Hip replacement is a big operation and all major surgery carries risks. Possible complications include:
- blood clots
- wound haematoma (bleeding)
- infection of the joint
- one leg longer than the other
- nerve damage
- ongoing discomfort
It’s very important to seek medical advice straight away if, following surgery, you have pain or swelling in the leg, chest pain or sudden breathlessness.
Some people can develop blood clots in the deep veins of the leg (deep vein thrombosis, or DVT) causing pain and/or swelling in the leg. This is because of changes in the way the blood flows and its ability to clot after surgery. There are various ways to reduce the risk of this happening, including special stockings, pumps to exercise the feet and drugs that are given by injection into the skin such as heparin or fondaparinux.
Rivaroxaban, dabigatran and apixaban tablets have recently become available to help prevent DVT. If your surgeon prescribes these, you’ll need to take them for five weeks after you go home from surgery. The tablets are more convenient than injections, and don’t need monitoring, which make them easier to take at home.
A small minority of blood clots, particularly those in the thigh veins, can detach and travel through the blood vessels to the lungs, where they may become stuck. This can cause sudden breathlessness, chest pain or even collapse. However, it’s usually possible to treat pulmonary embolism with blood-thinning medicines and oxygen therapy.
Sometimes an artificial hip may dislocate. This occurs in less than 1 in 20 cases, and the hip needs to be put back in place under anaesthetic. If the hip keeps dislocating, you may need further surgery or a brace to stabilise it. Even after you’ve started walking without support it’s important to continue with a programme of muscle-strengthening exercise to help stabilise your hip and improve function.
To reduce the risk of infection, special operating theatres that have clean air pumped through them are often used, and you’ll probably be given a short course of antibiotics at the time of the operation. Despite this, a deep infection can occur in about 1 in 100 cases. The infection can be treated but the new hip joint usually has to be removed until the infection clears up. New hip components are then implanted 6–12 weeks later.
Plastic hip sockets may wear over a period of time. The worn particles of plastic may cause inflammation and this can eat away the bone around the new hip. Ceramic-on-ceramic or metal-on-metal joints tend to wear less and are therefore less likely to cause this problem. New, harder-wearing plastics are also being developed.
The most common cause of failure of hip replacements is when the artificial hip loosens. This can happen at any time but is most common after 10–15 years. It usually causes pain, and your hip may become unstable. Loosening is usually linked with thinning of the bone around the implant, which makes the bone more prone to fracture. A fracture around the implant usually needs to be fixed through surgery and/or revision of the implant.
Bleeding and wound haematoma
A wound haematoma is when blood collects in a wound. It’s normal to have a small amount of blood leak from the wound after any surgery. Usually this stops within a couple of days. But occasionally blood may collect under the skin, causing a swelling. This can discharge by itself, causing a larger but temporary leakage from the wound usually a week or so after surgery, or it may require a smaller second operation to remove the blood collection. Drugs like aspirin and antibiotics can increase the risk of haematoma after surgery.