This application claims the benefit of priority under 35 U.S.C. §119(e) of U.S. Provisional Application No. 61/212,622, filed Apr. 14, 2009. This application is related to the following U.S. patent application Ser. No. 11/209,035 filed Aug. 22, 2005, Ser. No. 12/427,531 filed Apr. 21, 2009, Ser. No. 12/345,937 filed Dec. 30, 2008, and Ser. No. 12/578,163 filed Oct. 13, 2009; and is related to Provisional Application Nos. 60/842,805 filed Sep. 7, 2006 and 60/713,521 filed Sep. 1, 2005. The entire contents of all of the above applications are hereby incorporated by reference and should be considered a part of this specification.
Leakage of PMMA during vertebroplasty can result in very serious complications including compression of adjacent structures that necessitate emergency decompressive surgery. See Groen, R. et al., "Anatomical and Pathological Considerations in Percutaneous Vertebroplasty and Kyphoplasty: A Reappraisal of the Vertebral Venous System," Spine Vol. 29, No. 13, pp 1465-1471, 2004. Leakage or extravasation of PMMA is a critical issue and can be divided into paravertebral leakage, venous infiltration, epidural leakage and intradiscal leakage. The exothermic reaction of PMMA carries potential catastrophic consequences if thermal damage were to extend to the dural sac, cord, and nerve roots. Surgical evacuation of leaked cement in the spinal canal has been reported. It has been found that leakage of PMMA is related to various clinical factors such as the vertebral compression pattern, and the extent of the cortical fracture, bone mineral density, the interval from injury to operation, the amount of PMMA injected and the location of the injector tip. In one recent study, close to 50% of vertebroplasty cases resulted in leakage of PMMA from the vertebral bodies. See Hyun-Woo Do et al., "The Analysis of Polymethylmethacrylate Leakage after Vertebroplasty for Vertebral Body Compression Fractures," J. of Korean Neurosurg. Soc., Vol. 35, No. 5 (May/2004), pp 478-82, (http://www.jkns.or.kr/htm/abstract.asp?no=0042004086).
FIG. 3 illustrates another system 200 for combining a liquid monomer component 106 and a polymer powder component 105. In this system 200, the negative pressure source 130 is similar to that described above. The cement-carrying member 212 of FIG. 3 can have a syringe body configured for coupling to any manually actuated or hydraulically actuated plunger (not shown) for advancing in chamber 214. In one embodiment, the cement-carrying member 212 has a fitting 215 at its proximal end 216 for coupling to a hydraulic drive mechanism as illustrated in U.S. patent application Ser. Nos. 11/469,769 filed Sep. 1, 2006; Ser. No. 12/024,969 filed Feb. 1, 2008; Ser. No. 12/112,477 filed Apr. 30, 2008, 61/067,479, filed on Feb. 28, 2008; 61/067,480, filed on Feb. 28, 2008; 61/124,336, filed on Apr. 16, 2008; 61/190,375 filed Aug. 28, 2008; and 61/124,338 filed Apr. 16, 2008, all of which are incorporated by reference herein in their entirety.
In one embodiment, a method of providing an optimized saturation interval can use an initial pressure developed by an evacuated chamber (e.g., such as a syringe as in FIGS. 1 and 3) of at least 200 mmHg vacuum, at least 250 mmHg vacuum, or at least 350 mmHg vacuum. In the embodiment depicted in FIG. 3, the interior chamber 214 has a diameter of about 16 mm and length of about 60 mm thus providing a volume of approximately 12 cc. With a vacuum of about 400 mmHg, the monomer 106 will controllably saturate the polymer powder 105 in about 60 seconds. This is using a polymer powder formulation comprising first and second volumes of intermixed polymer particles wherein the first volume of PMMA particles has greater than about 0.5 wt. % benzoyl peroxide (BPO) and the second volume of PMMA particles comprises less than about 0.5 wt. % BPO, on the basis of the total weight of the polymer powder component. Further, the first volume of PMMA particles has a mean diameter less than about 50 μm and the second volume of PMMA particles has a mean diameter greater than about 100 μm. Other polymer powder and monomer formulations can be used and some formulations suitable for the system are found in U.S. patent application Ser. No. 12/395,532 filed Feb. 27, 2009 and Ser. No. 12/578,163 filed Oct. 13, 2009 and incorporated herein by reference in their entirety and made a part of this specification.
wherein the base comprises one or more pathways that communicate with the lumen of the one or more elongate members and the negative pressure source.
2. The system of claim 1, further comprising a pressure regulator for regulating the pressure of the negative pressure source applied to draw the liquid polymer into the elongate member.
3. The system of claim 1, further comprising a funnel member for coupling to an end of the elongate members.
4. The system of claim 1, further comprising a cement ejection mechanism configured to couple to one of the elongate members and to eject bone cement from the elongated member into bone.
5. The system of claim 1, wherein the computer controller is operatively coupled to the negative pressure source for controlling a negative pressure level applied to each elongate member.
6. The system of claim 1, further comprising at least one of a heating and cooling mechanism for respectively heating or cooling the plurality of elongate members and the component or bone cement contained therein.
7. The system of claim 6, wherein the computer controller is configured to control either or both of the heating and cooling mechanisms.
9. The system of claim 8, wherein each of the temperature regulating assemblies comprises a sleeve configured to receive and surround one of the plurality of bone cement preparation members.
10. The system of claim 9, wherein each of the temperature regulating assemblies is configured such that there is an air flow passage between an interior surface of the temperature regulating assembly and an exterior surface of the bone cement preparation member.
11. The system of claim 10, wherein each of the temperature regulating assemblies further comprises an input and an output port in fluid communication with the air flow passage and the system further comprises a heating or cooling source configured to generate a hot or cold flow of gas to enter the input port and exit the output port.
12. The system of claim 9, wherein each of the temperature regulating assemblies further comprises an inductive coil.
13. The system of claim 9, wherein each of the temperature regulating assemblies further comprises a seal configured to seal an access opening of the temperature regulating assembly once a bone cement preparation member has been placed inside the temperature regulating assembly.
14. The system of claim 8, further comprising a source of heat energy.
15. The system of claim 8, further comprising a liquid monomer heating assembly, configured for receiving, surrounding and heating a container of liquid monomer prior to combination with the polymer component.
16. The system of claim 8, wherein the structure further comprises a plurality of valves for selectively coupling the negative pressure source to particular bone cement preparation members.
17. The system of claim 8, further comprising the negative pressure source.
18. The system of claim 8, further comprising the plurality of bone cement preparation members.
19. The system of claim 8, further comprising a hydraulic computer control mechanism for injecting bone cement and first and second hydraulic drivers controlled by the computer control mechanism, wherein at least one bone cement preparation member is detachably coupleable to a hydraulic driver.
CH708198A8 (en) * 2013-06-04 2015-01-30 Medmix Systems Ag System for producing a bone substitute material, comprising a container and a retaining member.