Failure of implants is often very complicated. The fracture of an implant however is probably the easiest form of case in which to recover compensation. A fractured hip is caused by a deficient or defective prosthesis.
Fractures of standard orthopaedic implants are rare and should not happen.
Fractured stems are difficult to revise. These are less successful than primary hip replacements. Implant fractures still account for about 1% of all revision operations. Many fatigue fractures occur late after implantation of the device. When a crack in a structure reaches a certain size, the stress in the rest of the structure causes the implant to fail. This is known as fatigue failure. A fatigue failure can be diagnosed from an examination of the fractured surface.
The main failure of hip joint replacements is the loosening of the implant. This can cause aseptic osteolysis. This is release of debris from the polyethylene acetabular components. This causes inflammation and bone loss leading to loosening. This is more subtle and complicated than a catastrophic fracture. Most patients feel that their hip is prematurely painful and loose.
On the 26th September 2001, De Puy International Limited sent a list of Hylamer implant components to hospitals and clinics in the UK. The hospitals were advised not to implant any of the listed components and to identify all patients implanted with them. These patients were x-rayed and their progress was monitored. The surgeons looked for evidence of accelerated wear, progressive osteolysis or fractures of the component. They were told to inform the medical devices agency of any cases that had been revised or were awaiting revision with the reasons for the revision requested.
