Knee Replacement: Complications


The complication rate following total knee replacement is low. Serious complications, such as a knee joint infection, occur in fewer than 1-2% of patients. At Mount Auburn Hospital and New England Baptist, our rates are <1%. Major medical complications such as heart attack or stroke occur even less frequently. Chronic illnesses may increase the potential for complications. Although uncommon, when these complications occur, they can prolong or limit full recovery.

Factors known to increase surgical risks include diabetes, obesity, peripheral vascular disease, prior joint infections, and major depression or mental health concerns. Please talk with your surgeon if you have concerns about your risk for surgery.

Complications associated with Knee Replacement procedures include:

Infection. Infection may occur in the wound or deep around the prosthesis. It may happen while in the hospital or after you go home. It may even occur years later. Minor infections in the wound area are generally treated with antibiotics. Major or deep infections may require more surgery and removal of the prosthesis. Any infection in your body can spread to your joint replacement.

Blood clots. Blood clots in the leg veins are one of the most common complications of knee replacement surgery. These clots can be life-threatening if they break free and travel to your lungs. The best way to minimize your risk is to move and walk. While in the hospital, you will receive sequential compression devices (SCDs) and you may even go home with a portable pair. You will also receive medications to thin the blood. We typically use either Aspirin, Eliquis, Arixtra, Lovenox, or Coumadin. If you have any personal or family history of bleeding or clotting disorders, please alert your surgeon.

Implant problems. Although implant designs and materials, as well as surgical techniques, continue to advance, implant surfaces wear with time and the components may loosen. Additionally, although an average of 115° of motion is generally anticipated after surgery, scarring of the knee can occasionally occur, and motion may be more limited, particularly in patients with limited motion before surgery.

Instability. Knee replacement is really a recapping of the bones with careful attention and care for the soft tissues. In time, ligaments may stretch and cause the knee to feel “loose”. This often occurs in patients who have large weight shifts.

Continued pain. A small number of patients continue to have pain after a knee replacement. This complication is rare, however, and the vast majority of patients experience excellent pain relief following knee replacement.

Neurovascular injury. While rare, injury to the nerves or blood vessels around the knee can occur during surgery.