Lower extremity prosthesis

• US 5,888,215 A
• Filed: 06/18/1997
• Issued: 03/30/1999
• Est. Priority Date: 08/25/1994
• Status: Expired due to Fees

• Current Assignee: Birger Roos, Hannu Maattanen, Urban Lindgren
• Original Assignee: Birger Roos, Hannu Maattanen, Urban Lindgren
• Inventors: Roos, Birger, Maattanen, Hannu, Lindgren, Urban
• Primary Examiner(s): Jones, Mary Beth
• Assistant Examiner(s): SNOW, BRUCE EDWARD
• Application Number:
  US08/793,785
• Time in Patent Office: 650 Days
• Field of Search: 623/32, 623/33, 623/27, 623/28, 623/34-38, 623/57, 623/21, 623/47, 623/59, 623/53, 623/16, 623/49
• US Class Current: 623/33
• CPC Class Codes: A61B 17/8605 Heads, i.e. proximal ends projecting from bone
• CPC Class Codes: A61B 17/8625 Shanks, i.e. parts contacting bone tissue
• CPC Class Codes: A61B 17/88 Osteosynthesis instruments; Methods or means for implanting or extracting internal or external fixation devices A61B17/7074 takes precedence
• CPC Class Codes: A61F 2/02 Prostheses implantable into the body closure means for urethra or rectum or for artificial body openings therefor A61F2/0004
• CPC Class Codes: A61F 2/30749 Fixation appliances for connecting prostheses to the body
• CPC Class Codes: A61F 2/60 Artificial legs or feet or parts thereof
• CPC Class Codes: A61F 2/76 Means for assembling, fitting or testing prostheses, e.g. for measuring or balancing, e.g. alignment means
• CPC Class Codes: A61F 2/78 Means for protecting prostheses or for attaching them to the body, e.g. bandages, harnesses, straps, or stockings for the limb stump
• CPC Class Codes: A61F 2/80 Sockets, e.g. of suction type
• CPC Class Codes: A61F 2002/30433 using additional screws, bolts, dowels, rivets or washers e.g. connecting screws
• CPC Class Codes: A61F 2002/30476 locked by an additional locking mechanism
• CPC Class Codes: A61F 2002/3085 with a threaded, e.g. self-tapping, bone-engaging surface, e.g. external surface
• CPC Class Codes: A61F 2002/5001 Cosmetic coverings
• CPC Class Codes: A61F 2002/5079 Leaf springs A61F2002/6657 takes precedence
• CPC Class Codes: A61F 2002/7818 Stockings or socks for the limb stump cosmetic coverings A61F2002/5001
• CPC Class Codes: A61F 2002/7887 for connecting limb exoprostheses to the stump bone
• CPC Class Codes: A61F 2220/0008 Fixation appliances for connecting prostheses to the body
• CPC Class Codes: A61F 2220/0025 Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2220/0041 using additional screws, bolts, dowels or rivets, e.g. connecting screws
• CPC Class Codes: A61F 2310/00023 Titanium or titanium-based alloys, e.g. Ti-Ni alloys

Abstract

A lower extremity prosthesis solves the problem of relieving the end of the leg stump (S) from a portion of the vertical forces acting on it by pressure from the socket (1) surrounding and supporting the stump, by providing a mechanism capable of transferring forces to the tibia (T). The mechanism includes a first member (13) connected to the tibia and second members (5, 8) detachably connected to the first member and carried by the socket.

Claims

1. A lower extremity prosthesis, comprising a socket (1) having an upper portion adapted to surround a residual leg stump (S), located below the knee, and a lower portion carrying an artificial foot, wherein, at a front of the socket, said socket is provided with a mechanism adapted to transfer forces from the prosthesis directly to a tibia (T) of the stump, said mechanism comprising first means (13), adapted to extend transversely through the tibia from a front side thereof, and second means (5, 8) detachably connected to said first means and mounted on said socket.

2. A prosthesis as claimed in claim 1, wherein said first means (13), for implantation in the tibia, is adapted to be permanently anchored in recesses located opposite each other in front and back wall portions (F, B,) of the tibia.

3. A prosthesis as claimed in claim 2, wherein said first means (13) comprises sections (14, 15) provided with external threads for engagement with said recesses in the tibia.

4. A prosthesis as claimed in claim 2, wherein said first means (13) has a thicker, cylindrical section (14) for engagement with the recess in the front wall portion of the tibia, and a narrower cylindrical section (15) for engagement with the recess in the back wall portion of the tibia.

5. A prosthesis as claimed in claim 4, wherein the thicker cylindrical section and the narrower cylindrical section (14, 15) of said first means are interconnected by a conical intermediate section (16).

6. A prosthesis as claimed in claim 2, wherein said first means (13) has a cavity for receiving a connection member (8) included in the mechanism and mounted to the socket.

7. A prosthesis as claimed in claim 6, wherein said cavity is located in a separate, exchangeable member (17) screwed into said first means (13).

8. A prosthesis as claimed in claim 7 wherein the connection member comprises a pin (8) having an inner end shaped like a ball (8a) detachably seated in the cavity of the exchangeable member (17).

9. A prosthesis as claimed in claim 6, wherein the mechanism includes a resilient plate (5) which comprises an elastic, high tensile strength material having an opening (7) for the passage of the connection member (8) to parts (13-17) of the mechanism adapted to be located in the tibia (T), said resilient plate exhibiting multidirectional resilience properties which yield a tunable transfer of forces between the tibia and the socket.

10. A prosthesis as claimed in claim 2, wherein portions (13, 17) of the mechanism adapted to be in direct contact with tissues of the stump (S) comprise a biocompatible material.

11. A prosthesis as claimed in claim 10, wherein said biocompatible material is pure titanium.