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Sample records for interbody fusion alif

  1. Comparison of ALIF vs. XLIF for L4/5 interbody fusion: pros, cons, and literature review

    PubMed Central

    Gambhir, Shanu

    2016-01-01

    The incidence of lumbar fusion for the treatment of various degenerative lumbar spine diseases has increased dramatically over the last twenty years. Many lumbar fusion techniques have been developed and popularized, each with its own advantages and disadvantages. Anterior lumbar interbody fusion (ALIF) initially introduced in the 1930’s, has become a common and widely accepted technique for lumbar fusions over the last decade offering several advantages over standard posterior lumbar interbody fusion (PLIF) or transforaminal lumbar interbody fusion (TLIF). More recently, the lateral trans-psoas approach termed extreme, direct or lateral lumbar interbody fusion (XLIF, DLIF, LLIF) is gaining widespread popularity. The aim of this paper is to compare the approaches, advantages and disadvantages of ALIF and XLIF for L4/5 interbody fusion based on relevant literature. PMID:27683688

  2. Lumbar interbody fusion: techniques, indications and comparison of interbody fusion options including PLIF, TLIF, MI-TLIF, OLIF/ATP, LLIF and ALIF

    PubMed Central

    Phan, Kevin; Malham, Greg; Seex, Kevin; Rao, Prashanth J.

    2015-01-01

    Degenerative disc and facet joint disease of the lumbar spine is common in the ageing population, and is one of the most frequent causes of disability. Lumbar spondylosis may result in mechanical back pain, radicular and claudicant symptoms, reduced mobility and poor quality of life. Surgical interbody fusion of degenerative levels is an effective treatment option to stabilize the painful motion segment, and may provide indirect decompression of the neural elements, restore lordosis and correct deformity. The surgical options for interbody fusion of the lumbar spine include: posterior lumbar interbody fusion (PLIF), transforaminal lumbar interbody fusion (TLIF), minimally invasive transforaminal lumbar interbody fusion (MI-TLIF), oblique lumbar interbody fusion/anterior to psoas (OLIF/ATP), lateral lumbar interbody fusion (LLIF) and anterior lumbar interbody fusion (ALIF). The indications may include: discogenic/facetogenic low back pain, neurogenic claudication, radiculopathy due to foraminal stenosis, lumbar degenerative spinal deformity including symptomatic spondylolisthesis and degenerative scoliosis. In general, traditional posterior approaches are frequently used with acceptable fusion rates and low complication rates, however they are limited by thecal sac and nerve root retraction, along with iatrogenic injury to the paraspinal musculature and disruption of the posterior tension band. Minimally invasive (MIS) posterior approaches have evolved in an attempt to reduce approach related complications. Anterior approaches avoid the spinal canal, cauda equina and nerve roots, however have issues with approach related abdominal and vascular complications. In addition, lateral and OLIF techniques have potential risks to the lumbar plexus and psoas muscle. The present study aims firstly to comprehensively review the available literature and evidence for different lumbar interbody fusion (LIF) techniques. Secondly, we propose a set of recommendations and guidelines

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

    PubMed Central

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

    2014-01-01

    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

  4. Lumbar facet cyst resolution following anterior interbody fusion.

    PubMed

    Massey, Gene M; Caputo, Adam M; Michael, Keith W; Isaacs, Robert E; Brown, Christopher R

    2013-12-01

    Facet cysts are a relatively common source of neural compression in the lumbar spine. Open decompression and fusion are frequently used to treat the stenosis and instability associated with this pathology. Recently, anterior lumbar interbody fusion (ALIF) has increased in popularity for the treatment of lumbar degenerative conditions. ALIF may achieve indirect decompression of the neural elements with less surgical morbidity than conventional open approaches. To date, there are no published reports describing the use of indirect decompression or interbody fusion for the treatment of facet cysts. We report a patient who developed an L4-L5 facet cyst secondary to degenerative changes and spondylolisthesis. ALIF with posterior instrumentation was used to address his condition. Six months after surgery, the patient had complete resolution of his symptoms. MRI revealed complete resolution of the facet cyst. This patient provides previously unreported evidence that interbody fusion alone may result in facet cyst resolution. Clinical studies are needed to evaluate if interbody fusion can consistently relieve the symptoms associated with facet cysts without the use of direct decompression.

  5. PEEK-Halo effect in interbody fusion.

    PubMed

    Phan, Kevin; Hogan, Jarred A; Assem, Yusuf; Mobbs, Ralph J

    2016-02-01

    Recent developments have seen poly[aryl-ether-ether-ketone] (PEEK) being increasingly used in vertebral body fusion. More novel approaches to improve PEEK have included the introduction of titanium-PEEK (Ti-PEEK) composites and coatings. This paper aims to describe a potential complication of PEEK based implants relating to poorer integration with the surrounding bone, producing a "PEEK-Halo" effect which is not seen in Ti-PEEK composite implants. We present images from two patients undergoing anterior lumbar interbody fusion (ALIF). The first patient underwent an L5/S1 ALIF using a PEEK implant whilst the second patient underwent L4/L5 ALIF using a Ti-PEEK composite implant. Evidence of osseointegration was sought using CT imaging and confirmed using histological preparations of a sheep tibia model. The PEEK-Halo effect is demonstrated by a halo effect between the PEEK implant and the bone graft on CT imaging. This phenomenon is secondary to poor osseointegration of PEEK implants. The PEEK-Halo effect was not demonstrated in the second patient who received a Ti-PEEK composite graft. Histological analysis of graft/bone interface surfaces in PEEK versus Ti-PEEK implants in a sheep model further confirmed poorer osseointegration of the PEEK implant. In conclusion, the PEEK-Halo effect is seen secondary to minimal osseointegration of PEEK at the adjacent vertebral endplate following a PEEK implant insertion. This effect is not seen with Ti-PEEK implants, and may support the role of titanium in improving the bone-implant interface of PEEK substrates.

  6. Extreme lateral lumbar interbody fusion: Do the cons outweigh the pros?

    PubMed Central

    Epstein, Nancy E.

    2016-01-01

    Background: Major factors prompted the development of minimally invasive (MIS) extreme lateral interbody fusion (XLIF; NuVasive Inc., San Diego, CA, USE) for the thoracic/lumbar spine. These include providing interbody stabilization and indirect neural decompression while avoiding major visceral/vessel injury as seen with anterior lumbar interbody fusion (ALIF), and to avert trauma to paraspinal muscles/facet joints found with transforaminal lumbar interbody fusion (TLIF), posterior lumbar interbody fusion (PLIF), and posterior-lateral fusion techniques (PLF). Although anticipated pros of MIS XLIF included reduced blood loss, operative time, and length of stay (LOS), they also included, higher fusion, and lower infection rates. Unanticipated cons, however, included increased morbidity/mortality rates. Methods: We assessed the pros and cons (e.g., risks, complications, comparable value/superiority/inferiority, morbidity/mortality) of MIS XLIF vs. ALIF, TLIF, PLIF, and PLF. Results: Pros of XLIF included various biomechanical and technical surgical advantages, along with multiple cons vs. ALIF, TLIF, PLIF, and PLF. For example, XLIF correlated with a considerably higher frequency of major neurological deficits vs. other constructs; plexus injuries 13.28%, sensory deficits 0–75% (permanent in 62.5%), motor deficits 0.7–33.6%, and anterior thigh pain 12.5–25%. XLIF also disproportionately contributed to other major morbidity/mortality; sympathectomy, major vascular injuries (some life-ending others life-threatening), bowel perforations, and seromas. Furthermore, multiple studies documented no superiority, and the potential inferiority of XLIF vs. ALIF, TLIF, PLIF, and PLF. Conclusion: Reviewing the pros of XLIF (e.g. radiographic, technical, biomechanical) vs. the cons (inferiority, increased morbidity/mortality) vs. ALIF, TLIF, PLIF, and PLF, we question whether XLIF should remain part of the lumbar spinal surgical armamentarium. PMID:27843688

  7. Mini-Open Anterior Lumbar Interbody Fusion Combined with Lateral Lumbar Interbody Fusion in Corrective Surgery for Adult Spinal Deformity

    PubMed Central

    Lee, Chong-Suh; Chung, Sung-Soo; Lee, Jun-Young; Yum, Tae-Hoon; Shin, Seong-Kee

    2016-01-01

    Study Design Prospective observational study. Purpose To introduce the techniques and present the surgical outcomes of mini-open anterior lumbar interbody fusion (ALIF) at the most caudal segments of the spine combined with lateral lumbar interbody fusion (LLIF) for the correction of adult spinal deformity Overview of Literature Although LLIF is increasingly used to correct adult spinal deformity, the correction of sagittal plane deformity with LLIF alone is reportedly suboptimal. Methods Thirty-two consecutive patients with adult spinal deformity underwent LLIF combined with mini-open ALIF at the L5–S1 or L4–S1 levels followed by 2-stage posterior fixation. ALIF was performed for a mean 1.3 levels and LLIF for a mean 2.7 levels. Then, percutaneous fixation was performed in 11 patients (percutaneous group), open correction with facetectomy with or without laminectomy in 16 (open group), and additional pedicle subtraction osteotomy (PSO) in 5 (PSO group). Spinopelvic parameters were compared preoperatively and postoperatively. Hospitalization data and clinical outcomes were recorded. Results No major medical complications developed, and clinical outcomes improved postoperatively in all groups. The mean postoperative segmental lordosis was greater after ALIF (17.5°±5.5°) than after LLIF (8.1°±5.3°, p <0.001). Four patients (12.5%) had lumbar lordosis with a pelvic incidence of ±9° preoperatively, whereas this outcome was achieved postoperatively in 30 patients (93.8%). The total increase in lumbar lordosis was 14.7° in the percutaneous group, 35.3° in the open group, and 57.0° in the PSO group. The ranges of potential lumbar lordosis increase were estimated as 4°–25°, 23°–42°, and 45°–65°, respectively. Conclusions Mini-open ALIF combined with LLIF followed by posterior fixation may be a feasible technique for achieving optimal sagittal balance and reducing the necessity of more extensive surgery. PMID:27994777

  8. More nerve root injuries occur with minimally invasive lumbar surgery, especially extreme lateral interbody fusion: A review

    PubMed Central

    Epstein, Nancy E.

    2016-01-01

    Background: In the lumbar spine, do more nerve root injuries occur utilizing minimally invasive surgery (MIS) techniques versus open lumbar procedures? To answer this question, we compared the frequency of nerve root injuries for multiple open versus MIS operations including diskectomy, laminectomy with/without fusion addressing degenerative disc disease, stenosis, and/or degenerative spondylolisthesis. Methods: Several of Desai et al. large Spine Patient Outcomes Research Trial studies showed the frequency for nerve root injury following an open diskectomy ranged from 0.13% to 0.25%, for open laminectomy/stenosis with/without fusion it was 0%, and for open laminectomy/stenosis/degenerative spondylolisthesis with/without fusion it was 2%. Results: Alternatively, one study compared the incidence of root injuries utilizing MIS transforaminal lumbar interbody fusion (TLIF) versus posterior lumbar interbody fusion (PLIF) techniques; 7.8% of PLIF versus 2% of TLIF patients sustained root injuries. Furthermore, even higher frequencies of radiculitis and nerve root injuries occurred during anterior lumbar interbody fusions (ALIFs) versus extreme lateral interbody fusions (XLIFs). These high frequencies were far from acceptable; 15.8% following ALIF experienced postoperative radiculitis, while 23.8% undergoing XLIF sustained root/plexus deficits. Conclusions: This review indicates that MIS (TLIF/PLIF/ALIF/XLIF) lumbar surgery resulted in a higher incidence of root injuries, radiculitis, or plexopathy versus open lumbar surgical techniques. Furthermore, even a cursory look at the XLIF data demonstrated the greater danger posed to neural tissue by this newest addition to the MIS lumbar surgical armamentariu. The latter should prompt us as spine surgeons to question why the XLIF procedure is still being offered to our patients? PMID:26904372

  9. [Mechanical studies of lumbar interbody fusion implants].

    PubMed

    Bader, R J; Steinhauser, E; Rechl, H; Mittelmeier, W; Bertagnoli, R; Gradinger, R

    2002-05-01

    In addition to autogenous or allogeneic bone grafts, fusion cages composed of metal or plastic are being used increasingly as spacers for interbody fusion of spinal segments. The goal of this study was the mechanical testing of carbon fiber reinforced plastic (CFRP) fusion cages used for anterior lumbar interbody fusion. With a special testing device according to American Society for Testing and Materials (ASTM) standards, the mechanical properties of the implants were determined under four different loading conditions. The implants (UNION cages, Medtronic Sofamor Danek) provide sufficient axial compression, shear, and torsional strength of the implant body. Ultimate axial compression load of the fins is less than the physiological compression loads at the lumbar spine. Therefore by means of an appropriate surgical technique parallel grooves have to be reamed into the endplates of the vertebral bodies according to the fin geometry. Thereby axial compression forces affect the implants body and the fins are protected from damaging loading. Using a supplementary anterior or posterior instrumentation, in vivo failure of the fins as a result of physiological shear and torsional spinal loads is unlikely. Due to specific complications related to autogenous or allogeneic bone grafts, fusion cages made of metal or carbon fiber reinforced plastic are an important alternative implant in interbody fusion.

  10. Arthrodesis Rate and Patient Reported Outcomes After Anterior Lumbar Interbody Fusion Utilizing a Plasma-Sprayed Titanium Coated PEEK Interbody Implant: A Retrospective, Observational Analysis

    PubMed Central

    Bergen, Sophea R.; Staples, Miranda; Liang, Kevin; Raiszadeh, Ramin

    2017-01-01

    Background Anterior lumbar interbody fusion (ALIF) is utilized in symptomatic spinal disc destabilization due to degenerative lumbar disc disease, isthmic and degenerative spondylolisthesis, internal disc disruption, or pseudarthrosis after non-operative treatments fail. The addition of a plasma-sprayed titanium coating (PTC) to polyether ether ketone spacers (PEEK) may reduce the rate of implant subsidence or non-union secondary to poor osseous-integration of non-coated PEEK or metal interbody systems. Methods A retrospective, non-randomized, single-center chart review, evaluated the post-surgical follow-up data of patients receiving a PTC PEEK implant during single or multi-level ALIF procedures to determine the clinical efficacy and rate of arthrodesis after utilization of a coated spacer. Standard roentgenographs or computed tomography were used to identify successful arthrodesis following the ALIF procedure and longitudinal clinical improvements were determined by scores on the Visual Analog Scale (VAS) for low back and leg pain. Results Forty-four subjects (48% male, mean=53 years) were included in this chart review. Follow-up radiology demonstrated radiographic union with bridging bone formation across the interbody space for 42/44 (96%) individuals with solid arthrodesis occurring at an average of 7.3 ± 2.3 months. Subjects demonstrated significant improvement in VAS low back pain (4.5 ± 2.4 point improvement, p=0.0001) and VAS leg pain (4.1 ± 3.3 point improvement, p=0.0001). While there was a significant reduction in the improvement of VAS low back pain of Worker's Compensation claimants as compared to other patients (3.9 ± 2.4 vs. 5.3 ± 2.1), there was no difference in VAS low back pain or leg pain when the data was stratified by gender, age, tobacco use, comorbidities, prior surgery, fusion construct length, use of supplemental posterior instrumentation, BMI, or diagnosis. Conclusions This study provides support that the addition of a PTC coating

  11. The VariLift® Interbody Fusion System: expandable, standalone interbody fusion

    PubMed Central

    Emstad, Erik; del Monaco, Diana Cardenas; Fielding, Louis C; Block, Jon E

    2015-01-01

    Intervertebral fusion cages have been in clinical use since the 1990s. Cages offer the benefits of bone graft containment, restored intervertebral and foraminal height, and a more repeatable, stable procedure compared to interbody fusion with graft material alone. Due to concerns regarding postoperative stability, loss of lordosis, and subsidence or migration of the implant, interbody cages are commonly used with supplemental fixation such as pedicle screw systems or anterior plates. While providing additional stability, supplemental fixation techniques increase operative time, exposure, cost, and morbidity. The VariLift® Interbody Fusion System (VariLift® system) has been developed as a standalone solution to provide the benefits of intervertebral fusion cages without the requirement of supplemental fixation. The VariLift® system, FDA-cleared for standalone use in both the cervical and lumbar spine, is implanted in a minimal profile and then expanded in situ to provide segmental stability, restored lordosis, and a large graft chamber. Preclinical testing and analyses have found that the VariLift® System is durable, and reduces stresses that may contribute to subsidence and migration of other standalone interbody cages. Fifteen years of clinical development with the VariLift® system have demonstrated positive clinical outcomes, continued patient maintenance of segmental stability and lordosis, and no evidence of implant migration. The purpose of this report is to describe the VariLift® system, including implant characteristics, principles of operation, indications for use, patient selection criteria, surgical technique, postoperative care, preclinical testing, and clinical experience. The VariLift® System represents an improved surgical option for a stable interbody fusion without requiring supplemental fixation. PMID:26060414

  12. Mini-open anterior lumbar interbody fusion.

    PubMed

    Gandhoke, Gurpreet S; Ricks, Christian; Tempel, Zachary; Zuckerbraun, Brian; Hamilton, D Kojo; Okonkwo, David O; Kanter, Adam S

    2016-07-01

    In deformity surgery, anterior lumbar interbody fusion provides excellent biomechanical support, creates a broad surface area for arthrodesis, and induces lordosis in the lower lumbar spine. Preoperative MRI, plain radiographs, and, when available, CT scan should be carefully assessed for sacral slope as it relates to pubic symphysis, position of the great vessels (especially at L4/5), disc space height, or contraindication to an anterior approach. This video demonstrates the steps in an anterior surgical procedure with minimal open exposure. The video can be found here: https://youtu.be/r3bC4_vu1hQ .

  13. Multiexpandable cage for minimally invasive posterior lumbar interbody fusion

    PubMed Central

    Coe, Jeffrey D; Zucherman, James F; Kucharzyk, Donald W; Poelstra, Kornelis A; Miller, Larry E; Kunwar, Sandeep

    2016-01-01

    The increasing adoption of minimally invasive techniques for spine surgery in recent years has led to significant advancements in instrumentation for lumbar interbody fusion. Percutaneous pedicle screw fixation is now a mature technology, but the role of expandable cages is still evolving. The capability to deliver a multiexpandable interbody cage with a large footprint through a narrow surgical cannula represents a significant advancement in spinal surgery technology. The purpose of this report is to describe a multiexpandable lumbar interbody fusion cage, including implant characteristics, intended use, surgical technique, preclinical testing, and early clinical experience. Results to date suggest that the multiexpandable cage allows a less invasive approach to posterior/transforaminal lumbar interbody fusion surgery by minimizing iatrogenic risks associated with static or vertically expanding interbody prostheses while providing immediate vertebral height restoration, restoration of anatomic alignment, and excellent early-term clinical results. PMID:27729817

  14. Degenerative spondylolisthesis: contemporary review of the role of interbody fusion.

    PubMed

    Baker, Joseph F; Errico, Thomas J; Kim, Yong; Razi, Afshin

    2017-02-01

    Degenerative spondylolisthesis is a common presentation, yet the best surgical treatment continues to be a matter of debate. Interbody fusion is one of a number of options, but its exact role remains ill defined. The aim of this study was to provide a contemporary review of the literature to help determine the role, if any, of interbody fusion in the surgical treatment of degenerative spondylolisthesis. A systematic review of the literature since 2005 was performed. Details on study size, patient age, surgical treatments, levels of slip, patient reported outcome measures, radiographic outcomes, complications and selected utility measures were recorded. Studies that compared a cohort treated with interbody fusion and at least one other surgical intervention for comparison were included for review. Only studies examining the effect in degenerative spondylolisthesis were included. Two authors independently reviewed the manuscripts and extracted key data. Thirteen studies were included in the final analysis. A total of 565 underwent interbody fusion and 761 underwent other procedures including decompression alone, interspinous stabilisation and posterolateral fusion with or without instrumentation. Most studies were graded Level III evidence. Heterogeneous reporting of outcomes prevented formal statistical analysis. However, in general, studies reviewed concluded no significant clinical or radiographic difference in outcome between interbody fusion and other treatments. Two small studies suggested interbody fusion is a better option in cases of definite instability. Interbody fusion only provided outcomes as good as instrumented posterolateral fusion. However, most studies were Level III, and hence, we remain limited in defining the exact role of interbody fusion-cases with clear instability appear to be most appropriate. Future work should use agreed-upon common outcome measures and definitions.

  15. Surgical Management of Minimally Invasive Anterior Lumbar Interbody Fusion with Stand-Alone Interbody Cage for L4-5 Degenerative Disorders: Clinical and Radiographic Findings

    PubMed Central

    Hironaka, Yasuo; Morimoto, Tetsuya; Motoyama, Yasushi; Park, Young-Su; Nakase, Hiroyuki

    2013-01-01

    Surgical treatment for degenerative spinal disorders is controversial, although lumbar fusion is considered an acceptable option for disabling lower back pain. Patients underwent instrumented minimally invasive anterior lumbar interbody fusion (mini-ALIF) using a retroperitoneal approach except for requiring multilevel fusions, severe spinal canal stenosis, high-grade spondylolisthesis, and a adjacent segments disorders. We retrospectively reviewed the clinical records and radiographs of 142 patients who received mini-ALIF for L4-5 degenerative lumbar disorders between 1998 and 2010. We compared preoperative and postoperative clinical data and radiographic measurements, including the modified Japanese Orthopaedic Association (JOA) score, visual analog scale (VAS) score for back and leg pain, disc height (DH), whole lumbar lordosis (WL), and vertebral wedge angle (WA). The mean follow-up period was 76 months. The solid fusion rate was 90.1% (128/142 patients). The average length of hospital stay was 6.9 days (range, 3–21 days). The mean blood loss was 63.7 ml (range, 10–456 ml). The mean operation time was 155.5 min (range, 96–280 min). The postoperative JOA and VAS scores for back and leg pain were improved compared with the preoperative scores. Radiological analysis showed significant postoperative improvements in DH, WL, and WA, and the functional and radiographical outcomes improved significantly after 2 years. The 2.8% complication rate included cases of wound infection, liquorrhea, vertebral body fractures, and a misplaced cage that required revision. Mini-ALIF was found to be associated with improved clinical results and radiographic findings for L4-5 disorders. A retroperitoneal approach might therefore be a valuable treatment option. PMID:24140782

  16. Instrumented Posterior Lumbar Interbody Fusion in Adult Spondylolisthesis

    PubMed Central

    Yu, Ching-Hsiao; Wang, Chen-Ti

    2008-01-01

    It is unclear whether using artificial cages increases fusion rates compared with use of bone chips alone in posterior lumbar interbody fusion for patients with lumbar spondylolisthesis. We hypothesized artificial cages for posterior lumbar interbody fusion would provide better clinical and radiographic outcomes than bone chips alone. We assumed solid fusion would provide good clinical outcomes. We clinically and radiographically followed 34 patients with spondylolisthesis having posterior lumbar interbody fusion with mixed autogenous and allogeneic bone chips alone and 42 patients having posterior lumbar interbody fusion with implantation of artificial cages packed with morselized bone graft. Patients with the artificial cage had better functional improvement in the Oswestry disability index than those with bone chips alone, whereas pain score, patient satisfaction, and fusion rate were similar in the two groups. Postoperative disc height ratio, slip ratio, and segmental lordosis all decreased at final followup in the patients with bone chips alone but remained unchanged in the artificial cage group. The functional outcome correlated with radiographic fusion status. We conclude artificial cages provide better functional outcomes and radiographic improvement than bone chips alone in posterior lumbar interbody fusion for lumbar spondylolisthesis, although both techniques achieved comparable fusion rates. Level of Evidence: Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence. PMID:18846411

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

    PubMed Central

    Katzell, Jeffrey

    2014-01-01

    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

  18. Non-neurological major complications of extreme lateral and related lumbar interbody fusion techniques

    PubMed Central

    Epstein, Nancy E.

    2016-01-01

    Background: Complications exclusive of new neurological deficits/injuries that follow extreme lateral interbody fusion (XLIF) and related lateral lumbar interbody techniques should be better recognized to determine the safety of these procedures. Unfortunately, a review of the XLIF literature did not accurately reflect the frequency of these “other complications” as few US surgeons publish such adverse events that may lead to medicolegal suits. Methods: Major complications occurring with XLIF included sympathectomy, major vascular injuries, bowel perforations, sterile seromas, and instrumentation failures. Results: The frequency of sympathectomy was 4% for XLIF vs. 15% for anterior lumbar interbody fusion (ALIF). There were three major vascular injuries for XLIF; one fatal intraoperative event, one life-threatening retroperitoneal hematoma, and one iatrogenic lumbar artery pseudoaneurysm that was successfully embolized. Two bowel perforations were reported, whereas a third was a “direct communication.” One patient developed a sterile recurrent seroma due to vancomycin powder utilized for an XLIF. One study cited malpositioning of an XLIF cage resulting in a lateral L3–L4 extrusion, whereas the second series looked at the 45% risk of cage-overhang when XLIF devices were placed in the anterior one-third of the vertebral body. Conclusion: Excluding new neurological deficits, XLIF techniques resulted in multiple other major complications. However, these small numbers likely reflect just the tip of the iceberg (e.g., 10%) and the remaining 90% may never be known as many US-based spine surgeons fail to publish such adverse events as they are discoverable in a court of law and may lead to medicolegal suits. PMID:27843680

  19. Subsidence of metal interbody cage after posterior lumbar interbody fusion with pedicle screw fixation.

    PubMed

    Tokuhashi, Yasuaki; Ajiro, Yasumitsu; Umezawa, Natsuki

    2009-04-01

    Posterior lumbar interbody fusion is considered to be an excellent fusion procedure to stabilize anterior support, correct alignment in the sagittal and coronal plane, and achieve foraminal decompression by lifting the disk height. The metal interbody cage in posterior lumbar interbody fusion is thought to be useful to prevent collapse of the graft bone and to correct and maintain disk height; however, some studies have noted a gradual decrease of disk height due to cage subsidence. Therefore, to investigate the significance of cage subsidence, 86 disk levels radiographically confirmed to have good union in 66 patients with posterior lumbar interbody fusion combined with pedicle screw fixation and a single metal cage for degenerative lumbar disease were retrospectively evaluated. The follow-up period ranged from 3 years to 10 years 3 months, with a mean of 7 years 9 months. Cage subsidence often showed a gradual increase over time. At final follow-up, subsidence averaged 4.0 mm on the cranial surface and 2.7 mm on the caudal surface. Although the average increase of disk height was 3.2 mm immediately postoperatively, the final disk height decreased by 4.2 mm on average from that time. The degree of cage subsidence and decrease of disk height were not correlated with the final clinical results. Subsidence was not correlated with bone mineral density in the vertebral body, body weight, or site of the insertion. On the other hand, the wedge shape of the cage and the thickness of the resected endplate had a significant influence on cage subsidence.

  20. Biomechanical Characteristics of an Integrated Lumbar Interbody Fusion Device

    PubMed Central

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

    2014-01-01

    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

  1. Current Status of Lumbar Interbody Fusion for Degenerative Spondylolisthesis

    PubMed Central

    TAKAHASHI, Toshiyuki; HANAKITA, Junya; OHTAKE, Yasufumi; FUNAKOSHI, Yusuke; OICHI, Yuki; KAWAOKA, Taigo; WATANABE, Mizuki

    2016-01-01

    Instrumented lumbar fusion can provide immediate stability and assist in satisfactory arthrodesis in patients who have pain or instability of the lumbar spine. Lumbar adjunctive fusion with decompression is often a good procedure for surgical management of degenerative spondylolisthesis (DS). Among various lumbar fusion techniques, lumbar interbody fusion (LIF) has an advantage in that it maintains favorable lumbar alignment and provides successful fusion with the added effect of indirect decompression. This technique has been widely used and represents an advancement in spinal instrumentation, although the rationale and optimal type of LIF for DS remains controversial. We evaluated the current status and role of LIF in DS treatment, mainly as a means to augment instrumentation. We addressed the basic concept of LIF, its indications, and various types including minimally invasive techniques. It also has acceptable biomechanical features, and offers reconstruction with ideal lumbar alignment. Postsurgical adverse events related to each LIF technique are also addressed. PMID:27169496

  2. Large volume inside the cage leading incomplete interbody bone fusion and residual back pain after posterior lumbar interbody fusion.

    PubMed

    Takeuchi, Mikinobu; Kamiya, Mitsuhiro; Wakao, Norimitsu; Hirasawa, Atsuhiko; Kawanami, Katsuhisa; Osuka, Koji; Takayasu, Masakazu

    2015-07-01

    The purpose of this study is to compare intervertebral bone fusion and clinical outcomes in L4-5 posterior lumbar interbody fusion (PLIF) using the same posterior instrumentation with four combinations of one of three types of interbody cage with one of two bone grafts, iliac and local or only local. In 67 patients who underwent L4-5 PLIF, 19 patients had the Brantigan cage and iliac and local bone graft, 18 with the TELAMON C cage and iliac and local bone graft, 16 with the TELAMON C cage and local bone graft (TL), and 14 with the OIC PEEK cage and local bone graft. Clinical assessments were based on Japanese Orthopaedic Association (JOA) scores and on the visual analogue scale (VAS). The bone fusion assessments were based on radiography and CT scans according to the Brantigan, Steffee, and Fraser criteria. More than 2 years after surgery, these assessments were made. In the results, the fusion outcome for the group receiving TL was significantly less than those for the other three groups. In TL, multivariate logistic regression analysis showed that the inside volume of the cage of ≥2.0 mL was the only significant factor for incomplete fusion. Moreover, the VAS (low back pain) score was significantly higher for TL than for the other three groups. In conclusions, we believe that the large volume inside the cage (≥2.0 mL) with local bone graft may lead incomplete interbody bone fusion and residual postsurgical low back pain after PLIF.

  3. Review of early clinical results and complications associated with oblique lumbar interbody fusion (OLIF).

    PubMed

    Phan, Kevin; Maharaj, Monish; Assem, Yusuf; Mobbs, Ralph J

    2016-09-01

    Lumbar interbody fusion represents an effective surgical intervention for patients with lumbar degenerative diseases, spondylolisthesis, disc herniation, pseudoarthrosis and spinal deformities. Traditionally, conventional open anterior lumbar interbody fusion and posterior/transforaminal lumbar interbody fusion techniques have been employed with excellent results, but each with their own advantages and caveats. Most recently, the antero-oblique trajectory has been introduced, providing yet another corridor to access the lumbar spine. Termed the oblique lumbar interbody fusion, this approach accesses the spine between the anterior vessels and psoas muscles, avoiding both sets of structures to allow efficient clearance of the disc space and application of a large interbody device to afford distraction for foraminal decompression and endplate preparation for rapid and thorough fusion. This review aims to summarize the early clinical results and complications of this new technique and discusses potential future directions of research.

  4. Biomechanical evaluation of lateral lumbar interbody fusion with secondary augmentation.

    PubMed

    Reis, Marco T; Reyes, Phillip M; Bse; Altun, Idris; Newcomb, Anna G U S; Singh, Vaneet; Chang, Steve W; Kelly, Brian P; Crawford, Neil R

    2016-12-01

    OBJECTIVE Lateral lumbar interbody fusion (LLIF) has emerged as a popular method for lumbar fusion. In this study the authors aimed to quantify the biomechanical stability of an interbody implant inserted using the LLIF approach with and without various supplemental fixation methods, including an interspinous plate (IP). METHODS Seven human cadaveric L2-5 specimens were tested intact and in 6 instrumented conditions. The interbody implant was intended to be used with supplemental fixation. In this study, however, the interbody was also tested without supplemental fixation for a relative comparison of these conditions. The instrumented conditions were as follows: 1) interbody implant without supplemental fixation (LLIF construct); and interbody implant with supplemental fixation performed using 2) unilateral pedicle screws (UPS) and rod (LLIF + UPS construct); 3) bilateral pedicle screws (BPS) and rods (LLIF + BPS construct); 4) lateral screws and lateral plate (LP) (LLIF + LP construct); 5) interbody LP and IP (LLIF + LP + IP construct); and 6) IP (LLIF + IP construct). Nondestructive, nonconstraining torque (7.5 Nm maximum) induced flexion, extension, lateral bending, and axial rotation, whereas 3D specimen range of motion (ROM) was determined optoelectronically. RESULTS The LLIF construct reduced ROM by 67% in flexion, 52% in extension, 51% in lateral bending, and 44% in axial rotation relative to intact specimens (p < 0.001). Adding BPS to the LLIF construct caused ROM to decrease by 91% in flexion, 82% in extension and lateral bending, and 74% in axial rotation compared with intact specimens (p < 0.001), providing the greatest stability among the constructs. Adding UPS to the LLIF construct imparted approximately one-half the stability provided by LLIF + BPS constructs, demonstrating significantly smaller ROM than the LLIF construct in all directions (flexion, p = 0.037; extension, p < 0.001; lateral bending, p = 0.012) except axial rotation (p = 0

  5. Minimum 10-Year Follow-up Study of Anterior Lumbar Interbody Fusion for Degenerative Spondylolisthesis: Progressive Pattern of the Adjacent Disc Degeneration

    PubMed Central

    Yasuda, Taketoshi; Hori, Takeshi; Suzuki, Kayo; Kawaguchi, Yoshiharu

    2012-01-01

    Study Design Retrospective study. Purpose The aims of the current study are to evaluate the minimum 10-year follow-up clinical results of anterior lumbar interbody fusion (ALIF) for degenerative spondylolisthesis. Overview of Literature ALIF has been widely used as a treatment regimen in the management of lumbar spondylolisthesis. Still much controversy exists regarding the factors that affect the postoperative clinical outcomes. Methods The author performed a retrospective review of 20 patients with degenerative spondylolisthesis treated with ALIF (follow-up, 16.4 years). The clinical results were assessed by the Japanese Orthopaedic Association (JOA) score for low back pain, vertebral slip and disc height index on the radiographs. Results The mean preoperative JOA score was 7.1 ± 1.8 points (15-point-method). At 1 year, 5 years, and 10 years or more after surgery, the JOA scores were assessed as 12.4 ± 2.2 points, 12.7 ± 2.6 points, 12.0 ± 2.5 points, respectively (excluding the data of reoperated cases). The adjacent disc degeneration developed in all cases during the long-term follow-up. The progressive pattern of disc degeneration was divided into three types. Initially, disc degeneration occurred due to disc space narrowing. After that, the intervertebral discs showed segmental instability with translation at the upper level. But the lower discs showed osteophyte formation, and occasionally lead to the collapse or spontaneous union. Conclusions The clinical results of the long-term follow-up data after ALIF became worse due to the adjacent disc degeneration. The progressive pattern of disc degeneration was different according to the adjacent levels. PMID:22708014

  6. Interbody Spacer Material Properties and Design Conformity for Reducing Subsidence During Lumbar Interbody Fusion.

    PubMed

    Chatham, Lillian S; Patel, Vikas V; Yakacki, Christopher M; Dana Carpenter, R

    2017-05-01

    There is a need to better understand the effects of intervertebral spacer material and design on the stress distribution in vertebral bodies and endplates to help reduce complications such as subsidence and improve outcomes following lumbar interbody fusion. The main objective of this study was to investigate the effects of spacer material on the stress and strain in the lumbar spine after interbody fusion with posterior instrumentation. A standard spacer was also compared with a custom-fit spacer, which conformed to the vertebral endplates, to determine if a custom fit would reduce stress on the endplates. A finite element (FE) model of the L4-L5 motion segment was developed from computed tomography (CT) images of a cadaveric lumbar spine. An interbody spacer, pedicle screws, and posterior rods were incorporated into the image-based model. The model was loaded in axial compression, and strain and stress were determined in the vertebra, spacer, and rods. Polyetheretherketone (PEEK), titanium, poly(para-phenylene) (PPP), and porous PPP (70% by volume) were used as the spacer material to quantify the effects on stress and strain in the system. Experimental testing of a cadaveric specimen was used to validate the model's results. There were no large differences in stress levels (<3%) at the bone-spacer interfaces and the rods when PEEK was used instead of titanium. Use of the porous PPP spacer produced an 8-15% decrease of stress at the bone-spacer interfaces and posterior rods. The custom-shaped spacer significantly decreased (>37%) the stress at the bone-spacer interfaces for all materials tested. A 28% decrease in stress was found in the posterior rods with the custom spacer. Of all the spacer materials tested with the custom spacer design, 70% porous PPP resulted in the lowest stress at the bone-spacer interfaces. The results show the potential for more compliant materials to reduce stress on the vertebral endplates postsurgery. The custom spacer provided a

  7. Sagittal Balance Correction in Lateral Interbody Fusion for Degenerative Scoliosis

    PubMed Central

    Gallizzi, Michael A.; Sheets, Charles; Smith, Benjamin T.; Isaacs, Robert E.; Eure, Megan; Brown, Christopher R.

    2016-01-01

    Background Sagittal balance restoration has been shown to be an important determinant of outcomes in corrective surgery for degenerative scoliosis. Lateral interbody fusion (LIF) is a less-invasive technique which permits the placement of a high lordosis interbody cage without risks associated with traditional anterior or transforaminal interbody techniques. Studies have shown improvement in lumbar lordosis following LIF, but only one other study has assessed sagittal balance in this population. The objective of this study is to evaluate the ability of LIF to restore sagittal balance in degenerative lumbar scoliosis. Methods Thirty-five patients who underwent LIF for degenerative thoracolumbar scoliosis from July 2013 to March 2014 by a single surgeon were included. Outcome measures included sagittal balance, lumbar lordosis, Cobb Angle, and segmental lordosis. Measures were evaluated pre-operative, immediately post-operatively, and at their last clinical follow-up. Repeated measures ANOVAs were used to assess the differences between pre-operative, first postoperative, and a follow-up visit. Results The average sagittal balance correction was not significantly different: 1.06cm from 5.79cm to 4.74cm forward. The average Cobb angle correction was 14.1 degrees from 21.6 to 5.5 degrees. The average change in global lumbar lordosis was found to be significantly different: 6.3 degrees from 28.9 to 35.2 degrees. Conclusions This study demonstrates that LIF reliably restores lordosis, but does not significantly improve sagittal balance. Despite this, patients had reliable improvement in pain and functionality suggesting that sagittal balance correction may not be as critical in scoliosis correction as previous studies have indicated. Clinical Relevance LIF does not significantly change sagittal balance; however, clinical improvement does not seem to be contingent upon sagittal balance correction in the degenerative scoliosis population. The DUHS IRB has determined this

  8. Clinical comparison of Zero-profile interbody fusion device and anterior cervical plate interbody fusion in treating cervical spondylosis

    PubMed Central

    Yan, Bin; Nie, Lin

    2015-01-01

    Objective: the aim of the study was to compare the clinical effect of Zero-profile interbody fusion device (Zero-P) with anterior cervical plate interbody fusion system (PCB) in treating cervical spondylosis. Methods: a total of 98 patients with cervical spondylosis (110 segments) in February 2011 to January 2013 were included in our hospital. All participants were randomly divided into observation group and control group with 49 cases in each group. The observation group was treated with Zero-P, while the control group received PCB treatment. Comparison of the two groups in neurological function score (JOA), pain visual analogue scale (VAS), the neck disability index (NDI), quality of life score (SF-36) and cervical curvature (Cobb angle) change were recorded and analyzed before and after treatment. Results: The observation group was found with 90% excellent and good rate, which was higher than that of the control group (80%). Dysphagia rate in observational group was 16.33% (8/49), which was significantly less than that in control group (46.94%). Operation time and bleeding volume in the observation group was less than those in control group. Postoperative improvements of JOA score, VAS score, and NDI in observational group were also significantly better than that in control group (P<0.05). Conclusion: The clinical effect of Zero-P and PCB for the treatment of cervical spondylosis was quite fair, but Zero-P showed a better therapeutic effect with improvement of life quality. PMID:26550337

  9. Modified Mini-open Transforaminal Lumbar Interbody Fusion

    PubMed Central

    Pakzaban, Peyman

    2016-01-01

    Study Design. Retrospective case series. Objective. To describe a modified technique for mini-open transforaminal lumbar interbody fusion (TLIF) that improves visualization for decompression, fusion, and freehand pedicle screw insertion. Accuracy of freehand pedicle screw placement with this technique was assessed. Summary of Background Data. Mini-open TLIF is a minimally invasive technique that allows limited visualization of the bone and neural anatomy via an expandable tubular retractor inserted through the Wiltse plane. No significant modification that of this technique has been described in detail. Methods. In this study, 92 consecutive patients underwent one-level modified mini-open TLIF (MOTLIF). MOTLIF modifications consisted of (i) transmuscular dissection through the multifidus muscle rather than intermuscular dissection in the Wiltse plane; (ii) microsurgical detachment of multifidus from the facet rather than muscle dilation; (iii) en bloc total facetectomy (unilateral or bilateral, as needed for decompression); (iv) facet autograft used for interbody fusion; and (v) solid pedicle screws placed bilaterally by a freehand technique under direct vision. Results. The mean age was 53 years. Mean follow-up was 35 months (minimum 2 yrs). By 6 months, mean Visual Analog Scale for back and leg pain had improved from 51 to 19 and from 58 to 17, respectively, and mean Oswestry Disability Index (ODI) improved from 53 to 16. These improvements persisted at 2 years. Solid fusion, defined by computed tomography at 1 year, was achieved in 88.1%, whereas satisfactory fusion was achieved in 95.2% of patients. Pedicle screws were accurately placed in 335 of 336 imaged pedicles (pedicle breach grades: 91.1% grade 1; 8.6% grade 2; and 0.3% grade 3). Mean fluoroscopy time was 29.3 seconds. Conclusion. MOTLIF is a safe and effective minimally invasive technique with a high fusion rate. It allows accurate pedicle screw placement by a freehand technique. By eliminating bi

  10. Posterolateral versus posterior interbody fusion in isthmic spondylolisthesis.

    PubMed

    Farrokhi, Majid Reza; Rahmanian, Abdolkarim; Masoudi, Mohammad Sadegh

    2012-05-20

    Spondylolisthesis is a heterogeneous disorder characterized by subluxation of a vertebral body over another in the sagittal plane. Its most common form is isthmic spondylolisthesis (IS). This study aims to compare clinical outcomes of posterolateral fusion (PLF) with posterior lumbar interbody fusion (PLIF) with posterior instrumentation in the treatment of IS. We performed a randomized prospective study in which 80 patients out of a total of 85 patients with IS were randomly allocated to one of two groups: PLF with posterior instrumentation (group I) or PLIF with posterior instrumentation (group II). Posterior decompression was performed in the patients. The Oswestry low back pain disability (OLBP) scale and Visual Analogue Scale (VAS) were used to evaluate the quality of life (QoL) and pain, respectively. Fisher's exact test was used to evaluate fusion rate and the Mann-Whitney U test was used to compare categorical data. Fusion in group II was significantly better than in group I (p=0.012). Improvement in low back pain was statistically more significant in group I (p=0.001). The incidence of neurogenic claudication was significantly lower in group I than in group II (p=0.004). In group I, there was no significant correlation between slip Meyerding grade and disc space height, radicular pain, and low back pain. There was no significant difference in post-operative complications at 1-year follow-up. Our data showed that PLF with posterior instrumentation provides better clinical outcomes and more improvement in low back pain compared to PLIF with posterior instrumentation despite the low fusion rate.

  11. Effects of Strontium Ranelate on Spinal Interbody Fusion Surgery in an Osteoporotic Rat Model

    PubMed Central

    Tsai, Tsung-Ting; Ho, Natalie Yi-Ju; Lai, Po-Liang; Fu, Tsai-Sheng; Niu, Chi-Chien; Chen, Lih-Huei; Chen, Wen-Jer

    2017-01-01

    Osteoporosis is a bone disease that afflicts millions of people around the world, and a variety of spinal integrity issues, such as degenerative spinal stenosis and spondylolisthesis, are frequently concomitant with osteoporosis and are sometimes treated with spinal interbody fusion surgery. Previous studies have demonstrated the efficacy of strontium ranelate (SrR) treatment of osteoporosis in improving bone strength, promoting bone remodeling, and reducing the risk of fractures, but its effects on interbody fusion surgery have not been adequately investigated. SrR-treated rats subjected to interbody fusion surgery exhibited significantly higher lumbar vertebral bone mineral density after 12 weeks of treatment than rats subjected to the same surgery but not treated with SrR. Furthermore, histological and radiographic assessments showed that a greater amount of newly formed bone tissue was present and that better fusion union occurred in the SrR-treated rats than in the untreated rats. Taken together, these results show significant differences in bone mineral density, PINP level, histological score, SrR content and mechanical testing, which demonstrate a relatively moderate effect of SrR treatment on bone strength and remodeling in the specific context of recovery after an interbody fusion surgery, and suggest the potential of SrR treatment as an effective adjunct to spinal interbody fusion surgery for human patients. PMID:28052066

  12. Posterior Lumbar Interbody Fusion via a Unilateral Approach

    PubMed Central

    Shin, Hyun Chul; Yi, Seong; Kim, Sang Hyun; Yoon, Do Heum

    2006-01-01

    This study sought to determine the outcomes of posterior lumbar interbody fusion (PLIF), via a unilateral approach, in selected patients who presented with unilateral leg pain and segmental instability of the lumbar spine. Patients with a single level of a herniated disc disease in the lumbar spine, unilateral leg pain, chronic disabling lower back pain (LBP), and a failed conservative treatment, were considered for the procedure. A total of 41 patients underwent a single-level PLIF using two PEEK™ (Poly-Ether-Ether-Ketone) cages filled with iliac bone, via a unilateral approach. The patients comprised 21 women and 20 men with a mean age of 41 years (range: 22 to 63 years). Two cages were inserted using a unilateral medial facetectomy and a partial hemilaminectomy. At follow-up, the outcomes were assessed using the Prolo Scale. The success of the fusion was determined by dynamic lumbar radiography and/or computerized tomography scanning. All the patients safely underwent surgery without severe complications. During a mean follow-up period of 26 months, 1 patient underwent percutaneous pedicle screw fixation due to persistent LBP. A posterior displacement of the cage was found in one patient. At the last follow up, 90% of the patients demonstrated satisfactory results. An osseous fusion was present in 85% of the patients. A PLIF, via a unilateral approach, enables a solid union with satisfactory clinical results. This preserves part of the posterior elements of the lumbar spine in selected patients with single level instability and unilateral leg pain. PMID:16807980

  13. Treatment of symptomatic thoracic disc herniations with lateral interbody fusion

    PubMed Central

    Parker, Rhiannon M.

    2015-01-01

    Background Symptomatic thoracic herniated discs have historically been treated using open exposures (i.e., thoracotomy), posing a clinical challenge given the approach related morbidity. Lateral interbody fusion (LIF) is one modern minimally disruptive alternative to thoracotomy. The direct lateral technique for lumbar pathologies has seen a sharp increase in procedural numbers; however application of this technique in thoracic pathologies has not been widely reported. Methods This study presents the results of three cases where LIF was used to treat symptomatic thoracic disc herniations. Indications for surgery included thoracic myelopathy, radiculopathy and discogenic pain. Patients were treated with LIF, without supplemental internal fixation, and followed for 24 months postoperatively. Results: Average length of hospital stay was 5 days. One patient experienced mild persistent neuropathic thoracic pain, which was managed medically. At 3 months postoperative all patients had returned to work and by 12 months all patients were fused. From preoperative to 24-month follow-up there were mean improvements of 83.3% in visual analogue scale (VAS), 75.3% in Oswestry Disability Index (ODI), and 79.2% and 17.4% in SF-36 physical (PCS) and mental component scores (MCS), respectively. Conclusions LIF is a viable minimally invasive alternative to conventional approaches in treating symptomatic thoracic pathology without an access surgeon, rib resection, or lung deflation. PMID:27683683

  14. Posterior lumbar interbody fusion for the management of spondylolisthesis.

    PubMed

    Devkota, P; Shrestha, S K; Krishnakumar, R; Renjithkumar, J

    2011-03-01

    The ideal surgical treatment of spondylolisthesis still remains controversial. There are several methods of treatment and posterior lumbar interbody fusion (PLIF) is one of them. We analyze the results of spondylolisthesis treated by PLIF in term of radiological union, improvement of pre-operative symptoms like back pain, radiating pain and return to normal activities including that of employment, by the review of the medical records. Total of 72 patients, 20 male and 52 female and the age ranges from 15 to 68 years with the mean age being 44.38 years were included in the study. Thirty (41.66%) patients had isthmic spondylolisthesis, 26 (36.12%) had congenital spondylolisthesis, and 16 (22.22%) cases had degenerative spondylolisthesis. There were 38 (52.77%) cases of grade I, 14 (19.44%) cases of grade II and 20 (27.77%) cases of grade III according to the grading criteria of Meyerding. According to the evaluation criteria used by Stauffer and Coventry, 59 patients (81.94%) got good results, eight patients (11.11%) belonged to the fair group and five cases (6.94%) had the poor results. This study showed that PLIF is one of the effective and reliable techniques for the management of spondylolisthesis.

  15. Anterior Lumbar Interbody Fusion for Degenerative Discogenic Low Back Pain

    PubMed Central

    Ni, Jianqiang; Fang, Xiutong; Zhong, Weiye; Liu, Ning; Wood, Kirkham B.

    2015-01-01

    Abstract The treatment of degenerative discogenic pain is controversial, and anterior lumbar fusion for the treatment of degenerative discogenic low back pain has also been a controversial topic for over a generation. The aim of this systematic review was to evaluate the outcome of different anterior lumbar fusion levels for degenerative discogenic low back pain. In this study, we performed a clinical outcome subgroup analysis. The outcomes of 84 consecutive patients who underwent anterior lumbar interbody fusion from 2004 to 2009 were reviewed. The operative time, intraoperative blood loss, hospital stay, Oswestry Disability Index (ODI), visual analog scale (VAS) results, and complication rate were recorded separately. Medical indications were degenerative disc disease (73.8%), postdiscectomy disc disease (16.1%), and disc herniation (9.5%). Patients with severe spondylolysis or disc degeneration, with more than 3 or multilevel lesions, were excluded. The mean operative time was 124.5 ± 10.9 min (range 51–248 min), the mean intraoperative blood loss was 242.1 ± 27.7 mL (range 50–2700 mL), the mean hospital stay was 3.9 ± 1.1 days (range 3–6 days), the mean preoperative VAS score was 7.5 ± 1.4, and the mean preoperative ODI score was 60.0 ± 5.7. At the 1-year follow-up, the mean postoperative VAS score was 3.3 ± 1.3 and the mean postoperative ODI score was 13.6 ± 3.4 (P < 0.05). L4–L5 disc fusion led to better clinical results than 2-level L4–L5/L5–S1 disc fusion. Additionally, the 2-level fusion of L4–L5/L5–S1 had better clinical results than the L5–S1 disc fusion at both the 1 and 2-year postoperative follow-ups regarding the VAS score and the ODI score. The rate of complications was more frequent in the 2-level L4–L5/L5–S1 group (27.3%) (group C) than in the L4–L5 group (9.1%) (group A) and the L5–S1 group (12.5%) (group B). There was no difference between the L4–L5 group (9.1%) and the L

  16. Safety and Efficacy of Mini Open Transforaminal Lumbar Interbody Fusion

    PubMed Central

    Eissa, Ehab M.; Elmorsy, Haitham M.

    2016-01-01

    Objective Mini-transforaminal lumbar interbody fusion (Mini-TLIF) and other minimally invasive approaches introduced for the purpose of treating lumbar degenerative disc disease and instability are achieving high success and safety rates as the conventional approaches. Moreover, it has less soft tissue damage, minimal blood loss, and less hospital stay. Methods A prospective study was conducted from 2012 to 2014 on 28 patients who were subjected to Mini-open TLIF combined with transpedicular screw fixation for spondylolisthesis and degenerative disc disease. Two paramedian approaches were done, 4 cm for each, to insert the pedicular screws, along with inserting unilateral TLIF cage with autologous bone graft. Decompression was done either unilateral or bilateral according to the patient side of radiculopathy. Sixteen patients (57.2%) were diagnosed with degenerative spondylolisthesis, 7 patients (25%) were diagnosed with isthmic type spondylolisthesis, and 5 patients (17.8%) were diagnosed with degenerative disc disease, 2 of them(7.1%) had previous operations at the same level. Twenty patients (71.4%) were operated at the L4/5 level, and 8 patients (28.6%) at the L5/S1 level. Results All patients were able to ambulate the next day of surgery. The mean estimated blood loss was 251.79mL. The average hospital stay was 4.14 days. The average follow-up was 9 months. The mean visual analog scale was 1.86 at discharge, 1.68 after 3 months, and 1.38 after 6 months. After 6 months of the operation, MacNab's criteria were good in 23 patients and excellent in 5 patients. We had one case with transient weakness, 2 cases of screw malposition without clinical manifestations, and one case of infection. Conclusion Mini-TLIF approach is an efficient and safe approach for treating instability and degenerative diseases of the lumbar spine. The clinical outcome is encouraging and it may be an operation of choice for lumbar spinal fusion in selected patients. PMID:28127376

  17. Comparison between Minimally Invasive Transforaminal Lumbar Interbody Fusion and Conventional Open Transforaminal Lumbar Interbody Fusion: An Updated Meta-analysis

    PubMed Central

    Xie, Lei; Wu, Wen-Jian; Liang, Yu

    2016-01-01

    Background: The previous studies agree that minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) has better function outcomes, less blood loss, and shorter hospital stay, when compared to open-TLIF. However, there are no significance differences on operative time, complication, and reoperation rate between the two procedures. This could be from less relative literatures and lower grade evidence. The further meta-analysis is needed with more and higher grade evidences to compare the above two TLIF procedures. Methods: Prospective and retrospective studies that compared open-TLIF and MIS-TLIF were identified by searching the Medline, Embase, Web of Science, China National Knowledge Infrastructure, Wanfang, and VIP database (the literature search comprised Medical Subject Heading terms and key words or Emtree term). The retrieval time ranged from the date when the database was founded to January 2015. Pooled risk ratios (RRs) and weighted mean differences (WMDs) with 95% confidence intervals were calculated for the clinical outcomes and perioperative data. Results: Twenty-four studies (n = 1967 patients) were included in this review (n = 951, open-TLIF, n = 1016, MIS-TLIF). MIS-TLIF was associated with a significant decrease in the visual analog score (VAS)-back pain score (WMD = −0.44; P = 0.001), Oswestry Disabilities Index (WMD = −1.57; P = 0.005), early ambulation (WMD = −1.77; P = 0.0001), less blood loss (WMD = −265.59; P < 0.00001), and a shorter hospital stay (WMD = −1.89; P < 0.0001). However, there were no significant differences in the fusion rate (RR = 0.99; P = 0.34), VAS-leg pain (WMD = −0.10; P = 0.26), complication rate (RR = 0.84; P = 0.35), operation time (WMD = −5.23; P = 0.82), or reoperation rate (RR = 0.73; P = 0.32). Conclusions: MIS-TLIF resulted in a similar fusion rate with better functional outcome, less blood loss, shorter ambulation, and hospital stay; furthermore, it did not increase the complication or

  18. Clinical Outcomes of Posterior Lumbar Interbody Fusion versus Minimally Invasive Transforaminal Lumbar Interbody Fusion in Three-Level Degenerative Lumbar Spinal Stenosis

    PubMed Central

    Fan, Guoxin; Wu, Xinbo; Yu, Shunzhi; Sun, Qi; Zhang, Hailong; Gu, Xin

    2016-01-01

    The aim of this study was to directly compare the clinical outcomes of posterior lumbar interbody fusion (PLIF) and minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) in three-level lumbar spinal stenosis. This retrospective study involved a total of 60 patients with three-level degenerative lumbar spinal stenosis who underwent MIS-TLIF or PLIF from January 2010 to February 2012. Back and leg visual analog scale (VAS), Oswestry Disability Index (ODI), and Short Form-36 (SF-36) scale were used to assess the pain, disability, and health status before surgery and postoperatively. In addition, the operating time, estimated blood loss, and hospital stay were also recorded. There were no significant differences in back VAS, leg VAS, ODI, SF-36, fusion condition, and complications at 12-month follow-up between the two groups (P > 0.05). However, significantly less blood loss and shorter hospital stay were observed in MIS-TLIF group (P < 0.05). Moreover, patients undergoing MIS-TLIF had significantly lower back VAS than those in PLIF group at 6-month follow-up (P < 0.05). Compared with PLIF, MIS-TLIF might be a prior option because of noninferior efficacy as well as merits of less blood loss and quicker recovery in treating three-level lumbar spinal stenosis. PMID:27747244

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

    PubMed Central

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

    2014-01-01

    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

  20. An Innovative Use of Cortoss Bone Cement to Stabilize a Nonunion after Interbody Fusion

    PubMed Central

    Jacobson, Robert E

    2017-01-01

    A 65-year-old male originally had surgery for spondylolisthesis at L5-S1 in 2008 and then went on to have an L4-5 transforaminal lumbar interbody fusion (TLIF) with pedicle screw fixation from L4 to S1 and interbody graft in 2010. Despite having two surgical procedures, he continued with intractable back pain and was told he had a failed lumbar fusion. When he was evaluated with a computerized tomography (CT) scan from April 2015, it demonstrated an erosive nonunion of the L4-5 interbody fusion without incorporation of the polyetheretherketone (PEEK) cage. In an attempt to perform a minimally invasive stabilization of the L4-5 nonunion, he underwent a percutaneous lateral foraminal approach with an injection of Cortoss® cement (Stryker®, Malvern, PA) into the L4-5 interspace and around the graft. The objective was to stabilize the nonunion, resulting in intermediate relief of pain. PMID:28229033

  1. Failure of a carbon fiber-reinforced polymer implant used for transforaminal lumbar interbody fusion.

    PubMed

    Sardar, Zeeshan; Jarzem, Peter

    2013-12-01

    Lumbar interbody fusion is a common procedure owing to the high prevalence of degenerative spinal disorders. During such procedures, carbon fiber-reinforced polymer (CFRP) cages are frequently utilized to fill the void created between adjacent vertebral bodies, to provide mechanical stability, and to carry graft material. Failure of such implants can lead to significant morbidity. We discuss the possible causes leading to the failure of a CFRP cage in a patient with rheumatoid arthritis. Review of a 49-year-old woman who underwent revision anterior lumbar interbody fusion 2 years after posterior instrumentation and transforaminal lumbar interbody fusion at L4-L5 and L5-S1. The patient developed pseudarthrosis at the two previously fused levels with failure of the posterior instrumentation. Revision surgery reveled failure with fragmentation of the CFRP cage at the L5-S1 level. CFRP implants can break if mechanical instability or nonunion occurs in the spinal segments, thus emphasizing the need for optimizing medical management and meticulous surgical technique in achieving stability.

  2. Failure of a Carbon Fiber–Reinforced Polymer Implant Used for Transforaminal Lumbar Interbody Fusion

    PubMed Central

    Sardar, Zeeshan; Jarzem, Peter

    2013-01-01

    Lumbar interbody fusion is a common procedure owing to the high prevalence of degenerative spinal disorders. During such procedures, carbon fiber–reinforced polymer (CFRP) cages are frequently utilized to fill the void created between adjacent vertebral bodies, to provide mechanical stability, and to carry graft material. Failure of such implants can lead to significant morbidity. We discuss the possible causes leading to the failure of a CFRP cage in a patient with rheumatoid arthritis. Review of a 49-year-old woman who underwent revision anterior lumbar interbody fusion 2 years after posterior instrumentation and transforaminal lumbar interbody fusion at L4–L5 and L5–S1. The patient developed pseudarthrosis at the two previously fused levels with failure of the posterior instrumentation. Revision surgery reveled failure with fragmentation of the CFRP cage at the L5–S1 level. CFRP implants can break if mechanical instability or nonunion occurs in the spinal segments, thus emphasizing the need for optimizing medical management and meticulous surgical technique in achieving stability. PMID:24436878

  3. Simultaneous Lateral Interbody Fusion and Posterior Percutaneous Instrumentation: Early Experience and Technical Considerations

    PubMed Central

    Drazin, Doniel; Kim, Terrence T.; Johnson, J. Patrick

    2015-01-01

    Lumbar fusion surgery involving lateral lumbar interbody graft insertion with posterior instrumentation is traditionally performed in two stages requiring repositioning. We describe a novel technique to complete the circumferential procedure simultaneously without patient repositioning. Twenty patients diagnosed with worsening back pain with/without radiculopathy who failed exhaustive conservative management were retrospectively reviewed. Ten patients with both procedures simultaneously from a single lateral approach and 10 control patients with lateral lumbar interbody fusion followed by repositioning and posterior percutaneous instrumentation were analyzed. Pars fractures, mobile grade 2 spondylolisthesis, and severe one-level degenerative disk disease were matched between the two groups. In the simultaneous group, avoiding repositioning leads to lower mean operative times: 130 minutes (versus control 190 minutes; p = 0.009) and lower intraoperative blood loss: 108 mL (versus 93 mL; NS). Nonrepositioned patients were hospitalized for an average of 4.1 days (versus 3.8 days; NS). There was one complication in the control group requiring screw revision. Lateral interbody fusion and percutaneous posterior instrumentation are both readily accomplished in a single lateral decubitus position. In select patients with adequately sized pedicles, performing simultaneous procedures decreases operative time over sequential repositioning. Patient outcomes were excellent in the simultaneous group and comparable to procedures done sequentially. PMID:26649303

  4. An Innovative Use of Cortoss Bone Cement to Stabilize a Nonunion after Interbody Fusion.

    PubMed

    Granville, Michelle; Jacobson, Robert E

    2017-01-20

    A 65-year-old male originally had surgery for spondylolisthesis at L5-S1 in 2008 and then went on to have an L4-5 transforaminal lumbar interbody fusion (TLIF) with pedicle screw fixation from L4 to S1 and interbody graft in 2010. Despite having two surgical procedures, he continued with intractable back pain and was told he had a failed lumbar fusion. When he was evaluated with a computerized tomography (CT) scan from April 2015, it demonstrated an erosive nonunion of the L4-5 interbody fusion without incorporation of the polyetheretherketone (PEEK) cage. In an attempt to perform a minimally invasive stabilization of the L4-5 nonunion, he underwent a percutaneous lateral foraminal approach with an injection of Cortoss® cement (Stryker®, Malvern, PA) into the L4-5 interspace and around the graft. The objective was to stabilize the nonunion, resulting in intermediate relief of pain.

  5. Transforaminal lumbar interbody fusion versus instrumented posterolateral fusion in Grade I/II spondylolisthesis

    PubMed Central

    Pooswamy, Shanmugasundaram; Muralidharagopalan, Niranjanan Raghavn; Subbaiah, Sivasubramaniam

    2017-01-01

    Background: Spondylolisthesis refers to slippage of one vertebra over the other, which may be caused by a variety of reasons such as degenerative, trauma, and isthmic. Surgical management forms the mainstay of treatment to prevent further slip and worsening. However, there is no consensus regarding the best surgical option to treat these patients. This study compares TLIF and instrumented PLF in patients with Grade I and II spondylolisthesis and analysis the outcome with respect to functional outcome, pain, fusion rate, adequacy of medial facetectomy for decompression, and complications. Materials and Methods: Forty patients operated for spondylolisthesis by instrumented posterolateral or transforaminal fusion between January 1, 2010, and June 30, 2012 were included in this retrospective study. They were followed up for 3 years. Twenty one cases were of instrumented posterolateral fusion (PLF) and 19 cases were of transforaminal lumbar interbody fusion (TLIF). The patients were asked to fill up the Oswestry disability index (ODI), Dallas Pain Questionnaire (DPQ), and low back pain rating scale (LBPRS) preoperatively, at 1-month postoperatively, and at 6, 12, 24, and 36 months postoperatively. Radiological parameters were assessed using radiographs. Results: No significant differences were found in DPQ, LBPRS, or ODI scores preoperative, 1-month postoperative, and at 6, 12, 24 and 36 months followup. No significant difference was found between the two groups in blood loss. The only significant difference between the two groups was in the operative time, in which the instrumented PLF group had a mean of 50 min lesser than the TLIF group (P = 0.02). Conclusions: TLIF and instrumented PLF are equally efficacious options in the treatment of Grade I and II spondylolisthesis, except lytic type.

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

    PubMed Central

    Lee, Sandra; Vaidya, Rahul

    2008-01-01

    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

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

    PubMed

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

    2015-03-01

    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 20 years 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.

  8. Bone Morphogenic Protein Is a Viable Adjunct for Fusion in Minimally Invasive Transforaminal Lumbar Interbody Fusion

    PubMed Central

    Siddiqui, M Mashfiqul Arafin; Sta.Ana, Ana Rosario P.; Yeo, William

    2016-01-01

    Study Design Comparison of prospectively collected data of patients undergoing minimally invasive surgery transforaminal lumbar interbody fusion (MIS-TLIF) with and without recombinant human bone morphogenic protein 2 (BMP). Purpose To compare the clinical, radiological outcome and complications of patients undergoing MIS-TLIF with and without BMP. Overview of Literature BMP is an effective fusion enhancer with potential complications. Direct comparison of MIS-TLIF with and without BMP is limited to retrospective studies with short follow-up. Methods From June 2005 to February 2011, consecutive cases of MIS-TLIF performed by a single surgeon were included. North American Spine Society (NASS) score, Oswestry disability index (ODI), Short Form-36 (SF-36), and visual analogue score (VAS) were assessed preoperatively and at 6 and 24 months postoperatively. Fusion rates and complications were noted. Results The 252 cases comprised 104 non-BMP and 148 BMP cases. The BMP group was significantly older (mean age, 60.2 vs. 53.9; p<0.01). Preoperative scores were similar. Immediate postoperative morphine usage was significantly lower in the BMP group (12.4 mg vs. 20.1 mg, p<0.01). At 6 months, the BMP group had lower VAS back and leg pain scores (p<0.01). At 2 years, the BMP group had better leg pain scores (p<0.01), ODI (15.4 vs. 20.3, p=0.04) and NASS scores (8.8 vs. 15.8, p<0.01). Both groups showed significant clinical improvement compared to their preoperative levels. The BMP group attained a significantly higher rate of fusion at 6 months follow-up (88.4% vs. 76.8%, p=0.016) with no difference at 2 years. The non-BMP and BMP group had 12 (11.5%) and 9 (6.1%) complications and 5 (4.8%) and 2 (1.4%) reoperations, respectively. Conclusions The use of BMP to augment fusion in MIS-TLIF is an acceptable alternative that has potential benefits of less pain in early and intermediate postoperative follow-up. PMID:27994786

  9. Evaluation of ABM/P-15 versus autogenous bone in an ovine lumbar interbody fusion model

    PubMed Central

    Sherman, Blake P.; Lindley, Emily M.; Turner, A. Simon; Seim III, Howard B.; Benedict, James; Burger, Evalina L.

    2010-01-01

    A prospective, randomized study was performed in an ovine model to compare the efficacy of an anorganic bovine-derived hydroxyapatite matrix combined with a synthetic 15 amino acid residue (ABM/P-15) in facilitating lumbar interbody fusion when compared with autogenous bone harvested from the iliac crest. P-15 is a biomimetic to the cell-binding site of Type-I collagen for bone-forming cells. When combined with ABM, it creates the necessary scaffold to initiate cell invasion, binding, and subsequent osteogenesis. In this study, six adult ewes underwent anterior-lateral interbody fusion at L3/L4 and L4/L5 using PEEK interbody rings filled with autogenous bone at one level and ABM/P-15 at the other level and no additional instrumentation. Clinical CT scans were obtained at 3 and 6 months; micro-CT scans and histomorphometry analyses were performed after euthanization at 6 months. Clinical CT scan analysis showed that all autograft and ABM/P-15 treated levels had radiographically fused outside of the rings at the 3-month study time point. Although the clinical CT scans of the autograft treatment group showed significantly better fusion within the PEEK rings than ABM/P-15 at 3 months, micro-CT scans, clinical CT scans, and histomorphometric analyses showed there were no statistical differences between the two treatment groups at 6 months. Thus, ABM/P-15 was as successful as autogenous bone graft in producing lumbar spinal fusion in an ovine model, and it should be further evaluated in clinical studies. PMID:20694847

  10. Evaluation of ABM/P-15 versus autogenous bone in an ovine lumbar interbody fusion model.

    PubMed

    Sherman, Blake P; Lindley, Emily M; Turner, A Simon; Seim, Howard B; Benedict, James; Burger, Evalina L; Patel, Vikas V

    2010-12-01

    A prospective, randomized study was performed in an ovine model to compare the efficacy of an anorganic bovine-derived hydroxyapatite matrix combined with a synthetic 15 amino acid residue (ABM/P-15) in facilitating lumbar interbody fusion when compared with autogenous bone harvested from the iliac crest. P-15 is a biomimetic to the cell-binding site of Type-I collagen for bone-forming cells. When combined with ABM, it creates the necessary scaffold to initiate cell invasion, binding, and subsequent osteogenesis. In this study, six adult ewes underwent anterior-lateral interbody fusion at L3/L4 and L4/L5 using PEEK interbody rings filled with autogenous bone at one level and ABM/P-15 at the other level and no additional instrumentation. Clinical CT scans were obtained at 3 and 6 months; micro-CT scans and histomorphometry analyses were performed after euthanization at 6 months. Clinical CT scan analysis showed that all autograft and ABM/P-15 treated levels had radiographically fused outside of the rings at the 3-month study time point. Although the clinical CT scans of the autograft treatment group showed significantly better fusion within the PEEK rings than ABM/P-15 at 3 months, micro-CT scans, clinical CT scans, and histomorphometric analyses showed there were no statistical differences between the two treatment groups at 6 months. Thus, ABM/P-15 was as successful as autogenous bone graft in producing lumbar spinal fusion in an ovine model, and it should be further evaluated in clinical studies.

  11. Roseomonas spinal epidural abscess complicating instrumented posterior lumbar interbody fusion.

    PubMed

    Maraki, Sofia; Bantouna, Vasiliki; Lianoudakis, Efstratios; Stavrakakis, Ioannis; Scoulica, Efstathia

    2013-07-01

    The first case of a spinal epidural abscess caused by Roseomonas mucosa following instrumented posterior lumbar fusion is presented. Although rare, because of its highly resistant profile, Roseomonas species should be included in the differential diagnosis of epidural abscesses in both immunocompromised and immunocompetent hosts.

  12. [Anterior cervical fusion with tantalum interbody implants. Clinical and radiological results in a prospective study].

    PubMed

    Vicario, C; Lopez-Oliva, F; Sánchez-Lorente, T; Zimmermann, M; Asenjo-Siguero, J J; Ladero, F; Ibarzábal, A

    2006-04-01

    Anterior cervical discectomy and interbody fusion (ACDF) is a widely accepted surgical technique in the treatment of cervical disc disease. Tantalum cages have been recently introduced in spine surgery for interbody fusion because of the advantages of their mechanical properties. We present the results of a prospective clinical and radiological study on 24 consecutive patients who underwent an ACDF with tantalum cages. Clinical evaluation was assessed preoperatively and after surgery by a questionnaire that included a Visual Analogic Scale (VAS) of neck and arm pain, the Oswestry Disability Index and the Zung Depression Scale. Results were classified by Odom's criteria. Radiological evaluation included flexion-extension X-rays, and changes in distance between spinous processes and Cobb angle were measured. Postoperatively patients were reviewed 3 and 12 months after surgery. A statistical significative improvement in all clinical data was reported. According to Odom's criteria in 75% of patients the results were considered like excellent or good. Only one case of radiological and clinical pseudoarthrosis was confirmed. No significative differences were reported 3 and 12 months after surgery. Tantalum cages are a very promising and usefull alternative among implants available for ACDF. Compatibility with MRI postoperative studies and the unnecessariness of autograft are some of their advantages.

  13. Neurological complications using a novel retractor system for direct lateral minimally invasive lumbar interbody fusion.

    PubMed

    Sedra, Fady; Lee, Robert; Dominguez, Ignacio; Wilson, Lester

    2016-09-01

    We describe our experience using the RAVINE retractor (K2M, Leesburg, VA, USA) to gain access to the lateral aspect of the lumbar spine through a retroperitoneal approach. Postoperative neurological adverse events, utilising the mentioned retractor system, were recorded and analysed. We included 140 patients who underwent minimally invasive lateral lumbar interbody fusion (MI-LLIF) for degenerative spinal conditions between 2011 and 2015 at two major spinal centres. A total of 228 levels were treated, 35% one level, 40% two level, 20% three level and 5% 4 level surgeries. The L4/5 level was instrumented in 28% of cases. 12/140 patients had postoperative neurological complications. Immediately after surgery, 5% of patients (7/140) had transient symptoms in the thigh ranging from sensory loss, pain and paraesthesia, all of which recovered within 12weeks following surgery. There were five cases of femoral nerve palsy (3.6% - two ipsilateral and three contralateral), all of which recovered completely with no residual sensory or motor deficit within 6months. MI-LLIF done with help of the described retractor system has proved a safe and efficient way to achieve interbody fusion with minimal complications, mainly nerve related, that recovered quickly. Judicious use of the technique to access the L4/5 level is advised.

  14. Hybrid Biosynthetic Autograft Extender for Use in Posterior Lumbar Interbody Fusion: Safety and Clinical Effectiveness.

    PubMed

    Chedid, Mokbel K; Tundo, Kelly M; Block, Jon E; Muir, Jeffrey M

    2015-01-01

    Autologous iliac crest bone graft is the preferred option for spinal fusion, but the morbidity associated with bone harvest and the need for graft augmentation in more demanding cases necessitates combining local bone with bone substitutes. The purpose of this study was to document the clinical effectiveness and safety of a novel hybrid biosynthetic scaffold material consisting of poly(D,L-lactide-co-glycolide) (PLGA, 75:25) combined by lyophilization with unmodified high molecular weight hyaluronic acid (10-12% wt:wt) as an extender for a broad range of spinal fusion procedures. We retrospectively evaluated all patients undergoing single- and multi-level posterior lumbar interbody fusion at an academic medical center over a 3-year period. A total of 108 patients underwent 109 procedures (245 individual vertebral levels). Patient-related outcomes included pain measured on a Visual Analog Scale. Radiographic outcomes were assessed at 6 weeks, 3-6 months, and 1 year postoperatively. Radiographic fusion or progression of fusion was documented in 221 of 236 index levels (93.6%) at a mean (±SD) time to fusion of 10.2+4.1 months. Single and multi-level fusions were not associated with significantly different success rates. Mean pain scores (+SD) for all patients improved from 6.8+2.5 at baseline to 3.6+2.9 at approximately 12 months. Improvements in VAS were greatest in patients undergoing one- or two-level fusion, with patients undergoing multi-level fusion demonstrating lesser but still statistically significant improvements. Overall, stable fusion was observed in 64.8% of vertebral levels; partial fusion was demonstrated in 28.8% of vertebral levels. Only 15 of 236 levels (6.4%) were non-fused at final follow-up.

  15. Stand-Alone Lateral Interbody Fusion for the Treatment of Low-Grade Degenerative Spondylolisthesis

    PubMed Central

    Marchi, Luis; Abdala, Nitamar; Oliveira, Leonardo; Amaral, Rodrigo; Coutinho, Etevaldo; Pimenta, Luiz

    2012-01-01

    The purpose of this paper was to investigate the stand-alone lateral interbody fusion as a minimally invasive option for the treatment of low-grade degenerative spondylolisthesis with a minimum 24-month followup. Prospective nonrandomized observational single-center study. 52 consecutive patients (67.6 ± 10 y/o; 73.1% female; 27.4 ± 3.4 BMI) with single-level grade I/II single-level degenerative spondylolisthesis without significant spine instability were included. Fusion procedures were performed as retroperitoneal lateral transpsoas interbody fusions without screw supplementation. The procedures were performed in average 73.2 minutes and with less than 50cc blood loss. VAS and Oswestry scores showed lasting improvements in clinical outcomes (60% and 54.5% change, resp.). The vertebral slippage was reduced in 90.4% of cases from mean values of 15.1% preoperatively to 7.4% at 6-week followup (P < 0.001) and was maintained through 24 months (7.1%, P < 0.001). Segmental lordosis (P < 0.001) and disc height (P < 0.001) were improved in postop evaluations. Cage subsidence occurred in 9/52 cases (17%) and 7/52 cases (13%) spine levels needed revision surgery. At the 24-month evaluation, solid fusion was observed in 86.5% of the levels treated. The minimally invasive lateral approach has been shown to be a safe and reproducible technique to treat low-grade degenerative spondylolisthesis. PMID:22545019

  16. Change of Lumbar Ligamentum Flavum after Indirect Decompression Using Anterior Lumbar Interbody Fusion

    PubMed Central

    Orita, Sumihisa; Yamauchi, Kazuyo; Eguchi, Yawara; Aoki, Yasuchika; Nakamura, Junichi; Miyagi, Masayuki; Suzuki, Miyako; Kubota, Gou; Inage, Kazuhide; Sainoh, Takeshi; Sato, Jun; Fujimoto, Kazuki; Shiga, Yasuhiro; Abe, Koki; Kanamoto, Hiroto; Inoue, Gen; Takahashi, Kazuhisa; Furuya, Takeo; Koda, Masao

    2017-01-01

    Study Design Retrospective case series. Purpose The purpose of this study was to examine changes in the ligamentum flavum thickness and remodeling of the spinal canal after anterior fusion during a 10-year follow-up. Overview of Literature Extreme lateral interbody fusion provides minimally invasive treatment of the lumbar spine; this anterior fusion without direct posterior decompression, so-called indirect decompression, can achieve pain relief. Anterior fusion may restore disc height, stretch the flexure of the ligamentum flavum, and increase the spinal canal diameter. However, changes in the ligamentum flavum thickness and remodeling of the spinal canal after anterior fusion during a long follow-up have not yet been reported. Methods We evaluated 10 patients with L4 spondylolisthesis who underwent stand-alone anterior interbody fusion using the iliac crest bone. Magnetic resonance imaging was performed 10 years after surgery. The cross-sectional area (CSA) of the dural sac and the ligamentum flavum at L1–2 to L5–S1 was calculated using a Picture Archiving and Communication System. Results Spinal fusion with correction loss (average, 4.75 mm anterior slip) was achieved in all patients 10 years postsurgery. The average CSAs of the dural sac and the ligamentum flavum at L1–2 to L5–S1 were 150 mm2 and 78 mm2, respectively. The average CSA of the ligamentum flavum at L4–5 (30 mm2) (fusion level) was significantly less than that at L1–2 to L3–4 or L5–S1. Although patients had an average anterior slip of 4.75 mm, the average CSA of the dural sac at L4–5 was significantly larger than at the other levels. Conclusions Spinal stability induced a lumbar ligamentum flavum change and a sustained remodeling of the spinal canal, which may explain the long-term pain relief after indirect decompression fusion surgery. PMID:28243378

  17. Comparison of complication rates of minimally invasive transforaminal lumbar interbody fusion and lateral lumbar interbody fusion: a systematic review of the literature.

    PubMed

    Joseph, Jacob R; Smith, Brandon W; La Marca, Frank; Park, Paul

    2015-10-01

    OBJECT Minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) and lateral lumbar interbody fusion (LLIF) are 2 currently popular techniques for lumbar arthrodesis. The authors compare the total risk of each procedure, along with other important complication outcomes. METHODS This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Relevant studies (up to May 2015) that reported complications of either MI-TLIF or LLIF were identified from a search in the PubMed database. The primary outcome was overall risk of complication per patient. Secondary outcomes included risks of sensory deficits, temporary neurological deficit, permanent neurological deficit, intraoperative complications, medical complications, wound complications, hardware failure, subsidence, and reoperation. RESULTS Fifty-four studies were included for analysis of MI-TLIF, and 42 studies were included for analysis of LLIF. Overall, there were 9714 patients (5454 in the MI-TLIF group and 4260 in the LLIF group) with 13,230 levels fused (6040 in the MI-TLIF group and 7190 in the LLIF group). A total of 1045 complications in the MI-TLIF group and 1339 complications in the LLIF group were reported. The total complication rate per patient was 19.2% in the MI-TLIF group and 31.4% in the LLIF group (p < 0.0001). The rate of sensory deficits and temporary neurological deficits, and permanent neurological deficits was 20.16%, 2.22%, and 1.01% for MI-TLIF versus 27.08%, 9.40%, and 2.46% for LLIF, respectively (p < 0.0001, p < 0.0001, p = 0.002, respectively). Rates of intraoperative and wound complications were 3.57% and 1.63% for MI-TLIF compared with 1.93% and 0.80% for LLIF, respectively (p = 0.0003 and p = 0.034, respectively). No significant differences were noted for medical complications or reoperation. CONCLUSIONS While there was a higher overall complication rate with LLIF, MI-TLIF and LLIF both have

  18. Anterior column realignment following lateral interbody fusion for sagittal deformity correction.

    PubMed

    Pimenta, Luiz; Fortti, Fernanda; Oliveira, Leonardo; Marchi, Luis; Jensen, Rubens; Coutinho, Etevaldo; Amaral, Rodrigo

    2015-07-01

    Degenerative and iatrogenic diseases may lead to loss of lordosis or even kyphotic thoracolumbar deformity and sagittal misalignment. Traditional surgery with three-column osteotomies is associated with important neurologic risks and postoperative morbidity. In a novel technique, the lateral transpsoas interbody fusion (LTIF) is complemented with the sacrifice of the anterior longitudinal ligament and anterior portion of the annulus followed by the insertion of a hyperlordotic interbody cage. This is a less invasive lateral technique named anterior column realignment (ACR) and aims to correct sagittal misalignment in adult spinal deformity (ASD), with or without the addition of minor posterior osteotomies. In this article, we provide an account of the evolution to the ACR technique, the literature, and the Brazilian experience in the treatment of adult spinal deformity with this novel advanced application of LTIF. In the presence of ASD, the risk-to-benefit ratio of a surgical correction must be evaluated. Less invasive surgical strategies can be alternatives to treat the deformity and provide better quality of life to the patient. ACR is an advanced application of lateral transpsoas approach, up to date has shown to be reliable and effective when used for ASD, and may minimize complications and morbidity from traditional surgical procedures. Long-term follow-up and comparative studies are needed to evaluate real benefit.

  19. Symptomatic Adjacent Segment Pathology after Posterior Lumbar Interbody Fusion for Adult Low-Grade Isthmic Spondylolisthesis

    PubMed Central

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

    2013-01-01

    The incidence of symptomatic adjacent segment pathology (ASP) after fusion surgery for adult low-grade isthmic spondylolisthesis (IS) has been reported to be relatively low compared with other lumbar disease entities. However, there has been no study of symptomatic ASP incidence using posterior lumbar interbody fusion (PLIF) with pedicle screw instrumentation. We investigated the incidence of symptomatic ASP after PLIF with pedicle screw instrumentation for adult low-grade IS and identified significant risk factors for symptomatic ASP. We retrospectively studied records of 40 consecutive patients who underwent PLIF with pedicle screw instrumentation at the Department of Orthopaedic Surgery, Kansai Rosai Hospital, Amagasaki, Japan. The patients were followed for ≥ 4 years. Patients' medical records were retrospectively examined for evidence of symptomatic ASP. Age at time of surgery, sex, fusion level, whole lumbar lordosis, segmental lordosis, preexisting laminar inclination angle, and facet tropism at the cranial fusion segment were analyzed to identify risk factors for symptomatic ASP. Four patients (ASP group) developed symptomatic ASP at the cranial segment adjacent to the fusion. There were no significant differences in age, sex, fusion level, lumbar lordosis, segmental lordosis, or facet tropism at the cranial segment adjacent to the fusion between the ASP and the non-ASP groups. In contrast, laminar inclination angle at the cranial vertebra adjacent to the fusion was significantly higher in the ASP group than in the non-ASP group. Four patients (10%) developed symptomatic ASP after PLIF with transpedicular fixation for adult low-grade IS. Preexisting laminar horizontalization at the cranial vertebra adjacent to the fusion was a significant risk factor for symptomatic ASP. PMID:24436872

  20. 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)

    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

    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.

  1. Extreme lateral interbody fusion for the treatment of adult degenerative scoliosis.

    PubMed

    Caputo, Adam M; Michael, Keith W; Chapman, Todd M; Jennings, Jason M; Hubbard, Elizabeth W; Isaacs, Robert E; Brown, Christopher R

    2013-11-01

    Extreme lateral interbody fusion (XLIF; NuVasive Inc., San Diego, CA, USA) is a minimally invasive lateral transpsoas approach to the thoracolumbar spine. Though the procedure is rapidly increasing in popularity, limited data is available regarding its use in deformity surgery. We aimed to evaluate radiographic correction using XLIF in adults with degenerative lumbar scoliosis. Thirty consecutive patients were followed for an average of 14.3 months. Interbody fusion was completed using the XLIF technique with supplemental posterior instrumentation. Plain radiographs were obtained on all patients preoperatively, postoperatively, and at most recent follow-up. Plain radiographic measurements of coronal Cobb angle, apical vertebral translation, segmental lordosis, global lordosis, disc height, neuroforaminal height and neuroforaminal width were made at each time point. CT scans were obtained for all patients 1 year after surgery to evaluate for fusion. There was significant improvement in multiple radiographic parameters from preoperative to postoperative. Cobb angle corrected 72.3%, apical vertebral translation corrected 59.7%, neuroforaminal height increased 80.3%, neuroforaminal width increased 7.4%, and disc height increased 116.7%. Segmental lordosis at L4-L5 increased 14.1% and global lordosis increased 11.5%. There was no significant loss of correction from postoperative to most recent follow-up. There was an 11.8% pseudoarthrosis rate at levels treated with XLIF. Complications included lateral incisional hernia (n=1), rupture of anterior longitudinal ligament (n=2), wound breakdown (n=2), cardiac instability (n=1), pedicle fracture (n=1), and nonunion requiring revision (n=1). XLIF significantly improves coronal plane deformity in patients with adult degenerative scoliosis. XLIF has the ability to correct sagittal plane deformity, although it is most effective at lower lumbar levels.

  2. Treatment of Spinal Tuberculosis by Debridement, Interbody Fusion and Internal Fixation via Posterior Approach Only.

    PubMed

    Tang, Ming-xing; Zhang, Hong-qi; Wang, Yu-xiang; Guo, Chao-feng; Liu, Jin-yang

    2016-02-01

    Surgical treatment for spinal tuberculosis includes focal tuberculosis debridement, segmental stability reconstruction, neural decompression and kyphotic deformity correction. For the lesions mainly involved anterior and middle column of the spine, anterior operation of debridement and fusion with internal fixation has been becoming the most frequently used surgical technique for the spinal tuberculosis. However, high risk of structural damage might relate with anterior surgery, such as damage in lungs, heart, kidney, ureter and bowel, and the deformity correction is also limited. Due to the organs are in the front of spine, there are less complications in posterior approach. Spinal pedicle screw passes through the spinal three-column structure, which provides more powerful orthopedic forces compared with the vertebral body screw, and the kyphotic deformity correction effect is better in posterior approach. In this paper, we report a 68-year-old male patient with thoracic tuberculosis who underwent surgical treatment by debridement, interbody fusion and internal fixation via posterior approach only. The patient was placed in prone position under general anesthesia. Posterior midline incision was performed, and the posterior spinal construction was exposed. Then place pedicle screw, and fix one side rod temporarily. Make the side of more bone destruction and larger abscess as lesion debridement side. Resect the unilateral facet joint, and retain contralateral structure integrity. Protect the spinal cord, nerve root. Clear sequestrum, necrotic tissue, abscess of paravertebral and intervertebral space. Specially designed titanium mesh cages or bone blocks were implanted into interbody. Fix both side rods and compress both sides to make the mesh cages and bone blocks tight. Reconstruct posterior column structure with allogeneic bone and autologous bone. Using this technique, the procedures of debridement, spinal cord decompression, deformity correction, bone grafting

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

    PubMed

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

    2016-11-01

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

  4. Miniopen Transforaminal Lumbar Interbody Fusion with Unilateral Fixation: A Comparison between Ipsilateral and Contralateral Reherniation

    PubMed Central

    Liu, Fubing; Jiang, Chun

    2016-01-01

    The aim of this study was to evaluate the risk factors between ipsilateral and contralateral reherniation and to compare the effectiveness of miniopen transforaminal lumbar interbody fusion (TLIF) with unilateral fixation for each group. From November 2007 to December 2014, clinical and radiographic data of each group (ipsilateral or contralateral reherniation) were collected and compared. Functional assessment (Visual Analog Scale (VAS) score and Japanese Orthopaedic Association (JOA)) and radiographic evaluation (fusion status, disc height, lumbar lordosis (LL), and functional spine unit (FSU) angle) were applied to compare surgical effect for each group preoperatively and at final followup. MacNab questionnaire was applied to further evaluate the satisfactory rate after the discectomy and fusion. No difference except pain-free interval was found between ipsilateral and contralateral groups. There was a significant difference in operative time between two groups. No differences were found in clinical and radiographic data for assessment of surgical effect between two groups. The satisfactory rate was decreasing in both groups with time passing after discectomy. Difference in pain-free interval may be a distinction for ipsilateral and contralateral reherniation. Miniopen TLIF with unilateral pedicle screw fixation can be a recommendable way for single level reherniation regardless of ipsilateral or contralateral reherniation. PMID:27885358

  5. The Multiple Benefits of Minimally Invasive Spinal Surgery: Results Comparing Transforaminal Lumbar Interbody Fusion and Posterior Lumbar Fusion

    PubMed Central

    Starkweather, Angela R.; Witek-Janusek, Linda; Nockels, Russ P.; Peterson, Jonna; Mathews, Herb L.

    2013-01-01

    Minimally invasive transforaminal lumbar interbody fusion (TLIF) offers equivalent postoperative fusion rates compared to posterior lumbar fusion (PLF) and minimizes the amount of iatrogenic injury to the spinal muscles. The objective of this study was to examine the difference in pain perception, stress, mood disturbance, quality of life, and immunological indices throughout the perioperative course among patients undergoing TLIF and PLF. A prospective, nonrandomized descriptive design was used to evaluate these measures among patients undergoing TLIF (n = 17) or PLF (n = 18) at 1 week prior to surgery (T1), the day of surgery (T2), 24 hours postoperatively (T3), and 6 weeks postoperatively (T4). Among TLIF patients, pain, stress, fatigue, and mood disturbance were significantly decreased at the 6-week follow-up visit (T4) compared to patients who underwent PLF. The TLIF group also demonstrated significantly higher levels (near baseline) of CD8 cells atT4 than the PLF group. Interleukin-6 levels were significantly higher in the TLIF group as well, which may be an indicator of ongoing nerve regeneration and healing. Knowledge concerning the effect of pain and the psychological experience on immunity among individuals undergoing spinal fusion can help nurses tailor interventions to improve outcomes, regardless of the approach used. PMID:18330408

  6. Lateral interbody fusion combined with open posterior surgery for adult spinal deformity.

    PubMed

    Strom, Russell G; Bae, Junseok; Mizutani, Jun; Valone, Frank; Ames, Christopher P; Deviren, Vedat

    2016-12-01

    OBJECTIVE Lateral interbody fusion (LIF) with percutaneous screw fixation can treat adult spinal deformity (ASD) in the coronal plane, but sagittal correction is limited. The authors combined LIF with open posterior (OP) surgery using facet osteotomies and a rod-cantilever technique to enhance lumbar lordosis (LL). It is unclear how this hybrid strategy compares to OP surgery alone. The goal of this study was to evaluate the combination of LIF and OP surgery (LIF+OP) for ASD. METHODS All thoracolumbar ASD cases from 2009 to 2014 were reviewed. Patients with < 6 months follow-up, prior fusion, severe sagittal imbalance (sagittal vertical axis > 200 mm or pelvic incidence-LL > 40°), and those undergoing anterior lumbar interbody fusion were excluded. Deformity correction, complications, and outcomes were compared between LIF+OP and OP-only surgery patients. RESULTS LIF+OP (n = 32) and OP-only patients (n = 60) had similar baseline features and posterior fusion levels. On average, 3.8 LIFs were performed. Patients who underwent LIF+OP had less blood loss (1129 vs 1833 ml, p = 0.016) and lower durotomy rates (0% vs 23%, p = 0.002). Patients in the LIF+OP group required less ICU care (0.7 vs 2.8 days, p < 0.001) and inpatient rehabilitation (63% vs 87%, p = 0.015). The incidence of new leg pain, numbness, or weakness was similar between groups (28% vs 22%, p = 0.609). All leg symptoms resolved within 6 months, except in 1 OP-only patient. Follow-up duration was similar (28 vs 25 months, p = 0.462). LIF+OP patients had significantly less pseudarthrosis (6% vs 27%, p = 0.026) and greater improvement in visual analog scale back pain (mean decrease 4.0 vs 1.9, p = 0.046) and Oswestry Disability Index (mean decrease 21 vs 12, p = 0.035) scores. Lumbar coronal correction was greater with LIF+OP surgery (mean [± SD] 22° ± 13° vs 14° ± 13°, p = 0.010). LL restoration was 22° ± 13°, intermediately between OP-only with facet osteotomies (11° ± 7°, p < 0.001) and

  7. Long-Term Objective Physical Activity Measurements using a Wireless Accelerometer Following Minimally Invasive Transforaminal Interbody Fusion Surgery.

    PubMed

    Phan, Kevin; Mobbs, Ralph J

    2016-04-01

    We report on a case of a patient who underwent minimally invasive transforaminal lumbar interbody fusion (mi-TLIF) with objective physical activity measurements performed preoperatively and postoperatively at up to 12-months using wireless accelerometer technology. In the first postoperative month following surgery, the patient had reduced mobility, taking 2,397 steps over a distance of 1.8 km per day. However, the number of steps taken and distance travelled per day had returned to baseline levels by the second postoperative month. At one-year follow-up, the patient averaged 5,095 steps per day in the month over a distance of 3.8 km; this was a 60% improvement in both steps taken and distance travelled compared to the preoperative status. The use of wireless accelerometers is feasible in obtaining objective physical activity measurements before and after lumbar interbody fusion and may be applicable to other related spinal surgeries as well.

  8. Effect of steerable cage placement during minimally invasive transforaminal lumbar interbody fusion on lumbar lordosis.

    PubMed

    Lindley, Timothy E; Viljoen, Stephanus V; Dahdaleh, Nader S

    2014-03-01

    Minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) is commonly used for the treatment of a variety of degenerative spine disorders. Recently, steerable interbody cages have been developed which potentially allow for greater restoration of lumbar lordosis. Here we describe a technique and radiographic results following minimally invasive placement of steerable cages through a bilateral approach. A retrospective review was conducted of the charts and radiographs of 15 consecutive patients who underwent 19 levels of bilateral MIS-TLIF with the placement of steerable cages. These were compared to 10 patients who underwent 16 levels of unilateral MIS-TLIF with the placement of bullet cages. The average age, body mass index, distribution of the levels operated and follow-up were similar in both groups. The average height of the steerable cage placed was 10.9 mm compared to 8.5mm for bullet cages. The preoperative focal Cobb's angle per level was similar between both groups with a mean of -5.3 degrees for the steerable cage group and -4.8 degrees for the bullet cage group. There was a significant improvement in postoperative Cobb's angle after placement of a steerable cage with a mean of -13.7 (p<0.01) and this persisted at the last follow-up with -13 degrees (p<0.01). There was no significant change in Cobb's angle after bullet cage placement with -5.7 degrees postoperatively and a return to the baseline preoperative Cobb's angle of -4.8 at the last follow-up. Steerable cage placement for MIS-TLIF improves focal lordosis compared to bullet cage placement.

  9. Lateral Lumbar Interbody Fusion for Ossification of the Yellow Ligament in the Lumbar Spine: First Reported Case

    PubMed Central

    Abe, Tetsuya; Funayama, Toru; Noguchi, Hiroshi; Nakayama, Keita; Miura, Kousei; Nagashima, Katsuya; Kumagai, Hiroshi; Yamazaki, Masashi

    2017-01-01

    When ossification of the yellow ligament (OYL) occurs in the lumbar spine and extends to the lateral wall of the spinal canal, facetectomy is required to remove all of the ossified lesion and achieve decompression. Subsequent posterior fixation with interbody fusion will then be necessary to prevent postoperative progression of the ossification and intervertebral instability. The technique of lateral lumbar interbody fusion (LLIF) has recently been introduced. Using this procedure, surgeons can avoid excess blood loss from the extradural venous plexus and detachment of the ossified lesion and the ventral dura mater is avoidable. We present a 55-year-old male patient with OYL at L3/4 and anterior spondylolisthesis of L4 vertebra, with concomitant ossification of the posterior longitudinal ligament, who presented with a severe gait disturbance. He underwent a 2-stage operation without complications: LLIF for L3/4 and L4/5 was performed at the initial surgery, and posterior decompression fixation using pedicle screws from L3 to L5 was performed at the second surgery. His postoperative progress was favorable, and his interbody fusion was deemed successful. Here, we present the first reported case of LLIF for OYL of the lumbar spine. This procedure can be a good option for OYL of the lumbar spine. PMID:28352485

  10. A Biomechanical Stability Study of Extraforaminal Lumbar Interbody Fusion on the Cadaveric Lumbar Spine Specimens

    PubMed Central

    Guo, Song; Yan, Meijun; Han, Yingchao; Xia, Dongdong; Sun, Guixin; Li, Lijun; Tan, Jun

    2016-01-01

    Background Transforaminal lumbar interbody fusion (TLIF) is an effective surgery for lumbar degenerative disease. However, this fusion technique requires resection of inferior facet joint to provide access for superior facet joint resection, which results in reduced lumbar spinal stability and unnecessary trauma. We have previously developed extraforaminal lumbar interbody fusion (ELIF) that can avoid back muscle injury with direct nerve root decompression. This study aims to show that ELIF enhances lumbar spinal stability in comparison to TLIF by comparing lumbar spinal stability of L4–L5 range of motion (ROM) on 12 cadaveric spine specimens after performing TLIF or ELIF. Methods 12 cadaveric spine specimens were randomly divided and treated in accordance with the different internal fixations, including ELIF with a unilateral pedicle screw (ELIF+UPS), TLIF with a unilateral pedicle screw (TLIF+UPS), TLIF with a bilateral pedicle screw (TLIF+BPS), ELIF with a unilateral pedicle screw and translaminar facet screw (ELIF+UPS+TLFS) and ELIF with a bilateral pedicle screw (ELIF+BPS). The treatment groups were exposed to a 400-N load and 6 N·m movement force to calculate the angular displacement of L4-L5 during anterior flexion, posterior extension, lateral flexion and rotation operation conditions. Results The ROM in ELIF+UPS group was smaller than that of TLIF+UPS group under all operating conditions, with the significant differences in left lateral flexion and right rotation by 36.15% and 25.97% respectively. The ROM in ELIF+UPS group was higher than that in TLIF+BPS group. The ROM in the ELIF+UPS+TLFS group was much smaller than that in the ELIF+UPS group, but was not significantly different than that in the TLIF+BPS group. Conclusions Despite that TLIF+BPS has great stability, which can be comparable by that of ELIF+UPS. Additionally, ELIF stability can be further improved by using translaminar facet screws without causing more tissue damage to patient. PMID

  11. Minimally Invasive Direct Thoracic Interbody Fusion (MIS-DTIF): Technical Notes of a Single Surgeon Study

    PubMed Central

    Abbasi, Hamid

    2016-01-01

    Background Minimally invasive direct thoracic interbody fusion (MIS-DTIF) is a new single surgeon procedure for fusion of the thoracic vertebrae below the scapula (T6/7) to the thoracolumbar junction. In this proof of concept study, we describe the surgical technique for MIS-DTIF and report our experience and the perioperative outcomes of the first four patients who underwent this procedure. Study design/setting In this study we attempt to establish the safety and efficacy of MIS-DTIF. We have performed MIS-DTIF on six spinal levels in four patients with degenerative disk disease or disk herniation. We recorded surgery time, blood loss, fluoroscopy time, complications, and patient-reported pain. Methods Throughout the MIS-DTIF procedure, the surgeon is aided by biplanar fluoroscopic imaging and electrophysiological monitoring. The surgeon approaches the spine with a series of gentle tissue dilations and inserts a working tube that establishes a direct connection from the outside of the skin to the disk space. Through this working tube, the surgeon performs a discectomy and inserts an interbody graft or cage. The procedure is completed with minimally invasive (MI) posterior pedicle screw fixation. Results For the single level patients the mean blood loss was 90 ml, surgery time 43 minutes, fluoroscopy time 293 seconds, and hospital stay two days. For the two-level surgeries, the mean blood loss was 27 ml, surgery time 61 minutes, fluoroscopy time 321 seconds, and hospital stay three days. We did not encounter any clinically significant complications. Thirty days post-surgery, the patients reported a statistically significant reduction of 5.3 points on a 10-point sliding pain scale. Conclusions MIS-DTIF with pedicle screw fixation is a safe and clinically effective procedure for fusions of the thoracic spine. The procedure is technically straightforward and overcomes many of the limitations of the current minimally invasive (MI) approaches to the thoracic spine. MIS

  12. Minimally Invasive Direct Lateral Interbody Fusion (MIS-DLIF): Proof of Concept and Perioperative Results

    PubMed Central

    Abbasi, Hamid

    2017-01-01

    Background Minimally invasive direct lateral interbody fusion (MIS-DLIF) is a novel approach for fusions of the lumbar spine. In this proof of concept study, we describe the surgical technique and report our experience and the perioperative outcomes of the first nine patients who underwent this procedure. Study design/setting In this study we establish the safety and efficacy of this approach. MIS-DLIF was performed on 15 spinal levels in nine patients who failed to respond to conservative therapy for the treatment of a re-herniated disk, spondylolisthesis, or other severe disk disease of the lumbar spine. We recorded surgery time, blood loss, fluoroscopy time, patient-reported pain, and complications. Methods Throughout the MIS-DLIF procedure, the surgeon is aided by biplanar fluoroscopic imaging to place an interbody graft or cage into the disc space through the interpleural space. A discectomy is performed in the same minimally invasive fashion. The procedure is usually completed with posterior pedicle screw fixation. Results MIS-DLIF took 44/85 minutes, on average, for 1/2 levels, with 54/112 ml of blood loss, and 0.3/1.7 days of hospital stay. Four of nine patients did not require overnight hospitalization and were discharged two to four hours after surgery. We did not encounter any clinically significant complications. At more than ninety days post surgery, the patients reported a statistically significant reduction of 4.5 points on a 10-point sliding pain scale. Conclusions MIS-DLIF with pedicle screw fixation is a safe and clinically effective procedure for fusions of the lumbar spine. The procedure overcomes many of the limitations of the current minimally invasive approaches to the lumbar spine and is technically straightforward. MIS-DLIF has the potential to improve patient outcomes and reduce costs relative to the current standard of care and therefore warrants further investigation. We are currently expanding this study to a larger cohort and

  13. Oblique Lateral Lumbar Interbody Fusion (OLLIF): Technical Notes and Early Results of a Single Surgeon Comparative Study

    PubMed Central

    Abbasi, Hamid

    2015-01-01

    Background context: Lower back pain is one of the most prevalent and expensive health conditions in the Western world. The standard treatment, interbody fusion, is an invasive procedure that requires the stripping of muscles and soft tissue, leading to surgical morbidity. Current minimally invasive (MI) spinal fusions are technically demanding and suffer from technical limitations. Purpose: Oblique lumbar lateral interbody fusion (OLLIF) is a new technique for fusion of the lumbar spine that overcomes these complications. Outcome measures include patient demographics, reported outcomes, and surgical outcomes. Study design/Setting: Kambin's Triangle can easily be located as a silent window with an electrophysiological probe. Discectomy is performed through a single access portal with a 10 mm diameter. After a discectomy, the disc space is packed with beta-tricalcium phosphate soaked in autologous bone marrow, aspirated, and the cage is inserted. Finally, a minimally invasive posterior fixation is performed. Methods: OLLIF’s major innovation is to approach the disc through Kambin’s Triangle, aided by bilateral fluoroscopy. Results: We present data from 69 consecutive OLLIF surgeries on 128 levels with a control group of 55 consecutive open transformational lumbar interbody fusions (TLIFs) on 125 levels. For a single level OLLIF, the mean surgery time is 69 minutes (min) and blood loss is 29 ml. Surgery time was approximately twice as fast as open TLIF (mean: 135 min) and blood loss is reduced by over 80% compared to TLIF (mean: 355 ml). Conclusions: OLLIF is a minimally invasive fusion that significantly reduces surgery times compared to open surgery. OLLIF overcomes the difficulties of traditional open fusions, making it a safe and technically less demanding surgery than open or minimally invasive TLIF.  PMID:26623206

  14. Comparison of Posterior Lumbar Interbody Fusion and Posterolateral Lumbar Fusion in Monosegmental Vacuum Phenomenon within an Intervertebral Disc

    PubMed Central

    An, Ki-Chan; Kong, Gyu-Min; Park, Dae-Hyun; Youn, Ji-Hong; Lee, Woon-Seong

    2016-01-01

    Study Design Retrospective. Purpose To compare the clinical and radiological outcomes of posterolateral lumbar interbody fusion (PLIF) and posterolateral lumbar fusion (PLF) in monosegmental vacuum phenomenon within an intervertebral disc. Overview of Literature The vacuum phenomenon within an intervertebral disc is a serious form of degenerative disease that destabilizes the intervertebral body. Outcomes of PLIF and PLF in monosegmental vacuum phenomenon are unclear. Methods Monosegmental instrumented PLIF and PLF was performed on 84 degenerative lumbar disease patients with monosegmental vacuum phenomenon (PLIF, n=38; PLF, n=46). Minimum follow-up was 24 months. Clinical outcomes of leg and back pain were assessed using visual analogue scales for leg pain (LVAS) and back pain (BVAS), and the Oswestry disability index (ODI). The radiographic outcome was the estimated bony union rate. Results LVAS, BVAS, and ODI improved in both groups. There was no significant difference in the degree of these improvements between PLIF and PLF patients (p>0.05). Radiological union rate was 91.1% in PLIF group and 89.4% in PLF group at postoperative 24 months (p>0.05). Conclusions No significant differences in clinical results and union rates were found between PLIF and PLF patients. Selection of the operation technique will reflect the surgeon's preferences and patient condition. PMID:26949464

  15. [The posterior lumbar interbody fusion with cages (PLIF) and transpedicular stabilization].

    PubMed

    Diedrich, O; Kraft, C N; Perlick, L; Schmitt, O

    2001-01-01

    The development of intervertebral cages has significantly innovated the original technique of posterior lumbar interbody fusion (PLIF). In this study we present the results of patients treated for degenerative or postoperative segmental spinal instabilities by PLIF with cages and pedicular stabilisation (360 degrees-instrumentation). Between 1992 and 1999 we implanted either CFRP-, PEEK- or Titanium-cages in 86 patients. 78 patients were adequately followed up over a period of at least 12 months (average 2,6 years). 5 patients were stabilised over 2 segments, so that ultimately 83 fused segments were evaluated.15% of all patients had an excellent, 51% a good, 28% a moderate and 5% an insufficient clinical result. Degenerative instabilities had a better outcome with 73% good or excellent clinical results, compared to postoperative instabilities (56%). Based on stringent radiographic fusion criteria we found true bony fusion in 52% of all segments after 12 months, 63% after 24 months, 72% after 36 months, and 78% after 48 months. In 21 segments cage packing was performed with autologous spongiosa, while in 62 segments a combination of cortical bone and spongiosa obtained from osseous structures at the operation-site were used as packing material. At the 24 month radiographic control we found a slightly higher fusion rate for those segments treated with autologous spongiosa obtained from the iliac crest. Neither for cages nor for pedicular screws was implant failure or material fatigue found. Serious entero-, pulmo-, cardio- or urological complications were not observed. Nonetheless the necessity for operative revision was 9%. A postoperative semiquantitative evaluation of segments neighbouring the fused vertebra revealed in 28% an increase in degenerative changes. Particularly after 360 degrees-instrumentation, interpretation of the fusion-status should be based on structural and not on functional criteria. The modification of PLIF with cages compared to the use of

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

    PubMed

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

    2013-10-01

    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(ε-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.

  17. Reduction in adjacent-segment degeneration after multilevel posterior lumbar interbody fusion with proximal DIAM implantation.

    PubMed

    Lu, Kang; Liliang, Po-Chou; Wang, Hao-Kuang; Liang, Cheng-Loong; Chen, Jui-Sheng; Chen, Tai-Been; Wang, Kuo-Wei; Chen, Han-Jung

    2015-08-01

    OBJECT Multilevel long-segment lumbar fusion poses a high risk for future development of adjacent-segment degeneration (ASD). Creating a dynamic transition zone with an interspinous process device (IPD) proximal to the fusion has recently been applied as a method to reduce the occurrence of ASD. The authors report their experience with the Device for Intervertebral Assisted Motion (DIAM) implanted proximal to multilevel posterior lumbar interbody fusion (PLIF) in reducing the development of proximal ASD. METHODS This retrospective study reviewed 91 cases involving patients who underwent 2-level (L4-S1), 3-level (L3-S1), or 4-level (L2-S1) PLIF. In Group A (42 cases), the patients received PLIF only, while in Group B (49 cases), an interspinous process device, a DIAM implant, was put at the adjacent level proximal to the PLIF construct. Bone resection at the uppermost segment of the PLIF was equally limited in the 2 groups, with preservation of the upper portion of the spinous process/lamina and the attached supraspinous ligament. Outcome measures included a visual analog scale (VAS) for low-back pain and leg pain and the Oswestry Disability Index (ODI) for functional impairment. Anteroposterior and lateral flexion/extension radiographs were used to evaluate the fusion status, presence and patterns of ASD, and mobility of the DIAM-implanted segment. RESULTS Solid interbody fusion without implant failure was observed in all cases. Radiographic ASD occurred in 20 (48%) of Group A cases and 3 (6%) of Group B cases (p < 0.001). Among the patients in whom ASD was identified, 9 in Group A and 3 in Group B were symptomatic; of these patients, 3 in Group A and 1 in Group B underwent a second surgery for severe symptomatic ASD. At 24 months after surgery, Group A patients fared worse than Group B, showing higher mean VAS and ODI scores due to symptoms related to ASD. At the final follow-up evaluations, as reoperations had been performed to treat symptomatic ASD in some

  18. Deep vein thrombosis due to migrated graft bone after posterior lumbosacral interbody fusion. Case report.

    PubMed

    Yoshimoto, Hisashi; Sato, Shigenobu; Nakagawa, Izumi; Hyakumachi, Takahiko; Yanagibashi, Yasushi; Nitta, Fumihito; Masuda, Takeshi

    2007-01-01

    The authors report the case of an 83-year-old woman with refractory sciatica attributable to isthmic spondylolisthesis at L-5. Her symptoms were successfully improved after posterior lumbar interbody fusion (PLIF) at L5-S1; however, notable swelling in her left leg suddenly developed 2 days postoperatively. Anterior migration of a fragment of bone graft was demonstrated on computed tomography scanning, and there was obvious occlusion of the left common iliac vein (CIV) on magnetic resonance venography. Ultrasonography revealed a thrombus in the left CIV at the site of compression. To prevent a pulmonary embolism during manipulation of the affected vein, an inferior vena cava filter was placed just before excision of the migrated bone fragment. The swelling in the patient's leg subsided quickly after the surgery, and she was treated with heparin and warfarin to prevent recurrent deep vein thrombosis (DVT). Six months after the second surgery, complete restoration of blood flow to the left CIV and no recurrence of DVT were demonstrated on magnetic resonance venography. Especially in elderly patients with degenerative disc disease, excessive curettage and impaction of disc materials during the PLIF procedure may cause migration of bone graft fragments. Surgeons should be aware of the possible vascular complications of PLIF.

  19. Total 3D Airo® Navigation for Minimally Invasive Transforaminal Lumbar Interbody Fusion

    PubMed Central

    Lian, Xiaofeng; Berlin, Connor; Moriguchi, Yu; Zhang, Qiwei; Härtl, Roger

    2016-01-01

    Introduction. A new generation of iCT scanner, Airo®, has been introduced. The purpose of this study is to describe how Airo facilitates minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF). Method. We used the latest generation of portable iCT in all cases without the assistance of K-wires. We recorded the operation time, number of scans, and pedicle screw accuracy. Results. From January 2015 to December 2015, 33 consecutive patients consisting of 17 men and 16 women underwent single-level or two-level MIS-TLIF operations in our institution. The ages ranged from 23 years to 86 years (mean, 66.6 years). We treated all the cases in MIS fashion. In four cases, a tubular laminectomy at L1/2 was performed at the same time. The average operation time was 192.8 minutes and average time of placement per screw was 2.6 minutes. No additional fluoroscopy was used. Our screw accuracy rate was 98.6%. No complications were encountered. Conclusions. Airo iCT MIS-TLIF can be used for initial planning of the skin incision, precise screw, and cage placement, without the need for fluoroscopy. “Total navigation” (complete intraoperative 3D navigation without fluoroscopy) can be achieved by combining Airo navigation with navigated guide tubes for screw placement. PMID:27529069

  20. Assessment and classification of subsidence after lateral interbody fusion using serial computed tomography.

    PubMed

    Malham, Gregory M; Parker, Rhiannon M; Blecher, Carl M; Seex, Kevin A

    2015-07-24

    OBJECT Intervertebral cage settling during bone remodeling after lumbar lateral interbody fusion (LIF) is a common occurrence during the normal healing process. Progression of this settling with endplate collapse is defined as subsidence. The purposes of this study were to 1) assess the rate of subsidence after minimally invasive (MIS) LIF by CT, 2) distinguish between early cage subsidence (ECS) and delayed cage subsidence (DCS), 3) propose a descriptive method for classifying the types of subsidence, and 4) discuss techniques for mitigating the risk of subsidence after MIS LIF. METHODS A total of 128 consecutive patients (with 178 treated levels in total) underwent MIS LIF performed by a single surgeon. The subsidence was deemed to be ECS if it was evident on postoperative Day 2 CT images and was therefore the result of an intraoperative vertebral endplate injury and deemed DCS if it was detected on subsequent CT scans (≥ 6 months postoperatively). Endplate breaches were categorized as caudal (superior endplate) and/or cranial (inferior endplate), and as ipsilateral, contralateral, or bilateral with respect to the side of cage insertion. Subsidence seen in CT images (radiographic subsidence) was measured from the vertebral endplate to the caudal or cranial margin of the cage (in millimeters). Patient-reported outcome measures included visual analog scale, Oswestry Disability Index, and 36-Item Short Form Health Survey physical and mental component summary scores. RESULTS Four patients had ECS in a total of 4 levels. The radiographic subsidence (DCS) rates were 10% (13 of 128 patients) and 8% (14 of 178 levels), with 3% of patients (4 of 128) exhibiting clinical subsidence. In the DCS levels, 3 types of subsidence were evident on coronal and sagittal CT scans: Type 1, caudal contralateral, in 14% (2 of 14), Type 2, caudal bilateral with anterior cage tilt, in 64% (9 of 14), and Type 3, both endplates bilaterally, in 21% (3 of 14). The mean subsidence in the DCS

  1. Minimally Invasive Extraforaminal Lumbar Interbody Fusion for Revision Surgery: A Technique through Kambin's Triangle

    PubMed Central

    Lee, Jun Gue; Kim, Hyeun Sung

    2015-01-01

    Objective The purpose of this study was to evaluate the clinical outcomes of minimally invasive extraforaminal lumbar interbody fusion (ELIF) for revision surgery. Methods From January 2011 to December 2012, 12 patients who underwent minimally invasive ELIF through the Kambin's triangle for revision surgery were included in this study. All patients underwent the surgical procedure in the following sequence: (1) epidural anesthesia, (2) exposing the Kambin's triangle toward the lateral part of the dura (partial resection of the superior articular process), (3) bilateral cage insertion for reinforcement of stabilization and fusion, and (4) percutaneous transpedicular screwing. Clinical outcomes were assessed using the visual analogue scale (VAS), and Oswestry disability index (ODI). Imaging and clinical findings including surgical techniques, clinical outcomes, and related complications were depicted and analyzed. Results The mean age of the patients (5 men, 7 women) was 60.7±13.4 years, and the mean follow-up period was 27.1±4.9 months. The mean VAS (back and leg) score improved significantly at final follow-up. The mean ODI score decreased as follows: preoperative, 76.78±6.08; 3 months after the surgery, 37.74±6.67; and at final follow-up, 29.91±2.98. Two patients presented with transient nerve root irritation, but there were no cases of incidental dural tear or serious infection. No significant neurological deterioration or major complication was noted in any of the patients. Conclusion Minimally invasive ELIF for revision surgery is an effective surgical option with a low complication rate. PMID:26834815

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

    PubMed Central

    Hee, Hwan Tak

    2015-01-01

    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. PMID:25901228

  3. Extreme lateral lumbar interbody fusion. Surgical technique, outcomes and complications after a minimum of one year follow-up.

    PubMed

    Domínguez, I; Luque, R; Noriega, M; Rey, J; Alia, J; Marco-Martínez, F

    «Minimally invasive» techniques have been recently been developed in order to achieve good clinical results with a low incidence of complications. The extralateral interbody fusion or direct transpsoas is a minimally invasive anterior arthrodesis. A total of 97 patients with 138 segments received surgery between May 2012 and May 2015. The follow-up was from 12-44 months. The mean age was 68 years (41-86). The most common cause of intervention was the adjacent segment (30%), deformity (22%), and lumbar disc disease (21%). The interbody cage was implanted as: Single (stand-alone) in 33%, and additional fixation was used in the others: Screws, percutaneous unilateral (11%), bilateral (27%), or with a lateral plate (62%). The mean stay was 3.2 days (2-6). The score on a lumbar visual analogue scale decreased from 9 to 4.1, and dropped to 3 after one year. The improvement in disc height was from 8.4mm to 13.8mm, and a larger increase in the foramen diameter from 10.5 to 13.1mm, which were statistically significant. The early major complications recorded were, three motor femoral nerve injuries and retroperitoneal haematoma (4%), and the early minor were: two fractures (2%). As major late complications there was an abdominal hernia, a mobilization of 10mm and three radiculopathy (5%), and as minor late, three fracture, two mobilisations greater than 10mm, four mobilisations of less than 10mm, and one mobilisation of a screw plate (10%). The extralateral interbody fusion technique is a safe and reliable when performing a lumbar fusion by an alternative minimally invasive route.

  4. Utility of multilevel lateral interbody fusion of the thoracolumbar coronal curve apex in adult deformity surgery in combination with open posterior instrumentation and L5-S1 interbody fusion: a case-matched evaluation of 32 patients.

    PubMed

    Theologis, Alexander A; Mundis, Gregory M; Nguyen, Stacie; Okonkwo, David O; Mummaneni, Praveen V; Smith, Justin S; Shaffrey, Christopher I; Fessler, Richard; Bess, Shay; Schwab, Frank; Diebo, Bassel G; Burton, Douglas; Hart, Robert; Deviren, Vedat; Ames, Christopher

    2017-02-01

    OBJECTIVE The aim of this study was to evaluate the utility of supplementing long thoracolumbar posterior instrumented fusion (posterior spinal fusion, PSF) with lateral interbody fusion (LIF) of the lumbar/thoracolumbar coronal curve apex in adult spinal deformity (ASD). METHODS Two multicenter databases were evaluated. Adults who had undergone multilevel LIF of the coronal curve apex in addition to PSF with L5-S1 interbody fusion (LS+Apex group) were matched by number of posterior levels fused with patients who had undergone PSF with L5-S1 interbody fusion without LIF (LS-Only group). All patients had at least 2 years of follow-up. Percutaneous PSF and 3-column osteotomy (3CO) were excluded. Demographics, perioperative details, radiographic spinal deformity measurements, and HRQoL data were analyzed. RESULTS Thirty-two patients were matched (LS+Apex: 16; LS: 16) (6 men, 26 women; mean age 63 ± 10 years). Overall, the average values for measures of deformity were as follows: Cobb angle > 40°, sagittal vertical axis (SVA) > 6 cm, pelvic tilt (PT) > 25°, and mismatch between pelvic incidence (PI) and lumbar lordosis (LL) > 15°. There were no significant intergroup differences in preoperative radiographic parameters, although patients in the LS+Apex group had greater Cobb angles and less LL. Patients in the LS+Apex group had significantly more anterior levels fused (4.6 vs 1), longer operative times (859 vs 379 minutes), and longer length of stay (12 vs 7.5 days) (all p < 0.01). For patients in the LS+Apex group, Cobb angle, pelvic tilt (PT), lumbar lordosis (LL), PI-LL (lumbopelvic mismatch), Oswestry Disability Index (ODI) scores, and visual analog scale (VAS) scores for back and leg pain improved significantly (p < 0.05). For patients in the LS-Only group, there were significant improvements in Cobb angle, ODI score, and VAS scores for back and leg pain. The LS+Apex group had better correction of Cobb angles (56% vs 33%, p = 0.02), SVA (43% vs 5%, p = 0

  5. BMP-2-induced Neuroforaminal Bone Growth in the Setting of a Minimally Invasive Transforaminal Lumbar Interbody Fusion.

    PubMed

    Ahn, Junyoung; Tabaraee, Ehsan; Singh, Kern

    2015-06-01

    Minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) has become a popular alternative to traditional methods of lumbar decompression and fusion. When compared with the open technique, the minimally invasive approach can result in decreased pain and blood loss as well as a shorter length of hospitalization. However, the narrower working channel through the tubular retractor increases the difficulty of decortication and bone grafting. Therefore, recombinant human bone morphogenetic proteins (rhBMP-2) is often utilized (although this is off-label) to create a more favorable interbody fusion environment. Recently, the use of rhBMP-2 has been associated with excessive bone growth in an MIS-TLIF. If this bone growth compresses the neighboring neural structures, patients may present with either new or recurrent radicular pain. Computed tomographic (CT) imaging can demonstrate heterotopic bone growth extending from the disk space into either the ipsilateral neuroforamen or lateral recess, which may result in the compression of the exiting or traversing root, respectively. The purpose of this article and the accompanying video is to demonstrate a technique for defining and resecting rhBMP-2-induced heterotopic bone growth following a previous MIS-TLIF.

  6. Evaluation of a novel tool for bone graft delivery in minimally invasive transforaminal lumbar interbody fusion

    PubMed Central

    Kleiner, Jeffrey B; Kleiner, Hannah M; Grimberg, E John; Throlson, Stefanie J

    2016-01-01

    Study design Disk material removed (DMR) during L4-5 and L5-S1 transforaminal lumbar interbody fusion (T-LIF) surgery was compared to the corresponding bone graft (BG) volumes inserted at the time of fusion. A novel BG delivery tool (BGDT) was used to apply the BG. In order to establish the percentage of DMR during T-LIF, it was compared to DMR during anterior diskectomy (AD). This study was performed prospectively. Summary of background data Minimal information is available as to the volume of DMR during a T-LIF procedure, and the relationship between DMR and BG delivered is unknown. BG insertion has been empiric and technically challenging. Since the volume of BG applied to the prepared disk space likely impacts the probability of arthrodesis, an investigation is justified. Methods A total of 65 patients with pathology at L4-5 and/or L5-S1 necessitating fusion were treated with a minimally invasive T-LIF procedure. DMR was volumetrically measured during disk space preparation. BG material consisting of local autograft, BG extender, and bone marrow aspirate were mixed to form a slurry. BG slurry was injected into the disk space using a novel BGDT and measured volumetrically. An additional 29 patients who were treated with L5-S1 AD were compared to L5-S1 T-LIF DMR to determine the percent of T-LIF DMR relative to AD. Results DMR volumes averaged 3.6±2.2 mL. This represented 34% of the disk space relative to AD. The amount of BG delivered to the disk spaces was 9.3±3.2 mL, which is 2.6±2.2 times the amount of DMR. The BGDT allowed uncomplicated filling of the disk space in <1 minute. Conclusion The volume of DMR during T-LIF allows for a predictable volume of BG delivery. The BGDT allowed complete filling of the entire prepared disk space. The T-LIF diskectomy debrides 34% of the disk relative to AD. PMID:27274320

  7. Predisposing Factors for Intraoperative Endplate Injury of Extreme Lateral Interbody Fusion

    PubMed Central

    Kanemura, Tokumi; Yamaguchi, Hidetoshi; Segi, Naoki; Ouchida, Jun

    2016-01-01

    Study Design Retrospective study. Purpose To compare intraoperative endplate injury cases and no injury cases in consecutive series and to identify predisposing factors for intraoperative endplate injury. Overview of Literature Unintended endplate violation and subsequent cage subsidence is an intraoperative complication of extreme lateral interbody fusion (XLIF). It is still unknown whether it is derived from inexperienced surgical technique or patients' inherent problems. Methods Consecutive patients (n=102; mean age, 69.0±0.8 years) underwent XLIF at 201 levels at a single institute. Preoperative and immediately postoperative radiographs were compared and cases with intraoperative endplate injury were identified. Various parameters were reviewed in each patient and compared between the injury and no injury groups. Results Twenty one levels (10.4%) had signs of intraoperative endplate injury. The injury group had a significantly higher rate of females (p=0.002), lower bone mineral density (BMD) (p=0.02), higher rate of polyetheretherketone as cage material (p=0.04), and taller cage height (p=0.03) compared with the no injury group. Multivariate analysis indicated that a T-score of BMD as a negative (odds ratio, 0.52; 95% confidence interval, 0.27–0.93; p=0.03) and cage height as a positive (odds ratio, 1.84; 95% confidence interval, 1.01–3.17; p=0.03) were predisposing factors for intraoperative endplate injury. Conclusions Intraoperative endplate injury is correlated significantly with reduced BMD and taller cage height. Precise evaluation of bone quality and treatment for osteoporosis might be important and care should be taken not to choose excessively taller cage. PMID:27790319

  8. Comparison of the Dynesys Dynamic Stabilization System and Posterior Lumbar Interbody Fusion for Lumbar Degenerative Disease

    PubMed Central

    Zhang, Yang; Shan, Jian-Lin; Liu, Xiu-Mei; Li, Fang; Guan, Kai; Sun, Tian-Sheng

    2016-01-01

    Background There have been few studies comparing the clinical and radiographic outcomes between the Dynesys dynamic stabilization system and posterior lumbar interbody fusion (PLIF). The objective of this study is to compare the clinical and radiographic outcomes of Dynesys and PLIF for lumbar degenerative disease. Methods Of 96 patients with lumbar degenerative disease included in this retrospectively analysis, 46 were treated with the Dynesys system and 50 underwent PLIF from July 2008 to March 2011. Clinical and radiographic outcomes were evaluated. We also evaluated the occurrence of radiographic and symptomatic adjacent segment degeneration (ASD). Results The mean follow-up time in the Dynesys group was 53.6 ± 5.3 months, while that in the PLIF group was 55.2 ± 6.8 months. At the final follow-up, the Oswestry disability index and visual analogue scale score were significantly improved in both groups. The range of motion (ROM) of stabilized segments in Dynesys group decreased from 7.1 ± 2.2° to 4.9 ± 2.2° (P < 0.05), while that of in PLIF group decreased from 7.3 ± 2.3° to 0° (P < 0.05). The ROM of the upper segments increased significantly in both groups at the final follow-up, the ROM was higher in the PLIF group. There were significantly more radiographic ASDs in the PLIF group than in the Dynesys group. The incidence of complications was comparable between groups. Conclusions Both Dynesys and PLIF can improve the clinical outcomes for lumbar degenerative disease. Compared to PLIF, Dynesys stabilization partially preserves the ROM of the stabilized segments, limits hypermobility in the upper adjacent segment, and may prevent the occurrence of ASD. PMID:26824851

  9. Do Trunk Muscles Affect the Lumbar Interbody Fusion Rate?: Correlation of Trunk Muscle Cross Sectional Area and Fusion Rates after Posterior Lumbar Interbody Fusion Using Stand-Alone Cage

    PubMed Central

    Choi, Man Kyu; Park, Bong Jin; Park, Chang Kyu; Kim, Sung Min

    2016-01-01

    Objective Although trunk muscles in the lumbar spine preserve spinal stability and motility, little is known about the relationship between trunk muscles and spinal fusion rate. The aim of the present study is to evaluate the correlation between trunk muscles cross sectional area (MCSA) and fusion rate after posterior lumbar interbody fusion (PLIF) using stand-alone cages. Methods A total of 89 adult patients with degenerative lumbar disease who were performed PLIF using stand-alone cages at L4–5 were included in this study. The cross-sectional area of the psoas major (PS), erector spinae (ES), and multifidus (MF) muscles were quantitatively evaluated by preoperative lumbar magnetic resonance imaging at the L3–4, L4–5, and L5–S1 segments, and bone union was evaluated by dynamic lumbar X-rays. Results Of the 89 patients, 68 had bone union and 21 did not. The MCSAs at all segments in both groups were significantly different (p<0.05) for the PS muscle, those at L3–4 and L4–5 segments between groups were significantly different (p=0.048, 0.021) for the ES and MF muscles. In the multivariate analysis, differences in the PS MCSA at the L4–5 and L5–S1 segments remained significant (p=0.048, 0.043 and odds ratio=1.098, 1.169). In comparison analysis between male and female patients, most MCSAs of male patients were larger than female's. Fusion rates of male patients (80.7%) were higher than female's (68.8%), too. Conclusion For PLIF surgery, PS muscle function appears to be an important factor for bone union and preventing back muscle injury is essential for better fusion rate. PMID:27226860

  10. Particular Features of Surgical Site Infection in Posterior Lumbar Interbody Fusion

    PubMed Central

    Kim, Jin Hak; Kim, Jin Woo; Kim, Go We

    2015-01-01

    Background Previous reports have observed differences only in infection rates between posterolateral fusion and posterior lumbar interbody fusion (PLIF). There have been no reports that describe the particular features of surgical site infection (SSI) in PLIF. In this study, we endeavor to identify the distinguishing characteristics and risk factors of SSI in PLIF. Methods Our study undertook a review of a case series of an institute. Patients who had undergone PLIF consecutively in the author's hospital were reviewed. Two proactive procedures were introduced during the study period. One was irrigation of the autolocal bone, and the other was the intradiscal space irrigation with a nozzle. Infection rate and risk factors were analyzed. For subgroup analysis, the elapsed time to a diagnosis (ETD), clinical manifestations, hematologic findings, and causative bacteria were examined in patients with SSI. Results In a total of 1,831 cases, there were 30 cases of SSI (1.6%). Long operation time was an independent risk factor (p = 0.008), and local bone irrigation was an independent protective factor (p = 0.001). Two cases of referred SSI were included in the subgroup analysis. There were 6/32 (19%) superficial incisional infections (SII), 6/32 (19%) deep incisional infections (DII), and 20/32 (62%) organ/space infections (O/SI). The difference of incidence among three groups was significant (p = 0.002).The most common bacteria encountered were methicillin-resistant Staphylococcus epidermidis followed by methicillin-resistant S. aureus in incisional infections, and no growth followed by S. epidermidis in O/SI. ETD was 8.5 ± 2.3 days in SII, 8.7 ± 2.3 days in DII and 164.5 ± 131.1 days in O/SI (p = 0.013). Conclusions The rate of SSI in PLIF was 1.6%, with the most common type being O/SI. The causative bacteria of O/SI was of lower virulence than in the incisional infection, and thus diagnosis was delayed due to its latent and insidious feature. Contamination of auto

  11. How does back muscle strength change after posterior lumbar interbody fusion?

    PubMed

    Lee, Chong-Suh; Kang, Kyung-Chung; Chung, Sung-Soo; Park, Won-Hah; Shin, Won-Ju; Seo, Yong-Gon

    2017-02-01

    OBJECTIVE There is a lack of evidence of how back muscle strength changes after lumbar fusion surgery and how exercise influences these changes. The aim of this study was to evaluate changes in back muscle strength after posterior lumbar interbody fusion (PLIF) and to measure the effects of a postoperative exercise program on muscle strength and physical and mental health outcomes. METHODS This prospective study enrolled 59 women (mean age 58 years) who underwent PLIF at 1 or 2 spinal levels. To assess the effects of a supervised lumbar stabilization exercise (LSE), the authors allocated the patients to an LSE (n = 26) or a control (n = 33) group. The patients in the LSE group performed the LSEs between 3 and 6 months postoperatively. Back extensor strength, visual analog scale (VAS) scores in back pain, and physical component summary (PCS) and mental component summary (MCS) scores on the 36-Item Short Form Health Survey were determined for the both groups. RESULTS Mean strength of the back muscles tended to slightly decrease by 7.5% from preoperatively to 3 months after PLIF (p = 0.145), but it significantly increased thereafter and was sustained until the last follow-up (38.1%, p < 0.001). The mean back muscle strength was similar in the LSE and control groups preoperatively, but it increased significantly more in the LSE group (64.2%) than in the control group (21.7%) at the last follow-up 12 months after PLIF (p = 0.012). At the last follow-up, decreases in back pain VAS scores were more significant among LSE group patients, who had a pain reduction on average of 58.2%, than among control group patients (reduction of 26.1%) (p = 0.013). The patients in the LSE group also had greater improvement in both PCS (39.9% improvement) and MCS (20.7% improvement) scores than the patients in the control group (improvement of 18.0% and 1.1%, p = 0.042 and p = 0.035, respectively). CONCLUSIONS After PLIF, strength in back muscles decreased until 3 months postoperatively but

  12. One-stage removal of a large dumb-bell-shaped cervical neurinoma without laminectomy or interbody fusion in a child.

    PubMed

    Ryu, H; Nishizawa, S; Yamamoto, S

    1999-12-01

    A 12-year-old boy had a large dumb-bell-shaped cervical neurinoma originating at the C5 spinal root that was removed in a one-stage operation through the enlarged C4/5 intervertebral foramen. This technique required no laminectomy, discectomy or interbody fusion, which may frequently produce spinal deformity in children.

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

    PubMed

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

    2010-02-01

    Degenerative disc disease (DDD) causes gradual intervertebral space collapse, concurrent discogenic or facet-induced pain, and possible compression radiculopathy. A new minimal invasion procedure of percutaneous posterior-lateral lumbar interbody fusion (PPLIF) using a B-Twin stand-alone expandable spinal spacer (ESS) was designed to treat this disease and evaluated by follow-up more than 1 year. 12 cases with chronic low back pain and compressive radiculopathy due to DDD refractory were selected to conservative treatment. Under fluoroscopy in the posterior-lateral position, a K-wire was advanced into the intervertebral space and a dilator and working cannula were introduced into the disc space step by step. Discectomy and endplate scratching were performed through the cannula using pituitary forceps and endplate curettage. An ESS was inserted into the intervertebral space by a B-Twin expandable spinal delivery system after some bone graft chips implanted into the disc space. The ongoing study includes intraoperative difficulties, complications, radiologic evidence of fusion and clinical outcome as scored by pre- and postoperative questionnaires pertaining to pain intensity and degree of disability. The 12 procedures of lumbar interbody fusion using stand-alone expandable spinal system through percutaneous approach were successful. Radiologic study demonstrated fusion in a total of 11 cases and only 1 exception after more than 1 year visiting. The values of Visual Analog Scale (VAS) on movement and Oswestry Disability Index (ODI) dropped by more than 80 and 67.4%, respectively. Disk space heights averaging 9.0 mm before procedure were increased to 11.5 mm 1 month (a significant difference compared with preprocedure, P < 0.01) after surgery and stabilized at 10.8 mm upon final follow-up (a significant difference compared with preprocedure, P < 0.01). The results demonstrated that the percutaneous approach for posterior-lateral lumbar interbody fusion using

  14. Anterior cervical fusion with interbody cage containing beta-tricalcium phosphate augmented with plate fixation: a prospective randomized study with 2-year follow-up.

    PubMed

    Dai, Li-Yang; Jiang, Lei-Sheng

    2008-05-01

    A variety of bone graft substitutes, interbody cages, and anterior plates have been used in cervical interbody fusion, but no controlled study was conducted on the clinical performance of beta-tricalcium phosphate (beta-TCP) and the effect of supplemented anterior plate fixation. The objective of this prospective, randomized clinical study was to evaluate the effectiveness of implanting interbody fusion cage containing beta-TCP for the treatment of cervical radiculopathy and/or myelopathy, and the fusion rates and outcomes in patients with or without randomly assigned plate fixation. Sixty-two patients with cervical radiculopathy and/or myelopathy due to soft disc herniation or spondylosis were treated with one- or two-level discectomy and fusion with interbody cages containing beta-TCP. They were randomly assigned to receive supplemented anterior plate (n = 33) or not (n = 29). The patients were followed up for 2 years postoperatively. The radiological and clinical outcomes were assessed during a 2-year follow-up. The results showed that the fusion rate (75.0%) 3 months after surgery in patients treated without anterior cervical plating was significantly lower than that (97.9%) with plate fixation (P < 0.05), but successful bone fusion was achieved in all patients of both groups at 6-month follow-up assessment. Patients treated without anterior plate fixation had 11 of 52 (19.2%) cage subsidence at last follow-up. No difference (P > 0.05) was found regarding improvement in spinal curvature as well as neck and arm pain, and recovery rate of JOA score at all time intervals between the two groups. Based on the findings of this study, interbody fusion cage containing beta-TCP following one- or two-level discectomy proved to be an effective treatment for cervical spondylotic radiculopathy and/or myelopathy. Supplemented anterior plate fixation can promote interbody fusion and prevent cage subsidence but do not improve the 2-year outcome when compared with those treated

  15. Comparison of outcomes between minimally invasive transforaminal lumbar interbody fusion and traditional posterior lumbar intervertebral fusion in obese patients with lumbar disk prolapse

    PubMed Central

    Wang, Ya-Peng; An, Ji-Long; Sun, Ya-Peng; Ding, Wen-Yuan; Shen, Yong; Zhang, Wei

    2017-01-01

    Objective The aim of this study was to compare the curative effect between minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) and the posterior lumbar interbody fusion (PLIF) in obese patients with lumbar disk prolapse. Patients and methods In this study, 72 patients who underwent lumbar disk prolapse therapy in the Third Hospital of Hebei Medical University between March 2011 and 2015 were retrospectively analyzed and were divided into two groups, MIS-TLIF group (n=35) and PLIF group (n=37), according to different surgical procedures. Several clinical parameters were compared between these two groups. Results Compared with PLIF, MIS-TLIF was associated with longer operative time, less blood loss, less postoperative drainage and shorter postoperative time in bed; moreover, patients in the MIS-TLIF group had lower levels of serum creatine kinase on 1, 3 and 5 postoperative days. At the 3- and 6-month follow-up, Visual Analog Scale (VAS) scores of low back pain of patients in the MIS-TLIF group were significantly reduced and Japanese Orthopaedic Association (JOA) scores were increased, whereas the Oswestry Disability Index (ODI) showed no significant difference between the two groups. Conclusion Obese patients can achieve good efficacy with MIS-TLIF or PLIF treatment, but MIS-TLIF surgery showed longer operative time, fewer traumas and bleeding volume, less incidence of short-term pain, low complication rate and faster postoperative recovery. PMID:28176906

  16. Interbody Fusion in Low Grade Lumbar Spondylolsithesis: Clinical Outcome Does Not Correalte with Slip Reduction and Neural Foraminal Dimension

    PubMed Central

    Chatterjee, Atanu; McConnell, Jeffrey R.; Jha, Deepak K.; Chakraburtty, Tapas

    2016-01-01

    Study Design Prospective nonrandomized study. Purpose To find a possible correlation between clinical outcome and extent of lumbar spondylolisthesis reduction. Overview of Literature There is no consensus in the literature concerning whether a beneficial effect of reduction on outcome can be expected following reduction and surgical fusion for low grade lumbar spondylolisthesis. Methods Forty six patients with a mean age of 37.5 years (age, 17–48 years) with isthmic spondylolisthesis underwent interbody fusion with cages with posterior instrumentation (TLIF). Clinical outcome was measured using visual analogue score (VAS) and Oswestry disability index (ODI). Foraminal dimensions and disc heights were measured in standard digital radiographs. These were analyzed at baseline and 1 year after surgery and changes were compared. Radiographic fusion was judged with computed tomography scans at 1 year. Results Ninety percent of the patients had good or very good clinical results with fusion and instrumentation. Baseline and one-year postoperative mean VAS score was 6.33 (range, 5–8) and 0.76 (range, 0–3), respectively (p=0.004). Baseline and one-year postoperative, mean ODI score was 48 (range, 32–62) and 10 (range, 6–16), respectively (p<0.001). A mean spondylolisthesis slip of 32.1% was reduced to 6.7% at 1 year. Average anterior disc height, posterior disc height, vertical foraminal dimension), and foraminal) diameter improved from 9.8 to 11.7 mm (p=0.005), 4.5 to 5.8 mm (p=0.004), 11.3 to 12.6 mm (p=0.002), and 18.6 to 20.0 mm (p<0.001), respectively. The fusion rate was 75% with TLIF. There is no significant correlation between the improvements of ODI scores and the extent of slip reduction. Conclusions Neural decompression and interbody fusion can significantly improve pain and disability but the clinical outcome does not correlate with radiological improvement in the neural foraminal dimension. PMID:27114773

  17. Anatomy of the psoas muscle and lumbar plexus with respect to the surgical approach for lateral transpsoas interbody fusion.

    PubMed

    Kepler, Christopher K; Bogner, Eric A; Herzog, Richard J; Huang, Russel C

    2011-04-01

    Lateral transpsoas interbody fusion (LTIF) is a minimally invasive technique that permits interbody fusion utilizing cages placed via a direct lateral retroperitoneal approach. We sought to describe the locations of relevant neurovascular structures based on MRI with respect to this novel surgical approach. We retrospectively reviewed consecutive lumbosacral spine MRI scans in 43 skeletally mature adults. MRI scans were independently reviewed by two readers to identify the location of the psoas muscle, lumbar plexus, femoral nerve, inferior vena cava and right iliac vein. Structures potentially at risk for injury were identified by: a distance from the anterior aspect of the adjacent vertebral bodies of <20 mm, representing the minimum retraction necessary for cage placement, and extension of vascular structures posterior to the anterior vertebral body, requiring anterior retraction. The percentage of patients with neurovascular structures at risk for left-sided approaches was 2.3% at L1-2, 7.0% at L2-3, 4.7% at L3-4 and 20.9% at L4-5. For right-sided approaches, this rose to 7.0% at L1-2, 7.0% at L2-3, 9.3% at L3-4 and 44.2% at L4-5, largely because of the relatively posterior right-sided vasculature. A relationship between the position of psoas muscle and lumbar plexus is described which allows use of the psoas position as a proxy for lumbar plexus position to identify patients who may be at risk, particularly at the L4-5 level. Further study will establish the clinical relevance of these measurements and the ability of neurovascular structures to be retracted without significant injury.

  18. High neurological complication rates for extreme lateral lumbar interbody fusion and related techniques: A review of safety concerns

    PubMed Central

    Epstein, Nancy E.

    2016-01-01

    Background: There are frequent reports of lumbosacral plexus and other neurological injuries occurring with extreme lateral interbody fusions (XLIF) and other related lateral lumbar techniques. Methods: This review focuses on the new neurological deficits (e.g. lumbosacral plexus, root injuries) that occur following minimally invasive surgery (MIS) XLIF and other related lateral lumbar techniques. Results: A review of multiple articles revealed the following ranges of new postoperative neurological complications for XLIF procedures: plexus injuries 13.28%; sensory deficits 0–75% (permanent in 62.5%); motor deficits 0.7–33.6%; anterior thigh pain 12.5–25%. Of interest, in a study by Lykissas et al., the frequency of long-term neural injury following lateral lumber interbody fusion (LLIF) with BMP-2 (72 patients) was much higher than for LLIF performed with autograft/allograft (72 patients). The addition of bone morphogenetic protein led to persistent sensory deficits in 29 vs. 20 without BMP; persistent motor deficits in 35 with vs. 17 without BMP; and persistent anterior thigh/groin pain in 8 with vs. 0 without BMP. They should also have noted the unacceptably high incidence of neural injury occurring with LLIF alone without BMP. Conclusion: This review highlights the high risk of neural injury (up to 75% for sensory, 33.6% for motor, and an overall plexus injury rate of 13.28%) utilizing the XLIF and other similar lateral lumbar approaches. With such extensive neurological injuries, is the XLIF really safe, and should it still be performed? PMID:27843679

  19. Yemen's light, sweet Alif crude assayed

    SciTech Connect

    Rhodes, A.K.

    1994-05-23

    Crude oil from Yemen's Alif field has been assayed. The light sweet crude, also known as Marib, is part of the Marib al-Jawf concession in northern Yemen. Alif field was discovered in 1984 by Hunt Oil Co. The field was declared commercial in November 1985. Alif production averaged 118,500 b/d in 1992. Physical and chemical properties are listed for the whole crude and its fractions.

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

    PubMed

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

    2014-01-01

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

  1. Minimally Invasive Transforaminal Lumbar Interbody Fusion at L5-S1 through a Unilateral Approach: Technical Feasibility and Outcomes

    PubMed Central

    Choi, Won-Suh; Kim, Jin-Sung; Ryu, Kyeong-Sik; Hur, Jung-Woo; Seong, Ji-Hoon

    2016-01-01

    Background. Minimally invasive spinal transforaminal lumbar interbody fusion (MIS-TLIF) at L5-S1 is technically more demanding than it is at other levels because of the anatomical and biomechanical traits. Objective. To determine the clinical and radiological outcomes of MIS-TLIF for treatment of single-level spinal stenosis low-grade isthmic or degenerative spondylolisthesis at L5-S1. Methods. Radiological data and electronic medical records of patients who underwent MIS-TLIF between May 2012 and December 2014 were reviewed. Fusion rate, cage position, disc height (DH), disc angle (DA), disc slope angle, segmental lordotic angle (SLA), lumbar lordotic angle (LLA), and pelvic parameters were assessed. For functional assessment, the visual analogue scale (VAS), Oswestry disability index (ODI), and patient satisfaction rate (PSR) were utilized. Results. A total of 21 levels in 21 patients were studied. DH, DA, SLA, and LLA had increased from their preoperative measures at the final follow-up. Fusion rate was 86.7% (18/21) at 12 months' follow-up. The most common cage position was anteromedial (15/21). The mean VAS scores for back and leg pain mean ODI scores improved significantly at the final follow-up. PSR was 88%. Cage subsidence was observed in 33.3% (7/21). Conclusions. The clinical and radiologic outcomes after MIS-TLIF at L5-S1 in patients with spinal stenosis or spondylolisthesis are generally favorable. PMID:27433472

  2. Extreme lateral interbody fusion (XLIF): A single-center clinical and radiological follow-up study of 20 patients.

    PubMed

    Tessitore, Enrico; Molliqaj, Granit; Schaller, Karl; Gautschi, Oliver Pascal

    2017-02-01

    Extreme lateral interbody fusion (XLIF) is an alternative to standard posterior approaches for achieving fusion in the lumbar spine. It allows exposure of the lateral aspect of the lumbar disc through a lateral approach with the possibility to insert a wide footprint interbody cage as a stand-alone procedure or associated with a uni- or bilateral percutaneous fixation. This is a retrospective series of 20 consecutive patients operated with a XLIF procedure from 2014 to 2015. N=10 women and N=10 men with a mean age of 67.5years (range 37.9-81.2) were included in the study. N=18 patients have been operated at one level, while N=2 patients underwent a double-level XLIF. The index levels were: L2-L3 in 2, L3-L4 in 7, L4-L5 in 9 and L3-L5 in 2 patients, respectively. The mean clinico-radiological follow-up was 9.8months (range 2.5-16.6). The clinical outcome was assessed with the Oswestry Disability Index (ODI), Euro-Qol (EQ)-5D, visual analogue scale (VAS) and EQ-5D index scores. Preoperative, postoperative and follow-up sagittal balance was assessed by EOS full spine X-ray. Furthermore, presence or absence of fusion was assessed by thin cuts CT scan at the end of the follow-up. The analysis highlighted a clear clinical improvement for the study collective. The mean ODI improved from 41.6 preoperatively to 23.5 at the last follow-up (p<0.0036). EQ-5D VAS and EQ-5D index improved from 45.5 to 71.8 (p<0.0001) and from 0.454 to 0.693 (p<0.0002), respectively. Analysis of the sagittal balance revealed an increase of the total lumbar lordosis, however not in a statistically significant manner (p=0.164). Furthermore, an increase of 55.7% in mean disc height (from 7.0mm to 10.9mm) has been observed (p<0.0001). Surprisingly, the right foramen height was increased in a statistically significant manner compared to the left one, but both of them increased in absolute values. However, foraminal area on both sides did not significantly increase. The mean canal area was 115.7mm(2

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

    PubMed

    Staub, Blake N; Holman, Paul J

    2015-02-01

    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.

  4. Percutaneous Transforaminal Endoscopic Lumbar Interbody Fusion: Clinical and Radiological Results of Mean 46-Month Follow-Up

    PubMed Central

    Lee, Sang-Ho; Erken, H. Yener

    2017-01-01

    Background. Spinal fusion has been shown to be the preferred surgical option to reduce pain, recover function, and increase quality of life in the treatment of a variety of lumbar spinal disorders. The main goal of the present study is to report our clinical experience and results of percutaneous transforaminal endoscopic lumbar interbody fusion (PELIF) applications using the expandable spacer in a single institution. Methods. We performed a retrospective review of 18 patients with >12-month follow-up who had been operated on PELIF using expandable spacer from 2001 to 2007. Their clinical and radiological data were collected and analyzed. Results. The mean follow-up period was 46 months. The mean DH before the surgery was 8.3 mm which improved to 11.4 mm at the early postoperative period and regressed to 9.3 mm at the last follow-up visit. The VAS-B, VAS-L, and ODI scores at the last follow-up showed a 54%, 72%, and 69% improvement from the preoperative period, respectively. Conclusions. The presented PELIF technique with the expandable spacer seems to be a promising surgical technique for the treatment of a variety of lumbar spinal disorders. Conversely, radiological results including disc space subsidence make the stand-alone application of the expandable spacer debatable. PMID:28337448

  5. The Negligible Influence of Chronic Obesity on Hospitalization, Clinical Status, and Complications in Elective Posterior Lumbar Interbody Fusion

    PubMed Central

    Kombos, Theodoros; Bode, Frank

    2016-01-01

    Background. Posterior lumbar interbody fusion (PLIF) is a common surgical treatment for degenerative spinal instability, but many surgeons consider obesity a contraindication for elective spinal fusion. The aim of this study was to analyze whether obesity has any influence on hospitalization parameters, change in clinical status, or complications. Methods. In this prospective study, regression analysis was used to analyze the influence of the body mass index (BMI) on operating time, postoperative care, hospitalization time, type of postdischarge care, change in paresis or sensory deficits, pain level, wound complications, cerebrospinal fluid leakage, and implant complications. Results. Operating time increased only 2.5 minutes for each increase of BMI by 1. The probability of having a wound complication increased statistically with rising BMI. Nonetheless, BMI accounted for very little of the variation in the data, meaning that other factors or random chances play a much larger role. Conclusions. Obesity has to be considered a risk factor for wound complications in patients undergoing elective PLIF for degenerative instability. However, BMI showed no significant influence on other kinds of peri- or postoperative complications, nor clinical outcomes. So obesity cannot be considered a contraindication for elective PLIF. PMID:27478866

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

    PubMed

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

    2007-11-01

    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.

  7. Percutaneous Transforaminal Endoscopic Lumbar Interbody Fusion: Clinical and Radiological Results of Mean 46-Month Follow-Up.

    PubMed

    Lee, Sang-Ho; Erken, H Yener; Bae, Junseok

    2017-01-01

    Background. Spinal fusion has been shown to be the preferred surgical option to reduce pain, recover function, and increase quality of life in the treatment of a variety of lumbar spinal disorders. The main goal of the present study is to report our clinical experience and results of percutaneous transforaminal endoscopic lumbar interbody fusion (PELIF) applications using the expandable spacer in a single institution. Methods. We performed a retrospective review of 18 patients with >12-month follow-up who had been operated on PELIF using expandable spacer from 2001 to 2007. Their clinical and radiological data were collected and analyzed. Results. The mean follow-up period was 46 months. The mean DH before the surgery was 8.3 mm which improved to 11.4 mm at the early postoperative period and regressed to 9.3 mm at the last follow-up visit. The VAS-B, VAS-L, and ODI scores at the last follow-up showed a 54%, 72%, and 69% improvement from the preoperative period, respectively. Conclusions. The presented PELIF technique with the expandable spacer seems to be a promising surgical technique for the treatment of a variety of lumbar spinal disorders. Conversely, radiological results including disc space subsidence make the stand-alone application of the expandable spacer debatable.

  8. Posterolateral instrumented fusion with and without transforaminal lumbar interbody fusion for the treatment of adult isthmic spondylolisthesis: A randomized clinical trial with 2-year follow-up

    PubMed Central

    Etemadifar, Mohammad Reza; Hadi, Abdollah; Masouleh, Mehran Feizi

    2016-01-01

    Background: Spondylolisthesis is a common cause of surgery in patients with lower back pain. Although posterolateral fusion and pedicle screw fixation are a relatively common treatment method for the treatment of spondylolisthesis, controversy exists about the necessity of adding interbody fusion to posterolateral fusion. The aim of our study was to assess the functional disability, pain, and complications in patients with spondylolisthesis treated by posterolateral instrumented fusion (PLF) with and without transforaminal lumbar interbody fusion (TLIF) in a randomized clinical trial. Materials and Methods: From February 2007 to February 2011, 50 adult patients with spondylolisthesis were randomly assigned to be treated with PLF or PLF+TLIF techniques (25 patients in each group) by a single surgeon. Back pain, leg pain, and disability were assessed before treatment and until 2 years after surgical treatment using visual analog scale (VAS) and oswestry disability index (ODI). Patients were also evaluated for postoperative complications such as infection, neurological complications, and instrument failure. Results: All patients completed the 24 months of follow-up. Twenty patients were females and 30 were males. Average age of the patients was 53 ± 11 years for the PLF group and 51 ± 13 for the PLF + TLIF group. Back pain, leg pain, and disability score were significantly improved postoperatively compared to preoperative scores (P < 0.001). At 3 months of follow-up, there was no statistically significant difference in VAS score for back pain and leg pain in both groups; however, after 6 months and 1 year and 2 years follow-up, the reported scores for back pain and leg pain were significantly lower in the PLF+TLIF group (P < 0.05). The ODI score was also significantly lower in the PLF+TLIF group at 1 year and 2 years of follow-up (P < 0.05). One screw breakage and one superficial infection occurred in the PLF+TLIF group, which had no statistical significance (P = 0

  9. Full-endoscopic technique for anterior cervical discectomy and interbody fusion: 5-year follow-up results of 67 cases.

    PubMed

    Yao, Nuzhao; Wang, Cheng; Wang, Wenjun; Wang, Lushan

    2011-06-01

    With minimally invasive technique becoming more popular, endoscopic operations such as arthroscopy or laparoscopy have become the standard of care in several other areas. In this study, we evaluated the 5-year follow-up outcomes of anterior cervical (Ahn et al. in Photomed Laser Surg 23:362-368, 2005) discectomy and interbody fusion (ACDF) performed via endoscopic approach. Sixty-seven patients who underwent anterior cervical discectomy and cage fusion performed using endoscopic technique were followed for at least 5 years. We reviewed the clinical and radiographic records of these patients. The postoperative radiographic measures accessed were the anterior intervertebral height (AIH) and the lordosis angle (LDA). Clinical outcomes were determined using the previously validated Japanese Orthopaedic Association (JOA) and the pain visual analog scale (VAS). Patients included had a minimal follow-up period of 5 years and based on the outcomes criteria (JOA, VAS), 86.6% of patients reported excellent or good results. The AIH increased on average 18.7% of the original height (p < 0.01), and the LDA were more physiologic at final follow-up. Of the 67 cases, there was no segmental instability, and the bone fusion rate was 100%. One patient required revision open ACDF due to adjacent segment disc herniation 6 years postoperatively. There were no intraoperative complications, dysphasia or esophageal injury in this study group. It indicated endoscopic technique for ACDF can obtain satisfactory results in patients with cervical disc herniation, cervical myelopathy, or radiculopathy. Compared with a traditional approach, this technique may be associated with less morbidity while improving cosmesis and postoperative recovery. Prospective randomized control trials are needed to directly compare these two procedures.

  10. Clinical and radiological outcome of anterior–posterior fusion versus transforaminal lumbar interbody fusion for symptomatic disc degeneration: a retrospective comparative study of 133 patients

    PubMed Central

    Schwender, James D.; Safriel, Yair; Gilbert, Thomas J.; Mehbod, Amir A.; Denis, Francis; Transfeldt, Ensor E.; Wroblewski, Jill M.

    2009-01-01

    Abundant data are available for direct anterior/posterior spine fusion (APF) and some for transforaminal lumbar interbody fusion (TLIF), but only few studies from one institution compares the two techniques. One-hundred and thirty-three patients were retrospectively analyzed, 68 having APF and 65 having TLIF. All patients had symptomatic disc degeneration of the lumbar spine. Only those with one or two-level surgeries were included. Clinical chart and radiologic reviews were done, fusion solidity assessed, and functional outcomes determined by pre- and postoperative SF-36 and postoperative Oswestry Disability Index (ODI), and a satisfaction questionnaire. The minimum follow-up was 24 months. The mean operating room time and hospital length of stay were less in the TLIF group. The blood loss was slightly less in the TLIF group (409 vs. 480 cc.). Intra-operative complications were higher in the APF group, mostly due to vein lacerations in the anterior retroperitoneal approach. Postoperative complications were higher in the TLIF group due to graft material extruding against the nerve root or wound drainage. The pseudarthrosis rate was statistically equal (APF 17.6% and TLIF 23.1%) and was higher than most published reports. Significant improvements were noted in both groups for the SF-36 questionnaires. The mean ODI scores at follow-up were 33.5 for the APF and 39.5 for the TLIF group. The patient satisfaction rate was equal for the two groups. PMID:19125304

  11. Percutaneous Transforaminal Lumbar Interbody Fusion (pTLIF) with a Posterolateral Approach for the Treatment of Degenerative Disk Disease: Feasibility and Preliminary Results

    PubMed Central

    Morgenstern, Christian

    2015-01-01

    Background Interbody fusion by open discectomy is the usual treatment for degenerative disk disease but requires a relatively long recovery period. The transforaminal posterolateral approach is a well-known standard in endoscopic spine surgery that allows direct access to the disk with progressive tissue dilation. The aim of this study was to assess the feasibility of percutaneous transforaminal interbody fusion (pTLIF) with percutaneous insertion of an expandable or a standard rigid interbody implant for patients with degenerative disk disease with or without spondylolisthesis and for revision surgery with the endoscopic posterolateral approach. Methods Between 2009 and 2014, the pTLIF procedure was performed in 30 patients. Ten patients underwent insertion of a rigid implant (group A) and the remaining 20 underwent insertion of an expandable titanium interbody implant as the initial procedure (n = 10) (group B) or after failed back surgery (n = 10) (group C). Patient outcomes were scored with visual analogic scale (VAS), Oswestry disability index (ODI) and modified Macnab criteria. Results The mean follow-up period was 38 (17) (range 11 to 67) months. The outcome was excellent in 18, good in 10 and fair in 2. No poor results and no major complications were reported. No significant (p<0.05) differences in VAS and ODI scores according to the study group were found. Median postoperative time until hospital discharge was 26 hours (20 to 68 hours). Postoperative values for VAS and ODI scores improved significantly (p<0.05) compared to preoperative data in all study groups. Conclusions These preliminary results have shown the feasibility and efficacy of the pTLIF procedure using a percutaneous posterolateral approach for the treatment of degenerative disk disease with or without spondylolisthesis up to grade 2 and in revision surgery. No significant differences in outcome were observed between an expandable and a rigid cage. Median postoperative time until hospital

  12. Preserving Posterior Complex Can Prevent Adjacent Segment Disease following Posterior Lumbar Interbody Fusion Surgeries: A Finite Element Analysis

    PubMed Central

    Huang, Yun-Peng; Du, Cheng-Fei; Cheng, Cheng-Kung; Zhong, Zheng-Cheng; Chen, Xuan-Wei; Wu, Gui; Li, Zhe-Cheng; Ye, Jin-Duo; Lin, Jian-Hua; Wang, Li Zhen

    2016-01-01

    Objective To investigate the biomechanical effects of the lumbar posterior complex on the adjacent segments after posterior lumbar interbody fusion (PLIF) surgeries. Methods A finite element model of the L1–S1 segment was modified to simulate PLIF with total laminectomy (PLIF-LAM) and PLIF with hemilaminectomy (PLIF-HEMI) procedures. The models were subjected to a 400N follower load with a 7.5-N.m moment of flexion, extension, torsion, and lateral bending. The range of motion (ROM), intradiscal pressure (IDP), and ligament force were compared. Results In Flexion, the ROM, IDP and ligament force of posterior longitudinal ligament, intertransverse ligament, and capsular ligament remarkably increased at the proximal adjacent segment in the PLIF-LAM model, and slightly increased in the PLIF-HEMI model. There was almost no difference for the ROM, IDP and ligament force at L5-S1 level between the two PLIF models although the ligament forces of ligamenta flava remarkably increased compared with the intact lumbar spine (INT) model. For the other loading conditions, these two models almost showed no difference in ROM, IDP and ligament force on the adjacent discs. Conclusions Preserved posterior complex acts as the posterior tension band during PLIF surgery and results in less ROM, IDP and ligament forces on the proximal adjacent segment in flexion. Preserving the posterior complex during decompression can be effective on preventing adjacent segment degeneration (ASD) following PLIF surgeries. PMID:27870867

  13. Short-Term Results of Transforaminal Lumbar Interbody Fusion Using Pedicle Screw with Cortical Bone Trajectory Compared with Conventional Trajectory

    PubMed Central

    Miyakoshi, Naohisa; Hongo, Michio; Ishikawa, Yoshinori; Kudo, Daisuke; Shimada, Yoichi

    2015-01-01

    Study Design Case-control study. Purpose To evaluate clinical and radiological results of transforaminal lumbar interbody fusion (TLIF) performed with cortical bone trajectory (CBT) pedicle screw insertion with those of TLIF using 'conventional' or percutaneous pedicle screw insertion. Overview of Literature CBT is a new trajectory for pedicle screw insertion in the lumbar spine; clinical and radiological results of TLIF using pedicle screws inserted with CBT are unclear. Methods In total, 26 patients (11 males, 15 females) were enrolled in this retrospective study and divided into three groups: TLIF with pedicle screw insertion by conventional minimally invasive methods via the Wiltse approach (M-TLIF, n=10), TLIF with percutaneous pedicle screw insertion (P-TLIF, n=6), and TLIF with pedicle screw insertion with CBT (CBT-TLIF, n=10). Surgical results and preand postoperative radiological findings were evaluated and compared. Results Intraoperative blood loss was significantly less with CBT-TLIF (p=0.03) than with M-TLIF. Postoperative lordotic angles did not differ significantly among the three groups. Complete fusions were obtained in 10 of 12 levels (83%) with M-TLIF, in seven levels (100%) with P-TLIF, and in 10 of 11 levels (91%) with CBT-TLIF. On postoperative computed tomography, correct positioning was seen in 84.1% of M-TLIF screws, 88.5% of P-TLIF screws, and 90% of CBT-TLIF screws. Conclusions CBT-TLIF resulted in less blood loss and a shorter operative duration than M-TLIF or P-TLIF. Postoperative rates of bone union, maintenance of lordotic angles, and accuracy of pedicle screw positions were similar among the three groups. PMID:26097661

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

    PubMed Central

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

    2014-01-01

    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

  15. Microendoscopy-assisted minimally invasive transforaminal lumbar interbody fusion for lumbar degenerative disease: short-term and medium-term outcomes

    PubMed Central

    Yang, Yang; Liu, Bin; Rong, Li-Min; Chen, Rui-Qiang; Dong, Jian-Wen; Xie, Pei-Gen; Zhang, Liang-Ming; Feng, Feng

    2015-01-01

    Objective: To evaluate short-term and medium-term outcomes of microendoscopy-assisted minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) and open TLIF for lumbar degenerative disease. Methods: In this prospective, randomized control study, 50 cases received microendoscopy-assisted MIS-TLIF (MIS group), while another well-matched 50 cases accepted open TLIF (open group). Parameters between both groups, including surgical duration, intraoperative blood loss and radiologic exposure, postoperative analgesic usage and ambulatory time, visual analogue scale (VAS) for back and leg, functional scores, self-evaluation of surgical outcome (modified MacNab criteria), interbody fusion rate, adjacent segment degeneration (ASD) rate, as well as complication incidence were compared at 1 month and 24 months postoperatively. Results: Intraoperative blood loss and postoperative analgesic usage were significantly reduced in MIS group (P<0.05). Patients undergoing microendoscopy-assisted MIS-TLIF were able to ambulate earlier postoperatively than those receiving open TLIF (P<0.05). However, it showed prolonged surgical duration and enhanced radiologic exposure in MIS group (P<0.05). At 1 month postoperatively, MIS group was associated with more improvement of VAS and functional scores compared with open group (P<0.05). While at 24 months postoperatively, both groups revealed similar VAS and functional scores (P>0.05). Excellent and perfect scale rating by modified MacNab criteria, interbody fusion rate, ASD rate and complication incidence between both groups were nearly the same (P>0.05). Conclusions: Microendoscopy-assisted MIS-TLIF owns advantages of less iatrogenic injury, decreased blood loss, reduced analgesic usage and earlier rehabilitation, while it has drawbacks of more surgical duration and radiologic exposure. It is superior than open TLIF in terms of short-term clinical outcomes and has similar medium-term clinical outcomes. PMID:26885072

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

    PubMed Central

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

    2009-01-01

    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

  17. Fixation Strength of Caudal Pedicle Screws after Posterior Lumbar Interbody Fusion with the Modified Cortical Bone Trajectory Screw Method

    PubMed Central

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

    2016-01-01

    Study Design Clinical case series. Purpose In the posterior lumbar interbody fusion (PLIF) procedure in our institute, the cephalad screw trajectory follows a mediolateral and caudocephalad directed path according to the original cortical bone trajectory (CBT) method. However, the starting point of the caudal screw is at the medial border of the pedicle on an articular surface of the superior articular process, and the trajectory takes a mediolateral path parallel to the cephalad endplate. The incidence of caudal screw loosening after PLIF with this modified CBT screw method was investigated, and significant risk factors for caudal screw loosening were evaluated. Overview of Literature A biomechanical study of this modified caudal screw trajectory using the finite element method reported about a 20% increase in uniaxial yield pullout load compared with the traditional trajectory. However, there has been no clinical study concerning the fixation strength of this modified caudal screw trajectory. Methods The subjects were 193 consecutive patients who underwent single-level PLIF with modified CBT screw fixation. Caudal screw loosening was checked in computed tomography at 6 months after surgery, and screw loosening was defined as a radiolucency of 1 mm or more at the bone-screw interface. Results The incidence of caudal screw loosening after lumbosacral PLIF (46.2%) was significantly higher than that after floating PLIF (6.0%). No significant differences in sex, brand of the instruments, and diameter and length of the caudal screw were evident between patients with and without caudal screw loosening. Patients with caudal screw loosening were significantly older at the time of surgery than patients without caudal screw loosening. Conclusions Fixation strength of the caudal screw after floating PLIF with this modified CBT screw technique was sufficiently acceptable. Fixation strength after the lumbosacral procedure was not. PMID:27559442

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

    PubMed

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

    2014-02-01

    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.

  19. Comparison of Clinical and Radiological Results of Posterolateral Fusion and Posterior Lumbar Interbody Fusion in the Treatment of L4 Degenerative Lumbar Spondylolisthesis

    PubMed Central

    Kuraishi, Shugo; Mukaiyama, Keijiro; Shimizu, Masayuki; Ikegami, Shota; Futatsugi, Toshimasa; Hirabayashi, Hiroki; Ogihara, Nobuhide; Hashidate, Hiroyuki; Tateiwa, Yutaka; Kinoshita, Hisatoshi; Kato, Hiroyuki

    2016-01-01

    Study Design Multicenter analysis of two groups of patients surgically treated for degenerative L4 unstable spondylolisthesis. Purpose To compare the clinical and radiographic outcomes of posterolateral fusion (PLF) and posterior lumbar interbody fusion (PLIF) for degenerative L4 unstable spondylolisthesis. Overview of Literature Surgery for lumbar degenerative spondylolisthesis is widely performed. However, few reports have compared the outcome of PLF to that of PLIF for degenerative L4 unstable spondylolisthesis. Methods Patients with L4 unstable spondylolisthesis with Meyerding grade II or more, slip of >10° or >4 mm upon maximum flexion and extension bending, and posterior opening of >5 degree upon flexion bending were studied. Patients were treated from January 2008 to January 2010. Patients who underwent PLF (n=12) and PLIF (n=19) were followed-up for >2 years. Radiographic findings and clinical outcomes evaluated by the Japanese Orthopaedic Association (JOA) score were compared between the two groups. Radiographic evaluation included slip angle, translation, slip angle and translation during maximum flexion and extension bending, intervertebral disc height, lumbar lordotic angle, and fusion rate. Results JOA scores of the PLF group before surgery and at final follow-up were 12.3±4.8 and 24.1±3.7, respectively; those of the PLIF group were 14.7±4.8 and 24.2±7.8, respectively, with no significant difference between the two groups. Correction of slip estimated from postoperative slip angle, translation, and maintenance of intervertebral disc height in the PLIF group was significantly (p<0.05) better than those in the PLF group. However, there was no significant difference in lumbar lordotic angle, slip angle and translation angle upon maximum flexion, or extension bending. Fusion rates of the PLIF and PLF groups had no significant difference. Conclusions The L4–L5 level posterior instrumented fusion for unstable spondylolisthesis using both PLF and PLIF

  20. Posterior lumbar interbody fusion with instrumented posterolateral fusion in adult spondylolisthesis: description and association of clinico-surgical variables with prognosis in a series of 36 cases

    PubMed Central

    Gomez-Moreta, Juan A.; Hernandez-Vicente, Javier

    2015-01-01

    Background We present our experience in the treatment of patients with isthmic or degenerative spondylolisthesis, by means of a posterior lumbar interbody fusion (PLIF) and instrumented posterolateral fusion (IPLF), and we compare them with those published in the literature. We analyse whether there exists any statistical association between the clinical characteristics of the patient, radiological characteristics of the disease and our surgical technique, with the complications and the clinical-radiological prognosis of the cases. Method We designed a prospective study. A total of 36 cases were operated. The patients included were 14 men and 22 women, with an average age of 57.17±27.32 years. Our technique consists of PLIF+IPLF, using local bone for the fusion. The clinical results were evaluated with the Visual Analogical Scale (VAS) and the Kirkaldy-Willis criteria. The radiological evaluation followed the Bratingan (PLIF) and Lenke (IPLF) methodology. A total of 42 variables were statistically analysed by means of SPSS18. We used the Paired Student's T-test, logistic regression and Pearson's Chi-square-test. Results The spondylolisthesis was isthmic in 15 cases and degenerative in 21 cases. The postoperative evaluations had excellent or good results in 94.5% (n = 34), with a statistically significant improvement in the back pain and sciatica (p < 0.01). The rate of circumferential fusion reached was approximately 92%. We had 13.88% of transitory morbility and 0% of mortality associated with our technique. A greater age, degree of listhesis or length of illness before the intervention, weakly correlated with worse clinical results (p< -0.2). In our series, the logistical regression showed that the clinical characteristics of the patient, radiological characteristics of the lesion and our surgical technique were not associated with greater postoperative complications. Conclusion Although a higher level of training is necessary, we believe that the described

  1. Systematic Review of Thigh Symptoms after Lateral Transpsoas Interbody Fusion for Adult Patients with Degenerative Lumbar Spine Disease

    PubMed Central

    Gammal, Isaac D.; Bendo, John A.

    2015-01-01

    Background Lateral transpsoas interbody fusion (LTIF) is a minimally invasive technique for achieving lumbar spinal fusion. While it has many advantages over open techniques it carries with it a distinct set of risks, most commonly post-operative ipsilateral thigh pain, weakness and sensory disturbances. It is vital for both the surgeon and patient to understand the risks for and outcomes of injury associated with this procedure. We conducted a systematic review of the literature to evaluate the incidence, risks, and long-term clinical outcomes of post-operative thigh symptoms in patients treated with LTIF. Methods We conducted a search of MEDLINE, EMBASE, CINAHL, Scopus, Web of Science and the Cochrane Collaboration Library, using keywords and MeSH terms, for English-language literature published through September 2014, as well as reference lists from key articles. Studies were then manually filtered to retrieve articles that met inclusion criteria. We were interested in studies that reported postoperative lower extremity symptoms after LTIF, such as pain, weakness and changes in sensation. The strength of evidence was determined based on precepts outlined by the Grades of Recommendation Assessment, Development and Evaluation Working Group (GRADE). Results A total of 392 articles were initially retrieved, with 24 ultimately meeting criteria for inclusion. The incidence of any post-operative thigh symptom varied, ranging as high as 60.7%, with 9.3% of patients experiencing a motor deficit related to direct nerve injury. Several studies reported cases of persistent symptoms at 6 months follow up. Additionally, inclusion of the L4-5 disc space and a longer duration of surgery were both identified as risks for developing postoperative thigh symptoms. Conclusion The risk of postoperative thigh symptoms after LTIF is high. Thigh pain, paresthesias and weakness were the most commonly reported symptoms. While most patients’ symptoms resolved by 6 months follow up

  2. Quality-of-Life Outcomes With Minimally Invasive Transforaminal Lumbar Interbody Fusion Based on Long-Term Analysis of 304 Consecutive Patients

    PubMed Central

    Hussain, Namath S.; White, G. Zachary; Begun, Evan M.; Collins, Robert A.; Fahim, Daniel K.; Hiremath, Girish K.; Adbi, Fadumo M.; Yacob, Sammy A.

    2014-01-01

    Study Design. This was a prospective clinical study that took place in an outpatient spine clinic. Objective. To demonstrate the short-/long-term outcomes from a large cohort of patients undergoing minimally invasive transforaminal lumbar interbody fusion (MITLIF). Summary of Background Data. Long-term prospective outcomes in patients undergoing minimally invasive spinal fusion for debilitating back pain has not been well studied. Methods. Presenting diagnosis was determined from clinical findings and radiographical (radiograph, magnetic resonance image, computed tomographic scan) evaluations preoperatively. Patients were assessed with outcome measures preoperatively, and postoperatively at 2 weeks, 3 months, 6 months, 12 months, 24 months, and annually 2 to 7 years (mean follow-up: 47 mo) final follow-up. The rate of postoperative complications and reoperations at the initial level of MITLIF and adjacent level(s) were followed. Fusion rates were assessed blinded and independently by radiograph. Results. Visual analogue scale scores decreased significantly from 7.0 preoperatively to 3.5 at mean 47-month follow-up. Oswestry Disability Index scores declined from 43.1 preoperatively to 28.2 at mean 47-month follow-up. Short-Form 36 mental component scores increased from 43.8 preoperatively to 49.7 at 47-month follow-up. Short-Form 36 physical component scores increased from 30.6 preoperatively to 39.6 at 47-month follow-up (P < 0.05). Conclusion. This prospectively collected outcomes study shows long-term statistically significant clinical outcomes improvement after MITLIF in patients with clinically symptomatic spondylolisthesis and degenerative disc disease with or without stenosis. MITLIF resulted in a high rate of spinal fusion and very low rate of interbody fusion failure and/or adjacent segment disease requiring reoperation while reducing postoperative complications. Level of Evidence: 3 PMID:24150437

  3. Prevention of neurological complications using a neural monitoring system with a finger electrode in the extreme lateral interbody fusion approach.

    PubMed

    Narita, Wataru; Takatori, Ryota; Arai, Yuji; Nagae, Masateru; Tonomura, Hitoshi; Hayashida, Tatsuro; Ogura, Taku; Fujiwara, Hiroyoshi; Kubo, Toshikazu

    2016-10-01

    OBJECTIVE Extreme lateral interbody fusion (XLIF) is a minimally disruptive surgical procedure that uses a lateral approach. There is, however, concern about the development of neurological complications when this approach is used, particularly at the L4-5 level. The authors performed a prospective study of the effects of a new neural monitoring system using a finger electrode to prevent neurological complications in patients treated with XLIF and compared the results to results obtained in historical controls. METHODS The study group comprised 36 patients (12 male and 24 female) who underwent XLIF for lumbar spine degenerative spondylolisthesis or lumbar spine degenerative scoliosis at L4-5 or a lower level. Using preoperative axial MR images obtained at the mid-height of the disc at the treated level, we calculated the psoas position value (PP%) by dividing the distance from the posterior border of the vertebral disc to the posterior border of the psoas major muscle by the anteroposterior diameter of the vertebral disc. During the operation, the psoas major muscle was dissected using an index finger fitted with a finger electrode, and threshold values of the dilator were recorded before and after dissection. Eighteen cases in which patients had undergone the same procedure for the same indications but without use of the finger electrode served as historical controls. Baseline clinical and demographic characteristics, PP values, clinical results, and neurological complications were compared between the 2 groups. RESULTS The mean PP% values in the control and finger electrode groups were 17.5% and 20.1%, respectively (no significant difference). However, 6 patients in the finger electrode group had a rising psoas sign with PP% values of 50% or higher. The mean threshold value before dissection in the finger electrode group was 13.1 ± 5.9 mA, and this was significantly increased to 19.0 ± 1.5 mA after dissection (p < 0.001). A strong negative correlation was found

  4. Retroperitoneal hematoma after using the extreme lateral interbody fusion (XLIF) approach: Presentation of a case and a review of the literature.

    PubMed

    Peiró-García, A; Domínguez-Esteban, I; Alía-Benítez, J

    2016-01-01

    The transpsoas approach, also known as extreme lateral interbody fusion (XLIF), to the lumbar spine is a novel minimally invasive technique with positive clinical outcomes and a low complication rate. There is a low risk of bleeding, due to this approach causing less soft tissue disruption than traditional spine surgery, but segmental arteries and great vessels can be damaged. Retroperitoneal haematoma is a major complication, with few cases reported. This is the first case reported in a Stand-alone XLIF and also the first case reported with haemorrhagic shock. Non-specific symptoms such tachycardia, hypotension, and anaemia are the most prevalent in this complication. With this case, our aim is to describe serious complications related to XLIF.

  5. A Multi-center Clinical Study of Posterior Lumbar Interbody Fusion with the Expandable Stand-alone Cage (Tyche® Cage) for Degenerative Lumbar Spinal Disorders

    PubMed Central

    Kim, Jin Wook; Yoon, Seung Hwan; Oh, Seong Hoon; Roh, Sung Woo; Rim, Dae Cheol; Kim, Tae Sung

    2007-01-01

    Objective This multi-center clinical study was designed to determine the long-term results of patients who received a one-level posterior lumbar interbody fusion with expandable cage (Tyche® cage) for degenerative spinal diseases during the same period in each hospital. Methods Fifty-seven patients with low back pain who had a one-level posterior lumbar interbody fusion using a newly designed expandable cage were enrolled in this study at five centers from June 2003 to December 2004 and followed up for 24 months. Pain improvement was checked with a Visual Analogue Scale (VAS) and their disability was evaluated with the Oswestry Disability Index. Radiographs were obtained before and after surgery. At the final follow-up, dynamic stability, quality of bone fusion, interveretebral disc height, and lumbar lordosis were assessed. In some cases, a lumbar computed tomography scan was also obtained. Results The mean VAS score of back pain was improved from 6.44 points preoperatively to 0.44 at the final visit and the score of sciatica was reduced from 4.84 to 0.26. Also, the Oswestry Disability Index was improved from 32.62 points preoperatively to 18.25 at the final visit. The fusion rate was 92.5%. Intervertebral disc height, recorded as 9.94±2.69 mm before surgery was increased to 12.23±3.31 mm at postoperative 1 month and was stabilized at 11.43±2.23 mm on final visit. The segmental angle of lordosis was changed significantly from 3.54±3.70° before surgery to 6.37±3.97° by 24 months postoperative, and total lumbar lordosis was 20.37±11.30° preoperatively and 24.71±11.70° at 24 months postoperative. Conclusion There have been no special complications regarding the expandable cage during the follow-up period and the results of this study demonstrates a high fusion rate and clinical success. PMID:19096552

  6. The NEtherlands Cervical Kinematics (NECK) Trial. Cost-effectiveness of anterior cervical discectomy with or without interbody fusion and arthroplasty in the treatment of cervical disc herniation; a double-blind randomised multicenter study

    PubMed Central

    2010-01-01

    Background Patients with cervical radicular syndrome due to disc herniation refractory to conservative treatment are offered surgical treatment. Anterior cervical discectomy is the standard procedure, often in combination with interbody fusion. Accelerated adjacent disc degeneration is a known entity on the long term. Recently, cervical disc prostheses are developed to maintain motion and possibly reduce the incidence of adjacent disc degeneration. A comparative cost-effectiveness study focused on adjacent segment degeneration and functional outcome has not been performed yet. We present the design of the NECK trial, a randomised study on cost-effectiveness of anterior cervical discectomy with or without interbody fusion and arthroplasty in patients with cervical disc herniation. Methods/Design Patients (age 18-65 years) presenting with radicular signs due to single level cervical disc herniation lasting more than 8 weeks are included. Patients will be randomised into 3 groups: anterior discectomy only, anterior discectomy with interbody fusion, and anterior discectomy with disc prosthesis. The primary outcome measure is symptomatic adjacent disc degeneration at 2 and 5 years after surgery. Other outcome parameters will be the Neck Disability Index, perceived recovery, arm and neck pain, complications, re-operations, quality of life, job satisfaction, anxiety and depression assessment, medical consumption, absenteeism, and costs. The study is a randomised prospective multicenter trial, in which 3 surgical techniques are compared in a parallel group design. Patients and research nurses will be kept blinded of the allocated treatment for 2 years. The follow-up period is 5 years. Discussion Currently, anterior cervical discectomy with fusion is the golden standard in the surgical treatment of cervical disc herniation. Whether additional interbody fusion or disc prothesis is necessary and cost-effective will be determined by this trial. Trial Registration Netherlands

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

    PubMed

    Abbott, Allan; Halvorsen, Marie; Dedering, Asa

    2013-05-01

    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.

  8. Minimally Invasive Unilateral vs. Bilateral Pedicle Screw Fixation and Lumbar Interbody Fusion in Treatment of Multi-Segment Lumbar Degenerative Disorders

    PubMed Central

    Liu, Xiaoyang; Li, Guangrun; Wang, Jiefeng; Zhang, Heqing

    2015-01-01

    Background The choice for instrumentation with minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) in treatment of degenerative lumbar disorders (DLD) remains controversial. The goal of this study was to investigate clinical outcomes in consecutive patients with multi-segment DLD treated with unilateral pedicle screw (UPS) vs. bilateral pedicle screw (BPS) instrumented TLIF. Material/Methods Eighty-four consecutive patients who had multi-level MIS-TLIF were retrospectively reviewed. All data were collected to compare the clinical outcomes between the 2 groups. Results Both groups showed similar clinical function scores in VAS and ODI. The two groups differed significantly in operative time (P<0.001), blood loss (P<0.001), and fusion rate (P=0.043), respectively. Conclusions This study demonstrated similar clinical outcomes between UPS fixation and BPS procedure after MIS-TLIF for multi-level DLD. Moreover, UPS technique was superior in operative time and blood loss, but represented lower fusion rate than the BPS construct did. PMID:26603050

  9. Demineralized Bone Matrix (DBM) as a Bone Void Filler in Lumbar Interbody Fusion: A Prospective Pilot Study of Simultaneous DBM and Autologous Bone Grafts

    PubMed Central

    Kim, Bum-Joon; Kim, Se-Hoon; Lee, Haebin; Lee, Seung-Hwan; Kim, Won-Hyung; Jin, Sung-Won

    2017-01-01

    Objective Solid bone fusion is an essential process in spinal stabilization surgery. Recently, as several minimally invasive spinal surgeries have developed, a need of artificial bone substitutes such as demineralized bone matrix (DBM), has arisen. We investigated the in vivo bone growth rate of DBM as a bone void filler compared to a local autologous bone grafts. Methods From April 2014 to August 2015, 20 patients with a one or two-level spinal stenosis were included. A posterior lumbar interbody fusion using two cages and pedicle screw fixation was performed for every patient, and each cage was packed with autologous local bone and DBM. Clinical outcomes were assessed using the Numeric Rating Scale (NRS) of leg pain and back pain and the Korean Oswestry Disability Index (K-ODI). Clinical outcome parameters and range of motion (ROM) of the operated level were collected preoperatively and at 3 months, 6 months, and 1 year postoperatively. Computed tomography was performed 1 year after fusion surgery and bone growth of the autologous bone grafts and DBM were analyzed by ImageJ software. Results Eighteen patients completed 1 year of follow-up, including 10 men and 8 women, and the mean age was 56.4 (32–71). The operated level ranged from L3/4 to L5/S1. Eleven patients had single level and 7 patients had two-level repairs. The mean back pain NRS improved from 4.61 to 2.78 (p=0.003) and the leg pain NRS improved from 6.89 to 2.39 (p<0.001). The mean K-ODI score also improved from 27.33 to 13.83 (p<0.001). The ROM decreased below 2.0 degrees at the 3-month assessment, and remained less than 2 degrees through the 1 year postoperative assessment. Every local autologous bone graft and DBM packed cage showed bone bridge formation. On the quantitative analysis of bone growth, the autologous bone grafts showed significantly higher bone growth compared to DBM on both coronal and sagittal images (p<0.001 and p=0.028, respectively). Osteoporotic patients showed less bone

  10. Clinical efficacy of lumbar interbody fusion using a channel system combined with ozone therapy for the treatment of central-type L3-L4 lumbar disc herniation

    PubMed Central

    Wang, Yu; Sun, Hong; Qin, Shuzhen

    2017-01-01

    The clinical efficacy of minimally invasive lumbar interbody fusion via the intervertebral foramen combined with ozone (O3) therapy for the treatment of L3-L4 central-type lumbar disc herniation was explored. We recruited patients with sciatica who attended our hospital between July 2013 and October 2015 and underwent lumbar X-ray (anteroposterior and lateral view), lumbar flexion-extension radiographs, computed tomography, and magnetic resonance imaging after admission. Seventy-four patients with central-type lumbar disc herniation but no other complications were randomly selected and divided into the observation and control groups. The observation group comprised 37 patients treated with lumbar fusion using a channel system combined with O3 therapy, whereas the control group comprised 37 patients treated with lumbar fusion alone. The effects of the two therapies were evaluated using visual analog scale, Japanese Orthopaedic Association, and MacNab scores. There was no significant difference in scores between the two groups before surgery (P>0.05). The scores of the observation group after treatment were significantly lower than those before surgery and those of the control group (P<0.05). One patient in the observation group experienced no obvious improvement in symptoms after surgery, and two patients in the control group experienced postoperative recurrence; these three patients subsequently underwent laminectomy combined with planted bone fusion and internal fixation. There was no significant difference in total efficacy rates between the two groups (P>0.05). Lumbar fusion using a channel system combined with O3 therapy for the treatment of L3-L4 central-type lumbar disc herniation is safe and effective. It has the advantages of reduced trauma, fewer complications, and rapid pain relief, and it promotes the recovery of lumbar function. Strict mastery of the surgical indications is key to the success of the procedure; however, it is worth expanding its use in

  11. Hospital charges associated with "never events": comparison of anterior cervical discectomy and fusion, posterior lumbar interbody fusion, and lumbar laminectomy to total joint arthroplasty.

    PubMed

    Daniels, Alan H; Kawaguchi, Satoshi; Contag, Alec G; Rastegar, Farbod; Waagmeester, Garrett; Anderson, Paul A; Arthur, Melanie; Hart, Robert A

    2016-08-01

    OBJECTIVE Beginning in 2008, the Centers for Medicare and Medicaid Service (CMS) determined that certain hospital-acquired adverse events such as surgical site infection (SSI) following spine surgery should never occur. The following year, they expanded the ruling to include deep vein thrombosis (DVT) and pulmonary embolism (PE) following total joint arthroplasty. Due to their ruling that "never events" are not the payers' responsibility, CMS insists that the costs of managing these complications be borne by hospitals and health care providers, rather than billings to health care payers for additional care required in their management. Data comparing the expected costs of such adverse events in patients undergoing spine and orthopedic surgery have not previously been reported. METHODS The California State Inpatient Database (CA-SID) from 2008 to 2009 was used for the analysis. All patients with primary procedure codes indicating anterior cervical discectomy and fusion (ACDF), posterior lumbar interbody fusion (PLIF), lumbar laminectomy (LL), total knee replacement (TKR), and total hip replacement (THR) were analyzed. Patients with diagnostic and/or treatment codes for DVT, PE, and SSI were separated from patients without these complication codes. Patients with more than 1 primary procedure code or more than 1 complication code were excluded. Median charges for treatment from primary surgery through 3 months postoperatively were calculated. RESULTS The incidence of the examined adverse events was lowest for ACDF (0.6% DVT, 0.1% PE, and 0.03% SSI) and highest for TKA (1.3% DVT, 0.3% PE, 0.6% SSI). Median inpatient charges for uncomplicated LL was $51,817, compared with $73,432 for ACDF, $143,601 for PLIF, $74,459 for THR, and $70,116 for TKR. Charges for patients with DVT ranged from $108,387 for TKR (1.5 times greater than index) to $313,536 for ACDF (4.3 times greater than index). Charges for patients with PE ranged from $127,958 for TKR (1.8 times greater than

  12. Long-Term Follow-Up Radiologic and Clinical Evaluation of Cylindrical Cage for Anterior Interbody Fusion in Degenerative Cervical Disc Disease

    PubMed Central

    Kim, Suhyeong; Yi, Hyeon-Joong; Bak, Koang Hum; Kim, Dong Won; Lee, Yoon Kyoung

    2012-01-01

    Objective Various procedures have been introduced for anterior interbody fusion in degenerative cervical disc disease including plate systems with autologous iliac bone, carbon cages, and cylindrical cages. However, except for plate systems, the long-term results of other methods have not been established. In the present study, we evaluated radiologic findings for cylindrical cervical cages over long-term follow up periods. Methods During 4 year period, radiologic findings of 138 patients who underwent anterior cervical fusion with cylindrical cage were evaluated at 6, 12, 24, and 36 postoperative months using plain radiographs. We investigated subsidence, osteophyte formation (anterior and posterior margin), cage direction change, kyphotic angle, and bone fusion on each radiograph. Results Among the 138 patients, a minimum of 36 month follow-up was achieved in 99 patients (mean follow-up : 38.61 months) with 115 levels. Mean disc height was 7.32 mm for preoperative evaluations, 9.00 for immediate postoperative evaluations, and 4.87 more than 36 months after surgery. Osteophytes were observed in 107 levels (93%) of the anterior portion and 48 levels (41%) of the posterior margin. The mean kyphotic angle was 9.87° in 35 levels showing cage directional change. There were several significant findings : 1) related subsidence [T-score (p=0.039) and anterior osteophyte (p=0.009)], 2) accompanying posterior osteophyte and outcome (p=0.05). Conclusion Cage subsidence and osteophyte formation were radiologically observed in most cases. Low T-scores may have led to subsidence and kyphosis during bone fusion although severe neurologic aggravation was not found, and therefore cylindrical cages should be used in selected cases. PMID:23091668

  13. Mid-term Clinical Outcomes of Stand-alone Posterior Interbody Fusion with Rectangular Cages: A 4-year-minimum Follow-up

    PubMed Central

    Cho, Kyung Rae; Lee, Sun-Ho; Kim, Eun Sang

    2013-01-01

    Objective We sought to determine minimum 4 years of clinical outcomes including fusion rate, revision rate and complications of patients who underwent placement of rectangular stand-alone cages. Methods Thirty-three cases of degenerative spine that had been followed for at least 4-years were reviewed retrospectively. Cages were inserted at L4-L5 level or L5-S1 in 27 or in 6 cases respectively. Visual analogue scale (VAS), Odom's criteria, fusion rate, intervertebral disc height and lumbar lordosis were determined pre- and post-operatively on standing x-rays. Amount of intra- and postoperative blood loss, total volume transfused, duration of surgery and perioperative complications were also evaluated. Results The mean VAS score of back pain and sciatica were improved from 8.0 and 7.0 points to 3.4 and 2.4 during 1 years follow-up visit and the scores was raised gradually. Also, during the follow-up, 94% of patients showed excellent or good outcomes by the Odom's criteria. Intervertebral disc height was increased from 8.2±1.4mm to 9.2±1.9mm at the first year of follow-up, however, found to be decreased and stabilized to 8.3±1.8mm after 2 years. The fusion rate was approximately 91% after 4 year postoperative. The segmental angle of lordosis was increased significantly by two years but it was not maintained after four years. A statistically insignificant change in total lumbar lordosis was also observed. Three patients (9%) had experienced perioperative complications. Conclusion The use of rectangular stand-alone cages for posterior lumbar interbody fusion (PLIF) resulted in a various degree of subsidence and demonstrate very low complication rate, high functional stability and improved clinical outcomes in patients with degenerative lumbar disc disease. PMID:24757473

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

    PubMed Central

    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

    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

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

    PubMed

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

    2009-10-01

    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) implanted with mPCL-TCP + 0.6 mg rhBMP-2 as treatment group while four other pigs implanted with autogenous bone graft served as control. Computed tomographic scanning and histology revealed complete defect bridging in all (100%) specimen from the treatment group as early as 3 months. Histological evidence of continuing bone remodeling and maturation was observed at 6 months. In the control group, only partial bridging was observed at 3 months and only 50% of segments in this group showed complete defect bridging at 6 months. Furthermore, 25% of segments in the control group showed evidence of graft fracture, resorption and pseudoarthrosis. In contrast, no evidence of graft fractures, pseudoarthrosis or foreign body reaction was observed in the treatment group. These results reveal that mPCL-TCP scaffolds could act as bone graft substitutes by providing a suitable environment for bone regeneration in a dynamic load bearing setting such as in a porcine model of interbody spine fusion.

  16. Comparative Analysis of Interbody Cages Versus Tricortical Graft with Anterior Plate Fixation for Anterior Cervical Discectomy and Fusion in Degenerative Cervical Disc Disease

    PubMed Central

    Singh, Pritish; Shekhawat, Vishal

    2016-01-01

    Introduction Multiple techniques and modalities of fixation are used in Anterior Cervical Discectomy and interbody Fusion (ACDF), each with some merit and demerit against others. Such pool of techniques reflects lack of a consensus method conducive to uniformly good results. Aim A prospective study was done to analyse safety and efficacy of tricortical autograft and anterior cervical plate (Group A) with cylindrical titanium cage filled with cancellous bone (Group B) in procedure of ACDF for single level degenerative cervical disc disease. Materials and Methods Twenty patients with degenerative cervical disc disease were included in study for ACDF. After a computer generated randomisation, ten patients (10 segments) were operated with anterior locking plating and tricortical iliac crest graft (Group A, Tricortical graft group), while ten patients(10 segments) were operated with standalone cylindrical titanium cages filled with cancellous bone harvested using minimally invasive methods (Group B, Cage group) from April 2012 to May 2015. Odoms’s criteria, visual pain analogue score and sequential plain radiographs were obtained to assess for clinic-radiological outcome. Results According to Odom’s system of functional assessment, 9 patients from each group (90%) experienced good to excellent functional recovery and 9 of 10 (90%) patients of each groups were satisfied with outcome. In both groups, relief in neck pain or arm pain was similar without any statistical difference as assessed by visual analogue score. Fusion was present in 10 of 10 (100%) patients in tricortical graft group and 10 of 10 (100%) in cage group at the end of 6 months. There was no implant related complications in cage group. Transient postoperative dysphagia was recorded in 3 patients (2 in Group A and 1 in group B), which resolved within 3 days. In tricortical graft group, graft collapse and partial extrusion was detected in one patient, which did not correspond with good results obtained

  17. Long-Term Outcomes of Posterior Lumbar Interbody Fusion Using Stand-Alone Ray Threaded Cage for Degenerative Disk Disease: A 20-Year Follow-Up

    PubMed Central

    Medrano, Belen G.; Noriega, David C.

    2016-01-01

    Study Design Retrospective study. Purpose To analyze outcomes of posterior lumbar interbody fusion (PLIF) stand-alone cages. Overview of Literature PLIF for degenerative disk disease using stand-alone cages has lost its popularity owing to implant-related complications and pseudoarthrosis. Methods We analyzed the records of 45 patients (18 women, 27 men), operated between January 1994 and December 1996, with a mean follow-up of 18 years 3 months (20 years 3 months–22 years 3 months). Clinical outcomes were measured using visual analogue score (VAS), Oswestry disability index (ODI), Odom's criteria, and radiological measurements of fusion rate, Cobb angle, and implant-related complications conducted at the preoperative evaluation, hospital discharge, 12-month follow-up, and final follow-up. Results Preoperative mean VAS (back) was 6.9 and VAS (radicular) was 7.2, with mean improvements (p <0.05) of 2.9 and 3.1, respectively, at the final follow-up. Median preoperative ODI was 64.5, with a mean improvement to 34 and 42 at the 12-month and final follow-ups, respectively (p <0.05). Odom's criteria at the 12-month follow-up were excellent in 11.2% patients, good in 57.7%, fair in 31.1%, and poor in none of the patients; at the final follow-up, no patient was classified as excellent, 71.1% as good, 22.2% as fair, and 6.7% as poor (p <0.05). Pseudoarthrosis was observed in five patients (11.1%), of whom, three (6.6%) required re-operation. Preoperative disk height was 9.23 mm, which increased to 13.33 mm in the immediate postoperative evaluation and was maintained at 10.0 mm at the final follow-up (p <0.05). The preoperative mean L1–S1 Cobb angle was 34.7°, which changed to 44.7° in the immediate postoperative evaluation and dropped to 39.7° at the final follow-up (p <0.005). Conclusions PLIF stand-alone cages were associated with good clinical outcomes. Although the fusion rate was excellent, maintenance of disk heights and a lordotic alignment were not achieved

  18. Clinical Outcomes of Posterior Lumbar Interbody Fusion for Patients 80 Years of Age and Older with Lumbar Degenerative Disease: Minimum 2 Years' Follow-Up

    PubMed Central

    Hayashi, Kazunori; Matsumura, Akira; Konishi, Sadahiko; Kato, Minori; Namikawa, Takashi; Nakamura, Hiroaki

    2016-01-01

    Study Design Retrospective study. Objective To compare clinical outcomes, radiographic evaluations including bony union rate and incidence of osteoporotic vertebral fractures (OVFxs), and perioperative complications following posterior lumbar interbody fusion (PLIF) between patients ≥80 years of age and those <80 years. Methods Ninety-six patients ≥70 years old who underwent PLIF were reviewed. We divided the patients into the two age groups, ≥80 group (n = 19) and <80 group (n = 77), and compared the clinical outcomes using Japanese Orthopaedics Association (JOA) scores and the Short-Form Health Survey (SF-36). We also evaluated bony union and the incidence of OVFxs in the both groups. Results The JOA score improved 47.6% in the ≥80 group and 49.1% in the <80 group. There were no significant differences between the two groups. Only the bodily pain component of the SF-36 improved significantly in the ≥80 group, and seven of eight components (exception was general health) improved significantly in the <80 group. Bony union rate was significantly superior in the <80 group (94.8%) compared with that of the ≥80 group (73.7%, p = 0.013). OVFx prevalence and incidence were not significantly different between the two groups, although postoperative OVFx worsened the JOA score improvement in the ≥80 group (38.8%, p = 0.02). Conclusions The present study indicated that surgical outcomes of PLIF in patients ≥80 years were comparable to those < 80 years. However, bony union rate was significantly lower and postoperative OVFx worsened the clinical outcomes in patients ≥80 years. PMID:27781186

  19. Theater and ALife Art: Modeling Open and Closed Systems.

    PubMed

    Norman, Sally Jane

    2015-01-01

    The live art of theater remains curiously missing from ALife art history, despite the fact that its very existence is poised on the cusp of the living and the artificial, and on the modeling of life as artefact-what can be called the containment-versus-continuity dilemma. How far one seeks to affirm autonomy of the creative artwork or, in contrast, how far one seeks to affirm its continuity with its supposed real-life contexts is a question that has forever haunted theater, and that has naturally come to haunt ALife and ALife arts. Investigation of the boundary separating observers from modeled systems is as core to research into the live art of theater as to ALife research. This brief article seeks to open up discussion on links between ALife, ALife art, and the live art of theater, through key thematic threads that traverse these domains: their modeling of universes, the open or closed nature of the resultant modeled systems, and their implications with respect to observers, definitions, and instantiations of life regarding non-life or death as well as attributions of liveness to emergent synthetic biology and metamaterials.

  20. Dynamic stabilization for L4-5 spondylolisthesis: comparison with minimally invasive transforaminal lumbar interbody fusion with more than 2 years of follow-up.

    PubMed

    Kuo, Chao-Hung; Chang, Peng-Yuan; Wu, Jau-Ching; Chang, Hsuan-Kan; Fay, Li-Yu; Tu, Tsung-Hsi; Cheng, Henrich; Huang, Wen-Cheng

    2016-01-01

    OBJECTIVE In the past decade, dynamic stabilization has been an emerging option of surgical treatment for lumbar spondylosis. However, the application of this dynamic construct for mild spondylolisthesis and its clinical outcomes remain uncertain. This study aimed to compare the outcomes of Dynesys dynamic stabilization (DDS) with minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) for the management of single-level spondylolisthesis at L4-5. METHODS This study retrospectively reviewed 91 consecutive patients with Meyerding Grade I spondylolisthesis at L4-5 who were managed with surgery. Patients were divided into 2 groups: DDS and MI-TLIF. The DDS group was composed of patients who underwent standard laminectomy and the DDS system. The MI-TLIF group was composed of patients who underwent MI-TLIF. Clinical outcomes were evaluated by visual analog scale for back and leg pain, Oswestry Disability Index, and Japanese Orthopaedic Association scores at each time point of evaluation. Evaluations included radiographs and CT scans for every patient for 2 years after surgery. RESULTS A total of 86 patients with L4-5 spondylolisthesis completed the follow-up of more than 2 years and were included in the analysis (follow-up rate of 94.5%). There were 64 patients in the DDS group and 22 patients in the MI-TLIF group, and the overall mean follow-up was 32.7 months. Between the 2 groups, there were no differences in demographic data (e.g., age, sex, and body mass index) or preoperative clinical evaluations (e.g., visual analog scale back and leg pain, Oswestry Disability Index, and Japanese Orthopaedic Association scores). The mean estimated blood loss of the MI-TLIF group was lower, whereas the operation time was longer compared with the DDS group (both p < 0.001). For both groups, clinical outcomes were significantly improved at 6, 12, 18, and 24 months after surgery compared with preoperative clinical status. Moreover, there were no differences between the 2

  1. Posterior corrective surgery with a multilevel transforaminal lumbar interbody fusion and a rod rotation maneuver for patients with degenerative lumbar kyphoscoliosis.

    PubMed

    Matsumura, Akira; Namikawa, Takashi; Kato, Minori; Ozaki, Tomonori; Hori, Yusuke; Hidaka, Noriaki; Nakamura, Hiroaki

    2017-02-01

    The purpose of this study was to assess the clinical results of posterior corrective surgery using a multilevel transforaminal lumbar interbody fusion (TLIF) with a rod rotation (RR) and to evaluate the segmental corrective effect of a TLIF using CT imaging. The medical records of 15 consecutive patients with degenerative lumbar kyphoscoliosis (DLKS) who had undergone posterior spinal corrective surgery using a multilevel TLIF with an RR technique and who had a minimum follow-up of 2 years were retrospectively reviewed. Radiographic parameters were evaluated using plain radiographs, and segmental correction was evaluated using CT imaging. Clinical outcomes were evaluated with the Scoliosis Research Society Patient Questionnaire-22 (SRS-22) and the SF-36. The mean follow-up period was 46.7 months, and the mean age at the time of surgery was 60.7 years. The mean total SRS-22 score was 2.9 before surgery and significantly improved to 4.0 at the latest follow-up. The physical functioning, role functioning (physical), and social functioning subcategories of the SF-36 were generally improved at the latest follow-up, although the changes in these scores were not statistically significant. The bodily pain, vitality, and mental health subcategories were significantly improved at the latest follow-up (p < 0.05). Three complications occurred in 3 patients (20%). The Cobb angle of the lumbar curve was reduced to 20.3° after surgery. The overall correction rate was 66.4%. The pelvic incidence-lumbar lordosis (preoperative/postoperative = 31.5°/4.3°), pelvic tilt (29.2°/18.9°), and sagittal vertical axis (78.3/27.6 mm) were improved after surgery and remained so throughout the follow-up. Computed tomography image analysis suggested that a 1-level TLIF can result in 10.9° of scoliosis correction and 6.8° of lordosis. Posterior corrective surgery using a multilevel TLIF with an RR on patients with DLKS can provide effective correction in the coronal plane but allows only

  2. Static and dynamic fatigue behavior of topology designed and conventional 3D printed bioresorbable PCL cervical interbody fusion devices.

    PubMed

    Knutsen, Ashleen R; Borkowski, Sean L; Ebramzadeh, Edward; Flanagan, Colleen L; Hollister, Scott J; Sangiorgio, Sophia N

    2015-09-01

    Recently, as an alternative to metal spinal fusion cages, 3D printed bioresorbable materials have been explored; however, the static and fatigue properties of these novel cages are not well known. Unfortunately, current ASTM testing standards used to determine these properties were designed prior to the advent of bioresorbable materials for cages. Therefore, the applicability of these standards for bioresorbable materials is unknown. In this study, an image-based topology and a conventional 3D printed bioresorbable poly(ε)-caprolactone (PCL) cervical cage design were tested in compression, compression-shear, and torsion, to establish their static and fatigue properties. Difficulties were in fact identified in establishing failure criteria and in particular determining compressive failure load. Given these limitations, under static loads, both designs withstood loads of over 650 N in compression, 395 N in compression-shear, and 0.25 Nm in torsion, prior to yielding. Under dynamic testing, both designs withstood 5 million (5M) cycles of compression at 125% of their respective yield forces. Geometry significantly affected both the static and fatigue properties of the cages. The measured compressive yield loads fall within the reported physiological ranges; consequently, these PCL bioresorbable cages would likely require supplemental fixation. Most importantly, supplemental testing methods may be necessary beyond the current ASTM standards, to provide more accurate and reliable results, ultimately improving preclinical evaluation of these devices.

  3. Static and Dynamic Fatigue Behavior of Topology Designed and Conventional 3D Printed Bioresorbable PCL Cervical Interbody Fusion Devices

    PubMed Central

    Knutsen, Ashleen R.; Borkowski, Sean L.; Ebramzadeh, Edward; Flanagan, Colleen L.; Hollister, Scott J.; Sangiorgio, Sophia N.

    2015-01-01

    Recently, as an alternative to metal spinal fusion cages, 3D printed bioresorbable materials have been explored; however, the static and fatigue properties of these novel cages are not well known. Unfortunately, current ASTM testing standards used to determine these properties were designed prior to the advent of bioresorbable materials for cages. Therefore, the applicability of these standards for bioresorbable materials is unknown. In this study, an image-based topology and a conventional 3D printed bioresorbable poly(ε)-caprolactone (PCL) cervical cage design were tested in compression, compression-shear, and torsion, to establish their static and fatigue properties. Difficulties were in fact identified in establishing failure criteria and in particular determining compressive failure load. Given these limitations, under static loads, both designs withstood loads of over 650N in compression, 395N in compression-shear, and 0.25Nm in torsion, prior to yielding. Under dynamic testing, both designs withstood 5 million (5M) cycles of compression at 125% of their respective yield forces. Geometry significantly affected both the static and fatigue properties of the cages. The measured compressive yield loads fall within the reported physiological ranges; consequently, these PCL bioresorbable cages would likely require supplemental fixation. Most importantly, supplemental testing methods may be necessary beyond the current ASTM standards, to provide more accurate and reliable results, ultimately improving preclinical evaluation of these devices. PMID:26072198

  4. Combined transforaminal lumbar interbody fusion with posterolateral instrumented fusion for degenerative disc disease can be a safe and effective treatment for lower back pain

    PubMed Central

    Deukmedjian, Ara J; Cianciabella, Augusto J; Cutright, Jason; Deukmedjian, Arias

    2015-01-01

    Background: Lumbar fusion is a proven treatment for chronic lower back pain (LBP) in the setting of symptomatic spondylolisthesis and degenerative scoliosis; however, fusion is controversial when the primary diagnosis is degenerative disc disease (DDD). Our objective was to evaluate the safety and effectiveness of lumbar fusion in the treatment of LBP due to DDD. Materials and Methods: Two-hundred and five consecutive patients with single or multi-level DDD underwent lumbar decompression and instrumented fusion for the treatment of chronic LBP between the years of 2008 and 2011. The primary outcome measures in this study were back and leg pain visual analogue scale (VAS), patient reported % resolution of preoperative back pain and leg pain, reoperation rate, perioperative complications, blood loss and hospital length of stay (LOS). Results: The average resolution of preoperative back pain per patient was 84% (n = 205) while the average resolution of preoperative leg pain was 90% (n = 190) while a mean follow-up period of 528 days (1.5 years). Average VAS for combined back and leg pain significantly improved from a preoperative value of 9.0 to a postoperative value of 1.1 (P ≤ 0.0001), a change of 7.9 points for the cohort. The average number of lumbar disc levels fused per patient was 2.3 (range 1-4). Median postoperative LOS in the hospital was 1.2 days. Average blood loss was 108 ml perfused level. Complications occurred in 5% of patients (n = 11) and the rate of reoperation for symptomatic adjacent segment disease was 2% (n = 4). Complications included reoperation at index level for symptomatic pseudoarthrosis with hardware failure (n = 3); surgical site infection (n = 7); repair of cerebrospinal fluid leak (n = 1), and one patient death at home 3 days after discharge. Conclusion: Lumbar fusion for symptomatic DDD can be a safe and effective treatment for medically refractory LBP with or without leg pain. PMID:26692696

  5. Transdural retrieval of a retropulsed lumbar interbody cage: Technical case report.

    PubMed

    Zaidi, Hasan Aqdas; Shah, Ashish; Kakarla, Udaya Kumar

    2016-01-01

    The purpose of this case report was to describe a novel method to retrieve a herniated lumbar interbody cage. Transforaminal lumbar interbody fusion (TLIF) is an increasingly popular method of spinal fixation and fusion. Unexpected retropulsion of an interbody is a rare event that can result in intractable pain or motor compromise necessitating surgical retrieval of the interbody. Both anterior and posterior approaches to removing migrated cages may be associated with significant surgical morbidity and mortality. A 60-year-old woman underwent an L4-S1 TLIF coupled with pedicle screw fixation at a previous hospital 5 years prior to admission. She noted sudden-onset bilateral lower extremity weakness and right-sided foot drop. Magnetic resonance imaging and radiographs were notable for purely centrally herniated interbody. A posterior, midline transdural approach was used to retrieve the interbody. Situated in between nerve rootlets to the ventral canal, this virgin corridor allowed us to easily visualize and protect neurological structures while safely retrieving the interbody. The patient experienced an immediate improvement in symptoms and was discharged on postoperative day 3. At 12-month follow-up, she had no evidence of cerebrospinal fluid (CSF) leak and had returned to normal activities of daily living. While the risk of CSF leak may be higher with a transdural approach, we maintain that avoiding unnecessary retraction of the nerve roots may outweigh this risk. To our knowledge, this is the first case report of a transdural approach for the retrieval of a retropulsed lumbar interbody cage.

  6. Surgical Outcomes of Post-Fusion Lumbar Flatback Deformity with Sagittal Imbalance

    PubMed Central

    Kim, Jin Seong

    2016-01-01

    Objectives To review surgical results of post-fusion lumbar flatback treated with pedicle subtraction osteotomy (PSO) or Smith-Petersen osteotomies (SPOs). Methods Twenty-eight patients underwent osteotomies. Radiological outcomes by sagittal vertical axis (SVA), and pelvic tilt (PT), T1 pelvic angle (T1PA), and pelvic incidence (PI)-lumbar lordosis (LL) at preoperative, postoperative 1 month, and final were evaluated. Oswestry Disability Index (ODI), visual analog scale (VAS) score of back pain/leg pain, and Scoliosis Research Society-22 score (SRS-22r) were analyzed and compared. Patients were divided into 2 groups (SVA ≤5 cm : normal, SVA >5 cm : positive) at final and compared outcomes. Results Nineteen patients (68%) had PSO and the other 9 patients had SPOs with anterior lumbar interbody fusions (ALIFs) (Mean age : 65 years, follow-up : 31 months). The PT, PI-LL, SVA, T1PA were significantly improved at 1 month and at final (p<0.01). VAS score, ODI, and SRS-22r were also significantly improved at the final (p<0.01). 23 patients were restored with normal SVA and the rest 5 patients demonstrated to positive SVA. SVA and T1PA at 1 month and SVA, PI-LL, and T1PA at final were significantly different (p<0.05) while the ODI, VAS, and SRS-22r did not differ significantly between the groups (p>0.05). Common reoperations were early 4 proximal junctional failures (14%) and late four rod fractures. Conclusion Our results demonstrate that PSO and SPOs with ALIFs at the lower lumbar are significantly improves sagittal balance. For maintenance of normal SVA, PI-LL might be made negative value and T1PA might be less than 11° even though positive SVA group was also significantly improved clinical outcomes. PMID:27847576

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

    PubMed Central

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

    2014-01-01

    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

  8. A novel indication for a method in the treatment of lumbar tuberculosis through minimally invasive extreme lateral interbody fusion (XLIF) in combination with percutaneous pedicle screws fixation in an elderly patient

    PubMed Central

    Wang, Qiyou; Xu, Yichun; Chen, Ruiqiang; Dong, Jianwen; Liu, Bin; Rong, Limin

    2016-01-01

    Abstract Rationale: To describe a novel indication for a method through minimally invasive extreme lateral interbody fusion (XLIF) in combination with percutaneous pedicle screwsfixation in the treatment of lumbar tuberculosis (TB) in an elderly patient, and its clinical efficacy and feasibility. Lumbar TB is a destructive form of TB. Antituberculous treatment should be started as early as possible. In some circumstances, however, surgical debridement with or without stabilization of the spine appears to be beneficial and may be recommended. Surgeries through the approach of anterior or posterior are still challenging and often involve some complications. Patient concerns: The case is a 68-year-old female who was misdiagnosed as simple vertebral compression fracture and underwent L1 and L2 percutaneous vertebroplasty in another hospital 7 years ago. He complained of lumbosacral pain for 1 month this time. Magnetic resonance imaging (MRI) and computed tomography (CT) showed intervertebral space in L1/2 was seriously damaged like TB. Diagnoses: Lumbar tuberculosis Interventions: Antitubercular drugs, mini-invasive debridement with XLIF in combination with percutaneous pedicle screwsfixation was performed. This patient was followed up for 12 months. Outcomes: No obvious complication occurred during the operation and the wound healed well. Oswestry Disability Index (ODI: 56 vs 22) and visual analog scale (VAS: 4 vs 0) score significantly decreased atfinal follow-up of 12 months. Obvious recovery of kyphosis angle was found postoperatively (post: 14.8° vs pre: 33.5°). No recurrent infection occurred at the last follow-up. Lessons: Mini-invasive surgery by debridement through XLIF and percutaneous pedicle screwsfixation may be an effective and innovative treatment method for lumbar TB in the elderly. PMID:27902591

  9. Evaluation of Coflex interspinous stabilization following decompression compared with decompression and posterior lumbar interbody fusion for the treatment of lumbar degenerative disease: A minimum 5-year follow-up study.

    PubMed

    Yuan, Wei; Su, Qing-Jun; Liu, Tie; Yang, Jin-Cai; Kang, Nan; Guan, Li; Hai, Yong

    2017-01-01

    Few studies have compared the clinical and radiological outcomes between Coflex interspinous stabilization and posterior lumbar interbody fusion (PLIF) for degenerative lumbar disease. We compared the at least 5-year clinical and radiological outcomes of Coflex stabilization and PLIF for lumbar degenerative disease. Eighty-seven consecutive patients with lumbar degenerative disease were retrospectively reviewed. Forty-two patients underwent decompression and Coflex interspinous stabilization (Coflex group), 45 patients underwent decompression and PLIF (PLIF group). Clinical and radiological outcomes were evaluated. Coflex subjects experienced less blood loss, shorter hospital stays and shorter operative time than PLIF (all p<0.001). Both groups demonstrated significant improvement in Oswestry Disability Index and visual analogue scale back and leg pain at each follow-up time point. The Coflex group had significantly better clinical outcomes during early follow-up. At final follow-up, the superior and inferior adjacent segments motion had no significant change in the Coflex group, while the superior adjacent segment motion increased significantly in the PLIF group. At final follow-up, the operative level motion was significantly decreased in both groups, but was greater in the Coflex group. The reoperation rate for adjacent segment disease was higher in the PLIF group, but this did not achieve statistical significance (11.1% vs. 4.8%, p=0.277). Both groups provided sustainable improved clinical outcomes for lumbar degenerative disease through at least 5-year follow-up. The Coflex group had significantly better early efficacy than the PLIF group. Coflex interspinous implantation after decompression is safe and effective for lumbar degenerative disease.

  10. Applying the Mini-Open Anterolateral Lumbar Interbody Fusion with Self-Anchored Stand-Alone Polyetheretherketone Cage in Lumbar Revision Surgery

    PubMed Central

    Kuang, Lei; Chen, Yuqiao; Li, Lei; Lü, Guohua

    2016-01-01

    The author retrospectively studied twenty-two patients who underwent revision lumbar surgeries using ALLIF with a self-anchored stand-alone polyetheretherketone (PEEK) cage. The operation time, blood loss, and perioperative complications were evaluated. Oswestry disability index (ODI) scores and visual analog scale (VAS) scores of leg and back pain were analyzed preoperatively and at each time point of postoperative follow-up. Radiological evaluation including fusion, disc height, foraminal height, and subsidence was assessed. The results showed that the ALLIF with a self-anchored stand-alone PEEK cage is safe and effective in revision lumbar surgery with minor surgical trauma, low access-related complication rates, and satisfactory clinical and radiological results. PMID:27885355

  11. Anterior cervical discectomy and interbody fusion with porous tantalum implant. Results in a series with long-term follow-up.

    PubMed

    Papacci, Fabio; Rigante, Luigi; Fernandez, Eduardo; Meglio, Mario; Montano, Nicola

    2016-11-01

    Few papers have been published about the anterior cervical discectomy and fusion (ACDF) with implant of porous tantalum cages. These studies included patients submitted to operation at a single level. To our knowledge, we report the results of the largest series of ACDF with implant of porous tantalum cages. Our series included patients operated at a single or double level with a long follow-up (FU). We also discuss the pertinent literature. Clinical and outcome data of 99 consecutive patients (47 men, 52 women) submitted to ACDF with implant of porous tantalum cages (Trabecular Metal TM-S Cervical Fusion Device, Zimmer Spine, Minneapolis, MN) from June 2007 to September 2012, were retrospectively reviewed. Mean FU was 67.47±19.63months. The changes in pain were assessed using the Visual Analogue Scale (VAS). Patients were evaluated pre-operatively and at FU with the Short Form-36 Score Health Survey Version 2.0 (SF-36v2) for Physical Health and Mental Health Scores and the Neck Disability Index. We globally found a statistically significant improvement of all evaluated scores. Patients operated at two levels experienced a statistically significant improvement of all scores, with no statistical difference compared to patients operated at one level. No major complications occurred post-operatively and at FU. Only one patient (operated at two level) experienced an infection during FU. We conclude that ACDF with porous tantalum cages is a safe procedure, with long term clinical benefits (also in patients operated at two levels) and a very low rate of complications.

  12. The 'Lumbar Fusion Outcome Score' (LUFOS): a new practical and surgically oriented grading system for preoperative prediction of surgical outcomes after lumbar spinal fusion in patients with degenerative disc disease and refractory chronic axial low back pain.

    PubMed

    Mattei, Tobias A; Rehman, Azeem A; Teles, Alisson R; Aldag, Jean C; Dinh, Dzung H; McCall, Todd D

    2017-01-01

    In order to evaluate the predictive effect of non-invasive preoperative imaging methods on surgical outcomes of lumbar fusion for patients with degenerative disc disease (DDD) and refractory chronic axial low back pain (LBP), the authors conducted a retrospective review of 45 patients with DDD and refractory LBP submitted to anterior lumbar interbody fusion (ALIF) at a single center from 2007 to 2010. Surgical outcomes - as measured by Visual Analog Scale (VAS/back pain) and Oswestry Disability Index (ODI) - were evaluated pre-operatively and at 6 weeks, 3 months, 6 months, and 1 year post-operatively. Linear mixed-effects models were generated in order to identify possible preoperative imaging characteristics (including bone scan/99mTc scintigraphy increased endplate uptake, Modic endplate changes, and disc degeneration graded according to Pfirrmann classification) which may be predictive of long-term surgical outcomes . After controlling for confounders, a combined score, the Lumbar Fusion Outcome Score (LUFOS), was developed. The LUFOS grading system was able to stratify patients in two general groups (Non-surgical: LUFOS 0 and 1; Surgical: LUFOS 2 and 3) that presented significantly different surgical outcomes in terms of estimated marginal means of VAS/back pain (p = 0.001) and ODI (p = 0.006) beginning at 3 months and continuing up to 1 year of follow-up. In conclusion,  LUFOS has been devised as a new practical and surgically oriented grading system based on simple key parameters from non-invasive preoperative imaging exams (magnetic resonance imaging/MRI and bone scan/99mTc scintigraphy) which has been shown to be highly predictive of surgical outcomes of patients undergoing lumbar fusion for treatment for refractory chronic axial LBP.

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

    PubMed Central

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

    2010-01-01

    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

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

    PubMed

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

    2015-04-01

    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.

  15. Fusion

    NASA Astrophysics Data System (ADS)

    Herman, Robin

    1990-10-01

    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.

  16. The Memory Metal Minimal Access Cage: A New Concept in Lumbar Interbody Fusion—A Prospective, Noncomparative Study to Evaluate the Safety and Performance

    PubMed Central

    Kok, D.; Donk, R. D.; Wapstra, F. H.; Veldhuizen, A. G.

    2012-01-01

    Study Design/Objective. A single-centre, prospective, non-comparative study of 25 patients to evaluate the performance and safety of the Memory Metal Minimal Access Cage (MAC) in Lumbar Interbody Fusion. Summary of Background Data. Interbody fusion cages in general are designed to withstand high axial loads and in the meantime to allow ingrowth of new bone for bony fusion. In many cages the contact area with the endplate is rather large leaving a relatively small contact area for the bone graft with the adjacent host bone. MAC is constructed from the memory metal Nitinol and builds on the concept of sufficient axial support in combination with a large contact area of the graft facilitating bony ingrowth and ease in minimal access implantation due to its high deformability. Methods. Twenty five subjects with a primary diagnosis of disabling back and radicular leg pain from a single level degenerative lumbar disc underwent an interbody fusion using MAC and pedicle screws. Clinical performance was evaluated prospectively over 2 years using the Oswestry Disability Index (ODI), Short Form 36 questionnaire (SF-36) and pain visual analogue scale (VAS) scores. The interbody fusion status was assessed using conventional radiographs and CT scan. Safety of the device was studied by registration of intra- and post-operative adverse effects. Results. Clinical performance improved significantly (P < .0018), CT scan confirmed solid fusion in all 25 patients at two year follow-up. In two patients migration of the cage occurred, which was resolved uneventfully by placing a larger size at the subsequent revision. Conclusions. We conclude that the Memory Metal Minimal Access Cage (MAC) resulted in 100% solid fusions in 2 years and proved to be safe, although two patients required revision surgery in order to achieve solid fusion. PMID:22567409

  17. Anterolateral Radical Debridement and Interbody Bone Grafting Combined With Transpedicle Fixation in the Treatment of Thoracolumbar Spinal Tuberculosis

    PubMed Central

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

    2015-01-01

    Abstract 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

  18. Expandable Polyaryl-Ether-Ether-Ketone Spacers for Interbody Distraction in the Lumbar Spine

    PubMed Central

    Alimi, Marjan; Shin, Benjamin; Macielak, Michael; Hofstetter, Christoph P.; Njoku, Innocent; Tsiouris, Apostolos J.; Elowitz, Eric; Härtl, Roger

    2015-01-01

    Study Design Retrospective case series. Objective StaXx XD (Spine Wave, Inc., Shelton, CT, United States) is an expandable polyaryl-ether-ether-ketone (PEEK) wafer implant utilized in the treatment of lumbar degenerative disease. PEEK implants have been successfully used as interbody devices. Few studies have focused on expandable PEEK devices. The aim of the current study is to determine the radiographic and clinical outcome of expandable PEEK cages utilized for transforaminal lumbar interbody fusion in patients with lumbar degenerative diseases. Methods Forty-nine patients who underwent lumbar interbody fusion with implantation of expandable PEEK cages and posterior instrumentation were included. The clinical outcome was evaluated using the visual analog scale (VAS) and the Oswestry Disability Index (ODI). Radiographic parameters including disk height, foraminal height, listhesis, local disk angle of the index level/levels, regional lumbar lordosis, and graft subsidence were measured preoperatively, postoperatively, and at latest follow-up. Results At an average follow-up of 19.3 months, the minimum clinically important difference for the ODI and VAS back, buttock, and leg were achieved in 64, 52, 58, and 52% of the patients, respectively. There was statistically significant improvement in VAS back (6.42 versus 3.11, p < 0.001), VAS buttock (4.66 versus 1.97, p = 0.002), VAS leg (4.55 versus 1.96, p < 0.001), and ODI (21.7 versus 12.1, p < 0.001) scores. There was a significant increase in the average disk height (6.49 versus 8.18 mm, p = 0.037) and foraminal height (15.6 versus 18.53 mm, p = 0.0001), and a significant reduction in the listhesis (5.13 versus 3.15 mm, p = 0.005). The subsidence of 0.66 mm (7.4%) observed at the latest follow-up was not significant (p = 0.35). Conclusions Midterm results indicate that expandable PEEK spacers can effectively and durably restore disk and foraminal height and improve

  19. Novel spinal instrumentation to enhance osteogenesis and fusion: a preliminary study.

    PubMed

    MacEwan, Matthew R; Talcott, Michael R; Moran, Daniel W; Leuthardt, Eric C

    2016-09-01

    OBJECTIVE Instrumented spinal fusion continues to exhibit high failure rates in patients undergoing multilevel lumbar fusion or pseudarthrosis revision; with Grade II or higher spondylolisthesis; or in those possessing risk factors such as obesity, tobacco use, or metabolic disorders. Direct current (DC) electrical stimulation of bone growth represents a unique surgical adjunct in vertebral fusion procedures, yet existing spinal fusion stimulators are not optimized to enhance interbody fusion. To develop an advanced method of applying DC electrical stimulation to promote interbody fusion, a novel osteogenic spinal system capable of routing DC through rigid instrumentation and into the vertebral bodies was fabricated. A pilot study was designed to assess the feasibility of osteogenic instrumentation and compare the ability of osteogenic instrumentation to promote successful interbody fusion in vivo to standard spinal instrumentation with autograft. METHODS Instrumented, single-level, posterior lumbar interbody fusion (PLIF) with autologous graft was performed at L4-5 in adult Toggenburg/Alpine goats, using both osteogenic spinal instrumentation (plus electrical stimulation) and standard spinal instrumentation (no electrical stimulation). At terminal time points (3 months, 6 months), animals were killed and lumbar spines were explanted for radiographic analysis using a SOMATOM Dual Source Definition CT Scanner and high-resolution Microcat II CT Scanner. Trabecular continuity, radiodensity within the fusion mass, and regional bone formation were examined to determine successful spinal fusion. RESULTS Quantitative analysis of average bone density in pedicle screw beds confirmed that electroactive pedicle screws used in the osteogenic spinal system focally enhanced bone density in instrumented vertebral bodies. Qualitative and quantitative analysis of high-resolution CT scans of explanted lumbar spines further demonstrated that the osteogenic spinal system induced solid

  20. Midline Lumbar Fusion with Cortical Bone Trajectory Screw

    PubMed Central

    MIZUNO, Masaki; KURAISHI, Keita; UMEDA, Yasuyuki; SANO, Takanori; TSUJI, Masanori; SUZUKI, Hidenori

    2014-01-01

    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 mid-line 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

  1. ALIFE@Work: a randomised controlled trial of a distance counselling lifestyle programme for weight control among an overweight working population [ISRCTN04265725

    PubMed Central

    van Wier, Marieke F; Ariëns, Geertje AM; Dekkers, Johanna C; Hendriksen, Ingrid JM; Pronk, Nico P; Smid, Tjabe; van Mechelen, Willem

    2006-01-01

    Background The prevalence of overweight is increasing and its consequences will cause a major public health burden in the near future. Cost-effective interventions for weight control among the general population are therefore needed. The ALIFE@Work study is investigating a novel lifestyle intervention, aimed at the working population, with individual counselling through either phone or e-mail. This article describes the design of the study and the participant flow up to and including randomisation. Methods/Design ALIFE@Work is a controlled trial, with randomisation to three arms: a control group, a phone based intervention group and an internet based intervention group. The intervention takes six months and is based on a cognitive behavioural approach, addressing physical activity and diet. It consists of 10 lessons with feedback from a personal counsellor, either by phone or e-mail, between each lesson. Lessons contain educational content combined with behaviour change strategies. Assignments in each lesson teach the participant to apply these strategies to every day life. The study population consists of employees from seven Dutch companies. The most important inclusion criteria are having a body mass index (BMI) ≥ 25 kg/m2 and being an employed adult. Primary outcomes of the study are body weight and BMI, diet and physical activity. Other outcomes are: perceived health; empowerment; stage of change and self-efficacy concerning weight control, physical activity and eating habits; work performance/productivity; waist circumference, sum of skin folds, blood pressure, total blood cholesterol level and aerobic fitness. A cost-utility- and a cost-effectiveness analysis will be performed as well. Physiological outcomes are measured at baseline and after six and 24 months. Other outcomes are measured by questionnaire at baseline and after six, 12, 18 and 24 months. Statistical analyses for short term (six month) results are performed with multiple linear regression

  2. Outcomes of Demineralized Bone Matrix Enriched with Concentrated Bone Marrow Aspirate in Lumbar Fusion

    PubMed Central

    Eckardt, Mark A.; Hamamoto, Jason T.; Plotkin, Benjamin; Daubs, Michael D.; Wang, Jeffrey C.

    2016-01-01

    Background Multiple studies have demonstrated that a significant amount of variability exists in various demineralized bone matrix (DBM) formulations, which casts doubts on its reliability in consistently promoting fusion. Bone marrow aspirate (BMA) is a cellular based graft that contains mesenchymal stem cells (MSCs) and growth factors can confer osteogenic and osteoinductive potential to DBM. The goal of this study was to describe the outcome of DBM enriched with concentrated BMA in patients undergoing combined lumbar interbody and posterolateral fusion. Methods Eighty patients with a minimum of 12 months of follow-up were evaluated. Fusion and rates of complication were evaluated. Functional outcomes were assessed based on the modified Odom’s criteria. Multiple logistic regression analysis was used to examine the effects of independent variables on fusion outcome. Results The overall rate of solid fusion (i.e patients with both solid posterolateral and interbody fusion) was 81.3% (65/80). Specifically, the radiographic evidence of solid posterolateral and interbody fusions were 81.3% (65/80) and 92.5% (74/80), respectively. Seven (8.75%) patients developed hardware-related complications, 2 (2.5%) patients developed a postoperative infection and 2 (2.5%) patients developed clinical pseudarthrosis. Charlson comorbidity index (CCI) scores of 3 and 4 were associated with non-solid unions (CCI-3, p = 0.048; CCI-4, p = 0.03). Excellent or good outcomes were achieved in 58 (72.5%) patients. Conclusions Patients undergoing lumbar fusion using an enriched bone graft containing concentrated BMA added to DBM can achieve successful fusion with relatively low complications and good functional outcomes. Despite these findings, more studies with higher level of evidence are needed to better understand the efficacy of this promising graft option. PMID:27909656

  3. More nerve root injuries occur with minimally invasive lumbar surgery: Let's tell someone

    PubMed Central

    Epstein, Nancy E.

    2016-01-01

    Background: In a recent study entitled: “More nerve root injuries occur with minimally invasive lumbar surgery, especially extreme lateral interbody fusion (XLIF): A review”, Epstein documented that more nerve root injuries occurred utilizing minimally invasive surgery (MIS) versus open lumbar surgery for diskectomy, decompression of stenosis (laminectomy), and/or fusion for instability. Methods: In large multicenter Spine Patient Outcomes Research Trial reviews performed by Desai et al., nerve root injury with open diskectomy occurred in 0.13–0.25% of cases, occurred in 0% of laminectomy/stenosis with/without fusion cases, and just 2% for open laminectomy/stenosis/degenerative spondylolisthesis with/without fusion. Results: In another MIS series performed largely for disc disease (often contained nonsurgical disc herniations, therefore unnecessary procedures) or spondylolisthesis, the risk of root injury was 2% for transforaminal lumbar interbody fusion (TLIF) versus 7.8% for posterior lumbar interbody fusion (PLIF). Furthermore, the high frequencies of radiculitis/nerve root/plexus injuries incurring during anterior lumbar interbody fusions (ALIF: 15.8%) versus extreme lumbar interbody fusions (XLIF: 23.8%), addressing disc disease, failed back surgery, and spondylolisthesis, were far from acceptable. Conclusions: The incidence of nerve root injuries following any of the multiple MIS lumbar surgical techniques (TLIF/PLIF/ALIF/XLIF) resulted in more nerve root injuries when compared with open conventional lumbar surgical techniques. Considering the majority of these procedures are unnecessarily being performed for degenerative disc disease alone, spine surgeons should be increasingly asked why they are offering these operations to their patients? PMID:26904373

  4. Study ethnomathematics of aboge (alif, rebo, wage) calendar as determinant of the great days of Islam and traditional ceremony in Cirebon Kasepuhan Palace

    NASA Astrophysics Data System (ADS)

    Syahrin, Muhammad Alfi; Turmudi, Puspita, Entit

    2016-02-01

    This research attempts to show about the relationship between mathematics and culture. Paradigm that emerged currently, that mathematics is an abstract concept and difficult, therefore mathematics is not favored by most students. In the reality, indirectly mathematics is present in a culture of a society. Ethnomathematics study is a study to examine how does a group of people in a particular culture understand, express, and use the concepts and practices of culture that depicted mathematically. This research was conducted in Cirebon precisely in Kasepuhan Palace, which was in RW 04, Kasepuhan village, Lemah Wungkuk district, Cirebon city, West Java. The focus of the study and research purposes was the application of aboge (alif rebo wage) calendar as the calculation of days and the calendar rules determine the time of days, great days of Islam and traditional ceremony in Kasepuhan Palace. Qualitative methods with the principles of ethnography such as studies in ethnomathematics i.e observation, interviews, documentation and fieldnotes were used in this research. The findings of this ethnomathematics study show that the determining great days of Islam and the days of palace traditional ceremony have a close relationship with the counts and principles in mathematics. This study provides recommendations that mathematics is closely related to culture due to ethnomathematics.

  5. A Clinical Investigation of Contralateral Neurological Symptom after Transforaminal Lumbar Interbody Fusion (TLIF)

    PubMed Central

    Bai, Jiayue; Zhang, Wei; Zhang, Xin; Sun, Yapeng; Ding, Wenyuan; Shen, Yong

    2015-01-01

    Background The aim of this study was to analyze treatment outcomes and morbidity of contralateral neurological symptom in patients after TLIF surgery and to explore its possible causes. Material/Methods A retrospective study was conducted involving a total of 476 patients who underwent TILF from 2009 to 2012 in our hospital. These cases were divided into a symptomatic group (Group S) and a non-symptomatic group. The differences in contralateral foramen area and disc-height index(DHI) before and after surgery were compared between Group S and a random sample of 40 cases of non-symptomatic group patients (group N). In addition, according to whether the patient underwent second surgery, Group S patients were further divided into a transient neurologic symptoms group (Group T) and an operations exploration group (Group O). The time of symptom appearance, duration, and symptomatic severity (JOA VAS score) were compared between Group T and O. Results Among the 476 patients, 18 had postoperative contralateral neurological symptoms; thus, the morbidity was 3.7815%. The indicators in Group S were lower than in Group N in the differences in contralateral foramen area and disc-height index(DHI) before and after surgery (p<0.05). Five patients (Group O) in Group S had second surgery because of invalid conservative treatment. The surgical exploration rate was 1.0504%. Compared with Group T, the symptoms of Group O patients appeared earlier, persisted longer, and were more serious (p<0.05). Conclusions Contralateral neurological symptom is a potential complication after TLIF, and its causes are diverse. Surgical explorations should be conducted early for those patients with the complication who present with obvious nerve damage. PMID:26109143

  6. Spinal Fusion

    MedlinePlus

    ... concept of fusion is similar to that of welding in industry. Spinal fusion surgery, however, does not ... bone taken from the patient has a long history of use and results in predictable healing. Autograft ...

  7. [Early clinical effect of intervertebral fusion of lumbar degenerative disease using nano-hydroxyapatite/polyamide 66 intervertebral fusion cage].

    PubMed

    Yang, Bo; Ou, Yunsheng; Jiang, Dianming; An, Hong; Liu, Bo; Zhang, Jian; Li, Kaiting

    2014-10-01

    The present study is aimed to investigate the early clinical effects of nano-hydroxyapatite/polyamide 66 intervertebral fusion cage (n-HA/PA66 cage) for the treatment of lumbar degenerative diseases. We selected 27 patients with lumbar degenerative diseases who were managed by posterior decompression or reset operation combined with n-HA/PA66 cage intervertebral fusion and internal fixation from August 2010 to January 2012. The oswestry disability index (ODI), low back and leg pain visual analogue score (VAS), and intervertebral height (IH) were evaluated at preoperation, 1 week postoperation and the last follow-up period, respectively. Intervertebral bony fusion was evaluated at the last follow-up time. The patients were followed up for 12-24 months (averaged 19 months). The ODI, VAS and IH were significantly improved at 1 week postoperation and the last follow-up time compared with those at preoperative period (P < 0.05). But there was no significant difference between 1 week postoperative and the last follow-up time (P < 0.05). Brantigan's standard was used to evaluate fusion at the last follow-up time. There were 19 patients with grade 5 fusion, 8 with grade 4 fusion, with a fusion rate of 100%, and none with grade 1-3 fusions. There was no cage translocation and internal fixation breakage. These results suggested that n-HA/PA66 cage was an ideal biological material in the posterior lumbar interbody fusion and internal fixation operation for treatment of lumbar degenerative diseases. It can effectively maintain the intervertebral height and keep a high rate of bony fusion. The early clinical effect has been satisfactory.

  8. Radioscapholunate Fusions

    PubMed Central

    McGuire, Duncan Thomas; Bain, Gregory Ian

    2012-01-01

    Radiocarpal fusions are performed for a variety of indications, most commonly for debilitating painful arthritis. The goal of a wrist fusion is to fuse the painful, diseased joints and to preserve motion through the healthy joints. Depending on the extent of the disease process, radiocarpal fusions may take the form of radiolunate, radioscapholunate, or total wrist fusions. Surgical techniques and instrumentation have advanced over the last few decades, and consequently the functional outcomes have improved and complications decreased. Techniques for partial carpal fusions have improved and now include distal scaphoid and triquetrum excision, which improves range of motion and fusion rates. In this article we discuss the various surgical techniques and fixation methods available and review the corresponding evidence in the literature. The authors' preferred surgical technique of radioscapholunate fusion with distal scaphoid and triquetrum excision is outlined. New implants and new concepts are also discussed. PMID:24179717

  9. Shape optimization for the subsidence resistance of an interbody device using simulation-based genetic algorithms and experimental validation.

    PubMed

    Hsu, Ching-Chi

    2013-07-01

    Subsidence of interbody devices into the vertebral body might result in serious clinical problems, especially when the devices are not well designed and analyzed. Recently, some novel designs were proposed to reduce the risk of subsidence, but those designs are based on the researcher's experience. The purpose of this study was to discover the interbody device design with excellent subsidence resistance by changing the device's shape. The three-dimensional nonlinear finite element models, which consisted of the interbody device and vertebral body, were created first. Then, the simulation-based genetic algorithm, which combined the finite element model and the searching algorithm, was developed by using ANSYS® Parametric Design Language. Finally, the numerical results were carefully validated with the use of biomechanical tests. The optimum shape design obtained in this study looks like a flower with many petals and it has excellent subsidence resistance when compared with the other designs provided by the past studies. The results of the present study could help surgeons to understand the subsidence resistance of interbody devices in terms of their shapes and has directly provided the design rationales to engineers.

  10. Fusion breeder

    SciTech Connect

    Moir, R.W.

    1982-04-20

    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.

  11. Fusion breeder

    SciTech Connect

    Moir, R.W.

    1982-02-22

    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.

  12. Image fusion

    NASA Technical Reports Server (NTRS)

    Pavel, M.

    1993-01-01

    The topics covered include the following: a system overview of the basic components of a system designed to improve the ability of a pilot to fly through low-visibility conditions such as fog; the role of visual sciences; fusion issues; sensor characterization; sources of information; image processing; and image fusion.

  13. Fusion Power.

    ERIC Educational Resources Information Center

    Dingee, David A.

    1979-01-01

    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)

  14. Kinematic Magnetic Resonance Imaging Assessment of the Degenerative Cervical Spine: Changes after Anterior Decompression and Cage Fusion.

    PubMed

    Obradov, Marina; Bénard, Menno R; Janssen, Michiel M A; Anderson, Patricia G; Heesterbeek, Petra J C; Spruit, Maarten

    2016-11-01

    Study Design A prospective cohort study. Objective Decompression and fusion of cervical vertebrae is a combined procedure that has a high success rate in relieving radicular symptoms and stabilizing or improving cervical myelopathy. However, fusion may lead to increased motion of the adjacent vertebrae and cervical deformity. Both have been postulated to lead to adjacent segment pathology (ASP). Kinematic magnetic resonance imaging (MRI) has been increasingly used to evaluate range of motion (ROM) of the cervical spine and ASP. Our objective was to measure ASP, cervical curvature, and ROM of individual segments of the cervical spine using kinematic MRI before and 24 months after monosegmental cage fusion. Methods Eighteen patients who had single-level interbody fusion were included. ROM (using kinematic MRI) and degeneration, spinal stenosis, and cervical curvature were measured preoperatively and 24 months postoperatively. Results Using kinematic MRI, segmental motion of the cervical segments was measured with a precision of less than 3 degrees. The cervical fusion did not affect the ROM of adjacent levels. However, pre- and postoperative ROM was higher at the levels immediately adjacent to the fusion level compared with those further away. In addition, at 24 months postoperatively, the number of cases with ASP was higher at the levels immediately adjacent to fusion level. Conclusions Using kinematic MRI, ROM after spinal fusion can be measured with high precision. Kinematic MRI can be used not only in clinical practice, but also to study intervention and its effect on postoperative biomechanics and ASP of cervical vertebrae.

  15. Laser fusion

    SciTech Connect

    Smit, W.A.; Boskma, P.

    1980-12-01

    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 physics, simulating weapons effects, and applications for new weapons, the military interest shifted from developing a laser-ignited hydrogen bomb to more sophisticated weapons and civilian applications for power generation. Civilian and military research now overlap, making it possible for several countries to continue weapons activities and permitting proliferation of nuclear weapons. These countries are reluctant to include inertial confinement fusion research in the Non-Proliferation Treaty. 16 references. (DCK)

  16. Spinal fusion

    MedlinePlus

    Liu G, Wong HK. Laminectomy and fusion. In: Shen FH, Samartzis D, Fessler RG, eds. Textbook of the Cervical Spine . Philadelphia, PA: Elsevier Saunders; 2015:chap 34. Wood GW. Arthrodesis of the spine. In: Canale ST, Beaty JH, eds. Campbell's Operative ...

  17. Cold fusion, Alchemist's dream

    SciTech Connect

    Clayton, E.D.

    1989-09-01

    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.

  18. Subsidence after single-level anterior cervical fusion with a stand-alone cage.

    PubMed

    Park, Jae-Young; Choi, Ki-Young; Moon, Bong Ju; Hur, Hyuk; Jang, Jae-Won; Lee, Jung-Kil

    2016-11-01

    To investigate the risk factors for subsidence in patients treated with stand-alone anterior cervical discectomy and fusion (ACDF) using polyetheretherketone (PEEK) cages for single-level degenerative cervical disease. Seventy-seven consecutive patients who underwent single-level stand-alone ACDF with a PEEK cage between 2005 and 2012 were included. Subsidence was defined as a decrease in the interbody height of more than 3mm on radiographs at the 1-year follow-up compared with that in the immediate post-operative image. Patients were divided into the subsidence and non-subsidence groups. The following factors were investigated in relation to the occurrence of subsidence: age, pre-operative overall cervical sagittal angle, segmental angle of the operated level, interbody height, cage height, cage devices and cage location (distance between anterior margin of the body endplate and that of the cage). The clinical outcomes were assessed with visual analog scale, modified Japanese Orthopedic Association score and neck disability index. Twenty-six out of the 77 (33.8%) patients had radiological signs of cage subsidence. Solid fusion was achieved in 25 out of the 26 patients (96.2%) in the subsidence group and in 47 out of the 51 patients (92.2%) in the non-subsidence group. More than 3mm distance between anterior margin of the vertebral body and that of the cage was significantly associated with subsidence (p<0.05). However, subsidence did not correlate with fusion rate or clinical outcomes. Cage location was the only significant risk factor. Therefore, cage location should be taken into consideration during stand-alone ACDF using PEEK cages.

  19. A Preliminary Report on the CO2 Laser for Lumbar Fusion: Safety, Efficacy and Technical Considerations.

    PubMed

    Villavicencio, Alan T; Burneikiene, Sigita; Babuska, Jason M; Nelson, Ewell L; Mason, Alexander; Rajpal, Sharad

    2015-04-01

    The purpose of this study was to evaluate potential technical advantages of the CO2 laser technology in mini-open transforaminal lumbar interbody fusion (TLIF) surgeries and report our preliminary clinical data on the safety and clinical outcomes. There is currently no literature discussing the recently redeveloped CO2 laser technology application for lumbar fusion. Safety and clinical outcomes were compared between two groups: 24 patients that underwent CO2 laser-assisted one-level TLIF surgeries and 30 patients that underwent standard one-level TLIF surgeries without the laser. There were no neural thermal injuries or other intraoperative laser-related complications encountered in this cohort of patients. At a mean follow-up of 17.4 months, significantly reduced lower back pain scores (P=0.013) were reported in the laser-assisted patient group compared to a standard fusion patient group. Lower extremity radicular pain intensity scores were similar in both groups. Laser-assisted TLIF surgeries showed a tendency (P = 0.07) of shorter operative times that was not statistically significant. Based on this preliminary clinical report, the safety of the CO2 laser device for lumbar fusion surgeries was assessed. There were no neural thermal injuries or other intraoperative laser-related complications encountered in this cohort of patients. Further investigation of CO2 laser-assisted lumbar fusion procedures is warranted in order to evaluate its effect on clinical outcomes.

  20. Off-label innovation: characterization through a case study of rhBMP-2 for spinal fusion.

    PubMed

    Schnurman, Zane; Smith, Michael L; Kondziolka, Douglas

    2016-09-01

    OBJECTIVE Off-label therapies are widely used in clinical practice by spinal surgeons. Some patients and practitioners have advocated for increased regulation of their use, and payers have increasingly questioned reimbursment for off-label therapies. In this study, the authors applied a model that quantifies publication data to analyze the developmental process from initial on-label use to off-label innovation, using as an example recombinant human bone morphogenetic protein 2 (rhBMP-2) because of its wide off-label use. METHODS As a case study of off-label innovation, the developmental patterns of rhBMP-2 from FDA-approved use for anterior lumbar interbody fusion to several of its off-label uses, including posterolateral lumbar fusion, anterior cervical discectomy and fusion, and posterior lumbar interbody fusion/transforaminal lumbar interbody fusion, were evaluated using the "progressive scholarly acceptance" (PSA) model. In this model, PSA is used as an end point indicating acceptance of a therapy or procedure by the relevant scientific community and is reached when the total number of peer-reviewed studies devoted to refinement or improvement of a therapy surpasses the total number assessing initial efficacy. Report characteristics, including the number of patients studied and study design, were assessed in addition to the time to and pattern of community acceptance, and results compared with previous developmental study findings. Disclosures and reported conflicts of interest for all articles were reviewed, and these data were also used in the analysis. RESULTS Publication data indicated that the acceptance of rhBMP-2 off-label therapies occurred more rapidly and with less evidence than previously studied on-label therapies. Additionally, the community appeared to respond more robustly (by rapidly changing publication patterns) to reports of adverse events than to new questions of efficacy. CONCLUSIONS The development of off-label therapies, including the

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

    PubMed

    Liu, Jingchen; Li, Ye; Wu, Yuntao

    2013-03-01

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

  2. The Fusion Energy Option

    NASA Astrophysics Data System (ADS)

    Dean, Stephen O.

    2004-06-01

    Presentations from a Fusion Power Associates symposium, The Fusion Energy Option, are summarized. The topics include perspectives on fossil fuel reserves, fusion as a source for hydrogen production, status and plans for the development of inertial fusion, planning for the construction of the International Thermonuclear Experimental Reactor, status and promise of alternate approaches to fusion and the need for R&D now on fusion technologies.

  3. Revitalizing Fusion via Fission Fusion

    NASA Astrophysics Data System (ADS)

    Manheimer, Wallace

    2001-10-01

    Existing tokamaks could generate significant nuclear fuel. TFTR, operating steady state with DT might generate enough fuel for a 300 MW nuclear reactor. The immediate goals of the magnetic fusion program would necessarily shift from a study of advanced plasma regimes in larger sized devices, to mostly known plasmas regimes, but at steady state or high duty cycle operation in DT plasmas. The science and engineering of breeding blankets would be equally important. Follow on projects could possibly produce nuclear fuel in large quantity at low price. Although today there is strong opposition to nuclear power in the United States, in a 21st century world of 10 billion people, all of whom will demand a middle class life style, nuclear energy will be important. Concern over greenhouse gases will also drive the world toward nuclear power. There are studies indicating that the world will need 10 TW of carbon free energy by 2050. It is difficult to see how this can be achieved without the breeding of nuclear fuel. By using the thorium cycle, proliferation risks are minimized. [1], [2]. 1 W. Manheimer, Fusion Technology, 36, 1, 1999, 2.W. Manheimer, Physics and Society, v 29, #3, p5, July, 2000

  4. In vivo experimental study of hat type cervical intervertebral fusion cage (HCIFC).

    PubMed

    Gu, Yu-tong; Yao, Zhen-jun; Jia, Lian-shun; Qi, Jin; Wang, Jun

    2010-12-01

    The purpose of this study was to compare the characteristics of interbody fusion achieved using the hat type cervical intervertebral fusion cage (HCIFC) with those of an autologous tricortical iliac crest graft, Harms cage and the carbon cage in a goat cervical spine model. Thirty-two goats underwent C3-4 discectomy and fusion. They were subdivided into four groups of eight goats each: group 1, autologous tricortical iliac crest bone graft; group 2, Harms cage filled with autologous iliac crest graft; group 3, carbon cage filled with autologous iliac bone; and group 4, HCIFC filled with autologous iliac graft. Radiography was performed pre- and postoperatively and after one, two, four, eight and 12 weeks. At the same time points, disc space height, intervertebral angle, and lordosis angle were measured. After 12 weeks, the goats were killed and fusion sites were harvested. Biomechanical testing was performed in flexion, extension, axial rotation, and lateral bending to determine the stiffness and range of motion. All cervical fusion specimens underwent histomorphological analyses. One week after operation, the disc space height (DSH), intervertebral angle (IVA) and lordosis angle (LA) of HCIFC and carbon cage were statistically greater than those of autologous iliac bone graft and Harms cage. Significantly higher values for DSH, IVA and LA were shown in cage-treated goats than in those that received bone graft over a 12-week period. The stiffness of Harms cage in axial rotation and lateral bending were statistically greater than that of other groups. Radiographic and histomorphological evaluation showed better fusion results in the cage groups than in the autologous bone group. HCIFC can provide a good intervertebral distractability and sufficient biomechanical stability for cervical fusion.

  5. Fusion energy

    NASA Astrophysics Data System (ADS)

    1990-09-01

    The main purpose of the International Thermonuclear Experimental Reactor (ITER) is to develop an experimental fusion reactor through the united efforts of many technologically advanced countries. The ITER terms of reference, issued jointly by the European Community, Japan, the USSR, and the United States, call for an integrated international design activity and constitute the basis of current activities. Joint work on ITER is carried out under the auspices of the International Atomic Energy Agency (IAEA), according to the terms of quadripartite agreement reached between the European Community, Japan, the USSR, and the United States. The site for joint technical work sessions is at the Max Planck Institute of Plasma Physics. Garching, Federal Republic of Germany. The ITER activities have two phases: a definition phase performed in 1988 and the present design phase (1989 to 1990). During the definition phase, a set of ITER technical characteristics and supporting research and development (R and D) activities were developed and reported. The present conceptual design phase of ITER lasts until the end of 1990. The objectives of this phase are to develop the design of ITER, perform a safety and environmental analysis, develop site requirements, define future R and D needs, and estimate cost, manpower, and schedule for construction and operation. A final report will be submitted at the end of 1990. This paper summarizes progress in the ITER program during the 1989 design phase.

  6. Fusion energy

    SciTech Connect

    Not Available

    1990-09-01

    The main purpose of the International Thermonuclear Experimental Reactor (ITER) is to develop an experimental fusion reactor through the united efforts of many technologically advanced countries. The ITER terms of reference, issued jointly by the European Community, Japan, the USSR, and the United States, call for an integrated international design activity and constitute the basis of current activities. Joint work on ITER is carried out under the auspices of the International Atomic Energy Agency (IAEA), according to the terms of quadripartite agreement reached between the European Community, Japan, the USSR, and the United States. The site for joint technical work sessions is at the MaxPlanck Institute of Plasma Physics. Garching, Federal Republic of Germany. The ITER activities have two phases: a definition phase performed in 1988 and the present design phase (1989--1990). During the definition phase, a set of ITER technical characteristics and supporting research and development (R D) activities were developed and reported. The present conceptual design phase of ITER lasts until the end of 1990. The objectives of this phase are to develop the design of ITER, perform a safety and environmental analysis, develop site requirements, define future R D needs, and estimate cost, manpower, and schedule for construction and operation. A final report will be submitted at the end of 1990. This paper summarizes progress in the ITER program during the 1989 design phase.

  7. Anterior lumbar interbody surgery for spondylosis results from a classically-trained neurosurgeon.

    PubMed

    Chatha, Gurkirat; Foo, Stacy W L; Lind, Christopher R P; Budgeon, Charley; Bannan, Paul E

    2014-09-01

    Anterior lumbar surgery for degenerative disc disease (DDD) is a relatively novel technique that can prevent damage to posterior osseous, muscular and ligamentous spinal elements. This study reports the outcomes and complications in 286 patients who underwent fusion - with artificial disc implants or combined fusion and artificial disc implants - by a single-operator neurosurgeon, with up to 24 months of follow-up. The visual analogue scale (VAS), Oswestry Disability Index (ODI), Short Form 36 (SF36) and prospective log of adverse events were used to assess the clinical outcome. Radiographic assessments of implant position and bony fusion were analysed. Intraoperative and postoperative complications were also recorded. Irrespective of pre-surgical symptoms (back pain alone or back and leg pain combined), workers' compensation status and type of surgical implant, clinically significant improvements in VAS, ODI and SF36 were primarily observed at 3 and/or 6 month follow-up, and improvements were maintained at 24 months after surgery. A 94% fusion rate was obtained; the overall complication was 9.8% which included 3.5% with vascular complications. The anterior lumbar approach can be used for treating DDD for both back pain and back and leg pain with low complication rates. With appropriate training, single-operator neurosurgeons can safely perform these surgeries.

  8. Osteoconductive hydroxyapatite coated PEEK for spinal fusion surgery

    NASA Astrophysics Data System (ADS)

    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

    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.

  9. Anterior extrusion of fusion cage in posttraumatic cervical disk disease.

    PubMed

    Amelot, Aymeric; Bouazza, Schahrazed; George, Bernard; Orabi, Mikael; Bresson, Damien

    2015-03-01

    Anterior interbody fusion of the cervical spine (ACDF) with bone grafts or cages has become the gold standard for treating cervical disk disease. Several technical modifications have been developed, but currently no consensus exists regarding the optimal technique. In addition, there is also evidence that complications are frequently associated with this procedure. A frequent cause for implant failure in monosegmental ACDF is cage migration into the vertebral end plates or the spinal canal. We report a patient admitted for sudden quadriparesis with complete motor deficit caused by posttraumatic cervical disk protrusion at C4-C5, resulting in spinal compression. ACDF using a titanium stand-alone cage was performed and cured the patient. At the 1-year follow-up visit, imaging showed asymptomatic anterior complete extrusion of the cage out of the disk space. To our knowledge, such an anterior cage migration without trauma has not been reported in the literature to date, and we tried to find technical reasons to explain this complication.

  10. Review of fusion synfuels

    SciTech Connect

    Fillo, J.A.

    1980-01-01

    Thermonuclear fusion offers an inexhaustible source of energy for the production of hydrogen from water. Depending on design, electric generation efficiencies of approx. 40 to 60% and hydrogen production efficiencies by high-temperature electrolysis of approx. 50 to 65% are projected for fusion reactors using high-temperatures blankets. Fusion/coal symbiotic systems appear economically promising for the first generation of commercial fusion synfuels plants. Coal production requirements and the environmental effects of large-scale coal usage would be greatly reduced by a fusion/coal system. In the long term, there could be a gradual transition to an inexhaustible energy system based solely on fusion.

  11. Current strategies for the restoration of adequate lordosis during lumbar fusion.

    PubMed

    Barrey, Cédric; Darnis, Alice

    2015-01-18

    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.

  12. Current strategies for the restoration of adequate lordosis during lumbar fusion

    PubMed Central

    Barrey, Cédric; Darnis, Alice

    2015-01-01

    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

  13. Recombinant Human Bone Morphogenetic Protein-2 in Posterolateral Spinal Fusion: What's the Right Dose?

    PubMed Central

    Jones, Clifford Barry; Sietsema, Debra Lynn

    2016-01-01

    Study Design Single center retrospective cohort analysis. Purpose The goal was to evaluate the influence of varying amount of recombinant human bone morphogenetic protein 2 (rhBMP-2) per level on fusion rates and complications in posterolateral spinal fusions. Overview of Literature rhBMP-2 has been utilized for lumbar posterolateral fusions for many years. Initial rhBMP-2 recommendations were 20 mg/level of fusion. Dose and concentration per level in current studies vary from 4.2 to 40 mg and 1.5 to 2.0 mg/mL, respectively. Variable fusion and complication rates have been reported. Methods Patients (n=1,610) undergoing instrumented lumbar spinal fusion (2003–2009) with utilization of rhBMP-2 were retrospectively evaluated. Patient demographics, body mass index (BMI), comorbidities, number of levels, associated interbody fusion, and types of bone void filler were analyzed. Fusions rates and nonunions were subdivided into number of levels and amount of rhBMP-2 used per level. Results Patients (n=559) were evaluated with 58.5% females having an average age of 63 years, BMI of 31 kg/m2. Number of levels fused ranged from 1 to 8. rhBMP-2 averaged 7.3 mg/level (range, 1.5–24 mg/level) based upon length of collagen sponge in relation to length of fusion levels. Patients with non-union formation had lower rhBMP-2 dose per level (p=0.016). A significant difference in non-union rate was found between patients undergoing fusion with <6 mg/level compared to those with >6 mg/level (9.1% vs. 2.4%, χ2=0.012). No significant differences were noted between 6–11.9 mg/level and ≥12 mg/level. No threshold was found for seroma formation or bone overgrowth. Conclusions Previous recommendation of 20 mg/level of rhBMP-2 is more than what is required for predictable fusion rates of 98%. No dose related increase of infection, seroma formation, and bone overgrowth has been found. In order to provide variable dosing and cost reduction, industry generated rhBMP-2 kit size should be

  14. Viral membrane fusion.

    PubMed

    Harrison, Stephen C

    2015-05-01

    Membrane fusion is an essential step when enveloped viruses enter cells. Lipid bilayer fusion requires catalysis to overcome a high kinetic barrier; viral fusion proteins are the agents that fulfill this catalytic function. Despite a variety of molecular architectures, these proteins facilitate fusion by essentially the same generic mechanism. Stimulated by a signal associated with arrival at the cell to be infected (e.g., receptor or co-receptor binding, proton binding in an endosome), they undergo a series of conformational changes. A hydrophobic segment (a "fusion loop" or "fusion peptide") engages the target-cell membrane and collapse of the bridging intermediate thus formed draws the two membranes (virus and cell) together. We know of three structural classes for viral fusion proteins. Structures for both pre- and postfusion conformations of illustrate the beginning and end points of a process that can be probed by single-virion measurements of fusion kinetics.

  15. Viral membrane fusion

    PubMed Central

    Harrison, Stephen C.

    2015-01-01

    Membrane fusion is an essential step when enveloped viruses enter cells. Lipid bilayer fusion requires catalysis to overcome a high kinetic barrier; viral fusion proteins are the agents that fulfill this catalytic function. Despite a variety of molecular architectures, these proteins facilitate fusion by essentially the same generic mechanism. Stimulated by a signal associated with arrival at the cell to be infected (e.g., receptor or co-receptor binding, proton binding in an endosome), they undergo a series of conformational changes. A hydrophobic segment (a “fusion loop” or “fusion peptide”) engages the target-cell membrane and collapse of the bridging intermediate thus formed draws the two membranes (virus and cell) together. We know of three structural classes for viral fusion proteins. Structures for both pre- and postfusion conformations of illustrate the beginning and end points of a process that can be probed by single-virion measurements of fusion kinetics. PMID:25866377

  16. Cold fusion research

    SciTech Connect

    1989-11-01

    I am pleased to forward to you the Final Report of the Cold Fusion Panel. This report reviews the current status of cold fusion and includes major chapters on Calorimetry and Excess Heat, Fusion Products and Materials Characterization. In addition, the report makes a number of conclusions and recommendations, as requested by the Secretary of Energy.

  17. Magneto-Inertial Fusion

    SciTech Connect

    Wurden, G. A.; Hsu, S. C.; Intrator, T. P.; Grabowski, T. C.; Degnan, J. H.; Domonkos, M.; Turchi, P. J.; Campbell, E. M.; Sinars, D. B.; Herrmann, M. C.; Betti, R.; Bauer, B. S.; Lindemuth, I. R.; Siemon, R. E.; Miller, R. L.; Laberge, M.; Delage, M.

    2015-11-17

    In this community white paper, we describe an approach to achieving fusion which employs a hybrid of elements from the traditional magnetic and inertial fusion concepts, called magneto-inertial fusion (MIF). The status of MIF research in North America at multiple institutions is summarized including recent progress, research opportunities, and future plans.

  18. A systematic review and meta-analysis of outcomes in hybrid constructs for multi-level lumbar degenerative disc disease.

    PubMed

    Lackey, Alan; Phan, Kevin; Mobbs, Ralph

    2016-12-01

    A systematic review and meta-analysis was performed to assess the effect of hybrid constructs which involve a total disc arthroplasty (TDA) with stand-alone anterior lumbar interbody fusion (ALIF) versus non-hybrid constructs including multi-level TDA, multi-level transforaminal lumbar interbody fusion (TLIF) with posterior transpedicular fixation or multi-level stand-alone ALIF as a surgical intervention for degenerative disc disease (DDD) in the lumbar spine. Primary outcomes analysed included the Oswestry Disability Index (ODI) and the Visual Analogue Scale (VAS) for back pain. A systematic search of Medline, Embase, Pubmed, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews and Google Scholar was undertaken by two separate reviewers and a meta-analysis of the outcomes was performed. Three studies met our search criteria. When comparing hybrid constructs to multi-level TDA or lumbar fusion (LF) improvements in back pain were found with a VAS back pain score reduction of 1.38 (P<0.00001) postoperatively and a VAS back pain score reduction of 0.99 points (P=0.0006) at 2-years follow-up. Results so far slightly favour clinically significant improved VAS back pain score outcomes postoperatively and at 2-years follow-up for hybrid constructs in multi-level lumbar DDD of the spine when compared with non-hybrid multi-level LF or TDA. It cannot however be concluded that a hybrid construct is superior to multi-level LF or TDA based on this meta-analysis. The results highlight the need for further prospective studies to delineate best practice in the management of degenerative disc disease of the lumbar spine.

  19. Arthrodesis to L5 versus S1 in long instrumentation and fusion for degenerative lumbar scoliosis.

    PubMed

    Cho, Kyu-Jung; Suk, Se-Il; Park, Seung-Rim; Kim, Jin-Hyok; Choi, Sung-Wook; Yoon, Young-Hyun; Won, Man-Hee

    2009-04-01

    There is a debate regarding the distal fusion level for degenerative lumbar scoliosis. Whether a healthy L5-S1 motion segment should be included or not in the fusion remains controversial. The purpose of this study was to determine the optimal indication for the fusion to the sacrum, and to compare the results of distal fusion to L5 versus the sacrum in the long instrumented fusion for degenerative lumbar scoliosis. A total of 45 patients who had undergone long instrumentation and fusion for degenerative lumbar scoliosis were evaluated with a minimum 2 year follow-up. Twenty-four patients (mean age 63.6) underwent fusion to L5 and 21 patients (mean age 65.6) underwent fusion to the sacrum. Supplemental interbody fusion was performed in 12 patients in the L5 group and eleven patients in the sacrum group. The number of levels fused was 6.08 segments (range 4-8) in the L5 group and 6.09 (range 4-9) in the sacrum group. Intraoperative blood loss (2,754 ml versus 2,938 ml) and operative time (220 min versus 229 min) were similar in both groups. The Cobb angle changed from 24.7 degrees before surgery to 6.8 degrees after surgery in the L5 group, and from 22.8 degrees to 7.7 degrees in the sacrum group without statistical difference. Correction of lumbar lordosis was statistically better in the sacrum group (P = 0.03). Less correction of lumbar lordosis in the L5 group seemed to be associated with subsequent advanced L5-S1 disc degeneration. The change of coronal and sagittal imbalance was not different in both groups. Subsequent advanced L5-S1 disc degeneration occurred in 58% of the patients in the L5 group. Symptomatic adjacent segment disease at L5-S1 developed in five patients. Interestingly, the development of adjacent segment disease was not related to the preoperative grade of disc degeneration, which proved minimal degeneration in the five patients. In the L5 group, there were nine patients of complications at L5-S1 segment, including adjacent segment disease at

  20. Magnetized target fusion and fusion propulsion

    NASA Astrophysics Data System (ADS)

    Kirkpatrick, Ronald C.

    2002-01-01

    Magnetized target fusion (MTF) is a thermonuclear fusion concept that is intermediate between the two mainline approaches, magnetic confinement and inertial confinement fusion (MCF and ICF). MTF incorporates some aspects of each and offers advantages over each of the mainline approaches. First, it provides a means of reducing the driver power requirements, thereby admitting a wider range of drivers than ICF. Second, the magnetic field is only used for insulation, not confinement, and the plasma is wall confined, so that plasma instabilities are traded in for hydrodynamic instabilities. However, the degree of compression required to reach fusion condition is lower than for ICF, so that hydrodynamic instabilities are much less threatening. The standoff driver innovation proposes to dynamically form the target plasma and a gaseous shell that compresses and confines the target plasma. Therefore, fusion target fabrication is traded in for a multiplicity of plasma guns, which must work in synchrony. The standoff driver embodiment of MTF leads to a fusion propulsion system concept that is potentially compact and lightweight. We will discuss the underlying physics of MTF and some of the details of the fusion propulsion concept using the standoff driver approach. We discuss here the optimization of an MTF target design for space propulsion. .

  1. Viral membrane fusion

    SciTech Connect

    Harrison, Stephen C.

    2015-05-15

    Membrane fusion is an essential step when enveloped viruses enter cells. Lipid bilayer fusion requires catalysis to overcome a high kinetic barrier; viral fusion proteins are the agents that fulfill this catalytic function. Despite a variety of molecular architectures, these proteins facilitate fusion by essentially the same generic mechanism. Stimulated by a signal associated with arrival at the cell to be infected (e.g., receptor or co-receptor binding, proton binding in an endosome), they undergo a series of conformational changes. A hydrophobic segment (a “fusion loop” or “fusion peptide”) engages the target-cell membrane and collapse of the bridging intermediate thus formed draws the two membranes (virus and cell) together. We know of three structural classes for viral fusion proteins. Structures for both pre- and postfusion conformations of illustrate the beginning and end points of a process that can be probed by single-virion measurements of fusion kinetics. - Highlights: • Viral fusion proteins overcome the high energy barrier to lipid bilayer merger. • Different molecular structures but the same catalytic mechanism. • Review describes properties of three known fusion-protein structural classes. • Single-virion fusion experiments elucidate mechanism.

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

    PubMed

    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

    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.

  3. Materials research for fusion

    NASA Astrophysics Data System (ADS)

    Knaster, J.; Moeslang, A.; Muroga, T.

    2016-05-01

    Fusion materials research started in the early 1970s following the observation of the degradation of irradiated materials used in the first commercial fission reactors. The technological challenges of fusion energy are intimately linked with the availability of suitable materials capable of reliably withstanding the extremely severe operational conditions of fusion reactors. Although fission and fusion materials exhibit common features, fusion materials research is broader. The harder mono-energetic spectrum associated with the deuterium-tritium fusion neutrons (14.1 MeV compared to <2 MeV on average for fission neutrons) releases significant amounts of hydrogen and helium as transmutation products that might lead to a (at present undetermined) degradation of structural materials after a few years of operation. Overcoming the historical lack of a fusion-relevant neutron source for materials testing is an essential pending step in fusion roadmaps. Structural materials development, together with research on functional materials capable of sustaining unprecedented power densities during plasma operation in a fusion reactor, have been the subject of decades of worldwide research efforts underpinning the present maturity of the fusion materials research programme.

  4. The development of whole blood titanium levels after instrumented spinal fusion – Is there a correlation between the number of fused segments and titanium levels?

    PubMed Central

    2012-01-01

    Background Most modern spinal implants contain titanium and remain in the patient’s body permanently. Local and systemic effects such as tissue necrosis, osteolysis and malignant cell transformation caused by implants have been described. Increasing tissue concentration and whole blood levels of ions are necessary before a disease caused by a contaminant develops. The aim of the present study was the measurement of whole blood titanium levels and the evaluation of a possible correlation between these changes and the number of fused segments. Methods A prospective study was designed to determine changes in whole blood titanium levels after spinal fusion and to analyze the correlation to the number of pedicle screws, cross connectors and interbody devices implanted. Blood samples were taken preoperatively in group I (n = 15), on the first, second and 10th day postoperatively, as well as 3 and 12 months after surgery. Group II (n = 16) served as a control group of volunteers who did not have any metal implants in the body. Blood samples were taken once in this group. The number of screw-rod-connections and the length of the spinal fusion were determined using radiographic pictures. This study was checked and approved by the ethical committee of the University of Tuebingen. Results The mean age in group I was 47 ± 22 years (range 16 - 85 years). There were three male (20%) and twelve female (80%) patients. The median number of fused segments was 5 (range 1 to 11 segments). No statistically significant increase in the titanium level was seen 12 months after surgery (mean difference: -7.2 μg/l, 95% CI: -26.9 to 12.5 μg/l, p = 0.446). By observing the individual titanium levels, 4 out of 15 patients demonstrated an increase in titanium levels 12 months after surgery. No statistically significant correlation between fused segments (r = -0.188, p = 0.503) length of instrumentation (r = -0.329, p = 0.231), number of

  5. Muon Catalyzed Fusion

    NASA Technical Reports Server (NTRS)

    Armour, Edward A.G.

    2007-01-01

    Muon catalyzed fusion is a process in which a negatively charged muon combines with two nuclei of isotopes of hydrogen, e.g, a proton and a deuteron or a deuteron and a triton, to form a muonic molecular ion in which the binding is so tight that nuclear fusion occurs. The muon is normally released after fusion has taken place and so can catalyze further fusions. As the muon has a mean lifetime of 2.2 microseconds, this is the maximum period over which a muon can participate in this process. This article gives an outline of the history of muon catalyzed fusion from 1947, when it was first realised that such a process might occur, to the present day. It includes a description of the contribution that Drachrnan has made to the theory of muon catalyzed fusion and the influence this has had on the author's research.

  6. Acute vertebral fracture after spinal fusion: a case report illustrating the added value of single-source dual-energy computed tomography to magnetic resonance imaging in a patient with spinal Instrumentation.

    PubMed

    Fuchs, M; Putzier, M; Pumberger, M; Hermann, K G; Diekhoff, T

    2016-09-01

    Magnetic resonance imaging (MRI) is degraded by metal-implant-induced artifacts when used for the diagnostic assessment of vertebral compression fractures in patients with instrumented spinal fusion. Dual-energy computed tomography (DECT) offers a promising supplementary imaging tool in these patients. This case report describes an 85-year-old woman who presented with a suspected acute vertebral fracture after long posterior lumbar interbody fusion. This is the first report of a vertebral fracture that showed bone marrow edema on DECT; however, edema was missed by an MRI STIR sequence owing to metal artifacts. Bone marrow assessment using DECT is less susceptible to metal artifacts than MRI, resulting in improved visualization of vertebral edema in the vicinity of fused vertebral bodies.

  7. Magnetic fusion reactor economics

    SciTech Connect

    Krakowski, R.A.

    1995-12-01

    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.

  8. Magnetic-confinement fusion

    NASA Astrophysics Data System (ADS)

    Ongena, J.; Koch, R.; Wolf, R.; Zohm, H.

    2016-05-01

    Our modern society requires environmentally friendly solutions for energy production. Energy can be released not only from the fission of heavy nuclei but also from the fusion of light nuclei. Nuclear fusion is an important option for a clean and safe solution for our long-term energy needs. The extremely high temperatures required for the fusion reaction are routinely realized in several magnetic-fusion machines. Since the early 1990s, up to 16 MW of fusion power has been released in pulses of a few seconds, corresponding to a power multiplication close to break-even. Our understanding of the very complex behaviour of a magnetized plasma at temperatures between 150 and 200 million °C surrounded by cold walls has also advanced substantially. This steady progress has resulted in the construction of ITER, a fusion device with a planned fusion power output of 500 MW in pulses of 400 s. ITER should provide answers to remaining important questions on the integration of physics and technology, through a full-size demonstration of a tenfold power multiplication, and on nuclear safety aspects. Here we review the basic physics underlying magnetic fusion: past achievements, present efforts and the prospects for future production of electrical energy. We also discuss questions related to the safety, waste management and decommissioning of a future fusion power plant.

  9. Cell fusion and nuclear fusion in plants.

    PubMed

    Maruyama, Daisuke; Ohtsu, Mina; Higashiyama, Tetsuya

    2016-12-01

    Eukaryotic cells are surrounded by a plasma membrane and have a large nucleus containing the genomic DNA, which is enclosed by a nuclear envelope consisting of the outer and inner nuclear membranes. Although these membranes maintain the identity of cells, they sometimes fuse to each other, such as to produce a zygote during sexual reproduction or to give rise to other characteristically polyploid tissues. Recent studies have demonstrated that the mechanisms of plasma membrane or nuclear membrane fusion in plants are shared to some extent with those of yeasts and animals, despite the unique features of plant cells including thick cell walls and intercellular connections. Here, we summarize the key factors in the fusion of these membranes during plant reproduction, and also focus on "non-gametic cell fusion," which was thought to be rare in plant tissue, in which each cell is separated by a cell wall.

  10. Controlled Nuclear Fusion.

    ERIC Educational Resources Information Center

    Glasstone, Samuel

    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…

  11. Antiproton catalyzed fusion

    SciTech Connect

    Morgan, D.L. Jr.; Perkins, L.J.; Haney, S.W.

    1995-05-15

    Because of the potential application to power production, it is important to investigate a wide range of possible means to achieve nuclear fusion, even those that may appear initially to be infeasible. In antiproton catalyzed fusion, the negative antiproton shields the repulsion between the positively charged nuclei of hydrogen isotopes, thus allowing a much higher level of penetration through the repulsive Coulomb barrier, and thereby greatly enhancing the fusion cross section. Because of their more compact wave function, the more massive antiprotons offer considerably more shielding than do negative muons. The effects of the shielding on fusion cross sections are most predominate, at low energies. If the antiproton could exist in the ground state with a nucleus for a sufficient time without annihilating, the fusion cross sections are so enhanced that at room temperature energies, values up to about 1,000 barns (that for d+t) would be possible. Unfortunately, the cross section for antiproton annihilation with the incoming nucleus is even higher. A model that provides an upper bound for the fusion to annihilation cross section for all relevant energies indicates that each antiproton will catalyze no more than about one fusion. Because the energy required to make one antiproton greatly exceeds the fusion energy that is released, this level of catalysis is far from adequate for power production.

  12. Fusion Science Education Outreach

    NASA Astrophysics Data System (ADS)

    Danielson, C. A.; DIII-D Education Group

    1996-11-01

    This presentation will focus on education outreach activities at General Atomics that have been expanded to include the general population on science education with a focus on fusion energy. Outreach materials are distributed upon request both nationally and internationally. These materials include a notebook containing copies of DIII--D tour panels, fusion poster, new fusion energy video, new fusion energy brochure, and the electromagnetic spectrum curriculum. The 1996 Fusion Forum (held in the House Caucus Room) included a student/ teacher lunch with Energy Secretary Hazel O'Leary and a private visit to the Forum exhibits. The continuing partnership with Kearny High School includes lectures, job shadowing, internship, equipment donations and an award-winning electric car-racing program. Development of distribution by CD of the existing interactive fusion energy kiosk and a virtual reality tour of the DIII--D facility are underway. The DIII--D fusion education WWW site includes e-mail addresses to ``Ask the Wizard,'' and/or receive GA's outreach materials. Steve Rodecker, a local science teacher, aided by DIII--D fusion staff, won his second Tapestry Award; he also was named the ``1995 National Science Teacher of the Year'' and will be present to share his experiences with the DIII--D educational outreach program.

  13. Two Horizons of Fusion

    ERIC Educational Resources Information Center

    Lo, Mun Ling; Chik, Pakey Pui Man

    2016-01-01

    In this paper, we aim to differentiate the internal and external horizons of "fusion." "Fusion" in the internal horizon relates to the structure and meaning of the object of learning as experienced by the learner. It clarifies the interrelationships among an object's critical features and aspects. It also illuminates the…

  14. Fusion Power Deployment

    SciTech Connect

    J.A. Schmidt; J.M. Ogden

    2002-02-06

    Fusion power plants could be part of a future portfolio of non-carbon dioxide producing energy supplies such as wind, solar, biomass, advanced fission power, and fossil energy with carbon dioxide sequestration. In this paper, we discuss key issues that could impact fusion energy deployment during the last half of this century. These include geographic issues such as resource availability, scale issues, energy storage requirements, and waste issues. The resource needs and waste production associated with fusion deployment in the U.S. should not pose serious problems. One important feature of fusion power is the fact that a fusion power plant should be locatable within most local or regional electrical distribution systems. For this reason, fusion power plants should not increase the burden of long distance power transmission to our distribution system. In contrast to fusion power, regional factors could play an important role in the deployment of renewable resources such as wind, solar and biomass or fossil energy with CO2 sequestration. We examine the role of these regional factors and their implications for fusion power deployment.

  15. Clinical outcomes following spinal fusion using an intraoperative computed tomographic 3D imaging system.

    PubMed

    Xiao, Roy; Miller, Jacob A; Sabharwal, Navin C; Lubelski, Daniel; Alentado, Vincent J; Healy, Andrew T; Mroz, Thomas E; Benzel, Edward C

    2017-03-03

    -related readmission (0.8% vs 2.2%, risk ratio [RR] 0.37; p = 0.05) and overall readmissions (4.9% vs 7.4%, RR 0.66; p = 0.07). The O-arm was significantly associated with decreased risk of reoperation for hardware failure (2.9% vs 5.9%, RR 0.50; p = 0.01), screw misplacement (1.6% vs 4.2%, RR 0.39; p < 0.01), and all-cause reoperation (5.2% vs 10.9%, RR 0.48; p < 0.01). Mixed-effects Cox proportional hazards modeling revealed that O-arm-assisted navigation was a significant predictor of decreased risk of reoperation (HR 0.49; p < 0.01). The protective effect of O-arm-assisted navigation against reoperation was durable in subset analysis of procedures involving < 5 vertebral levels (HR 0.44; p = 0.01) and ≥ 5 levels (HR 0.48; p = 0.03). Further subset analysis demonstrated that O-arm-assisted navigation predicted decreased risk of reoperation among patients undergoing posterolateral fusion only (HR 0.39; p < 0.01) and anterior lumbar interbody fusion (HR 0.22; p = 0.03), but not posterior/transforaminal lumbar interbody fusion. CONCLUSIONS To the authors' knowledge, the present study is the first to investigate clinical outcomes associated with O-arm-assisted navigation following thoracolumbar spinal fusion. O-arm-assisted navigation decreased the risk of reoperation to less than half the risk associated with freehand and fluoroscopic approaches. Future randomized controlled trials to corroborate the findings of the present study are warranted.

  16. Fusion Studies in Japan

    NASA Astrophysics Data System (ADS)

    Ogawa, Yuichi

    2016-05-01

    A new strategic energy plan decided by the Japanese Cabinet in 2014 strongly supports the steady promotion of nuclear fusion development activities, including the ITER project and the Broader Approach activities from the long-term viewpoint. Atomic Energy Commission (AEC) in Japan formulated the Third Phase Basic Program so as to promote an experimental fusion reactor project. In 2005 AEC has reviewed this Program, and discussed on selection and concentration among many projects of fusion reactor development. In addition to the promotion of ITER project, advanced tokamak research by JT-60SA, helical plasma experiment by LHD, FIREX project in laser fusion research and fusion engineering by IFMIF were highly prioritized. Although the basic concept is quite different between tokamak, helical and laser fusion researches, there exist a lot of common features such as plasma physics on 3-D magnetic geometry, high power heat load on plasma facing component and so on. Therefore, a synergetic scenario on fusion reactor development among various plasma confinement concepts would be important.

  17. Particle beam fusion

    SciTech Connect

    1980-12-31

    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.

  18. Spherical torus fusion reactor

    DOEpatents

    Martin Peng, Y.K.M.

    1985-10-03

    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.

  19. Fusion for Space Propulsion

    NASA Technical Reports Server (NTRS)

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

    2001-01-01

    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

  20. Laser-Driven Fusion.

    ERIC Educational Resources Information Center

    Gibson, A. F.

    1980-01-01

    Discusses the present status and future prospects of laser-driven fusion. Current research (which is classified under three main headings: laser-matter interaction processes, compression, and laser development) is also presented. (HM)

  1. Viral membrane fusion

    PubMed Central

    Harrison, Stephen C

    2008-01-01

    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 two bilayers. We describe three examples—the influenza virus hemagglutinin, the flavivirus E protein and the vesicular stomatitis virus G protein—in some detail, to illustrate the ways in which different structures have evolved to implement this common mechanism. Fusion inhibitors can be effective antiviral agents. PMID:18596815

  2. Fusion-breeder program

    SciTech Connect

    Moir, R.W.

    1982-11-19

    The various approaches to a combined fusion-fission reactor for the purpose of breeding /sup 239/Pu and /sup 233/U are described. Design aspects and cost estimates for fuel production and electricity generation are discussed. (MOW)

  3. Complication rate during multilevel lumbar fusion in patients above 60 years

    PubMed Central

    Mahesh, Bijjawara; Upendra, Bidre; Vijay, S; Kumar, GC Arun; Reddy, Srinivas

    2017-01-01

    reducing the number of interbody fusions can help in reducing the complications.

  4. Glossary of fusion energy

    NASA Astrophysics Data System (ADS)

    Whitson, M. O.

    1985-02-01

    The Glossary of Fusion Energy is an attempt to present a concise, yet comprehensive collection of terms that may be beneficial to scientists and laymen who are directly or tangentially concerned with this burgeoning energy enterprise. Included are definitions of terms in theoretical plasma physics, controlled thermonuclear fusion, and some related physics concepts. Also, short descriptions of some of the major thermonuclear experiments currently under way in the world today are included.

  5. Cold nuclear fusion

    SciTech Connect

    Tsyganov, E. N.

    2012-02-15

    Recent accelerator experiments on fusion of various elements have clearly demonstrated that the effective cross-sections of these reactions depend on what material the target particle is placed in. In these experiments, there was a significant increase in the probability of interaction when target nuclei are imbedded in a conducting crystal or are a part of it. These experiments open a new perspective on the problem of so-called cold nuclear fusion.

  6. Fusion ignition research experiment

    SciTech Connect

    Dale Meade

    2000-07-18

    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.

  7. Magnetized Target Fusion

    NASA Technical Reports Server (NTRS)

    Griffin, Steven T.

    2002-01-01

    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.

  8. ITER Fusion Energy

    ScienceCinema

    Dr. Norbert Holtkamp

    2016-07-12

    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.

  9. Porous titanium-nickel for intervertebral fusion in a sheep model: part 2. Surface analysis and nickel release assessment.

    PubMed

    Assad, M; Chernyshov, A V; Jarzem, P; Leroux, M A; Coillard, C; Charette, S; Rivard, C H

    2003-02-15

    Porous titanium-nickel (PTN) devices represent an alternative to traditional cage implants. PTN materials possess an interconnecting network of pores with capillarity properties that may promote bone ingrowth, long-term fixation, and intervertebral fusion without the need for bone grafting. However, their considerable surface area and nickel content may elicit concerns over sensitization potential. Therefore, PTN surface corrosion and nickel release resistance must be carefully studied. To evaluate this possibility, a PTN interbody fusion device (IFD) was compared to a conventional nonporous cage made of TiAlV, a well-known biocompatible biomaterial, in a sheep model. PTN and TiAlV IFDs were inserted at two non-contiguous lumbar sites for 3, 6, and 12 months postsurgery. Their surface was then evaluated by scanning electron microscopy (SEM) combined with backscattered electron analysis (BSE). No evidence of surface corrosion was observed either pre- or postimplantation, regardless of device type. Dosage of nickel ions was also performed with the use of inductively coupled plasma-mass spectrometry (ICP-MS). Blood nickel levels were observed to be within acceptable levels at all postinstrumentation times. Nickel content in PTN-adjacent tissue, as well as in detoxification and remote organs, was equivalent both in PTN-treated and control sheep. Therefore, porous titanium-nickel demonstrated resistance to both in vivo surface corrosion and nickel ion release and compared very well with a conventional titanium implant in the course of a 12-month sheep study.

  10. Fusion for Space Propulsion

    NASA Technical Reports Server (NTRS)

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

    2001-01-01

    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

  11. Myoblast fusion in Drosophila

    SciTech Connect

    Haralalka, Shruti; Abmayr, Susan M.

    2010-11-01

    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.

  12. Fusion, magnetic confinement

    SciTech Connect

    Berk, H.L.

    1992-08-06

    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.

  13. Clear Zone Formation around Screws in the Early Postoperative Stages after Posterior Lumbar Fusion Using the Cortical Bone Trajectory Technique

    PubMed Central

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

    2015-01-01

    Study Design Retrospective study. Purpose To evaluate the initial fixation using the cortical bone trajectory (CBT) technique for posterior lumbar fusion through assessment of the clear zones around the screws and the risk factors involved. Overview of Literature Postoperative radiolucent zones (clear zones) are an indicator of poor conventional pedicle screw fixation. Methods Between January 2013 and April 2014, 19 patients (8 men and 11 women) underwent posterior lumbar interbody fusion or posterior lumbar fusion using the CBT technique. A total of 109 screws were used for evaluation with measurement of the maximum insertional torque of last two screw rotations. Clear zone-positivity on plain radiographs was investigated 6 months after surgery. The relation between intraoperative insertional torque and clear zone-positivity was investigated by one-way analysis of variance. In addition, the correlation between clear zone-positivity and gender, age (<75 years old or >75 years old), or operative stabilization level (<2 or >3 vertebral levels) was evaluated using the chi-square test. Results Clear zones were observed around six screws (5.50%) in five patients (26.3%). The mean insertional torque (4.00±2.09 inlbs) of clear zone-positive screws was lower than that of clear zone-negative screws (8.12±0.50 in-lbs), but the difference was not significant. There was a significant correlation between clear zone-positivity and operative level of stabilization. Conclusions The low incidence of clear zone-positive screws indicates good initial fixation using the CBT technique. Multilevel fusions may be risk factors for clear zone generation. PMID:26713120

  14. Instrumented reduction and monosegmental fusion for Meyerding Grade IV developmental spondylolisthesis: a report of 3 cases.

    PubMed

    Mizuno, Kentaro; Mikami, Yasuo; Nagae, Masateru; Tonomura, Hitoshi; Ikeda, Takumi; Fujiwara, Hiroyoshi; Kubo, Toshikazu

    2014-12-01

    There are numerous reports of treatment methods for spondylolisthesis with a Meyerding Grade of more than III. In high dysplastic spondylosthesis, surgical treatment was selected because there is considered to be a high possibility of low back pain and lower limb neurological symptoms worsening if slippage progresses. Monosegmental lumbar interbody fusion (L5-S1) with a pedicle screw system (PPS) was used to treat three cases of Meyerding Grade IV developmental spondylolisthesis. Patients gave written informed consent. The spondylolisthesis was reduced to Meyerding Grade I and sagittal balance improved in all three cases. In two cases with severe spinal instability, there were no postoperative neurological complications and the course was favorable. However, in one case with little spinal mobility due to vertebral body dysplasia, despite performing sufficient decompression of the nerve root at L5 and slow reduction to avoid placing excessive tension on the nerve root, a transient neurological disorder was observed. A PPS was used to increase the reduction strength and favorable reduction was possible. However, in the case with a long clinical course and the case with poor spinal mobility, since the mobility and plasticity of the nerve root itself may have been reduced, it was considered that reduction should be performed carefully using intraoperative neurological monitoring.

  15. Instrumented Reduction and Monosegmental Fusion for Meyerding Grade IV Developmental Spondylolisthesis

    PubMed Central

    Mizuno, Kentaro; Mikami, Yasuo; Nagae, Masateru; Tonomura, Hitoshi; Ikeda, Takumi; Fujiwara, Hiroyoshi; Kubo, Toshikazu

    2014-01-01

    Abstract There are numerous reports of treatment methods for spondylolisthesis with a Meyerding Grade of more than III. In high dysplastic spondylosthesis, surgical treatment was selected because there is considered to be a high possibility of low back pain and lower limb neurological symptoms worsening if slippage progresses. Monosegmental lumbar interbody fusion (L5–S1) with a pedicle screw system (PPS) was used to treat three cases of Meyerding Grade IV developmental spondylolisthesis. Patients gave written informed consent. The spondylolisthesis was reduced to Meyerding Grade I and sagittal balance improved in all three cases. In two cases with severe spinal instability, there were no postoperative neurological complications and the course was favorable. However, in one case with little spinal mobility due to vertebral body dysplasia, despite performing sufficient decompression of the nerve root at L5 and slow reduction to avoid placing excessive tension on the nerve root, a transient neurological disorder was observed. A PPS was used to increase the reduction strength and favorable reduction was possible. However, in the case with a long clinical course and the case with poor spinal mobility, since the mobility and plasticity of the nerve root itself may have been reduced, it was considered that reduction should be performed carefully using intraoperative neurological monitoring. PMID:25546662

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

    PubMed

    König, M A; Boszczyk, B M

    2012-03-01

    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

  17. Peaceful Uses of Fusion

    DOE R&D Accomplishments Database

    Teller, E.

    1958-07-03

    Applications of thermonuclear energy for peaceful and constructive purposes are surveyed. Developments and problems in the release and control of fusion energy are reviewed. It is pointed out that the future of thermonuclear power reactors will depend upon the construction of a machine that produces more electric energy than it consumes. The fuel for thermonuclear reactors is cheap and practically inexhaustible. Thermonuclear reactors produce less dangerous radioactive materials than fission reactors and, when once brought under control, are not as likely to be subject to dangerous excursions. The interaction of the hot plasma with magnetic fields opens the way for the direct production of electricity. It is possible that explosive fusion energy released underground may be harnessed for the production of electricity before the same feat is accomplished in controlled fusion processes. Applications of underground detonations of fission devices in mining and for the enhancement of oil flow in large low-specific-yield formations are also suggested.

  18. Spherical torus fusion reactor

    DOEpatents

    Peng, Yueng-Kay M.

    1989-01-01

    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.

  19. Spherical torus fusion reactor

    DOEpatents

    Peng, Yueng-Kay M.

    1989-04-04

    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.

  20. Ceramics for fusion applications

    SciTech Connect

    Clinard, F.W. Jr.

    1986-01-01

    Ceramics are required for a variety of uses in both near-term fusion devices and in commercial powerplants. These materials must retain adequate structural and electrical properties under conditions of neutron, particle, and ionizing irradiation; thermal and applied stresses; and physical and chemical sputtering. Ceramics such as Al/sub 2/O/sub 3/, MgAl/sub 2/O/sub 4/, BeO, Si/sub 3/N/sub 4/ and SiC are currently under study for fusion applications, and results to date show widely-varying response to the fusion environment. Materials can be identified today which will meet initial operating requirements, but improvements in physical properties are needed to achieve satisfactory lifetimes for critical applications.

  1. Fusion research at ORNL

    SciTech Connect

    Not Available

    1982-03-01

    The ORNL Fusion Program includes the experimental and theoretical study of two different classes of magnetic confinement schemes - systems with helical magnetic fields, such as the tokamak and stellarator, and the ELMO Bumpy Torus (EBT) class of toroidally linked mirror systems; the development of technologies, including superconducting magnets, neutral atomic beam and radio frequency (rf) heating systems, fueling systems, materials, and diagnostics; the development of databases for atomic physics and radiation effects; the assessment of the environmental impact of magnetic fusion; and the design of advanced demonstration fusion devices. The program involves wide collaboration, both within ORNL and with other institutions. The elements of this program are shown. This document illustrates the program's scope; and aims by reviewing recent progress.

  2. Simulation of Fusion Plasmas

    ScienceCinema

    Holland, Chris [UC San Diego, San Diego, California, United States

    2016-07-12

    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.

  3. Study on the anatomy of the lumbosacral anterior great vessels pertinent to L5/S1 anterior interbody surgery with computer tomography angiography.

    PubMed

    Liu, Liehua; Liang, Yong; Zhou, Qiang; Zhang, Hong; Wang, Haoming; Li, Songtao; Zhao, Chen; Hou, Tianyong; Liu, Ling

    2014-12-01

    We investigate the anatomy of the lumbosacral anterior great vessels using computer tomography (CT) angiography before L5/S1 anterior interbody surgery. Sixty-two adult patients were selected. The location of the abdominal aortic bifurcation and common iliac venous confluence in the lumbar vertebrae and the anatomic parameters of the iliac vascular space (e.g., distances from the included angle vertex of the iliac vascular space to the median sagittal plane and to the inferior boundary of L5 and distances between the left and right iliac vessels on the inferior boundary of L5 and on the superior boundary of S1) were analysed. Overall, 67.73% of the 62 cases had an abdominal aortic bifurcation located at L4 and L4/5 intervertebral disc; 61.29%, the common iliac venous confluence located at L5. The four distances mentioned above were 0.98 cm ± 0.38 cm, 2.01 cm ± 1.26 cm, 3.11 cm ± 1.35 cm and 4.34 cm ± 1.10 cm, respectively. A classification system of types A, B and C was developed. The calculated L5/S1 intervertebral space exposure percentages of types A, B and C were 32.21%, 82.58% and 54.68%, respectively. During L5/S1 anterior interbody surgery, type B intervertebral discs can be exposed conveniently, preventing injury of the iliac vessels, which was also observed in 54.68% and 32.21% of the type C and type A discs, respectively. Because the type A intervertebral disc has minimal exposure, the risk of iliac vascular injury is relatively high in these patients.

  4. Intense fusion neutron sources

    NASA Astrophysics Data System (ADS)

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

    2010-04-01

    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.

  5. Atomic data for fusion

    SciTech Connect

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

    1990-07-01

    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.

  6. Fusion welding process

    DOEpatents

    Thomas, Kenneth C.; Jones, Eric D.; McBride, Marvin A.

    1983-01-01

    A process for the fusion welding of nickel alloy steel members wherein a ferrite containing pellet is inserted into a cavity in one member and melted by a welding torch. The resulting weld nugget, a fusion of the nickel containing alloy from the members to be welded and the pellet, has a composition which is sufficiently low in nickel content such that ferrite phases occur within the weld nugget, resulting in improved weld properties. The steel alloys encompassed also include alloys containing carbon and manganese, considered nickel equivalents.

  7. Fusion for Space Propulsion

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

    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

  8. Multisensor data fusion algorithm development

    SciTech Connect

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

    1995-12-01

    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.

  9. Workmanship standards for fusion welding

    NASA Technical Reports Server (NTRS)

    Phillips, M. D.

    1967-01-01

    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.

  10. Fusion Engineering Device design description

    SciTech Connect

    Flanagan, C.A.; Steiner, D.; Smith, G.E.

    1981-12-01

    The US Magnetic Fusion Engineering Act of 1980 calls for the operation of a Fusion Engineering Device (FED) by 1990. It is the intent of the Act that the FED, in combination with other testing facilities, will establish the engineering feasibility of magnetic fusion energy. During 1981, the Fusion Engineering Design Center (FEDC), under the guidance of a Technical Management Board (TMB), developed a baseline design for the FED. This design is summarized herein.

  11. Fusion engineering device design description

    SciTech Connect

    Flanagan, C.A.; Steiner, D.; Smith, G.E.

    1981-12-01

    The US Magnetic Fusion Engineering Act of 1980 calls for the operation of a Fusion Engineering Device (FED) by 1990. It is the intent of the Act that the FED, in combination with other testing facilities, will establish the engineering feasibility of magnetic fusion energy. During 1981, the Fusion Engineering Design Center (FEDC), under the guidance of a Technical Management Board (TMB), developed a baseline design for the FED. This design is summarized herein.

  12. Mars manned fusion spaceship

    SciTech Connect

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

    1991-01-01

    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. Helium can be obtained from lunar mining. There will be minimal external radiation from the reactor resulting in a safe, efficient propulsion system.

  13. Mars manned fusion spaceship

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

    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.

  14. Auditory Fusion in Children.

    ERIC Educational Resources Information Center

    Davis, Sylvia M.; McCroskey, Robert L.

    1980-01-01

    Focuses on auditory fusion (defined in terms of a listerner's ability to distinguish paired acoustic events from single acoustic events) in 3- to 12-year-old children. The subjects listened to 270 pairs of tones controlled for frequency, intensity, and duration. (CM)

  15. A fusion of minds

    NASA Astrophysics Data System (ADS)

    Corfield, Richard

    2013-02-01

    Mystery still surrounds the visit of the astronomer Sir Bernard Lovell to the Soviet Union in 1963. But his collaboration - and that of other British scientists - eased geopolitical tensions at the height of the Cold War and paved the way for today's global ITER fusion project, as Richard Corfield explains.

  16. Synergetic Multisensor Fusion

    DTIC Science & Technology

    1990-11-30

    technology have led to increased interest in using DEMs for navigation and other applications. In particular, DEMs are attractive for use in aircraft...Multisensor Fusion for Computer Vision [67]. 30 6. POSI!IONAL zSTIM&TION TECEnIQUzs FOR AN OUTDOOR MOBLE ROBOT The autonomous navigation of mobile robots is

  17. Fusion reactor materials

    SciTech Connect

    none,

    1989-01-01

    This paper discuses the following topics on fusion reactor materials: irradiation, facilities, test matrices, and experimental methods; dosimetry, damage parameters, and activation calculations; materials engineering and design requirements; fundamental mechanical behavior; radiation effects; development of structural alloys; solid breeding materials; and ceramics.

  18. Human-Centered Fusion Framework

    SciTech Connect

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

    2007-05-16

    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.

  19. Graphite for fusion energy applications

    SciTech Connect

    Eatherly, W.P.; Clausing, R.E.; Strehlow, R.A.; Kennedy, C.R.; Mioduszewski, P.K.

    1987-03-01

    Graphite is in widespread and beneficial use in present fusion energy devices. This report reflects the view of graphite materials scientists on using graphite in fusion devices. Graphite properties are discussed with emphasis on application to fusion reactors. This report is intended to be introductory and descriptive and is not intended to serve as a definitive information source. (JDH)

  20. Anterior to psoas (ATP) fusion of the lumbar spine: evolution of a technique facilitated by changes in equipment

    PubMed Central

    Seex, Kevin

    2016-01-01

    Background Lateral interbody cages have been proven useful in spinal fusions. Spanning both lateral cortical rims while sparing the Anterior Longitudinal Ligament, the lateral interbody cages restore and maintain disc height while adding stability prior to supplemental fixation. The standard approach for their insertion is by a 90-degree lateral transpsoas method. This is relatively bloodless compared to other techniques although has its limitations, requiring neuro-monitoring and being, at times, very difficult at L4/5 due to iliac crest obstruction or an anterior plexus position. An oblique approach, with the patient in lateral decubitus, passes anterior to the iliac crest, retroperitoneal, and being anterior to psoas, eliminates the need for neuro-monitoring. Methods Twenty-one consecutive patients underwent surgery for a total of 32 levels instrumented with the ATP technique. Mean age at the time of surgery was 62.4±7.4 years. There was a 6 months minimum clinical follow up, with imaging to assess fusion, at 6 and 12 months. Indications included symptomatic degenerative lumbar spondylosis +/− spondylolisthesis, leg and back pain. All patients were assessed with the Oswestry Disability Index (ODI), Visual Analog Scale 100 mm for back pain (VASb) and for leg pain (VASl) preoperatively, at 3, 6 and 12 months. Last follow-up was at 12 months for 9 patients and the rest had 6 months follow up. Results Statistical analysis showed significance for the results in ODI, VASb and VASl with improvement in all components except for one patient with worsening VASl. Eight patients had complications related to surgery which were still present at last follow-up including moderate weakness of hip flexion and EHL weakness. Lateral cutaneous nerve (LCN) palsy on the side of the approach was also seen as well as sympathectomy effect related to the mobilization of the sympathetic trunk. One patient, who also suffered from multiple sclerosis, experienced psoas abscess 3 months

  1. Accelerators for heavy ion fusion

    SciTech Connect

    Bangerter, R.O.

    1985-10-01

    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.

  2. Surgical fusion in childhood spondylolisthesis.

    PubMed

    Stanton, R P; Meehan, P; Lovell, W W

    1985-01-01

    Twenty cases of surgical fusion for spondylolisthesis were reviewed at the Scottish Rite Hospital (Atlanta, GA, U.S.A.) to determine whether a procedure other than a simple posterolateral fusion is necessary for most patients. The patients were treated postoperatively with pantaloon spica cast immobilization. The fusion rate was high (90%), and patient satisfaction was high. One patient developed neurologic loss postoperatively. Two patients' slips progressed greater than 10% before solid fusion occurred. Thus, bilateral posterolateral fusion, followed by pantaloon spica cast immobilization, is effective for patients with symptomatic spondylolisthesis or asymptomatic children with grade 3 or greater slips. Reduction was not performed in this series.

  3. The path to fusion power.

    PubMed

    Llewellyn Smith, Chris; Ward, David

    2007-04-15

    Fusion is potentially an environmentally responsible and intrinsically safe source of essentially limitless power. It should be possible to build viable fusion power stations, and it looks as if the cost of fusion power will be reasonable. But time is needed to further develop the technology and to test in power station conditions the materials that would be used in their construction. Assuming no major adverse surprises, an orderly fusion development programme could lead to a prototype fusion power station putting electricity into the grid within 30 years, with commercial fusion power following some 10 or more years later. In the second half of the century, fusion could therefore be an important part of the portfolio of measures that are needed to cope with rising demand for energy in an environmentally responsible manner. In this paper, we describe the basics of fusion, its potential attractions, the status of fusion R&D, the remaining challenges and how they will be tackled at the International Tokamak Experimental Reactor and the proposed International Fusion Materials Irradiation Facility, and the timetable for the subsequent commercialization of fusion power.

  4. The Need for Fusion Propulsion

    NASA Technical Reports Server (NTRS)

    Cassibry, Jason

    2005-01-01

    Fusion propulsion is inevitable if the human race remains dedicated to exploration of the solar system. There are fundamental reasons why fusion surpasses more traditional approaches to routine crewed missions to Mars, crewed missions to the outer planets, and deep space high speed robotic missions, assuming that reduced trip times, increased payloads, and higher available power are desired. A recent series of informal discussions were held among members from government, academia, and industry concerning fusion propulsion. We compiled a sufficient set of arguments for utilizing fusion in space. If the U.S. is to lead the effort and produce a working system in a reasonable amount of time, NASA must take the initiative, relying on, but not waiting for, DOE guidance. In this talk those arguments for fusion propulsion are presented, along with fusion enabled mission examples, fusion technology trade space, and a proposed outline for future efforts.

  5. Fusion Data Grid Service

    NASA Astrophysics Data System (ADS)

    Shasharina, Svetlana; Wang, Nanbor

    2004-11-01

    Simulations and experiments in the fusion and plasma physics community generate large datasets at remote sites. Visualization and analysis of these datasets are difficult because of the incompatibility among the various data formats adopted by simulation, experiments, and analysis tools, and the large sizes of analyzed data. Grids and Web Services technologies are capable of providing solutions for such heterogeneous settings, but need to be customized to the field-specific needs and merged with distributed technologies currently used by the community. This paper describes how we are addressing these issues in the Fusion Grid Service under development. We also present performance results of relevant data transfer mechanisms including binary SOAP, DIME, GridFTP and MDSplus and CORBA. We will describe the status of data converters (between HDF5 and MDSplus data types), developed in collaboration with MIT (J. Stillerman). Finally, we will analyze bottlenecks of MDSplus data transfer mechanism (work performed in collaboration with General Atomics (D. Schissel and M. Qian).

  6. Experiments in cold fusion

    SciTech Connect

    Palmer, E.P.

    1986-03-28

    The work of Steve Jones and others in muon-catalyzed cold fusion of deuterium and hydrogen suggests the possibility of such fusion catalyzed by ions, or combinations of atoms, or more-or-less free electrons in solid and liquid materials. A hint that this might occur naturally comes from the heat generated in volcanic action in subduction zones on the earth. It is questionable whether the potential energy of material raised to the height of a midocean ridge and falling to the depth of an ocean trench can produce the geothermal effects seen in the volcanoes of subduction zones. If the ridge, the trench, the plates, and the asthenosphere are merely visible effects of deeper density-gradient driven circulations, it is still uncertain that observed energy-concentration effects fit the models.

  7. Fusion pumped laser

    DOEpatents

    Pappas, D.S.

    1987-07-31

    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.

  8. Unconventional approaches to fusion

    SciTech Connect

    Brunelli, B.; Leotta, G.G.

    1982-01-01

    This volume is dedicated to unconventional approaches to fusionthose thermonuclear reactors that, in comparison with Tokamak and other main lines, have received little attention in the worldwide scientific community. Many of the approaches considered are still in the embryonic stages. The authors-an international group of active nuclear scientists and engineers-focus on the parameters achieved in the use of these reactors and on the meaning of the most recent physical studies and their implications for the future. They also compare these approaches with conventional ones, the Tokamak in particular, stressing the non-plasma-physics requirements of fusion reactors. Unconventional compact toroids, linear systems, and multipoles are considered, as are the ''almost conventional'' fusion machines: stellarators, mirrors, reversed-field pinches, and EBT.

  9. Maximum Likelihood Fusion Model

    DTIC Science & Technology

    2014-08-09

    data fusion, hypothesis testing,maximum likelihood estimation, mobile robot navigation REPORT DOCUMENTATION PAGE 11. SPONSOR/MONITOR’S REPORT...61 vi 9 Bibliography 62 vii 10 LIST OF FIGURES 1.1 Illustration of mobile robotic agents. Land rovers such as (left) Pioneer robots ...simultaneous localization and mapping 1 15 Figure 1.1: Illustration of mobile robotic agents. Land rovers such as (left) Pioneer robots , (center) Segways

  10. Fusion development and technology

    SciTech Connect

    Montgomery, D.B.

    1992-01-01

    This report discusses the following: superconducting magnet technology; high field superconductors; advanced magnetic system and divertor development; poloidal field coils; gyrotron development; commercial reactor studies--aries; ITER physics: alpha physics and alcator R D for ITER; lower hybrid current drive and heating in the ITER device; ITER superconducting PF scenario and magnet analysis; ITER systems studies; and safety, environmental and economic factors in fusion development.

  11. (Fusion energy research)

    SciTech Connect

    Phillips, C.A.

    1988-01-01

    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.

  12. Modular Aneutronic Fusion Engine

    SciTech Connect

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

    2012-05-11

    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. __________________________________________________

  13. Pain acceptance potentially mediates the relationship between pain catastrophizing and post-surgery outcomes among compensated lumbar fusion patients

    PubMed Central

    Dance, Cassie; DeBerard, M. Scott; Gundy Cuneo, Jessica

    2017-01-01

    Purpose Chronic low back pain is highly prevalent and often treatment recalcitrant condition, particularly among workers’ compensation patients. There is a need to identify psychological factors that may predispose such patients to pain chronicity. The primary aim of this study was to examine whether pain acceptance potentially mediated the relationship between pain catastrophizing and post-surgical outcomes in a sample of compensated lumbar fusion patients. Patients and methods Patients insured with the Workers Compensation Fund of Utah and who were at least 2 years post-lumbar fusion surgery completed an outcome survey. These data were obtained from a prior retrospective-cohort study that administered measures of pain catastrophizing, pain acceptance, mental and physical health, and disability. Results Of the 101 patients who completed the outcome survey, 75.2% were male with a mean age of 42.42 years and predominantly identified as White (97.0%). The majority of the participants had a posterior lumbar interbody fusion surgery. Pain acceptance, including activity engagement and pain willingness, was significantly correlated with better physical health and mental health, and lower disability rates. Pain catastrophizing was inversely correlated with measures of pain acceptance (activity engagement r=−0.67, p<0.01, pain willingness r=−0.73, p<0.01) as well as the outcome measures: mental health, physical health, and disability. Pain acceptance significantly mediated the relationship between pain catastrophizing and both mental and physical health and also the relationship between pain catastrophizing and disability. Conclusion This study demonstrated that the relationship between pain catastrophizing and negative patient outcomes was potentially mediated by pain acceptance. Understanding this mediating relationship offers insight into how pain acceptance may play a protective role in patients’ pain and disability and has potential implications for pain

  14. Cold fusion studies

    NASA Astrophysics Data System (ADS)

    Hembree, D. M.; Burchfield, L. A.; Fuller, E. L., Jr.; Perey, F. G.; Mamantov, G.

    1990-06-01

    A series of experiments designed to detect the by-products expected from deuterium fusion occurring in the palladium and titanium cathodes of heavy water, D2O, electrolysis cells is reported. The primary purpose of this account is to outline the integrated experimental design developed to test the cold fusion hypothesis and to report preliminary results that support continuing the investigation. Apparent positive indicators of deuterium fusion were observed, but could not be repeated or proved to originate from the electrochemical cells. In one instance, two large increases in the neutron count rate, the largest of which exceeded the background by 27 standard deviations, were observed. In a separate experiment, one of the calorimetry cells appeared to be producing approximately 18 percent more power that the input value, but thermistor failure prevented an accurate recording of the event as a function of time. In general, the tritium levels in most cells followed the slow enrichment expected from the electrolysis of D2O containing a small amount of tritium. However, after 576 hours of electrolysis, one cell developed a tritium concentration approximately seven times greater than expected level.

  15. Stabilized Spheromak Fusion Reactors

    SciTech Connect

    Fowler, T

    2007-04-03

    The U.S. fusion energy program is focused on research with the potential for studying plasmas at thermonuclear temperatures, currently epitomized by the tokamak-based International Thermonuclear Experimental Reactor (ITER) but also continuing exploratory work on other plasma confinement concepts. Among the latter is the spheromak pursued on the SSPX facility at LLNL. Experiments in SSPX using electrostatic current drive by coaxial guns have now demonstrated stable spheromaks with good heat confinement, if the plasma is maintained near a Taylor state, but the anticipated high current amplification by gun injection has not yet been achieved. In future experiments and reactors, creating and maintaining a stable spheromak configuration at high magnetic field strength may require auxiliary current drive using neutral beams or RF power. Here we show that neutral beam current drive soon to be explored on SSPX could yield a compact spheromak reactor with current drive efficiency comparable to that of steady state tokamaks. Thus, while more will be learned about electrostatic current drive in coming months, results already achieved in SSPX could point to a productive parallel development path pursuing auxiliary current drive, consistent with plans to install neutral beams on SSPX in the near future. Among possible outcomes, spheromak research could also yield pulsed fusion reactors at lower capital cost than any fusion concept yet proposed.

  16. [Image fusion in medical radiology].

    PubMed

    Burger, C

    1996-07-20

    Image fusion supports the correlation between images of two or more studies of the same organ. First, the effect of differing geometries during image acquisitions, such as a head tilt, is compensated for. As a consequence, congruent images can easily be obtained. Instead of merely putting them side by side in a static manner and burdening the radiologist with the whole correlation task, image fusion supports him with interactive visualization techniques. This is especially worthwhile for small lesions as they can be more precisely located. Image fusion is feasible today. Easy and robust techniques are readily available, and furthermore DICOM, a rapidly evolving data exchange standard, diminishes the once severe compatibility problems for image data originating from systems of different manufacturers. However, the current solutions for image fusion are not yet established enough for a high throughput of fusion studies. Thus, for the time being image fusion is most appropriately confined to clinical research studies.

  17. High Level Information Fusion (HLIF) with nested fusion loops

    NASA Astrophysics Data System (ADS)

    Woodley, Robert; Gosnell, Michael; Fischer, Amber

    2013-05-01

    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.

  18. Network-centric data fusion

    NASA Astrophysics Data System (ADS)

    Nicholson, David; Lloyd, C. M.; Collins, Peter R. C.

    2002-08-01

    The performance of three distributed sensor fusion network architectures is investigated: a fully-connected and a partially-connected measurement fusion system and a partially-connected track fusion system. The investigation employs an advanced military scenario generator, FLAMES, which was customised for exercising a range of distributed data fusion experiments. Specifically, it includes a representative model of the delays in a communication system (such as JTIDS or Link 16). Here the delays were used to modify communication bandwidth and to evaluate how this affected the performance of the fusion architectures/algorithms. Under certain specific scenario conditions, it was found that decentralised measurement fusion system was severely affected by reduced bandwidth. This is because each node loads its communication buffer with every measurement and consequently some measurements are never transmitted. The decentralised track fusion system exhibits improved performance because it lumps measurements into tracks and thereby it makes much more effective use of the bandwidth. Moreover, it was found that the performance of the partially connected decentralised track fusion system was very close to the optimal performance achieved by the fully-connected decentralised measurement fusion system.

  19. OCULUS Sea Track Fusion Service

    NASA Astrophysics Data System (ADS)

    Panagiotou, Stylianos C.; Rizogiannis, Constantinos; Katsoulis, Stavros; Lampropoulos, Vassilis; Kanellopoulos, Sotirios; Thomopoulos, Stelios C. A.

    2015-06-01

    Oculus Sea is a complete solution regarding maritime surveillance and communications at Local as well as Central Command and Control level. It includes a robust and independent track fusion service whose main functions include: 1) Interaction with the User to suggest the fusion of two or more tracks, confirm Track ID and Vessel Metadata creation for the fused track, and suggest de-association of two tracks 2) Fusion of same vessel tracks arriving simultaneously from multiple radar sensors featuring track Association, track Fusion of associated tracks to produce a more accurate track, and Multiple tracking filters and fusion algorithms 3) Unique Track ID Generator for each fused track 4) Track Dissemination Service. Oculus Sea Track Fusion Service adopts a system architecture where each sensor is associated with a Kalman estimator/tracker that obtains an estimate of the state vector and its respective error covariance matrix. Finally, at the fusion center, association and track state estimation fusion are carried out. The expected benefits of this system include multi-sensor information fusion, enhanced spatial resolution, and improved target detection.

  20. Economic potential of inertial fusion

    SciTech Connect

    Nuckolls, J.H.

    1984-04-01

    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.

  1. Cold nuclear fusion

    NASA Astrophysics Data System (ADS)

    Tsyganov, E. N.; Bavizhev, M. D.; Buryakov, M. G.; Dabagov, S. B.; Golovatyuk, V. M.; Lobastov, S. P.

    2015-07-01

    If target deuterium atoms were implanted in a metal crystal in accelerator experiments, a sharp increase in the probability of DD-fusion reaction was clearly observed when compared with the reaction's theoretical value. The electronic screening potential, which for a collision of free deuterium atoms is about 27 eV, reached 300-700 eV in the case of the DD-fusion in metallic crystals. These data leads to the conclusion that a ban must exist for deuterium atoms to be in the ground state 1s in a niche filled with free conduction electrons. At the same time, the state 2p whose energy level is only 10 eV above that of state 1s is allowed in these conditions. With anisotropy of 2p, 3p or above orbitals, their spatial positions are strictly determined in the lattice coordinate system. When filling out the same potential niches with two deuterium atoms in the states 2p, 3p or higher, the nuclei of these atoms can be permanently positioned without creating much Coulomb repulsion at a very short distance from each other. In this case, the transparency of the potential barrier increases dramatically compared to the ground state 1s for these atoms. The probability of the deuterium nuclei penetrating the Coulomb barrier by zero quantum vibration of the DD-system also increases dramatically. The so-called cold nuclear DD-fusion for a number of years was registered in many experiments, however, was still rejected by mainstream science for allegedly having no consistent scientific explanation. Finally, it received the validation. Below, we outline the concept of this explanation and give the necessary calculations. This paper also considers the further destiny of the formed intermediate state of 4He∗.

  2. Physics of Fusion Welding

    NASA Technical Reports Server (NTRS)

    Nunes, A. C., Jr.

    1986-01-01

    Applicabilities and limitations of three techniques analyzed. NASA technical memorandum discusses physics of electron-beam, gas/ tungsten-arc, and laser-beam welding. From comparison of capabilities and limitations of each technique with regard to various welding conditions and materials, possible to develop criteria for selecting best welding technique in specific application. All three techniques classified as fusion welding; small volume of workpiece melted by intense heat source. Heat source moved along seam, leaving in wake solid metal that joins seam edges together.

  3. Cold Fusion Verification.

    DTIC Science & Technology

    1991-03-01

    published work, talking with others in the field, and attending conferences, that CNF probably is chimera and will go the way of N-rays and polywater ...way of N-rays and polywater . To date, no one, including Pons and Fleischmann, has been able to construct a so-called CNF electrochemical cell that...Cold Nuclear Fusion (CNF), as originally reported in 1989. The conclusion is that CNF probably is chimera and will go the way of N-rays and polywater

  4. Fusion reactor pumped laser

    DOEpatents

    Jassby, Daniel L.

    1988-01-01

    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.

  5. In-vitro MRI detectability of interbody test spacers made of carbon fibre-reinforced polymers, titanium and titanium-coated carbon fibre-reinforced polymers.

    PubMed

    Ernstberger, Thorsten; Buchhorn, Gottfried; Baums, Mike Herbert; Heidrich, Gabert

    2007-04-01

    The purpose of this study was to investigate how different materials affect the magnetic resonance imaging (MRI) detectability of interbody test spacers (ITS). We evaluated the post-implantation MRI scans with T1 TSE sequences for three different ITS made of titanium, carbon fibre-reinforced polymers (CFRP) and titanium-coated CFRP, respectively. The main target variables were total artefact volume (TAV) and median artefact area (MAA). Additionally, implant volume (IV)/TAV and cross section (CS)/MAA ratio were determined. The t test and Newman-Keuls test for multiple comparisons were used for statistical analysis. TAV and MAA did not differ significantly between CFRP and titanium-coated CFRP, but were approximately twice as high for the titanium ITS (p < 0.001). MRI detectability was optimum for CFRP and titanium-coated CFRP, but was limited at the implant-bone interface of the titanium ITS. The material's susceptibility and the implant's dimensions affected MRI artefacting. Based on TAV, the volume of titanium surface coating in the ITS studied has no influence on susceptibility in MRI scans with T1 TSE sequences.

  6. Inertial confinement fusion

    SciTech Connect

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

    1992-01-01

    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.

  7. Statistics in fusion experiments

    NASA Astrophysics Data System (ADS)

    McNeill, D. H.

    1997-11-01

    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).

  8. Helium Find Thaws the Cold Fusion Trail.

    ERIC Educational Resources Information Center

    Pennisi, E.

    1991-01-01

    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)

  9. Fusion Power measurement at ITER

    SciTech Connect

    Bertalot, L.; Barnsley, R.; Krasilnikov, V.; Stott, P.; Suarez, A.; Vayakis, G.; Walsh, M.

    2015-07-01

    Nuclear fusion research aims to provide energy for the future in a sustainable way and the ITER project scope is to demonstrate the feasibility of nuclear fusion energy. ITER is a nuclear experimental reactor based on a large scale fusion plasma (tokamak type) device generating Deuterium - Tritium (DT) fusion reactions with emission of 14 MeV neutrons producing up to 700 MW fusion power. The measurement of fusion power, i.e. total neutron emissivity, will play an important role for achieving ITER goals, in particular the fusion gain factor Q related to the reactor performance. Particular attention is given also to the development of the neutron calibration strategy whose main scope is to achieve the required accuracy of 10% for the measurement of fusion power. Neutron Flux Monitors located in diagnostic ports and inside the vacuum vessel will measure ITER total neutron emissivity, expected to range from 1014 n/s in Deuterium - Deuterium (DD) plasmas up to almost 10{sup 21} n/s in DT plasmas. The neutron detection systems as well all other ITER diagnostics have to withstand high nuclear radiation and electromagnetic fields as well ultrahigh vacuum and thermal loads. (authors)

  10. Multi-sensor fusion development

    NASA Astrophysics Data System (ADS)

    Bish, Sheldon; Rohrer, Matthew; Scheffel, Peter; Bennett, Kelly

    2016-05-01

    The U.S. Army Research Laboratory (ARL) and McQ Inc. are developing a generic sensor fusion architecture that involves several diverse processes working in combination to create a dynamic task-oriented, real-time informational capability. Processes include sensor data collection, persistent and observational data storage, and multimodal and multisensor fusion that includes the flexibility to modify the fusion program rules for each mission. Such a fusion engine lends itself to a diverse set of sensing applications and architectures while using open-source software technologies. In this paper, we describe a fusion engine architecture that combines multimodal and multi-sensor fusion within an Open Standard for Unattended Sensors (OSUS) framework. The modular, plug-and-play architecture of OSUS allows future fusion plugin methodologies to have seamless integration into the fusion architecture at the conceptual and implementation level. Although beyond the scope of this paper, this architecture allows for data and information manipulation and filtering for an array of applications.

  11. Cellulose binding domain fusion proteins

    SciTech Connect

    Shoseyov, Oded; Shpiegl, Itai; Goldstein, Marc A.; Doi, Roy H.

    1998-01-01

    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.

  12. Cold fusion; Myth versus reality

    SciTech Connect

    Rabinowitz, M. )

    1990-01-01

    Experiments indicate that several different nuclear reactions are taking place. Some of the experiments point to D-D fusion with a cominant tritium channel as one of the reactions. The article notes a similarity between Prometheus and the discoveries of cold fusion.

  13. Fusion Policy Advisory Committee (FPAC)

    SciTech Connect

    Not Available

    1990-09-01

    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.

  14. Cold Fusion, A Journalistic Investigation

    NASA Astrophysics Data System (ADS)

    Krivit, Steven B.

    2005-03-01

    Author of the recent book, The Rebirth of Cold Fusion, and founder of New Energy Times, Steven B. Krivit presents a summary of cold fusion's, past, present and possible future. This talk will briefly review five highlights of the recent New Energy Times investigation into cold fusion research:1. Analysis of early studies that supposedly disproved cold fusion.2. Key early corroborations that supported the claims of Fleischmann and Pons.3. The evolving understanding of cold fusion reaction paths and by-products.4. A look at volumetric power density.5. Brief comparison of the progress in hot fusion research as compared to cold fusion research.New Energy Times, founded in 2000, is an independent communications company which currently specializes in reporting on cold fusion researchootnotetextReferences and copies of the presentation are available at www.newenergytimes.com/reports/aps2005.htmhttp://www.newenergytimes.com/reports/aps2005.htm. It has no affiliations with any organization, entity or party which invests in these technologies, nor any individual researcher or research facility.

  15. Cellulose binding domain fusion proteins

    DOEpatents

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

    1998-02-17

    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.

  16. Membrane fusion during poxvirus entry.

    PubMed

    Moss, Bernard

    2016-12-01

    Poxviruses comprise a large family of enveloped DNA viruses that infect vertebrates and invertebrates. Poxviruses, unlike most DNA viruses, replicate in the cytoplasm and encode enzymes and other proteins that enable entry, gene expression, genome replication, virion assembly and resistance to host defenses. Entry of vaccinia virus, the prototype member of the family, can occur at the plasma membrane or following endocytosis. Whereas many viruses encode one or two proteins for attachment and membrane fusion, vaccinia virus encodes four proteins for attachment and eleven more for membrane fusion and core entry. The entry-fusion proteins are conserved in all poxviruses and form a complex, known as the Entry Fusion Complex (EFC), which is embedded in the membrane of the mature virion. An additional membrane that encloses the mature virion and is discarded prior to entry is present on an extracellular form of the virus. The EFC is held together by multiple interactions that depend on nine of the eleven proteins. The entry process can be divided into attachment, hemifusion and core entry. All eleven EFC proteins are required for core entry and at least eight for hemifusion. To mediate fusion the virus particle is activated by low pH, which removes one or more fusion repressors that interact with EFC components. Additional EFC-interacting fusion repressors insert into cell membranes and prevent secondary infection. The absence of detailed structural information, except for two attachment proteins and one EFC protein, is delaying efforts to determine the fusion mechanism.

  17. Is there hope for fusion

    SciTech Connect

    Fowler, T.K. . Dept. of Nuclear Engineering)

    1990-04-12

    From the outset in the 1950's, fusion research has been motivated by environmental concerns as well as long-term fuel supply issues. Compared to fossil fuels both fusion and fission would produce essentially zero emissions to the atmosphere. Compared to fission, fusion reactors should offer high demonstrability of public protection from accidents and a substantial amelioration of the radioactive waste problem. Fusion still requires lengthy development, the earliest commercial deployment being likely to occur around 2025--2050. However, steady scientific progress is being made and there is a wide consensus that it is time to plan large-scale engineering development. A major international effort, called the International Thermonuclear Experimental Reactor (ITER), is being carried out under IAEA auspices to design the world's first fusion engineering test reactor, which could be constructed in the 1990's. 4 figs., 3 tabs.

  18. Adjoint affine fusion and tadpoles

    NASA Astrophysics Data System (ADS)

    Urichuk, Andrew; Walton, Mark A.

    2016-06-01

    We study affine fusion with the adjoint representation. For simple Lie algebras, elementary and universal formulas determine the decomposition of a tensor product of an integrable highest-weight representation with the adjoint representation. Using the (refined) affine depth rule, we prove that equally striking results apply to adjoint affine fusion. For diagonal fusion, a coefficient equals the number of nonzero Dynkin labels of the relevant affine highest weight, minus 1. A nice lattice-polytope interpretation follows and allows the straightforward calculation of the genus-1 1-point adjoint Verlinde dimension, the adjoint affine fusion tadpole. Explicit formulas, (piecewise) polynomial in the level, are written for the adjoint tadpoles of all classical Lie algebras. We show that off-diagonal adjoint affine fusion is obtained from the corresponding tensor product by simply dropping non-dominant representations.

  19. Information integration for data fusion

    SciTech Connect

    Bray, O.H.

    1997-01-01

    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.

  20. Fusion heating technology

    SciTech Connect

    Cole, A.J.

    1982-06-01

    John Lawson established the criterion that in order to produce more energy from fusion than is necessary to heat the plasma and replenish the radiation losses, a minimum value for both the product of plasma density and confinement time t, and the temperature must be achieved. There are two types of plasma heating: neutral beam and electromagnetic wave heating. A neutral beam system is shown. Main development work on negative ion beamlines has focused on the difficult problem of the production of high current sources. The development of a 30 keV-1 ampere multisecond source module is close to being accomplished. In electromagnetic heating, the launcher, which provides the means of coupling the power to the plasma, is most important. The status of heating development is reviewed. Electron cyclotron resonance heating (ECRH), lower hybrid heating (HHH), and ion cyclotron resonance heating (ICRH) are reviewed.

  1. Fusion Power Demonstration III

    SciTech Connect

    Lee, J.D.

    1985-07-01

    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.

  2. Fusion pumped light source

    DOEpatents

    Pappas, Daniel S.

    1989-01-01

    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.

  3. Fusion pumped laser

    DOEpatents

    Pappas, Daniel S.

    1989-01-01

    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.

  4. Multiple shell fusion targets

    DOEpatents

    Lindl, J.D.; Bangerter, R.O.

    1975-10-31

    Multiple shell fusion targets for use with electron beam and ion beam implosion systems are described. The multiple shell targets are of the low-power type and use a separate relatively low Z, low density ablator at large radius for the outer shell, which reduces the focusing and power requirements of the implosion system while maintaining reasonable aspect ratios. The targets use a high Z, high density pusher shell placed at a much smaller radius in order to obtain an aspect ratio small enough to protect against fluid instability. Velocity multiplication between these shells further lowers the power requirements. Careful tuning of the power profile and intershell density results in a low entropy implosion which allows breakeven at low powers. For example, with ion beams as a power source, breakeven at 10-20 Terrawatts with 10 MeV alpha particles for imploding a multiple shell target can be accomplished.

  5. Fusion reactor pumped laser

    DOEpatents

    Jassby, D.L.

    1987-09-04

    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.

  6. Microwave superheaters for fusion

    SciTech Connect

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

    1987-10-16

    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/sup 0/K is possible when the wall temperature is maintained at 1000/sup 0/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-/sup 3/He. 5 refs.

  7. Prospects for bubble fusion

    SciTech Connect

    Nigmatulin, R.I.; Lahey, R.T. Jr.

    1995-09-01

    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.

  8. Soldier systems sensor fusion

    NASA Astrophysics Data System (ADS)

    Brubaker, Kathryne M.

    1998-08-01

    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.

  9. LiWall Fusion - The New Concept of Magnetic Fusion

    SciTech Connect

    L.E. Zakharov

    2011-01-12

    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.

  10. Comparison of allograft and polyetheretherketone (PEEK) cage subsidence rates in anterior cervical discectomy and fusion (ACDF).

    PubMed

    Yson, Sharon C; Sembrano, Jonathan N; Santos, Edward Rainier G

    2017-04-01

    Structural allografts and PEEK cages are commonly used interbody fusion devices in ACDF. The subsidence rates of these two spacers have not yet been directly compared. The primary aim of this study was to compare the subsidence rate of allograft and PEEK cage in ACDF. The secondary aim was to determine if the presence of subsidence affects the clinical outcome. We reviewed 67 cases (117 levels) of ACDF with either structural allograft or PEEK cages. There were 85 levels (48 cases) with PEEK and 32 levels (19 cases) with allograft spacers. Anterior and posterior disc heights at each operative level were measured at immediate and 6months post-op. Subsidence was defined as a decrease in anterior or posterior disc heights >2mm. NDI of the subsidence (SG) and non-subsidence group (NSG) were recorded. Chi-square test was used to analyze subsidence rates. T-test was used to analyze clinical outcomes (α=0.05). There was no statistically significant difference between subsidence rates of the PEEK (29%; 25/85) and allograft group (28%; 9/32) (p=0.69). Overall mean subsidence was 2.3±1.7mm anteriorly and 2.6±1.2mm posteriorly. Mean NDI improvement was 11.7 (from 47.1 to 35.4; average follow-up: 12mos) for the SG and 14.0 (from 45.8 to 31.8; average follow-up: 13mos) for the NSG (p=0.74). Subsidence rate does not seem to be affected by the use of either PEEK or allograft as spacers in ACDF. Furthermore, subsidence alone does not seem to be predictive of clinical outcomes of ACDF.

  11. Ex vivo loading of trussed implants for spine fusion induces heterogeneous strains consistent with homeostatic bone mechanobiology.

    PubMed

    Caffrey, Jason P; Cory, Esther; Wong, Van W; Masuda, Koichi; Chen, Albert C; Hunt, Jessee P; Ganey, Timothy M; Sah, Robert L

    2016-12-08

    A truss structure was recently introduced as an interbody fusion cage. As a truss system, some of the connected elements may be in a state of compression and others in tension. This study aimed to quantify both the mean and variance of strut strains in such an implant when loaded in a simulated fusion condition with vertebral body or contoured plastic loading platens ex vivo. Cages were each instrumented with 78 fiducial spheres, loaded between platens (vertebral body or contoured plastic), imaged using high resolution micro-CT, and analyzed for deformation and strain of each of the 221 struts. With repeated loading of a cage by vertebral platens, the distribution (variance, indicated by SD) of strut strains widened from 50N control (4±114με, mean±SD) to 1000N (-23±273με) and 2000N (-48±414με), and between 1000N and 2000N. With similar loading of multiple cages, the strain distribution at 2000N (23±389με) increased from 50N control. With repeated loading by contoured plastic platens, induced strains at 2000N had a distribution similar to that induced by vertebral platens (84±426με). In all studies, cages exhibited increases in strut strain amplitude when loaded from 50N to 1000N or 2000N. Correspondingly, at 2000N, 59-64% of struts exhibited strain amplitudes consistent with mechanobiologically-regulated bone homeostasis. At 2000N, vertically-oriented struts exhibited deformation of -2.87±2.04μm and strain of -199±133με, indicating overall cage compression. Thus, using an ex vivo 3-D experimental biomechanical analysis method, a truss implant can have strains induced by physiological loading that are heterogeneous and of amplitudes consistent with mechanobiological bone homeostasis.

  12. Analytical performance evaluation for autonomous sensor fusion

    NASA Astrophysics Data System (ADS)

    Chang, K. C.

    2008-04-01

    A distributed data fusion system consists of a network of sensors, each capable of local processing and fusion of sensor data. There has been a great deal of work in developing distributed fusion algorithms applicable to a network centric architecture. Currently there are at least a few approaches including naive fusion, cross-correlation fusion, information graph fusion, maximum a posteriori (MAP) fusion, channel filter fusion, and covariance intersection fusion. However, in general, in a distributed system such as the ad hoc sensor networks, the communication architecture is not fixed. Each node has knowledge of only its local connectivity but not the global network topology. In those cases, the distributed fusion algorithm based on information graph type of approach may not scale due to its requirements to carry long pedigree information for decorrelation. In this paper, we focus on scalable fusion algorithms and conduct analytical performance evaluation to compare their performance. The goal is to understand the performance of those algorithms under different operating conditions. Specifically, we evaluate the performance of channel filter fusion, Chernoff fusion, Shannon Fusion, and Battachayya fusion algorithms. We also compare their results to NaÃve fusion and "optimal" centralized fusion algorithms under a specific communication pattern.

  13. Fusion Simulation Project Workshop Report

    NASA Astrophysics Data System (ADS)

    Kritz, Arnold; Keyes, David

    2009-03-01

    The mission of the Fusion Simulation Project is to develop a predictive capability for the integrated modeling of magnetically confined plasmas. This FSP report adds to the previous activities that defined an approach to integrated modeling in magnetic fusion. These previous activities included a Fusion Energy Sciences Advisory Committee panel that was charged to study integrated simulation in 2002. The report of that panel [Journal of Fusion Energy 20, 135 (2001)] recommended the prompt initiation of a Fusion Simulation Project. In 2003, the Office of Fusion Energy Sciences formed a steering committee that developed a project vision, roadmap, and governance concepts [Journal of Fusion Energy 23, 1 (2004)]. The current FSP planning effort involved 46 physicists, applied mathematicians and computer scientists, from 21 institutions, formed into four panels and a coordinating committee. These panels were constituted to consider: Status of Physics Components, Required Computational and Applied Mathematics Tools, Integration and Management of Code Components, and Project Structure and Management. The ideas, reported here, are the products of these panels, working together over several months and culminating in a 3-day workshop in May 2007.

  14. Control of mechanically activated polymersome fusion: Factors affecting fusion

    DOE PAGES

    Henderson, Ian M.; Paxton, Walter F.

    2014-12-15

    Previously we have studied the mechanically-activated fusion of extruded (200 nm) polymer vesicles into giant polymersomes using agitation in the presence of salt. In this study we have investigated several factors contributing to this phenomenon, including the effects of (i) polymer vesicle concentration, (ii) agitation speed and duration, and iii) variation of the salt and its concentration. It was found that increasing the concentration of the polymer dramatically increases the production of giant vesicles through the increased collisions of polymersomes. Our investigations also found that increasing the frequency of agitation increased the efficiency of fusion, though ultimately limited the sizemore » of vesicle which could be produced due to the high shear involved. Finally it was determined that salt-mediation of the fusion process was not limited to NaCl, but is instead a general effect facilitated by the presence of solvated ionic compounds, albeit with different salts initiating fusion at different concentration.« less

  15. Control of mechanically activated polymersome fusion: Factors affecting fusion

    SciTech Connect

    Henderson, Ian M.; Paxton, Walter F.

    2014-12-15

    Previously we have studied the mechanically-activated fusion of extruded (200 nm) polymer vesicles into giant polymersomes using agitation in the presence of salt. In this study we have investigated several factors contributing to this phenomenon, including the effects of (i) polymer vesicle concentration, (ii) agitation speed and duration, and iii) variation of the salt and its concentration. It was found that increasing the concentration of the polymer dramatically increases the production of giant vesicles through the increased collisions of polymersomes. Our investigations also found that increasing the frequency of agitation increased the efficiency of fusion, though ultimately limited the size of vesicle which could be produced due to the high shear involved. Finally it was determined that salt-mediation of the fusion process was not limited to NaCl, but is instead a general effect facilitated by the presence of solvated ionic compounds, albeit with different salts initiating fusion at different concentration.

  16. Advanced fusion concepts: project summaries

    SciTech Connect

    1980-12-01

    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)

  17. Effect of aniseikonia on fusion.

    PubMed

    Sharma, P; Prakash, P

    1991-01-01

    Physiological aniseikonia is the basis of stereopsis but beyond certain limits it becomes an obstacle to fusion. It is not well established as to how much aniseikonia can be tolerated by the fusional mechanism. Different tests under different testing conditions have given a wide range of variation. On the synoptophore we had observed tolerance upto 35% aniseikonia in some cases. Under more physiological conditions on a polaroid dissociation stereoprojector we observed lesser baseline fusional vergences but tolerance in about 70% of the cases upto 30% aniseikonia while 25% could tolerate even 35% aniseikonia. However we realise that these indicate the maximal potential and not the symptom free tolerable limits.

  18. The path to fusion power†

    PubMed Central

    Smith, Chris Llewellyn; Cowley, Steve

    2010-01-01

    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

  19. Generalized Chernoff Fusion Approximation for Practical Distributed Data Fusion

    DTIC Science & Technology

    2009-07-01

    Generalized Chernoff Fusion Approximation for Practical Distributed Data Fusion William J. Farrell III R&D Department Adaptive Methods , Inc...independence or modify legacy systems with pedigree tagging techniques . Leveraging the well- known Covariance Intersection algorithm, its generalization...Adaptive Methods , Inc.,Centreville, VA , , 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR

  20. Characterization of fusion genes and the significantly expressed fusion isoforms in breast cancer by hybrid sequencing.

    PubMed

    Weirather, Jason L; Afshar, Pegah Tootoonchi; Clark, Tyson A; Tseng, Elizabeth; Powers, Linda S; Underwood, Jason G; Zabner, Joseph; Korlach, Jonas; Wong, Wing Hung; Au, Kin Fai

    2015-10-15

    We developed an innovative hybrid sequencing approach, IDP-fusion, to detect fusion genes, determine fusion sites and identify and quantify fusion isoforms. IDP-fusion is the first method to study gene fusion events by integrating Third Generation Sequencing long reads and Second Generation Sequencing short reads. We applied IDP-fusion to PacBio data and Illumina data from the MCF-7 breast cancer cells. Compared with the existing tools, IDP-fusion detects fusion genes at higher precision and a very low false positive rate. The results show that IDP-fusion will be useful for unraveling the complexity of multiple fusion splices and fusion isoforms within tumorigenesis-relevant fusion genes.

  1. Osmotic control of bilayer fusion.

    PubMed Central

    Fisher, L R; Parker, N S

    1984-01-01

    We have used photography and capacitance measurement to monitor the steps in the interaction and eventual fusion of optically black lipid bilayers (BLMs), hydrostatically bulged to approximately hemispherical shape and pushed together mechanically. A necessary first step is drainage of aqueous solution from between the bilayers to allow close contact of the bilayers. The drainage can be controlled by varying the osmotic difference across the bilayers. If the differences are such as to remove water from between the bilayers, fusion occurs after a time that depends on the net osmotic difference and the area of contact. If there is an osmotic flow of water into the space between the bilayers, fusion never occurs. In the fusion process, a single central bilayer forms from the original apposed pair of bilayers. The central bilayer may later burst to allow mixing of the two volumes originally bounded by the separate bilayer; the topological equivalent of exocytosis. Images FIGURE 2 PMID:6541065

  2. Overview of fusion reactor safety

    SciTech Connect

    Cohen, S.; Crocker, J.G.

    1981-01-01

    Use of deuterium-tritium burning 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 magnets and radio frequency heating devices, and (5) handling and disposal of radioactive waste. Early recognition of potential safety problems with fusion reactors provides the opportunity for improvement in design and materials to eliminate or greatly reduce these problems. With an early start in this endeavor, fusion should be among the lower risk technologies for generation of commercial electrical power.

  3. Pulsed Power Driven Fusion Energy

    SciTech Connect

    SLUTZ,STEPHEN A.

    1999-11-22

    Pulsed power is a robust and inexpensive technology for obtaining high powers. Considerable progress has been made on developing light ion beams as a means of transporting this power to inertial fusion capsules. However, further progress is hampered by the lack of an adequate ion source. Alternatively, z-pinches can efficiently convert pulsed power into thermal radiation, which can be used to drive an inertial fusion capsule. However, a z-pinch driven fusion explosion will destroy a portion of the transmission line that delivers the electrical power to the z-pinch. They investigate several options for providing standoff for z-pinch driven fusion. Recyclable Transmission Lines (RTLs) appear to be the most promising approach.

  4. Polyetheretherketone Cage with Demineralized Bone Matrix Can Replace Iliac Crest Autografts for Anterior Cervical Discectomy and Fusion in Subaxial Cervical Spine Injuries

    PubMed Central

    Kim, Soo-Han; Lee, Jung-Kil; Jang, Jae-Won; Park, Hyun-Woong; Hur, Hyuk

    2017-01-01

    Objective This study aimed to compare the clinical and radiologic outcomes of patients with subaxial cervical injury who underwent anterior cervical discectomy and fusion (ACDF) with autologous iliac bone graft or polyetheretherketone (PEEK) cages using demineralized bone matrix (DBM). Methods From January 2005 to December 2010, 70 patients who underwent one-level ACDF with plate fixation for post-traumatic subaxial cervical spinal injury in a single institution were retrospectively investigated. Autologous iliac crest grafts were used in 33 patients (Group I), whereas 37 patients underwent ACDF using a PEEK cage filled with DBM (Group II). Plain radiographs were used to assess bone fusion, interbody height (IBH), segmental angle (SA), overall cervical sagittal alignment (CSA, C2–7 angle), and development of adjacent segmental degeneration (ASD). Clinical outcome was assessed using a visual analog scale (VAS) for pain and Frankel grade. Results The mean follow-up duration for patients in Group I and Group II was 28.9 and 25.4 months, respectively. All patients from both groups achieved solid fusion during the follow-up period. The IBH and SA of the fused segment and CSA in Group II were better maintained during the follow-up period. Nine patients in Group I and two patients in Group II developed radiologic ASD. There were no statistically significant differences in the VAS score and Frankel grade between the groups. Conclusion This study showed that PEEK cage filled with DBM, and plate fixation is at least as safe and effective as ACDF using autograft, with good maintenance of cervical alignment. With advantages such as no donor site morbidity and no graft-related complications, PEEK cage filled with DBM, and plate fixation provide a promising surgical option for treating traumatic subaxial cervical spine injuries. PMID:28264242

  5. World progress toward fusion energy

    NASA Astrophysics Data System (ADS)

    Clarke, J. F.

    1989-09-01

    This paper will describe the progress in fusion science and technology from a world perspective. The paper will cover the current technical status, including the understanding of fusion's economic, environmental, and safety characteristics. Fusion experiments are approaching the energy breakeven condition. An energy gain (Q) of 30 percent has been achieved in magnetic confinement experiments. In addition, temperatures required for an ignited plasma (Ti = 32 KeV) and energy confinements (about 75 percent of that required for ignition) have been achieved in separate experiments. Two major facilities have started the experimental campaign to extend these results and achieve or exceed Q = 1 plasma conditions by 1990. Inertial confinement fusion experiments are also approaching thermonuclear conditions and have achieved a compression factor 100-200 times liquid D-T. Because of this progress, the emphasis in fusion research is turning toward questions of engineering feasibility. Leaders of the major fusion R and D programs in the European Community (EC), Japan, the United States, and the U.S.S.R. have agreed on the major steps that are needed to reach the point at which a practical fusion system can be designed. The United States is preparing for an experiment to address the last unexplored scientific issue, the physics of an ignited plasma, during the late 1990's. The EC, Japan, U.S.S.R., and the United States have joined together under the auspices of the International Atomic Energy Agency (IAEA) to jointly design and prepare the validating R&D for an international facility, the International Thermonuclear Experimental Reactor (ITER), to address all the remaining scientific issues and to explore the engineering technology of fusion around the turn of the century.

  6. Magnetic fusion 1985: what next

    SciTech Connect

    Fowler, T.K.

    1985-03-01

    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.

  7. Horizontal model fusion paradigm

    NASA Astrophysics Data System (ADS)

    Julier, Simon J.; Durrant-Whyte, Hugh F.

    1996-05-01

    In navigation and tracking problems, the identification of an appropriate model of vehicular or target motion is vital to most practical data fusion algorithms. The true system dynamics are rarely known, and approximations are usually employed. Since systems can exhibit strikingly different behaviors, multiple models may be needed to describe each of these behaviors. Current methods either use model switching (a single process model is chosen from the set using a decision rule) or consider the models as a set of competing hypothesis, only one of which is 'correct'. However, these methods fail to exploit the fact that all models are of the same system and that all of them are, to some degree, 'correct'. In this paper we present a new paradigm for fusing information from a set of multiple process models. The predictions from each process model are regarded as observations which are corrupted by correlated noise. By employing the standard Kalman filter equations we combine data from multiple sensors and multiple process models optimally. There are a number of significant practical advantages to this technique. First, the performance of the system always equals or betters that of the best estimator in the set of models being used. Second, the same decision theoretic machinery can be used to select the process models as well as the sensor suites.

  8. Cold fusion verification

    NASA Astrophysics Data System (ADS)

    North, M. H.; Mastny, G. F.; Wesley, E. J.

    1991-03-01

    The objective of this work to verify and reproduce experimental observations of Cold Nuclear Fusion (CNF), as originally reported in 1989. The method was to start with the original report and add such additional information as became available to build a set of operational electrolytic CNF cells. Verification was to be achieved by first observing cells for neutron production, and for those cells that demonstrated a nuclear effect, careful calorimetric measurements were planned. The authors concluded, after laboratory experience, reading published work, talking with others in the field, and attending conferences, that CNF probably is chimera and will go the way of N-rays and polywater. The neutron detector used for these tests was a completely packaged unit built into a metal suitcase that afforded electrostatic shielding for the detectors and self-contained electronics. It was battery-powered, although it was on charge for most of the long tests. The sensor element consists of He detectors arranged in three independent layers in a solid moderating block. The count from each of the three layers as well as the sum of all the detectors were brought out and recorded separately. The neutron measurements were made with both the neutron detector and the sample tested in a cave made of thick moderating material that surrounded the two units on the sides and bottom.

  9. Prospects for Tokamak Fusion Reactors

    SciTech Connect

    Sheffield, J.; Galambos, J.

    1995-04-01

    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.

  10. Tritium accountancy in fusion systems

    SciTech Connect

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

    2015-03-15

    The US Department of Energy (DOE) has clearly defined requirements for nuclear material control and accountability (MCA) of tritium whereas the International Atomic Energy Agency (IAEA) does not since tritium is not a fissile material. MCA 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 (MBA) are defined to aid in the tracking and reporting of nuclear material movements and inventories. Material sub-accounts (MSA) are established along with key measurement points (KMP) 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 MSA. 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 breeding, 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. (authors)

  11. TRITIUM ACCOUNTANCY IN FUSION SYSTEMS

    SciTech Connect

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

    2014-03-06

    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.

  12. Successful anterior fusion following posterior cervical fusion for revision of anterior cervical discectomy and fusion pseudarthrosis.

    PubMed

    Elder, Benjamin D; Sankey, Eric W; Theodros, Debebe; Bydon, Mohamad; Goodwin, C Rory; Lo, Sheng-Fu; Kosztowski, Thomas A; Belzberg, Allen J; Wolinsky, Jean-Paul; Sciubba, Daniel M; Gokaslan, Ziya L; Bydon, Ali; Witham, Timothy F

    2016-02-01

    Pseudarthrosis occurs after approximately 2-20% of anterior cervical discectomy and fusion (ACDF) procedures; it is unclear if posterior or anterior revision should be pursued. In this study, we retrospectively evaluate the outcomes in 22 patients with pseudarthrosis following ACDF and revision via posterior cervical fusion (PCF). Baseline demographics, preoperative symptoms, operative data, time to fusion failure, symptoms of pseudarthrosis, and revision method were assessed. Fusion outcome and clinical outcome were determined at last follow-up (LFU). Thirteen females (59%) and 9 (41%) males experienced pseudarthrosis at a median of 11 (range: 3-151)months after ACDF. Median age at index surgery was 51 (range: 33-67)years. All patients with pseudarthrosis presented with progressive neck pain, with median visual analog scale (VAS) score of 8 (range: 0-10), and/or myeloradiculopathy. Patients with pseudarthrosis <12 months compared to >12 months after index surgery were older (p=0.013), had more frequent preoperative neurological deficits (p=0.064), and lower baseline VAS scores (p=0.006). Fusion was successful after PCF in all patients, with median time to fusion of 10 (range: 2-14)months. Eighteen patients fused both anteriorly and posteriorly, two patients fused anteriorly only, and two patients fused posteriorly only. Median VAS neck score at LFU significantly improved from the time of pseudarthrosis (p=0.012). While uncommon, pseudarthrosis may occur after ACDF. All patients achieved successful fusion after subsequent posterior cervical fusion, with 91% fusing a previous anterior pseudarthrosis after posterior stabilization. Neck pain significantly improved by LFU in the majority of patients in this study.

  13. Novel Hydrophobin Fusion Tags for Plant-Produced Fusion Proteins

    PubMed Central

    Ritala, Anneli; Linder, Markus; Joensuu, Jussi

    2016-01-01

    Hydrophobin fusion technology has been applied in the expression of several recombinant proteins in plants. Until now, the technology has relied exclusively on the Trichoderma reesei hydrophobin HFBI. We screened eight novel hydrophobin tags, T. reesei HFBII, HFBIII, HFBIV, HFBV, HFBVI and Fusarium verticillioides derived HYD3, HYD4 and HYD5, for production of fusion proteins in plants and purification by two-phase separation. To study the properties of the hydrophobins, we used N-terminal and C-terminal GFP as a fusion partner. Transient expression of the hydrophobin fusions in Nicotiana benthamiana revealed large variability in accumulation levels, which was also reflected in formation of protein bodies. In two-phase separations, only HFBII and HFBIV were able to concentrate GFP into the surfactant phase from a plant extract. The separation efficiency of both tags was comparable to HFBI. When the accumulation was tested side by side, HFBII-GFP gave a better yield than HFBI-GFP, while the yield of HFBIV-GFP remained lower. Thus we present here two alternatives for HFBI as functional fusion tags for plant-based protein production and first step purification. PMID:27706254

  14. Fusion Plasma Theory project summaries

    SciTech Connect

    Not Available

    1993-10-01

    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.

  15. Ultrastructural Analysis of Myoblast Fusion in Drosophila

    PubMed Central

    Zhang, Shiliang; Chen, Elizabeth H.

    2015-01-01

    Summary Myoblast fusion in Drosophila has become a powerful genetic system with which to unravel the mechanisms underlying cell fusion. The identification of important components of myoblast fusion by genetic analysis has led to a molecular pathway toward our understanding of this cellular process. In addition to the application of immunohistochemistry and live imaging techniques to visualize myoblast fusion at the light microscopic level, ultrastructural analysis using electron microscopy remains an indispensable tool to reveal fusion intermediates and specific membrane events at sites of fusion. In this chapter, we describe conventional chemical fixation and high-pressure freezing/freeze substitution methods for visualizing fusion intermediates during Drosophila myoblast fusion. Furthermore, we describe an immunoelectron microscopic method for localizing specific proteins relative to the fusion apparatus. PMID:18979250

  16. Kinetic advantage of controlled intermediate nuclear fusion

    SciTech Connect

    Guo Xiaoming

    2012-09-26

    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.

  17. Accelerators for Fusion Materials Testing

    NASA Astrophysics Data System (ADS)

    Knaster, Juan; Okumura, Yoshikazu

    Fusion materials research is a worldwide endeavor as old as the parallel one working toward the long term stable confinement of ignited plasma. In a fusion reactor, the preservation of the required minimum thermomechanical properties of the in-vessel components exposed to the severe irradiation and heat flux conditions is an indispensable factor for safe operation; it is also an essential goal for the economic viability of fusion. Energy from fusion power will be extracted from the 14 MeV neutron freed as a product of the deuterium-tritium fusion reactions; thus, this kinetic energy must be absorbed and efficiently evacuated and electricity eventually generated by the conventional methods of a thermal power plant. Worldwide technological efforts to understand the degradation of materials exposed to 14 MeV neutron fluxes >1018 m-2s-1, as expected in future fusion power plants, have been intense over the last four decades. Existing neutron sources can reach suitable dpa (“displacement-per-atom”, the figure of merit to assess materials degradation from being exposed to neutron irradiation), but the differences in the neutron spectrum of fission reactors and spallation sources do not allow one to unravel the physics and to anticipate the degradation of materials exposed to fusion neutrons. Fusion irradiation conditions can be achieved through Li (d, xn) nuclear reactions with suitable deuteron beam current and energy, and an adequate flowing lithium screen. This idea triggered in the late 1970s at Los Alamos National Laboratory (LANL) a campaign working toward the feasibility of continuous wave (CW) high current linacs framed by the Fusion Materials Irradiation Test (FMIT) project. These efforts continued with the Low Energy Demonstrating Accelerator (LEDA) (a validating prototype of the canceled Accelerator Production of Tritium (APT) project), which was proposed in 2002 to the fusion community as a 6.7MeV, 100mA CW beam injector for a Li (d, xn) source to bridge

  18. Accelerators for Fusion Materials Testing

    NASA Astrophysics Data System (ADS)

    Knaster, Juan; Okumura, Yoshikazu

    Fusion materials research is a worldwide endeavor as old as the parallel one working toward the long term stable confinement of ignited plasma. In a fusion reactor, the preservation of the required minimum thermomechanical properties of the in-vessel components exposed to the severe irradiation and heat flux conditions is an indispensable factor for safe operation; it is also an essential goal for the economic viability of fusion. Energy from fusion power will be extracted from the 14 MeV neutron freed as a product of the deuterium-tritium fusion reactions; thus, this kinetic energy must be absorbed and efficiently evacuated and electricity eventually generated by the conventional methods of a thermal power plant. Worldwide technological efforts to understand the degradation of materials exposed to 14 MeV neutron fluxes > 1018 m-2s-1, as expected in future fusion power plants, have been intense over the last four decades. Existing neutron sources can reach suitable dpa ("displacement-per-atom", the figure of merit to assess materials degradation from being exposed to neutron irradiation), but the differences in the neutron spectrum of fission reactors and spallation sources do not allow one to unravel the physics and to anticipate the degradation of materials exposed to fusion neutrons. Fusion irradiation conditions can be achieved through Li (d, xn) nuclear reactions with suitable deuteron beam current and energy, and an adequate flowing lithium screen. This idea triggered in the late 1970s at Los Alamos National Laboratory (LANL) a campaign working toward the feasibility of continuous wave (CW) high current linacs framed by the Fusion Materials Irradiation Test (FMIT) project. These efforts continued with the Low Energy Demonstrating Accelerator (LEDA) (a validating prototype of the canceled Accelerator Production of Tritium (APT) project), which was proposed in 2002 to the fusion community as a 6.7MeV, 100mA CW beam injector for a Li (d, xn) source to bridge

  19. Fusion reactions at low energy

    SciTech Connect

    Beckerman, M.

    1985-01-01

    Fusion measurement methods at low energies are briefly described, and experimental and theoretical fusion cross sections for /sup 58/Ni + /sup 58/Ni, /sup 58/Ni + /sup 64/Ni and /sup 64/Ni + /sup 64/Ni reactions are discussed. It is shown that quantal tunneling calculations do not describe the near- and sub-barrier behavior of the fusion data. Instead, the WKB predictions fall progressively further blow the experimental results as the energy is lowered. At far subbarrier energies the measured cross sections exceed the WKB predictions by more than three orders of magnitude. The unexpectedly strong dependence of the fusion probability upon the nuclear valence structure is illustrated and discussed. The relationship of channel coupling and quantal tunneling is discussed. In conclusion, it was established that atomic nuclei fuse far more readily at low energies that would be expected from quantal tunneling considerations alone. It was found that the behavior of the cross sections for fusion depends strongly upon the valence structure of the collision partners. This structural dependence extends from light 1p-shell systems to systems involving nearly 200 nucleons. These new phenomena may be viewed as characterizing the tunneling of a quantal system with many degrees of freedom. The failure of standard tunneling models may be understood as resulting from the ability of the dinuclear system to tunnel into the classically forbidden region by means of couplings to intrinsic degrees of freedom. 38 refs. (WHK)

  20. A Model for Membrane Fusion

    NASA Astrophysics Data System (ADS)

    Ngatchou, Annita

    2010-01-01

    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.

  1. Nuclear Fusion prize laudation Nuclear Fusion prize laudation

    NASA Astrophysics Data System (ADS)

    Burkart, W.

    2011-01-01

    Clean energy in abundance will be of critical importance to the pursuit of world peace and development. As part of the IAEA's activities to facilitate the dissemination of fusion related science and technology, the journal Nuclear Fusion is intended to contribute to the realization of such energy from fusion. In 2010, we celebrated the 50th anniversary of the IAEA journal. The excellence of research published in the journal is attested to by its high citation index. The IAEA recognizes excellence by means of an annual prize awarded to the authors of papers judged to have made the greatest impact. On the occasion of the 2010 IAEA Fusion Energy Conference in Daejeon, Republic of Korea at the welcome dinner hosted by the city of Daejeon, we celebrated the achievements of the 2009 and 2010 Nuclear Fusion prize winners. Steve Sabbagh, from the Department of Applied Physics and Applied Mathematics, Columbia University, New York is the winner of the 2009 award for his paper: 'Resistive wall stabilized operation in rotating high beta NSTX plasmas' [1]. This is a landmark paper which reports record parameters of beta in a large spherical torus plasma and presents a thorough investigation of the physics of resistive wall mode (RWM) instability. The paper makes a significant contribution to the critical topic of RWM stabilization. John Rice, from the Plasma Science and Fusion Center, MIT, Cambridge is the winner of the 2010 award for his paper: 'Inter-machine comparison of intrinsic toroidal rotation in tokamaks' [2]. The 2010 award is for a seminal paper that analyzes results across a range of machines in order to develop a universal scaling that can be used to predict intrinsic rotation. This paper has already triggered a wealth of experimental and theoretical work. I congratulate both authors and their colleagues on these exceptional papers. W. Burkart Deputy Director General Department of Nuclear Sciences and Applications International Atomic Energy Agency, Vienna

  2. Anterior cervical discectomy and fusion with titanium cages for simple or multilevel herniated discs and spur of the cervical spine: Report of 2 cases and experience in Bali

    PubMed Central

    Mahadewa Tjokorda, G. B.; Nyoman, Golden; Sri, Maliawan; Junichi, Mizuno

    2016-01-01

    This report presents two cases of cervicobrachialgia and radiculopathy due to multiple cervical herniated discs and spur formation that dealt with anterior cervical discectomy and fusion (ACDF) using different titanium interbody cages. The description of the clinical presentation, magnetic resonance imaging (MRI) appearances and management strategy are discussed. Both cases showed chronic neck pain and radiating pain from the shoulder to the arm. They had a history of blurry vision, cluster head ache, weakness, and numbness on the shoulder for 2 years. MRI revealed multiple herniated discs between C4-7 and accompanied by the spur formation leading to the narrowness of the spinal canal and its foramina bilaterally. ACDF were performed and complete decompression of the spinal canal and its foramina were carried out. Twin M-cages (Ammtec Inc.-Japan) were placed in the first case at C5-7 levels and single cage of Smith Robinson (SR) was placed in the second case at C5-6 levels. There were no more blurry vision, cluster headache, weakness, and numbness, immediately after surgery. To our knowledge, this is the first reported cases of ACDF, using twin M-cages and single SR cage in Indonesia, with improvement immediately after surgery. Cervical spondylosis can present with cervicobrachialgia and radiculopathy and surgical treatment produces good functional outcome. PMID:27695567

  3. Anterior cervical discectomy and fusion with titanium cages for simple or multilevel herniated discs and spur of the cervical spine: Report of 2 cases and experience in Bali.

    PubMed

    Mahadewa Tjokorda, G B; Nyoman, Golden; Sri, Maliawan; Junichi, Mizuno

    2016-01-01

    This report presents two cases of cervicobrachialgia and radiculopathy due to multiple cervical herniated discs and spur formation that dealt with anterior cervical discectomy and fusion (ACDF) using different titanium interbody cages. The description of the clinical presentation, magnetic resonance imaging (MRI) appearances and management strategy are discussed. Both cases showed chronic neck pain and radiating pain from the shoulder to the arm. They had a history of blurry vision, cluster head ache, weakness, and numbness on the shoulder for 2 years. MRI revealed multiple herniated discs between C4-7 and accompanied by the spur formation leading to the narrowness of the spinal canal and its foramina bilaterally. ACDF were performed and complete decompression of the spinal canal and its foramina were carried out. Twin M-cages (Ammtec Inc.-Japan) were placed in the first case at C5-7 levels and single cage of Smith Robinson (SR) was placed in the second case at C5-6 levels. There were no more blurry vision, cluster headache, weakness, and numbness, immediately after surgery. To our knowledge, this is the first reported cases of ACDF, using twin M-cages and single SR cage in Indonesia, with improvement immediately after surgery. Cervical spondylosis can present with cervicobrachialgia and radiculopathy and surgical treatment produces good functional outcome.

  4. Membrane fusion in muscle development and repair

    PubMed Central

    Demonbreun, Alexis R.; Biersmith, Bridget H.

    2015-01-01

    Mature skeletal muscle forms from the fusion of skeletal muscle precursor cells, myoblasts. Myoblasts fuse to other myoblasts to generate multinucleate myotubes during myogenesis, and myoblasts also fuse to other myotubes during muscle growth and repair. Proteins within myoblasts and myotubes regulate complex processes such as elongation, migration, cell adherence, cytoskeletal reorganization, membrane coalescence, and ultimately fusion. Recent studies have identified cell surface proteins, intracellular proteins, and extracellular signaling molecules required for the proper fusion of muscle. Many proteins that actively participate in myoblast fusion also coordinate membrane repair. Here we will review mammalian membrane fusion with specific attention to proteins that mediate myoblast fusion and muscle repair. PMID:26537430

  5. The Path to Magnetic Fusion Energy

    SciTech Connect

    Prager, Stewart

    2011-05-04

    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.

  6. (Meeting on fusion reactor materials)

    SciTech Connect

    Jones, R.H. ); Klueh, R.L.; Rowcliffe, A.F.; Wiffen, F.W. ); Loomis, B.A. )

    1990-11-01

    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.

  7. Fusion power for space propulsion.

    NASA Technical Reports Server (NTRS)

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

    1972-01-01

    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.

  8. Superconducting magnets for fusion applications

    SciTech Connect

    Henning, C.D.

    1987-07-02

    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.

  9. Tissue fusion over nonadhering surfaces

    PubMed Central

    Nier, Vincent; Deforet, Maxime; Duclos, Guillaume; Yevick, Hannah G.; Cochet-Escartin, Olivier; Marcq, Philippe; Silberzan, Pascal

    2015-01-01

    Tissue fusion eliminates physical voids in a tissue to form a continuous structure and is central to many processes in development and repair. Fusion events in vivo, particularly in embryonic development, often involve the purse-string contraction of a pluricellular actomyosin cable at the free edge. However, in vitro, adhesion of the cells to their substrate favors a closure mechanism mediated by lamellipodial protrusions, which has prevented a systematic study of the purse-string mechanism. Here, we show that monolayers can cover well-controlled mesoscopic nonadherent areas much larger than a cell size by purse-string closure and that active epithelial fluctuations are required for this process. We have formulated a simple stochastic model that includes purse-string contractility, tissue fluctuations, and effective friction to qualitatively and quantitatively account for the dynamics of closure. Our data suggest that, in vivo, tissue fusion adapts to the local environment by coordinating lamellipodial protrusions and purse-string contractions. PMID:26199417

  10. Laser fusion experiments at LLL

    SciTech Connect

    Ahlstrom, H.G.

    1980-06-16

    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.

  11. Fusion Breeder Program interim report

    SciTech Connect

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

    1982-06-11

    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.

  12. Percutaneous Hindfoot and Midfoot Fusion.

    PubMed

    Bauer, Thomas

    2016-09-01

    Hindfoot and midfoot fusions can be performed with percutaneous techniques. Preliminary results of these procedures are encouraging because they provide similar results than those obtained with open techniques with less morbidity and quick recovery. The best indications are probably fusions for mild-to-moderate reducible hindfoot and midfoot deformities in fragile patients with general or local bad conditions. The main limit is linked to the surgeon's experience in percutaneous foot surgery because a learning curve with the specific tools is necessary before doing these procedures.

  13. Method for vacuum fusion bonding

    DOEpatents

    Ackler, Harold D.; Swierkowski, Stefan P.; Tarte, Lisa A.; Hicks, Randall K.

    2001-01-01

    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.

  14. Z-Pinch Fusion Propulsion

    NASA Technical Reports Server (NTRS)

    Miernik, Janie

    2011-01-01

    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.

  15. The first fusion reactor: ITER

    NASA Astrophysics Data System (ADS)

    Campbell, D. J.

    2016-11-01

    Established by the signature of the ITER Agreement in November 2006 and currently under construction at St Paul-lez-Durance in southern France, the ITER project [1,2] involves the European Union (including Switzerland), China, India, Japan, the Russian Federation, South Korea and the United States. ITER (`the way' in Latin) is a critical step in the development of fusion energy. Its role is to provide an integrated demonstration of the physics and technology required for a fusion power plant based on magnetic confinement.

  16. Fusion bonding and alignment fixture

    DOEpatents

    Ackler, Harold D.; Swierkowski, Stefan P.; Tarte, Lisa A.; Hicks, Randall K.

    2000-01-01

    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.

  17. Plasma physics goes beyond fusion

    NASA Astrophysics Data System (ADS)

    Franklin, Raoul

    2008-11-01

    I was interested to read the fusion supplement published with the October issue of Physics World. However, in asserting that fusion created the need to recognize plasma physics as a separate branch of the subject, Stephen Cowley, the new director of the United Kingdom Atomic Energy Authority, was not quite correct. In fact, the word "plasma" was appropriated from the Greek by the chemical physicist (and later Nobel laureate) Irving Langmuir in 1928. It was used to describe the positive column of a gas discharge, which was then the subject of research into better lighting sources and advertising displays, as well as the underlying science.

  18. Equivalence of measurement space solution data fusion and complete fusion

    NASA Astrophysics Data System (ADS)

    Ceccherini, Simone

    2016-10-01

    Many observation systems are operating on space-borne and airborne platforms, as well as from ground-based stations, providing measurements of vertical profiles of atmospheric parameters. When independent measurements of the same profile are available data fusion methods can be used to combine them and exploit all the available information for a more comprehensive and accurate description of the atmospheric state. Several data fusion methods can be used. Among the others, both the measurement space solution data fusion method and the complete fusion method have the remarkable properties of using all the acquired information and of providing results that are independent from a priori information used in the individual retrievals. For this reason, though the two methods use two completely different procedures, it is reasonable to expect that they give the same results and in this paper the rigorous proof of the equivalence of the two methods is given. Therefore, the choice between them is only driven by the advantages of the different implementations.

  19. A Plan for the Development of Fusion Energy. Final Report to Fusion Energy Sciences Advisory Committee, Fusion Development Path Panel

    SciTech Connect

    None, None

    2003-03-05

    This report presents a plan for the deployment of a fusion demonstration power plant within 35 years, leading to commercial application of fusion energy by mid-century. The plan is derived from the necessary features of a demonstration fusion power plant and from the time scale defined by President Bush. It identifies critical milestones, key decision points, needed major facilities and required budgets.

  20. Mechanisms of influenza viral membrane fusion.

    PubMed

    Blijleven, Jelle S; Boonstra, Sander; Onck, Patrick R; van der Giessen, Erik; van Oijen, Antoine M

    2016-12-01

    Influenza viral particles are enveloped by a lipid bilayer. A major step in infection is fusion of the viral and host cellular membranes, a process with large kinetic barriers. Influenza membrane fusion is catalyzed by hemagglutinin (HA), a class I viral fusion protein activated by low pH. The exact nature of the HA conformational changes that deliver the energy required for fusion remains poorly understood. This review summarizes our current knowledge of HA structure and dynamics, describes recent single-particle experiments and modeling studies, and discusses their role in understanding how multiple HAs mediate fusion. These approaches provide a mechanistic picture in which HAs independently and stochastically insert into the target membrane, forming a cluster of HAs that is collectively able to overcome the barrier to membrane fusion. The new experimental and modeling approaches described in this review hold promise for a more complete understanding of other viral fusion systems and the protein systems responsible for cellular fusion.

  1. Collescipoli - An unusual fusion crust glass. [chondrite

    NASA Technical Reports Server (NTRS)

    Nozette, S.

    1979-01-01

    An electron microprobe study was conducted on glass fragments taken from the fusion crust and an internal glass-lined vein in the H-5 chondrite Collescipoli. Microprobe analyses of the glasses revealed an unusual fusion crust composition, and analyses of glass from inside the meteorite showed compositions expected for a melt of an H-group chondrite. Studies of fusion crusts by previous workers, e.g., Krinov and Ramdohr, showed that fusion crusts contain large amounts of magnetite and other oxidized minerals. The Collescipoli fusion crusts do contain these minerals, but they also contain relatively large amounts of reduced metal, sulphide, and a sodium-rich glass. This study seems to indicate that Collescipoli preserved an early type of fusion crust. Oxidation was incomplete in the fusion crust melt that drained into a crack. From this study it is concluded that fusion crust formation does not invariably result in complete oxidation of metal and sulphide phases.

  2. Cold fusion catalyzed by muons and electrons

    SciTech Connect

    Kulsrud, R.M.

    1990-10-01

    Two alternative methods have been suggested to produce fusion power at low temperature. The first, muon catalyzed fusion or MCF, uses muons to spontaneously catalyze fusion through the muon mesomolecule formation. Unfortunately, this method fails to generate enough fusion energy to supply the muons, by a factor of about ten. The physics of MCF is discussed, and a possible approach to increasing the number of MCF fusions generated by each muon is mentioned. The second method, which has become known as Cold Fusion,'' involves catalysis by electrons in electrolytic cells. The physics of this process, if it exists, is more mysterious than MCF. However, it now appears to be an artifact, the claims for its reality resting largely on experimental errors occurring in rather delicate experiments. However, a very low level of such fusion claimed by Jones may be real. Experiments in cold fusion will also be discussed.

  3. Advanced Concepts: Aneutronic Fusion Power and Propulsion

    NASA Technical Reports Server (NTRS)

    Chapman, John J.

    2012-01-01

    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.

  4. Z-Pinch Fusion for Energy Applications

    SciTech Connect

    SPIELMAN,RICK B.

    2000-01-01

    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.

  5. Exo-endo cellulase fusion protein

    SciTech Connect

    Bower, Benjamin S; Larenas, Edmund A; Mitchinson, Colin

    2012-01-17

    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.

  6. A review of data fusion techniques.

    PubMed

    Castanedo, Federico

    2013-01-01

    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.

  7. A Review of Data Fusion Techniques

    PubMed Central

    2013-01-01

    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

  8. Proton Collimators for Fusion Reactors

    NASA Technical Reports Server (NTRS)

    Miley, George H.; Momota, Hiromu

    2003-01-01

    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.

  9. Magnetic Inertial Confinement Fusion (MICF)

    NASA Astrophysics Data System (ADS)

    Miao, Feng; Zheng, Xianjun; Deng, Baiquan; Liu, Wei; Ou, Wei; Huang, Yi

    2016-11-01

    Based on the similarity in models of the early Sun and the 3-D common focal region of the micro-pinch in X-pinch experiments, a novel hybrid fusion configuration by continuous focusing of multiple Z-pinched plasma beams on spatially symmetric plasma is proposed. By replacing gravity with Lorentz force with subsequent centripetal spherical pinch, the beam-target fusion reactivity is enhanced in a quasi-spherical converging region, thus achieving MICF. An assessment, presented here, suggests that a practical fusion power source could be achieved using deuterium alone. Plasma instabilities can be suppressed by fast rotation resulting from an asymmetric tangential torsion in the spherical focal region of this configuration. Mathematical equivalence with the Sun allows the development of appropriate equations for the focal region of MICF, which are solved numerically to provide density, temperature and pressure distributions that produce net fusion energy output. An analysis of MICF physics and a preliminary experimental demonstration of a single beam are also carried out. supported by National Natural Science Foundation of China (Nos. 11374217 and 11176020)

  10. Advanced algorithms for distributed fusion

    NASA Astrophysics Data System (ADS)

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

    2008-03-01

    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.

  11. Prospects for fusion neutron NPLs

    SciTech Connect

    Petra, M.; Miley, G.H.; Batyrbekov, E.; Jassby, D.L.; McArthur, D.

    1996-05-01

    To date, nuclear pumped lasers (NPLs) have been driven by neutrons from pulsed research fission reactors. However, future applications using either a Magnetic Confinement Fusion (MCF) neutron source or an Inertial Confinement Fusion (ICF) source appear attractive. One unique combination proposed earlier would use a neutron feedback NPL driver in an ICF power plant. 14-MeV D-T neutrons (and 2.5-MeV D-D neutrons) provide a unique opportunity for a neutron recoil pumped NPL. Alternatively, these neutrons can be thermalized to provide thermal-neutron induced reactions for pumping. Initial experience with a fusion-pumped NPL can possibly be obtained using the D-T burn experiments in progress/planning at the Tokamak Fusion Test Reactor (TFTR) and Joint European Torus (JET) tokamak devices or at the planned National Ignition Facility (NIF) high-gain ICF target experimental facility. With neutron fluxes presently available, peak thermalized fluxes at a test laser in the shield region could exceed 10{sup 14} n/cm{sup 2}/sec. Several low-threshold NPLs might be utilized in such an experiment, including the He-Ne-H{sub 2} NPL and the Ar-Xe NPL. Experimental set-ups for both the tokamak and the NIF will be described. {copyright} {ital 1996 American Institute of Physics.}

  12. Seismic data fusion anomaly detection

    NASA Astrophysics Data System (ADS)

    Harrity, Kyle; Blasch, Erik; Alford, Mark; Ezekiel, Soundararajan; Ferris, David

    2014-06-01

    Detecting anomalies in non-stationary signals has valuable applications in many fields including medicine and meteorology. These include uses such as identifying possible heart conditions from an Electrocardiography (ECG) signals or predicting earthquakes via seismographic data. Over the many choices of anomaly detection algorithms, it is important to compare possible methods. In this paper, we examine and compare two approaches to anomaly detection and see how data fusion methods may improve performance. The first approach involves using an artificial neural network (ANN) to detect anomalies in a wavelet de-noised signal. The other method uses a perspective neural network (PNN) to analyze an arbitrary number of "perspectives" or transformations of the observed signal for anomalies. Possible perspectives may include wavelet de-noising, Fourier transform, peak-filtering, etc.. In order to evaluate these techniques via signal fusion metrics, we must apply signal preprocessing techniques such as de-noising methods to the original signal and then use a neural network to find anomalies in the generated signal. From this secondary result it is possible to use data fusion techniques that can be evaluated via existing data fusion metrics for single and multiple perspectives. The result will show which anomaly detection method, according to the metrics, is better suited overall for anomaly detection applications. The method used in this study could be applied to compare other signal processing algorithms.

  13. Inertial confinement fusion (ICF) review

    SciTech Connect

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

    1996-03-01

    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.

  14. Tritium breeding in fusion reactors

    SciTech Connect

    Abdou, M.A.

    1982-10-01

    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.

  15. Nuclear data requirements for fusion reactor nucleonics

    SciTech Connect

    Bhat, M.R.; Abdou, M.A.

    1980-01-01

    Nuclear data requirements for fusion reactor nucleonics are reviewed and the present status of data are assessed. The discussion is divided into broad categories dealing with data for Fusion Materials Irradiation Test Facility (FMIT), D-T Fusion Reactors, Alternate Fuel Cycles and the Evaluated Data Files that are available or would be available in the near future.

  16. Fusion probability in heavy nuclei

    NASA Astrophysics Data System (ADS)

    Banerjee, Tathagata; Nath, S.; Pal, Santanu

    2015-03-01

    Background: Fusion between two massive nuclei is a very complex process and is characterized by three stages: (a) capture inside the potential barrier, (b) formation of an equilibrated compound nucleus (CN), and (c) statistical decay of the CN leading to a cold evaporation residue (ER) or fission. The second stage is the least understood of the three and is the most crucial in predicting yield of superheavy elements (SHE) formed in complete fusion reactions. Purpose: A systematic study of average fusion probability, , is undertaken to obtain a better understanding of its dependence on various reaction parameters. The study may also help to clearly demarcate onset of non-CN fission (NCNF), which causes fusion probability, PCN, to deviate from unity. Method: ER excitation functions for 52 reactions leading to CN in the mass region 170-220, which are available in the literature, have been compared with statistical model (SM) calculations. Capture cross sections have been obtained from a coupled-channels code. In the SM, shell corrections in both the level density and the fission barrier have been included. for these reactions has been extracted by comparing experimental and theoretical ER excitation functions in the energy range ˜5 %-35% above the potential barrier, where known effects of nuclear structure are insignificant. Results: has been shown to vary with entrance channel mass asymmetry, η (or charge product, ZpZt ), as well as with fissility of the CN, χCN. No parameter has been found to be adequate as a single scaling variable to determine . Approximate boundaries have been obtained from where starts deviating from unity. Conclusions: This study quite clearly reveals the limits of applicability of the SM in interpreting experimental observables from fusion reactions involving two massive nuclei. Deviation of from unity marks the beginning of the domain of dynamical models of fusion. Availability of precise ER cross

  17. MAD for visual tracker fusion

    NASA Astrophysics Data System (ADS)

    Becker, Stefan; Krah, Sebastian B.; Hübner, Wolfgang; Arens, Michael

    2016-10-01

    Existing tracking methods vary strongly in their approach and therefore have different strengths and weaknesses. For example, a single tracking algorithm may be good at handling variations in illumination, but does not cope well with deformation. Hence, their failures can occur on entirely different time intervals on the same sequence. One possible solution for overcoming limitations of a single tracker and for benefitting from individual strengths, is to run a set of tracking algorithms in parallel and fuse their outputs. But in general, tracking algorithms are not designed to receive feedback from a higher level fusion strategy or require a high degree of integration between individual levels. Towards this end, we introduce a fusion strategy serving the purpose of online single object tracking, for which no knowledge about individual tracker characteristics is needed. The key idea is to combine several independent and heterogeneous tracking approaches and to robustly identify an outlier subset based on the "Median Absolute Deviations" (MAD) measure. The MAD fusion strategy is very generic and only requires frame-based object bounding boxes as input. Thus, it can work with arbitrary tracking algorithms. Furthermore, the MAD fusion strategy can also be applied for combining several instances of the same tracker to form a more robust ensemble for tracking an object. The evaluation is done on public available datasets. With a set of heterogeneous, commonly used trackers we show that the proposed MAD fusion strategy improves the tracking results in comparison to a classical combination of parallel trackers and that the tracker ensemble helps to deal with the initialization uncertainty of a single tracker.

  18. Fusion safety regulations in the United States: Progress and trends

    SciTech Connect

    DeLooper, J.

    1994-07-01

    This paper explores the issue of regulations as they apply to current and future fusion experimental machines. It addresses fusion regulatory issues, current regulations used for fusion, the Tokamak Fusion Test Reactor experience with regulations, and future regulations to achieve fusion`s safety and environmental potential.

  19. Magnetized Target Fusion: Prospects for Low-Cost Fusion Energy

    NASA Technical Reports Server (NTRS)

    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

    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

  20. Fusion - An energy source for synthetic fuels

    NASA Astrophysics Data System (ADS)

    Fillo, J. A.; Powell, J.; Steinberg, M.

    1980-05-01

    An important first step in the synthesis of liquid and gaseous fuels is the production of hydrogen. Thermonuclear fusion offers an inexhaustible source of energy for the production of hydrogen from water. Depending on design, electric generation efficiencies of 40 to 60% and hydrogen production efficiencies by high temperature electrolysis of 50 to 70% are projected for fusion reactors using high temperature blankets. Fusion/coal symbiotic systems appear economically promising for the first generation of commercial fusion synfuels plants. In the long term, there could be a gradual transition to an inexhaustible energy system based solely on fusion.

  1. Mechanisms of myoblast fusion during muscle development

    PubMed Central

    Kim, Ji Hoon; Jin, Peng; Duan, Rui; Chen, Elizabeth H.

    2015-01-01

    The development and regeneration of skeletal muscles require the fusion of mononulceated muscle cells to form multinucleated, contractile muscle fibers. Studies using a simple genetic model, Drosophila melanogaster, have discovered many evolutionarily conserved fusion-promoting factors in vivo. Recent work in zebrafish and mouse also identified several vertebrate-specific factors required for myoblast fusion. Here, we integrate progress in multiple in vivo systems and highlight conceptual advance in understanding how muscle cell membranes are brought together for fusion. We focus on the molecular machinery at the fusogenic synapse and present a three-step model to describe the molecular and cellular events leading to fusion pore formation. PMID:25989064

  2. Henipavirus membrane fusion and viral entry.

    PubMed

    Aguilar, Hector C; Iorio, Ronald M

    2012-01-01

    Nipah (NiV) and Hendra (HeV) viruses cause cell-cell fusion (syncytia) in brain, lung, heart, and kidney tissues, leading to encephalitis, pneumonia, and often death. Membrane fusion is essential to both viral entry and virus-induced cell-cell fusion, a hallmark of henipavirus infections. Elucidiation of the mechanism(s) of membrane fusion is critical to understanding henipavirus pathobiology and has the potential to identify novel strategies for the development of antiviral therapeutic agents. Henipavirus membrane fusion requires the coordinated actions of the viral attachment (G) and fusion (F) glycoproteins. Current henipavirus fusion models posit that attachment of NiV or HeV G to its cell surface receptors releases F from its metastable pre-fusion conformation to mediate membrane fusion. The identification of ephrinB2 and ephrinB3 as henipavirus receptors has paved the way for recent advances in our understanding of henipavirus membrane fusion. These advances highlight mechanistic similarities and differences between membrane fusion for the henipavirus and other genera within the Paramyxoviridae family. Here, we review these mechanisms and the current gaps in our knowledge in the field.

  3. Comparison Study between Conventional Sequence and Slice-Encoding Metal Artifact Correction (SEMAC) in the Diagnosis of Postoperative Complications in Patients Receiving Lumbar Inter-Body Fusion and Pedicle Screw Fixation Surgery

    PubMed Central

    Han, Sol Bee; Kwon, Jong Won

    2016-01-01

    Background and Purpose Slice-Encoding Metal Artifact Correction (SEMAC) sequence is one of the metal artifact reduction techniques of anatomical structure, but there has been no report about evaluation of post-operative complications. The purpose of this article is to compare the anatomical visibility between fast spin echo (FSE) and FSE-SEMAC and to evaluate the additional value of FSE-SEMAC in diagnostic confidence of the complications. Materials and Methods We conducted a retrospective study with 54 patients who received lumbar spinal surgery and MR images including FSE-SEMAC. For the semi-quantitative evaluation, the visibility of anatomical structures (neural foramen, bone-inter-body cage interface, central canal, nerve root in epidural space, back muscle, and bone-pedicle screw interface) was evaluated. For qualitative evaluation, we evaluated FSE and FSE with FSE-SEMAC independently, and recorded the diagnostic confidence level of post-operative complications. Generalized estimating equation regression analysis was used for statistical analysis, and a weighted kappa was used for inter-observer agreement. Results Scores of 6 imaging findings with FSE-SEMAC were significantly higher than that of FSE (P-value < .0001). Inter-observer agreements show good reliability (weighted kappa = 0.45–0.75). Both reviewers deemed 37 (reviewer 1) or 19 more (reviewer 2) post-operative complications with FSE plus FSE-SEMAC, compared to FSE only. Except for central canal stenosis (P-value = .2408), diagnostic confidence level for other post-operative complications were significantly higher with FSE plus FSE-SEMAC (P-value = .0000) than FSE. Conclusions FSE-SEMAC significantly reduces image distortion, compared to FSE sequence in 3.0-T MR. Also, diagnostic confidence for post-operative complications was higher when FSE with additional FSE-SEMAC compared to FSE only. PMID:27711137

  4. Fusion technologies for Laser Inertial Fusion Energy (LIFE)

    NASA Astrophysics Data System (ADS)

    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

    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.

  5. Acoustically Driven Magnetized Target Fusion At General Fusion: An Overview

    NASA Astrophysics Data System (ADS)

    O'Shea, Peter; Laberge, M.; Donaldson, M.; Delage, M.; the Fusion Team, General

    2016-10-01

    Magnetized Target Fusion (MTF) involves compressing an initial magnetically confined plasma of about 1e23 m-3, 100eV, 7 Tesla, 20 cm radius, >100 μsec life with a 1000x volume compression in 100 microseconds. If near adiabatic compression is achieved, the final plasma of 1e26 m-3, 10keV, 700 Tesla, 2 cm radius, confined for 10 μsec would produce interesting fusion energy gain. General Fusion (GF) is developing an acoustic compression system using pneumatic pistons focusing a shock wave on the CT plasma in the center of a 3 m diameter sphere filled with liquid lead-lithium. Low cost driver, straightforward heat extraction, good tritium breeding ratio and excellent neutron protection could lead to a practical power plant. GF (65 employees) has an active plasma R&D program including both full scale and reduced scale plasma experiments and simulation of both. Although acoustic driven compression of full scale plasmas is the end goal, present compression studies use reduced scale plasmas and chemically accelerated Aluminum liners. We will review results from our plasma target development, motivate and review the results of dynamic compression field tests and briefly describe the work to date on the acoustic driver front.

  6. Photoinduced Fusion of Lipid Bilayer Membranes.

    PubMed

    Suzuki, Yui; Nagai, Ken H; Zinchenko, Anatoly; Hamada, Tsutomu

    2017-03-14

    We have developed a novel system for photocontrol of the fusion of lipid vesicles through the use of a photosensitive surfactant containing an azobenzene moiety (AzoTAB). Real-time microscopic observations clarified a change in both the surface area and internal volume of vesicles during fusion. We also determined the optimal cholesterol concentrations and temperature for inducing fusion. The mechanism of fusion can be attributed to a change in membrane tension, which is caused by the solubilization of lipids through the isomerization of AzoTAB. We used a micropipet technique to estimate membrane tension and discuss the mechanism of fusion in terms of membrane elastic energy. The obtained results regarding this novel photoinduced fusion could lead to a better understanding of the mechanism of membrane fusion in living cells and may also see wider applications, such as in drug delivery and biomimetic material design.

  7. Object recognition approach based on feature fusion

    NASA Astrophysics Data System (ADS)

    Wang, Runsheng

    2001-09-01

    Multi-sensor information fusion plays an important pole in object recognition and many other application fields. Fusion performance is tightly depended on the fusion level selected and the approach used. Feature level fusion is a potential and difficult fusion level though there might be mainly three fusion levels. Two schemes are developed for key issues of feature level fusion in this paper. In feature selecting, a normal method developed is to analyze the mutual relationship among the features that can be used, and to be applied to order features. In object recognition, a multi-level recognition scheme is developed, whose procedure can be controlled and updated by analyzing the decision result obtained in order to achieve a final reliable result. The new approach is applied to recognize work-piece objects with twelve classes in optical images and open-country objects with four classes based on infrared image sequence and MMW radar. Experimental results are satisfied.

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

    SciTech Connect

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

    2013-03-15

    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.

  9. Fusion evaporation and fusion-fission with aligned /sup 23/Na ions at energies near and below the fusion barrier

    SciTech Connect

    Butsch, R.; Jaensch, H.; Kraemer, D.; Moebius, K.; Ott, W.; Steffens, E.; Tungate, G.; Weller, a.A.; Becker, K.; Blatt, K.; and others

    1987-10-01

    Using aligned /sup 23/Na beams, fusion cross sections sigma/sup fus/ and second-rank tensor analyzing powers for fusion T/sub 20//sup fus/ have been measured at energies near and below the fusion barrier for /sup 23/Na+ /sup 48/Ti and for /sup 23/Na+ /sup 206/Pb. At sub-barrier energies, large, nearly maximal, values of T/sub 20//sup fus/ occur, especially for fusion with the heavy target /sup 206/Pb. This reflects the strong influence of the spectroscopic deformation of the projectile on the fusion process at energies below the barrier. However, within a quantum-mechanical coupled-channels calculation this degree of freedom is not enough to describe both the fusion cross section and the second-rank tensor analyzing power for fusion in the energy regime below the fusion barrier. It is shown that the coupling of the fusion channel to inelastic excitations of the projectile and the target can describe the magnitude and energy dependence of T/sub 20//sup fus/ for both heavy ion systems, but fails to reproduce the ''sub-barrier enhancement'' of the fusion cross section for both systems.

  10. Studies on the fusion peptide of a paramyxovirus fusion glycoprotein: roles of conserved residues in cell fusion.

    PubMed Central

    Horvath, C M; Lamb, R A

    1992-01-01

    The role of residues in the conserved hydrophobic N-terminal fusion peptide of the paramyxovirus fusion (F) protein in causing cell-cell fusion was examined. Mutations were introduced into the cDNA encoding the simian virus 5 (SV5) F protein, the altered F proteins were expressed by using an eukaryotic vector, and their ability to mediate syncytium formation was determined. The mutant F proteins contained both single- and multiple-amino-acid substitutions, and they exhibited a variety of intracellular transport properties and fusion phenotypes. The data indicate that many substitutions in the conserved amino acids of the simian virus 5 F fusion peptide can be tolerated without loss of biological activity. Mutant F proteins which were not transported to the cell surface did not cause cell-cell fusion, but all of the mutants which were transported to the cell surface were fusion competent, exhibiting fusion properties similar to or better than those of the wild-type F protein. Mutant F proteins containing glycine-to-alanine substitutions had altered intracellular transport characteristics, yet they exhibited a great increase in fusion activity. The potential structural implications of this substitution and the possible importance of these glycine residues in maintaining appropriate levels of fusion activity are discussed. Images PMID:1548771

  11. Prospects for toroidal fusion reactors

    SciTech Connect

    Sheffield, J.; Galambos, J.D.

    1994-06-01

    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.

  12. Investigation of condensed matter fusion

    SciTech Connect

    Jones, S.E.; Berrondo, M.; Czirr, J.B.; Decker, D.L.; Harrison, K.; Jensen, G.L.; Palmer, E.P.; Rees, L.B.; Taylor, S.; Vanfleet, H.B.; Wang, J.C.; Bennion, D.N.; Harb, J.N.; Pitt, W.G.; Thorne, J.M.; Anderson, A.N.; McMurtry, G.; Murphy, N.; Goff, F.E.

    1990-12-01

    Work on muon-catalyzed fusion led to research on a possible new type of fusion occurring in hydrogen isotopes embedded in metal lattices. While the nuclear-product yields observed to date are so small as to require careful further checking, rates observed over short times appear sufficiently large to suggest that significant neutrons and triton yields could be realized -- if the process could be understood and controlled. During 1990, we have developed two charged-particle detection systems and three new neutron detectors. A segmented, high-efficiency neutron counter was taken into 600 m underground in a mine in Colorado for studies out of the cosmic-ray background. Significant neutron emissions were observed in this environment in both deuterium-gas-loaded metals and in electrolytic cells, confirming our earlier observations.

  13. Interpreting inertial fusion neutron spectra

    NASA Astrophysics Data System (ADS)

    Munro, David H.

    2016-03-01

    A burning laser fusion plasma produces a neutron spectrum first described by Brysk (1973 Plasma Phys. Control. Fusion 15 611). This and more recent work deals with the spectrum produced by a single fluid element. The distribution of temperatures and velocities in multiple fluid elements combine in any real spectrum; we derive formulas for how the neutron spectrum averages these contributions. The single element momentum spectrum is accurately Gaussian, but the multi-element spectrum exhibits higher moments. In particular, the skew and kurtosis are likely to be large enough to measure. Even the single fluid element spectrum may exhibit measurable directional anisotropy, so that instruments with different lines of sight should see different yields, mean velocities, mean temperatures, and higher moments. Finally, we briefly discuss how scattering in the imploded core modifies the neutron spectrum by changing the relative weighting of fuel regions with different temperatures and velocities.

  14. Interplanetary propulsion using inertial fusion

    SciTech Connect

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

    1987-01-01

    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.

  15. Endoscopic Accessory Navicular Synchondrosis Fusion.

    PubMed

    Lui, Tun Hing

    2016-12-01

    The accessory navicular bone is one of the most common accessory ossicles of the foot. Fewer than 1% of accessory navicular bones are symptomatic, and most of these are type II accessory navicular bones. A separation of the synchondrosis is considered one of the main causes of pain. After an injury to the synchondrosis has resulted in a chondro-osseous disruption, the combined forces of tension and shear from the posterior tibial tendon and the foot aggravate the injury and prevent it from healing. Fusion of the synchondrosis is a logical surgical treatment option if the pain is recalcitrant to conservative measures. The purpose of this technical note is to report an endoscopic approach to achieve fusion. It has the advantages of better cosmesis, less scar pain, less risk of nonunion, and potential to examine the tibialis posterior tendon and the talonavicular joint.

  16. FUSION WELDING METHOD AND APPARATUS

    DOEpatents

    Wyman, W.L.; Steinkamp, W.I.

    1961-01-17

    An apparatus for the fusion welding of metal pieces at a joint is described. The apparatus comprises a highvacuum chamber enclosing the metal pieces and a thermionic filament emitter. Sufficient power is applied to the emitter so that when the electron emission therefrom is focused on the joint it has sufficient energy to melt the metal pieces, ionize the metallic vapor abcve the molten metal, and establish an arc discharge between the joint and the emitter.

  17. Inertial-confinement-fusion targets

    SciTech Connect

    Hendricks, C.D.

    1981-11-16

    Inertial confinement fusion (ICF) targets are made as simple flat discs, as hollow shells or as complicated multilayer structures. Many techniques have been devised for producing the targets. Glass and metal shells are made by using drop and bubble techniques. Solid hydrogen shells are also produced by adapting old methods to the solution of modern problems. Some of these techniques, problems and solutions are discussed. In addition, the applications of many of the techniques to fabrication of ICF targets is presented.

  18. Inertial fusion experiments and theory

    NASA Astrophysics Data System (ADS)

    Mima, Kunioki; Tikhonchuk, V.; Perlado, M.

    2011-09-01

    Inertial fusion research is approaching a critical milestone, namely the demonstration of ignition and burn. The world's largest high-power laser, the National Ignition Facility (NIF), is under operation at the Lawrence Livermore National Laboratory (LLNL), in the USA. Another ignition machine, Laser Mega Joule (LMJ), is under construction at the CEA/CESTA research centre in France. In relation to the National Ignition Campaign (NIC) at LLNL, worldwide studies on inertial fusion applications to energy production are growing. Advanced ignition schemes such as fast ignition, shock ignition and impact ignition, and the inertial fusion energy (IFE) technology are under development. In particular, the Fast Ignition Realization Experiment (FIREX) at the Institute of Laser Engineering (ILE), Osaka University, and the OMEGA-EP project at the Laboratory for Laser Energetics (LLE), University Rochester, and the HiPER project in the European Union (EU) for fast ignition and shock ignition are progressing. The IFE technology research and development are advanced in the frameworks of the HiPER project in EU and the LIFE project in the USA. Laser technology developments in the USA, EU, Japan and Korea were major highlights in the IAEA FEC 2010. In this paper, the status and prospects of IFE science and technology are described.

  19. Gasdynamic Mirror Fusion Propulsion Experiment

    NASA Technical Reports Server (NTRS)

    Emrich, William J., Jr.; Rodgers, Stephen L. (Technical Monitor)

    2001-01-01

    Nuclear fusion appears to be the most promising concept for producing extremely high specific impulse rocket engines. One particular fusion concept which seems to be particularly well suited for fusion propulsion applications is the gasdynamic mirror (GDM). This device would operate at much higher plasma densities and with much larger LD ratios than previous mirror machines. Several advantages accrue from such a design. First, the high LA:) ratio minimizes to a large extent certain magnetic curvature effects which lead to plasma instabilities causing a loss of plasma confinement. Second, the high plasma density will result in the plasma behaving much more Re a conventional fluid with a mean free path shorter than the length of the device. This characteristic helps reduce problems associated with "loss cone" microinstabilities. An experimental GDM device is currently being constructed at the NASA Marshall Space Flight Center to provide an initial assessment of the feasibility of this type of propulsion system. Initial experiments are expected to commence in the late fall of 2000.

  20. Observations of membrane fusion in a liposome dispersion: the missing fusion intermediate?

    PubMed Central

    Foldvari, Marianna

    2015-01-01

    Early intermediate structures of liposome-liposome fusion events were captured by freeze-fracture electron microscopic (EM) technique. The images show the morphology of the fusion interface at several different stages of the fusion event. One of the intermediates was captured at a serendipitous stage of two vesicles’ membranes (both leaflets) merging and their contents starting to intermix clearly showing the fusion interface with a previously unseen fusion rim. From the morphological information a hypothetical sequence of the fusion event and corresponding lipid structural arrangements are described. PMID:26069726

  1. A local approach for focussed Bayesian fusion

    NASA Astrophysics Data System (ADS)

    Sander, Jennifer; Heizmann, Michael; Goussev, Igor; Beyerer, Jürgen

    2009-04-01

    Local Bayesian fusion approaches aim to reduce high storage and computational costs of Bayesian fusion which is separated from fixed modeling assumptions. Using the small world formalism, we argue why this proceeding is conform with Bayesian theory. Then, we concentrate on the realization of local Bayesian fusion by focussing the fusion process solely on local regions that are task relevant with a high probability. The resulting local models correspond then to restricted versions of the original one. In a previous publication, we used bounds for the probability of misleading evidence to show the validity of the pre-evaluation of task specific knowledge and prior information which we perform to build local models. In this paper, we prove the validity of this proceeding using information theoretic arguments. For additional efficiency, local Bayesian fusion can be realized in a distributed manner. Here, several local Bayesian fusion tasks are evaluated and unified after the actual fusion process. For the practical realization of distributed local Bayesian fusion, software agents are predestinated. There is a natural analogy between the resulting agent based architecture and criminal investigations in real life. We show how this analogy can be used to improve the efficiency of distributed local Bayesian fusion additionally. Using a landscape model, we present an experimental study of distributed local Bayesian fusion in the field of reconnaissance, which highlights its high potential.

  2. Multiscale Medical Image Fusion in Wavelet Domain

    PubMed Central

    Khare, Ashish

    2013-01-01

    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

  3. Fusion Nuclear Science Pathways Assessment

    SciTech Connect

    C.E. Kessel, et. al.

    2012-02-23

    With the strong commitment of the US to the success of the ITER burning plasma mission, and the project overall, it is prudent to consider how to take the most advantage of this investment. The production of energy from fusion has been a long sought goal, and the subject of several programmatic investigations and time line proposals [1]. The nuclear aspects of fusion research have largely been avoided experimentally for practical reasons, resulting in a strong emphasis on plasma science. Meanwhile, ITER has brought into focus how the interface between the plasma and engineering/technology, presents the most challenging problems for design. In fact, this situation is becoming the rule and no longer the exception. ITER will demonstrate the deposition of 0.5 GW of neutron heating to the blanket, deliver a heat load of 10-20 MW/m2 or more on the divertor, inject 50-100 MW of heating power to the plasma, all at the expected size scale of a power plant. However, in spite of this, and a number of other technologies relevant power plant, ITER will provide a low neutron exposure compared to the levels expected to a fusion power plant, and will purchase its tritium entirely from world reserves accumulated from decades of CANDU reactor operations. Such a decision for ITER is technically well founded, allowing the use of conventional materials and water coolant, avoiding the thick tritium breeding blankets required for tritium self-sufficiency, and allowing the concentration on burning plasma and plasma-engineering interface issues. The neutron fluence experienced in ITER over its entire lifetime will be ~ 0.3 MW-yr/m2, while a fusion power plant is expected to experience 120-180 MW-yr/m2 over its lifetime. ITER utilizes shielding blanket modules, with no tritium breeding, except in test blanket modules (TBM) located in 3 ports on the midplane [2], which will provide early tests of the fusion nuclear environment with very low tritium production (a few g per year).

  4. Materials issues in fusion reactors

    NASA Astrophysics Data System (ADS)

    Suri, A. K.; Krishnamurthy, N.; Batra, I. S.

    2010-02-01

    The world scientific community is presently engaged in one of the toughest technological tasks of the current century, namely, exploitation of nuclear fusion in a controlled manner for the benefit of mankind. Scientific feasibility of controlled fusion of the light elements in plasma under magnetic confinement has already been proven. International efforts in a coordinated and co-operative manner are presently being made to build ITER - the International Thermonuclear Experimental Reactor - to test, in this first step, the concept of 'Tokamak' for net fusion energy production. To exploit this new developing option of making energy available through the route of fusion, India too embarked on a robust fusion programme under which we now have a working tokamak - the Aditya and a steady state tokamak (SST-1), which is on the verge of functioning. The programme envisages further development in terms of making SST-2 followed by a DEMO and finally the fusion power reactor. Further, with the participation of India in the ITER program in 2005, and recent allocation of half - a - port in ITER for placing our Lead - Lithium Ceramic Breeder (LLCB) based Test Blanket Module (TBM), meant basically for breeding tritium and extracting high grade heat, the need to understand and address issues related to materials for these complex systems has become all the more necessary. Also, it is obvious that with increasing power from the SST stages to DEMO and further to PROTOTYPE, the increasing demands on performance of materials would necessitate discovery and development of new materials. Because of the 14.1 MeV neutrons that are generated in the D+T reaction exploited in a tokamak, the materials, especially those employed for the construction of the first wall, the diverter and the blanket segments, suffer crippling damage due to the high He/dpa ratios that result due to the high energy of the neutrons. To meet this challenge, the materials that need to be developed for the tokamaks

  5. Lipids as modulators of membrane fusion mediated by viral fusion proteins.

    PubMed

    Teissier, Elodie; Pécheur, Eve-Isabelle

    2007-11-01

    Enveloped viruses infect host cells by fusion of viral and target membranes. This fusion event is triggered by specific glycoproteins in the viral envelope. Fusion glycoproteins belong to either class I, class II or the newly described third class, depending upon their arrangement at the surface of the virion, their tri-dimensional structure and the location within the protein of a short stretch of hydrophobic amino acids called the fusion peptide, which is able to induce the initial lipid destabilization at the onset of fusion. Viral fusion occurs either with the plasma membrane for pH-independent viruses, or with the endosomal membranes for pH-dependent viruses. Although, viral fusion proteins are parted in three classes and the subcellular localization of fusion might vary, these proteins have to act, in common, on lipid assemblies. Lipids contribute to fusion through their physical, mechanical and/or chemical properties. Lipids can thus play a role as chemically defined entities, or through their preferential partitioning into membrane microdomains called "rafts", or by modulating the curvature of the membranes involved in the fusion process. The purpose of this review is to make a state of the art on recent findings on the contribution of cholesterol, sphingolipids and glycolipids in cell entry and membrane fusion of a number of viral families, whose members bear either class I or class II fusion proteins, or fusion proteins of the recently discovered third class.

  6. Study of fusion Q-value rule in sub-barrier fusion of heavy ions

    NASA Astrophysics Data System (ADS)

    Liu, Xing-Xing; Zhang, Gao-Long; Zhang, Huan-Qiao

    2015-07-01

    A vast body of fusion data has been analyzed for different projectiles and target nuclei. It is indicated that the sub-barrier fusion depends on the fusion Q-value. In terms of a recently introduced fusion Q-value rule and an energy scaling reduction procedure, the experimental fusion excitation functions are reduced and compared with each other. It is found that the reduced fusion excitations of selected fusion systems show a similar trend. The fusion data for massive nuclei are in agreement with the Q-value rule. In the fusion process, the Q contribution should be considered. Within this approach, the sub-barrier fusion cross sections of most fusion systems can be predicted without involving any structure effects of colliding nuclei. Instances of disagreement are presented in a few fusion systems. The use of the energy scaling as a criterion of possible experimental data inconsistency is discussed. More precise experimental fusion data need to be measured. Supported by National Nature Science Foundation of China (11475013, 11035007, 11175011), State Key Laboratory of Software Development Environment (SKLSDE-2014ZX-08), Fundamental Research Funds for the Central Universities and the Key Laboratory of High Precision Nuclear Spectroscopy, Institute of Modern Physics, Chinese Academy of Sciences

  7. Nuclear Fusion Award 2009 speech Nuclear Fusion Award 2009 speech

    NASA Astrophysics Data System (ADS)

    Sabbagh, Steven Anthony

    2011-01-01

    This is an exceptional moment in my career, and so I want to thank all of my teachers, colleagues and mentors who have made this possible. From my co-authors and myself, many thanks to the International Atomic Energy Agency, IOP Publishing, the Nuclear Fusion journal team, and the selection committee for the great honor of receiving this award. Also gratitude to Kikuchi-sensei, not only for the inventive and visionary creation of this award, but also for being a key mentor dating back to his efforts in producing high neutron output in JT-60U. It was also a great honor to receive the award directly from IAEA Deputy Director General Burkart during the 23rd IAEA Fusion Energy Conference in Daejeon. Receiving the award at this venue is particularly exciting as Daejeon is home to the new, next-generation KSTAR tokamak device that will lead key magnetic fusion research areas going forward. I would also like to thank the mayor of Daejeon, Dr Yum Hong-Chul, and all of the meeting organizers for giving us all a truly spectacular and singular welcoming event during which the award was presented. The research leading to the award would not have been possible without the support of the US Department of Energy, and I thank the Department for the continued funding of this research. Special mention must be made to a valuable co-author who is no longer with us, Professor A. Bondeson, who was a significant pioneer in resistive wall mode (RWM) research. I would like to thank my wife, Mary, for her infinite patience and encouragement. Finally, I would like to personally thank all of you that have approached and congratulated me directly. There are no units to measure how important your words have been in this regard. When notified that our paper had been shortlisted for the 2009 Nuclear Fusion Award, my co-authors responded echoing how I felt—honored to be included in such a fine collection of research by colleagues. It was unfathomable—would this paper follow the brilliant work

  8. Inertial-confinement fusion with lasers

    NASA Astrophysics Data System (ADS)

    Betti, R.; Hurricane, O. A.

    2016-05-01

    The quest for controlled fusion energy has been ongoing for over a half century. The demonstration of ignition and energy gain from thermonuclear fuels in the laboratory has been a major goal of fusion research for decades. Thermonuclear ignition is widely considered a milestone in the development of fusion energy, as well as a major scientific achievement with important applications in national security and basic sciences. The US is arguably the world leader in the inertial confinement approach to fusion and has invested in large facilities to pursue it, with the objective of establishing the science related to the safety and reliability of the stockpile of nuclear weapons. Although significant progress has been made in recent years, major challenges still remain in the quest for thermonuclear ignition via laser fusion. Here, we review the current state of the art in inertial confinement fusion research and describe the underlying physical principles.

  9. Carbon Nanotubes Mediate Fusion of Lipid Vesicles.

    PubMed

    Bhaskara, Ramachandra M; Linker, Stephanie M; Vögele, Martin; Köfinger, Jürgen; Hummer, Gerhard

    2017-02-28

    The fusion of lipid membranes is opposed by high energetic barriers. In living organisms, complex protein machineries carry out this biologically essential process. Here we show that membrane-spanning carbon nanotubes (CNTs) can trigger spontaneous fusion of small lipid vesicles. In coarse-grained molecular dynamics simulations, we find that a CNT bridging between two vesicles locally perturbs their lipid structure. Their outer leaflets merge as the CNT pulls lipids out of the membranes, creating an hourglass-shaped fusion intermediate with still intact inner leaflets. As the CNT moves away from the symmetry axis connecting the vesicle centers, the inner leaflets merge, forming a pore that completes fusion. The distinct mechanism of CNT-mediated membrane fusion may be transferable, providing guidance in the development of fusion agents, e.g., for the targeted delivery of drugs or nucleic acids.

  10. Technical Note: Estimating fusion properties for polyacids

    NASA Astrophysics Data System (ADS)

    Compernolle, S.; Ceulemans, K.; Müller, J.-F.

    2011-03-01

    Organic aerosol (OA) components are generally assumed to be liquid-like. Hence, to describe the partitioning of these components, the liquid vapor pressure of these components is desired. Polyacids and functionalized polyacids can be a significant part of OA. But often, measurements are available only for solid state vapor pressure, which can differ by orders of magnitude from their liquid counterparts. To convert such a sublimation pressure to a subcooled liquid vapor pressure, fusion properties (two out of these three quantities: fusion enthalpy, fusion entropy, fusion temperature) are required. Unfortunately, experimental knowledge of fusion properties is sometimes missing in part or totally, hence an estimation method is required. Several fusion data estimation methods are tested here against experimental data of polyacids. Next, we develop a simple estimation method, specifically for this kind of compounds, reducing significantly the estimation error.

  11. Lunar Helium-3 and Fusion Power

    NASA Technical Reports Server (NTRS)

    1988-01-01

    The NASA Office of Exploration sponsored the NASA Lunar Helium-3 and Fusion Power Workshop. The meeting was held to understand the potential of using He-3 from the moon for terrestrial fusion power production. It provided an overview, two parallel working sessions, a review of sessions, and discussions. The lunar mining session concluded that mining, beneficiation, separation, and return of He-3 from the moon would be possible but that a large scale operation and improved technology is required. The fusion power session concluded that: (1) that He-3 offers significant, possibly compelling, advantages over fusion of tritium, principally increased reactor life, reduced radioactive wastes, and high efficiency conversion, (2) that detailed assessment of the potential of the D/He-3 fuel cycle requires more information, and (3) D/He-3 fusion may be best for commercial purposes, although D/T fusion is more near term.

  12. Is Fusion Inhibited for Weakly Bound Nuclei?

    SciTech Connect

    Takahashi, J.; Munhoz, M.; Szanto, E.M.; Carlin, N.; Added, N.; Suaide, A.A.; de Moura, M.M.; Liguori Neto, R.; Szanto de Toledo, A.; Canto, L.F.

    1997-01-01

    Complete fusion of light radioactive nuclei is predicted to be hindered at near-barrier energies. This feature is investigated in the case of the least bound stable nuclei. Evaporation residues resulting from the {sup 6,7}Li+{sup 9}Be and {sup 6,7}Li+{sup 12}C fusion reactions have been measured in order to study common features in reactions involving light weakly bound nuclei. The experimental excitation functions revealed that the fusion cross section is significantly smaller than the total reaction cross section and also smaller than the fusion cross section expected from the available systematics. A clear correlation between the fusion probability and nucleon (cluster) separation energy has been established.The results suggest that the breakup process has a strong influence on the hindrance of the fusion cross section. {copyright} {ital 1996} {ital The American Physical Society}

  13. Fusion: an energy source for synthetic fuels

    SciTech Connect

    Fillo, J A; Powell, J; Steinberg, M

    1980-01-01

    The decreasing availability of fossil fuels emphasizes the need to develop systems which will produce synthetic fuel to substitute for and supplement the natural supply. An important first step in the synthesis of liquid and gaseous fuels is the production of hydrogen. Thermonuclear fusion offers an inexhaustible source of energy for the production of hydrogen from water. Depending on design, electric generation efficiencies of approx. 40 to 60% and hydrogen production efficiencies by high temperature electrolysis of approx. 50 to 70% are projected for fusion reactors using high temperature blankets. Fusion/coal symbiotic systems appear economically promising for the first generation of commercial fusion synfuels plants. Coal production requirements and the environmental effects of large-scale coal usage would be greatly reduced by a fusion/coal system. In the long term, there could be a gradual transition to an inexhaustible energy system based solely on fusion.

  14. Influence of breakup on fusion barrier distributions

    NASA Astrophysics Data System (ADS)

    Patel, D.; Nayak, B. K.; Mukherjee, S.; Biswas, D. C.; Mirgule, E. T.; John, B. V.; Gupta, Y. K.; Mukhopadhyay, S.; Prajapati, G.; Danu, L. S.; Rath, P. K.; Desai, V.; Deshmukh, N.; Saxena, A.

    2013-04-01

    Fusion barrier distributions have been extracted from the quasi-elastic scattering excitation functions, measured at backward angle θlab = 160° in reactions of 6,7Li+209Bi. The present results have been compared with the barrier distributions obtained from the fusion excitation function measurements for the above mentioned systems. The fusion barrier distributions from the quasi-elastic scattering excitation functions have been analyzed with simplified Coupled Channels calculations using Fresco. Inclusions of resonant states for both 6,7Li projectiles improve the predictions to describe the measured quasi-elastic scattering excitation functions and barrier distributions. For both the reactions peak positions of fusion barrier distributions are shifted towards a lower energy side in comparison to that obtained from the fusion excitation function measurements. The observed discrepancy in peak positions of barrier distributions obtained from quasi-elastic scattering and fusion excitation function measurements has been discussed in terms of total reaction threshold distribution.

  15. The Dark Side of Cell Fusion

    PubMed Central

    Bastida-Ruiz, Daniel; Van Hoesen, Kylie; Cohen, Marie

    2016-01-01

    Cell fusion is a physiological cellular process essential for fertilization, viral entry, muscle differentiation and placental development, among others. In this review, we will highlight the different cancer cell-cell fusions and the advantages obtained by these fusions. We will specially focus on the acquisition of metastatic features by cancer cells after fusion with bone marrow-derived cells. The mechanism by which cancer cells fuse with other cells has been poorly studied thus far, but the presence in several cancer cells of syncytin, a trophoblastic fusogen, leads us to a cancer cell fusion mechanism similar to the one used by the trophoblasts. The mechanism by which cancer cells perform the cell fusion could be an interesting target for cancer therapy. PMID:27136533

  16. Signaling mechanisms in mammalian myoblast fusion.

    PubMed

    Hindi, Sajedah M; Tajrishi, Marjan M; Kumar, Ashok

    2013-04-23

    Myoblast fusion is a critical process that contributes to the growth of muscle during development and to the regeneration of myofibers upon injury. Myoblasts fuse with each other as well as with multinucleated myotubes to enlarge the myofiber. Initial studies demonstrated that myoblast fusion requires extracellular calcium and changes in cell membrane topography and cytoskeletal organization. More recent studies have identified several cell-surface and intracellular proteins that mediate myoblast fusion. Furthermore, emerging evidence suggests that myoblast fusion is also regulated by the activation of specific cell-signaling pathways that lead to the expression of genes whose products are essential for the fusion process and for modulating the activity of molecules that are involved in cytoskeletal rearrangement. Here, we review the roles of the major signaling pathways in mammalian myoblast fusion.

  17. History of Nuclear Fusion Research in Japan

    NASA Astrophysics Data System (ADS)

    Iguchi, Harukazu; Matsuoka, Keisuke; Kimura, Kazue; Namba, Chusei; Matsuda, Shinzaburo

    In the late 1950s just after the atomic energy research was opened worldwide, there was a lively discussion among scientists on the strategy of nuclear fusion research in Japan. Finally, decision was made that fusion research should be started from the basic, namely, research on plasma physics and from cultivation of human resources at universities under the Ministry of Education, Science and Culture (MOE). However, an endorsement was given that construction of an experimental device for fusion research would be approved sooner or later. Studies on toroidal plasma confinement started at Japan Atomic Energy Research Institute (JAERI) under the Science and Technology Agency (STA) in the mid-1960s. Dualistic fusion research framework in Japan was established. This structure has lasted until now. Fusion research activities over the last 50 years are described by the use of a flowchart, which is convenient to glance the historical development of fusion research in Japan.

  18. Indirect drive targets for fusion power

    DOEpatents

    Amendt, Peter A.; Miles, Robin R.

    2016-10-11

    A hohlraum for an inertial confinement fusion power plant is disclosed. The hohlraum includes a generally cylindrical exterior surface, and an interior rugby ball-shaped surface. Windows over laser entrance holes at each end of the hohlraum enclose inert gas. Infrared reflectors on opposite sides of the central point reflect fusion chamber heat away from the capsule. P2 shields disposed on the infrared reflectors help assure an enhanced and more uniform x-ray bath for the fusion fuel capsule.

  19. Review of alternative concepts for magnetic fusion

    SciTech Connect

    Krakowski, R.A.; Miller, R.L.; Hagenson, R.L.

    1980-01-01

    Although the Tokamak represents the mainstay of the world's quest for magnetic fusion power, with the tandem mirror serving as a primary backup concept in the US fusion program, a wide range of alternative fusion concepts (AFC's) have been and are being pursued. This review presents a summary of past and present reactor projections of a majority of AFC's. Whenever possible, quantitative results are given.

  20. Magnetic fusion driventransmutation of nuclear waste (FTW)

    SciTech Connect

    Peng, Yueng Kay Martin; Cheng, E.T.

    1993-01-01

    The possibility of magnetic Fusion driven Transmutation of Waste (FTW) was revisted and discussed recently. Nuclear wastes include all transuranium elements: Pu isotopes, minor actinides separated from the spent fission fuel, and fissile products. Elimination of thse long-life nuclear wastes is necessary for the long-term viability of fission power. A Small Business Innovative Research program has been initiated under the leadership of TSI Research to examine the efficacy of fusion transmutation of waste utilizing small fusion drivers.

  1. Line tension at lipid phase boundaries as driving force for HIV fusion peptide-mediated fusion.

    PubMed

    Yang, Sung-Tae; Kiessling, Volker; Tamm, Lukas K

    2016-04-26

    Lipids and proteins are organized in cellular membranes in clusters, often called 'lipid rafts'. Although raft-constituent ordered lipid domains are thought to be energetically unfavourable for membrane fusion, rafts have long been implicated in many biological fusion processes. For the case of HIV gp41-mediated membrane fusion, this apparent contradiction can be resolved by recognizing that the interfaces between ordered and disordered lipid domains are the predominant sites of fusion. Here we show that line tension at lipid domain boundaries contributes significant energy to drive gp41-fusion peptide-mediated fusion. This energy, which depends on the hydrophobic mismatch between ordered and disordered lipid domains, may contribute tens of kBT to fusion, that is, it is comparable to the energy required to form a lipid stalk intermediate. Line-active compounds such as vitamin E lower line tension in inhomogeneous membranes, thereby inhibit membrane fusion, and thus may be useful natural viral entry inhibitors.

  2. Line tension at lipid phase boundaries as driving force for HIV fusion peptide-mediated fusion

    NASA Astrophysics Data System (ADS)

    Yang, Sung-Tae; Kiessling, Volker; Tamm, Lukas K.

    2016-04-01

    Lipids and proteins are organized in cellular membranes in clusters, often called `lipid rafts'. Although raft-constituent ordered lipid domains are thought to be energetically unfavourable for membrane fusion, rafts have long been implicated in many biological fusion processes. For the case of HIV gp41-mediated membrane fusion, this apparent contradiction can be resolved by recognizing that the interfaces between ordered and disordered lipid domains are the predominant sites of fusion. Here we show that line tension at lipid domain boundaries contributes significant energy to drive gp41-fusion peptide-mediated fusion. This energy, which depends on the hydrophobic mismatch between ordered and disordered lipid domains, may contribute tens of kBT to fusion, that is, it is comparable to the energy required to form a lipid stalk intermediate. Line-active compounds such as vitamin E lower line tension in inhomogeneous membranes, thereby inhibit membrane fusion, and thus may be useful natural viral entry inhibitors.

  3. Generomak: Fusion physics, engineering and costing model

    SciTech Connect

    Delene, J.G.; Krakowski, R.A.; Sheffield, J.; Dory, R.A.

    1988-06-01

    A generic fusion physics, engineering and economics model (Generomak) was developed as a means of performing consistent analysis of the economic viability of alternative magnetic fusion reactors. The original Generomak model developed at Oak Ridge by Sheffield was expanded for the analyses of the Senior Committee on Environmental Safety and Economics of Magnetic Fusion Energy (ESECOM). This report describes the Generomak code as used by ESECOM. The input data used for each of the ten ESECOM fusion plants and the Generomak code output for each case is given. 14 refs., 3 figs., 17 tabs.

  4. Mechanical tension drives cell membrane fusion.

    PubMed

    Kim, Ji Hoon; Ren, Yixin; Ng, Win Pin; Li, Shuo; Son, Sungmin; Kee, Yee-Seir; Zhang, Shiliang; Zhang, Guofeng; Fletcher, Daniel A; Robinson, Douglas N; Chen, Elizabeth H

    2015-03-09

    Membrane fusion is an energy-consuming process that requires tight juxtaposition of two lipid bilayers. Little is known about how cells overcome energy barriers to bring their membranes together for fusion. Previously, we have shown that cell-cell fusion is an asymmetric process in which an "attacking" cell drills finger-like protrusions into the "receiving" cell to promote cell fusion. Here, we show that the receiving cell mounts a Myosin II (MyoII)-mediated mechanosensory response to its invasive fusion partner. MyoII acts as a mechanosensor, which directs its force-induced recruitment to the fusion site, and the mechanosensory response of MyoII is amplified by chemical signaling initiated by cell adhesion molecules. The accumulated MyoII, in turn, increases cortical tension and promotes fusion pore formation. We propose that the protrusive and resisting forces from fusion partners put the fusogenic synapse under high mechanical tension, which helps to overcome energy barriers for membrane apposition and drives cell membrane fusion.

  5. Two heretical thoughts on fusion and climate

    NASA Astrophysics Data System (ADS)

    Manheimer, Wallace

    2016-10-01

    This presents and explores 2 heretical thoughts regarding controlled fusion and climate. First, the only way that fusion can contribute to midcentury power is by switching its goal from pure fusion, to fusion breeding. Fusion breeding makes many fewer demands on the fusion device than does pure fusion. Fusion breeding could lead to a sustainable, carbon free, environmentally and economically viable, midcentury infrastructure, with little or no proliferation risk, which could provide terawatts of power for the world. The second involves climate. We are all inundated by media warnings, not only of warming from CO2 in the atmosphere, but all sorts of other environmental disasters. For instance there will be more intense storms, rising sea levels, wild fires, retreating glaciers, droughts, loss of agricultural productivity... These assertions are very easy to check out. Such a search shows that we are nowhere near any sort of environmental crisis. The timing could be serendipitous; the time necessary to develop fusion breeding could well match up to the time when it is needed so as to avoid harm to the earth's climate and/or depletion of finite energy resources.

  6. Fusion metrics for dynamic situation analysis

    NASA Astrophysics Data System (ADS)

    Blasch, Erik P.; Pribilski, Mike; Daughtery, Bryan; Roscoe, Brian; Gunsett, Josh

    2004-08-01

    To design information fusion systems, it is important to develop metrics as part of a test and evaluation strategy. In many cases, fusion systems are designed to (1) meet a specific set of user information needs (IN), (2) continuously validate information pedigree and updates, and (3) maintain this performance under changing conditions. A fusion system"s performance is evaluated in many ways. However, developing a consistent set of metrics is important for standardization. For example, many track and identification metrics have been proposed for fusion analysis. To evaluate a complete fusion system performance, level 4 sensor management and level 5 user refinement metrics need to be developed simultaneously to determine whether or not the fusion system is meeting information needs. To describe fusion performance, the fusion community needs to agree on a minimum set of metrics for user assessment and algorithm comparison. We suggest that such a minimum set should include feasible metrics of accuracy, confidence, throughput, timeliness, and cost. These metrics can be computed as confidence (probability), accuracy (error), timeliness (delay), throughput (amount) and cost (dollars). In this paper, we explore an aggregate set of metrics for fusion evaluation and demonstrate with information need metrics for dynamic situation analysis.

  7. Correcting mitochondrial fusion by manipulating mitofusin conformations

    PubMed Central

    Franco, Antonietta; Kitsis, Richard N.; Fleischer, Julie A.; Gavathiotis, Evripidis; Kornfeld, Opher S.; Gong, Guohua; Biris, Nikolaos; Benz, Ann; Qvit, Nir; Donnelly, Sara K; Chen, Yun; Mennerick, Steven; Hodgson, Louis; Mochly-Rosen, Daria; Dorn, Gerald W

    2017-01-01

    Summary Mitochondria are dynamic organelles, remodeling and exchanging contents during cyclic fusion and fission. Genetic mutations of mitofusin (Mfn) 2 interrupt mitochondrial fusion and cause the untreatable neurodegenerative condition, Charcot Marie Tooth disease type 2A (CMT2A). It has not been possible to directly modulate mitochondrial fusion, in part because the structural basis of mitofusin function is incompletely understood. Here we show that mitofusins adopt either a fusion-constrained or fusion-permissive molecular conformation directed by specific intramolecular binding interactions, and demonstrate that mitofusin-dependent mitochondrial fusion can be regulated by targeting these conformational transitions. Based on this model we engineered a cell-permeant minipeptide to destabilize fusion-constrained mitofusin and promote the fusion-permissive conformation, reversing mitochondrial abnormalities in cultured fibroblasts and neurons harboring CMT2A gene defects. The relationship between mitofusin conformational plasticity and mitochondrial dynamism uncovers a central mechanism regulating mitochondrial fusion whose manipulation can correct mitochondrial pathology triggered by defective or imbalanced mitochondrial dynamics. PMID:27775718

  8. Modes of Paramyxovirus Fusion: a Henipavirus perspective

    PubMed Central

    Lee, Benhur; Akyol-Ataman, Zeynep

    2011-01-01

    Henipavirus is a new genus of paramyxovirus that uses protein-based receptors (EphrinB2 and EphrinB3) for virus entry. Paramyxovirus entry requires the coordinated action of the fusion (F) and attachment viral envelope glycoproteins. Receptor binding to the attachment protein triggers F to undergo a conformational cascade that results in membrane fusion. The accumulation of structural and functional studies on many paramyxoviral fusion and attachment proteins, including recent structures of Nipah and Hendra virus G bound and unbound to cognate ephrinB receptors, indicate that henipavirus entry and fusion differs mechanistically from paramyxoviruses that use glycan-based receptors. PMID:21511478

  9. Inhibition of HIV-1 by fusion inhibitors.

    PubMed

    Eggink, Dirk; Berkhout, Ben; Sanders, Rogier W

    2010-01-01

    The envelope glycoprotein complex (Env) is responsible for entry of the human immunodeficiency virus type 1 (HIV-1) into cells by mediating attachment to target cells and subsequent membrane fusion. Env consists of three gp120 subunits that mediate receptor and co-receptor attachment and three gp41 subunits responsible for membrane fusion. Several steps of the entry process can serve as drug targets. Receptor antagonists prevent attachment of gp120 to the receptor or co-receptor and conformational changes within gp41 required for membrane fusion can be inhibited by fusion inhibitors. Enfuvirtide (T20, Fuzeon) is a peptide based on the gp41 sequence and is the only approved fusion inhibitor. It prevents membrane fusion by competitively binding to gp41 and blocking the formation of the post-fusion structure. New generations of T20-like peptides have been developed with improved potency and stability. Besides T20 and derivatives, other fusion inhibitors have been developed that target different domains of gp41. Here we discuss the development of fusion inhibitors, their mode of action and their potential for incorporation in future drug regimens.

  10. Fusion as a future energy source

    NASA Astrophysics Data System (ADS)

    Ward, D. J.

    2016-11-01

    Fusion remains the main source of energy generation in the Universe and is indirectly the origin of nearly all terrestrial energy (including fossil fuels) but it is the only fundamental energy source not used directly on Earth. Here we look at the characteristics of Earth-based fusion power, how it might contribute to future energy supply and what that tells us about the future direction of the R&D programme. The focus here is Magnetic Confinement Fusion although many of the points apply equally to inertial confinement fusion.

  11. Mitochondrial fusion is essential for steroid biosynthesis.

    PubMed

    Duarte, Alejandra; Poderoso, Cecilia; Cooke, Mariana; Soria, Gastón; Cornejo Maciel, Fabiana; Gottifredi, Vanesa; Podestá, Ernesto J

    2012-01-01

    Although the contribution of mitochondrial dynamics (a balance in fusion/fission events and changes in mitochondria subcellular distribution) to key biological process has been reported, the contribution of changes in mitochondrial fusion to achieve efficient steroid production has never been explored. The mitochondria are central during steroid synthesis and different enzymes are localized between the mitochondria and the endoplasmic reticulum to produce the final steroid hormone, thus suggesting that mitochondrial fusion might be relevant for this process. In the present study, we showed that the hormonal stimulation triggers mitochondrial fusion into tubular-shaped structures and we demonstrated that mitochondrial fusion does not only correlate-with but also is an essential step of steroid production, being both events depend on PKA activity. We also demonstrated that the hormone-stimulated relocalization of ERK1/2 in the mitochondrion, a critical step during steroidogenesis, depends on mitochondrial fusion. Additionally, we showed that the SHP2 phosphatase, which is required for full steroidogenesis, simultaneously modulates mitochondrial fusion and ERK1/2 localization in the mitochondrion. Strikingly, we found that mitofusin 2 (Mfn2) expression, a central protein for mitochondrial fusion, is upregulated immediately after hormone stimulation. Moreover, Mfn2 knockdown is sufficient to impair steroid biosynthesis. Together, our findings unveil an essential role for mitochondrial fusion during steroidogenesis. These discoveries highlight the importance of organelles' reorganization in specialized cells, prompting the exploration of the impact that organelle dynamics has on biological processes that include, but are not limited to, steroid synthesis.

  12. Inertial fusion: strategy and economic potential

    SciTech Connect

    Nuckolls, J.H.

    1983-01-01

    Inertial fusion must demonstrate that the high target gains required for practical fusion energy can be achieved with driver energies not larger than a few megajoules. Before a multi-megajoule scale driver is constructed, inertial fusion must provide convincing experimental evidence that the required high target gains are feasible. This will be the principal objective of the NOVA laser experiments. Implosions will be conducted with scaled targets which are nearly hydrodynamically equivalent to the high gain target implosions. Experiments which demonstrate high target gains will be conducted in the early nineties when multi-megajoule drivers become available. Efficient drivers will also be demonstrated by this time period. Magnetic fusion may demonstrate high Q at about the same time as inertial fusion demonstrates high gain. Beyond demonstration of high performance fusion, economic considerations will predominate. Fusion energy will achieve full commercial success when it becomes cheaper than fission and coal. Analysis of the ultimate economic potential of inertial fusion suggests its costs may be reduced to half those of fission and coal. Relative cost escalation would increase this advantage. Fusions potential economic advantage derives from two fundamental properties: negligible fuel costs and high quality energy (which makes possible more efficient generation of electricity).

  13. Nuclear Fusion Award 2010 speech Nuclear Fusion Award 2010 speech

    NASA Astrophysics Data System (ADS)

    Rice, John

    2011-01-01

    Following the suggestion of Earl Marmar in 1995, I installed a compact von Hamos type x-ray spectrometer (originally built with Elisabeth Rachlew and Jan Kallne) on a tangentially viewing port on the Alcator C-Mod tokamak. The spectrometer views the plasma through a 2 cm diameter hole, and is tuned to H-like argon, suitable for passive measurement of the core toroidal rotation velocity from the Doppler shift. It soon became evident that the rotation in Ohmic L-mode discharges, while for the most part directed counter-current, depends in a very complicated fashion on plasma parameters, notably the electron density, current and magnetic configuration. The rotation can even flip sign for almost no apparent reason! In Ohmic and ion cyclotron range of frequencies (ICRF) heated H-mode plasmas the rotation is in the co-current direction and has a relatively simple dependence on plasma parameters, proportional to the stored energy normalized to the current. Rotation velocities as high as 130 km s-1 have been observed without external momentum input. In dimensionless terms this intrinsic (or spontaneous rotation) depends on the normalized plasma pressure. The association of toroidal rotation with plasma pressure in ICRF H-modes was first observed by Lars-Goran Eriksson in JET discharges. Similar results were subsequently reported for Tore Supra enhanced confinement plasmas. In the early 2000s concerns began to surface about the lack of substantial neutral beam driven rotation in ITER, and intrinsic rotation became a topic of interest in the ITPA Transport Group. Through that connection, similar observations from DIII-D, TCV and JT-60U were added to the growing list. A database of intrinsic rotation observations was assembled with the goal of extrapolating to the expected values for ITER. Both dimensional and dimensionless scalings were developed and formed the backbone of the 2007 Nuclear Fusion paper. I gratefully acknowledge the important contributions to this paper from

  14. Laser fusion pulse shape controller

    DOEpatents

    Siebert, Larry D.

    1977-01-01

    An apparatus for controlling the pulse shape, i.e., the pulse duration and intensity pattern, of a pulsed laser system, and which is particularly well adapted for controlling the pellet ignition pulse in a laser-driven fusion reaction system. The apparatus comprises a laser generator for providing an optical control pulse of the shape desired, a pulsed laser triggered by the control pulse, and a plurality of optical Kerr-effect gates serially disposed at the output of the pulsed laser and selectively triggered by the control pulse to pass only a portion of the pulsed laser output generally corresponding in shape to the control pulse.

  15. A. Sakharov and Fusion Research

    NASA Astrophysics Data System (ADS)

    Coppi, Bruno

    2012-02-01

    In the landmark paper by Tamm and Sakharov [1], a controlled nuclear fusion reactor based on an axisymmetric magnetic confinement configuration whose principles remain valid to this day, was proposed. In the light of present understanding of plasma physics the virtues (e.g. that of considering the D-D reaction) and the shortcomings of this paper are pointed out. In fact, relatively recent results of theoretical plasma physics (e.g. discovery of the so called second stability region) and advances in high field magnet technology have made it possible to identify the parameters of meaningful experiments capable of exploring D-D and D-^3He burn conditions. At the same time an experimental program (IGNIR) has been undertaken through a (funded) collaboration between Italy and Russia to investigate D-T plasmas close to ignition conditions based on an advanced high field toroidal confinement configuration. A. Sakharov envisioned a bolder approach to fusion research than that advocated by some of his contemporaries. The time taken to design and decide to fabricate the first experiment capable of reaching ignition conditions is due in part to the problem of gaining an adequate understanding the expected physics of fusion burning plasmas. However, most of the relevant financial effort has gone in the pursuit of slow and indirect enterprises complying with the ``playing it safe'' tendencies of large organizations or motivated by the purpose to develop technologies or maintain a high level of expertise in plasma physics to the expected benefit of other kinds of endeavors. The creativity demonstrated by A. Sakharov in dealing with civil rights and disarmament issues is needed, while maintaining our concerns for energy and the environment on a global scale, to orient the funding for fusion research toward a direct and well based scientific effort on concepts for which a variety of developments can be envisioned. These can span from uncovering new physics relevant, for instance

  16. Thomson scattering at general fusion

    NASA Astrophysics Data System (ADS)

    Young, W. C.; Parfeniuk, D.

    2016-11-01

    This paper provides an overview of the Thomson scattering diagnostic in use at General Fusion, including recent upgrades and upcoming plans. The plasma experiment under examination produces temperatures in the 50-500 eV range with density on the order of 1020 m-3. A four spatial point collection optics scheme has been implemented, with plans to expand to six spatial points. Recent changes to the optics of the laser beamline have reduced stray light. The system employs a frequency doubled Nd:YAG laser (532 nm), a grating spectrometer, and a photomultiplier array based detector.

  17. Introduction to Nuclear Fusion Power and the Design of Fusion Reactors. An Issue-Oriented Module.

    ERIC Educational Resources Information Center

    Fillo, J. A.

    This three-part module focuses on the principles of nuclear fusion and on the likely nature and components of a controlled-fusion power reactor. The physical conditions for a net energy release from fusion and two approaches (magnetic and inertial confinement) which are being developed to achieve this goal are described. Safety issues associated…

  18. Estimating the melting point, entropy of fusion, and enthalpy of fusion of organic compounds via SPARC

    EPA Science Inventory

    The entropies of fusion, enthalies of fusion, and melting points of organic compounds can be estimated through three models developed using the SPARC (SPARC Performs Automated Reasoning in Chemistry) platform. The entropy of fusion is modeled through a combination of interaction ...

  19. Magnetized Target Fusion in Advanced Propulsion Research

    NASA Technical Reports Server (NTRS)

    Cylar, Rashad

    2003-01-01

    The Magnetized Target Fusion (MTF) Propulsion lab at NASA Marshall Space Flight Center in Huntsville, Alabama has a program in place that has adopted to attempt to create a faster, lower cost and more reliable deep space transportation system. In this deep space travel the physics and development of high velocity plasma jets must be understood. The MTF Propulsion lab is also in attempt to open up the solar system for human exploration and commercial use. Fusion, as compared to fission, is just the opposite. Fusion involves the light atomic nuclei combination to produce denser nuclei. In the process, the energy is created by destroying the mass according to the distinguished equation: E = mc2 . Fusion energy development is being pursued worldwide as a very sustainable form of energy that is environmentally friendly. For the purposes of space exploration fusion reactions considered include the isotopes of hydrogen-deuterium (D2) and tritium (T3). Nuclei have an electrostatic repulsion between them and in order for the nuclei to fuse this repulsion must be overcome. One technique to bypass repulsion is to heat the nuclei to very high temperatures. The temperatures vary according to the type of reactions. For D-D reactions, one billion degrees Celsius is required, and for D-T reactions, one hundred million degrees is sufficient. There has to be energy input for useful output to be obtained form the fusion To make fusion propulsion practical, the mass, the volume, and the cost of the equipment to produce the reactions (generally called the reactor) need to be reduced by an order of magnitude or two from the state-of-the-art fusion machines. Innovations in fusion schemes are therefore required, especially for obtaining thrust for propulsive applications. Magnetized target fusion (MTF) is one of the innovative fusion concepts that have emerged over the last several years. MSFC is working with Los Alamos National Laboratory and other research groups in studying the

  20. Magnetized Target Fusion Driven by Plasma Liners

    NASA Technical Reports Server (NTRS)

    Thio, Y. C. Francis; Kirkpatrick, Ronald C.; Knapp, Charles E.; Rodgers, Stephen L. (Technical Monitor)

    2002-01-01

    Magnetized target fusion is an emerging, relatively unexplored approach to fusion for electrical power and propulsion application. The physical principles of the concept are founded upon both inertial confinement fusion (ICF) and magnetic confinement fusion (MCF). It attempts to combine the favorable attributes of both these orthogonal approaches to fusion, but at the same time, avoiding the extreme technical challenges of both by exploiting a fusion regime intermediate between them. It uses a material liner to compress, heat and contain the fusion reacting plasma (the target plasma) mentally. By doing so, the fusion burn could be made to occur at plasma densities as high as six orders of magnitude higher than conventional MCF such as tokamak, thus leading to an approximately three orders of magnitude reduction in the plasma energy required for ignition. It also uses a transient magnetic field, compressed to extremely high intensity (100's T to 1000T) in the target plasma, to slow down the heat transport to the liner and to increase the energy deposition of charged-particle fusion products. This has several compounding beneficial effects. It leads to longer energy confinement time compared with conventional ICF without magnetized target, and thus permits the use of much lower plasma density to produce reasonable burn-up fraction. The compounding effects of lower plasma density and the magneto-insulation of the target lead to greatly reduced compressional heating power on the target. The increased energy deposition rate of charged-particle fusion products also helps to lower the energy threshold required for ignition and increasing the burn-up fraction. The reduction in ignition energy and the compressional power compound to lead to reduced system size, mass and R&D cost. It is a fusion approach that has an affordable R&D pathway, and appears attractive for propulsion application in the nearer term.

  1. Robust fusion with reliabilities weights

    NASA Astrophysics Data System (ADS)

    Grandin, Jean-Francois; Marques, Miguel

    2002-03-01

    The reliability is a value of the degree of trust in a given measurement. We analyze and compare: ML (Classical Maximum Likelihood), MLE (Maximum Likelihood weighted by Entropy), MLR (Maximum Likelihood weighted by Reliability), MLRE (Maximum Likelihood weighted by Reliability and Entropy), DS (Credibility Plausibility), DSR (DS weighted by reliabilities). The analysis is based on a model of a dynamical fusion process. It is composed of three sensors, which have each it's own discriminatory capacity, reliability rate, unknown bias and measurement noise. The knowledge of uncertainties is also severely corrupted, in order to analyze the robustness of the different fusion operators. Two sensor models are used: the first type of sensor is able to estimate the probability of each elementary hypothesis (probabilistic masses), the second type of sensor delivers masses on union of elementary hypotheses (DS masses). In the second case probabilistic reasoning leads to sharing the mass abusively between elementary hypotheses. Compared to the classical ML or DS which achieves just 50% of correct classification in some experiments, DSR, MLE, MLR and MLRE reveals very good performances on all experiments (more than 80% of correct classification rate). The experiment was performed with large variations of the reliability coefficients for each sensor (from 0 to 1), and with large variations on the knowledge of these coefficients (from 0 0.8). All four operators reveal good robustness, but the MLR reveals to be uniformly dominant on all the experiments in the Bayesian case and achieves the best mean performance under incomplete a priori information.

  2. Plasma effects on resonant fusion

    NASA Astrophysics Data System (ADS)

    Sawyer, R. F.

    2012-11-01

    I investigate the effects of plasma interactions on resonance-enhanced fusion rates in stars. Starting from basic principles we derive an expression for the fusion rate that can serve as a basis for discussion of approximation schemes The present state-of-the-art correction algorithms, based on the classical correlation function for the fusing particles and the classical energy shift for the resonant state, do not follow from this result, even as an approximation. The results of expanding in a perturbation solution for the case of a weakly coupled plasma are somewhat enlightening. But at this point we are at a loss as to how to do meaningful calculations in systems with even moderate plasma coupling strength. Examples where this can matter are the effect of a possible low-energy 12C+12C resonance on x-ray bursts from accreting neutron stars or on supernova 1A simulations, and the calculation of the triple α rate in some of the more strongly coupled regions in which the process enters, such as accretion onto a neutron star.

  3. Controlled Nuclear Fusion: Status and Outlook

    ERIC Educational Resources Information Center

    Rose, David J.

    1971-01-01

    Presents the history, current concerns and potential developments of nuclear fusion as a major energy source. Controlled fusion research is summarized, technological feasibility is discussed and environmental factors are examined. Relationships of alternative energy sources as well as energy utilization are considered. (JM)

  4. Method of controlling fusion reaction rates

    DOEpatents

    Kulsrud, Russell M.; Furth, Harold P.; Valeo, Ernest J.; Goldhaber, Maurice

    1988-01-01

    A method of controlling the reaction rates of the fuel atoms in a fusion reactor comprises the step of polarizing the nuclei of the fuel atoms in a particular direction relative to the plasma confining magnetic field. Fusion reaction rates can be increased or decreased, and the direction of emission of the reaction products can be controlled, depending on the choice of polarization direction.

  5. Method of controlling fusion reaction rates

    DOEpatents

    Kulsrud, Russell M.; Furth, Harold P.; Valeo, Ernest J.; Goldhaber, Maurice

    1988-03-01

    A method of controlling the reaction rates of the fuel atoms in a fusion reactor comprises the step of polarizing the nuclei of the fuel atoms in a particular direction relative to the plasma confining magnetic field. Fusion reaction rates can be increased or decreased, and the direction of emission of the reaction products can be controlled, depending on the choice of polarization direction.

  6. Plasmas are Hot and Fusion is Cool

    SciTech Connect

    2011-01-01

    Plasmas are Hot and Fusion is Cold. The DOE Princeton Plasma Physics Laboratory (PPPL) collaborates to develop fusion as a safe, clean and abundant energy source for the future. This video discusses PPPL's research and development on plasma, the fourth state of matter.

  7. Highlights of the heavy ion fusion symposium

    SciTech Connect

    Keefe, D.

    1986-07-01

    The current status and prospects for inertial confinement fusion based on the use of intense beams of heavy ions will be described in the light of results presented at the International Symposium on Heavy Ion Fusion, (Washington, DC, May 27-29, 1986).

  8. Computer Modeling of a Fusion Plasma

    SciTech Connect

    Cohen, B I

    2000-12-15

    Progress in the study of plasma physics and controlled fusion has been profoundly influenced by dramatic increases in computing capability. Computational plasma physics has become an equal partner with experiment and traditional theory. This presentation illustrates some of the progress in computer modeling of plasma physics and controlled fusion.

  9. National Ignition Facility for Inertial Confinement Fusion

    SciTech Connect

    Paisner, J.A.; Murray, J.R.

    1997-10-08

    The National Ignition Facility for inertial confinement fusion will contain a 1.8 MJ, 500 TW frequency-tripled neodymium glass laser system that will be used to explore fusion ignition and other problems in the physics of high temperature and density. We describe the facility briefly. The NIF is scheduled to be completed in 2003.

  10. Plasma physics and controlled thermonuclear fusion

    SciTech Connect

    Krikorian, R. )

    1989-01-01

    This proceedings contains papers on plasma physics and controlled thermonuclear fusion. Included are the following topics: Plasma focus and Z-pinch, Review of mirror fusion research, Progress in studies of x-ray and ion-beam emission from plasma focus facilities.

  11. A fusion based plasma propulsion system

    NASA Technical Reports Server (NTRS)

    George, J. A.; Anderson, B.; Bryant, D.; Creese, C.; Djordjevic, V.; Peddicord, K. L.

    1987-01-01

    The Fusion Plasma Propulsion System scoping study was performed to investigate the possibilities of a fusion powered plasma propulsion system for space applications. Specifically, it was to be compared against existing electric propulsion concepts for a manned Mars mission. Design parameters consist of 1000 N thrust for 500 days, and the minimum mass possible. This investigation is briefly presented and conclusions drawn.

  12. Fusion Propulsion Z-Pinch Engine Concept

    NASA Technical Reports Server (NTRS)

    Miernik, J.; Statham, G.; Fabisinski, L.; Maples, C. D.; Adams, R.; Polsgrove, T.; Fincher, S.; Cassibry, J.; Cortez, R.; Turner, M.; Percy, T.

    2011-01-01

    Fusion-based nuclear propulsion has the potential to enable fast interplanetary transportation. Due to the great distances between the planets of our solar system and the harmful radiation environment of interplanetary space, high specific impulse (Isp) propulsion in vehicles with high payload mass fractions must be developed to provide practical and safe vehicles for human spaceflight missions. The Z-Pinch dense plasma focus method is a Magneto-Inertial Fusion (MIF) approach that may potentially lead to a small, low cost fusion reactor/engine assembly1. Recent advancements in experimental and theoretical understanding of this concept suggest favorable scaling of fusion power output yield 2. The magnetic field resulting from the large current compresses the plasma to fusion conditions, and this process can be pulsed over short timescales (10(exp -6 sec). This type of plasma formation is widely used in the field of Nuclear Weapons Effects testing in the defense industry, as well as in fusion energy research. A Decade Module 2 (DM2), approx.500 KJ pulsed-power is coming to the RSA Aerophysics Lab managed by UAHuntsville in January, 2012. A Z-Pinch propulsion concept was designed for a vehicle based on a previous fusion vehicle study called "Human Outer Planet Exploration" (HOPE), which used Magnetized Target Fusion (MTF) 3 propulsion. The reference mission is the transport of crew and cargo to Mars and back, with a reusable vehicle.

  13. Splenogonadal Fusion – Not Just Another Hydrocoele

    PubMed Central

    Kennedy, KP; Barnard, S; Speakman, MJ

    2006-01-01

    Splenogonadal fusion is a rare congenital abnormality. In this case report, the diagnosis of splenogonadal fusion was made after the removal of an abnormal mass at ‘routine’ left herniotomy. A cautious approach at surgery resulted in no apparent damage to the testicle. A short review of the literature is included. PMID:16551409

  14. Mass Producing Targets for Nuclear Fusion

    NASA Technical Reports Server (NTRS)

    Wang, T. G.; Elleman, D. D.; Kendall, J. M.

    1983-01-01

    Metal-encapsulating technique advances prospects of controlling nuclear fusion. Prefilled fusion targets form at nozzle as molten metal such as tin flows through outer channel and pressurized deuterium/tritium gas flows through inner channel. Molten metal completely encloses gas charge as it drops off nozzle.

  15. Fusion breeder: its potential role and prospects

    SciTech Connect

    Lee, J.D.

    1981-01-01

    The fusion breeder is a concept that utilizes 14 MeV neutrons from D + T ..-->.. n(14.1 MeV) + ..cap alpha..(3.5 MeV) fusion reactions to produce more fuel than the tritium (T) needed to sustain the fusion process. This excess fuel production capacity is used to produce fissile material (Pu-239 or U-233) for subsequent use in fission reactors. We are concentrating on a class of blankets we call fission suppressed. The blanket is the region surrounding the fusion plasma in which fusion neutrons interact to produce fuel and heat. The fission-suppressed blanket uses non-fission reactions (mainly (n,2n) or (n,n't)) to generate excess neutrons for the production of net fuel. This is in contrast to the fast fission class of blankets which use (n,fiss) reactions to generate excess neutrons. Fusion reactors with fast fission blankets are commony known as fusion-fission hybrids because they combine fusion and fission in the same device.

  16. The Fusion Gain Analysis of the Inductively Driven Liner Compression Based Fusion

    NASA Astrophysics Data System (ADS)

    Shimazu, Akihisa; Slough, John

    2016-10-01

    An analytical analysis of the fusion gain expected in the inductively driven liner compression (IDLC) based fusion is conducted to identify the fusion gain scaling at various operating conditions. The fusion based on the IDLC is a magneto-inertial fusion concept, where a Field-Reversed Configuration (FRC) plasmoid is compressed via the inductively-driven metal liner to drive the FRC to fusion conditions. In the past, an approximate scaling law for the expected fusion gain for the IDLC based fusion was obtained under the key assumptions of (1) D-T fuel at 5-40 keV, (2) adiabatic scaling laws for the FRC dynamics, (3) FRC energy dominated by the pressure balance with the edge magnetic field at the peak compression, and (4) the liner dwell time being liner final diameter divided by the peak liner velocity. In this study, various assumptions made in the previous derivation is relaxed to study the change in the fusion gain scaling from the previous result of G ml1 / 2 El11 / 8 , where ml is the liner mass and El is the peak liner kinetic energy. The implication from the modified fusion gain scaling on the performance of the IDLC fusion reactor system is also explored.

  17. Fusion research: the past is prologue

    SciTech Connect

    Post, R F

    1998-10-14

    At this juncture fusion research can be viewed as being at a turning point, a time to review its past and to imagine its future. Today, almost 50 years since the first serious attempts to address the daunting problem of achieving controlled fusion, we have both an opportunity and a challenge. Some predictions place fusion research today at a point midway between its first inception and its eventual maturation - in the middle of the 21st century - when fusion would become a major source of energy. Our opportunity therefore is to assess what we have learned from 50 years of hard work and use that knowledge as a starting point for new and better approaches to solving the fusion problem. Our challenge is to prove the "50 more years" prophesy wrong, by finding ways to shorten the time when fusion power becomes a reality. The thesis will be advanced that in the magnetic confinement approach to fusion open-ended magnetic confinement geometries offer much in responding to the challenge. A major advantage of open systems is that, owing to their theoretically and experimentally demonstrated ability to suppress plasma instabilities of both the MHD and the high-frequency wave-particle variety, the confinement becomes predictable from "classical," i.e., Fokker-Planck-type analysis. In a time of straitened budgetary circumstances for magnetic fusion research now being faced in the United States, the theoretical tractability of mirror-based systems is a substantial asset. In pursuing this avenue it is also necessary to keep an open mind as to the forms that mirror-based fusion power plants might take. For example, one can look to the high-energy physics community for a possible model: This community has shown the feasibility of constructing large and complex particle accelerators using superconducting magnets, vacuum chambers and complicated particle-handling technology, housed in underground tunnels that are 20 or more kilometers long. In the paper examples of mirror

  18. Estimating the melting point, entropy of fusion, and enthalpy of fusion of organic compounds via SPARC.

    PubMed

    Whiteside, T S; Hilal, S H; Brenner, A; Carreira, L A

    2016-08-01

    The entropy of fusion, enthalpy of fusion, and melting point of organic compounds can be estimated through three models developed using the SPARC (SPARC Performs Automated Reasoning in Chemistry) platform. The entropy of fusion is modelled through a combination of interaction terms and physical descriptors. The enthalpy of fusion is modelled as a function of the entropy of fusion, boiling point, and flexibility of the molecule. The melting point model is the enthalpy of fusion divided by the entropy of fusion. These models were developed in part to improve SPARC's vapour pressure and solubility models. These models have been tested on 904 unique compounds. The entropy model has a RMS of 12.5 J mol(-1) K(-1). The enthalpy model has a RMS of 4.87 kJ mol(-1). The melting point model has a RMS of 54.4°C.

  19. Dependence of fusion on isospin dynamics

    NASA Astrophysics Data System (ADS)

    Godbey, K.; Umar, A. S.; Simenel, C.

    2017-01-01

    We introduce a new microscopic approach to calculate the dependence of fusion barriers and cross sections on isospin dynamics. The method is based on the time-dependent Hartree-Fock theory and the isoscalar and isovector properties of the energy density functional (EDF). The contribution to the fusion barriers originating from the isoscalar and isovector parts of the EDF is calculated. It is shown that, for nonsymmetric systems, the isovector dynamics influence the subbarrier fusion cross sections. For most systems this results in an enhancement of the subbarrier cross sections, while for others we observe differing degrees of hindrance. We use this approach to provide an explanation of recently measured fusion cross sections which show a enhancement at low Ec .m . energies for the system 40Ca+132Sn as compared with the more neutron-rich system 48Ca+132Sn and discuss the dependence of subbarrier fusion cross sections on transfer.

  20. Mechanics of membrane fusion/pore formation.

    PubMed

    Fuhrmans, Marc; Marelli, Giovanni; Smirnova, Yuliya G; Müller, Marcus

    2015-01-01

    Lipid bilayers play a fundamental role in many biological processes, and a considerable effort has been invested in understanding their behavior and the mechanism of topological changes like fusion and pore formation. Due to the time- and length-scale on which these processes occur, computational methods have proven to be an especially useful tool in their study. With their help, a number of interesting findings about the shape of fusion intermediates could be obtained, and novel hypotheses about the mechanism of topological changes and the involvement of peptides therein were suggested. In this work, we try to present a summary of these developments together with some hitherto unpublished results, featuring, among others, the shape of stalks and fusion pores, possible modes of action of the influenza HA fusion peptide and the SNARE protein complex, the mechanism of supported lipid bilayer formation by vesicle spreading, and the free energy and transition pathway of the fusion process.

  1. Inertial-confinement fusion with lasers

    SciTech Connect

    Betti, R.; Hurricane, O. A.

    2016-05-03

    The quest for controlled fusion energy has been ongoing for over a half century. The demonstration of ignition and energy gain from thermonuclear fuels in the laboratory has been a major goal of fusion research for decades. Thermonuclear ignition is widely considered a milestone in the development of fusion energy, as well as a major scientific achievement with important applications to national security and basic sciences. The U.S. is arguably the world leader in the inertial con fment approach to fusion and has invested in large facilities to pursue it with the objective of establishing the science related to the safety and reliability of the stockpile of nuclear weapons. Even though significant progress has been made in recent years, major challenges still remain in the quest for thermonuclear ignition via laser fusion.

  2. INTRODUCTION: Status report on fusion research

    NASA Astrophysics Data System (ADS)

    Burkart, Werner

    2005-10-01

    A major milestone on the path to fusion energy was reached in June 2005 on the occasion of the signing of the joint declaration of all parties to the ITER negotiations, agreeing on future arrangements and on the construction site at Cadarache in France. The International Atomic Energy Agency has been promoting fusion activities since the late 1950s; it took over the auspices of the ITER Conceptual Design Activities in 1988, and of the ITER Engineering and Design Activities in 1992. The Agency continues its support to Member States through the organization of consultancies, workshops and technical meetings, the most prominent being the series of International Fusion Energy Conferences (formerly called the International Conference on Plasma Physics and Controlled Nuclear Fusion Research). The meetings serve as a platform for experts from all Member States to have open discussions on their latest accomplishments as well as on their problems and eventual solutions. The papers presented at the meetings and conferences are routinely published, many being sent to the journal it Nuclear Fusion, co-published monthly by Institute of Physics Publishing, Bristol, UK. The journal's reputation is reflected in the fact that it is a world-renowned publication, and the International Fusion Research Council has used it for the publication of a Status Report on Controlled Thermonuclear Fusion in 1978 and 1990. This present report marks the conclusion of the preparatory phases of ITER activities. It provides background information on the progress of fusion research within the last 15 years. The International Fusion Research Council (IFRC), which initiated the report, was fully aware of the complexities of including all scientific results in just one paper, and so decided to provide an overview and extensive references for the interested reader who need not necessarily be a fusion specialist. Professor Predhiman K. Kaw, Chairman, prepared the report on behalf of the IFRC, reflecting

  3. A Reliability-Based Track Fusion Algorithm

    PubMed Central

    Xu, Li; Pan, Liqiang; Jin, Shuilin; Liu, Haibo; Yin, Guisheng

    2015-01-01

    The common track fusion algorithms in multi-sensor systems have some defects, such as serious imbalances between accuracy and computational cost, the same treatment of all the sensor information regardless of their quality, high fusion errors at inflection points. To address these defects, a track fusion algorithm based on the reliability (TFR) is presented in multi-sensor and multi-target environments. To improve the information quality, outliers in the local tracks are eliminated at first. Then the reliability of local tracks is calculated, and the local tracks with high reliability are chosen for the state estimation fusion. In contrast to the existing methods, TFR reduces high fusion errors at the inflection points of system tracks, and obtains a high accuracy with less computational cost. Simulation results verify the effectiveness and the superiority of the algorithm in dense sensor environments. PMID:25950174

  4. Laser-fusion rocket for interplanetary propulsion

    SciTech Connect

    Hyde, R.A.

    1983-09-27

    A rocket powered by fusion microexplosions is well suited for quick interplanetary travel. Fusion pellets are sequentially injected into a magnetic thrust chamber. There, focused energy from a fusion Driver is used to implode and ignite them. Upon exploding, the plasma debris expands into the surrounding magnetic field and is redirected by it, producing thrust. This paper discusses the desired features and operation of the fusion pellet, its Driver, and magnetic thrust chamber. A rocket design is presented which uses slightly tritium-enriched deuterium as the fusion fuel, a high temperature KrF laser as the Driver, and a thrust chamber consisting of a single superconducting current loop protected from the pellet by a radiation shield. This rocket can be operated with a power-to-mass ratio of 110 W gm/sup -1/, which permits missions ranging from occasional 9 day VIP service to Mars, to routine 1 year, 1500 ton, Plutonian cargo runs.

  5. Inertial-confinement fusion with lasers

    DOE PAGES

    Betti, R.; Hurricane, O. A.

    2016-05-03

    The quest for controlled fusion energy has been ongoing for over a half century. The demonstration of ignition and energy gain from thermonuclear fuels in the laboratory has been a major goal of fusion research for decades. Thermonuclear ignition is widely considered a milestone in the development of fusion energy, as well as a major scientific achievement with important applications to national security and basic sciences. The U.S. is arguably the world leader in the inertial con fment approach to fusion and has invested in large facilities to pursue it with the objective of establishing the science related to themore » safety and reliability of the stockpile of nuclear weapons. Even though significant progress has been made in recent years, major challenges still remain in the quest for thermonuclear ignition via laser fusion.« less

  6. Magnetic systems for fusion devices

    SciTech Connect

    Henning, C.D.

    1985-02-01

    Mirror experiments have led the way in applying superconductivity to fusion research because of unique requirements for high and steady magnetic fields. The first significant applications were Baseball II at LLNL and IMP at ORNL. More recently, the MFTF-B yin-yang coil was successfully tested and the entire tandem configuration is nearing completion. Tokamak magnets have also enjoyed recent success with the large coil project tests at ORNL, preceded by single coil tests in Japan and Germany. In the USSR, the T-7 Tokamak has been operational for many years and the T-15 Tokamak is under construction, with the TF coils nearing completion. Also the Tore Supra is being built in France.

  7. Inertial-confinement-fusion targets

    SciTech Connect

    Hendricks, C.D.

    1982-08-10

    Much of the research in laser fusion has been done using simple ball on-stalk targets filled with a deuterium-tritium mixture. The targets operated in the exploding pusher mode in which the laser energy was delivered in a very short time (approx. 100 ps or less) and was absorbed by the glass wall of the target. The high energy density in the glass literally exploded the shell with the inward moving glass compressing the DT fuel to high temperatures and moderate densities. Temperatures achieved were high enough to produce DT reactions and accompanying thermonuclear neutrons and alpha particles. The primary criteria imposed on the target builders were: (1) wall thickness, (2) sphere diameter, and (3) fuel in the sphere.

  8. Vanadium recycling for fusion reactors

    SciTech Connect

    Dolan, T.J.; Butterworth, G.J.

    1994-04-01

    Very stringent purity specifications must be applied to low activation vanadium alloys, in order to meet recycling goals requiring low residual dose rates after 50--100 years. Methods of vanadium production and purification which might meet these limits are described. Following a suitable cooling period after their use, the vanadium alloy components can be melted in a controlled atmosphere to remove volatile radioisotopes. The aim of the melting and decontamination process will be the achievement of dose rates low enough for ``hands-on`` refabrication of new reactor components from the reclaimed metal. The processes required to permit hands-on recycling appear to be technically feasible, and demonstration experiments are recommended. Background information relevant to the use of vanadium alloys in fusion reactors, including health hazards, resources, and economics, is provided.

  9. Status of cold fusion (2010).

    PubMed

    Storms, Edmund

    2010-10-01

    The phenomenon called cold fusion has been studied for the last 21 years since its discovery by Profs. Fleischmann and Pons in 1989. The discovery was met with considerable skepticism, but supporting evidence has accumulated, plausible theories have been suggested, and research is continuing in at least eight countries. This paper provides a brief overview of the major discoveries and some of the attempts at an explanation. The evidence supports the claim that a nuclear reaction between deuterons to produce helium can occur in special materials without application of high energy. This reaction is found to produce clean energy at potentially useful levels without the harmful byproducts normally associated with a nuclear process. Various requirements of a model are examined.

  10. Pulsed Power Fusion Program update

    SciTech Connect

    Quintenz, J.P.; Adams, R.G.; Allshouse, G.O.

    1998-06-01

    The US Department of Energy has supported a substantial research program in Inertial Confinement Fusion (ICF) since the early 1970s. Over the course of the ensuing 25 years, pulsed power energy, efficiency, and relatively low cost of the technology when compared to the mainline ICF approach involving large glass lasers. These compelling advantages of pulsed power, however, have been tempered with the difficulty that has been encountered in concentrating the energy in space and time to create the high energy and power density required to achieve temperatures useful in indirect drive ICF. Since the Beams `96 meeting two years ago, the situation has changed dramatically and extremely high x-ray power ({approximately}290 TW) and energy ({approximately}1.8 MJ) have been produced in fast x-pinch implosions on the Z accelerator. These sources have been utilized to heat hohlraums to >150 eV and have opened the door to important ICF capsule experiments.

  11. Laser-driven fusion reactor

    DOEpatents

    Hedstrom, J.C.

    1973-10-01

    A laser-driven fusion reactor consisting of concentric spherical vessels in which the thermonuclear energy is derived from a deuterium-tritium (D + T) burn within a pellet'', located at the center of the vessels and initiated by a laser pulse. The resulting alpha -particle energy and a small fraction of the neutron energy are deposited within the pellet; this pellet energy is eventually transformed into sensible heat of lithium in a condenser outside the vessels. The remaining neutron energy is dissipated in a lithium blanket, located within the concentric vessels, where the fuel ingredient, tritium, is also produced. The heat content of the blanket and of the condenser lithium is eventually transferred to a conventional thermodynamic plant where the thermal energy is converted to electrical energy in a steam Rankine cycle. (Official Gazette)

  12. Ion Rings for Magnetic Fusion

    SciTech Connect

    Greenly, John, B.

    2005-07-31

    This Final Technical Report presents the results of the program, Ion Rings for Magnetic Fusion, which was carried out under Department of Energy funding during the period August, 1993 to January, 2005. The central objective of the program was to study the properties of field-reversed configurations formed by ion rings. In order to reach this objective, our experimental program, called the Field-reversed Ion Ring Experiment, FIREX, undertook to develop an efficient, economical technology for the production of field-reversed ion rings. A field-reversed configuration (FRC) in which the azimuthal (field-reversing) current is carried by ions with gyro-radius comparable to the magnetic separatrix radius is called a field-reversed ion ring. A background plasma is required for charge neutralization of the ring, and this plasma will be confined within the ring's closed magnetic flux. Ion rings have long been of interest as the basis of compact magnetic fusion reactors, as the basis for a high-power accelerator for an inertial fusion driver, and for other applications of high power ion beams or plasmas of high energy density. Specifically, the FIREX program was intended to address the longstanding question of the contribution of large-orbit ions to the observed stability of experimental FRCs to the MHD tilt mode. Typical experimental FRCs with s {approx} 2-4, where s is the ratio of separatrix radius to ion gyro-radius, have been stable to tilting, but desired values for a fusion reactor, s > 20, should be unstable. The FIREX ring would consist of a plasma with large s for the background ions, but with s {approx} 1 for the ring ions. By varying the proportions of these two populations, the minimum proportion of large-orbit ions necessary for stability could be determined. The incorporation of large-orbit ions, perhaps by neutral-beam injection, into an FRC has been advanced for the purpose of stabilizing, heating, controlling angular momentum, and aiding the formation of a

  13. Modular Stellarator Fusion Reactor concept

    SciTech Connect

    Miller, R.L.; Krakowski, R.A.

    1981-08-01

    A preliminary conceptual study is made of the Modular Stellarator Reactor (MSR). A steady-state ignited, DT-fueled, magnetic fusion reactor is proposed for use as a central electric-power station. The MSR concept combines the physics of the classic stellarator confinement topology with an innovative, modular-coil design. Parametric tradeoff calculations are described, leading to the selection of an interim design point for a 4-GWt plant based on Alcator transport scaling and an average beta value of 0.04 in an l = 2 system with a plasma aspect ratio of 11. The physics basis of the design point is described together with supporting magnetics, coil-force, and stress computations. The approach and results presented herein will be modified in the course of ongoing work to form a firmer basis for a detailed conceptual design of the MSR.

  14. Multishell inertial confinement fusion target

    DOEpatents

    Holland, James R.; Del Vecchio, Robert M.

    1984-01-01

    A method of fabricating multishell fuel targets for inertial confinement fusion usage. Sacrificial hemispherical molds encapsulate a concentric fuel pellet which is positioned by fiber nets stretched tautly across each hemispherical mold section. The fiber ends of the net protrude outwardly beyond the mold surfaces. The joint between the sacrificial hemispheres is smoothed. A ceramic or glass cover is then deposited about the finished mold surfaces to produce an inner spherical surface having continuously smooth surface configuration. The sacrificial mold is removed by gaseous reaction accomplished through the porous ceramic cover prior to enclosing of the outer sphere by addition of an outer coating. The multishell target comprises the inner fuel pellet concentrically arranged within a surrounding coated cover or shell by fiber nets imbedded within the cover material.

  15. Multishell inertial confinement fusion target

    DOEpatents

    Holland, James R.; Del Vecchio, Robert M.

    1987-01-01

    A method of fabricating multishell fuel targets for inertial confinement fusion usage. Sacrificial hemispherical molds encapsulate a concentric fuel pellet which is positioned by fiber nets stretched tautly across each hemispherical mold section. The fiber ends of the net protrude outwardly beyond the mold surfaces. The joint between the sacrificial hemispheres is smoothed. A ceramic or glass cover is then deposited about the finished mold surfaces to produce an inner spherical surface having continuously smooth surface configuration. The sacrificial mold is removed by gaseous reactions accomplished through the porous ceramic cover prior to enclosing of the outer sphere by addition of an outer coating. The multishell target comprises the inner fuel pellet concentrically arranged within a surrounding coated cover or shell by fiber nets imbedded within the cover material.

  16. Fusion Energy Sciences Network Requirements

    SciTech Connect

    Dart, Eli; Tierney, Brian

    2012-09-26

    The Energy Sciences Network (ESnet) is the primary provider of network connectivity for the U.S. Department of Energy Office of Science, the single largest supporter of basic research in the physical sciences in the United States. In support of the Office of Science programs, ESnet regularly updates and refreshes its understanding of the networking requirements of the instruments, facilities, scientists, and science programs that it serves. This focus has helped ESnet to be a highly successful enabler of scientific discovery for over 25 years. In December 2011, ESnet and the Office of Fusion Energy Sciences (FES), of the DOE Office of Science (SC), organized a workshop to characterize the networking requirements of the programs funded by FES. The requirements identified at the workshop are summarized in the Findings section, and are described in more detail in the body of the report.

  17. Progress in Heavy Ion Fusion

    SciTech Connect

    Herrmannsfeldt, W.B.

    1988-09-01

    The progress of the field of Heavy Ion Fusion has been documented in the proceedings of the series of International Symposia that, in recent years, have occurred every second year. The latest of these conferences was hosted by Gesellshaft fuer Schwerionenforshung (GSI) in Darmstadt, West Germany, June 28-30, 1988. For this report, a few highlights from the conference are selected, stressing experimental progress and prospects for future advances. A little extra time is devoted to report on the developments at the Lawrence Berkeley Laboratory (LBL) which is the center for most of the HIFAR program. The Director of the HIFAR program at LBL is Denis Keefe, who presented the HIF report at the last two of the meetings in this series, and in whose place the author is appearing now. 4 refs., 1 fig.

  18. Hendra virus fusion protein transmembrane domain contributes to pre-fusion protein stability.

    PubMed

    Webb, Stacy; Nagy, Tamas; Moseley, Hunter; Fried, Michael; Dutch, Rebecca Ellis

    2017-02-17

    Enveloped viruses utilize fusion (F) proteins studding the surface of the virus to facilitate membrane fusion with a target cell membrane. Fusion of the viral envelope with a cellular membrane is required for release of viral genomic material so the virus can ultimately reproduce and spread. To drive fusion, the F protein undergoes an irreversible conformational change, transitioning from a meta-stable pre-fusion conformation to a more thermodynamically stable post-fusion structure. Understanding the elements which control stability of the pre-fusion state and triggering to the post-fusion conformation is important for understanding F protein function. Mutations in F protein transmembrane (TM) domains implicated the TM domain in the fusion process, but the structural and molecular details in fusion remain unclear. Previously, analytical ultracentrifugation was utilized to demonstrate that isolated TM domains of Hendra virus F protein associate in a monomer-trimer equilibrium (Smith EC, et al. Trimeric transmembrane domain interactions in paramyxovirus fusion proteins. 2013. J Biol Chem. 288, 35726). To determine factors driving this association, 140 paramyxovirus F protein TM domain sequences were analyzed. A heptad repeat of β-branched residues was found and analysis of the Hendra virus F TM domain revealed a heptad repeat leucine-isoleucine zipper motif (LIZ). Replacement of the LIZ with alanine resulted in dramatically reduced TM-TM association. Mutation of the LIZ in the whole protein resulted in decreased protein stability, including pre-fusion conformation stability. Together our data suggest that the heptad repeat LIZ contributed to TM-TM association and is important for F protein function and pre-fusion stability.

  19. Parameterizing loop fusion for automated empirical tuning

    SciTech Connect

    Zhao, Y; Yi, Q; Kennedy, K; Quinlan, D; Vuduc, R

    2005-12-15

    Traditional compilers are limited in their ability to optimize applications for different architectures because statically modeling the effect of specific optimizations on different hardware implementations is difficult. Recent research has been addressing this issue through the use of empirical tuning, which uses trial executions to determine the optimization parameters that are most effective on a particular hardware platform. In this paper, we investigate empirical tuning of loop fusion, an important transformation for optimizing a significant class of real-world applications. In spite of its usefulness, fusion has attracted little attention from previous empirical tuning research, partially because it is much harder to configure than transformations like loop blocking and unrolling. This paper presents novel compiler techniques that extend conventional fusion algorithms to parameterize their output when optimizing a computation, thus allowing the compiler to formulate the entire configuration space for loop fusion using a sequence of integer parameters. The compiler can then employ an external empirical search engine to find the optimal operating point within the space of legal fusion configurations and generate the final optimized code using a simple code transformation system. We have implemented our approach within our compiler infrastructure and conducted preliminary experiments using a simple empirical search strategy. Our results convey new insights on the interaction of loop fusion with limited hardware resources, such as available registers, while confirming conventional wisdom about the effectiveness of loop fusion in improving application performance.

  20. Statistical label fusion with hierarchical performance models

    NASA Astrophysics Data System (ADS)

    Asman, Andrew J.; Dagley, Alexander S.; Landman, Bennett A.

    2014-03-01

    Label fusion is a critical step in many image segmentation frameworks (e.g., multi-atlas segmentation) as it provides a mechanism for generalizing a collection of labeled examples into a single estimate of the underlying segmentation. In the multi-label case, typical label fusion algorithms treat all labels equally - fully neglecting the known, yet complex, anatomical relationships exhibited in the data. To address this problem, we propose a generalized statistical fusion framework using hierarchical models of rater performance. Building on the seminal work in statistical fusion, we reformulate the traditional rater performance model from a multi-tiered hierarchical perspective. This new approach provides a natural framework for leveraging known anatomical relationships and accurately modeling the types of errors that raters (or atlases) make within a hierarchically consistent formulation. Herein, we describe several contributions. First, we derive a theoretical advancement to the statistical fusion framework that enables the simultaneous estimation of multiple (hierarchical) performance models within the statistical fusion context. Second, we demonstrate that the proposed hierarchical formulation is highly amenable to the state-of-the-art advancements that have been made to the statistical fusion framework. Lastly, in an empirical whole-brain segmentation task we demonstrate substantial qualitative and significant quantitative improvement in overall segmentation accuracy.

  1. Myoblast fusion: Experimental systems and cellular mechanisms.

    PubMed

    Schejter, Eyal D

    2016-12-01

    Fusion of myoblasts gives rise to the large, multi-nucleated muscle fibers that power and support organism motion and form. The mechanisms underlying this prominent form of cell-cell fusion have been investigated by a variety of experimental approaches, in several model systems. The purpose of this review is to describe and discuss recent progress in the field, as well as point out issues currently unresolved and worthy of further investigation. Following a description of several new experimental settings employed in the study of myoblast fusion, a series of topics relevant to the current understanding of the process are presented. These pertain to elements of three major cellular machineries- cell-adhesion, the actin-based cytoskeleton and membrane-associated elements- all of which play key roles in mediating myoblast fusion. Among the issues raised are the diversity of functions ascribed to different adhesion proteins (e.g. external cell apposition and internal recruitment of cytoskeleton regulators); functional significance of fusion-associated actin structures; and discussion of alternative mechanisms employing single or multiple fusion pore formation as the basis for muscle cell fusion.

  2. Establishment of an Institute for Fusion Studies

    SciTech Connect

    Hazeltine, R.D.

    1992-07-01

    The Institute for Fusion Studies is a national center for theoretical fusion plasma physics research. Its purposes are: (1) to conduct research on theoretical questions concerning the achievement of controlled fusion energy by means of magnetic confinement--including both fundamental problems of long-range significance, as well as shorter-term issues; (2) to serve as a center for information exchange, nationally and internationally, by hosting exchange visits, conferences, and workshops; (3) and to train students and postdoctoral research personnel for the fusion energy program and plasma physics research areas. The theoretical research results that are obtained by the Institute contribute mainly to the progress of national and international efforts in nuclear fusion research, whose goal is the development of fusion power.as a basic energy source. In addition to its primary focus on fusion physics, the Institute is also involved with research in related fields, such as advanced computing techniques, nonlinear dynamics, plasma astrophysics, and accelerator physics. The work of EFS scientists continued to receive national and international recognition. Numerous invited papers were given during the past year at workshops, conferences, and scientific meetings. Last year IFS scientists published 95 scientific articles in technical journals and monographs.

  3. Engineering Challenges in Antiproton Triggered Fusion Propulsion

    SciTech Connect

    Cassenti, Brice; Kammash, Terry

    2008-01-21

    During the last decade antiproton triggered fusion propulsion has been investigated as a method for achieving high specific impulse, high thrust in a nuclear pulse propulsion system. In general the antiprotons are injected into a pellet containing fusion fuel with a small amount of fissionable material (i.e., an amount less than the critical mass) where the products from the fission are then used to trigger a fusion reaction. Initial calculations and simulations indicate that if magnetically insulated inertial confinement fusion is used that the pellets should result in a specific impulse of between 100,000 and 300,000 seconds at high thrust. The engineering challenges associated with this propulsion system are significant. For example, the antiprotons must be precisely focused. The pellet must be designed to contain the fission and initial fusion products and this will require strong magnetic fields. The fusion fuel must be contained for a sufficiently long time to effectively release the fusion energy, and the payload must be shielded from the radiation, especially the excess neutrons emitted, in addition to many other particles. We will review the recent progress, possible engineering solutions and the potential performance of these systems.

  4. Dynamical effects in fusion with exotic nuclei

    NASA Astrophysics Data System (ADS)

    Vo-Phuoc, K.; Simenel, C.; Simpson, E. C.

    2016-08-01

    Background: Reactions with stable beams have demonstrated strong interplay between nuclear structure and fusion. Exotic beam facilities open new perspectives to understand the impact of neutron skin, large isospin, and weak binding energies on fusion. Microscopic theories of fusion are required to guide future experiments. Purpose: To investigate new effects of exotic structures and dynamics in near-barrier fusion with exotic nuclei. Method: Microscopic approaches based on the Hartree-Fock (HF) mean-field theory are used for studying fusion barriers in -54Ca40+116Sn reactions for even isotopes. Bare potential barriers are obtained assuming frozen HF ground-state densities. Dynamical effects on the barrier are accounted for in time-dependent Hartree-Fock (TDHF) calculations of the collisions. Vibrational couplings are studied in the coupled-channel framework and near-barrier nucleon transfer is investigated with TDHF calculations. Results: The development of a neutron skin in exotic calcium isotopes strongly lowers the bare potential barrier. However, this static effect is not apparent when dynamical effects are included. On the contrary, a fusion hindrance is observed in TDHF calculations with the most neutron-rich calcium isotopes which cannot be explained by vibrational couplings. Transfer reactions are also important in these systems due to charge equilibration processes. Conclusions: Despite its impact on the bare potential, the neutron skin is not seen as playing an important role in the fusion dynamics. However, the charge transfer with exotic projectiles could lead to an increase of the Coulomb repulsion between the fragments, suppressing fusion. The effects of transfer and dissipative mechanisms on fusion with exotic nuclei deserve further studies.

  5. Visualize Your Data with Google Fusion Tables

    NASA Astrophysics Data System (ADS)

    Brisbin, K. E.

    2011-12-01

    Google Fusion Tables is a modern data management platform that makes it easy to host, manage, collaborate on, visualize, and publish tabular data online. Fusion Tables allows users to upload their own data to the Google cloud, which they can then use to create compelling and interactive visualizations with the data. Users can view data on a Google Map, plot data in a line chart, or display data along a timeline. Users can share these visualizations with others to explore and discover interesting trends about various types of data, including scientific data such as invasive species or global trends in disease. Fusion Tables has been used by many organizations to visualize a variety of scientific data. One example is the California Redistricting Map created by the LA Times: http://goo.gl/gwZt5 The Pacific Institute and Circle of Blue have used Fusion Tables to map the quality of water around the world: http://goo.gl/T4SX8 The World Resources Institute mapped the threat level of coral reefs using Fusion Tables: http://goo.gl/cdqe8 What attendees will learn in this session: This session will cover all the steps necessary to use Fusion Tables to create a variety of interactive visualizations. Attendees will begin by learning about the various options for uploading data into Fusion Tables, including Shapefile, KML file, and CSV file import. Attendees will then learn how to use Fusion Tables to manage their data by merging it with other data and controlling the permissions of the data. Finally, the session will cover how to create a customized visualization from the data, and share that visualization with others using both Fusion Tables and the Google Maps API.

  6. IPFR: Integrated Pool Fusion Reactor concept

    SciTech Connect

    Sze, D.K.

    1986-01-01

    The IPFR (Integrated Pool Fusion Reactor) concept is to place a fusion reactor into a pool of molten Flibe. The Flibe will serve the multiple functions of breeding, cooling, shielding, and moderating. Therefore, the only structural material between the superconducting magnets and the plasma is the first wall. The first wall is a stand-alone structure with no coolant connection and is cooled by Flibe at the atmospheric pressure. There is also no need of the primary coolant loop. The design is expected to improve the safety, reliability, and maintainability aspects of the fusion system.

  7. Fusion Utility in the Knudsen Layer

    SciTech Connect

    Davidovits, Seth; Fisch, Nathaniel J.

    2014-08-01

    In inertial confi nement fusion, the loss of fast ions from the edge of the fusing hot-spot region reduces the reactivity below its Maxwellian value. The loss of fast ions may be pronounced because of the long mean free paths of fast ions, compared to those of thermal ions. We introduce a fusion utility function to demonstrate essential features of this Knudsen layer e ffect, in both magnetized and unmagnetized cases. The fusion utility concept is also used to evaluate restoring the reactivity in the Knudsen layer by manipulating fast ions in phase space using waves.

  8. Cold-fusion television show angers APS

    NASA Astrophysics Data System (ADS)

    Cartwright, Jon

    2009-06-01

    Cold fusion has been controversial since its inception on 23 March 1989, when chemists Martin Fleischmann and Stanley Pons at the University of Utah in the US announced that they had achieved a sustained nuclear-fusion reaction at room temperature. Two decades on, a US television documentary about the field has stirred up fresh debate after it linked the American Physical Society (APS) to an evaluation of some cold-fusion results by Robert Duncan, a physicist and vice chancellor of the University of Missouri.

  9. Fusion utility in the Knudsen layer

    SciTech Connect

    Davidovits, Seth; Fisch, Nathaniel J.

    2014-09-15

    In inertial confinement fusion, the loss of fast ions from the edge of the fusing hot-spot region reduces the reactivity below its Maxwellian value. The loss of fast ions may be pronounced because of the long mean free paths of fast ions, compared with those of thermal ions. We introduce a fusion utility function to demonstrate essential features of this Knudsen layer effect, in both magnetized and unmagnetized cases. The fusion utility concept is also used to evaluate the restoring reactivity in the Knudsen layer by manipulating fast ions in phase space using waves.

  10. Intermediates and kinetics of membrane fusion.

    PubMed Central

    Bentz, J

    1992-01-01

    Recently, it has become clear that the influenza virus fusion protein, hemagglutinin (HA), produces membrane destabilization and fusion by a multistep process, which involves the aggregation of the HAs to form a fusion site. While the details of this process are under debate, it is important to recognize that proposing any sequence of "microscopic" fusion intermediates encumbers general "macroscopic" kinetic consequences, i.e., with respect to membrane mixing rates. Using a kinetic scheme which incorporates the essential elements of several recently proposed models, some of these measurable properties have been elucidated. First, a rigorous mathematical relationship between fusion intermediates and the fusion event itself is defined. Second, it is shown that what is measured as the macroscopic "fusion rate constant" is a simple function of all of the rate constants governing the transitions between intermediates, whether or not one of the microscopic steps is rate limiting. Third, while this kinetic scheme predicts a delay (or lag) time for fusion, as has been observed, it will be very difficult to extract reliable microscopic information from these data. Furthermore, it is predicted that the delay time can depend upon HA surface density even when the HA aggregation step is very rapid compared with fusion, i.e., the delay time need not be due to HA aggregation. Fourth, the inactivation process observed for influenza virions at low pH can be described within this kinetic scheme simply, yet rigorously, via the loss of the fusion intermediates. Fifth, predicted Arrhenius plots of fusion rates can be linear for this multistep scheme, even though there is no single rate-determining step and even when a branched step is introduced, i.e., where one pathway predominates at low temperature and the other pathway predominates at high temperature. Furthermore, the apparent activation energies obtained from these plots bear little or no quantitative resemblance to the

  11. The dengue virus type 2 envelope protein fusion peptide is essential for membrane fusion

    SciTech Connect

    Huang, Claire Y.-H.; Butrapet, Siritorn; Moss, Kelly J.; Childers, Thomas; Erb, Steven M.; Calvert, Amanda E.; Silengo, Shawn J.; Kinney, Richard M.; Blair, Carol D.; Roehrig, John T.

    2010-01-20

    The flaviviral envelope (E) protein directs virus-mediated membrane fusion. To investigate membrane fusion as a requirement for virus growth, we introduced 27 unique mutations into the fusion peptide of an infectious cDNA clone of dengue 2 virus and recovered seven stable mutant viruses. The fusion efficiency of the mutants was impaired, demonstrating for the first time the requirement for specific FP AAs in optimal fusion. Mutant viruses exhibited different growth kinetics and/or genetic stabilities in different cell types and adult mosquitoes. Virus particles could be recovered following RNA transfection of cells with four lethal mutants; however, recovered viruses could not re-infect cells. These viruses could enter cells, but internalized virus appeared to be retained in endosomal compartments of infected cells, thus suggesting a