Complications from total knee replacement include implant failure, loss of motion in the knee, nerve damage, arterial injuries, wound complications, allergic reaction to metal parts, and blood clots. The most dangerous potential complication is clotting, according to Healthline.
Blood clotting is a risk with any type of surgery; as the body tries to close the wound after the procedure, it starts the clotting process. Normally, this just leads to a scab over the wound to protect it while it is healing. When the body produces too much clotting material, though, it can form a clot inside the bloodstream. If this happens with a knee replacement, it occurs within a couple of weeks of the surgery in most cases, notes Healthline.
Infection is a possible complication because of the exposure of knee joints to the open air. However, hospitals generally filter air into surgical rooms to limit particles, and surgeons and medical staff go through an extensive cleansing process to meet standards for sterility. Doctors also frequently prescribe antibiotics before, during and after the surgery to stave off infection, as stated by Healthline.
Knee replacement components are usually made of cobalt-chromium alloy or titanium, and patients occasionally experience allergic reactions. In other cases, wounds heal slowly as a result of bleeding complications, particularly for people on blood thinners. Scar tissue and other complications can limit range of motion, requiring physical therapy and/or special exercises. Severe stiffness may require an extra procedure to adjust the prosthesis or break up scar tissue, states Healthline.