Antimicrobial methacrylate cements

1. A method of making a temporary spacer implant using a two-part bone cement, the method comprising:

transferring premixed powder and a liquid component into a mixing receptacle, the premixed powder component comprising:

an acrylic polymer;

a radical initiator;

a gentamicin source providing gentamicin in an amount from about 5% to about 6% by weight of the powder component, wherein the gentamicin source comprises gentamicin sulfate that is recrystallized having a mean particle size diameter from about 60 μm to about 250 μm; and

a vancomycin source providing vancomycin in an amount from about 4% to about 5% by weight of the powder component;

mixing the powder polymer component and the liquid component to form a bone cement composition; and

filling a mold cavity with the bone cement composition to form a temporary spacer implant, wherein the bone cement composition provides a viscosity profile sufficient for the bone cement composition to flow within the mold cavity for an elapsed working time period of greater than about 6 minutes from the start of mixing at approximately 23° C.

2. The method of claim 1 , wherein the bone cement composition maintains a viscosity profile suitable to extrude cement from an OPTIVAC® mixing cartridge at a rate of about 7 cc/min using a force of less than about 18 lb f during a working time period at about 23° C.

3. The method of claim 1 , wherein the powder polymer component is sterilized using gamma irradiation prior to mixing with the liquid component.

4. The method of claim 1 , wherein the vancomycin source comprises vancomycin hydrochloride.

5. The method of claim 4 , wherein the vancomycin hydrochloride has a mean particle size diameter from about 10 μm to about 295 μm.

6. The method of claim 1 , wherein the liquid component comprises methylmethacrylate and a radical activator.

7. The method of claim 1 , wherein the acrylic polymer comprises methylmethacrylate-methylacrylate copolymer.

8. The method of claim 1 , wherein the bone cement has an ISO bending strength in excess of about 49 MPa after hardening.

9. The method of claim 1 , wherein the bone cement has an ISO compressive strength in excess of about 99 MPa after hardening.

10. A bone cement for forming a temporary spacer implant, the bone cement comprising:

a powder component comprising:

(a) an acrylic polymer;

(b) a radical initiator;

(c) a gentamicin source providing gentamicin in an amount from about 5% to about 6% by weight of the powder polymer component, wherein the gentamicin source comprises gentamicin sulfate that is recrystallized having a mean particle size diameter from about 60 μm to about 250 μm; and

(d) a vancomycin source providing vancomycin in an amount from about 4% to about 5% by weight of the powder polymer component;

a liquid monomer component,

wherein a reaction of the powder polymer component and liquid monomer component provides a bone cement composition having a viscosity profile sufficient to yield a delivery time period of about 6 minutes from the onset of the reaction at approximately 23° C.

11. The bone cement of claim 10 , comprising a viscosity profile suitable to extrude cement from an OPTIVAC® mixing cartridge at a rate of about 7 cc/min using a force of less than about 18 lb f during a working time period at about 23° C.

12. The bone cement of claim 10 , wherein the acrylic polymer comprises methylmethacrylate-methylacrylate copolymer and a radical initiator.

13. The bone cement of claim 10 , providing an elution of gentamicin in excess of about 880 ug/cm 2 within about 24 hours.

14. The bone cement of claim 10 , providing an elution of gentamicin in excess of about 78 ug/cm 2 between about 48 and 72 hours.

15. The bone cement of claim 10 , wherein the vancomycin source comprises vancomycin hydrochloride.

16. The bone cement of claim 15 , wherein the vancomycin hydrochloride has a mean particle size diameter from about 10 μm to about 295 μm.

17. The bone cement of claim 10 , providing an elution of vancomycin in excess of about 174 ug/cm 2 within about 24 hours.

18. The bone cement of claim 10 , providing an elution of vancomycin in excess of about 25 ug/cm 2 between about 48 and 72 hours.

19. The bone cement of claim 10 , comprising an ISO bending strength in excess of about 49 MPa after hardening.

20. The bone cement of claim 10 , comprising an ISO compressive strength in excess of about 99 MPa after hardening.