Implantable joint prosthesis

• US 6,702,854 B1
• Filed: 05/30/2000
• Issued: 03/09/2004
• Est. Priority Date: 06/01/1999
• Status: Expired due to Term

• Current Assignee: Omnilife Science, Inc. (OrthoUnited, Inc.)
• Original Assignee: Apex Surgical, LLC (OrthoUnited, Inc.)
• Inventors: Cipolletti, George B., Cheal, Edward J.
• Primary Examiner(s): McDermott, Corrine
• Assistant Examiner(s): STEWART, ALVIN J
• Application Number:
  US09/583,805
• Time in Patent Office: 1,379 Days
• Field of Search: 623/23.32, 623/22.41, 623/22.42, 623/23.18, 623/23.15, 623/23.23, 623/23.26, 623/23.31, 623/23.35
• US Class Current: 623/22.42
• CPC Class Codes: A61F 2/36 Femoral heads ; Femoral endoprostheses
• CPC Class Codes: A61F 2/3672 Intermediate parts of shafts
• CPC Class Codes: A61F 2/38 for elbows or knees
• CPC Class Codes: A61F 2/40 for shoulders
• CPC Class Codes: A61F 2/42 for wrists or ankles; for hands, e.g. fingers; for feet, e.g. toes
• CPC Class Codes: A61F 2002/30171 rosette- or star-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 2002/30484 Mechanically expandable devices located on the first prosthetic part for locking into or onto the second prosthetic part
• 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 2002/30594 slotted, e.g. radial or meridian slot ending in a polar aperture, non-polar slots, horizontal or arcuate slots
• 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 2002/30797 internally-threaded
• CPC Class Codes: A61F 2002/30881 Circumferential ribs, flanges or fins
• CPC Class Codes: A61F 2002/30884 Fins or wings, e.g. longitudinal wings for preventing rotation within the bone cavity
• CPC Class Codes: A61F 2002/3631 with an integral complete or partial peripheral collar or bearing shoulder at its base
• CPC Class Codes: A61F 2002/3652 Connections of necks to shafts
• CPC Class Codes: A61F 2002/4619 for extraction
• CPC Class Codes: A61F 2002/4641 for disconnecting
• 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 2230/005 : Rosette-shaped, e.g. star-shaped

Abstract

The present invention discloses systems, kits and methods for prosthetic joint replacement. In one embodiment, a modular implantable surgical device including a stem, a neck and a head is disclosed that is suitable for replacement of a hip joint. In another embodiment, a kit is provided that includes at least two stems, necks and heads that can be used by the surgeon to adapt the size and shape of the assembled prosthetic device to conform to an individual patient'"'"'s anatomy. In a practice according to the methods of the present invention, steps are disclosed for positioning the prosthesis in an individual patient in an anatomically correct position.

Claims

1. A system for replacing a joint, comprising;

a stern portion with a proximal end, a midshaft bearing at least one axially directed ridge and a distal non-ridged shaft, wherein the at least one axially directed ridge projects radially from a surface of the stem portion and the distal non-ridged shaft comprises at least 10% of the stem portion, said stem portion being insertable into a medullary canal of a bone shaft to engage a cortical bone surface thereof;

a head portion dimensionally adapted to articulate with a surgically prepared joint socket; and

a neck portion with a first end and a second end, said first end being contiguous with the proximal end of the stem portion and protruding from the medullary canal when the stem portion is secured within said medullary canal and said second end being dimensionally adapted for bearing the head portion into an anatomically correct relationship with the surgically prepared joint socket.

2. The system of claim 1, wherein the mid shaft bears a plurality of axially directed flutes and ridges.

3. The system of claim 1, further comprising means for removing the stem portion from the medullary canal of the bone shaft.

4. The system of claim 1, wherein the neck portion is formed integrally with the stem portion.

5. The system of claim 1, wherein the neck portion is removably attachable to the stem portion and mates with said stem portion.

6. The system of claim 5, further comprising coupling means for securely attaching the neck portion to the stem portion.

7. The system of claim 6, further comprising means for detaching the neck portion from the stem portion after said neck portion has been securely attached to said stem portion.

8. The system of claim 5, wherein the first end of the neck portion comprises a male spigot dimensionally adapted for insertion into a female bore machined into the proximal end of the stem portion, said male spigot securing the neck portion to the stem portion when said male spigot is inserted into said female bore.

9. The system of claim 8, wherein the male spigot is split distally with at least one axially oriented slot, and wherein the female bore is fitted with a protrusion dimensionally adapted for insertion into the axially oriented slot when the male spigot is inserted into the female bore, said protrusion further being dimensionally adapted for radially expanding the male spigot to secure the male spigot within the female bore when the male spigot is fully seated in the female bore.

10. The system of claim 8, wherein the male spigot and the female bore are substantially cylindrical.

11. The system of claim 10, wherein the male spigot comprises at least one proximal cylinder and at least one distal cylinder, each cylinder having a preselected circumference wherein the preselected circumference of the at least one proximal cylinder is greater than the preselected circumference of the at least one distal cylinder.

12. The system of claim 11, wherein a transition zone of tapering circumference is positioned between the at least one proximal cylinder and the at least one distal cylinder.

13. The system of claim 5, wherein the neck portion and the stem portion comprise means for positioning the neck portion with respect to the stem portion.

14. The system of claim 5, wherein the proximal end of the stem portion ends proximally with a flat platform that supports the neck portion.

15. The system of claim 14, wherein the first end of the neck portion comprises a flat surface that mates with the flat platform, said flat surface being supported by said flat platform.

16. The system of claim 1, wherein the axially directed ridge comprises at least one cutting edge suitable for cutting bone.

17. The system of claim 1, wherein the distal non-ridged shaft is slotted with at least one axially oriented slot.

18. The system of claim 17, wherein the at least one axially oriented slot is a single coronal slot.

19. The system of claim 17, wherein the distal non-ridged shaft is slotted with at least two axially oriented slots.

20. The system of claim 19, wherein two of the at least two axially oriented slots meet to form an acute angle.

21. The system of claim 20, wherein at least one edge of the stem portion facing the acute angle has been contoured to decrease its sharpness.

22. The system of claim 21, wherein a third axially directed slot is formed normal to the acute angle, said third axially directed slot extending into the edge of the stem portion facing the acute angle, thereby to decrease its sharpness.

23. The system of claim 17, wherein the distal non-ridged shaft is slotted with three slot.

24. The system of claim 23, wherein only two of the three slots are of equal length.

25. The system of claim 1, wherein the distal non-ridged shaft comprises between 20% and 40% of the stem portion.

26. The system of claim 1, wherein the distal non-ridged shaft comprises less than 75% of the stem portion.

27. A kit for assembly of a prosthesis for replacing a joint, comprising:

at least four prosthetic members selected from the group consisting of stem members, neck members and head members, said kit comprising at least one stem member, at least one neck member and at least one head member,

each stem member having a proximal end, a midshaft bearing at least one axially directed ridge and a distal non-ridged shaft, wherein the at least one axially directed ridge projects radially from a surface of the stem member and the distal non-ridged shaft comprises at least 10% of the stem member, said stem member having a predetermined shape for insertion into a surgically prepared medullary cavity of a long bone, and each stem member being selected from the group consisting of differently sized and shaped stem members, and

each neck member being dimensionally adapted to mate with at least one stem member, each neck member having a predetermined size and shape to replace a segment of the joint extending from the long bone to a joint head, and each neck member being selected from the group consisting of differently sized and shaped neck members.

28. The kit of claim 27, wherein the midshaft bears a plurality of axially directed flutes and ridges.

29. The kit of claim 27, wherein each head member is adapted to mate with at least one neck member and wherein each head member has a predetermined size and shape to replace the joint head and to articulate with a surgically prepared joint socket.

30. The kit of claim 27, wherein at least one stem member is slotted with at least one axially oriented slot.

31. The kit of claim 27, wherein each neck member comprises a first end adjacent the stem member and a second end dimensionally adapted for bearing the head member into articulation with a surgically prepared joint socket said first end further being dimensionally adapted for being supported by the proximal end of at least one stem member.

32. The kit or claim 27, further comprising at least one preparation tool for preparing a segment of the joint to receive at least one prosthetic member.

33. The kit of claim 27, wherein the distal non-ridged shaft comprises between 20% and 40% of the stem member.

34. The kit of claim 27, wherein the distal non-ridged shaft comprises less than 75% of the stem member.

35. A kit for assembly of a hip prosthesis for reconstruction of a hip joint, comprising:

at least four prosthetic members selected from the group consisting of stem members, neck members and head members, said kit comprising at least one stem member, at least one neck member and at least one head member,

each stem member having a proximal flared end, a midshaft bearing at least one axially directed ridge and a distal non-ridged shaft, wherein the at least one axially directed ridge projects radially from a surface of the stem member and the distal non-ridged shaft comprises at least 10% of the stem member, said stem member having a predetermined shape for insertion into a surgically prepared medullary cavity of a femur, and each stem member being selected from the group consisting of differently sized and shaped stem members, and

each neck member being dimensionally adapted to mate with at least one stem members and having a predetermined size and shape to replace a portion of the femur comprising a femoral neck and a proximal femur adjacent said femoral neck and to restore the hip joint to an anatomically correct position, each neck member further being dimensionally adapted for being supported by an upper portion of at least one stem member when in a proper anatomic position, and each neck member being formed to include an attachment portion for securement with the upper portion of at least one stem member, and each neck member being selected from the group consisting of differently sized and shaped neck members.

36. The kit of claim 35, wherein the midshaft bears a plurality of axially directed ridges and flutes.

37. The kit of claim 35, wherein each head member is dimensionally adapted to mate with at least one neck member and wherein each neck member has a predetermined size and shape to replace a joint head and to articulate with a surgically prepared acetabulum.

38. The kit of claim 35, wherein at least one stem member is slotted with at least one axially oriented slot.

39. The kit of claim 35, wherein each of the two neck members comprises a first end adjacent the stem and a second end dimensionally adapted for bearing a head member into articulation with the surgically prepared joint socket, said first end being further dimensionally adapted for being supported by the proximal end of at least one stem member.

40. The kit of claim 35, further including at least one preparation tool for preparing a segment of the joint to receive at least one prosthetic member.

41. The kit of claim 40, wherein the at least one preparation tool is selected from the group consisting of broaches and reamers.

42. The kit of claim 35, wherein the distal non-ridged shaft comprises between 20% and 40% of the stem member.

43. The kit of claim 35, wherein the distal non-ridged shaft comprises less than 75% of the stem member.

44. A stem component of a joint replacement system, comprising:

a proximal end, a midshaft bearing at least one axially directed ridge, a distal non-ridged shaft, and a distal end, wherein the at least one axially directed ridge projects radially from a surface of the stem component and the distal non-ridged shaft comprises at least 10% of the stem component, said stem component being insertable into a medullary canal of a bone shaft to engage a cortical bone surface thereof wherein the distal end is slotted with at least one axially oriented slot.

45. The stem component of claim 44, wherein the at least one axially oriented slot is a single coronal slot.

46. The stem component of claim 44, wherein the at least one axially oriented slot extends into the shaft.

47. The stem component of claim 44, wherein the distal end is slotted with at least two axially oriented slots.

48. The stem component of claim 47, wherein two of the at least two axially oriented slots meet to form an angle that splits the distal stem into three stem tines, including at least one acutely angled stem tine.

49. The stem component of claim 48, wherein the at least one acutely angled stem tine has at least one sharp cutting edge.

50. The stem component of claim 49, wherein the at least one sharp cutting edge of the at least one acutely angled stem tine has been contoured to decrease its sharpness.

51. The stem component of claim 50, wherein a third axially directed slot is formed normal to the acutely angled stem tine, said third axially directed slot extending into the at least one sharp cutting edge thereby to decrease its sharpness.

52. The stem component of claim 44, wherein the distal non-ridged shaft comprises between 20% and 40% of the stem component.

53. The stem component of claim 44, wherein the distal non-ridged shaft comprises less than 75% of the stem component.

54. A system for seating an implantable joint prosthesis in a surgically prepared bone, comprising:

a stem with a proximal end, a distal end, a mid-shaft and a distal shaft, wherein the distal end is dimensionally adapted for insertion into a medullary cavity of a bone, wherein the distal end is slotted with at least one axially oriented slot, wherein the mid-shaft bears at least one axially oriented ridge suitable for cutting into a cortical surface of the medullary cavity, wherein the at least one axially directed ridge projects radially from a surface of the stem, wherein the distal shaft is unridged, wherein the unridged distal shaft comprises at least 10% of the stem, and wherein the proximal end is dimensionally adapted for extruding from a proximal end of the surgically prepared bone.

55. An implantable modular prosthesis for replacement of a hip joint, comprising:

a stem portion with a proximal flared end, a midshaft bearing a plurality of axially directed ridges, and a distal non-ridged shaft, wherein at least one of the axially directed ridges projects radially from a surface of the stem portion and the distal non-ridged shaft comprises at least 10% of the stem portion, said stem portion being insertable into the medullary canal of a femur to engage a cortical bone surface thereof;

a head dimensionally adapted for insertion into a surgically prepared acetabulum; and

a neck portion positioned in contiguity with the proximal flared end of the stem portion and positioned proximal to a proximal end of the femur said neck portion dimensionally adapted for bearing the head into an anatomically correct relationship with the surgically prepared acetabulum and further dimensionally adapted for orienting the surgically prepared femur in an anatomically correct position.

56. A method for replacing a joint, comprising:

providing a stem portion with a midshaft bearing a plurality of axially directed flutes and ridges and a distal non-ridged shaft, wherein at least one of the axially directed ridges projects radially from a surface of the stem portion and the distal non-ridged shaft comprises at least 10% of the stem portion, a head portion dimensionally adapted to replace a joint head of a bone, and a neck portion with a proximal end dimensionally adapted for bearing the head portion and a distal end matable with the stem portion;

resecting the joint head and preparing a medullary cavity of a bone shaft of the bone;

identifying a proper position for assembling the stem portion, the neck portion and the head portion wherein their assembly restores a proper anatomic relationship to the joint;

positioning the stem portion in the medullary cavity;

assembling the stem portion, the neck portion and the head portion in positions that restore the proper anatomic relationship to the joint; and

securing the stem portion, the neck portion and the head portion in the positions.

57. A method for replacing a joint, comprising:

providing a modular joint replacement system comprising a stem, a neck and a head, the stem comprising a distal non-ridged shaft, wherein the distal non-ridged shaft comprises at least 10% of the stem, a fluted and ridged midshaft bearing at least one axially directed ridge that projects radially from a surface of the stem, and a proximal end, the neck comprising a first end dimensionally adapted for positioning in contiguity with the proximal end of the stem and a second end adapted for bearing at least one head, the stem being selected from the group consisting of differently sized stems and the neck being selected from the group consisting of differently sized necks;

resecting a joint head of the joint and preparing the medullary cavity of the bone shaft of the joint;

selecting a stem of proper anatomic dimension for insertion into the medullary cavity;

selecting a head dimensionally adapted for insertion into the prepared joint socket;

selecting a neck which, when placed in contiguity with the stem and when bearing the head in the prepared joint socket, is dimensionally adapted for restoring a proper anatomic relationship to the joint;

positioning the stem in the medullary cavity of the bone shaft;

identifying a proper position for assembling the stem, the neck and the head wherein their assembly restores the proper anatomic relationship;

assembling the stem, the neck and the head in the proper position; and

securing the stem, the neck and the head in the proper position.

58. A method for replacing a hip joint, comprising:

providing a stem portion comprising a midshaft bearing a plurality of axially directed flutes and ridges and a distal non-ridged shaft, wherein at least one of the axially directed ridges projects radially from a surface of the stem portion and the distal non-ridged shaft comprises at least 10% of the stem portion, a head portion dimensionally adapted to replace a joint head of a femur, and a neck portion comprising a proximal end dimensionally adapted for bearing the head portion into a proper anatomic relationship with a surgically prepared acetabulum and a distal end matable with the stem portion;

rejecting the joint head and preparing a medullary cavity of the femur;

identifying a proper position for assembling the stem portion, the neck portion and the head portion wherein their assembly restores a proper anatomic relationship to the hip joint;

positioning the stem portion in the medullary cavity;

assembling the stem portion, the neck portion and the head portion in positions that restore the proper anatomic relationship to the hip joint; and

securing the stem portion, the neck portion and the head portion in the positions.

59. The method of claim 58, wherein the stem portion further comprises a proximal flared portion dimensionally adapted for insertion into a proximal end of a surgically prepared femur.

60. The method of claim 58, wherein preparing the medullary cavity further comprises reaming the medullary cavity and broaching the proximal end of the femur medially.