The Da Vinci Robot, a Promising Yet Underused Minimally Invasive Tool for Spine Surgery: a Scoping Review of its Current Role and Limits.

Background: The Da Vinci robot ® (DVR), released in the early 2000s, provided a set of innovation aiming at pushing minimally invasive surgery forward. Its stereoscopic magnified visualization camera, motions that exceed the natural range of the human hand, or tremor reduction enhanced the surgeon's skills and added value in many surgical fields.

Objective: To map the current use of the DVR in spine surgery, identify gaps, address its limits and future perspectives.

Exploring the effect of displacement rate on the mechanical properties of denticulate ligaments through uniaxial tensile testing.

Denticulate ligaments play a key role in stabilizing the spinal cord (SC). Accurate representation of these structures in finite element modelling, whether in quasi-static or dynamic conditions, is essential for providing biofidelic responses. Therefore, understanding, characterizing and comparing the tensile mechanical properties of denticulate ligaments at different loading velocities is crucial.

Mechanical differences of anterior and posterior spinal nerve roots revealed by tensile testing.

Cervical spondylotic myelopathy can damage the nerves and structures of the subarachnoidal canal. The spinal cord is attached to the subarachnoidal canal via structures such as nerve roots (NR), which play an important role in its positioning and can be affected by cervical spondylotic myelopathy Understanding the tensile mechanical properties of nerve roots is therefore crucial. A total of 37 swine nerve samples (15 bundles, 12 posterior roots, and 10 anterior roots) were mechanically tested within 12 h of sacrifice by a tensile test on a Mach 1 system (Biomomentum, Montreal, Canada) equipped with a 17 N load cell.

Cerebro-spinal flow pattern in the cervical subarachnoid space of healthy volunteers: Influence of the spinal cord morphology.

Introduction: Toward further cerebro-spinal flow quantification in clinical practice, this study aims at assessing the variations in the cerebro spinal fluid flow pattern associated with change in the morphology of the subarachnoid space of the cervical canal of healthy humans by developing a computational fluid dynamics model.

Methods: 3D T2-space MRI sequence images of the cervical spine were used to segment 11 cervical subarachnoid space. Model validation (time-step, mesh size, size and number of boundary layers, influences of parted inflow and inflow continuous velocity) was performed a 40-year-old patient-specific model.

Monte Carlo simulations of microdosimetry and radiolytic species production at long time post proton irradiation using GATE and Geant4-DNA.

Background: Radiobiological effectiveness of radiation in cancer treatment can be studied at different scales (molecular till organ scale) and different time post irradiation. The production of free radicals and reactive oxygen species during water radiolysis is particularly relevant to understand the fundamental mechanisms playing a role in observed biological outcomes. The development and validation of Monte Carlo tools integrating the simulation of physical, physico-chemical and chemical stages after radiation is very important to maintain with experiments.

Methodology for small animals targeted irradiations at conventional and ultra-high dose rates 65 MeV proton beam.

As part of translational research projects, mice may be irradiated on radiobiology platforms such as the one at the ARRONAX cyclotron. Generally, these platforms do not feature an integrated imaging system. Moreover, in the context of ultra-high dose-rate radiotherapy (FLASH-RT), treatment planning should consider potential changes in the beam characteristics and internal movements in the animal.

Assessment of the tolerance angle for pedicle screw insertion.

Cannulation process intervenes before implantation of pedicle screw and depends on the surgeon's experience. A reliable experimental protocol has been developed for the characterization of the slipping behavior of the surgical tool on the cortical shell simulated by synthetic materials. Three types of synthetic foam samples with three different densities were tested using an MTS Acumen 3 A/T electrodynamic device with a tri-axis 3 kN Kistler load cell mounted on a surgical tool, moving at a constant rotational speed of 10° mm and performing a three-step cannulation test.

Sliding on cortical shell: Biomechanical characterization of the vertebral cannulation for pedicle screw insertion.

Background: Pedicular screws pull-out has been well studied unlike their insertion. A need for characterizing cannulation before pedicle screw implantation is highlighted in literature and offers promising prospects for future intra-operation instrumentation. A reliable cannulation protocol for ex-vivo testing in swine and cadaver vertebrae is presented in this work to predict extra pedicular perforation.

First evidence of in vivo effect of FLASH radiotherapy with helium ions in zebrafish embryos.

The ability to reduce toxicity of ultra-high dose rate (UHDR) helium ion irradiation has not been reported in vivo. Here, we tested UHDR helium ion irradiation in an embryonic zebrafish model. Our results show that UHDR helium ions spare body development and reduce spine curvature, compared to conventional dose rate.

Morphological analysis of ventricular septal defect by echocardiography for prediction of aortic regurgitation in pediatric population.

Ventricular septal defects (VSD) are the most common congenital heart diseases in children. Among them, perimembranous VSD (pm-VSD) have a higher risk of complications, including aortic valve prolapse and aortic regurgitation (AR). The aim of our study was to assess echocardiographic criteria associated with AR during follow-up of pm-VSD.

Ultrahigh-Dose-Rate Proton Irradiation Elicits Reduced Toxicity in Zebrafish Embryos.

Purpose: Recently, ultrahigh-dose-rate radiation therapy (UHDR-RT) has emerged as a promising strategy to increase the benefit/risk ratio of external RT. Extensive work is on the way to characterize the physical and biological parameters that control the so-called "Flash" effect. However, this healthy/tumor differential effect is observable in in vivo models, which thereby drastically limits the amount of work that is achievable in a timely manner.

Traction mechanical characterization of porcine mitral valve annulus.

The Mitral Annulus (MA) is an anisotropic, fibrous, flexible and dynamical structure. While MA dynamics are well documented, its passive mechanical properties remain poorly investigated to complete the design of adequate prostheses. Mechanical properties in traction on four sections of the MA (aortic, left, posterior and right segments) were assessed using a traction test system with a 30 N load cell and pulling jaws for sample fixation.

Biomechanical evaluation of Back injuries during typical snowboarding backward falls.

To prevent spinal and back injuries in snowboarding, back protector devices (BPDs) have been increasingly used. The biomechanical knowledge for the BPD design and evaluation remains to be explored in snowboarding accident conditions. This study aims to evaluate back-to-snow impact conditions and the associated back injury mechanisms in typical snowboarding backward falls.

Experimental Bi-axial tensile tests of spinal meningeal tissues and constitutive models comparison.

Introduction This study aims at identifying mechanical characteristics under bi-axial loading conditions of extracted swine pia mater (PM) and dura and arachnoid complex (DAC). Methods 59 porcine spinal samples have been tested on a bi-axial experimental device with a pre-load of 0.01 N and a displacement rate of 0.

Tensile mechanical properties of the cervical, thoracic and lumbar porcine spinal meninges.

Background: The spinal meninges play a mechanical protective role for the spinal cord. Better knowledge of the mechanical behavior of these tissues wrapping the cord is required to accurately model the stress and strain fields of the spinal cord during physiological or traumatic motions. Then, the mechanical properties of meninges along the spinal canal are not well documented.

Biomechanical comparison of spinal cord compression types occurring in Degenerative Cervical Myelopathy.

Background: Degenerative Cervical Myelopathy results from spine degenerations narrowing the spinal canal and inducing cord compressions. Prognosis is challenging. This study aimed at simulating typical spinal cord compressions observed in patients with a realistic model to better understand pathogenesis for later prediction of patients' evolution.

Influence of the scale reduction in designing sockets for trans-tibial amputees.

The development of artificial prosthetic lower limbs aims to improve patient's mobility while avoiding secondary problems resulting from the use of the prostheses themselves. The residual limb is a pressure-sensitive area where skin injuries and pain are more likely to develop. Requirements for adequate prosthetic limbs have now become urgent to improve amputee's quality of life.

Effect of experimental, morphological and mechanical factors on the murine spinal cord subjected to transverse contusion: A finite element study.

Finite element models combined with animal experimental models of spinal cord injury provides the opportunity for investigating the effects of the injury mechanism on the neural tissue deformation and the resulting tissue damage. Thus, we developed a finite element model of the mouse cervical spinal cord in order to investigate the effect of morphological, experimental and mechanical factors on the spinal cord mechanical behavior subjected to transverse contusion. The overall mechanical behavior of the model was validated with experimental data of unilateral cervical contusion in mice.

Cervical Canal Morphology: Effects of Neck Flexion in Normal Condition: New Elements for Biomechanical Simulations and Surgical Management.

Study Design: Continuous measurements and computation of absolute metrics of cervical subarachnoid space (CSS) and spinal cord (SC) geometries proposed are based on in vivo magnetic resonance imaging and 3D reconstruction.

Objective: The aim of the study is to offer a new methodology to continuously characterize and to quantify the detailed morphology of the CSS and the cervical SC in 3D for healthy subjects in both neutral supine and flexion.

Summary Of Background Data: To the best of our knowledge, no study provides a morphological quantification by absolute indices based on the 3D reconstruction of SC and CSS thanks to in vivo magnetic resonance imaging.

Is skin pressure a relevant factor for socket assessment in patients with lower limb amputation?

Background: Prosthetic rehabilitation improves the overall quality of life of patients, despite discomfort and medical complications. No quantitative assessment of prosthesis-patient interaction is used in routine protocols and prosthesis quality still results from the manufacturer's know-how.

Objective: Our objective is to investigate whether pressure can be a relevant factor for assessing socket adequacy.

Investigating heartbeat-related in-plane motion and stress levels induced at the aortic root.

Background: The axial motion of aortic root (AR) due to ventricular traction was previously suggested to contribute to ascending aorta (AA) dissection by increasing its longitudinal stress, but AR in-plane motion effects on stresses have never been studied. The objective is to investigate the contribution of AR in-plane motion to AA stress levels.

Methods: The AR in-plane motion was assessed on magnetic resonance imagining data from 25 healthy volunteers as the movement of the AA section centroid.

Experimental assessment of cervical ranges of motion and compensatory strategies.

Background: Literature is still limited regarding reports of non-invasive assessment of the cervical range of motion in normal subjects. Investigations into compensatory motions, defined as the contribution of an additional direction to the required motion, are also limited.The objectives of this work were to develop and assess a reliable method for measuring the cervical range of motion in order to investigate motion and compensatory strategies.

Spinal injury analysis for typical snowboarding backward falls.

Spinal injury (SPI) often causes death and disability in snow-sport accidents. SPIs often result from spinal compression and flexion, but the injury risks due to over flexion have not been studied. Back protectors are used to prevent SPIs but the testing standards do not evaluate the flexion-extension resistance.