TECHNIQUE TO MAP THE BIOMECHANICAL PROPERTIES OF ENTIRE ARTICULAR - - PowerPoint PPT Presentation

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TECHNIQUE TO MAP THE BIOMECHANICAL PROPERTIES OF ENTIRE ARTICULAR - - PowerPoint PPT Presentation

Oct 26, 2023 406 likes •634 views

EVALUATION OF A NOVEL TECHNIQUE TO MAP THE BIOMECHANICAL PROPERTIES OF ENTIRE ARTICULAR SURFACES USING INDENTATION S. Sim 1, 2 , E. Quenneville 2 , M. Garon 2 , C.D. Hoemann 1 , M. Hurtig 3 and M.D. Buschmann 1 1. Biomedical & Chemical

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SLIDE 1

EVALUATION OF A NOVEL TECHNIQUE TO MAP THE BIOMECHANICAL PROPERTIES OF ENTIRE ARTICULAR SURFACES USING INDENTATION

  • S. Sim1, 2, E. Quenneville2, M. Garon2, C.D. Hoemann1, M. Hurtig3 and M.D. Buschmann1
  • 1. Biomedical & Chemical Engineering, Ecole Polytechnique de Montreal, Montreal, QC, Canada
  • 2. Biomomentum Inc., Laval, Qc, Canada
  • 3. Comparative Orthopaedic Research Laboratory, Department of Clinical Studies, University of Guelph,

Guelph, Ontario, Canada

ICRS 2013

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SLIDE 2

Purpose

  • Mechanical testing of articular cartilage is a useful outcome measure in studies of

cartilage degeneration and cartilage repair.

  • Mechanical testing can be done in different experimental configurations:

Indentation Compression Shear Torsion Tension Bending

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SLIDE 3

Practical Advantages

  • f Indentation
  • Cartilage need not be harvested

from the articular surface

  • Minimal disruption of the articular surface
  • Maintains the mechanical environment of the cartilage layer and its

interaction with the subchondral bone

  • Testing multiple sites

Indentation requires the compression axis aligned perpendicular to the articular surface. Mathematical models are more complex in indentation with a spherical indenter.

Picture from: http://www.kneeclinic.info/

Articular surface

Tide mark Calcified cartilage Subchondral bone Cancellous bone

However

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SLIDE 4

Methods

Thickness is missing

  • Automated Perpendicular Indentation:
  • spherical indenter for a new automated indentation technique
  • multiaxial load cell – uses Fx, Fy and Fz to calculate the normal force
  • 3-axis mechanical tester – uses 3 displacement components to provide

a perpendicular displacement based on the surface orientation Contact coordinates (x,y,z)

  • f predefined positions and 4

surrounding positions Surface orientation (θz) Normal force/displacement vs time

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SLIDE 5

Methods

Thickness is missing

  • Automated Perpendicular Indentation:
  • spherical indenter for a new automated indentation technique
  • multiaxial load cell – uses Fx, Fy and Fz to calculate the normal force
  • 3-axis mechanical tester – uses 3 displacement components to provide

a perpendicular displacement based on the surface orientation Contact coordinates (x,y,z)

  • f predefined positions and 4

surrounding positions Surface orientation (θz) Normal force/displacement vs time

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SLIDE 6

Methods

Thickness is missing

  • Automated Perpendicular Indentation:
  • spherical indenter for a new automated indentation technique
  • multiaxial load cell – uses Fx, Fy and Fz to calculate the normal force
  • 3-axis mechanical tester – uses 3 displacement components to provide

a perpendicular displacement based on the surface orientation Contact coordinates (x,y,z)

  • f predefined positions and 4

surrounding positions Surface orientation (θz) Normal force/displacement vs time

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SLIDE 7

Methods

Thickness is missing

  • Automated Perpendicular Indentation:
  • spherical indenter for a new automated indentation technique
  • multiaxial load cell – uses Fx, Fy and Fz to calculate the normal force
  • 3-axis mechanical tester – uses 3 displacement components to provide

a perpendicular displacement based on the surface orientation Contact coordinates (x,y,z)

  • f predefined positions and 4

surrounding positions Surface orientation (θz) Normal force/displacement vs time

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SLIDE 8

Methods

Thickness is missing

  • Automated Perpendicular Indentation:
  • spherical indenter for a new automated indentation technique
  • multiaxial load cell – uses Fx, Fy and Fz to calculate the normal force
  • 3-axis mechanical tester – uses 3 displacement components to provide

a perpendicular displacement based on the surface orientation Contact coordinates (x,y,z)

  • f predefined positions and 4

surrounding positions Surface orientation (θz) Normal force/displacement vs time

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SLIDE 9

Methods

  • Thickness measurement:

Technique adapted from Jurvelin et al., 1995

Position of the cartilage surface Position of the subchondral bone Vertical force/displacement vs time

Thickness can be obtained

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SLIDE 10

Methods

  • Thickness measurement:

Technique adapted from Jurvelin et al., 1995

Position of the cartilage surface Position of the subchondral bone Vertical force/displacement vs time

Thickness can be obtained

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SLIDE 11

Analysis – Thickness

Vertical Distance

Thickness = vertical distance x cosine (surface orientation)

Surface orientation Cartilage surface Subchondral bone

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SLIDE 12

Analysis – Automated Indentation

Instantaneous Modulus (MPa) Elastic Model in Indentation (Hayes, 1972)

Using the known thickness

Normal Force (N)

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SLIDE 13

Spherical indenter Intradermal Bever Needle from Precision Glide Camera from Point Grey Research Radius of 0.5 mm Needle size of 26G 3/8” FMVU USB 2.0

Methods

Mach-1 v500css from Biomomentum Inc.

Multiaxial mechanical tester

Device Equipment

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SLIDE 14

Methods

  • Mechanically-Controlled Surface Mapping

sample

camera

picture (1280x960 pixels) position grid superimposed converted in units of length (mm) MACH-1

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SLIDE 15

Methods

  • Samples:

Ovine Murine current use in articular cartilage repair studies use in many disease and developmental studies Male Male 100-140 lbs 0.08 lbs 4-5 y.o Mature

  • No indications of joint pathology
  • Visually normal tibial plateau and femoral condyles were collected from

closed stifle joints

Pictures from: http://www.123rf.com/

Small dimensions To reveal the high spatial resolution and sensitivity of this novel technique

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SLIDE 16

Results

≈ 150 measurements/articular surface ≈ 1 minute per indentation ≈ 30 seconds per thickness

3 D S U R F A C E

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SLIDE 17

Discussion

Works with any type of articular

cartilage as thin as murine.

Thickness obtained are in line with those

reported in the literature (Stockwell et al., 1971; Frisbie et al., 2006).

Results can also be fit with poroelastic models,

e.g. the fibril-reinforced poroelastic model where the permeability, the matrix modulus and fibril modulus can be extracted.

≠

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SLIDE 18

Discussion

  • Possible applications:
  • Characterization of articular surfaces in cartilage

repair studies

  • Monitoring of cartilage degeneration
  • Monitoring of the mechanical properties in

knockout mice knee joints

  • Characterization of bone, skin or

different materials for implants

Pictures from: http://www.genome.gov/

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SLIDE 19

Conclusions

  • This novel indentation mapping technique allows

to highlight the spatial variation over the entire surface.

  • A promising tool for studies that need to

characterize mechanical properties

  • f

the articular surface.

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SLIDE 20

Acknowledgement

  • Funding provided by National Sciences and

Engineering Research Council (NSERC), the Fonds du recherche du Québec - Nature et technologies (FRQ-NT) and Biomomentum Inc.

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SLIDE 21

Questions