Prophylactic bactericidal implant

Abstract

A medical implant system is described for inhibiting infection associated with a joint prosthesis implant. An inventive system includes an implant body made of a biocompatible material which has a metal component disposed on an external surface of the implant body. A current is allowed to flow to the metal component, stimulating release of metal ions toxic to microbes, such as bacteria, protozoa, fungi, and viruses. One detailed system is completely surgically implantable in the patient such that no part of the system is external to the patient while the system is in use. In addition, externally controlled devices are provided which allow for modulation of implanted components.

Description

REFERENCE TO RELATED APPLICATION [0001] This application claims priority from U.S. Provisional Patent Application Ser. No. 60 / 585,159, filed Jul. 1, 2004, the entire content of which is incorporated herein by reference.FIELD OF THE INVENTION [0002] The invention relates to systems and methods for inhibition of microbial infection related to surgical implant devices. In particular, the invention relates to systems and methods for inhibition of microbial infection related to orthopedic implants. BACKGROUND OF THE INVENTION [0003] Joint degeneration is the leading chronic condition in the elderly; it affects one in every eight Americans and almost half the population over the age of 65. (Brooks, P. M, Med. J. Aust., 173:307-308, 2000) The most common form of joint degeneration is osteoarthritis. Osteoarthritis weakens and breaks down cartilage and bone, causing pain as bones rub together. Eventually the constant rubbing of the bony surfaces destroys the surfaces that are rubbing agains...

AI Technical Summary

Benefits of technology

[0025] An inventive system may be configured such that the power source is continuously powering a current conducted to the metal component for release of metal ions. Alternatively, a system includes a switch for powering the current on or off. In a further embodiment, the current is modulated by circuitry adapted to control the current so as to increase or decrease the amount of current flowing and the amount of metal ions released. Thus, a resistor in electrical communication with the power source is optionally included. In a preferred embodiment, the resistor and power source are positioned in an internal cavity of the implant body. Optionally, a switch in electrical communication with the power source is included to control the power source. Further optionally, a controller in signal communication with the switch is provided. Such a controller is operated to send a signal to a system component adapted to receive the signal and to control the switch. Preferably, a controller is external to an individual having the implant, such that activation of the switch may be performed by a doctor, technician or by the patient.

[0026] Also described is a method for inhibiting microbial infection associated with an orthopedic implant, which includes providing an inventive system and delivering a current to a metal component disposed on an external surface of an implant body, the implant body located in a human body at a site of potential infection. Delivery of current to the metal component is associated with antimicrobial action such as release of metal ions toxic to an infectious microbe at the site of potential infection, such that microbial infection is inhibited.

Problems solved by technology

Osteoarthritis weakens and breaks down cartilage and bone, causing pain as bones rub together.

Eventually the constant rubbing of the bony surfaces destroys the surfaces that are rubbing against one another leading to rough, painful movement.

However, as the disease progresses the pain intensifies.

Although joint replacement is a relatively large field within orthopedics, the number of fracture fixation devices utilized around the world far outranks the number of artificial joints.

Unfortunately, as the number of implant surgeries increases, the number of associated infections also increases.

Any person who has an implant is at risk for developing an infection associated with the device.

The effects of implant infection are expensive as well as a danger to the health and well-being of the affected individual.

For example, infection results in direct medical and surgical costs and additionally may cause patient pain, suffering, lost wages, lost work and decreased productivity.

Once microorganisms colonize an implant, it is often very difficult to eradicate or even inhibit the infection.

For example, systemic administration of antibiotics is often ineffective due to limited blood supply to the areas of the implant.

Where infection cannot be inhibited it may spread and become even more serious, as in patients who have an infection within the bone, osteomyelitis.

Such patients often must undergo a difficult and costly treatment involving extended hospitalization, joint debridement, aggressive antimicrobial therapy, total joint removal followed by total joint replacement and possible amputation if the infection can not be eliminated.

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