University of Pennsylvania

Zimmer Gmbh

Osteonics Corp.

Electro-biology, Inc.

Jonathan Black

Carl T Brighton

Thomas J Baranowski, Jr

Paul Serekian

Joyce K Eyerly

Michael T Manley

William Redka

Robert A Latour, Jr

Structural elements of biocompatible material are interlocked with one another in an array to repair, augment or replace natural bone, the structural elements each including a hub having a center, and a plurality of posts projecting from the hub and spaced from one another to establish inter-post spaces between adjacent posts, each post having a root at the hub, an opposite tip, a length, and a transverse cross-sectional configuration, the number of posts and the relative length, cross-sectional configuration, and location of adjacent posts in each structural element being such that the inter-post spaces of one structural element will receive the posts of adjacent structural elements in the array to promote interlocking of adjacent structural elements in a relatively tightly meshed relationship for resisting shear stress in essentially all directions within the array.

Interlocking structural elements and method for bone repair,

Invented are methods and an apparatus for faradic stimulation of osteogenesis by control of electrochemical reactions through maintenance of a stimulus between a cathode and anode yielding only beneficial electrochemical reactions at the cathode, the site of desired osteogenesis, while preventing any detrimental reaction at the same. Said methods and apparatus maintain a stimulus yielding the maximum acceptable level of oxygen consumption and pH elevation at the cathode, either with or without the formation of hydrogen peroxide as only an intermediate chemical species, while preventing the initiation of hydrogen gas evolution at the same such that the stimulus results in depression of oxygen tension plus elevation of pH, environmental effects that favor osteogenesis, and prevents a reaction resulting in elevation of pH plus hydrogen gas evolution, the latter effect being detrimental to the same.

Electrochemically controlled faradic stimulation of osteogenesis

Mechanical testing apparatus and methods are disclosed for providing closed-loop dynamic mechanical testing under small loads. The testing machine includes an electrically-driven actuator and light weight load transducer. The load transducer converts the applied load into a voltage feedback signal, which is then fed into a closed-loop control means for regulating the applied load in response, in part, to the voltage feedback signal. The testing machine is extremely sensitive and is capable of testing samples with an applied load force of less than about 20 grams.

Miniature closed-loop dynamic universal mechanical testing machine

Disclosed is an implantable bone growth stimulator which needs no internal battery or large buffer capacitor. A receiving coil in a preferred embodiment, a ferrite core coil, receives RF energy from a transmitter external to the patient. The received RF energy is voltage doubled and rectified and provided to a constant current generator which in turn supplies a constant amount of current between implanted cathodes and an implanted anode. In preferred embodiments, the receiving coil, power supply, and cathodes are one unit which is located in place on an internal fixation device attached to the bones near the fracture site. In another embodiment, only the cathodes are located in the vicinity of the fracture site and the receiver coil voltage multiplier circuit and constant current source are located remote from the fracture site. Additionally, the internal fixation device in a preferred embodiment may have a plastic insert therein having one or more holes therethrough for the insertion of cathodes into the vicinity of the fracture site. While a preferred embodiment utilizes the completely implanted bone growth stimulator, the plate is effectively utilized with an external bone growth stimulator power supply and percutaneous cathodes inserted through positioning holes in the plastic insert of the fixation device.

Implantable bone growth stimulator

Disclosed is a method and apparatus for maintaining the potential between a cathode and a reference electrode substantially constant during electrically-induced osteogenesis. Two separate embodiments of electronic circuits are provided which will generate a D.C. current to flow between a cathode and anode while maintaining the potential between the cathode and the reference electrode substantially constant within the range of 0.1 to 1.26 Volts and preferably within the range of 1.0 to 1.26 Volts. Improvement in the amount of new bone grown over prior art bone growth stimulators is on the order of 200 to 300 percent. The electronic circuits provide the substantially constant cathodic potential over a wide range of load impedances between the anode and cathode. The disclosure is applicable not only to improving osteogenesis in bone fracture sites, but also to applications in which it is desirable to provide bone accretion for any reason.

Method and apparatus for cathodic potential control in electrically

Disclosed is an improved bone-piercing cathode for providing electrical stimulation of osteogenesis at a plurality of locations. A conventional bone-piercing cathode is modified by adding a number of 'ports' extending through the insulative covering to expose the cathode permitting a flow of osteogenesis stimulating current therethrough. In a preferred embodiment, seven ports are spaced three on one side and four on the other of a conventional bone-piercing cathode which is inserted into the fracture site. Sufficient current is supplied to the cathode in order to insure that each port as well as the insulation-bare wire junction can supply 20 microamperes of osteogenesis stimulating current into the body tissues. This permits bone growth stimulation adjacent a plurality of sites on the cathode.

Method of stimulating osteogenesis with distributed port cathode

Distributed port bone-piercing cathode for electrically stimulated

A cathode assembly for use in conjunction with an internal fracture fixation device for the purpose of stimulating osteogenesis (bone growth) within a fracture site. The assembly is comprised of a carrier made from an implantable non-conductive material containing a cathode with a conductive cable leading from the cathode to the patient's electrical bone growth stimulating apparatus. The carrier is mountable on the fixation device for maintenance at the desired location. In a preferred embodiment, a sleeve carrier contains a plurality of ports which allow the current generated by the stimulating device to flow through the cable to the cathode where it is evenly distributed through the ports to the bone tissue. The sleeve can be slipped onto a fracture fixation device, such as a compression hip screw, and is located on the device such that the sleeve containing the cathode lies across the fracture site.

Growing community of inventors

King of Prussia, PA, United States of America

Jonathan Black