Every prosthesis replacing a joint is subjected to mechanical stress that gradually causes wear of the materials from which it is made. Total hip replacements are no exception.
WHY DOES A HIP REPLACEMENT HAVE A LIMITED LIFESPAN?
A hip replacement is composed of two types of materials:
A metal alloy fixed to the bony surfaces of the pelvis (acetabular cup) and the femur (femoral stem). These components are generally made from titanium or cobalt-chromium alloy. These elements do not wear out.
A polyethylene or ceramic bearing surface, which forms the interface between the two metal components and acts as an “artificial cartilage”. With every step, this component is subjected to friction and the body’s weight, resulting in gradual wear over time.
HIP REPLACEMENT: AN ESTIMATED LIFESPAN OF 25 YEARS
Significant advances have been made in the materials used for hip replacements, considerably increasing their longevity.
A recent study compiled data from clinical studies and national joint replacement registries. It is now estimated that 90% of hip replacements remain functional after 25 years.
This lifespan varies depending on the type of prosthesis used and on patient-specific risk factors.
WHICH FACTORS CAN AFFECT THE LIFESPAN OF A HIP REPLACEMENT?
The lifespan of a hip replacement depends on the mechanical stresses to which it is subjected. Two main factors may reduce its longevity:
- Excess body weight (BMI >35);
- Excessive levels of physical activity;
- Participation in high-impact sports such as running, football, squash, martial arts or rugby.
In these situations, premature wear of the prosthesis may occur.
HOW CAN YOU TAKE CARE OF YOUR HIP REPLACEMENT?
Avoid excess body weight: Maintaining a healthy weight reduces the pressure exerted on the hip replacement, thereby lowering the risk of premature wear.
Adapt your physical activities: Swimming, cycling and walking are recommended to strengthen the hip without placing excessive stress on the prosthesis.
Avoid high-impact activities: Sports such as running, rugby, martial arts and football should be avoided or practised at a low intensity, as they place considerable stress on the prosthesis and may lead to premature wear.