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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. Posterior lumbar interbody fusion.

    PubMed

    DiPaola, Christian P; Molinari, Robert W

    2008-03-01

    Posterior lumbar interbody fusion (PLIF) and transforaminal lumbar interbody fusion (TLIF) create intervertebral fusion by means of a posterior approach. Both techniques are useful in managing degenerative disk disease, severe instability, spondylolisthesis, deformity, and pseudarthrosis. Successful results have been reported with allograft, various cages (for interbody support), autograft, and recombinant human bone morphogenetic protein-2. Interbody fusion techniques may facilitate reduction and enhance fusion. The rationale for PLIF and TLIF is biomechanically sound. However, clinical outcomes of different anterior and posterior spinal fusion techniques tend to be similar. PLIF has a high complication rate (dural tear, 5.4% to 10%; neurologic injury, 9% to 16%). These findings, coupled with the versatility of TLIF throughout the entire lumbar spine, may make TLIF the ideal choice for an all-posterior interbody fusion. PMID:18316711

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

    PubMed Central

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

    2014-01-01

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

  4. Anterior Lumbar Interbody Fusion for the Treatment of Postoperative Spondylodiscitis

    PubMed Central

    Kim, Sung Han; Kang, Moo-Sung; Chin, Dong-Kyu; Kim, Keun-Su; Cho, Yong-Eun

    2014-01-01

    Objective To analyze the clinical courses and outcomes after anterior lumbar interbody fusion (ALIF) for the treatment of postoperative spondylodiscitis. Methods A total of 13 consecutive patients with postoperative spondylodiscitis treated with ALIF at our institute from January, 1994 to August, 2013 were included (92.3% male, mean age 54.5 years old). The outcome data including inflammatory markers (leukocyte count, C-reactive protein, erythrocyte sedimentation rate), the Oswestry Disability Index (ODI), the modified Visual Analogue Scale (VAS), and bony fusion rate using spine X-ray were obtained before and 6 months after ALIF. Results All of the cases were effectively treated with combination of systemic antibiotics and ALIF with normalization of the inflammatory markers. The mean VAS for back and leg pain before ALIF was 6.8±1.1, which improved to 3.2±2.2 at 6 months after ALIF. The mean ODI score before ALIF was 70.0±14.8, which improved to 34.2±27.0 at 6 months after ALIF. Successful bony fusion rate was 84.6% (11/13) and the remaining two patients were also asymptomatic. Conclusion Our results suggest that ALIF is an effective treatment option for postoperative spondylodiscitis. PMID:25371780

  5. 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

  6. 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

  7. 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

  8. 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

  9. Mini-Open Anterior Retroperitoneal Lumbar Interbody Fusion: Oblique Lateral Interbody Fusion for Lumbar Spinal Degeneration Disease

    PubMed Central

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

    2015-01-01

    Purpose Surgery for lumbar spinal degeneration disease is widely performed. While posterior decompression and fusion are popular, anterior lumbar interbody fusion (ALIF) is also used for treatment. Extreme lateral interbody fusion (XLIF) is commonly used for noninvasive ALIF; however, several complications, such as spinal nerve and psoas muscle injury, have been reported. In the current study, we examined the clinical efficacy and complications of oblique lateral interbody fusion (OLIF) for lumbar spinal degeneration disease. Materials and Methods Thirty-five patients with degenerated spondylolisthesis, discogenic pain, and kyphoscoliosis were examined. All patients underwent OLIF surgery (using a cage and bone graft from the iliac crest) with or without posterior decompression, without real-time electromyography monitoring. Posterior screws were used in all patients. Visual analog scale (VAS) score and Oswestry Disability Index (ODI) were evaluated before and 6 months after surgery. Surgical complications were also evaluated. Results Pain scores significantly improved after surgery, compared to those before surgery (p<0.05). There was no patient who underwent revision surgery. There was no spinal nerve, major vessel, peritoneal, or urinary injury. Few patients showed symptoms from psoas invasion. Conclusion OLIF surgery produced good surgical results without any major complication. PMID:26069130

  10. Radiographic Comparison of Lateral Lumbar Interbody Fusion Versus Traditional Fusion Approaches: Analysis of Sagittal Contour Change

    PubMed Central

    Sembrano, Jonathan N.; Horazdovsky, Ryan D.; Santos, Edward Rainier G.; Polly, David W.

    2015-01-01

    Background Lateral approach to lumbar fusion has been gaining popularity in recent years. With increasing awareness of the significance of sagittal balance restoration in spinal surgery, it is important to investigate the potential of this relatively new approach in correcting sagittal deformities in comparison to conventional approaches. The aim of this study was to evaluate sagittal contour changes seen in lateral lumbar interbody fusion and compare them with radiographic changes in traditional approaches to lumbar fusion. Methods Lumbar fusion procedures from January 2008 to December 2009 were reviewed. Four approaches were compared: anterior lumbar interbody fusion (ALIF), lateral lumbar interbody fusion (LLIF), transforaminal interbody fusion (TLIF) and posterior spinal fusion (PSF). Standing pre-operative and 6-week post-operative radiographs were measured in terms of operative level, suprajacent and subjacent level, and regional lumbar lordosis (L1-S1) as well as operative level anterior (ADH) and posterior disc heights (PDH). T-test was used to analyze differences between and within different approaches (α=0.05). Results A total of 147 patients underwent lumbar fusion at 212 levels. Mean operative level segmental lordosis change after each procedure is as follows: ALIF 3.8 ± 6.6° (p < 0.01); LLIF 3.2 ± 3.6° (p<0.01); TLIF 1.9 ± 3.9° (p<0.01); and PSF 0.7 ± 2.9° (p =0.13). Overall lumbar lordosis change after each procedure is as follows: ALIF 4.2 ± 5.8° (p < 0.01); LLIF 2.5 ± 4.1° (p<0.01); TLIF 2.1 ± 6.0 (p = 0.02); PSF -0.5 ± 6.2° (p = 0.66). There were no significant changes in the supradjcent and subjacent level lordosis in all approaches except in ALIF where a significant decrease in supradjecent level lordosis was seen. Mean ADH and PDH significantly increased for all approaches except in PSF where PDH decreased post-operatively. Conclusion LLIF has the ability to improve sagittal contour as well as other interbody approaches and is superior to posterioronly approach in disc height restoration. However, ALIF provides the greatest amount of segmental and overall lumbar lordosis correction. Level of Evidence This is a Level III study. Clinical Relevance Regional lordosis correction may be effectively achieved with LLIF. This approach is a good addition to a surgeon's armamentarium in maintenance or restoration of normal lumbar sagittal alignment. PMID:26114085

  11. Extreme lateral interbody fusion with posterior instrumentation for spondylodiscitis.

    PubMed

    Blizzard, Daniel J; Hills, Christopher P; Isaacs, Robert E; Brown, Christopher R

    2015-11-01

    The purpose of this study was to evaluate our initial experience utilizing extreme lateral interbody fusion (XLIF; NuVasive, San Diego, CA, USA) with percutaneous posterior instrumentation to treat 11 spondylodiscitis patients between January 2011 and February 2014. Although medical management is the first line treatment for spondylodiscitis, many patients fail antibiotic therapy and bracing, or present with instability, neurologic deficits, or sepsis, requiring operative debridement and stabilization. High rates of fusion and infection clearance have been reported with anterior lumbar interbody fusion (ALIF), but this approach requires a morbid exposure, associated with non-trivial rates of vascular and peritoneal complications. XLIF is an increasingly popular interbody fusion technique which utilizes a fast and minimally invasive approach, sparing the anterior longitudinal ligament, and allowing sufficient visualization of the intervertebral discs and bodies to debride and place a large, lordotic cage. The outcome measures for this study included lumbar lordosis, sagittal balance, subsidence, fusion, pain, neurological deficit, and microbiology/laboratory evidence of infection. The mean follow-up time was 9.3 months. All patients had improvements in pain and neurological symptoms. The mean lordosis change was 11.0°, from 23.1° preoperatively to 34.0° postoperatively. Fusion was confirmed with CT scans in five of six patients. At the last follow-up, all patients had normalization of inflammatory markers, no symptoms of infection, and none required repeat surgical treatment for spondylodiscitis. XLIF with percutaneous posterior instrumentation is a minimally invasive technique with reduced morbidity for lumbar spine fusion which affords adequate exposure to the vertebral bodies and discs to aggressively debride necrotic and infected tissue. This study suggests that XLIF may be a safe and effective alternative to ALIF for the treatment of spondylodiscitis. PMID:26138052

  12. Perioperative complications of threaded cylindrical lumbar interbody fusion devices: anterior versus posterior approach.

    PubMed

    Scaduto, Anthony A; Gamradt, Seth C; Yu, Warren D; Huang, Jerry; Delamarter, Rick B; Wang, Jeffrey C

    2003-12-01

    Few data are available to evaluate approach-related differences in perioperative complications with lumbar interbody fusion devices. Complications occurring in the intraoperative and immediate postoperative period were identified and categorized for 31 consecutive posterior lumbar interbody fusions (PLIFs) and 88 consecutive anterior lumbar interbody fusions (ALIFs). In this study, all lumbar interbody fusions were conducted with threaded cylindrical devices as stand-alone internal fixation devices. Multivariate analysis was used to account for potential covariates and identify factors associated with an increased complication risk. Twenty-two percent of the patients had a perioperative complication. The relative risk of having a perioperative complication was 4.75 times higher for the PLIF group. All intraoperative complications occurred in the PLIF group. The relative risk of having a major postoperative complication was 6.8 times higher in the PLIF group than the ALIF group. Anterior approached patients tended to have visceral (ileus, 6%) and vascular (deep venous thrombosis, 2%) complications. In the posterior group, complications were neurologic and dura related (pseudomeningocele, 16%; epidural hematoma, 3%) and occurred most frequently in patients that had had previous posterior lumbar surgery (31% with major complication). PMID:14657745

  13. Biomechanical comparison of anterior lumbar interbody fusion: stand-alone interbody cage versus interbody cage with pedicle screw fixation - a finite element analysis

    PubMed Central

    2013-01-01

    Background Anterior lumbar interbody fusion (ALIF) followed by pedicle screw fixation (PSF) is used to restore the height of the intervertebral disc and provide stability. Recently, stand-alone interbody cage with anterior fixation has been introduced, which eliminates the need for posterior surgery. We compared the biomechanics of the stand-alone interbody cage to that of the interbody cage with additional PSF in ALIF. Methods A three-dimensional, non-linear finite element model (FEM) of the L2-5 segment was modified to simulate ALIF in L3-4. The models were tested under the following conditions: (1) intact spine, (2) destabilized spine, (3) with the interbody cage alone (type 1), (4) with the stand-alone cage with anterior fixation (SynFix-LR®; type 2), and (5) with type 1 in addition to PSF (type 3). Range of motion (ROM) and the stiffness of the operated level, ROM of the adjacent segments, load sharing distribution, facet load, and vertebral body stress were quantified with external loading. Results The implanted models had decreased ROM and increased stiffness compared to those of the destabilized spine. The type 2 had differences in ROM limitation of 8%, 10%, 4%, and 6% in flexion, extension, axial rotation, and lateral bending, respectively, compared to those of type 3. Type 2 had decreased ROM of the upper and lower adjacent segments by 3-11% and 3-6%, respectively, compared to those of type 3. The greatest reduction in facet load at the operated level was observed in type 3 (71%), followed by type 2 (31%) and type 1 (23%). An increase in facet load at the adjacent level was highest in type 3, followed by type 2 and type 1. The distribution of load sharing in type 2 (anterior:posterior, 95:5) was similar to that of the intact spine (89:11), while type 3 migrated posterior (75:25) to the normal. Type 2 reduced about 15% of the stress on the lower vertebral endplate compared to that in type 1. The stress of type 2 increased two-fold compared to the stress of type 3, especially in extension. Conclusions The stand-alone interbody cage can provide sufficient stability, reduce stress in adjacent levels, and share the loading distribution in a manner similar to an intact spine. PMID:23890389

  14. 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

  15. 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

  16. [Interbody metal implants ("cages") for lumbar fusion].

    PubMed

    Freiherr von Salis-Soglio, G; Scholz, R; Seller, K

    2005-10-01

    Over the last 15 years, interbody metal implants have become commonly used worldwide for lumbar interbody fusion. The so called "cages" are made of metal or absorbable materials. By using different surgical techniques, they can be implanted either regularly or via endoscopy. The published results on surgical techniques using cages for the lumbar spine show, in most cases and with or without additional instrumentation, rates of fusion of more than 90%. It seems that the use of osteoinductive substances (especially BMP) leads to even better results. Dorsoventral fusion with internal fixation and bone show the same rate of consolidation, but the advantages of cages are primarily in the maintenance of the distraction and the possibility of a single surgical procedure without additional instrumentation (including endoscopy), and in a lower donor side morbidity. PMID:16075251

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

    PubMed

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

    2012-07-13

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

  18. 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

  19. 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

  20. The VariLift(®) Interbody Fusion System: expandable, standalone interbody fusion.

    PubMed

    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

  1. 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

  2. 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

  3. 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

  4. 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

  5. Surgical Results of Lumbar Interbody Fusion Using Calcium Phosphate Cement

    PubMed Central

    HIRASAWA, Motohiro; MURE, Hideo; TOI, Hiroyuki; NAGAHIRO, Shinji

    2014-01-01

    Clinical and radiological outcomes of lumbar interbody fusion using artificial fusion cages filled with calcium phosphate cements (CPCs) were retrospectively reviewed. Between 2002 and 2011, 25 patients underwent lumbar interbody fusion at Tokushima University Hospital, and 22 patients were enrolled in this study. Of these, 5 patients received autologous local bone grafts and 17 received CPC. Japan Orthopedic Association (JOA) score was used for clinical outcome assessments. Lumbar radiography and computed tomography (CT) were performed at 12, 24 months and last follow-up period to assess bony fusion. The mean JOA score of all patients improved from 9.3 before surgery to 21.0 at 24 months after surgery. Fusion had occurred in 5 of 5 patients in the local bone graft group and in 16 of 17 patients in CPC group at 24 months postoperatively. No surgically related complication was occurred in both groups. CPC is a useful and safe graft material for lumbar interbody fusion. PMID:25169138

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

    PubMed Central

    Katzell, Jeffrey

    2014-01-01

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

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

    PubMed Central

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

    2014-01-01

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

  8. Minimally invasive anterior lumbar interbody fusion for adult degenerative scoliosis with 1 or 2 dislocated levels.

    PubMed

    Flouzat-Lachaniette, Charles-Henri; Ratte, Louis; Poignard, Alexandre; Auregan, Jean-Charles; Queinnec, Steffen; Hernigou, Philippe; Allain, Jrme

    2015-12-01

    OBJECT Frequent complications of posterolateral instrumented fusion have been reported after treatment of degenerative scoliosis in elderly patients. Considering that in some cases, most of the symptomatology of adult degenerative scoliosis (ADS) is a consequence of the segmental instability at the dislocated level, the use of minimally invasive anterior lumbar interbody fusion (ALIF) to manage symptoms can be advocated to reduce surgical morbidity. The purpose of this study was to evaluate the midterm outcomes of 1- or 2-level minimally invasive ALIFs in ADS patients with 1- or 2-level dislocations. METHODS A total of 47 patients (average age 64 years; range 43-80 years) with 1- or 2-level ALIF performed for ADS (64 levels) in a single institution were included in the study. An independent spine surgeon retrospectively reviewed all the patients' medical records and radiographs to assess operative data and surgery-related complications. Clinical outcome was reported using the Oswestry Disability Index (ODI) and the visual analog scale (VAS) for lumbar and leg pain. Intraoperative data and complications were collected. Fusion and risk for adjacent-level degeneration were assessed. RESULTS The mean follow-up duration was 3 years (range 1-10 years). ODI, and back and leg pain VAS scores were significantly improved at last follow-up. A majority of patients (74%) had a statistically significant improvement in their ODI score of more than 20 points at latest follow-up and 1 had a worsening of his disability. The mean operating time was 166 minutes (range 70-355 minutes). The mean estimated blood loss was 410 ml (range 50-1700 ml). Six (5 major and 1 minor) surgical complications (12.7% of patients) and 13 (2 major and 11 minor) medical complications (27.7% of patients) occurred without death or wound infection. Fusion was achieved in 46 of 47 patients. Surgery resulted in a slight but significant decrease of the Cobb angle, and improved the pelvic parameters and lumbar lordosis, but had no effect on the global sagittal balance. At latest follow-up, 9 patients (19.1%) developed adjacent-segment disease at a mean of 2 years' delay from the index surgery; 4 were symptomatic but treated medically, and none required iterative surgery. CONCLUSIONS Single- or 2-level minimally invasive fusion through a minimally invasive anterior approach in some selected cases of ADS produced a good functional outcome with a high fusion rate. They were associated with a significantly lower rate of complications in this study than the historical control. PMID:26315959

  9. Clinical outcome of stand-alone ALIF compared to posterior instrumentation for degenerative disc disease: A pilot study and a literature review.

    PubMed

    Udby, Peter M; Bech-Azeddine, Rachid

    2015-06-01

    The objective of the article was to: a) present results from a case cohort pilot study comparing stand-alone ALIF and TLIF and, b) review the literature on studies comparing the clinical outcome of stand-alone ALIF with posterior instrumentation including TLIF or PLIF, in patients with disabling low back pain resulting from degenerative disc disease. ALIF surgery has previously been linked with certain high risk complications and unfavorable long term fusion results. Newer studies suggest that stand-alone ALIF can possibly be advantageous compared to other types of posterior instrumented interbody fusion for a selected group of DDD patients. The methods and material consisted of a cohort pilot study of patients, with DDD treated with stand-alone ALIF or TLIF followed by a literature review conducted through a comprehensive PubMed database search of the English literature. Studies comparing stand-alone ALIF with posterior instrumented interbody fusion were selected and reviewed. Results from the pilot study, n = 21, showed a reduced perioperative blood loss, shorter operative time and a trend towards better pain reduction and decreased use of opioid analgesics in patients undergoing stand-alone ALIF compared to posterior instrumented fusion with TLIF. The literature review included three studies, n = 630. All three studies were retrospective cohort studies. The average patient follow-up was 2-years but with heterogeneous selected outcomes. Two of three articles documented significant advantages when using stand-alone ALIF on outcomes such as ODI, VAS, surgical time, blood loss and patient satisfaction. No study found stand-alone ALIF inferior in chosen outcomes including fusion. In conclusion the pilot study and the literature review, finds similar clinical outcomes and fusion rates after stand-alone ALIF and posterior interbody fusion. Stand-alone ALIF was associated with a shorter duration of surgery, less perioperative blood loss and a faster improvement post-operatively. Therefore stand-alone ALIF is a viable and important surgical option, which could be considered first choice as surgical treatment. PMID:25855474

  10. Use of an advanced formulation of beta-tricalcium phosphate as a bone extender in interbody lumbar fusion.

    PubMed

    Linovitz, Raymond J; Peppers, Timothy A

    2002-05-01

    Despite numerous advances in the development of bone graft substitutes over the past 20 years, iliac crest autograft remains the gold standard for lumbar spinal fusion. However, donor site morbidity associated with the harvesting of iliac crest autograft remains problematic. Acute and chronic pain, prolonged operative time, bleeding, infection, deformity, and nerve and vascular injury still produce significant postoperative morbidity, even in the presence of careful surgical technique. Although allograft circumvents donor site morbidity, the growing number of spinal fusions performed in the United States and worldwide is creating a shortage of cadaver bone acceptable for use. Additionally, the extensive processing and storage of allograft is expensive. Synthetic materials, such as beta-tricalcium phosphate (beta-TCP), have been developed as alternatives to both autograft and allograft. A novel formulation of ultraporous beta-TCP (Vitoss, Orthovita, Malvern, Pa) offers interconnected microporosity, providing it with good wicking and hydrophilic properties. These properties allow the migration of nutrients, growth factors, and osteogenic cells into the ultraporous beta-TCP scaffold, thereby promoting new bone growth and concurrent scaffold resorption. This study presents a retrospective review of 7 patients who underwent anterior (ALIF) or posterior (PLIF) interbody fusion at 12 levels with a 3- to 6-month follow-up. At the patients' last radiographic examination, all 12 levels were solidly fused with interbody grafting material consisting only of allograft plus a combination of ultraporous beta-TCP and venous blood as an extender. Additionally, all 7 patients had segmental pedicle-screw fixation. PMID:12038846

  11. Mini-Open Anterior Retroperitoneal Lumbar Interbody Fusion: Oblique Lateral Interbody Fusion for Degenerated Lumbar Spinal Kyphoscoliosis

    PubMed Central

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

    2015-01-01

    Study Design Prospective case series. Purpose To examine the clinical efficacy of mini-open anterior retroperitoneal lumbar interbody fusion: oblique lateral interbody fusion (OLIF) for degenerated lumbar spinal kyphoscoliosis. Overview of Literature The existing surgical procedures for the treatment of spinal kyphotic deformity, including Smith-Petersen osteotomy, pedicle subtraction osteotomy, and vertebral column resection procedures, are invasive in nature. Extreme lateral interbody fusion to provide less invasive treatment of the deformity has been reported, but complications including spinal nerve and psoas muscle injury have been noted. In the current study, we examined the clinical efficacy and complications of OLIF for degenerated lumbar spinal kyphoscoliosis. Methods Twelve patients with degenerated lumbar spinal kyphoscoliosis were examined. All patients underwent OLIF surgery (using a cage and bone graft from the iliac crest) with open pedicle screws or percutaneous pedicle screws, without real-time monitoring by electromyography. Visual analog scale score and Oswestry disability index were evaluated before and 12 months after surgery, and fusion rate at OLIF cage, correction of the deformity, total blood loss, and surgical complications were also evaluated. Results Pain scores significantly improved after surgery (p<0.05). Fusion rate was found to be 90%, balance parameters also improved after surgery (p<0.05), and average total blood loss was less than 350 mL. There was no spinal nerve, major vessel, peritoneal, or urinary injury, or breakage of instrumentation. Conclusions OLIF surgery for degenerated lumbar spinal kyphoscoliosis is less invasive than other procedures and good surgical results were produced without major complications. PMID:26240716

  12. Biomechanical Evaluation of a Novel Autogenous Bone Interbody Fusion Cage for Posterior Lumbar Interbody Fusion in a Cadaveric Model.

    PubMed

    Wang, Le; Huang, Hai; Zhang, Zhenshan; Zhang, Zhi; Zhang, Liang; Li, Jian

    2014-02-27

    Study Design. A human cadaveric biomechanical study of a novel, prefabricated autogenous bone interbody fusion (ABIF) cage.Objective. To evaluate the biomechanical properties of the ABIF cage in a single-level construct with and without transpedicular screw and rod fixation.Summary of Background Data. In current practice, posterior lumbar interbody fusion (PLIF) is generally carried out using synthetic interbody spacers or corticocancellous iliac crest bone graft (ICBG) in combination with posterior instrumentation. However, questions remain concerning the use of synthetic intervertebral implants as well as the morbidity ICBG harvesting. Therefore, ABIF cage has been developed to obviate some of the challenges in conventional PLIF instrumentation and to facilitate the fusion process.Methods. Eighteen adult cadaveric lumbosacral (L3-S1) specimens were tested. Test conditions included single lumbosacral segments across (1) intact, (2) decompressed, (3) intervertebral cage alone, and (4) intervertebral cage with bilateral transpedicular fixation. Range of motion (ROM), neutral zone (NZ) and axial failure load were tested for each condition.Resluts. The ICBG, PEEK cage or ABIF cage alone exhibited a significantly lower (p<0.05) ROM and NZ compared to the decompressed spine. In comparison with the intact spine, all three test conditions without supplemental fixation was able to decrease ROM and NZ to near intact levels. When stabilized with pedicle screws, the ROM was significantly less and the NZ significantly lower (p<0.05) for each group both compared to the intact spine. In axial compression testing, the failure load of PEEK cage was the highest, with no significant difference between the ICBG and the ABIF cage.Conclusion. These data suggest the novel ABIF cage can bear the physiologic intervertebral peak load, similar to ICBG. When combined with pedicle screw and rod fixation, it exhibits similar biomechanical properties as the PEEK cage plus posterior instrumentation. Based on the biomechanical properties of ABIF cage, the prospect of these cages in clinical practice is expected. PMID:24583726

  13. 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

  14. Interobserver agreement using computed tomography to assess radiographic fusion criteria with a unique titanium interbody device.

    PubMed

    Slosar, Paul J; Kaiser, Jay; Marrero, Luis; Sacco, Damon

    2015-02-01

    The accuracy of using computed tomography (CT) to assess interbody fusion in patients with titanium implants has been questioned in the past. Radiologists have reported difficulty assessing fusion bone quality because of metal artifact and small graft windows. A new titanium interbody implant with a large footprint and a wide graft aperture has been developed. We conducted a study to determine the interobserver reliability of using CT to assess radiographic fusion variables with the new titanium interbody device. Patients underwent anterior lumbar interbody fusion with the same titanium interbody implant. Reconstructed CT images were obtained randomly at 6, 9, or 12 months. Two independent radiologists reviewed the scans. Interobserver reliability was calculated using the κ statistic. Fifty-six spinal fusion levels (33 patients) were analyzed. The radiologists agreed on 345 of the 392 fusion data points reviewed (κ = .88). Agreement for solid fusion formation was 0.77. This interbody device demonstrated minimal artifact and minimal subsidence, and trabecular bone was easily identified throughout the implant in the vast majority of cases reviewed. High interobserver agreement was noted across all radiographic variables assessed. PMID:25658078

  15. Posterior lumbar interbody fusion with facet-screw fixation.

    PubMed

    Stonecipher, T; Wright, S

    1989-04-01

    The optimal surgical construct for lumbar fusion remains controversial. The posterior lumbar interbody fusion (PLIF) operation offers advantages including total nuclear disc excision, restoration of disc-space height, root decompression, limited muscle retraction and injury, and solid mechanical arthrodesis. Major disadvantages have included graft displacement, neurologic injury and nonunion. The use of posterior fixation as an adjunct to PLIF reduces the probability of these complications and increases the chances of fusion. This study examines 35 patients who underwent PLIF and facet-screw fixation. Indications for surgery included disabling low-back pain with discographic/MRI-demonstrated disc derrangement, recurrent disc herniation, and failed inter-transverse process fusions. Follow-up ranged from 6 to 18 months. There were no patients with significant neurologic injury or functional root loss. One patient developed graft displacement and failure of fixation (laminar fracture in markedly obese patient). Three patients had subcutaneous hematomas (no surgical treatment required). None of the cases required blood replacement. The authors have concluded that the addition of facet fixation/fusion to the PLIF operation substantially reduces the complication rate of the procedure. PMID:2718053

  16. Transforaminal lumbar interbody fusion and posterior lumbar interbody fusion utilizing BMP-2 in treatment of degenerative spondylolisthesis: neither safe nor cost effective

    PubMed Central

    Moatz, Bradley; Tortolani, P. Justin

    2013-01-01

    Background: With the rise of health care costs, there is increased emphasis on evaluating the cost of a particular surgical procedure for quality adjusted life year (QALY) gained. Recent data have shown that surgical intervention for the treatment of degenerative spondylolisthesis (DS) is as cost-effective as total joint arthroplasty. Despite these excellent outcomes, some argue that the addition of interbody fusion supplemented with bone morphogenetic protein (BMP) enhances the value of this procedure. Methods: This review examines the current research regarding the cost-effectiveness of the surgical management of lumbar DS utilizing interbody fusion along with BMP. Results: Posterolateral spinal fusion with instrumentation for focal lumbar spinal stenosis with DS can provide and maintain improvement in self-reported quality of life. Based on the available literature, including nonrandomized comparative studies and case series, the addition of interbody fusion along with BMP does not lead to significantly better clinical outcomes and increases costs when compared with more routine posterolateral fusion techniques. Conclusions: To enhance the value of the surgical management for DS, costs must decrease or there should be substantial improvement in effectiveness as measured by clinical outcomes. To date, there is insufficient evidence to support the use of interbody fusion devices along with BMP to treat routine cases of focal stenosis accompanied by DS, which are routinely adequately treated utilizing posterolateral fusion techniques. PMID:23646277

  17. 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

  18. Repeated migration of a fusion cage after posterior lumbar interbody fusion.

    PubMed

    Lee, Jun Gue; Lee, Sung Myung; Kim, Seok Won; Shin, Ho

    2013-03-01

    Although posterior lumbar interbody fusion (PLIF) is a widely accepted procedure, perioperative and postoperative complications are still encountered. In particular, cage migration can result in severe sequelae, and revision surgery is technically demanded. Here, we report a rare case of repeated migration of a fusion cage after PLIF. To the best of our knowledge, no report has been previously issued on repeated migration of a fusion cage after PLIF. The authors discuss the radiological and clinical findings of this unusual complication with a review of the literature. PMID:24757453

  19. Direct Lateral Lumbar Interbody Fusion: Clinical and Radiological Outcomes

    PubMed Central

    Lee, Young Seok; Kim, Young Baeg

    2014-01-01

    Objective According to the recent development of minimally invasive spinal surgery, direct lumbar interbody fusion (DLIF) was introduced as an effective option to treat lumbar degenerative diseases. However, comprehensive results of DLIF have not been reported in Korea yet. The object of this study is to summarize radiological and clinical outcomes of our DLIF experience. Methods We performed DLIF for 130 patients from May 2011 to June 2013. Among them, 90 patients, who could be followed up for more than 6 months, were analyzed retrospectively. Clinical outcomes were compared using visual analog scale (VAS) score and Oswestry Disability Index (ODI). Bilateral foramen areas, disc height, segmental coronal and sagittal angle, and regional sagittal angle were measured. Additionally, fusion rate was assessed. Results A total of 90 patients, 116 levels, were underwent DLIF. The VAS and ODI improved statistically significant after surgery. All the approaches for DLIF were done on the left side. The left and right side foramen area changed from 99.5 mm2 and 102.9 mm2 to 159.2 mm2 and 151.2 mm2 postoperatively (p<0.001). Pre- and postoperative segmental coronal and sagittal angles changed statistically significant from 4.1° and 9.9° to 1.1° and 11.1°. Fusion rates of 6 and 12 months were 60.9% and 87.8%. Complications occurred in 17 patients (18.9%). However, most of the complications were resolved within 2 months. Conclusion DLIF is not only effective for indirect decompression and deformity correction but also shows satisfactory mechanical stability and fusion rate. PMID:25132930

  20. Posterior lumbar interbody fusion using rhBMP-2

    PubMed Central

    Schnöring, Mark; Hohaus, Christian; Minkus, Yvonne; Beier, Andre; Ganey, Timothy; Mansmann, Ulrich

    2008-01-01

    The use of biological technologies for the treatment of degenerative spinal diseases has undergone rapid clinical and scientific development. BMP strategies have gained wide support for an inherent potential to improve the ossification process. It has been extensively studied in combination with various techniques for spinal stabilisation from both anterior and posterior approach. We studied the fusion process after implantation of rhBMP-2 in 17 patients with degenerative lumbar spine diseases in combination with dorsal fixation with pedicle screws and poly-ether-ether-ketone (PEEK) interbody cages. We used 12 mg rhBMP-2 carried by collagen sponge, 6 mg in every cage. Patient follow up consisted of pre-operative radiographic and clinical evaluation. Similar post-operative evaluations were performed at 3 and 6 months. Clinical assessment demonstrated clear improvement in all patients despite evidence of vertebral endplate osteoclastic activity in the 3-month radiographs. The 6-month radiograph, however, confirmed evidence of fusion, and no untoward results or outcomes were noted. While previous studies have shown exclusively positive results in both fusion rates and process, our study demonstrated an intermediate morphology at 3 months during the ossification process using Induct Os in combination with peek-cages using a PLIF-technique. The transient resorption of bone surrounding the peek cage did not result in subsidence, pain or complication, and fusion was reached in all cases within a 6-month-controlled evaluation. Although there was no negative influence on clinical outcome, the potential for osteoclastic or metabolic resorption bears watching during the post-surgical follow up. PMID:18839225

  1. Posterior lumbar interbody fusion using rhBMP-2.

    PubMed

    Meisel, Hans Jörg; Schnöring, Mark; Hohaus, Christian; Minkus, Yvonne; Beier, Andre; Ganey, Timothy; Mansmann, Ulrich

    2008-12-01

    The use of biological technologies for the treatment of degenerative spinal diseases has undergone rapid clinical and scientific development. BMP strategies have gained wide support for an inherent potential to improve the ossification process. It has been extensively studied in combination with various techniques for spinal stabilisation from both anterior and posterior approach. We studied the fusion process after implantation of rhBMP-2 in 17 patients with degenerative lumbar spine diseases in combination with dorsal fixation with pedicle screws and poly-ether-ether-ketone (PEEK) interbody cages. We used 12 mg rhBMP-2 carried by collagen sponge, 6 mg in every cage. Patient follow up consisted of pre-operative radiographic and clinical evaluation. Similar post-operative evaluations were performed at 3 and 6 months. Clinical assessment demonstrated clear improvement in all patients despite evidence of vertebral endplate osteoclastic activity in the 3-month radiographs. The 6-month radiograph, however, confirmed evidence of fusion, and no untoward results or outcomes were noted. While previous studies have shown exclusively positive results in both fusion rates and process, our study demonstrated an intermediate morphology at 3 months during the ossification process using Induct Os in combination with peek-cages using a PLIF-technique. The transient resorption of bone surrounding the peek cage did not result in subsidence, pain or complication, and fusion was reached in all cases within a 6-month-controlled evaluation. Although there was no negative influence on clinical outcome, the potential for osteoclastic or metabolic resorption bears watching during the post-surgical follow up. PMID:18839225

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

    PubMed Central

    Tangviriyapaiboon, Teera

    2014-01-01

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

  3. Complications and Morbidities of Mini-open Anterior Retroperitoneal Lumbar Interbody Fusion: Oblique Lumbar Interbody Fusion in 179 Patients

    PubMed Central

    Mac-Thiong, Jean-Marc; Hilmi, Radwan; Roussouly, Pierre

    2012-01-01

    Study Design A retrospective study including 179 patients who underwent oblique lumbar interbody fusion (OLIF) at one institution. Purpose To report the complications associated with a minimally invasive technique of a retroperitoneal anterolateral approach to the lumbar spine. Overview of Literature Different approaches to the lumbar spine have been proposed, but they are associated with an increased risk of complications and a longer operation. Methods A total of 179 patients with previous posterior instrumented fusion undergoing OLIF were included. The technique is described in terms of: the number of levels fused, operative time and blood loss. Persurgical and postsurgical complications were noted. Results Patients were age 54.1 ± 10.6 with a BMI of 24.8 ± 4.1 kg/m2. The procedure was performed in the lumbar spine at L1-L2 in 4, L2-L3 in 54, L3-L4 in 120, L4-L5 in 134, and L5-S1 in 6 patients. It was done at 1 level in 56, 2 levels in 107, and 3 levels in 16 patients. Surgery time and blood loss were, respectively, 32.5 ± 13.2 minutes and 57 ± 131 ml per level fused. There were 19 patients with a single complication and one with two complications, including two patients with postoperative radiculopathy after L3-5 OLIF. There was no abdominal weakness or herniation. Conclusions Minimally invasive OLIF can be performed easily and safely in the lumbar spine from L2 to L5, and at L1-2 for selected cases. Up to 3 levels can be addressed through a 'sliding window'. It is associated with minimal blood loss and short operations, and with decreased risk of abdominal wall weakness or herniation. PMID:22708012

  4. Acute Contralateral Radiculopathy after Unilateral Transforaminal Lumbar Interbody Fusion

    PubMed Central

    Jang, Kyoung-Min; Kim, Young-Baeg; Park, Yong-Sook; Nam, Taek-Kyun; Lee, Young-Seok

    2015-01-01

    Objective Cases of contralateral radiculopathy after a transforaminal lumbar interbody fusion with a single cage (unilateral TLIF) had been reported, but the phenomenon has not been explained satisfactorily. The purpose of this study was to determine its incidence, causes, and risk factors. Methods We did retrospective study with 546 patients who underwent a unilateral TLIF, and used CT and MRI to study the causes of contralateral radicular symptoms that appeared within a week postoperatively. Clinical and radiological results were compared by dividing the patients into the symptomatic group and asymptomatic group. Results Contralateral symptoms occurred in 32 (5.9%) of the patients underwent unilateral TLIF. The most common cause of contralateral symptoms was a contralateral foraminal stenosis in 22 (68.8%), screw malposition in 4 (12.5%), newly developed herniated nucleus pulposus in 3 (9.3%), hematoma in 1 (3.1%), and unknown origin in 2 patients (6.3%). 16 (50.0%) of the 32 patients received revision surgery. There was no difference in visual analogue scale and Oswestry disability index between the two groups at discharge. Both preoperative and postoperative contralateral foraminal areas were significantly smaller, and postoperative segmental angle was significantly greater in the symptomatic group comparing to those of the asymptomatic group (p<0.05). Conclusion The incidence rate is not likely to be small (5.9%). If unilateral TLIF is performed for cases when preoperative contralateral foraminal stenosis already exists or when a large restoration of segmental lordosis is required, the probability of developing contralateral radiculopathy is increased and caution from the surgeon is needed. PMID:26587189

  5. Comparison of posterior versus transforaminal lumbar interbody fusion using finite element analysis

    PubMed Central

    Tang, Shujie

    2015-01-01

    Objectives: To compare the influence of posterior lumbar interbody fusion (PLIF) and transforaminal lumbar interbody fusion (TLIF) on adjacent segment degeneration. Methods: The study was carried out in the Traumatology and Orthopedics Laboratory, Department of Traditional Chinese Medicine, Medical School, Jinan University, Guangzhou, China, between December 2013 and November 2014. A normal, healthy finite element model of L3-5 was developed, a PLIF and a TLIF model were modified from the normal model, and interbody fusions were performed in the L4-5 segment. An 800 N compressive loading plus 10 Nm moments simulating flexion, extension, lateral bending, and axial rotation were imposed on the L3 superior endplate. Intradiscal pressure and intersegmental rotation in L3-4 were investigated. Results: The values of intradiscal pressure and intersegmental rotation in the PLIF or TLIF model were higher than those in the normal, healthy model, but the values in the TLIF model were relatively lower than those in the PLIF model in all directions. Conclusion: Posterior lumbar interbody fusion has more adverse influence on the superior adjacent segment than TLIF. PMID:26219453

  6. 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 (0.93 additional points; 95% CI 0.10 to 1.77; p = 0.029) and higher leg pain at baseline (0.83 points additional pain relief per level of preoperative leg pain; 95% CI 0.70 to 0.96). In both models the L3/4 segment showed 2.36 points (95% CI -4.27 to -0.45; p = 0.016) and 3.69 points (95% CI -5.66 to -1.71; p < 0.001) less pain relief than L5/S1. Discussion Significantly higher back and leg pain relief were observed after viscoelastic total disc replacement in comparison with anterior lumbar interbody fusion. The new less rigid materials used in the second generation total disc replacements (TDRs) may make artificial disc replacement an increasingly attractive option for patients with degenerative lumbar disc disease. Further controlled and long-term follow-up studies are required for more detailed comparisons of the outcomes of these types of disc implants. The Freedom Lumbar Disc is limited by U.S. federal law to investigational use only. PMID:26196033

  7. Posterior lumbar interbody fusion versus posterolateral fusion in spondylolisthesis: a prospective controlled study in the Han nationality

    PubMed Central

    Nie, Lin; Zhang, Li

    2008-01-01

    In this prospective study, our aim was to compare the clinical outcome of posterior lumbar interbody fusion (PLIF) and posterolateral fusion (PLF) in spondylolisthesis. A total of 138 patients with spondylolisthesis were randomly assigned to two groups: those operated on with pedicle screw fixation and posterior lumbar interbody fusion by autografting (PLIF), and those operated on with pedicle screw fixation and posterolateral fusion by autografting (PLF). The patients were followed-up for four years. Clinical evaluation was carried out using the Oswestry disability index (ODI) and pain index (VAS). Radiography was performed preoperatively and postoperatively to assess the fusion. Both surgical procedures were effective, but the PLF group showed more complications related to hardware biomechanics. There was no significant statistical difference in clinical and functional outcome in the two groups. The PLIF group presented a better fusion rate than the PLF group. PMID:18521599

  8. Treatment of Surgical Site Infection in Posterior Lumbar Interbody Fusion

    PubMed Central

    Lee, Jung Su; Chang, Byung Kwon; Lee, Jae Il

    2015-01-01

    Study Design A retrospective observational and case control study. Purpose To identify appropriate treatment options according to the types of surgical site infections (SSI) in instrumented posterior lumbar interbody fusion (PLIF). Overview of Literature There has been no agreement or consensus with regard to this matter. Methods Thirty-two consecutive SSIs were included and followed for more than one year. The elapsed time to diagnosis (ETD) according to the type of SSI was analyzed. The treatment options for each type and consequent clinical results were reviewed. The risk factors of removing the implants were analyzed. Results There were 6/32 (19%) superficial incisional, 6/32 (19%) deep incisional, and 20/32 (62%) organ/space infection cases (SII, DII, and O/SI, respectively) (p=0.002). ETD was 8.5±2.3 days in SII, 8.7±2.3 days in DII, and 164.5±131.1 days in O/SI (p=0.013). All cases of SII and DII retained implants and were treated by repeated irrigation and secondary closure. Among O/SIs, 10/20 were treated conservatively. Nine out of ten underwent posterior one stage simultaneous revision (POSSR) and in one case, the cage was removed anteriorly. Those who had ETDs longer than 3 months showed a significant risk of implant removal (p=0.008, odds ratio [OR]=40.3). The Oswestry disability index (ODI) improved from 47.3% to 33.8% in SII, from 55.0% to 32.3% in DII, and from 53.4% to 42.1% in O/SI (p=0.002). There was no difference among the three groups (p=0.106); however, there was a partial correlation between ETD and final ODI (r=0.382, p=0.034). Conclusions Latent O/SI was the most common type of SSI in PLIF. In cases of SII and DII, early aggressive wound management and secondary closure was effective and implant removal was not necessary. In some cases of O/SI, implant removal was unavoidable. However, implant removal could be averted by an earlier diagnosis. POSSR was feasible and safe. Functional outcomes were improved; however, disability increased as ETD increased. PMID:26713114

  9. Posterior lumbar interbody fusion using cages, combined with instrumented posterolateral fusion: a study of 75 cases.

    PubMed

    Periasamy, Kumar; Shah, Kalpesh; Wheelwright, Eugene F

    2008-04-01

    Posterior lumbar interbody fusion (PLIF) with cages can be combined with decompression of the spinal canal and with instrumented posterolateral fusion (IPLF) with pedicle screws, through a single posterior incision. The authors wanted to assess retrospectively the clinical and radiological outcome of PLIF + IPLF performed by the senior author. Between July 1997 and December 2003, 75 patients underwent PLIF with cages and IPLF with transpedicular instrumentation, for either degenerative disc disease, stenosis, spondylolisthesis or post-discectomy syndrome. The clinical outcome was evaluated according to the criteria of Kirkaldy-Willis. Flexion/extension radiographs and CT-scans were obtained in cases where there was any doubt about the fixation/fusion status. The mean age was 48.7 years (range: 30 to 75). The mean duration of follow-up was 29.17 months (range: 12 to 67). The clinical outcome was excellent or good in 85.3% of the patients. There were 4/75 patients (5.3%) who failed to return to their original occupation. Four posterolateral fusions were uncertain, but all anterior fusions succeeded: thus circumferential fusion was obtained in 71 out of 75 cases, or 94.6%. Three patients sustained a neurological complication, but only one was left with a partial drop foot. The results were comparable with similar studies. Therefore the authors recommend further use of PLIF + IPLF in painful lumbar degenerative spinal disease where conservative management has failed. PMID:18564483

  10. Extraforaminal lumbar interbody fusion for cage migration after screw removal: a case report.

    PubMed

    Kim, Myung Hoon; Kim, Seok Won; Kim, Sung Hoon; Kim, Hyeun Sung

    2013-06-01

    The use of titanium cages for posterior lumbar interbody fusion (PLIF) has gained popularity because it offers the advantages of anterior column support and stabilization. However, cage migration into the spinal canal may have severe or disastrous consequences. Here, the authors report an unexpected case of posterior migration of fusion cages after screw removal in a patient that underwent PLIF 12 months previously. Removal of the offending cages through revision extraforaminal lumbar interbody fusion (ELIF) with percutaneous screw fixation successfully managed this complication. As far as the authors' knowledge, this is the first case report to describe this sort of complication, and cautions that care must be taken to prevent cage migration. PMID:24757471

  11. 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

  12. Allograft Cellular Bone Matrix in Extreme Lateral Interbody Fusion: Preliminary Radiographic and Clinical Outcomes

    PubMed Central

    Tohmeh, Antoine G.; Watson, Blake; Tohmeh, Mirna; Zielinski, Xavier J.

    2012-01-01

    Introduction. Extreme lateral interbody fusion (XLIF) is a minimally disruptive alternative for anterior lumbar interbody fusion. Recently, synthetic and allograft materials have been increasingly used to eliminate donor-site pain and complications secondary to autogenous bone graft harvesting. The clinical use of allograft cellular bone graft has potential advantages over autograft by eliminating the need to harvest autograft while mimicking autograft's biologic function. The objective of this study was to examine 12-month radiographic and clinical outcomes in patients who underwent XLIF with Osteocel Plus, one such allograft cellular bone matrix. Methods. Forty (40) patients were treated at 61 levels with XLIF and Osteocel Plus and included in the analysis. Results. No complications were observed. From preoperative to 12-month postoperative followup, ODI improved 41%, LBP improved 55%, leg pain improved 43.3%, and QOL (SF-36) improved 56%. At 12 months, 92% reported being “very” or “somewhat” satisfied with their outcome and 86% being either “very” or “somewhat likely” to choose to undergo the procedure again. Complete fusion was observed in 90.2% (55/61) of XLIF levels. Conclusions. Complete interbody fusion with Osteocel Plus was shown in 90.2% of XLIF levels, with the remaining 9.8% being partially consolidated and progressing towards fusion at 12 months. PMID:23251099

  13. 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

  14. Perioperative complications of minimally invasive surgery (MIS): comparison of MIS and open interbody fusion techniques.

    PubMed

    Bagan, Bradley; Patel, Nimesh; Deutsch, Harel; Harrop, James; Sharan, Ashwini; Vaccaro, Alexander R; Ratliff, John K

    2008-01-01

    The risk of perioperative complications while adopting minimally invasive spine surgery techniques may slow the acceptance of this technology. We assess the perioperative complication rate with minimally invasive single- and two-level interbody fusions and compare this incidence with a contemporaneous cohort of open single- and two-level open interbody fusions, with all procedures completed by a single surgeon in a single practice group. We compiled all open and MIS interbody fusion cases completed during the study period. Sofamor-Danek X-Tube and Stryker Luxor minimally invasive systems were used on all patients. Medical records were reviewed to assess any adverse events occurring in the perioperative period. Care was taken to include all medical and surgical adverse events and complications occurring within 30 days of surgery. Over the study period, 28 minimally invasive lumbar fusions were identified: 24 single- and 4 two-level cases. Both TLIF and PLIF techniques were used. This cohort was compared with a group of 19 single- and two-level open interbody fusion cases completed over the same period. The complication rate for the MIS cohort was 18%, with 7 complications occurring in 5 patients. In the open group, 8 complications occurred in 7 patients, an incidence of 37%. A standard distribution of complications occurred, and the difference between the two groups was not statistically significant. Limiting our analysis to severe complications yielded rates of 7% and 21% for the two groups, also not significantly divergent. Perioperative complications are not more common in well-selected MIS patients. Allowing for proper patient selection, MIS techniques have a favorable complication profile. PMID:18802914

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

    PubMed Central

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

    2012-01-01

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

  16. [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

  17. Clinical Outcome and Fusion Rates after the First 30 Extreme Lateral Interbody Fusions

    PubMed Central

    Malham, Gregory M.; Ellis, Ngaire J.; Parker, Rhiannon M.; Seex, Kevin A.

    2012-01-01

    Introduction. The lateral transpsoas approach for lumbar interbody fusion (XLIF) is gaining popularity. Studies examining a surgeon's early experience are rare. We aim to report treatment, complication, clinical, and radiographic outcomes in an early series of patients. Methods. Prospective data from the first thirty patients treated with XLIF by a single surgeon was reviewed. Outcome measures included pain, disability, and quality of life assessment. Radiographic assessment of fusion was performed by computed tomography. Results. Average follow-up was 11.5 months, operative time was 60 minutes per level and blood loss was 50 mL. Complications were observed: clinical subsidence, cage breakage upon insertion, new postoperative motor deficit and bowel injury. Approach side-effects were radiographic subsidence and anterior thigh sensory changes. Two patients required reoperation; microforaminotomy and pedicle screw fixation respectively. VAS back and leg pain decreased 63% and 56%, respectively. ODI improved 41.2% with 51.3% and 8.1% improvements in PCS and MCS. Complete fusion (last follow-up) was observed in 85%. Conclusion. The XLIF approach provides superior treatment, clinical outcomes and fusion rates compared to conventional surgical approaches with lowered complication rates. Mentor supervision for early cases and strict adherence to the surgical technique including neuromonitoring is essential. PMID:23213282

  18. 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

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

    PubMed Central

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

    2014-01-01

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

  20. 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

  1. Posterior lumbar interbody fusion combined with instrumented postero-lateral fusion: 5-year results in 60 patients.

    PubMed

    Freeman, B J; Licina, P; Mehdian, S H

    2000-02-01

    The technique of posterior lumbar interbody fusion allows decompression of the spinal canal and interbody fusion through one posterior incision. A number of techniques exist to achieve additional posterior stability. The literature reports wide variation in outcomes for these different techniques. We assessed retrospectively the clinical and radiological outcome of posterior lumbar interbody fusion (PLIF) supplemented with an instrumented postero-lateral fusion (IPLF) using a pedicle screw system. Between July 1987 and April 1997, 60 patients underwent PLIF + IPLF. Clinical outcome was measured with physical examination in the outpatient setting and a patient questionnaire (patient satisfaction, analgesic use, return to work, Oswestry Disability Index). Radiological outcome was assessed with serial radiographs. If doubt existed regarding fixation, flexion/extension radiographs and plain tomograms were performed. The mean age was 44 years (range 19-69 years). The average follow-up was 5.3 years (range 1-10 years). Eighty percent of patients returned sufficiently completed questionnaires; 83% of these patients rated their outcome as good or excellent. Fifty percent of patients were able to return to full-time employment. All patients showed radiographic evidence of stable fixation. Four patients sustained a neurological complication, three of which resolved completely. The combination of PLIF with IPLF demonstrates clinical success, a stable circumferential fixation and a low complication rate. PMID:10766076

  2. Instrumented transforaminal lumbar interbody fusion with bioabsorbable polymer implants and iliac crest autograft.

    PubMed

    Coe, Jeffrey D

    2004-03-15

    Object. The purpose of this study was to evaluate the clinical and radiographic results in 31 patients from one center who underwent instrumented transforaminal lumbar interbody fusion (TLIF) for primarily degenerative indications. Methods. Bioabsorbable polymer spacers manufactured with a copolymer of 70:30 poly(L-lactide-co-D,L-lactide) and filled with iliac crest autograft bone were used for the TLIF procedure. In this paper the details of this procedure, intermediate (1- to 2-year) clinical and radiographic outcomes, and the basic science and rationale for the use of bioabsorbable polymers are discussed. At a mean of 18.4 months of follow up, 30 patients (96.8%) were judged to have attained solid fusions and 25 patients (81%) had good to excellent results. Three patients (9.7%) experienced complications, none of which were directly or indirectly attributable to the use of the bioabsorbable polymer implant. Only one implant in one patient (3.2%) demonstrated mechanical failure on insertion, and that patient experienced no clinical sequelae. Conclusions. This is the first clinical series to be published in which the mean follow-up duration equals or exceeds the biological life expectancy of this material (12-18 months). Both the clinical and radiographic results of this study support the use of interbody devices manufactured from biodegradable polymers for structural interbody support in the TLIF procedure. PMID:15198499

  3. [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

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

    PubMed

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

    2015-03-01

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

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

    PubMed Central

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

    2014-01-01

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

  6. 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

  7. Combined magnetic fields provide robust coverage for interbody and posterolateral lumbar spinal fusion sites.

    PubMed

    Stippick, Timothy Wade; Sheller, Michael Richard

    2016-01-01

    Electromagnetic fields generated by spinal bone growth stimulation devices have been computationally modelled to determine coverage of the lumbar spinal vertebrae. The underlying assumption of these models was that the electric field, but not the magnetic field, was therapeutically relevant. However, there are no published studies examining the therapeutic coverage of spinal fusion sites by stimulators utilizing combined magnetic fields. To assess the coverage, an anatomical model of the vertebrae and discs of the lumbar spine was developed to represent interbody and posterolateral fusion sites. Computer simulations of the induced electromagnetic fields were analysed to determine coverage of the fusion sites. For both interbody and posterolateral fusion models, combined magnetic fields provided 100% coverage of the fusion sites for all intervertebral disc spaces and for all posterior planes from L1 to L5, respectively. Within the vertebral column, the magnitude of the electric field reached a maximum value of 3.6נ10(-4)V/m, which is several orders of magnitude less than any reported study demonstrating a biological effect. Given its clinical efficacy,a bone growth stimulator utilizing combined magnetic fields must rely on the action of its magnetic field rather than its electric field for a therapeutic effect. PMID:26044553

  8. Non-Union Rate With Stand-Alone Lateral Lumbar Interbody Fusion

    PubMed Central

    Watkins, Robert; Watkins, Robert; Hanna, Robert

    2014-01-01

    Abstract Retrospective radiographic analysis. To determine the fusion rate of stand-alone lateral lumbar interbody fusion (LLIF). Biomechanical studies have indicated that LLIF may be more stable than anterior or transforaminal lumbar interbody fusion. Early clinical reports of stand-alone LLIF have shown success in obtaining fusion and indirectly decompressing nerve roots. A consecutive case series of stand-alone LLIF was analyzed with chart and radiographic review. Non-union was determined by symptomatology consistent with non-union and absence of bridging bone on the CT scan. Thirty-nine levels of stand alone LLIF were performed in 23 patients. Eleven patients received 1-level surgery, 7 patients received 2-level surgery, 3 patients received 3-level surgery, and 1 patient received 4-level surgery. Excluding 1 infected case, we analyzed 37 levels of stand alone LLIF in 22 patients. Non-union incidence was 7 levels in 6 patients. Non-union rate was 7/37 (19%) per level and 6/22 (27%) per patient. While our study population was relatively low, a non-union rate of 19% to 27% is concerning for modern spine surgery. Currently in our practice, we occasionally still perform stand-alone LLIF utilizing 22 mm wide grafts in low-demand levels in non-smoking and non-osteoporotic patients. However, in a majority of patients, we provide supplemental fixation: bilateral pedicle screws in most patients and unilateral pedicle screws or spinous process plates in some patients. PMID:25546670

  9. Non-union rate with stand-alone lateral lumbar interbody fusion.

    PubMed

    Watkins, Robert; Watkins, Robert; Hanna, Robert

    2014-12-01

    Retrospective radiographic analysis.To determine the fusion rate of stand-alone lateral lumbar interbody fusion (LLIF). Biomechanical studies have indicated that LLIF may be more stable than anterior or transforaminal lumbar interbody fusion. Early clinical reports of stand-alone LLIF have shown success in obtaining fusion and indirectly decompressing nerve roots. A consecutive case series of stand-alone LLIF was analyzed with chart and radiographic review. Non-union was determined by symptomatology consistent with non-union and absence of bridging bone on the CT scan. Thirty-nine levels of stand alone LLIF were performed in 23 patients. Eleven patients received 1-level surgery, 7 patients received 2-level surgery, 3 patients received 3-level surgery, and 1 patient received 4-level surgery. Excluding 1 infected case, we analyzed 37 levels of stand alone LLIF in 22 patients. Non-union incidence was 7 levels in 6 patients. Non-union rate was 7/37 (19%) per level and 6/22 (27%) per patient. While our study population was relatively low, a non-union rate of 19% to 27% is concerning for modern spine surgery. Currently in our practice, we occasionally still perform stand-alone LLIF utilizing 22 mm wide grafts in low-demand levels in non-smoking and non-osteoporotic patients. However, in a majority of patients, we provide supplemental fixation: bilateral pedicle screws in most patients and unilateral pedicle screws or spinous process plates in some patients. PMID:25546670

  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. Axial lumbar interbody fusion: a 6-year single-center experience

    PubMed Central

    Zeilstra, Dick J; Miller, Larry E; Block, Jon E

    2013-01-01

    Introduction The aim of this study is to report our 6-year single-center experience with L5–S1 axial lumbar interbody fusion (AxiaLIF). Methods A total of 131 patients with symptomatic degenerative disc disease refractory to nonsurgical treatment were treated with AxiaLIF at L5–S1, and were followed for a minimum of 1 year (mean: 21 months). Main outcomes included back and leg pain severity, Oswestry Disability Index score, working status, analgesic medication use, patient satisfaction, and complications. Computed tomography was used to determine postoperative fusion status. Results No intraoperative complications, including vascular, neural, urologic, or bowel injuries, were reported. Back and leg pain severity decreased by 51% and 42%, respectively, during the follow-up period (both P < 0.001). Back function scores improved 50% compared to baseline. Clinical success, defined as improvement ≥30%, was 67% for back pain severity, 65% for leg pain severity, and 71% for back function. The employment rate increased from 47% before surgery to 64% at final follow-up (P < 0.001). Less than one in four patients regularly used analgesic medications postsurgery. Patient satisfaction with the AxiaLIF procedure was 83%. The fusion rate was 87.8% at final follow-up. During follow-up, 17 (13.0%) patients underwent 18 reoperations on the lumbar spine, including pedicle screw fixation (n = 10), total disc replacement of an uninvolved level (n = 3), facet screw fixation (n = 3), facet screw removal (n = 1), and interbody fusion at L4–L5 (n = 1). Eight (6.1%) reoperations were at the index level. Conclusion Single-level AxiaLIF is a safe and effective means to achieve lumbosacral fusion in patients with symptomatic degenerative disc disease. PMID:23976846

  14. 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 10year 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 8.8months. 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

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

    PubMed Central

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

    2012-01-01

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

  16. Stand-alone minimally invasive lateral lumbar interbody fusion: multicenter clinical outcomes.

    PubMed

    Ahmadian, Amir; Bach, Konrad; Bolinger, Bryan; Malham, Gregory M; Okonkwo, David O; Kanter, Adam S; Uribe, Juan S

    2015-04-01

    Stand-alone minimally invasive lateral transpsoas interbody fusion (MIS-LIF), without posterior instrumentation, is feasible because the technique does not necessitate the disruption of the stabilizing elements. The objectives of this study are to evaluate the efficacy and clinical outcomes of patients who underwent stand-alone lateral interbody fusion. A multicenter chart review was conducted to identify patients who underwent stand-alone MIS-LIF between 2008 and 2012. Patients were classified by spinal pathology (degenerative disc disease [DDD], spondylolisthesis [SL] and adult degenerative scoliosis [ADS]). Routine clinical follow-up was scheduled at 3, 6, and12 months. Outcome measures included hospital length of stay, fusion rates, neurologic complications, integrity of construct and clinical outcome questionnaires (Visual Analog Scale [VAS] and Oswestry Disability Index [ODI]). A total of 59 patients met the inclusion criteria. The average age was 60 years (range 31-86 years). Spinal pathologies treated were DDD in 37 (63%), SL in four (7%) and ADS in 18 (30%) patients. Fusion rate was 93% of patients (95% of levels) at 12 months. Two patients required re-operation. Mean hospital stay and follow-up were 3.3days (range 1-10) and 14.6 months, respectively. The mean preoperative VAS and ODI were 69.1 and 51.8, respectively. VAS improved to 37.8 (p<0.0005). ODI improved to 31.8 (p<0.0005). Seventy percent of patients had grade 0 subsidence while 30% had grade I and grade II subsidence. Stand-alone MIS-LIF is viable option in a carefully selected patient population for both single and multilevel disease and shows significant improvement in health related quality of life. PMID:25684343

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

    PubMed

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

    2015-10-01

    OBJECT Minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) and lateral lumbar interbody fusion (LLIF) are 2 currently popular techniques for lumbar arthrodesis. The authors compare the total risk of each procedure, along with other important complication outcomes. METHODS This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Relevant studies (up to May 2015) that reported complications of either MI-TLIF or LLIF were identified from a search in the PubMed database. The primary outcome was overall risk of complication per patient. Secondary outcomes included risks of sensory deficits, temporary neurological deficit, permanent neurological deficit, intraoperative complications, medical complications, wound complications, hardware failure, subsidence, and reoperation. RESULTS Fifty-four studies were included for analysis of MI-TLIF, and 42 studies were included for analysis of LLIF. Overall, there were 9714 patients (5454 in the MI-TLIF group and 4260 in the LLIF group) with 13,230 levels fused (6040 in the MI-TLIF group and 7190 in the LLIF group). A total of 1045 complications in the MI-TLIF group and 1339 complications in the LLIF group were reported. The total complication rate per patient was 19.2% in the MI-TLIF group and 31.4% in the LLIF group (p < 0.0001). The rate of sensory deficits and temporary neurological deficits, and permanent neurological deficits was 20.16%, 2.22%, and 1.01% for MI-TLIF versus 27.08%, 9.40%, and 2.46% for LLIF, respectively (p < 0.0001, p < 0.0001, p = 0.002, respectively). Rates of intraoperative and wound complications were 3.57% and 1.63% for MI-TLIF compared with 1.93% and 0.80% for LLIF, respectively (p = 0.0003 and p = 0.034, respectively). No significant differences were noted for medical complications or reoperation. CONCLUSIONS While there was a higher overall complication rate with LLIF, MI-TLIF and LLIF both have acceptable complication profiles. LLIF had higher rates of sensory as well as temporary and permanent neurological symptoms, although rates of intraoperative and wound complications were less than MI-TLIF. Larger, prospective comparative studies are needed to confirm these findings as the current literature is of relative poor quality. PMID:26424344

  18. 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

  19. 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

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

    PubMed Central

    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

  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. Comparison of adjacent segment disease after minimally invasive or open transforaminal lumbar interbody fusion.

    PubMed

    Yee, Timothy J; Terman, Samuel W; La Marca, Frank; Park, Paul

    2014-10-01

    Adjacent segment disease (ASD) is a potential long-term risk after lumbar fusion. Its incidence has been evaluated in anterior and posterior lumbar interbody fusions, but few studies have focused on transforaminal lumbar interbody fusion (TLIF). Relative risk of ASD with open or minimally invasive (MI) TLIF is poorly understood. To report our experience with risk for ASD in patients receiving TLIF and test its association with surgical approach, we performed a retrospective cohort study based on medical record review at a single institution. Eligible patients were ⩾ 18 years old at operation, underwent single-level TLIF during the period 2007-2008, and had at least 6 months postoperative follow-up. Patients were categorized by surgical approach (open versus MI). Primary outcome of interest was development of symptomatic ASD, defined by (1) new back and/or leg pain, (2) imaging findings adjacent to original surgical level, and (3) decision to treat. A total of 68 patients (16 open, 52 MI) were included in the analysis. Groups had similar baseline characteristics, except the open group tended to be older (p=0.04). Seven (10%) patients developed ASD. Mean patient age was 62 years and three were male. Three underwent open and four underwent MI TLIF. Risk of ASD did not differ significantly by surgical approach. The MI group showed a trend toward decreased risk of ASD compared to the open group, although it was not statistically significant. This suggests MI TLIF may be associated with decreased long-term morbidity compared to the open approach. Large prospective studies are needed to confirm these findings. PMID:24880486

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

    PubMed Central

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

    2013-01-01

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

  4. 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.

  5. 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

  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. 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

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

    PubMed Central

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

    2015-01-01

    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 = 0.110, not significant). The global assessment was clearly superior in the TLIF group: 63% of patients scored “much better” in the TLIF group as compared with 48% in the PLF group (p = 0.017). Conclusions The results of the current study support the use of TLIF rather than uninstrumented PLF in the surgical treatment of the degenerative lumbar spine. The less optimal outcome after uninstrumented PLF may be explained by the much higher reoperation rate. PMID:26225282

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

    PubMed Central

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

    2014-01-01

    Study Design Meta-analysis. Background Bilateral pedicle screw fixation (PS) after lumbar interbody fusion is a widely accepted method of managing various spinal diseases. Recently, unilateral PS fixation has been reported as effective as bilateral PS fixation. This meta-analysis aimed to comparatively assess the efficacy and safety of unilateral PS fixation and bilateral PS fixation in the minimally invasive (MIS) lumbar interbody fusion for one-level degenerative lumbar spine disease. Methods MEDLINE/PubMed, EMBASE, BIOSIS Previews, and Cochrane Library were searched through March 30, 2014. Randomized controlled trials (RCTs) and controlled clinical trials (CCTs) on unilateral versus bilateral PS fixation in MIS lumbar interbody fusion that met the inclusion criteria and the methodological quality standard were retrieved and reviewed. Data on participant characteristics, interventions, follow-up period, and outcomes were extracted from the included studies and analyzed by Review Manager 5.2. Results Six studies (5 RCTs and 1 CCT) involving 298 patients were selected. There were no significant differences between unilateral and bilateral PS fixation procedures in fusion rate, complications, visual analogue score (VAS) for leg pain, VAS for back pain, Oswestry disability index (ODI). Both fixation procedures had similar length of hospital stay (MD = 0.38, 95% CI = −0.83 to 1.58; P = 0.54). In contrast, bilateral PS fixation was associated with significantly more intra-operative blood loss (P = 0.002) and significantly longer operation time (P = 0.02) as compared with unilateral PS fixation. Conclusions Unilateral PS fixation appears as effective and safe as bilateral PS fixation in MIS lumbar interbody fusion but requires less operative time and causes less blood loss, thus offering a simple alternative approach for one-level lumbar degenerative disease. PMID:25375315

  10. Fueling the debate: Are outcomes better after posterior lumbar interbody fusion (PLIF) or after posterolateral fusion (PLF) in adult patients with low-grade adult isthmic spondylolisthesis?

    PubMed Central

    Barbanti Bròdano, G.; Lolli, F.; Martikos, K.; Gasbarrini, A.; Bandiera, S.; Greggi, T.; Parisini, P.; Boriani, S.

    2010-01-01

    Study design: Retrospective cohort study. Clinical question: Do more adult patients affected by low grade isthmic spondylolisthesis have significant clinical and radiological improvement following posterior lumbar interbody fusion (PLIF) than those who receive posterolateral fusion (PLF)? Methods: One hundred and fourteen patients affected by adult low grade isthmic spondylolisthesis, treated with posterior lumbar interbody fusion or posterolateral fusion, were reviewed. Clinical outcome was assessed by means of the questionnaires ODI, RMDQ and VAS. Radiographic evaluation included CT, MRI, and x-rays. The results were analyzed using the Student t-test. Results: The two groups were similar with respect to demographic and surgical characteristics. At an average follow-up of 62.1 months, 71 patients were completely reviewed. Mean ODI, RMDQ and VAS scores didn't show statistically significant differences. Fusion rate was similar between the two groups (97% in PLIF group, 95% in PLF group). Major complications occurred in 5 of 71 patients reviewed (7%): one in the PLIF group (3.6%), four in the PLF group (9.3%). Pseudarthrosis occurred in one case in the PLIF group (3,6%) and in two cases in PLF group (4.6%). Conclusions: In our series, there does not appear to be a clear advantage of posterior lumbar interbody fusion (PLIF) over posterolateral fusion (PLF) in terms of clinical and radiological outcome for treatment of adult low grade isthmic spondylolisthesis. PMID:23544021

  11. 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

  12. Arthroscopic discectomy and interbody fusion of the thoracic spine: A report of ipsilateral 2-portal approach

    PubMed Central

    Osman, Said G.; Schwartz, Jeremy A.; Marsolais, E. B.

    2012-01-01

    Background The standard approach to the thoracic disc is through thoracotomy. The video-assisted thoracoscopic approach has been used as an alternative to the open approach for nearly 20 years, and more recently, extracavitary, posterolateral approaches have been introduced. Both the transthoracic procedures involve deflating the lung for access to the spine, and postoperative thoracic drainage is necessary; postoperative morbidity can be significant. The retropleural procedures are in their infancy, but the published results are promising. The purpose of this study is to introduce the posterolateral arthroscopic thoracic decompression and fusion procedure, which is extrapleural, less disruptive to normal anatomy, and cost-effective. Methods Fifteen consecutive patients who underwent arthroscopic decompression and interbody fusion of the thoracic spine were prospectively studied according to the hospital's institutional review board protocol. The Short Form 36 and visual analog scale questionnaires were completed preoperatively and postoperatively. Paired t tests were used for statistical analysis. The patient was placed in the prone position on a radiolucent table, and instrumentation was performed under fluoroscopic control. Two portals were developed ipsilaterally (one for the arthroscope and the other for instruments) on the side of disc herniation, and a single portal was used on the contralateral side. Various instruments were used for disc excision and exploration of the spinal canal. Fusion was accomplished with bilateral corticocancellous dowels obtained from the iliac crests. Infiltration of the access channel and facet injections of the contiguous joints were performed with bupivacaine, for immediate postoperative pain control. Results Fifteen patients with a mean age of 54 years were followed up for 28 months postoperatively. The overall back pain score decreased from 7.2 (SD, 1.5) to 3 (SD, 2) after the procedure (P < .005). Eleven patients were satisfied with their current lifestyle postoperatively as opposed to one preoperatively. Two patients had reoccurrences. Hospital stay averaged 18.5 hours. The operating room cost and the cost of hospital stay was 51.9% of the cost of anterior open discectomy. Conclusions The extrapleural, biportal, ipsilateral arthroscopic approach for the decompression and interbody fusion of the thoracic spine is feasible, cost-effective, less traumatic, and associated with minimal complications. The best results were obtained in patients with single-level thoracic disc herniation. The technique is applicable for most thoracic disc herniations. PMID:25694878

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

    PubMed Central

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

    2015-01-01

    Objective: The purpose of this study was to evaluate the disability in patients with spondylolisthesis who assigned either to posterolateral fusion (PLF) or posterior lumbar interbody fusion (PLIF) and to compare it between two groups. Methods: In a prospective observational study, 102 surgical candidates with low-grade degenerative and isthmic spondylolisthesis enrolled from 2012 to 2014, and randomly assigned into two groups: PLF and PLIF. Evaluation of disability has been done by a questionnaire using Oswestry Disability Index (ODI). The questionnaire was completed by all patients before the surgery, the day after surgery, after 6 months and after 1-year. Results: There were no statistically significant differences in terms of age and sex distribution and pre-operation ODI between groups (P > 0.05). Comparison of the mean ODI scores of two groups over the whole study period showed no significant statistical difference (P = 0.074). ODIs also showed no significant differences between two groups the day after surgery, 6th months and 1-year after surgery (P = 0.385, P = 0.093, P = 0.122 and P = 433) respectively. Analyzing the course of ODI over the study period, showed a significant descending pattern for either of groups (P < 0.0001). Conclusion: Both surgical fusion techniques (PLF and PLIF) were efficient to lessen the disability of patients with spondylolisthesis, and none of the fusion techniques were related to a better outcome in terms of disability. PMID:25767584

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

    PubMed Central

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

    2015-01-01

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

  15. 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 occurred during surgery and was successfully repaired in 6 of the 84 patients. Also, out of the 84 patients, 6 were found with pseudarthrosis during the follow-up, and these patients underwent a spinal fusion with instrumentation, with a posterior approach after a mean of 1 year. The complications secondary to the surgical approach were persistent abdominal pain (1/84, 1.2%) and wound dehiscence (1/84, 1.2%).Anterior lumbar interbody fusion for L4-L5 had better clinical results than the 2-segmental L4-L5/L5-S1 disc fusion, and the 2-segmental L4-L5/L5-S1 disc fusion had better clinical results than the L5-S1 disc fusion. Also, the 2-segmental L4-L5/L5-S1 disc fusion had a higher complication rate (27.3%), but there was no difference between the L4-L5 group (9.1%) and the L5-S1 group (12.5%). PMID:26512594

  16. Instrumented transforaminal lumbar interbody fusion in surgical treatment of recurrent disc herniation

    PubMed Central

    Omidi-Kashani, Farzad; Ghayem Hasankhani, Ebrahim; Noroozi, Hamid Reza

    2014-01-01

    Background: The incidence of recurrence in patients undergoing primary discectomy due to lumbar disc herniation (LDH), is regularly reported as 5-15%. In this study we aimed to evaluate surgical outcome of instrumented transforaminal lumbar interbody fusion (TLIF) in the patients suffering from recurrent LDH. Methods: We retrospectively studied 51 patients (30 female, 21 male) from August 2007 to October 2011. The mean age and follow-up of the patients was 46.4±14.8 (ranged; 29-77 years old) and 31.4±6.8 (ranged; 25-50 months), respectively. Clinical improvement was assessed by Oswestry Disability Index (ODI), visual analogue scale (VAS), and subjective satisfaction rate, while fusion was appraised radiologically. Data analysis was by one sample Kolmogorov-Smirnov, paired t, and Mann-Whitney tests. Results: Surgery could significantly improve mean leg and lumbar VAS and ODI from preoperative 7.4±2.5, 7.8±3.1, and 72.1±21.5 to postoperative 3.4±3.6, 3.5±2.6, and 27.5±18.0, respectively at the last follow-up visit. Subjective satisfaction rate was excellent in 24 patients (47.1%), good in 14 (27.5%), fair 11 (21.6%), and poor in two (3.9%). We had one patient with iatrogenic partial L5 nerve root injury and one with unknown late onset refractory postoperative back pain. Fusion rate was 100% and instrument failure was nil. Conclusion: In surgical treatment of the patients with recurrent LDH, bilaterally instrumented TLIF is a relatively safe and effective procedure and can be associated with least instrument failure and highest fusion rate while no postoperative bracing is also needed. PMID:25679003

  17. 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

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

    PubMed Central

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

    2015-01-01

    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

  19. Clinical and Radiological Comparison of Posterolateral Fusion and Posterior Interbody Fusion Techniques for Multilevel Lumbar Spinal Stabilization In Manual Workers

    PubMed Central

    Çakar, Albert; Hüseyinoğlu, Nergiz; Hüseyinoğlu, Urfettin; Çelik, Recep

    2014-01-01

    Study Design Eighty-four patients who had been treated for degenerative spinal diseases between January 2006 and June 2009 were reviewed retrospectively. Purpose We aimed to compare the clinical and radiologic findings of manual workers who underwent posterolateral fusion (PLF) or posterior interbody fusion (PLIF) involving fusion of 3 or more levels of the spine. Overview of Literature Previous studies have concluded that there is no significant difference between the clinical outcome of PLF and PLIF techniques. Methods After standard decompression, 42 patients underwent PLF and the other 42 patients underwent PLIF. Radiologic findings, Oswestry disability index (ODI) scores, and visual analogue scale (VAS) scores were assessed preoperatively and at 6-month intervals postoperatively and return to work times/rates were assessed for 48 months. Results Patients who underwent PLF had significantly shorter surgical time and less blood loss. According to the 48-month clinical results, ODI and VAS scores were reduced significantly in the two groups, but the PLIF group showed better results than the PLF group at the last follow-up. Return to work rate was 63% in the PLF group and 87% in the PLIF group. Union rates were found to be 81% and 89%, respectively, after 24 months (p=0.154). Conclusions PLIF is a preferable technique with respect to stability and correction, but the result does not depend on only the fusion rates. Discectomy and fusion mass localization should be considered for achieving clinical success with the fusion technique. Before performing PLIF, the association of the long operative time and high blood loss with mortality and morbidity should be taken into consideration, particularly in the elderly and disabled patients. PMID:25346809

  20. 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

  1. 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

  2. Biomechanical evaluation of three surgical scenarios of posterior lumbar interbody fusion by finite element analysis

    PubMed Central

    2012-01-01

    Background For the treatment of low back pain, the following three scenarios of posterior lumbar interbody fusion (PLIF) were usually used, i.e., PLIF procedure with autogenous iliac bone (PAIB model), PLIF with cages made of PEEK (PCP model) or titanium (Ti) (PCT model) materiel. But the benefits or adverse effects among the three surgical scenarios were still not fully understood. Method Finite element analysis (FEA), as an efficient tool for the analysis of lumbar diseases, was used to establish a three-dimensional nonlinear L1-S1 FE model (intact model) with the ligaments of solid elements. Then it was modified to simulate the three scenarios of PLIF. 10 Nm moments with 400 N preload were applied to the upper L1 vertebral body under the loading conditions of extension, flexion, lateral bending and torsion, respectively. Results Different mechanical parameters were calculated to evaluate the differences among the three surgical models. The lowest stresses on the bone grafts and the greatest stresses on endplate were found in the PCT model. The PCP model obtained considerable stresses on the bone grafts and less stresses on ligaments. But the changes of stresses on the adjacent discs and endplate were minimal in the PAIB model. Conclusions The PCT model was inferior to the other two models. Both the PCP and PAIB models had their own relative merits. The findings provide theoretical basis for the choice of a suitable surgical scenario for different patients. PMID:22709659

  3. Subsidence after anterior cervical inter-body fusion. A randomized prospective clinical trial.

    PubMed

    Kast, Erich; Derakhshani, Sharam; Bothmann, Matthias; Oberle, Joachim

    2009-04-01

    In ventral fusion after anterior cervical discectomy there is still a remarkable number of cage subsidence and segmental kyphosis seen. The aim of the present study is to assess whether the cage design influences the extent of correction loss during follow-up. Sixty patients with single-level cervical disc herniation were randomly treated with two different cervical inter-body cages (group 1: Solis cage, Stryker Company and group 2: Shell cage, AMT Company). Clinical and radiological follow-up was done before and after surgery, 3 and 6 months post-surgery. Clinical follow-up was done with the help of Odom's criteria. Both groups were similar in the baseline parameters (age, sex, treated level). Statistically, the subsidence was significantly higher at 3 and 6-month follow-ups in group 1 than in group 2, however, clinical results showed no significant differences. In 67%, subsidence was seen in the anterior lower aspect of the treated segment. Segmental kyphosis was seen in seven patients of group 1 and two patients of group 2. A significant correlation is found between Odom's criteria and subsidence. Although there was no significant difference in a short-term clinical result between the two treatment groups, we recommend the use of cages which preserve the determined segmental height and lordosis. PMID:18797946

  4. 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

  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. 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

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

    PubMed Central

    Lee, Jun Gue; Kim, Hyeun Sung

    2015-01-01

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

  8. Allogeneic morphogenetic protein vs. recombinant human bone morphogenetic protein-2 in lumbar interbody fusion procedures: a radiographic and economic analysis

    PubMed Central

    2013-01-01

    Background Since the introduction of rhBMP-2 (Infuse®) in 2002, surgeons have had an alternative substitute to autograft and its related donor site morbidity. Recently, the prevalence of reported adverse events and complications related to the use of rhBMP-2 has raised many ethical and legal concerns for surgeons. Additionally, the cost and decreasing reimbursement landscape of rhBMP-2 use have required identification of a viable alternative. Osteo allogeneic morphogenetic protein (OsteoAMP®) is a commercially available allograft-derived growth factor rich in osteoinductive, angiogenic, and mitogenic proteins. This study compares the radiographic fusion outcomes between rhBMP-2 and OsteoAMP allogeneic morphogenetic protein in lumbar interbody fusion spine procedures. Methods Three hundred twenty-one (321) patients from three centers underwent a transforaminal lumbar interbody fusion (TLIF) or lateral lumbar interbody fusion (LLIF) procedure and were assessed by an independent radiologist for fusion and radiographically evident complications. The independent radiologist was blinded to the intervention, product, and surgeon information. Two hundred and twenty-six (226) patients received OsteoAMP with autologous local bone, while ninety-five (95) patients received Infuse with autologous local bone. Patients underwent radiographs (x-ray and/or CT) at standard postoperative follow-up intervals of approximately 1, 3, 6, 12, and 18 months. Fusion was defined as radiographic evidence of bridging across endplates, or bridging from endplates to interspace disc plugs. Osteobiologic surgical supply costs were also analyzed to ascertain cost differences between OsteoAMP and rhBMP-2. Results OsteoAMP produced higher rates of fusion at 6, 12, and 18 months (p ≤ 0.01). The time required for OsteoAMP to achieve fusion was approximately 40% less than rhBMP-2 with approximately 70% fewer complications. Osteobiologic supply costs were 80.5% lower for OsteoAMP patients (73.7% lower per level) than for rhBMP-2. Conclusions Results of this study indicate that OsteoAMP is a viable alternative to rhBMP-2 both clinically and economically when used in TLIF and LLIF spine procedures. PMID:24373225

  9. 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

  10. Correction of Coronal Imbalance in Degenerative Lumbar Spine Disease Following Direct Lateral Interbody Fusion (DLIF)

    PubMed Central

    Kim, Ju Seong; Lee, Hyo Sang; Shin, Dong Ah; Yoon, Do Heum

    2012-01-01

    Objective The authors have recently been using a surgical technique of minimally invasive direct lateral interbody fusion (DLIF) for correcting of coronal imbalance. The purpose of this study was to evaluate the surgical outcome and complication of DLIF. Methods We undertook retrospective analysis of a consecutive series of 8 DLIF procedures in Degenerative lumbar spine disease since May 2011. Four patients underwent DLIF only, and the others underwent combined DLIF and posterior fixation. Data on intra- and postoperative complications were collected. The pre- and postoperative X-rays were reviewed. We investigated coronal deformity, Cobb's angle, and apical vertebral translation (AVT). The mean follow-up period was months with a range of 2 to 8 months. Results A mean preoperative coronal Cobb's angle was 21.8° (range 11.5-32.4°). Following after DLIF, the mean Cobb's angle was decreased to 13.0° (range 2.9-21.5°). Following additional posterior screw fixation, mean Cobb's angle was further decreased to 7.4° (range 2.9-13.2°). A mean preoperative AVT was 2.0 cm(range 0.6-3.5 cm), and improved to 1.4 cm(range 0.3-2.4 cm) and 0.8 cm(range 0.2-1.8 cm) postoperatively (DLIF and, posterior fixation respectively). One patient (12.5%) showed cage migration during follow-up period. Two patients (25%) developed motor weakness, and 4 patients (50%) experienced postoperative thigh paresthesias or dysesthesias. During follow up period, motor weakness had resolved in 1 patient. Sensory symptoms were improved in all patients at the last follow-up. Conclusion Degenerative lumbar disease can be effectively corrected by DLIF with acceptable complications. PMID:25983811

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

    PubMed Central

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

    2014-01-01

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

  12. 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

  13. Mast Quadrant-assisted Minimally Invasive Modified Transforaminal Lumbar Interbody Fusion: Single Incision Versus Double Incision

    PubMed Central

    Xia, Xin-Lei; Wang, Hong-Li; Lyu, Fei-Zhou; Wang, Li-Xun; Ma, Xiao-Sheng; Jiang, Jian-Yuan

    2015-01-01

    Background: The concept of minimally invasive techniques is to make every effort to reduce tissue damage. Certainly, reducing skin incision is an important part of these techniques. This study aimed to investigate the clinical feasibility of Mast Quadrant-assisted modified transforaminal lumbar interbody fusion (TLIF) with a small single posterior median incision. Methods: During the period of March 2011 to March 2012, 34 patients with single-segment degenerative lumbar disease underwent the minimally invasive modified TLIF assisted by Mast Quadrant with a small single posterior median incision (single incision group). The cases in this group were compared to 37 patients with single-segment degenerative lumbar disease in the double incision group. The perioperative conditions of patients in these two groups were statistically analyzed and compared. The Oswestry Disability Index (ODI) scores, Visual Analog Scale (VAS) scores, and sacrospinalis muscle damage evaluation indicators before operation and 3, 12 months postoperation were compared. Results: A total of 31 and 35 cases in the single incision and double incision groups, respectively, completed at least 12 months of systemic follow-up. The differences in perioperative conditions between the two groups were not statistically significant. The incision length of the single incision group was significantly shorter than that of the double incision group (P < 0.01). The ODI and VAS scores of patients in both groups improved significantly at 3 and 12 months postoperation. However, these two indicators at 3 and 12 months postoperation and the sacrospinalis muscle damage evaluation indicators at 3 months postoperation did not differ significantly between the two groups (P ≥ 0.05). Conclusions: Mast Quadrant-assisted modified TLIF with a small single posterior median incision has excellent clinical feasibility compared to minimally invasive TLIF with a double paramedian incision. PMID:25836605

  14. 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

  15. Outcome of posterior lumbar interbody fusion for L4-L5 degenerative spondylolisthesis

    PubMed Central

    Hayashi, Hiroyuki; Murakami, Hideki; Demura, Satoru; Kato, Satoshi; Kawahara, Norio; Tsuchiya, Hiroyuki

    2015-01-01

    Background: Posterior lumbar interbody fusion (PLIF) has become the standard in the treatment for degenerative spondylolisthesis since improvement of spinal instrumentation However, few published studies have reported long term outcomes of PLIF using a same surgical procedure. The purpose of this study is to evaluate a long term outcome of PLIF using a same surgical procedure for L4-L5 degenerative spondylolisthesis. Materials and Methods: Out of 45 patients who underwent L4-L5 PLIF for degenerative spondylolisthesis between 1995 and 2003, 37 patients (16 males and 21 females) were evaluated in this study. Mean age was 61.8 years. The average followup period was 121 months. We evaluated % slip, lordosis at L4/L5, lumbar lordosis, Japanese Orthopedic Association's (JOA) score and adjacent segment degeneration. Results: The % slip significantly improved from an average of 17.0% before surgery to 9.7% at the last followup. Lordosis at L4/L5 averaged 3.6° before surgery, 8.2° after surgery and 6.9° at the last followup. Although patients experienced some loss of correction at last followup, their lordosis at L4/L5 at last followup still was significantly different from their lordosis at L4/L5 before surgery. Lumbar lordosis did not significantly change. Mean JOA score was 13.4 before surgery and 24.5 at the last followup; mean recovery ratio was 71.2%. Adjacent segment degeneration occurred in 40.5% of patients, almost all of which occurred in the cranial adjacent segment. Three patients (8.1%) required reoperation due to adjacent segment degeneration, at an average of 76 months after their initial surgery. Conclusions: With more than 10-year followup after L4-L5 PLIF for degenerative spondylolisthesis, the adjacent segment degeneration occurred in 40.5% and reoperation was required in 8.1%. PMID:26015627

  16. 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

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed Central

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

    2015-01-01

    Background Previous reports have observed differences only in infection rates between posterolateral fusion and posterior lumbar interbody fusion (PLIF). There have been no reports that describe the particular features of surgical site infection (SSI) in PLIF. In this study, we endeavor to identify the distinguishing characteristics and risk factors of SSI in PLIF. Methods Our study undertook a review of a case series of an institute. Patients who had undergone PLIF consecutively in the author's hospital were reviewed. Two proactive procedures were introduced during the study period. One was irrigation of the autolocal bone, and the other was the intradiscal space irrigation with a nozzle. Infection rate and risk factors were analyzed. For subgroup analysis, the elapsed time to a diagnosis (ETD), clinical manifestations, hematologic findings, and causative bacteria were examined in patients with SSI. Results In a total of 1,831 cases, there were 30 cases of SSI (1.6%). Long operation time was an independent risk factor (p = 0.008), and local bone irrigation was an independent protective factor (p = 0.001). Two cases of referred SSI were included in the subgroup analysis. There were 6/32 (19%) superficial incisional infections (SII), 6/32 (19%) deep incisional infections (DII), and 20/32 (62%) organ/space infections (O/SI). The difference of incidence among three groups was significant (p = 0.002).The most common bacteria encountered were methicillin-resistant Staphylococcus epidermidis followed by methicillin-resistant S. aureus in incisional infections, and no growth followed by S. epidermidis in O/SI. ETD was 8.5 ± 2.3 days in SII, 8.7 ± 2.3 days in DII and 164.5 ± 131.1 days in O/SI (p = 0.013). Conclusions The rate of SSI in PLIF was 1.6%, with the most common type being O/SI. The causative bacteria of O/SI was of lower virulence than in the incisional infection, and thus diagnosis was delayed due to its latent and insidious feature. Contamination of auto-local bone was presumed attributable to the progression of SSI. Irrigation of auto-local bone helped in the reduction of SSI. PMID:26330956

  19. 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 instrumentation stresses are observed in all loading modes with plate fixation, and bilateral fixation could reduce stress concentration. PMID:26649749

  20. 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 their iliac crest was at maximal bed break. An awareness of the iliac crest or greater trochanter at the break of the bed should be considered to prevent pain and increased pressure based on the patient's sex and BMI. PMID:26512342

  1. 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

  2. [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

  3. 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.

  4. 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.

  5. 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

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

    PubMed

    Baron, Eli M; 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

  7. 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

  8. 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 successful when compared with open surgery. This initial experience demonstrates the possible utility of this procedure. PMID:26828882

  9. Clinical and radiographic outcomes with L4–S1 axial lumbar interbody fusion (AxiaLIF) and posterior instrumentation: a multicenter study

    PubMed Central

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

    2013-01-01

    Introduction Previous studies have confirmed the benefits and limitations of the presacral retroperitoneal approach for L5–S1 interbody fusion. The purpose of this study was to determine the safety and effectiveness of the minimally invasive axial lumbar interbody approach (AxiaLIF) for L4–S1 fusion. Methods In this retrospective series, 52 patients from four clinical sites underwent L4–S1 interbody fusion with the AxiaLIF two-level system with minimum 2-year clinical and radiographic follow-up (range: 24–51 months). Outcomes included back pain severity (on a 10-point scale), the Oswestry Disability Index (ODI), and Odom’s criteria. Flexion and extension radiographs, as well as computed tomography scans, were evaluated to determine fusion status. Longitudinal outcomes were assessed with repeated measures analysis of variance. Results Mean subject age was 52 ± 11 years and the male:female ratio was 1:1. Patients sustained no intraoperative bowel or vascular injury, deep infection, or neurologic complication. Median procedural blood loss was 220 cc and median length of hospital stay was 3 days. At 2-year follow-up, mean back pain had improved 56%, from 7.7 ± 1.6 at baseline to 3.4 ± 2.7 (P < 0.001). Back pain clinical success (ie, ≥30% improvement from baseline) was achieved in 39 (75%) patients at 2 years. Mean ODI scores improved 42%, from 60% ± 16% at baseline to 35% ± 27% at 2 years (P < 0.001). ODI clinical success (ie, ≥30% improvement from baseline) was achieved in 26 (50%) patients. At final follow-up, 45 (87%) patients were rated as good or excellent, five as fair, and two as poor by Odom’s criteria. Interbody fusion observed on imaging was achieved in 97 (93%) of 104 treated interspaces. During follow-up, five patients underwent reoperation on the lumbar spine, including facet screw removal (two), laminectomy (two), and transforaminal lumbar interbody fusion (one). Conclusion The AxiaLIF two-level device is a safe, effective treatment adjunct for patients with L4–S1 disc pathology resistant to conservative treatments. PMID:24092998

  10. 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

  11. 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

  12. 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 acceptable clinical outcomes, although results varied among studies. Clinical relevance The AxiaLIF approach allows access to the L5-S1 interspace without violating the annulus or longitudinal ligaments and with minimal risk to dorsal neural elements. It may be a viable alternative to other approaches to interbody fusion at the L5-S1 level. It is important that the patients be selected carefully and surgeons are familiar with the presacral anatomy and the surgical approach. PMID:25694879

  13. 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

  14. 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 = 0.373). Conclusion: It seems that accompanying TLIF with PLF might lead to better functional improvement and pain reduction in patients with spondylolisthesis. PMID:27041885

  15. The Effect of the Retroperitoneal Transpsoas Minimally Invasive Lateral Interbody Fusion on Segmental and Regional Lumbar Lordosis

    PubMed Central

    Le, Tien V.; Vivas, Andrew C.; Dakwar, Elias; Baaj, Ali A.; Uribe, Juan S.

    2012-01-01

    Background. The minimally invasive lateral interbody fusion (MIS LIF) in the lumbar spine can correct coronal Cobb angles, but the effect on sagittal plane correction is unclear. Methods. A retrospective review of thirty-five patients with lumbar degenerative disease who underwent MIS LIF without supplemental posterior instrumentation was undertaken to study the radiographic effect on the restoration of segmental and regional lumbar lordosis using the Cobb angles on pre- and postoperative radiographs. Mean disc height changes were also measured. Results. The mean follow-up period was 13.3 months. Fifty total levels were fused with a mean of 1.42 levels fused per patient. Mean segmental Cobb angle increased from 11.10° to 13.61° (P < 0.001) or 22.6%. L2-3 had the greatest proportional increase in segmental lordosis. Mean regional Cobb angle increased from 52.47° to 53.45° (P = 0.392). Mean disc height increased from 6.50 mm to 10.04 mm (P < 0.001) or 54.5%. Conclusions. The MIS LIF improves segmental lordosis and disc height in the lumbar spine but not regional lumbar lordosis. Anterior longitudinal ligament sectioning and/or the addition of a more lordotic implant may be necessary in cases where significant increases in regional lumbar lordosis are desired. PMID:22919332

  16. 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

  17. 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

  18. Slip Reduction Rate between Minimal Invasive and Conventional Unilateral Transforaminal Interbody Fusion in Patients with Low-Grade Isthmic Spondylolisthesis

    PubMed Central

    Oh, Chang Hyun; Ji, Gyu Yeul; Jeon, Jae Kyun; Lee, Junho; Hyun, Dong Keun

    2013-01-01

    Objective To compare the slip reduction rate and clinical outcomes between unilateral conventional transforaminal lumbar interbody fusion (conventional TLIF) and unilateral minimal invasive TLIF (minimal TLIF) with pedicle screw fixation for treatment of one level low-grade symptomatic isthmic spondylolisthesis. Methods Between February 2008 and April 2012, 25 patients with low-grade isthmic spondylolisthesis underwent conventional TLIF (12 patients) and minimal TLIF (13 patients) in single university hospital by a single surgeon. Lateral radiographs of lumbar spine were taken 12 months after surgery to analyze the degree of slip reduction and the clinical outcome. All measurements were performed by a single observer. Results The demographic data between conventional TLIF and minimal TLIF were not different. Slip percentage was reduced from 15.00% to 8.33% in conventional TLIF, and from 14.15% to 9.62% in minimal TLIF. In both groups, slip percentage was significantly improved postoperatively (p=0.002), but no significant intergroup differences of slip percentage in preoperative and postoperative were found. The reduction rate also not different between conventional TLIF (45.41±28.80%) and minimal TLIF (32.91±32.12%, p=0.318). Conclusion Conventional TLIF and minimal TLIF with pedicle screw fixation showed good slip reduction in patients with one level low-grade symptomatic isthmic spondylolisthesis. The slip percentage and reduction rate were similar in the conventional TLIF and minimal TLIF. PMID:24891854

  19. 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

  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 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

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

    PubMed Central

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

    2014-01-01

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

  2. Surgical Outcomes of Minimally Invasive Transforaminal Lumbar Interbody Fusion for the Treatment of Spondylolisthesis and Degenerative Segmental Instability

    PubMed Central

    Ha, Joong Won; Lee, Yun Tae; Oh, Hyun Chul; Yoo, Ju Hyung; Kim, Hyung Bok

    2011-01-01

    Study Design This is a retrospective case study. Purpose This study was designed to analyze the surgical outcomes of patients who underwent minimally invasive transforaminal lumbar interbody fusion (TLIF) for the treatment of spondylolisthesis and degenerative segmental instability. Overview of Literature If the surgical outcomes of a procedure are evaluated together with multiple indications, it is not clear how the procedure helped each subgroup of patients. For the reason that some indications achieve better outcomes than the others, we performed a subgroup analysis using validated outcome measures to demonstrate the optimal indications and the treatment results of TLIF. Methods We conducted subgroup analyses by comparing the prospectively collecting data from the consecutive patients who underwent single-level minimally invasive TLIF for the treatment of the following 3 subgroups of indications: 23 cases of low-grade spondylolytic spondylolisthesis, 24 cases of degenerative spondylolisthesis, and 19 cases of degenerative segmental instability. Results The average duration of follow up was 36.1 ± 9.9 months (range, 24 to 63 months). The preoperative pain and disability scores were significantly improved at final postoperative follow-up in all the subgroups (all measurements: p < 0.0001). The 3 subgroups exhibited an equivalent improvement of the pain and disability scores at the final follow-up. The rates of radiographic solid fusion and complications were also similar among the 3 groups. Conclusions Our data suggests that minimally invasive TLIF optimally and equivalently alleviates all of the associated symptoms and disabilities from low-grade spondylolisthesis and degenerative segmental instability. Furthermore, these patients seem to have optimal surgical indications for minimally invasive TLIF, while maintaining favorable surgical outcomes. PMID:22164317

  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 2years. 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 24months 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 2year 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. Prospective Randomized Controlled Trial of The Stabilis Stand Alone Cage (SAC) Versus Bagby and Kuslich (BAK) Implants for Anterior Lumbar Interbody Fusion

    PubMed Central

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

    2014-01-01

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

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

    PubMed Central

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

    2015-01-01

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

  7. Initial Clinical Outcomes of Minimally Invasive Lateral Lumbar Interbody Fusion in Degenerative Lumbar Disease: A Preliminary Report on the Experience of a Single Institution with 30 Cases

    PubMed Central

    Na, Young Cheol; Lee, Hyo Sang; Shin, Dong Ah; Ha, Yoon; Yoon, Do Heum

    2012-01-01

    Objective The object of this study was to evaluate the clinical and radiological outcomes of minimally invasive lateral lumbar interbody fusion. Methods This study included 30 patients who underwent minimally invasive lateral lumbar interbody fusion at our hospital between May 2011 and February 2012 for the following diagnoses: degenerative disc disease, adjacent-segment degeneration, degenerative spondylolisthesis and lumbar degenerative scoliosis. Pain assessment was reported from 0 to 10 using a subjective visual analog scale (VAS) upon admission and at every follow-up day. Lumbar X-rays were obtained in the standing position upon admission and the 1st and 5th postoperative day, and at every follow-up day after the operation. The heights of the intervertebral disc space and neural foramen were measured using an electronic caliper with the PACS software. The surgical outcome was assessed as excellent, good, fair or poor using the Odom scale at the last follow-up. Results The mean VAS for low back pain were 4.93±1.47 on admission and 2.01±1.35 at last follow-up, respectively, and for leg pain, the scores were 4.87±2.16 on admission and 1.58±1.52 at last follow-up. The mean height of intervertebral disc space increased by 34% (7.93±2.33 preoperatively, and 11.09±4.33 immediately after surgery, p<0.01). The mean height of neural foramen also increased by 6.4% without any statistical significance (19.17±2.84 preoperatively, and 20.49±4.50 immediately after the surgery). Minimally invasive lateral lumbar interbody fusion was successful in 27 patients (90%) at last follow-up. Surgical complications were reported as transient postoperative thigh sensory changes (5 patients, 16.7%), transient psoas muscle weakness (3 patients, 10%), cage migration (2 patients, 6.7%), lumbar plexus injury (1 patient, 3.3%), and pain aggravation (1 patient, 3.3%). Conclusion The minimally invasive lateral lumbar interbody fusion is a safe and effective procedure for treating degenerative lumbar disease with good outcomes and moderate complications. Further follow-up is necessary to establish its safety and efficacy. PMID:25983813

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

    PubMed Central

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

    2015-01-01

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

  9. 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 surgeon's hands, should be carefully monitored. PMID:24736321

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

    PubMed Central

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

    2014-01-01

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

  11. 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, several studies reported patients with symptoms persistent as far as 12 months removed from surgery. Surgery at the L4-5 disc space and longer surgical duration place the patient at greater risk for developing postoperative and long-term thigh symptoms. PMID:26767154

  12. 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 could ameliorate clinical symptoms when local stability is achieved. PMID:26949470

  13. 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 technique is a very effective decision in cases of spondylolisthesis, isthmic or degenerative, refractory to conservative treatment, for the obtaining the best clinical results and rates of fusion, with similar risks to those of the other published techniques. Our statistical analysis could contribute to improve outcomes after surgery. PMID:26196029

  14. 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

  15. Clinical outcomes of lumbar degenerative disc disease treated with posterior lumbar interbody fusion allograft spacer: a prospective, multicenter trial with 2-year follow-up.

    PubMed

    Arnold, Paul M; Robbins, Stephen; Paullus, Wayne; Faust, Stephen; Holt, Richard; McGuire, Robert

    2009-07-01

    The clinical benefits and complications of posterior lumbar interbody fusion (PLIF) have been studied over the past 60 years. In recent years, spine surgeons have had the option of treating low back pain caused by degenerative disc disease using PLIF with machined allograft spacers and posterior pedicle fixation. The purpose of this clinical series was to assess the clinical benefits of using a machined PLIF allograft spacer and posterior pedicle fixation to treat degenerative disc disease, both in terms of fusion rates and patient outcomes, and to compare these results with those in previous studies using autograft and metal interbody fusion devices. Results were also compared with results from studies using transverse process fusion. This prospective, nonrandomized clinical series was conducted at 10 US medical centers. Eighty-nine (55 male, 34 female) patients underwent PLIF with a presized, machined allograft spacer and posterior pedicle fixation between January 2000 and April 2003. Their outcomes were compared with outcomes in previous series described in the literature. All patients had experienced at least 6 months of low back pain that had been unresponsive to nonsurgical treatment. Physical examinations were performed before surgery, after surgery, and at 4 follow-up visits (6 weeks, 6 months, 12 months, 24 months). At each interval, we obtained radiographs and patient outcome measures, including SF-36 Bodily Pain Score, visual analog scale pain rating, and Oswestry Disability Index. The primary outcome was fusion results at 12 and 24 months; the secondary outcomes were pain, disability, function/quality of life, and satisfaction. One-level PLIFs were performed in 65 patients, and 2-level PLIFs in 24 patients. Flexion-extension radiographs at 12 and 24 months revealed a 98% fusion rate. Of the 72 patients who reached the 12-month follow-up, 86% reported decreased pain and disability as measured with the Oswestry Disability Index. Decreased pain as measured with the SF-36 Bodily Pain Score was reported by 74% of patients who reached the 12-month follow-up. The graft-related complication rate among all patients who underwent PLIF was 1.61%. When performed with machined allograft spacers and posterior pedicle fixation, PLIF is a safe and effective surgical treatment for low back pain caused by degenerative disc disease. The patients in this clinical series had outcomes equal or superior to the outcomes in previous series. PMID:19714280

  16. 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

  17. Complications in patients undergoing combined transforaminal lumbar interbody fusion and posterior instrumentation with deformity correction for degenerative scoliosis and spinal stenosis

    PubMed Central

    Burneikiene, Sigita; Nelson, E. Lee; Mason, Alexander; Rajpal, Sharad; Serxner, Benjamin; Villavicencio, Alan T.

    2012-01-01

    Background: Utilization of the transforaminal lumbar interbody fusion (TLIF) approach for scoliosis offers the patients deformity correction and interbody fusion without the additional morbidity associated with more invasive reconstructive techniques. Published reports on complications associated with these surgical procedures are limited. The purpose of this study was to quantify the intra- and postoperative complications associated with the TLIF surgical approach in patients undergoing surgery for spinal stenosis and degenerative scoliosis correction. Methods: This study included patients undergoing TLIF for degenerative scoliosis with neurogenic claudication and painful lumbar degenerative disc disease. The TLIF technique was performed along with posterior pedicle screw instrumentation. The average follow-up time was 30 months (range, 15–47). Results: A total of 29 patients with an average age of 65.9 years (range, 49–83) were evaluated. TLIFs were performed at 2.2 levels on average (range, 1–4) in addition to 6.0 (range, 4–9) levels of posterolateral instrumented fusion. The preoperative mean lumbar lordosis was 37.6° (range, 16°–55°) compared to 40.5° (range, 26°–59.2°) postoperatively. The preoperative mean coronal Cobb angle was 32.3° (range, 15°–55°) compared to 15.4° (range, 1°–49°) postoperatively. The mean operative time was 528 min (range, 276–906), estimated blood loss was 1091.7 mL (range, 150–2500), and hospitalization time was 8.0 days (range, 3–28). A baseline mean Visual Analog Scale (VAS) score of 7.6 (range, 4–10) decreased to 3.6 (range, 0–8) postoperatively. There were a total of 14 (49%) hardware and/or surgical technique related complications, and 8 (28%) patients required additional surgeries. Five (17%) patients developed pseudoarthrosis. The systemic complications (31%) included death (1), cardiopulmonary arrest with resuscitation (1), myocardial infarction (1), pneumonia (5), and pulmonary embolism (1). Conclusion: This study suggests that although the TLIF approach is a feasible and effective method to treat degenerative adult scoliosis, it is associated with a high rate of intra- and postoperative complications and a long recovery process. PMID:22439116

  18. 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

  19. 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

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

    PubMed Central

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

    2015-01-01

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

  1. 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

  2. Effects of Lordotic Angle of a Cage on Sagittal Alignment and Clinical Outcome in One Level Posterior Lumbar Interbody Fusion with Pedicle Screw Fixation

    PubMed Central

    Lee, Ji-Ho; Lee, Dong-Oh; Lee, Jae Hyup; Shim, Hee Jong

    2015-01-01

    This study aims to assess the differences in the radiological and clinical results depending on the lordotic angles of the cage in posterior lumbar interbody fusion (PLIF). We reviewed 185 segments which underwent PLIF using two different lordotic angles of 4° and 8° of a polyetheretherketone (PEEK) cage. The segmental lordosis and total lumbar lordosis of the 4° and 8° cage groups were compared preoperatively, as well as on the first postoperative day, 6th and 12th months postoperatively. Clinical assessment was performed using the ODI and the VAS of low back pain. The pre- and immediate postoperative segmental lordosis angles were 12.9° and 12.6° in the 4° group and 12° and 12.0° in the 8° group. Both groups exhibited no significant different segmental lordosis angle and total lumbar lordosis over period and time. However, the total lumbar lordosis significantly increased from six months postoperatively compared with the immediate postoperative day in the 8° group. The ODI and the VAS in both groups had no differences. Cages with different lordotic angles of 4° and 8° showed insignificant results clinically and radiologically in short-level PLIF surgery. Clinical improvements and sagittal alignment recovery were significantly observed in both groups. PMID:25685795

  3. 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

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

    2015-11-01

    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 clinical results with significant less operative time, blood loss, and surgical complication. This procedure seems to be a reasonable treatment option for selective patients with thoracolumbar fractures. PMID:26554800

  4. 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 in particular patient. Conclusion Use of cylindrical titanium cage packed with cancellous bone graft provide adequate stability and reliable functional outcome after fusion in cervical disc disease. Titanium cages for fusion after cervical discectomy constitute a safe and equally efficient alternative to tricortical autograft with anterior cervical plate by providing adequate stability and cessation of rediculopathy symptoms. PMID:27134955

  5. A comparison of radiostereometric analysis and computed tomography for the assessment of lumbar spinal fusion in a sheep model.

    PubMed

    Humadi, Ali; Freeman, Brian J C; Moore, Rob J; Callary, Stuart; Halldin, Klas; David, Vikram; Maclaurin, William; Tauro, Paul; Schoenwaelder, Mark

    2013-10-01

    Study Design?Prospective animal study. Objective?The aim of this animal study is to evaluate the accuracy of radiostereometric analysis (RSA) compared with computed tomographic (CT) scan in the assessment of spinal fusion after anterior lumbar interbody fusion (ALIF) using histology as a gold standard. Methods?Three non-adjacent ALIFs (L1-L2, L3-L4, and L5-L6) were performed in nine sheep. The sheep were divided into three groups of three sheep. All the animals were humanely killed immediately after having the last scheduled RSA. The lumbar spine was removed and in vitro fine cut CT and histopathology were performed. Results?Using histological assessment as the gold standard for assessing fusion, RSA demonstrated better results (100% sensitivity and 66.7% specificity; positive predictive value [PPV]?=?27.3%, negative predictive value [NPV] =100.0%) compared with CT (66.7% sensitivity and 60.0% specificity [PPV?=?16.7%, NPV?=?93.8%]). Conclusions?RSA demonstrated higher sensitivity and specificity when compared with CT. Furthermore, RSA has the advantage of much lower radiation exposure compared with fine cut CT. Further studies are required to see if RSA remains superior to CT scan for the assessment spinal fusion in the clinical setting. [Table: see text]. PMID:24436705

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

    PubMed

    Norman, Sally Jane

    2015-01-01

    The live art of theater remains curiously missing from ALife art history, despite the fact that its very existence is poised on the cusp of the living and the artificial, and on the modeling of life as artefact-what can be called the containment-versus-continuity dilemma. How far one seeks to affirm autonomy of the creative artwork or, in contrast, how far one seeks to affirm its continuity with its supposed real-life contexts is a question that has forever haunted theater, and that has naturally come to haunt ALife and ALife arts. Investigation of the boundary separating observers from modeled systems is as core to research into the live art of theater as to ALife research. This brief article seeks to open up discussion on links between ALife, ALife art, and the live art of theater, through key thematic threads that traverse these domains: their modeling of universes, the open or closed nature of the resultant modeled systems, and their implications with respect to observers, definitions, and instantiations of life regarding non-life or death as well as attributions of liveness to emergent synthetic biology and metamaterials. PMID:26280075

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

    PubMed Central

    Sulaiman, Wale A. R.; Singh, Manish

    2014-01-01

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

  8. The Significance of Removing Ruptured Intervertebral Discs for Interbody Fusion in Treating Thoracic or Lumbar Type B and C Spinal Injuries through a One-Stage Posterior Approach

    PubMed Central

    Zhang, Qian-Shi; Lü, Guo-Hua; Wang, Xiao-Bin; Li, Jing

    2014-01-01

    Objectives To identify the negative effect on treatment results of reserving damaged intervertebral discs when treating type B and type C spinal fracture-dislocations through a one-stage posterior approach. Methods This is a retrospective review of 53 consecutive patients who were treated in our spine surgery center from January 2005 to May 2012 due to severe thoracolumbar spinal fracture-dislocation. The patients in Group A (24 patients) underwent long-segment instrumentation laminectomy with pedicle screw-rod fixators for neural decompression. In Group B (29 patients), the patients underwent long-segment instrumentation laminectomy with pedicle screw-rod fixators for neural decompression evacuating of the ruptured disc and inserting of a bone graft into the evacuated disc space for interbody fusion. The mean time between injury and operation was 4.1 days (range 2–15 days). The clinical, radiologic and complication outcomes were analyzed retrospectively. Results Periodic follow-ups were carried out until an affirmative union or treatment failure took place. A progressive kyphosis angle larger than 10°, loss of disc height, pseudoarthrosis, recurrence of dislocation or subluxation, or instrument failure before fusion were considered treatment failures. Treatment failures were detected in 13 cases in Group A (failure rate was 54.2%). In Group B, there were 28 cases in which definitive bone fusion was demonstrated on CT scans, and CT scans of the other cases demonstrated undefined pseudoarthrosis without hardware failure. There were statistically significant differences between the two groups (p<0.001 chi-square test). The neurologic recoveries, assessed by the ASIA scoring system, were not satisfactory for the neural deficit patients in either group, indicating there was no significant difference with regard to neurologic recovery between the two groups (p>0.05 Fisher's exact test). Conclusion Intervertebral disc damage is a common characteristic in type B and C spinal fracture-dislocation injuries. The damaged intervertebral disc should be removed and substituted with a bone graft because reserving the damaged disc in situ increases the risk of treatment failure. PMID:24827733

  9. 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. Implementation of any new device should only be done after completion of randomized controlled effectiveness trials. PMID:23947902

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

    PubMed

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

    2016-01-01

    OBJECTIVE In the past decade, dynamic stabilization has been an emerging option of surgical treatment for lumbar spondylosis. However, the application of this dynamic construct for mild spondylolisthesis and its clinical outcomes remain uncertain. This study aimed to compare the outcomes of Dynesys dynamic stabilization (DDS) with minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) for the management of single-level spondylolisthesis at L4-5. METHODS This study retrospectively reviewed 91 consecutive patients with Meyerding Grade I spondylolisthesis at L4-5 who were managed with surgery. Patients were divided into 2 groups: DDS and MI-TLIF. The DDS group was composed of patients who underwent standard laminectomy and the DDS system. The MI-TLIF group was composed of patients who underwent MI-TLIF. Clinical outcomes were evaluated by visual analog scale for back and leg pain, Oswestry Disability Index, and Japanese Orthopaedic Association scores at each time point of evaluation. Evaluations included radiographs and CT scans for every patient for 2 years after surgery. RESULTS A total of 86 patients with L4-5 spondylolisthesis completed the follow-up of more than 2 years and were included in the analysis (follow-up rate of 94.5%). There were 64 patients in the DDS group and 22 patients in the MI-TLIF group, and the overall mean follow-up was 32.7 months. Between the 2 groups, there were no differences in demographic data (e.g., age, sex, and body mass index) or preoperative clinical evaluations (e.g., visual analog scale back and leg pain, Oswestry Disability Index, and Japanese Orthopaedic Association scores). The mean estimated blood loss of the MI-TLIF group was lower, whereas the operation time was longer compared with the DDS group (both p < 0.001). For both groups, clinical outcomes were significantly improved at 6, 12, 18, and 24 months after surgery compared with preoperative clinical status. Moreover, there were no differences between the 2 groups in clinical outcomes at each evaluation time point. Radiological evaluations were also similar and the complication rates were equally low in both groups. CONCLUSIONS At 32.7 months postoperation, the clinical and radiological outcomes of DDS were similar to those of MI-TLIF for Grade I degenerative spondylolisthesis at L4-5. DDS might be an alternative to standard arthrodesis in mild lumbar spondylolisthesis. However, unlike fusion, dynamic implants have issues of wearing and loosening in the long term. Thus, the comparable results between the 2 groups in this study require longer follow-up to corroborate. PMID:26721577

  11. 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

  12. 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

  13. Extreme Lateral Interbody Fusion Procedure

    MedlinePlus Videos and Cool Tools

    ... and there is always the potential for nerve damage, the assistants have a way to monitor nerve ... retractor and you perform the discectomies, you minimize damage to the nerve. This is the initial step ...

  14. 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

  15. A Comparison of Radiostereometric Analysis and Computed Tomography for the Assessment of Lumbar Spinal Fusion in a Sheep Model

    PubMed Central

    Humadi, Ali; Freeman, Brian J. C.; Moore, Rob J.; Callary, Stuart; Halldin, Klas; David, Vikram; Maclaurin, William; Tauro, Paul; Schoenwaelder, Mark

    2013-01-01

    Study Design Prospective animal study. Objective The aim of this animal study is to evaluate the accuracy of radiostereometric analysis (RSA) compared with computed tomographic (CT) scan in the assessment of spinal fusion after anterior lumbar interbody fusion (ALIF) using histology as a gold standard. Methods Three non-adjacent ALIFs (L1–L2, L3–L4, and L5–L6) were performed in nine sheep. The sheep were divided into three groups of three sheep. All the animals were humanely killed immediately after having the last scheduled RSA. The lumbar spine was removed and in vitro fine cut CT and histopathology were performed. Results Using histological assessment as the gold standard for assessing fusion, RSA demonstrated better results (100% sensitivity and 66.7% specificity; positive predictive value [PPV] = 27.3%, negative predictive value [NPV] =100.0%) compared with CT (66.7% sensitivity and 60.0% specificity [PPV = 16.7%, NPV = 93.8%]). Conclusions RSA demonstrated higher sensitivity and specificity when compared with CT. Furthermore, RSA has the advantage of much lower radiation exposure compared with fine cut CT. Further studies are required to see if RSA remains superior to CT scan for the assessment spinal fusion in the clinical setting. Assessment of Class of Evidence (CoE) for individual studies of diagnostic test evaluation Methodological principle Study design  Prospective cohort design X  Retrospective cohort design  Case–control design Broad spectrum of patients with expected condition a Appropriate reference standard used X Adequate description of test and reference for replication X Blinded comparison with appropriate reference X Reference standard performed independently of test X Evidence level II Note: Blank box indicates criterion not met, could not be determined, or information not reported by author or was not reported. aThis study contained nine animal subjects. PMID:24436705

  16. 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

  17. 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 trial in which the silicon nitride cage is compared with the PEEK cage in patients with symptomatic degenerative lumbar disc disorders. Trial registration NCT01557829 PMID:24568365

  18. Extent of intraoperative muscle dissection does not affect long-term outcomes after minimally invasive surgery versus open-transforaminal lumbar interbody fusion surgery: A prospective longitudinal cohort study

    PubMed Central

    Adogwa, Owoicho; Johnson, Kwame; Min, Elliot T.; Issar, Neil; Carr, Kevin R.; Huang, Kevin; Cheng, Joseph

    2012-01-01

    Background: Minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) versus open TLIF, addressing lumbar degenerative disc disease (DDD) or grade I spondylolisthesis (DS), are associated with shorter hospital stays, decreased blood loss, quicker return to work, and equivalent short- and long-term outcomes. However, no prospective study has assessed whether the extent of intraoperative muscle trauma utilizing creatinine phosphokinase levels (CPK) differently impacts long-term outcomes. Methods: Twenty-one patients underwent MIS-TLIF (n = 14) versus open-TLIF (n = 7) for DDD or DS. Serum CPK levels were measured at baseline, and postoperatively (days 1, 7, and 1.5, 3 and 6 months). The correlation between the extent of intraoperative muscle trauma and two-year improvement in functional disability was evaluated (multivariate regression analysis). Additionally, baseline and two-year changes in Visual Analog Scale (VAS)-leg pain (LP), VAS-back pain (BP), Oswestry Disability Index (ODI), Short-Form-36 (SF-36) Physical Component Score (PCS) and SF-36 Mental Component Score (MCS), and postoperative satisfaction with surgical care were assessed. Results: Although the mean change from baseline in the serum creatine phosphokinase level on POD 1 was greater for MIS-TLIF (628.07) versus open-TLF (291.42), this did not correlate with lesser two-year improvement in functional disability. Both cohorts also showed similar two-year improvement in VAS-LP, ODI, and SF-36 PCS/MCS. Conclusion: Increased intraoperative muscle trauma unexpectedly observed in higher postoperative CPK levels for MIS-TLIF versus open-TLIF did not correlate with any differences in two-year improvement in pain and functional disability. PMID:23248754

  19. Dynamic stabilization using the Dynesys system versus posterior lumbar interbody fusion for the treatment of degenerative lumbar spinal disease: a clinical and radiological outcomes-based meta-analysis.

    PubMed

    Lee, Chang-Hyun; Jahng, Tae-Ahn; Hyun, Seung-Jae; Kim, Chi Heon; Park, Sung-Bae; Kim, Ki-Jeong; Chung, Chun Kee; Kim, Hyun-Jib; Lee, Soo-Eon

    2016-01-01

    OBJECTIVE The Dynesys, a pedicle-based dynamic stabilization (PDS) system, was introduced to overcome the drawbacks of fusion procedures. Nevertheless, the theoretical advantages of PDS over fusion have not been clearly confirmed. The aim of this study was to compare clinical and radiological outcomes of patients who underwent PDS using the Dynesys system with those who underwent posterior lumbar interbody fusion (PLIF). METHODS The authors searched PubMed, Embase, Web of Science, and the Cochrane Database. Studies that reported outcomes of patients who underwent PDS or PLIF for the treatment of degenerative lumbar spinal disease were included. The primary efficacy end points were perioperative outcomes. The secondary efficacy end points were changes in the Oswestry Disability Index (ODI) and back and leg pain visual analog scale (VAS) scores and in range of motion (ROM) at the treated and adjacent segments. A meta-analysis was performed to calculate weighted mean differences (WMDs), 95% confidence intervals, Q statistics, and I(2) values. Forest plots were constructed for each analysis group. RESULTS Of the 274 retrieved articles, 7 (which involved 506 participants [Dynesys, 250; PLIF, 256]) met the inclusion criteria. The Dynesys group showed a competitive advantage in mean surgery duration (20.73 minutes, 95% CI 8.76-32.70 minutes), blood loss (81.87 ml, 95% CI 45.11-118.63 ml), and length of hospital stay (1.32 days, 95% CI 0.23-2.41 days). Both the Dynesys and PLIF groups experienced improved ODI and VAS scores after 2 years of follow-up. Regarding the ODI and VAS scores, no statistically significant difference was noted according to surgical procedure (ODI: WMD 0.12, 95% CI -3.48 to 3.72; back pain VAS score: WMD -0.15; 95% CI -0.56 to 0.26; leg pain VAS score: WMD -0.07; 95% CI -0.47 to 0.32). The mean ROM at the adjacent segment increased in both groups, and there was no substantial difference between them (WMD 1.13; 95% CI -0.33 to 2.59). Although the United States is the biggest market for Dynesys, no eligible study from the United States was found, and 4 of 8 enrolled studies were performed in China. The results must be interpreted with caution because of publication bias. During Dynesys implantation, surgeons have to decide the length of the spacer and cord pretension. These values are debatable and can vary according to the surgeon's experience and the patient's condition. Differences between the surgical procedures were not considered in this study. CONCLUSIONS Fusion still remains the method of choice for advanced degeneration and gross instability. However, spinal degenerative disease with or without Grade I spondylolisthesis, particularly in patients who require a quicker recovery, will likely constitute the main indication for PDS using the Dynesys system. PMID:26721581

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

    PubMed Central

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

    2014-01-01

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

  1. 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

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

    PubMed

    Jutte, P C; Castelein, R M

    2002-12-01

    Pedicle screw fixation is technically demanding and associated with high complication rates. The aim of this study was to identify and quantify the pedicle screw-related complications in 105 consecutive operations. We retrospectively analysed 105 consecutive primary operations. We found complications of varying severity in 54% of the patients. Deep infections were found in 4.7%, all successfully cured by debridement and antibiotics. There were no permanent neurological complications related to the screws. One serious neurological sequela, a T10 paraplegia, was unrelated to screw placement between L3 and S1. Screw misplacement was found in 6.5% of the screws. Screw breakage occurred in 12.4% of the patients, inevitably leading to loss of correction. Reduced spondylolisthesis L5-S1 without anterior support was found to be especially prone to screw breakage. The study confirmed that pedicle screw placement is a technically demanding procedure with a high complication rate. Fortunately, most complications are not severe. Infections can be dealt with by thorough debridement and parenteral antibiotics. Neurological sequelae can be minimised by careful tactile technique. To avoid screw breakage and subsequent loss of correction, anterior support should be provided, through either posterior or anterior lumbar interbody fusion (PLIF or ALIF) techniques, in reduced spondylolisthesis L5-S1. PMID:12522719

  3. 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

  4. Lateral Transpsoas Fusion: Indications and Outcomes

    PubMed Central

    Patel, Vishal C.; Park, Daniel K.; Herkowitz, Harry N.

    2012-01-01

    Spinal fusion historically has been used extensively, and, recently, the lateral transpsoas approach to the thoracic and lumbar spine has become an increasingly common method to achieve fusion. Recent literature on this approach has elucidated its advantage over more traditional anterior and posterior approaches, which include a smaller tissue dissection, potentially lower blood loss, no need for an access surgeon, and a shorter hospital stay. Indications for the procedure have now expanded to include degenerative disc disease, spinal stenosis, degenerative scoliosis, nonunion, trauma, infection, and low-grade spondylolisthesis. Lateral interbody fusion has a similar if not lower rate of complications compared to traditional anterior and posterior approaches to interbody fusion. However, lateral interbody fusion has unique complications that include transient neurologic symptoms, motor deficits, and neural injuries that range from 1 to 60% in the literature. Additional studies are required to further evaluate and monitor the short- and long-term safety, efficacy, outcomes, and complications of lateral transpsoas procedures. PMID:23213303

  5. 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 infection (one case). At follow-up of 29.4 months, patients with radiographic ASD had worse ODI scores than patients without (54.7 vs. 36.6; P<0.001). Multilevel fusion for degenerative disease still has a high rate of complications, up to 50%. The problem of adjacent segment disease after fusion surgery has not yet been solved. This study underscores the need for strict indication guidelines to perform lumbar spine fusion of more than two levels. PMID:21808698

  6. Stabilizing Effects of a Particulate Demineralized Bone Matrix in the L4 Interbody Space with and without PEEK Cage - A Literature Review and Preliminary Results of a Cadaveric Biomechanical Study.

    PubMed

    Bruce, C; Chin, K R; Cumming, V; Crawford, N R

    2013-11-01

    We reviewed the biological elements supporting the usefulness of a specifically designed particulate form of demineralized bone matrix (DBM) with spinal fusion, and report some limitations of its use described in the medical literature and in the interbody space using a cadaveric biomechanical model. A literature review and description of the techniques used to augment spinal fusion are presented, including a more thorough review of recent findings of cadaveric biomechanical flexibility studies using DBM alone at different percentage fills of the existing disc space and DBM with a polyetheretherketone (PEEK) interbody cage. The need for DBM was established by reviewing limitations of autografts and allografts in spinal fusion. Demineralized bone matrix used alone did not increase stability post discectomy at L4-L5, but was demonstrated to exhibit satisfactory stability when used with a PEEK interbody cage. There may be a future role for DBM that hardens and fills disc space more rigidly, overcoming this limitation to its use. PMID:25014862

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

    PubMed Central

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

    2012-01-01

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

  8. [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

  9. Fusion

    NASA Astrophysics Data System (ADS)

    Herman, Robin

    1991-06-01

    Acknowledgments; 1. The invention of Dr Spitzer; 2. Behind closed doors; 3. Friends and rivals; 4. Searching for answers; 5. Dawn of the tokamak; 6. Building big science; 7. Forming the major league; 8. The political plasma; 9. The modern fusion lab; 10. The plasma olympics; 11. Different directions; 12. Struggling to sell fusion; 13. In sight of breakeven; 14. Fusion's past and future; Notes; Glossary; Appendices; Index.

  10. Fusion

    NASA Astrophysics Data System (ADS)

    Herman, Robin

    2006-03-01

    Acknowledgments; 1. The invention of Dr Spitzer; 2. Behind closed doors; 3. Friends and rivals; 4. Searching for answers; 5. Dawn of the tokamak; 6. Building big science; 7. Forming the major league; 8. The political plasma; 9. The modern fusion lab; 10. The plasma olympics; 11. Different directions; 12. Struggling to sell fusion; 13. In sight of breakeven; 14. Fusion's past and future; Notes; Glossary; Appendices; Index.

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

    PubMed Central

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

    2015-01-01

    Study Design Retrospective case series. Objective StaXx XD (Spine Wave, Inc., Shelton, CT, United States) is an expandable polyaryl-ether-ether-ketone (PEEK) wafer implant utilized in the treatment of lumbar degenerative disease. PEEK implants have been successfully used as interbody devices. Few studies have focused on expandable PEEK devices. The aim of the current study is to determine the radiographic and clinical outcome of expandable PEEK cages utilized for transforaminal lumbar interbody fusion in patients with lumbar degenerative diseases. Methods Forty-nine patients who underwent lumbar interbody fusion with implantation of expandable PEEK cages and posterior instrumentation were included. The clinical outcome was evaluated using the visual analog scale (VAS) and the Oswestry Disability Index (ODI). Radiographic parameters including disk height, foraminal height, listhesis, local disk angle of the index level/levels, regional lumbar lordosis, and graft subsidence were measured preoperatively, postoperatively, and at latest follow-up. Results At an average follow-up of 19.3 months, the minimum clinically important difference for the ODI and VAS back, buttock, and leg were achieved in 64, 52, 58, and 52% of the patients, respectively. There was statistically significant improvement in VAS back (6.42 versus 3.11, p < 0.001), VAS buttock (4.66 versus 1.97, p = 0.002), VAS leg (4.55 versus 1.96, p < 0.001), and ODI (21.7 versus 12.1, p < 0.001) scores. There was a significant increase in the average disk height (6.49 versus 8.18 mm, p = 0.037) and foraminal height (15.6 versus 18.53 mm, p = 0.0001), and a significant reduction in the listhesis (5.13 versus 3.15 mm, p = 0.005). The subsidence of 0.66 mm (7.4%) observed at the latest follow-up was not significant (p = 0.35). Conclusions Midterm results indicate that expandable PEEK spacers can effectively and durably restore disk and foraminal height and improve the outcome without significant subsidence. PMID:26131383

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

    PubMed

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

    2015-06-01

    Study Design Retrospective case series. Objective StaXx XD (Spine Wave, Inc., Shelton, CT, United States) is an expandable polyaryl-ether-ether-ketone (PEEK) wafer implant utilized in the treatment of lumbar degenerative disease. PEEK implants have been successfully used as interbody devices. Few studies have focused on expandable PEEK devices. The aim of the current study is to determine the radiographic and clinical outcome of expandable PEEK cages utilized for transforaminal lumbar interbody fusion in patients with lumbar degenerative diseases. Methods Forty-nine patients who underwent lumbar interbody fusion with implantation of expandable PEEK cages and posterior instrumentation were included. The clinical outcome was evaluated using the visual analog scale (VAS) and the Oswestry Disability Index (ODI). Radiographic parameters including disk height, foraminal height, listhesis, local disk angle of the index level/levels, regional lumbar lordosis, and graft subsidence were measured preoperatively, postoperatively, and at latest follow-up. Results At an average follow-up of 19.3 months, the minimum clinically important difference for the ODI and VAS back, buttock, and leg were achieved in 64, 52, 58, and 52% of the patients, respectively. There was statistically significant improvement in VAS back (6.42 versus 3.11, p < 0.001), VAS buttock (4.66 versus 1.97, p = 0.002), VAS leg (4.55 versus 1.96, p < 0.001), and ODI (21.7 versus 12.1, p < 0.001) scores. There was a significant increase in the average disk height (6.49 versus 8.18 mm, p = 0.037) and foraminal height (15.6 versus 18.53 mm, p = 0.0001), and a significant reduction in the listhesis (5.13 versus 3.15 mm, p = 0.005). The subsidence of 0.66 mm (7.4%) observed at the latest follow-up was not significant (p = 0.35). Conclusions Midterm results indicate that expandable PEEK spacers can effectively and durably restore disk and foraminal height and improve the outcome without significant subsidence. PMID:26131383

  13. 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

  14. 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

  15. Midline Lumbar Fusion with Cortical Bone Trajectory Screw

    PubMed Central

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

    2014-01-01

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

  16. 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

  17. 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

  18. 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

  19. 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.

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

    PubMed Central

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

    2015-01-01

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

  1. 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

  2. Minimally Invasive Versus Open Lumbar Fusion: A Comparison of Blood Loss, Surgical Complications, and Hospital Course

    PubMed Central

    Patel, Amar A.; Zfass-Mendez, Matthew; Lebwohl, Nathan H.; Wang, Michael Y.; Green, Barth A.; Levi, Allan D.; Vanni, Steven; Williams, Seth K.

    2015-01-01

    Background Perioperative blood loss is a frequent concern in spine surgery and often necessitates the use of allogeneic transfusion. Minimally invasive technique (MIS) is an option that minimizes surgical trauma and therefore intra-operative bleeding. The purpose of this study is to evaluate the blood loss, surgical complications, and duration of inpatient hospitalization in patients undergoing open posterolateral lumbar fusion (PLF), open posterior lumbar interbody fusion (PLIF) with PLF, or MIS transforaminal lumbar interbody fusion (MIS TLIF). Methods Operative reports and perioperative data of patients undergoing single-level, primary open PLF (n=41), open PLIF/PLF (n=42), and MIS TLIF (n=71) were retrospectively evaluated. Patient demographics, operative blood loss, use of transfusion products, complications, and length of stay were tabulated. Patient data was controlled for age, BMI, and gender for statistical analysis. Results Patients undergoing open PLF and open PLIF/PLF respectively experienced a significantly higher blood loss (p<0.001), higher volume of blood transfusion (p<0.001), higher volume of cell saver transfusion (p<0.001), and more surgical complications (dural injury, wound infections, screw malposition) (p=0.02) than those undergoing MIS TLIF. There was no statistically significant difference in duration of hospital stay (p=0.11). Conclusions MIS TLIF provides interbody fusion with less intraoperative blood loss and subsequently a lower transfusion rate compared to open techniques, but this did not influence length of hospital stay. MIS TLIF is at least as safe as open techniques with respect to dural tear, wound infection, and screw placement. Level of Evidence Level III, Therapeutic PMID:26361455

  3. 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

  4. First report of major vascular injury due to lateral transpsoas approach leading to fatality.

    PubMed

    Assina, Rachid; Majmundar, Neil J; Herschman, Yehuda; Heary, Robert F

    2014-11-01

    Extreme lateral interbody fusion (XLIF) has gained popularity among spine surgeons for treating multiple conditions of the lumbar spine. In contrast to the anterior lumbar interbody fusion (ALIF) approach, the minimally invasive XLIF approach affords wide access to the lumbar disc space without an access surgeon and causes minimal tissue disruption. The XLIF approach offers many advantages over other lumbar spine approaches, with a reportedly low complication profile. The authors describe the first fatality reported in the literature following an XLIF approach. They describe the case of a 50-year-old woman who suffered a fatal intraoperative injury to the great vessels during a lateral transpsoas approach to the L4-5 disc space. PMID:25192374

  5. Early experience with endoscopic revision of lumbar spinal fusions.

    PubMed

    McGrath, Lynn B; Madhavan, Karthik; Chieng, Lee Onn; Wang, Michael Y; Hofstetter, Christoph P

    2016-02-01

    Approximately half a million spinal fusion procedures are performed annually in the US. It is estimated that up to one-third of arthrodesis constructs require revision surgeries. In this study the authors present endoscopic treatment strategies targeting 3 types of complications following arthrodesis surgery: 1) adjacent-level foraminal stenosis; 2) foraminal stenosis at an arthrodesis segment; and 3) stenosis caused by a displaced interbody cage. A retrospective chart review of 11 patients with a mean age of 68 ± 15 years was performed (continuous variables are shown as the mean ± SEM). All patients had a history of lumbar arthrodesis surgery and suffered from unilateral radiculopathy. Endoscopic revision surgeries were done as outpatient procedures, and there were no intraoperative or perioperative complications. The cohort included 3 patients with foraminal stenosis at the level of previous arthrodesis. They presented with unilateral radicular leg pain (visual analog scale [VAS] score: 7.3 ± 2.1) and were severely disabled, as evidenced by an Oswestry Disability Index (ODI) of 46 ± 4.9. Transforaminal endoscopic foraminotomies were performed, and at a mean follow-up time of 9.0 ± 2.5 months VAS was reduced by an average of 6.3. The cohort also includes 7 patients suffering unilateral radiculopathy due to adjacent-level foraminal stenosis. Preoperative VAS for leg pain of the symptomatic side was 6.0 ± 1.6, VAS for back pain was 5.2 ± 1.7, and ODI was 40 ± 6.33. Endoscopic decompression led to reduction of the ipsilateral leg VAS score by an average of 5, resulting in leg pain of 1 ± 0.5 at an average of 8 months of follow-up. The severity of back pain remained stable (VAS 4.2 ± 1.4). Two of these patients required revision surgery for recurrent symptoms. Finally, this study includes 1 patient who presented with weakness and pain due to retropulsion of an L5/S1 interbody spacer. The patient underwent an endoscopic interlaminar approach with partial resection of the interbody cage, which resulted in complete resolution of her radicular symptoms. Endoscopic surgery may be a useful adjunct for management of certain arthrodesis-related complications. Endoscopic foraminal decompression of previously fused segments and resection of displaced interbody cages appears to have excellent outcomes, whereas decompression of adjacent segments remains challenging and requires further investigation. PMID:26828879

  6. 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 interbody fusion procedure revealed possibly accelerative degeneration of the annulus and facet joint at both adjacent levels. PMID:18760654

  7. Ectopic bone formation with joint impingement after posterior lumbar fusion with rhBMP-2.

    PubMed

    Bannwarth, M; Kleiber, J C; Marlier, B; Eap, C; Duntze, J; Litre, C F

    2016-04-01

    Recombinant human bone morphogenetic protein-2 (rhBMP-2) was recently licensed for local administration during posterior lumbar fusion. In this indication, considerable uncertainty remains about the nature and mechanisms of the many adverse effects of rhBMP-2, such as ectopic bone formation. We report a case of ectopic bone formation with impingement on a facet joint and incapacitating low back pain after minimally invasive transforaminal L5-S1 interbody fusion with local application of rhBMP-2 (InductOs(®)). Revision surgery was eventually performed to alleviate the symptoms by removing the ectopic bone. Caution is in order regarding the use of rhBMP-2 during posterior lumbar fusion. Every effort should be made to minimise the risk of complications. PMID:26947733

  8. A prospective, multi-center clinical and radiographic outcomes evaluation of ChronOS strip for lumbar spine fusion.

    PubMed

    Kanter, Adam S; Gandhoke, Gurpreet S; Welch, William C; Arnold, Paul M; Cheng, Joseph S; Okonkwo, David O

    2016-03-01

    This prospective clinical study evaluated the use of a composite bone void filler (ChronOS Strip, DePuy Synthes, West Chester, PA, USA), combined with bone marrow aspirate plus local autologous bone, in a series of patients undergoing instrumented posterolateral spinal fusion with interbody support. Seventy-six patients were enrolled and treated per protocol at 13 clinical sites. At 24months, 55/76 patients (72%) were evaluated, with 49/76 (65%) having sufficient data to determine the primary endpoint. The primary endpoint, posterolateral fusion success, was achieved in 48/54 (88.9%) patients at 12months and in 45/49 (91.8%) patients at 24months. At all follow-up time points, statistically significant improvements were observed when compared to baseline in back and leg pain and functional status as measured by visual analog scale, Oswestry Disability Index and 12-Item Short Form health surveys. This prospective multi-center series provides evidence that the composite bone void filler, when applied posterolaterally with instrumentation, bone marrow aspirate and/or local autologous bone and concomitant interbody support, can be used to achieve a successful posterolateral fusion, resulting in improvements in clinical outcomes in patients with degenerative disc disease. PMID:26602602

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

    PubMed

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

    2012-04-01

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

  10. Nuclear Fusion

    NASA Astrophysics Data System (ADS)

    Veres, G.

    This chapter is devoted to the fundamental concepts of nuclear fusion. To be more precise, it is devoted to the theoretical basics of fusion reactions between light nuclei such as hydrogen, helium, boron, and lithium. The discussion is limited because our purpose is to focus on laboratory-scale fusion experiments that aim at gaining energy from the fusion process. After discussing the methods of calculating the fusion cross section, it will be shown that sustained fusion reactions with energy gain must happen in a thermal medium because, in beam-target experiments, the energy of the beam is randomized faster than the fusion rate. Following a brief introduction to the elements of plasma physics, the chapter is concluded with the introduction of the most prominent fusion reactions ongoing in the Sun.

  11. Mirror fusion

    NASA Astrophysics Data System (ADS)

    Harrison, M. A.; McGregor, C. K.

    1980-07-01

    Progress reported in the mirror fusion energy program covers (1) fusion, plasma theory, and computation; (2) magnetic mirror system and tandem mirror experiments; (3) superconducting magnetic development; (4) fusion reactor materials; (5) experiments in the mirror fusion test facility; and (6) design and construction of the facility. Topics covered include fiber optic communication links; desorption of deuterium and contaminants; neutral beam injection; operating point for the Yin-Yang cell; and reverse field pinch.

  12. Anterior lumbar fusion. A comparison of noncompensation patients with compensation patients.

    PubMed

    Greenough, C G; Taylor, L J; Fraser, R D

    1994-03-01

    One hundred fifty-one patients had an anterior interbody lumbar spinal fusion for intractable back pain. A solid bony fusion was obtained in 76% of the patients. Of patients unemployed before surgery, 50% had returned to work at review. Sixty-eight percent of patients rated themselves as significantly improved by the procedure. Posterior distraction instrumentation neither increased the rate of union nor improved the final results. Compensation status and psychological disturbance at presentation were significant prognostic factors. Psychological disturbance at review had a profound effect on the outcome and patient satisfaction ratings. It is recommended that in future studies compensation status and psychological disturbances are explicitly included in the outcome statistics. PMID:8131353

  13. Guideline update for the performance of fusion procedures for degenerative disease of the lumbar spine. Part 4: radiographic assessment of fusion status.

    PubMed

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

    2014-07-01

    The ability to identify a successful arthrodesis is an essential element in the management of patients undergoing lumbar fusion procedures. The hypothetical gold standard of intraoperative exploration to identify, under direct observation, a solid arthrodesis is an impractical alternative. Therefore, radiographic assessment remains the most viable instrument to evaluate for a successful arthrodesis. Static radiographs, particularly in the presence of instrumentation, are not recommended. In the absence of spinal instrumentation, lack of motion on flexion-extension radiographs is highly suggestive of a successful fusion; however, motion observed at the treated levels does not necessarily predict pseudarthrosis. The degree of motion on dynamic views that would distinguish between a successful arthrodesis and pseudarthrosis has not been clearly defined. Computed tomography with fine-cut axial images and multiplanar views is recommended and appears to be the most sensitive for assessing fusion following instrumented posterolateral and anterior lumbar interbody fusions. For suspected symptomatic pseudarthrosis, a combination of techniques including static and dynamic radiographs as well as CT images is recommended as an option. Lack of facet fusion is considered to be more suggestive of a pseudarthrosis compared with absence of bridging posterolateral bone. Studies exploring additional noninvasive modalities of fusion assessment have demonstrated either poor potential, such as with (99m)Tc bone scans, or provide insufficient information to formulate a definitive recommendation. PMID:24980581

  14. 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.

  15. Fusion breeder

    SciTech Connect

    Moir, R.W.

    1982-02-22

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

  16. "Polarized" Fusion

    NASA Astrophysics Data System (ADS)

    Schieck, Hans Paetz Gen.

    Increasing energy demand in view of limited supply, as well as environmental and nuclear-safety concerns leading to increased emphasis on renewable energy sources such as solar or wind energy are expected to focus public and scientific interest increasingly also on fusion energy. With the decision to build ITER (low-density magnetic confinement) and also continuing research on (high-density) inertial-confinement fusion (cf. the inauguration of the laser fusion facility at the Lawrence Livermore National Laboratory) prospects of fusion energy have probably entered a new era.

  17. 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.

  18. 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

  19. 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

  20. 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

  1. 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 assessable in 54% (52/96) of cases (p < 0.01). The presence of anterior plate fixation had minimal impact on visualization of the spinal cord (99% [213/216] for plated cases vs 98% [159/162] for nonplated cases; p = 1.0) or nerve roots (79% [170/216] for plated cases vs 77% [124/162] for nonplated cases; p = 0.62). CONCLUSIONS Interbody fusion with tantalum cage following anterior cervical discectomy imparts significant paramagnetic artifact, which significantly decreases visualization and assessment of ongoing surgical level nerve root, but not spinal cord, compression. Anterior plate constructs do not affect visualization of these structures. TSE T2-weighted sequences significantly improve nerve root visualization and should be performed as part of a standard postoperative protocol when imaging the cervical spine following interbody implantation of materials with potential for paramagnetic artifact. PMID:26613279

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

    PubMed

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

    2015-04-01

    The purpose of this study was to evaluate potential technical advantages of the CO2 laser technology in mini-open transforaminal lumbar interbody fusion (TLIF) surgeries and report our preliminary clinical data on the safety and clinical outcomes. There is currently no literature discussing the recently redeveloped CO2 laser technology application for lumbar fusion. Safety and clinical outcomes were compared between two groups: 24 patients that underwent CO2 laser-assisted one-level TLIF surgeries and 30 patients that underwent standard one-level TLIF surgeries without the laser. There were no neural thermal injuries or other intraoperative laser-related complications encountered in this cohort of patients. At a mean follow-up of 17.4 months, significantly reduced lower back pain scores (P=0.013) were reported in the laser-assisted patient group compared to a standard fusion patient group. Lower extremity radicular pain intensity scores were similar in both groups. Laser-assisted TLIF surgeries showed a tendency (P = 0.07) of shorter operative times that was not statistically significant. Based on this preliminary clinical report, the safety of the CO2 laser device for lumbar fusion surgeries was assessed. There were no neural thermal injuries or other intraoperative laser-related complications encountered in this cohort of patients. Further investigation of CO2 laser-assisted lumbar fusion procedures is warranted in order to evaluate its effect on clinical outcomes. PMID:26180686

  3. Spinal fusion

    MedlinePlus

    ... the wound or vertebral bones Damage to a spinal nerve, causing weakness, pain, loss of sensation, problems with your bowels or bladder The vertebrae above and below the fusion are more likely to wear away, leading to more problems later

  4. 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)

  5. Guideline update for the performance of fusion procedures for degenerative disease of the lumbar spine. Part 16: bone graft extenders and substitutes as an adjunct for lumbar fusion.

    PubMed

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

    2014-07-01

    In an attempt to enhance the potential to achieve a solid arthrodesis and avoid the morbidity of harvesting autologous iliac crest bone (AICB) for a lumbar fusion, numerous alternatives have been investigated. The use of these fusion adjuncts has become routine despite a lack of convincing evidence demonstrating a benefit to justify added costs or potential harm. Potential alternatives to AICB include locally harvested autograft, calcium-phosphate salts, demineralized bone matrix (DBM), and the family of bone morphogenetic proteins (BMPs). In particular, no option has created greater controversy than the BMPs. A significant increase in the number of publications, particularly with respect to the BMPs, has taken place since the release of the original guidelines. Both DBM and the calciumphosphate salts have demonstrated efficacy as a graft extender or as a substitute for AICB when combined with local autograft. The use of recombinant human BMP-2 (rhBMP-2) as a substitute for AICB, when performing an interbody lumbar fusion, is considered an option since similar outcomes have been observed; however, the potential for heterotopic bone formation is a concern. The use of rhBMP-2, when combined with calcium phosphates, as a substitute for AICB, or as an extender, when used with local autograft or AICB, is also considered an option as similar fusion rates and clinical outcomes have been observed. Surgeons electing to use BMPs should be aware of a growing body of literature demonstrating unique complications associated with the use of BMPs. PMID:24980593

  6. Cell fusion.

    PubMed Central

    Podbilewicz, Benjamin

    2006-01-01

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

  7. 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)

  8. Exploratory meta-analysis on dose-related efficacy and morbidity of bone morphogenetic protein in spinal arthrodesis surgery.

    PubMed

    Hofstetter, Christoph P; Hofer, Anna S; Levi, Allan D

    2016-03-01

    OBJECT Bone morphogenetic protein (BMP) is frequently used for spinal arthrodesis procedures in an "off-label" fashion. Whereas complications related to BMP usage are well recognized, the role of dosage is less clear. The objective of this meta-analysis was to assess dose-dependent effectiveness (i.e., bone fusion) and morbidity of BMP used in common spinal arthrodesis procedures. A quantitative exploratory meta-analysis was conducted on studies reporting fusion and complication rates following anterior cervical discectomy and fusion (ACDF), posterior cervical fusion (PCF), anterior lumbar interbody fusion (ALIF), transforaminal lumbar interbody fusion (TLIF), posterior lumbar interbody fusion (PLIF), and posterolateral lumbar fusion (PLF) supplemented with BMP. METHODS A literature search was performed to identify studies on BMP in spinal fusion procedures reporting fusion and/or complication rates. From the included studies, a database for each spinal fusion procedure, including patient demographic information, dose of BMP per level, and data regarding fusion rate and complication rates, was created. The incidence of fusion and complication rates was calculated and analyzed as a function of BMP dose. The methodological quality of all included studies was assessed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Data were analyzed using a random-effects model. Event rates are shown as percentages, with a 95% CI. RESULTS Forty-eight articles met the inclusion criteria: ACDF (n = 7), PCF (n = 6), ALIF (n = 9), TLIF/PLIF (n = 17), and PLF (n = 9), resulting in a total of 5890 patients. In ACDF, the lowest BMP concentration analyzed (0.2-0.6 mg/level) resulted in a fusion rate similar to the highest dose (1.1-2.1 mg/level), while permitting complication rates comparable to ACDF performed without BMP. The addition of BMP to multilevel constructs significantly (p < 0.001) increased the fusion rate (98.4% [CI 95.4%-99.4%]) versus the control group fusion rate (85.8% [CI 77.4%-91.4%]). Studies on PCF were of poor quality and suggest that BMP doses of ≤ 2.1 mg/level resulted in similar fusion rates as higher doses. Use of BMP in ALIF increased fusion rates from 79.1% (CI 57.6%-91.3%) in the control cohort to 96.9% (CI 92.3%-98.8%) in the BMP-treated group (p < 0.01). The rate of complications showed a positive correlation with the BMP dose used. Use of BMP in TLIF had only a minimal impact on fusion rates (95.0% [CI 92.8%-96.5%] vs 93.0% [CI 78.1%-98.0%] in control patients). In PLF, use of ≥ 8.5 mg BMP per level led to a significant increase of fusion rate (95.2%; CI 90.1%-97.8%) compared with the control group (75.3%; CI 64.1%-84.0%, p < 0.001). BMP did not alter the rate of complications when used in PLF. CONCLUSIONS The BMP doses used for various spinal arthrodesis procedures differed greatly between studies. This study provides BMP dosing recommendations for the most common spine procedures. PMID:26613283

  9. 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

  10. 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.

  11. Fusion ambassador

    NASA Astrophysics Data System (ADS)

    Smith, Chris Llewellyn

    2009-02-01

    With his glasses and shock of thick, white hair, Chris Llewellyn Smith does not look like a superhero saving the world from peril. Yet the slim, 66-year-old physicist is seemingly becoming a potential saviour in the public eye. At least that is the reaction he says he got while recently moving house in Oxford. "I was quite surprised by my new neighbours' knowledge of energy issues when they said 'The world is relying on you to develop fusion!'."

  12. Flexibility and fatigue evaluation of oblique as compared with anterior lumbar interbody cages with integrated endplate fixation.

    PubMed

    Freeman, Andrew L; Camisa, William J; Buttermann, Glenn R; Malcolm, James R

    2016-01-01

    OBJECT This study was undertaken to quantify the in vitro range of motion (ROM) of oblique as compared with anterior lumbar interbody devices, pullout resistance, and subsidence in fatigue. METHODS Anterior and oblique cages with integrated plate fixation (IPF) were tested using lumbar motion segments. Flexibility tests were conducted on the intact segments, cage, cage + IPF, and cage + IPF + pedicle screws (6 anterior, 7 oblique). Pullout tests were then performed on the cage + IPF. Fatigue testing was conducted on the cage + IPF specimens for 30,000 cycles. RESULTS No ROM differences were observed in any test group between anterior and oblique cage constructs. The greatest reduction in ROM was with supplemental pedicle screw fixation. Peak pullout forces were 637 ± 192 N and 651 ± 127 N for the anterior and oblique implants, respectively. The median cage subsidence was 0.8 mm and 1.4 mm for the anterior and oblique cages, respectively. CONCLUSIONS Anterior and oblique cages similarly reduced ROM in flexibility testing, and the integrated fixation prevented device displacement. Subsidence was minimal during fatigue testing, most of which occurred in the first 2500 cycles. PMID:26407089

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

    PubMed Central

    Barrey, Cédric; Darnis, Alice

    2015-01-01

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

  14. 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.

  15. Pros, cons, and costs of INFUSE in spinal surgery

    PubMed Central

    Epstein, Nancy E.

    2011-01-01

    Background: INFUSE (recombinant human bone morphogenetic protein-2 [rh-BMP-2]; Medtronic, Memphis, TN, USA) is approved by the Federal Drug Administration (FDA) only for use with the lumbar tapered fusion device (LT Cage; Medtronic) to perform single-level anterior lumbar interbody fusions (ALIF: L2-S1 levels). INFUSE, however, is widely utilized in an “off-label” capacity for anterior and/or posterior cervical, thoracic, and lumbar surgery. Nevertheless, Medicare and other insurance companies, are now increasingly denying reimbursement (average cost of a “large” INFUSE to the hospital without overhead $5000-6000) to hospitals for INFUSE when utilized “off-label”. Methods: This commentary looks at several representative studies citing the cons associated with utilizing INFUSE in spinal surgery, contraindications, complications, and cost factors. Results: There are multiple cons of utilizing INFUSE in an “off-label” capacity for spinal surgery. Direct contraindications include pregnancy, allergy to titanium, allergy to bovine type I collagen or rhBMP-2, infection, tumor, liver or kidney disease, immunosuppression (e.g., lupus, HIV/AIDS); contraindications are also seen in those receiving radiation, chemotherapy, or steroids. Reported complications include exuberant/ectopic bone formation, paralysis (cord, nerve damage), dural tears, bowel–bladder and sexual dysfunction, respiratory failure, inflammation of adjacent tissues, fetal developmental complications, scar, excessive bleeding, and even death. Complications are so prevalent in the anterior cervical spine, that many surgeons no longer use it in this region. Similarly, INFUSE complications and indications for posterior lumbar interbody fusions (PLIFs) and transforaminal interbody lumbar fusions (TLIFs) should also be reexamined. Conclusions: More surgeons need to question the safety, efficacy, and appropriate “off-label” use of INFUSE in all spine surgeries. PMID:21297932

  16. Revitalizing Fusion via Fission Fusion

    NASA Astrophysics Data System (ADS)

    Manheimer, Wallace

    2001-10-01

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

  17. 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

  18. 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). VAS, ODI, and SF-36 scores demonstrated significant improvements at 10 out of 12 postoperative time points compared with preoperative baseline. Conclusions Lumbar discography with post-discography CT can be an effective method to evaluate patients with discogenic back pain refractory to non-operative treatments. Those patients with one- or two-level high concordant pain scores with associated annular tears and negative control disc represent good surgical candidates for lumbar interbody spinal fusion. PMID:27026838

  19. 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). VAS, ODI, and SF-36 scores demonstrated significant improvements at 10 out of 12 postoperative time points compared with preoperative baseline. Conclusions Lumbar discography with post-discography CT can be an effective method to evaluate patients with discogenic back pain refractory to non-operative treatments. Those patients with one- or two-level high concordant pain scores with associated annular tears and negative control disc represent good surgical candidates for lumbar interbody spinal fusion.

  20. 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

  1. 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

  2. Comparison between Instrumented Mini-TLIF and Instrumented Circumferential Fusion in Adult Low-Grade Lytic Spondylolisthesis : Can Mini-TLIF with PPF Replace Circumferential Fusion?

    PubMed Central

    Kim, Dong-Hyun; Lee, Sang-Ho

    2009-01-01

    Objective To evaluate clinical and radiological results of two different fusion techniques in adult low-grade isthmic spondylolisthesis. Methods Between November 2003 and December 2004, 46 consecutive patients underwent instrumented mini-transforaminal lumbar interbody fusion (mini-TLIF) (group I) at Wooridul Spine Hospital, Seoul, Korea. Between February 2003 and October 2006, 32 consecutive patients underwent instrumented circumferential fusion (group II) at Leon Wiltse Memorial Hospital, Suwon, Korea. The mean follow-up periods were 29.7 and 26.1 months, respectively. Results Mean visual analog scale (VAS) scores for back and leg pain decreased, respectively, from 6.98 and 6.33 to 2.3 and 2.2 in group I and from 7.38 and 6.00 to 1.7 and 1.0 in group II. Mean Oswestry disability index (ODI) improved from 51.85% to 14.4% in group I and from 60% to 9.1% in group II. In both groups, VAS and ODI scores significantly changed from pre- to postoperatively (p<0.001), but postoperative outcome between groups was statistically not significant. Radiologic evidence of fusion was noted in 95.7% and 100% of the patients in group I and II, respectively. In both groups, changes in disc height, segmental lordosis, degree of listhesis, and whole lumbar lordosis between the pre- and postoperative periods were significant except whole lumbar lordosis in both groups. Conclusion Clinical and functional outcomes demonstrate no significant differences between groups in treating back and leg pain of adult patients with low-grade isthmic spondylolisthesis. However, in terms of operative data (i.e. operation time and hospital stay), instrumented mini-TLIF demonstrated better results. PMID:19274115

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

    PubMed Central

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

    2011-01-01

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

  4. 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.

  5. Cold fusion

    SciTech Connect

    Bush, R.T. )

    1991-03-01

    The transmission resonance model (TRM) is combined with some electrochemistry of the cathode surface and found to provide a good fit to new data on excess heat. For the first time, a model for cold fusion not only fits calorimetric data but also predicts optimal trigger points. This suggests that the model is meaningful and that the excess heat phenomenon claimed by Fleischmann and Pons is genuine. A crucial role is suggested for the overpotential and, in particular, for the concentration overpotential, i.e., the hydrogen overvoltage. Self-similar geometry, or scale invariance, i.e., a fractal nature, is revealed by the relative excess power function. Heat bursts are predicted with a scale invariance in time, suggesting a possible link between the TRM and chaos theory. The model describes a near-surface phenomenon with an estimated excess power yield of {approximately}1 kW/cm{sup 3} Pd, as compared to 50 W/cm{sup 3} of reactor core for a good fission reactor. Transmission resonance-induced nuclear transmutation, a new type of nuclear reaction, is strongly suggested with two types emphasized: transmission resonance-induced neutron transfer reactions yielding essentially the same end result as Teller's hypothesized catalytic neutron transfer and a three-body reaction promoted by standing de Broglie waves. In this paper suggestions for the anomalous production of heat, particles, and radiation are given.

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

    PubMed Central

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

    2007-01-01

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

  7. Review of fusion synfuels

    SciTech Connect

    Fillo, J.A.

    1980-01-01

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

  8. Multilevel image fusion

    NASA Astrophysics Data System (ADS)

    Petrovic, Vladimir

    2003-04-01

    Signal-level image fusion has in recent years established itself as a useful tool for dealing with vast amounts of image data obtained by disparate sensors. In many modern multisensor systems, fusion algorithms significantly reduce the amount of raw data that needs to be presented or processed without loss of information content as well as provide an effective way of information integrations. One of the most useful and widespread applications of signal-level image fusion is for display purposes. Fused images provide the observer with a more reliable and more complete representation of the scene than would be obtained through single sensor display configurations. In recent years, a plethora of algorithms that deal with problem of fusion for display has been proposed. However, almost all are based on relatively basic processing techniques and do not consider information from higher levels of abstraction. As some recent studies have shown this does not always satisfy the complex demands of a human observer and a more subjectively meaningful approach is required. This paper presents a fusion framework based on the idea that subjectively relevant fusion could be achieved in information at higher levels of abstraction such as image edges and image segment boundaries are used to guide the basic signal-level fusion process. Fusion of processed, higher level information to form a blueprint for fusion at signal level and fusion of information from multiple levels of extraction into a single fusion engine are both considered. When tested on two conventional signal-level fusion methodologies, such multi-level fusion structures eliminated undesirable effects such as a fusion artifacts and loss of visually vital information that compromise their usefulness. Images produced by inclusion of multi-level information in the fusion process are clearer and of generally better quality than those obtained through conventional low-level fusion. This is verified through subjective evaluation and established objective fusion performance metrics.

  9. 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

  10. 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.

  11. 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.

  12. Arthroscopic partial wrist fusion.

    PubMed

    Ho, Pak-Cheong

    2008-12-01

    The wide intraarticular exposure of the wrist joint under arthroscopic view provides an excellent ground for various forms of partial wrist fusion. Combining with percutaneous fixation technique, arthroscopic partial wrist fusion can potentially generate the best possible functional outcome by preserving the maximal motion pertained with each type of partial wrist fusion because the effect of extraarticular adhesion associated with open surgery can be minimized. From November 1997 to May 2008, the author had performed 12 cases of arthroscopic partial wrist fusion, including scaphotrapeziotrapezoid fusion in 3, scaphoidectomy and 4-corner fusion in 4, radioscapholunate fusion in 3, radiolunate fusion in 1, and lunotriquetral fusion in 1 case. Through the radiocarpal or midcarpal joint, the corresponding articular surfaces were denuded of cartilage using arthroscopic burr and curette. Carpal bones involved in the fusion process were then transfixed with K wires percutaneously after alignment corrected and confirmed under fluoroscopic control. Autogenous cancellous bone graft or bone substitute were inserted and impacted to the fusion site through cannula under direct arthroscopic view. Final fixation could be by multiple K wires or cannulated screw system. Early mobilization was encouraged. Surgical complications were minor, including pin tract infection, skin burn, and delay union in 1 case. Uneventful radiologic union was obtained in 9 cases, stable fibrous union in 2, and nonunion in 1. The average follow-up period was 70 months. Symptom was resolved or improved, and functional motion was gained in all cases. All surgical scars were almost invisible, and aesthetic outcome was excellent. PMID:19060685

  13. Adaptive fusion processor

    NASA Astrophysics Data System (ADS)

    Dasarathy, Belur V.

    1995-07-01

    An adaptive learning fusion processor, capable of fusion of a mix of information at the data, feature, and decision levels, acquired from multiple sources (sensors as well as feature extractors and/or decision processors) is presented. Four alternative approaches: a self- partitioning neural net, an adaptive fusion process, an evidential reasoning approach, and a concurrence seeking approach were initially evaluated from a conceptual viewpoint followed by some limited simulation and testing. Based on this assessment, an adaptive fusion processor employing innovative advances of the nearest neighbor concept was selected for detailed implementation and testing using real-world field data. Results show the benefits of fusion in terms of improved performance as compared to those obtainable from the individual component information streams being input to the fusion processor and clearly bring out the feasibility and effectiveness of the new multi-level fusion concepts.

  14. 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.

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

    PubMed

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

    2003-02-15

    Porous titanium-nickel (PTN) devices represent an alternative to traditional cage implants. PTN materials possess an interconnecting network of pores with capillarity properties that may promote bone ingrowth, long-term fixation, and intervertebral fusion without the need for bone grafting. However, their considerable surface area and nickel content may elicit concerns over sensitization potential. Therefore, PTN surface corrosion and nickel release resistance must be carefully studied. To evaluate this possibility, a PTN interbody fusion device (IFD) was compared to a conventional nonporous cage made of TiAlV, a well-known biocompatible biomaterial, in a sheep model. PTN and TiAlV IFDs were inserted at two non-contiguous lumbar sites for 3, 6, and 12 months postsurgery. Their surface was then evaluated by scanning electron microscopy (SEM) combined with backscattered electron analysis (BSE). No evidence of surface corrosion was observed either pre- or postimplantation, regardless of device type. Dosage of nickel ions was also performed with the use of inductively coupled plasma-mass spectrometry (ICP-MS). Blood nickel levels were observed to be within acceptable levels at all postinstrumentation times. Nickel content in PTN-adjacent tissue, as well as in detoxification and remote organs, was equivalent both in PTN-treated and control sheep. Therefore, porous titanium-nickel demonstrated resistance to both in vivo surface corrosion and nickel ion release and compared very well with a conventional titanium implant in the course of a 12-month sheep study. PMID:12516086

  16. Disc height reduction in adjacent segments and clinical outcome 10 years after lumbar 360° fusion

    PubMed Central

    Leistra, Freek; Bullmann, Viola; Osada, Nani; Vieth, Volker; Marquardt, Björn; Lerner, Thomas; Liljenqvist, Ulf; Hackenberg, Lars

    2007-01-01

    Adjacent segment degeneration (ASD) is discussed to impair long-term outcome after lumbar interbody fusion. Nevertheless the amount and origin of degeneration and its clinical relevance remain unclear. Only little data is published studying quantitative disc height reduction (DHR) as indicator for ASD in long-term follow-up. Forty patients (23 men, 17 women) (group 1: degenerative disc disease, n = 27; group 2: lytic spondylolisthesis, n = 13) underwent lumbar 360° instrumentation and fusion between 1991 and 1997. Preoperative and follow-up lateral lumbar radiographs were studied. Disc heights of first and second cephalad adjacent segments were measured by Farfan’s technique and Hurxthal’s technique modified by Pope. Clinical outcome was studied using Oswestry disability index (ODI) and visual analogue scale (VAS). Age, gender, prior surgery, fusion rate and number of fusion levels were investigated as potential factors affecting the outcome. Mean follow-up was 114 (72–161) months. Clinical outcome showed an improvement of 44.6% in ODI and 43.8% in VAS with a tendency towards better results in group 2. Fusion rate was 95%. Disc height of the first cephalad adjacent segment in all patients was reduced by on average 21% (Farfan, P < 0.001) and 19% (Pope, P < 0.001), respectively, and that of the second adjacent level by on average 16% (Farfan, P < 0.001) and 14% (Pope, P < 0.001), respectively. A tendency towards more disc height reduction (DHR) in the degenerative group was observed. Advanced age correlated with advanced DHR (P ≤ 0.003, r = 0.5). Multiple level fusion led to a more pronounced DHR than 1-level fusion (P = 0.028). There was a tendency towards more DHR in the first adjacent disc compared to the second. Gender, prior surgery of the fused segment and fusion level did not affect the amount of DHR. There was no correlation between the clinical outcome and DHR. Lumbar fusion is associated with DHR of adjacent discs. This may be induced by additional biomechanical stress, ongoing degeneration affecting the lumbar spine and advancing age. However, clinical outcome is not correlated with adjacent DHR. PMID:17922149

  17. Fusion Energy Division

    NASA Astrophysics Data System (ADS)

    1984-09-01

    Progress in fusion energy is reported. The work includes: (1) experimental and theoretical research on two magnetic confinement concepts; the ELMO Bumpy Torus (EBT) and the Tokamak; (2) theoretical and engineering studies on a third concept, the stellarator; (3) engineering and physics of present generation fusion devices; (4) development and testing of diagnostic tools and techniques; (5) development and testing of materials for fusion devices; (6) development and testing of essential technologies for heating and fueling fusion plasmas; (7) development and testing of the superconducting magnets that will be needed to confine these plasmas; (8) design of future devices; (9) assessment of the environmental impact on fusion energy; and (10) assembly and distribution to the fusion community of data bases on atomic physics and radiation effects.

  18. Limited wrist fusion.

    PubMed

    Mih, A D

    1997-11-01

    Limited wrist fusion can provide patients a measure of pain relief with retention of a functional range of motion. Recent biomechanic investigations have shed light on the potential benefits of such procedures. Clinical studies have demonstrated the usefulness of limited wrist fusion for the treatment of numerous conditions involving the wrist. Significant complications are associated with many of these fusions and should be considered before performing these procedures. PMID:9403297

  19. Magnetic fusion reactor economics

    SciTech Connect

    Krakowski, R.A.

    1995-12-01

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

  20. 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.

  1. 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

  2. Nuclear fusion inside condense matters

    NASA Astrophysics Data System (ADS)

    He, Jing-Tang

    2007-03-01

    This article describes in detail the nuclear fusion inside condense matters—the Fleischmann-Pons effect, the reproducibility of cold fusions, self-consistentcy of cold fusions and the possible applications.

  3. Mirror fusion - Another path to fusion power

    NASA Astrophysics Data System (ADS)

    Werne, R. W.; Fisher, D. K.; Hirschfeld, F.

    1981-07-01

    Developments in the mirror program at Lawrence Livermore National Laboratory are discussed. Major innovations discussed in the mirror approach include the mirror concept, and the minimum-B field (magnetic well) assuring gross magnetohydrodynamic stability. Also presented are the tandem mirror, and the thermal barrier, which greatly enhances plasma potential confinement. The Mirror Fusion Test Facility objectives include construction and operation of a Nb-Ti superconducting magnet system, long pulsed, high-current, high-voltage, neutral beams, and a large-scale cryopanel vacuum pump. With commercialization and government support, the program hopes to make mirror fusion an important energy option.

  4. 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…

  5. 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…

  6. 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.

  7. Fusion Power Deployment

    SciTech Connect

    J.A. Schmidt; J.M. Ogden

    2002-02-06

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

  8. Nuclear fusion: The issues

    SciTech Connect

    Griffin, R.D.

    1993-01-22

    The taming of fusion energy, has proved one of the most elusive quests of modern science. For four decades, the United States has doggedly pursued energy's holy grail, pumping more than $9 billion into research and reactor prototypes. This year, the federal government is slated to spend $339 million on fusion, more than the combined amount the government will spend for research on oil, natural gas, solar power, wind power, geothermal energy, biofuels and conservation. This article summarizes the technical, political in terms of international cooperation, economic, planning, etc. issues surrounding the continued development of fusion as a possible power source for the next century. Brief descriptions of how fusion works and of the design of a tokamak fusion machine are included.

  9. Affine fusion tadpoles

    NASA Astrophysics Data System (ADS)

    Urichuk, Andrew

    Fusion dimensions are integer-valued quantities equal to the dimensions of the spaces of conformal blocks, which describe the interactions of a conformal field theory (CFT). Our focus was on the Wess-Zumino-Witten models, a particularly interesting type of CFT, whose primary fields correspond to representations of affine Lie groups. Arguably, affine fusion tadpoles are the simplest g ? 1 fusion dimension, having only a single incoming field and g = 1. We study the symmetries of the SU(N) tadpole and Verlinde formula with the intention of finding a non-negative-integer decomposition. Such a decomposition might be indicative of a combinatorial atom for fusion, which could suggest a new combinatorial account of fusion dimensions. From produced tables we found that tadpole values appeared to be polynomial in the level k. Several conjectures were made and we sketch a method obtaining general forms of SU(N) tadpoles via dominant weight sums.

  10. 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.

  11. Indian fusion test reactor

    NASA Astrophysics Data System (ADS)

    Srinivasan, R.; FTR Team

    2012-06-01

    The fusion reactor as a volumetric neutron source can serve many applications needed for realizing fusion power reactor. For the Indian energy scenario, such a device can also produce fissile fuel for accelerating the nuclear power production. The Indian Fusion Test Reactor (FTR) is a low fusion gain (Q = 3-5) device to be used as component test facility for qualifying future reactor materials as well as for demonstrating the production of fissile fuel. FTR will be a medium sized tokamak device with a neutron wall load of 0.2 MW/m2. The presently available structural materials can be used for this device and such a device can be realized in ten years time from now. This device should produce about 25-50 kg of fissile fuel in one full-power-year and also produce the tritium needed for its operation. This device will greatly help the nuclear fission power program by producing fissile fuel.

  12. Fusion-breeder program

    SciTech Connect

    Moir, R.W.

    1982-11-19

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

  13. Label Fusion Strategy Selection

    PubMed Central

    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 techniquesSTAPLE, 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

  14. 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.

  15. 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.

  16. Fusion ignition research experiment

    SciTech Connect

    Dale Meade

    2000-07-18

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

  17. 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.

  18. Fusion energy breakthrough

    NASA Astrophysics Data System (ADS)

    Bell, Peter M.

    The physics of harnessing nuclear fusion as a heat source is not well known. No such power generator has been made yet and significant breakthroughs will be necessary before the concept is proven. All such advances in energy research are followed with keen interest by geophysicists. One such breakthrough was made recently at the Massachusetts Institute of Technology (MIT) in experiments with a model Tokamak fusion reactor.The MIT experimental high-field nuclear fusion reactor with the name of Alcator-C experienced a large technological advance when its operating parameters exceeded the socalled “Lawson criterion,” one of the minimum requirements of a successful nuclear fusion power generator. The nuclear fusion of hydrogen to form helium releases heat, but to make such a process workable for a power plant, there must be a sizable efficiency in the ratio of energy input to bring about the reaction to the thermal energy released by the reaction, and even this advance falls far short of the breakeven point. The advance is, however, a great step in the learning curve about fusion magnetohydrodynamic plasma systems.

  19. 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.

  20. Biomechanical evaluation of a new AxiaLIF technique for two-level lumbar fusion

    PubMed Central

    Erkan, Serkan; Mehbod, Amir A.; Hsu, Brian; Pahl, Douglas W.; Transfeldt, Ensor E.

    2009-01-01

    Single level axial lumbar interbody fusion (AxiaLIF) using a transsacral rod through a paracoccygeal approach has been developed with promising early clinical results and biomechanical stability. Recently, the transsacral rod has been extended to perform a two-level fusion at both L4–L5 and L5–S1 levels (AxiaLIF II). No biomechanical studies have been conducted on multilevel fusion using the AxiaLIF technique. In this study, the biomechanics of L4–S1 motion segments instrumented with the AxiaLIF II transsacral rod was evaluated. Six human cadaveric lumbosacral spine segments from L4 to S1 were used (age ranges 46–74 years). Unconstrained and non-destructive pure moments in axial torsion, lateral bending, and flexion extension were applied to each specimen following intact, standalone AxiaLIF II, and AxiaLIF II with two posterior fixation options: facet screws and pedicle screws with rods. Range of motion was calculated from the raw data collected with an optical motion tracking system. The two-level transsacral rod was successfully inserted in all the specimens. At L4–L5 level in axial torsion (AT) and flexion extension (FE), none of the surgical treatments showed statistically significant difference between the procedures (all P > 0.05) although facet screws and pedicle screws had higher stability on average. In lateral bending (LB), the two posterior fixation techniques had significantly higher construct stability (P < 0.05) than the standalone rod. No significant difference was found between facet screws and pedicle screws (P = 0.821). At L5–S1 level in AT and LB, none of the surgical treatments were found to be statistically significant (all P > 0.05). In FE, standalone two-level transsacral rod had significantly higher range of motion (ROM) compared with the posterior fixation techniques (P < 0.05). In conclusion, the standalone rod reduced intact ROM significantly. Supplementary fixations including facet screws and pedicle screws are required to achieve higher construct stability for successful fusion. Further clinical studies are essential to evaluate the practical success of this technique. PMID:19352729

  1. 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 somewhat different from those for terrestrial electrical power generation. Thus fusion schemes that are initially attractive for electrical power generation might not necessarily be attractive also for propulsion and vice versa, though the underlying fusion science and engineering enjoy much overlap. Parallel efforts to develop these qualitatively differently fusion schemes for the two applications could benefit greatly from each other due to the synergy in the underlying physics and engineering. Pulsed approaches to fusion have not been explored to the same degree as steady-state or long-pulse approaches to fusion in the fusion power research program. The concerns early on were several. One was that the pulsed power components might not have the service lifetimes meeting the requirements of a practical power generating plant. Another was that, for many pulsed fusion schemes, it was not clear whether the destruction of hardware per pulse could be minimized or eliminated or recycled to such an extent as to make economical electrical power generation feasible, Significant development of the underlying pulsed power component technologies have occurred in the last two decades because of defense and other energy requirements. The state of development of the pulsed power technologies are sufficiently advanced now to make it compelling to visit or re-visit pulsed fusion approaches for application to propulsion where the cost of energy is not so demanding a factor as in the case of terrestrial power application. For propulsion application, the overall mass of the fusion system is the critical factor. Producing fusion reactions require extreme states of matter. Conceptually, these extreme states of matter are more readily realizable in the pulsed states, at least within appropriate bounds, than in the steady states. Significant saving in system mass may result in such systems. Magnetic fields are effective in confining plasma energy, whereas inertial compression is an effective way of heating and containing the plasma. Intensive research in developing magnetic energy containment and inertial plasma compression are being pursued in distinctively different fusion experiments in the terrestrial fusion power program. Fusion schemes that attempt to combine the favorable attributes of these two aspects into one single integrated fusion scheme appear to have benefits that are worth exploring for propulsion application.

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

    PubMed

    Epstein, Nancy E

    2013-01-01

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

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

    PubMed Central

    Epstein, Nancy E.

    2013-01-01

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

  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. 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.

  6. 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

  7. CRYOGENICS FOR FUSION

    SciTech Connect

    Dauguet, P.; Bonneton, M.; Fauve, E.; Bernhardt, J. M.; Beauvisage, J.; Andrieu, F.; Gistau-Baguer, G. M.; Boissin, J. C.

    2008-03-16

    Fusion of Hydrogen to produce energy is one of the technologies under study to meet the mankind raising need in energy and as a substitute to fossil fuels for the future. This technology is under investigation for more than 30 years already, with, for example, the former construction of the experimental reactors Tore Supra, DIII-D and JET. With the construction of ITER to start, the next step to 'fusion for energy' will be done. In these projects, an extensive use of cryogenic systems is requested. Air Liquide has been involved as cryogenic partner in most of former and presently constructed fusion reactors. In the present paper, a review of the cryogenic systems we delivered to Tore Supra, JET, IPR and KSTAR will be presented.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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 engineering capabilities have been demonstrated for a fusion reactor gain (Q) of the order of unity (TFTR: 0.25, JET: 0.65, JT-60: Q(sub eq) approx. 1.25). These technological advances made it compelling for considering fusion for propulsion.

  15. 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.

  16. Fusion's $372-Million Mothball

    SciTech Connect

    Booth, W.

    1987-10-09

    Lawrence Livermore National Laboratory's Mirror Fusion Test Facility (MFTF-B) was built to prove that a design using magnetic mirrors could compete in an international race to produce a commercial fusion reactor. The MFTF-B was to be used to propel the magnetic mirror program into a real contest against Livermore's arch rival: the Princeton Plasma Physics Laboratory and its tokamak machine. On 21 February 1986, after 9 years of construction and $372 million, MTFT-B was officially dedicated. However, due to budget restriction DOE demanded the facility be put on standby the very next day.

  17. 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.

  18. Cold fusion before Congress

    NASA Astrophysics Data System (ADS)

    Maggs, William Ward

    Stanley Pons and Martin Fleischmann took their cold fusion show to Capitol Hill last week, saying they were “as sure as sure can be” that the heat produced in their experiments at the University of Utah is the result of some form of nuclear fusion and vigorously defending themselves against charges that they have set the scientific world on its ear by creating a good battery.The two chemists asked for “tens of millions of dollars” in federal funds to move directly into commercial development of energy devices based on the new discovery, but provided no more than tantalizing hints at what is going on in their experiments.

  19. Fusion welding process

    SciTech Connect

    Jones, E.D.; Mcbride, M.A.; Thomas, K.C.

    1983-06-28

    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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. Advanced fusion diagnostics

    NASA Astrophysics Data System (ADS)

    1991-07-01

    This research program is divided into two diagnostic development projects: Task 1. charged fusion product diagnostics by spectral analysis of ioncyclotron emission; and Task 2. safety factor, q(r) measurements, a study of transport in the PBX-M tokamak plasma.

  6. 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.

  7. 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.

  8. Directions for improved fusion reactors

    SciTech Connect

    Krakowski, R.A.; Miller, R.L.; Delene, J.G.

    1986-01-01

    Conceptual fusion reactor studies over the past 10 to 15 years have projected systems that may be too large, complex, and costly to be of commercial interest. One main direction for improved fusion reactors points towards smaller, higher-power-density approaches. First-order economic issues (i.e., unit direct cost and cost of electricity) are used to support the need for more compact fusion reactors. A generic fusion physics/engineering/costing model is used to provide a quantiative basis for these arguments for specific fusion concepts.

  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. Research on fusion neutron sources

    SciTech Connect

    Gryaznevich, M. P.

    2012-06-19

    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.

  11. The path to fusion power.

    PubMed

    Llewellyn Smith, Chris; Ward, David

    2007-04-15

    Fusion is potentially an environmentally responsible and intrinsically safe source of essentially limitless power. It should be possible to build viable fusion power stations, and it looks as if the cost of fusion power will be reasonable. But time is needed to further develop the technology and to test in power station conditions the materials that would be used in their construction. Assuming no major adverse surprises, an orderly fusion development programme could lead to a prototype fusion power station putting electricity into the grid within 30 years, with commercial fusion power following some 10 or more years later. In the second half of the century, fusion could therefore be an important part of the portfolio of measures that are needed to cope with rising demand for energy in an environmentally responsible manner. In this paper, we describe the basics of fusion, its potential attractions, the status of fusion R&D, the remaining challenges and how they will be tackled at the International Tokamak Experimental Reactor and the proposed International Fusion Materials Irradiation Facility, and the timetable for the subsequent commercialization of fusion power. PMID:17272246

  12. 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.

  13. Physics of magnetic confinement fusion

    NASA Astrophysics Data System (ADS)

    Wagner, F.

    2013-06-01

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

  14. 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

  15. 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.

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

    PubMed

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

    2013-12-01

    Interbody fusion cages made of poly-ether-ether-ketone (PEEK) have been widely used in clinics for spinal disorders treatment; however, they do not integrate well with surrounding bone tissue. Ti-6Al-4V (Ti) has demonstrated greater osteoconductivity than PEEK, but the traditional Ti cage is generally limited by its much greater elastic modulus (110 GPa) than natural bone (0.05-30 GPa). In this study, we developed a porous Ti cage using electron beam melting (EBM) technique to reduce its elastic modulus and compared its spinal fusion efficacy with a PEEK cage in a preclinical sheep anterior cervical fusion model. A porous Ti cage possesses a fully interconnected porous structure (porosity: 68 ± 5.3%; pore size: 710 ± 42 μm) and a similar Young's modulus as natural bone (2.5 ± 0.2 GPa). When implanted in vivo, the porous Ti cage promoted fast bone ingrowth, achieving similar bone volume fraction at 6 months as the PEEK cage without autograft transplantation. Moreover, it promoted better osteointegration with higher degree (2-10x) of bone-material binding, demonstrated by histomorphometrical analysis, and significantly higher mechanical stability (P < 0.01), shown by biomechanical testing. The porous Ti cage fabricated by EBM could achieve fast bone ingrowth. In addition, it had better osseointegration and superior mechanical stability than the conventional PEEK cage, demonstrating great potential for clinical application. PMID:24147953

  18. (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.

  19. 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. __________________________________________________

  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. Mitochondrial fission and fusion

    PubMed Central

    Scott, Iain; Youle, Richard J.

    2016-01-01

    Mitochondria are highly dynamic cellular organelles, with the ability to change size, shape and position over the course of a few seconds. Many of these changes are related to the ability of mitochondria to undergo the highly co-ordinated processes of fission (division of a single organelle into two or more independent structures) or fusion (the opposing reaction). These actions occur simultaneously and continuously in many cell types, and the balance between them regulates the overall morphology of mitochondria within any given cell. Fission and fusion are active processes which require many specialized proteins, including mechanical enzymes that physically alter mitochondrial membranes, and adaptor proteins that regulate the interaction of these mechanical proteins with organelles. Although not fully understood, alterations in mitochondrial morphology appear to be involved in several activities that are crucial to the health of cells. In the present chapter we discuss the mechanisms behind mitochondrial fission and fusion, and discuss the implications of changes in organelle morphology during the life of a cell. PMID:20533902

  2. 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.

  3. Data fusion handoff within a federation of fusion systems

    NASA Astrophysics Data System (ADS)

    Shea, Peter J.; Roskamp, Bryce

    2007-09-01

    As the military continues to move forward with an increased number of sensor and fusion systems, it becomes necessary for these systems to be able to communicate efficiently and effectively. In these environments there are multiple sensor and fusion systems that in the past have operated independently of one another. As an increasing number of systems become available, eventually an overlap in the coverage area occurs between these fusion systems. This results in a need for coordination between these semi-autonomous fusion systems. Short of a complete redesign of all the fusion systems, a solution is required to address the handoff of data between these systems. The primary goal of this paper is to describe a data fusion handoff capability that is able to augment these existing systems. This is accomplished by the use of a Handoff Manager that is added to each fusion system. The Handoff Manager is responsible for developing a global representation the track information displayed onboard its own fusion system that is common with the other members of the federation of fusion systems. This is accomplished by using a global track numbering scheme that requires communication and adjudication between the multiple Handoff Manager components that are present on the different fusion systems within the federation. This paper will define the data fusion handoff problem and describe our approach for handling the data fusion handoff problem within the context of overlapping and non-overlapping sensor environments. We will conclude with a discussion of results for a sample problem and of the path forward.

  4. Dicentric breakage at telomere fusions

    PubMed Central

    Pobiega, Sabrina; Marcand, Stéphane

    2010-01-01

    Nonhomologous end-joining (NHEJ) inhibition at telomeres ensures that native chromosome ends do not fuse together. But the occurrence and consequences of rare telomere fusions are not well understood. It is notably unclear whether a telomere fusion could be processed to restore telomere ends. Here we address the behavior of individual dicentrics formed by telomere fusion in the yeast Saccharomyces cerevisiae. Our approach was to first stabilize and amplify fusions between two chromosomes by temporarily inactivating one centromere. Next we analyzed dicentric breakage following centromere reactivation. Unexpectedly, dicentrics often break at the telomere fusions during progression through mitosis, a process that restores the parental chromosomes. This unforeseen result suggests a rescue pathway able to process telomere fusions and to back up NHEJ inhibition at telomeres. PMID:20360388

  5. 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

  6. 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 Explanation of the JET n = 0 chirping mode Nucl. Fusion 46 S888-97 Urano H. et al 2006 Confinement degradation with beta for ELMy HH-mode plasmas in JT-60U tokamak Nucl. Fusion 46 781-7 Izzo V.A. et al 2006 A numerical investigation of the effects of impurity penetration depth on disruption mitigation by massive high-pressure gas jet Nucl. Fusion 46 541-7 Inagaki S. et al 2006 Comparison of transient electron heat transport in LHD helical and JT-60U tokamak plasmas Nucl. Fusion 46 133-41 Watanabe T.-H. et al 2006 Velocity-space structures of distribution function in toroidal ion temperature gradient turbulence Nucl. Fusion 46 24-32 2010 Nuclear Fusion Award nominees For the 2010 award, the papers published in the 2007 volume were assessed and the following papers were nominated, all of which are magnetic confinement experiments and theory. Rice J.E. et al 2007 Inter-machine comparison of intrinsic toroidal rotation in tokamaks Nucl. Fusion 47 1618-24 Lipschultz B. et al 2007 Plasma-surface interaction, scrape-off layer and divertor physics: implications for ITER Nucl. Fusion 47 1189-205 Loarer T. et al 2007 Gas balance and fuel retention in fusion devices Nucl. Fusion 47 1112-20 Garcia O.E et al 2007 Fluctuations and transport in the TCV scrape-off layer Nucl. Fusion 47 667-76 Zonca F. et al 2007 Electron fishbones: theory and experimental evidence Nucl. Fusion 47 1588-97 Maggi C.F. et al 2007 Characteristics of the H-mode pedestal in improved confinement scenarios in ASDEX Upgrade, DIII-D, JET and JT-60U Nucl. Fusion 47 535-51 Yoshida M. et al 2007 Momentum transport and plasma rotation profile in toroidal direction in JT-60U L-mode plasmas Nucl. Fusion 47 856-63 Zohm H. et al 2007 Control of MHD instabilities by ECCD: ASDEX Upgrade results and implications for ITER Nucl. Fusion 47 228-32 Snyder P.B. et al 2007 Stability and dynamics of the edge pedestal in the low collisionality regime: physics mechanisms for steady-state ELM-free operation Nucl. Fusion 47 961-8 Urano H. et al 2007 H-mode pedestal structure in the variation of toroidal rotation and toroidal field ripple in JT-60U Nucl. Fusion 47 706-13 Günter S. et al 2007 Interaction of energetic particles with large and small scale instabilities Nucl. Fusion 47 920-8

  7. 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.

  8. 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.

  9. 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.

  10. Fusion by Diffusion Model Revisited

    NASA Astrophysics Data System (ADS)

    Cap, T.; Siwek-Wilczyńska, K.; Wilczyński, J.

    A complete set of 27 excitation functions for synthesis of superheavy nuclei produced in cold fusion reactions was analyzed in terms of the "Fusion by Diffusion Model" of Światecki et al., modified to account for the angular momentum dependence of the fusion hindrance factor. The data on cold fusion reactions originate from experiments carried out at GSI Darmstadt, RIKEN Tokyo and LBNL Berkeley in which 208Pb and 209Bi targets were bombarded with the variety of projectiles ranging from 48,50Ti to 70Zn.

  11. 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∗.

  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. 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.

  14. Microwave superheaters for fusion

    NASA Astrophysics Data System (ADS)

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

    1987-10-01

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

  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. Magnetless magnetic fusion

    SciTech Connect

    Beklemishev, A.D. |; Tajima, T.

    1994-02-01

    The authors propose a concept of thermonuclear fusion reactor in which the plasma pressure is balanced by direct gas-wall interaction in a high-pressure vessel. The energy confinement is achieved by means of the self-contained toroidal magnetic configuration sustained by an external current drive or charged fusion products. This field structure causes the plasma pressure to decrease toward the inside of the discharge and thus it should be magnetohydrodynamically stable. The maximum size, temperature and density profiles of the reactor are estimated. An important feature of confinement physics is the thin layer of cold gas at the wall and the adjacent transitional region of dense arc-like plasma. The burning condition is determined by the balance between these nonmagnetized layers and the current-carrying plasma. They suggest several questions for future investigation, such as the thermal stability of the transition layer and the possibility of an effective heating and current drive behind the dense edge plasma. The main advantage of this scheme is the absence of strong external magnets and, consequently, potentially cheaper design and lower energy consumption.

  17. Collaborations in fusion research

    SciTech Connect

    Barnes, D.; Davis, S.; Roney, P.

    1995-01-01

    This paper reviews current experimental collaborative efforts in the fusion community and extrapolates to operational scenarios for the Tokamak Physics Experiment (TPX) and the International Thermonuclear Experimental Reactor (ITER). Current requirements, available technologies and tools, and problems, issues and concerns are discussed. This paper specifically focuses on the issues that apply to experimental operational collaborations. Special requirements for other types of collaborations, such as theoretical or design and construction efforts, will not be addressed. Our current collaborative efforts have been highly successful, even though the tools in use will be viewed as primitive by tomorrow`s standards. An overview of the tools and technologies in today`s collaborations can be found in the first section of this paper. The next generation of fusion devices will not be primarily institutionally based, but will be national (TPX) and international (ITER) in funding, management, operation and in ownership of scientific results. The TPX will present the initial challenge of real-time remotely distributed experimental data analysis for a steady state device. The ITER will present new challenges with the possibility of several remote control rooms all participating in the real-time operation of the experimental device. A view to the future of remote collaborations is provided in the second section of this paper.

  18. Utility requirements for fusion

    SciTech Connect

    Vondrasek, R.J.

    1982-02-01

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

  19. 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.

  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. 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)

  2. 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.

  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. 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.

  5. 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.

  6. Data fusion qualitative sensitivity analysis

    SciTech Connect

    Clayton, E.A.; Lewis, R.E.

    1995-09-01

    Pacific Northwest Laboratory was tasked with testing, debugging, and refining the Hanford Site data fusion workstation (DFW), with the assistance of Coleman Research Corporation (CRC), before delivering the DFW to the environmental restoration client at the Hanford Site. Data fusion is the mathematical combination (or fusion) of disparate data sets into a single interpretation. The data fusion software used in this study was developed by CRC. The data fusion software developed by CRC was initially demonstrated on a data set collected at the Hanford Site where three types of data were combined. These data were (1) seismic reflection, (2) seismic refraction, and (3) depth to geologic horizons. The fused results included a contour map of the top of a low-permeability horizon. This report discusses the results of a sensitivity analysis of data fusion software to variations in its input parameters. The data fusion software developed by CRC has a large number of input parameters that can be varied by the user and that influence the results of data fusion. Many of these parameters are defined as part of the earth model. The earth model is a series of 3-dimensional polynomials with horizontal spatial coordinates as the independent variables and either subsurface layer depth or values of various properties within these layers (e.g., compression wave velocity, resistivity) as the dependent variables.

  7. 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.

  8. 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.

  9. Radioactive wastes from fusion reactors.

    PubMed

    Parkfr, F L

    1968-01-01

    Calculation of the amount of tritium released from a hypothetical fusion reactor shows that it is 2 x 10(5) the amount released by generation of an equivalent amount of electricity by a fission reactor. Release of the tritium generated by a power economy, if the nuclear power were all fusion, would result in unacceptable worldwide dosages by the year 2000. PMID:17737473

  10. 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.

  11. 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.

  12. Role of Sequence and Structure of the Hendra Fusion Protein Fusion Peptide in Membrane Fusion*

    PubMed Central

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

    2012-01-01

    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

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. Soldier systems sensor fusion

    NASA Astrophysics Data System (ADS)

    Brubaker, Kathryne M.

    1998-08-01

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

  2. 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.

  3. 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.

  4. 91039: Magnetic fusion: The DOE fusion energy sciences program

    SciTech Connect

    Rowberg, R.E.

    1997-01-24

    For over 40 years, the U.S. has been trying to harness the energy source of the hydrogen bomb to produce electricity. Controlling fusion, the nuclear reaction that powers the sun, requires confining and heating deuterium and tritium nuclei to the point where they will collide (a D-T reaction) producing nuclear energy in a sustained, regulated way. One path to this goal, called magnetic fusion energy (MFE), is to use very strong magnetic fields to confine a deuterium and tritium plasma while heating it to fusion temperatures. The potential benefits from fusion are enormous. The fuel resources are vast. Radioactive waste would be generated from a D-T reaction, but the long term buildup would be orders of magnitude less than that of a comparable fission reactor.

  5. 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

  6. 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.

  7. 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

  8. 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)

  9. Economic analysis of fusion breeders

    SciTech Connect

    Delene, J.G.

    1985-01-01

    This paper presents a study of the economic performance of Fission/Fusion Hybrid devices. This work takes fusion breeder cost estimates and applies methodology and cost factors used in the fission reactor programs to compare fusion breeders with Liquid Metal Fast Breeder Reactors (LMFBR). The results of the analysis indicate that the Hybrid will be in the same competitive range as proposed LMFBRs and have the potential to provide economically competitive power in a future of rising uranium prices. The sensitivity of the results to variations in key parameters is included.

  10. Fusion materials irradiations at MaRIE's fission fusion facility

    SciTech Connect

    Pitcher, Eric J

    2010-10-06

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

  11. 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.

  12. 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.

  13. 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.

  14. Condensed hydrogen for thermonuclear fusion

    NASA Astrophysics Data System (ADS)

    Kucheyev, S. O.; Hamza, A. V.

    2010-11-01

    Inertial confinement fusion (ICF) power, in either pure fusion or fission-fusion hybrid reactors, is a possible solution for future world's energy demands. Formation of uniform layers of a condensed hydrogen fuel in ICF targets has been a long standing materials physics challenge. Here, we review the progress in this field. After a brief discussion of the major ICF target designs and the basic properties of condensed hydrogens, we review both liquid and solid layering methods, physical mechanisms causing layer nonuniformity, growth of hydrogen single crystals, attempts to prepare amorphous and nanostructured hydrogens, and mechanical deformation behavior. Emphasis is given to current challenges defining future research areas in the field of condensed hydrogens for fusion energy applications.

  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. 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

  17. 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

  18. World progress toward fusion energy

    NASA Astrophysics Data System (ADS)

    Clarke, J. F.

    1989-09-01

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

  19. Mirror fusion test facility status

    NASA Astrophysics Data System (ADS)

    Fowler, T. K.; Thomassen, K. I.

    1981-11-01

    A review of the mirror fusion test facility (MFTF) physics and project status is given. The tandem mirror concept is the leading alternative to the Tokamak magnetic fusion program. Mirror reactors have two advantages: steady state rather than pulsed operation, and a simpler shape, a straight tube as compared with the doughnut shape of the Tokamak. Progress is made in identifying promising configurational improvements and in assessing their impact on the MFTF-B design.

  20. 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.

  1. Cold fusion verification

    NASA Astrophysics Data System (ADS)

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

    1991-03-01

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

  2. Heavy ion fusion sources

    SciTech Connect

    Grote, D.P.; Kwan, J.; Westenskow, G.

    2003-02-01

    In Heavy-Fusion and in other applications, there is a need for high brightness sources with both high current and low emittance. The traditional design with a single monolithic source, while very successful, has significant constraints on it when going to higher currents. With the Child-Langmuir current-density limit, geometric aberration limits, and voltage breakdown limits, the area of the source becomes a high power of the current, A {approx} I{sup 8/3}. We are examining a multi-beamlet source, avoiding the constraints by having many beamlets each with low current and small area. The beamlets are created and initially accelerated separately and then merged to form a single beam. This design offers a number of potential advantages over a monolithic source, such as a smaller transverse footprint, more control over the shaping and aiming of the beam, and more flexibility in the choice of ion sources. A potential drawback, however, is the emittance that results from the merging of the beamlets. We have designed injectors using simulation that have acceptably low emittance and are beginning to examine them experimentally.

  3. 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.

  4. 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)

  5. 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.

  6. Interkingdom gene fusions

    PubMed Central

    Wolf, Yuri I; Kondrashov, Alexey S; Koonin, Eugene V

    2000-01-01

    Background: Genome comparisons have revealed major lateral gene transfer between the three primary kingdoms of life - Bacteria, Archaea, and Eukarya. Another important evolutionary phenomenon involves the evolutionary mobility of protein domains that form versatile multidomain architectures. We were interested in investigating the possibility of a combination of these phenomena, with an invading gene merging with a pre-existing gene in the recipient genome. Results: Complete genomes of fifteen bacteria, four archaea and one eukaryote were searched for interkingdom gene fusions (IKFs); that is, genes coding for proteins that apparently consist of domains originating from different primary kingdoms. Phylogenetic analysis supported 37 cases of IKF, each of which includes a 'native' domain and a horizontally acquired 'alien' domain. IKFs could have evolved via lateral transfer of a gene coding for the alien domain (or a larger protein containing this domain) followed by recombination with a native gene. For several IKFs, this scenario is supported by the presence of a gene coding for a second, stand-alone version of the alien domain in the recipient genome. Among the genomes investigated, the greatest number of IKFs has been detected in Mycobacterium tuberculosis, where they are almost always accompanied by a stand-alone alien domain. For most of the IKF cases detected in other genomes, the stand-alone counterpart is missing. Conclusions: The results of comparative genome analysis show that IKF formation is a real, but relatively rare, evolutionary phenomenon. We hypothesize that IKFs are formed primarily via the proposed two-stage mechanism, but other than in the Actinomycetes, in which IKF generation seems to be an active, ongoing process, most of the stand-alone intermediates have been eliminated, perhaps because of functional redundancy. PMID:11178267

  7. 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.

  8. 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.

  9. 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.

  10. 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 with the International Fusion Materials Irradiation Facility (IFMIF) under discussion at the time. Worldwide technological efforts are maturing soundly and the time for a fusion-relevant neutron source has arrived according to world fusion roadmaps; if decisions are taken we could count the next decade with a powerful source of 14 MeV neutrons thanks to the expected significant results of the Engineering Validation and Engineering Design Activity (EVEDA) phase of the IFMIF project. The accelerator know-how has matured in all possible aspects since the times of FMIT conception in the 1970s; today, operating 125 mA deuteron beam at 40 MeV in CW with high availabilities seems feasible thanks to the understanding of the beam halo physics and the three main technological breakthroughs in accelerator technology: (1) the ECR ion source for light ions developed at Chalk River Laboratories in the early 1990s, (2) the RFQ operation of H+ in CW with 100 mA demonstrated by LEDA in LANL in the late 1990s, and (3) the growing maturity of superconducting resonators for light hadrons and low β beams achieved in recent years.

  11. 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 with the International Fusion Materials Irradiation Facility (IFMIF) under discussion at the time. Worldwide technological efforts are maturing soundly and the time for a fusion-relevant neutron source has arrived according to world fusion roadmaps; if decisions are taken we could count the next decade with a powerful source of 14 MeV neutrons thanks to the expected significant results of the Engineering Validation and Engineering Design Activity (EVEDA) phase of the IFMIF project. The accelerator know-how has matured in all possible aspects since the times of FMIT conception in the 1970s; today, operating 125 mA deuteron beam at 40 MeV in CW with high availabilities seems feasible thanks to the understanding of the beam halo physics and the three main technological breakthroughs in accelerator technology: (1) the ECR ion source for light ions developed at Chalk River Laboratories in the early 1990s, (2) the RFQ operation of H+ in CW with 100 mA demonstrated by LEDA in LANL in the late 1990s, and (3) the growing maturity of superconducting resonators for light hadrons and low β beams achieved in recent years.

  12. 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.

  13. 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.

  14. Fusion under a complex barrier

    NASA Astrophysics Data System (ADS)

    Sahu, Basudeb; Jamir, I.; Lyngdoh, E. F. P.; Shastry, C. S.

    1998-04-01

    The mechanism of fusion of two heavy nuclei is formulated within the concept of transmission across a mildly absorptive effective fusion barrier (EFB). The intensity of transmitted waves across such a barrier could be represented by the product TRPS where TR stands for the transmission coefficient across the corresponding real barrier and PS is a factor of survival probability against absorption under the complex barrier. The justification of this result and the physical basis of the above EFB transmission model of fusion, which is complementary to the definition of fusion based on absorption in the interior region known as the direct reaction model (DRM), are demonstrated in the case of a complex square well potential with a complex rectangular barrier. Based on a WKB approach, expressions for TR for different partial waves utilizing a realistic nucleus-nucleus potential are derived. Using the resulting expressions for the fusion cross section (?F), the experimental values of ?F and the corresponding data of the average angular momentum of the fused body are explained satisfactorily over a wide range of energy around the Coulomb barrier in various heavy ion systems such as 16O+152,154Sm, 58,64Ni+58,64Ni, 64Ni+92Zr, and 64Ni+100Mo.

  15. 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, Austria References [1] Sabbagh S. et al 2006 Nucl. Fusion 46 635-44 [2] Rice J.E. et al 2007 Nucl. Fusion 47 1618-24

  16. Hot fusion or cold fusion, best route to the SHEs?

    NASA Astrophysics Data System (ADS)

    Loveland, Walter

    2010-02-01

    Elements 102-113 have been synthesized using cold fusion reactions (Pb or Bi target nuclei, massive projectiles., E*=13 MeV, high survival probabilities,significant fusion hindrance). The production cross sections decrease with increasing ZCN with a cross section of 27 fb being measured for element 113. Synthesis of elements 102-108 by hot fusion reactions (actinide target nuclei, intermediate mass projectiles, E*=30-50 MeV, low survival probability, small fusion hindrance) shows decreasing production cross sections for Z=102 to Z=108 and then the cross sections level out at a few pb out to Z=118. Upper limit cross sections for the production of Z=120 nuclei in hot fusion reactions are ˜ 0.1 pb. How should one go forward to make nuclei with Z > 120 or with large neutron numbers, N ˜ 184? The cross section for the production of an evaporation residue, σEVR, is σEVR=σCNWsur where σCN is the complete fusion cross section and Wsur is the survival probability of the completely fused system. The complete fusion cross section can be written as σCN=∑J=0^J σcapture (Ec.m.,J)PCN( Ec.m.,J) where σcapture(Ec.m.,J) is the capture cross section and PCN is the probability that the projectile-target system will evolve inside the fission saddle point to form a completely fused system rather than reseparating (quasifission). I have used this formalism to make estimates of the best reactions to make new heavy nuclei using stable and radioactive beams. I conclude that stable beams offer the best opportunities to make new chemical elements and that radioactive beams offer new opportunities to make nuclei to study the atomic physics and chemistry of the heaviest elements. The radioactive beam reactions involve the light neutron-rich projectiles interacting in hot fusion reactions. If time permits I will also discuss recent experiments to make heavy nuclei using multi-nucleon transfer reactions. )

  17. [Fusion tags technology and their applications].

    PubMed

    Li, Yong-Jin; Chen, Yuan-Yuan; Bi, Li-Jun

    2006-07-01

    Fusion tags are originally developed to facilitate the purification of recombinant protein from crude extracts. In recent years, the discovery of different tags and the development of fusion strategy make the function of fusion tags diversified. However, there was no a cure-all fusion tag for different applications. We here give an overview of fusion tag technology and the different applications of fusion tags, including the purification, detection and oriented immobilization of recombinant protein, the visualization of bioevent in vivo, the enhancement of the yield of protein, the improvement of the solubility and stability of the expressed protein. PMID:16894881

  18. 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.

  19. 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.

  20. 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.

  1. Fusion: Power for the future

    NASA Astrophysics Data System (ADS)

    Webster, Anthony J.

    2003-03-01

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

  2. 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.

  3. (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.

  4. 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

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. Structural materials for fusion reactors

    NASA Astrophysics Data System (ADS)

    Victoria, M.; Baluc, N.; Sptig, P.

    2001-08-01

    In order to preserve the conditions for an environmentally safe machine, at present the selection of materials for the structural components of fusion reactors is made not only on the basis of adequate mechanical properties, behaviour under irradiation, and compatibility with other materials and cooling media, but also on their radiological properties, i.e. radioactivity, decay heat and radiotoxicity. These conditions strongly limit the number of suitable materials to a few families of alloys, generically known as low activation materials. The criteria for making decisions about such materials, the alloys resulting from the application of these ideas and the main issues and problems with their use in a fusion environment are discussed.

  11. 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.

  12. Electromagnetic computations for fusion devices

    SciTech Connect

    Turner, L.R.

    1989-09-01

    Among the difficulties in making nuclear fusion a useful energy source, two important ones are producing the magnetic fields needed to drive and confine the plasma, and controlling the eddy currents induced in electrically conducting components by changing fields. All over the world, researchers are developing electromagnetic codes and employing them to compute electromagnetic effects. Ferromagnetic components of a fusion reactor introduce field distortions. Eddy currents are induced in the vacuum vessel, blanket and other torus components of a tokamak when the plasma current disrupts. These eddy currents lead to large forces, and 3-D codes are being developed to study the currents and forces. 35 refs., 6 figs.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. Generic magnetic fusion reactor cost assessment

    SciTech Connect

    Sheffield, J.

    1984-01-01

    A generic D-T burning magnetic fusion reactor model shows that within the constraints set by generic limitations it is possible for magnetic fusion to be a competitive source of electricity in the 21st century.

  18. 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.

  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. 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.

  1. 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

  2. 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.

  3. Magnetic fusion and project ITER

    SciTech Connect

    Park, H.K.

    1992-01-01

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

  4. Magnetic fusion and project ITER

    SciTech Connect

    Park, H.K.

    1992-09-01

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

  5. Inertial confinement fusion (ICF) review

    SciTech Connect

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

    1996-03-01

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

  6. Power Exhaust in Fusion Plasmas

    NASA Astrophysics Data System (ADS)

    Fundamenski, Wojciech

    2014-07-01

    Preface; 1. Introduction; 2. Magnetized plasma physics; 3. Magnetized plasma equilibrium; 4. Magnetized plasma stability; 5. Collisional transport in magnetized plasmas; 6. Turbulent transport in magnetized plasmas; 7. Tokamak plasma boundary and power exhaust; 8. Outlook: power exhaust in fusion reactors; Appendix A. Maxwellian distribution; Appendix B. Curvilinear co-ordinates; References; Index.

  7. Theoretical atomic physics for fusion

    SciTech Connect

    Pindzola, M.S.

    1992-01-01

    The understanding of electron-ion collision processes in high temperature plasmas remains a key factor in the ultimate development of nuclear fusion as a viable energy source for the nation. Our 1990--1992 research proposal delineated 3 main areas of research in electron-ion scattering theory. Summaries our 1992 efforts in each of these research areas are presented.

  8. Proton Collimators for Fusion Reactors

    NASA Technical Reports Server (NTRS)

    Miley, George H.; Momota, Hiromu

    2003-01-01

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

  9. 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

  10. Virtual experiment of pyroelectric fusion

    NASA Astrophysics Data System (ADS)

    Nasseri, Mohammad Mehdi

    2015-11-01

    The virtual experiment of pyroelectric fusion was conducted by Geant4 simulator. Despite the limitations of the code for simulating the pyroelectric fusion experiment precisely, the following interesting results were obtained. Two crystals were separated by a certain distance. A constant electric field with varying intensities was applied between the crystals. As initial particles, deuterium ions were emitted to deuterated polypropylene (CD2). This virtual experiment showed that the number of ions that hit the target, for different distances between the crystals, increases with the increase of the intensity of the electric field; however, further increase of the electric field results in the reduction of the number of hit ions, which attains a constant value of about 57% of the initial number of ions. For a (D, D) fusion reaction to occur, the distance between the two crystals should be <1.5 cm and for a (D, T) fusion reaction to occur, this distance could be up to 2 cm. The energy spectra of ions for low and high electric fields were narrow and long and wide and short, respectively.

  11. Tritium breeding in fusion reactors

    SciTech Connect

    Abdou, M.A.

    1982-10-01

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

  12. 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.

  13. 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.

  14. 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.

  15. 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 sections over a wider energy range for many more reactions is desired for accurate determination of and more insight into the dynamics of fusion in the heavy mass region.

  16. 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 of mapping methods of magnetic field lines, 3D-plasma transport modelling efforts of ergodized plasmas and island divertors, and on the penetration of the external field including the resulting force transfer. We hope that the article series in Nuclear Fusion will stimulate interest in this fascinating subject of plasma physics.

  17. 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 toroids called Field-Reversed Configurations. As reported earlier, it appears that the existing pulsed-power Shiva Star facility at the Air Force Research Laboratory in Albuquerque, NM can satisfy the heating requirements by means of imploding a thin metal cylinder (called a "liner") surrounding an FRC of the type presently being developed. The proposed next step is an integrated liner-on-plasma experiment in which an FRC would be heated to 10 keV by the imploding liner.

  18. 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.

  19. 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.

  20. Review of Japanese fusion program and role of inertial fusion

    NASA Astrophysics Data System (ADS)

    Motojima, O.

    2007-08-01

    The high compression of 600 times liquid density and the recent fast heating of a compressed core to 1-keV temperature have provided proof-of-principle of the fast ignition concept, and these results have significantly contributed to approve first phase of the Fast Ignition Realization EXperiment (FIREX) project. The goal of FIREX-I is to demonstrate fast heating of a fusion fuel up to the ignition temperature of 5-10 keV. Although the fuel size of FIREX-I is too small to ignite, sufficient heating will provide the scientific viability of ignition-and-burn by increasing the laser energy thereby the fuel size. Based on the result of FIREX-I, the decision of the start of FIREX-II to achieve ignition-and-burn can be made. The FIREX program is under the collaboration of the Institute of Laser Engineering and the National Institute for Fusion Science.

  1. Rabies virus-induced membrane fusion pathway.

    PubMed

    Gaudin, Y

    2000-08-01

    Fusion of rabies virus with membranes is triggered at low pH and is mediated by the viral glycoprotein (G). The rabies virus-induced fusion pathway was studied by investigating the effects of exogenous lipids having various dynamic molecular shapes on the fusion process. Inverted cone-shaped lysophosphatidylcholines (LPCs) blocked fusion at a stage subsequent to fusion peptide insertion into the target membrane. Consistent with the stalk-hypothesis, LPC with shorter alkyl chains inhibited fusion at lower membrane concentrations and this inhibition was compensated by the presence of oleic acid. However, under suboptimal fusion conditions, short chain LPCs, which were translocated in the inner leaflet of the membranes, considerably reduced the lag time preceding membrane merging, resulting in faster kinetics of fusion. This indicated that the rate limiting step for fusion is the formation of a fusion pore in a diaphragm of restricted hemifusion. The previously described cold-stabilized prefusion complex was also characterized. This intermediate is at a well-advanced stage of the fusion process when the hemifusion diaphragm is destabilized, but lipid mixing is still restricted, probably by a ring-like complex of glycoproteins. I provide evidence that this state has a dynamic character and that its lipid organization can reverse back to two lipid bilayers. PMID:10931871

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Probabilistic fusion of ATR results

    SciTech Connect

    Simonson, K.M.

    1998-08-01

    The problem of combining multi-source information in applications related to automatic target recognition (ATR) is addressed. A mathematical approach is proposed for fusing the (possibly dependent) outputs of multiple ATR systems or algorithms. The method is derived from statistical principles, and the fused decision takes the form of an hypothesis test. The distribution of the test statistic is approximated as gamma, with parameters estimated from available training data. In a brief simulation study, the proposed method outperforms several alternative fusion techniques.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. National mirror fusion program plan

    SciTech Connect

    Not Available

    1980-01-01

    Experiments are under way in the Tandem Mirror Experiment (TMX) facility at Livermore, which was built to test the principles of the new tandem-mirror concept. Recently this idea has been greatly improved by incorporating a new element called the thermal barrier, a concept that promises a higher power gain factor (Q = 10 to 20) with much less demanding neutral-beam and magnet technology and a higher fusion power density in the reactor. In addition to the tandem-mirror experiments in TMX, a new attempt will be made in the Beta II facility during FY 1980 to create and sustain a field-reversed mirror configuration, which is a different mirror fusion approach that could lead to early commercialization of small reactors. The plan presented here is designed to exploit the results of these and other mirror experiments and theoretical developments toward a variety of applications. The main objective is electric power generation. Other applications being studied include a hybrid fusion reactor that breeds fuel for fission reactors and a reactor for producing synthetic fuel (H/sub 2/) by means of thermochemical processes.

  20. 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.

  1. 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.

  2. 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. .

  3. 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

  4. Pharmacokinetics of Recombinant Bifunctional Fusion Proteins

    PubMed Central

    Chen, Xiaoying; Zaro, Jennica L.; Shen, Wei-Chiang

    2013-01-01

    Introduction The development of biotechnology has enabled the creation of various recombinant fusion proteins as a new class of biotherapeutics. The uniqueness of fusion proteins lies in their ability to fuse two or more protein domains, providing vast opportunities to generate novel combinations of functions. Pharmacokinetic (PK) studies, which are critical components in preclinical and clinical drug development, have not been fully explored for fusion proteins. The lack of general PK models and study guidelines has become a bottleneck for translation of fusion proteins from basic research to the clinic. Areas covered This article reviews the current status of PK studies for fusion proteins, covering the processes that affect PK. According to their PK properties, a classification of fusion proteins is suggested along with examples from the clinic or under development. Current limitations and future perspectives for PK of fusion proteins are also discussed. Expert opinion A PK model for bifunctional fusion proteins is presented to highlight the importance of mechanistic studies for a thorough understanding of the PK properties of fusion proteins. The model suggests investigating the receptor binding and subsequent intracellular disposition of individual domains, which can have dramatic impact on the PK of fusion proteins. PMID:22428984

  5. Polyetheretherketone as a biomaterial for spinal applications.

    PubMed

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

    2006-01-01

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

  6. 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).

  7. 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 are steels for the first wall and other structurals, copper alloys for the heat sink, and beryllium for facing the plasma. For the TBMs, the materials that need to be developed include beryllium and/or beryllium-titanium alloys for neutron multiplication, lithium-bearing compounds for tritium generation, and the liquid metal coolants like lead-lithium eutectic in which lead acts as a neutron multiplier and lithium as a tritium breeder. The other materials that need attention of the materials scientists include superconductors made of NbTi, Nb3Sn and Nb3Al for the tokamaks, coatings or ceramic inserts to offset the effect of corrosion and the MHD in liquid metal cooled TBMs, and a host of other materials like nano-structured materials, special adhesives and numerous other alloys and compounds. Apart from this, the construction of the tokamaks would necessitate development of methodologies of joining the selected materials. This presentation would deal with the issues related to the development, characterization and qualification of both the structural as well as the functional materials required to carry forward the challenging task of harnessing fusion energy for use of mankind in engineered systems.

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

    NASA Astrophysics Data System (ADS)

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

    2015-07-01

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

  9. Paramyxovirus fusion: Real-time measurement of parainfluenza virus 5 virus-cell fusion

    SciTech Connect

    Connolly, Sarah A.; Lamb, Robert A. . E-mail: ralamb@northwestern.edu

    2006-11-25

    Although cell-cell fusion assays are useful surrogate methods for studying virus fusion, differences between cell-cell and virus-cell fusion exist. To examine paramyxovirus fusion in real time, we labeled viruses with fluorescent lipid probes and monitored virus-cell fusion by fluorimetry. Two parainfluenza virus 5 (PIV5) isolates (W3A and SER) and PIV5 containing mutations within the fusion protein (F) were studied. Fusion was specific and temperature-dependent. Compared to many low pH-dependent viruses, the kinetics of PIV5 fusion was slow, approaching completion within several minutes. As predicted from cell-cell fusion assays, virus containing an F protein with an extended cytoplasmic tail (rSV5 F551) had reduced fusion compared to wild-type virus (W3A). In contrast, virus-cell fusion for SER occurred at near wild-type levels, despite the fact that this isolate exhibits a severely reduced cell-cell fusion phenotype. These results support the notion that virus-cell and cell-cell fusion have significant differences.

  10. 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 of Dr Todd Evans, another significant mentor of mine, as winner of this prestigious award? Then, it happened. The paper covers several key topics related to high beta tokamak physics. For me, the greatest satisfaction in receiving this award is because it was the first Nuclear Fusion Award to recognize research on the National Spherical Torus Experiment (NSTX) located at the Princeton Plasma Physics Laboratory. The achievement of record stability parameters in a mega-Ampere class spherical torus (ST) device reported in the paper represents a multi-year effort, contributed to by the entire research team. Research to maintain such plasmas for an indefinite period continues today. Understanding RWM stabilization physics is crucial for this goal, and leveraging the high beta ST operating space uniquely tests theory for application to future STs and to tokamaks in general, including advanced operational scenarios of ITER. For instance, the RWM was found to have significant amplitude in components with the toroidal mode number greater than unity. This has important implications for general active RWM control. Evidence that the RWM passive stabilization physics and marginal stability criterion are indeed more complex than originally thought was shown in this paper. Present work shows the greater complexity has a direct impact on how we should extrapolate RWM stabilization to future devices. The paper also reported the qualitative observation of neoclassical toroidal viscosity (NTV), followed by a companion paper by our group in 2006 reporting the quantitative observation of this effect and comparison to theory. The physics of this interesting and important phenomenon was introduced to me by Professor J. Callen (who has given an overview talk at this conference including this subject) and Professor Kerchung Shaing of the University of Wisconsin, to whom I am quite indebted. The paper also reported the first measurement of resonant field amplification at high beta in the NSTX, following work of the Columbia University group at DIII-D during that period. My greatest hope in our stability physics research effort is that our insight in this portion of the much larger research effort, of which we all partake, to make fusion reactors a practical reality, will give new and future researchers the input and motivation to amplify our work and create realities that we had thought were just out of reach. Receiving the 2009 IAEA Nuclear Fusion Award is a substantial honor that greatly motivates me to continue to support the international nuclear fusion research effort at the highest level possible. So, please allow me to raise this beautiful trophy high, here today, to best remember this fine honor. Thank you. Steven Anthony Sabbagh 2009 Nuclear Fusion Award winner Columbia University, New York, NY, USA

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. 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.

  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. 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 est