Method of forming a temporary prosthetic joint using a disposable mold

• US 7,429,346 B2
• Filed: 06/28/2004
• Issued: 09/30/2008
• Est. Priority Date: 03/13/2002
• Status: Active Grant

• Current Assignee: Ortho Development Corporation (Japan Medical Dynamic Marketing, Inc.)
• Original Assignee: Ortho Development Corporation (Japan Medical Dynamic Marketing, Inc.)
• Inventors: Ensign, Michael D., Lowe, Matthew M., Mariani, E. Marc, Bourne, Michael H.
• Primary Examiner(s): McDowell; Suzanne E.
• Application Number:
  US10/879,683
• Publication Number:
  US 20040236429A1
• Time in Patent Office: 1,555 Days
• Field of Search: 264/261, 264/313, 623/20.14, 623/20.19, 623/20.21, 623/20.32, 623/901, 623/2.32
• US Class Current: 264/264
• 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 2002/30133 kidney-shaped or bean-shaped
• CPC Class Codes: A61F 2002/30616 Sets comprising a plurality of prosthetic parts of different sizes or orientations
• CPC Class Codes: A61F 2002/30672 temporary
• CPC Class Codes: A61F 2002/30957 using a positive or a negative model, e.g. moulds
• CPC Class Codes: B29C 2043/3652 Elastic moulds or mould parts, e.g. cores or inserts
• CPC Class Codes: B29C 33/405 Elastomers, e.g. rubber B29C33/50 takes precedence
• CPC Class Codes: B29C 39/10 incorporating preformed parts or layers, e.g. casting around inserts or for coating articles coating a surface by casting in general B05D1/30, B29C39/126 takes precedence
• CPC Class Codes: B29C 43/36 Moulds for making articles of definite length, i.e. discrete articles
• CPC Class Codes: B29K 2995/0056 Biocompatible, e.g. biopolymers or bioelastomers
• CPC Class Codes: B29L 2031/7532 Artificial members, protheses
• CPC Class Codes: Y10S 264/30 Use of anatomy in making a mold or using said mold
• CPC Class Codes: Y10S 425/044 Rubber mold
• CPC Class Codes: Y10S 623/901 Method of manufacturing prosthetic device

Abstract

An orthopedic implant device and method is disclosed. Specifically, a knee mold system is disclosed, including elastic tibial and femoral molds, each of which may be configured and dimensioned as a unitary mold for in situ placement during a surgical procedure. Each mold may be manufactured from an elastic material that may be disposable. The tibial mold may further comprise a sidewall forming a cavity, markings for relative depth measurement, and depth rings for use as a guide for scoring, cutting, and/or trimming and tearing away an excess portion of the tibial mold. The femoral mold may further comprise a sidewall defining a cavity, two legs extending from a body of the femoral mold for forming the artificial condyles, and an eyelet for aiding in placement and removal of the femoral mold. The resulting prosthetic tibial and femoral components may form an articulation surface that mimics, at least in part, the natural articulation surface of the knee.

Claims

1. A method of forming at least one component of a temporary prosthetic knee joint on a bone during an in situ surgical procedure, the method comprising the steps of:

providing an elastic mold configured and dimensioned for being affixed to a portion of the bone, said elastic mold having a cavity defined by a sidewall, wherein the elastic mold comprises an elastic femoral mold that is characterized by the absence of a substantially enclosed casing;

placing an amount of biocompatible material within the cavity of the elastic mold for forming the at least one component of the prosthetic knee joint;

positioning the elastic mold on the portion of the bone; and

removing the elastic mold from said portion of said bone after the amount of biocompatible material has been at least partially cured thereby forming said at least one component.

2. The method of forming at least one component of a temporary prosthetic knee joint of claim 1, wherein the step of providing an elastic mold further comprises providing an elastic femoral mold having a protruding arched surface on an interior surface that forms a depression in a resulting femoral prosthesis.

3. The method of forming at least one component of a temporary prosthetic knee joint of claim 1, wherein the step of providing an elastic mold further comprises providing an elastic femoral mold, wherein said cavity is characterized by an open face.

4. The method of forming at least one component of a temporary prosthetic knee joint of claim 1, wherein the step of providing an elastic mold further comprises providing an elastic femoral mold, wherein the femoral mold has an eyelet for aiding a surgeon in wrapping the femoral mold around a distal portion of a femur and for further aiding in the removal of said femoral mold by separating the femoral mold from a resulting femoral prosthesis.

5. The method of forming at least one component of a temporary prosthetic knee joint of claim 1, wherein the step of providing an elastic mold further comprises providing an elastic femoral mold, wherein the sidewall extends around a perimeter of the femoral mold, and said sidewall is configured to provide a barrier such that the biocompatible material is substantially retained within said cavity by said sidewall.

6. The method of forming at least one component of a temporary prosthetic knee joint of claim 1, wherein the step of providing an elastic mold further comprises providing an elastic femoral mold, wherein the femoral mold has a main body portion, a medial leg and a lateral leg, each leg having a substantially arcuate inner surface designed to form a prosthetic femoral condyle to simulate, at least in part, the biomechanics of the natural femoral condyle such that the prosthetic femoral condyle is configured to articulate with a tibial surface.

7. The method of forming at least one component of a temporary prosthetic knee joint of claim 6, wherein the step of providing the elastic mold comprises providing the femoral mold with a gap formed between the medial leg and the lateral leg, wherein the medial leg joins the lateral leg at a junction, said junction defining a crotch portion of the main body portion.

8. The method of forming at least one component of a temporary prosthetic knee joint of claim 1, wherein the step of providing an elastic mold further comprises providing an elastic femoral mold, wherein the femoral mold comprises an elastic material such that the femoral mold is configured to be wrapped around a distal portion of a patient'"'"'s femur to bring the biocompatible material into contact with a surface of the distal portion of the femur, wherein said elastic material permits the femoral mold to stretch, thereby allowing a single femoral mold to accommodate various distal femur sizes, and also aids a surgeon in removing the femoral mold from the femur.

9. The method of forming at least one component of a temporary prosthetic knee joint of claim 1, wherein the step of providing an elastic mold further comprises manufacturing said elastic mold from an elastic material, and said elastic mold is designed for being used once and then disposed of, and wherein the elastic mold is configured to allow a surgeon to alter and adjust the mold to accommodate an anatomy of a patient.

10. The method of forming at least one component of a temporary prosthetic knee joint of claim 1, wherein the step of placing the amount of biocompatible material within the cavity further comprises substantially filling the femoral mold with said biocompatible material to a desired thickness.

11. The method of forming at least one component of a temporary prosthetic knee joint of claim 1, wherein the step of positioning the elastic mold on the portion of the bone further comprises locating the femoral mold on a distal end of a femur by stretching and firmly wrapping the femoral mold around a distal portion of the femur.

12. The method of forming at least one component of a temporary prosthetic knee joint of claim 1, wherein the step of placing the amount of biocompatible material within the cavity further comprises the step of permitting the biocompatible material to slightly cure before positioning the elastic mold on the portion of the bone.

13. The method of forming at least one component of a temporary prosthetic knee joint of claim 1, wherein the step of removing the elastic mold further comprises scoring, cutting, tearing, ripping, splitting, peeling and otherwise pulling the femoral mold away from the bone and a resulting femoral component of the prosthetic knee joint.

14. The method of forming at least one component of a temporary prosthetic knee joint of claim 1, wherein the step of providing an elastic mold further comprises providing a tibial mold, wherein the tibial mold has an inner base surface comprising at least one protrusion and at least one depression, which are configured for forming a corresponding and opposing at least one depression and at least one protrusion in a tibial component of the prosthetic knee joint so as to simulate, at least in part, a natural tibial plateau.

15. The method of forming at least one component of a temporary prosthetic knee joint of claim 1, wherein the step of providing an elastic mold further comprises providing a tibial mold, wherein the tibial mold has a plurality of markings formed on an outer surface of the tibial mold so as to provide a guide for visually determining a thickness of bone cement needed for fitting between an extension gap formed between a patient'"'"'s tibial bone and femoral bone.

16. The method of forming at least one component of a temporary prosthetic knee joint of claim 15, wherein the plurality of markings further comprises a series of symbols representing a predetermined size and thickness of a femoral prosthesis.

17. The method of forming at least one component of a temporary prosthetic knee joint of claim 1, wherein the step of providing an elastic mold further comprises providing a tibial mold, wherein the tibial mold has a plurality of depth rings for scoring, cutting and peeling off an excess portion of said tibial mold, said plurality of depth rings comprising a series of indentations in an outer surface of the tibial mold configured for running a cutting instrument in said plurality of depth rings such that the series of indentations acts as a guide.

18. The method of forming at least one component of a temporary prosthetic knee joint of claim 1, wherein the step of providing an elastic mold further comprises providing a tibial mold, wherein the tibial mold has an external shape defined by an outer surface of said tibial mold, wherein said external shape is substantially kidney shaped and corresponds to a cross sectional shape of a natural tibial bone.

19. The method of forming at least one component of a temporary prosthetic knee joint of claim 1, wherein the step of providing an elastic mold further comprises providing an elastic tibial mold that is characterized by the absence of a substantially enclosed casing.

20. The method of forming at least one component of a temporary prosthetic knee joint of claim 1, wherein the method further comprises the step of making a depth determination that corresponds to a size of a resulting tibial component of the prosthetic knee joint by measuring an extension gap between a distal end of a femur and a proximal end of a tibia by utilizing a marking formed on an outer surface of a tibial mold.

21. The method of forming at least one component of a temporary prosthetic knee joint of claim 20, wherein the method further comprises the step of scoring the tibial mold at a desired thickness at the marking by utilizing a plurality of depth rings configured for use as a guide, wherein said plurality of depth rings at least partially circumscribe the tibial mold.

22. The method of forming at least one component of a temporary prosthetic knee joint of claim 21, wherein the method further comprises the step of removing an excess portion of the tibial mold such that only the desired thickness for forming the resulting tibial component of the prosthetic knee joint remains.

23. The method of forming at least one component of a temporary prosthetic knee joint of claim 1, wherein the step of placing the amount of biocompatible material within the cavity further comprises substantially filling the cavity of a tibial mold with said biocompatible material to a previously determined depth.

24. The method of forming at least one component of a temporary prosthetic knee joint of claim 1, wherein the step of positioning the elastic mold on the bone further comprises positioning a tibial mold on a proximal end of a tibia.

25. The method of forming at least one component of a temporary prosthetic knee joint of claim 1, wherein the step of placing the amount of biocompatible material within the cavity further comprises placing said biocompatible material in a tibial mold and permitting the biocompatible material to slightly cure before positioning the tibial mold on the bone.

26. The method of forming at least one component of a temporary prosthetic knee joint of claim 1, wherein the step of removing the elastic mold further comprises removing a tibial mold from the bone and a resulting tibial component of the prosthetic knee joint.

27. The method of forming at least one component of a temporary prosthetic knee joint of claim 1, wherein the step of positioning the elastic mold on the portion of the bone further includes stretching the elastic mold around said portion of said bone to thereby affix the elastic mold to said bone in a friction fit.

28. The method of forming at least one component of a temporary prosthetic knee joint of claim 1, wherein the method further comprises ascertaining a gap size using a means for determining the gap size between a proximal region of a tibia and a distal region of a femur for receipt of the prosthetic component and providing an articulation surface that allows for at least some range of motion with a complementary prosthetic component.

29. The method of forming at least one component of a temporary prosthetic knee joint of claim 28, wherein the means for determining a gap size includes a spacer block.

30. The method of forming at least one component of a temporary prosthetic knee joint of claim 28, wherein the means for determining a gap size includes calipers.

31. A method of forming at least one component of a temporary prosthetic knee joint on a bone during an in situ surgical procedure, the method comprising the steps of:

providing an elastic mold configured and dimensioned for being affixed to a portion of the bone, said elastic mold having a cavity defined by a sidewall, wherein the elastic mold comprises an elastic femoral mold, wherein the femoral mold has a main body portion, a medial leg and a lateral leg, each leg having a substantially arcuate inner surface designed to form a prosthetic femoral condyle to simulate, at least in part, the biomechanics of the natural femoral condyle such that the prosthetic femoral condyle is configured to articulate with a tibial surface;

placing an amount of biocompatible material within the cavity of the elastic mold for forming the at least one component of the prosthetic knee joint;

positioning the elastic mold on the portion of the bone; and

removing the elastic mold from said portion of said bone after the amount of biocompatible material has been at least partially cured thereby forming said at least one component.

32. A method of forming at least one component of a temporary prosthetic knee joint on a bone during an in situ surgical procedure, the method comprising the steps of:

providing an elastic mold configured and dimensioned for being affixed to a portion of the bone, said elastic mold having a cavity defined by a sidewall, wherein the elastic mold comprises a tibial mold, wherein the tibial mold has an inner base surface comprising at least one protrusion and at least one depression, which are configured for forming a corresponding and opposing at least one depression and at least one protrusion in a tibial component of the prosthetic knee joint so as to simulate, at least in part, a natural tibial plateau;

placing an amount of biocompatible material within the cavity of the elastic mold for forming the at least one component of the prosthetic knee joint;

positioning the elastic mold on the portion of the bone; and

removing the elastic mold from said portion of said bone after the amount of biocompatible material has been at least partially cured thereby forming said at least one component.

33. A method of forming at least one component of a temporary prosthetic knee joint on a bone during an in situ surgical procedure, the method comprising the steps of:

providing an elastic mold configured and dimensioned for being affixed to a portion of the bone, said elastic mold having a cavity defined by a sidewall, wherein the elastic mold comprises a tibial mold, wherein the tibial mold has an external shape defined by an outer surface of said tibial mold, wherein said external shape is substantially kidney shaped and corresponds to a cross sectional shape of a natural tibial bone;

placing an amount of biocompatible material within the cavity of the elastic mold for forming the at least one component of the prosthetic knee joint;

positioning the elastic mold on the portion of the bone; and

removing the elastic mold from said portion of said bone after the amount of biocompatible material has been at least partially cured thereby forming said at least one component.

34. A method of forming at least one component of a temporary prosthetic knee joint on a bone during an in situ surgical procedure, the method comprising the steps of:

providing an elastic mold configured and dimensioned for being affixed to a portion of the bone, said elastic mold having a cavity defined by a sidewall, wherein the elastic mold comprises an elastic tibial mold that is characterized by the absence of a substantially enclosed casing;

placing an amount of biocompatible material within the cavity of the elastic mold for forming the at least one component of the prosthetic knee joint;

positioning the elastic mold on the portion of the bone; and

removing the elastic mold from said portion of said bone after the amount of biocompatible material has been at least partially cured thereby forming said at least one component.

35. A method of forming at least one component of a temporary prosthetic knee joint on a bone during an in situ surgical procedure, the method comprising the steps of:

providing an elastic mold configured and dimensioned for being affixed to a portion of the bone, said elastic mold having a cavity defined by a sidewall, wherein the elastic mold comprises an elastic tibial mold that is characterized by the absence of a substantially enclosed casing;

ascertaining a gap size using a means for determining the gap size between a proximal region of a tibia and a distal region of a femur for receipt of the prosthetic component;

placing an amount of biocompatible material within the cavity of the elastic mold for forming the at least one component of the prosthetic knee joint;

positioning the elastic mold on the portion of the bone;

removing the elastic mold from said portion of said bone after the amount of biocompatible material has been at least partially cured thereby forming said at least one component; and

providing an articulation surface that allows for at least some range of motion with a complementary prosthetic component.