Methods, materials and apparatus for treating bone and other tissue
View Patent ↗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.
1. A hydraulic delivery system for delivering bone cement to a patient's vertebra, comprising:
a hydraulic actuator for generating a fluid pressure;
a reservoir having a quantity of bone cement contained therein, the bone cement comprising PMMA polymer and MMA monomer, the PMMA polymer having an average molecular weight and further containing a population of pre-polymerized PMMA beads having a high molecular weight, wherein the high molecular weight is greater than the average molecular weight and 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 PMMA polymer and MMA monomer produces a mixture which has a stable high viscosity during a working time and solidifies after the working time;
a flexible tube connected to the hydraulic actuator and to the reservoir to transmit the fluid pressure from the hydraulic actuator to the reservoir; and
a cannula connected to the reservoir such that the fluid pressure from the hydraulic actuator forces bone cement from the reservoir through the cannula;
wherein the bone cement has a stable high viscosity of 200 to 2000 Pascal-second during a working time of at least 5 minutes, the bone cement solidifying after the working time; and
wherein the system is configured to deliver the bone cement to a patient's vertebra during the working time.
2. The system of claim 1 , wherein the viscosity is at least 900 Pascal-seconds during the working time.
3. The system of claim 1 , wherein the flexible tube has a length of between 0.2 and 3 meters.
4. The system of claim 1 , wherein the flexible tube has a length of between 1 and 2 meters.
5. The system of claim 1 , wherein the cannula is a deformable cannula.
6. The system of claim 1 , wherein the hydraulic actuator is a manual actuator.
7. The system of claim 1 , wherein the hydraulic actuator is an electric actuator.
8. The system of claim 7 , wherein the electric actuator includes a motor.
9. The system of claim 1 , wherein the cannula is removably connected to the reservoir.
10. The system of claim 1 , wherein the reservoir includes a piston for transforming hydraulic pressure into a motive force for driving delivery of the bone cement.
11. The system of claim 1 , wherein the working time is about 10 minutes.
12. The system of claim 1 , wherein, during the working time, the bone cement remains sufficiently flowable such that it can be delivered to the patient's vertebra.
13. The system of claim 1 , wherein the working time is at least 20 minutes.
14. The system of claim 1 , wherein the working time is at least 10 minutes.
15. A system for delivering bone cement to a patient's vertebra, comprising:
a hydraulic actuator for generating a fluid pressure;
a reservoir having a quantity of bone cement contained therein, the bone cement comprising PMMA polymer and MMA monomer, the PMMA polymer having an average molecular weight and further containing a population of pre-polymerized PMMA beads having a high molecular weight, wherein the high molecular weight is greater than the average molecular weight and 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 PMMA polymer and MMA monomer produces a mixture which has a stable high viscosity during a working time and solidifies after the working time;
a flexible tube connected to the hydraulic actuator and to the reservoir to transmit the fluid pressure from the hydraulic actuator to the reservoir; and
a cannula connected to the reservoir such that the fluid pressure from the hydraulic actuator forces bone cement from the reservoir through the cannula;
wherein the bone cement has a stable high viscosity of 200 to 2000 Pascal-second during a working time of at least 5 minutes, the stable viscosity changing by less than 20% during a period of 5 minutes and the bone cement solidifying after the working time; and
wherein the system is configured to deliver the bone cement to a patient's vertebra during the working time.
16. The system of claim 15 , wherein the hydraulic actuator is an electric actuator.
17. A system for delivering bone cement to a patient's vertebra, comprising:
a hydraulic actuator for generating a fluid pressure;
a reservoir having a quantity of bone cement contained therein, the bone cement comprising PMMA polymer and MMA monomer, the PMMA polymer having an average molecular weight and further containing a population of pre-polymerized PMMA beads having a high molecular weight, wherein the high molecular weight is greater than the average molecular weight and 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 PMMA polymer and MMA monomer produces a mixture which has a stable high viscosity during a working time and solidifies after the working time;
a flexible tube connected to the hydraulic actuator and to the reservoir to transmit the fluid pressure from the hydraulic actuator to the reservoir; and
a cannula connected to the reservoir such that the fluid pressure from the hydraulic actuator forces bone cement from the reservoir through the cannula;
wherein the bone cement has a stable high viscosity of 200 to 2000 Pascal-second during a working time of at least 5 minutes, the stable viscosity changing by less than 200 Pascal-seconds during a period of 2 minutes within the working time and the bone cement solidifying after the working time; and
wherein the system is configured to deliver the bone cement to a patient's vertebra during the working time.
18. The system of claim 17 , wherein the hydraulic actuator is an electric actuator.
19. The system of claim 17 , wherein the system is configured to generate a pressure of 50-300 atmospheres to force the bone cement out of the reservoir and into the patient's vertebra.
20. The system of claim 15 , wherein the system is configured to generate a pressure of 50-300 atmospheres to force the bone cement out of the reservoir and into the patient's vertebra.
21. The system of claim 1 , wherein the bone cement includes an initiator incorporated into the polymer and a chemical activator incorporated into the monomer.
22. The system of claim 21 , wherein the initiator comprises benzoyl peroxide and the chemical activator comprises DMPT.
23. The system of claim 21 , further comprising a hydroquinone added to the monomer to prevent spontaneous polymerization during storage.
24. The system of claim 15 , wherein the bone cement includes an initiator incorporated into the polymer, a chemical activator incorporated into the monomer, and a hydroquinone added to the monomer to prevent spontaneous polymerization during storage.
25. The system of claim 24 , wherein the initiator comprises benzoyl peroxide and the chemical activator comprises DMPT.
26. The system of claim 17 , wherein the bone cement includes an initiator incorporated into the polymer, a chemical activator incorporated into the monomer, and a hydroquinone added to the monomer to prevent spontaneous polymerization during storage.
27. The system of claim 26 , wherein the initiator comprises benzoyl peroxide and the chemical activator comprises DMPT.
28. The system of claim 23 , wherein the bone cement is radiopaque.
29. The system of claim 24 , wherein the bone cement is radiopaque.
30. The system of claim 26 , wherein the bone cement includes barium sulfate.
31. The system of claim 1 , wherein the viscosity is at least 500 Pascal-seconds during the working time.
32. The system of claim 15 , wherein the viscosity is at least 500 Pascal-seconds during the working time.
33. The system of claim 17 , wherein the viscosity is at least 500 Pascal-seconds during the working time.
34. The system of claim 15 , wherein the viscosity is at least 900 Pascal-seconds during the working time.
35. The system of claim 17 , wherein the viscosity is at least 900 Pascal-seconds during the working time.