Risks after total hip and knee replacement
The complication rate following total joint replacement is low. Serious complications, such as a knee joint infection, occur in fewer than 2% of patients. While the need for reoperation is uncommon, there is increased risk for complication and reoperation for certain patients, notably in patients age 55 and younger, for patients with certain medical conditions, and for patients who have had prior surgery on their joint.
Major medical complications such as heart attack or stroke occur even less frequently. Chronic illnesses, prior surgery, and other patient factors may increase the potential for complications. Although uncommon, when these complications occur, they can prolong or limit full recovery, and may require further surgery.
Discuss your concerns thoroughly with your orthopaedic surgeon prior to surgery. While this does not list all possible complications, these are some of the more common ones.
Infection. Infection may occur in the wound or deep around the prosthesis. It may happen within days or weeks of your surgery. 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. Severe infections may have devastating consequences, such as need for amputation or joint fusion.
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. Your orthopaedic surgeon will outline a prevention program, which may include periodic elevation of your legs, lower leg exercises to increase circulation, support stockings, and medication to thin your blood.
Implant problems. Although implant designs and materials, as well as surgical techniques, continue to advance, implant surfaces may wear down and the components may loosen. If the implants become loose from the bone, revision (redo) surgery may be required. Implants can catastrophically fail if too much force is applied. They can also wear out over time. Rate of wear depends on patient factors and how the joint is used over time.
Stiffness and Laxity. Normally, postoperative range of motion depends on preoperative motion, but most patients can achieve good functional range after surgery and recovery.
For knees: Scar tissue formation around the knee can occasionally occur, and motion may be more limited, particularly in patients with limited motion before surgery. Some patients may require additional surgery to manipulate or change the size of the bearing surface in the knee if stiffness does not improve with physical therapy. Other patients may have a tendency towards the knee becoming more flexible and loose as recovery progresses. If the soft tissues around the new knee stretch out to the point where the knee becomes less stable, further surgery may be recommended to adjust the size of the polyethylene bearing surface.
For hips: Stiffness after total hip replacement may occur if the soft tissues form scar or become calcified. Laxity around the hip may occur and the hip may become unstable and dislocate. Modern navigation techniques have been shown to improve hip stability. However, there is still risk. Recurrent instability may require additional surgery. Some patients are at higher risk for postoperative instability.
Continued pain. A small number of patients continue to have pain after a joint replacement. Sometimes the source of pain can be determined and addressed. Pain in other parts of the body are very common for many months as patients recover from joint replacement. Many patients describe ankle pain, low back pain, or other pains as the body adjusts to new alignment and different gait patterns. Most of this is completely normal. Please ask your surgeon if there are questions or concerns.
Leg length difference. When deformity is corrected during joint replacement, the alignment and length of the leg may change. Modern joint replacement techniques have improved matching of leg lengths, particularly for total hip replacements. However, it is very common for the operated leg to "feel long" for months after surgery until the body adjusts to new alignment. Please discuss this with your doctor if there are concerns.
Neurovascular injury. While rare, injury to the nerves or blood vessels around the hip or knee can occur during surgery. Certain deformities increase this risk. Patients who have existing nerve pain or nerve problems may be at increased risk for nerve complications. These problems may require use of a brace, or may require further surgery.
