METHOD AND DEVICE FOR PRODUCING TEMPORARY KNEE JOINT SPACERS WITH STEMS OF VARIOUS SIZES

• US 20180339440A1
• Filed: 08/02/2018
• Published: 11/29/2018
• Est. Priority Date: 12/12/2012
• Status: Active Grant

• Current Assignee: Biomet Manufacturing, LLC (Zimmer Biomet Holdings, Inc.)
• Original Assignee: Biomet Manufacturing, LLC (Zimmer Biomet Holdings, Inc.)
• Inventors: Smith, Daniel B., Kreider, Tayler
• Granted Patent: US 10,449,703 B2
• Time in Patent Office: Days
• CPC Class Codes: A61F 2/30942 for designing or making customized prostheses, e.g. using templates, CT or NMR scans, finite-element analysis or CAD-CAM techniques
• CPC Class Codes: A61F 2/38 for elbows or knees
• CPC Class Codes: A61F 2/3859 Femoral components
• CPC Class Codes: A61F 2/389 Tibial components A61F2/3868 takes precedence
• CPC Class Codes: A61F 2/4684 Trial or dummy prostheses
• CPC Class Codes: A61F 2002/30329 Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2002/30604 modular
• CPC Class Codes: A61F 2002/30672 temporary
• CPC Class Codes: A61F 2002/30677 Means for introducing or releasing pharmaceutical products, e.g. antibiotics, into the body
• CPC Class Codes: A61F 2002/30957 using a positive or a negative model, e.g. moulds
• CPC Class Codes: A61F 2220/0025 Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2310/00353 Bone cement, e.g. polymethylmethacrylate or PMMA
• CPC Class Codes: B29C 45/0001 characterised by the choice of material
• CPC Class Codes: B29C 45/26 Moulds

Abstract

A cement mold assembly configured to form a temporary implant for use in delivering antibiotics to an infected site can includes a first mold and a second mold. The first mold can have an open end and an inner wall. The first mold can define a tibial component forming cavity including a platform forming cavity and a stem forming cavity. The second mold can have a body portion configured to be slidably and progressively receivable by the inner wall into the tibial component forming cavity in a direction toward the closed end. Progressive advancement of the second mold into the tibial component forming cavity urges cement within the tibial component forming cavity against the body portion and the inner wall to form a unitary tibial component having a tibial tray portion formed by the platform forming cavity and a stem portion formed by the stem forming cavity.

Claims

1. A cement mold assembly configured to form a temporary implant for use in delivering antibiotics to an infected site, the cement mold assembly comprising:

a first mold having an open end and an inner wall, the first mold defining a tibial component forming cavity including a platform forming cavity and a stem forming cavity;

a second mold having a body portion configured to be slidably and progressively receivable by the inner wall into the tibial component forming cavity in a direction toward the closed end; and

wherein progressive advancement of the second mold into the tibial component forming cavity urges cement within the tibial component forming cavity against the body portion and the inner wall to form a unitary tibial component having a tibial tray portion formed by the platform forming cavity and a stem portion formed by the stem forming cavity.

2. The cement mold assembly of claim 1 wherein the first mold defines a port opposite the open end configured to receive cement therethrough.

3. The cement mold assembly of claim 2, further comprising a first plate and a second plate positioned outboard of the first and second molds, respectively.

7. The cement mold assembly of claim 1 wherein the body of the second mold includes a geometry substantially corresponding to a tibial bearing surface.

8. The cement mold assembly of claim 1 wherein the first mold is formed of silicone.

9. The cement mold assembly of claim 1 wherein the second mold is formed of silicone.

4. The cement mold assembly of claim 4, further comprising at least two rods connected between the first and second plates.

5. The cement mold assembly of claim 4 wherein the at least two rods and the first and second plates are selectively and progressively indexable and wherein the first and second plates are moveable in discrete increments toward each other while the second mold is progressively advanced into the tibial component forming cavity.

6. The cement mold assembly of claim 5 wherein the at least two rods include teeth formed thereon that cooperatively engage an opposing surface on one of the first and second plates.

10. A cement mold assembly configured to form a temporary implant for use in delivering antibiotics to an infected site, the cement mold assembly comprising:

a first mold having a first closed end, a second open end and a sidewall, the first mold defining a cavity;

a second mold having a base portion and a cannulated member extending therefrom, the base portion having a footprint complementary to the sidewall of the first mold such that the second mold is slidably and progressively receivable by the sidewall into the cavity in a direction toward the closed end; and

wherein progressive advancement of the second mold into the cavity urges cement within the cavity into the cannulated member, the first mold cooperating with the second mold to form a unitary tibial component having a tibial tray portion formed by the cavity and a stem portion formed by the cannulated member.

11. The cement mold assembly of claim 10, further comprising a reinforcement member configured to be placed at least partially within the cavity prior to progressive advancement of the second mold into the cavity, wherein the reinforcement member is configured to be molded into the unitary tibial component.

12. The cement mold assembly of claim 11 wherein the reinforcement member comprises a first lateral portion that generally opposes the first closed end and a second longitudinal portion that is received by the cannulated member.

13. The cement mold assembly of claim 10 wherein the cannulated member has a generally rectangular cross-section.

14. The cement mold assembly of claim 10 wherein the base portion of the second mold has a textured end surface.

15. The cement mold assembly of claim 10 wherein the first mold includes gradations on the sidewall.

16. The cement mold assembly of claim 10 wherein the first mold is formed of silicone.

17. The cement mold assembly of claim 10 wherein the second mold is formed of polyethylene.

18. The cement mold assembly of claim 11 wherein the reinforcement member is formed of biocompatible metal.

19. A cement mold assembly configured to form a temporary implant for use in delivering antibiotics to an infected site, the cement mold comprising:

a mold body having an outer sidewall and an inner sidewall that cooperate to define a cavity, the inner sidewall operable to define a shape of the temporary implant, the mold body including an articulating forming portion, and a stem forming portion, the articulating and stem forming portions cooperating to form a unitary femoral component having an articulating portion formed by the articulating forming portion and a stem portion formed by the stem forming portion.

20. The cement mold assembly of claim 19 wherein the stem forming portion is removably coupled to the articulating forming portion.