The overall mortality rate with TKA is less than 1%, but this figure increases with age, male sex, and t
he number of preexisting medical conditions. Identification and optimization of such conditions prior
to surgery is important to reduce perioperative complications.
Complications of TKA include the following:
· Thromboembolism: Thromboembolism includes deep vein thrombosis (DVT) with subsequent
life-threatening pulmonary embolism (PE). Predisposing factors for increased risk of DVT include
age older than 40 years, female sex, obesity, varicose veins, smoking, past history of DVT, diabetes
mellitus, and coronary artery disease. Overall incidence of DVT following total knee replacement
without any prophylaxis has been reported at 40-88%. Most of these are calf thromboses. The risk
of fatal PE, however, is the important figure and varies from 0.1-1%.
· Infection: Prevention of infection in TKA begins in the preoperative examination to exclude
intercurrent infection. In the operating room, personnel should be kept to the smallest number,
and traffic in and out of the room should be kept to a minimum. Use of vertical laminar flow in
operating theaters, prophylactic antibiotics, ultraviolet light, body exhaust systems to prevent
bacterial shedding, and meticulous and expeditious surgery all help to reduce the occurrence of
infections to less than 1% of operations performed.
· Patellofemoral complications: Patellofemoral complications include patellofemoral instability
(see the image below), patellar fracture, patellar component failure, patellar clunk syndrome,
and extensor mechanism tendon rupture. All of these complications have been cited as the common
reasons for reoperation. These can be avoided by attention to detail, meticulous technique, and
avoidance of component malposition.
· Aseptic loosening: Loosening leads to the ultimate failure of the prosthesis and occurs in approximately
5-10% of patients at 10-15 years. It may be complicated by bone loss or osteolysis, which can lead
to catastrophic deterioration and make revision surgery difficult. The etiology of this problem is not
entirely understood but is related to polyethylene debris causing cellular alterations that result in bone
resorption. Once a component is loose, it becomes mechanically unstable with worsening osteolysis.
Treatment is revision with bone grafting.