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.
Similar content being viewed by others
References
Andriacchi TP, Schultz AB, Belytschko TB, Dewald R (1976) Milwaukee brace correction of idiopathic scoliosis. A biomechanical analysis and a restrospective study. J Bone Joint Surg Am 58(6):806–815
Aubin CE, Dansereau J, De Guise JA, Labelle H (1996) A study of biomechanical coupling between spine and rib cage in the treatment by orthosis of scoliosis. Ann Chir 50(8):641–650
Aubin CE, Descrimes JL, Dansereau J, Skalli W, Lavaste F, Labelle H (1995) Geometrical modeling of the spine and the thorax for the biomechanical analysis of scoliotic deformities using the finite element method. Ann Chir 49(8):749–761
Aubin CE, Dansereau J, Parent F, Labelle H, de Guise JA (1997) Morphometric validations of personalized 3-D reconstructions and geometric models of the human spine. Med Biol Eng Comput 35(6):611–618
Aubin CE, Labelle H, Ruszkowski A, Petit Y, Gignac D, Joncas J, Dansereau J (1999) Variability of strap tension in brace treatment for adolescent idiopathic scoliosis. Spine 24(4):349–354
Chase AP, Bader DL, Houghton GR (1989) The biomechanical effectiveness of the Boston brace in the management of adolescent idiopathic scoliosis. Spine 14(6):636–642
Delorme S, Petit Y, de Guise JA, Labelle H, Aubin CE, Dansereau J (2003) Assessment of the 3-D reconstruction and high-resolution geometrical modeling of the human skeletal trunk from 2-D radiographic images. IEEE Trans Biomed Eng 50(8):989–998
Descrimes JL, Aubin CE, Skalli W et al (1995) Introduction des facettes articulaires dans une modélisation par éléments finis de la colonne vertébrale et du thorax scoliotique : aspects mécaniques. Rachis 5:301–314
Duke K, Aubin CE, Dansereau J, Labelle H (2005) Biomechanical simulations of scoliotic spine correction due to prone position and anaesthesia prior to surgical instrumentation. Clin Biomech (Bristol, Avon). Jul 29
Emans John (2003) The bracing manual, the Boston brace. Scoliosis Research Society (http://www.srs.org)
Galante J, Schultz A, Dewald RL, Ray RD (1970) Forces acting in the Milwaukee brace on patients undergoing treatment for idiopathic scoliosis. J Bone Joint Surg Am 52(3):498–506
Gignac D, Aubin CE, Dansereau J, Labelle H (2000) Optimization method for 3D bracing correction of scoliosis using a finite element model. Eur Spine J 9(3):185–190
Goldberg CJ, Moore DP, Fogarty EE, Dowling FE (2001) Adolescent idiopathic scoliosis: the effect of brace treatment on the incidence of surgery. Spine 26(1):42–47
Jiang H, Raso V, Hill D et al (1992) Interface pressures in the Boston brace treatment for scoliosis: a preliminary study. In: Dansereau J (ed) International symposium on 3-D scoliotic deformities. Montréal: Éditions de l’École Polytechnique, and Stuttgart: Gustav Fisher Verlag pp 395–399
Labelle H, Dansereau J, Bellefleur C, Poitras B (1992) 3-D study of the immediate effect of the Boston brace on the scoliotic lumbar spine. Ann Chir 46(9):814–820
Labelle H, Dansereau J, Bellefleur C, Poitras B (1996) Three-dimensional effect of the Boston brace on the thoracic spine and rib cage. Spine 21(1):59–64
Mac-Thiong JM, Petit Y, Aubin CE, Delorme S, Dansereau J, Labelle H (2004) Biomechanical evaluation of the Boston brace system for the treatment of adolescent idiopathic scoliosis: relationship between strap tension and brace interface forces. Spine 29(1):26–32
Nachemson AL, Peterson LE (2004) Effectiveness of treatment with a brace in girls who have adolescent idiopathic scoliosis. Prospective, controlled study based on data from the brace study of the Scoliosis Research Society. J Bone Joint Surg Am 77(6):815–822
Noonan KJ, Weinstein SL, Jacobson WC, Dolan LA (1996) Use of the Milwaukee brace for progressive idiopathic scoliosis. J Bone Joint Surg Am 78(4):557–567
Odermatt D, Mathieu PA, Beausejour M, Labelle H, Aubin CE (2003) Electromyography of scoliotic patients treated with a brace. J Orthop Res 21(5):931–936
Patwardhan AG, Bunch WH, Meade KP, Vanderby R Jr, Knight GW (1986) A biomechanical analog of curve progression and orthotic stabilization in idiopathic scoliosis. J Biomech 19(2):103–117
Perie D, Aubin CE, Lacroix M, Lafon Y, Labelle H (2004) Biomechanical modelling of orthotic treatment of the scoliotic spine including a detailed representation of the brace-torso interface. Med Biol Eng Comput 42(3):339–344
Perie D, Aubin CE, Petit Y, Beausejour M, Dansereau J, Labelle H (2003) Boston brace correction in idiopathic scoliosis: a biomechanical study. Spine 28(15):1672–1677
Perie D, Aubin CE, Petit Y, Labelle H, Dansereau J (2004) Personalized biomechanical simulations of orthotic treatment in idiopathic scoliosis. Clin Biomech (Bristol, Avon) 19(2):190–195
Petit Y, Aubin CE, Labelle H (2004) Patient-specific mechanical properties of a flexible multi-body model of the scoliotic spine. Med Biol Eng Comput 42(1):55–60
Rowe DE et al (1997) A meta-analysis of the efficacy of non-operative treatments for idiopathic scoliosis. J Bone Joint Surg Am 79:664–674
Sanders JE, Greve JM, Mitchell SB, Zachariah SG (1998) Material properties of commonly-used interface materials and their static coefficients of friction with skin and socks. J Rehabil Res Dev 35(2):161–176
Stokes IA (1994) Three-dimensional terminology of spinal deformity. A report presented to the Scoliosis Research Society by the Scoliosis Research Society working group on 3-D terminology of spinal deformity. Spine 19(2):236–248
Van den Hout JA, van Rhijn LW, van den Munckhof RJ, van Ooy A (2002) Interface corrective force measurements in Boston brace treatment. Eur Spine J 11(4):332–335
Vaz G, Roussouly P, Berthonnaud E, Dimnet J (2002) Sagittal morphology and equilibrium of pelvis and spine. Eur Spine J 11(1):80–87
Wong MS, Mak AF, Luk KD, Evans JH, Brown B (2000) Effectiveness and biomechanics of spinal orthoses in the treatment of adolescent idiopathic scoliosis (AIS). Prosthet Orthot Int 24(2):148–162
Wynarsky GT, Schultz AB (1991) Optimization of skeletal configuration: studies of scoliosis correction biomechanics. J Biomech 24(8):721–732
Wynarsky GT, Schultz AB (1989) Trunk muscle activities in braced scoliosis patients. Spine 14(12):1283–1286
Zhang M, Mak AF (1999) In vivo friction properties of human skin. Prosthet Orthot Int 23(2):135–141
Acknowledgments
This study was funded by the Natural Sciences and Engineering Research Council of Canada. Thanks to Dr. Kajsa Duke Ph.D. for the careful revision of the text.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Clin, J., Aubin, CÉ. & Labelle, H. Virtual prototyping of a brace design for the correction of scoliotic deformities. Med Bio Eng Comput 45, 467–473 (2007). https://doi.org/10.1007/s11517-007-0171-4
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11517-007-0171-4