A novel dynamic fixation system with biodegradable components on lumbar fusion between articular processes in a canine model

2020 ◽  
Vol 234 (7) ◽  
pp. 738-748
Author(s):  
Tailong Yu ◽  
Leyu Zheng ◽  
Guanghua Chen ◽  
Xiaoyan Wang ◽  
Hui Chi ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Lumbar Fusion ◽  
Rigid Fixation ◽  
The Novel ◽  
Initial Shape ◽  
Posterior Lumbar Fusion ◽  
Dynamic Fixation ◽  
Manual Palpation ◽  
Biomechanical Changes ◽  
Fixation System

The objective of this study was to design a novel dynamic fixation system with biodegradable components, apply it for lumbar fusion between articular processes and compare the fusion results and biomechanical changes to those of conventional rigid fixation. The novel dynamic fixation system was designed using a finite element model, stress distributions were compared and 24 mongrel dogs were randomly assigned to two groups and subjected to either posterior lumbar fusion surgery with a novel dynamic fixation system or titanium rods at the L5-L6 segments. Lumbar spines were assessed in both groups to detect radiographic, manual palpation and biomechanical changes. Histological examination was performed on organs and surrounding tissues. In the novel dynamic fixation system, stress was mainly distributed on the meshing teeth of the magnesium alloy spacer. The magnesium alloy components maintained their initial shape 8 weeks after the operation, but the meshing teeth were almost completely degraded at 16 weeks. The novel dynamic fixation system revealed an increased lateral bending range of motion at 8 weeks; however, both groups showed similar radiographic grades, fusion stiffness, manual palpation and histological results. The novel dynamic fixation system design is suitable, and its degradation in vivo is safe. The novel dynamic fixation system can be applied for posterior lumbar fusion between articular processes and complete the fusion like titanium rods.

A Study to Compare the Efficacy of a Biodegradable Dynamic Fixation System With Titanium Devices in Posterior Spinal Fusion Between Articular Processes in a Canine Model

2020 ◽  
Vol 143 (3) ◽  
Author(s):  
Tailong Yu ◽  
Leyu Zheng ◽  
Guanghua Chen ◽  
Nanxiang Wang ◽  
Xiaoyan Wang ◽  
...  
Keyword(s):  
Lumbar Fusion ◽  
Biomechanical Analysis ◽  
Adjacent Segment ◽  
Rigid Fixation ◽  
Initial Shape ◽  
Posterior Lumbar Fusion ◽  
Dynamic Fixation ◽  
Flexion Extension ◽  
Biomechanical Tests ◽  
Fixation System

Abstract The objective of this study was to apply a biodegradable dynamic fixation system (BDFS) for lumbar fusion between articular processes and compare the fusion results and biomechanical changes with those of conventional rigid fixation. Twenty-four mongrel dogs were randomly assigned to 2 groups and subjected to either posterior lumbar fusion surgery with a BDFS or titanium rods (TRs) at the L5–L6 segments. Six animals in each group were sacrificed at 8 or 16 weeks. Fusion conditions were evaluated by computed tomography (CT), manual palpation, biomechanical tests, and histological analysis. Biomechanical tests were performed at the L4–7 (for range of motion (ROM)) and L5–6 (for fusion stiffness) segments. Histological examination was performed on organs, surrounding tissues, and the fused area. The magnesium alloy components maintained their initial shape 8 weeks after the operation, but the meshing teeth were almost completely degraded at 16 weeks. The biomechanical analysis revealed an increased lateral bending ROM at 8 weeks and axial torsion ROM at 16 weeks. The L4–5 extension–flexion ROMs in the BDFS group were 2.29 ± 0.86 deg and 3.17 ± 1.08 deg at 16 weeks, respectively, compared with 3.22 ± 0.56 deg and 5.55 ± 1.84 deg in TR group. However, both groups showed similar fusion results. The BDFS design is suitable, and its degradation in vivo is safe. The BDFS can be applied for posterior lumbar fusion between articular processes to complete the fusion well. Additionally, the BDFS can reduce the decline in lateral motion and hypermotion of the cranial adjacent segment in flexion–extension motion.

Rheumatoid Arthritis Increases Risk of Medical Complications Following Posterior Lumbar Fusion

2021 ◽  
Author(s):  
Joshua Bell ◽  
Sean Sequeira ◽  
Pramod Kamalapathy ◽  
Varun Puvanesarajah ◽  
Hamid Hassanzadeh
Keyword(s):  
Rheumatoid Arthritis ◽  
Lumbar Fusion ◽  
Medical Complications ◽  
Posterior Lumbar Fusion

scholarly journals Using Predictive Modeling and Supervised Machine Learning to Identify Patients at Risk for Venous Thromboembolism Following Posterior Lumbar Fusion

2021 ◽  
pp. 219256822110193
Author(s):  
Kevin Y. Wang ◽  
Ijezie Ikwuezunma ◽  
Varun Puvanesarajah ◽  
Jacob Babu ◽  
Adam Margalit ◽  
...  
Keyword(s):  
Machine Learning ◽  
At Risk ◽  
Venous Thromboembolism ◽  
Risk Stratification ◽  
Predictive Model ◽  
Predictive Modeling ◽  
Lumbar Fusion ◽  
Posterior Lumbar Fusion ◽  
Single Level ◽  
Patients At Risk

Study Design: Retrospective review. Objective: To use predictive modeling and machine learning to identify patients at risk for venous thromboembolism (VTE) following posterior lumbar fusion (PLF) for degenerative spinal pathology. Methods: Patients undergoing single-level PLF in the inpatient setting were identified in the National Surgical Quality Improvement Program database. Our outcome measure of VTE included all patients who experienced a pulmonary embolism and/or deep venous thrombosis within 30-days of surgery. Two different methodologies were used to identify VTE risk: 1) a novel predictive model derived from multivariable logistic regression of significant risk factors, and 2) a tree-based extreme gradient boosting (XGBoost) algorithm using preoperative variables. The methods were compared against legacy risk-stratification measures: ASA and Charlson Comorbidity Index (CCI) using area-under-the-curve (AUC) statistic. Results: 13, 500 patients who underwent single-level PLF met the study criteria. Of these, 0.95% had a VTE within 30-days of surgery. The 5 clinical variables found to be significant in the multivariable predictive model were: age > 65, obesity grade II or above, coronary artery disease, functional status, and prolonged operative time. The predictive model exhibited an AUC of 0.716, which was significantly higher than the AUCs of ASA and CCI (all, P < 0.001), and comparable to that of the XGBoost algorithm ( P > 0.05). Conclusion: Predictive analytics and machine learning can be leveraged to aid in identification of patients at risk of VTE following PLF. Surgeons and perioperative teams may find these tools useful to augment clinical decision making risk stratification tool.

Study and Analysis of Mechanical Behavior between Rigid and Dynamic Fixation Systems Analyzed by the Finite Element Method

2017 ◽  
Vol 33 ◽  
pp. 12-31 ◽  
Author(s):  
Samir Zahaf ◽  
Said Kebdani
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Intervertebral Disc ◽  
Spinal Diseases ◽  
Main Role ◽  
Rigid Fixation ◽  
Dynamic Fixation ◽  
Motion Segment ◽  
Fixation Devices ◽  
Element Method

Orthopedic fixation devices are widely used in treatment of spinal diseases. It is expected that application of dynamic stabilization confers valuable movement possibility besides its main role of load bearing. Comparative investigation between pedicle screw model rigid fixation and (B Dyne, Elaspine, Bioflex, Coflexe rivet) models dynamic fixation systems may elucidate the efficacy of each design. The goal of the present study is to evaluate the efficacy of five fixation systems mounted on L4-L5 motion segment. In this numerical study, a 3D precious model of L4, L5 and their intervertebral disc has been employed based on CT images. five fixation devices have been also implanted internally to the motion segment. Finite element method was used to evaluate stress distribution in the disc and determine the overall displacement of the segment as a measure of movement possibility. The results show that The Coflex rivet implantation can provide stability in all motions and reduce disc annulus stress at the surgical segment (L4-L5), on the other hand, Maximum stress in the disc has been observed in dynamic systems but within the safe range. The greater movement of the motion segment has been also appeared in dynamic fixations. Existence of the fixation systems reduced the stress on the intervertebral disc which might be exerted in intact cases. Use of the fixation devices can considerably reduce the load on the discs and prepare conditions for healing of the injured ones. Furthermore, dynamic modes of fixation confer possibility of movement to the motion segments in order to facilitate the spinal activities.

Three-Dimensional Computed Tomography and Multiplanar Reformations in the Assessment of Pseudarthrosis in Posterior Lumbar Fusion Patients

Spine ◽  
1988 ◽  
Vol 13 (1) ◽  
pp. 69-75 ◽  
Author(s):  
PHILIPP LANG ◽  
HARRY K. GENANT ◽  
NEIL CHAFETZ ◽  
PETER STEIGER ◽  
JAMES M. MORRIS
Keyword(s):  
Computed Tomography ◽  
Lumbar Fusion ◽  
Three Dimensional ◽  
Posterior Lumbar Fusion ◽  
Multiplanar Reformations
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