Ciments Acryliques N. Sahraoui

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March 23, 2009
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Ciments Acryliques N. Sahraoui

JV 2009 8h30-8h45 Ciments Acryliques N. Sahraoui

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journeevertebro

March 23, 2009
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  1. ACTUALITES EN VERTEBROPLASTIE Comité Scientifique National du S.T.I.C. « Cyphoplastie

    par Ballonnets » du Ministère de la Santé 23 M A R S 2 0 0 9
  2. ACTUALITES EN VERTEBROPLASTIE Comité Scientifique National du S.T.I.C. « Cyphoplastie

    par Ballonnets » du Ministère de la Santé 23 M A R S 2 0 0 9
  3. ACTUALITES EN VERTEBROPLASTIE Comité Scientifique National du S.T.I.C. « Cyphoplastie

    par Ballonnets » du Ministère de la Santé 23 M A R S 2 0 0 9
  4. Momomer release from PMMA bone cements during vertebroplasty Dr N.

    SAHRAOUI Dr C. LAVERGNE Dr C. Sender TEKNIMED
  5. Propagation Initiation LIQUID phase + POWDER (MMA – DMPT -

    HQ) (PMMA beads – BPO – opacifier..) Polymerization reaction LIQUID phase + POWDER (MMA – DMPT - HQ) (PMMA beads – BPO – opacifier..) Polymerization reaction LIQUID phase + POWDER (MMA – DMPT - HQ) (PMMA beads – BPO – opacifier..) Polymerization reaction LIQUID phase + POWDER (MMA – DMPT - HQ) (PMMA beads – BPO – opacifier..) Polymerization reaction LIQUID phase + POWDER (MMA – DMPT - HQ) (PMMA beads – BPO – opacifier..) Polymerization reaction LIQUID phase + POWDER (MMA – DMPT - HQ) (PMMA beads – BPO – opacifier..) Polymerization reaction LIQUID phase + POWDER (MMA – DMPT - HQ) (PMMA beads – BPO – opacifier..) Polymerization reaction Initiation LIQUID phase + POWDER (MMA – DMPT - HQ) (PMMA beads – BPO – opacifier..) Polymerization reaction Propagation Initiation LIQUID phase + POWDER (MMA – DMPT - HQ) (PMMA beads – BPO – opacifier..) Polymerization reaction Polymerization reaction LIQUID phase + POWDER (MMA – DMPT - HQ) (PMMA beads – BPO – opacifier..) Polymerization reaction LIQUID phase + POWDER (MMA – DMPT - HQ) (PMMA beads – BPO – opacifier..) Polymerization reaction LIQUID phase + POWDER (MMA – DMPT - HQ) (PMMA beads – BPO – opacifier..) Polymerization reaction LIQUID phase + POWDER (MMA – DMPT - HQ) (PMMA beads – BPO – opacifier..) Polymerization reaction LIQUID phase + POWDER (MMA – DMPT - HQ) (PMMA beads – BPO – opacifier..) Polymerization reaction LIQUID phase + POWDER (MMA – DMPT - HQ) (PMMA beads – BPO – opacifier..) Polymerization reaction Initiation LIQUID phase + POWDER (MMA – DMPT - HQ) (PMMA beads – BPO – opacifier..) Polymerization reaction Propagation Initiation LIQUID phase + POWDER (MMA – DMPT - HQ) (PMMA beads – BPO – opacifier..) Polymerization reaction Propagation Initiation LIQUID phase + POWDER (MMA – DMPT - HQ) (PMMA beads – BPO – opacifier..) Polymerization reaction Propagation Initiation LIQUID phase + POWDER (MMA – DMPT - HQ) (PMMA beads – BPO – opacifier..) Polymerization reaction Propagation LIQUID phase + POWDER (MMA – DMPT - HQ) (PMMA beads – BPO – opacifier..) LIQUID phase + POWDER (MMA – DMPT - HQ) (PMMA beads – BPO – opacifier..)
  6. None
  7. Initiation Act Init LIQUID phase + POWDER (MMA – DMPT

    - HQ) (PMMA beads – BPO – opacifier..) Polymerization reaction Propagation
  8. Polymerization reaction

  9. What about the MMA release

  10. -II/ Cement thickness : less than thick ones thin specimens

    release MMA release depends of various factors: Monomer release - I/ Powder/liquid ratio (g/ml): 2.5 < P/L < 2 increased porosity longer curing time monomer release
  11. - Start of cooling of bone cement practically no release

    - Mixing setting of bone cement Largest and most rapid release Monomer release
  12. Residual MMA after curing ≅ 2-6 % Monomer release

  13. 1st STUDY

  14. P/L Spineplex (w/w) 1,5 KyphX (w/ w) 1,5 Osteopal V

    (w/w) 1,5 Opacity+ 1,5 Powder 20g 20g 26g 27.2g PMMA 11.7 54.6 49.5 MMA- styrene 56.8 68.0 BPO 1.5 2.0 0.4 0.5 BaSO4 30 30.0 ZrO2 45 45 HAP 5 Liquid 10ml 10ml 10ml 9.2ml MMA 97.4 99.1 97.9 99.0 DMPT 2.6 0.9 2.1 1.0 HQ 75ppm 75ppm 20ppm Method : simulated monomer release on 4 vertebroplasty bone cements Bone cement compositions
  15. Determination of waiting time 40 Pa/s First step :Viscosity kinetics

    at 20°C / 45% RH with a Viscosafe rheometer from Anton Paar 1- Mixing for 1 minute 2-Tranfer into the sample container 3- Starting measurement 3min after onset of mixing 4- End at 2000 Pa.s viscosity Method
  16. Second step :In vitro injection of PMMA 1- Injection of

    4ml cement in a cancellous like foam immersed in water at 37°C; injection time corresponds to a viscosity of 40Pa.s 2- Sampling of 2ml from aqueous medium at 1, 3, 5, 10, 30 min, 1h and 1day after injection 3- Measurement of concentration of each sample by High Pressure Liquid Chromatography Method 37°
  17. Two types of bone cement Results – Viscosity kinetics

  18. Injection time at 4/5 and 11/12 min Results - Viscosity

    kinetics
  19. Main release during mixing and doughing phases Vertebroplasty/arthroplasty: less MAA

    in circulating system in spine surgery Results – Monomer release 0 3.3750 6.7500 10.1250 13.5000 1min 3min 5min 10min 30min 1h 24h MMA (mg/mL cement) Time after injection OsteopalV Spineplex Opacity+ KyphX
  20. Conclusions - Ajusting the composition of the powder phase, kinetics

    of viscosity can be controlled - Despite differences of composition, monomer release are quite similar for all tested vertebroplasty bone cements → Key parameter = visosity - Comparing verebroplasty to arthroplasty → Equivalent level of release but → Less MMA amount due to low volume injected
  21. SOLUTION : Development of a cement with a higher initial

    viscosity limiting diffusion of MMA and a slow controlled kinetics of polymerisation permitting a longer injection period. How can we reduce monomer release ? - reducing mobility of the monomer, thus injecting a cement at a higher viscosity. Drawback : the injection window is decreased Perspectives
  22. Viscosity Time No waiting time Short working time Long waiting

    time Short working time Short waiting time Long working time 40 Pa.s Confidence Classic bone cement V New generation bone cement Perspectives
  23. (Williams, 1981) MMA toxicity -Release of monomer into blood during

    curing -Systemic effect on the lung ⇒ respiratory failure - liver and kidney - cardiovascular system ⇒ cardiac arrest, fall in blood pressure
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  28. Thank you For a better life, a better health…