Instruments for Total Knee Arthroplasty

• US 20070213738A1
• Filed: 03/09/2007
• Published: 09/13/2007
• Est. Priority Date: 03/09/2006
• Status: Active Grant

• Current Assignee: MicroPort Orthopedics Holdings, Inc. (MicroPort Scientific Corp.)
• Original Assignee: MicroPort Orthopedics Holdings, Inc. (MicroPort Scientific Corp.)
• Inventors: Wong, Kevin, Harris, Brian R., Martin, Jeffrey W.
• Granted Patent: US 8,702,714 B2
• Time in Patent Office: Days
• US Class Current: 606/87
• CPC Class Codes: A61B 17/155 Cutting femur
• CPC Class Codes: A61B 17/1764 for the knee
• CPC Class Codes: A61B 17/72 Intramedullary pins, nails or other devices A61B17/744 takes precedence
• CPC Class Codes: A61B 17/7283 with special cross-section of the nail

Abstract

An instrument assembly for resecting a distal femur for receipt of a knee implant, comprising an intramedullary rod and resection instruments. A valgus portion of the intramedullary rod has series of engagement members positioned to provide a plurality of engagement positions for use in fixing the resection instruments on the valgus portion. The resection instruments are configured to selectively engage and selectively lock on the valgus rod at the engagement positions via the engagement members. The engagement members preferably comprise pairs of substantially vertical indents arranged in parallel along opposing sides of said valgus portions. The resection instruments preferably engages and locks to said engagement members via a sliding rod engagement member. The resection instruments preferably include a distal cut guide having a distal resection slot and a femoral resection block.

Claims

1. An instrument assembly for use in preparing a distal femur for receipt of an implant, said instrument assembly comprising:

an intramedullary rod having an intramedullary portion and a valgus portion, said valgus portion having a series of engagement members thereon positioned to provide a plurality of engagement positions, each said engagement position for use in fixing resection instruments on said valgus portion at said engagement position, and

at least one resection instrument, said at least one resection instrument configured to selectively engage and selectively lock on said valgus rod at said engagement positions via said engagement members.

2. An instrument assembly of claim 1, wherein said engagement members of said valgus rod comprise pairs substantially vertical indents arranged in parallel along opposing sides of said valgus portions, and

said at least one resection instrument engages and locks to said engagement members via a rod engagement member, said rod engagement member slidingly disposed in said resection instrument, said rod engagement member comprising a pair of opposing rail members, each said rail member having a detent on an internal side thereof, said detents sized and configured to selectively slide into and engage said pairs of indents to thereby lock said resection instrument in a selected engagement position.

4. An instrument assembly of claim 2, wherein said at least one resection instrument includes a distal cut guide having a distal resection slot.

5. An instrument assembly of claim 4, wherein said at least one resection instrument includes a femoral resection block configured for making resections corresponding to an internal box geometry of a femoral implant.

6. An instrument assembly of claim 5, wherein a main body of said distal cut guide is provided with a pair of drill guides, each said drill guide having a drill aperture therethrough, said drill apertures positioned to coincide with femoral pegs on said femoral resection block for use in a establishing a position for said femoral resection block on the femur.

7. An instrument assembly of claim 2, further comprising a retaining means for retaining said rod engagement member in said resection instrument.

8. An instrument assembly of claim 6, further comprising a retaining means for retaining said rod engagement member in said resection instrument.

9. An instrument assembly of claim 4, wherein said distal cut guide is configured for anterior-posterior adjustment of said distal cut guide relative to said valgus rod.

10. An instrument assembly of claim 9, wherein said anterior-posterior adjustment is provided by a valgus rod mount slidingly engaged to a main body portion of said distal cut guide, said valgus rod mount having a valgus rod aperture sized and configured to closely receive said valgus rod, so as to substantially prevent rotation of said valgus rod mount relative to said valgus rod.

11. An instrument assembly of claim 10, further comprising a selective locking mechanism positioned for use in selectively locking said valgus rod mount on said distal cut guide such that said main body portion can no longer translate relative to said valgus rod.

12. An instrument assembly of claim 6, wherein said distal cut guide is configured for anterior-posterior adjustment of said distal cut guide relative to said valgus rod.

13. An instrument assembly of claim 12, wherein said anterior-posterior adjustment is provided by a valgus rod mount slidingly engaged to a main body portion of said distal cut guide, said valgus rod mount having a valgus rod aperture sized and configured to closely receive said valgus rod, so as to substantially prevent rotation of said valgus rod mount relative to said valgus rod.

14. An instrument assembly of claim 13, further comprising a selective locking mechanism positioned for use in selectively locking said valgus rod mount on said distal cut guides such that said main body portion can no longer translate relative to said valgus rod.

15. An instrument assembly of claim 1, wherein said valgus rod has a narrow medial-lateral width to facilitate resection of the femur while said intramedullary rod is an intramedullary canal of the femur.

16. An instrument assembly of claim 15, wherein opposing medial and lateral sides of said valgus rod are substantially flat and lengthwise.

17. An instrument assembly of claim 6, wherein said valgus rod has a narrow medial-lateral width to facilitate resection of the femur while said intramedullary rod is an intramedullary canal of the femur.

18. An instrument assembly of claim 17, wherein opposing medial and lateral sides of said valgus rod are substantially flat and lengthwise.

19. An instrument assembly of claim 1, wherein said engagement members are indents.

3. An instrument assembly of claim 3, wherein said detents of said rail members are arranged to slide along opposing medial and lateral edges of a valgus rod aperture portion of said at least one resection instrument, said valgus rod aperture portion configured to closely receive said valgus rod in at least a generally medial-lateral orientation.

20. An instrument assembly for use in preparing a distal femur for receipt of an implant, said instrument assembly, comprising:

an intramedullary rod having an intramedullary portion and a valgus portion, said valgus portion having a series of engagement members thereon positioned to provide a plurality of engagement positions, each said engagement position for use in selectively fixing resection instruments on said valgus portion at said engagement position, and

at least one resection instrument, said resection instrument configured to mount on said valgus rod, said resection instrument having an engagement means for selectively locking said resection instrument on said valgus rod at said engagement positions.