Patents by Inventor Frederick F. Buechel

Frederick F. Buechel 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).

  • Patent number: 7485147
    Abstract: The tibial component of a prosthetic ankle joint including a tibial component, a talar component, and an intermediate sliding plastic bearing, with the tibial component including a depending peripheral wall that surrounds and is spaced from the plastic bearing and is intended to reduce rubbing of the plastic bearing against tissue which would produce wear particles that lead to the formation of bone cysts. The depending peripheral wall of the tibial component is intended to reduce such possible abrasions by at least partially shielding the plastic bearing from the surrounding tissue.
    Type: Grant
    Filed: February 3, 2005
    Date of Patent: February 3, 2009
    Inventors: Michael J. Pappas, Frederick F. Buechel
  • Patent number: 6224632
    Abstract: A tibia fixturing device comprises a metal tray formed with annularly spaced recesses in its underside at a depth of at least about 1.5 mm and from which a stem depends for axial insertion into a tibia conical cavity. The stem has a circular cylindrical portion proximal the tray and a conical portion distal the tray. Fins radially extend from the stem cylindrical portion and penetrate the tibia to provide some torsional resistance. Axially extending channels are formed about the stem periphery which channels have bottom surfaces parallel to the stem axis to provide further torsional resistance. The channels are arranged to not interlock with the cement in the axial direction to permit the cement to separate first from the device during axial removal of the device from the bone. The fins have inclined edges distal the tray and inclined radial outer edges to align and center the stem to the bone cavity edge.
    Type: Grant
    Filed: September 20, 1996
    Date of Patent: May 1, 2001
    Assignee: Biomedical Engineering Trust I
    Inventors: Michael J. Pappas, Frederick F. Buechel
  • Patent number: 5941911
    Abstract: A prosthetic system is provided for secure mounting of a prosthetic component to a bone, and particularly to a bone that may be diseased, damaged or deteriorated. The prosthetic system includes a plurality of screws that are mounted to healthy bone stock. Each screw includes a threaded portion extending from one end and a non-threaded portion extending from the opposed end. The non-threaded portion includes a discontinuous surface configuration thereon. Ends of the screws are positioned to support the prosthetic component. The bone cement is then disposed between the prosthetic component and the bone and in surrounding relationship to portions of the screws that project from the bone. The cement surrounds and attaches to the protrusions on the screws so that the screws and the cement reinforce one another in response to loads imposed thereon during use of the prosthesis.
    Type: Grant
    Filed: October 17, 1997
    Date of Patent: August 24, 1999
    Inventor: Frederick F. Buechel
  • Patent number: 5868797
    Abstract: A tibia fixturing device comprises a metal tray formed with annularly spaced recesses in its underside at a depth of at least about 1.5 mm and from which a stem depends for axial insertion into a tibia conical cavity. The stem has a circular cylindrical portion proximal the tray and a conical portion distal the tray. Fins radially extend from the stem cylindrical portion and penetrate the tibia to provide some torsional resistance. Axially extending channels are formed about the stem periphery which channels have bottom surfaces parallel to the stem axis to provide further torsional resistance. The channels are arranged to not interlock with the cement in the axial direction to permit the cement to separate first from the device during axial removal of the device from the bone. The fins have inclined edges distal the tray and inclined radial outer edges to align and center the stem to the bone cavity edge.
    Type: Grant
    Filed: January 17, 1996
    Date of Patent: February 9, 1999
    Assignee: Biomedical Engineering Trust I
    Inventors: Michael J. Pappas, Frederick F. Buechel
  • Patent number: 5861042
    Abstract: A prosthesis is provided having at least a smooth non-articulating load bearing surface disposed adjacent a bone. The prosthesis includes a substrate formed from a metallic alloy. At least the regions of the substrate defining the load bearing surface are coated with a biologically inert abrasion resistant material harder than the substrate for preventing leaching of ions from the substrate into adjacent body tissue and for preventing wear. The coating may be titanium nitride or zirconium or other such material exhibiting biological inertness and acceptable hardness. The coating preferably defines a thickness of 8-10 microns.
    Type: Grant
    Filed: April 1, 1997
    Date of Patent: January 19, 1999
    Inventors: Frederick F. Buechel, Michael J. Pappas
  • Patent number: 5824096
    Abstract: A femoral component with a femoral stabilizing implanted rod has condylar surfaces of different radii which mate with a thermoplastic bearing. A mating tibial platform is stabilized in the tibia with a rod, the bearing translating on the platform in the posterior-anterior directions in response to knee flexion and extension. The bearing bears the full extension load on congruent articulating contact regions with the condylar surfaces and lesser flexion loads via incongruent articulating contact. A hinge assembly is pinned to the femoral condylar component through a head having a depending shaft fixed to a thermoplastic tapered bearing axially floating and rotatably movable in a tibia platform component mating cavity. The head passes through the bearing and stops the bearing translations at extreme posterior and anterior positions.
    Type: Grant
    Filed: December 12, 1994
    Date of Patent: October 20, 1998
    Assignee: Biomedical Engineering Trust I
    Inventors: Michael J. Pappas, Frederick F. Buechel
  • Patent number: 5702466
    Abstract: A joint prosthesis having a femoral element, a tibial element and a bearing for articulation therebetween is disclosed to further include an intermediate element. The intermediate element permits rotation of the bearing with respect to the tibial element and longitudinal translation of the bearing with respect to the intermediate element. Transverse translation of the bearing with respect to the intermediate element is precluded. In an alternative embodiment, the longitudinal translation may be limited either in the anterior or posterior direction.
    Type: Grant
    Filed: May 16, 1996
    Date of Patent: December 30, 1997
    Assignee: Biomedical Engineering Trust I
    Inventors: Michael J. Pappas, Frederick F. Buechel
  • Patent number: 5702448
    Abstract: A prosthesis is provided having at least a smooth non-articulating load bearing surface disposed adjacent a bone. The prosthesis includes a substrate formed from a metallic alloy. At least the regions of the substrate defining the load bearing surface are coated with a biologically inert abrasion resistant material harder than the substrate for preventing leaching of ions from the substrate into adjacent body tissue and for preventing wear. The coating may be titanium nitride or zirconium or other such material exhibiting biological inertness and acceptable hardness. The coating preferably defines a thickness of 8-10 microns.
    Type: Grant
    Filed: July 5, 1995
    Date of Patent: December 30, 1997
    Inventors: Frederick F. Buechel, Michael J. Pappas
  • Patent number: 5702461
    Abstract: A tibia fixturing device comprises a metal tray formed with annularly spaced recesses in its underside at a depth of at least about 1.5 mm and from which a stem depends for axial insertion into a tibia conical cavity. The stem has a circular cylindrical portion proximal the tray and a conical portion distal the tray. Fins radially extend from the stem cylindrical portion and penetrate the tibia to provide some torsional resistance. Axially extending channels are formed about the stem periphery which channels have bottom surfaces parallel to the stem axis to provide further torsional resistance. The channels are arranged to not interlock with the cement in the axial direction to permit the cement to separate first from the device during axial removal of the device from the bone. The fins have inclined edges distal the tray and inclined radial outer edges to align and center the stem to the bone cavity edge.
    Type: Grant
    Filed: January 18, 1996
    Date of Patent: December 30, 1997
    Assignee: Biomedical Engineering Trust I
    Inventors: Michael J. Pappas, Frederick F. Buechel
  • Patent number: 5462548
    Abstract: An acetabular reamer is provided with a shaft having opposed front and rear ends. A mounting cap is securely connected to the front end of the shaft and includes a skirt having an interior surface spaced radially outwardly from the shaft and an opposed non-cylindrical exterior surface. At least one aperture extends through the skirt. A locking spring is disposed adjacent the interior surface of the skirt and includes a locking detent extending through the aperture in the skirt. The spring can be deflected radially inwardly to bring the detent into alignment with the exterior surface of the skirt. A reamer head is mountable over the mounting cap such that the rear wall of the reamer head deflects the spring radially inwardly during mounting and unmounting. In the fully mounted condition of the reamer head, the locking detent of the spring engages an inwardly facing surface of the rear wall of the reamer head. The.degree.
    Type: Grant
    Filed: July 6, 1992
    Date of Patent: October 31, 1995
    Inventors: Michael J. Pappas, Frederick F. Buechel
  • Patent number: 5376122
    Abstract: A multi-component hip joint prosthesis is provided comprising an acetabular cup and a plastic bearing liner, each of which defines a segmented open shell with an inferior segment thereof removed to provide enhanced flexibility. The enhanced flexibility substantially facilitates the assembly and disassembly of the components. The liner and the cup are retained in their assembled condition by interengagement between a plurality of ridges and at least one groove on the respective components. The plurality of independent ridges enhances the flexibility of the ridges, thereby further minimizing the assembly forces required. Interengageable keys and keyways on the respective components may be provided to prevent relative rotation therebetween. The cup may comprise a removable tab to facilitate the insertion of a tool between the cup and the liner for prying the liner from the cup if necessary.
    Type: Grant
    Filed: June 17, 1992
    Date of Patent: December 27, 1994
    Inventors: Michael J. Pappas, Frederick F. Buechel
  • Patent number: 5171283
    Abstract: A prosthetic joint includes a first bearing element which is attached to a first bone and has a substantially flat bearing surface. A second element having a bearing surface is attached to a second bone. A bearing is disposed between the first and second elements. The bearing has a central axis and is defined by a first surface and a second surface. The first surface is substantially flat and is at least partially in contact with the first flat surface of the first element. At least a portion of the second surface is in contact with the surface of the second element. The area of the planform of the first surface of the bearing is smaller than, and dissimilar in shape from, the area of the planform defined by the second surface of the bearing.
    Type: Grant
    Filed: October 22, 1990
    Date of Patent: December 15, 1992
    Assignee: Biomedical Engineering Trust
    Inventors: Michael J. Pappas, Frederick F. Buechel
  • Patent number: 5133764
    Abstract: A multi-component hip joint prosthesis is provided comprising an acetabular cup and a plastic bearing liner, each of which defines a segmented open shell with an inferior segment thereof removed to provide enhanced flexibility. The enhanced flexibility substantially facilitates the assembly and disassembly of the components. The liner and the cup are retained in their assembled condition by interengagement between a plurality of ridges and at least one groove on the respective components. The plurality of independent ridges enhances the flexibility of the ridges, thereby further mimimizing the assembly forces required. Interengageable keys and keyways on the respective components may be provided to prevent relative rotation therebetween. The cup may comprise a removable tab to facilitate the insertion of a tool between the cup and the liner for prying the liner from the cup if necessary.
    Type: Grant
    Filed: June 10, 1988
    Date of Patent: July 28, 1992
    Inventors: Michael J. Pappas, Frederick F. Buechel
  • Patent number: 5074879
    Abstract: A modular stem type prosthesis is provided which includes a stem and an extension which are connected to one another with a slip fit interconnection that minimizes surface tensile forces in regions of the prosthesis adjacent the interface between the stem and the extension. Engagement between the stem and the extension is provided by deflectable end portions of one component of the prosthesis which are engaged in a mating deformation in the other component. The mating structures may define an interfitting ridge and groove. Micromotion between the respective parts may be prevents by a screw which may be tapered to achieve a lock fit. The extension may be of any selected length and any selected diameter in accordance with the needs of the patient.
    Type: Grant
    Filed: October 26, 1990
    Date of Patent: December 24, 1991
    Inventors: Michael J. Pappas, Frederick F. Buechel
  • Patent number: 5047062
    Abstract: An improved stem-type prosthesis, including a head, stem and neck providing reduced bending and shear loading of the neck thereby allowing the use of a smaller neck to improve the range of motion between the prosthesis and an acetabular cavity and to allow the use of a more complete spherical head thereby improving wear and separation resistance of the prosthesis from other components such as from an acetabular component.
    Type: Grant
    Filed: December 29, 1989
    Date of Patent: September 10, 1991
    Inventors: Michael J. Pappas, Frederick F. Buechel
  • Patent number: 5030234
    Abstract: A modular stem type prosthesis is provided which includes a stem and an extension which are connected to one another with a slip fit interconnection that minimizes surface tensile forces in regions of the prosthesis adjacent the interface between the stem and the extension. Engagement between the stem and the extension is provided by deflectable end portions of one component of the prosthesis which are engaged in a mating deformation in the other component. The mating structures may define an interfitting ridge and groove. Micromotion between the respective parts may be prevents by a screw which may be tapered to achieve a lock fit. The extension may be of any selected length and any selected diameter in accordance with the needs of the patient.
    Type: Grant
    Filed: December 12, 1989
    Date of Patent: July 9, 1991
    Inventors: Michael J. Pappas, Frederick F. Buechel
  • Patent number: 5030221
    Abstract: A prosthesis holding system is provided for holding and positioning a prosthetic cup during surgery. The rim of the cup includes opposed inwardly and outwardly facing recesses. A holder includes an elongated rod having a shoe at one end. The shoe includes a tab for engaging the inwardly facing recess in the rim of the cup. The shoe further includes a threaded aperture alignable with the outwardly facing recess in the rim of the cup. A clamping screw is engageable with the threaded aperture and is further engageable with the outwardly facing recess in the rim of the cup. Tightening of the clamping screw securely holds the cup without interfering with either the interior concave surface of the cup or the exterior convex surface of the cup, to enable efficient implantation of the cup in a patient during surgery.
    Type: Grant
    Filed: December 13, 1989
    Date of Patent: July 9, 1991
    Inventors: Frederick F. Buechel, Michael J. Pappas
  • Patent number: 4969905
    Abstract: Surgical method for facilitating bone healing using prosthetic device such as bone plates, stem-type prostheses such as femoral or humeral prostheses, or intrameduallary rods utilizing casting techniques that provide columnar or monocrystalline grain structure, with the <001> crystal direction oriented substantially parallel to the neutral axis, thereby increasing flexibility of the prosthesis and increasing loading on the bone, whereby disuse-atrophy is reduced and bone healing is facilitated; similarly, the crystal direction may be oriented to increase the stiffness of the prosthesis to resist tension.
    Type: Grant
    Filed: May 15, 1989
    Date of Patent: November 13, 1990
    Inventors: Michael J. Pappas, Frederick F. Buechel
  • Patent number: 4955919
    Abstract: Multi-component joint prosthesis including first and second components for being assembled together and the assembly of which requires the application of assembly forces, e.g. a hip joint prosthesis including an acetabular cup and plastic bearing liner for being assembled together and wherein such assembly requires the application of assembly forces. One or both of the components being a segmented open shell including a wall having a major load supporting segment resisting the assembly force removed which increases the flexibility of the wall and facilitates assembly of the components, e.g. in one hip prosthesis embodiment an inferior segment of the wall of each component is removed to increase the flexibility of the wall and facilitate the assembly of the acetabular cup and plastic bearing liner.
    Type: Grant
    Filed: March 15, 1985
    Date of Patent: September 11, 1990
    Inventors: Michael J. Pappas, Frederick F. Buechel
  • Patent number: 4932974
    Abstract: Prosthetic device such as bone plates, stem-type prostheses such as femoral or humeral prostheses, or intramedullary rods are substantially improved by utilizing casting techniques that provide columnar or monocrystalline grain structure, with the <001> crystal direction oriented substantially parallel to the neutral axis, thereby increasing flexibility of the prosthesis and increasing loading on the bone, whereby disuse-atrophy is reduced and bone healing is facilitated; similarly, the crystal direction may be oriented to increase the stiffness of the prosthesis to resist tension.
    Type: Grant
    Filed: July 6, 1989
    Date of Patent: June 12, 1990
    Inventors: Michael J. Pappas, Frederick F. Buechel