There are always risks associated with surgery, and you need to be fully aware of those risks before making your decision to proceed with an operation like Knee Replacement

Do not hesitate to ask questions of your surgeon, anaesthetist or of other medical specialists who are managing your health in the lead up to your surgery. If you do not understand what you have been told, do not hesitate to seek clarification from us.

The vast majority of people get through the surgery with no problems at all and will be surprised at how good they feel so soon afterwards. Some will experience minor issues and occasionally there may be more serious complications.

These problems are rare and most can be treated quickly and effectively. Below is a list which covers the major risks and complications you may face. Additionally, there may be other risks, particularly if you have a complex medical history or particular conditions which need to be managed by a medical specialist.

Risks associated with Knee Replacement Surgery


Superficial infection of the wound soon after surgery can occur and it is usually treated quickly and successfully with a week of antibiotics. If you are concerned about your wound or the possibility of infection in your joint then contact our rooms for advice. If you cannot reach us out-of-hours, you can contact the Mater Hospital or your GP for immediate attention. Remember, it is best not to touch your wound unnecessarily, as this is a likely way to introduce organisms to the wound.

Deep infection (infection of the prosthesis) is one of the complications of joint replacement surgery. It is very uncommon, but it can happen and patients should be aware that this is a risk of surgery. Infection can occur when you are in hospital, or when you are at home and usually appears as pain, swelling, redness and warmth of the joint. This may be accompanied by fever and sweats. Acute deep infection may require surgical wash-out and chronic deep infection may require removal or revision of the joint. If you are concerned about the possibility of deep infection, seek immediate medical advice.

Other infections in the body unrelated to the wound or replaced. Other infections in the body (mouth, superficial cuts on the skin etc) which are not related to your joint replacement surgery, should be treated immediately by your general practitioner, because it is possible for infection to spread from another part of the body to the joint replacement.

Remember to tell your dentist. If you are having extensive dental work such as root canal therapy or treatment for a tooth abscess, you should ensure your dentist knows you have a knee replacement and provides you with appropriate antibiotics if needed.  Arthroplasty Society of Australia has prepared a document specifically for dentists

Loosening of implant

Loosening is a very rare complication with the modern cement-free implants we use. It is usually detected on follow-up X-rays and can be fixed with further surgery.

Impaired nerve function

On very rare occasions, nerves in the vicinity of the joint replacement can be stretched or injured during the operation causing paralysis (footdrop) and/or numbness of the leg. With time, these nerves usually begin to function again. In rare instances, there can be a permanent deficit.

Deep vein thrombosis (DVT) and pulmonary embolism (PE).

With any surgery there is a risk of developing blood clots. This risk is increased in people who undergo joint replacement surgery. Numerous steps are taken to prevent patients from developing clots but some patients still get them. Early mobilisation is the best way to prevent clots.

If you are at particular risk of DVT you will be instructed to wear TED (thromboembolic) stockings. TED stockings help reduce the incidence of blood clots. You may also receive blood-thinning medication and wear calf compression devices post operatively to help prevent blood clots from forming. DVT is usually treated with extended use of blood thinning medications.

Prior to your discharge from hospital an ultrasound may be done on both lower legs to determine if a clot is present. If a blood clot is found, it will be treated. A pulmonary embolism may occur if the clot detaches from the veins in the legs and travels to the lungs.

This form of clot requires more extensive treatment. Pulmonary embolism can cause breathing difficulties and is rarely fatal. Blood clots in the legs are common occurring in around 15% of patients but pulmonary embolism is unlikely (around 1%) and fatal pulmonary embolism is extremely rare.

Stroke/Heart attack/Pneumonia resulting in death

Stroke, heart attack and pneumonia resulting in death, can occur following any anaesthesia and surgery. Fortunately they are extremely rare.