Liner assembly for prosthetic components

• US 20030187512A1
• Filed: 04/01/2002
• Published: 10/02/2003
• Est. Priority Date: 04/01/2002
• Status: Active Grant

• Current Assignee: Smith & Nephew Incorporated (Smith & Nephew PLC)
• Original Assignee: Smith & Nephew Incorporated (Smith & Nephew PLC)
• Inventors: McKinnon, Brian, Kelman, David, Frederick, Phil, Shea, Jeff
• Granted Patent: US 6,916,342 B2
• Time in Patent Office: Days
• US Class Current: 623/22.2
• CPC Class Codes: A61F 2/32 for the hip
• CPC Class Codes: A61F 2/34 Acetabular cups
• CPC Class Codes: A61F 2/36 Femoral heads ; Femoral endoprostheses
• CPC Class Codes: A61F 2/4637 for connecting or disconnecting two parts of a prosthesis
• CPC Class Codes: A61F 2002/30136 undulated or wavy, e.g. serpentine-shaped or zigzag-shaped
• CPC Class Codes: A61F 2002/30331 made by longitudinally pushing a protrusion into a complementarily-shaped recess, e.g. held by friction fit
• CPC Class Codes: A61F 2002/30332 Conically- or frustoconically-shaped protrusion and recess
• CPC Class Codes: A61F 2002/30367 with additional means for preventing said rotation
• CPC Class Codes: A61F 2002/30405 made by screwing complementary threads machined on the parts themselves
• CPC Class Codes: A61F 2002/30448 using adhesives
• CPC Class Codes: A61F 2002/30449 the adhesive being cement
• CPC Class Codes: A61F 2002/30487 Circumferential cooperating grooves and beads on cooperating lateral surfaces of a mainly longitudinal connection
• CPC Class Codes: A61F 2002/30495 using a locking ring
• CPC Class Codes: A61F 2002/3054 about a connection axis or implantation axis for selecting any one of a plurality of radial orientations between two modular parts, e.g. Morse taper connections, at discrete positions, angular positions or continuous positions
• CPC Class Codes: A61F 2002/30604 modular
• CPC Class Codes: A61F 2002/30616 Sets comprising a plurality of prosthetic parts of different sizes or orientations
• CPC Class Codes: A61F 2002/3069 Revision endoprostheses
• CPC Class Codes: A61F 2002/30769 madreporic
• CPC Class Codes: A61F 2002/3082 Grooves
• CPC Class Codes: A61F 2002/3233 having anti-luxation means for preventing complete dislocation of the femoral head from the acetabular cup
• CPC Class Codes: A61F 2002/3241 : having a ring, e.g. for locking the femoral head into the acetabular cup
• CPC Class Codes: A61F 2002/3403 : Polar aperture
• CPC Class Codes: A61F 2002/3611 : Heads or epiphyseal parts of femur
• CPC Class Codes: A61F 2002/3625 : Necks
• CPC Class Codes: A61F 2002/365 : Connections of heads to necks
• CPC Class Codes: A61F 2002/4619 : for extraction
• CPC Class Codes: A61F 2002/4629 : connected to the endoprosthesis or implant via a threaded connection
• CPC Class Codes: A61F 2002/4641 : for disconnecting
• CPC Class Codes: A61F 2002/4681 : by applying mechanical shocks, e.g. by hammering
• CPC Class Codes: A61F 2002/4689 : acoustic
• CPC Class Codes: A61F 2220/0025 : Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2220/0033 : made by longitudinally pushing a protrusion into a complementary-shaped recess, e.g. held by friction fit
• CPC Class Codes: A61F 2220/005 : using adhesives
• CPC Class Codes: A61F 2230/0004 : Rounded shapes, e.g. with rounded corners
• CPC Class Codes: A61F 2310/00011 : Metals or alloys
• CPC Class Codes: A61F 2310/00017 : Iron- or Fe-based alloys, e.g. stainless steel
• CPC Class Codes: A61F 2310/00023 : Titanium or titanium-based alloys, e.g. Ti-Ni alloys
• CPC Class Codes: A61F 2310/00179 : Ceramics or ceramic-like structures

Abstract

Methods, systems and devices related to prosthetic implants, including a device for preventing prosthetic components from separating from each other, and more specifically to an assembly for adapting a prosthetic component to receive a device for preventing an implant stem head from dislocating from a prosthetic component. Methods, systems and devices according to this invention seek to provide improved orthopedic prosthetic components and more specifically, improved constrained components that may be utilized with existing implanted prosthetic components. Liner assemblies and systems according to various embodiments of this invention may include an adapter component designed to link current prosthetic cup geometry to a constrained liner, while providing optimal range of motion and sufficient lever out.

Claims

1. An adapter component for coupling an orthopedic prosthetic cup to a constrained liner, the adapter component comprising:

a first adapter element having a first surface adapted to mate with a prosthetic cup, and a second surface adapted to mate with a second adapter element; and

a second adapter element having a first surface adapted to mate with the second surface of the first adapter element;

wherein the second surface of the first adapter element is tapered and the first surface of the second adapter element is tapered, forming a taper locking interface between the first and second adapter elements when the elements are coupled and

wherein the adapter component provides an orthopedic prosthetic device a greater resistance to disassembly than is provided by the prosthetic device alone.

2. The adapter component of claim 1, wherein the second adapter element further comprises a second surface adapted to mate with an outer surface of the liner.

3. The adapter component of claim 1, further comprising a locking member.

4. The adapter component of claim 3, wherein the locking member is a locking ring.

5. The adapter component of claim 3, wherein the first adapter element further comprises a recess adapted to receive the locking member, and wherein the locking member couples the liner to the first adapter element.

6. The adapter component of claim 5, wherein the locking member is adapted to be received in a groove in the liner.

7. The adapter component of claim 3, wherein the locking member further comprises an opening that expands to receive a liner.

8. The adapter component of claim 1, further comprising a positioning element, wherein the positioning element aligns the first and second adapter elements.

9. The adapter component of claim 1, wherein the first adapter element includes splines adapted to mate with splines on an inner surface of a prosthetic cup.

10. The adapter component of claim 1, wherein the second adapter element includes splines adapted to mate with splines on an outer surface of the liner.

11. The adapter component of claim 1, wherein the first and second adapter elements are rings.

12. The adapter component of claim 1, wherein the first and second adapter elements are metal.

13. A constrained liner assembly for use with an orthopedic prosthetic device, comprising:

(a) a prosthetic cup, comprising a cavity adapted to receive a liner;

(b) a liner comprising a cavity adapted to receive an implant stem head;

(c) a member connected to the liner, which member is adapted to impede the head from escaping the cavity; and

(d) structure for retaining the liner in the cup;

wherein the constrained liner assembly provides resistance to disassembly.

14. The constrained liner assembly of claim 13, wherein the liner further comprises a channel adapted to receive a retaining member.

15. The constrained liner assembly of claim 14, wherein the retaining member is adapted to deform to allow insertion of a prosthetic component.

16. The constrained liner assembly of claim 13, wherein the member connected to the liner comprises a capture member.

17. The constrained liner assembly of claim 16, wherein the capture member further comprises tabs adapted to be received in slots on the face of the liner.

18. The constrained liner assembly of claim 17, wherein capture member deforms the retaining member, capturing the head in the liner.

19. The constrained liner assembly of claim 13, wherein the structure for retaining the liner in the cup comprises an adapter component, the adapter component comprising:

a first adapter element having a first surface adapted to mate with a prosthetic cup, and a second surface adapted to mate with a second adapter element, and

a second adapter element having a first surface adapted to mate with the second surface of the first adapter element;

wherein the second surface of the first adapter element is tapered and the first surface of the second adapter element is tapered, forming a taper locking interface between the first and second adapter elements when the elements are coupled.

20. The constrained liner assembly of claim 19, wherein the adapter component further comprises a locking member.

21. The adapter component of claim 20, wherein the locking member is a locking ring.

22. The constrained liner assembly of claim 20, wherein the first adapter element further comprises a recess adapted to receive the locking member.

23. The constrained liner assembly of claim 22, wherein the locking member couples the liner to the first adapter element.

24. The constrained liner assembly of claim 20, wherein the locking member is adapted to be received in a groove in the liner.

25. The constrained liner assembly of claim 20, wherein the locking member further comprises an opening that expands to receive a liner.

26. The constrained liner assembly of claim 19, further comprising a positioning element, wherein the positioning element aligns the first and second adapter elements.

27. The constrained liner assembly of claim 19, wherein the adapter component further comprises a second surface on the second adapter element adapted to mate with an outer surface of the liner.

28. The constrained liner assembly of claim 19, wherein the first adapter element includes splines adapted to mate with splines on an inner surface of a prosthetic cup.

29. The constrained liner assembly of claim 19, wherein the second adapter element includes splines adapted to mate with splines on an outer surface of the liner.

30. The constrained liner assembly of claim 19, wherein the first and second adapter elements are rings.

31. The constrained liner assembly of claim 19, wherein the first and second adapter elements are metal.

32. A constrained liner assembly for use with an orthopedic prosthetic device, comprising:

(a) an adapter component comprising

a first adapter element having a first surface adapted to mate with a prosthetic cup, a second surface adapted to mate with a second adapter element and a recess adapted to receive a locking member,

a second adapter element having a first surface adapted to mate with the second surface of the first adapter element, and

a locking member; and

(b) a liner component comprising

a liner having a groove adapted to receive the locking member, a channel adapted to receive a retaining member, and a cavity adapted to receive an implant stem head,

a retaining member having a slit, and

a capture member adapted to compress the retaining member to retain an implant stem head in the cavity in the liner,

wherein the adapter component couples the liner component to a prosthetic cup.

33. The constrained liner assembly of claim 32, wherein the second adapter element further comprises a second surface adapted to mate with an outer surface of the liner.

34. The constrained liner assembly of claim 33, wherein the second surface of the second adapter element is tapered.

35. The constrained liner assembly of claim 33, wherein the second surface of the second adapter element includes splines.

36. The constrained liner assembly of claim 32, wherein the second surface of the first adapter element is tapered and the first surface of the second adapter element is tapered, forming a taper locking interface between the first and second adapter elements when the elements are coupled.

37. The constrained liner assembly of claim 32, wherein the first and second adapter elements are rings.

38. The constrained liner assembly of claim 32, wherein the locking member is a locking ring.

39. The constrained liner assembly of claim 32, wherein the adapter component is metal.

40. The constrained liner assembly of claim 32, wherein the liner component is plastic.

41. The constrained liner assembly of claim 32, wherein the capture member is metal.

42. A prosthetic device for use in replacing at least part of a hip joint comprising:

(a) a prosthetic acetabular cup;

(b) a constrained liner assembly, comprising;

(i) an adapter component comprising

a first adapter element having a first surface adapted to mate with a prosthetic cup, a second surface adapted to mate with a second adapter element and a recess adapted to receive a locking member

a second adapter element having a first surface adapted to mate with the second surface of the first adapter element, and

a locking member; and

(ii) a liner component comprising

a liner having a groove adapted to receive the locking member, a channel adapted to receive a retaining member, and a cavity adapted to receive an implant stem head,

a retaining member having a slit, and

a capture member adapted to compress the retaining member to retain an implant stem head in the cavity in the liner,

(c) a femoral component, comprising

(i) an implant stem head adapted to approximate the size and shape of the head of a femur; and

(ii) an implant stem component adapted to be fitted to a resected femur;

wherein the constrained liner assembly couples the acetabular cup to the femoral component and wherein the constrained liner assembly provides resistance to disassembly.

43. A prosthetic device according to claim 42, wherein the second adapter element further comprises a second surface adapted to mate with an outer surface of the liner.

44. The prosthetic device of claim 42, wherein the second surface of the second adapter element is tapered.

45. The prosthetic device of claim 42, wherein the second surface of the second adapter element includes splines.

46. The prosthetic device of claim 42, wherein the second surface of the first adapter element is tapered and the first surface of the second adapter element is tapered, forming a taper locking interface between the first and second adapter elements when the elements are coupled.

47. The prosthetic device of claim 42, wherein the first and second adapter elements are rings.

48. The prosthetic device of claim 42, wherein the locking member is a locking ring.

49. The prosthetic device of claim 42, wherein the adapter component is metal.

50. The prosthetic device of claim 42, wherein the liner component is plastic.

51. The prosthetic device of claim 42, wherein the capture member is metal.

52. A method of replacing at least part of a hip joint in a patient, comprising:

(a) selecting and assembling an appropriately sized adapter component, the adapter component comprising

a first adapter element having a first surface adapted to mate with a prosthetic cup, and a second surface adapted to mate with a second adapter element, and

a second adapter element having a first surface adapted to mate with the second surface of the first adapter element;

wherein the second surface of the first adapter element is tapered and the first surface of the second adapter element is tapered, forming a taper locking interface between the first and second adapter elements when the elements are coupled; and

(b) placing the adapter component in an acetabular cup;

(c) inserting a liner into the adapter component and cup;

(d) rotating the liner as required to obtain optimal positioning;

(e) seating the liner;

(f) selecting and assembling an appropriately sized implant stem head and femoral stem component;

(g) inserting the implant stem head into the cavity of the liner;

(h) rotating the femoral component to check mobility.

53. A method of replacing at least part of a hip joint in a patient, comprising:

(a) removing a prosthetic liner and apex hole cover from an implanted acetabular cup;

(b) selecting and assembling an appropriately sized adapter component, including first and second adapter elements and a locking member;

(c) placing the adapter component in the acetabular cup;

(d) placing a positioning element on the adapter component;

(e) threading an alignment rod to an apex hole of the cup;

(f) sliding an impactor over the alignment rod;

(g) striking a surface of the impactor until sufficient force engages the first and second adapter components, expanding the first adapter element into engagement with the cup;

(h) removing the positioning element;

(i) inserting an assembled liner and retaining member into the adapter component and cup;

(j) rotating the liner as required to obtain optimal positioning;

(k) seating the liner using a liner impactor tool, forcing the locking member into a groove on the liner;

(l) selecting and assembling an appropriately sized implant stem head and femoral stem component;

(m) placing a capture member over the implant stem head;

(n) inserting the implant stem head into the cavity of the liner;

(o) rotating the femoral component to check mobility;

(p) inserting the capture member into slots on the liner.