Outcome of fractures of dorso lumbar spine treated by short segment posterior stabilization with intermediate pedicle screws

Background: Spine fractures are common in today’s world due to high frequency of motor vehicle accidents and work place injuries. These are major cause of disability in adult population. The mortality rate following spinal injuries is 7%. The aim of the study was to study the functional and radiological outcome of fractures of dorso lumbar spine treated by short segment posterior stabilization with intermediate pedicle screws.Methods: Dorso-lumbar fractures with intact pedicle on the fractured segment, Load sharing classification score of equal or less than 6, Neurologic involvement caused by the fracture, loss of vertebral body height by more than 50% and kyphosis angle more than 20° are included. Patients with multiple level fractures and pathological fractures were excluded from the study. Denis classification and AO classification were used. Load sharing score is used to decision making for intermediate screw fixation.Results: L1 is more frequently fractured followed by D12. Distraction type (AO) and burst (Denis) are most common types. 4 of our patients had complete neurological deficit. 15 had incomplete deficit and 11 patients doesn’t have any neurological involvement. Frankel A grade cases remained in the same grade. Mean Kyphotic correction is 6.7°. Mean AVBCP in the postoperative cases 26. None of the cases developed kyphosis or loss of correction in the follow up. Outcome using Roland Morris disability questionnaire is excellent in 64.3%, good in 21.6% and poor in 14.3% cases.Conclusions: To conclude that short segment posterior stabilisation with intermediate screws provides better biomechanical stability when compared with conventional short segment fixation.

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Is It Necessary to Reduce Thoracolumbar Compression Fractures with Intermediate Screws in the Fractured Vertebra?

10.21203/rs.3.rs-542387/v1 ◽

2021 ◽

Author(s):

ZeJun Xing ◽

Shuai Hao ◽

XiaoFei Wu

Keyword(s):

Blood Loss ◽

Body Height ◽

Pedicle Screws ◽

Operation Time ◽

Short Segment ◽

Compression Fractures ◽

Significant Difference ◽

Before And After ◽

Screw Group

Abstract PurposeTo compare the efficacy and safety of percutaneous short-segment pedicle screws fixation (PPSF) with or without intermediate screws (IS) for the treatment of thoracolumbar compression fractures.MethodsFrom January 2016 to March 2019, a retrospective study of 38 patients with thoracolumbar compression fractures conducted. The patients were divided into a 4-screw group (without IS) and a 6-screw group (with IS) according to whether pedicle screws were placed in the fractured vertebrae. Combined positional reduction effects with the technique of pre-contoured lordotic rods were used to reduce the fracture by lengthening the anterior column of the fractured vertebrae. The posterior structure of the fractured vertebrae was undertaken as the fulcrum point for both groups. The operation time, intra-operative blood loss, visual analogue scale (VAS), anterior vertebral body height (AVBH), segment kyphosis（SK）before and after operation and complications were recorded.ResultsAlthough the operation time and blood loss in the 6-screw group were higher than in the 4-screw group, difference was not significant (P＞0.05). There was no significant difference in VAS, AVBH and SK between the two groups (P＞0.05). Nevertheless, these results were significant differences between the preoperative and the immediate postoperative, between preoperative and follow-up groups (P < 0.001). No neurologic injury was observed in either groups. ConclusionsIn the treatment of thoracolumbar compression fractures, percutaneous short-segment pedicle screws fixation without intermediate screws in the 4-screw construct may obtain the same clinical effect as that in the 6-screw construct.

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Early Clinical Results of Short Same-Segment Posterior Fixation in Thoracolumbar Burst Fractures

Ortopedia Traumatologia Rehabilitacja ◽

10.5604/01.3001.0012.2129 ◽

2018 ◽

Vol 20 (3) ◽

pp. 211-217 ◽

Cited By ~ 1

Author(s):

Misbah Mehraj ◽

Farid H. Malik

Keyword(s):

Lumbar Spine ◽

Sagittal Plane ◽

Posterior Instrumentation ◽

Body Height ◽

Posterior Fixation ◽

Spine Fractures ◽

Short Segment ◽

Thoracolumbar Burst Fractures ◽

Burst Fractures ◽

Thoracic And Lumbar Spine

Background. We did a prospective study to study the efficiency of Short Segment Posterior Instrumentation using a Universal Spine System with incorporation of the fractured vertebra in post-traumatic thoracic and lumbar spine fractures. Material and methods. 25 cases in the age group of I5-50 years with thoracic and lumbar spine fractures were included in the study. The operative decision was made on the basis of instability of spine fractures with or without neurological deficit. Patients were followed up for an average period of twelve months, reporting for assessment at 3-monthly intervals. The final result was analyzed on the basis of neurological recovery as per Frankel’s Grading, spine stability as per kyphotic angle by Cobb’s method, vertebral body height and complications. Results. Post-operatively at the final follow-up visit, 36% patients had Frankel’s grade E neurological status. The mean sagittal plane kyphosis pre-operatively was 31.16°, which reduced to 21.52° post-operatively, which represents 30.93% reduction. Mean anterior body compression was 38.6°, which decreased to 23.4° post-operatively, corresponding to 15% increase. Conclusions. 1. Although conventional short segment posterior fixation (SSPF) has become an increasingly popular method of treatment of thoracolumbar burst fractures, providing the advantage of incorporating fewer motion segments in the fixation, a review of literature demonstrated that SSPF led to 9-55% incidence of implant failure and long term loss of kyphosis correction. 2. Short segment posterior fixation with pedicle fixation at the level of the fractured vertebra (short same-segment fixation) provides more biomechanical stability than traditional SSPF.

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A comparative study on screw loosening in osteoporotic lumbar spine fusion between expandable and conventional pedicle screws

Archives of Orthopaedic and Trauma Surgery ◽

10.1007/s00402-011-1439-6 ◽

2011 ◽

Vol 132 (4) ◽

pp. 471-476 ◽

Cited By ~ 85

Author(s):

Zi-xiang Wu ◽

Fu-tai Gong ◽

Li Liu ◽

Zhen-sheng Ma ◽

Yang Zhang ◽

...

Keyword(s):

Lumbar Spine ◽

Comparative Study ◽

Pedicle Screws ◽

Spine Fusion ◽

Screw Loosening ◽

Lumbar Spine Fusion

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Hybrid dynamic stabilization: a biomechanical assessment of adjacent and supraadjacent levels of the lumbar spine

Journal of Neurosurgery Spine ◽

10.3171/2012.6.spine111054 ◽

2012 ◽

Vol 17 (3) ◽

pp. 232-242 ◽

Cited By ~ 18

Author(s):

Prasath Mageswaran ◽

Fernando Techy ◽

Robb W. Colbrunn ◽

Tara F. Bonner ◽

Robert F. McLain

Keyword(s):

Lumbar Spine ◽

Lumbar Fusion ◽

Industrial Robot ◽

Pedicle Screws ◽

Axial Rotation ◽

Dynamic Stabilization ◽

Follower Load ◽

Lateral Bending ◽

Intact Specimen ◽

Flexion Extension

Object The object of this study was to evaluate the effect of hybrid dynamic stabilization on adjacent levels of the lumbar spine. Methods Seven human spine specimens from T-12 to the sacrum were used. The following conditions were implemented: 1) intact spine; 2) fusion of L4–5 with bilateral pedicle screws and titanium rods; and 3) supplementation of the L4–5 fusion with pedicle screw dynamic stabilization constructs at L3–4, with the purpose of protecting the L3–4 level from excessive range of motion (ROM) and to create a smoother motion transition to the rest of the lumbar spine. An industrial robot was used to apply continuous pure moment (± 2 Nm) in flexion-extension with and without a follower load, lateral bending, and axial rotation. Intersegmental rotations of the fused, dynamically stabilized, and adjacent levels were measured and compared. Results In flexion-extension only, the rigid instrumentation at L4–5 caused a 78% decrease in the segment's ROM when compared with the intact specimen. To compensate, it caused an increase in motion at adjacent levels L1–2 (45.6%) and L2–3 (23.2%) only. The placement of the dynamic construct at L3–4 decreased the operated level's ROM by 80.4% (similar stability as the fusion at L4–5), when compared with the intact specimen, and caused a significant increase in motion at all tested adjacent levels. In flexion-extension with a follower load, instrumentation at L4–5 affected only a subadjacent level, L5–sacrum (52.0%), while causing a reduction in motion at the operated level (L4–5, −76.4%). The dynamic construct caused a significant increase in motion at the adjacent levels T12–L1 (44.9%), L1–2 (57.3%), and L5–sacrum (83.9%), while motion at the operated level (L3–4) was reduced by 76.7%. In lateral bending, instrumentation at L4–5 increased motion at only T12–L1 (22.8%). The dynamic construct at L3–4 caused an increase in motion at T12–L1 (69.9%), L1–2 (59.4%), L2–3 (44.7%), and L5–sacrum (43.7%). In axial rotation, only the placement of the dynamic construct at L3–4 caused a significant increase in motion of the adjacent levels L2–3 (25.1%) and L5–sacrum (31.4%). Conclusions The dynamic stabilization system displayed stability characteristics similar to a solid, all-metal construct. Its addition of the supraadjacent level (L3–4) to the fusion (L4–5) did protect the adjacent level from excessive motion. However, it essentially transformed a 1-level lumbar fusion into a 2-level lumbar fusion, with exponential transfer of motion to the fewer remaining discs.

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P75. Is it safer to place pedicle screws in the lower thoracic spine than in the upper lumbar spine? Comparison of pedicle isthmic width of the lower thoracic and the upper lumbar spine using MRI

The Spine Journal ◽

10.1016/j.spinee.2005.05.290 ◽

2005 ◽

Vol 5 (4) ◽

pp. S145-S146

Author(s):

Elisha Ofiram ◽

David Polly ◽

Theodore Choma ◽

Thomas Gilbert

Keyword(s):

Lumbar Spine ◽

Thoracic Spine ◽

Pedicle Screws ◽

Lower Thoracic Spine

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Confirmation of accuracy/inaccuracy of lumbar pedicle screw placement using postoperative computed tomography

Surgical Neurology International ◽

10.25259/sni_290_2021 ◽

2021 ◽

Vol 12 ◽

pp. 518

Author(s):

Mohamed M. Arnaout ◽

Magdy O. ElSheikh ◽

Mansour A. Makia

Keyword(s):

Computed Tomography ◽

Lumbar Spine ◽

Pedicle Screw ◽

Pedicle Screws ◽

Operative Intervention ◽

Screw Placement ◽

Lumbar Spine Surgery ◽

Pedicle Screw Placement ◽

Lumbar Pedicle ◽

Ct Studies

Background: Transpedicular screws are extensively utilized in lumbar spine surgery. The placement of these screws is typically guided by anatomical landmarks and intraoperative fluoroscopy. Here, we utilized 2-week postoperative computed tomography (CT) studies to confirm the accuracy/inaccuracy of lumbar pedicle screw placement in 145 patients and correlated these findings with clinical outcomes. Methods: Over 6 months, we prospectively evaluated the location of 612 pedicle screws placed in 145 patients undergoing instrumented lumbar fusions addressing diverse pathology with instability. Routine anteroposterior and lateral plain radiographs were obtained 48 h after the surgery, while CT scans were obtained at 2 postoperative weeks (i.e., ideally these should have been performed intraoperatively or within 24–48 h of surgery). Results: Of the 612 screws, minor misplacement of screws (≤2 mm) was seen in 104 patients, moderate misplacement in 34 patients (2–4 mm), and severe misplacement in 7 patients (>4 mm). Notably, all the latter 7 (4.8% of the 145) patients required repeated operative intervention. Conclusion: Transpedicular screw insertion in the lumbar spine carries the risks of pedicle medial/lateral violation that is best confirmed on CT rather than X-rays/fluoroscopy alone. Here, we additional found 7 patients (4.8%) who with severe medial/lateral pedicle breach who warranting repeated operative intervention. In the future, CT studies should be performed intraoperatively or within 24–48 h of surgery to confirm the location of pedicle screws and rule in our out medial or lateral pedicle breaches.

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Investigation of Lumbosacral Spine Anatomical Variation Effect on Load-Partitioning Under Follower Load Using Geometrically Personalized Finite Element Model

Volume 3: Biomedical and Biotechnology Engineering ◽

10.1115/imece2014-40231 ◽

2014 ◽

Cited By ~ 2

Author(s):

Sadegh Naserkhaki ◽

Jacob L. Jaremko ◽

Greg Kawchuk ◽

Samer Adeeb ◽

Marwan El-Rich

Keyword(s):

Finite Element ◽

Lumbar Spine ◽

Anatomical Variation ◽

Load Sharing ◽

Element Model ◽

Collagen Fibers ◽

Spinal Curvature ◽

Lumbosacral Spine ◽

Follower Load ◽

Spinal Load

The spinal load sharing and mechanical stresses developed in the spine segments due to mechanical loads are dependent on the unique spinal anatomy (geometry and posture). Variation in spinal curvature alters the load sharing of the lumbar spine as well as the stiffness and stability of the passive tissues. In this paper, effects of lumbar spine curvature variation on spinal load sharing under compressive Follower Load (FL) are investigated numerically. 3D nonlinear Finite Element (FE) models of three ligamentous lumbosacral spines are developed based on personalized geometries; hypo-lordotic (Hypo-L), normal (Normal-L) and hyper-lordotic (Hyper-L) cases. Analysis of each model is performed under Follower Load and developed stress in the discs and forces in the collagen fibers are investigated. Stresses on the discs vary in magnitude and distribution depending on the degree of lordosis. A straight hypo-lordotic spine shows stresses more equally distributed among discs while a highly curved hyper-lordotic spine has stresses concentrated at lower discs. Stresses are uniformly distributed in each disc for Hypo-L case while they are concentrated posteriorly for Hyper-L case. Also, the maximum force in collagen fibers is developed in the Hyper-L case. These differences might be clinically significant related to back pain.

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