Scoliose-correctie. Prof.dr.ir. Bart Verkerke Dr. A.G. Veldhuizen

Transcriptie

1 Scoliose-correctie Prof.dr.ir. Bart Verkerke Dr. A.G. Veldhuizen

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4 Dept of Biomedical Engineering

5 BMSA 1: Injury, repair, intervention and support Aim: To realize the development and application of advanced optical and biochemical diagnostic techniques for assessment of organ function, and the development of interventional strategies to assist, repair, or replace injured organs within translational setting. Approach: -Development of diagnostic tools and markers -Design of mechanical organ support systems -Development of transplantation models -Performance of applied clinical research -Design and evaluation of interventional strategies -Product-driven research BMSA 2: Microbial adhesion and infection Aim: To determine physico-chemical and biological mechanisms for the interaction of biological components with biomaterials surfaces to be applied for infection prevention by developing technology-based or tissueengineered solutions for the repair of human function. Approach: -Study of mechanisms of biomaterial-related infections -Development and assessment of adhesion-modifying coatings -Study of molecular mechanisms of biofilm-formation -Study of biofilm architecture -Analysis of clinical biofilms -Prevention of biofilm formation Normothermic liver machine perfusion for better preservation of organ function before transplantation. Organ function control is achieved by diagnostic markers/tools and by support systems Heart assist devices can be used to bridge to transplantation, or to relieve the heart muscle and therewith allow it to recover Confocal laser microscopic image of an ingrowing biofilm on a silicone rubber voice prosthesis (insert) isolated from a patient Confocal laser microscopic image of an E. coli biofilm on a monofilament surgical polypropylene mesh (insert) for abdominal wall reconstruction

6 BMSA 3: Permanent implants for function restoration Aim: To realise and test permanent implants and diagnostic instruments for the repair of human function. Approach: -Design of innovative implants -Realization of prototypes of innovative implants -Exploration of potential use of hybrid implants -Design of diagnostic tools / instruments -Development of algorithms for analysing complex images BMSA 4: Tissue engineering and scaffold materials Aim: To realise new strategies for the repair of human tissues and organs based on (biodegradable) polymers and/or humoral factors and (stem)cells. Approach: -Study of cell-scaffold interactions -Isolation,expansion, differentiation of autologous (stem/progenitor) cells -Design of innovative, smart, degradable scaffolds -Study of mechanisms of tissue repair (inflammatory niche) -Implementation of modulation of inflammation for repair -Induction of stem cell homing and angiogenesis -Development of a cell-based implantable kidney -Focus on cardiovascular, renal, bone/cartilage applications Application of memory metal as a scoliosis correction device. Scoliosis can be detected by image analysis algorithms Examples of innovative implant design: the Groningen temporomandibular joint prosthesis and a voice-producing prosthesis for laryngectomised patients (insert) Design of a degradable polyurethane scaffold material with interconnected pores, and the tissue response to the degrading scaffold (insert) Clinical evaluation of the tissue response to implants lens epithelial cells responding to the presence of an accommodating intra-ocular lens

7 Scoliose

8 Scoliose

9 Hippocrates (400 BC) Scoliose-correctie

10 Scoliose-correctie

11 Scoliose-correctie Milwaukee brace Boston brace

12 Scoliose-correctie Luque systeem Harrington methode Cotrel-Dubousset systeem

13 A vd Plaats Ontstaan van scoliose

14 Ontstaan van scoliose 3 0, ,1 0,05 Ux Uy Uz Rotx Roty Rotz 0 0 Displacement [mm] ,05-0,1 Rotation [rad] -3-0,15-4 eis: koppeling van laterale verplaatsing en axiale rotatie A vd Plaats Sacr L5 L4 L3 L2 L1 T12 T11 T10 T9 T8 T7 T6 T5 T4 T3 T2 T1-0,2 alleen als asymmetrie in: ligamentum flavum en intertransversale ligament

15 Progressie van scoliose achterblijvende groei spieren + ligamenten visco-elastisch gedrag discus, ligamenten G Nijenbanning, DJ Wever

16 Progressie van scoliose G Nijenbanning in FEM geen mm rotatores, mm multifidus, facetgewrichten; discus als balkelement

17 Ontstaan, progressie van scoliose numeriek rigid body model initiatie: symm én asymm achterblijven in groei van spieren en ligamenten progressie afhankelijk van rek in spieren en ligamenten echter: discus als bolscharnier; geen facetgewrichten; spieren en ligamenten identiek LLJ Kamman

18 Progressie van scoliose ontstaan door stoornis in evenwichtssysteem voorspelling progressie adhv spinale groei en EMG-ratio J Cheung

19 Virtuele scoliose-chirurgie optimalisatie braces optimalisatie implantaten ontstaan van scoliose progressie van scoliose bepaling stijfheid X-ray / echo digitalisatie wervelkolom geometrie operatiestrategie gebruikersinterface Numeriek model chirurgisch resultaat expert-systeem grafische representatie feedback

20 Numeriek model

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22 Model of motion segment Body-disc-body: Based on concave endplates Vertebrae: rigid bodies Intervertebral disc: annulus and nucleus Geometry: Panjabi et al.

23 Model of motion segment Intervertebral disc: Annulus fibrosus 2 layers of fibers (double mesh) +/-30 degrees with local x-axis Volume fraction 16% Nucleus Pulposus Incompressible fluid

24 Model of motion segment Validation body-disc-body with literature: High range in measured stiffness. Overall mechanical behavior corresponds well. Model is stiff in lateral bending. = model. *=measured in Thoracic region.

25 Model of motion segment Facet joints: Modeled as surfaces with cartilage in between, with low shear and tension resistance. Facet angles determine restricted motions. Results: Increase of stressstiffening (non-linear) behavior in flexion, extension and AP-shear. Geometry: Panjabi et al.

26 Model of motion segment Ligaments: Bilinear load-deformation curves: constant throughout spine. Tension only. 6 ligaments (Lumbar). Measurements: Chazal et al.

27 Sensitivity analysis Interpersonal differences Growth ±5% +10% width ±6% +20% depth ±60% +3% height ±12% ±13% ±55% +23% +43% -3% torsion ±17% ±6% ±56% +33% +21% -3% lateral bending ±4% ±20% ±58% +8% +66% -3% extension ±5% ±21% ±54% +10% +69% -3% flexion ±3% ±6% ±66% +6% +19% -3% axial compression width depth height width depth height Interpersonal differences Growth

28 Sensitivity analysis Geometry of disc and vertebrae have large influence on stiffness Growth has influence Patient specific data has to be accurate Relative size (30-50%) of nucleus has little influence No patient-specific data required.

29 Model of motion segment Influence ligaments & facet joints

30 Lumbar model Level-specific: Geometry vertebra (processes) and disc. Wedge angle of vertebrae. Facet angles (averaged for left and right).

31 Lumbar model Validation with literature: stiffness in flexion too high. Theoretical stiffness lumbar level: ¼ of motion segment. NOT in measurements: protocol or specimen differences? => Measurements with same specimen (Iris).

32 Numeriek model Motion segment with facet joints in response to extension loading. The contours represent the Von Mises stresses, in N/mm 2.

33 Numeriek model

34 Stijfheidsmeting I Busscher (ism dr Veldhuizen, Orthopedie; prof van Dieën, VUmc)

35 3D visualisatie

36 3D visualisatie X-Rays 3D CT Spine Template 2D US Spine Individual 3D CT Spine TA Sardjono, KE Purnama

37 Automatische detectie Cobb-hoek

38 Scannen met ultrageluid

39 Scannen met ultrageluid axial sagittal coronal

40 Scannen met ultrageluid

41 Scannen met ultrageluid

42 Scoliose-correctie Vormgestuurd vs Krachtgestuurd, gebruikmakend van visco-elasticiteit

43 Memory metal

44 Memory metal

45 Scoliose-correctie TriaC brace Baat Engineering, Somas, Boston Brace G Nijenbanning

46 Scoliose-correctie geheugenmetalen correctiesysteem DePuy-Spine MM Sanders, DJ Wever

47 Non-fusie scoliose-correctie Voordeel: Eerder ingrijpen, want groei is mogelijk Geen fusie

48 BMT - De kunst van het beter maken