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Hubert Labelle - One of the best experts on this subject based on the ideXlab platform.

  • the effectiveness of the spinecor Brace for the conservative treatment of adolescent idiopathic scoliosis comparison with the Boston Brace
    The Spine Journal, 2016
    Co-Authors: Gabriel Gutman, Hubert Labelle, Marie Beausejour, Mathieu Benoit, Julie Joncas, Soraya Barchi, Stefan Parent, Jeanmarc Macthiong
    Abstract:

    Abstract Background Context The Boston Brace (Bb) is the most widely used Brace design to treat adolescent idiopathic scoliosis (AIS). The dynamic SpineCor (SC) Brace is prescribed in several scoliosis clinics worldwide, but its effectiveness remains controversial. Purpose The study aimed to compare the treatment effectiveness of SC in patients with AIS treated by the developers of the Brace with that of the Bb at a single institution. Study Design/Setting This is a retrospective comparison between a cohort of AIS patients treated using the SC Brace and a cohort treated using the Bb. Patient Sample We assessed 243 patients treated with either Bb or SC Brace to prevent the progression of AIS. Outcome Measures The primary outcome was the progression in main Cobb angle when reaching one of the following end point criteria: (1) progression in Cobb angle of ≥6°, (2) main Cobb angle of ≥45°, (3) surgery undertaken, or (4) reaching skeletal maturity (Risser sign of 5 or growth of Methods Patients were identified at a single institution between 2000 and 2012 following the Scoliosis Research Society criteria for Brace treatment: (1) diagnosis of AIS, (2) Risser sign of ≤2, (3) curve magnitude between 25° and 40°, and (4) age ≥10 years. A total of 97 patients treated with SC by the developers of the Brace and 146 patients treated with Bb were identified. Data collection and radiograph measurements were performed by a single experienced nurse not involved in the decision-making for Brace treatment or in the data analysis. Age and Risser sign at onset of treatment, initialmain Cobb angle, curve type, and duration of follow-up were similar in both cohorts. Statistical analysis was done using chi-square and logistic regression models, with a level of significance of .05. Results The average progression was 14.7°±11.9° in the SC cohort compared with 9.6°±13.7° in the Bb cohort (p=.003). The average Cobb angle at the end point of the study reached 47°±13° in the SC cohort and 41.7°±14.2° in the Bb cohort (p=.005), whereas at the onset of bracing it was 32.2°±4.9° and 32.2°±4.4°, respectively, for the SC and Bb cohorts. The percentage of patients with a progression of ≥6° was 76% in the SC cohort and 55% in the Bb cohort (p=.001). The proportion of patients reaching 45° in the SC and Bb cohorts was, respectively, 51% and 37% (p=.03), whereas the proportion of patients referred to surgery was 39% and 30%, respectively, for the SC and Bb cohorts (p=.2). The odds of progressing ≥6° and of reaching ≥45° were 2.67 and 2.07 times greater, respectively, when using the SC Brace. Conclusions The SC Brace did not prevent curve progression as effectively as the Bb. Although it has the potential benefit of increasing mobility during Brace wear, the SC Brace was associated with increased curve progression in comparison with the Bb. There is also a trend for increased risk of requiring surgery when the SC Brace is worn.

  • 1 Geometric Variability of the Scoliotic Spine Using Statistics on Articulated Shape Models
    2012
    Co-Authors: Jonathan Boisvert, Hubert Labelle, Farida Cheriet, Xavier Pennec, Nicholas Ayache
    Abstract:

    Abstract — This paper introduces a method to analyze the variability of the spine shape and of the spine shape deformations using articulated shape models. The spine shape was expressed as a vector of relative poses between local coordinate systems of neighbouring vertebrae. Spine shape deformations were then modeled by a vector of rigid transformations that transforms one spine shape into another. Because rigid transforms do not naturally belong to a vector space, conventional mean and covariance could not be applied. The Fréchet mean and a generalized covariance were used instead. The spine shapes of a group of 295 scoliotic patients were quantitatively analyzed as well as the spine shape deformations associated with the Cotrel-Dubousset corrective surgery (33 patients), the Boston Brace (39 patients) and the scoliosis progression without treatment (26 patients). The variability of inter-vertebral poses was found to be inhomogeneous (lumbar vertebrae were more variable than the thoracic ones) and anisotropic (with maximal rotational variability around the coronal axis and maximal translational variability along the axial direction). Finally, Brace and surgery were found to have a significant effect on the Fréchet mean and on the generalized covariance in specific spine regions where treatments modified the spine shape

  • Virtual prototyping of a Brace design for the correction of scoliotic deformities
    Medical & Biological Engineering & Computing, 2007
    Co-Authors: Julien Clin, Carl-eric Aubin, Hubert Labelle
    Abstract:

    Based on a three-dimensional patient-specific finite element model of the spine, rib cage, pelvis and abdomen, a parametric model of a thoraco-lumbo-sacral orthosis (TLSO) was built. Its geometry is custom-fit to the patient. The rigid shell, pads and openings are all represented. The interaction between the trunk and the Brace is modeled by a point-to-surface contact interface. During the nonlinear simulation process, the Brace is opened, positioned on the patient and strap tension is applied. A TLSO similar to Boston Brace system was built for a right-thoracic scoliotic patient. The influences of the trochanter pad and strap tension on the 3-D geometrical corrections and on the forces generated by the Brace were evaluated. The role of the trochanter pad as a lever arm is confirmed by the model. The Brace induces a reduction of the lordosis and pelvic tilt. The reduction of the frontal curvature is about 20% for a strap tension of 60 N. Axial rotation does not significantly change and rib hump is worsened. By using an explicit Brace model and a contact interface, a more realistic simulation of orthotic treatment of scoliosis can be achieved. The stabilization of the Brace on the patient can be represented and less restrictive boundary conditions can be applied. This model could be used to study the effect of design parameters on the Brace efficiency.

  • biomechanical evaluation of the Boston Brace system for the treatment of adolescent idiopathic scoliosis relationship between strap tension and Brace interface forces
    Spine, 2004
    Co-Authors: Jeanmarc Macthiong, Carl-eric Aubin, Jean Dansereau, Yvan Petit, Sebastien Delorme, Hubert Labelle
    Abstract:

    Study Design. Prospective study to evaluate the association between strap tension and Brace interface forces in the treatment of adolescent idiopathic scoliosis using the Boston Brace system. Objectives. To determine the strap tension associated with optimal Brace interface forces. Summary of Background Data. Trim lines, pad placement, and areas of relief for the Brace are guided by radiographic studies. However, optimal adjustment of strap tension is unclear and remains mostly empirical. Methods. Brace interface forces in all regions of the trunk were measured for 41 patients with adolescent idiopathic scoliosis at three standardized strap tensions (20 N, 40 N, and 60 N). The Brace interface forces were assessed using a mat made of force-sensing transducers. Equivalent interface pressure for each trunk region was also calculated to estimate the distribution of the interface forces. Results. The Brace interface forces and the corresponding effective areas increased along with the strap tension for all patients. For patients with a single right thoracic curve, the interface pressure tended to increase with increasing strap tension. This increase was significant in the left axillary, right thoracic, right pelvic, and sternal regions. For double right thoracic–left lumbar curves, the increase in interface pressure was significant in the left axillary, right pelvic, and sternal regions. However, most of this increase occurred between 20 N and 40 N of strap tension, with only slight increase or even a decrease in interface pressures between 40 N and 60 N. Conclusions. The strap tension should be set as high as possible (up to 60 N) for right thoracic curves. For right thoracic–left lumbar curves, the optimal strap tension was ∼40 N. However, clinicians should ensure that the prescribed strap tension does not cause excessive skin pressure or affect the compliance with the Brace. A side opening in the right lumbar area may improve the effectiveness of the Brace for double right thoracic-left lumbar curves, but care must be taken to avoid skin problems at the opening.

  • Boston Brace correction in idiopathic scoliosis a biomechanical study
    Spine, 2003
    Co-Authors: Delphine Perie, Carl-eric Aubin, Jean Dansereau, Yvan Petit, Marie Beausejour, Hubert Labelle
    Abstract:

    STUDY DESIGN To analyze Boston Brace biomechanics, pressure measurements and finite element simulations were done on 12 adolescent idiopathic scoliosis patients. OBJECTIVES The aim was to analyze the Boston Brace effectiveness using a finite element model and experimental measurements. SUMMARY OF BACKGROUND DATA There are not very many biomechanical studies of Boston Brace effectiveness, and its biomechanical action is not completely understood. METHODS This study was performed on 12 girls with scoliosis treated with the Boston Brace system. The experimental protocol was composed of the acquisition of two sets of multiplanar radiographs with and without Brace followed by the pressure acquisition at the Brace-torso interface. A personalized finite element modeling of the trunk was generated from the 3D reconstruction of the patient's geometry. The Brace treatment was simulated by the application of equivalent forces calculated from the pressure measurements. RESULTS Two Boston Brace force patterns were defined from the pressure measurements. The first one consisted of high right thoracic forces of 31-113 N, lumbar forces less than 47 N, and included a left thoracic extension working as a counter pad. The second one consisted of low thoracic forces less than 20 N, lumbar forces up to 70 N, without left thoracic extension. The simulations showed that the passive forces only produced a coronal Cobb angle correction up to 9 degrees, whereas real correction was up to 16 degrees. CONCLUSION High thoracic pads reduced more effectively both thoracic and lumbar scoliotic curves than lumbar pads only. The study suggests that mechanisms other than Brace pads produce correction and contribute to the force equilibrium within the Brace.

Jean Dansereau - One of the best experts on this subject based on the ideXlab platform.

  • biomechanical evaluation of the Boston Brace system for the treatment of adolescent idiopathic scoliosis relationship between strap tension and Brace interface forces
    Spine, 2004
    Co-Authors: Jeanmarc Macthiong, Carl-eric Aubin, Jean Dansereau, Yvan Petit, Sebastien Delorme, Hubert Labelle
    Abstract:

    Study Design. Prospective study to evaluate the association between strap tension and Brace interface forces in the treatment of adolescent idiopathic scoliosis using the Boston Brace system. Objectives. To determine the strap tension associated with optimal Brace interface forces. Summary of Background Data. Trim lines, pad placement, and areas of relief for the Brace are guided by radiographic studies. However, optimal adjustment of strap tension is unclear and remains mostly empirical. Methods. Brace interface forces in all regions of the trunk were measured for 41 patients with adolescent idiopathic scoliosis at three standardized strap tensions (20 N, 40 N, and 60 N). The Brace interface forces were assessed using a mat made of force-sensing transducers. Equivalent interface pressure for each trunk region was also calculated to estimate the distribution of the interface forces. Results. The Brace interface forces and the corresponding effective areas increased along with the strap tension for all patients. For patients with a single right thoracic curve, the interface pressure tended to increase with increasing strap tension. This increase was significant in the left axillary, right thoracic, right pelvic, and sternal regions. For double right thoracic–left lumbar curves, the increase in interface pressure was significant in the left axillary, right pelvic, and sternal regions. However, most of this increase occurred between 20 N and 40 N of strap tension, with only slight increase or even a decrease in interface pressures between 40 N and 60 N. Conclusions. The strap tension should be set as high as possible (up to 60 N) for right thoracic curves. For right thoracic–left lumbar curves, the optimal strap tension was ∼40 N. However, clinicians should ensure that the prescribed strap tension does not cause excessive skin pressure or affect the compliance with the Brace. A side opening in the right lumbar area may improve the effectiveness of the Brace for double right thoracic-left lumbar curves, but care must be taken to avoid skin problems at the opening.

  • Boston Brace correction in idiopathic scoliosis a biomechanical study
    Spine, 2003
    Co-Authors: Delphine Perie, Carl-eric Aubin, Jean Dansereau, Yvan Petit, Marie Beausejour, Hubert Labelle
    Abstract:

    STUDY DESIGN To analyze Boston Brace biomechanics, pressure measurements and finite element simulations were done on 12 adolescent idiopathic scoliosis patients. OBJECTIVES The aim was to analyze the Boston Brace effectiveness using a finite element model and experimental measurements. SUMMARY OF BACKGROUND DATA There are not very many biomechanical studies of Boston Brace effectiveness, and its biomechanical action is not completely understood. METHODS This study was performed on 12 girls with scoliosis treated with the Boston Brace system. The experimental protocol was composed of the acquisition of two sets of multiplanar radiographs with and without Brace followed by the pressure acquisition at the Brace-torso interface. A personalized finite element modeling of the trunk was generated from the 3D reconstruction of the patient's geometry. The Brace treatment was simulated by the application of equivalent forces calculated from the pressure measurements. RESULTS Two Boston Brace force patterns were defined from the pressure measurements. The first one consisted of high right thoracic forces of 31-113 N, lumbar forces less than 47 N, and included a left thoracic extension working as a counter pad. The second one consisted of low thoracic forces less than 20 N, lumbar forces up to 70 N, without left thoracic extension. The simulations showed that the passive forces only produced a coronal Cobb angle correction up to 9 degrees, whereas real correction was up to 16 degrees. CONCLUSION High thoracic pads reduced more effectively both thoracic and lumbar scoliotic curves than lumbar pads only. The study suggests that mechanisms other than Brace pads produce correction and contribute to the force equilibrium within the Brace.

  • personalized biomechanical modeling of Boston Brace treatment in idiopathic scoliosis
    Studies in health technology and informatics, 2002
    Co-Authors: Delphine Perie, Jean Dansereau, Ce Aubin, M Lacroix, Y Lafon, H Labelle
    Abstract:

    The aim of this study was to describe how the Boston Brace modify the scoliotic curvatures using a finite element (FE) model and experimental measurements. The experimental protocol, applied on 12 scoliotic girls, was composed of the pressure measurement at the Brace-torso interface followed by two radiographic acquisitions of the patient's torso with and without Brace. A 3D FE model of the trunk was built for each unBraced patient. The Brace treatment was represented by two different modeling approaches: 1) using equivalent forces calculated from the measured pressures; 2) by an explicit personalized FE model of the Brace (hexahedral elements) and its interface with the torso (contact elements). In the first model, measured Brace forces less than 40N and up to 113N induced respectively less than 21% and up to 87% of real correction. Thoracic forces induced the main correction, affecting partially both lumbar and thoracic curves, in agreement with the literature. In the second model, the Brace closing reduced the curves up to 35% of real correction. Contact reaction forces (16-79N) were similar to real Brace forces (11-72N). The results suggested that other mechanisms than Brace pads contribute to the equilibrium of the patients. Postural control by the muscular system remains a problem to address in a future study. The second model represented more realistically the load transfer from the Brace to the spine than external forces application. With such model, it is expected to predict the effect of a Brace before its design and manufacturing, and also to improve its design.

  • Rib cage-spine coupling patterns involved in Brace treatment of adolescent idiopathic scoliosis.
    Spine, 1997
    Co-Authors: Carl-eric Aubin, Jean Dansereau, Jacques A. De Guise, Hubert Labelle
    Abstract:

    Study Design. The three-dimensional (3-D) interrelations in the correction of the spine and rib cage produced by the Boston Brace were analyzed in a group of adolescents with idiopathic scoliosis, Objectives. To investigate the coupiing movements between the spine and rib cage initiated by Brace wear (i.e, the displacements of the spine that take place in other directions than the ones generated by Brace pressures on the thorax). Summary of Background Data. The effects of thoraco-lumbo-sacral orthosis in the frontal plane have been well documented, but they have never been studied in terms of 3-D coupled movements between the spine and rib cage. Methods. The spine and rib cage of 36 adolescents with idiopathic scoliosis with and without their Boston Brace were reconstructed in 3-D using a stereo-radiographic technique. Several geometric indices were evaluated on the trunk, and the relative motions of the spine and rib cage resulting from Brace wearing were compared by means of Student t tests. Pearson correlation matrices, and linear regressions. Results. Rib cage transverse plane translations resulting from Brace pressures are related to those of the spine. Coupled movements between the spine and rib cage were found to alter substantially the expected 3-D correction of the trunk. Significant anterior displacements of the thorax were observed and were statistically associated with lateral displacements of the spine and with an increase of spinal thoracic curvatures in the frontal and sagittal planes. Conclusion. Brace loads- are not applied in an opti-mal way to correct the 3-D- deformities associated with thoracic idiopathic scoliosis. Loads applied on the posterior rib hump should be reequilibrated to reduce anterior displacement of the trunk.

  • Three-dimensional Effect of the Boston Brace on the Thoracic Spine and Rib Cage
    Spine, 1996
    Co-Authors: Hubert Labelle, Jean Dansereau, C. Bellefleur, Benoit Poitras
    Abstract:

    Study design Three-dimensional reconstructions of the spine and rib cage were done and compared just before and 1 month after initiation of treatment with a Boston Brace in a group of adolescents with idiopathic scoliosis. Objectives To document the immediate changes in shape of the thoracic spine and rib cage induced by the original Boston Brace design. Summary of background data The effect of the Boston Brace has been well documented in the frontal plane but is poorly understood in the other planes of deformity. Methods Three-dimensional reconstructions were obtained with and without the Brace using a stereoradiographic technique in a group of 40 adolescents with idiopathic scoliosis. Several geometric indices of the spine and rib cage were compared using Student t tests. Results The Brace produced significant curve correction of the spinal deformity in the frontal plane at the expense of a significant reduction of thoracic kyphosis in the sagittal plane, as well as in the plane of minimum deformity. No significant effect on rotation of the thoracic apical vertebra, on the rib hump, or on frontal balance could be documented, but changes were noted in the sagittal orientation of the rib cage and in the sagittal balance of the spine. Conclusions The original Boston Brace does not completely correct the three-dimensional deformities associated with thoracic idiopathic scoliosis, although it reduces Cobb angles in the frontal plane.

Carl-eric Aubin - One of the best experts on this subject based on the ideXlab platform.

  • Virtual prototyping of a Brace design for the correction of scoliotic deformities
    Medical & Biological Engineering & Computing, 2007
    Co-Authors: Julien Clin, Carl-eric Aubin, Hubert Labelle
    Abstract:

    Based on a three-dimensional patient-specific finite element model of the spine, rib cage, pelvis and abdomen, a parametric model of a thoraco-lumbo-sacral orthosis (TLSO) was built. Its geometry is custom-fit to the patient. The rigid shell, pads and openings are all represented. The interaction between the trunk and the Brace is modeled by a point-to-surface contact interface. During the nonlinear simulation process, the Brace is opened, positioned on the patient and strap tension is applied. A TLSO similar to Boston Brace system was built for a right-thoracic scoliotic patient. The influences of the trochanter pad and strap tension on the 3-D geometrical corrections and on the forces generated by the Brace were evaluated. The role of the trochanter pad as a lever arm is confirmed by the model. The Brace induces a reduction of the lordosis and pelvic tilt. The reduction of the frontal curvature is about 20% for a strap tension of 60 N. Axial rotation does not significantly change and rib hump is worsened. By using an explicit Brace model and a contact interface, a more realistic simulation of orthotic treatment of scoliosis can be achieved. The stabilization of the Brace on the patient can be represented and less restrictive boundary conditions can be applied. This model could be used to study the effect of design parameters on the Brace efficiency.

  • biomechanical evaluation of the Boston Brace system for the treatment of adolescent idiopathic scoliosis relationship between strap tension and Brace interface forces
    Spine, 2004
    Co-Authors: Jeanmarc Macthiong, Carl-eric Aubin, Jean Dansereau, Yvan Petit, Sebastien Delorme, Hubert Labelle
    Abstract:

    Study Design. Prospective study to evaluate the association between strap tension and Brace interface forces in the treatment of adolescent idiopathic scoliosis using the Boston Brace system. Objectives. To determine the strap tension associated with optimal Brace interface forces. Summary of Background Data. Trim lines, pad placement, and areas of relief for the Brace are guided by radiographic studies. However, optimal adjustment of strap tension is unclear and remains mostly empirical. Methods. Brace interface forces in all regions of the trunk were measured for 41 patients with adolescent idiopathic scoliosis at three standardized strap tensions (20 N, 40 N, and 60 N). The Brace interface forces were assessed using a mat made of force-sensing transducers. Equivalent interface pressure for each trunk region was also calculated to estimate the distribution of the interface forces. Results. The Brace interface forces and the corresponding effective areas increased along with the strap tension for all patients. For patients with a single right thoracic curve, the interface pressure tended to increase with increasing strap tension. This increase was significant in the left axillary, right thoracic, right pelvic, and sternal regions. For double right thoracic–left lumbar curves, the increase in interface pressure was significant in the left axillary, right pelvic, and sternal regions. However, most of this increase occurred between 20 N and 40 N of strap tension, with only slight increase or even a decrease in interface pressures between 40 N and 60 N. Conclusions. The strap tension should be set as high as possible (up to 60 N) for right thoracic curves. For right thoracic–left lumbar curves, the optimal strap tension was ∼40 N. However, clinicians should ensure that the prescribed strap tension does not cause excessive skin pressure or affect the compliance with the Brace. A side opening in the right lumbar area may improve the effectiveness of the Brace for double right thoracic-left lumbar curves, but care must be taken to avoid skin problems at the opening.

  • Boston Brace correction in idiopathic scoliosis a biomechanical study
    Spine, 2003
    Co-Authors: Delphine Perie, Carl-eric Aubin, Jean Dansereau, Yvan Petit, Marie Beausejour, Hubert Labelle
    Abstract:

    STUDY DESIGN To analyze Boston Brace biomechanics, pressure measurements and finite element simulations were done on 12 adolescent idiopathic scoliosis patients. OBJECTIVES The aim was to analyze the Boston Brace effectiveness using a finite element model and experimental measurements. SUMMARY OF BACKGROUND DATA There are not very many biomechanical studies of Boston Brace effectiveness, and its biomechanical action is not completely understood. METHODS This study was performed on 12 girls with scoliosis treated with the Boston Brace system. The experimental protocol was composed of the acquisition of two sets of multiplanar radiographs with and without Brace followed by the pressure acquisition at the Brace-torso interface. A personalized finite element modeling of the trunk was generated from the 3D reconstruction of the patient's geometry. The Brace treatment was simulated by the application of equivalent forces calculated from the pressure measurements. RESULTS Two Boston Brace force patterns were defined from the pressure measurements. The first one consisted of high right thoracic forces of 31-113 N, lumbar forces less than 47 N, and included a left thoracic extension working as a counter pad. The second one consisted of low thoracic forces less than 20 N, lumbar forces up to 70 N, without left thoracic extension. The simulations showed that the passive forces only produced a coronal Cobb angle correction up to 9 degrees, whereas real correction was up to 16 degrees. CONCLUSION High thoracic pads reduced more effectively both thoracic and lumbar scoliotic curves than lumbar pads only. The study suggests that mechanisms other than Brace pads produce correction and contribute to the force equilibrium within the Brace.

  • Rib cage-spine coupling patterns involved in Brace treatment of adolescent idiopathic scoliosis.
    Spine, 1997
    Co-Authors: Carl-eric Aubin, Jean Dansereau, Jacques A. De Guise, Hubert Labelle
    Abstract:

    Study Design. The three-dimensional (3-D) interrelations in the correction of the spine and rib cage produced by the Boston Brace were analyzed in a group of adolescents with idiopathic scoliosis, Objectives. To investigate the coupiing movements between the spine and rib cage initiated by Brace wear (i.e, the displacements of the spine that take place in other directions than the ones generated by Brace pressures on the thorax). Summary of Background Data. The effects of thoraco-lumbo-sacral orthosis in the frontal plane have been well documented, but they have never been studied in terms of 3-D coupled movements between the spine and rib cage. Methods. The spine and rib cage of 36 adolescents with idiopathic scoliosis with and without their Boston Brace were reconstructed in 3-D using a stereo-radiographic technique. Several geometric indices were evaluated on the trunk, and the relative motions of the spine and rib cage resulting from Brace wearing were compared by means of Student t tests. Pearson correlation matrices, and linear regressions. Results. Rib cage transverse plane translations resulting from Brace pressures are related to those of the spine. Coupled movements between the spine and rib cage were found to alter substantially the expected 3-D correction of the trunk. Significant anterior displacements of the thorax were observed and were statistically associated with lateral displacements of the spine and with an increase of spinal thoracic curvatures in the frontal and sagittal planes. Conclusion. Brace loads- are not applied in an opti-mal way to correct the 3-D- deformities associated with thoracic idiopathic scoliosis. Loads applied on the posterior rib hump should be reequilibrated to reduce anterior displacement of the trunk.

  • biomechanical simulation of the effect of the Boston Brace on a model of the scoliotic spine and thorax
    Annales De Chirurgie, 1993
    Co-Authors: Carl-eric Aubin, Jean Dansereau, H Labelle
    Abstract:

    A biomechanical model was developed to investigate the immediate effect of the Boston Brace on the spine and thorax of two scoliotic patients (12 year old females with identical lumbar curves of 37 degrees and thoracic curves of 32 degrees and 25 degrees). This model is an improvement of Stokes model and incorporates several modifications concerning the modelling of costo-vertebral and costo-transverse joints. Forces generated by Braces on the thorax were measured by pressure sensors and used as input into the finite element model. The deformed models were compared to the geometry of the same patients wearing their Brace and with Stokes model. Concordance of results supports the modelling method. Differences between Stokes and improved models were observed. However, because of the small amount of patients included in this study, it is not possible to conclude on the effect of the modelling improvements.

Rene M Castelein - One of the best experts on this subject based on the ideXlab platform.

  • spinal growth in patients with juvenile idiopathic scoliosis treated with Boston Brace a retrospective study
    Spine, 2020
    Co-Authors: Johan L Heemskerk, Sebastiaan P J Wijdicks, Mark Altena, Rene M Castelein, Moyo C Kruyt, Diederik H R Kempen
    Abstract:

    Study design Retrospective comparative cohort. Objective The aim of this study was to determine whether spinal growth is restricted by Brace treatment in patients with juvenile idiopathic scoliosis (JIS). Summary of background data Spinal fusion can negatively affect spinal growth if performed before the growth spurt. Brace treatment is often given in this young population to control the spinal deformity while allowing spinal growth. It is unknown whether the applied pressure of Brace treatment on spine results in growth restriction. The aim of the study is to evaluate spinal growth in Braced JIS patients. Methods A total of 49 JIS patients treated with Boston Brace were retrospectively selected from a scoliosis database. T1-T12/T1-S1 perpendicular and freehand (height following the curvature of the spine) height were measured on radiographs of patients that had reached skeletal maturity and were matched with 49 controls without scoliosis. Spinal growth was calculated from Brace initiation until cessation and was compared with normal spinal growth values as reported by Dimeglio. Results The mean age of diagnosis was 7.4 years. The age of the Braced scoliosis patients at skeletal maturity was 17.5 years. The average T1-T12 and T1-S1 freehand height measured by following the curvature of the scoliosis was 29.3 cm (±2.4) and 47.2cm (±4.0), respectively, and was not significant different from the control group. Brace treatment was initiated at a mean age of 11.2 and the mean age of cessation was 14.8. Spinal growth (freehand) during Brace treatment was 1.10 cm/year for the thoracic spine and 1.78 cm/year for the full spine and was not significant different from normal values. Conclusion No significant influence of bracing on spinal growth could be detected in this cohort of JIS patients. The spinal height measurements at skeletal maturity were similar to matched controls. In addition, spinal growth did not significantly differ from Dimeglio normal growth data, indicating that the effect of bracing on spinal growth is absent or minimal. Level of evidence 3.

  • Idiopathic scoliosis: prognostic value of the profile
    European Spine Journal, 1992
    Co-Authors: Rene M Castelein, Ben Veraart
    Abstract:

    A study was undertaken to establish the significance of the sagittal shape of the spine in 138 consecutively treated girls with early idiopathic thoracic scoliosis. All were treated in a Boston Brace. Two groups were formed: group I consisted of 120 girls whose scoliosis remained stable in the Brace, group II of 18 girls who required a spinal fusion for progressive curves despite the Brace. For each spine, the orientation of each vertebra to the horizontal in the sagittal plane was measured on the earliest lateral radiogram, taken when the anterior curve still had a Cobb angle of less than 20°. A significant difference in spinal profile was found between the two groups. Progressive curves showed a more retroverted orientation of mid- and high thoracic vertebrae than stable curves. Une étude a été entreprise sur une série consécutive, pour définir la valeur de la disposition sagittale du rachis chez 138 filles présentant une scoliose thoracique idiopathique d'installation précoce. Toutes ont été traitées par un corset de Boston. On a pu distinguer deux groupes: un groupe I comportant 120 filles restant stables sous corset, et un groupe II formé de 18 filles ayant nécessité une fusion rachidienne en raison de la progressivité de leur courbure scoliotique malgré le corset. Pour chaque rachis, l'orientation de chaque vertèbre par rapport à l'horizontale a été mesurée dans le plan sagittal, sur le premier cliché de profil, au moment où la courbure frontale mesurée selon la méthode de Cobb était inférieure à 20°. Une différence significative a été mise en évidence entre les profils rachidiens des deux groupes. Les vertèbres thoraciques moyennes et hautes présentaient une rétroversion plus marquée dans les courbures évolutives que dans les courbures stables.

Nikolaos V Bardakos - One of the best experts on this subject based on the ideXlab platform.

  • METHODOLOGY Open Access Brace technology thematic series: the dynamic
    2013
    Co-Authors: Theodoros B Grivas, Achilles Bountis, Irene Vrasami, Nikolaos V Bardakos
    Abstract:

    Background: The dynamic derotation Brace (DDB) was designed in Greece in 1982, as a modification of the Boston Brace. It is a custom-made, underarm spinal orthosis featuring aluminium blades set to produce derotating and anti-rotating effects on the thorax and trunk of patients with scoliosis. It is indicated for the non-operative correction of most curves, barring the very high thoracic ones, (when the apex vertebra is T5 or above). The purpose of this article is to familiarize physicians with the DDB, analyze the rationale behind its design, and present the published results of its application. Description & Principles: The key feature of the DDB is the addition of the aluminium-made derotating blades posteriorly. These function as a force couple, which is added to the side forces exerted by the Brace itself. Corrective forces are also directed through pads. One or more of previously proposed pathomechanical models of scoliosis may underline the corrective function of the DDB: it may act directly on the apical intervertebral disc, effecting correction through the Heuter-Volkman principle; the blades may produce an anti-rotatory element against the deforming “spiral composite muscle trunk rotator"; or it may alter the neuro-motor response by constantly providing new somatosensory input to the patient. Results: Based on measurements of the Cobb and Perdriolle angles, up to 82 % of patients remained stable or improved with the use of the DDB. Results have varied, though, depending on the type/location of the deformity. The overall results showed that 35 % of the curves improved, 46 % remained stable and 18 % became worse, as assessed by measuring the Cobb angle. The DDB has also been shown to improve cosmesis (except for right thoracic curves) and leave several aspects of patient quality of life unaffected during use. Conclusion: Conservative treatment of idiopathic scoliosis using the DDB has shown favorable results. Thoracic curves appear more resistant to both angular and rotatory correction. The published outcome data on the DDB support our belief that the incorporation of aluminium blades to other orthoses would likely improve their efficacy

  • Brace technology thematic series: the dynamic derotation Brace
    Scoliosis, 2010
    Co-Authors: Theodoros B Grivas, Achilles Bountis, Irene Vrasami, Nikolaos V Bardakos
    Abstract:

    Background The dynamic derotation Brace (DDB) was designed in Greece in 1982, as a modification of the Boston Brace. It is a custom-made, underarm spinal orthosis featuring aluminium blades set to produce derotating and anti-rotating effects on the thorax and trunk of patients with scoliosis. It is indicated for the non-operative correction of most curves, barring the very high thoracic ones, (when the apex vertebra is T5 or above). The purpose of this article is to familiarize physicians with the DDB, analyze the rationale behind its design, and present the published results of its application. Description & Principles The key feature of the DDB is the addition of the aluminium-made derotating blades posteriorly. These function as a force couple, which is added to the side forces exerted by the Brace itself. Corrective forces are also directed through pads. One or more of previously proposed pathomechanical models of scoliosis may underline the corrective function of the DDB: it may act directly on the apical intervertebral disc, effecting correction through the Heuter-Volkman principle; the blades may produce an anti-rotatory element against the deforming "spiral composite muscle trunk rotator"; or it may alter the neuro-motor response by constantly providing new somatosensory input to the patient. Results Based on measurements of the Cobb and Perdriolle angles, up to 82% of patients remained stable or improved with the use of the DDB. Results have varied, though, depending on the type/location of the deformity. The overall results showed that 35% of the curves improved, 46% remained stable and 18% became worse, as assessed by measuring the Cobb angle. The DDB has also been shown to improve cosmesis (except for right thoracic curves) and leave several aspects of patient quality of life unaffected during use. Conclusion Conservative treatment of idiopathic scoliosis using the DDB has shown favorable results. Thoracic curves appear more resistant to both angular and rotatory correction. The published outcome data on the DDB support our belief that the incorporation of aluminium blades to other orthoses would likely improve their efficacy.