SPACER MOLDS WITH RELEASABLE SECUREMENT

• US 20100102484A1
• Filed: 12/04/2008
• Published: 04/29/2010
• Est. Priority Date: 10/29/2008
• Status: Active Grant

• Current Assignee: Zimmer Orthopaedic Surgical Products (Zimmer Biomet Holdings, Inc.)
• Original Assignee: Zimmer Orthopaedic Surgical Products (Zimmer Biomet Holdings, Inc.)
• Inventors: HANEY, Sean, Sporer, Scott M.
• Granted Patent: US 8,414,286 B2
• Time in Patent Office: Days
• US Class Current: 264/328.100
• 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 45/66 mechanical

Abstract

A mold for forming a temporary prosthesis has at least two mold members at least partially separable from each other. The at least two mold members cooperatively define a generally enclosed interior cavity for forming the temporary prosthesis. The mold has a securement structure mounted on the at least two mold members for securing the at least two mold members to each other during the forming of the temporary prosthesis. The securement structure is removable from the at least two mold members by hand and without the use of a tool.

Claims

1. A mold for forming a temporary prosthesis comprising:

at least two mold members being at least partially separable from each other, the at least two mold members cooperatively defining a generally enclosed interior cavity for forming the temporary prosthesis; and

an initially separate non-threaded securement structure detachably mounted on the at least two mold members for securing the at least two mold members to each other during the forming of the temporary prosthesis, the securement structure being removable from the at least two mold members by hand, and without the use of a tool.

2. The mold of claim 1 wherein the securement structure secures the at least two mold members to each other while the mold receives pressurized, curable material for forming the temporary prosthesis.

3. The mold of claim 1 wherein the securement structure includes at least one pin disposed so that moving the at least one pin axially secures and unsecures the at least two mold members to and from each other.

4. The mold of claim 3 wherein the securement structure includes a finger pull ring mounted on the at least one pin.

5. The mold of claim 1 wherein the securement structure includes a frame comprising at least two frame members disposed on different sides of the at least two mold members.

6. The mold of claim 5 wherein the securement structure further comprises at least one locking member interconnecting the at least two frame members and restricting separation of the at least two mold members away from each other by restricting further separation of the at least two frame members away from each other.

7. The mold of claim 6 wherein the at least one locking member generally defines an axial direction, has at least one axially fixed retainer for engaging one of the at least two frame members, and has a retractable retainer for engaging the other of the at least two frame members.

8. The mold of claim 6 wherein at least one of the at least two mold members has an exterior surface defining a semi-circular recess for receiving the at least one locking member.

9. The mold of claim 8 wherein the at least one mold member has an array of flanges extending from the exterior surface and defining the semi-circular recess on a plurality of the flanges.

10. The mold of claim 5 wherein the securement structure includes at least two locking members interconnecting the at least two frame members, the at least two mold members being disposed between, and retained together by, the at least two locking members.

11. The mold of claim 10 wherein an engagement between the at least two locking members and the at least two mold members limits motion of the at least two mold members in at least two directions perpendicular to one another.

12. The mold of claim 11 wherein the at least two frame members limits motion of the at least two mold members in a third direction perpendicular to the at least two perpendicular directions.

13. The mold of claim 5 wherein the at least two frame members has a plurality of through-holes, and wherein the securement structure further comprises a plurality of generally parallel elongate members received by the through-holes on the frame members.

14. The mold of claim 1 wherein the mold is adjustable to form the temporary prosthesis with or without a stem.

15. The mold of claim 1 further comprising a stem forming section defining a stem cavity as part of the interior cavity and having an entrance, and a movable member disposed in the interior cavity and being adjustable for opening and closing the entrance to the stem cavity.

16. The mold of claim 15 wherein the at least two mold members and securement structure are configured for providing access for moving the movable member while the at least two mold members are secured together.

17. The mold of claim 1 being provided in a plurality of alternative sizes.

18. The mold of claim 1 being provided in alternative configurations wherein the interior cavity is shaped to form the temporary prosthesis to comprise a body being provided in either of a first shape specifically configured for placement on a left leg or a second shape specifically configured for placement on a right leg.

19. The mold of claim 18 wherein the interior cavity is shaped to provide the body with a medial side and a stem having a central axis generally inclined toward the medial side.

20. The mold of claim 18 wherein the interior cavity is shaped to provide the body with a medial side, a main portion, and a posterior flange generally extending in a superior-inferior direction from the main portion, the flange having a distal, superior tip disposed on the medial side of the body.

21. The mold of claim 1 wherein the temporary prosthesis is a femoral knee prosthesis.

22. The mold of claim 1 wherein the at least two mold members includes a first mold and a second mold secured together by the securement structure to cooperatively define the interior cavity therebetween, the first mold and second mold being configured to be secured at one of a plurality of alternative positions relative to each other to provide alternative dimensions for the interior cavity.

23. The mold of claim 22 wherein the securement structure includes at least one pin, wherein the first mold and the second mold are secured together by the at least one pin, one of the first and second molds defining at least one hole for receiving the pin, and the other of the first and second molds having a retainer for restricting movement of the pin.

24. The mold of claim 23 wherein one of the first and second mold defines a plurality of holes for alternatively receiving the at least one pin and to define different secured positions of the second mold relative to the first mold.

25. The mold of claim 22 wherein one of the first or second mold comprises at least one extension defining at least one hole, the securement structure including a pin received within the hole, and wherein the other of the first or second mold having a retainer defining at least one through-opening for receiving the at least one extension.

26. The mold of claim 25 wherein the other of the first or second mold comprises a sidewall, and

wherein the retainer comprises at least one arm extending from the sidewall and defining the at least one through-opening, an insertion side of the through-opening, and an exit side of the through-opening, and

wherein the at least one extension is configured to be placed through the at least one through-opening for placing the at least one hole exteriorly of the exit side of the through-opening for receiving the pin, whereby the pin retains the extension in the arm.

27. The mold of claim 22 wherein both the first mold and the second mold are generally tub shaped, wherein one of the first mold and second mold is configured to fit into the other of the first mold or second mold.

28. The mold of claim 22 wherein the first mold is configured for forming a side of the temporary prosthesis that will engage bone, the first mold having a stem forming section defining a stem cavity of the interior cavity, the mold further comprising a plug received in the stem cavity for optionally closing the stem cavity to restrict formation of a stem on the prosthesis.

29. The mold of claim 22 further comprising a bearing member inserted into one of the first and second molds to become a part of the temporary prosthesis.

30. The mold of claim 1 wherein the temporary prosthesis is a tibial knee prosthesis and wherein multiple holes provide an adjustable superior-inferior thickness of the tibial knee prosthesis.

31. A mold for forming a temporary prosthesis comprising:

at least two mold members being at least partially separable from each other, the at least two mold members cooperatively defining a generally enclosed interior cavity for forming the temporary prosthesis; and

an initially separate non-threaded securement structure having at least two frame members and at least one locking member interconnecting the at least two frame members, the securement structure being mounted on the at least two mold members to secure the at least two mold members together.

32. The mold of claim 31 wherein the at least one locking member engages at least one of the at least two mold members for restricting motion of the at least two mold members.

33. The mold of claim 31 including at least two of the locking members extending generally parallel relative to each other on different sides of the at least two mold members.

34. A method of forming a temporary prosthesis comprising:

assembling at least two mold members to cooperatively define a generally enclosed interior cavity;

after the at least two mold members are assembled, connecting a non-threaded securement structure to the at least two mold members to secure the at least two mold members together;

injecting pressurized, curable material into the interior cavity;

curing the material to form the temporary prosthesis; and

detaching at least a part of the securement structure from the at least two mold members before disassembling the at least two mold members from each other to retrieve the temporary prosthesis.

35. The method of claim 34 wherein connecting the securement structure further comprises mounting the at least two mold members on a partially assembled frame, and completing the assembly of the frame to secure the at least two mold members together.

36. The method of claim 34 wherein connecting the securement structure and detaching at least a part of the securement structure comprises axially moving, by hand, at least one pin interconnecting at least two frame members disposed on different sides of the at least two mold members.

37. The method of claim 34 wherein assembling at least two mold members comprises securing a first mold member to a second mold member at one of a plurality of alternative positions relative to each other for providing alternative dimensions within the interior cavity.

38. The method of claim 37 wherein the temporary prosthesis formed by the at least two mold members is a tibial knee spacer and alternative dimensions correspond to a superior-inferior thickness of the temporary prosthesis.

39. The method of claim 34 wherein assembling at least two mold members comprises placing at least one extension of a first mold member through an opening defined on a second mold member, and wherein connecting the securement structure comprises inserting a pin into a hole defined on the extension to secure the extension to the second mold member.

40. The method of claim 39 wherein inserting the pin further comprises inserting the pin in one of a plurality of holes defined on the extension where each hole on the extension corresponds to a different secured position of the first mold relative to the second mold to provide a different dimension in the interior cavity.

41. The method of claim 34 further comprising pulling tear strips on the at least two molds for removing the at least two molds from the cured temporary prosthesis.