Intramedullary reference datum instrument

• US 6,120,509 A
• Filed: 09/01/1998
• Issued: 09/19/2000
• Est. Priority Date: 09/01/1998
• Status: Expired due to Fees

• Current Assignee: Zimmer Incorporated (Zimmer Biomet Holdings, Inc.)
• Original Assignee: Sulzer Orthopedics Inc. (Centerpulse Orthopedics Incorporated)
• Inventors: Wheeler, John L.
• Primary Examiner(s): Buiz, Michael
• Assistant Examiner(s): Woo, Julian W.
• Application Number:
  US09/145,363
• Time in Patent Office: 749 Days
• Field of Search: 606/87, 606/88, 606/80, 623/20
• US Class Current: 606/87
• CPC Class Codes: A61B 17/155 Cutting femur

Abstract

An intramedullary reference instrument is provided for aligning a cutting instrument in connection with surgical implantation of an orthopedic prosthesis having a stem component. The intramedullary reference instrument includes a stem trial having a length and diameter corresponding to that of the stem component of the prosthesis, and also includes a first connector. The instrument further includes a shaft adapter having a first end portion including a second connector. The second connector is configured for mating with the first connector of the stem trial to removably connect the shaft adapter to the stem trial. The shaft adapter is engageable with the cutting instrument to properly align the cutting instrument.

Claims

1. An intramedullary reference instrument for aligning a cutting instrument in connection with surgical implantation of an orthopedic prosthesis having a stem component, comprising:

a stem trial having a length and diameter corresponding to that of the stem component of said prosthesis, said stem trial including a first connector;

a shaft adapter having a first end portion including a second connector, and a second end having a third connector, said second connector configured for mating with said first connector of said stem trial to removably connect said shaft adapter to said stem trial, said shaft adapter further includes an elongate shaft adjacent said first end portion, said elongate shaft being engageable with said cutting instrument to property align said cutting instrument; and

a handle having a fourth connector for releasably engaging said third connector of said shaft adapter to removably attach said handle to said shaft adapter.

2. An intramedullary reference instrument according to claim 1, wherein said elongate shaft has an intermediate portion that is substantially cylindrical.

3. An intramedullary reference instrument accordingly to claim 2, wherein said first end portion of said shaft adapter is substantially cylindrical and has a knurled outer surface, said first end portion having a diameter greater than that of said intermediate portion.

4. An intramedullary reference instrument according to claim 1, wherein said prosthesis includes a stem mounting boss, and said first end portion of said shaft adapter has a length corresponding to that of said stem mounting boss.

5. An intramedullary reference instrument according to claim 1, wherein said elongate shaft has an intermediate portion that is substantially cylindrical.

6. An intramedullary reference instrument according to claim 5, wherein said first end portion of said shaft adapter is substantially cylindrical and has a knurled outer surface, said first end portion having a diameter greater than that of said intermediate portion.

7. An intramedullary reference instrument for aligning a cutting instrument in connection with surgical implantation of orthopedic prostheses of varying sizes each having a stem component, comprising:

a plurality of stem trials having varying lengths and diameters corresponding to those of the stem components of said prostheses of varying sizes, said stem trial including a first connector;

a shaft adapter having a first end portion including a second connector, and a second end portion including a third connector, said second connector configured for mating with any of said first connectors of said stem trials to removably connect said shaft adapter to any of said stem trials, said shaft adapter being engageable with said cutting instrument to properly align said cutting instrument; and

a handle having a fourth connector for releasably engaging said third connector of said of said shaft adapter to removably attach said handle to said shaft adapter.

8. An intramedullary reference instrument according to claim 7, wherein said shaft adapter further includes an elongate shaft adjacent said first end portion, said elongate shaft being engageable with said cutting instrument to properly align said cutting instrument.

9. An intramedullary reference instrument according to claim 8, wherein said elongate shaft has an intermediate portion that is substantially cylindrical.

10. The intramedullary reference instrument according to claim 9, wherein said first end portion of said shaft adapter is substantially cylindrical and has a knurled outer surface, said first end portion having a diameter greater than that of said intermediate portion.

11. An intramedullary reference instrument according to claim 10, wherein said prosthesis includes a stem mounting boss, and said first end portion of said shaft adapter has a length corresponding to that of said stem mounting boss.

12. A method for aligning a cutting instrument in connection with surgical implantation of an orthopedic prosthesis having a stem component, comprising the steps of:

forming a cavity in the medullar canal of a bone of a patient to receive said orthopedic prosthesis;

connecting a stem trial having a length and diameter corresponding to that of said stem component of said orthopedic prosthesis to a shaft adapter by engaging a first connector of said stem trial with a second connector of said shaft adapter located at a first end portion of said shaft adapter, wherein said shaft adapter further includes an elongate shaft having an intermediate portion adjacent said first end portion that is substantially cylindrical, said intermediate portion of said elongate shaft being engageable with said cutting instrument to properly align said cutting instrument, said first end portion having a diameter greater than that of said intermediate portion;

inserting said connected stem trial and adapter shaft into said cavity in said medullary canal; and

engaging said cutting instrument with the shaft adapter to properly align said cutting instrument.

13. The method according to claim 12, wherein said prothesis includes a stem mounting boss, and said first end portion of said shaft adapter has a length corresponding to that of said stem mounting boss.