As with any surgical procedure, complications can occur. Prosthetic joints can become infected. However, with the use of special operating rooms, antibiotics and improved surgical techniques, the risk of infection should be less than one percent. Blood loss from the surgery can sometimes necessitate a blood transfusion. The risk of needing a transfusion is small for otherwise healthy individuals undergoing single joint replacement. However, the risk is increased in elderly patients, patients with anemia and in patients having revision or bilateral joint replacement procedures.
Blood clots can form in the leg veins after hip or knee replacement. With the use of blood thinning medication after surgery, the risk of this complication can be lowered and should be around one percent.
Patients undergoing hip replacement surgery are at risk of dislocating their hip afterwards. The greatest risk of this is in the first six weeks after surgery and should be less than one percent. This risk has been reduced significantly with newer surgical techniques and the use of larger femoral ball sizes. In addition, patients are given precautions to observe for six weeks after surgery, and are instructed in proper hip positioning afterward.
Because of the location of the nerves and blood vessels in the leg, there is a small risk of injuring one of these structures during hip or knee replacement. The most common nerve injury involves the sciatic nerve during total hip replacement. Injury to this nerve can lead to temporary or permanent loss of sensation in parts of the leg, or a “foot drop” or inability to raise the foot at the ankle. This complication occurs in about 0.1 percent of the cases.
Late complications can include wearing out the polyethylene bearing or loosening of the prosthesis from the bone. This may cause pain in the joint similar to arthritis pain. Either of these problems can be repaired by a secondary or revision joint replacement. In this situation, the surgeon may replace part or all of the artificial components, again with significant improvement in pain and function.