Fastening element for an implant, in particular a hip prosthesis

• US 20020107520A1
• Filed: 11/07/2001
• Published: 08/08/2002
• Est. Priority Date: 11/07/2000
• Status: Abandoned Application

• Current Assignee: Erik Leonard Hoffman
• Original Assignee: Erik Leonard Hoffman
• Inventors: Hoffman, Erik Leonard
• Application Number:
  US10/037,318
• Publication Number:
  US 20020107520A1
• Time in Patent Office: Days
• US Class Current: 606/72
• CPC Class Codes: A61B 17/15 Guides therefor arrangements for guiding straight saw blades in general B23D51/025
• CPC Class Codes: A61B 17/1604 Chisels; Rongeurs; Punches; Stamps
• CPC Class Codes: A61B 17/175 for preparing the femur for hip prosthesis insertion
• CPC Class Codes: A61B 17/742 having one or more longitudinal elements oriented along or parallel to the axis of the neck
• CPC Class Codes: A61B 17/842 Flexible wires, bands or straps A61B17/72, A61B17/82, A61B17/86 take precedence
• CPC Class Codes: A61F 2/3601 for replacing only the epiphyseal or metaphyseal parts of the femur, e.g. endoprosthetic femoral heads or necks directly fixed to the natural femur by internal fixation devices non-prosthetic internal fixation devices for the femoral head or neck A61B17/74
• CPC Class Codes: A61F 2002/30092 using shape memory or superelastic materials, e.g. nitinol
• CPC Class Codes: A61F 2002/30112 Rounded shapes, e.g. with rounded corners
• CPC Class Codes: A61F 2002/30125 elliptical or oval
• CPC Class Codes: A61F 2002/30126 oval-O-shaped
• CPC Class Codes: A61F 2002/30153 rectangular
• CPC Class Codes: A61F 2002/30158 trapezoidal
• CPC Class Codes: A61F 2002/30332 Conically- or frustoconically-shaped protrusion and recess
• CPC Class Codes: A61F 2002/30354 Cylindrically-shaped protrusion and recess, e.g. cylinder of circular basis
• CPC Class Codes: A61F 2002/30405 made by screwing complementary threads machined on the parts themselves
• CPC Class Codes: A61F 2002/30433 using additional screws, bolts, dowels, rivets or washers e.g. connecting screws
• CPC Class Codes: A61F 2002/30462 retained or tied with a rope, string, thread, wire or cable
• CPC Class Codes: A61F 2002/305 Snap connection
• CPC Class Codes: A61F 2002/30507 using a threaded locking member, e.g. a locking screw or a set screw
• CPC Class Codes: A61F 2002/30546 for adjusting elasticity, flexibility, spring rate or mechanical tension
• CPC Class Codes: A61F 2002/30553 : for adjusting a position by translation along an axis
• CPC Class Codes: A61F 2002/30574 : with an integral complete or partial collar or flange
• CPC Class Codes: A61F 2002/30593 : hollow
• CPC Class Codes: A61F 2002/30616 : Sets comprising a plurality of prosthetic parts of different sizes or orientations
• CPC Class Codes: A61F 2002/30774 : internally-threaded
• CPC Class Codes: A61F 2002/30787 : inclined obliquely with respect to each other
• CPC Class Codes: A61F 2002/3079 : Stepped or enlarged apertures, e.g. having discrete diameter changes
• CPC Class Codes: A61F 2002/30845 : with cutting edges
• CPC Class Codes: A61F 2002/30892 : parallel
• CPC Class Codes: A61F 2002/3631 : with an integral complete or partial peripheral collar or bearing shoulder at its base
• CPC Class Codes: A61F 2002/365 : Connections of heads to necks
• CPC Class Codes: A61F 2002/4635 : using minimally invasive surgery
• CPC Class Codes: A61F 2210/0014 : using shape memory or superelastic materials, e.g. nitinol
• CPC Class Codes: A61F 2210/0019 : operated at only one temperature whilst inside or touching the human body, e.g. constrained in a non-operative shape during surgery, another temperature only occurring before the operation
• 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 2220/0041 : using additional screws, bolts, dowels or rivets, e.g. connecting screws
• CPC Class Codes: A61F 2220/0075 : sutured, ligatured or stitched, retained or tied with a rope, string, thread, wire or cable
• CPC Class Codes: A61F 2230/0004 : Rounded shapes, e.g. with rounded corners
• CPC Class Codes: A61F 2230/0008 : elliptical or oval
• CPC Class Codes: A61F 2230/0019 : rectangular
• CPC Class Codes: A61F 2230/0026 : trapezoidal
• CPC Class Codes: A61F 2250/0008 : for adjusting a position by translation along an axis or two perpendicular axes
• CPC Class Codes: A61F 2250/0012 : for adjusting elasticity, flexibility, spring rate or mechanical tension

Abstract

This invention relates to a fastening element for an orthesis pr prosthesis, in particular a hip prosthesis, comprising a supporting element and an at least largely hollow pin extending from the supporting element, while the fixing means are provided for fixing the fastening element in a position in which the hollow pin extends at least largely into a bone.

Claims

1. A fastening element for an implant, in particular a hip prosthesis, comprising a supporting element and an at least largely hollow pin extending from the supporting element, while fixing means are provided for fixing the fastening element in a position in which the hollow pin extends at least largely into a bone.

2. A fastening element according to claim 1, wherein the supporting element is substantially plate-shaped and extends on at least two sides beyond an outer longitudinal edge of the pin.

3. A fastening element according to claim 1, wherein the pin has a longitudinal axis which includes an angle with a main surface of the supporting element, such that during use the supporting element abuts against a sawn-off surface of a bone and the longitudinal axis of the pin extends at an angle with respect to said surface.

4. A fastening element according to claim 1, wherein the fixing means comprise at least one wire element which during use extends from a side remote from the supporting element, of the bone or bone system in which the pin is fitted, into or alongside the pin and has been fixed to the pin and/or the supporting element.

5. A fastening element according to claim 1, wherein the supporting element comprises on the side remote from the pin a coupling element for a further part of a prosthesis or orthesis.

6. A fastening element according to claim 5, wherein the coupling element is offset with respect to the longitudinal axis of the pin.

7. A fastening element according to claim 1, arranged as a fastening element for a hip prosthesis, the pin comprising a longitudinal axis, the supporting element at least adjacent the pin being plate-shaped, and the longitudinal axis including an angle with at least the plate-shaped part of the supporting element which is between 125°

and 145°

.

8. A fastening element according to claim 1, arranged as a fastening element for a hip prosthesis, the pin comprising a longitudinal axis, the supporting element at least adjacent the pin being plate-shaped, and the longitudinal axis including an angle with at least the plateshaped part of the supporting element which is smaller than about 125°

, for use with a coxa vara.

9. A fastening element according to claim 1, arranged as a fastening element for a hip prosthesis, the pin comprising a longitudinal axis, the supporting element at least adjacent the pin being plate-shaped, and the longitudinal axis including an angle with at least the plate-shaped part of the supporting element which is greater than about 145°

, for use with a coxa valga.

10. A fastening element according to claim 1, wherein the pin has at least partly a cross section, at right angles to the longitudinal axis thereof, which is not symmetrical with respect to said longitudinal axis, preferably slightly triangular or multiangular.

11. A fastening element according to claim 1, wherein the pin is provided, on at least the outside or the inside, preferably on both sides, with a finish which enables, preferably improves, bone ingrowth.

12. A fastening element according to claim 1, wherein the fixing means are manufactured at least partly from memory metal.

13. A fastening element according to claim 1, wherein the fixing means comprise tensioning means with which a bias can be set.

14. A fastening element according to claim 1, wherein the fixing means comprise at least one screw which is screwable into the pin and/or the supporting element from the side remote from the supporting element.

15. A fastening element according to claim 14, wherein at least two and preferably three or four screws are provided, screwable into the supporting element, at a distance from the pin.

17. An assembly according to claim 16, wherein fixing means are used which comprise at least one fixing element which, remote from the fastening element, has been inserted through cortical bone of the bone in question and has been coupled to the fastening element, which fixing element has a supporting surface for being supported against said cortical bone.

18. An assembly according to claim 16, wherein the bone is a femur or portion thereof, wherein the femur head has been sawn off, wherein at least a part of the neck has been maintained, such that an abutment surface has been obtained, preferably such that in the normal upright position of the femur the abutment surface extends approximately horizontally, while the longitudinal axis of the pin includes an angle with the supporting element, and the pin has been driven into the spongy bone, such that the supporting element lies flat against the abutment surface.

19. An assembly according to claim 18, wherein said angle between longitudinal axis and supporting element corresponds approximately to the CCD angle of the femur in question.

20. An assembly according to claim 17, wherein a fastening pin has been inserted through the lateral cortical bone and is connected with the pin or the supporting element, while the fastening pin is provided with supporting means which are supported against the lateral cortical bone.

21. An assembly according to claim 16, wherein on the supporting element a coupling element is provided for a portion of the prosthesis or orthesis, in particular a hip head, so positioned that it has an offset with respect to the longitudinal axis of the femur.

22. An assembly according to claim 21, wherein on the coupling element a hip head has been placed, while the longitudinal axis of the pin intersects the hip head, preferably approximately through the center thereof.

23. An assembly according to claim 21, wherein the coupling element is cone-shaped and has a longitudinal axis which includes an angle with the longitudinal axis of the pin, which corresponds approximately to the CCD angle of the femur in question.

24. An assembly according to claim 16, wherein the pin is of hollow design and is provided with a sidewall with openings and/or slots into which and/or through which bone has grown.

25. An assembly according to claim 16, wherein at least one bolt has been screwed from the lateral cortex into the supporting element, in particular into the pin.

26. An assembly according to claim 16, wherein at least two and preferably three or four bolts have been screwed from the lateral cortex into the supporting element, at a distance from the pin.

27. A tool for fitting a fastening element according to claim 1 in a bone, in particular in a surface obtained by sawing off a portion of said bone, which surface contains at least a portion defined by spongy bone, which tool comprises a template provided with a hole pattern corresponding to a circumference of a pin of the fastening element, which holes have a centerline which extends parallel to the angle between a supporting element of the fastening element and the longitudinal axis of the pin, such that after placement of the template on said surface, through said holes a series of bores in the bone can be provided, whereafter the pin can be driven into the bone, steered by said bores.

28. A tool according to claim 27, wherein at least one central opening is provided for drilling a passage for a fastening pin.

30. A method according to claim 29, wherein the pin is driven into the bone at an angle with respect to said surface.

31. A method according to claim 30, wherein as bone a femur is chosen, whose head is subcapitally sawn off, whereafter the pin is driven into the bone at an angle such that the longitudinal axis of the pin extends approximately parallel to the longitudinal axis of the neck, at least prior to removal.

32. A method according to claim 29, wherein in the bone drillings are performed prior to driving the pin into the bone.

33. A method according to claim 29, wherein the fastening element is fixed from a cortical bone part remote from the abutment surface by introducing at least one pin through said cortical bone, which pin is fixed to the fastening element.

16. An assembly of a bone and a fastening element for an orthesis or prosthesis, which fastening element comprises a supporting element and a pin extending from the supporting element and being preferably at least largely hollow, with a portion of the bone having been sawn off, such that an abutment surface has been obtained which is at least partly defined by spongy bone, while the pin has been driven at least partly into the spongy bone, such that the supporting element abuts against said abutment surface, preferably at least partly against cortical bone, with at least the pin having been fixed in the bone.

29. A method for fastening an implant in a bone of a patient, wherein a bone is at least partly sawn off for forming an abutment surface, the abutment surface being provided such that it extends approximately at right angles to the load axis of the joint, at least bone, in question, whereafter at least one pin of a fastening element is driven from the abutment surface into the bone, such that a supporting element to which the pin is fastened comes to lie against said abutment surface.