Loosening of a hip prosthesis
In surgical orthopedics, the implantation of hip prostheses is one of the most successful and complication-free procedures. In more than 90% of the cases there are no late complications such as prosthesis loosening. Although rare, this serious complication can occur in less than 10% of cases.
The cause of material loosening may be, on the one hand, changes in the connection between bone and prosthesis or between bone and bone cement, but on the other hand it may also be caused by tiny particles which are caused by material abrasion and which, over time, are deposited in the surrounding tissue between bone and prosthesis and may lead to irritation and inflammatory processes. This in turn leads to tissue changes and bone defects, which cause the prosthesis to loosen. This is usually manifested by pulling pain in the groin, buttocks or thigh, which increases over time, initially depending on the load, but later can also turn into pain at rest and can even lead to inability to walk.
If the prosthesis has become loose, which has been confirmed by adequate imaging (e.g. an x-ray), a new operation to change the prosthesis (replacement operation) is indicated. If the prosthesis head slips out of the prosthesis socket after a successful implantation operation, this is also referred to as a dislocated artificial hip joint or a so-called hip prosthesis luxation. It is one of the possible risks after hip surgery, since an artificial joint is generally less stable and resilient than the body’s own.
There is an increased risk of dislocation, especially in the first 3 months after the operation, mainly due to excessive, incorrect movements in the hip joint, muscular insufficiencies, hyperlaxicity of the joint or incorrect positioning of the prosthesis components. If a dislocation has occurred, the artificial joint must be put back into place under short anaesthesia. The complication rate for a luxation is around 17-18%, so that 11-24% of all revision operations are performed as a result.
