Complications of knee replacement surgery are more common in older patients and those suffering from other illnesses including obesity. These include

Failure of implant which may require repeat surgery. It may occur due to wearing out of the prosthesis or loosening off of the components. Surgeons with experience show a higher success rate compared to those who perform rarer knee replacement surgeries.

Delayed healing of wound

Infection. Patients with rheumatoid arthritis, diabetes, obesity and those taking corticosteroids may be at increased risk of infection

Deep vein thrombosis. Clots may form in the deep veins. These could travel via the blood into the lungs and lead to a life threatening condition called pulmonary embolism. They could also travel to the heart and result in a heart attack. Blood thinners may be administered during surgery to patients who are at a very high risk of suffering from deep vein thrombosis

Pneumonia

Fracture of the knee cap

Instability, stiffness and malalignment of the knee joint

Injury to the nerves or blood vessels

Anemia due to blood loss that may need blood transfusion

Difficulty in squatting or kneeling, numbness near the surgical scar, and mechanical noises from the knee