Method for implanting and subsequently removing mechanical connecting elements from living tissue

• US 4,170,990 A
• Filed: 01/27/1978
• Issued: 10/16/1979
• Est. Priority Date: 01/28/1977
• Status: Expired due to Term

• Current Assignee: Fried. Krupp Gesellschaft mit beschrankter Haftung
• Original Assignee: Fried. Krupp Gesellschaft mit beschrankter Haftung
• Inventors: Muller, Manfred, Hartwig, Jurgen, Baumgart, Frank, Bensmann, Gunter, Jorde, Joachim, Schlegel, Karl F., Haasters, Jorg
• Primary Examiner(s): Crowder, Clifford D.
• Application Number:
  US05/873,052
• Time in Patent Office: 627 Days
• Field of Search: 3/1.7, 128/84 R, 128/69, 128/92 D, 128/92 B, 128/92 BC, 128/92 G
• US Class Current: 606/78
• CPC Class Codes: A61B 17/0644 penetrating the tissue, deformable to closed position
• CPC Class Codes: A61B 17/0682 for applying U-shaped staples or clamps, e.g. without a forming anvil
• CPC Class Codes: A61B 17/7258 with laterally expanding parts, e.g. for gripping the bone
• CPC Class Codes: A61B 2017/00867 shape memory effect
• CPC Class Codes: A61F 2002/30092 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 2310/00023 Titanium or titanium-based alloys, e.g. Ti-Ni alloys
• CPC Class Codes: A61L 27/06 Titanium or titanium alloys
• CPC Class Codes: A61L 31/022 Metals or alloys

Abstract

Method for implanting and subsequently removing mechanical implants of an Ni-Ti or a Ti-Nb alloy material which exhibits the memory effect which occurs due to heating of the implant to a temperature above the specific temperature for the alloy material. The memory effect is actuated by heating the implant after implantation of same in the living tissue, and upon completion of the healing process, the implant is substantially returned to its shape upon implantation by cooling it to a temperature below the temperature which actuates the opposite memory effect to facilitate removal.

Claims

1. A method of implanting and subsequently removing mechanical connecting elements from living tissue comprising:

providing a connecting element which is formed from the group consisting of a Ni-Ti or a Ti-Nb alloy material which exhibits a memory effect due to heating to a temperature above a material specific temperature and which has been plastically deformed;

implanting the connecting element;

thereafter heating the connecting element to a temperature sufficient to actuate the memory effect to cause the element to assume substantially its shape prior to being plastically deformed and to provide the desired connection between portions of living tissue;

upon completion of the healing process for the living tissue, cooling the implanted connecting element to a temperature below that which actuates the opposite memory effect to return the implanted connecting element to substantially its shape upon implantation; and

then removing the connecting element.

2. A method as defined in claim 1 wherein said step of cooling includes cooling to a temperature below that at which the formation of martinsitic structures of said alloy material is completed.

3. A method as defined in claim 1 wherein said connecting elements are thin walled hollow bodies;

wherein said step of heating includes placing a heating probe in the interior of the hollow body; and

wherein said step of cooling includes placing a cooling probe in the interior of the hollow body.