stars for energy production on earth would present many difficulties. The state of matter at such temperatures--the plasma state--may be considered a gas of electrons and nuclei, so one problem is the need to confine a hot, reacting plasma. Because the plasma is an electric conductor, it is subject to magnetic

Torkil H. Jensen

1994-01-01

410

Prospects for spheromak fusion reactors  

Microsoft Academic Search

The reactor study of Hagenson and Krakowski demonstrated the attractiveness of the spheromak as a compact fusion reactor, based on physics principles confirmed in CTX experiments in many respects. Most uncertain was the energy confinement time and the role of magnetic turbulence inherent in the concept. In this paper, a one-dimensional model of heat confinement, calibrated by CTX, predicts negligible

T. K. Fowler; D. D. Hua

1995-01-01

411

Proton Collimators for Fusion Reactors  

NASA Technical Reports Server (NTRS)

Proton collimators have been proposed for incorporation into inertial-electrostatic-confinement (IEC) fusion reactors. Such reactors have been envisioned as thrusters and sources of electric power for spacecraft and as sources of energetic protons in commercial ion-beam applications.

Miley, George H.; Momota, Hiromu

2003-01-01

412

Advanced algorithms for distributed fusion  

NASA Astrophysics Data System (ADS)

The US Military has been undergoing a radical transition from a traditional "platform-centric" force to one capable of performing in a "Network-Centric" environment. This transformation will place all of the data needed to efficiently meet tactical and strategic goals at the warfighter's fingertips. With access to this information, the challenge of fusing data from across the batttlespace into an operational picture for real-time Situational Awareness emerges. In such an environment, centralized fusion approaches will have limited application due to the constraints of real-time communications networks and computational resources. To overcome these limitations, we are developing a formalized architecture for fusion and track adjudication that allows the distribution of fusion processes over a dynamically created and managed information network. This network will support the incorporation and utilization of low level tracking information within the Army Distributed Common Ground System (DCGS-A) or Future Combat System (FCS). The framework is based on Bowman's Dual Node Network (DNN) architecture that utilizes a distributed network of interlaced fusion and track adjudication nodes to build and maintain a globally consistent picture across all assets.

Gelfand, A.; Smith, C.; Colony, M.; Bowman, C.; Pei, R.; Huynh, T.; Brown, C.

2008-03-01

413

Interface Model of Cold Fusion  

Microsoft Academic Search

The interface theory of cold fusion is a variant of Ion Band State (IBS) Theory.1 It models Bloch symmetry deuterons in a 2-dimensional metal lattice instead of the 3-dimensional metal lattice first used. Both IBS variants recognize that the required lattice symmetry has limited extent, with the reactive deuterons being bound inside a closed volume like a box. The reactive

Talbot A. Chubb

414

On the Theory of Fusion  

Microsoft Academic Search

Although equilibrium between two phases is in general determined by both phases, fusion stands somewhat apart in that a crystal cannot be overheated. As a type of the simplest possible crystal, the exact equation of state of frozen argon has been developed here. It has been found that the pressure as function of the volume at a given temperature has

K. F. Herzfeld; Maria Goeppert Mayer

1934-01-01

415

EDITORIAL: Stochasticity in fusion plasmas  

NASA Astrophysics Data System (ADS)

In recent years the importance of externally imposed resonant magnetic fields on plasma has become more and more recognized. These fields will cause ergodization at well defined plasma layers and can induce large size islands at rational q-surfaces. A hope for future large scale tokamak devices is the development of a reliable method for mitigating the large ELMs of type 1 ELMy-H-modes by modifying the edge transport. Other topics of interest for fusion reactors are the option of distributing the heat to a large area and optimizing methods for heat and particle exhaust, or the understanding of the transport around tearing mode instabilities. The cluster of papers in this issue of Nuclear Fusion is a successor to the 2004 special issue (Nuclear Fusion 44 S1-122 ) intended to raise interest in the subject. The contents of this present issue are based on presentations at the Second Workshop on Stochasticity in Fusion Plasmas (SFP) held in Juelich, Germany, 15-17 March 2005. The SFP workshops have been stimulated by the installation of the Dynamic Ergodic Divertor (DED) in the TEXTOR tokamak. It has attracted colleagues working on various plasma configurations such as tokamaks, stellarators or reversed field pinches. The workshop was originally devoted to phenomena on the plasma edge but it has been broadened to transport questions over the whole plasma cross-section. It is a meeting place for experimental and theoretical working groups. The next workshop is planned for February/March 2007 in Juelich, Germany. For details see http://www.fz-juelich.de/sfp/. The content of the workshop is summarized in the following conference summary (K.H. Finken 2006 Nuclear Fusion 46 S107-112). At the workshop experimental results on the plasma transport resulting from ergodization in various devices were presented. Highlights were the results from DIII-D on the mitigation of ELMs (see also T.E. Evans et al 2005 Nuclear Fusion 45 595 ). Theoretical work was focused around the topics of mapping methods of magnetic field lines, 3D-plasma transport modelling efforts of ergodized plasmas and island divertors, and on the penetration of the external field including the resulting force transfer. We hope that the article series in Nuclear Fusion will stimulate interest in this fascinating subject of plasma physics.

Finken, K. H.

2006-04-01

416

Scientific Breakeven for Fusion Energy For the past 40 years, the IFE fusion research community has adopted: achieving a fusion gain of 1 as  

E-print Network

, with fusion energy equal to laser energy. The LLNL definition of scientific breakeven was also published inScientific Breakeven for Fusion Energy For the past 40 years, the IFE fusion research community has as fusion energy produced divided the external energy incident on the fusion reaction chamber. Typical

417

Magnetized Target Fusion: Prospects for Low-Cost Fusion Energy  

NASA Technical Reports Server (NTRS)

Magnetized Target Fusion (MTF) has attracted renewed interest in recent years because it has the potential to resolve one of the major problems with conventional fusion energy research - the high cost of facilities to do experiments and in general develop practical fusion energy. The requirement for costly facilities can be traced to fundamental constraints. The Lawson condition implies large system size in the case of conventional magnetic confinement, or large heating power in the case of conventional inertial confinement. The MTF approach is to use much higher fuel density than with conventional magnetic confinement (corresponding to megabar pressures), which results in a much-reduced system size to achieve Lawson conditions. Intrinsically the system must be pulsed because the pressures exceed the strength of any known material. To facilitate heating the fuel (or "target") to thermonuclear conditions with a high-power high-intensity source of energy, magnetic fields are used to insulate the high-pressure fuel from material surroundings (thus "magnetized target"). Because of magnetic insulation, the required heating power intensity is reduced by many orders of magnitude compared to conventional inertial fusion, even with relatively poor energy confinement in the magnetic field, such as that characterized by Bohm diffusion. In this paper we show semi-quantitatively why MTF-should allow fusion energy production without costly facilities within the same generally accepted physical constraints used for conventional magnetic and inertial fusion. We also briefly discuss potential applications of this technology ranging from nuclear rockets for space propulsion to a practical commercial energy system. Finally, we report on the exploratory research underway, and the interesting physics issues that arise in the MTF regime of parameters. Experiments at Los Alamos are focused on formation of a suitable plasma target for compression, utilizing the knowledge base for compact toroids called Field-Reversed Configurations. As reported earlier, it appears that the existing pulsed-power Shiva Star facility at the Air Force Research Laboratory in Albuquerque, NM can satisfy the heating requirements by means of imploding a thin metal cylinder (called a "liner") surrounding an FRC of the type presently being developed. The proposed next step is an integrated liner-on-plasma experiment in which an FRC would be heated to 10 keV by the imploding liner.

Siemon, Richard E.; Turchi, Peter J.; Barnes, Daniel C.; Degnan, James; Parks, Paul; Ryutov, Dmitri D.; Thio, Y. C. Francis; Schafer, Charles (Technical Monitor)

2001-01-01

418

Security on the US Fusion Grid  

SciTech Connect

The National Fusion Collaboratory project is developing and deploying new distributed computing and remote collaboration technologies with the goal of advancing magnetic fusion energy research. This work has led to the development of the US Fusion Grid (FusionGrid), a computational grid composed of collaborative, compute, and data resources from the three large US fusion research facilities and with users both in the US and in Europe. Critical to the development of FusionGrid was the creation and deployment of technologies to ensure security in a heterogeneous environment. These solutions to the problems of authentication, authorization, data transfer, and secure data storage, as well as the lessons learned during the development of these solutions, may be applied outside of FusionGrid and scale to future computing infrastructures such as those for next-generation devices like ITER.

Burruss, Justin R.; Fredian, Tom W.; Thompson, Mary R.

2005-06-01

419

Data security on the national fusion grid  

SciTech Connect

The National Fusion Collaboratory project is developing and deploying new distributed computing and remote collaboration technologies with the goal of advancing magnetic fusion energy research. This work has led to the development of the US Fusion Grid (FusionGrid), a computational grid composed of collaborative, compute, and data resources from the three large US fusion research facilities and with users both in the US and in Europe. Critical to the development of FusionGrid was the creation and deployment of technologies to ensure security in a heterogeneous environment. These solutions to the problems of authentication, authorization, data transfer, and secure data storage, as well as the lessons learned during the development of these solutions, may be applied outside of FusionGrid and scale to future computing infrastructures such as those for next-generation devices like ITER.

Burruss, Justine R.; Fredian, Tom W.; Thompson, Mary R.

2005-06-01

420

The elementary fusion modalities of osteoclasts.  

PubMed

The last step of the osteoclast differentiation process is cell fusion. Most efforts to understand the fusion mechanism have focused on the identification of molecules involved in the fusion process. Surprisingly, the basic fusion modalities, which are well known for fusion of other cell types, are not known for the osteoclast. Here we show that osteoclast fusion partners are characterized by differences in mobility, nuclearity, and differentiation level. Our demonstration was based on time-laps videos of human osteoclast preparations from three donors where 656 fusion events were analyzed. Fusions between a mobile and an immobile partner were most frequent (62%), while fusion between two mobile (26%) or two immobile partners (12%) was less frequent (p<0.001). In general, the immobile fusion partner contained more nuclei than the mobile one (p<0.01). Furthermore, enrichment in nuclei of an osteoclast with three or more nuclei resulted from fusion with a mono-nucleated cell in 67% of the cases (p<0.001), while mono-nucleated cells fused with a multinucleated cell in 61% of the cases (p<0.05). This observation suggested that a more mature osteoclast prefers to fuse with a less mature pre-osteoclast. This hypothesis was supported by a nucleus-tracing approach in a co-culture of more and less differentiated pre-osteoclasts/osteoclasts. Furthermore, we found that osteoclast fusion proceeds through primarily two different types of cell contacts: phagocytic-cup and broad-contact-surfaces (>80% of all fusions). We conclude that osteoclasts most often gain nuclei by addition of one nucleus at a time, and that this nucleus is most often delivered by a moving cell to an immobile cell. These characteristics fit the in vivo observations where mono-nucleated precursors migrating from the bone marrow fuse with more mature osteoclasts sitting on the bone surface. They also fit the fusion modalities of other cell types. PMID:25527420

Søe, Kent; Hobolt-Pedersen, Anne-Sofie; Delaisse, Jean-Marie

2015-04-01

421

Measuring time of flight of fusion products in an inertial electrostatic confinement fusion device for spatial profiling of fusion reactions  

SciTech Connect

A new diagnostic has been developed that uses the time of flight (TOF) of the products from a nuclear fusion reaction to determine the location where the fusion reaction occurred. The TOF diagnostic uses charged particle detectors on opposing sides of the inertial electrostatic confinement (IEC) device that are coupled to high resolution timing electronics to measure the spatial profile of fusion reactions occurring between the two charged particle detectors. This diagnostic was constructed and tested by the University of Wisconsin-Madison Inertial Electrostatic Confinement Fusion Group in the IEC device, HOMER, which accelerates deuterium ions to fusion relevant energies in a high voltage ({approx}100 kV), spherically symmetric, electrostatic potential well [J. F. Santarius, G. L. Kulcinski, R. P. Ashley, D. R. Boris, B. B. Cipiti, S. K. Murali, G. R. Piefer, R. F. Radel, T. E. Radel, and A. L. Wehmeyer, Fusion Sci. Technol. 47, 1238 (2005)]. The TOF diagnostic detects the products of D(d,p)T reactions and determines where along a chord through the device the fusion event occurred. The diagnostic is also capable of using charged particle spectroscopy to determine the Doppler shift imparted to the fusion products by the center of mass energy of the fusion reactants. The TOF diagnostic is thus able to collect spatial profiles of the fusion reaction density along a chord through the device, coupled with the center of mass energy of the reactions occurring at each location. This provides levels of diagnostic detail never before achieved on an IEC device.

Donovan, D. C. [Sandia National Laboratories, 7011 East Avenue, Livermore, California 94550 (United States); Boris, D. R. [Naval Research Laboratory, 4555 Overlook Avenue, South West, Washington, DC 20375 (United States); Kulcinski, G. L.; Santarius, J. F. [Fusion Technology Institute, University of Wisconsin-Madison, 1500 Engineering Drive, Madison, Wisconsin 53706 (United States); Piefer, G. R. [Phoenix Nuclear Labs, 2555 Industrial Drive, Madison, Wisconsin 53713 (United States)

2013-03-15

422

Measuring time of flight of fusion products in an inertial electrostatic confinement fusion device for spatial profiling of fusion reactions  

NASA Astrophysics Data System (ADS)

A new diagnostic has been developed that uses the time of flight (TOF) of the products from a nuclear fusion reaction to determine the location where the fusion reaction occurred. The TOF diagnostic uses charged particle detectors on opposing sides of the inertial electrostatic confinement (IEC) device that are coupled to high resolution timing electronics to measure the spatial profile of fusion reactions occurring between the two charged particle detectors. This diagnostic was constructed and tested by the University of Wisconsin-Madison Inertial Electrostatic Confinement Fusion Group in the IEC device, HOMER, which accelerates deuterium ions to fusion relevant energies in a high voltage (˜100 kV), spherically symmetric, electrostatic potential well [J. F. Santarius, G. L. Kulcinski, R. P. Ashley, D. R. Boris, B. B. Cipiti, S. K. Murali, G. R. Piefer, R. F. Radel, T. E. Radel, and A. L. Wehmeyer, Fusion Sci. Technol. 47, 1238 (2005)]. The TOF diagnostic detects the products of D(d,p)T reactions and determines where along a chord through the device the fusion event occurred. The diagnostic is also capable of using charged particle spectroscopy to determine the Doppler shift imparted to the fusion products by the center of mass energy of the fusion reactants. The TOF diagnostic is thus able to collect spatial profiles of the fusion reaction density along a chord through the device, coupled with the center of mass energy of the reactions occurring at each location. This provides levels of diagnostic detail never before achieved on an IEC device.

Donovan, D. C.; Boris, D. R.; Kulcinski, G. L.; Santarius, J. F.; Piefer, G. R.

2013-03-01

423

ProFusion*: Intelligent Fusion from Multiple, Distributed Search Engines  

Microsoft Academic Search

The explosive growth of the World Wide Web, and the resulting information overload, has led to a mini-explosion in World Wide Web search engines. This mini-explosion, in turn, led to the development of ProFusion, a meta search engine. Educators, like other users, do not have the time to evaluate multiple search engines to knowledgeably select the best for their uses.

Susan Gauch; Guijun Wang; Mario Gomez

1996-01-01

424

Recent progress on fusion nuclear technology in inertial fusion  

Microsoft Academic Search

Inertial fusion energy (IFE) ignition and gain facilities based on lasers, the national ignition facility (NIF\\/USA) and the laser megajoule (LMJ\\/France), will be operating in the first years (2002–2010) of the next century. The conceptual design of another ignition and gain facility, the heavy ion design of ignition facility (HIDIF), is under way in an European initiative. NIF's target emission

J. M. Perlado; J. Sanz

1998-01-01

425

Fusion technologies for Laser Inertial Fusion Energy (LIFE)  

NASA Astrophysics Data System (ADS)

The Laser Inertial Fusion-based Energy (LIFE) engine design builds upon on going progress at the National Ignition Facility (NIF) and offers a near-term pathway to commercial fusion. Fusion technologies that are critical to success are reflected in the design of the first wall, blanket and tritium separation subsystems. The present work describes the LIFE engine-related components and technologies. LIFE utilizes a thermally robust indirect-drive target and a chamber fill gas. Coolant selection and a large chamber solid-angle coverage provide ample tritium breeding margin and high blanket gain. Target material selection eliminates the need for aggressive chamber clearing, while enabling recycling. Demonstrated tritium separation and storage technologies limit the site tritium inventory to attractive levels. These key technologies, along with the maintenance and advanced materials qualification program have been integrated into the LIFE delivery plan. This describes the development of components and subsystems, through prototyping and integration into a First Of A Kind power plant. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Kramer, K. J.; Latkowski, J. F.; Abbott, R. P.; Anklam, T. P.; Dunne, A. M.; El-Dasher, B. S.; Flowers, D. L.; Fluss, M. J.; Lafuente, A.; Loosmore, G. A.; Morris, K. R.; Moses, E.; Reyes, S.

2013-11-01

426

Fission Fusion Hybrids: a nearer term application of Fusion  

NASA Astrophysics Data System (ADS)

Fission-fusion hybrids enjoy unique advantages for addressing long standing societal acceptability issues of nuclear fission power at a much lower level of technical development than a competitive fusion power plant. For waste incineration, hybrids burn intransigent transuranic residues (with the long lived biohazard) from light water reactors (LWRs). The number of hybrids needed is 5-10 times less than the corresponding number of fast reactors (FRs). The highly sub-critical hybrids, with a thermal/epithermal spectrum, incinerate > 95% of the waste in decades rather than the centuries needed for FRs. For fuel production, hybrids can produce fuel for 3-4 times as many LWRs with no fuel reprocessing. Thorium fuel rods exposed to neutrons in the hybrid reach fissile concentrations that enable efficient burning in LWR without the proliferation risks of reprocessing. The proliferation risks of this method are far less than other fuel breeding approaches, including today's gas centrifuge. With this cycle, US Thorium reserves could supply the entire US electricity supply for centuries. The centerpiece of the fuel cycle is a high power density Compact Fusion Neutron Source (major+minor radius ˜ 2.5-3.5 m), which is made feasible by the super-X divertor.

Kotschenreuther, M.; Valanju, P.; Mahajan, S.; Covele, B.

2011-11-01

427

Overview of advanced fuel fusion  

SciTech Connect

The status and issues related to the development of advanced fuel fusion are discussed. D-{sup 3}He is a key advanced fuel since it has the potential of igniting in a variety of confinement concepts. However, to obtain a plentiful source of {sup 3}He, either lunar mining or breeding becomes necessary. Highly non-Maxwellian plasmas, such as might occur in beam-beam fusion concepts, are necessary to address fuels like p-{sup 11}B which have the added advantages of a more aneutronic character and plentiful fuel supply. Such plasmas appear very difficult to achieve but several possible approaches such as electrostatic confinement are noted. 52 refs., 13 figs, 5 tabs.

Miley, G.H.

1989-01-01

428

Interplanetary propulsion using inertial fusion  

NASA Technical Reports Server (NTRS)

Inertial fusion can be used to power spacecraft within the solar system and beyond. Such spacecraft have the potential for short-duration manned-mission performance exceeding other technologies. We are conducting a study to assess the systems aspects of inertial fusion as applied to such missions, based on the conceptual engine design of Hyde (1983) we describe the required systems for an entirely new spacecraft design called VISTA that is based on the use of DT fuel. We give preliminary design details for the power conversion and power conditioning systems for manned missions to Mars of total duration of about 100 days. Specific mission performance results will be published elsewhere, after the study has been completed.

Orth, C. D.; Hogan, W. J.; Hoffman, N.; Murray, K.; Klein, G.; Diaz, F. C.

1987-01-01

429

Trust metrics in information fusion  

NASA Astrophysics Data System (ADS)

Trust is an important concept for machine intelligence and is not consistent across many applications. In this paper, we seek to understand trust from a variety of factors: humans, sensors, communications, intelligence processing algorithms and human-machine displays of information. In modeling the various aspects of trust, we provide an example from machine intelligence that supports the various attributes of measuring trust such as sensor accuracy, communication timeliness, machine processing confidence, and display throughput to convey the various attributes that support user acceptance of machine intelligence results. The example used is fusing video and text whereby an analyst needs trust information in the identified imagery track. We use the proportional conflict redistribution rule as an information fusion technique that handles conflicting data from trusted and mistrusted sources. The discussion of the many forms of trust explored in the paper seeks to provide a systems-level design perspective for information fusion trust quantification.

Blasch, Erik

2014-05-01

430

Fusion of \\ade Lattice Models  

E-print Network

Fusion hierarchies of \\ade face models are constructed. The fused critical $D$, $E$ and elliptic $D$ models yield new solutions of the Yang-Baxter equations with bond variables on the edges of faces in addition to the spin variables on the corners. It is shown directly that the row transfer matrices of the fused models satisfy special functional equations. Intertwiners between the fused \\ade models are constructed by fusing the cells that intertwine the elementary face weights. As an example, we calculate explicitly the fused $2\\times 2$ face weights of the 3-state Potts model associated with the $D_4$ diagram as well as the fused intertwiner cells for the $A_5$--$D_4$ intertwiner. Remarkably, this $2\\times 2$ fusion yields the face weights of both the Ising model and 3-state CSOS models.

Yu-kui Zhou; Paul A. Pearce

1994-05-04

431

Prospects for toroidal fusion reactors  

NASA Astrophysics Data System (ADS)

Work on the International Thermonuclear Experimental Reactor (ITER) tokamak has refined understanding of the realities of a deuterium-tritium (D-T) burning magnetic fusion reactor. An ITER-like tokamak reactor using ITER costs and performance would lead to a cost of electricity (COE) of about 130 mills/kWh. Advanced tokamak physics to be tested in the Toroidal Physics Experiment (TPX), coupled with moderate components in engineering, technology, and unit costs, should lead to a COE comparable with best existing fission systems around 60 mills/kWh. However, a larger unit size, approximately 2000 MW(e), is favored for the fusion system. Alternative toroidal configurations to the conventional tokamak, such as the stellarator, reversed-field pinch, and field-reversed configuration, offer some potential advantage, but are less well developed, and have their own challenges.

Sheffield, J.; Galambos, J. D.

1994-06-01

432

Multiscale Medical Image Fusion in Wavelet Domain  

PubMed Central

Wavelet transforms have emerged as a powerful tool in image fusion. However, the study and analysis of medical image fusion is still a challenging area of research. Therefore, in this paper, we propose a multiscale fusion of multimodal medical images in wavelet domain. Fusion of medical images has been performed at multiple scales varying from minimum to maximum level using maximum selection rule which provides more flexibility and choice to select the relevant fused images. The experimental analysis of the proposed method has been performed with several sets of medical images. Fusion results have been evaluated subjectively and objectively with existing state-of-the-art fusion methods which include several pyramid- and wavelet-transform-based fusion methods and principal component analysis (PCA) fusion method. The comparative analysis of the fusion results has been performed with edge strength (Q), mutual information (MI), entropy (E), standard deviation (SD), blind structural similarity index metric (BSSIM), spatial frequency (SF), and average gradient (AG) metrics. The combined subjective and objective evaluations of the proposed fusion method at multiple scales showed the effectiveness and goodness of the proposed approach. PMID:24453868

Khare, Ashish

2013-01-01

433

Distribution Category: Magnetic Fusion Energy  

E-print Network

Distribution Category: Magnetic Fusion Energy (UC-20) ANL/FPP/TM-175 ANL/FPP/TM--175 DE83 015751 on the reference 11mlter 4 3-2 Eroslon/redeposltion of a carbon limiter coating at a 150 eV edge temperature. 4 4 to be a reasonable design and should provide an opportunity to test high power and particle loadings. Carbon Is recom

Harilal, S. S.

434

ACE Mission - Fusion and Nucleosynthesis  

NSDL National Science Digital Library

This educational brief explains the idea that nuclear fusion is thought to be the mechanism by which virtually all of the elements around us are created. Topics include the proton-proton cycle, the carbon-nitrogen-oxygen cycle, and endothermic reactions in supernova explosions. There is also a discussion of the Advanced Composition Explorer (ACE), a spacecraft intended to study the origin and evolution of the elements produced by our Sun.

435

Nuclear fusion in dense plasmas  

Microsoft Academic Search

The review begins by grouping the fundamental nuclear reactions into two classifications, namely, the usual binary processes and few-particle processes. In the few-particle processes, the possibility of electron-screened cold fusion is remarked. The special features of dense plasmas rest in the enhancement of reaction rates over these fundamental processes due to internuclear many-particle processes. The manyparticle processes arise from a

Setsuo Ichimaru

1993-01-01

436

Status of cold fusion (2010)  

Microsoft Academic Search

The phenomenon called cold fusion has been studied for the last 21 years since its discovery by Profs. Fleischmann and Pons\\u000a in 1989. The discovery was met with considerable skepticism, but supporting evidence has accumulated, plausible theories have\\u000a been suggested, and research is continuing in at least eight countries. This paper provides a brief overview of the major\\u000a discoveries and some

Edmund Storms

2010-01-01

437

Prospects for spheromak fusion reactors  

NASA Astrophysics Data System (ADS)

The reactor study of Hagenson and Krakowski demonstrated the attractiveness of the spheromak as a compact fusion reactor, based on physics principles confirmed in CTX experiments in many respects. Most uncertain was the energy confinement time and the role of magnetic turbulence inherent in the concept. In this paper, a one-dimensional model of heat confinement, calibrated by CTX, predicts negligible heat loss by magnetic turbulence at reactor scale.

Fowler, T. K.; Hua, D. D.

1995-06-01

438

Heavy Ion Fusion Injector Program  

SciTech Connect

A program is underway to construct a 2 MV, 800 mA, K{sup +} injector for heavy ion fusion. The Electrostatic Quadrupole (ESQ) injector configuration consists of a zeolite source, a diode of up to 1 MV, together with several electrostatic quadrupole units to simultaneously focus and accelerate the beam to 2 MV. The key issues of source technology, high voltage breakdown, beam aberrations, and transient effects will be discussed. Results from ongoing experiments and simulations will be presented.

Yu, S.; Eylon, S.;