Joint replacement risks

Partial and total joint replacements have some specific risks that patients must be aware of before undergoing surgery.

There is initially a fair amount of pain and swelling following a joint replacement and without hard work and physiotherapy there is a risk of persistent stiffness and pain following the surgery. For this reason it is very important to make the effort with the physiotherapy and work hard in the early post operative period even though it is difficult.

All operations carry a small risk of damage to the structures around the surgical field (nerves, blood vessels, ligaments, tendons and bone) and there is a risk of pain, numbness and disability following injury to these structures. As an artificial joint is held in place by the soft tissues around it and the shape of the joint surfaces there is a risk of dislocation or partial dislocation (subluxation) and this may require further surgery to put right.

As the replacement is not part of your natural body it is unable to fight infection once it has bacteria on it. Therefore an infected joint replacement is bad news and often requires further surgery to either washout the joint if caught early or to redo the replacement. A failed redo operation for infection is the worst possible situation and may ultimately require an amputation.

The risk of infection is countered by several different measures, the preoperative screening you have prior to surgery, the special clean air operating theatre used for orthopaedic surgery, antibiotics are given with the anaesthetic and are embedded in the cement (grout) that is used to fix the replacement in your bones. These measures reduce the risk of an infection to around 0.5%

The other major risk of a joint replacement is that it will wear. This is because the artificial joint does not regrow in the way your hair and fingernails do and so will become worn over time, much like a set of tyres on your car. When it has worn for a long time the knee can become loose or unstable (wobbly) and cause pain and will need to be redone. Modern knee replacements have an excellent track record and we expect 90% to be well functioning at 15 years.