Retaining mechanism for a modular tibial component of a knee prosthesis

• US 6,126,692 A
• Filed: 06/25/1998
• Issued: 10/03/2000
• Est. Priority Date: 06/25/1998
• Status: Expired due to Term

• Current Assignee: Orthopedic Innovations Inc. (Wi-LAN Inc.)
• Original Assignee: New York Society For The Relief of The Ruptured and Crippled Manufacturing The Hospital For Special Surgery
• Inventors: Rosenthal, Daniel E., Robie, Bruce H., Schmidt, Peter Nelson
• Primary Examiner(s): Yu, Mickey
• Assistant Examiner(s): STEWART, ALVIN J
• Application Number:
  US09/104,562
• Time in Patent Office: 831 Days
• Field of Search: 623/20, 623/18, 29/243.56
• US Class Current: 623/20.32
• CPC Class Codes: A61F 2/3886 for stabilising knees against anterior or lateral dislocations
• CPC Class Codes: A61F 2/389 Tibial components A61F2/3868 takes precedence
• CPC Class Codes: A61F 2002/30153 rectangular
• CPC Class Codes: A61F 2002/30169 Pi-shaped
• CPC Class Codes: A61F 2002/30176 V-shaped
• CPC Class Codes: A61F 2002/30383 made by laterally inserting a protrusion, e.g. a rib into a complementarily-shaped groove
• CPC Class Codes: A61F 2002/30387 Dovetail connection
• CPC Class Codes: A61F 2002/30481 using a locking clip
• CPC Class Codes: A61F 2002/305 Snap connection
• CPC Class Codes: A61F 2002/30604 modular
• CPC Class Codes: A61F 2002/30772 Apertures or holes, e.g. of circular cross section
• CPC Class Codes: A61F 2002/30777 Oblong apertures
• CPC Class Codes: A61F 2002/30878 with non-sharp protrusions, for instance contacting the bone for anchoring, e.g. keels, pegs, pins, posts, shanks, stems, struts
• CPC Class Codes: A61F 2220/0025 Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2230/0019 rectangular
• CPC Class Codes: A61F 2230/0047 Pi-shaped
• CPC Class Codes: A61F 2230/0054 V-shaped

Abstract

The present invention provides a tibial prosthetic knee component. The prosthesis includes a tibial tray having a posterior rail and an anterior rail, and a tibial insert. The tibial insert has a posterior dovetailed surface matching the posterior rail in the tibial tray, and an anterior surface matching the anterior rail in the tibial tray. The posterior rail of the tibial tray and the posterior dovetailed surface of the tibial insert are curved to provide clearance for the posterior cruciate ligament. A retaining clip is provided for retaining the tibial insert in the tibial tray. The clip includes a tab which extends through the tray into the insert and a resilient holding member remains unloaded when loads are applied to the knee, reducing the likelihood of dissociation of the tray and insert.

Claims

1. A tibial prosthetic knee component comprising:

a tibial tray for replacing a portion of a patient'"'"'s tibia, said tibial tray including a dovetailed posterior rail and an anterior rail, said tibial tray further including a clip tab cutout in said anterior rail and a support shelf;

a tibial insert having a posterior dovetail matching said posterior rail in said tibial tray, and an anterior surface matching said anterior rail in said tibial tray, said tibial insert including a cutout in said anterior surface; and

a clip for locking said tibial insert to said tibial tray, said clip including a holding member and a tab spaced from the holding member, said clip retaining said tibial insert in said tibial tray when said tab is inserted through said clip tab cutout and into said cutout in said insert, and said holding member is engaged with said tray, wherein the tray includes an opening disposed beneath said clip tab cutout, and the holding member is received in said opening.

2. The tibial prosthetic knee component recited in claim 1, wherein the opening comprises a recess formed on the bottom of the tray, and the holding member comprises a deflectable finger formed with an upwardly extending knob adjacent a distal end of the finger, the knob being sized for receipt in the recess.

3. The tibial prosthetic knee component recited in claim 1, wherein the opening comprises a passage formed in the tray which leads to an upwardly opening recess, and the holding member comprises a deflectable finger having a downwardly projecting knob adjacent a distal end of the finger, the knob being sized for receipt in the recess.

4. The tibial prosthetic knee component recited in claim 1, wherein the opening comprises a generally trapezoidal recess formed in the tray, and the holding member comprises a pair of deflectable fingers in a generally V-shaped configuration and sized for receipt in the recess.

5. A tibial prosthetic knee component comprising:

a tibial tray for replacing a portion of a patient'"'"'s tibia, said tibial tray including a dovetailed posterior rail and an anterior rail, said tibial tray further including a clip tab cutout in said anterior rail and a support shelf;

a tibial insert having a posterior dovetail matching said posterior rail in said tibial tray, and an anterior surface matching said anterior rail in said tibial tray, said tibial insert including a cutout in said anterior surface; and

a clip for locking said tibial insert to said tibial tray, said clip including a holding member and a tab spaced from the holding member, said clip retaining said tibial insert in said tibial tray when said tab is inserted through said clip tab cutout and into said cutout in said insert, and said holding member is engaged with said tray, wherein the holding member comprises a pair of spaced apart tines.