Patents by Inventor Mark A. Heldreth

Mark A. Heldreth has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20020082607
    Abstract: A tibial trial assembly for evaluating the stability and kinematics of a tibial implant, particularly a mobile bearing implant, prior to committing to the final preparation of the proximal tibia is described. The tibial trail assembly includes a trial tray adapted to be secured onto a resected proximal end of a patient's tibia. An evaluation bullet is adapted to removably fit into a configured recess in the trial tray. Alternatively, it is possible that the evaluation bullet is made integral with the trial tray. A trunnion on the evaluation bullet accepts a recess in a corresponding articular tibial insert trial. The tibial insert trial is thus received on the trunnion. In this manner, a surgeon may evaluate the stability and kinematics prior to committing to the use of the final tibial implant design. In one form, the evaluation bullet allows the tibial insert trial to move, such as rotate, thereon for checking a mobile bearing implant.
    Type: Application
    Filed: December 14, 2001
    Publication date: June 27, 2002
    Inventors: Mark A. Heldreth, Deborah S. German
  • Patent number: 5405396
    Abstract: A modular tibial prosthesis contains a dovetail mechanism (4, 5 & 14) and a posterior tongue (15) and groove (8) arrangement. The dovetail mechanism cooperates with a reinforcing component (22) to allow alternate use of a spined component (20) with the same base plate (1).
    Type: Grant
    Filed: July 1, 1993
    Date of Patent: April 11, 1995
    Assignee: Zimmer, Inc.
    Inventors: Mark A. Heldreth, Dale E. Hileman, Jay T. Vansickle
  • Patent number: 5323954
    Abstract: A femoral component of a knee prosthesis, including a cobalt-based alloy substrate and a titanium fiber metal pad bonded thereto by means of an interlayer of a cobalt-based alloy including nickel. More specifically, a method of bonding a titanium porous surface to a cobalt-based alloy in an orthopaedic implant device, by first applying an interlayer of a cobalt-based alloy including nickel to the substrate and then bonding a porous structure to the interlayer. In one embodiment, an interlayer of L-605 is first applied to a substrate of Co--Cr--Mo by diffusion bonding at approximately 2200.degree. F. and then a fiber metal pad of CP-titanium is diffusion bonded to the interlayer at approximately 1650.degree. F. A layer of CP-titanium may optionally be placed intermediate the fiber metal pad and interlayer before the second diffusion step. In an alternative embodiment, MP-35N alloy may be substituted for the L-605 alloy.
    Type: Grant
    Filed: November 30, 1992
    Date of Patent: June 28, 1994
    Assignee: Zimmer, Inc.
    Inventors: H. Ravindranath Shetty, Mark A. Heldreth, Jack E. Parr
  • Patent number: 5290313
    Abstract: A modular prosthesis system which includes a modular stem extension which has an offset between its attachment point to the prosthesis base portion and the main body of the stem. The stem extension can be attached in a selected orientation with respect to the base portion, thus enabling the main body of the stem to be positioned in any of one of a plurality of orientations with respect to the base portion.
    Type: Grant
    Filed: November 23, 1992
    Date of Patent: March 1, 1994
    Assignee: Zimmer, Inc.
    Inventor: Mark A. Heldreth
  • Patent number: 5221096
    Abstract: A multiple piece seal and method for reducing the leakage of air through a narrow gap separating a higher pressure section from a lower pressure in a gas turbine engine. The seal is comprised of a first sealing member having a thickness sufficiently small so that the first sealing member will deform into sealing contact across the gap when subjected to a pressure differential, and a second sealing member having a thickness sufficiently large so as to prevent both sealing members from buckling when inserted the gap.
    Type: Grant
    Filed: June 16, 1992
    Date of Patent: June 22, 1993
    Assignee: Allied-Signal Inc.
    Inventors: Mark A. Heldreth, Stephen R. Buckert
  • Patent number: 5198308
    Abstract: A femoral component of a knee prosthesis, including a cobalt-based alloy substrate and a titanium fiber metal pad bonded thereto by means of an interlayer of a cobalt-based alloy including nickel. More specifically, a method of bonding a titanium porous surface to a cobalt-based alloy in an orthopaedic implant device, by first applying an interlayer of a cobalt-based alloy including nickel to the substrate and then bonding a porous structure to the interlayer. In one embodiment, an interlayer of L-605 is first applied to a substrate of Co-Cr-Mo by diffusion bonding at approximately 2200.degree. F. and then a fiber metal pad of CP-titanium is diffusion bonded to the interlayer at approximately 1650.degree. F. A layer of CP-titanium may optionally be placed intermediate the fiber metal pad and interlayer before the second diffusion step. In an alternative embodiment, MP-35N alloy may be substituted for the L-605 alloy.
    Type: Grant
    Filed: December 21, 1990
    Date of Patent: March 30, 1993
    Assignee: Zimmer, Inc.
    Inventors: H. Ravindranath Shetty, Mark A. Heldreth, Jack E. Parr
  • Patent number: 5129907
    Abstract: A patellar clamp and reamer for performing either a total surfacing procedure or insetting procedure for preparing the patellar surface for a prosthetic implant, including an adjustable stop connected to the clamp and engaging a collar on the reamer shaft to space the reamer blade a calibrated distance from the clamp's reference jaw. The stop is calibrated and includes indicia thereon in terms of the thickness of patellar bone to remain after resection.
    Type: Grant
    Filed: December 10, 1990
    Date of Patent: July 14, 1992
    Assignee: Zimmer, Inc.
    Inventors: Mark A. Heldreth, Cary R. Reeves
  • Patent number: D372309
    Type: Grant
    Filed: July 6, 1995
    Date of Patent: July 30, 1996
    Assignee: Zimmer, Inc.
    Inventor: Mark A. Heldreth