Methods, materials, and apparatus for treating bone and other tissue

• US 8,415,407 B2
• Filed: 02/22/2006
• Issued: 04/09/2013
• Est. Priority Date: 03/21/2004
• Status: Active Grant

• Current Assignee: Depuy Synthes Products Incorporated (Johnson & Johnson)
• Original Assignee: Depuy Spine Incorporated (Johnson & Johnson)
• Inventors: Beyar, Mordechay, Globerman, Oren, Shavit, Ronen, Wachsler-Avrahami, Hila
• Primary Examiner(s): ZISKA, SUZANNE E
• Application Number:
  US11/360,251
• Publication Number:
  US 20070027230A1
• Time in Patent Office: 2,603 Days
• Field of Search: None
• US Class Current: 523/117
• CPC Class Codes: A61B 17/1604 Chisels; Rongeurs; Punches; Stamps
• CPC Class Codes: A61B 17/1671 for the spine
• CPC Class Codes: A61B 17/3421 Cannulas
• CPC Class Codes: A61B 17/8811 characterised by the introducer tip, i.e. the part inserted into or onto the bone
• CPC Class Codes: A61B 17/8816 characterised by the conduit, e.g. tube, along which fluid flows into the body or by conduit connections
• CPC Class Codes: A61B 17/8822 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 Class Codes: A61B 17/8836 for heating, cooling or curing of bone cement or fluid fillers
• CPC Class Codes: A61B 2017/00539 hydraulically
• CPC Class Codes: A61B 2017/2905 flexible
• CPC Class Codes: A61B 2090/3937 Visible markers
• CPC Class Codes: A61F 2/44 for the spine, e.g. vertebrae, spinal discs
• CPC Class Codes: A61F 2/4601 for introducing bone substitute, for implanting bone graft implants or for compacting them in the bone cavity
• CPC Class Codes: A61F 2002/4693 hydraulic
• CPC Class Codes: A61L 24/043 Mixtures of macromolecular materials
• CPC Class Codes: A61L 24/06 obtained by reactions only involving carbon-to-carbon unsaturated bonds A61L24/043, A61L24/046 take precedence
• CPC Class Codes: A61L 2430/02 for reconstruction of bones; weight-bearing implants
• CPC Class Codes: A61L 2430/38 for reconstruction of the spine, vertebrae or intervertebral discs
• CPC Class Codes: A61L 27/26 Mixtures of macromolecular compounds
• CPC Class Codes: B01F 27/95 with stirrers having planetary motion, i.e. rotating about their own axis and about a sun axis
• CPC Class Codes: B01F 35/3202 Hand driven
• CPC Class Codes: B01F 35/53 : characterised by the configuration of the interior, e.g. baffles for facilitating the mixing of components
• CPC Class Codes: B01F 35/75425 : using pistons or plungers
• CPC Class Codes: B01F 35/754251 : reciprocating in the mixing receptacle
• CPC Class Codes: C08L 33/12 : Homopolymers or copolymers of methyl methacrylate

Abstract

A bone cement comprising a first component and a second component, wherein contacting the first component and the second component produces a mixture which attains a high viscosity an initial period and the viscosity of the mixture remains relatively stable for a working time of at least 5 minutes after the initial setting period, and the mixture is suitable for in-vivo use.

Claims

1. A bone cement comprising:

a first liquid component containing MMA (methyl methacrylate) monomers; and

a second powder component containing pre-polymerized PMMA (polymethyl methacrylate) beads having an average molecular weight and further containing a population of pre-polymerized PMMA beads having a high molecular weight,

wherein, the average molecular weight, the high molecular weight, and the percentage of beads having the high molecular weight are selected so that contacting the first component and the second component produces a mixture which achieves a high viscosity during an initial period, has a stable viscosity during a working time, and solidifies after the working time;

wherein the mixture attains the high viscosity of greater than 900 Pascal seconds within the initial period of about 180 seconds following initiation of mixing of the first liquid component and the second powder component,

wherein the working time is for at least 5 minutes and the working time follows the initial period;

wherein the viscosity of the mixture is between 900 Pascal seconds and 2000 Pascal seconds during the working time;

wherein the viscosity of the mixture changes by less than 200 Pascal seconds during a window of at least 2 minutes after mixing; and

wherein the mixture is suitable for in-vivo use.

2. The bone cement of claim 1, wherein the working time is at least 8 minutes long.

3. The bone cement of claim 1, wherein the initial period does not exceed 1 minute.

4. The bone cement of claim 1, wherein the initial period is less than 3 minutes and the mixture solidifies after the working time.

5. The bone cement of claim 1, wherein the viscosity of greater than 900 Pascal-second results at least partly from a polymerization reaction.

7. The bone cement of claim 1, wherein the initial period does not exceed 2 minutes.

8. The bone cement of claim 1, wherein the mixture produced by contacting the first component and the second component attains a viscosity greater than 1000 Pascal seconds within the initial period.

6. A bone cement comprising:

a first liquid component containing MMA monomers; and

a second powder component containing pre-polymerized PMMA beads having an average molecular weight and further containing a population of pre-polymerized PMMA beads having a high molecular weight,

wherein, the average molecular weight, the high molecular weight, and the percentage of beads having the high molecular weight are selected so that contacting the first component and the second component produces a mixture which has substantially no liquid phase during an initial period, a stable viscosity during a working time, and solidifies after the working time;

wherein the mixture attains a viscosity greater than 200 Pascal seconds within the initial period of 3 minutes following initiation of mixing of the first liquid component with the second powder component,

wherein the viscosity of the mixture remains between 200 and 2000 Pascal seconds for a working time of at least 5 minutes after the initial period,

wherein the viscosity of said cement is changing by less than 10% in a period of 2 minutes within said working time, and

wherein the mixture is suitable for in-vivo use.

9. The bone cement of claim 6, wherein the viscosity of the mixture changes by less than 200 Pascal second during a window of at least 2 minutes after mixing.