Patents Assigned to Howmedica, Inc.
  • Patent number: 5514141
    Abstract: A reamer designed to create convex, curved shapes on small bones. The reamer comprises a body with a center bore throughout, and a concave head with at least three flutes. The flutes extend from the center of the head outward, being unconnected to each other in any way except at the center of the head portion. Each flute has an outer curved surface, which together form the partially hemispherical outer surface of the head. The inner curved surface is angled to facilitate rapid clearing of bone chips from the work surface. The distal end of each flute has a flat end surface, which is sufficiently large to prevent the flutes from breaking. Each flute also has two side surfaces, a cutting surface and a non-cutting surface. The small joint reamer according to the invention allows bone chips to be cleared easily during operation. This prevents overheating of the bone surface, which can cause necrosis of the bone, preventing proper healing of the patient.
    Type: Grant
    Filed: May 26, 1994
    Date of Patent: May 7, 1996
    Assignee: Howmedica, Inc.
    Inventor: John Prizzi, Jr.
  • Patent number: 5507832
    Abstract: A prosthesis with an integral proximal spacer is described. The prosthesis has a base element with a textured surface to aid in adhesion to bone cement. The integral spacer has a generally tripod shape. A top circumferential portion at least partially surrounds the proximal end of the prosthesis, and three legs extend distally along the length of the prosthesis. Also disclosed is the process for making the prosthesis and spacer, which preferably involves injection molding of PMMA.
    Type: Grant
    Filed: April 28, 1994
    Date of Patent: April 16, 1996
    Assignee: Howmedica, Inc.
    Inventors: Michael Michielli, Glen Kashuba, J. Mel Goldenberg, Jon I. Klippel
  • Patent number: 5498265
    Abstract: An implant comprising a specially adapted bone screw having a threaded shank portion and a sleeve which mates with and operates in cooperation with the threaded shank portion is provided. Also provided is a driver specially adapted for inserting and removing the implant of the invention. A method of compressing a fracture in a bone is also provided. The implant generates bone compression by itself and can be used either alone or with plates and washers. It is easily inserted into a fracture and also is easily removed from the fracture. The driver which is specially adapted to be used in combination with the implant of the invention aids in the ease of insertion and removal of the implant.
    Type: Grant
    Filed: April 1, 1994
    Date of Patent: March 12, 1996
    Assignee: Howmedica Inc.
    Inventors: Stanley E. Asnis, John S. Crombie
  • Patent number: 5449745
    Abstract: A medical implant made of polymeric material having an increased oxidation resistance is formed by a method including the steps of placing a resin powder in a sealed container. A substantial portion of the oxygen is removed from the sealed container by either a vacuum, an oxygen absorbent or by flushing with inert gas. The container is then repressurized with a gas such as nitrogen, argon, helium or neon so that long term storage may be possible. On use, the resin is transferred to a forming device which both melts and forms the resin in an oxygen reduced atmosphere to produce a polymeric raw material such as a rod or bar stock. The medical implant is then formed from this raw material annealed and sealed in an air-tight package in an oxygen reduced atmosphere. The implant is then radiation sterilized and thereafter annealed in the package for a predetermined time and temperature sufficient to form cross-links between any free radicals in neighboring polymeric chains.
    Type: Grant
    Filed: October 7, 1994
    Date of Patent: September 12, 1995
    Assignee: Howmedica Inc.
    Inventors: Deh-Chuan Sun, Casper F. Stark
  • Patent number: 5449375
    Abstract: A method of making a hemostatic plug for placement at a site where hemostatic treatment is indicated. The method comprises rolling a sheet of a hemostatic material a plurality of turns onto a generally cylindrical forming tool to thereby produce a rolled hemostatic plug having an opening therethrough along its longitudinal axis. In addition to employing one sheet of hemostatic material having a single density to form a plug, two sheets of hemostatic material having different densities can be rolled in tandem to each other on the forming tool, with one sheet overlapping an exposed wedge portion of the other sheet. The plugs thus formed can be longitudinally compressed if subsequent longitudinal expansion is desired. A typical placement site for which the plug is preferably employed is a puncture wound wherein an entry penetration of an artery and a tissue channel leading thereto are present.
    Type: Grant
    Filed: April 26, 1994
    Date of Patent: September 12, 1995
    Assignee: Howmedica Inc.
    Inventors: Claude A. Vidal, Russel J. Redmond, Joshua Makower
  • Patent number: 5443513
    Abstract: A beam adapted for implantation within a bone is able to support bending and torsional loading forces applied thereto. The beam has a stiffness defined by a modulus elasticity, which stiffness varies along the length of the beam to match the corresponding stiffness of the cortical bone adjacent the beam after implantation within the bone. The beam is made from an elongated core formed of chopped carbon fibers embedded in a thermoplastic polymer matrix. Encasing the core is a sheath formed of carbon reinforced filament fibers embedded in the thermoplastic polymer which is wound in spiral formation around the core and molded thereto. The winding angle and the sheath thickness along the beam may be varied to vary the modulus of elasticity to match that of the cortical bone adjacent thereto.
    Type: Grant
    Filed: December 22, 1993
    Date of Patent: August 22, 1995
    Assignee: Howmedica Inc.
    Inventors: Missoum Moumene, Ruey Y. Lin, Casper F. Stark
  • Patent number: 5443471
    Abstract: A handle for use in implanting a prothesis has an elongate body portion and a post-retaining structure at the end of the body portion. The post-retaining portion or structure includes a core member which has a bore formed therein to receive a post connected, for example, to a broach or rasp. The core member also includes a channel formed therein in communication with the bore and a pin movable within the channel between a locked position at the distal end of the channel in communication with the bore and a released position. A spring and a collar are provided where the collar is adapted to slide over the core member, move the pin within the channel and retain the pin in the locked position while the spring is adapted to bias and/or move the collar toward the front end of the core to retain the pin. A movable sleeve fits over the collar and spring and is provided with a shoulder to engage and move the collar to release the pin within the channel.
    Type: Grant
    Filed: February 16, 1993
    Date of Patent: August 22, 1995
    Assignee: Howmedica, Inc.
    Inventor: Glenn Swajger
  • Patent number: 5441537
    Abstract: An improved metallic bone prosthesis having a porous coating for bone ingrowth or interlocking with bone cement is disclosed. The porous coating comprises two layers of generally ball-shaped metallic particles bonded together at their points of contact, e.g. by sintering, and defining between them a plurality of connected interstitial pores having an average pore size of from about 350 microns to about 500 microns. A high resistance to failure at the coating-substrate and bone-coating (or cement-coating) interfaces is achieved with the use of the improved prosthesis. Also disclosed are a novel method for affixing the porous coating to a metal substrate, and a knee joint prosthesis having bearing portions designed so that the function of said prosthesis closely approximates that of the natural knee.
    Type: Grant
    Filed: December 4, 1992
    Date of Patent: August 15, 1995
    Assignee: Howmedica Inc.
    Inventor: Robert V. Kenna
  • Patent number: 5417696
    Abstract: An acetabular cup for use as a prosthetic implant has an insert with a body including a central bore for receiving a positioning rod therein. A key element is formed on the bore and is adapted to align the positioning rod. The insert has a locating element formed on an outer surface of the body and also includes spring elements extending radially outwardly from the body. The acetabular cup has a generally hemispherical shell member coupled to the outer surface of the insert. The shell has an outer surface for engaging the acetabulum and an inner surface having a circumferential groove for receiving the spring elements. The spring elements may be deflected radially inwardly out of engagement with the groove for releasing the insert from the shell. The spring elements can be deflected by pushing a sleeve down the rod to make contact with and deflect the spring element.
    Type: Grant
    Filed: March 23, 1993
    Date of Patent: May 23, 1995
    Assignee: Howmedica Inc.
    Inventors: Glen A. Kashuba, Jon I. Klippel
  • Patent number: 5414049
    Abstract: A medical implant made of polymeric material having an increased oxidation resistance is formed by a method including the steps of placing a resin powder in a sealed container. A substantial portion of the oxygen is removed from the sealed container by either a vacuum, an oxygen absorbent or by flushing with inert gas. The container is then repressurized with a gas such as nitrogen, argon, helium or neon so that long term storage may be possible. On use, the resin is transferred to a forming device which both melts and forms the resin in an oxygen reduced atmosphere to produce a polymeric raw material such as a rod or bar stock. The medical implant is then formed from this raw material annealed and sealed in an airtight package in an oxygen reduced atmosphere. The implant is then radiation sterilized and thereafter annealed in the package for a predetermined time and temperature sufficient to form cross-links between any free radicals in neighboring polymeric chains.
    Type: Grant
    Filed: June 1, 1993
    Date of Patent: May 9, 1995
    Assignee: Howmedica Inc.
    Inventors: Deh-Chuan Sun, Casper F. Stark
  • Patent number: 5358534
    Abstract: A femoral component for a hip prosthesis has a distal portion defining a central longitudinal axis. The component has a generally conically shaped mid-shaft portion and a proximal portion with a shape based on the reamer and a shaped chisel used by the surgeon to prepare the proximal metaphysis and medullary canal. The proximal portion is shaped in a manner wherein a cross-section taken perpendicular to the central axis has a medial side formed as a first circular arc, a corner of the cross-section formed by the posterior and lateral sides as a second circular arc with a center on the central axis. The posterior side is arcuate and concave and tangent to the first and second circular arcs, with the anterior side being arcuate and convex.
    Type: Grant
    Filed: April 29, 1993
    Date of Patent: October 25, 1994
    Assignee: Howmedica Inc.
    Inventors: Michael W. Dudasik, Anthony K. Hedley, David S. Hungerford, Matthew P. Poggie
  • Patent number: 5352227
    Abstract: A kit for coupling two bone segments has a first longitudinally extending intercalary element with a first end for insertion into the medullary canal of one of the bone segments and a second end in the form of a male conically tapered section, The kit also has a second longitudinally extending intercalary element having a first end for insertion into the medullary canal of the other bone segment which element has a second end in the form of a female conically tapered section for mating with the male section of the first intercalary element, Both intercalary elements have engagement elements formed thereon intermediate the first and second ends thereof.
    Type: Grant
    Filed: February 3, 1993
    Date of Patent: October 4, 1994
    Assignee: Howmedica Inc.
    Inventor: April L. O'Hara
  • Patent number: 5334216
    Abstract: A method of making a hemostatic plug for placement at a site where hemostatic treatment is indicated. The method comprises rolling a sheet of a hemostatic material a plurality of turns onto a generally cylindrical forming tool to thereby produce a rolled hemostatic plug having an opening therethrough along its longitudinal axis. In addition to employing one sheet of hemostatic material having a single density to form a plug, two sheets of hemostatic material having different densities can be rolled in tandem to each other on the forming tool, with one sheet overlapping an exposed wedge portion of the other sheet. The plugs thus formed can be longitudinally compressed if subsequent longitudinal expansion is desired. A typical placement site for which the plug is preferably employed is a puncture wound wherein an entry penetration of an artery and a tissue channel leading thereto are present.
    Type: Grant
    Filed: December 10, 1992
    Date of Patent: August 2, 1994
    Assignee: Howmedica Inc.
    Inventors: Claude A. Vidal, Russel J. Redmond, Joshua Makower
  • Patent number: 5326368
    Abstract: A modular prosthetic acetabular cup for use in restorative hip replacement is disclosed. The acetabular cup is of modular construction whereby extension members can be attached to an acetabular cup to provide a acetabular cup device with a cross section of a desired configuration. The extension members can be attached to the acetabular cup by means including dovetail joints, mechanical fasteners, and locking taper joints similar to those in femoral hip components.
    Type: Grant
    Filed: September 22, 1992
    Date of Patent: July 5, 1994
    Assignee: Howmedica, Inc.
    Inventor: Carlos E. Collazo
  • Patent number: 5326354
    Abstract: An improved method of producing a site for tissue ingrowth on a surgical implant by embedding a space occupier possessing a desired pattern in the surface of the implant at the desired location for ingrowth and then solubilizing the embedded space occupier to leave the pattern on the implant surface. Preferably, the implant is fabricated from a composite comprising a semi-crystalline thermoplastic resin such as polyetheretherketone or polyphenylene sulfide, and the space occupier is an acid-soluble metal plate machined to produce the desired pattern and removed by aqueous acid solution. The space occupier is embedded onto the composite surface by induction heating.
    Type: Grant
    Filed: July 2, 1993
    Date of Patent: July 5, 1994
    Assignee: Howmedica Inc.
    Inventor: Kofi B. Kwarteng
  • Patent number: 5324306
    Abstract: A puncture seal device for stemming the flow of blood from a punctured blood vessel includes an elongated outer sheath affixed to a generally tubular housing where the housing contains a manually actuable slide which is affixed to a rigid tubular pusher member coaxially disposed within the outer sheath. Also contained within the outer sheath in longitudinal alignment with the pusher and distally thereof is a ring-shaped plug of a hemostatic material. The assembly thus far described may be fitted over a tubular introducer or the body of a catheter and then advanced therealong until the distal end of the outer sheath is proximate a bleeding blood vessel. By actuating the pusher member, the hemostatic plug surrounding the introducer or catheter is ejected from the distal end of the outer sheath and held in abutting relationship to the bleeding blood vessel.
    Type: Grant
    Filed: May 28, 1993
    Date of Patent: June 28, 1994
    Assignee: Howmedica, Inc.
    Inventors: Joshua Makower, Claude A. Vidal, Steven R. LeMott, Rodney E. Wells, Thomas F. Banks
  • Patent number: 5290310
    Abstract: A puncture seal device for stemming the flow of blood from a punctured blood vessel has an elongated outer sheath affixed to a generally tubular housing where the housing contains a manually actuable slide which is affixed to a rigid tubular pusher member coaxially disposed within the outer sheath. Also contained within the outer sheath in longitudinal alignment with the pusher and distally thereof is a ring-shaped plug of a hemostatic material. The assembly thus far described may be fitted over a tubular introducer or the body of a catheter and then advanced therealong until the distal end of the outer sheath is proximate a bleeding blood vessel. By actuating the pusher member, the hemostatic plug surrounding the introducer or catheter is ejected from the distal end of the outer sheath and held in abutting relationship to the bleeding blood vessel.
    Type: Grant
    Filed: July 13, 1992
    Date of Patent: March 1, 1994
    Assignee: Howmedica, Inc.
    Inventors: Joshua Makower, Claude A. Vidal, Steven R. LeMott, Rodney E. Wells, Thomas F. Banks
  • Patent number: 5242447
    Abstract: A pin is disclosed that includes an elongated shaft having a constant diameter, and an elongated threaded portion having first and second axially separated ends, the first axial end being axially closer to the elongated shaft than the second axial end. The threaded portion has a root diameter that tapers linearly from a maximum value at the first axial end to a minimum value at the second axial end. The root diameter at the first axial end is substantially equal to the diameter of the elongated shaft itself. The pin also includes a drill end extending axially from the second axial end of the threaded portion such that the drill end is connected to the elongated shaft by the threaded portion.
    Type: Grant
    Filed: February 6, 1992
    Date of Patent: September 7, 1993
    Assignee: Howmedica Inc.
    Inventor: Rocco R. Borzone
  • Patent number: 5226906
    Abstract: A surgical speed wrench useful in installing spinal implant devices is provided with a thin profile and means for holding a part to be installed with a threaded fastener. The thin profile is achieved by a socket formed directly in a torque transmitting gear. The threaded fastener head is received directly in the socket and no other tool or adapter is required which would increase the profile. The holding means includes two extending arms terminating in spherical members which biasly engage a bore in the part to be installed. With the part thus held, the threaded fastener is received in the wrench socket and may be started and driven without the surgeon using his or her fingers or other instruments.
    Type: Grant
    Filed: February 13, 1991
    Date of Patent: July 13, 1993
    Assignee: Howmedica, Inc.
    Inventors: John S. Crombie, Martin H. Krag
  • Patent number: 5219349
    Abstract: A reduction frame according to the present invention is secured to shaft handles extending from the pedicle screws of a Vermont Spinal Fixator type implant. Shaft clamps secure two T-handles of the reduction frame to the shaft handles. A lower-rod assembly joins the two opposite T-frames by means of lower-rod clamps. The shaft clamps are provided with four degrees of freedom. The joint between the lower-rod assembly and T-handle is provided with five degrees of freedom. The lower-rod assembly and the T-handle are provided with power screw threads to allow for precise translational control. The shaft clamps and lower-rod clamps are provided with taper fit joints to allow for infinite rotational adjustment and fixture. An upper-rod assembly is also provided on the T-handles to produce rotation of the T-handles by providing means for changing the distance between the upper ends of the T-handles.
    Type: Grant
    Filed: February 15, 1991
    Date of Patent: June 15, 1993
    Assignee: Howmedica, Inc.
    Inventors: Martin H. Krag, John S. Crombie