Implantation of articulating joint prosthesis

• US 4,636,214 A
• Filed: 10/17/1985
• Issued: 01/13/1987
• Est. Priority Date: 04/19/1982
• Status: Expired due to Term

• Current Assignee: Tranquil Prospects Limited
• Original Assignee: Charles A. Homsy
• Inventors: Homsy, Charles A.
• Primary Examiner(s): Apley, Richard J.
• Assistant Examiner(s): Isabella, David J.
• Application Number:
  US06/788,421
• Time in Patent Office: 453 Days
• Field of Search: 623/16, 623/18, 623/20, 623/21, 623/22, 623/23, 128/92 C, 128/92 CA, 128/92 E, 128/92 EB, 128/92 EC, 128/312, 128/315, 128/333, 128/305, 128/310
• US Class Current: 128/898
• CPC Class Codes: A61F 2/0095 Packages or dispensers for prostheses or other implants for intraocular lenses A61F2/1691; for dental surgery A61C19/02
• CPC Class Codes: A61F 2/30767 Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
• CPC Class Codes: A61F 2/30907 Nets or sleeves applied to surface of prostheses or in cement
• CPC Class Codes: A61F 2/36 Femoral heads ; Femoral endoprostheses
• CPC Class Codes: A61F 2/3662 Femoral shafts
• CPC Class Codes: A61F 2/3676 Distal or diaphyseal parts of shafts
• CPC Class Codes: A61F 2002/30112 Rounded shapes, e.g. with rounded corners
• CPC Class Codes: A61F 2002/30113 circular
• CPC Class Codes: A61F 2002/30158 trapezoidal
• CPC Class Codes: A61F 2002/30187 D-shaped or half-disc-shaped
• CPC Class Codes: A61F 2002/30574 with an integral complete or partial collar or flange
• CPC Class Codes: A61F 2002/30718 Means for protecting prosthetic parts, e.g. during operation
• CPC Class Codes: A61F 2002/3611 Heads or epiphyseal parts of femur
• CPC Class Codes: A61F 2002/3625 Necks
• CPC Class Codes: A61F 2002/3631 with an integral complete or partial peripheral collar or bearing shoulder at its base
• CPC Class Codes: A61F 2002/369 Stepped shaft, i.e. having discrete diameter changes
• CPC Class Codes: A61F 2230/0004 Rounded shapes, e.g. with rounded corners
• CPC Class Codes: A61F 2230/0006 circular
• CPC Class Codes: A61F 2230/0026 trapezoidal
• CPC Class Codes: A61F 2230/0034 D-shaped
• CPC Class Codes: A61F 2310/00029 : Cobalt-based alloys, e.g. Co-Cr alloys or Vitallium
• CPC Class Codes: Y10S 623/908 : Bone

Abstract

An intramedullary prosthesis device and the method of orthopedic implantation of the prosthesis device, particularly for a hip prosthesis. The prosthesis device and the method of implantation utilize an elongate stem undersized precisely with respect to a precisely formed stem socket defined by cortical bone or dense cancellous bone of a long bone. Bone cement is used to fill the void area between the stem of the prosthesis device and the precisely formed stem socket.

Claims

1. A method of surgical orthopedic implantation of an intramedullary prosthesis device having an elongate stem with distal and proximate ends into the medullary canal of a long bone defined by the cortex of a long bone and comprising the steps of:

forming in said medullary canal a stem socket;

sizing the stem socket with an appropriately sized tool to form a socket defined substantially by the inner periphery of compact bone formed by cortical or dense cancellous bone, said stem having transverse sectional dimensions along substantially its entire length which are undersized with respect to adjacent corresponding transverse sectional dimensions of said stem socket;

then injecting bone cement in the completed stem socket; and

finally pushing said stem into said stem socket with said bone cement therein surrounding the stem for its entire length including its distal and proximate ends whereby said cement forms a liner around the outer surface of said stem between the stem and the adjacent compact bone, the transverse sectional dimensions of the liner and stem constituting at least around seventy percent (70%) of the corresponding transverse sectional dimensions of the long bone defined by cortical bone or metaphyseal and epiphyseal segments of said long bone, and at least around ninety percent (90%) of the corresponding transverse sectional dimensions of the long bone defined by cortical bone of the diaphyseal segment of said long bone.

2. A method of surgical orthopedic implantation of an intramedullary prosthesis device into the medullary canal defined by the cortex of a femur in a human body, comprising the steps of:

first forming in said canal a stem socket by developing an entrance cavity for a suitable sizing tool along the longitudinal axis of said femur thereby to gain access to said medullary canal;

placing a suitable sizing tool down the longitudinal axis of said femur following the developed entrance cavity to progressively increase the cross sectional size of the stem socket until endosteal cortical bone is contacted in the diaphyseal segment of said medullary canal and dense cancellous bone is contacted in the metaphyseal and epiphyseal segments of said medullary canal, whereupon the stem socket is completed;

providing a prosthesis device having an elongated stem with distal and proximate ends;

injecting bone cement into the completed stem socket; and

pushing said stem into said socket with said bone cement therein surrounding the stem for its entire length including its distal and proximate ends and forming a cement liner between the stem and adjacent bone forming the socket, the transverse sectional dimensions of the liner and stem constituting at least seventy percent (70%) of the transverse sectional dimensions of said medullary canal of the metaphyseal and epiphyseal segments of said femur, and at least ninety percent (90%) of the transverse sectional dimensions of said medullary canal of the diaphyseal segment of said femur.

3. The method as set forth in claim 2, wherein

said prosthesis device comprises a head portion on one end thereof with said stem extending from said head portion, and

said stem has an end flange at its free end to aid in centralizing the stem within the socket, said end flange being grooved vertically to permit bone cement to flow therethrough upon insertion of the stem within the socket.

4. A method of human implantation of an intramedullary prosthesis device having a tapered elongate stem with distal and proximate ends into the medullary canal of a long bone defined by the cortex thereof, said method comprising the steps of:

providing in said medullary canal a stem socket defined by an inner periphery of compact bone formed by cortical or dense cancellous bone, the elongate stem of the prosthesis device having transverse sectional dimensions along substantially its entire length which are undersized with respect to adjacent corresponding transverse sectional dimensions of said elongate stem socket; and

Inserting a deformable material and said elongate stem within said stem socket with said deformable material surrounding the stem for its entire length including its distal and proximate ends and filling the void area between the precisely formed undersized stem and the compact bone defining the precisely formed socket whereby said deformable material forms a liner around the outer surface of said stem between the elongate stem and the adjacent compact bone, the transverse sectional dimensions of the liner and elongate stem constituting at least around seventy percent (70%) of the corresponding transverse sectional dimensions of the long bone defined by cortical bone of metaphyseal and epiphyseal segments of said long bone, and at least around ninety percent (90%) of the corresponding transverse sectional dimensions of the long bone defined by cortical bone of the diaphyseal segment of said long bone.