What Is an Infection of Prosthetic Devices?
Implantable and prosthetic devices have grown in use recently due to research and development and better availability. Electronic and mechanical implantation has been used in many specialties successfully.
Types of implants and prosthetics vary in indications and materials used:
- Breast implants and dermal fillers for cosmetic or reconstructive purposes
- Intrathecal (cerebrospinal fluid) shunts and pumps, and epidural neurostimulators
- Cochlear implants
- Artificial joints
- Intraocular lenses
- Mesh used in urogynecology
- Cadaver, animal (porcine, bovine), and human donor tissues
- Arteriovenous shunts for dialysis
- Contraceptive and hormonal subdermal and intrauterine delivery capsules
- Wearable prosthetics (limb-replacement)
Problems associated with implantable devices arise from the following:
- Rejection due to a foreign body response
- Infection introduced by the device or the device acting as a reservoir for infection
- Device failure
The two complications of rejection and infection are often simultaneous, each synergistic with the other. Rejection induces an immune response which attracts transudates (fluid) which can be a nidus of infection. Overt infection can create an exudate (inflammatory fluid such as pus) that can hasten the rejection process. Device failure in an otherwise sterile environment is limited to the cessation of device benefit, which in the case of drug delivery can be important to health.
With wearable devices such as prosthetic limbs, improper fitting or sizing can cause pressure points that are prone to breakdown and subsequent infection.
Infection in Implantables and Prosthetics
Sterile procedure is a methodical process, and infection risks increase with breaks in sterile procedure during the implantation process. Besides the risk of device malfunction in a septic environment, there is the risk of infectious spread to adjacent or target tissues.
For example, an intrathecal pain pump, which is filled via percutaneous injection, communicates with the cerebrospinal fluid and can be a source of bacterial meningitis. Infection of an artificial joint risks further joint damage which can negatively impact the success of future attempts to implant prosthetics. Infected heart valves can seed the entire arterial tree with septic emboli, risking distant organ infection and systemic sepsis.