Abstract:
STUDY DESIGN:The pretension of the Dynesys cord was varied to evaluate its effects on both tissue responses and screw-spacer behaviors by the finite-element method. OBJECTIVE:This study aimed to provide detailed information about the motion-preserving and load-shielding mechanisms of the Dynesys screw-spacer joint. SUMMARY OF BACKGROUND DATA:Intuitively, higher cord pretension aims to ensure the occurrence of screw-spacer contact, thus making the spacer the transmitter of the vertebral loads. However, detailed investigations of the cord-pretension effects have not yet been carried out. METHODS.: Using a validated lumbosacral model, the moderately degenerative L4-L5 segment was instrumented by a static fixator and the Dynesys fixator was further used to bridge a mildly degenerative L3-L4 segment. The pre-tended cord was modeled as an elastic spring with 0- and 300-N pretensions. The disc range-of-motion, disc stress, facet force, bone-screw stress, and screw-spacer force were chosen as comparison indices. RESULTS.: At the transition and adjacent segments, the range-of-motion differences between the 2 pretensions were 7.7% and 2.0% on average, respectively. The mechanical differences at the transition and adjacent segments were 9.0% and 5.2% (disc stress) and 9.4% and 9.1% (facet force), respectively. The results indicated that the cord pretension has a minor effect on the adjacent segments in comparison with the transition segment. However, the stress at the screw hub and force of the screw-spacer contact of the 300-N pretension were increased by 33.7% and 316.5% on average than without pretension, respectively. CONCLUSION:The moment arm from the screw-cord center to the fulcrum is significantly less than that of vertebral loads. This leads to the minor effect of increasing the cord pretension on the responses of the adjacent segments. However, the cord pretension can significantly affect both screw-spacer force and bone-screw stress. LEVEL OF EVIDENCE:4.
journal_name
Spine (Phila Pa 1976)journal_title
Spineauthors
Chien CY,Tan CH,Lu TH,Lin SC,Chuang WH,Chiang MC,Luh YP,Chen YJdoi
10.1097/BRS.0b013e318290fb2esubject
Has Abstractpub_date
2013-06-01 00:00:00pages
E775-82issue
13eissn
0362-2436issn
1528-1159journal_volume
38pub_type
杂志文章相关文献
SPINE文献大全abstract:STUDY DESIGN:Prospective cohort study of randomly selected Veterans Affairs out-patients without baseline low back pain (LBP). OBJECTIVE:To determine predictors of new LBP as well as the 3-year incidence of magnetic resonance imaging (MRI) findings. SUMMARY OF BACKGROUND DATA:Few prospective studies have examined cli...
journal_title:Spine
pub_type: 杂志文章
doi:10.1097/01.brs.0000167536.60002.87
更新日期:2005-07-01 00:00:00
abstract:STUDY DESIGN:A prospective, randomized clinical study comparing beta-tricalcium phosphate (beta-TCP) with autograft bone graft with follow-up of 3 years. OBJECTIVE:To determine the efficacy of beta-TCP as a bone graft substitute combined with local autograft obtained from decompression compared with the use of autolog...
journal_title:Spine
pub_type: 杂志文章,随机对照试验
doi:10.1097/BRS.0b013e3181732a8e
更新日期:2008-05-20 00:00:00
abstract::A retrospective study was done to determine the entire clinical spectrum of lumbar spine disease in 47 adult patients, averaging 27.6 years of age, with achondroplasia. Five distinct clinical categories were defined. Twenty-eight percent of the patients were asymptomatic; 28% had only mechanical or degenerative lumbar...
journal_title:Spine
pub_type: 杂志文章
doi:10.1097/00007632-198203000-00008
更新日期:1982-03-01 00:00:00
abstract:STUDY DESIGN:A retrospective analysis. OBJECTIVE:To evaluate the long-term clinical and radiographic outcomes and to investigate who achieved the successful outcomes after lumbar total disc replacement (TDR) using ProDisc II. SUMMARY OF BACKGROUND DATA:There are few evidences regarding the long-term efficacy and safe...
journal_title:Spine
pub_type: 杂志文章
doi:10.1097/BRS.0000000000001527
更新日期:2016-06-01 00:00:00
abstract:STUDY DESIGN:We measured the expression and responses of Toll-Like Receptor 4 (TLR4) activation in the intervertebral disc (IVD) in vitro and in vivo. We hypothesize that stimulation of the IVD with the TLR4 ligand lipopolysaccharide (LPS) results in upregulation of a coordinated set of proinflammatory mediators and in...
journal_title:Spine
pub_type: 杂志文章
doi:10.1097/BRS.0b013e31826b71f4
更新日期:2013-07-15 00:00:00
abstract:STUDY DESIGN:We measured the cross-sectional area of the intervertebral discs of normal volunteers after an overnight rest; before, during, and after 5 or 17 weeks of bed rest; and before and after 8 days of weightlessness. OBJECTIVES:This study sought to determine the degree of expansion of the lumbar discs resulting...
journal_title:Spine
pub_type: 杂志文章
doi:10.1097/00007632-199404000-00015
更新日期:1994-04-01 00:00:00
abstract:STUDY DESIGN:In vitro accuracy assessment of a novel virtual fluoroscopy system. OBJECTIVES:To investigate a new technology combining image-guided surgery with C-arm fluoroscopy. SUMMARY OF BACKGROUND DATA:Fluoroscopy is a useful and familiar technology to all musculoskeletal surgeons. Its limitations include radiati...
journal_title:Spine
pub_type: 杂志文章
doi:10.1097/00007632-200102150-00009
更新日期:2001-02-15 00:00:00
abstract:STUDY DESIGN:Retrospective clinical study. OBJECTIVE:The aim of this study was to examine whether the Tokuhashi score correlates with the neurologic outcome in early surgical treatment in metastatic spinal cord compression (MSCC). A retrospective analysis of 35 consecutive incomplete tetraplegic and paraplegic patient...
journal_title:Spine
pub_type: 杂志文章
doi:10.1097/BRS.0b013e318188b98f
更新日期:2008-11-15 00:00:00
abstract::Sixty-six consecutive patients with adolescent idiopathic scoliosis treated by posterior spinal fusion using Harrington distraction compression instrumentation were followed for a minimum of 3 years. Initial surgical correction was satisfactory, but during the follow-up period, mean 4.4 years (3-5 years), there was a ...
journal_title:Spine
pub_type: 杂志文章
doi:
更新日期:1990-08-01 00:00:00
abstract:STUDY DESIGN:Observational study. OBJECTIVE:To evaluate the publication rate of podium presentations from the Cervical Spine Research Society (CSRS) annual meeting and to evaluate the publication rate of award-winning papers from the CSRS annual meeting. SUMMARY OF BACKGROUND DATA:Although various publication rates f...
journal_title:Spine
pub_type: 杂志文章
doi:10.1097/BRS.0000000000000838
更新日期:2015-05-15 00:00:00
abstract:STUDY DESIGN:A report of a patient in whom progressive symptomatic thoracolumbar scoliosis developed after breast reconstruction with a latissimus dorsi myocutaneous flap. OBJECTIVES:To present the first reported case of progressive symptomatic scoliosis after breast reconstruction with a latissimus dorsi myocutaneous...
journal_title:Spine
pub_type: 杂志文章
doi:10.1097/00007632-200003010-00014
更新日期:2000-03-01 00:00:00
abstract:STUDY DESIGN:A retrospective study to analyze the effect of decompressive extent on the posterior shift of spinal cord after expansive open-door laminoplasty (ELAP). OBJECTIVE:To investigate the effect of decompressive extent on cord shift distance after ELAP, and determine the morphologic limitations of posterior app...
journal_title:Spine
pub_type: 杂志文章,多中心研究
doi:10.1097/BRS.0b013e3181e80507
更新日期:2011-06-01 00:00:00
abstract:STUDY DESIGN:Effectiveness of a pre-employment worker fitness evaluation in a sample of grocery warehouse order selectors was studied retrospectively. Implementation of the program began in March 1990 and as of September 10, 1993, 1100 prospective employees have been tested. OBJECTIVES:Identification of prospective em...
journal_title:Spine
pub_type: 杂志文章
doi:10.1097/00007632-199409150-00001
更新日期:1994-09-15 00:00:00
abstract::An anatomic study of lumbar nerve root lesions in the foraminal zone was performed on 35 cadavers. Two morphologic abnormalities of the nerve roots in the intervertebral foramen were found. The first was an abnormal transverse course of the nerve roots. The second was an indentation on the dorsal root ganglia caused b...
journal_title:Spine
pub_type: 杂志文章
doi:10.1097/00007632-199311000-00017
更新日期:1993-11-01 00:00:00
abstract:STUDY DESIGN:An in vivo rat-tail model was adopted to study the structural changes of degenerated intervertebral disc after different traction protocols. OBJECTIVE:To investigate the effects of traction with different modes and magnitudes on disc with simulated degeneration. SUMMARY OF BACKGROUND DATA:Traction has be...
journal_title:Spine
pub_type: 杂志文章
doi:10.1097/BRS.0b013e3181c617f6
更新日期:2010-06-15 00:00:00
abstract::The outcome of spinal cord injury depends on the extent of secondary damage produced by a series of cellular and molecular events initiated by the primary trauma. This article reviews the evidence that secondary spinal cord injury involves the apoptotic as well as necrotic death of neurons and glial cells. Also discus...
journal_title:Spine
pub_type: 杂志文章,评审
doi:10.1097/00007632-200007150-00022
更新日期:2000-07-15 00:00:00
abstract:STUDY DESIGN:Multicenter review of prospectively collected data. OBJECTIVE:The purpose of this study was to evaluate the incidence of distal adding-on and associated risk factors in each of the 2 Lenke 1A curve patterns. SUMMARY OF BACKGROUND DATA:Previous work has demonstrated 2 distinct Lenke 1A curve patterns on t...
journal_title:Spine
pub_type: 杂志文章,多中心研究
doi:10.1097/BRS.0b013e31824bac7a
更新日期:2012-07-15 00:00:00
abstract:STUDY DESIGN:Case report of a solitary osteochondroma of the cervical spine causing myelopathy in a 66-year-old woman. OBJECTIVES:To review the relevant literature and describe a highly unusual clinical manifestation of solitary osteochondroma. SUMMARY OF BACKGROUND DATA:Osteochondromas are common benign bony lesions...
journal_title:Spine
pub_type: 杂志文章,评审
doi:10.1097/00007632-200005150-00017
更新日期:2000-05-15 00:00:00
abstract:STUDY DESIGN:Prospective randomized study to compare the efficacy of facet joint injection with lidocaine and facet joint injection with saline in two groups of patients with low back pain, with and without clinical criteria that were determined in a previous study to implicate the facet joint as the primary source of ...
journal_title:Spine
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1097/00007632-199809150-00011
更新日期:1998-09-15 00:00:00
abstract:STUDY DESIGN:A retrospective radiographic and chart review of patients who underwent computed tomography with three-dimensional reconstructions before single stage anterior and posterior hemivertebra excision. OBJECTIVE:To assess the efficacy of three-dimensional computed tomography reconstructions in accurately ident...
journal_title:Spine
pub_type: 杂志文章
doi:10.1097/01.BRS.0000092382.80487.F0
更新日期:2003-11-15 00:00:00
abstract:STUDY DESIGN:Retrospective analysis of a prospective registry. OBJECTIVE:We utilized the Quality Outcomes Database (QOD) registry to investigate the "July Effect" at QOD spondylolisthesis module sites with residency trainees. SUMMARY OF BACKGROUND DATA:There is a paucity of investigation on the long-term outcomes fol...
journal_title:Spine
pub_type: 杂志文章
doi:10.1097/BRS.0000000000003903
更新日期:2020-12-24 00:00:00
abstract:STUDY DESIGN:In vitro human cadaveric study simultaneously quantifying sagittal plane flexibility and spinal canal stenosis. OBJECTIVE:To compare biomechanical stability and the change in cross-sectional area during flexion and extension after laminectomy and open-door laminoplasty. SUMMARY OF BACKGROUND DATA:Spinal ...
journal_title:Spine
pub_type: 杂志文章
doi:10.1097/BRS.0b013e3181aa0214
更新日期:2009-07-15 00:00:00
abstract:STUDY DESIGN:Animal model study of three healthy commercial pigs was conducted. OBJECTIVE:To determine whether near infrared spectroscopic monitoring of the spinal cord is feasible, and whether changes in near infrared spectroscopy correlate with changes in blood flow to the cord or operative maneuvers. SUMMARY OF BA...
journal_title:Spine
pub_type: 杂志文章
doi:10.1097/00007632-200201010-00007
更新日期:2002-01-01 00:00:00
abstract:STUDY DESIGN:A biomechanical study was designed to assess implant cut-out of three different angular stable anterior spinal implants. Subsidence of the implant relative to the vertebral body was measured during an in vitro cyclic loading test. OBJECTIVES:The objective of the study was to evaluate two prototypes (Synth...
journal_title:Spine
pub_type: 杂志文章
doi:10.1097/01.brs.0000199894.63450.70
更新日期:2006-02-15 00:00:00
abstract:STUDY DESIGN:A cross-sectional survey among health professionals working in a Kuwait hospital. OBJECTIVE:To investigate the prevalence and factors associated with low back pain (LBP). SUMMARY OF BACKGROUND DATA:The literature suggests that health professionals are exposed to occupational risk factors that predispose ...
journal_title:Spine
pub_type: 杂志文章
doi:10.1097/BRS.0b013e3181657df7
更新日期:2008-03-01 00:00:00
abstract:STUDY DESIGN:A biomechanical study of the compressive creep behavior of the human intervertebral disc before and after frozen storage. OBJECTIVES:To determine whether frozen storage alters the time-dependent response of the intact human intervertebral disc. SUMMARY OF BACKGROUND DATA:The biomechanical properties of t...
journal_title:Spine
pub_type: 杂志文章
doi:10.1097/00007632-200104150-00011
更新日期:2001-04-15 00:00:00
abstract:STUDY DESIGN:Retrospective review of medical records. OBJECTIVE:To describe pre- and postoperative ambulatory status and lower limb motor power, and compare characteristics of patients with metastatic spinal cord compression (MSCC) who were ambulatory at 48 hours postoperatively with those of patients with MSCC who we...
journal_title:Spine
pub_type: 杂志文章
doi:10.1097/BRS.0b013e3182927559
更新日期:2013-06-01 00:00:00
abstract:STUDY DESIGN:An experimental animal study. OBJECTIVE:To investigate the relationship between pain-related behavior and the expression of neurotrophic factors in the dorsal root ganglion (DRG) and spinal cord (SC) using a nucleus pulposus (NP) rat model. SUMMARY OF BACKGROUND DATA:Neurotrophic factors are released fro...
journal_title:Spine
pub_type: 杂志文章
doi:10.1097/BRS.0000000000002223
更新日期:2018-01-01 00:00:00
abstract:STUDY DESIGN:Observational cohort study. OBJECTIVE:To determine the accuracy of the Revised Cardiac Risk Index (RCRI) in predicting major adverse cardiac events in patients undergoing spine fusion surgery of 3 levels or more. SUMMARY OF BACKGROUND DATA:Preoperative cardiac testing is extensively guided by the RCRI, w...
journal_title:Spine
pub_type: 杂志文章
doi:10.1097/BRS.0000000000000405
更新日期:2014-08-01 00:00:00
abstract:STUDY DESIGN:An experimental model of spinal cord injury (SCI) intended to characterize changes in renal function. OBJECTIVE:The aim of this study was to evaluate the possible influence of SCI level on renal function during spinal shock. SUMMARY OF BACKGROUND DATA:SCI triggers multiple systemic and metabolic alterati...
journal_title:Spine
pub_type: 杂志文章
doi:10.1097/BRS.0000000000002578
更新日期:2018-08-01 00:00:00