Implantable prosthesis with radiographic marker

• US 5,405,402 A
• Filed: 04/14/1993
• Issued: 04/11/1995
• Est. Priority Date: 04/14/1993
• Status: Expired due to Term

• Current Assignee: Zimmer Incorporated (Zimmer Biomet Holdings, Inc.)
• Original Assignee: Intermedics Orthopedics, Inc.
• Inventors: Dye, Donald W., Arlitt, Mark L.
• Primary Examiner(s): ISABELLA, DAVID J
• Application Number:
  US08/048,416
• Time in Patent Office: 727 Days
• Field of Search: 623/16, 623/18, 623/19, 623/20, 623/22, 623/23
• US Class Current: 623/22.38
• CPC Class Codes: A61B 2017/00902 transparent or translucent
• CPC Class Codes: A61B 90/39 Markers, e.g. radio-opaque or breast lesions markers
• CPC Class Codes: A61F 2/30724 Spacers for centering an implant in a bone cavity, e.g. in a cement-receiving cavity
• CPC Class Codes: A61F 2/34 Acetabular cups
• CPC Class Codes: A61F 2/4081 Glenoid components, e.g. cups
• CPC Class Codes: A61F 2002/30056 differing in radiographic density
• CPC Class Codes: A61F 2002/3008 radio-opaque, e.g. radio-opaque markers
• CPC Class Codes: A61F 2002/30136 undulated or wavy, e.g. serpentine-shaped or zigzag-shaped
• CPC Class Codes: A61F 2002/30158 trapezoidal
• CPC Class Codes: A61F 2002/302 toroidal, e.g. rings
• CPC Class Codes: A61F 2002/30451 soldered or brazed or welded
• CPC Class Codes: A61F 2002/3054 about a connection axis or implantation axis for selecting any one of a plurality of radial orientations between two modular parts, e.g. Morse taper connections, at discrete positions, angular positions or continuous positions
• CPC Class Codes: A61F 2002/30565 having spring elements
• CPC Class Codes: A61F 2002/30604 modular
• CPC Class Codes: A61F 2002/30822 Circumferential grooves
• CPC Class Codes: A61F 2002/30827 Plurality of grooves
• CPC Class Codes: A61F 2002/30884 Fins or wings, e.g. longitudinal wings for preventing rotation within the bone cavity
• CPC Class Codes: A61F 2002/30894 inclined obliquely with respect to each other
• CPC Class Codes: A61F 2002/3241 having a ring, e.g. for locking the femoral head into the acetabular cup
• 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 2002/3429 : with an integral peripheral collar or flange, e.g. oriented away from the shell centre line
• CPC Class Codes: A61F 2002/3443 : with an anti-luxation elevated rim portion, e.g. on the inner shell
• CPC Class Codes: A61F 2002/4631 : the prosthesis being specially adapted for being cemented
• CPC Class Codes: A61F 2220/0058 : soldered or brazed or welded
• CPC Class Codes: A61F 2230/0004 : Rounded shapes, e.g. with rounded corners
• CPC Class Codes: A61F 2230/0026 : trapezoidal
• CPC Class Codes: A61F 2230/0065 : toroidal, e.g. ring-shaped, doughnut-shaped
• CPC Class Codes: A61F 2250/0032 : differing in radiographic density
• CPC Class Codes: A61F 2250/0098 : radio-opaque, e.g. radio-opaque markers
• CPC Class Codes: A61F 2310/00017 : Iron- or Fe-based alloys, e.g. stainless steel

Abstract

An implantable prosthesis comprises a polyethylene prosthetic member that is substantially transparent to x-rays and a radiographic marker that is substantially opaque to x-rays. The radiographic marker is configured as a tension spring arranged as a continuous ring encircling the prosthetic member.

Claims

1. An implantable prosthesis comprising:

a prosthetic member that is substantially transparent to X-rays; and

a radiographic marker that is substantially opaque to X-rays, said radiographic marker being configured as a tension spring arranged as an unbroken, non-overlapping continuous ring encircling said prosthetic member,

said prosthetic member including an outer surface having areas of differential surface elevation for receiving and retaining said radiographic marker against movement in a direction generally perpendicular to the ring of the radiographic marker and generally parallel to the outer surface of the prosthetic member.

2. The implantable prosthesis of claim 1, in which said areas of differential surface elevation comprise a groove in the outer surface at least partially circumscribing the prosthetic member.

3. The implantable prosthesis of claim 2, in which said groove is substantially annular.

4. The implantable prosthesis of claim 2, in which said groove is substantially continuous.

5. The implantable prosthesis of claim 1, in which said radiographic marker differs in radiographic density about its circumference to provide X-ray detection of the orientation of the implantable prosthesis.

6. The implantable prosthesis of claim 5, in which said radiographic marker has a joint at which ends of the tension spring are joined to form a ring, said joint comprising an area of differential radiographic density.

7. The implantable prosthesis of claim 1, in which said radiographic marker has sufficient spring elasticity to permit it to be elastically expanded in diameter for assembly to said prosthetic member, and thereafter decrease in diameter under tension for retention thereon.

10. The implantable prosthesis of claim 7, in which said radiographic marker is comprised of biologically compatible wire configured as a serpentine spring.

11. The implantable prosthesis of claim 10, in which said radiographic marker is comprised of stainless steel.

8. An implantable prosthesis comprising:

a prosthetic member that is substantially transparent to X-rays; and

a radiographic marker that is substantially opaque to X-rays, said radiographic marker being configured as a tension spring arranged as an unbroken, non-overlapping continuous ring encircling said prosthetic member, said radiographic marker having sufficient spring elasticity to permit it to be elastically expanded in diameter for assembly to said prosthetic member, and thereafter decrease in diameter under tension for retention thereon, said radiographic marker being comprised of biologically compatible wire configured as a coil spring.

9. The implantable prosthesis of claim 8, in which said radiographic marker is comprised of stainless steel.

12. A set of implantable prostheses in different sizes from which one implantable prosthesis sized appropriately for a patient'"'"'s anatomy is selected for implantation, comprising:

a plurality of prosthetic members in different sizes that are substantially transparent to X-rays; and

only one radiographic marker that is substantially opaque to X-rays, said radiographic marker being configured as a tension spring arranged as an unbroken, non-overlapping continuous ring for encircling a selected one of said plurality of prosthetic members, said radiographic marker having sufficient spring elasticity to permit it to be elastically expanded in diameter for assembly to any one of said plurality of prosthetic members, and thereafter decrease in diameter under tension for retention thereon;

said prosthetic member including an outer surface having areas of differential surface elevation for receiving and retaining said radiographic marker against movement in a direction generally perpendicular to the ring of the radiographic marker and generally parallel to the outer surface of the prosthetic member.

13. The implantable prosthesis of claim 12, in which said areas of differential surface elevation comprise a groove in the outer surface at least partially circumscribing the prosthetic member.

14. A set of implantable prostheses in different sizes from which one implantable prosthesis sized appropriately for a patient'"'"'s anatomy is selected for implantation, comprising:

a plurality of prosthetic members in different sizes that are substantially transparent to X-ray; and

only one radiographic marker that is substantially opaque to X-rays, said radiographic marker being configured as a tension spring arranged as an unbroken, non-overlapping continuous ring for encircling a selected one of said plurality of prosthetic members, said radiographic marker having sufficient spring elasticity to permit it to be elastically expanded in diameter for assembly to any one of said plurality of prosthetic members, and thereafter decrease in diameter under tension for retention thereon, said radiographic marker differing in radiographic density about its circumference to provide X-ray detection of the orientation of the implantable prosthesis, said radiographic marker having a joint at which ends of the tension spring are joined to form a ring, said joint comprising an area of differential radiographic density, said radiographic marker being comprised of biologically compatible wire configured as a coil spring.

15. The implantable prosthesis of claim 14, in which said radiographic marker is comprised of biologically compatible wire configured as a serpentine spring.