Abstract: A device for centralizing a prosthetic femoral stem within a prepared natural femur and plugging the femoral canal inculdes a first member having a shape generally similar to the shape of the femoral stem for temporary insertion within the natural femur, a rod member for slidable insertion through a bore in the first member, and a second member releasably connected to the distal end of the rod member for permanent insertion within the natural femur for aligning the distal end of the femoral stem and plugging the canal of the natural femur.

Abstract: Orthopedic device of biocompatible polymer with oriented fiber reinforcement. There is provided a device such as a hip stem which has a longitudinally curved body. The reinforcing fibers are continuous filament fiber plies with parallel oriented fibers in each ply. The plies are curved longitudinally to approximately correspond to the curve of the body. In one embodiment, there are longitudinally oriented fiber plies at or near the surfaces of the device and plies with fibers offset at 5.degree.-40.degree. from the longitudinal axis between the surface layers. The fiber orientation is balanced by providing a ply of negatively angled offset fibers of a similar angle for each positively angled offset ply. The device is made by molding plies preimpregnated with polymer (prepregs) simultaneously, by molding a plurality of prepregs into segments which are then molded together, or by molding a segment and incrementally molding additional layers of prepregs thereto in a series of progressively larger molds.

Abstract: Surgical instrumentation and a method for cutting bones on one or both sides of a joint such as the knee joint to allow the application of a joint prosthesis. A rod is inserted into the medullary canal of the bone to be cut. The rod is secured within the medullary canal and a router guide is mounted on the rod for rotation thereabout while being restrained against movement axially of the rod. A router or side cutting drill is inserted through the router guide into contact with the rod and actuated to rotate about its own axis. The router guide and the router are then caused to rotate about the rod to thereby cut the bone to produce a substantially planar surface thereon suitable to bear against a joint prosthesis.

Abstract: Orthopedic implants of zirconium or zirconium-based alloy coated with zirconium oxide to provide low friction, highly wear resistant coatings especially useful in artificial joints, such as hip joints, knee joints, elbows, etc. The invention zirconium oxide coated prostheses are also useful in that the zirconium oxide coatings provide a barrier against implant corrosion caused by ionization of the metal prosthesis. Such protection can be extended by the use of oxidized porous coatings of zirconium or zirconium alloy beads or wire mesh into which bone spicules may grow so that the prosthesis may be integrated into the living skeleton.

Abstract: A modular broach handle for use with a broach having a tapered configuration beginning at a wider upper end tapering to a smaller lower end. An elongated handle body portion has a longitudinal axis, with one end portion of the handle body defining a connection end portion for attaching a broach thereto at the wide upper end portion of the broach. A slot extends a distance along the handle terminating at one end thereof adjacent a connection end poriton of the handle body. A socket communicating with the slot is formed at the connection end portion of the handle body, the socket having an open end portion receptive of an attachment post on the wide end portion of the broach. A spring loaded slider bar is disposed within the slot for sliding movement therein and with respect to the handle between engaged and disengaged positions, and includes an end portion that extends into the socket when in the engaged position to form a connection with the post.

Abstract: A compression hip screw for repairing a bone fracture includes a non-absorbable plate and a non-absorbable barrel section connected to the plate adapted to be inserted into a hole formed in the hip bone. A non-absorbable lag screw with a longitudinal opening therein and with internal and external threads is adapted to be inserted through the longitudinal opening in the barrel and into the portion of the bone on one side of a fracture. A compressing screw with threads adapted to cooperate with the internal threads of the lag screw and a head adapted to abut the outer portion of the barrel adjacent to the longitudinal opening can be inserted into the opening in the barrel for compressing the portions of the bone on both sides of the fracture. The compressing screw has at least a head portion formed of a material that absorbs on contact with body fluids.

Abstract: An instrument for determining the variation in tension of a ligament graft extending between first and second proposed fixation sites positioned on first and second articulated bones, respectively, comprises a yoke which carries a device for securing the yoke to one of the first and second bones. A yoke plate is rotatably carried by the yoke. A main housing is adapted for connection to the yoke plate. A sled is slidably carried by the main housing. The sled is adapted for connection to the ligament graft. A mechanism is provided for adjusting the position of the sled relative to the housing so as to place a desired degree of tension on the ligament graft. A transducer is associated with the mechanism for adjusting for determining changes in tension, if any, from the desired degree of tension as the first and second bones are moved relative to one another.

Abstract: A shielded magnetic assembly for use in a magnetic hearing aid is described. The shielded assembly uses a disc-shaped magnet with a high permeability, low coercivity material placed on the face of the magnet away from the air gap. Preferably, the shielding material also covers portions of the edge of the magnet to form a cap. The shielding focuses the magnet's energy into the air gap to improve coupling and reduce interference from external magnetic fields.

Abstract: A prosthetic ligament assembly includes a nonaugmented prosthetic ligament for permanently replacing a natural ligament spanning first and second body members, such as the femur and tibia, and a bone screw adapted for tensioning the prosthetic ligament during implantation. The prosthetic ligament includes a load bearing member intertwined into a plain braid from a plurality of biocompatible, high strength, ultra high molecular weight polyethylene yarns. Each yarn includes at least fifty fibers and has a tensile strength greater than or equal to about 100,000 psi. The load bearing member has a gage section and a loop at each end thereof for anchoring the load bearing member to the body members. The load bearing member is preloaded to remove slack therefrom. The load bearing member may be used alone or may be formed into a hollow braid having a core disposed within the hollow portion of the braid to permit radiographic visualization of the prosthetic ligament.

Abstract: This invention is an ossicular replacement prosthesis made of porous polymeric material with a metal core of the type that includes a head portion for fitting against the tympanic membrane and a shaft for bridging the middle ear to provide conduction of sound to the middle ear.

Abstract: This invention is an ossicular replacement prosthesis made of porous polymeric material with a metal core of the type that includes a head portion for fitting against the tympanic membrane and a shaft for bridging the middle ear to provide conduction of sound to the middle ear.

Abstract: An orthopedic prosthesis including a trunk engaging means, an arm engaging means and a lift assist means. The trunk engaging means includes a shoulder engaging means comprised of a strap which passes over the injured shoulder and a support plate attached to each end of the shoulder strap, the support plates being positioned in front of and behind the shoulder to be supported. The trunk engaging means also includes a lateral support strap, one end of the strap being connected to one of the support plates and around the body of the wearer under the arm opposite of the shoulder to be supported where it is connected to the second support plate. The arm engaging means includes a strap passing around the humerus of the arm of the wearer. The lift assist means utilizes two pulley systems, one mounted on the arm engaging means and one on the support plate of the shoulder engaging means.

Abstract: An apparatus for treating fractures of the femur including a screw and an intramedullary rod. The screw has a threaded portion and a smooth portion. The rod has a head, stem and a longitudinal bore. There is at least one pair of coaxial holes through the stem, transverse to the longitudinal axis of the rod, for receiving first anchoring means, such as a nail, screw or bolt, to secure the rod within the marrow canal of the femur. There are at least a proximal pair of coaxial holes and a distal pair of coaxial holes in the head of the rod in an angled direction toward the femoral head relative to the longitudinal axis of the rod. The distal pair of head holes are adapted to slidingly receive the screw to permit the threaded portion of the screw, in use, to engage the femoral head and to allow sliding compression of a femoral neck or intertrochanteric fracture.

Abstract: An ossicular replacement prosthesis containing a magnet in the head of the prosthesis so that when used with a magnetic induction hearing aid having a coil producing a magnetic field, the hearing losses resulting from insertion of the prosthesis and any other remaining hearing losses can be corrected without the difficulties associated with conventional acoustic hearing aids.

Abstract: A method for making an adhesive for use in joining soft living tissue including the steps of preparing a hydroxyl-terminated polyester by reacting a biodegradable monomer with a polyhydroxy polymerization initiator in the presence of an amount up to about 2.0 weight percent of a catalyst, and then preparing a diisocyanate-terminated prepolymer adhesive by reacting about 24 to 92 weight percent of the hydroxy-terminated polyester with about 8 to 76 weight percent excess aromatic diisocyante. The polyester and the diisocyanate are preferably dissolved in an organic solvent prior to the mixture thereof in a ratio of solids to solvent of about 60:40. The polyester is a polymer or copolymer of lactide, glycolide or .epsilon.-caprolactone. The initiator is ethylene glycol, diethylene glycol, pentaerythritol or 1,1,1-tris (hydroxymethyl) ethane. The catalyst is stannous octoate, a zinc compound, an aliphatic tertiary amine, dibutyltin diacetate or 1,4-diazabicyclo [2,2,2] octane.

Abstract: An electric motor-driven drill has an irrigating tube for squirting water onto a drill bur. The tube has convolutions surrounding the motor for cooling the motor and warming the irrigating water. A quick-release chuck holds the bur shank coupled to the motor shaft.

Abstract: A magnetic induction hearing aid where the microphone, the amplifying electronics, the battery and a coil are contained in a single housing which is located deep in the ear canal. A magnet is attached to portions of the middle ear by means of a malleus clip or by implantation between the tympanic membrane and the malleus. The magnet is vibrated by interaction with the magnetic field produced by the coil. Two amplifier designs are disclosed for use with different levels of hearing loss. The magnet can be coated with hydroxyapatite for permanent attachment to the body. The magnet is coated with hydroxyapatite by an ion implantation process, a plasma spraying technique or a method of applying the hydroxyapatite while a precoating polymeric material has not fully solidified.

Abstract: A prosthetic ligament assembly includes a nonaugmented prosthetic ligament for permanently replacing a natural ligament spanning first and second body members, such as the femur and tibia, and a bone screw adapted for tensioning the prosthetic ligament during implantation. The prosthetic ligament includes a load bearing member intertwined into a plain braid from a plurality of biocompatible, high strength, ultra high molecular weight polyethylene yarns. Each yarn includes at least fifty fibers and has a tensile strength greater than or equal to about 100,000 psi. The load bearing member has a gage section and a loop at each end thereof for anchoring the load bearing member to the body members. The load bearing member is preloaded to remove slack therefrom. The load bearing member may be used alone or may be formed into a hollow braid having a core disposed within the hollow portion of the braid to permit radiographic visualization of the prosthetic ligament.

Abstract: A method for repairing a bone fracture with a compression screw assembly is provided. First and second non-resorbable compression members are positioned so that the head portion of the compression screw can protrude from the surface of the second non-resorbable compression member after further compression is effected by the normal healing process. At least the head portion of the screw is formed of a material that resorbs upon contact with body fluids.

Abstract: A surgical implant is disclosed manufactured from cast austenitic stainless steel and cold-forged to a final shape. The endoprosthesis is initially a preform which is cast oversized in shape and dimensions. It is then compressed using the cold-forging process to its final size and shape. Using a cast material as a starting material and then compressing it substantially reduces the porosity of the material and increases its strength compared to a machined product from a wrought material.