Joint replacement surgery or arthroplasty is a procedure in which a joint surface that is an arthritic or dysfunctional is replaced with an artificial joint known as a prosthesis. Joint replacement is considered as a treatment when severe joint pain or dysfunction is not alleviated by non-operative management.
It is most commonly performed for a joint that is worn by a degenerative condition such as osteoarthritis or an inflammatory joint condition such as rheumatoid arthritis. However, it may also be used to replaced fractured joints or congenitally deformed joints.
Essentially, the native joint is removed and surgically replaced by an artificial one made of various materials including stainless steel, titanium or pyrocarbon. Plastic or ceramic are used in the actual weight-bearing areas of the artificial joint.
It is now also possible to replace only part of a joint, for example, unicondylar knee replacement (half a knee replacement) and also to perform these procedures less invasively. The artificial components are attached to the bones using a special cement grout or they may be uncemented where the surface of the components encourages bone growth to help integrate the replacement.
Most joints in the body may be replaced including the small joints of the hand to the largest joint in the body – the knee. The most commonly replaced joints are the hip, knee and shoulder in that order. In Malta, around 1,500 joint replacements are carried out yearly.
Most people can expect their joint replacement to last for many years, providing them with an improved quality of life that includes less pain
The aim of the surgery is to allow the patient to carry out his/her daily activities more easily. Most people can expect their joint replacement to last for many years, providing them with an improved quality of life that includes less pain, along with improved motion and strength that would not have been possible otherwise.
Joint-replacement surgery is considered to be major procedure with potential risks and complications including infection, stiffness, dislocation and loosening. In knee and hip replacements, deep vein clots as well as heart and lung problems may also occur. Steps are taken before, during and after the joint-replacement operation to mitigate these risks.
Post-operative rehabilitation typically takes several weeks and involves intensive physiotherapy to strengthen the muscles around the prosthesis, decrease the stiffness and allow mobilisation.
As these joint replacements are artificial, they wear away and disintegrate with use and time. On average, prostheses last around 15 years although recent developments and improvement in technology have increased their lifespan.
In patients who do physical or manual work, the rate of disintegration is quicker, so replacements are not recommended in young patients.
The success rates for these operations also vary with the size of the joint replacement. Smaller replacements, for example of the hand or foot, tend to have less success rates (around 70 per cent) manifesting more problems such as loosening, wear and dislocation. The larger the joint replacement, the higher the success rate. In fact, hip and knee replacements have a 90-99 per cent success rate.
Joint-replacement surgery has revolutionised the treatment of debilitating painful joints and has significantly improved the quality of life of patients by decreasing pain levels and improving function.
Alistair Pace is a consultant orthopaedic surgeon who works at St Thomas Hospital in Qormi, St James Hospital in Sliema and Da Vinci Hospital in Birkirkara.