Implant failure refers to the failure of any

medical implant An implant is a medical device manufactured to replace a missing biological structure, support a damaged biological structure, or enhance an existing biological structure. Medical implants are man-made devices, in contrast to a transplant, whi ...

to meet the claims of its manufacturer or the health care provider involved in its installation. Implant failure can have any number of causes. The rates of failure vary for different implants. The monitoring of the safety of implants is conducted within the context of broader pharmacovigilance.

Common types of failure

Material degradation

Implant failure can occur due to the degradation of the material an implant is made of. With time, mechanical degradation, in the form of

wear Wear is the damaging, gradual removal or deformation of material at solid surfaces. Causes of wear can be mechanical (e.g., erosion) or chemical (e.g., corrosion). The study of wear and related processes is referred to as tribology. Wear in ...

fatigue Fatigue describes a state of tiredness that does not resolve with rest or sleep. In general usage, fatigue is synonymous with extreme tiredness or exhaustion that normally follows prolonged physical or mental activity. When it does not resolve ...

, or electrochemical degradation, in the form of

corrosion Corrosion is a natural process that converts a refined metal into a more chemically stable oxide. It is the gradual deterioration of materials (usually a metal) by chemical or electrochemical reaction with their environment. Corrosion engi ...

, can occur. Biotoxicity, particularly in metal implants, can arise due to ion release.

Bacterial infection

Implants, made of synthetic materials, are naturally coated by a

biofilm A biofilm comprises any syntrophic consortium of microorganisms in which cells stick to each other and often also to a surface. These adherent cells become embedded within a slimy extracellular matrix that is composed of extracellular po ...

by the body, which may function as a favorable medium for bacteria growth. Implant failure due to bacterial infection of the implant can occur at any point of implant lifetime. Bacteria may already reside on the implant or be introduced during the implantation. Typical failure mechanisms include tissue damage and implant detachment due to bacteria generated biofilm.

Hip replacement failure

Hip replacement Hip replacement is a surgical procedure in which the hip joint is replaced by a prosthetic implant, that is, a hip prosthesis. Hip replacement surgery can be performed as a total replacement or a hemi (half) replacement. Such joint replacement o ...

implants can fail. Outcomes are normally recorded in a joint replacement registry to ensure patterns are picked up upon. In 2013

Johnson & Johnson Johnson & Johnson (J&J) is an American multinational corporation founded in 1886 that develops medical devices, pharmaceuticals, and consumer packaged goods. Its common stock is a component of the Dow Jones Industrial Average and the company i ...

shared documents which indicated that 40% of a class of hip replacement implants which it manufactured had failed.

Pacemaker failure

Pacemaker failure is the inability of an implanted artificial pacemaker to perform its intended function of regulating the beating of the heart. It is defined by the requirement of repeat surgical pacemaker-related procedure after the initial implantation. Causes of pacemaker failure included: lead related failure (lead migration, lead fracture, ventricular perforation), unit malfunction (battery failure or component malfunction), problems at the insertion site (infections, tissue breakdown, battery pack migration), and failures related to exposure to high voltage electricity or high intensity microwaves.

Cochlear implant failure

Cochlear implants are used to treat severe to profound hearing loss by electrically stimulating the hearing nerve. Clinical symptoms of cochlear implant failure include auditory symptoms (tinnitus, buzzing, roaring, popping sounds), non-auditory symptoms (pain, shocking sensation, burning sensation, facial stimulation, itching), and decrease in the patient's hearing performance. When such symptoms occur, the patient's clinical team evaluates the patient and the device using in-situ methods, and determines if revision surgery is necessary. The most commonly reported device failures are due to impacts, loss of hermeticity, and electrode lead malfunctions. Most manufacturers provide on their websites the survival rate of their marketed implants, although they are not required to do so. In order to improve and standardize failure reporting practices to the public, the AAMI is developing an American standard for cochlear implants in collaboration with the FDA, major cochlear implant manufacturers, the CALCE center for reliability, doctors, and clinicians.

Dental implant failure

Failure of a dental implant is often related to the failure of the implant to osseointegrate correctly with the bone, or vice versa. A dental implant is considered to be a failure if it is lost, mobile or shows peri-implant (around the implant) bone loss of greater than 1.0 mm in the first year and greater than 0.2 mm a year after. Dental implant failures have been studied. Persons who

smoke Smoke is a suspension of airborne particulates and gases emitted when a material undergoes combustion or pyrolysis, together with the quantity of air that is entrained or otherwise mixed into the mass. It is commonly an unwanted by-produc ...

habitually prior to having dental implants are significantly more likely to have their implants fail. Individuals who have diabetes and those who disregard general oral hygiene are also at higher risk of having their implants fail.

Responses to implant failure

In 2012

Royal College of Surgeons of England The Royal College of Surgeons of England (RCS England) is an independent professional body and registered charity that promotes and advances standards of surgical care for patients, and regulates surgery and dentistry in England and Wales. T ...

and the

British Orthopaedic Association The British Orthopaedic Association is a professional association in Britain for doctors who specialize in orthopaedic surgery. History The British Orthopaedic Association was founded in 1918. One of the founders was Harry Platt, who went on t ...

called for increased regulation of implants to prevent implant failure. A 2011 study by Dr. Diana Zuckerman and Paul Brown of the National Research Center for Women and Families, and Dr. Steven Nissen of the Cleveland Clinic, published in the Archives of Internal Medicine, showed that most medical devices recalled in the last five years for "serious health problems or death" had been previously approved by the FDA using the less stringent, and cheaper, 510(k) process. In a few cases the devices had been deemed so low-risk that they did not need FDA regulation. Of the 113 devices recalled, 35 were for cardiovascular issues. This may lead to a reevaluation of FDA procedures and better oversight.

References

External links

2011 United States government report on implant safetyFailed Implant Device Alliance
a grassroots organization advocating for implant safety Implants (medicine) Medical error Product safety