Early stage disc degeneration does not have an appreciable affect on stiffness and load transfer following vertebroplasty and kyphoplasty

Kosmopoulos, Victor; Keller, Tony S.; Schizas, Constantin

doi:10.1007/s00586-008-0828-1

Cited by 11 publications

(11 citation statements)

References 35 publications

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“…Numerous studies utilizing finite element analysis have examined the effects of motion preserving implants, fusions, and cementation techniques on stiffness at the treated and adjacent levels. 4,13,20–24,34,35 . The optimal stiffness of motion preserving implants is not truly known, and may need to be individualized for the patient undergoing this type of surgery.…”

Section: Discussionmentioning

confidence: 99%

Dynamic Biomechanical Examination of the Lumbar Spine With Implanted Total Disc Replacement Using a Pendulum Testing System

Daniels¹,

Paller²,

Koruprolu³

et al. 2012

Spine

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Study Design Biomechanical cadaver investigation Objective To examine dynamic bending stiffness and energy absorption of the lumbar spine with and without implanted Total Disc Replacement (TDR) under simulated physiologic motion. Summary of background data The pendulum testing system is capable of applying physiologic compressive loads without constraining motion of functional spinal units (FSUs). The number of cycles to equilibrium observed under pendulum testing is a measure of the energy absorbed by the FSU. Methods Five unembalmed, frozen human lumbar FSUs were tested on the pendulum system with axial compressive loads of 181N, 282N, 385N, and 488N before and after Synthes ProDisc-L TDR implantation. Testing in flexion, extension, and lateral bending began by rotating the pendulum to 5° resulting in unconstrained oscillatory motion. The number of rotations to equilibrium was recorded and bending stiffness (N-m/°) was calculated and compared for each testing mode. Results In flexion/extension, the TDR constructs reached equilibrium with significantly (p<0.05) fewer cycles than the intact FSU with compressive loads of 282N, 385N and 488N. Mean dynamic bending stiffness in flexion, extension, and lateral bending increased significantly with increasing load for both the intact FSU and TDR constructs (p<0.001). In flexion, with increasing compressive loading from 181N to 488N, the bending stiffness of the intact FSUs increased from 4.0N-m/° to 5.5N-m/°, compared to 2.1N-m/° to 3.6N-m/° after TDR implantation. At each compressive load, the intact FSU was significantly more stiff than the TDR (p<0.05). Conclusion Lumbar FSUs with implanted TDR were found to be less stiff, but also absorbed more energy during cyclic loading with an unconstrained pendulum system. Although the effects on clinical performance of motion preserving devices are not fully known, these results provide further insight into the biomechanical behavior of this device under approximated physiologic loading conditions.

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Section: Discussionmentioning

confidence: 99%

Dynamic Biomechanical Examination of the Lumbar Spine With Implanted Total Disc Replacement Using a Pendulum Testing System

Daniels¹,

Paller²,

Koruprolu³

et al. 2012

Spine

View full text Add to dashboard Cite

show abstract

Section: Discussionmentioning

confidence: 99%

Dynamic Biomechanical Examination of the Lumbar Spine with Implanted Total Spinal Segment Replacement (TSSR) Utilizing a Pendulum Testing System

et al. 2013

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BackgroundBiomechanical investigations of spinal motion preserving implants help in the understanding of their in vivo behavior. In this study, we hypothesized that the lumbar spine with implanted total spinal segment replacement (TSSR) would exhibit decreased dynamic stiffness and more rapid energy absorption compared to native functional spinal units under simulated physiologic motion when tested with the pendulum system.MethodsFive unembalmed, frozen human lumbar functional spinal units were tested on the pendulum system with axial compressive loads of 181 N, 282 N, 385 N, and 488 N before and after Flexuspine total spinal segment replacement implantation. Testing in flexion, extension, and lateral bending began by rotating the pendulum to 5°; resulting in unconstrained oscillatory motion. The number of rotations to equilibrium was recorded and bending stiffness (N-m/°) was calculated and compared for each testing mode.ResultsThe total spinal segment replacement reached equilibrium with significantly fewer cycles to equilibrium compared to the intact functional spinal unit at all loads in flexion (p<0.011), and at loads of 385 N and 488 N in lateral bending (p<0.020). Mean bending stiffness in flexion, extension, and lateral bending increased with increasing load for both the intact functional spinal unit and total spinal segment replacement constructs (p<0.001), with no significant differences in stiffness between the intact functional spinal unit and total spinal segment replacement in any of the test modes (p>0.18).ConclusionsLumbar functional spinal units with implanted total spinal segment replacement were found to have similar dynamic bending stiffness, but absorbed energy at a more rapid rate than intact functional spinal units during cyclic loading with an unconstrained pendulum system. Although the effects on clinical performance of motion preserving devices is not fully known, these results provide further insight into the biomechanical behavior of this device under approximated physiologic loading conditions.

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“…Bone, marrow, cartilage, and bone cement elements were modelled with corresponding material properties. Later, the model was extended [47] to account for the intervertebral disc degeneration in the process of the degeneration of the whole motion segment and included several augmentation patterns for vertebroplasty ( Figure 4 ). The reduced disc mobility was simulated by increasing the stiffness of the nucleus to the value of the surrounding annulus.…”

Section: Computational Modelling For Strength Predictionmentioning

confidence: 99%

“…While the procedure for the geometry generation is generally standardised, simulations of augmented bone have been performed with a variety of different approaches. Several simulations include a prior simulation of bone fracture [36] , [46] , [47] , [48] , [49] . Models including fracture simulation are performed in two or more loading cycles [36] , [46] , [47] , [48] .…”

Section: Computational Modelling For Strength Predictionmentioning

confidence: 99%

Computational modelling of bone augmentation in the spine

Badilatti

Kuhn

Ferguson

et al. 2015

Journal of Orthopaedic Translation

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SummaryComputational models are gaining importance not only for basic science, but also for the analysis of clinical interventions and to support clinicians prior to intervention. Vertebroplasty has been used to stabilise compression fractures in the spine for years, yet there are still diverging ideas on the ideal deposition location, volume, and augmentation material. In particular, little is known about the long-term effects of the intervention on the surrounding biological tissue. This review aims to investigate computational efforts made in the field of vertebroplasty, from the augmentation procedure to strength prediction and long-term in silico bone biology in augmented human vertebrae. While there is ample work on simulating the augmentation procedure and strength prediction, simulations predicting long-term effects are lacking. Recent developments in bone remodelling simulations have the potential to show adaptation to cement augmentation and, thus, close this gap.

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Early stage disc degeneration does not have an appreciable affect on stiffness and load transfer following vertebroplasty and kyphoplasty

Cited by 11 publications

References 35 publications

Dynamic Biomechanical Examination of the Lumbar Spine With Implanted Total Disc Replacement Using a Pendulum Testing System

Dynamic Biomechanical Examination of the Lumbar Spine With Implanted Total Disc Replacement Using a Pendulum Testing System

Dynamic Biomechanical Examination of the Lumbar Spine with Implanted Total Spinal Segment Replacement (TSSR) Utilizing a Pendulum Testing System

Computational modelling of bone augmentation in the spine

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