How is the Hip Prosthesis Fixated?
An artificial hip joint can be fixated to the bone in a number of different ways. In essence, there are two main types of fixation – with bone cement or without bone cement:
The correct choice therefore not only depends on the patient’s age but also on the nature of the bone. The surgeon decides upon the appropriate method together with the patient during the preoperative discussion.
With this method, the artificial acetabular cup and the prosthesis stem are bonded to the bone using bone cement.
For older patients, in particular, the use of bone cement for securing hip replacements is often advisable. The slow bony ingrowth process of the artificial hip joint is avoided and the patient is able to load the leg again soon after the operation.
Furthermore, major studies have shown that cemented hip replacement is particularly durable. This may prevent the necessity of a second operation to change the prosthesis, or at the least postpone it.
As opposed to cemented techniques, here the prosthesis components are wedged or, in part, screwed into the bone.
To this end, the surgeon has to fit the artificial acetabular cup and the prosthesis stem into bone accurately. Consequently, the metal surfaces of the prosthesis components are in direct contact with the bone.
The latter slowly grows into the prosthesis to form a secure attachment for the artificial hip joint.
Hybrid prostheses combine both cemented and cementless fixation methods; the acetabular cup is placed without cement whilst the prosthesis stem is cemented.