Bone treatment systems and methods

Patent metadata

Field	Value
Publication number	US-9445854-B2
Application number	US-39552709-A
Country	US
Kind code	B2
Filing date	Feb 27, 2009
Priority date	Feb 1, 2008
Publication date	Sep 20, 2016
Grant date	Sep 20, 2016

Abstract

The present disclosure relates to bone cement formulations that have an extended working time for use in vertebroplasty procedures and other osteoplasty procedures together with cement injectors that include energy delivery systems for on-demand control of cement viscosity and flow parameters. The bone cement formulations may include a liquid component having at least one monomer and a non-liquid component including polymer particles and benzoyl peroxide (BPO). The non-liquid component may be further configured to allow controlled exposure of the BPO to the liquid monomer so as to enable control of the viscosity of the bone cement composition.

First claim

What is claimed is:

1. A bone cement system, comprising:
a pre-mixture comprising:
a first monomer-carrying component; and
a second polymer-carrying component, separate from the first monomer-carrying component, the second polymer-carrying component comprising a plurality of bead populations that have different mean particle sizes and an initiator in different amounts, the second polymer-carrying component comprising:
a first polymer bead population having a first mean particle size and including the initiator at a first weight percent of the first polymer bead population, wherein the initiator is integrated throughout the volume of each of the first polymer beads;
a second polymer bead population having a second mean particle size smaller than the first mean particle size and including the initiator at a second weight percent of the second polymer bead population that is higher than the first weight percent, wherein the initiator is integrated throughout the volume of each of the second polymer; and
a third polymer bead population having a third mean particle size smaller than the second mean particle size and including an initiator at a third weight percent of the third polymer bead population that is lower than the first weight percent,

wherein upon forming a mixture of the first monomer-carrying component and the second polymer-carrying component, different dissolution rates and the different initiator amounts of the plurality of bead populations control an availability of the initiator in the mixture that is sufficiently low and slow-varying over time, such that the temperature of the mixture remains below 75° C. and, after an initial exposure period post-mixing, a time-viscosity curve slope remains less than or equal to about 200 Pa·s/minute until the mixture reaches a viscosity of about 2500 Pa·s.

2. The bone cement system of claim 1 , wherein post-mixing the mixture is characterized as having a time-viscosity curve slope of less than or equal to about 200 Pa·s/minute for at least 5 minutes after reaching a viscosity of about 500 Pa·s.

3. The bone cement system of claim 1 , wherein after the initial exposure period post-mixing, the time-viscosity curve slope remains less than or equal to about 200 Pa·s/minute until the mixture reaches a viscosity of about 3000 Pa·s.

4. The bone cement system of claim 1 , wherein after the initial exposure period post-mixing, the mixture has a viscosity of greater than or equal to about 2000 Pa·s at about 18 minutes post-mixing and substantially before the set time of the cement.

5. The bone cement system of claim 1 , wherein after the initial exposure period post-mixing, the mixture is characterized by a change of viscosity of less than or equal to about 30%/minute for at least three minutes after reaching about 1000 Pa·s.

6. The bone cement system of claim 5 , wherein after the initial exposure period post-mixing, the mixture is characterized by a change of viscosity of less than or equal to about 30%/minute for at least about five minutes after reaching about 1000 Pa·s.

7. The bone cement system of claim 6 , wherein after the initial exposure period post-mixing, the mixture is characterized by a change of viscosity of less than or equal to about 30%/minute for at least about five minutes after reaching about 4000 Pa·s.

8. A bone cement system, comprising:
a pre-mixture comprising:
a first monomer-carrying component; and
a second polymer-carrying component, separate from the first monomer-carrying component, the second polymer-carrying component comprising a plurality of bead populations that have different mean particle sizes and an initiator in different amounts, the second polymer-carrying component comprising:
a first polymer bead population having a first mean particle size and including the initiator at a first weight percent of the first polymer bead population, wherein the initiator is integrated throughout the volume of each of the first polymer beads;
a second polymer bead population having a second mean particle size smaller than the first mean particle size and including the initiator at a second weight percent of the second polymer bead population that is higher than the first weight percent, wherein the initiator is integrated throughout the volume of each of the second polymer; and
a third polymer bead population having a third mean particle size smaller than the second mean particle size and including an initiator at a third weight percent of the third polymer bead population that is lower than the first weight percent,

wherein upon forming a mixture of the first monomer-carrying component and the second polymer-carrying component, different dissolution rates and the different initiator amounts of the plurality of bead populations control an availability of the initiator in the mixture that is sufficiently low and slow-varying over time, such that the temperature of the mixture remains below 75° C. and a time-viscosity curve slope remains less than or equal to about 200 Pa·s/minute immediately before the mixture reaches a viscosity of about 2000 Pa·s.

9. The bone cement system of claim 8 , wherein the time-viscosity curve slope is less than or equal to about 100 Pa·s/minute before the mixture reaches a viscosity of about 1500 Pa·s.

10. The bone cement system of claim 8 , wherein the time-viscosity curve slope is less than or equal to about 200 Pa·s/minute immediately before the mixture reaches a viscosity of about 1000 Pa·s.

11. A bone cement system, comprising:
a pre-mixture comprising:
a first monomer-carrying component; and
a second polymer-carrying component, separate from the first monomer-carrying component, the second polymer-carrying component comprising a plurality of bead populations that have different mean particle sizes and an initiator in different amounts, the second polymer-carrying component comprising:
a first polymer bead population having a first mean particle size and including the initiator at a first weight percent of the first polymer bead population, wherein the initiator is integrated throughout the volume of each of the first polymer beads;
a second polymer bead population having a second mean particle size smaller than the first mean particle size and including the initiator at a second weight percent of the second polymer bead population that is higher than the first weight percent, wherein the initiator is integrated throughout the volume of each of the second polymer; and
a third polymer bead population having a third mean particle size smaller than the second mean particle size and including an initiator at a third weight percent of the third polymer bead population that is lower than the first weight percent,

wherein upon forming a mixture of the first monomer-carrying component and the second polymer-carrying component, different dissolution rates and the different initiator amounts of the plurality of bead populations control an availability of the initiator in the mixture that is sufficiently low and slow-varying over time, such that the temperature of the mixture remains below 75° C. and, after an initial exposure period post-mixing, a time-viscosity curve slope remains less than or equal to about 200 Pa·s/minute at about 25 minutes.

12. The bone cement system of claim 11 , wherein after the initial exposure period post-mixing, the time-viscosity curve slope remains less than about 200 Pa·s/minute for at least about 5 minutes after reaching a viscosity of about 500 Pa·s.

13. The bone cement system of claim 11 , wherein after the initial exposure period post-mixing, the mixture has a viscosity less than about 200 Pa·s at about 15 minutes post-mixi

Assignees

• Truckai Csaba
• Kohm Andrew
• Shadduck John
• Luzzi Robert
• Dfine Inc

Inventors

• Truckai Csaba
• Kohm Andrew
• Shadduck John
• Luzzi Robert

Classifications

• A61B17/8833

  Osteosynthesis tools specially adapted for handling bone cement or fluid fillers; Means for supplying bone cement or fluid fillers to introducing tools, e.g. cartridge handling means · CPC title

• A61B17/8805

  for introducing fluid filler into bone or extracting it (A61B17/7097, A61B17/8833 take precedence) · CPC title

• A61B17/8822 Primary

  characterised by means facilitating expulsion of fluid from the introducer, e.g. a screw pump plunger, hydraulic force transmissions, application of vibrations or a vacuum · CPC title

• A61L2400/06

  Flowable or injectable implant compositions · CPC title

• A61L24/06 Primary

  obtained by reactions only involving carbon-to-carbon unsaturated bonds {(A61L24/043, A61L24/046 take precedence)} · CPC title