Method for fastening an implant to bone tissue and corresponding implant system

• US 8,357,201 B2
• Filed: 04/18/2008
• Issued: 01/22/2013
• Est. Priority Date: 04/20/2007
• Status: Active Grant

• Current Assignee: Woodwelding AG
• Original Assignee: Woodwelding AG
• Inventors: Mayer, Jorg, Muller, Andrea
• Primary Examiner(s): Tyson, Melanie
• Assistant Examiner(s): DANG, PHONG SON H
• Application Number:
  US12/105,670
• Publication Number:
  US 20090018560A1
• Time in Patent Office: 1,740 Days
• Field of Search: 623/18.11, 606/151
• US Class Current: 623/18.11
• CPC Class Codes: A61B 17/68 Internal fixation devices , including fasteners and spinal fixators, even if a part thereof projects from the skin bone staples A61B17/0642
• CPC Class Codes: A61F 2/30 Joints
• CPC Class Codes: A61F 2/30721 Accessories
• CPC Class Codes: A61F 2/30749 Fixation appliances for connecting prostheses to the body
• CPC Class Codes: A61F 2/30767 Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
• CPC Class Codes: A61F 2/3804 for elbows
• CPC Class Codes: A61F 2/389 Tibial components A61F2/3868 takes precedence
• CPC Class Codes: A61F 2/4081 Glenoid components, e.g. cups
• CPC Class Codes: A61F 2/42 for wrists or ankles; for hands, e.g. fingers; for feet, e.g. toes
• CPC Class Codes: A61F 2002/30065 thermoplastic, i.e. softening or fusing when heated, and hardening and becoming rigid again when cooled
• 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 2002/30451 soldered or brazed or welded
• 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 2002/30772 Apertures or holes, e.g. of circular cross section
• CPC Class Codes: A61F 2002/30777 Oblong apertures
• CPC Class Codes: A61F 2002/3082 Grooves
• CPC Class Codes: A61F 2002/30845 with cutting edges
• CPC Class Codes: A61F 2002/30878 with non-sharp protrusions, for instance contacting the bone for anchoring, e.g. keels, pegs, pins, posts, shanks, stems, struts
• CPC Class Codes: A61F 2002/30892 : parallel
• CPC Class Codes: A61F 2002/3412 : with pins or protrusions, e.g. non-sharp pins or protrusions projecting from a shell surface
• CPC Class Codes: A61F 2210/0071 : thermoplastic
• 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 2220/0058 : soldered or brazed or welded

Abstract

An implant designed e.g. as a replacement for an articulating surface of a human or animal joint is secured to the bone tissue with the aid of a plurality of fasteners (3). The implant (2) comprises a bone side to be brought into contact with the bone tissue, which bone side is equipped with a plurality of fastening structures restricted to this bone side. The fasteners (3) comprise a distal and a proximal side, wherein the distal side is equipped for being anchored in bone tissue and the proximal side is equipped for being connected with one of the fastening structures of the implant (2). The distal sides of the fasteners (3) are anchored in the bone tissue of the appropriately prepared bone and the implant (2) is then attached to the anchored fasteners (3) by connecting the fastening structures with the proximal sides of the fasteners (3), wherein the implant (2) is pressed against the proximal sides of the anchored fasteners (3).

Claims

1. Method for fastening an implant to human or animal bone tissue), the method comprising the steps of:

preparing the bone tissue;

providing an implant comprising a bone side to be brought into contact with the bone tissue, the bone side of the implant being equipped with a plurality of fastening structures restricted to said bone side,

providing a plurality of fasteners, each with a distal side and a proximal side, wherein the distal side is equipped for anchoring the fastener in the bone tissue and the proximal side is equipped for a connection with the fastening structures of the implant so that the proximal side of the fastener does not reach to a side of the implant facing away from the bone side,

and anchoring the distal sides of the fasteners in the prepared bone tissue prior to fastening the implant to the fasteners by connecting the fastening structures with the proximal sides of the fasteners, wherein the implant is pressed against the proximal sides of the fasteners, wherein at least one of the following conditions holds;

one of;

the fastening structures and the proximal sides of the fasteners, comprises undercut recesses and the other one of;

the fastening structures and the proximal sides of the fasteners, comprises protrusions which are insertable or snappable into the undercut recesses;

one of;

the fastening structures and the proximal sides of the fasteners, comprises undercut recesses and the other one of;

the fastening structures and the proximal sides of the fasteners, comprises a thermoplastic material embeddable in the undercut recesses when melted or at least softened;

one of;

the fastening structures and the proximal sides of the fasteners, comprises conical protrusions and the other of;

the fastening structures and the proximal sides of the fasteners, comprises conical recesses, wherein pressing the conical protrusions into the conical recesses results in a press fit connection;

the fastening structures and the proximal sides of the fasteners comprise thermoplastic material capable of making a material connection

wherein, for the step of fastening, heat or mechanical oscillation is applied to the implant from a side other than the bone side.

2. Method according to claim 1, wherein all fastening structures are connected to the proximal sides of the fasteners simultaneously.

3. Method according to claim 1, wherein the fastening structures are connected with the proximal sides of the fasteners by positive fit connections achieved by liquefying or softening and re-solidifying a thermoplastic material, by snap connections, by press fit connections and/or by fusing two thermoplastic materials together.

4. Method according to claim 1, wherein the fasteners are anchored in openings provided in the bone tissue.

5. Method according to claim 1, wherein the fasteners are anchored in the bone tissue by means of mechanical oscillation and a material which is liquefiable by mechanical oscillation, by means of a screw thread, by means of malleting the fasteners into the bone tissue and/or by means of a bone cement.

6. Method for fastening an implant to human or animal bone tissue), the method comprising the steps of:

preparing the bone tissue;

providing an implant comprising a bone side to be brought into contact with the bone tissue, the bone side of the implant being equipped with a plurality of fastening structures restricted to said bone side,

providing a plurality of fasteners, each with a distal side and a proximal side, wherein the distal side is equipped for anchoring the fastener in the bone tissue and the proximal side is equipped for a connection with the fastening structures of the implant so that the proximal side of the fastener does not reach to a side of the implant facing away from the bone side,

and anchoring the distal sides of the fasteners in the prepared bone tissue prior to fastening the implant to the fasteners by connecting the fastening structures with the proximal sides of the fasteners, wherein the implant is pressed against the proximal sides of the fasteners, wherein at least one of the following conditions holds;

one of;

the fastening structures and the proximal sides of the fasteners, comprises undercut recesses and the other one of;

the fastening structures and the proximal sides of the fasteners, comprises protrusions which are insertable or snappable into the undercut recesses;

one of;

the fastening structures and the proximal sides of the fasteners, comprises undercut recesses and the other one of;

the fastening structures and the proximal sides of the fasteners, comprises a thermoplastic material embeddable in the undercut recesses when melted or at least softened;

one of;

the fastening structures and the proximal sides of the fasteners, comprises conical protrusions and the other of;

the fastening structures and the proximal sides of the fasteners, comprises conical recesses, wherein pressing the conical protrusions into the conical recesses results in a press fit connection;

the fastening structures and the proximal sides of the fasteners comprise thermoplastic material capable of making a material connection

wherein the step of anchoring comprises pushing the fastener into an opening provided in the bone tissue and wherein the proximal side of the anchored fastener is trimmed before the step of fastening.