Properties with Histological Scores and Mechanical Properties in - - PowerPoint PPT Presentation

▶
properties with histological scores
SMART_READER_LITE
LIVE PREVIEW

Properties with Histological Scores and Mechanical Properties in - - PowerPoint PPT Presentation

Oct 28, 2022 240 likes •502 views

Correlation of Electromechanical Properties with Histological Scores and Mechanical Properties in Human Tibial Plateau S. Sim 1,2 A. Chevrier 1 M. Garon 2 E. Quenneville 2 M.D. Buschmann 1 1. Biomedical & Chemical Engineering, Polytechnique

slide-1
SLIDE 1

Correlation of Electromechanical Properties with Histological Scores and Mechanical Properties in Human Tibial Plateau

  • S. Sim1,2
  • A. Chevrier1
  • M. Garon2
  • E. Quenneville2

M.D. Buschmann1

  • 1. Biomedical & Chemical Engineering, Polytechnique Montreal, Montreal, QC, Canada
  • 2. Biomomentum Inc., Laval, QC, Canada

12th ICRS World Congress May 08-11 2015

slide-2
SLIDE 2

D isclosure

Eric Quenneville and Martin Garon are the owners of Biomomentum Inc.

slide-3
SLIDE 3

There is still an enduring demand in Orthopaedics for an

  • bjective and reliable clinically applicable technique to evaluate

articular cartilage tissue health (Spahn et al., 2011).

I ntroduction

Quantitative MRI Arthroscopy

  • Ultrasound imaging
  • Optical reflection spectroscopy
  • Pulsed laser irradiation
  • Near-infrared spectroscopy
  • dGEMRIC
  • T2 mapping
  • T1rho mapping
  • Sodium MRI

Current lack in monitoring AC degeneration with accuracy and sensitivity, mostly at an early stage of degeneration where treatments may be useful. Many research groups have focused

  • n techniques to evaluate articular cartilage:
slide-4
SLIDE 4

Our research group has developed the electromechanical probe Arthro-BST

I ntroduction

Electromechanical properties of AC Streaming potentials electric fields produced by the cartilage under load

In vitro studies showed that streaming potentials reflect the structure/function and composition of cartilage and are sensitive to degradation.

(Frank, 1987) (Legare, 2002) (Garon, 2002)

slide-5
SLIDE 5

Origins of streaming potentials?

I ntroduction

Aggrecan immobilized in a network of collagen fibrils

Positive ions In the fluid

GAG

E=0

GAG

Mobile Positive Ions

slide-6
SLIDE 6

Origins of streaming potentials?

I ntroduction

Aggrecan immobilized in a network of collagen fibrils

Positive ions In the fluid

GAG

E

Streaming potentials Fluid flow induced by cartilage loading

slide-7
SLIDE 7

I ntroduction

Streaming potentials are recorded by the Arthro-BST by each microelectrode when the indenter is manually compressed against the articular cartilage

  • surface. The quantitative parameter (QP) corresponds to the number of

microelectrodes in contact with the cartilage (contact area) when the sum of their streaming potentials reaches 100 mV.

  • High QP = Weak electromechanical properties

Contact Area on Spherical Tip

mV Time

slide-8
SLIDE 8

I ntroduction

Contact Area on Spherical Tip

mV Time

Streaming potentials are recorded by the Arthro-BST by each microelectrode when the indenter is manually compressed against the articular cartilage

  • surface. The quantitative parameter (QP) corresponds to the number of

microelectrodes in contact with the cartilage (contact area) when the sum of their streaming potentials reaches 100 mV.

  • Low QP = Strong electromechanical properties
slide-9
SLIDE 9

A previous study on human distal femurs (Sim et al., 2014) showed that the electromechanical QP correlated strongly:

  • with the Mankin score
  • with unconfined compression parameters (fibril modulus, matrix modulus,

permeability) While weaker correlations were observed with the biochemical composition (GAG per wet weight) and water content.

I ntroduction

(Sim et al., 2014)

slide-10
SLIDE 10

The purpose of this study was to investigate if electromechanical properties of human tibial plateau correlate strongly with histological scores and with mechanical properties as in human distal femurs.

I ntroduction

slide-11
SLIDE 11

Samples Six pairs of tibial plateau from human donors (5 males and 1 female, average age 48 years) were provided by RTI Surgical (FL, USA).

M ethods

slide-12
SLIDE 12

Overview

M ethods

Visual Assessment ICRS Grading Electromechanical Assessment Arthro-BSTTM Extraction of cores Tubular chisels Unconfined compression of cores Mach-1TM Histological assessment of cores Mankin score

ICRS Grade > 0

slide-13
SLIDE 13

Visual Assessment

M ethods

Normal Degraded

ICRS Grade > 0

slide-14
SLIDE 14

Camera-Registration System + Electromechanical Assessment

M ethods

slide-15
SLIDE 15

Camera-Registration System + Electromechanical Assessment

M ethods

Contact Area on Spherical Tip

16.0

slide-16
SLIDE 16

Camera-Registration System + Electromechanical Assessment

M ethods

Contact Area on Spherical Tip

7.0

slide-17
SLIDE 17

Extraction of cores

M ethods

  • Harvested from normal and degraded regions
  • Precisely document the location of each core relative to the position grid used for

Arthro-BST measurements

  • The QP of each core was calculated as the average of all QPs measured within 6 mm

from the core center location

slide-18
SLIDE 18

Unconfined compression on cores

M ethods

  • 56 cores
  • Thickness measured using a calibrated dissection microscope
  • Using Mach-1 (Biomomentum) mechanical tester
  • Precompression of 10% of thickness
  • Followed by 5 compressions each of 2% of thickness

Fibril modulus (Ef) Equilibrium modulus (Em) Permeability (k) Soulhat et al., 1999

Time (s) Load (N)

slide-19
SLIDE 19

Histology on cores

M ethods

  • 56 cores
  • Safranin O-Fast Green-stained sections
  • Scored with the Mankin histological-histochemical grading system (Mankin et al., 1971)
  • One blinded observer

Mankin Score

slide-20
SLIDE 20

R esults

Electromechanical QP vs. Unconfined Compression

Strong correlations between QP and :

  • Ef

(r=−0.73, p<0.0001)

  • permeability log (k)

(r=0.64, p<0.0001) Weak correlations between QP and:

  • Em

(r=−0.30, p=0.0186)

  • thickness of AC

(r=0.42, p=0.0006)

The electromechanical QP decreases with increasing Ef and Em whereas the electromechanical QP increases with permeability and thickness, as expected.

slide-21
SLIDE 21

R esults

Electromechanical QP vs. Histology

Mankin 8 QP = 22 Mankin 0 QP = 8 Mankin 3 QP = 15

  • Strong correlation between electromechanical QP and Mankin score (r = 0.50, p = 0.0004)

Safranin O/Fast Green stained sections showed that GAG staining in the cartilage matrix and structural integrity decreased as the electromechanical QP increased, corresponding to weaker electromechanical properties.

slide-22
SLIDE 22

D iscussion

  • Measured electromechanical QP in human tibial plateau

correlated significantly with mechanical parameters and with the histological Mankin score, similar to what was found previously in human distal femurs (Sim et al., 2014).

  • A weak correlation was found between the electromechanical QP

and the thickness of the cartilage on tibial plateau (no correlation was observed on distal femurs (Sim et al., 2014)). This might be related to the fact that there is more variation in the thickness of the tibial plateau surface than distal femurs.

slide-23
SLIDE 23

C onclusion

  • These results demonstrate that the Arthro-BST QP

correlates with mechanical parameters and histological Mankin score in the tibial plateau.

  • A significant advantage is the non-destructive nature
  • f the method allowing for subsequent analysis.
  • The Arthro-BST has been designed for compatibility

with arthroscopy, and could be useful in assessing cartilage quality during surgery.

slide-24
SLIDE 24

A knowledgements

Funding was provided by:

  • National Sciences and Engineering Research Council (NSERC)
  • Fonds québécois de la recherche sur la nature et les technologies (FQRNT)
  • Biomomentum Inc.

We acknowledge the technical contributions of:

  • Geneviève Picard
  • Viorica Lascau-Coman
  • Camille Larose
  • Philippe Martel
slide-25
SLIDE 25

R eferences

  • Matzat 2013, Quant Imaging Med Surg 3:162
  • Nieminen 2012, J Magn Reson Imaging 36:1287
  • Virén 2010, Ultrasound Med Biol 36:833
  • Johansson 2011, Phys Med Biol 56:1865
  • Sato 2011, Lasers Surg Med 43:421
  • Spahn 2013, Arch Orthop Trauma Surg 133:997
  • Frank 1987, J Orthop Res 5:497
  • Legare 2002, J Orthop Res 20:819
  • Garon 2002, J Biomech 35:207
  • Sim 2014, Osteoarthritis and Cartilage 22:1926
  • Soulhat 1999, J Biomech Eng 121:340
  • Mankin 1971, J Bone Joint Surg Am 53:523