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Sample records for interbody fusion alif

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

    PubMed Central

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

    2014-01-01

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

  2. Lateral Lumbar Interbody Fusion

    PubMed Central

    Hughes, Alexander; Girardi, Federico; Sama, Andrew; Lebl, Darren; Cammisa, Frank

    2015-01-01

    The lateral lumbar interbody fusion (LLIF) is a relatively new technique that allows the surgeon to access the intervertebral space from a direct lateral approach either anterior to or through the psoas muscle. This approach provides an alternative to anterior lumbar interbody fusion with instrumentation, posterior lumbar interbody fusion, and transforaminal lumbar interbody fusion for anterior column support. LLIF is minimally invasive, safe, better structural support from the apophyseal ring, potential for coronal plane deformity correction, and indirect decompression, which have has made this technique popular. LLIF is currently being utilized for a variety of pathologies including but not limited to adult de novo lumbar scoliosis, central and foraminal stenosis, spondylolisthesis, and adjacent segment degeneration. Although early clinical outcomes have been good, the potential for significant neurological and vascular vertebral endplate complications exists. Nevertheless, LLIF is a promising technique with the potential to more effectively treat complex adult de novo scoliosis and achieve predictable fusion while avoiding the complications of traditional anterior surgery and posterior interbody techniques. PMID:26713134

  3. Lateral Lumbar Interbody Fusion.

    PubMed

    Pawar, Abhijit; Hughes, Alexander; Girardi, Federico; Sama, Andrew; Lebl, Darren; Cammisa, Frank

    2015-12-01

    The lateral lumbar interbody fusion (LLIF) is a relatively new technique that allows the surgeon to access the intervertebral space from a direct lateral approach either anterior to or through the psoas muscle. This approach provides an alternative to anterior lumbar interbody fusion with instrumentation, posterior lumbar interbody fusion, and transforaminal lumbar interbody fusion for anterior column support. LLIF is minimally invasive, safe, better structural support from the apophyseal ring, potential for coronal plane deformity correction, and indirect decompression, which have has made this technique popular. LLIF is currently being utilized for a variety of pathologies including but not limited to adult de novo lumbar scoliosis, central and foraminal stenosis, spondylolisthesis, and adjacent segment degeneration. Although early clinical outcomes have been good, the potential for significant neurological and vascular vertebral endplate complications exists. Nevertheless, LLIF is a promising technique with the potential to more effectively treat complex adult de novo scoliosis and achieve predictable fusion while avoiding the complications of traditional anterior surgery and posterior interbody techniques. PMID:26713134

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

    PubMed

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

    2014-01-01

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

  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. PMID:26474500

  6. Choice of Approach Does Not Affect Clinical and Radiologic Outcomes: A Comparative Cohort of Patients Having Anterior Lumbar Interbody Fusion and Patients Having Lateral Lumbar Interbody Fusion at 24 Months

    PubMed Central

    Malham, Gregory M.; Parker, Rhiannon M.; Blecher, Carl M.; Chow, Fiona Y.; Seex, Kevin A.

    2015-01-01

    Study Design  Retrospective analysis of prospectively collected registry data. Objective  This study aimed to compare the clinical and radiologic outcomes between comparative cohorts of patients having anterior lumbar interbody fusion (ALIF) and patients having lateral lumbar interbody fusion (LLIF). Methods  Ninety consecutive patients were treated by a single surgeon with either ALIF (n = 50) or LLIF (n = 40). Inclusion criteria were patients age 45 to 70 years with degenerative disk disease or grade 1 to 2 spondylolisthesis and single-level pathology from L1 to S1. Patient-reported outcome measures included pain (visual analog scale), disability (Oswestry Disability Index [ODI]), and quality of life (Short Form 36 physical component score [PCS] and mental component scores [MCS]). Assessment of fusion and measurement of lordosis and posterior disk height were performed on computed tomography scans. Results  At 24 months, patients having ALIF had significant improvements in back (64%) and leg (65%) pain and ODI (60%), PCS (44%), and MCS (26%; p < 0.05) scores. Patients having LLIF had significant improvements in back (56%) and leg (57%) pain and ODI (52%), PCS (48%), and MCS (12%; p < 0.05) scores. Fourteen complications occurred in the ALIF group, and in the LLIF group, there were 17 complications (p > 0.05). The fusion rate was 100% for ALIF and 95% for LLIF (p = 0.1948). ALIF added ∼6 degrees of lordosis and 3 mm of height, primarily measured at L5–S1, and LLIF added ∼3 degrees of lordosis and 2 mm of height between L1 to L5. Mean follow-up was 34.1 months. Conclusions  In comparative cohorts of patients having ALIF and patients having LLIF at 24 months postoperatively, there were no significant differences in clinical outcomes, complication rates, or fusion rates. PMID:27433432

  7. Anterior Lumbar Interbody Fusion as a Salvage Technique for Pseudarthrosis following Posterior Lumbar Fusion Surgery

    PubMed Central

    Mobbs, Ralph J.; Phan, Kevin; Thayaparan, Ganesha K.; Rao, Prashanth J.

    2015-01-01

    Study Design Retrospective analysis of prospectively collected observational data. Objective To assess the safety and efficacy of anterior lumbar interbody fusion (ALIF) as a salvage option for lumbar pseudarthrosis following failed posterior lumbar fusion surgery. Methods From 2009 to 2013, patient outcome data was collected prospectively over 5 years from 327 patients undergoing ALIF performed by a single surgeon (R.J.M.) with 478 levels performed. Among these, there were 20 cases of failed prior posterior fusion that subsequently underwent ALIF. Visual analog score (VAS), Oswestry Disability Index (ODI), and Short Form 12-item health survey (SF-12) were measured pre- and postoperatively. The verification of fusion was determined by utilizing a fine-cut computed tomography scan at 12-month follow-up. Results There was a significant difference between the preoperative (7.25 ± 0.8) and postoperative (3.1 ± 2.1) VAS scores (p < 0.0001). The ODI scale also demonstrated a statistically significant reduction from preoperative (56.3 ± 16.5) and postoperative (30.4 ± 19.3) scores (p < 0.0001). The SF-12 scores were significantly improved after ALIF salvage surgery: Physical Health Composite Score (32.18 ± 5.5 versus 41.07 ± 9.67, p = 0.0003) and Mental Health Composite Score (36.62 ± 12.25 versus 50.89 ± 10.86, p = 0.0001). Overall, 19 patients (95%) achieved successful fusion. Conclusions Overall, our results suggest that the ALIF procedure results not only in radiographic improvements in bony fusion but in significant improvements in the patient's physical and mental experience of pain secondary to lumbar pseudarthrosis. Future multicenter registry studies and randomized controlled trials should be conducted to confirm the long-term benefit of ALIF as a salvage option for failed posterior lumbar fusion. PMID:26835197

  8. Anterior Lumbar Interbody Fusion as a Salvage Technique for Pseudarthrosis following Posterior Lumbar Fusion Surgery.

    PubMed

    Mobbs, Ralph J; Phan, Kevin; Thayaparan, Ganesha K; Rao, Prashanth J

    2016-02-01

    Study Design Retrospective analysis of prospectively collected observational data. Objective To assess the safety and efficacy of anterior lumbar interbody fusion (ALIF) as a salvage option for lumbar pseudarthrosis following failed posterior lumbar fusion surgery. Methods From 2009 to 2013, patient outcome data was collected prospectively over 5 years from 327 patients undergoing ALIF performed by a single surgeon (R.J.M.) with 478 levels performed. Among these, there were 20 cases of failed prior posterior fusion that subsequently underwent ALIF. Visual analog score (VAS), Oswestry Disability Index (ODI), and Short Form 12-item health survey (SF-12) were measured pre- and postoperatively. The verification of fusion was determined by utilizing a fine-cut computed tomography scan at 12-month follow-up. Results There was a significant difference between the preoperative (7.25 ± 0.8) and postoperative (3.1 ± 2.1) VAS scores (p < 0.0001). The ODI scale also demonstrated a statistically significant reduction from preoperative (56.3 ± 16.5) and postoperative (30.4 ± 19.3) scores (p < 0.0001). The SF-12 scores were significantly improved after ALIF salvage surgery: Physical Health Composite Score (32.18 ± 5.5 versus 41.07 ± 9.67, p = 0.0003) and Mental Health Composite Score (36.62 ± 12.25 versus 50.89 ± 10.86, p = 0.0001). Overall, 19 patients (95%) achieved successful fusion. Conclusions Overall, our results suggest that the ALIF procedure results not only in radiographic improvements in bony fusion but in significant improvements in the patient's physical and mental experience of pain secondary to lumbar pseudarthrosis. Future multicenter registry studies and randomized controlled trials should be conducted to confirm the long-term benefit of ALIF as a salvage option for failed posterior lumbar fusion. PMID:26835197

  9. Minimally invasive transforaminal lumbosacral interbody fusion.

    PubMed

    Chang, Peng-Yuan; Wang, Michael Y

    2016-07-01

    In minimally invasive spinal fusion surgery, transforaminal lumbar (sacral) interbody fusion (TLIF) is one of the most common procedures that provides both anterior and posterior column support without retraction or violation to the neural structure. Direct and indirect decompression can be done through this single approach. Preoperative plain radiographs and MR scan should be carefully evaluated. This video demonstrates a standard approach for how to perform a minimally invasive transforaminal lumbosacral interbody fusion. The video can be found here: https://youtu.be/bhEeafKJ370 . PMID:27364426

  10. 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

  11. Lateral Lumbar Interbody Fusion: Indications, Outcomes, and Complications.

    PubMed

    Kwon, Brian; Kim, David Hanwuk

    2016-02-01

    Lateral lumbar interbody fusion is a minimally invasive spinal fusion technique that uses the retroperitoneal approach to the anterior spinal column. Mechanical and technical results of the technique compare favorably with those of anterior lumbar interbody fusion in regard to large graft placement, graft volumes, and early initial stability. Lateral lumbar interbody fusion uses the transpsoas approach and traverses near the lumbar plexus. It is not, however, without its unique complications. Groin pain or numbness is well tolerated and often temporary; however, quadriceps palsy can be long-lasting and debilitating. Rarer but serious complications include vascular and visceral injury. Lateral lumbar interbody fusion has been used successfully to treat common degenerative spinal conditions such as spinal instability, stenosis, scoliosis, and degenerative disk disease. While understanding of the lumbar plexus and the technical challenges of the procedure improves, lateral lumbar interbody fusion will continue to provide safe and successful clinical outcomes with less morbidity than traditional procedures. PMID:26803545

  12. 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

  13. 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 . PMID:27364424

  14. Minimally Invasive Transforaminal Lumbar Interbody Fusion.

    PubMed

    Ahn, Junyoung; Tabaraee, Ehsan; Singh, Kern

    2015-07-01

    Minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) is performed via tubular dilators thereby preserving the integrity of the paraspinal musculature. The decreased soft tissue disruption in the MIS technique has been associated with significantly decreased blood loss, shorter length of hospitalization, and an expedited return to work while maintaining comparable arthrodesis rates when compared with the open technique particularly in the setting of spondylolisthesis (isthmic and degenerative), recurrent symptomatic disk herniation, spinal stenosis, pseudoarthrosis, iatrogenic instability, and spinal trauma. The purpose of this article and the accompanying video wass to demonstrate the techniques for a primary, single-level MIS TLIF. PMID:26079840

  15. Survivorship and clinical outcomes after multi-level anterior lumbar reconstruction with stand-alone anterior lumbar interbody fusion or hybrid construct.

    PubMed

    Chen, Benjamin; Akpolat, Yusuf T; Williams, Paul; Bergey, Darren; Cheng, Wayne K

    2016-06-01

    In multilevel disc disease, there is still uncertainty regarding whether multiple total disc replacement is more effective and safer than fusion. Our objective was to measure and compare the clinical outcome of multilevel hybrid constructs with stand-alone anterior lumbar interbody fusion (ALIF) using a retrospective analysis. Sixty-four patients with chronic low back pain determined to be from two or three-level degenerative disc disease were included. Thirty-three patients were treated with hybrid fusion and 31 with ALIF. Several parameters were retrospectively reviewed, including blood loss, operation time, hospital stay, Visual Analog Scale (VAS) score, Oswestry Disability Index (ODI), and survivorship without the need for revision surgery. Telephone follow-ups were conducted to ascertain survivorship, clinical outcomes (VAS, ODI) and patient satisfaction. Operation time was longer in the hybrid group (p=0.021). The hybrid group showed a significant improvement in VAS and ODI with 52.2% and 50.0% improvement versus 28.3% and 25.5% in the ALIF group (p<0.05). At the telephone follow-up for patient satisfaction, 95.7% (n=22) of the hybrid group were satisfied and 95.2% (n=21) of the ALIF group were satisfied. Seventy-four percent (n=17) in the hybrid group and 85.7% (n=18) in the ALIF group would choose to do the initial surgery again. Kaplan-Meier analysis showed 80.5% survivorship for hybrids and 75.9% for ALIF at 5years. With our clinical outcomes in VAS and ODI scores, these results, when taken together, indicate that hybrid fusion is a valid and viable alternative to ALIF fusion, with at least equal if not better clinical outcomes in terms of survivorship, back pain, and disability scores. PMID:26896904

  16. Intervertebral prosthesis versus anterior lumbar interbody fusion: one-year results of a prospective non-randomised study.

    PubMed

    Schroven, Ive; Dorofey, Dimitri

    2006-01-01

    The authors conducted a prospective non-randomised study on the ProDisc intervertebral prosthesis versus anterior lumbar interbody fusion (ALIF). The first group included 14 patients, the second group 10 patients. In the ProDisc group the Oswestry Disability Index improved from +/- 38.42 preoperatively (60 being the worst possible condition) to +/- 15.21 after 6 months and to +/- 12.5 after 12 months. This was definitely better than the ALIF group, where the corresponding figures were +/- 38, +/- 25 and +/- 21.4. The ProDisc patients also scored better with respect to duration of hospitalisation, blood loss and operation time. The complications were comparable in both groups. PMID:16570900

  17. Approach-Related Complications of Anterior Lumbar Interbody Fusion: Results of a Combined Spine and Vascular Surgical Team

    PubMed Central

    Mobbs, Ralph J.; Phan, Kevin; Daly, Daniel; Rao, Prashanth J.; Lennox, Andrew

    2015-01-01

    Study Design Retrospective analysis of prospectively collected cohort data. Objective Anterior lumbar interbody fusion (ALIF) is a commonly performed procedure for the treatment of degenerative diseases of the lumbar spine. Detailed and comprehensive descriptions of intra- and postoperative complications of ALIF are surprisingly limited in the literature. In this report, we describe our experience with a team model for ALIF and report all complications occurring in our patient series. Methods Patients were prospectively enrolled between January 2009 and January 2013 by a combined spine surgeon and vascular surgeon team. All patients underwent an open ALIF using an anterior approach to the lumbosacral spine. Results From the 227 ALIF cases, mean operative blood loss was 103 mL, ranging from 30 to 900 mL. Mean operative time was 78 minutes. The average length of stay was 5.2 days. Intraoperative vascular injury requiring primary repair with suturing occurred in 15 patients (6.6%). There were 2 cases of postoperative retroperitoneal hematoma. Three patients (1.3%) had incisional hernia requiring revision surgery; 7 (3.1%) patients had prolonged ileus (>7 days) managed conservatively. Four patients described retrograde ejaculation. Sympathetic dysfunction occurred in 15 (6.6%) patients. There were 5 (2.2%) cases of superficial wound infection treated with oral antibiotics, with no deep wound infections requiring reoperation or intravenous therapy. There were no mortalities in this series. Conclusions ALIF is a safe procedure when performed by a combined vascular surgeon and spine surgeon team with acceptably low complication rates. Our series confirms that the team approach results in short operative times and length of stay, with rapid control of intraoperative vessel injury and low overall blood loss. PMID:26933616

  18. Approach-Related Complications of Anterior Lumbar Interbody Fusion: Results of a Combined Spine and Vascular Surgical Team.

    PubMed

    Mobbs, Ralph J; Phan, Kevin; Daly, Daniel; Rao, Prashanth J; Lennox, Andrew

    2016-03-01

    Study Design Retrospective analysis of prospectively collected cohort data. Objective Anterior lumbar interbody fusion (ALIF) is a commonly performed procedure for the treatment of degenerative diseases of the lumbar spine. Detailed and comprehensive descriptions of intra- and postoperative complications of ALIF are surprisingly limited in the literature. In this report, we describe our experience with a team model for ALIF and report all complications occurring in our patient series. Methods Patients were prospectively enrolled between January 2009 and January 2013 by a combined spine surgeon and vascular surgeon team. All patients underwent an open ALIF using an anterior approach to the lumbosacral spine. Results From the 227 ALIF cases, mean operative blood loss was 103 mL, ranging from 30 to 900 mL. Mean operative time was 78 minutes. The average length of stay was 5.2 days. Intraoperative vascular injury requiring primary repair with suturing occurred in 15 patients (6.6%). There were 2 cases of postoperative retroperitoneal hematoma. Three patients (1.3%) had incisional hernia requiring revision surgery; 7 (3.1%) patients had prolonged ileus (>7 days) managed conservatively. Four patients described retrograde ejaculation. Sympathetic dysfunction occurred in 15 (6.6%) patients. There were 5 (2.2%) cases of superficial wound infection treated with oral antibiotics, with no deep wound infections requiring reoperation or intravenous therapy. There were no mortalities in this series. Conclusions ALIF is a safe procedure when performed by a combined vascular surgeon and spine surgeon team with acceptably low complication rates. Our series confirms that the team approach results in short operative times and length of stay, with rapid control of intraoperative vessel injury and low overall blood loss. PMID:26933616

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

    NASA Astrophysics Data System (ADS)

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

    2012-09-01

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

  20. 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

  1. 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

  2. Biomechanical comparison of two different concepts for stand alone anterior lumbar interbody fusion

    PubMed Central

    Gerlach, R.; Schär, B.; Cain, C. M. J.; Achatz, W.; Pflugmacher, R.; Haas, N. P.; Kandziora, F.

    2008-01-01

    Segmental instability in degenerative disc disease is often treated with anterior lumbar interbody fusion (ALIF). Current techniques require an additional posterior approach to achieve sufficient stability. The test device is an implant which consists of a PEEK-body and an integrated anterior titanium plate hosting four diverging locking screws. The test device avoids posterior fixation by enhancing stability via the locking screws. The test device was compared to an already established stand alone interbody implant in a human cadaveric three-dimensional stiffness test. In the biomechanical test, the L4/5 motion segment of 16 human cadaveric lumbar spines were isolated and divided into two test groups. Tests were performed in flexion, extension, right and left lateral bending, right and left axial rotation. Each specimen was tested in native state first, then a discectomy was performed and either of the test implants was applied. Finite element analysis (FE) was also performed to investigate load and stress distribution within the implant in several loading conditions. The FE models simulated two load cases. These were flexion and extension with a moment of 5 Nm. The biomechanical testing revealed a greater stiffness in lateral bending for the SynFix-LR™ compared to the established implant. Both implants showed a significantly higher stiffness in all loading directions compared to the native segment. In flexion loading, the PEEK component takes on most of the load, whereas the majority of the extension load is put on the screws and the screw–plate junction. Clinical investigation of the test device seems reasonable based on the good results reported here. PMID:18841399

  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. PMID:27349468

  4. 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

  5. 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. PMID:25666390

  6. A Comparative Study of Lateral Lumbar Interbody Fusion and Posterior Lumbar Interbody Fusion in Degenerative Lumbar Spondylolisthesis

    PubMed Central

    Hughes, Alexander P.; Sama, Andrew A.; Girardi, Federico P.; Lebl, Darren R.; Cammisa, Frank P.

    2015-01-01

    Study Design Level 4 retrospective review. Purpose To compare the radiographic and clinical outcomes between posterior lumbar interbody fusion (PLIF) and lateral lumbar interbody fusion (LLIF) with posterior segmental spinal instrumentation (SSI) for degenerative lumbar spondylolisthesis. Overview of Literature Both PLIF and LLIF have been performed for degenerative spondylolisthesis with good results, but no study has directly compared these two techniques so far. Methods The electronic medical and radiographic records of 78 matched patients were analyzed. In one group, 39 patients underwent PLIF with SSI at 41 levels (L3-4/L4-5), while in the other group, 39 patients underwent the LLIF procedure at 48 levels (L3-4/L4-5). Radiological outcomes such as restoration of disc height and neuroforaminal height, segmental lumbar lordosis, total lumbar lordosis, incidence of endplate fracture, and subsidence were measured. Perioperative parameters were also recorded in each group. Clinical outcome in both groups was assessed by the short form-12, Oswestry disability index and visual analogue scale scores. The average follow-up period was 16.1 months in the LLIF group and 21 months in the PLIF group. Results The restoration of disc height, foraminal height, and segmental lumbar lordosis was significantly better in the LLIF group (p<0.001). The duration of the operation was similar in both groups, but the average blood loss was significantly lower in the LLIF group (p<0.001). However, clinical outcome scores were similar in both groups. Conclusions Safe, effective interbody fusion can be achieved at multiple levels with neuromonitoring by the lateral approach. LLIF is a viable treatment option in patients with new onset symptoms due to degenerative spondylolisthesis who have had previous lumbar spine surgery, and it results in improved sagittal alignment and indirect foraminal decompression. PMID:26435782

  7. Outcome of instrumented lumbar fusion for low grade spondylolisthesis; Evaluation of interbody fusion with & without cages

    PubMed Central

    Fathy, Mostafa; Fahmy, Mohamed; Fakhri, Mazen; Aref, Khaled; Abdin, Khaled; Zidan, Ihab

    2010-01-01

    Object: The aim is to evalute the outcome of posterior lumbar interbody fusion with autologous bone graft versus titanium Cages, BAK system (Bagby – Kuslich, Spine Tech, Inc. Minneapolis, MN) for low grade spondyloisthesis (Grade1,11). Interbody cages have been developed to replace tricortical Interbody grafts in posterior lumbar interbody fusion (PLIF) procedures. The cages provide immediate post operative stability and facilitate bony union with cancellous bone packed in the cage itself. METHOD: We Evaluated 50 consecutive patients in whom surgery was performed between June 2000 to June 2003 in the Main Alexandria University Hospital at EGYPT. Twenty five patients were operated using autologous bone graft and 25 patients using the BAK cages. The neuro–radiologic al work up consisted of; plain X – ray lumbosacral spine including dynamic films preoperative and postoperative follow up; C.T lumbosacral spine and MRI lumbosacral spine. The surgery was performed at L4-5 level in 34 cases and at L5-S1 level in 16 cases. The median follow up was 15 months. RESULTS: Satisfactory fusion was obtained at all levels at a minimum one year follow – up. The fusion rate was 96% (24 patients) for the cage group and 80% (20 patients) for bone graft group however clinical improvement was 64% (16 patients) for those with bone graft group. CONCLUSION: A higher fusion rates and a better clinical outcome have been obtained by Instrumented PLIF with titanium cages that with bone graft. Inderbody fusion cages help to stabilize spainal segment primarily by distracting them as well as by allowing bone ingrowth and fusion. The procedure is safe and effective with 96% fusion rate and 76% overall Satisfactory rate. The use of cages help to distract the space between the vertebral bodies making the correction of the degree of spondylolisthesis easier. Long term follow up revealed better fusion rate and better realignment and less resorption with cages than with bone grafts. PMID

  8. 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

  9. Operative treatment of isthmic spondylolisthesis with posterior stabilization and ALIF. Cages versus autogenous bone grafts.

    PubMed

    Pankowski, Rafal; Smoczynski, Andrzej; Roclawski, Marek; Ceynowa, Marcin; Kloc, Wojciech; Wasilewski, Wojciech; Jende, Piotr; Liczbik, Wieslaw; Beldzinski, Piotr; Libionka, Witold; Pierzak, Olaf; Adamski, Stanislaw; Niedbala, Miroslaw

    2012-01-01

    In the following study the use of cages and autogenous bone grafts were compared in the operative treatment of isthmic spondylolisthesis with the posterior stabilization and Anterior Lumbosacral Interbody Fusion (ALIF). 55 patients were divided into two groups. Autogenous bone grafts were used in the first group (34 patients) and titanium interbody implants (cages) in the second group (21 patients). The mean follow up period in the first group was 8.6 years and 3.4 years in the second group. The radiological outcome was based upon the evaluation of the degree of spondylolisthesis, the angle of the lumbar lordosis, the height of the interbody space and intervertebral foramen and the evaluation of the spinal fusion. The objective clinical outcome assessment was based on Oswestry Disability Index. Subjective clinical evaluation was performed with the use of Visual Analog Pain Score (VAS) and the two questions concerning the evaluation of success of the operative treatment and a possible agreement to the following operation if necessary. The use of autogenous bone grafts alone in ALIF was related to the significant loss of achieved segmental spine anatomy restoration. The implantation of the cages prevented the loss of slippage correction, permanently reconstructed the anatomical conditions in the area of the operated spinal segment. PMID:22744517

  10. Analysis of Internet Information on Lateral Lumbar Interbody Fusion.

    PubMed

    Belayneh, Rebekah; Mesfin, Addisu

    2016-07-01

    Lateral lumbar interbody fusion (LLIF) is a surgical technique that is being increasingly used. The authors' objective was to examine information on the Internet pertaining to the LLIF technique. An analysis was conducted of publicly accessible websites pertaining to LLIF. The following search engines were used: Google (www.google.com), Bing (www.bing.com), and Yahoo (www.yahoo.com). DuckDuckGo (www.duckduckgo.com) was an additional search engine used due to its emphasis on generating accurate and consistent results while protecting searchers' privacy and reducing advertisements. The top 35 websites providing information on LLIF from the 4 search engines were identified. A total of 140 websites were evaluated. Each web-site was categorized based on authorship (academic, private, medical industry, insurance company, other) and content of information. Using the search term lateral lumbar interbody fusion, 174,000 Google results, 112,000 Yahoo results, and 112,000 Bing results were obtained. DuckDuckGo does not display the number of results found for a search. From the top 140 websites collected from each website, 78 unique websites were identified. Websites were authored by a private medical group in 46.2% of the cases, an academic medical group in 26.9% of the cases, and the biomedical industry in 5.1% of the cases. Sixty-eight percent of websites reported indications, and 24.4% reported contraindications. Benefits of LLIF were reported by 69.2% of websites. Thirty-six percent of websites reported complications of LLIF. Overall, the quality of information regarding LLIF on the Internet is poor. Spine surgeons and spine societies can assist in improving the quality of the information on the Internet regarding LLIF. [Orthopedics. 2016; 39(4):e701-e707.]. PMID:27111081

  11. A Biomechanical Comparison of Shape Design and Positioning of Transforaminal Lumbar Interbody Fusion Cages

    PubMed Central

    Comer, Garet C.; Behn, Anthony; Ravi, Shashank; Cheng, Ivan

    2015-01-01

    Study Design  Cadaveric biomechanical analysis. Objective  The aim of this study was to compare three interbody cage shapes and their position within the interbody space with regards to construct stability for transforaminal lumbar interbody fusion. Methods  Twenty L2–L3 and L4–L5 lumbar motion segments from fresh cadavers were potted in polymethyl methacrylate and subjected to testing with a materials testing machine before and after unilateral facetectomy, diskectomy, and interbody cage insertion. The three cage types were kidney-shaped, articulated, and straight bullet-shaped. Each cage type was placed in a common anatomic area within the interbody space before testing: kidney, center; kidney, anterior; articulated, center; articulated, anterior; bullet, center; bullet, lateral. Load-deformation curves were generated for axial compression, flexion, extension, right bending, left bending, right torsion, and left torsion. Finally, load to failure was tested. Results  For all applied loads, there was a statistically significant decrease in the slope of the load-displacement curves for instrumented specimens compared with the intact state (p < 0.05) with the exception of right axial torsion (p = 0.062). Among all instrumented groups, there was no statistically significant difference in stiffness for any of the loading conditions or load to failure. Conclusions  Our results failed to show a clearly superior cage shape design or location within the interbody space for use in transforaminal lumbar interbody fusion. PMID:27433426

  12. Sacrum fracture following L5-S1 stand-alone interbody fusion for isthmic spondylolisthesis.

    PubMed

    Phan, Kevin; Mobbs, Ralph J

    2015-11-01

    We report a 72-year-old man with a rare sacral fracture following stand-alone L5-S1 anterior lumbar interbody fusion for isthmic spondylolisthesis. The man underwent a minimally invasive management strategy using posterior percutaneous pedicle fixation and partial reduction of the deformity. We also discuss the current literature on fusion procedures for isthmic spondylolisthesis. PMID:26100158

  13. Successful salvage surgery for failed transforaminal lumbosacral interbody fusion using the anterior transperitoneal approach.

    PubMed

    Hozumi, Takashi; Orita, Sumihisa; Inage, Kazuhide; Fujimoto, Kazuki; Sato, Jun; Shiga, Yasuhiro; Kanamoto, Hirohito; Abe, Koki; Yamauchi, Kazuyo; Aoki, Yasuchika; Nakamura, Junichi; Matsuura, Yusuke; Suzuki, Takane; Takahashi, Kazuhisa; Ohtori, Seiji; Sainoh, Takeshi

    2016-05-01

    Transforaminal lumbar interbody fusion (TLIF) is a popular posterior spinal fusion technique, but sometimes require salvage surgery when implant failure occurs, which involves possible neural damage due to postoperative adhesion. The current report deals with successful anterior transperitoneal salvage surgery for failed L5-S TLIF with less neural invasiveness. PMID:27190611

  14. Matched Comparison of Fusion Rates between Hydroxyapatite Demineralized Bone Matrix and Autograft in Lumbar Interbody Fusion

    PubMed Central

    Kim, Dae Hwan; Lee, Nam; Shin, Dong Ah; Yi, Seong; Kim, Keung Nyun

    2016-01-01

    Objective To compare the fusion rate of a hydroxyapatite demineralized bone matrix (DBM) with post-laminectomy acquired autograft in lumbar interbody fusion surgery and to evaluate the correlation between fusion rate and clinical outcome. Methods From January 2013 to April 2014, 98 patients underwent lumbar interbody fusion surgery with hydroxyapatite DBM (HA-DBM group) in our institute. Of those patients, 65 received complete CT scans for 12 months postoperatively in order to evaluate fusion status. For comparison with autograft, we selected another 65 patients who underwent lumbar interbody fusion surgery with post-laminectomy acquired autograft (Autograft group) during the same period. Both fusion material groups were matched in terms of age, sex, body mass index (BMI), and bone mineral density (BMD). To evaluate the clinical outcomes, we analyzed the results of visual analogue scale (VAS), Oswestry Disability Index (ODI), and Short Form Health Survey (SF-36). Results We reviewed the CT scans of 149 fusion levels in 130 patients (HA-DBM group, 75 levels/65 patients; Autograft group, 74 levels/65 patients). Age, sex, BMI, and BMD were not significantly different between the groups (p=0.528, p=0.848, p=0.527, and p=0.610, respectively). The HA-DBM group showed 39 of 75 fused levels (52%), and the Autograft group showed 46 of 74 fused levels (62.2%). This difference was not statistically significant (p=0.21). In the HA-DBM group, older age and low BMD were significantly associated with non-fusion (61.24 vs. 66.68, p=0.027; -1.63 vs. -2.29, p=0.015, respectively). VAS and ODI showed significant improvement after surgery when fusion was successfully achieved in both groups (p=0.004, p=0.002, HA-DBM group; p=0.012, p=0.03, Autograft group). Conclusion The fusion rates of the hydroxyapatite DBM and Autograft groups were not significantly different. In addition, clinical outcomes were similar between the groups. However, older age and low BMD are risk factors that might

  15. Minimally invasive transforaminal lumbar interbody fusion with percutaneous navigated guidewireless lumbosacral pedicle screw fixation.

    PubMed

    Chen, Kevin S; Park, Paul

    2016-07-01

    This video details the minimally invasive approach for treatment of a symptomatic Grade II lytic spondylolisthesis with high-grade foraminal stenosis. In this procedure, the use of a navigated, guidewireless technique for percutaneous pedicle screw placement at the lumbosacral junction is highlighted following initial decompression and transforaminal interbody fusion. Key steps of the procedure are delineated that include positioning, exposure, technique for interbody fusion, intraoperative image acquisition, and use of a concise 2-step process for navigated screw placement without using guidewires. The video can be found here: https://youtu.be/2u6H4Pc_8To . PMID:27364422

  16. Minimally invasive L5-S1 oblique lumbar interbody fusion with anterior plate.

    PubMed

    Pham, Martin H; Jakoi, Andre M; Hsieh, Patrick C

    2016-07-01

    Lumbar interbody fusion is an important technique for the treatment of degenerative disc disease and degenerative scoliosis. The oblique lumbar interbody fusion (OLIF) establishes a minimally invasive retroperitoneal exposure anterior to the psoas and lumbar plexus. In this video case presentation, the authors demonstrate the techniques of the OLIF at L5-S1 performed on a 69-year-old female with degenerative scoliosis as one component of an overall strategy for her deformity correction. The video can be found here: https://youtu.be/VMUYWKLAl0g . PMID:27364428

  17. Viscoelastic Disc Arthroplasty Provides Superior Back and Leg Pain Relief in Patients with Lumbar Disc Degeneration Compared to Anterior Lumbar Interbody Fusion

    PubMed Central

    Rischke, Burkhard; Smith, Eric

    2015-01-01

    Background Lumbar disc degeneration (LDD) is one of the most frequently diagnosed spinal diseases. The symptoms these disorders cause are anticipated to increase as the population in Western countries ages. Purpose Compare back and leg pain alleviation in patients with LDD and a viscoelastic disc prosthesis documented in the SWISSspine registry versus patients with anterior lumbar interbody fusion documented in the Spine Tango registry. Study Design Prospectively collected clinical and outcome data in two independent spine registries. Outcome Measures were back and leg pain relief on 0 to 10 numerical rating scales. Materials and Methods The analysis included a single surgeon series of 48 patients with viscoelastic total disc replacement (VTDR) from the SWISSspine registry which were compared to 131 patients with anterior lumbar interbody fusion (ALIF) from the Spine Tango registry. Two linear multivariate regression models were built to assess the associations of patient characteristics with back and leg pain relief. The following covariates were included in the models: patient age and sex, disc herniation as additional diagnosis, number of treated segments, level of treated segment, treatment type (VTDR, ALIF), preoperative back and leg pain levels and follow-up interval. Results Both models showed VTDR to be associated with significantly higher back (2.76 points; 95% confidence interval (CI) 1.78 - 3.73; p < 0.001) and leg pain (2.12 points; 95% CI 1.12 to 3.13; p < 0.001) relief than ALIF. Other influential factors for higher back pain relief were female sex compared with male sex (1.03 additional points; 95% CI 0.27 to 1.78; p = 0.008), monosegmental surgery compared with bisegmental surgery (1.02 additional points; 95% CI 0.21 to 1.83; p = 0.014), and higher back pain at baseline (0.87 points additional pain relief per level of preoperative back pain; 95% CI 0.70 to 1.03; p < 0.001). Other influential factors for leg pain relief were monosegmental surgery (0

  18. 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

  19. Healing properties of allograft from alendronate-treated animal in lumbar spine interbody cage fusion.

    PubMed

    Xue, Qingyun; Li, Haisheng; Zou, Xuenong; Bünger, Mathias; Egund, Niels; Lind, Martin; Christensen, Finn Bjarke; Bünger, Cody

    2005-04-01

    This study investigated the healing potential of allograft from bisphosphonate-treated animals in anterior lumbar spine interbody fusion. Three levels of anterior lumbar interbody fusion with Brantigan cages were performed in two groups of five landrace pigs. Empty Brantigan cages or cages filled with either autograft or allograft were located randomly at different levels. The allograft materials for the treatment group were taken from the pigs that had been fed with alendronate, 10 mg daily for 3 months. The histological fusion rate was 2/5 in alendronate-treated allograft and 3/5 in non-treated allograft. The mean bone volume was 39% and 37.2% in alendronate-treated or non-treated allograft (NS), respectively. No statistical difference was found between the same grafted cage comparing two groups. The histological fusion rate was 7/10 in all autograft cage levels and 5/10 in combined allograft cage levels. No fusion was found at all in empty cage levels. With the numbers available, no statistically significant difference was found in histological fusion between autograft and allograft applications. There was a significant difference of mean bone volume between autograft (49.2%) and empty cage (27.5%) (P<0.01). In conclusion, this study did not demonstrate different healing properties of alendronate-treated and non-treated allograft for anterior lumbar interbody fusion in pigs. PMID:15248057

  20. True Percutaneous Transforaminal Lumbar Interbody Fusion: Case Illustrations, Surgical Technique, and Limitations.

    PubMed

    Syed, Hasan; Voyadzis, Jean-Marc

    2016-07-01

    Objective The last decade has seen significant advances in minimally invasive techniques for lumbar interbody fusion that have reduced approach-related morbidity. Percutaneous lumbar interbody fusion involves a posterior transforaminal approach to the disk space with a minimal access port through the Kambin triangle. This technique obviates the need for the facetectomy or laminectomy required in a traditional transforaminal approach. This article describes the surgical technique, potential advantages and limitations, and representative case illustrations. Methods Percutaneous transforaminal interbody fusion was performed on two patients with axial back and leg pain as a result of degenerative disk disease. Diskectomy and interbody cage insertion were completed through a tubular dilator placed onto the disk space in the Kambin triangle. Posterior fixation was achieved with percutaneous transfacet screws. Clinical outcome and postoperative complications are discussed. Results Both patients demonstrated significant clinical improvement after surgery with > 1 year follow-up despite experiencing transient neurologic symptoms. Conclusion Although this report demonstrates the feasibility and advantages of the approach, the technique is limited by the potential for nerve root injury and pseudoarthrosis. PMID:26291889

  1. Percutaneous Transpedicular Interbody Fusion Technique in Percutaneous Pedicle Screw Stabilization for Pseudoarthrosis Following Pyogenic Spondylitis

    PubMed Central

    Masuda, Keigo; Yonekura, Yutaka; Kitamura, Takahiro; Senba, Hideyuki; Shidahara, Satoshi

    2016-01-01

    This report introduces a percutaneous transpedicular interbody fusion (PTPIF) technique in posterior stabilization using percutaneous pedicle screws (PPSs). An 81-year-old man presented with pseudoarthrosis following pyogenic spondylitis 15 months before. Although no relapse of infection was found, he complained of obstinate low back pain and mild neurological symptoms. Radiological evaluations showed a pseudoarthrosis following pyogenic spondylitis at T11–12. Posterior stabilization using PPSs from Th9 to L2 and concomitant PTPIF using autologous iliac bone graft at T11–12 were performed. Low back pain and neurological symptoms were immediately improved after surgery. A solid interbody fusion at T11–12 was completed 9 months after surgery. The patient had no restriction of daily activity and could play golf at one year after surgery. PTPIF might be a useful option for perform segmental fusion in posterior stabilization using PPSs. PMID:27114777

  2. Percutaneous Transpedicular Interbody Fusion Technique in Percutaneous Pedicle Screw Stabilization for Pseudoarthrosis Following Pyogenic Spondylitis.

    PubMed

    Ikuta, Ko; Masuda, Keigo; Yonekura, Yutaka; Kitamura, Takahiro; Senba, Hideyuki; Shidahara, Satoshi

    2016-04-01

    This report introduces a percutaneous transpedicular interbody fusion (PTPIF) technique in posterior stabilization using percutaneous pedicle screws (PPSs). An 81-year-old man presented with pseudoarthrosis following pyogenic spondylitis 15 months before. Although no relapse of infection was found, he complained of obstinate low back pain and mild neurological symptoms. Radiological evaluations showed a pseudoarthrosis following pyogenic spondylitis at T11-12. Posterior stabilization using PPSs from Th9 to L2 and concomitant PTPIF using autologous iliac bone graft at T11-12 were performed. Low back pain and neurological symptoms were immediately improved after surgery. A solid interbody fusion at T11-12 was completed 9 months after surgery. The patient had no restriction of daily activity and could play golf at one year after surgery. PTPIF might be a useful option for perform segmental fusion in posterior stabilization using PPSs. PMID:27114777

  3. Computational comparison of three posterior lumbar interbody fusion techniques by using porous titanium interbody cages with 50% porosity.

    PubMed

    Lee, Yung-Heng; Chung, Chi-Jen; Wang, Chih-Wei; Peng, Yao-Te; Chang, Chih-Han; Chen, Chih-Hsien; Chen, Yen-Nien; Li, Chun-Ting

    2016-04-01

    This study investigated the biomechanical response of porous cages and lumbar spine segments immediately after surgery and after bone fusion, in addition to the long-term effects of various posterior lumbar interbody fusion (PLIF) techniques, by using the finite element method. Lumbar L3-L4 models based on three PLIF techniques (a single cage at the center of the intervertebral space, a single cage half-anterior to the intervertebral space, and two cages bilateral to the intervertebral space) with and without bone ingrowth were used to determine the biomechanical response of porous cages and lumbar segments instrumented with porous titanium cages (cage porosity=50%, pore diameter=1mm). The results indicated that bone fusion enhanced the stability of the lumbar segments with porous cages without any posterior instrumentation and reduced the peak von Mises stress in the cortical bones and porous cages. Two cages placed bilateral to the intervertebral space achieved the highest structural stability in the lumbar segment and lowest von Mises stress in the cages under both bone fusion conditions. Under identical loading (2-Nm), the range of motion in the single cage at the center of the intervertebral space with bone fusion decreased by 11% (from 1.18° to 1.05°) during flexion and by 66.5% (from 4.46° to 1.5°) during extension in the single cage half-anterior to the intervertebral space with bone fusion compared with no-fusion models. Thus, two porous titanium cages with 50% porosity can achieve high stability of a lumbar segment with PLIF. If only one cage is available, placing the cage half-anterior to the intervertebral space is recommended for managing degenerated lumbar segments. PMID:26874064

  4. [The comparison of the use of cages with the use of autogenous bone grafts in the operative treatment of the isthmic spondylolisthesis by the posterior stabilisation and ALIF].

    PubMed

    Pankowski, Rafał; Smoczyński, Andrzej; Jaskólski, Dawid; Rocławski, Marek; Samson, Lucjan; Piotrowski, Maciej

    2009-01-01

    In the following study the use of cages and autogenous bone grafts were comparised in the operative treatment of isthmic spondylolisthesis by the posterior stabilization and anterior lumbosacral interbody fusion. 55 patients were divided into two groups. Patients underwent ALIF with the use of autogenous bone grafts in the first group (34) and with the use of titanium interbody implants (cages) in the second group (21). The mean follow up period in the first group was 8.6 years and in the second group was 3.4 years. The objective clinical outcome assessment was based on Oswestry disability questionnaire. Subjective clinical evaluation was conducted with the use of visual analog pain score and two questions concerning the evaluation of success of the operative treatment and a possible agreement to the following operation if necessary. The radiological results were based upon the evaluation of the degree of spondylolisthesis, the angle of the lumbar lordosis, the height of the interbody space and intervertebral foramen and the evaluation of the spinal fusion. The usage of autogenous bone grafts alone in ALIF was related to the significant loss of achieved segmental spine anatomy restoration. The implantation of the cages prevented the loss of slippage correction, permanently reconstructed the anatomical conditions in the area of the operated spinal segment. PMID:19514478

  5. Intraoperative antepulsion of a posterior lumbar interbody fusion cage: three case reports

    PubMed Central

    Ceylan, Davut; Yaldiz, Can; Asil, Kiyasettin; Kaçira, Tibet; Tatarli, Necati; Can, Aytaç

    2015-01-01

    Spinal fusion surgery techniques develop together with technologic advancements. New complications are seen as the result of new techniques and these may be very severe due to spinal cord and vascular structures in the lumbar region. The posterior lumbar interbody fusion cage (PLIFC) was shown to enhance spinal fusion and to prevent pseudoarthrosis due to its basic dynamic characteristics. PLIFC migrations are usually observed during the postoperative period, just after the mobilization of the patient and usually toward spinal canal. Migration to the retroperitoneal region is a extremely rare condition in the literature. In this article we discussed three cases of PLIFC antepulsion into the retroperitoneal region during the intraoperative period. PMID:26175832

  6. 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

  7. 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

  8. [The results of decompression and anterior lumbar interbody fusion with the use of interbody cages for the treatment of degenerative lumbar spondylolisthesis].

    PubMed

    Luczkiewicz, Piotr; Smoczyński, Andrzej; Smoczyński, Maciej; Pankowski, Rafał; Piotrowski, Maciej

    2006-01-01

    In this paper we reviewed 28 patients who had been treated surgically for lumbar degenerative spondylolisthesis. They were operated between 1998-2003. The decompression and anterior lumbar interbody fusion with the use of interbody cages, was performed in all of them. The outcome was assessed using rating system of Prolo and VAPS. The disc height, degree of slippage and segmental lordosis were measured, on the radiographs, before surgery, after 6 weeks and at the time of final follow-up. In all cases spinal fusion was achieved. The disc height, degree of slipage and segmental lordosis were improved and these results were stable in time. A significant decrease in radicular pain and low back pain were seen but the relation between clinical and radiological autcomes was not observed. PMID:17131721

  9. Mini posterior lumbar interbody fusion with presacral screw stabilization in early lumbosacral instability

    PubMed Central

    Shetty, Arjun; Kini, Abhishek R; Chacko, A; Sunil, Upadhyaya; Vinod, K; Geover, Lobo

    2015-01-01

    Background: Surgical options for the management of early lumbosacral spondylolisthesis and degenerative disc disease with instability vary from open lumbar interbody fusion with transpedicular fixation to a variety of minimal access fusion and fixation procedures. We have used a combination of micro discectomy and axial lumbosacral interbody fusion with presacral screw fixation to treat symptomatic patients with lumbosacral spondylolisthesis or lumbosacral degenerative disc disease, which needed surgical stabilization. This study describes the above technique along with analysis of results. Materials and Methods: Twelve patients with symptomatic lumbosacral (L5-S1) instability and degenerative lumbosacral disc disease were treated by micro discectomy and interbody fusion using presacral screw stabilization. Patients with history of bowel, bladder dysfunction and local anorectal diseases were excluded from this study. Postoperatively all patients were evaluated neurologically and radiologically for screw position, fusion and stability. Oswestry disability index was used to evaluate results. Results: We had nine females and three males with a mean age of 47.33 years (range 26–68 years). Postoperative assessment revealed three patients to have screw placed in anterior 1/4th of the 1st sacral body, in rest nine the screws were placed in the posterior 3/4th of sacral body. At 2 years followup, eight patients (67%) showed evidence of bridging trabeculae at bone graft site and none of the patients showed evidence of instability or implant failure. Conclusion: Presacral screw fixation along with micro discectomy is an effective procedure to manage early symptomatic lumbosacral spondylolisthesis and degenerative disc disease with instability. PMID:26015626

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

    PubMed

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

    2013-02-01

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

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

    SciTech Connect

    Mooney, V. )

    1990-07-01

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

  12. Prevalence and Risk Factors of Deep Vein Thrombosis in Patients Undergoing Lumbar Interbody Fusion Surgery

    PubMed Central

    Yang, Si-Dong; Ding, Wen-Yuan; Yang, Da-Long; Shen, Yong; Zhang, Ying-Ze; Feng, Shi-Qing; Zhao, Feng-Dong

    2015-01-01

    Abstract This cross-sectional study was designed to obtain the current prevalence of deep vein thrombosis (DVT) and analyze related risk factors in patients undergoing lumbar interbody fusion. Medical record data were collected from Department of Spinal Surgery, The Third Hospital of Hebei Medical University, between July 2014 and March 2015. Both univariate analysis and binary logistic regression analysis were performed to determine risk factors for DVT. A total of 995 patients were admitted into this study, including 484 men and 511 women, aged from 14 to 89 years old (median 50, IQR 19). The detection rate of lower limb DVT by ultrasonography was 22.4% (223/995) in patients undergoing lumbar interbody fusion. Notably, average VAS (visual analog scale) score in the first 3 days after surgery in the DVT group was more than that in the non-DVT group (Z = −21.69, P < 0.001). The logistic regression model was established as logit P = −13.257 + 0.056∗X1 − 0.243∗X8 + 2.085∗X10 + 0.001∗X12, (X1 = age; X8 = HDL; X10 = VAS; X12 = blood transfusion; x2 = 677.763, P < 0.001). In conclusion, advanced age, high postoperative VAS scores, and blood transfusion were risk factors for postoperative lower limb DVT. As well, the logistic regression model may contribute to an early evaluation postoperatively to ascertain the risk of lower limb DVT in patients undergoing lumbar interbody fusion surgery. PMID:26632909

  13. Outcome of posterior lumbar interbody fusion versus posterolateral fusion in lumbar degenerative disease.

    PubMed

    Wu, Yungang; Tang, Hao; Li, Zhonghai; Zhang, Qiulin; Shi, Zhicai

    2011-06-01

    Between March 2003 and September 2007, 170 consecutive patients with lumbar degenerative disease were studied retrospectively. Eighty patients underwent posterior lumbar interbody fusion (PLIF group) with pedicle screw (PS) fixation, and 82 patients underwent posterolateral fusion (PLF group) with PS fixation. Eight patients were lost to follow-up. The minimum follow-up period in each group was 2.0years. The mean follow-up period for the PLIF group was 3.6years, and for the PLF group, the mean follow-up was 3.4years: there was no significant difference between the two groups for length of follow-up. The Pain Index (PI) improved from 66 to 27 in the PLF group (p<0.001) and from 69 to 29 in the PLIF group (p<0.001), but there was no significant difference between the two groups (p>0.05). In the PLF group, the preoperative mean Oswestry Disability Index (ODI) score was 34.5, which reduced to 14.2 at the final follow-up. In the PLIF group, the mean preoperative ODI was 36.4, which reduced to 16.2 at the final follow-up. There was no significant statistical difference between the two groups for ODI (p>0.05). Eighty-eight percent (n=72) of patients in the PLF group and 91% (n=73) in the PLIF group had radiologically confirmed union, with no significant difference in fusion percentage between the two groups (p>0.05). Twenty-two of 162 patients (14%) underwent a second operation: 18 (22%) in the PLF group and four (5%) patients in the PLIF group (p<0.001). The clinical and functional outcomes in both groups were similar, and no significant difference was found in the parameters tested. Both surgical procedures were effective, but patients in the PLF group showed more complications related to hardware biomechanics than patients in the PLIF group (p<0.001). PMID:21507656

  14. 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. PMID:27349467

  15. [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. PMID:16721480

  16. Incidence of graft extrusion following minimally invasive transforaminal lumbar interbody fusion.

    PubMed

    Bakhsheshian, Joshua; Khanna, Ryan; Choy, Winward; Lawton, Cort D; Nixon, Alex T; Wong, Albert P; Koski, Tyler R; Liu, John C; Song, John K; Dahdaleh, Nader S; Smith, Zachary A; Fessler, Richard G

    2016-02-01

    Minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) has been scrutinized for having a complex learning curve. Careful assessment of MI-TLIF complications and critical analyses of prevention may aid a safe adoption of this technique. The current report focuses on the incidence of interbody cage extrusions following MI-TLIF in a series of 513 patients. The authors discuss their experience with graft extrusions and provide methods to minimize this complication. This study retrospectively reviewed 513 prospectively followed patients who underwent MI-TLIF over a 10 year period. The inclusion criteria consisted of all patients who underwent one to three level MI-TLIF, from whom the incidence of cage extrusion was analyzed. Cage extrusion was defined as an interbody graft migrating outside the cephalad and caudal vertebral body posterior margin. Cage extrusions were diagnosed by comparing the intraoperative radiographs to the postoperative radiographs. Patients with >10° coronal curves, significant sagittal malalignment, infection, and preoperative instrumentation failure were excluded. Of 513 patients undergoing MI-TLIF, five patients (0.97%) were diagnosed with cage migrations. The mean follow-up duration was 13.6 ± standard deviation of 8.8 months. Complications included asymptomatic cage migration alone (two patients) neurological decline (two patients) and epidural hematoma (one patient). On average, cage migrations cost a university hospital an additional $US17,217 for revision treatment. While the incidence of cage migrations is low (0.97%), it can lead to postoperative complications that require revision surgery and increased hospital costs. The risk for this significant complication can be minimized with proper technique and patient selection. PMID:26578209

  17. Focal Correction of Severe Fixed Kyphosis with Single Level Posterior Ponte Osteotomy and Interbody Fusion

    PubMed Central

    Molloy, Seth S; Ahmad, Faiz U; Green, Barth A; Lebwohl, Nathan H

    2016-01-01

    Objective: To report the successful correction of a severe, fixed kyphotic deformity utilizing a combination posterior lumbar interbody fusion (PLIF) and Ponte osteotomy at the site of acute kyphosis. Summary of Background Data: There have been no reports on the experience and surgical strategy of combined one-level focal PLIF and Ponte osteotomy for fixed severe kyphotic deformity. Typically, these corrections would need a pedicle subtraction osteotomy or a vertebrectomy. Methods: A 24-year-old man presented with progressive back pain and a fixed severe thoracolumbar kyphosis centered at the L2-L3 disc space seven years after removal of instrumentation for intractable infection following correction of Scheuermann's Kyphosis. The patient also demonstrated pseudoarthrosis of the posterior thoracolumbar fusion bed. The original operative plan was to perform a vertebral column resection (VCR) of L2 to correct his severe kyphosis.  During preparation for the VCR, the patient’s deformity corrected completely after insertion of blunt distraction paddles for the interbody fusion after the Ponte osteotomy at L2-L3. A VCR was avoided, and the construct was able to be completed with simple rod insertion and posterolateral fusion. Results: The described technique achieved 69 degrees of correction at the L2-L3 disc space without any remodeling of the surrounding vertebrae. The C7 plumb line was normalized, and the patient was able to stand upright with horizontal gaze and without pre-existing discomfort. At the six-month follow-up, the patient reported a significant improvement in pain and was able to resume normal activities. PMID:27462479

  18. 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. PMID:26161161

  19. Clinical and Radiological Results of Microsurgical Posterior Lumbar Interbody Fusion and Decompression without Posterior Instrumentation for Lateral Recess Stenosis

    PubMed Central

    Şişman, Lokman; Türkmen, Faik; Efe, Duran; Pekince, Oğuzhan; Göncü, Recep Gani; Sever, Cem

    2015-01-01

    Study Design A single-center, retrospective patient review of clinical and radiological outcomes of microsurgical posterior lumbar interbody fusion and decompression, without posterior instrumentation, for the treatment of lateral recess stenosis. Purpose This study documented the clinical and radiological results of microsurgical posterior lumbar interbody fusion and decompression of the lateral recess using interbody cages without posterior instrumentation for the treatment of lateral recess stenosis. Overview of Literature Although microsurgery has some advantages, various complications have been reported following microsurgical decompression, including cage migration, pseudoarthrosis, neurologic deficits, and persistent pain. Methods A total of 34 patients (13 men, 21 women), with a mean age of 56.65±9.1 years (range, 40-77 years) confirmed spinal stability, and preoperative radiological findings of lateral recess stenosis, were included in the study. Interbody polyetheretherketone cages and auto grafts were used in all patients. Posterior instrumentation was not used because of limited resection of the posterior lumbar structures. Preoperative and postoperative radiographs, computed tomography scans, and magnetic resonance imaging were assessed and compared to images taken at the final follow-up. Functional recovery was also evaluated according to the Macnab criteria at the final follow-up. Results The average follow-up time was 35.05±8.65 months (range, 24-46 months). The clinical results, operative time, intraoperative blood loss, and duration of hospital stay were similar to previously published results; the fusion rate (85.2%) was decreased and the migration rate (5.8%) was increased, compared with prior reports. Conclusions Although microsurgery has some advantages, migration and pseudoarthrosis remain challenges to achieving adequate lumbar interbody fusion. PMID:26435789

  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. 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. PMID:25971442

  2. 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. PMID:23906522

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

    PubMed Central

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

    2014-01-01

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

  4. Transforaminal Lumbar Interbody Fusion for Lumbar Degenerative Disorders: Mini-open TLIF and Corrective TLIF

    PubMed Central

    HARA, Masahito; NISHIMURA, Yusuke; NAKAJIMA, Yasuhiro; UMEBAYASHI, Daisuke; TAKEMOTO, Masaya; YAMAMOTO, Yuu; HAIMOTO, Shoichi

    Minimally invasive transforaminal lumbar interbody fusion (TLIF) as a short fusion is widely accepted among the spine surgeons. However in the long fusion for degenerative kyphoscoliosis, corrective spinal fixation by an open method is thought to be frequently selected. Our objective is to study whether the mini-open TLIF and corrective TLIF contribute to the improvement of the spinal segmental and global alignment. We divided the patients who performed lumbar fixation surgery into three groups. Group 1 (G1) consisted of mini-open TLIF procedures without complication. Group 2 (G2) consisted of corrective TLIF without complication. Group 3 (G3) consisted of corrective TLIF with instrumentation-related complication postoperatively. In all groups, the lumbar lordosis (LL) highly correlated with developing surgical complications. LL significantly changed postoperatively in all groups, but was not corrected in the normal range in G3. There were statistically significant differences in preoperative and postoperative LL and mean difference between the pelvic incidence (PI) and LL between G3 and other groups. The most important thing not to cause the instrumentation-related failure is proper correction of the sagittal balance. In the cases with minimal sagittal imbalance with or without coronal imbalance, short fusion by mini-open TLIF or long fusion by corrective TLIF contributes to good clinical results if the lesion is short or easily correctable. However, if the patients have apparent sagittal imbalance with or without coronal imbalance, we should perform proper correction of the sagittal spinal alignment introducing various technologies. PMID:26119895

  5. Improvement of Segmental Lordosis in Transforaminal Lumbar Interbody Fusion: A Comparison of Two Techniques.

    PubMed

    Rice, James W; Sedney, Cara L; Daffner, Scott D; Arner, Justin W; Emery, Sanford E; France, John C

    2016-05-01

    Study Design Retrospective review. Objective The purpose of this study was to determine the radiographic impact of a transforaminal lumbar interbody fusion (TLIF) versus a cantilever TLIF technique on segmental lordosis, segmental coronal alignment, and disk height. Methods A retrospective review was done of all patients undergoing TLIF procedures from 2006 to 2011 by three spine surgeons. Traditional TLIF versus cantilever TLIF results were compared, and radiographic outcomes were assessed. Results One hundred one patients were included in the study. Patients undergoing the cantilever TLIF procedure had a significantly greater change in segmental lordosis and disk height compared with those who underwent the traditional procedure (p > 0.0001). Conclusions The cantilever TLIF technique can lead to greater change in segmental lordosis based upon radiographic outcomes. PMID:27099813

  6. Improvement of Segmental Lordosis in Transforaminal Lumbar Interbody Fusion: A Comparison of Two Techniques

    PubMed Central

    Rice, James W.; Sedney, Cara L.; Daffner, Scott D.; Arner, Justin W.; Emery, Sanford E.; France, John C.

    2015-01-01

    Study Design Retrospective review. Objective The purpose of this study was to determine the radiographic impact of a transforaminal lumbar interbody fusion (TLIF) versus a cantilever TLIF technique on segmental lordosis, segmental coronal alignment, and disk height. Methods A retrospective review was done of all patients undergoing TLIF procedures from 2006 to 2011 by three spine surgeons. Traditional TLIF versus cantilever TLIF results were compared, and radiographic outcomes were assessed. Results One hundred one patients were included in the study. Patients undergoing the cantilever TLIF procedure had a significantly greater change in segmental lordosis and disk height compared with those who underwent the traditional procedure (p > 0.0001). Conclusions The cantilever TLIF technique can lead to greater change in segmental lordosis based upon radiographic outcomes. PMID:27099813

  7. A Randomized Controlled Trial Comparing Transforaminal Lumbar Interbody Fusion and Uninstrumented Posterolateral Fusion in the Degenerative Lumbar Spine.

    PubMed

    Jalalpour, Kourosh; Neumann, Pavel; Johansson, Christer; Hedlund, Rune

    2015-08-01

    Study Design Randomized controlled trial. Objective Despite a large number of publications of outcomes after spinal fusion surgery, there is still no consensus on the efficacy of the several different fusion methods. The aim of this study was to determine whether transforaminal lumbar interbody fusion (TLIF) results in an improved clinical outcome compared with uninstrumented posterolateral fusion (PLF) in the surgical treatment for chronic low back pain. Methods This study included 135 patients with degenerative disk disease (n = 96) or postdiskectomy syndrome (n = 39). Inclusion criteria were at least 1 year of back pain with or without leg pain in patients aged 20 to 65 with one- or two-level disease. Exclusion criteria were sequestration of disk hernia, psychosocial instability, isthmic spondylolisthesis, drug abuse, and previous spine surgery other than diskectomy. Pain was assessed by visual analog scale (pain index). Functional disability was quantified by the disability rating index and Oswestry Disability Index. The global outcome was assessed by the patient and classified as much better, better, unchanged, or worse. The patients were randomized to conventional uninstrumented PLF (n = 67) or TLIF (n = 68). PLF was performed in a standardized fashion using autograft. TLIF was performed with pedicle titanium screw fixation and a porous tantalum interbody spacer with interbody and posterolateral autograft. The clinical outcome measurements were obtained preoperatively and at 12 and 24 months postoperatively. The 2-year follow-up rate was 98%. Results The two treatment groups improved significantly from preoperatively to 2 years' follow-up. At final follow-up, the results in the TLIF group were significantly superior to those in the PLF group in pain index (2.0 versus 3.9, p = 0.007) and in disability rating index (22 versus 36, p = 0.003). The Oswestry Disability Index was better in the TLIF group (20 versus 28, p = 0

  8. 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

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

    PubMed Central

    Tang, Ming‐xing; Wang, Yu‐xiang; Guo, Chao‐feng; Liu, Jin‐yang

    2016-01-01

    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

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

    PubMed Central

    Mobbs, Ralph J.

    2016-01-01

    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. PMID:27114781

  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. Anterior Lumbar Interbody Fusion for Degenerative Discogenic Low Back Pain: Evaluation of L4-S1 Fusion.

    PubMed

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

    2015-10-01

    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 L5-S1 group (12.5%). A venous tear

  13. Application of transforaminal lumbar interbody fusion in old thoracolumbar fracture and dislocation

    PubMed Central

    Fang, Xiangqian; Fan, Shunwu; Zhao, Xing

    2011-01-01

    Background The main indications for surgery for old thoracolumbar fractures are pain, progressive deformity, neurological damage, or increasing neurological deficit. These fractures have been one of the greatest therapeutic challenges in spinal surgery. Anterior, posterior, or combined anterior and posterior procedures have been successful to some extent. As far as we know, there is no report in the literature of transforaminal lumbar interbody fusion (TLIF) for old thoracolumbar fracture and dislocation. Methods Case report. Results A 26-year-old man with old fracture and dislocation of T12/L1 was treated with TLIF. At 12 months' follow-up, multi-slice computed tomography (CT) scans showed that solid fusion had been achieved between T12 and L1. Back pain had resolved completely at 2-year follow-up. Conclusions We performed TLIF for in a man with old fracture and dislocation of T12/L1, with good clinical outcome. TLIF might be an option in the treatment of old thoracolumbar fracture. PMID:22330118

  14. Lifestyle-Related Diseases Affect Surgical Outcomes after Posterior Lumbar Interbody Fusion.

    PubMed

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

    2016-02-01

    Study Design Retrospective study. Objective Hyperlipidemia (HL) and hypertension (HT) lead to systemic atherosclerosis. Not only atherosclerosis but also bone fragility and/or low bone mineral density result from diabetes mellitus (DM) and chronic kidney disease (CKD). The purpose of this study was to examine whether these lifestyle-related diseases affected surgical outcomes after posterior lumbar interbody fusion (PLIF). Methods The subjects comprised 122 consecutive patients who underwent single-level PLIF for degenerative lumbar spinal disorders. The clinical results were assessed using the Japanese Orthopaedic Association (JOA) score before surgery and at 2 years postoperatively. The fusion status was graded as union in situ, collapsed union, or nonunion at 2 years after surgery. The abdominal aorta calcification (AAC) score was assessed using preoperative lateral radiographs of the lumbar spine. Results HL did not significantly affect the JOA score recovery rate. On the other hand, HT and CKD (stage 3 to 4) had a significant adverse effect on the recovery rate. The recovery rate was also lower in the DM group than in the non-DM group, but the difference was not significant. The AAC score was negatively correlated with the JOA score recovery rate. The fusion status was not significantly affected by HL, HT, DM, or CKD; however, the AAC score was significantly higher in the collapsed union and nonunion group than in the union in situ group. Conclusions At 2 years after PLIF, the presence of HT, CKD, and AAC was associated with significantly worse clinical outcomes, and advanced AAC significantly affected fusion status. PMID:26835195

  15. Treatment of Symptomatic Lumbar Disc Degeneration with the VariLift-L Interbody Fusion System: Retrospective Review of 470 Cases

    PubMed Central

    Neely, Warren F.; Fichtel, Frank; del Monaco, Diana Cardenas

    2016-01-01

    Background Many first generation stand-alone fusion cages required endplate decortication and surgical impaction during the procedure resulting in segmental subsidence, implant migration and loss of lordosis postoperatively. The primary objective of this study was to evaluate radiographically, in a large series of patients, whether engineering and design modifications incorporated in a specific stand-alone, expandable interbody fusion device (VariLift®-L) adequately addressed previously recognized deficiencies of stand-alone interbody cages. Methods In this retrospective chart review of 470 patients (642 treated levels), we evaluated radiographic evidence of fusion, subsidence and migration following a one- or two-level PLIF procedure utilizing this stand-alone expandable interbody fusion device. A secondary objective was to corroborate the low morbidity and symptomatic improvements achieved with previous interbody cage devices used to treat symptomatic disc degeneration. Results The average postoperative followup was 3.9 ± 1.8 years and a solid fusion rate of 94% was achieved among patients with ≥ 9 months of radiographic followup. Subsidence > 3 mm was noted at 10 levels with no cases of device migration. Composite back pain severity scores improved from 8.5 ± 1.5 preoperatively to 0.8 ± 1.5 at final followup (p<0.001) and 94% of patients met or exceeded the minimal clinical important difference of 3.8 points. Eighteen patients required reoperation following the index procedure; 16 of these patients were treated for adjacent segment disease. Conclusions (LOE) The VariLift-L device has excellent clinical and technical performance characteristics, providing adequate stabilization of the anterior column without the need for supplemental posterior instrumentation. Level of Evidence IV. IRB Approval: Expedited Federal Register Categories 5& 7: Methodist IRB 3/30/2011; Informed Consent statement: retrospective data collection, patients signed consent forms

  16. 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

  17. [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

  18. Neurogenic Shock Immediately following Posterior Lumbar Interbody Fusion: Report of Two Cases.

    PubMed

    Matsumoto, Tomiya; Okuda, Shinya; Haku, Takamitsu; Maeda, Kazuya; Maeno, Takafumi; Yamashita, Tomoya; Yamasaki, Ryoji; Kuratsu, Shigeyuki; Iwasaki, Motoki

    2015-08-01

    Study Design Case report. Objective To present two cases of neurogenic shock that occurred immediately following posterior lumbar interbody fusion (PLIF) and that appeared to have been caused by the vasovagal reflex after dural injury and incarceration of the cauda equina. Case Report We present two cases of neurogenic shock that occurred immediately following PLIF. One patient had bradycardia, and the other developed cardiac arrest just after closing the surgical incision and opening the drainage tube. Cardiopulmonary resuscitation was performed immediately, and the patients recovered successfully, but they showed severe motor loss after awakening. The results of laboratory data, chest X-ray, electrocardiogram, computed tomography, and echocardiography ruled out pulmonary embolism, hemorrhagic shock, and cardiogenic shock. Although the reasons for the postoperative shock were obscure, reoperation was performed to explore the cause of paralysis. At reoperation, a cerebrospinal fluid collection and the incarceration of multiple cauda equina rootlets through a small dural tear were observed. The incarcerated cauda equina rootlets were reduced, and the dural defect was closed. In both cases, the reoperation was uneventful. From the intraoperative findings at reoperation, it was thought that the pathology was neurogenic shock via the vasovagal reflex. Conclusion Incarceration of multiple cauda equina rootlets following the accidental dural tear by suction drainage caused a sudden decrease of cerebrospinal fluid pressure and traction of the cauda equina, which may have led to the vasovagal reflex. PMID:26225287

  19. Accidental Durotomy in Minimally Invasive Transforaminal Lumbar Interbody Fusion: Frequency, Risk Factors, and Management

    PubMed Central

    Volz, Florian; Krüger, Marie T.; Kogias, Evangelos; Rölz, Roland; Sircar, Ronen; Hubbe, Ulrich

    2015-01-01

    Purpose. To assess the frequency, risk factors, and management of accidental durotomy in minimally invasive transforaminal lumbar interbody fusion (MIS TLIF). Methods. This single-center study retrospectively investigates 372 patients who underwent MIS TLIF and were mobilized within 24 hours after surgery. The frequency of accidental durotomies, intraoperative closure technique, body mass index, and history of previous surgery was recorded. Results. We identified 32 accidental durotomies in 514 MIS TLIF levels (6.2%). Analysis showed a statistically significant relation of accidental durotomies to overweight patients (body mass index ≥25 kg/m2; P = 0.0493). Patient age older than 65 years tended to be a positive predictor for accidental durotomies (P = 0.0657). Mobilizing patients on the first postoperative day, we observed no durotomy-associated complications. Conclusions. The frequency of accidental durotomies in MIS TLIF is low, with overweight being a risk factor for accidental durotomies. The minimally invasive approach seems to minimize durotomy-associated complications (CSF leakage, pseudomeningocele) because of the limited dead space in the soft tissue. Patients with accidental durotomy can usually be mobilized within 24 hours after MIS TLIF without increased risk. The minimally invasive TLIF technique might thus be beneficial in the prevention of postoperative immobilization-associated complications such as venous thromboembolism. This trial is registered with DRKS00006135. PMID:26075294

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

    PubMed

    Lian, Xiaofeng; Navarro-Ramirez, Rodrigo; Berlin, Connor; Jada, Ajit; 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

  1. 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

  2. Neurogenic Shock Immediately following Posterior Lumbar Interbody Fusion: Report of Two Cases

    PubMed Central

    Matsumoto, Tomiya; Okuda, Shinya; Haku, Takamitsu; Maeda, Kazuya; Maeno, Takafumi; Yamashita, Tomoya; Yamasaki, Ryoji; Kuratsu, Shigeyuki; Iwasaki, Motoki

    2014-01-01

    Study Design Case report. Objective To present two cases of neurogenic shock that occurred immediately following posterior lumbar interbody fusion (PLIF) and that appeared to have been caused by the vasovagal reflex after dural injury and incarceration of the cauda equina. Case Report We present two cases of neurogenic shock that occurred immediately following PLIF. One patient had bradycardia, and the other developed cardiac arrest just after closing the surgical incision and opening the drainage tube. Cardiopulmonary resuscitation was performed immediately, and the patients recovered successfully, but they showed severe motor loss after awakening. The results of laboratory data, chest X-ray, electrocardiogram, computed tomography, and echocardiography ruled out pulmonary embolism, hemorrhagic shock, and cardiogenic shock. Although the reasons for the postoperative shock were obscure, reoperation was performed to explore the cause of paralysis. At reoperation, a cerebrospinal fluid collection and the incarceration of multiple cauda equina rootlets through a small dural tear were observed. The incarcerated cauda equina rootlets were reduced, and the dural defect was closed. In both cases, the reoperation was uneventful. From the intraoperative findings at reoperation, it was thought that the pathology was neurogenic shock via the vasovagal reflex. Conclusion Incarceration of multiple cauda equina rootlets following the accidental dural tear by suction drainage caused a sudden decrease of cerebrospinal fluid pressure and traction of the cauda equina, which may have led to the vasovagal reflex. PMID:26225287

  3. 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

  4. Transforaminal Lumbar Interbody Fusion for Management of Recurrent Lumbar Disc Herniation

    PubMed Central

    2016-01-01

    Study Design Retrospective study. Purpose To study the surgical outcome of transforaminal lumbar interbody fusion (TLIF) combined with trans-pedicular screws fixation for management of selected cases of recurrent lumbar disc herniation. Overview of Literature Recurrent lumbar disc herniation is a major cause of surgical failure, occurring in 5%–11% of cases. The optimal technique for treatment is controversial. Some authors believe that repeated simple discectomy is the treatment of choice, but approach-related complications can be considerable. Other surgeons prefer more removal of posterior elements (as lamina and facet joints) with posterior fusion. Methods The study included 15 patients who presented with symptomatic recurrent lumbar disc herniation who underwent reoperation through posterior trans-pedicular screws and TLIF in our department from April 2008 to May 2010, with a 24-month follow-up. Japanese Orthopedic Association Scale (JOA) was used for low back pain. The results of surgery were also evaluated with the MacNab classification. Results The mean JOA score showed significant improvement, increasing from 9.5 before surgery to 24.0 at the end of follow-up (p<0.001). Clinical outcome was excellent in 7 patients (46% of cases), good in 6 patients (40%) and fair in only 2 patients (14%). There was a significant difference (p<0.05) between patients presenting with recurrent disc at the ipsilateral side and those at the contralateral side. Conclusions In spite of the small number of patients and the short follow-up period, the good clinical and radiological outcome achieved in this study encourage the belief that TLIF is an effective option for the treatment of selected cases of recurrent lumbar disc herniation. PMID:26949458

  5. 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

  6. Bilateral pulmonary emboli associated with intraoperative use of thrombin-based hemostatic matrix following lumbar spine interbody fusion.

    PubMed

    Wei, Zhikui; Elder, Benjamin D; Goodwin, C Rory; Witham, Timothy F

    2015-09-01

    Here we describe a patient with bilateral pulmonary emboli (PE) associated with thrombin-based hemostatic matrix (TBHM) use in the setting of a possible venous injury during transforaminal lumbar interbody fusion in the treatment of degenerative spondylolisthesis at L4-5. TBHM products are gelatin granules mixed with human or bovine thrombin. They have been used in a wide variety of surgical procedures to facilitate local hemostasis though their use is not without complications. This is the first reported patient, to our knowledge, with a TBHM-related PE following spinal fusion. As TBHM is a widely used intraoperative hemostatic agent, surgeons should be aware of the risk of TBHM-associated PE, particularly when there is the potential for intravascular injection or dissemination. While our experience indicates that common pharmacological prophylaxis such as subcutaneous heparin is likely ineffective in reducing occurrence of PE in the setting of TBHM use, the PE was successfully treated with standard systemic anticoagulation. The authors would also add that when iliac injury is encountered during discectomy or interbody fusion through a posterior approach, use of TBHM may be a life-saving technique. Postoperatively, vascular surgery consultation is recommended and consideration should be given to systemic anticoagulation. PMID:25943630

  7. Preliminary Results of Bioactive Amniotic Suspension with Allograft for Achieving One and Two-Level Lumbar Interbody Fusion

    PubMed Central

    Kerr, Eubulus J.; Utter, Philip A.; Cavanaugh, David A.; Frank, Kelly A.; Moody, Devan; McManus, Brian; Stone, Marcus B.

    2016-01-01

    Background Bone graft material for lumbar fusion was historically autologous bone graft (ABG). In recent years alternatives such as allograft, demineralized bone matrix (DBM), ceramics, and bone morphogenetic protein (BMP) have gained favor, although the complications of these are not fully understood. Bioactive amniotic suspension (BAS) with allograft is a new class of material derived from human amniotic tissue. Methods Eligible patients receiving a one or two level lumbar interbody fusion with Nucel, a BAS with allograft, were contacted and scheduled for a mininmim 12 month follow-up visit. Patients were evaluated for fusion using CT's and plain radiographs. Clincal outcomes, including ODI, VAS back and leg were collected, as well as comorbidities including BMI, smoking status, diabetes and previous lumbar surgery. Results One-level patients (N=38) were 71.1% female with mean age of 58.4 ± 12.7 and mean BMI of 30.6 ± 6.08. Two-level patients (N=34) were 58.8% female with mean age of 49.3 ±10.9 and mean BMI of 30.1 ± 5.82. Kinematic fusion was achieved in 97.4% of one-level patients and 100% of two-level patients. Baseline comorbidities were present in 89.5% of one-level patients and 88.2% of two-level patients. No adverse events related to BAS were reported in this study. Conclusion Fusion status is evaluated with many different biologics and varying methods in the literature. BAS with allograft in this study demonstrated high fusion rates with no complications within a largely comorbid population. Although a small population, BAS with allograft results were encouraging for one and two-level lumbar interbody fusion in this study. Further prospective studies should be conducted to investigate safety and efficacy in a larger population. PMID:27162714

  8. 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

  9. Vasculopathy, Ischemia, and the Lateral Lumbar Interbody Fusion Surgery: Report of Three Cases.

    PubMed

    Allison, David W; Allen, Richard T; Kohanchi, David D; Skousen, Collin B; Lee, Yu-Po; Gertsch, Jeffrey H

    2015-12-01

    Multi-modal neurophysiologic monitoring consisting of triggered and spontaneous electromyography and transcranial motor-evoked potentials may detect and prevent both acute and slow developing mechanical and vascular nerve injuries in lateral lumbar interbody fusion (LLIF) surgery. In case report 1, a marked reduction in the transcranial motor-evoked potentials on the operative side alerted to a 28% decrease in mean arterial blood pressure in a 54-year-old woman during an L3-4, L4-5 LLIF. After hemodynamic stability was regained, transcranial motor-evoked potentials returned to baseline and the patient suffered no postoperative complications. In case report 2, a peroneal nerve train-of-four stimulation threshold of 95 mA portended the potential for a triggered electromyography false negative in a 70-year-old woman with type 2 diabetes, peripheral neuropathy, and body mass index of 30.7 kg/m undergoing an L3-4, L4-5 LLIF. Higher triggered electromyography threshold values were applied to this patient's relatively quiescent triggered electromyography and the patient suffered no postoperative complications. In case report 3, the loss of right quadriceps motor-evoked potentials detected a retractor related nerve injury in a 59-year-old man undergoing an L4-5 LLIF. The surgery was aborted, but the patient suffered persistent postoperative right leg paresthesia and weakness. These reports highlight the sensitivity of peripheral nerve elements to ischemia (particularly in the presence of vascular risk factors) during the LLIF procedure and the need for dynamic multi-modal intraoperative monitoring. PMID:26629762

  10. Effect of Psychological Status on Outcome of Posterior Lumbar Interbody Fusion Surgery

    PubMed Central

    Lakkol, Sandesh; Budithi, Chakra; Bhatia, Chandra; Krishna, Manoj

    2012-01-01

    Study Design Prospective longitudinal study. Purpose To determine if preoperative psychological status affects outcome in spinal surgery. Overview of Literature Low back pain is known to have a psychosomatic component. Increased bodily awareness (somatization) and depressive symptoms are two factors that may affect outcome. It is possible to measure these components using questionnaires. Methods Patients who underwent posterior interbody fusion (PLIF) surgery were assessed preoperatively and at follow-up using a self-administered questionnaire. The visual analogue scale (VAS) for back and leg pain severity and the Oswestry Disability Index (ODI) were used as outcome measures. The psychological status of patients was classified into one of four groups using the Distress and Risk Assessment Method (DRAM); normal, at-risk, depressed somatic and distressed depressive. Results Preoperative DRAM scores showed 14 had no psychological disturbance (normal), 39 were at-risk, 11 distressed somatic, and 10 distressed depressive. There was no significant difference between the 4 groups in the mean preoperative ODI (analysis of variance, p = 0.426). There was a statistically and clinically significant improvement in the ODI after surgery for all but distressed somatic patients (9.8; range, -5.2 to 24.8; p = 0.177). VAS scores for all groups apart from the distressed somatic showed a statistically and clinically significant improvement. Our results show that preoperative psychological state affects outcome in PLIF surgery. Conclusions Patients who were classified as distressed somatic preoperatively had a less favorable outcome compared to other groups. This group of patients may benefit from formal psychological assessment before undergoing PLIF surgery. PMID:22977697

  11. 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

  12. 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

  13. Posterior convex release and interbody fusion for thoracic scoliosis: technical note.

    PubMed

    Mac-Thiong, Jean-Marc; Asghar, Jahangir; Parent, Stefan; Shufflebarger, Harry L; Samdani, Amer; Labelle, Hubert

    2016-09-01

    Anterior release and fusion is sometimes required in pediatric patients with thoracic scoliosis. Typically, a formal anterior approach is performed through open thoracotomy or video-assisted thoracoscopic surgery. The authors recently developed a technique for anterior release and fusion in thoracic scoliosis referred to as "posterior convex release and interbody fusion" (PCRIF). This technique is performed via the posterior-only approach typically used for posterior instrumentation and fusion and thus avoids a formal anterior approach. In this article the authors describe the technique and its use in 9 patients-to prevent a crankshaft phenomenon in 3 patients and to optimize the correction in 6 patients with a severe thoracic curve showing poor reducibility. After Ponte osteotomies at the levels requiring anterior release and fusion, intervertebral discs are approached from the convex side of the scoliosis. The annulus on the convex side of the scoliosis is incised from the lateral border of the pedicle to the lateral annulus while visualizing and protecting the pleura and spinal cord. The annulus in contact with the pleura and the anterior longitudinal ligament are removed before completing the discectomies and preparing the endplates. The PCRIF was performed at 3 levels in 4 patients and at 4 levels in 5 patients. Mean correction of the main thoracic curve, blood loss, and length of stay were 74.9%, 1290 ml, and 7.6 days, respectively. No neurological deficit, implant failure, or pseudarthrosis was observed at the last follow-up. Two patients had pleural effusion postoperatively, with 1 of them requiring placement of a chest tube. One patient had pulmonary edema secondary to fluid overload, while another patient underwent reoperation for a deep wound infection 3 weeks after the initial surgery. The technique is primarily indicated in skeletally immature patients with open triradiate cartilage and/or severe scoliosis. It can be particularly useful if there is

  14. Finite Element Analysis of a New Pedicle Screw-Plate System for Minimally Invasive Transforaminal Lumbar Interbody Fusion

    PubMed Central

    Zhou, Yue; Li, Changqing; Liu, Huan

    2015-01-01

    Purpose Minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) is increasingly popular for the surgical treatment of degenerative lumbar disc diseases. The constructs intended for segmental stability are varied in MI-TLIF. We adopted finite element (FE) analysis to compare the stability after different construct fixations using interbody cage with posterior pedicle screw-rod or pedicle screw-plate instrumentation system. Methods A L3–S1 FE model was modified to simulate decompression and fusion at L4–L5 segment. Fixation modes included unilateral plate (UP), unilateral rod (UR), bilateral plate (BP), bilateral rod (BR) and UP+UR fixation. The inferior surface of the S1 vertebra remained immobilized throughout the load simulation, and a bending moment of 7.5 Nm with 400N pre-load was applied on the L3 vertebra to recreate flexion, extension, lateral bending, and axial rotation. Range of motion (ROM) and Von Mises stress were evaluated for intact and instrumentation models in all loading planes. Results All reconstructive conditions displayed decreased motion at L4–L5. The pedicle screw-plate system offered equal ROM to pedicle screw-rod system in unilateral or bilateral fixation modes respectively. Pedicle screw stresses for plate system were 2.2 times greater than those for rod system in left lateral bending under unilateral fixation. Stresses for plate were 3.1 times greater than those for rod in right axial rotation under bilateral fixation. Stresses on intervertebral graft for plate system were similar to rod system in unilateral and bilateral fixation modes respectively. Increased ROM and posterior instrumentation stresses were observed in all loading modes with unilateral fixation compared with bilateral fixation in both systems. Conclusions Transforaminal lumbar interbody fusion augmentation with pedicle screw-plate system fixation increases fusion construct stability equally to the pedicle screw-rod system. Increased posterior

  15. Lateral Pressure and VAS Pain Score Analysis for the Lateral Lumbar Interbody Fusion Procedure

    PubMed Central

    2015-01-01

    Background The lateral lumbar interbody fusion (LLIF) procedure is a minimally invasive procedure that has become widely utilized. The LLIF procedure typically involves bending the table to access the disc spaces of interest due to anatomical constraints. It is unknown if this bending process is painful or what pressures are exhibited on the downside part of the body. The goal of the study was to determine whether sex, height, weight, body mass index, bed angle, or positioning relative to the break of the bed affects the downside skin pressures and VAS pain scores in awake volunteers. Methods Fifty-six volunteers were placed in the lateral decubitus position and pressure sensors were placed at the downside part of their anatomy (shoulder, T10 rib , iliac crest, and greater trochanter). The pressures were checked with the iliac crest or greater trochanter at 0, 10, 20, 30, 40 degree bed angles. VAS scores were checked when the iliac crest or greater trochanter were at the maximum bed break angles. Results A significant positive association was found between increased bed angle and pressure at all five areas on the downside body locations (p<0.0001). The greatest pressures were located at the iliac crest and greater trochanter when these specific locations were centered over the break of the bed (p<0.0001). When the iliac crest was placed at maximal bed break, each unit increase in BMI increased the VAS pain by 0.13 (p<0.0001)and men had 1.96 (p=0.0009)higher VAS scores then women. When the greater trochanter was placed at the maximal bed break, each unit increase in BMI decreased VAS pain by 0.19 (p<0.0001) and women had 1.55 (p=0.0002)higher VAS pain scores then men. Conclusions In awake volunteers, the pressure at the iliac crest or greater trochanter at the break of the bed increases by increasing the bed angle. Women with a lower BMI had high VAS pain scores when their greater trochanter was at maximal bed break. Men with higher BMI had high VAS pain scores when

  16. The influence of cage positioning and cage type on cage migration and fusion rates in patients with monosegmental posterior lumbar interbody fusion and posterior fixation

    PubMed Central

    Abbushi, Alexander; Čabraja, Mario; Thomale, Ulrich-Wilhelm; Woiciechowsky, Christian

    2009-01-01

    In posterior lumbar interbody fusion, cage migrations and lower fusion rates compared to autologous bone graft used in the anterior lumbar interbody fusion procedure are documented. Anatomical and biomechanical data have shown that the cage positioning and cage type seem to play an important role. Therefore, the aim of the present study was to evaluate the impact of cage positioning and cage type on cage migration and fusion. We created a grid system for the endplates to analyze different cage positions. To analyze the influence of the cage type, we compared “closed” box titanium cages with “open” box titanium cages. This study included 40 patients with 80 implanted cages. After pedicle screw fixation, 23 patients were treated with a “closed box” cage and 17 patients with an “open box” cage. The follow-up period averaged 25 months. Twenty cages (25%) showed a migration into one vertebral endplate of <3 mm and four cages (5%) showed a migration of ≥3 mm. Cage migration was highest in the medio-medial position (84.6%), followed by the postero-lateral (42.9%), and the postero-medial (16%) cage position. Closed box cages had a significantly higher migration rate than open box cages, but fusion rates did not differ. In conclusion, cage positioning and cage type influence cage migration. The medio-medial cage position showed the highest migration rate. Regarding the cage type, open box cages seem to be associated with lower migration rates compared to closed box cages. However, the cage type did not influence bone fusion. PMID:19475436

  17. [Three-dimensional Finite Element Analysis of Biomechanical Effect of Rigid Fixation and Elastic Fixation on Lumbar Interbody Fusion].

    PubMed

    Wei, Jiangbo; Song, Yueming; Liu, Limin; Zhou, Chunguan; Yang, Xi

    2015-04-01

    This study was aimed to compare the mechanical characteristics under different physiological load conditions with three-dimensional finite element model of rigid fixation and elastic fixation in the lumbar. We observed the stress distribution characteristics of a sample of healthy male volunteer modeling under vertical, flexion and extension torque situation. The outcomes showed that there existed 4-6 times pressure on the connecting rod of rigid fixation compared with the elastic fixations under different loads, and the stress peak and area of force on elastic fixation were much higher than that of the rigid fixations. The elastic fixation has more biomechanical advantages than rigid fixation in promoting interbody lumbar fusion after surgery. PMID:26211247

  18. 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

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

    PubMed Central

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

    2014-01-01

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

  20. Modeled cost-effectiveness of transforaminal lumbar interbody fusion compared with posterolateral fusion for spondylolisthesis using N(2)QOD data.

    PubMed

    Carreon, Leah Y; Glassman, Steven D; Ghogawala, Zoher; Mummaneni, Praveen V; McGirt, Matthew J; Asher, Anthony L

    2016-06-01

    OBJECTIVE Transforaminal lumbar interbody fusion (TLIF) has become the most commonly used fusion technique for lumbar degenerative disorders. This suggests an expectation of better clinical outcomes with this technique, but this has not been validated consistently. How surgical variables and choice of health utility measures drive the cost-effectiveness of TLIF relative to posterolateral fusion (PSF) has not been established. The authors used health utility values derived from Short Form-6D (SF-6D) and EQ-5D and different cost-effectiveness thresholds to evaluate the relative cost-effectiveness of TLIF compared with PSF. METHODS From the National Neurosurgery Quality and Outcomes Database (N(2)QOD), 101 patients with spondylolisthesis who underwent PSF were propensity matched to patients who underwent TLIF. Health-related quality of life measures and perioperative parameters were compared. Because health utility values derived from the SF-6D and EQ-5D questionnaires have been shown to vary in patients with low-back pain, quality-adjusted life years (QALYs) were derived from both measures. On the basis of these matched cases, a sensitivity analysis for the relative cost per QALY of TLIF versus PSF was performed in a series of cost-assumption models. RESULTS Operative time, blood loss, hospital stay, and 30-day and 90-day readmission rates were similar for the TLIF and PSF groups. Both TLIF and PSF significantly improved back and leg pain, Oswestry Disability Index (ODI) scores, and EQ-5D and SF-6D scores at 3 and 12 months postoperatively. At 12 months postoperatively, patients who had undergone TLIF had greater improvements in mean ODI scores (30.4 vs 21.1, p = 0.001) and mean SF-6D scores (0.16 vs 0.11, p = 0.001) but similar improvements in mean EQ-5D scores (0.25 vs 0.22, p = 0.415) as patients treated with PSF. At a cost per QALY threshold of $100,000 and using SF-6D-based QALYs, the authors found that TLIF would be cost-prohibitive compared with PSF at a

  1. Biomechanical comparison of a new stand-alone anterior lumbar interbody fusion cage with established fixation techniques – a three-dimensional finite element analysis

    PubMed Central

    Chen, Shih-Hao; Tai, Ching-Lung; Lin, Chien-Yu; Hsieh, Pang-Hsing; Chen, Weng-Pin

    2008-01-01

    Background Initial promise of a stand-alone interbody fusion cage to treat chronic back pain and restore disc height has not been realized. In some instances, a posterior spinal fixation has been used to enhance stability and increase fusion rate. In this manuscript, a new stand-alone cage is compared with conventional fixation methods based on the finite element analysis, with a focus on investigating cage-bone interface mechanics and stress distribution on the adjacent tissues. Methods Three trapezoid 8° interbody fusion cage models (dual paralleled cages, a single large cage, or a two-part cage consisting of a trapezoid box and threaded cylinder) were created with or without pedicle screws fixation to investigate the relative importance of the screws on the spinal segmental response. The contact stress on the facet joint, slip displacement of the cage on the endplate, and rotational angle of the upper vertebra were measured under different loading conditions. Results Simulation results demonstrated less facet stress and slip displacement with the maximal contact on the cage-bone interface. A stand-alone two-part cage had good slip behavior under compression, flexion, extension, lateral bending and torsion, as compared with the other two interbody cages, even with the additional posterior fixation. However, the two-part cage had the lowest rotational angles under flexion and torsion, but had no differences under extension and lateral bending. Conclusion The biomechanical benefit of a stand-alone two-part fusion cage can be justified. This device provided the stability required for interbody fusion, which supports clinical trials of the cage as an alternative to circumferential fixations. PMID:18559117

  2. 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.

  3. 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

  4. Postoperative Cyst Associated with Bone Morphogenetic Protein Use in Posterior and Transforaminal Lumbar Interbody Fusion Managed Conservatively: Report of Two Cases

    PubMed Central

    Mejía, Diana M; Drazin, Doniel; Anand, Neel

    2016-01-01

    Bone morphogenetic protein use in spinal surgery for off-label indications continues to remain popular. One area where its use has known associated radicular complications is posterior or transforaminal lumbar interbody fusion. These complications include radiculitis, cyst development, and heterotopic ossification, amongst others. Typically, cyst development has been treated surgically. We present two cases of bone morphogenetic protein-related cysts treated medically and thus, present medical treatment as an alternative treatment option. PMID:27014519

  5. Endoscopic minimally invasive transforaminal interbody fusion without general anesthesia: initial clinical experience with 1-year follow-up.

    PubMed

    Wang, Michael Y; Grossman, Jay

    2016-02-01

    OBJECTIVE One of the principal goals of minimally invasive surgery has been to speed postoperative recovery. In this case series, the authors used an endoscopic technique for interbody fusion combined with percutaneous screw fixation to obviate the need for general anesthesia. METHODS The first 10 consecutive patients treated with a minimum of 1 year's follow-up were included in this series. The patients were all treated using endoscopic access through Kambin's triangle to allow for neural decompression, discectomy, endplate preparation, and interbody fusion. This was followed by percutaneous pedicle screw and connecting rod placement using liposomal bupivacaine for long-acting analgesia. No narcotics or regional anesthetics were used during surgery. RESULTS All patients underwent the procedure successfully without conversion to open surgery. The patients' average age was 62.2 ± 9.0 years (range 52-78 years). All patients had severe disc height collapse, and 60% had a Grade I spondylolisthesis. The mean operative time was 113.5 ± 6.3 minutes (range 105-120 minutes), and blood loss was 65 ± 38 ml (range 30-190 ml). The mean length of hospital stay was 1.4 ± 1.3 nights. There were no intraoperative or postoperative complications. Comparison of preoperative and final clinical metrics demonstrated that the Oswestry Disability Index improved from 42 ± 11.8 to 13.3 ± 15.1; the 36-Item Short Form Health Survey (SF-36) Physical Component Summary improved from 47.6 ± 3.8 to 49.7 ± 5.4; the SF-36 Mental Component Summary decreased from 47 ± 3.9 to 46.7 ± 3.4; and the EQ-5D improved from 10.7 ± 9.5 to 14.2 ± 1.6. There were no cases of nonunion identified radiographically on follow-up imaging. CONCLUSIONS Endoscopic fusion under conscious sedation may represent a feasible alternative to traditional lumbar spine fusion in select patients. Larger clinical series are necessary to validate that clinical improvements are sustained and that arthrodesis rates are

  6. 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. PMID:25415482

  7. 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. PMID:17415762

  8. 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

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

    PubMed Central

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

    2012-01-01

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

  10. The anatomic rationale for transforaminal endoscopic interbody fusion: a cadaveric analysis.

    PubMed

    Hardenbrook, Mitchell; Lombardo, Sergio; Wilson, Miles C; Telfeian, Albert E

    2016-02-01

    OBJECTIVE The authors describe a cadaveric analysis to determine the ideal dimensions and trajectory for considering endoscopic transforaminal interbody implantation. METHODS The soft tissues of 8 human cadavers were removed from L-1 to the sacrum, exposing the posterior bony elements. Facetectomies were performed bilaterally at each lumbar level with resection of the pars interarticularis, revealing the pedicles, nerve roots, and interbody disc space. Each level was digitally photographed with a marker for scale and evaluated with digital analysis software. The traversing and exiting nerve roots and pedicle margins were identified, and the distances between these structures and their relationships to the surrounding structures were documented. RESULTS The dimensions of 2 areas were measured: the working triangle and safe zone. The working triangle is the triangle between the exiting and traversing nerve roots above the superior margin of the inferior pedicle. The safe zone is the trapezoid bounded by the widths of the superior and inferior pedicles between the exiting and traversing nerve roots. The mean surface area for the working triangle was 1.83 cm(2), with L5-S1 having the largest area at 2.19 cm(2). The mean surface area of the safe zone was 1.19 cm(2), with L5-S1 having the largest area at 1.26 cm(2). At the medial border of the pedicle extending superiorly, there were no nerve structures within 1.19 cm at any level. On the lateral border of the pedicle, the exiting nerve root was closer superiorly, with the closest being 0.3 cm. CONCLUSIONS The working triangle is a relatively large area. The safe zone, just superior to the pedicle, is free of nerve structures. By utilizing the superior border of the pedicle, the disc space can be accessed within this safe zone without risk of injury to the nerves. A thorough understanding of foraminal anatomy is fundamental for considering how to safely access the disc space, thereby utilizing less invasive endoscopic

  11. Minimally invasive trans-sacral approach to L5-S1 interbody fusion: Preliminary results from 1 center and review of the literature

    PubMed Central

    Bradley, W. Daniel; Hisey, Michael S.; Verma-Kurvari, Sunita; Ohnmeiss, Donna D.

    2012-01-01

    Background Lumbar interbody fusion has long been used for the treatment of painful degenerative spinal conditions. The anterior approach is not feasible in some patients, and the posterior approach is associated with a risk of neural complications and possibly muscle injury. A trans-sacral technique was developed that allows access to the L5-S1 disc space. The purposes of this study were to investigate the clinical outcome of trans-sacral interbody fusion in a consecutive series of patients from 1 center and to perform a comprehensive review of the literature on this procedure. Methods A literature search using PubMed was performed to identify articles published on trans-sacral axial lumbar interbody fusion (AxiaLIF). Articles reviewed included biomechanical testing, feasibility of the technique, and clinical results. The data from our center were collected retrospectively from charts for the consecutive series, beginning with the first case, of all patients undergoing fusion using the AxiaLIF technique. In most cases, posterior instrumentation was also used. A total of 41 patients with at least 6 months’ follow-up were included (mean follow-up, 22.2 months). The primary clinical outcome measures were visual analog scales separately assessing back and leg pain and the Oswestry Disability Index. Radiographic assessment of fusion was also performed. Results In the group of 28 patients undergoing single-level AxiaLIF combined with posterior fusion, the visual analog scale scores assessing back and leg pain and mean Oswestry Disability Index scores improved significantly (P < .01). In the remaining 13 patients, back pain improved significantly with a trend for improvement in leg pain. Reoperation occurred in 19.5% of patients; in half of these, reoperation was not related to the anterior procedure. Conclusions A review of the literature found that the AxiaLIF technique was similar to other fusion techniques with respect to biomechanical properties and produced

  12. 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 insertion of an expandable or a standard rigid interbody implant for patients with degenerative disk disease with or without spondylolisthesis and for revision surgery. 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 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 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 discharge was faster compared to standard TLIF (26 hours vs. 9.3 days). PMID:26484004

  13. 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

  14. Long-Term Follow-Up Results of Anterior Cervical Inter-Body Fusion with Stand-Alone Cages

    PubMed Central

    Kim, Woong-Beom; Choi, Hoyong; Kim, Ki-Jeong; Jahng, Tae-Ahn; Kim, Hyun-Jib

    2016-01-01

    Objective The purpose of this study was to evaluate long-term follow-up radiologic/clinical outcomes of patients who underwent anterior cervical discectomy and inter-body fusion (ACDF) with stand-alone cages (SAC) in a single academic institution. Methods Total 99 patients who underwent ACDF with SAC between February 2004 and December 2012 were evaluated retrospectively. A total of 131 segments were enrolled in this study. Basic demographic information, radiographic [segmental subsidence rate, fusion rate, C2–7 global angle, and segmental angle changes)/clinical outcomes (by Odom's criteria and visual analog score (VAS)] and complications were evaluated to determine the long-term outcomes. Results The majority were males (55 vs. 44) with average age of 53.2. Mean follow-up period was 62.9 months. The segmental subsidence rate was 53.4% and fusion rate was 73.3%. In the subsidence group, anterior intervertebral height (AIH) had more tendency of subsiding than middle or posterior intervertebral height (p=0.01). The segmental angle led kyphotic change related to the subsidence of the AIH. Adjacent segmental disease was occurred in 18 (18.2%) patients. Total 6 (6%) reoperations were performed at the index level. There was no statistical significance between clinical and radiological outcomes. But, overall long-term clinical outcome by Odom's criteria was unsatisfactory (64.64%). The neck and arm VAS score were increased by over time. Conclusion Long-term outcomes of ACDF with SAC group were acceptable but not satisfactory. For optimal decision making, more additional comparative long-term outcome data is needed between ACDF with SAC and ACDF with plating. PMID:27446521

  15. Neurological Complications after Lateral Transpsoas Approach to Anterior Interbody Fusion with a Novel Flat-Blade Spine-Fixed Retractor

    PubMed Central

    Nunley, Pierce; Sandhu, Faheem; Frank, Kelly; Stone, Marcus

    2016-01-01

    Introduction. The lateral lumbar interbody fusion (LLIF) surgical approach has potential advantages over other approaches but is associated with some unique neurologic risks due to the proximity of the lumbosacral plexus. The present study analyzed complications following LLIF surgical approach using a novel single flat-blade retractor system. Methods. A retrospective data collection of patients receiving LLIF using a novel single flat-blade retractor system at two institutions in the US. Inclusion criteria were all patients receiving an LLIF procedure with the RAVINE® Lateral Access System (K2M, Inc., Leesburg, VA, USA). There was no restriction on preoperative diagnosis or number of levels treated. Approach-related neurologic complications were collected and analyzed postoperatively through a minimum of one year. Results. Analysis included 253 patients with one to four treated lateral levels. Immediate postoperative neurologic complications were present in 11.1% (28/253) of patients. At one-year follow-up the approach-related neurologic complications resolved in all except 5 patients (2.0%). Conclusion. We observed an 11.1% neurologic complication rate in LLIF procedures. There was resolution of symptoms for most patients by 12-month follow-up, with only 2% of patients with residual symptoms. This supports the hypothesis that the vast majority of approach-related neurologic symptoms are transient. PMID:27294140

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

    PubMed Central

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

    2014-01-01

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

  17. Clinical outcomes of single-level lumbar artificial disc replacement compared with transforaminal lumbar interbody fusion in an Asian population

    PubMed Central

    Lee, Wei Ting; Liu, Gabriel; Thambiah, Joseph; Wong, Hee Kit

    2015-01-01

    INTRODUCTION The objective of this study was to examine the clinical outcome of single-level lumbar artificial disc replacement (ADR) compared to that of transforaminal lumbar interbody fusion (TLIF) for the treatment of symptomatic degenerative disc disease (DDD) in an Asian population. METHODS This was a retrospective review of 74 patients who had surgery performed for discogenic lower backs that involved only the L4/5 and L5/S1 levels. All the patients had lumbar DDD without radiculopathy or spondylolithesis, and concordant pain with discogram at the pathological level. The patients were divided into two groups – those who underwent ADR and those who underwent TLIF. RESULTS A trend suggesting that the ADR group had better perioperative outcomes (less blood loss, shorter operating time, shorter hospital stay and shorter time to ambulation) than the TLIF group was observed. However, a trend indicating that surgical-approach-related complications occurred more frequently in the ADR group than the TLIF group was also observed. The rate of revision surgery was comparable between the two groups. CONCLUSION Our findings suggest that for the treatment of discogenic lower back pain, lumbar ADR has better perioperative outcomes and a similar revision rate when compared with TLIF. However, the use of ADR was associated with a higher incidence of surgical-approach-related complications. More studies with bigger cohort sizes and longer follow-up periods are needed to determine the long-term efficacy and safety of ADR in lumbar DDD. PMID:25917472

  18. Neurological Complications after Lateral Transpsoas Approach to Anterior Interbody Fusion with a Novel Flat-Blade Spine-Fixed Retractor.

    PubMed

    Nunley, Pierce; Sandhu, Faheem; Frank, Kelly; Stone, Marcus

    2016-01-01

    Introduction. The lateral lumbar interbody fusion (LLIF) surgical approach has potential advantages over other approaches but is associated with some unique neurologic risks due to the proximity of the lumbosacral plexus. The present study analyzed complications following LLIF surgical approach using a novel single flat-blade retractor system. Methods. A retrospective data collection of patients receiving LLIF using a novel single flat-blade retractor system at two institutions in the US. Inclusion criteria were all patients receiving an LLIF procedure with the RAVINE® Lateral Access System (K2M, Inc., Leesburg, VA, USA). There was no restriction on preoperative diagnosis or number of levels treated. Approach-related neurologic complications were collected and analyzed postoperatively through a minimum of one year. Results. Analysis included 253 patients with one to four treated lateral levels. Immediate postoperative neurologic complications were present in 11.1% (28/253) of patients. At one-year follow-up the approach-related neurologic complications resolved in all except 5 patients (2.0%). Conclusion. We observed an 11.1% neurologic complication rate in LLIF procedures. There was resolution of symptoms for most patients by 12-month follow-up, with only 2% of patients with residual symptoms. This supports the hypothesis that the vast majority of approach-related neurologic symptoms are transient. PMID:27294140

  19. Hemothorax caused by the trocar tip of the rod inserter after minimally invasive transforaminal lumbar interbody fusion: case report.

    PubMed

    Maruo, Keishi; Tachibana, Toshiya; Inoue, Shinichi; Arizumi, Fumihiro; Yoshiya, Shinichi

    2016-03-01

    Minimally invasive surgery (MIS) for transforaminal lumbar interbody fusion (MIS-TLIF) is widely used for lumbar degenerative diseases. In the paper the authors report a unique case of a hemothorax caused by the trocar tip of the rod inserter after MIS-TLIF. A 61-year-old woman presented with thigh pain and gait disturbance due to weakness in her lower right extremity. She was diagnosed with a lumbar disc herniation at L1-2 and the MIS-TLIF procedure was performed. Immediately after surgery, the patient's thigh pain resolved and she remained stable with normal vital signs. The next day after surgery, she developed severe anemia and her hemoglobin level decreased to 7.6 g/dl, which required blood transfusions. A chest radiograph revealed a hemothorax. A CT scan confirmed a hematoma of the left paravertebral muscle. A chest tube was placed to treat the hemothorax. After 3 days of drainage, there was no active bleeding. The patient was discharged 14 days after surgery without leg pain or any respiratory problems. This complication may have occurred due to injury of the intercostal artery by the trocar tip of the rod inserter. A hemothorax after spine surgery is a rare complication, especially in the posterior approach. The rod should be caudally inserted in the setting of the thoracolumbar spine. PMID:26588499

  20. 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

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

    2009-02-01

    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

  1. 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

  2. Impact on Neurological Recovery of Transforaminal Debridement and Interbody Fusion versus Transpedicular Decompression in Combination with Pedicle Screw Instrumentation for Treating Thoracic and Lumbar Spinal Tuberculosis

    PubMed Central

    Choovongkomol, Kongtush; Piyapromdee, Urawit; Leownorasate, Manoon

    2016-01-01

    Study Design Retrospective study. Purpose To compare the neurological outcome of transforaminal debridement and interbody fusion with transpedicular decompression for treatment of thoracic and lumbar spinal tuberculosis. Overview of Literature Few articles have addressed the impact of neurological recovery in patients with tuberculosis who were treated by two different operative methods via the posterior-only approach. Methods Clinical and radiographic results of one-stage posterior instrumented spinal fusion for treatment of tuberculous spondylodiscitis with neurological deficits were reviewed and analyzed from 2009 to 2013. The extensive (E) group consisted of patients who received transforaminal debridement and interbody fusion, whereas transpedicular decompression was performed on limited (L) group. Rapid recovery was improvement of at least one Frankel grade within 6 weeks after operation. Otherwise, it was slow recovery. Results All 39 patients had improved neurological signs. The median follow-up period was 24 months. Proportionately younger patients (under 65 years of age) received extensive surgery (15 of 18, 83.3% vs. 11 of 21, 52.4%; p=0.04). The mean operative time and blood loss in the group E were higher than in the group L (both p<0.01). With regard to type of procedure, especially at thoracic and thoracolumbar spine, patients who underwent extensive surgery had rapid neurological recovery significantly different from those of limited surgery (p=0.01; Relative Risk, 3.06; 95% Confidence Interval, 1.13 to 8.29). Conclusions Transforaminal debridement and interbody fusion provides more rapid neurological recovery in patients with thoracic and thoracolumbar spinal tuberculosis compared to transpedicular decompression. PMID:27340536

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

    PubMed Central

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

    2014-01-01

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

  4. Do obese patients have worse outcomes after direct lateral interbody fusion compared to non-obese patients?

    PubMed

    Adogwa, Owoicho; Farber, S Harrison; Fatemi, Parastou; Desai, Rupen; Elsamadicy, Aladine; Cheng, Joseph; Bagley, Carlos; Gottfried, Oren; Isaacs, Robert E

    2016-03-01

    Obese patients undergoing lumbar spinal fusion surgery are a challenge to the operating surgeon. Direct lateral interbody fusion (DLIF) has been performed for degenerative disease of the lumbar spine with good outcomes; nevertheless, how obese patients fare compared to non-obese patients after DLIF remains unknown. The primary aim of this study is to compare rates of postoperative complications and long-term outcomes between obese and non-obese patients undergoing DLIF. Sixty-three patients (obese: 29, non-obese: 34) undergoing index DLIF for degenerative disease of the spine between 2010 and 2012 at our institution were retrospectively enrolled. We analyzed data on demographics, postoperative complications, back and leg pain, and functional disability over 2 years. Patients completed the Oswestry Disability Index (ODI) and Visual Analog Scale (VAS) back and leg pain numerical rating scores before surgery, then at 12 and 24 months after surgery. Outcomes and complication rates were compared between the cohorts. The cohorts were similar at baseline. Postoperative complications rates were similar between obese and non-obese patients. There was no statistically significant difference in the incidence of durotomy (p=0.91), anterior thigh numbness (p=0.60), cerebrospinal fluid leak (p=0.91), postoperative infection (p=0.37), or bleeding requiring transfusion (p=0.16). No patient experienced a nerve injury or psoas hematoma. Both cohorts had similar 2 year improvement in VAS for back pain, leg pain, and ODI. Our study demonstrates that obese and non-obese patients undergoing DLIF have similar complication profiles; hence, a patient's weight should not be a contraindication to DLIF. PMID:26549673

  5. Prevalence and Risk Factors of Deep Vein Thrombosis in Patients Undergoing Lumbar Interbody Fusion Surgery: A Single-Center Cross-Sectional Study.

    PubMed

    Yang, Si-Dong; Ding, Wen-Yuan; Yang, Da-Long; Shen, Yong; Zhang, Ying-Ze; Feng, Shi-Qing; Zhao, Feng-Dong

    2015-12-01

    This cross-sectional study was designed to obtain the current prevalence of deep vein thrombosis (DVT) and analyze related risk factors in patients undergoing lumbar interbody fusion. Medical record data were collected from Department of Spinal Surgery, The Third Hospital of Hebei Medical University, between July 2014 and March 2015. Both univariate analysis and binary logistic regression analysis were performed to determine risk factors for DVT. A total of 995 patients were admitted into this study, including 484 men and 511 women, aged from 14 to 89 years old (median 50, IQR 19). The detection rate of lower limb DVT by ultrasonography was 22.4% (223/995) in patients undergoing lumbar interbody fusion. Notably, average VAS (visual analog scale) score in the first 3 days after surgery in the DVT group was more than that in the non-DVT group (Z = -21.69, P < 0.001). The logistic regression model was established as logit P = -13.257 + 0.056*X1 - 0.243*X8 + 2.085*X10 + 0.001*X12, (X1 = age; X8 = HDL; X10 = VAS; X12 = blood transfusion; x = 677.763, P < 0.001). In conclusion, advanced age, high postoperative VAS scores, and blood transfusion were risk factors for postoperative lower limb DVT. As well, the logistic regression model may contribute to an early evaluation postoperatively to ascertain the risk of lower limb DVT in patients undergoing lumbar interbody fusion surgery. PMID:26632909

  6. Surgeons' Exposure to Radiation in Single- and Multi-Level Minimally Invasive Transforaminal Lumbar Interbody Fusion; A Prospective Study

    PubMed Central

    Funao, Haruki; Ishii, Ken; Momoshima, Suketaka; Iwanami, Akio; Hosogane, Naobumi; Watanabe, Kota; Nakamura, Masaya; Toyama, Yoshiaki; Matsumoto, Morio

    2014-01-01

    Although minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) has widely been developed in patients with lumbar diseases, surgeons risk exposure to fluoroscopic radiation. However, to date, there is no studies quantifying the effective dose during MIS-TLIF procedure, and the radiation dose distribution is still unclear. In this study, the surgeons' radiation doses at 5 places on the bodies were measured and the effective doses were assessed during 31 consecutive 1- to 3-level MIS-TLIF surgeries. The operating surgeon, assisting surgeon, and radiological technologist wore thermoluminescent dosimeter on the unshielded thyroid, chest, genitals, right middle finger, and on the chest beneath a lead apron. The doses at the lens and the effective doses were also calculated. Mean fluoroscopy times were 38.7, 53.1, and 58.5 seconds for 1, 2, or 3 fusion levels, respectively. The operating surgeon's mean exposures at the lens, thyroid, chest, genitals, finger, and the chest beneath the shield, respectively, were 0.07, 0.07, 0.09, 0.14, 0.32, and 0.05 mSv in 1-level MIS-TLIF; 0.07, 0.08, 0.09, 0.18, 0.34, and 0.05 mSv in 2-level; 0.08, 0.09, 0.14, 0.15, 0.36, and 0.06 mSv in 3-level; and 0.07, 0.08, 0.10, 0.15, 0.33, and 0.05 mSv in all cases. Mean dose at the operating surgeon's right finger was significantly higher than other measurements parts (P<0.001). The operating surgeon's effective doses (0.06, 0.06, and 0.07 mSv for 1, 2, and 3 fusion levels) were low, and didn't differ significantly from those of the assisting surgeon or radiological technologist. Revision MIS-TLIF was not associated with higher surgeons' radiation doses compared to primary MIS-TLIF. There were significantly higher surgeons' radiation doses in over-weight than in normal-weight patients. The surgeons' radiation exposure during MIS-TLIF was within the safe level by the International Commission on Radiological Protection's guidelines. The accumulated radiation exposure, especially to

  7. 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

  8. 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

  9. Autogenous bone marrow stromal cell sheets-loaded mPCL/TCP scaffolds induced osteogenesis in a porcine model of spinal interbody fusion.

    PubMed

    Abbah, Sunny A; Lam, Christopher X F; Ramruttun, Kumarsing A; Goh, James C H; Wong, Hee-Kit

    2011-03-01

    This study was designed to investigate whether a tissue-engineered construct composed of autogenous cell sheets and a polycaprolactone-based bioresorbable scaffold would enhance bone regeneration and spinal interbody fusion in a large animal model. Porcine-derived autogenous bone marrow stromal cells (BMSCs) cultured into multilayered cell sheets were induced into osteogenic differentiation with dexamethasone, l-ascorbic acid, and β-glycerol phosphate. These cell sheets were assembled with bioresorbable scaffolds made from medical-grade poly(epsilon-caprolactone) incorporating 20% β-tricalcium phosphate (mPCL/TCP) as tissue-engineered BMSC constructs. L2/3, L4/5 discectomies and decortication of the vertebral end plates were performed on 16 SPF Yorkshire pigs through an anterolateral approach. The tissue-engineered BMSC constructs were transplanted into the prepared intervertebral disc spaces of half of the pigs (n = 8), whereas cell-free mPCL/TCP served as controls in the remaining pigs. New bone formation and spinal fusion were evaluated at 3 and 6 months using microcomputed tomography, histology, fluorochrome bone labeling, and biomechanical testing. New bone formation was evident as early as 3 months in the BMSC group. At 6 months, bony fusion was observed in >60% (5/8) of segments in the BMSC group. None of the control animals with cell-free scaffold showed fusion at both time points. Biomechanical evaluation further revealed a significantly increased segmental stability in the BMSC group compared with the cell-free group at 6 months postimplantation (p < 0.01). These findings suggest that mPCL/TCP scaffolds loaded with in vitro differentiated autogenous BMSC sheets could induce bone formation and interbody fusion. This in turn resulted in enhanced segmental stability of the lumbar spine. PMID:20973747

  10. 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

  11. 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

  12. Load- and displacement-controlled finite element analyses on fusion and non-fusion spinal implants.

    PubMed

    Zhong, Z-C; Chen, S-H; Hung, C-H

    2009-02-01

    This study used finite element (FE) analysis with the load-controlled method (LCM) and the displacement-controlled method (DCM) to examine motion differences at the implant level and adjacent levels between fusion and non-fusion implants. A validated three-dimensional intact (INT) L1-L5 FE model was used. At the L3-L4 level, the INT model was modified to surgery models, including the artificial disc replacement (ADR) of ProDisc II, and the anterior lumbar interbody fusion (ALIF) cage with pedicle screw fixation. The LCM imposed 10 Nm moments of four physiological motions and a 150 N preload at the top of L1. The DCM process was in accordance with the hybrid testing protocol. The average percentage changes in the range of motion (ROM) for whole non-operated levels were used to predict adjacent level effects (ALE%). At the implant level, the ALIF model showed similar stability with both control methods. The ADR model using the LCM had a higher ROM than the model using the DCM, especially in extension and torsion. At the adjacent levels, the ALIF model increased ALE% (at least 17 per cent) using the DCM compared with the LCM. The ADR model had an ALE% close to that of the INT model, using the LCM (average within 6 per cent), while the ALE% decreased when using the DCM. The study suggests that both control methods can be adopted to predict the fusion model at the implant level, and similar stabilization characteristics can be found. The LCM will emphasize the effects of the non-fusion implants. The DCM was more clinically relevant in evaluating the fusion model at the adjacent levels. In conclusion, both the LCM and the DCM should be considered in numerical simulations to obtain more realistic data in spinal implant biomechanics. PMID:19278192

  13. 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. PMID:25703640

  14. 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

  15. 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

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

    PubMed Central

    Raskin, Yannic

    2015-01-01

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

  17. Septic hematogenous lumbar spondylodiscitis in elderly patients with multiple risk factors: efficacy of posterior stabilization and interbody fusion with iliac crest bone graft

    PubMed Central

    Mater, Eckhardt; Schön, Ralph

    2010-01-01

    The conservative and operative treatment strategies of hematogenous spondylodiscitis in septic patients with multiple risk factors are controversial. The present series demonstrates the outcome of 18 elderly patients (median age, 72 years) with septic hematogenous spondylodiscitis and intraspinal abscess treated with microsurgical decompression and debridement of the infective tissue, followed by posterior stabilization and interbody fusion with iliac crest bone graft in one or two lumbar segments. The majority of the patients were unsuccessfully treated with intravenous antibiotics prior to the operation. Antibiotic therapy was continued for more than 6 weeks postoperatively. Morbidity and early mortality amounted to 50 and 17%, respectively. Three patients died in the hospital from internal complications after an initial postoperative improvement of the inflammatory clinical signs and laboratory parameters. Fifteen patients recovered from the spinal infection. Three of them died several months after discharge (cerebral hemorrhage, malignancy and unknown cause). Twelve patients had excellent or good outcomes during the follow-up period of at least 1 year. The series shows that operative decompression and eradication of the intraspinal and intervertebral infective tissue with fusion and stabilization via a posterior approach is possible in septic patients with multiple risk factors and leads to good results in those patients, who survive the initial severe stage of the septic disease. However, the morbidity and mortality suggest that this surgical treatment is not the therapy of first choice in high-risk septic patients, but may be considered in patients when conservative management has failed. PMID:20495933

  18. 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. PMID:19540586

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

    PubMed Central

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

    2015-01-01

    Purpose This study aims to compare the biomechanical properties of the novel pedicle screw and plate system with the traditional rod system in asymmetrical posterior stabilization for minimally invasive transforaminal lumbar interbody fusion (MI-TLIF). We compared the immediate stabilizing effects of fusion segment and the strain distribution on the vertebral body. Methods Seven fresh calf lumbar spines (L3-L6) were tested. Flexion/extension, lateral bending, and axial rotation were induced by pure moments of ± 5.0 Nm and the range of motion (ROM) was recorded. Strain gauges were instrumented at L4 and L5 vertebral body to record the strain distribution under flexion and lateral bending (LB). After intact kinematic analysis, a right sided TLIF was performed at L4-L5. Then each specimen was tested for the following constructs: unilateral pedicle screw and rod (UR); unilateral pedicle screw and plate (UP); UR and transfacet pedicle screw (TFS); UP and TFS; UP and UR. Results All instrumented constructs significantly reduced ROM in all motion compared with the intact specimen, except the UR construct in axial rotation. Unilateral fixation (UR or UP) reduced ROM less compared with the bilateral fixation (UP/UR+TFS, UP+UR). The plate system resulted in more reduction in ROM compared with the rod system, especially in axial rotation. UP construct provided more stability in axial rotation compared with UR construct. The strain distribution on the left and right side of L4 vertebral body was significantly different from UR and UR+TFS construct under flexion motion. The strain distribution on L4 vertebral body was significantly influenced by different fixation constructs. Conclusions The novel plate could provide sufficient segmental stability in axial rotation. The UR construct exhibits weak stability and asymmetrical strain distribution in fusion segment, while the UP construct is a good alternative choice for unilateral posterior fixation of MI-TLIF. PMID:25807513

  20. 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

  1. Comparison Between Posterior Short-segment Instrumentation Combined With Lateral-approach Interbody Fusion and Traditional Wide-open Anterior-Posterior Surgery for the Treatment of Thoracolumbar Fractures

    PubMed Central

    Li, Xiang; Zhang, Junwei; Tang, Hehu; Lu, Zhen; Liu, Shujia; Chen, Shizheng; Hong, Yi

    2015-01-01

    Abstract The aim of the study was to compare the radiographic and clinical outcomes between posterior short-segment pedicle instrumentation combined with lateral-approach interbody fusion and traditional anterior-posterior (AP) surgery for the treatment of thoracolumbar fractures. Lateral-approach interbody fusion has achieved satisfactory results for thoracic and lumbar degenerative disease. However, few studies have focused on the use of this technique for the treatment of thoracolumbar fractures. Inclusion and exclusion criteria were established. All patients who meet the above criteria were prospectively treated by posterior short-segment instrumentation and secondary-staged minimally invasive lateral-approach interbody fusion, and classified as group A. A historical group of patients who were treated by traditional wide-open AP approach was used as a control group and classified as group B. The radiological and clinical outcomes were compared between the 2 groups. There were 12 patients in group A and 18 patients in group B. The mean operative time and intraoperative blood loss of anterior reconstruction were significantly higher in group B than those in group A (127.1 ± 21.7 vs 197.5 ± 47.7 min, P < 0.01; 185.8 ± 62.3 vs 495 ± 347.4 mL, P < 0.01). Two of the 12 (16.7%) patients in group A experienced 2 surgical complications: 1 (8.3%) major and 1 (8.3%) minor. Six of the 18 (33%) patients in group B experienced 9 surgical complications: 3 (16.7%) major and 6 (33.3%) minor. There was no significant difference between the 2 groups regarding loss of correction (4.3 ± 2.1 vs 4.2 ± 2.4, P = 0.89) and neurological function at final follow-up (P = 0.77). In both groups, no case of instrumentation failure, pseudarthrosis, or nonunion was noted. Compared with the wide-open AP surgery, posterior short-segment pedicle instrumentation, combined with minimally invasive lateral-approach interbody fusion, can achieve similar

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

    PubMed Central

    Truszczyńska, Aleksandra; Rąpała, Kazimierz; Łukawski, Stanislaw; Trzaskoma, Zbigniew; Tarnowski, Adam; Drzal-Grabiec, Justyna; Cabak, Anna

    2014-01-01

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

  3. Spontaneous slip reduction of low-grade isthmic spondylolisthesis following circumferential release via bilateral minimally invasive transforaminal lumbar interbody fusion: technical note and short-term outcome.

    PubMed

    Pan, Jie; Li, Lijun; Qian, Lie; Zhou, Wei; Tan, Jun; Zou, Le; Yang, Mingjie

    2011-02-15

    STUDY DESIGN.: Retrospective clinical data analysis. OBJECTIVE.: To investigate and verify our philosophy of spontaneous slip reduction following circumferential release via bilateral minimally invasive transforaminal lumbar interbody fusion (Mini-TLIF) for treatment of low-grade symptomatic isthmic spondylolisthesis. SUMMARY OF BACKGROUND DATA.: Symptomatic isthmic spondylolisthesis usually requires surgical intervention, and the most currently controversial focus is on method and degree of reduction; and Mini-TLIF is an attractive surgical procedure for isthmic spondylolisthesis. METHODS.: Between February 2004 and June 2008, 21 patients with low-grade isthmic spondylolisthesis underwent Mini-TLIF in our institute. Total resection of the scar around the pars interarticularis liberated the nerve roots, achieving posterior release as well. The disc was thoroughly resected, and the disc space was gradually distracted and thoroughly released with sequential disc shavers until rupture of anulus conjunct with anterior longitudinal ligament, accomplishing anterior release, so as to insert Cages. Because of circumferential release, the slipped vertebrae would tend to obtain spontaneous reduction, and with pedicle screw fixation, additional reduction would be achieved without any application of posterior translation force. Radiographs, Visual Analogue Scale, and Oswestry Disability Index were documented. All the cases were followed up for 10 to 26 months. RESULTS.: Slip percentage was reduced from 24.2% ± 6.9% to 10.5% ± 4.0%, and foraminal area percentage increased from 89.1% ± 3.0% to 93.6% ± 2.1%. Visual Analogue Scale and Oswestry Disability Index decreased from 7.8 ± 1.5 to 2.1 ± 1.1 and from 53.3 ± 16.2 to 17.0 ± 7.8, respectively. No neurologic complications were encountered. There were no signs of instrumentation failure. The fusion rate approached 100%. CONCLUSION.: Slip reduction is based on circumferential release. The procedure can be well performed

  4. The CASCADE trial: effectiveness of ceramic versus PEEK cages for anterior cervical discectomy with interbody fusion; protocol of a blinded randomized controlled trial

    PubMed Central

    2013-01-01

    Background Anterior cervical discectomy with interbody fusion cages is considered the standard surgical procedure in patients with cervical disc herniation. However, PEEK or metal cages have some undesirable imaging characteristics, leading to a search for alternative materials not creating artifacts on images; silicon nitride ceramic. Whether patients treated with silicon nitride ceramic cages have similar functional outcome as patients treated with PEEK cages is not known. We present the design of the CASCADE trial on effectiveness of ceramic cages versus PEEK cages in patients with cervical disc herniation and/or osteophytes. Methods/Design Patients (age 18–75 years) with monoradicular symptoms in one or both arms lasting more than 8 weeks, due to disc herniation and/or osteophytes, are eligible for the trial. The study is designed as a randomized controlled equivalence trial in which patients are blinded to the type of cage for 1 year. The total follow-up period is 2 years. The primary outcome measure is improvement in the Neck and Disability Index (NDI). Secondary outcomes measures include improvement in arm pain and neck pain (VAS), SF-36 and patients' perceived recovery. The final elements of comparison are perioperative statistics including operating time, blood loss, length of hospital stay, and adverse events. Lateral plane films at each follow-up visit and CT scan (at 6 months) will be used to judge fusion and the incidence of subsidence. Based on a power of 90% and assuming 8% loss to follow-up, 100 patients will be randomized into the 2 groups. The first analysis will be conducted when all patients have 1 year of follow-up, and the groups will be followed for 1 additional year to judge stability of outcomes. Discussion While the new ceramic cage has received the CE Mark based on standard compliance and animal studies, a randomized comparative study with the golden standard product will provide more conclusive information for clinicians

  5. Biomechanical comparison of unilateral and bilateral pedicle screws fixation for transforaminal lumbar interbody fusion after decompressive surgery -- a finite element analysis

    PubMed Central

    2012-01-01

    Background Little is known about the biomechanical effectiveness of transforaminal lumbar interbody fusion (TLIF) cages in different positioning and various posterior implants used after decompressive surgery. The use of the various implants will induce the kinematic and mechanical changes in range of motion (ROM) and stresses at the surgical and adjacent segments. Unilateral pedicle screw with or without supplementary facet screw fixation in the minimally invasive TLIF procedure has not been ascertained to provide adequate stability without the need to expose on the contralateral side. This study used finite element (FE) models to investigate biomechanical differences in ROM and stress on the neighboring structures after TLIF cages insertion in conjunction with posterior fixation. Methods A validated finite-element (FE) model of L1-S1 was established to implant three types of cages (TLIF with a single moon-shaped cage in the anterior or middle portion of vertebral bodies, and TLIF with a left diagonally placed ogival-shaped cage) from the left L4-5 level after unilateral decompressive surgery. Further, the effects of unilateral versus bilateral pedicle screw fixation (UPSF vs. BPSF) in each TLIF cage model was compared to analyze parameters, including stresses and ROM on the neighboring annulus, cage-vertebral interface and pedicle screws. Results All the TLIF cages positioned with BPSF showed similar ROM (<5%) at surgical and adjacent levels, except TLIF with an anterior cage in flexion (61% lower) and TLIF with a left diagonal cage in left lateral bending (33% lower) at surgical level. On the other hand, the TLIF cage models with left UPSF showed varying changes of ROM and annulus stress in extension, right lateral bending and right axial rotation at surgical level. In particular, the TLIF model with a diagonal cage, UPSF, and contralateral facet screw fixation stabilize segmental motion of the surgical level mostly in extension and contralaterally axial

  6. Ant- and Ant-Colony-Inspired ALife Visual Art.

    PubMed

    Greenfield, Gary; Machado, Penousal

    2015-01-01

    Ant- and ant-colony-inspired ALife art is characterized by the artistic exploration of the emerging collective behavior of computational agents, developed using ants as a metaphor. We present a chronology that documents the emergence and history of such visual art, contextualize ant- and ant-colony-inspired art within generative art practices, and consider how it relates to other ALife art. We survey many of the algorithms that artists have used in this genre, address some of their aims, and explore the relationships between ant- and ant-colony-inspired art and research on ant and ant colony behavior. PMID:26280070

  7. 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. PMID:26072198

  8. 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

  9. Clinical outcomes of two types of cages used in transforaminal lumbar interbody fusion for the treatment of degenerative lumbar diseases: n-HA/PA66 cages versus PEEK cages.

    PubMed

    Deng, Qian-xing; Ou, Yun-sheng; Zhu, Yong; Zhao, Zeng-hui; Liu, Bo; Huang, Qiu; Du, Xing; Jiang, Dian-ming

    2016-06-01

    This study reports the clinical effects of nano-hydroxyapatite/polyamide66 cages (n-HA/PA66 cages) and compares the clinical outcomes between n-HA/PA66 and polyetheretherketone cages (PEEK cages) for application in transforaminal lumbar interbody fusion (TLIF). A retrospective and case-control study involving 124 patients using n-HA/PA66 cages and 142 patients using PEEK cages was conducted. All patients underwent TLIF and had an average of 2-years of follow-up. The Oswestry Disability Index and Visual Analog Scale were selected to assess the pain of low back and leg, as well as neurological status. The intervertebral space height and segmental angle were also measured to estimate the radiological changes. At the 1-year and final follow-ups, the fusion and subsidence rates were evaluated. There was no significant difference between the two groups regarding clinical and radiological results. At the final follow-up, the bony fusion rate was 92.45 and 91.57 % for the n-HA/PA66 and PEEK groups, respectively, and the subsidence rate was 7.55 and 8.99 %, respectively. The study indicated that both n-HA/PA66 and PEEK cages could promote effective clinical and radiographic outcomes when used to treat degenerative lumbar diseases. The high fusion and low subsidence rates revealed that n-HA/PA66 cages could be an alternative ideal choice as the same to PEEK cages for lumbar reconstruction after TLIF. PMID:27091044

  10. 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

  11. Extreme Lateral Interbody Fusion Procedure

    MedlinePlus

    ... by Dr. Fernando Vale, vice chief of the Neurosciences Department at Tampa General Hospital. Dr. Vale will ... perform this operation. Of course, everything requires a learning curve. This is something that is done many ...

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

    PubMed Central

    2014-01-01

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

  13. 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. PMID:26889290

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

    PubMed Central

    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. PMID:26889290

  15. 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

  16. One-stage surgical treatment for thoracic and lumbar Spinal tuberculosis by transpedicular fixation, debridement, and combined interbody and posterior fusion via a posterior-only approach.

    PubMed

    Ran, Bing; Xie, Yuan-Long; Yan, Lei; Cai, Lin

    2016-08-01

    This study examined the clinical outcomes of one-stage surgical treatment for patients with spinal tuberculosis via a posterior-only approach. Twenty-four patients with thoracic or lumbar spinal tuberculosis whose lesions were confined to adjacent segments were admitted to our hospital and treated. The American Spinal Injury Association (ASIA) impairment scale was used to assess the neurological function. All patients were treated with one-stage surgical treatment via a posterior-only approach. The clinical efficacy was evaluated by the Japanese Orthopaedic Association (JOA) scores and oswestry disability index (ODI) of nerve function. Patients were evaluated preoperatively and postoperatively by measurement of spinal deformity using Cobb angle and radiological examination. All the patients were followed up for 13 to 27 months. They had significantly postoperative improvement in JOA score, ODI and ASIA classification scores. The kyphotic angles were significantly corrected and maintained at the final follow-up. Bone fusion was achieved within 4-12 months. It was concluded that one-stage surgical treatment via a posterior-only approach is effective and feasible for the treatment of spinal tuberculosis. PMID:27465330

  17. Lumbar interbody expanding cage. A preliminary study on an animal model.

    PubMed

    Manunta, M L; Careddu, G M; Masala, G; Columbano, N; Doria, C; Crissantu, L; Sanna Passino, E

    2008-01-01

    Interbody fusion devices are used in human medicine for treating degenerative diseases of the spine. Currently, there is not a universally accepted assessment tool for determining fusion, and the definitive criteria for diagnosing a successful interbody fusion remain controversial. The aim of this study was to describe microscopic and helical computed tomography (CT) imaging in the assessment of lumbar interbody fusion using cylindrical threaded titanium expanding cage in sheep. One cylindrical threaded expanding titanium cage (Proconcept--SA, Orange, France) was inserted through a transperitoneal approach after radical discectomy and packed with cancellous bone autograft in five adult sheep. The subjects were euthanatized after three, six, 12, 18 and 24 months. CT images revealed lumbar fusion at 12 months post operation, whereas microscopic evaluations indicated the presence of lumbar fusion at 18 months. CT and histological grades were the same in 65% of the cases observed. There were not a significant difference between CT, histological and micro radiographic grades. Helical CT scanning can be considered to be a suitable method for the monitoring of lumbar fusion as it enables observation of the deposition of bony bridging within the cage. PMID:18704248

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

    PubMed Central

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

    2012-01-01

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

  19. Spine interbody implants: material selection and modification, functionalization and bioactivation of surfaces to improve osseointegration.

    PubMed

    Rao, Prashanth J; Pelletier, Matthew H; Walsh, William R; Mobbs, Ralph J

    2014-05-01

    The clinical outcome of lumbar spinal fusion is correlated with achievement of bony fusion. Improving interbody implant bone on-growth and in-growth may enhance fusion, limiting pseudoarthrosis, stress shielding, subsidence and implant failure. Polyetheretherketone (PEEK) and titanium (Ti) are commonly selected for interbody spacer construction. Although these materials have desirable biocompatibility and mechanical properties, they require further modification to support osseointegration. Reports of extensive research on this topic are available in biomaterial-centric published reports; however, there are few clinical studies concerning surface modification of interbody spinal implants. The current article focuses on surface modifications aimed at fostering osseointegration from a clinician's point of view. Surface modification of Ti by creating rougher surfaces, modifying its surface topography (macro and nano), physical and chemical treatment and creating a porous material with high interconnectivity can improve its osseointegrative potential and bioactivity. Coating the surface with osteoconductive materials like hydroxyapatite (HA) can improve osseointegration. Because PEEK spacers are relatively inert, creating a composite by adding Ti or osteoconductive materials like HA can improve osseointegration. In addition, PEEK may be coated with Ti, effectively bio-activating the coating. PMID:24890288

  20. 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

  1. Evaluation of the 96/4 PLDLLA polymer resorbable lumbar interbody cage in a long term animal model.

    PubMed

    Lazennec, Jean Y; Madi, Abdallah; Rousseau, Marc A; Roger, Bernard; Saillant, Gérard

    2006-10-01

    Arthrodesis using interbody cages has demonstrated high fusion rates. However, permanent cages are exposed to stress-shielding, corrosion, and may require explanation when necessary. Polylactic acid (PLA) bioresorbable cages are developed for avoiding these problems, but significant tissue reaction has been reported with 70/30 PLDLLA in some preclinical animal studies. The objective was to evaluate 96/4 PLDLLA cages in a sheep model over 3 years. Sixteen sheeps underwent one level anterior lumbar interbody fusion using 96/4 PLDLLA cages, filled and surrounded with cancellous bone graft from the iliac crest. Six groups of three animals were killed after 3, 6, 9, 12, 24, and 36 months. Harvested lumbar spine had radiographic, MRI, and CT evaluation and histological analysis. Histological results: cage swelling and slight signs of fragmentation associated to fibrocartilaginous tissue apposition at 3 months; bone remodeling around the cage with direct apposition of the mineralization front at 6 months; active cage degradation and complete fusion around the cage at 9 months; cage fragmentation and partial replacement by bone tissue at 12 months; bone bridges in and around the cage at 24 months; full resorption and intervertebral fusion at 36 months. Radiological results: partial arthrodesis at 3 months; definite peripheral arthrodesis at 6 months; similar aspect at 9 months; significant cage resorption at 12 months; definite inner and outer fusion at 24 months; complete cage resorption and calcification at the location of the cage at 36 months confirmed histological observations. Radiographic, CT scan, MRI, and histological data were consistent for showing progressive resorption of 96/4 PLDLLA, interbody fusion, and bone remodeling, with no significant signs of local intolerance reaction. These results are promising and suggest further development of 96/4 PLDLLA cages. PMID:16736199

  2. Modified distraction-stabilization technique using an interbody polymethyl methacrylate plug in dogs with caudal cervical spondylomyelopathy.

    PubMed

    Dixon, B C; Tomlinson, J L; Kraus, K H

    1996-01-01

    A modified technique for distraction-stabilization that used an interbody polymethyl methacrylate plug was performed in 22 dogs with confirmed caudal cervical spondylomyelopathy. Myelographically, all compressive lesions were dynamic and predominantly located ventral to the spinal cord. Nineteen of 21 (90%) dogs for which success/failure could be determined had a successful outcome, and 11 of 22 (50%) dogs attained normal neurologic status. The 2 cases that were considered failures involved dogs that were nonambulatory tetraparetic prior to surgery and failed to improve to a functional status. Complications were self-limiting and included ventral displacement of the cement without loss of distraction in 1 dog and diskosponsylitis at an adjacent disk space in another dog. Evidence of fusion of the affected vertebrae, in the distracted position, was radiographically evident in all dogs. Use of the interbody polymethyl methacrylate plug appears to be a viable surgical treatment of caudal cervical spondylomyelopathy in dogs. PMID:8682707

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

    PubMed

    Best, M L

    1997-01-01

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

  4. [Anterior and posterior stabilization of the lumbosacral spine with the usage of interbody cages in the operational treatment of the isthmic spondylolisthesis].

    PubMed

    Pankowski, Rafał; Smoczyński, Andrzej; Smoczyński, Maciej; Luczkiewicz, Piotr; Piotrowski, Maciej

    2006-01-01

    In the following work results of the operational treatment of the isthmic spondylolisthesis by the posterior stabilization and anterior lumbosacral interbody fusion with the use of interbody implants--cages was taken under evaluation. The test group consisted of 21 patients (13 male and 8 male). The follow up period exceeded 2 years. The objective clinical outcome assessment was based on Oswestry disability questionnaire. Subjective clinical evaluation was done by the visual analog pain score and two questions concerning the evaluation of success of the operative treatment and a possible agreement to a following operation if necessary. The radiological results were done upon evaluation of the degree of the spondylolisthesis, the angle of the lumbosacral lordosis, the height of the interbody space and intervertebral foramen and the evaluation of the spinal fusion. The conclusion was that the usage of the distraction of the lumbosacral spine in the operational treatment of the isthmic spondylolisthesis result in the reduction of the slippage and the dynamic decompression of the compressed neural roots. The usage of the interbody cages prevented the loss of slippage correction, permanently reconstructed the anatomical conditions in the area of the operated spinal segment and helped to achieve good and very good clinical results in over 95% of patients. The fusion rate was 100%. The restoration of the correct height of the intervertebral foramen in the slip segment caused an improvement of the neurologic state. The usage of two level stabilization in the operative treatment of the isthmic spondylolisthesis prevented the initiation of the secondary degenerative changes adjacent to the fusion. PMID:17128767

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

    PubMed

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

    2015-04-01

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

  6. 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.

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

    PubMed Central

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

    2007-01-01

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

  8. Outcomes of Two Different Techniques Using the Lateral Approach for Lumbar Interbody Arthrodesis

    PubMed Central

    Cheng, Ivan; Briseño, Michael R.; Arrigo, Robert T.; Bains, Navpreet; Ravi, Shashank; Tran, Andrew

    2015-01-01

    Study Design Retrospective cohort study. Objective To determine the short-term outcomes of two different lateral approaches to the lumbar spine. Methods This was a retrospective review performed with four fellowship-trained spine surgeons from a single institution. Two different approach techniques were identified. (1) Traditional transpsoas (TP) approach: dissection was performed through the psoas performed using neuromonitored sequential dilation. (2) Direct visualization (DV) approach: retractors are placed superficial to the psoas followed by directly visualized dissection through psoas. Outcome measures included radiographic fusion and adverse event (AE) rate. Results In all, 120 patients were identified, 79 women and 41 men. Average age was 64.2 years (22 to 86). When looking at all medical and surgical AEs, 31 patients (25.8%) had one or more AEs; 22 patients (18.3%) had a total of 24 neurologically related AEs; 15 patients (12.5%) had anterior/lateral thigh dysesthesias; 6 patients (5.0%) had radiculopathic pain; and 3 patients (2.5%) had postoperative weakness. Specifically, for neurologic AEs, the DV group had a rate of 28.0% and the TP group had a rate of 14.2% (p < 0.18). When looking at the rate of neurologic AEs in patients undergoing single-level fusions only, the DV group rate was 28.6% versus 10.2% for the TP group (p < 0.03). Conclusion Overall, 18.3% of patients sustained a postoperative neurologic AE following lateral interbody fusions. The TP approach had a statistically lower rate of neurologic-specific AE for single-level fusions. PMID:26225280

  9. Iatrogenic Baastrup's Syndrome: A Potential Complication Following Anterior Interbody Lumbar Spinal Surgery

    PubMed Central

    Russo, Glenn S.; Castro, Carlos A.

    2015-01-01

    Background Baastrup's Syndrome is a condition that occurs when there is abnormal contact between two adjacent spinous processes resulting in back pain. An alteration in lumbar spinal alignment and/or adjacent segment compensatory motion is thought to be potential causative factors. The objective of this study was to present a case series of what appears to be iatrogenic Baastrup's Syndrome as a mid-to-late term complication following anterior lumbar interbody surgery. Methods A retrospective chart review was performed of all patients undergoing anterior lumbar surgery for either fusion or disc replacement to determine the prevalence of Baastrup's Syndrome. Results Over a 12-year period, 855 patients who had undergone an anterior approach for lumbar spine surgery were identified. Of them 8 patients with evidence of Baastrup's Syndrome were found; this demonstrated a prevalence of 0.9%. Diagnostic injection was a helpful clinical tool in confirming the diagnosis of iatrogenic Baastrup's Syndrome. The partial removal of the impinging spinous processes resulted in excellent clinical relief. Conclusions Iatrogenic Baastrup's Syndrome may be an iatrogenic result of anterior lumbar surgery in small group of patients. Spinous process excision is a suggested treatment option. Further studies are necessary to explore the above phenomenon. This study is a Level 3 retrospective case series. PMID:26767158

  10. Use of Aortic Endograft for Repair of Intraoperative Iliocaval Injury during Anterior Spine Exposure.

    PubMed

    Chou, Elizabeth L; Colvard, Benjamin D; Lee, Jason T

    2016-02-01

    Vascular injury during anterior lumbar interbody fusion (ALIF) is a well-documented occurrence. Most vascular injuries continue to be managed with direct open repair. We report the outcome of a 61-year-old woman who experienced inferior vena cava and left common iliac vein injury during a difficult exposure for multilevel ALIF. The distal cava and common iliac vein were repaired with a Gore Excluder cuff and limb. The endovascular repair permitted control of the injury without more morbid maneuvers such as iliac artery transection. Thus endovascular repair of intraoperative caval injury is a valuable option in emergent situations with low morbidity and good durability. PMID:26597236

  11. 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

  12. Early Radiographic and Clinical Outcomes Study Evaluating an Integrated Screw and Interbody Spacer for One- and Two-Level ACDF

    PubMed Central

    Lane, Paul D.; Cox, Jacob L.; Gaskins, Roger B.; Billys, James B.; Castellvi, Antonio E.

    2015-01-01

    Background Multiple techniques and implants can be used in ACDF, the newest of which are integrated cage and screw constructs. These devices may be beneficial over anterior plate constructs due to a negligible anterior profile that may reduce dysphagia. The goal of this study is to review the early radiographical and clinical results associated with a low profile integrated intervertebral cage in one- and two-level anterior column fusions. Methods Fusion rates, incidence of hardware failure and deformity correction were assessed through 1 year. Patientreported scores, including VAS for neck pain, and improvements in axial neck pain and neurologic deficit from the preoperative baseline were quantified at 3, 6 and 12 months post-operatively. The incidence of dysphagia was recorded. Results Lordosis and disc space height at the operated levels increased an average of 4.5° and 3.3mm after device placement (p<0.001). Sagittal plane correction was maintained at 1 year. VAS improved from an average of 5.1 preoperatively to 3.1 immediately postoperatively and was maintained at 12 months. At 3 months, patient-reported improvements in axial neck pain and neurologic deficit were 85% and 93%, respectively. Reported improvements were sustained for both parameters at 12 months (77% and 86%, respectively). Fusion was noted in 93% of the operated levels. There were two documented cases of dysphagia that lasted more than 5 weeks, both following two level ACDFs with the test device (3.5% rate of chronic dysphagia). Conclusions The low profile integrated device improved lordosis at the operated level that was maintained at 1 year. Fusion rates with the new device are consistent with ACDF using anterior plating. In combination with improvements in pain and a minimal rate of dysphagia, study findings support the use of integrated interbody spacers for use in one- and two-level ACDF procedures. Level of Evidence Level IV, Case Series. PMID:26273557

  13. 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

  14. 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.

  15. Spinal fusion

    MedlinePlus

    ... Anterior spinal fusion; Spine surgery - spinal fusion; Low back pain - fusion; Herniated disk - fusion ... If you had chronic back pain before surgery, you will likely still have some pain afterward. Spinal fusion is unlikely to take away all your pain ...

  16. Stability and Load Sharing Characteristics of a Posterior Dynamic Stabilization Device

    PubMed Central

    Cook, Daniel J.; Yeager, Matthew S.; Thampi, Shankar S.; Whiting, Donald M.

    2015-01-01

    Background Lumbar interbody fusion is a common treatment for a variety of spinal pathologies. It has been hypothesized that insufficient mechanical loading of the interbody graft can prevent proper fusion of the joint. The purpose of this study was to evaluate the mechanical stability and anterior column loading sharing characteristics of a posterior dynamic system compared to titanium rods in an anterior lumbar interbody fusion (ALIF) model. Methods Range of motion, interpedicular kinematics and interbody graft loading were measured in human cadaveric lumbar segments tested under a pure moment flexibility testing protocol. Results Both systems provided significant fixation compared to the intact condition and to an interbody spacer alone in flexion extension and lateral bending. No significant differences in fixation were detected between the devices. A significant decrease in graft loading was detected in flexion for the titanium rod treatment compared to spacer alone. No significant differences in graft loading were detected between the spacer alone and posterior dynamic system or between the posterior dynamic system and the titanium rod. Conclusions The results of this study indicate that the posterior dynamic system provides similar fixation compared to that of a titanium rod, however, studies designed to evaluate the efficacy of fixation in a cadaver model may not be sufficiently powered to establish differences in load sharing using the techniques described here. PMID:26131403

  17. A review: Reduced reoperation rate for multilevel lumbar laminectomies with noninstrumented versus instrumented fusions

    PubMed Central

    Epstein, Nancy Ellen

    2016-01-01

    Background: The reoperation rate, including for adjacent segment disease (ASD), is lower following multilevel lumbar laminectomy with noninstrumented versus instrumented fusions. Methods: This study reviews selected literature focusing on the reoperation rate, including for ASD, following multilevel laminectomies with noninstrumented versus instrumented fusions. Several prior studies document a 1.3–5.6% reoperation rate following multilevel laminectomy with/without noninstrumented fusions. Results: The reoperation rates for instrumented fusions, including for ASD, are substantially higher. One study cited a 12.2–18.5% frequency for reoperation following instrumented transforaminal lumbar and posterior lumbar interbody fusions (TLIF and PLIFs) at an average of 164 postoperative months. Another study cited a 9.9% reoperation rate for ASD 1 year following PLIF; this increased to 80% at 5 postoperative years. A further study compared 380 patients variously undergoing laminectomies/noninstrumented posterolateral fusions, laminectomies with instrumented fusions (PLFs), and laminectomies with instrumented PLF plus an interbody fusions; this study documented no significant differences in outcomes for any of these operations at 4 postoperative years. Furthermore, other series showed fusion rates for 1–2 level procedures which were often similar with or without instrumentation, while instrumentation increased reoperation rates and morbidity. Conclusions: Many studies document no benefit for adding instrumentation to laminectomies performed for degenerative disease, including spondylolisthesis. Reoperation rates for laminectomy alone/laminectomy with noninstrumented fusions vary from 1.3% to 5.6% whereas reoperation rates for ASD after instrumented PLIF was 80% at 5 postoperative years. This review should prompt spinal surgeons to reexamine when, why, and whether instrumentation is really necessary, particularly for treating degenerative lumbar disease. PMID:27274408

  18. Older literature review of increased risk of adjacent segment degeneration with instrumented lumbar fusions

    PubMed Central

    Epstein, Nancy E.

    2016-01-01

    Background: Adjacent segment degeneration (ASD) following lumbar spine surgery occurs in up to 30% of cases, and descriptions of such changes are not new. Here, we review some of the older literature concerning the rate of ASD, typically more severe cephalad than caudad, and highly correlated with instrumented fusions. Therefore, for degenerative lumbar disease without frank instability, ASD would be markedly reduced by avoiding instrumented fusions. Methods: In a prior review, the newer literature regarding the frequency of ASD following lumbar instrumented fusions (e.g., transforaminal or posterior lumbar interbody fusions [TLIF/PLIF] fusions or occasionally, posterolateral fusions [PLFs]) was presented. Some studies cited an up to an 18.5% incidence of ASD following instrumented versus noninstrumented fusions/decompressions alone (5.6%). A review of the older literature similarly documents a higher rate of ASD following instrumented fusions performed for degenerative lumbar disease alone. Results: More frequent and more severe ASD follows instrumented lumbar fusions performed for degenerative lumbar disease without instability. Alternatively, this entity should be treated with decompressions alone or with noninstrumented fusions, without the addition of instrumentation. Conclusions: Too many studies assume that TLIF, PLIF, and even PLF instrumented fusions are the “gold standard of care” for dealing with degenerative disease of the lumbar spine without documented instability. It is time to correct that assumption, and reassess the older literature along with the new to confirm that decompression alone and noninstrumented fusion avoid significant morbidity and even potentially mortality attributed to unnecessary instrumentation. PMID:26904370

  19. Intervertebral Fusion with Mobile Microendoscopic Discectomy for Lumbar Degenerative Disc Disease.

    PubMed

    Xu, Bao-Shan; Liu, Yue; Xu, Hai-Wei; Yang, Qiang; Ma, Xin-Long; Hu, Yong-Cheng

    2016-05-01

    The aim of this article is to introduce a technique for lumbar intervertebral fusion that incorporates mobile microendoscopic discectomy (MMED) for lumbar degenerative disc disease. Minimally invasive transforaminal lumbar interbody fusion is frequently performed to treat degenerative diseases of the lumbar spine; however, the scope of such surgery and vision is limited by what the naked eye can see through the expanding channel system. To expand the visual scope and reduce trauma, we perform lumbar intervertebral fusion with the aid of a MMED system that provides a wide field through freely tilting the surgical instrument and canals. We believe that this technique is a good option for treating lumbar degenerative disc disease that requires lumbar intervertebral fusion. PMID:27384734

  20. Biomechanical comparison between lumbar disc arthroplasty and fusion.

    PubMed

    Chen, Shih-Hao; Zhong, Zheng-Cheng; Chen, Chen-Sheng; Chen, Wen-Jer; Hung, Chinghua

    2009-03-01

    The artificial disc is a mobile implant for degenerative disc replacement that attempts to lessen the degeneration of the adjacent elements. However, inconsistent biomechanical results for the neighboring elements have been reported in a number of studies. The present study used finite element (FE) analysis to explore the biomechanical differences at the surgical and both adjacent levels following artificial disc replacement and interbody fusion procedures. First, a three-dimensional FE model of a five-level lumbar spine was established by the commercially available medical imaging software Amira 3.1.1, and FE software ANSYS 9.0. After validating the five-level intact (INT) model with previous in vitro studies, the L3/L4 level of the INT model was modified to either insert an artificial disc (ProDisc II; ADR) or incorporate bilateral posterior lumbar interbody fusion (PLIF) cages with a pedicle screw fixation system. All models were constrained at the bottom of the L5 vertebra and subjected to 150N preload and 10Nm moments under four physiological motions. The ADR model demonstrated higher range of motion (ROM), annulus stress, and facet contact pressure at the surgical level compared to the non-modified INT model. At both adjacent levels, ROM and annulus stress were similar to that of the INT model and varied less than 7%. In addition, the greatest displacement of posterior annulus occurred at the superior-lateral region. Conversely, the PLIF model showed less ROM, less annulus stress, and no facet contact pressure at the surgical level compared to the INT model. The adjacent levels had obviously high ROM, annulus stress, and facet contact pressure, especially at the adjacent L2/3 level. In conclusion, the artificial disc replacement revealed no adjacent-level instability. However, instability was found at the surgical level, which might accelerate degeneration at the highly stressed annulus and facet joint. In contrast to disc replacement results, the posterior

  1. Comparison of Fusion Rates between Glycerol-Preserved and Frozen Composite Allografts in Cervical Fusion

    PubMed Central

    Rodway, Ian; Gander, Julie

    2014-01-01

    Background. This retrospective, two cohort series study was designed to compare a room temperature, glycerol-preserved composite pinned bone allograft (G-CPBA) with the same graft type provided in a frozen state (F-CPBA) for use as a cervical interbody spacer in anterior cervical discectomy and fusion (ACDF). Methods. A comprehensive chart review was performed for 67 sequential patients that received either a F-CPBA or a G-CPBA and had at least one-year follow-up. Twenty-eight patients had received G-CPBA grafts and 37 patients had received F-CPBA grafts. Two additional 2-level patients had received one of each type of grafts. Results. At 3 months, 45.3% (29 of 64) of glycerol-preserved and 41.4% (29 of 70) of frozen allografts, respectively, were considered to be fused radiographically. At 12 months, 100% of both treatment groups (41 glycerol-preserved and 45 frozen) were considered fused. Fusion rates for G-CPBA were statistically similar to F-CPBA at both 3 and 12 months (P = 0.6535 and >0.999, resp.). There were no allograft related complications in either treatment group. Conclusions. 100% fusion rates were attained by both treatment groups at 12 months and were similar at short-term follow-up for all comparable levels. Level of Evidence. Level of evidence is III.

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

    PubMed Central

    Marawar, Satyajit; Jung, Jin; Sun, Mike

    2014-01-01

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

  3. Magnetic resonance imaging on disc degeneration changes after implantation of an interspinous spacer and fusion of the adjacent segment

    PubMed Central

    Liu, Xiaokang; Liu, Yingjie; Lian, Xiaofeng; Xu, Jianguang

    2015-01-01

    The aim of the study was to investigate the changes of the lumbar intervertebral disc degeneration by magnetic resonance imaging (MRI) after the implantation of interspinous device and the fusion of the adjacent segment. A total of 62 consecutive patients suffering L5/S1 lumbar disc herniation (LDH) with concomitant disc space narrowing or low-grade instability up to 5 mm translational slip in L5/S1 level were treated with lumbar interbody fusion (LIF) via posterior approach. Thirty-four of these patients (Coflex group) received an additional implantation of the interspinous spacer device (Coflex™) in the level L4/L5, while the rest of 28 patients (fusion group) underwent the fusion surgery alone. Clinical and radiographic examinations were performed at pre- and postoperative visits to compare the clinical outcomes and the changes of the L4/L5 vertebral disc degeneration on MRI in both Coflex and fusion group. Although both Coflex and fusion group showed improvements of the clinical outcomes assessed by the Oswestry Disability Index (ODI) after surgery, patients in Coflex group had more significant amelioration (P < 0.05) compared to fusion group. During follow up, the postoperative disc degeneration changes in Coflex group assessed by the relative signal intensity (RSI) differed from those in fusion group (P < 0.05). The supplemental implantation of Coflex™ after the fusion surgery could delay the disc degeneration of the adjacent segment. PMID:26131210

  4. Fast degradable citrate-based bone scaffold promotes spinal fusion

    PubMed Central

    Tang, Jiajun; Guo, Jinshan; Li, Zhen; Yang, Cheng; Xie, Denghui; Chen, Jian; Li, Shengfa; Li, Shaolin; Kim, Gloria B.; Bai, Xiaochun; Zhang, Zhongmin; Yang, Jian

    2015-01-01

    It is well known that high rates of fusion failure and pseudoarthrosis development (5~35%) are concomitant in spinal fusion surgery, which was ascribed to the shortage of suitable materials for bone regeneration. Citrate was recently recognized to play an indispensable role in enhancing osteconductivity and osteoinductivity, and promoting bone formation. To address the material challenges in spinal fusion surgery, we have synthesized mechanically robust and fast degrading citrate-based polymers by incorporating N-methyldiethanolamine (MDEA) into clickable poly(1, 8-octanediol citrates) (POC-click), referred to as POC-M-click. The obtained POC-M-click were fabricated into POC-M-click-HA matchstick scaffolds by compositing with hydroxyapatite (HA) for interbody spinal fusion in a rabbit model. Spinal fusion was analyzed by radiography, manual palpation, biomechanical testing, and histological evaluation. At 4 and 8 weeks post surgery, POC-M-click-HA scaffolds presented optimal degradation rates that facilitated faster new bone formation and higher spinal fusion rates (11.2±3.7, 80±4.5 at week 4 and 8, respectively) than the poly(L-lactic acid)-HA (PLLA-HA) control group (9.3±2.4 and 71.1±4.4) (p<0.05). The POC-M-click-HA scaffold-fused vertebrates possessed a maximum load and stiffness of 880.8±14.5 N and 843.2±22.4 N/mm, respectively, which were also much higher than those of the PLLA-HA group (maximum: 712.0±37.5 N, stiffness: 622.5±28.4 N/mm, p<0.05). Overall, the results suggest that POC-M-click-HA scaffolds could potentially serve as promising bone grafts for spinal fusion applications. PMID:26213625

  5. 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.

  6. Fusion Implementation

    SciTech Connect

    J.A. Schmidt

    2002-02-20

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

  7. 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.

  8. Retroperitoneal fluid collection following anterior spine surgery--differential and management.

    PubMed

    VanValkenburg, Scott; Trussell, J C; Lavelle, William F

    2016-04-01

    Iatrogenic ureteral injuries are rare and must be accurately identified to minimizing the risk for additional complications. Anterior lumbar interbody fusion (ALIF) is a valuable technique utilized in spine surgery, with its own unique set of complications. For example, retroperitoneal fluid collections, following ALIF surgery are rare and may result in back pain, radicular pain, nausea, and even death. It is important to rapidly identify the nature of the fluid collection to clarify appropriate management options. The purpose of this case report is to present a differential diagnosis for a delayed presentation of an extremely large retroperitoneal fluid collection following anterior lumbar surgery, as well as to provide discussion on this rare complication. Specifically, a 51-year-old female with a history of numerous previous abdominal surgeries underwent an L3-S1 ALIF through a paramedian retroperitoneal approach. Postoperatively, she developed a large retroperitoneal fluid collection heralded by unilateral left lower extremity swelling and paresthesias. Fluid aspiration suggested a urine leak, but no specific injury was identified on retrograde pyelogram, most likely due to hardware obscuration in the area of presumed injury. A presumptive ureteral injury resulted in a ureteral stent placement, with resolution of the fluid collection and hydronephrosis. A high index of suspicion allowed for proper treatment, healing, and ultimately, a satisfactory outcome. PMID:27085832

  9. Complication with removal of a lumbar spinal locking plate.

    PubMed

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

    2015-01-01

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

  10. Complication with Removal of a Lumbar Spinal Locking Plate

    PubMed Central

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

    2015-01-01

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

  11. 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

  12. 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)

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

    PubMed Central

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

    2015-01-01

    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. PMID:26180686

  14. Magnetic resonance imaging artifact following anterior cervical discectomy and fusion with a trabecular metal cage.

    PubMed

    Elliott, Cameron A; Fox, Richard; Ashforth, Robert; Gourishankar, Sita; Nataraj, Andrew

    2016-03-01

    OBJECT This study was undertaken to evaluate the impact of postoperative MRI artifact on the assessment of ongoing spinal cord or nerve root compression after anterior cervical discectomy and fusion (ACDF) using a trabecular tantalum cage or bone autograft or allograft. METHODS The authors conducted a retrospective review of postoperative MRI studies of patients treated surgically for cervical disc degenerative disease or cervical instability secondary to trauma. Standard ACDF with either a trabecular tantalum cage or interbody bone graft had been performed. Postoperative MR images were shown twice in random order to each of 3 assessors (2 spine surgeons, 1 neuroradiologist) to determine whether the presence of a tantalum interbody cage and/or anterior cervical fixation plate or screws imparted MRI artifact significant enough to prevent reliable postoperative assessment of ongoing spinal cord or nerve root compression. RESULTS A total of 63 patients were identified. One group of 29 patients received a tantalum interbody cage, with 13 patients (45%) undergoing anterior plate fixation. A second group of 34 patients received bone auto- or allograft, with 23 (68%) undergoing anterior plate fixation. The paramagnetic implant construct artifact had minimal impact on visualization of postoperative surgical level spinal cord compression. In the cage group, 98% (171/174) of the cases were rated as assessable versus 99% in the bone graft group (201/204), with high intraobserver reliability. In contrast, for the assessment of ongoing surgical level nerve root compression, the presence of a tantalum cage significantly decreased visualization of nerve roots to 70% (121/174) in comparison with 85% (173/204) in the bone graft group (p < 0.001). When sequences using turbo spin echo (TSE), a T2-weighted axial sequence, were acquired, nerve roots were rated as assessable in 88% (69/78) of cases; when only axial T2-weighted sequences were available, the nerve roots were rated as

  15. Clinical outcomes following sublaminar decompression and instrumented fusion for lumbar degenerative spinal pathology.

    PubMed

    Peddada, Kranti; Elder, Benjamin D; Ishida, Wataru; Lo, Sheng-Fu L; Goodwin, C Rory; Boah, Akwasi O; Witham, Timothy F

    2016-08-01

    Traditional treatment for lumbar stenosis with instability is laminectomy and posterolateral arthrodesis, with or without interbody fusion. However, laminectomies remove the posterior elements and decrease the available surface area for fusion. Therefore, a sublaminar decompression may be a preferred approach for adequate decompression while preserving bone surface area for fusion. A retrospective review of 71 patients who underwent sublaminar decompression in conjunction with instrumented fusion for degenerative spinal disorders at a single institution was performed. Data collected included demographics, preoperative symptoms, operative data, and radiographical measurements of the central canal, lateral recesses, and neural foramina, and fusion outcomes. Paired t-tests were used to test significance of the outcomes. Thirty-one males and 40 females with a median age 60years underwent sublaminar decompression and fusion. A median of two levels were fused. The mean Visual Analog Scale pain score improved from 6.7 preoperatively to 2.9 at last follow-up. The fusion rate was 88%, and the median time to fusion was 11months. Preoperative and postoperative mean thecal sac cross-sectional area, right lateral recess height, left lateral recess height, right foraminal diameter, and left foraminal diameter were 153 and 209mm(2) (p<0.001), 5.9 and 5.9mm (p=0.43), 5.8 and 6.3mm (p=0.027), 4.6 and 5.2mm (p=0.008), and 4.2 and 5.2mm (p<0.001), respectively. Sublaminar decompression provided adequate decompression, with significant increases in thecal sac cross-sectional area and bilateral foraminal diameter. It may be an effective alternative to laminectomy in treating central and foraminal stenosis in conjunction with instrumented fusion. PMID:27056673

  16. 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)

  17. 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. PMID:24786717

  18. 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.

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

    PubMed Central

    LIU, JINGCHEN; LI, YE; WU, YUNTAO

    2013-01-01

    The present study aimed to evaluate the effect of using one-stage posterior C2 and C3 pedicle screw fixation or combined anterior C2-C3 fusion in the treatment of unstable hangman’s fracture. A total of 13 patients with unstable hangman’s fractures underwent C2 and C3 pedicle screw fixation, lamina interbody fusion or combined anterior C2-C3 fusion and imaging examinations to evaluate the fracture fixation and healing condition at three days and three months following surgery. Postoperative X-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. PMID:23408668

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

    PubMed Central

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

    2010-01-01

    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. PMID:20195596

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

    PubMed Central

    Barrey, Cédric; Perrin, Gilles; Champain, Sabina

    2013-01-01

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

  2. 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.

  3. 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

  4. Experimental laparoscopic and thoracoscopic discectomy and instrumented spinal fusion. A feasibility study using a porcine model.

    PubMed

    Mühlbauer, M; Ferguson, J; Losert, U; Koos, W T

    1998-03-01

    To explore the safety and the effectiveness of laparoscopic and thoracoscopic spinal surgery, an acute/non-survival animal trial was performed in 5 pigs using rigid and flexible endoscopes, flouroscopy, a holmium-YAG laser, and prototype instruments and implants. Our study aimed to approach the intervertebral disc space and spinal canal using laparoscopic and thoracoscopic techniques and to explore the potential and limits for endoscopic anterior spinal decompression and fusion. In a lateral recumbency access was provided to the anterolateral aspect of the lumbar spine from L1/2 to L7/S1, the thoracic spine was accessible from T2/3 to the diaphragmatic insertion. Complete disc space emptying with penetration into the spinal canal could be performed, epidural bleeding could be controlled by a hemostatic sponge, however bleeding restricted visualization for further endoscopic manipulation in the spinal canal. Intervertebral fusion was accomplished at T6/7, L4/5 and L7/S1 using small fragment plates with 3.5 mm screws and iliac bone grafts or prototype carbon fiber cages. On post mortem examination we found no dural tears and no nerve root damage, all animals had stabilized fusion sites and good implant position. We conclude that minimally invasive thoracoscopic and laparoscopic approaches to the spine are feasible and safe to perform disc decompression and implant placement for spinal fusion. In addition to currently performed laparoscopic interbody fusion, also plate fixation to reestablish lordosis of the lumbar spine is feasible at least in the porcine model. Careful disc decompression must be performed prior to implant introduction to prevent iatrogenic disc protrusion and spinal cord or nerve root compression. However, further surgical exploration of the spinal canal using these techniques does not provide adequate visualization of epidural spaces and therefore must be regarded as unsafe. PMID:9565956

  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. Using Provocative Discography and Computed Tomography to Select Patients with Refractory Discogenic Low Back Pain for Lumbar Fusion Surgery

    PubMed Central

    Tong, Henry C; Fahim, Daniel K; Perez-Cruet, Mick

    2016-01-01

    Background Context Controversy remains over the use of provocative discography in conjunction with computed tomography (CT) to locate symptomatic intervertebral discs in patients with chronic, low back pain (LBP). The current study explores the relationship between discogenic pain and disc morphology using discography and CT, respectively, and investigates the efficacy of this combined method in identifying surgical candidates for lumbar fusion by evaluating outcomes. Methods 43 consecutive patients between 2006 and 2013 who presented with refractory low back pain and underwent discography and CT were enrolled in the study. For this study, "refractory LBP" was defined as pain symptoms that persisted or worsened after 6 months of non-operative treatments. Concordant pain was defined as discography-provoked LBP of similar character and location with an intensity of ≥ 8/10. Fusion candidates demonstrated positive-level discography and concordant annular tears on CT at no more than two contiguous levels, and at least one negative control disc with intact annulus. Surgical outcomes were statistically analyzed using Visual Analog Scale (VAS), Oswestry Disability Index (ODI), and Short Form-36 (SF-36) for back-related pain and disability preoperatively, and 2 weeks, 3, 6, 12, and 24 months postoperatively. Results Annular tears were found in 87 discs. Concordant pain was reported by 9 (20.9%) patients at L3-L4, 21 (50.0%) at L4-L5, and 34 (82.9%) at L5-S1; pain occurred significantly more often in discs with annular tears than those without (p<0.001). Painless discs were independent of annulus status (p=0.90). 18 (42%) of the original 43 patients underwent lumbar fusion at L3-L4 (n=1(6%)), L4-L5 (n=6 (33%)), L5-S1 (n=5 (28%)), and two-level L4-S1 (n=6 (33%)) via a minimally invasive transforaminal lumbar interbody fusion (MITLIF) approach with the aim to replace the nucleus pulposus with bone graft material. Median follow-up time was 18 months (range: 12–78 months

  8. Using Provocative Discography and Computed Tomography to Select Patients with Refractory Discogenic Low Back Pain for Lumbar Fusion Surgery.

    PubMed

    Xi, Mengqiao Alan; Tong, Henry C; Fahim, Daniel K; Perez-Cruet, Mick

    2016-01-01

    Background Context Controversy remains over the use of provocative discography in conjunction with computed tomography (CT) to locate symptomatic intervertebral discs in patients with chronic, low back pain (LBP). The current study explores the relationship between discogenic pain and disc morphology using discography and CT, respectively, and investigates the efficacy of this combined method in identifying surgical candidates for lumbar fusion by evaluating outcomes. Methods 43 consecutive patients between 2006 and 2013 who presented with refractory low back pain and underwent discography and CT were enrolled in the study. For this study, "refractory LBP" was defined as pain symptoms that persisted or worsened after 6 months of non-operative treatments. Concordant pain was defined as discography-provoked LBP of similar character and location with an intensity of ≥ 8/10. Fusion candidates demonstrated positive-level discography and concordant annular tears on CT at no more than two contiguous levels, and at least one negative control disc with intact annulus. Surgical outcomes were statistically analyzed using Visual Analog Scale (VAS), Oswestry Disability Index (ODI), and Short Form-36 (SF-36) for back-related pain and disability preoperatively, and 2 weeks, 3, 6, 12, and 24 months postoperatively. Results Annular tears were found in 87 discs. Concordant pain was reported by 9 (20.9%) patients at L3-L4, 21 (50.0%) at L4-L5, and 34 (82.9%) at L5-S1; pain occurred significantly more often in discs with annular tears than those without (p<0.001). Painless discs were independent of annulus status (p=0.90). 18 (42%) of the original 43 patients underwent lumbar fusion at L3-L4 (n=1(6%)), L4-L5 (n=6 (33%)), L5-S1 (n=5 (28%)), and two-level L4-S1 (n=6 (33%)) via a minimally invasive transforaminal lumbar interbody fusion (MITLIF) approach with the aim to replace the nucleus pulposus with bone graft material. Median follow-up time was 18 months (range: 12-78 months

  9. 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. PMID:27270922

  10. 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. PMID:24980580

  11. Posterior Interspinous Fusion Device for One-Level Fusion in Degenerative Lumbar Spine Disease : Comparison with Pedicle Screw Fixation - Preliminary Report of at Least One Year Follow Up

    PubMed Central

    Kim, Ho Jung; Chun, Hyoung Joon; Oh, Suck Jun; Kang, Tae Hoon; Yang, Moon Sool

    2012-01-01

    Objective Transpedicular screw fixation has some disadvantages such as postoperative back pain through wide muscle dissection, long operative time, and cephalad adjacent segmental degeneration (ASD). The purposes of this study are investigation and comparison of radiological and clinical results between interspinous fusion device (IFD) and pedicle screw. Methods From Jan. 2008 to Aug. 2009, 40 patients underwent spinal fusion with IFD combined with posterior lumbar interbody fusion (PLIF). In same study period, 36 patients underwent spinal fusion with pedicle screw fixation as control group. Dynamic lateral radiographs, visual analogue scale (VAS), and Korean version of the Oswestry disability index (K-ODI) scores were evaluated in both groups. Results The lumbar spine diseases in the IFD group were as followings; spinal stenosis in 26, degenerative spondylolisthesis in 12, and intervertebral disc herniation in 2. The mean follow up period was 14.24 months (range; 12 to 22 months) in the IFD group and 18.3 months (range; 12 to 28 months) in pedicle screw group. The mean VAS scores was preoperatively 7.16±2.1 and 8.03±2.3 in the IFD and pedicle screw groups, respectively, and improved postoperatively to 1.3±2.9 and 1.2±3.2 in 1-year follow ups (p<0.05). The K-ODI was decreased significantly in an equal amount in both groups one year postoperatively (p<0.05). The statistics revealed a higher incidence of ASD in pedicle screw group than the IFD group (p=0.029). Conclusion Posterior IFD has several advantages over the pedicle screw fixation in terms of skin incision, muscle dissection and short operative time and less intraoperative estimated blood loss. The IFD with PLIF may be a favorable technique to replace the pedicle screw fixation in selective case. PMID:23133725

  12. Single-stage Anterior and Posterior Fusion Surgery for Correction of Cervical Kyphotic Deformity Using Intervertebral Cages and Cervical Lateral Mass Screws: Postoperative Changes in Total Spine Sagittal Alignment in Three Cases with a Minimum Follow-up of Five Years.

    PubMed

    Ogihara, Satoshi; Kunogi, Junichi

    2015-01-01

    The surgical treatment of cervical kyphotic deformity remains challenging. As a surgical method that is safer and avoids major complications, the authors present a procedure of single-stage anterior and posterior fusion to correct cervical kyphosis using anterior interbody fusion cages without plating, as illustrated by three consecutive cases. Case 1 was a 78-year-old woman who presented with a dropped head caused by degeneration of her cervical spine. Case 2 was a 54-year-old woman with athetoid cerebral palsy. She presented with cervical myelopathy and cervical kyphosis. Case 3 was a 71-year-old woman with cervical kyphotic deformity following a laminectomy. All three patients underwent anterior release and interbody fusion with cages and posterior fusion with cervical lateral mass screw (LMS) fixation. Postoperative radiographs showed that correction of kyphosis was 39° in case 1, 43° in case 2, and 39° in case 3. In all three cases, improvement of symptoms was established without major perioperative complications, solid fusion was achieved, and no loss of correction was observed at a minimum follow-up of 61 months. We also report that preoperative total spine sagittal malalignment was improved after corrective surgery for cervical kyphosis and was maintained at the latest follow-up in all three cases. The combination of anterior fusion cages and LMS is considered a safe and effective procedure in cases of severe cervical kyphotic deformity. Preoperative total spine sagittal malalignment improved, accompanied by correction of cervical kyphosis, and was maintained at last follow-up in all three cases. PMID:26119893

  13. 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

  14. Magneto-Inertial Fusion

    DOE PAGESBeta

    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.; et al

    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.

  15. Slow liner fusion

    SciTech Connect

    Shaffer, M.J.

    1997-08-01

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

  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. Cluster-impact fusion

    SciTech Connect

    Echenique, P.M.; Manson, J.R.; Ritchie, R.H. )

    1990-03-19

    We present a model for the cluster-impact-fusion experiments of Buehler, Friedlander, and Friedman, Calculated fusion rates as a function of bombarding energy for constant cluster size agree well with experiment. The dependence of the fusion rate on cluster size at fixed bombarding energy is explained qualitatively. The role of correlated, coherent collisions in enhanced energy loss by clusters is emphasized.

  18. 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.

  19. The fusion breeder

    NASA Astrophysics Data System (ADS)

    Moir, Ralph W.

    1982-10-01

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

  20. 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.

  1. 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.

  2. 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.

  3. 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…

  4. 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.

  5. 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…

  6. 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

  7. Decomposition of incomplete fusion

    SciTech Connect

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

    1989-01-01

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

  8. 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.

  9. 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.

  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. Label fusion strategy selection.

    PubMed

    Robitaille, Nicolas; Duchesne, Simon

    2012-01-01

    Label fusion is used in medical image segmentation to combine several different labels of the same entity into a single discrete label, potentially more accurate, with respect to the exact, sought segmentation, than the best input element. Using simulated data, we compared three existing label fusion techniques-STAPLE, Voting, and Shape-Based Averaging (SBA)-and observed that none could be considered superior depending on the dissimilarity between the input elements. We thus developed an empirical, hybrid technique called SVS, which selects the most appropriate technique to apply based on this dissimilarity. We evaluated the label fusion strategies on two- and three-dimensional simulated data and showed that SVS is superior to any of the three existing methods examined. On real data, we used SVS to perform fusions of 10 segmentations of the hippocampus and amygdala in 78 subjects from the ICBM dataset. SVS selected SBA in almost all cases, which was the most appropriate method overall. PMID:22518113

  12. HIV-1 Fusion Assay

    PubMed Central

    Cavrois, Marielle; Neidleman, Jason; Greene, Warner C.

    2016-01-01

    The HIV-1 fusion assay measures all steps in the HIV-1 life cycle up to and including viral fusion. It relies on the incorporation of a β-lactamase Vpr (BlaM-Vpr) protein chimera into the virion and the subsequent transfer of this chimera into the target cell by fusion (Figure 1). The transfer is monitored by the enzymatic cleavage of CCF2, a fluorescent dye substrate of β-lactamase, loaded into the target cells. Cleavage of the β-lactam ring in CCF2 by β-lactamase changes the fluorescence emission spectrum of the dye from green (520 nm) to blue (447 nm). This change reflects virion fusion and can be detected by flow cytometry (Figure 2).

  13. Fusion power demonstration

    SciTech Connect

    Henning, C.D.; Logan, B.G.

    1983-09-01

    As a satellite to the MARS (Mirror Advanced Reactor Study) a smaller, near-term device has been scoped, called the FPD (Fusion Power Demonstration). Envisioned as the next logical step toward a power reactor, it would advance the mirror fusion program beyond MFTF-B and provide an intermediate step toward commercial fusion power. Breakeven net electric power capability would be the goal such that no net utility power would be required to sustain the operation. A phased implementation is envisioned, with a deuterium checkout first to verify the plasma systems before significant neutron activation has occurred. Major tritium-related facilities would be installed with the second phase to produce sufficient fusion power to supply the recirculating power to maintain the neutral beams, ECRH, magnets and other auxiliary equipment.

  14. 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)

  15. Progress toward fusion energy

    SciTech Connect

    Thomassen, K.I.

    1981-03-11

    This paper summarizes the basis for the present optimism in the magnetic fusion program, and describes some of the remaining tasks leading to a demonstration power reactor and the primary technologies necessary for that endeavor.

  16. 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.

  17. Glossary of fusion energy

    SciTech Connect

    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.

  18. Advances in fusion technology

    NASA Astrophysics Data System (ADS)

    Baker, Charles C.

    2000-12-01

    The US fusion technology program is an essential element in the development of the knowledge base for an attractive fusion power source. The technology program incorporates both near and long term R&D, contributes to material and engineering sciences as well as technology development, ranges from hardware production to theory and modeling, contributes significantly to spin-off applications, and performs global systems assessments and focused design studies.

  19. 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.

  20. ITER Fusion Energy

    ScienceCinema

    Dr. Norbert Holtkamp

    2010-01-08

    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.

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

    PubMed

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

    2014-07-01

    to increase in tandem with new bone ingrowth into the pores, while maintaining good structural integrity necessary for supporting the spinal interbody segments. Therefore, with the better osteointegration, more bone tissue ingrowth as well as its favorable biodegradable and radiolucent properties, PCL-TCP cage has been demonstrated to be a promising candidate as an autograft-free fusion cage for clinical application. PMID:24743032

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. Simulation of Fusion Plasmas

    ScienceCinema

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

    2010-01-08

    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.

  7. 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.

  8. Colliding Beam Fusion Reactors

    NASA Astrophysics Data System (ADS)

    Rostoker, Norman; Qerushi, Artan; Binderbauer, Michl

    2003-06-01

    The recirculating power for virtually all types of fusion reactors has previously been calculated [1] with the Fokker-Planck equation. The reactors involve non-Maxwellian plasmas. The calculations are generic in that they do not relate to specific confinement devices. In all cases except for a Tokamak with D-T fuel the recirculating power was found to exceed the fusion power by a large factor. In this paper we criticize the generality claimed for this calculation. The ratio of circulating power to fusion power is calculated for the Colliding Beam Reactor with fuels D-T, D-He3 and p-B11. The results are respectively, 0.070, 0.141 and 0.493.

  9. 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.

  10. 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.

  11. [Ultrasound-assisted neuraxial anesthesia in a patient with previous lumbar laminectomy and fusion: a case report].

    PubMed

    Geng, J; Li, M

    2016-02-18

    A patient with previous L3-4 posterior lumbar interbody fusion, pedicle screws instrumentation and L3-4 decompression, was scheduled for left total hip arthroplasty. Two years ago, due to poor landmarks palpation, the patient experienced a failed lumbar puncture after multiple attempts before herniorrhaphy. His plain radiography showed bilateral partial laminectomy at L3-4 level, and between L3 and L4, two posterior pedicle screws connected by metal rods on both sides. This time, we used ultrasound to locate L4-5 interlaminar space in paramedian sagittal oblique view and identified the spine midline by transverse interlaminar view before puncture. According to this information, L4-5 puncture point was verified and the combined spinal-epidural anesthesia was performed in a paramedian approach. After withdrawing clear cerebral spinal fluid, 15 mg hyperbaric bupivicaine was injected into intrathecal space. An epidural catheter was then inserted into the epidural space. The sensory block level was fixed at T10 to S within 10 minutes. Intraoperatively, the patient received 10 mL 2% (mass fraction) lidocaine through the epidural catheter in total. The surgery was uneventful. No neurologic complication was observed after the surgery. This case report demonstrates that ultRASound imaging can provide useful information for neuraxial needle placement and can be a valuable tool in managing patients with anatomical change around the spine. PMID:27538165

  12. 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.

  13. DD fusion in crystals

    SciTech Connect

    Tsyganov, E. N.

    2010-12-15

    The article discusses the mechanism of DD {sup {yields} 4}He fusion and so-called nonradiative thermalization of the reaction in crystals. The dynamics of this process is considered. The assumption that the decay time of the compound nucleus depends on its excitation energy makes experiments in crystals compatible with the acceleration data.We consider the processes in the crystals that increase the intensity ofDD fusion in comparison to the amorphous media, and the yield of the reaction is estimated.

  14. 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.

  15. 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.

  16. 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

  17. Fusion technology status and requirements

    SciTech Connect

    Thomassen, K.I.

    1982-01-26

    This paper summarizes the status of fusion technology and discusses the requirements to be met in order to build a demonstration fusion plant. Strategies and programmatic considerations in pursuing engineering feasibility are also outlined.

  18. 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.

  19. Cost effectiveness of disc prosthesis versus lumbar fusion in patients with chronic low back pain: randomized controlled trial with 2-year follow-up.

    PubMed

    Fritzell, Peter; Berg, Svante; Borgström, Fredrik; Tullberg, Tycho; Tropp, Hans

    2011-07-01

    This randomized controlled health economic study assesses the cost-effectiveness of the concept of total disc replacement (TDR) (Charité/Prodisc/Maverick) when compared with the concept of instrumented lumbar fusion (FUS) [posterior lumbar fusion (PLF) /posterior lumbar interbody fusion (PLIF)]. Social and healthcare perspectives after 2 years are reported. In all, 152 patients were randomized to either TDR (n = 80) or lumbar FUS (n = 72). Cost to society (total mean cost/patient, Swedish kronor = SEK, standard deviation) for TDR was SEK 599,560 (400,272), and for lumbar FUS SEK 685,919 (422,903) (ns). The difference was not significant: SEK 86,359 (-45,605 to 214,332). TDR was significantly less costly from a healthcare perspective, SEK 22,996 (1,202 to 43,055). Number of days on sick leave among those who returned to work was 185 (146) in the TDR group, and 252 (189) in the FUS group (ns). Using EQ-5D, the total gain in quality adjusted life years (QALYs) over 2 years was 0.41 units for TDR and 0.40 units for FUS (ns). Based on EQ-5D, the incremental cost-effectiveness ratio (ICER) of using TDR instead of FUS was difficult to analyze due to the "non-difference" in treatment outcome, which is why cost/QALY was not meaningful to define. Using cost-effectiveness probabilistic analysis, the net benefit (with CI) was found to be SEK 91,359 (-73,643 to 249,114) (ns). We used the currency of 2006 where 1 EURO = 9.26 SEK and 1 USD = 7.38 SEK. It was not possible to state whether TDR or FUS is more cost-effective after 2 years. Since disc replacement and lumbar fusion are based on different conceptual approaches, it is important to follow these results over time. PMID:21053028

  20. 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.

  1. Multilevel fusion exploitation

    NASA Astrophysics Data System (ADS)

    Lindberg, Perry C.; Dasarathy, Belur V.; McCullough, Claire L.

    1996-06-01

    This paper describes a project that was sponsored by the U.S. Army Space and Strategic Defense Command (USASSDC) to develop, test, and demonstrate sensor fusion algorithms for target recognition. The purpose of the project was to exploit the use of sensor fusion at all levels (signal, feature, and decision levels) and all combinations to improve target recognition capability against tactical ballistic missile (TBM) targets. These algorithms were trained with simulated radar signatures to accurately recognize selected TBM targets. The simulated signatures represent measurements made by two radars (S-band and X- band) with the targets at a variety of aspect and roll angles. Two tests were conducted: one with simulated signatures collected at angles different from those in the training database and one using actual test data. The test results demonstrate a high degree of recognition accuracy. This paper describes the training and testing techniques used; shows the fusion strategy employed; and illustrates the advantages of exploiting multi-level fusion.

  2. 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.

  3. Status of inertial fusion

    NASA Astrophysics Data System (ADS)

    Keefe, D.

    1987-04-01

    The technology advancement to high-power beams has also given birth to new technologies. That class of Free Electron Lasers that employs RF linacs, synchrotrons, and storage rings - although the use of the tools of High Energy Physics (HEP) - was developed well behind the kinetic energy frontier. The induction linac, however, is something of an exception; it was born directly from the needs of the magnetic fusion program, and was not motivated by a high-energy physics application. The heavy-ion approach to inertial fusion starts with picking from the rich menu of accelerator technologies those that have, ab initio, the essential ingredients needed for a power plant driver: multigap acceleration - which leads to reliability/lifetime; electrical efficiency; repetition rate; and beams that can be reliably focused over a suitably long distance. The report describes the programs underway in Heavy Ion Fusion Accelerator Research as well as listing expected advances in driver, target, and beam quality areas in the inertial fusion power program.

  4. Separating Fusion from Rivalry

    PubMed Central

    Dechent, Peter; Forster, Clemens; von Steinbüchel, Nicole; Wüstenberg, Torsten; Strasburger, Hans

    2014-01-01

    Visual fusion is the process in which differing but compatible binocular information is transformed into a unified percept. Even though this is at the basis of binocular vision, the underlying neural processes are, as yet, poorly understood. In our study we therefore aimed to investigate neural correlates of visual fusion. To this end, we presented binocularly compatible, fusible (BF), and incompatible, rivaling (BR) stimuli, as well as an intermediate stimulus type containing both binocularly fusible and monocular, incompatible elements (BFR). Comparing BFR stimuli with BF and BR stimuli, respectively, we were able to disentangle brain responses associated with either visual fusion or rivalry. By means of functional magnetic resonance imaging, we measured brain responses to these stimulus classes in the visual cortex, and investigated them in detail at various retinal eccentricities. Compared with BF stimuli, the response to BFR stimuli was elevated in visual cortical areas V1 and V2, but not in V3 and V4 – implying that the response to monocular stimulus features decreased from V1 to V4. Compared to BR stimuli, the response to BFR stimuli decreased with increasing eccentricity, specifically within V3 and V4. Taken together, it seems that although the processing of exclusively monocular information decreases from V1 to V4, the processing of binocularly fused information increases from earlier to later visual areas. Our findings suggest the presence of an inhibitory neural mechanism which, depending on the presence of fusion, acts differently on the processing of monocular information. PMID:25054904

  5. 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.

  6. 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.

  7. 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.

  8. Enhanced image capture through fusion

    NASA Technical Reports Server (NTRS)

    Burt, Peter J.; Hanna, Keith; Kolczynski, Raymond J.

    1993-01-01

    Image fusion may be used to combine images from different sensors, such as IR and visible cameras, to obtain a single composite with extended information content. Fusion may also be used to combine multiple images from a given sensor to form a composite image in which information of interest is enhanced. We present a general method for performing image fusion and show that this method is effective for diverse fusion applications. We suggest that fusion may provide a powerful tool for enhanced image capture with broad utility in image processing and computer vision.

  9. Research on fusion neutron sources

    NASA Astrophysics Data System (ADS)

    Gryaznevich, M. P.

    2012-06-01

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

  10. 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.

  11. Acquired spondylolysis after spinal fusion.

    PubMed

    Brunet, J A; Wiley, J J

    1984-11-01

    Spondylolysis occurring after a spinal fusion is considered to result from operative damage to the pars interarticularis on both sides. Fourteen cases are reported, and compared with the 23 cases which have previously been published. The defects are usually recognised within five years of fusion, and usually occur immediately above the fusion mass. Other contributory causes may be: fatigue fracture from concentration of stress; damage and altered function of the posterior ligament complex; and degenerative disc disease immediately above or below the fusion. Fusion technique is critical, since virtually all cases occurred after posterior interlaminar fusions. This complication is easily overlooked in patients with recurrent back pain after an originally successful posterior spinal fusion. PMID:6501368

  12. 50 years of fusion research

    NASA Astrophysics Data System (ADS)

    Meade, Dale

    2010-01-01

    Fusion energy research began in the early 1950s as scientists worked to harness the awesome power of the atom for peaceful purposes. There was early optimism for a quick solution for fusion energy as there had been for fission. However, this was soon tempered by reality as the difficulty of producing and confining fusion fuel at temperatures of 100 million °C in the laboratory was appreciated. Fusion research has followed two main paths—inertial confinement fusion and magnetic confinement fusion. Over the past 50 years, there has been remarkable progress with both approaches, and now each has a solid technical foundation that has led to the construction of major facilities that are aimed at demonstrating fusion energy producing plasmas.

  13. Evaluation of a Hybrid Dynamic Stabilization and Fusion System in the Lumbar Spine: A 10 Year Experience

    PubMed Central

    Kashkoush, Ahmed; Agarwal, Nitin; Paschel, Erin; Goldschmidt, Ezequiel

    2016-01-01

    Introduction: The development of adjacent-segment disease is a recognized consequence of lumbar fusion surgery. Posterior dynamic stabilization, or motion preservation, techniques have been developed which theoretically decrease stress on adjacent segments following fusion. This study presents the experience of using a hybrid dynamic stabilization and fusion construct for degenerative lumbar spine pathology in place of rigid arthrodesis. Methods: A clinical cohort investigation was conducted of 66 consecutive patients (31 female, 35 male; mean age: 53 years, range: 25 – 76 years) who underwent posterior lumbar instrumentation with the Dynesys Transition Optima (DTO) implant (Zimmer-Biomet Spine, Warsaw, IN) hybrid dynamic stabilization and fusion system over a 10-year period. The median length of follow-up was five years. DTO consists of pedicle screw fixation coupled to a rigid rod as well as a flexible longitudinal connecting system. All patients had symptoms of back pain and neurogenic claudication refractory to non-surgical treatment. Patients underwent lumbar arthrodesis surgery in which the hybrid system was used for stabilization instead of arthrodesis of the stenotic adjacent level. Results: Indications for DTO instrumentation were primary degenerative disc disease (n = 52) and failed back surgery syndrome (n = 14). The most common dynamically stabilized and fused segments were L3-L4 (n = 37) and L5-S1 (n = 33), respectively. Thirty-eight patients (56%) underwent decompression at the dynamically stabilized level, and 57 patients (86%) had an interbody device placed at the level of arthrodesis. Complications during the follow-up period included a single case of screw breakage and a single case of pseudoarthrosis. Ten patients (15%) subsequently underwent conversion of the dynamic stabilization portion of their DTO instrumentation to rigid spinal arthrodesis. Conclusion: The DTO system represents a novel hybrid dynamic stabilization and fusion construct

  14. 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.

  15. Synaptic vesicle fusion

    PubMed Central

    Rizo, Josep; Rosenmund, Christian

    2008-01-01

    The core of the neurotransmitter release machinery is formed by SNARE complexes, which bring the vesicle and plasma membranes together and are key for fusion, and by Munc18-1, which controls SNARE-complex formation and may also have a direct role in fusion. In addition, SNARE complex assembly is likely orchestrated by Munc13s and RIMs, active-zone proteins that function in vesicle priming and diverse forms of presynaptic plasticity. Synaptotagmin-1 mediates triggering of release by Ca2+, probably through interactions with SNAREs and both membranes, as well as through a tight interplay with complexins. Elucidation of the release mechanism will require a full understanding of the network of interactions among all these proteins and the membranes. PMID:18618940

  16. Spectral Label Fusion

    PubMed Central

    Wachinger, Christian; Golland, Polina

    2012-01-01

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

  17. Adaptive sensor fusion

    NASA Astrophysics Data System (ADS)

    Kadar, Ivan

    1995-07-01

    A perceptual reasoning system adaptively extracting, associating, and fusing information from multiple sources, at various levels of abstraction, is considered as the building block for the next generation of surveillance systems. A system architecture is presented which makes use of both centralized and distributed predetection fusion combined with intelligent monitor and control coupling both on-platform and off-board track and decision level fusion results. The goal of this system is to create a `gestalt fused sensor system' whose information product is greater than the sum of the information products from the individual sensors and has performance superior to either individual or a sub-group of combined sensors. The application of this architectural concept to the law enforcement arena (e.g. drug interdiction) utilizing multiple spatially and temporally diverse surveillance platforms and/or information sources, is used to illustrate the benefits of the adaptive perceptual reasoning system concept.

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

    PubMed Central

    2013-01-01

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

  19. Fc-fusion mimetics.

    PubMed

    Khalili, H; Khaw, P T; Brocchini, S

    2016-06-24

    The Fc-fusion mimetic RpR 2[combining low line] was prepared by disulfide bridging conjugation using PEG in the place of the Fc. RpR 2[combining low line] displayed higher affinity for VEGF than aflibercept. This is caused primarily by a slower dissociation rate, which can prolong a drug at its site of action. RpRs have considerable potential for development as stable, organ specific therapeutics. PMID:27127811

  20. 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.

  1. Inertial Confinement fusion targets

    NASA Technical Reports Server (NTRS)

    Hendricks, C. D.

    1982-01-01

    Inertial confinement fusion (ICF) targets are made as simple flat discs, as hollow shells or as complicated multilayer structures. Many techniques were 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.

  2. (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.

  3. 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. __________________________________________________

  4. 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.

  5. 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.

  6. Sensor fusion for synthetic vision

    NASA Technical Reports Server (NTRS)

    Pavel, M.; Larimer, J.; Ahumada, A.

    1991-01-01

    Display methodologies are explored for fusing images gathered by millimeter wave sensors with images rendered from an on-board terrain data base to facilitate visually guided flight and ground operations in low visibility conditions. An approach to fusion based on multiresolution image representation and processing is described which facilitates fusion of images differing in resolution within and between images. To investigate possible fusion methods, a workstation-based simulation environment is being developed.

  7. EDITORIAL: The Nuclear Fusion Award The Nuclear Fusion Award

    NASA Astrophysics Data System (ADS)

    Kikuchi, M.

    2011-01-01

    The Nuclear Fusion Award ceremony for 2009 and 2010 award winners was held during the 23rd IAEA Fusion Energy Conference in Daejeon. This time, both 2009 and 2010 award winners were celebrated by the IAEA and the participants of the 23rd IAEA Fusion Energy Conference. The Nuclear Fusion Award is a paper prize to acknowledge the best distinguished paper among the published papers in a particular volume of the Nuclear Fusion journal. Among the top-cited and highly-recommended papers chosen by the Editorial Board, excluding overview and review papers, and by analyzing self-citation and non-self-citation with an emphasis on non-self-citation, the Editorial Board confidentially selects ten distinguished papers as nominees for the Nuclear Fusion Award. Certificates are given to the leading authors of the Nuclear Fusion Award nominees. The final winner is selected among the ten nominees by the Nuclear Fusion Editorial Board voting confidentially. 2009 Nuclear Fusion Award nominees For the 2009 award, the papers published in the 2006 volume were assessed and the following papers were nominated, most of which are magnetic confinement experiments, theory and modeling, while one addresses inertial confinement. Sabbagh S.A. et al 2006 Resistive wall stabilized operation in rotating high beta NSTX plasmas Nucl. Fusion 46 635-44 La Haye R.J. et al 2006 Cross-machine benchmarking for ITER of neoclassical tearing mode stabilization by electron cyclotron current drive Nucl. Fusion 46 451-61 Honrubia J.J. et al 2006 Three-dimensional fast electron transport for ignition-scale inertial fusion capsules Nucl. Fusion 46 L25-8 Ido T. et al 2006 Observation of the interaction between the geodesic acoustic mode and ambient fluctuation in the JFT-2M tokamak Nucl. Fusion 46 512-20 Plyusnin V.V. et al 2006 Study of runaway electron generation during major disruptions in JET Nucl. Fusion 46 277-84 Pitts R.A. et al 2006 Far SOL ELM ion energies in JET Nucl. Fusion 46 82-98 Berk H.L. et al 2006

  8. 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.

  9. Generic magnetic fusion rocket model

    SciTech Connect

    Santarius, J.F.; Logan, B.G.

    1993-06-01

    A generic magnetic fusion rocket model is developed and used to explore the limits of fusion propulsion systems. Two fusion fuels are examined, D-T and D-(He-3), and the D-(He-3) fuel cycle is found to give a higher specific power in almost all parameter regimes. The key findings are that (1) magnetic fusion should ultimately be able to deliver specific powers of about 10 kW/kg and (2) specific powers of 15 kW/kg could be achieved with only modest extrapolations of present technology. 9 refs.

  10. 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.

  11. 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.

  12. COLLABORATIVE: FUSION SIMULATION PROGRAM

    SciTech Connect

    Chang, Choong Seock

    2012-06-05

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

  13. 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∗.

  14. 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.

  15. 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.

  16. 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)

  17. Biomechanical evaluation of an endplate-conformed polycaprolactone-hydroxyapatite intervertebral fusion graft and its comparison with a typical nonconformed cortical graft.

    PubMed

    Agarwal, Aakash; Palepu, Vivek; Agarwal, Anand K; Goel, Vijay K; Yildirim, Eda D

    2013-06-01

    In the thoracolumbar region, between 7% and 30% of spinal fusion failures are at risk for pseudarthrosis. From a biomechanical perspective, the nonconformity of the intervertebral graft to the endplate surface could contribute to pseudarthrosis, given suboptimal stress distributions. The objective of this study was to quantify the effect of endplate-graft conformation on endplate stress distribution, maximum Von Mises stress development, and stability. The study design used an experimentally validated finite element (FE) model of the L4-L5 functional spinal unit to simulate two types of interbody grafts (cortical bone and polycaprolactone (PCL)-hydroxyapatite (HA) graft), with and without endplate-conformed surfaces. Two case studies were completed. In Case Study I, the endplate-conformed grafts and nonconformed grafts were compared under without posterior instrumentation condition, while in Case Study II, the endplate-conformed and nonconformed grafts were compared with posterior instrumentation. In both case studies, the results suggested that the increased endplate-graft conformity reduced the maximum stress on the endplate, created uniform stress distribution on endplate surfaces, and reduced the range of motion of L4-L5 segments by increasing the contact surface area between the graft and the endplate. The stress distributions in the endplate suggest that the load sharing is greater with the endplate-conformed PCL-HA graft, which might reduce the graft subsidence possibility. PMID:23699717

  18. 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.

  19. 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).

  20. Fusion processor simulation (FPSim)

    NASA Astrophysics Data System (ADS)

    Barnell, Mark D.; Wynne, Douglas G.; Rahn, Brian J.

    1998-07-01

    The Fusion Processor Simulation (FPSim) is being developed by Rome Laboratory to support the Discrimination Interceptor Technology (DITP) and Advanced Sensor Technology (ASTP) Programs of the Ballistic Missile Defense Organization. The purpose of the FPSim is to serve as a test bed and evaluation tool for establishing the feasibility of achieving threat engagement timelines. The FPSim supports the integration, evaluation, and demonstration of different strategies, system concepts, and Acquisition Tracking & Pointing (ATP) subsystems and components. The environment comprises a simulation capability within which users can integrate and test their application software models, algorithms and databases. The FPSim must evolve as algorithm developments mature to support independent evaluation of contractor designs and the integration of a number of fusion processor subsystem technologies. To accomplish this, the simulation contains validated modules, databases, and simulations. It possesses standardized engagement scenarios, architectures and subsystem interfaces, and provides a hardware and software framework which is flexible to support growth, reconfigurration, and simulation component modification and insertion. Key user interaction features include: (1) Visualization of platform status through displays of the surveillance scene as seen by imaging sensors. (2) User-selectable data analysis and graphics display during the simulation execution as well as during post-simulation analysis. (3) Automated, graphical tools to permit the user to reconfigure the FPSim, i.e., 'Plug and Play' various model/software modules. The FPSim is capable of hosting and executing user's software algorithms of image processing, signal processing, subsystems, and functions for evaluation purposes.

  1. The status of cold fusion

    NASA Astrophysics Data System (ADS)

    Storms, E.

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

  2. 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.

  3. Cellulose binding domain fusion proteins

    DOEpatents

    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.

  4. 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.

  5. Feature-level sensor fusion

    NASA Astrophysics Data System (ADS)

    Peli, Tamar; Young, Mon; Knox, Robert; Ellis, Kenneth K.; Bennett, Frederick

    1999-03-01

    This paper describes two practical fusion techniques for automatic target cueing that combine features derived from each sensor data ta the object-level. In the hybrid fusion method each of the input sensor data is prescreened before the fusion stage. The cued fusion method assumes that one of the sensors is designated as a primary sensor, and thus ATC is only applied to its input data. If one of the sensors exhibits a higher Pd and/or a lower false alarm rate, it can be selected as the primary sensor. However, if the ground coverage can be segmented to regions in which one of the sensors is known to exhibit better performance, then the cued fusion can be applied locally/adaptively by switching the choice of a primary sensor. Otherwise, the cued fusion is applied both ways and the outputs of each cued mode are combined. Both fusion approaches use a back-end discrimination stage that is applied to a combined feature vector to reduce false alarms. The two fusion processes were applied to spectral and radar sensor data nd were shown to provide substantial false alarm reduction. The approaches are easily extendable to more than two sensors.

  6. The quest for fusion power

    NASA Astrophysics Data System (ADS)

    Cowley, Steven C.

    2016-05-01

    Fusion power is one of a very few sustainable options to replace fossil fuels as the world's primary energy source. Although the conditions for fusion have been reached, much remains to be done to turn scientific success into commercial electrical power.

  7. 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.

  8. Magnetic fusion energy and computers

    SciTech Connect

    Killeen, J.

    1982-01-01

    The application of computers to magnetic fusion energy research is essential. In the last several years the use of computers in the numerical modeling of fusion systems has increased substantially. There are several categories of computer models used to study the physics of magnetically confined plasmas. A comparable number of types of models for engineering studies are also in use. To meet the needs of the fusion program, the National Magnetic Fusion Energy Computer Center has been established at the Lawrence Livermore National Laboratory. A large central computing facility is linked to smaller computer centers at each of the major MFE laboratories by a communication network. In addition to providing cost effective computing services, the NMFECC environment stimulates collaboration and the sharing of computer codes among the various fusion research groups.

  9. 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.

  10. Role of sequence and structure of the Hendra fusion protein fusion peptide in membrane fusion.

    PubMed

    Smith, Everett Clinton; Gregory, Sonia M; Tamm, Lukas K; Creamer, Trevor P; Dutch, Rebecca Ellis

    2012-08-24

    Viral fusion proteins are intriguing molecular machines that undergo drastic conformational changes to facilitate virus-cell membrane fusion. During fusion a hydrophobic region of the protein, termed the fusion peptide (FP), is inserted into the target host cell membrane, with subsequent conformational changes culminating in membrane merger. Class I fusion proteins contain FPs between 20 and 30 amino acids in length that are highly conserved within viral families but not between. To examine the sequence dependence of the Hendra virus (HeV) fusion (F) protein FP, the first eight amino acids were mutated first as double, then single, alanine mutants. Mutation of highly conserved glycine residues resulted in inefficient F protein expression and processing, whereas substitution of valine residues resulted in hypofusogenic F proteins despite wild-type surface expression levels. Synthetic peptides corresponding to a portion of the HeV F FP were shown to adopt an α-helical secondary structure in dodecylphosphocholine micelles and small unilamellar vesicles using circular dichroism spectroscopy. Interestingly, peptides containing point mutations that promote lower levels of cell-cell fusion within the context of the whole F protein were less α-helical and induced less membrane disorder in model membranes. These data represent the first extensive structure-function relationship of any paramyxovirus FP and demonstrate that the HeV F FP and potentially other paramyxovirus FPs likely require an α-helical structure for efficient membrane disordering and fusion. PMID:22761418

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. Future of Inertial Fusion Energy

    SciTech Connect

    Nuckolls, J H; Wood, L L

    2002-09-04

    In the past 50 years, fusion R&D programs have made enormous technical progress. Projected billion-dollar scale research facilities are designed to approach net energy production. In this century, scientific and engineering progress must continue until the economics of fusion power plants improves sufficiently to win large scale private funding in competition with fission and non-nuclear energy systems. This economic advantage must be sustained: trillion dollar investments will be required to build enough fusion power plants to generate ten percent of the world's energy. For Inertial Fusion Energy, multi-billion dollar driver costs must be reduced by up to an order of magnitude, to a small fraction of the total cost of the power plant. Major cost reductions could be achieved via substantial improvements in target performance-both higher gain and reduced ignition energy. Large target performance improvements may be feasible through a combination of design innovations, e.g., ''fast ignition,'' propagation down density gradients, and compression of fusion fuel with a combination of driver and chemical energy. The assumptions that limit projected performance of fusion targets should be carefully examined. The National Ignition Facility will enable development and testing of revolutionary targets designed to make possible economically competitive fusion power plants.

  1. Simulation Science for Fusion Plasmas

    NASA Astrophysics Data System (ADS)

    Skoric, M. M.; Sudo, S.

    2008-07-01

    The world fusion effort has recently entered a new age with the construction of ITER in Cadarache, France, which will be the first magnetic confinement fusion plasma experiment dominated by the self-heating of fusion reactions. In order to operate and control burning plasmas and future demo fusion reactors, an advanced ability for comprehensive computer simulations that are fully verified and validated against experimental data will be necessary. The ultimate goal is to develop the capability to predict reliably the behavior of plasmas in toroidal magnetic confinement devices on all relevant time and space scales. In addition to developing a sophisticated integrated simulation codes, directed advanced research in fusion physics, applied mathematics and computer science is envisaged. In this talk we review the basic strategy and main research efforts at the Department of Simulation Science of the National Institute for Fusion Science (NIFS)- which is the Inter University Institute and the coordinating Center of Excellence for academic fusion research in Japan. We overview a simulation research at NIFS, in particular relation to experiments in the Large Helical Device (LHD), the world's largest superconducting heliotron device, as a National Users' facility (see Motojima et al. 2003). Our main goal is understanding and systemizing the rich hierarchy of physical mechanisms in fusion plasmas, supported by exploring a basic science of complexity of plasma as a highly nonlinear, non-equilibrium, open system. The aim is to establish a simulation science as a new interdisciplinary field by fostering collaborative research in utilizing the large-scale supercomputer simulators. A concept of the hierarchy-renormalized simulation modelling will be invoked en route toward the LHD numerical test reactor. Finally, a perspective role is given on the ITER Broad Approach program at Rokkasho Center, as an integrated part of ITER and Development of Fusion Energy Agreement.

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

    DOE PAGESBeta

    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

  3. 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.

  4. 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

  5. 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)

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

    PubMed Central

    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

    2015-01-01

    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. PMID:26040699

  7. Systematic analysis of advanced fusion fuel in inertial fusion energy

    NASA Astrophysics Data System (ADS)

    Velarde, G.; Eliezer, S.; Henis, Z.; Piera, M.; Martinez-Val, J. M.

    1997-04-01

    Aneutronic fusion reactions can be considered as the cleanest way to exploit nuclear energy. However, these reactions present in general two main drawbacks.—very high temperatures are needed to reach relevant values of their cross sections—Moderate (and even low) energy yield per reaction. This value is still lower if measured in relation to the Z number of the reacting particles. It is already known that bremsstrahlung overruns the plasma reheating by fusion born charged-particles in most of the advanced fuels. This is for instance the case for proton-boron-11 fusion in a stoichiometric plasma and is also so in lithium isotopes fusion reactions. In this paper, the use of deuterium-tritium seeding is suggested to allow to reach higher burnup fractions of advanced fuels, starting at a lower ignition temperature. Of course, neutron production increases as DT contents does. Nevertheless, the ratio of neutron production to energy generation is much lower in DT-advanced fuel mixtures than in pure DT plasmas. One of the main findings of this work is that some natural resources (as D and Li-7) can be burned-up in a catalytic regime for tritium. In this case, neither external tritium breeding nor tritium storage are needed, because the tritium inventory after the fusion burst is the same as before it. The fusion reactor can thus operate on a pure recycling of a small tritium inventory.

  8. Enabling Technology in Support of Fusion Science

    NASA Astrophysics Data System (ADS)

    Baker, Charles C.

    1999-03-01

    This paper summarizes remarks made at Fusion Power Associates annual meeting, July 17, 2000 in San Diego. It describes the U.S. Department of Energy Office of Fusion Enegy Sciences programs in plasma and fusion technology in support of the U. S. fusion energy sciences program.

  9. Class II virus membrane fusion proteins

    SciTech Connect

    Kielian, Margaret . E-mail: kielian@aecom.yu.edu

    2006-01-05

    Enveloped animal viruses fuse their membrane with a host cell membrane, thus delivering the virus genetic material into the cytoplasm and initiating infection. This critical membrane fusion reaction is mediated by a virus transmembrane protein known as the fusion protein, which inserts its hydrophobic fusion peptide into the cell membrane and refolds to drive the fusion reaction. This review describes recent advances in our understanding of the structure and function of the class II fusion proteins of the alphaviruses and flaviviruses. Inhibition of the fusion protein refolding reaction confirms its importance in fusion and suggests new antiviral strategies for these medically important viruses.

  10. Fusion of the ear bones

    MedlinePlus

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

  11. Fusion power and the environment.

    PubMed

    Flakus, F N

    1975-09-01

    Fusion reactor design concepts are being pursued in the research and development programme of various countries and studies are being undertaken on the possible environmental impact of fusion power reactors. The paper reviews and summarizes the results of such environmental impact studies. Attention is restricted to deuterium-tritium fusion reactor concepts and a preliminary environmental impact assessment is presented. The possible inventory tritium and radioactive materials in the neutron-activated blanket structure of fusion power reactors is described and potential hazards posed by this radioactive materials inventory are discussed. Non-radiological implications and accident considerations are outlined. In conclusion, various areas still awaiting further investigation and research work are identified. The paper contains 8 tables and 50 references. PMID:1212270

  12. 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.

  13. Distributed multi-sensor fusion

    NASA Astrophysics Data System (ADS)

    Scheffel, Peter; Fish, Robert; Knobler, Ron; Plummer, Thomas

    2008-03-01

    McQ has developed a broad based capability to fuse information in a geographic area from multiple sensors to build a better understanding of the situation. The paper will discuss the fusion architecture implemented by McQ to use many sensors and share their information. This multi sensor fusion architecture includes data sharing and analysis at the individual sensor, at communications nodes that connect many sensors together, at the system server/user interface, and across multi source information available through networked services. McQ will present a data fusion architecture that integrates a "Feature Information Base" (FIB) with McQ's well known Common Data Interchange Format (CDIF) data structure. The distributed multi sensor fusion provides enhanced situation awareness for the user.

  14. Membrane tension and membrane fusion.

    PubMed

    Kozlov, Michael M; Chernomordik, Leonid V

    2015-08-01

    Diverse cell biological processes that involve shaping and remodeling of cell membranes are regulated by membrane lateral tension. Here we focus on the role of tension in driving membrane fusion. We discuss the physics of membrane tension, forces that can generate the tension in plasma membrane of a cell, and the hypothesis that tension powers expansion of membrane fusion pores in late stages of cell-to-cell and exocytotic fusion. We propose that fusion pore expansion can require unusually large membrane tensions or, alternatively, low line tensions of the pore resulting from accumulation in the pore rim of membrane-bending proteins. Increase of the inter-membrane distance facilitates the reaction. PMID:26282924

  15. Fusion - From science to engineering

    NASA Astrophysics Data System (ADS)

    Kenton, J.

    1981-12-01

    The principles and state of advancement in fusion energy devices are explored, along with the transition from theoretical problems to engineering difficulties. Tokamaks are noted to be the closest to actual break-even, the point where the energy extracted from the reactor is equal to the energy necessary to initiate the process, although linear, mirror fusion machines also show promise. Attention is also given to poloidal diverter systems and the ELMO bumpy torus, which has demonstrated continuous operation for the first time. The prospects for a U.S. fusion engineering facility are uncertain in the light of current budget cuts, with most funding being concentrated on military applications. Laser inertial fusion devices are reviewed, as well as particle and ion accelerators for fuel pellet implosions. Finally, the most complex engineering problem is asserted to be the development of the reactor blanket system.

  16. Laser fusion monthly -- August 1980

    SciTech Connect

    Ahlstrom, H.G.

    1980-08-01

    This report documents the monthly progress for the laser fusion research at Lawrence Livermore National Laboratory. First it gives facilities report for both the Shiva and Argus projects. Topics discussed include; laser system for the Nova Project; the fusion experiments analysis facility; optical/x-ray streak camera; Shiva Dante System temporal response; 2{omega}{sub 0} experiment; and planning for an ICF engineering test facility.

  17. Simulation science for fusion plasmas

    NASA Astrophysics Data System (ADS)

    Sudo, S.; Škorić, M. M.; Watanabe, T.-H.; Todo, Y.; Ishizawa, A.; Miura, H.; Ishizaki, R.; Ito, A.; Ohtani, H.; Usami, S.; Nakamura, H.; Ito, Atsushi; Ishiguro, S.; Tomita, Y.; Takayama, A.; Sato, M.; Yamamoto, T.; Den, M.; Sakagami, H.; Horiuchi, R.; Okamura, S.; Nakajima, N.

    2008-10-01

    The world fusion effort has embarked into a new age with the construction of ITER in Cadarache, France, which will be the first magnetic confinement fusion plasma experiment dominated by the self-heating of fusion reactions. In order to operate and control burning plasmas and next generation demo fusion reactors, an advanced capability for comprehensive integrated computer simulations that are fully verified and validated against experimental data will be necessary. The ultimate goal is to predict reliably the behaviour of plasmas in toroidal magnetic confinement devices on all relevant scales, both in time and space. In addition to developing a sophisticated integrated simulation codes, directed advanced research in fusion physics, applied mathematics, computer science and software is envisaged. In this paper we review the basic strategy and main research efforts at the Department of Simulation Science of the National Institute for Fusion Science (NIFS)- which is the Inter University Institute and the coordinating Center of Excellence for academic fusion research in Japan. We overview a simulation research at NIFS, in particular relation to experiments in the Large Helical Device (LHD), the world's largest superconducting heliotron device, as a National Users' facility (see Motojima et al. [1]). Our main goal is understanding and systemizing the rich hierarchy of physical mechanisms in fusion plasmas, supported by exploring a basic science of complexity of plasma as a highly nonlinear, non-equilibrium, open system. The aim is to establish a simulation science as a new interdisciplinary field by fostering collaborative research in utilizing the large-scale supercomputer simulators. A concept of the hierarchy-renormalized simulation modelling will be invoked en route toward the LHD numerical test reactor.

  18. The last word on fusion

    NASA Astrophysics Data System (ADS)

    Hellberg, Manfred A.

    2009-03-01

    Letter writers Raoul Franklin and Nicholas Braithwaite (November 2008 p22; December 2008 p19) have commented on the suggestion - made by UK Atomic Energy Authority director Stephen Cowley in your October 2008 fusion supplement - that plasma science effectively started with the growth of fusion research. Braithwaite also raised the question of the origin of the name "plasma", suggesting two possible sources: neon discharges and blood plasma.

  19. 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)

  20. 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.

  1. 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.

  2. 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; Rory Goodwin, C; 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. PMID:26482460

  3. 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.

  4. 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.

  5. Kinetic advantage of controlled intermediate nuclear fusion

    NASA Astrophysics Data System (ADS)

    Guo, Xiaoming

    2012-09-01

    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.

  6. 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

  7. 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

  8. 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.

  9. Fusion in Magnetically Compressed Targets

    NASA Astrophysics Data System (ADS)

    Mokhov, V. N.

    2004-11-01

    A comparative analysis is presented of the positive and negative features of systems using magnetic compression of the thermonuclear fusion target (MAGO/MTF) aimed at solving the controlled thermonuclear fusion (CTF) problem. The niche for the MAGO/MTF system, among the other CTF systems, in the parameter space of the energy delivered to the target, and its input time to the target, is shown. This approach was investigated at RFNC-VNIIEF for more than 15 years using the unique technique of applying explosive magnetic generators (EMG) as the energy source to preheat fusion plasma, and accelerate a liner to compress the preheated fusion plasma to the parameters required for ignition. EMG based systems produce already fusion neutrons, and their relatively low cost and record energy yield enable full scale experiments to study the possibility of achieving ignition threshold without constructing expensive stationary installations. A short review of the milestone results on the road to solving the CTF problem in the MAGO/MTF system is given.

  10. Benchmarking image fusion algorithm performance

    NASA Astrophysics Data System (ADS)

    Howell, Christopher L.

    2012-06-01

    Registering two images produced by two separate imaging sensors having different detector sizes and fields of view requires one of the images to undergo transformation operations that may cause its overall quality to degrade with regards to visual task performance. This possible change in image quality could add to an already existing difference in measured task performance. Ideally, a fusion algorithm would take as input unaltered outputs from each respective sensor used in the process. Therefore, quantifying how well an image fusion algorithm performs should be base lined to whether the fusion algorithm retained the performance benefit achievable by each independent spectral band being fused. This study investigates an identification perception experiment using a simple and intuitive process for discriminating between image fusion algorithm performances. The results from a classification experiment using information theory based image metrics is presented and compared to perception test results. The results show an effective performance benchmark for image fusion algorithms can be established using human perception test data. Additionally, image metrics have been identified that either agree with or surpass the performance benchmark established.

  11. Fusion neutronics experiments and analysis

    SciTech Connect

    Not Available

    1992-01-01

    UCLA has led the neutronics R D effort in the US for the past several years through the well-established USDOE/JAERI Collaborative Program on Fusion Neutronics. Significant contributions have been made in providing solid bases for advancing the neutronics testing capabilities in fusion reactors. This resulted from the hands-on experience gained from conducting several fusion integral experiments to quantify the prediction uncertainties of key blanket design parameters such as tritium production rate, activation, and nuclear heating, and when possible, to narrow the gap between calculational results and measurements through improving nuclear data base and codes capabilities. The current focus is to conduct the experiments in an annular configuration where the test assembly totally surrounds a simulated line source. The simulated line source is the first-of-a-kind in the scope of fusion integral experiments and presents a significant contribution to the world of fusion neutronics. The experiments proceeded through Phase IIIA to Phase IIIC in these line source simulation experiments started in 1989.

  12. 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

  13. 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.

  14. Bioenergetic roles of mitochondrial fusion.

    PubMed

    Silva Ramos, Eduardo; Larsson, Nils-Göran; Mourier, Arnaud

    2016-08-01

    Mitochondria are bioenergetic hotspots, producing the bulk of ATP by the oxidative phosphorylation process. Mitochondria are also structurally dynamic and undergo coordinated fusion and fission to maintain their function. Recent studies of the mitochondrial fusion machinery have provided new evidence in detailing their role in mitochondrial metabolism. Remarkably, mitofusin 2, in addition to its role in fusion, is important for maintaining coenzyme Q levels and may be an integral player in the mevalonate synthesis pathway. Here, we review the bioenergetic roles of mitochondrial dynamics and emphasize the importance of the in vitro growth conditions when evaluating mitochondrial respiration. This article is part of a Special Issue entitled 'EBEC 2016: 19th European Bioenergetics Conference, Riva del Garda, Italy, July 2-6, 2016,' edited by Prof. Paolo Bernardi. PMID:27060252

  15. Fusion Blanket Development in FDF

    NASA Astrophysics Data System (ADS)

    Wong, C. P. C.; Smith, J. P.; Stambaugh, R. D.

    2008-11-01

    To satisfy the electricity and tritium self-sufficiency missions of a Fusion Development Facility (FDF), suitable blanket designs will need to be evaluated, selected and developed. To demonstrate closure of the fusion fuel cycle, 2-3 main tritium breeding blankets will be used to cover most of the available chamber surface area in order to reach the project goal of achieving a tritium breeding ratio, TBR > 1. To demonstrate the feasibility of electricity and tritium production for subsequent devices such as the fusion demonstration power reactor (DEMO), several advanced test blankets will need to be selected and tested on the FDF to demonstrate high coolant outlet temperature necessary for efficient electricity production. Since the design goals for the main and test blankets are different, the design criteria of these blankets will also be different. The considerations in performing the evaluation of blanket and structural material options in concert with the maintenance approach for the FDF will be reported in this paper.

  16. (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.

  17. Cell fusion in Neurospora crassa.

    PubMed

    Herzog, Stephanie; Schumann, Marcel R; Fleißner, André

    2015-12-01

    In recent years, the filamentous fungus Neurospora crassa has advanced as a model organism for studying eukaryotic cell-cell communication and fusion. Cell merger in this fungus employs an unusual mode of communication, in which the fusion partners appear to switch between signal sending and receiving. Many molecular factors mediating this intriguing mechanism and the subsequent membrane merger have been identified. It has become apparent that conserved factors, such as MAP kinases, NADPH oxidases and the STRIPAK complex, together with fungal specific proteins are wired into an intricate signaling network. Here, we will present an overview of recent findings on the molecular mechanism mediating fusion in N. crassa and will discuss the current working model. PMID:26340439

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. Fusion - A potential power source

    SciTech Connect

    Jensen, T.H. )

    1994-10-01

    Duplicating the fusion process of the sun and the stars for energy production on earth would present many difficulties. The state of matter at such temperatures--the plasma state--may be considered a gas of electrons and nuclei, so one problem is the need to confine a hot, reacting plasma. Because the plasma is an electric conductor, it is subject to magnetic forces. Thus, one approach is to confine the hot plasma by a magnetic field. Another approach is to heat the matter so rapidly that the fusion reactions take place before the matter has had time to fly apart, that is, to use inertial confinement. At the United Nations' Atoms for Peace Conference in 1958, a remarkably cooperative, international research effort began. In spite of many difficulties, substantial progress has been made. Initially, many tokamaks were built with circular cross sections. However, shaped plasmas were shown to have clear advantages. The cross sections of some of the larger ones are illustrated here. The two largest devices in the US are the Tokamak Fusion Test Reactor (TFTR) at Princeton and the Doublet III-D (DIII-D) at General Atomics in San Diego. The TFTR device is constructed with neutron shielding and equipped to handle the superheavy hydrogen isotope tritium, which is radioactive. This makes it possible to operate the device with the optimum fuel mixture: an equal mixture of deuterium and tritium. This mixture is optimal because the cross section for the DT reaction has by far the largest cross section of the fusion reactions mentioned above. A large effort is presently under way to design the International Thermonuclear Experimental Reactor (ITER). This is a joint effort by the European Community, Japan, Russia, and the US. Goals include the production of fusion power in excess of 1,000 MW for studying the physics of igniting plasmas, and the integrated demonstration of fusion-reactor technologies.

  3. 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.

  4. 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.

  5. 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.

  6. 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. PMID:27524709

  7. 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.

  8. 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.

  9. Calculation of fusion product angular correlation coefficients for fusion plasmas

    SciTech Connect

    Murphy, T.J.

    1987-08-01

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

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Role of atomic collisions in fusion

    SciTech Connect

    Post, D.E.

    1982-04-01

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

  15. 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

  16. Exo-endo cellulase fusion protein

    DOEpatents

    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.

  17. Dinuclear systems in complete fusion reactions

    NASA Astrophysics Data System (ADS)

    Adamian, G. G.; Antonenko, N. V.; Zubov, A. S.

    2014-09-01

    Formation and evolution of dinuclear systems in reactions of complete fusion are considered. Based on the dinuclear system concept, the process of compound nucleus formation is studied. Arguments confirming the validity of this concept are given. The main problems of describing the complete fusion in adiabatic approximation are listed. Calculations of evaporation residue cross sections in complete fusion reactions leading to formation of superheavy nuclei are shown. Isotopic trends of the cross sections of heavy nuclei formation in complete fusion reactions are considered.

  18. 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.

  19. Fusion and Breakup of Weakly Bound Nuclei

    SciTech Connect

    Gomes, P. R. S.; Lubian, J.; Padron, I.; Crema, E.; Chamon, L. C.; Hussein, M. S.; Canto, L. F.

    2006-08-14

    We discuss the influence of the breakup process of weakly bound nuclei on the fusion cross section. The complete fusion for heavy targets is found to be suppressed due to the incomplete fusion following the breakup, whereas this effect is negligible for light targets. The total fusion cross sections for stable projectiles are not affected by the breakup process, whereas it is suppressed for halo projectiles. The non capture breakup is the dominant process at sub-barrier energies.

  20. Feasibility of cluster-type controlled fusion

    NASA Astrophysics Data System (ADS)

    Kingsep, A. S.; Okorokov, V. V.; Chuvilo, I. V.

    1991-10-01

    A method is proposed for generating high-temperature fusion plasma through the collision of accelerated clusters of heavy hydrogen inside a magnetic trap. It is noted that the physical feasibility of this method of fusion plasma generation can now be verified using the existing and functioning equipment. Some features of the controlled fusion method proposed here are examined.

  1. 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.

  2. Microwave kinoform for magnetic fusion

    SciTech Connect

    Gallagher, N.C. Jr.; Sweeney, D.W.

    1983-07-19

    A microwave kinoform that modifies both the phase and polarization of an incident wavefront has been designed. This kinoform for the TMX-U magnetic fusion experiment has been fabricated and tested. The design procedure, method of fabrication, and experimental test results are discussed.

  3. Membrane fusion during phage lysis.

    PubMed

    Rajaure, Manoj; Berry, Joel; Kongari, Rohit; Cahill, Jesse; Young, Ry

    2015-04-28

    In general, phages cause lysis of the bacterial host to effect release of the progeny virions. Until recently, it was thought that degradation of the peptidoglycan (PG) was necessary and sufficient for osmotic bursting of the cell. Recently, we have shown that in Gram-negative hosts, phage lysis also requires the disruption of the outer membrane (OM). This is accomplished by spanins, which are phage-encoded proteins that connect the cytoplasmic membrane (inner membrane, IM) and the OM. The mechanism by which the spanins destroy the OM is unknown. Here we show that the spanins of the paradigm coliphage lambda mediate efficient membrane fusion. This supports the notion that the last step of lysis is the fusion of the IM and OM. Moreover, data are provided indicating that spanin-mediated fusion is regulated by the meshwork of the PG, thus coupling fusion to murein degradation by the phage endolysin. Because endolysin function requires the formation of μm-scale holes by the phage holin, the lysis pathway is seen to require dramatic dynamics on the part of the OM and IM, as well as destruction of the PG. PMID:25870259

  4. Membrane fusion during phage lysis

    PubMed Central

    Berry, Joel; Kongari, Rohit; Cahill, Jesse; Young, Ry

    2015-01-01

    In general, phages cause lysis of the bacterial host to effect release of the progeny virions. Until recently, it was thought that degradation of the peptidoglycan (PG) was necessary and sufficient for osmotic bursting of the cell. Recently, we have shown that in Gram-negative hosts, phage lysis also requires the disruption of the outer membrane (OM). This is accomplished by spanins, which are phage-encoded proteins that connect the cytoplasmic membrane (inner membrane, IM) and the OM. The mechanism by which the spanins destroy the OM is unknown. Here we show that the spanins of the paradigm coliphage lambda mediate efficient membrane fusion. This supports the notion that the last step of lysis is the fusion of the IM and OM. Moreover, data are provided indicating that spanin-mediated fusion is regulated by the meshwork of the PG, thus coupling fusion to murein degradation by the phage endolysin. Because endolysin function requires the formation of μm-scale holes by the phage holin, the lysis pathway is seen to require dramatic dynamics on the part of the OM and IM, as well as destruction of the PG. PMID:25870259

  5. Progress in pulsed power fusion

    SciTech Connect

    Quintenz, J.P.; Adams, R.G.; Bailey, J.E.

    1996-07-01

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

  6. 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.

  7. 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

  8. EDITORIAL: Stochasticity in fusion plasmas

    NASA Astrophysics Data System (ADS)

    Finken, K. H.

    2006-04-01

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

  9. 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

  10. Fusion reactor nucleonics: status and needs

    SciTech Connect

    Lee, J.D.; Engholm, B.A.; Dudziak, D.J.; Haight, R.C.

    1980-01-01

    The national fusion technology effort has made a good start at addressing the basic nucleonics issues, but only a start. No fundamental nucleonics issues are seen as insurmountable barriers to the development of commercial fusion power. To date the fusion nucleonics effort has relied almost exclusively on other programs for nuclear data and codes. But as we progress through and beyond ETF type design studies the fusion program will need to support a broad based nucleonics effort including code development, sensitivity studies, integral experiments, data acquisition etc. It is clear that nucleonics issues are extremely important to fusion development and that we have only scratched the surface.

  11. Fusion energy calorimeter for the tokamak fusion test reactor

    SciTech Connect

    Jassby, D.L.; Imel, G.R.

    1981-04-01

    One and two-dimensional neutronic analyses treating the transport and scattering of neutrons and the production and transport of gamma rays in the TFTR demonstrate that the fusion energy production in a D-T pulse in the TFTR can be determined with an uncertainty of +- 15% or less, simply by integrating the measured profile of temperature increase along the central radial axis of a large hydrocarbon moderator that fills the bay between adjacent toroidal-field coils, just outside the vacuum vessel. Limitations in thermopile temperature measurements dictate a minimum fusion-neutron fluence at the vacuum vessel of the order of 10/sup 12/ n/cm/sup 2/ per pulse (a source strength of 10/sup 18/ n/pulse in TFTR), in order that this simple calorimeter can provide useful accuracy.

  12. Fusion of Enveloped Viruses in Endosomes.

    PubMed

    White, Judith M; Whittaker, Gary R

    2016-06-01

    Ari Helenius launched the field of enveloped virus fusion in endosomes with a seminal paper in the Journal of Cell Biology in 1980. In the intervening years, a great deal has been learned about the structures and mechanisms of viral membrane fusion proteins as well as about the endosomes in which different enveloped viruses fuse and the endosomal cues that trigger fusion. We now recognize three classes of viral membrane fusion proteins based on structural criteria and four mechanisms of fusion triggering. After reviewing general features of viral membrane fusion proteins and viral fusion in endosomes, we delve into three characterized mechanisms for viral fusion triggering in endosomes: by low pH, by receptor binding plus low pH and by receptor binding plus the action of a protease. We end with a discussion of viruses that may employ novel endosomal fusion-triggering mechanisms. A key take-home message is that enveloped viruses that enter cells by fusing in endosomes traverse the endocytic pathway until they reach an endosome that has all of the environmental conditions (pH, proteases, ions, intracellular receptors and lipid composition) to (if needed) prime and (in all cases) trigger the fusion protein and to support membrane fusion. PMID:26935856

  13. Class III viral membrane fusion proteins

    PubMed Central

    Backovic, Marija

    2010-01-01

    SUMMARY Accumulating structural studies of viral fusion glycoproteins have revealed unanticipated structural relationships between unrelated virus families and allowed the grouping of these membrane fusogens into three distinct classes. Here we review the newly identified group of class III viral fusion proteins, whose members include fusion proteins from rhabdoviruses, herpesviruses and baculoviruses. While clearly related in structure, the class III viral fusion proteins exhibit distinct structural features in their architectures as well as in their membrane-interacting fusion loops, which are likely related to their virus-specific differences in cellular entry. Further study of the similarities and differences in the class III viral fusion glycoproteins may provide greater insights into protein:membrane interactions that are key to promoting efficient bilayer fusion during virus entry. PMID:19356922

  14. Controlled thermonuclear fusion, high temperature plasma physics

    NASA Astrophysics Data System (ADS)

    1985-05-01

    The primary source of nuclear energy comes from the fission process of heavy nuclei. To utilize the energy released by a thermonuclear fusion process, methods of controlling the fusion reaction were studied. This is controlled thermonuclear fusion technology. The fuel used in a thermonuclear fusion process are isotopes of hydrogen: deuterium and tritium. They can be extracted from the almost unlimited seawater. Nuclear fusion also produces very little radioactive waste. Thermonuclear fusion is a promising energy source with an almost unlimited supply; it is economical, safe, and relatively clean. Ways to raise plasma temperature to a very high level and to maintain it to allow fusion reactions to take place are studied. The physical laws of high temperature plasma was studied to reach this goal which resulted in the development of high temperature plasma physics.

  15. Security on the US Fusion Grid

    SciTech Connect

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

    2005-06-01

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

  16. Data security on the national fusion grid

    SciTech Connect

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

    2005-06-01

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

  17. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2013-03-01

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

  19. 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

  20. 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.

  1. 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.

  2. Interplanetary propulsion using inertial fusion

    NASA Technical Reports Server (NTRS)

    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.

  3. MR-TRUS Fusion Biopsy.

    PubMed

    Margolis, Daniel J A

    2016-06-01

    The leading application of multiparametric magnetic resonance imaging (mpMRI) of the prostate is for lesion detection with the intention of tissue sampling (biopsy). Although direct in-bore magnetic resonance (MR)-guided biopsy allows for confirmation of the biopsy site, this can be expensive, time-consuming, and most importantly limited in availability. MR-transrectal ultrasound (MR-TRUS) image fusion targeted biopsy (TBx) allows for lesions identified on MRI to be targeted with the ease, efficiency, and availability of ultrasound.The learning objectives are optimized mpMRI protocol and reporting for image fusion targeted biopsy; methods of TRUS TBx; performance and limitations of MR-TRUS TBx; future improvements and applications. PMID:27187163

  4. Transmutations in fusion test facilities

    SciTech Connect

    Mann, F.M.

    1986-04-01

    Using an expanded nuclear data base, the transmutation of PCA, AMCR33 (a reduced activation austenitic steel), HT-9, Rafer2 (a reduced activation ferritic steel), V-15%Cr-5%Ti alloy, and SiAlON (a ceramic) were calculated for two positions in the Fast Flux Test Facility (FFTF), three positions in the High Flux Isotope Reactor (HFIR), and the first wall position of both the STARFIRE and MARS conceptual fusion reactors. The peripheral test (PTP) position, and to a lesser extent the radial beryllium (RB) position, of HFIR show significant transmutations which are often in the opposite direction to the transmutations in the fusion conceptual designs. The positions in FFTF, as well as the hafnium covered location in the HFIR RB position show relative minor transmutations.

  5. 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.

  6. 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.

  7. Trust metrics in information fusion

    NASA Astrophysics Data System (ADS)

    Blasch, Erik

    2014-05-01

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

  8. 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.

  9. 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.

  10. Fusion for Earth and Space

    NASA Astrophysics Data System (ADS)

    Williams, Pharis E.

    2009-03-01

    The compact reactor concept (Williams, 2007) has the potential to provide clean, safe and unlimited supply of energy for Earth and Space applications. The concept is a potential fusion reactor wherein deuterium nuclei are preferentially fused into helium nuclei. Because the deuterium nuclei are preferentially fused into helium nuclei at temperatures and energies lower than specified by the standard model there is no harmful radiation as a byproduct of this fusion process. Therefore, a reactor using this reaction does not need any shielding to contain such radiation. The energy released from each reaction and the absence of shielding makes the deuterium-plus-deuterium-to-helium (DDH) reactor very compact when compared to other reactors, both fission and fusion types. Moreover, the potential energy output per reactor weight and the absence of harmful radiation makes the DDH reactor an ideal candidate for individual home and space power. The concept also would make it possible for each plant or remote location to have it's own power source, on site, without the need for a connection to the power grid. This would minimize, or eliminate, power blackouts. The concept could replace large fission reactors and fossil fuel power plants plus provide energy for ships, locomotives, trucks and autos. It would make an ideal source of energy for space power applications and for space propulsion.

  11. Fusion for Earth and Space

    SciTech Connect

    Williams, Pharis E

    2009-03-16

    The compact reactor concept (Williams, 2007) has the potential to provide clean, safe and unlimited supply of energy for Earth and Space applications. The concept is a potential fusion reactor wherein deuterium nuclei are preferentially fused into helium nuclei. Because the deuterium nuclei are preferentially fused into helium nuclei at temperatures and energies lower than specified by the standard model there is no harmful radiation as a byproduct of this fusion process. Therefore, a reactor using this reaction does not need any shielding to contain such radiation. The energy released from each reaction and the absence of shielding makes the deuterium-plus-deuterium-to-helium (DDH) reactor very compact when compared to other reactors, both fission and fusion types. Moreover, the potential energy output per reactor weight and the absence of harmful radiation makes the DDH reactor an ideal candidate for individual home and space power. The concept also would make it possible for each plant or remote location to have it's own power source, on site, without the need for a connection to the power grid. This would minimize, or eliminate, power blackouts. The concept could replace large fission reactors and fossil fuel power plants plus provide energy for ships, locomotives, trucks and autos. It would make an ideal source of energy for space power applications and for space propulsion.

  12. Fission fusion hybrids- recent progress

    NASA Astrophysics Data System (ADS)

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

    2012-03-01

    Fission-fusion hybrids enjoy unique advantages for addressing long standing societal acceptability issues of nuclear fission power, and can do this at a much lower level of technical development than a competitive fusion power plant- so it could be a nearer term application. For waste incineration, hybrids can burn intransigent transuranic residues (with the long lived biohazard) from light water reactors (LWRs) with far fewer hybrid reactors than a comparable system within the realm of fission alone. For fuel production, hybrids can produce fuel for ˜4 times as many LWRs with NO fuel reprocessing. For both waste incineration or fuel production, the most severe kind of nuclear accident- runaway criticality- can be excluded, unlike either fast reactors or typical accelerator based reactors. The proliferation risks for hybrid fuel production are, we strongly believe, far less than any other fuel production method, including today's gas centrifuges. US Thorium reserves could supply the entire US electricity supply for centuries. The centerpiece of the fuel cycle is a high power density Compact Fusion Neutron Source (major+minor radius ˜ 2.5-3.5 m), which is made feasible by the super-X divertor.

  13. National Mirror Fusion Program Plan

    SciTech Connect

    Gerich, C.A.

    1982-08-01

    This Plan is current as of August 1982. The major milestones listed herein represent an aggressive, success-oriented program paced primarily by technical results. Consistent with applicable government policies and the overall program planning of the Department's Office of Fusion Energy, this Plan assumes approval of the Mirror Program's next major step beyond MFTF-B - a deuterium-tritium (D-T) burning engineering reactor called the Fusion Power Demonstration (FPD) facility (formerly the Tandem Mirror Next Step). The near-term goal of the tandem mirror program is to lay the scientific and technical groundwork for an economically attractive, D-T fusion reactor design before the end of the 1980s. Construction of the FPD facility based on the tandem mirror could be initited around 1988. A second phase, complete with a nuclear power blanket demonstration, could be initiated in the mid-1990s, based on nuclear engineering data from a facility such as the Technology Demonstration Facility (TDF) described below. The outline of an acceptable tandem mirror reactor (TMR) design was first published in 1981, and will be further developed and described in the Mirror Advanced Reactor Study (MARS) during FY 1982-1983.

  14. Gasdynamic mirror fusion propulsion experiment

    NASA Astrophysics Data System (ADS)

    Emrich, William J.

    2001-02-01

    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 L/D ratios than previous mirror machines. Several advantages accrue from such a design. First, the high L/D 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 like 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. .

  15. 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.

  16. Gasdynamic Mirror Fusion Propulsion Experiment

    NASA Astrophysics Data System (ADS)

    Emrich, Bill

    2000-10-01

    A gasdynamic mirror (GDM) fusion propulsion experiment is currently being constructed at the NASA Marshall Space Flight Center (MSFC) to test the feasibility of this particular type of fusion device. Because of the open magnetic field line configuration of mirror fusion devices, they are particularly well suited for propulsion system applications since they allow for the easy ejection of thrust producing plasma. Currently, the MSFC GDM is constructed in three segments. The vacuum chamber mirror segment, the plasma injector mirror segment, and the main plasma chamber segment. Enough magnets are currently available to construct up to three main plasma chamber segments. The mirror segments are also segmented such that they can be expanded to accommodate new end plugging strategies without requiring the disassembly of the entire mirror segment. The plasma for the experiment is generated in a microwave cavity located between the main magnets and the mirror magnets. Ion heating is accomplished through ambipolar diffusion. The objective of the experiment is to investigate the stability characteristics of the gasdynamic mirror and to map a region of parameter space within which the plasma can be confined in a stable steady state configuration. The mirror ratio, plasma density, and plasma ``b" will be varied over a range of values and measurements subsequently taken to determine the degree of plasma stability.

  17. Gasdynamic Mirror Fusion Propulsion Experiment

    NASA Technical Reports Server (NTRS)

    Emrich, Bill; Rodgers, Stephen L. (Technical Monitor)

    2000-01-01

    A gasdynamic mirror (GDM) fusion propulsion experiment is currently being constructed at the NASA Marshall Space Flight Center (MSFC) to test the feasibility of this particular type of fusion device. Because of the open magnetic field line configuration of mirror fusion devices, they are particularly well suited for propulsion system applications since they allow for the easy ejection of thrust producing plasma. Currently, the MSFC GDM is constructed in three segments. The vacuum chamber mirror segment, the plasma injector mirror segment, and the main plasma chamber segment. Enough magnets are currently available to construct up to three main plasma chamber segments. The mirror segments are also segmented such that they can be expanded to accommodate new end plugging strategies with out requiring the disassembly of the entire mirror segment. The plasma for the experiment is generated in a microwave cavity located between the main magnets and the mirror magnets. Ion heating is accomplished through ambipolar diffusion. The objective of the experiment is to investigate the stability characteristics of the gasdynamic mirror and to map a region of parameter space within which the plasma can be confined in a stable steady state configuration. The mirror ratio, plasma density, and plasma "b" will be varied over a range of values and measurements subsequently taken to determine the degree of plasma stability.

  18. 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

  19. Multiscale medical image fusion in wavelet domain.

    PubMed

    Singh, Rajiv; 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

  20. Zn2+ depletion blocks endosome fusion.

    PubMed Central

    Aballay, A; Sarrouf, M N; Colombo, M I; Stahl, P D; Mayorga, L S

    1995-01-01

    Fusion among endosomes is an important step for transport and sorting of internalized macromolecules. Working in a cell-free system, we previously reported that endosome fusion requires cytosol and ATP, and is sensitive to N-ethylmaleimide. Fusion is regulated by monomeric and heterotrimeric GTP-binding proteins. We now report that fusion can proceed at very low Ca2+ concentrations, i.e. < 30 nM. Moreover, fusion is not affected when intravesicular Ca2+ is depleted by preincubation of vesicles with calcium ionophores (5 microM ionomycin or A23187) in the presence of calcium chelators (5 mM EGTA or 60 mM EDTA). The results indicate that fusion can proceed at extremely low concentrations of intravesicular and extravesicular Ca2+. However, BAPTA [1,2-bis-(o-aminophenoxy)ethane-N,N,N',N'-tetra-acetic acid], a relatively specific Ca2+ chelator, inhibits fusion. BAPTA binds other metals besides Ca2+. We present evidence that BAPTA inhibition is due not to Ca2+ chelation but to Zn2+ depletion. TPEN [N,N,N',N'-tetrakis-(2-pyridylmethyl) ethylenediamine], another metal-ion chelator with low affinity for Ca2+, also inhibited fusion. TPEN- and BAPTA-inhibited fusions were restored by addition of Zn2+. Zn(2+)-dependent fusion presents the same characteristics as control fusion. In intact cells, TPEN inhibited transport along the endocytic pathway. The results indicate that Zn2+ depletion blocks endosome fusion, suggesting that this ion is necessary for the function of one or more factors involved in the fusion process. Images Figure 1 PMID:8554539

  1. 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).

  2. 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

  3. Cell Fusion Connects Oncogenesis with Tumor Evolution

    PubMed Central

    Zhou, Xiaofeng; Merchak, Kevin; Lee, Woojin; Grande, Joseph P.; Cascalho, Marilia; Platt, Jeffrey L.

    2016-01-01

    Cell fusion likely drives tumor evolution by undermining chromosomal and DNA stability and/or by generating phenotypic diversity; however, whether a cell fusion event can initiate malignancy and direct tumor evolution is unknown. We report that a fusion event involving normal, nontransformed, cytogenetically stable epithelial cells can initiate chromosomal instability, DNA damage, cell transformation, and malignancy. Clonal analysis of fused cells reveals that the karyotypic and phenotypic potential of tumors formed by cell fusion is established immediately or within a few cell divisions after the fusion event, without further ongoing genetic and phenotypic plasticity, and that subsequent evolution of such tumors reflects selection from the initial diverse population rather than ongoing plasticity of the progeny. Thus, one cell fusion event can both initiate malignancy and fuel evolution of the tumor that ensues. PMID:26066710

  4. 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.

  5. EDITORIAL: Safety aspects of fusion power plants

    NASA Astrophysics Data System (ADS)

    Kolbasov, B. N.

    2007-07-01

    This special issue of Nuclear Fusion contains 13 informative papers that were initially presented at the 8th IAEA Technical Meeting on Fusion Power Plant Safety held in Vienna, Austria, 10-13 July 2006. Following recommendation from the International Fusion Research Council, the IAEA organizes Technical Meetings on Fusion Safety with the aim to bring together experts to discuss the ongoing work, share new ideas and outline general guidance and recommendations on different issues related to safety and environmental (S&E) aspects of fusion research and power facilities. Previous meetings in this series were held in Vienna, Austria (1980), Ispra, Italy (1983), Culham, UK (1986), Jackson Hole, USA (1989), Toronto, Canada (1993), Naka, Japan (1996) and Cannes, France (2000). The recognized progress in fusion research and technology over the last quarter of a century has boosted the awareness of the potential of fusion to be a practically inexhaustible and clean source of energy. The decision to construct the International Thermonuclear Experimental Reactor (ITER) represents a landmark in the path to fusion power engineering. Ongoing activities to license ITER in France look for an adequate balance between technological and scientific deliverables and complying with safety requirements. Actually, this is the first instance of licensing a representative fusion machine, and it will very likely shape the way in which a more common basis for establishing safety standards and policies for licensing future fusion power plants will be developed. Now that ITER licensing activities are underway, it is becoming clear that the international fusion community should strengthen its efforts in the area of designing the next generations of fusion power plants—demonstrational and commercial. Therefore, the 8th IAEA Technical Meeting on Fusion Safety focused on the safety aspects of power facilities. Some ITER-related safety issues were reported and discussed owing to their potential

  6. Can 250 fusions per muon be achieved

    SciTech Connect

    Jones, S.E.

    1987-01-01

    Nuclear fusion of hydrogen isotopes can be induced by negative muons ( ) in reactions such as: + d + t + n + . This reaction is analagous to the nuclear fusion reaction achieved in stars in which hydrogen isotopes (such as deuterium, d, and tritium, t) at very high temperatures first penetrate the Coulomb repulsive barrier and then fuse together to produce an alpha particle ( ) and a neutron (n), releasing energy. The muon in general reappears after inducing fusion so that the reaction can be repeated many (N) times. Thus, the muon may serve as an effective catalyst for nuclear fusion. Muon-catalozed fusion is unique in that it proceeds rapidly in deuterium-tritium mixtures at relatively cold temperatures, e.g., room temperature. The need for plasma temperatures to initiate fusion is overcome by the presence of the muon.

  7. Incomplete fusion dynamics by spin distribution measurements

    SciTech Connect

    Singh, D.; Ali, R.; Ansari, M. Afzal; Singh, Pushpendra P.; Sharma, M. K.; Singh, B. P.; Babu, K. Surendra; Sinha, Rishi K.; Kumar, R.; Muralithar, S.; Singh, R. P.; Bhowmik, R. K.

    2010-02-15

    Spin distributions for various evaporation residues populated via complete and incomplete fusion of {sup 16}O with {sup 124}Sn at 6.3 MeV/nucleon have been measured, using charged particles (Z=1,2)-{gamma} coincidence technique. Experimentally measured spin distributions of the residues produced as incomplete fusion products associated with 'fast'{alpha}- and 2{alpha}-emission channels observed in the 'forward cone' are found to be distinctly different from those of the residues produced as complete fusion products. Moreover, 'fast'{alpha}-particles that arise from larger angular momentum in the entrance channel are populated at relatively higher driving input angular momentum than those produced through complete fusion. The incomplete fusion residues are populated in a limited, higher-angular-momentum range, in contrast to the complete fusion products, which are populated over a broad spin range.

  8. 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.

  9. Myoblast fusion: lessons from flies and mice

    PubMed Central

    Abmayr, Susan M.; Pavlath, Grace K.

    2012-01-01

    The fusion of myoblasts into multinucleate syncytia plays a fundamental role in muscle function, as it supports the formation of extended sarcomeric arrays, or myofibrils, within a large volume of cytoplasm. Principles learned from the study of myoblast fusion not only enhance our understanding of myogenesis, but also contribute to our perspectives on membrane fusion and cell-cell fusion in a wide array of model organisms and experimental systems. Recent studies have advanced our views of the cell biological processes and crucial proteins that drive myoblast fusion. Here, we provide an overview of myoblast fusion in three model systems that have contributed much to our understanding of these events: the Drosophila embryo; developing and regenerating mouse muscle; and cultured rodent muscle cells. PMID:22274696

  10. 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.

  11. 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

  12. On Affine Fusion and the Phase Model

    NASA Astrophysics Data System (ADS)

    Walton, Mark A.

    2012-11-01

    A brief review is given of the integrable realization of affine fusion discovered recently by Korff and Stroppel. They showed that the affine fusion of the su(n) Wess-Zumino-Novikov-Witten (WZNW) conformal field theories appears in a simple integrable system known as the phase model. The Yang-Baxter equation leads to the construction of commuting operators as Schur polynomials, with noncommuting hopping operators as arguments. The algebraic Bethe ansatz diagonalizes them, revealing a connection to the modular S matrix and fusion of the su(n) WZNW model. The noncommutative Schur polynomials play roles similar to those of the primary field operators in the corresponding WZNW model. In particular, their 3-point functions are the su(n) fusion multiplicities. We show here how the new phase model realization of affine fusion makes obvious the existence of threshold levels, and how it accommodates higher-genus fusion.

  13. 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.

  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. Fusion of bacterial spheroplasts by electric fields.

    PubMed

    Ruthe, H J; Adler, J

    1985-09-25

    Spheroplasts of Escherichia coli or Salmonella typhimurium were found to fuse in an electric field. We employed the fusion method developed by Zimmermann and Scheurich (1981): Close membrane contact between cells is established by dielectrophoresis (formation of chains of cells by an a.c. field), then membrane fusion is induced by the application of short pulses of direct current. Under optimum conditions the fusion yield was routinely 90%. Fusable spheroplasts were obtained by first growing filamentous bacteria in the presence of cephalexin, then converting these to spheroplasts by the use of lysozyme. The fusion products were viable and regenerated to the regular bacterial form. Fusion of genetically different spheroplasts resulted in strains of bacteria possessing a combination of genetic markers. Fusion could not be achieved with spheroplasts obtained by growing the cells in the presence of penicillin or by using lysozyme on bacteria of usual size. PMID:3899175

  16. 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}

  17. 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

  18. 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.

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

    PubMed

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

    2016-01-01

    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. PMID:27113279

  20. Adaptive sensor fusion using genetic algorithms

    SciTech Connect

    Fitzgerald, D.S.; Adams, D.G.

    1994-08-01

    Past attempts at sensor fusion have used some form of Boolean logic to combine the sensor information. As an alteniative, an adaptive ``fuzzy`` sensor fusion technique is described in this paper. This technique exploits the robust capabilities of fuzzy logic in the decision process as well as the optimization features of the genetic algorithm. This paper presents a brief background on fuzzy logic and genetic algorithms and how they are used in an online implementation of adaptive sensor fusion.

  1. 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.

  2. Plasma Physics and Controlled Nuclear Fusion

    NASA Astrophysics Data System (ADS)

    Fisch, N. J.

    2010-01-01

    Already while making his famous contributions in uncontrolled nuclear fusion for wartime uses, Edward Teller contemplated how the abundant energy release through nuclear fusion might serve peacetime uses as well. His legacy in controlled nuclear fusion, and the associated physics of plasmas, spans both magnetic and inertial confinement approaches. His contributions in plasma physics, both the intellectual and the administrative, continue to impact the field.

  3. Cold Metal-Enhanced Fusion, Geo-Fusion and Cold Nucleosynthesis

    NASA Astrophysics Data System (ADS)

    Jones, S. E.; Ellsworth, J. E.

    2005-12-01

    In our 1986 and 1989 papers, we discussed the hypothesis of cold nuclear fusion in condensed matter (which we also call metal-enhanced fusion), particularly in the planets.1,2 The purpose of this paper is to provide an update on geo-fusion research, then to consider an important extension of the cold-fusion idea: cold nucleosynthesis in condensed matter. Cold nucleosynthesis experiments are underway at Brigham Young University.

  4. Fusion Concept Exploration Experiments at PPPL

    SciTech Connect

    Stewart Zweben; Samuel Cohen; Hantao Ji; Robert Kaita; Richard Majeski; Masaaki Yamada

    1999-05-01

    Small ''concept exploration'' experiments have for many years been an important part of the fusion research program at the Princeton Plasma Physics Laboratory (PPPL). this paper describes some of the present and planned fusion concept exploration experiments at PPPL. These experiments are a University-scale research level, in contrast with the larger fusion devices at PPPL such as the National Spherical Torus Experiment (NSTX) and the Tokamak Fusion Test Reactor (TFTR), which are at ''proof-of-principle'' and ''proof-of-performance'' levels, respectively.

  5. Recurrent Gene Fusions in Prostate Cancer

    PubMed Central

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

    2009-01-01

    The discovery of recurrent gene fusions in a majority of prostate cancers has important clinical and biological implications in the study of common epithelial tumors. Gene fusion and chromosomal rearrangements were previously thought to be the primary oncogenic mechanism of hematological malignancies and sarcomas. The prostate cancer gene fusions that have been identified thus far are characterized by 5’ genomic regulatory elements, most commonly controlled by androgen, fused to members of the ETS family of transcription factors, leading to the over-expression of oncogenic transcription factors. ETS gene fusions likely define a distinct class of prostate cancer which may have a bearing on diagnosis, prognosis and rational therapeutic targeting. PMID:18563191

  6. Radiation hardening of diagnostics for fusion reactors

    SciTech Connect

    Baur, J.F.; Engholm, B.A.; Hacker, M.P.; Maya, I.; Miller, P.H.; Toffolo, W.E.; Wojtowicz, S.S.

    1981-12-01

    A list of the diagnostic systems presently used in magnetic confinement fusion experiments is compiled herein. The radiation-sensitive components are identified, and their locations in zones around the machine are indicated. A table of radiation sensitivities of components is included to indicate the data available from previous work in fission reactor, space probe, and defense-related programs. Extrapolation and application to hardening of fusion diagnostic systems requires additional data that are more specific to the fusion radiation environment and fusion components. A list is also given of present radiation-producing facilities where near-term screening tests of materials and components can be performed.

  7. Ash fusion study of West Virginia coals

    SciTech Connect

    Ashton, K.C., Smith, C.J.; Hohn, M.E.

    1984-12-01

    As more industries and utilities convert to coal, ash fusion information becomes more important for boiler design (waste disposal systems). For example, burning a low fusion temperature coal can cause slagging - the buildup of molten ash on boiler waterwall tubes. Not only is boiler efficiency lowered, but downtime is also increased. Recently, potential buyers of West Virginia coal have inquired frequently about ash fusion. However, the amount of information in the West Virginia Geological and Economic Survey's data base is limited to data from about 800 samples, 50% of which were collected in five counties. Thus, the survey is conducting a study of ash fusion temperatures for the state's coals, to increase available data and its geographic coverage. A Leco AF-500 automated ash fusion analyzer was used in this study, which addresses: 1) reliability of results from an automated analyzer, 2) comparison of automated data with conventional data, 3) techniques of sample preparation, high-temperature ashing, and cone preparation, 4) ash-fusion trends in the state, and 5) research developments. The research sought to develop for West Virginia coal a statistical correlation model relating ash-elemental data with fusion data, and to investigate the relationship between ash color and fusion temperature. (Light-colored ashes generally have higher fusion temperatures than darker ashes.)

  8. Mitochondrial Fusion Is Essential for Steroid Biosynthesis

    PubMed Central

    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. PMID:23029265

  9. Present status and trends of image fusion

    NASA Astrophysics Data System (ADS)

    Xiang, Dachao; Fu, Sheng; Cai, Yiheng

    2009-10-01

    Image fusion information extracted from multiple images which is more accurate and reliable than that from just a single image. Since various images contain different information aspects of the measured parts, and comprehensive information can be obtained by integrating them together. Image fusion is a main branch of the application of data fusion technology. At present, it was widely used in computer vision technology, remote sensing, robot vision, medical image processing and military field. This paper mainly presents image fusion's contents, research methods, and the status quo at home and abroad, and analyzes the development trend.

  10. 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).

  11. Establishment of an Institute for Fusion Studies

    NASA Astrophysics Data System (ADS)

    Hazeltine, R. D.

    1994-07-01

    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 national and international center for information exchange by hosting exchange visits, conferences, and workshops; and (3) to train students and postdoctoral research personnel for the fusion energy program and plasma physics research areas. The theoretical research results obtained by the Institute contribute to the progress of nuclear fusion research, whose goal is the development of fusion power as a basic energy source. Close collaborative relationships have been developed with other university and national laboratory fusion groups, both in the US and abroad. In addition to its primary focus on mainstream fusion physics, the Institute is also involved with research in fusion-sidestream fields, such as advanced computing techniques, nonlinear dynamics, space plasmas and astrophysics, statistical mechanics, fluid dynamics, and accelerator physics. Important research discoveries are briefly described.

  12. 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.

  13. Multifocus image fusion using phase congruency

    NASA Astrophysics Data System (ADS)

    Zhan, Kun; Li, Qiaoqiao; Teng, Jicai; Wang, Mingying; Shi, Jinhui

    2015-05-01

    We address the problem of fusing multifocus images based on the phase congruency (PC). PC provides a sharpness feature of a natural image. The focus measure (FM) is identified as strong PC near a distinctive image feature evaluated by the complex Gabor wavelet. The PC is more robust against noise than other FMs. The fusion image is obtained by a new fusion rule (FR), and the focused region is selected by the FR from one of the input images. Experimental results show that the proposed fusion scheme achieves the fusion performance of the state-of-the-art methods in terms of visual quality and quantitative evaluations.

  14. 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…

  15. 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

  16. Laser fusion target illumination system.

    PubMed

    Thomas, C E

    1975-06-01

    Laser fusion experiments require the focusing of very intense pulsed laser beams onto very small fuel pellets. All reported experiments to date have used lenses to focus one or more laser beams onto the target. This paper describes a combined refractive/reflective illumination system that provides nearly uniform irradiance with nearly orthogonal incidence over the complete spherical target, with only two laser beams. This illumination system was used in the experiments that produced the first known symmetric target implosions. Furthermore, these experiments produced what we believe were the first thermonuclear neutrons generated by a laser-driven implosion. PMID:20154815

  17. Interplanetary propulsion using inertial fusion

    NASA Technical Reports Server (NTRS)

    Orth, Charles D.; Hoffman, Nate; Murray, Kathy; Klein, Gail; Diaz, Franklin Chang

    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. A study was conducted to assess the systems aspects of inertial as applied to such missions, based on the conceptual engine design of Hyde (1983). The required systems for an entirely new spacecraft design called VISTA that is based on the use of DT fuel is described. Preliminary design details are given for the power conversion and power conditioning systems for manned missions to Mars of total duration of about 100 days.

  18. Mitochondrial fusion through membrane automata.

    PubMed

    Giannakis, Konstantinos; Andronikos, Theodore

    2015-01-01

    Studies have shown that malfunctions in mitochondrial processes can be blamed for diseases. However, the mechanism behind these operations is yet not sufficiently clear. In this work we present a novel approach to describe a biomolecular model for mitochondrial fusion using notions from the membrane computing. We use a case study defined in BioAmbient calculus and we show how to translate it in terms of a P automata variant. We combine brane calculi with (mem)brane automata to produce a new scheme capable of describing simple, realistic models. We propose the further use of similar methods and the test of other biomolecular models with the same behaviour. PMID:25417022

  19. Nonlinear control in fusion reactors

    NASA Astrophysics Data System (ADS)

    Schuster, Eugenio

    There is consensus in the fusion reactor community that active control will be one of the key enabling technologies. With further advancements in reduced-order fusion modeling, advances in control systems for fusion will continue, including vertical and shape control, kinetic and current profile control, MHD (magnetohydrodynamic) stabilization and plasma transport reduction. This dissertation addresses different control problems in tokamaks using as common denominator a nonlinear control approach. Contributions are made in the areas of kinetic control, magnetic control, and MHD flow control. In the area of kinetic control, we approach the problem of nonlinear control of burn instability in fission reactors, where a lumped-parameter nonlinear model involving approximate conservation equations for the energy and the densities of the species is used to synthesize a nonlinear feedback controller (backstepping, feedback linearization, passivity and input to state stability) for stabilizing the thermally unstable burn condition of a fusion reactor. In addition, the problem of control of kinetic profiles in non-burning plasmas, where a set of nonlinear partial differential equations (PDE's) describing approximately the dynamics of the density and energy was considered as the plant model used to synthesize a boundary controller (infinite-dimensional nonlinear backstepping) whose goal was the control of the density and energy spatial distributions, is also considered. In the area of magnetic control, the problem of plasma vertical position stabilization and shape control under actuation saturation in the DIII-D Tokamak at General Atomics is approached. In this case, modifications of the nominal control loops (nonlinear anti-windup augmentation) are proposed to ensure stability of the plant and good behavior of the nominal controller under the presence of voltage saturation in the coils that are used to vertically position and shape the plasma inside the tokamak. In the area

  20. 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.

  1. 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

  2. Multisensor Fusion for Change Detection

    NASA Astrophysics Data System (ADS)

    Schenk, T.; Csatho, B.

    2005-12-01

    Combining sensors that record different properties of a 3-D scene leads to complementary and redundant information. If fused properly, a more robust and complete scene description becomes available. Moreover, fusion facilitates automatic procedures for object reconstruction and modeling. For example, aerial imaging sensors, hyperspectral scanning systems, and airborne laser scanning systems generate complementary data. We describe how data from these sensors can be fused for such diverse applications as mapping surface erosion and landslides, reconstructing urban scenes, monitoring urban land use and urban sprawl, and deriving velocities and surface changes of glaciers and ice sheets. An absolute prerequisite for successful fusion is a rigorous co-registration of the sensors involved. We establish a common 3-D reference frame by using sensor invariant features. Such features are caused by the same object space phenomena and are extracted in multiple steps from the individual sensors. After extracting, segmenting and grouping the features into more abstract entities, we discuss ways on how to automatically establish correspondences. This is followed by a brief description of rigorous mathematical models suitable to deal with linear and area features. In contrast to traditional, point-based registration methods, lineal and areal features lend themselves to a more robust and more accurate registration. More important, the chances to automate the registration process increases significantly. The result of the co-registration of the sensors is a unique transformation between the individual sensors and the object space. This makes spatial reasoning of extracted information more versatile; reasoning can be performed in sensor space or in 3-D space where domain knowledge about features and objects constrains reasoning processes, reduces the search space, and helps to make the problem well-posed. We demonstrate the feasibility of the proposed multisensor fusion approach

  3. Ch. 37, Inertial Fusion Energy Technology

    SciTech Connect

    Moses, E

    2010-06-09

    Nuclear fission, nuclear fusion, and renewable energy (including biofuels) are the only energy sources capable of satisfying the Earth's need for power for the next century and beyond without the negative environmental impacts of fossil fuels. Substantially increasing the use of nuclear fission and renewable energy now could help reduce dependency on fossil fuels, but nuclear fusion has the potential of becoming the ultimate base-load energy source. Fusion is an attractive fuel source because it is virtually inexhaustible, widely available, and lacks proliferation concerns. It also has a greatly reduced waste impact, and no danger of runaway reactions or meltdowns. The substantial environmental, commercial, and security benefits of fusion continue to motivate the research needed to make fusion power a reality. Replicating the fusion reactions that power the sun and stars to meet Earth's energy needs has been a long-sought scientific and engineering challenge. In fact, this technological challenge is arguably the most difficult ever undertaken. Even after roughly 60 years of worldwide research, much more remains to be learned. the magnitude of the task has caused some to declare that fusion is 20 years away, and always will be. This glib criticism ignores the enormous progress that has occurred during those decades, progress inboth scientific understanding and essential technologies that has enabled experiments producing significant amounts of fusion energy. For example, more than 15 megawatts of fusion power was produced in a pulse of about half a second. Practical fusion power plants will need to produce higher powers averaged over much longer periods of time. In addition, the most efficient experiments to date have required using about 50% more energy than the resulting fusion reaction generated. That is, there was no net energy gain, which is essential if fusion energy is to be a viable source of electricity. The simplest fusion fuels, the heavy isotopes of

  4. 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

  5. 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.

  6. Perioperative outcomes and adverse events of minimally invasive versus open posterior lumbar fusion: meta-analysis and systematic review.

    PubMed

    Goldstein, Christina L; Macwan, Kevin; Sundararajan, Kala; Rampersaud, Y Raja

    2016-03-01

    OBJECT The objective of this study was to determine the clinical comparative effectiveness and adverse event rates of posterior minimally invasive surgery (MIS) compared with open transforaminal or posterior lumbar interbody fusion (TLIF/PLIF). METHODS A systematic review of the Medline, EMBASE, PubMed, Web of Science, and Cochrane databases was performed. A hand search of reference lists was conducted. Studies were reviewed by 2 independent assessors to identify randomized controlled trials (RCTs) or comparative cohort studies including at least 10 patients undergoing MIS or open TLIF/PLIF for degenerative lumbar spinal disorders and reporting at least 1 of the following: clinical outcome measure, perioperative clinical or process measure, radiographic outcome, or adverse events. Study quality was assessed using the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) protocol. When appropriate, a meta-analysis of outcomes data was conducted. RESULTS The systematic review and reference list search identified 3301 articles, with 26 meeting study inclusion criteria. All studies, including 1 RCT, were of low or very low quality. No significant difference regarding age, sex, surgical levels, or diagnosis was identified between the 2 cohorts (856 patients in the MIS cohort, 806 patients in the open cohort). The meta-analysis revealed changes in the perioperative outcomes of mean estimated blood loss, time to ambulation, and length of stay favoring an MIS approach by 260 ml (p < 0.00001), 3.5 days (p = 0.0006), and 2.9 days (p < 0.00001), respectively. Operative time was not significantly different between the surgical techniques (p = 0.78). There was no significant difference in surgical adverse events (p = 0.97), but MIS cases were significantly less likely to experience medical adverse events (risk ratio [MIS vs open] = 0.39, 95% confidence interval 0.23-0.69, p = 0.001). No difference in nonunion (p = 0.97) or reoperation rates (p = 0.97) was

  7. 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.

  8. Pedestrian detection by multispectral fusion

    NASA Astrophysics Data System (ADS)

    Ma, Yunqian; Wang, Zheng; Bazakos, Mike

    2006-04-01

    Security systems increasingly rely on the use of Automated Video Surveillance (AVS) technology. In particular the use of digital video renders itself to internet and local communications, remote monitoring, and to computer processing. AVS systems can perform many tedious and repetitive tasks currently performed by trained security personnel. AVS technology has already made some significant steps towards automating some basic security functions such as: motion detection, object tracking and event-based video recording. However, there are still many problems associated with just these automated functions, which need to be addressed further. Some examples of these problems are: the high "false alarm rate" and the "loss of track" under total or partial occlusion, when used under a wide range of operational parameters (day, night, sunshine, cloudy, foggy, range, viewing angle, clutter, etc.). Current surveillance systems work well only under a narrow range of operational parameters. Therefore, they need be hardened against a wide range of operational conditions. In this paper, we present a Multi-spectral fusion approach to perform accurate pedestrian segmentation under varying operational parameters. Our fusion method combines the "best" detection results from the visible images and the "best" from the thermal images. Commonly, the motion detection results in the visible images are easily affected by noise and shadows. The objects in the thermal image are relatively stable, but they may be missing some parts of the objects, because they thermally blend with the background. Our method makes use of the "best" object components and de-emphasize the "not best".

  9. Graphene's Viability for Fusion Applications

    NASA Astrophysics Data System (ADS)

    Navarro, Marcos; Hall, Karla; Rojas, Richard; Santarius, John; Kulcinski, Gerald

    2015-11-01

    Graphene is a source of interest for multiple applications due to its unusual electronic and physical properties. As a coating material, it has reduced oxidation of the main substrate, though no effort has been reported of testing it under fusion conditions. A number of experimental studies have established that defect-free graphene is an excellent barrier material for gases. We explore its viability to maintain a significant pressure difference under ion irradiation. Deuterium is used as a projectile on graphene coated silicon over a range of 10-50 keV energies and various fluences. The vacancy yield (amount of damage) and natural resonance for graphene are found at around 1350 cm-1 and 1550 cm-1, respectively. Damage of each sample is quantified via Raman spectroscopy (RS) using the ratio of the intensities at these wavenumbers. Graphene is also tested here as a coating for some fusion components. Though tungsten is a very promising divertor and first wall candidate, after intense irradiation, it is prone to developing fuzz or grass structures, leading to a diminished lifetime. Graphene grown on tungsten is tested under reactor conditions with 30 keV He ions at several fluences, and the sputtering of both materials is studied via RS and Scanning Electron Microscopy. This work was supported by the Graduate Engineering Research Scholars and the TEAM-Science program at the University of Wisconsin-Madison.

  10. Review of the magnetic fusion program by the 1986 ERAB Fusion Panel

    NASA Astrophysics Data System (ADS)

    Davidson, Ronald C.

    1987-09-01

    The 1986 ERAB Fusion Panel finds that fusion energy continues to be an attractive energy source with great potential for the future, and that the magnetic fusion program continues to make substantial technical progress. In addition, fusion research advances plasma physics, a sophisticated and useful branch of applied science, as well as technologies important to industry and defense. These factors fully justify the substantial expenditures by the Department of Energy in fusion research and development (R&D). The Panel endorses the overall program direction, strategy, and plans, and recognizes the importance and timeliness of proceeding with a burning plasma experiment, such as the proposed Compact Ignition Tokamak (CIT) experiment.

  11. 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.

  12. NTRK1 Fusion in Glioblastoma Multiforme

    PubMed Central

    Cho, Hee-Jin; Lee, Young-Eun; An, Jaeyeol; Cho, Gye-Hyun; Ko, Young-Hyeh; Joo, Kyeung Min; Nam, Do-Hyun

    2014-01-01

    Glioblastoma multiforme (GBM) is the most aggressive form of brain tumor, yet with no targeted therapy with substantial survival benefit. Recent studies on solid tumors showed that fusion genes often play driver roles and are promising targets for pharmaceutical intervention. To survey potential fusion genes in GBMs, we analysed RNA-Seq data from 162 GBM patients available through The Cancer Genome Atlas (TCGA), and found that 3′ exons of neurotrophic tyrosine kinase receptor type 1 (NTRK1, encoding TrkA) are fused to 5′ exons of the genes that are highly expressed in neuronal tissues, neurofascin (NFASC) and brevican (BCAN). The fusions preserved both the transmembrane and kinase domains of NTRK1 in frame. NTRK1 is a mediator of the pro-survival signaling of nerve growth factor (NGF) and is a known oncogene, found commonly altered in human cancer. While GBMs largely lacked NTRK1 expression, the fusion-positive GBMs expressed fusion transcripts in high abundance, and showed elevated NTRK1-pathway activity. Lentiviral transduction of the NFASC-NTRK1 fusion gene in NIH 3T3 cells increased proliferation in vitro, colony formation in soft agar, and tumor formation in mice, suggesting the possibility that the fusion contributed to the initiation or maintenance of the fusion-positive GBMs, and therefore may be a rational drug target. PMID:24647444

  13. 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.

  14. 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.

  15. Acquired spondylolysis after posterolateral spinal fusion.

    PubMed

    Blasier, R D; Monson, R C

    1987-01-01

    A case of spondylolysis occurring immediately above a posterolateral lumbar spinal fusion in a 12-year-old girl is described. This case illustrates a potential problem of stress concentration at the pars interarticularis, previously only described after posterior interlaminar fusion. PMID:3558808

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. Approximation for nonresonant beam target fusion reactivities

    SciTech Connect

    Mikkelsen, D.R.

    1988-11-01

    The beam target fusion reactivity for a monoenergetic beam in a Maxwellian target is approximately evaluated for nonresonant reactions. The approximation is accurate for the DD and TT fusion reactions to better than 4% for all beam energies up to 300 keV and all ion temperatures up to 2/3 of the beam energy. 12 refs., 1 fig., 1 tab.

  1. 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.

  2. Application of polarized nuclei to fusion

    SciTech Connect

    Kulsrud, R.M.

    1987-07-01

    It is shown that the d-t fusion reaction can be modified by polarizing nuclear spins. The ways in which this improves reactor performance are mentioned and the feasibility of the process of spin polarization for magnetic fusion is discussed. 18 refs.

  3. Fusion rule algebras from graph theory

    NASA Astrophysics Data System (ADS)

    Caselle, M.; Ponzano, G.

    1989-06-01

    We describe a new class of fusion algebras related to graph theory which bear intriguing connections with group algebras. The structure constants and the matrix S, which diagonalizes the fusion rules, are explicitly computed in terms of SU(2) coupling coefficients.

  4. 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)

  5. 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.

  6. Working with Fusion in Lesbian Couples.

    ERIC Educational Resources Information Center

    Roth, Nicki F.

    The phenomena of fusion within a lesbian relationship is described in a six-phased model. Fusion in relationships is defined as two incomplete people coming together in an attempt to make one more complete whole, the merging of two ego boundaries. The six phases discussed include ecstacy, getting married, the routine, depression/withdrawal,…

  7. Fluidized wall for protecting fusion chamber walls

    SciTech Connect

    Maniscalco, J.A.; Meier, W.R.

    1982-08-17

    Apparatus for protecting the inner wall of a fusion chamber from microexplosion debris, x-rays, neutrons, etc. Produced by deuterium-tritium (DT) targets imploded within the fusion chamber. The apparatus utilizes a fluidized wall similar to a waterfall comprising liquid lithium or solid pellets of lithiumceramic, the waterfall forming a blanket to prevent damage of the structural materials of the chamber.

  8. Applied and fundamental aspects of fusion science

    NASA Astrophysics Data System (ADS)

    Melnikov, Alexander V.

    2016-05-01

    Fusion research is driven by the applied goal of energy production from fusion reactions. There is, however, a wealth of fundamental physics to be discovered and studied along the way. This Commentary discusses selected developments in diagnostics and present-day research topics in high-temperature plasma physics.

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

    PubMed Central

    Lee, Donald W.; Thapar, Vikram; Clancy, Paulette; Daniel, Susan

    2014-01-01

    Influenza enters the host cell cytoplasm by fusing the viral and host membrane together. Fusion is mediated by hemagglutinin (HA) trimers that undergo conformational change when acidified in the endosome. It is currently debated how many HA trimers, w, and how many conformationally changed HA trimers, q, are minimally required for fusion. Conclusions vary because there are three common approaches for determining w and q from fusion data. One approach correlates the fusion rate with the fraction of fusogenic HA trimers and leads to the conclusion that one HA trimer is required for fusion. A second approach correlates the fusion rate with the total concentration of fusogenic HA trimers and indicates that more than one HA trimer is required. A third approach applies statistical models to fusion rate data obtained at a single HA density to establish w or q and suggests that more than one HA trimer is required. In this work, all three approaches are investigated through stochastic fusion simulations and experiments to elucidate the roles of HA and its ability to bend the target membrane during fusion. We find that the apparent discrepancies among the results from the various approaches may be resolved if nonfusogenic HA participates in fusion through interactions with a fusogenic HA. Our results, based on H3 and H1 serotypes, suggest that three adjacent HA trimers and one conformationally changed HA trimer are minimally required to induce membrane fusion (w = 3 and q = 1). PMID:24559987

  10. 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. PMID:27586365

  11. 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

  12. 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

  13. 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.

  14. 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

  15. Economic potential of magnetic fusion energy

    SciTech Connect

    Henning, C.D.

    1981-03-10

    Scientific feasibility of magnetic fusion is no longer seriously in doubt. Rapid advances have been made in both tokamak and mirror research, leading to a demonstration in the TFTR tokamak at Princeton in 1982 and the tandem mirror MFTF-B at Livermore in 1985. Accordingly, the basis is established for an aggressive engineering thrust to develop a reactor within this century. However, care must be taken to guide the fusion program towards an economically and environmentally viable goal. While the fusion fuels are essentially free, capital costs of reactors appear to be at least as large as current power plants. Accordingly, the price of electricity will not decline, and capital availability for reactor constructions will be important. Details of reactor cost projections are discussed and mechanisms suggested for fusion power implementation. Also discussed are some environmental and safety aspects of magnetic fusion.

  16. Grand challenges of inertial fusion energy

    NASA Astrophysics Data System (ADS)

    Nuckolls, J. H.

    2010-08-01

    As soon as practical, Earth's low-cost, abundant, environmentally attractive fusion energy resources should be applied to the urgent global challenges of climate change, energy supply, economic growth, and the developing world. A National Ignition Campaign is under way at the recently completed National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) to ignite high-gain inertial fusion targets in the 2010-2012 time frame. Achieving ignition on NIF could be the catalyst for national and global leaders to support the development of inertial fusion energy (IFE) to meet the future's worldwide electric power demand. With sustained, high-priority funding could practical IFE be possible by the 2020 timeframe? The answer lies in how well can the community address and solve technical challenges in four key areas: achieving ignition, producing advanced targets and drivers, creating a practical fusion engine, and developing economical fusion power plants.

  17. Public Relations on Fusion in Europe

    NASA Astrophysics Data System (ADS)

    Ongena, J.; van Oost, G.; Paris, P. J.

    2000-10-01

    A summary will be presented of PR efforts on fusion energy research in Europe. A 3-D movie of a fusion research experimental reactor has been realized at the start of this year. It has been made entirely on virtual animation basis. Two versions exists, a short version of 3 min., as a video clip, and a longer version of nearly 8 min. Both could be viewed in 3D, using special projections and passive glasses or in normal VHS video projections. A new CD-ROM for individual and classroom use will be presented, discussing (i) the different energy forms, (ii) general principles of fusion, (iii) current research efforts and (iv) future prospects of fusion. This CD-ROM is now produced in English, German, French, Spanish, Italian and Portuguese Several new brochures and leaflets intended to increase the public awareness on fusion in Europe will be on display.

  18. Inertial-confinement fusion with lasers

    DOE PAGESBeta

    Betti, R.; Hurricane, O. A.

    2016-05-03

    Here, 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 tomore » 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.« less

  19. Mechanisms of Mitochondrial Fission and Fusion

    PubMed Central

    van der Bliek, Alexander M.; Shen, Qinfang; Kawajiri, Sumihiro

    2013-01-01

    Mitochondria continually change shape through the combined actions of fission, fusion, and movement along cytoskeletal tracks. The lengths of mitochondria and the degree to which they form closed networks are determined by the balance between fission and fusion rates. These rates are influenced by metabolic and pathogenic conditions inside mitochondria and by their cellular environment. Fission and fusion are important for growth, for mitochondrial redistribution, and for maintenance of a healthy mitochondrial network. In addition, mitochondrial fission and fusion play prominent roles in disease-related processes such as apoptosis and mitophagy. Three members of the Dynamin family are key components of the fission and fusion machineries. Their functions are controlled by different sets of adaptor proteins on the surface of mitochondria and by a range of regulatory processes. Here, we review what is known about these proteins and the processes that regulate their actions. PMID:23732471

  20. Magnetic-fusion energy and computers

    SciTech Connect

    Killeen, J.

    1982-01-01

    The application of computers to magnetic fusion energy research is essential. In the last several years the use of computers in the numerical modeling of fusion systems has increased substantially. There are several categories of computer models used to study the physics of magnetically confined plasmas. A comparable number of types of models for engineering studies are also in use. To meet the needs of the fusion program, the National Magnetic Fusion Energy Computer Center has been established at the Lawrence Livermore National Laboratory. A large central computing facility is linked to smaller computer centers at each of the major MFE laboratories by a communication network. In addition to providing cost effective computing services, the NMFECC environment stimulates collaboration and the sharing of computer codes among the various fusion research groups.