The main reason for prosthesis replacement surgery is pain. Pain indicates that the prosthesis is not functioning properly. The most frequent cause of prosthesis replacement is aseptic loosening.
The duration of a prosthesis depends on many factors and not only depends on the type of implant, but also on the position of the components and the surgical technique.
Pain is almost always the symptom that justifies replacement. There is only one exception, those cases of patients without symptomatology in which a wear in the prosthesis is detected during radiographic controls.
In this situation the symptomatology, however slight, should be evaluated, the controls repeated and the risks and benefits of a revision theoretically simple but not free of complications should be discussed.
Generally, in the presence of a painful prosthesis, the possibility of an infection must be ruled out, which sometimes may not give the typical symptoms. For this, the patient’s clinical history is fundamental.
Causes of prosthesis replacement
It is very important to know what is the cause that raises to carry out a prosthesis replacement surgery; since, for example, in the case of hip prosthesis replacement, the risk of suffering a dislocation increases.
The most frequent cause of prosthesis replacement is aseptic loosening. The wear of the components of the prosthesis generates particles and an inflammatory reaction of our organism against these particles that does not distinguish our own bone, affecting it and causing loosening and bone loss. In this situation, prosthesis replacement is performed in a single surgery. Generally, more complex implants are required.
The wear of the prosthesis will depend on the quality of the friction surfaces and the friction pair, the orientation or position of the components in the first surgery; but there is an individual variation of the reaction of the organism to wear.
The friction pairs with less wear are hard pairs: ceramic/ceramic and metal/metal (the latter pair is less used due to other problems) and non-hard pairs, which are more frequent, ceramic/polyethylene and metal/polyethylene. Currently, with the latest generation of polyethylenes, wear is expected to be lower.
On the other hand, if the cause of the prosthesis replacement is an infection, the most frequent is to perform this replacement surgery in two surgeries. One surgery to remove the implants, after which a treatment with antibiotics should be done. Subsequently, the second surgery is performed in which another new prosthesis is implanted. Currently, in certain situations, replacement can be performed in surgery, although it is not the most common.