What kind of complications may occur?

All operations involves an inherent risk – complications can also occur with knee prosthesis operations. The advantages offered, however, are usually argument enough for this surgical intervention: patients normally regain significant quality of life.

Injury to bones

In isolated cases the femur or tibia may be injured during the operation. Depending on the bone structure and the care taken by the surgeon, hairline cracks or indeed larger bone fractures may appear in the bones. These may require further surgery to be stabilised, in such cases this extends the postoperative treatment time.

Postoperative bleeding and effusions of blood

Directly after the operation, bleeding or effusions of blood may rarely occur in the wound region. For this reason, small tubes, so-called Redon drains, are placed in the wound which allow the secretions and blood to drain away. These can be removed two to three days after the operation.

Thromboses and embolisms

Thrombosis refers to the formation of a blood clot in a blood vessel. As a consequence, small components can become released and block the blood vessels in the lungs (embolism). In the case of surgical interventions, the risk of thrombosis is primarily increased by confinement to the bed. Thus measures to prevent thromboses are taken, these include anti-thrombosis injections and compression stockings.

Wound-healing impairment

In addition to the incision in the skin, the subcutaneous tissue structures also have to heal. In such cases, so-called wound-healing impairment may be experienced whereby the wound takes longer to close, and this is associated with intense pain and inflammation.

Infection

There is an increased risk of infection during and after surgery. For this reason, nowadays bone cement which includes an antibiotic is used for the majority of knee prosthesis operations. This reduces the risk of infection with the endoprosthesis.

Question: Can other infections in the body affect the endoprosthesis?: Bacterial infections can spread via the bloodstream and in this way also reach the artificial joint where they may cause an inflammation. All wearers of prostheses face a higher risk of a prosthesis infection as a result of minor infections of the bladder, tooth roots and sinuses, etc. At the first sign of an infection, patients are advised to consult their family doctor; in the majority of such cases antibiotics are required to prevent the bacteria from spreading.

Premature loosening of the prosthesis

Infections or mechanical problems may cause the prosthesis to become loose in the bone just a few weeks or months after the knee prosthesis operation. This manifests itself in pain and restricted mobility and, in part, signs of inflammation such as fever and listlessness.

Antibiotics can be used to fight the infection but in the majority of cases the damaged knee endoprosthesis must be replaced with a new one in a second operation.

Intra-articular adhesions

As is the case after all open surgery on the knee joint, joint cartilage adhesions can also occur after a knee prosthesis operation. This causes pain and reduced mobility – precisely the complaints which one hoped to remedy with the knee joint replacement. Adhesions occur if early postoperative mobilisation is not started soon enough. As a precautionary measure the physiotherapy exercises therefore start one day after the operation.

Question: How long can a knee endoprosthesis remain in the body?: The life of any knee endoprosthesis is limited at present – as a rule it lasts about 10 to 15 years. Ultimately, its fixation becomes loose and the prosthesis then causes problems such as pain and restricted mobility. A second operation in which the old worn prosthesis is replaced with a new one is then performed.