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Papers by Luigi La Barbera
Journal of The Mechanical Behavior of Biomedical Materials, Apr 1, 2023
Objective: Preclinical evaluation of spinal implants is a mandatory step to ensure their reliabil... more Objective: Preclinical evaluation of spinal implants is a mandatory step to ensure their reliability and safety before clinical use and implantation. The American Society of Testing and Materials reapproved a standard for the evaluation and comparison of mechanical properties of posterior spinal fixators[for full text, please go to the a.m. URL]
Bioengineering, Jul 23, 2023
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Journal of Mechanical Science and Technology, Jan 28, 2023
Journal of Applied Biomaterials & Functional Materials, 2016
Background. One of the most frequent clinical consequences of osteoporosis is vertebral compressi... more Background. One of the most frequent clinical consequences of osteoporosis is vertebral compression fractures, which occur mainly in the thoraco-lumbar junction and cause the collapse of the vertebral body. For their treatment two mini-invasive surgical procedures, vertebroplasty and balloon kyphoplasty, are used. In terms of efficacy, cost and safety, in particular about the risk of new adjacent fractures, it is still unknown which technique is preferred. Methods. Finite element models of the thoracic human spine were developed to evaluate the biomechanical outcomes of vertebroplasty and kyphoplasty, with a computational comparative analysis. An intact model and two fractured conditions were generated in order to study a wedge compression fracture and the possible treatments. With the aim to determine the stress distribution in the adjacent structures to the treated vertebral body, stresses on the endplates and intradiscal pressures were extrapolated. Findings. In case of mild fracture we noticed an average von Mises stress reduction of about 20%. For a severe fracture, when there is a partial height restoration, an average stress reduction of 15% was calculated, while with a full recovery of the anterior wall of the fractured vertebrae a further stress reduction of about 35% was obtained. Interpretation. The effect of cement injection in the fractured vertebra is negligible compared to the effect of the geometry. In our opinion, in order to reduce the stresses and consequently the risk of fracture, the best choice is to perform a kyphoplasty trying to restore the physiological situation.
The Spine Journal, Oct 1, 2015
Fig. 1. Experimental setups according to the American Society for Testing Materials (ASTM F1717) ... more Fig. 1. Experimental setups according to the American Society for Testing Materials (ASTM F1717) standard (Left) and according to the International Organization for Standardization (ISO 12189) standard (Right).
Bioengineering
CFR-PEEK is gaining popularity in spinal oncological applications due to its reduction of imaging... more CFR-PEEK is gaining popularity in spinal oncological applications due to its reduction of imaging artifacts and radiation scattering compared with titanium, which allows for better oncological follow-up and efficacy of radiotherapy. We evaluated the use of these materials for the treatment of lumbar degenerative diseases (DDs) and considered the biomechanical potential of the carbon fiber in relation to its modulus of elasticity being similar to that of bone. Twenty-eight patients with DDs were treated using CRF-PEEK instrumentation. The clinical and radiographic outcomes were collected at a 12-month FU. Spinal fusion was evaluated in the CT scans using Brantigan scores, while the clinical outcomes were evaluated using VAS, SF-12, and EQ-5D scores. Out of the patients evaluated at the 12-month FU, 89% showed complete or almost certain fusion (Brantigan score D and E) and presented a significant improvement in all clinical parameters; the patients also presented VAS scores ranging fr...
Journal of the Mechanical Behavior of Biomedical Materials
Journal of Mechanical Science and Technology
Journal of NeuroInterventional Surgery
BackgroundThere is limited literature regarding the re-fracture of a previously augmented vertebr... more BackgroundThere is limited literature regarding the re-fracture of a previously augmented vertebral compression fracture (VCF). These re-fractures may present as an asymptomatic remodeling of the vertebral body around the cement cast while in other cases they involve the middle column, at the transition zone between the cement-augmented and non-augmented vertebral body. In the latter, a posterior wall retropulsion is possible and, if left untreated, might progress to vertebral body splitting, central canal stenosis, and kyphotic deformity. There is no consensus regarding the best treatment for these re-fractures. There are cases in which a repeated augmentation relieves the pain, but this is considered an undertreatment in cases with middle column involvement, posterior wall retropulsion, and kyphosis.MethodsWe report four cases of re-fracture with middle column collapse of a previously augmented VCF, treated with the stent-screw assisted internal fixation (SAIF) technique. A modifi...
Spine deformity, Sep 9, 2022
Journal of the Mechanical Behavior of Biomedical Materials
Global Spine Journal, 2017
Introduction: A prior study showed the touched vertebra (TV), defined as the most cephalad thorac... more Introduction: A prior study showed the touched vertebra (TV), defined as the most cephalad thoracolumbar/lumbar vertebra “touched” by the center sacral vertical line (CSVL), as a potential landmark vertebra & recommended lowest instrumented vertebra (LIV) as well. We evaluated a large cohort of Lenke type 1 & 2 cases to determine if selecting the TV as the LIV will produce optimal positioning at a min. 5 yrs postoperative. Our hypothesis was that it would and that fusing short of the TV would lead to a suboptimal result. Material and Methods: 299 pts with Lenke 1 (n = 207) or Lenke 2 (n = 92) AIS curves at a min. 5 yr f/u were evaluated. The TV was selected on the preoperative x-ray by 2 independent examiners & confirmed for agreement. The LIV selected was compared to the preoperative TV as well as the LIV-CSVL distance at min. 5 yr f/u. Comparison was made on the LIV-CSVL distance in pts fused short of the TV, to the TV or distal to the TV using standard statistical software. Resul...
Computer Methods in Biomechanics and Biomedical Engineering, 2021
Abstract Computational models are increasingly used to assess spine biomechanics and support surg... more Abstract Computational models are increasingly used to assess spine biomechanics and support surgical planning. However, varying levels of model verification and validation, along with characterization of uncertainty effects limit the level of confidence in their predictive potential. The objective was to assess the credibility of an adult spine deformity instrumentation model for proximal junction failure (PJF) analysis using the ASME V&V40:2018 framework. To assess model applicability, the surgery, erected posture, and flexion movement of actual clinical cases were simulated. The loads corresponding to PJF indicators for a group of asymptomatic patients and a group of PJF patients were compared. Model consistency was demonstrated by finding PJF indicators significantly higher for the simulated PJF vs. asymptomatic patients. A detailed sensitivity analysis and uncertainty quantification were performed to further establish the model credibility.
Journal of The Mechanical Behavior of Biomedical Materials, Nov 1, 2022
Journal of The Mechanical Behavior of Biomedical Materials, Apr 1, 2023
Objective: Preclinical evaluation of spinal implants is a mandatory step to ensure their reliabil... more Objective: Preclinical evaluation of spinal implants is a mandatory step to ensure their reliability and safety before clinical use and implantation. The American Society of Testing and Materials reapproved a standard for the evaluation and comparison of mechanical properties of posterior spinal fixators[for full text, please go to the a.m. URL]
Bioengineering, Jul 23, 2023
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Journal of Mechanical Science and Technology, Jan 28, 2023
Journal of Applied Biomaterials & Functional Materials, 2016
Background. One of the most frequent clinical consequences of osteoporosis is vertebral compressi... more Background. One of the most frequent clinical consequences of osteoporosis is vertebral compression fractures, which occur mainly in the thoraco-lumbar junction and cause the collapse of the vertebral body. For their treatment two mini-invasive surgical procedures, vertebroplasty and balloon kyphoplasty, are used. In terms of efficacy, cost and safety, in particular about the risk of new adjacent fractures, it is still unknown which technique is preferred. Methods. Finite element models of the thoracic human spine were developed to evaluate the biomechanical outcomes of vertebroplasty and kyphoplasty, with a computational comparative analysis. An intact model and two fractured conditions were generated in order to study a wedge compression fracture and the possible treatments. With the aim to determine the stress distribution in the adjacent structures to the treated vertebral body, stresses on the endplates and intradiscal pressures were extrapolated. Findings. In case of mild fracture we noticed an average von Mises stress reduction of about 20%. For a severe fracture, when there is a partial height restoration, an average stress reduction of 15% was calculated, while with a full recovery of the anterior wall of the fractured vertebrae a further stress reduction of about 35% was obtained. Interpretation. The effect of cement injection in the fractured vertebra is negligible compared to the effect of the geometry. In our opinion, in order to reduce the stresses and consequently the risk of fracture, the best choice is to perform a kyphoplasty trying to restore the physiological situation.
The Spine Journal, Oct 1, 2015
Fig. 1. Experimental setups according to the American Society for Testing Materials (ASTM F1717) ... more Fig. 1. Experimental setups according to the American Society for Testing Materials (ASTM F1717) standard (Left) and according to the International Organization for Standardization (ISO 12189) standard (Right).
Bioengineering
CFR-PEEK is gaining popularity in spinal oncological applications due to its reduction of imaging... more CFR-PEEK is gaining popularity in spinal oncological applications due to its reduction of imaging artifacts and radiation scattering compared with titanium, which allows for better oncological follow-up and efficacy of radiotherapy. We evaluated the use of these materials for the treatment of lumbar degenerative diseases (DDs) and considered the biomechanical potential of the carbon fiber in relation to its modulus of elasticity being similar to that of bone. Twenty-eight patients with DDs were treated using CRF-PEEK instrumentation. The clinical and radiographic outcomes were collected at a 12-month FU. Spinal fusion was evaluated in the CT scans using Brantigan scores, while the clinical outcomes were evaluated using VAS, SF-12, and EQ-5D scores. Out of the patients evaluated at the 12-month FU, 89% showed complete or almost certain fusion (Brantigan score D and E) and presented a significant improvement in all clinical parameters; the patients also presented VAS scores ranging fr...
Journal of the Mechanical Behavior of Biomedical Materials
Journal of Mechanical Science and Technology
Journal of NeuroInterventional Surgery
BackgroundThere is limited literature regarding the re-fracture of a previously augmented vertebr... more BackgroundThere is limited literature regarding the re-fracture of a previously augmented vertebral compression fracture (VCF). These re-fractures may present as an asymptomatic remodeling of the vertebral body around the cement cast while in other cases they involve the middle column, at the transition zone between the cement-augmented and non-augmented vertebral body. In the latter, a posterior wall retropulsion is possible and, if left untreated, might progress to vertebral body splitting, central canal stenosis, and kyphotic deformity. There is no consensus regarding the best treatment for these re-fractures. There are cases in which a repeated augmentation relieves the pain, but this is considered an undertreatment in cases with middle column involvement, posterior wall retropulsion, and kyphosis.MethodsWe report four cases of re-fracture with middle column collapse of a previously augmented VCF, treated with the stent-screw assisted internal fixation (SAIF) technique. A modifi...
Spine deformity, Sep 9, 2022
Journal of the Mechanical Behavior of Biomedical Materials
Global Spine Journal, 2017
Introduction: A prior study showed the touched vertebra (TV), defined as the most cephalad thorac... more Introduction: A prior study showed the touched vertebra (TV), defined as the most cephalad thoracolumbar/lumbar vertebra “touched” by the center sacral vertical line (CSVL), as a potential landmark vertebra & recommended lowest instrumented vertebra (LIV) as well. We evaluated a large cohort of Lenke type 1 & 2 cases to determine if selecting the TV as the LIV will produce optimal positioning at a min. 5 yrs postoperative. Our hypothesis was that it would and that fusing short of the TV would lead to a suboptimal result. Material and Methods: 299 pts with Lenke 1 (n = 207) or Lenke 2 (n = 92) AIS curves at a min. 5 yr f/u were evaluated. The TV was selected on the preoperative x-ray by 2 independent examiners & confirmed for agreement. The LIV selected was compared to the preoperative TV as well as the LIV-CSVL distance at min. 5 yr f/u. Comparison was made on the LIV-CSVL distance in pts fused short of the TV, to the TV or distal to the TV using standard statistical software. Resul...
Computer Methods in Biomechanics and Biomedical Engineering, 2021
Abstract Computational models are increasingly used to assess spine biomechanics and support surg... more Abstract Computational models are increasingly used to assess spine biomechanics and support surgical planning. However, varying levels of model verification and validation, along with characterization of uncertainty effects limit the level of confidence in their predictive potential. The objective was to assess the credibility of an adult spine deformity instrumentation model for proximal junction failure (PJF) analysis using the ASME V&V40:2018 framework. To assess model applicability, the surgery, erected posture, and flexion movement of actual clinical cases were simulated. The loads corresponding to PJF indicators for a group of asymptomatic patients and a group of PJF patients were compared. Model consistency was demonstrated by finding PJF indicators significantly higher for the simulated PJF vs. asymptomatic patients. A detailed sensitivity analysis and uncertainty quantification were performed to further establish the model credibility.
Journal of The Mechanical Behavior of Biomedical Materials, Nov 1, 2022