Percutaneous implant for limb salvage

• US 20080200995A1
• Filed: 02/21/2007
• Published: 08/21/2008
• Est. Priority Date: 02/21/2007
• Status: Active Grant

• Current Assignee: BioMedtrix, LLC
• Original Assignee: Christopher G. Sidebotham
• Inventors: Sidebotham, Christopher G.
• Granted Patent: US 7,909,883 B2
• Time in Patent Office: Days
• US Class Current: 623/28
• CPC Class Codes: A61B 17/0401 Suture anchors, buttons or pledgets, i.e. means for attaching sutures to bone, cartilage or soft tissue; Instruments for applying or removing suture anchors A61B17/0642 takes precedence; fixation devices for tendons or ligaments A61F2/0811
• CPC Class Codes: A61B 17/06166 Sutures suture materials A61L17/00; manufacture of artificial threads D01D; treatment of threads D06M
• CPC Class Codes: A61F 2/2814 Bone stump caps
• CPC Class Codes: A61F 2/30749 Fixation appliances for connecting prostheses to the body
• CPC Class Codes: A61F 2/30965 Reinforcing the prosthesis by embedding particles or fibres during moulding or dipping
• CPC Class Codes: A61F 2/54 Artificial arms or hands or parts thereof
• CPC Class Codes: A61F 2/66 Feet; Ankle joints
• 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 2002/30224 cylindrical
• CPC Class Codes: A61F 2002/30233 Stepped cylinders, i.e. having discrete diameter changes
• CPC Class Codes: A61F 2002/30332 Conically- or frustoconically-shaped protrusion and recess
• CPC Class Codes: A61F 2002/30574 with an integral complete or partial collar or flange
• CPC Class Codes: A61F 2002/30604 modular
• CPC Class Codes: A61F 2002/307 Prostheses for animals
• CPC Class Codes: A61F 2002/30795 Blind bores, e.g. of circular cross-section
• CPC Class Codes: A61F 2002/30827 Plurality of grooves
• CPC Class Codes: A61F 2002/30919 Sleeves
• CPC Class Codes: A61F 2002/30968 Sintering
• CPC Class Codes: A61F 2002/7887 for connecting limb exoprostheses to the stump bone
• 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 2230/0069 : cylindrical
• CPC Class Codes: A61F 2310/00023 : Titanium or titanium-based alloys, e.g. Ti-Ni alloys
• CPC Class Codes: A61F 2310/00029 : Cobalt-based alloys, e.g. Co-Cr alloys or Vitallium
• CPC Class Codes: A61F 2310/00095 : Niobium or Nb-based alloys
• CPC Class Codes: A61F 2310/00131 : Tantalum or Ta-based alloys
• CPC Class Codes: A61F 2310/00407 : Coating made of titanium or of Ti-based alloys
• CPC Class Codes: A61F 2310/00491 : Coating made of niobium or Nb-based alloys
• CPC Class Codes: A61F 2310/00544 : Coating made of tantalum or Ta-based alloys

Abstract

A percutaneous implant device is biologically attached to bone and soft tissue of a broken limb or amputated limb without longitudinal or lateral movement. Bone and soft tissue in-growth are promoted. The percutaneous implant device has a bio-compatible metal alloy stem member, having an integral tapered fluted section designed to fit into a taper reamed bone canal. A precisely dimensioned cylindrical central core cooperates with a suture ring and an external extension member, facilitating attachment of the percutaneous implant device to a hand or foot prosthesis. A porous metal outer body having a female taper at one end and the capacity to promote growth of bone and soft tissue, is press fitted on the central core contacting suture ring. The assembled implant is inserted into a taper reamed bone cavity until the male taper-reamed bone free end contacts the female taper. Soft skin is extended over the outer surface of the porous metal outer body and the surrounding suture ring.

Claims

1. A percutaneous implant device, comprising:

a. an integral biologically compatible metal alloy stem and a press fitted porous metal outer body having bone and soft tissue in-growth characteristics;

b. said integral stem having a fluted male tapered stem member designed to be inserted into a female tapered cavity drilled within the bone of a broken limb;

c. said integral stem having a cylindrical portion contacting said fluted male tapered stem portion, the cylindrical portion having precise dimensional tolerance to accept press fitting of said porous titanium outer body;

d. said porous metal outer body having a central aperture with precise dimensional tolerance to mate with said cylindrical inner portion of the stem;

e. said integral stem having a suture ring contacting the distal side from said fluted male tapered stem;

f. one end of said press fitted porous metal outer body contacting said suture ring;

g. another end of said porous metal outer body having a female taper on the side distal from the stem suture ring contacting side to mate with a corresponding male taper surgically created on the bone end;

h. said integral stem having an external member extending from said suture ring member for attachment to a hand or foot prosthesis;

whereby the porous metal outer body, upon being press fitted over the stem cylindrical portion, functions as a single unit, the bone contacts both the fluted tapered stem and the female taper of the porous metal outer body, generating bone in-growth, soft tissue contacts an outer surface of said porous metal body and is sutured to said suture ring generating soft tissue in-growth, and the percutaneous implant is thereby prevented from lateral and longitudinal displacement during the healing process, promoting bone and soft tissue in-growth.

2. A percutaneous implant device as recited by claim 1, wherein said dimensional tolerance for press fitting of said cylindrical portion of said stem and central aperture of said porous metal body is an interference of 0.005 to 0.20 mm.

3. A percutaneous implant device as recited by claim 1, wherein said porous metal outer body comprises sintered beads, sintered wire segments or foam.

4. A percutaneous implant device as recited by claim 1, wherein said fluted tapered stem member connects to said female tapered bone cavity with interference.

5. A percutaneous implant device as recited by claim 1, wherein said female taper of said porous metal outer body contacts a male taper at the extremity of the bone over a length of about 8 mm.

6. A percutaneous implant device as recited by claim 1, wherein said porous outer body has a length of 37 mm, and provides soft tissue contact for soft tissue in-growth.

7. A percutaneous implant device as recited by claim 1, wherein said suture ring has suture holes provided for suturing skin surrounding an outer surface of said suture ring.

8. A surgical procedure for attaching a percutaneous implant to a broken or amputated limb, comprising the steps of:

a. sectioning a broken limb sectioned perpendicular to the length of a bone forming a free end with some soft tissue extending beyond the sectioned bone;

b. drilling a bone canal within said free end of said bone to a depth matching the specifications of said percutaneous implant device;

c. providing said free end with a precise male taper matching a female taper of the porous metal outer body of a percutaneous implant device using a surgical conical planer;

d. enlarging said bone canal with a surgical tapered reamer to form a tapered bone cavity;

e. inserting a fluted male tapered stem of the percutaneous implant device into a porous metal outer body, the latter being already press fitted on the cylindrical inner core, and being inserted into said tapered bone cavity using hand pressure followed by pressure from an impactor until the male taper at said free end of the bone contacts and seats against a female taper of the porous metal outer body;

f. extending the soft tissue to contact the external surface of said porous metal outer body, enclosing the suture ring; and

g. inserting a suture needle carrying a suture through holes provided in the suture ring to attach soft tissue and skin to the porous metal outer body and the suture ring;

whereby the percutaneous implant device with press fitted porous metal outer body is secured immediately after surgery by contact between the fluted tapered stem portion and the bone tissue on top and contact between the bone seated at the bottom and the female taper of the porous metal outer body, preventing lateral displacement and promoting bone in-growth, and soft tissue contacting the porous metal outer body is secured by skin sutures surrounding a suture ring, thereby providing in-growth soft tissue.

9. A surgical procedure as recited by claim 8, wherein said bone cavity is formed by drilling to a length of 60 mm.

10. A surgical procedure as recited by claim 8 wherein the taper reaming according to step ‘

d’

further includes placement of four cerclage wires in the bone canal.

11. A surgical procedure as recited by claim 8 further comprising the step of attaching a foot or hand prosthesis to an external member of the percutaneous implant device.

12. A percutaneous implant device, comprising:

a. an integral biologically compatible titanium or cobalt-chromium alloy stem and a press fitted porous tantalum outer body having bone and soft tissue in-growth characteristics;

b. said integral stem having a fluted male tapered stem member designed to be inserted into a female tapered cavity drilled within the bone of a broken limb;

c. said integral stem having a cylindrical portion contacting said fluted male tapered stem portion, the cylindrical portion having precise dimensional tolerance to accept press fitting of said porous tantalum outer body;

d. said porous tantalum outer body having a central aperture with precise dimensional tolerance to mate with said cylindrical inner portion of the stem;

e. said integral stem having a suture ring contacting the distal side from said fluted male tapered stem;

f. one end of said press fitted porous tantalum outer body contacting said suture ring;

g. another end of said porous tantalum outer body having a female taper on the side distal from the stem suture ring contacting side to mate with a corresponding male taper surgically created on the bone end;

h. said integral stem having an external member extending from said suture ring member for attachment to a hand or foot prosthesis;

whereby the porous tantalum outer body, upon being press fitted over the stem cylindrical portion, functions as a single unit, the bone contacts both the fluted tapered stem and the female taper of the porous tantalum outer body, generating bone in-growth, soft tissue contacts an outer surface of said porous tantalum body and is sutured to said suture ring generating soft tissue in-growth, and the percutaneous implant is thereby prevented from lateral and longitudinal displacement during the healing process, promoting bone and soft tissue in-growth.

13. A percutaneous implant device as recited by claim 12, wherein said dimensional tolerance for press fitting of said cylindrical portion of said stem and central aperture of said porous metal body is an interference of 0.01 to 0.015 mm.

14. A percutaneous implant device as recited by claim 12, wherein said fluted tapered stem member connects to said female tapered bone cavity with interference.