The doctor has determined that the best option for my problem is the implantation of a hip prosthesis but, what types of prosthesis are there? In which cases are each of them indicated? How is it fixed to the bone? All these are common questions that are often asked by patients, in this post we will answer them.
What kind of hip prosthesis will implant me?
The prosthesis to be used depends on multiple factors, the most decisive being the type of pathology (fracture or joint wear), the patient's age or the quality of their bones. The existence of previous surgeries is also determinant, as is the experience and personal preferences of the surgeon who operates.
What types of hip prostheses exist in the market?
What is the hip and when do I need a prosthesis? We have defined the hip as the joint between the upper part of the femur and the acetabulum of the pelvis. The prostheses are used to return the function and restore the function of the area and therefore have different components. Hip prostheses are classified according to how the affected bones are replaced.
Hip prosthesis: types
Total hip prosthesis: Composed by a stem that joins the prosthesis to the femur; a cup that fixes it to the pelvis and two components that articulate each other: the femoral head and the acetabular insert. Total hip prostheses are usually used by orthopedics surgery hospitals in cases of osteoarthritis or joint wear.
Partial hip prosthesis: Like the total prosthesis, it is fixed to the femur using a shank, but the femoral head (larger than in the case of total prostheses) articulates directly against the pelvis. This is because it is used in the treatment of fractures of the femur and it is assumed that the acetabulum may not be worn out. Also, fractures tend to occur in patients who walk a little and not using acetabulum makes the surgery somewhat less aggressive.
The prosthesis of revision: It can be total or partial. They are prostheses that are used to replace an existing one, and that presents a problem. They are usually larger and can have modular components to fit anatomy that is no longer the patient's original.
Resurfacing prosthesis (or resurfacing): They are a kind of metal cap that sits on the femoral head and articulates against a metal cup also. They were designed thinking of young patients with good bone quality and who, due to their life expectancy, could have to face one or several surgeries of revision of the prosthesis. However, some models have presented problems of durability, and today it is more common to use total prostheses with shorter shanks than conventional ones.
How is the prosthesis fixed to the bone?
In the previous point, we saw that the hip prosthesis have elements that hold it to the bone (stem and cup) and others that allow joint movement (femoral head and acetabular insert).
There are two ways to anchor the prosthesis to the bone:
Cemented fixation: Bone cement is used around the prosthesis that, when set, holds the implant to the bone. Knee replacement surgery in India has the advantage of providing immediate support that allows the patient to be mobilized as soon as the patient can tolerate it, regardless of their bone quality. In return, the cement may degenerate over time. It is usually used in patients with severe osteoporosis, and its use in the treatment of fractures is every day.
Fixation not cemented: The surfaces of the prosthesis are covered with porous materials that mimic the texture of the bone and allow it to intermix with the coating, thus fixing the implant. It has the advantage of being a more natural fixation than that provided by cement, but its success depends on the patient's previous conditions. It is usually used in patients with relatively good bone quality.