Perioperative Management in Total Knee Arthroplasty
Perioperative Management in Total Knee Arthroplasty
TKA increases the probability of a venous thromboembolic event. The surgical insult, application of a tourniquet, and postoperative immobility contribute to Virchow's triad (venous stasis, endothelial damage, and hypercoagulability), increasing the risk for a venous thromboembolic event after TKA. The deep venous thrombosis rate after TKA is as high as 88% in untreated patients with I-labeled fibrinogen leg scanning. The incidence of distal deep venous thrombosis with routine screening in treated patients ranges from 7–28%. The sequelae of a deep venous thrombosis after TKA are significant, including proximal propagation of a distal thrombus, postthrombotic syndrome, pulmonary embolism, and increased use of healthcare resources. Thromboprophylaxis is the standard of care after TKA as recommended by the guidelines of the American Academy of Orthopaedic Surgeons and American College of Chest Physicians. A multimodal risk stratified approach to thromboprophylaxis reduces the incidence of symptomatic deep venous thrombosis to approximately 0.5% and symptomatic pulmonary embolism to approximately 0.25%. Routine screening for deep venous thrombosis is not advised in asymptomatic patients.
Early mobilization, periodic dorsiflexion and plantarflexion, and mechanical compressive devices are the mainstay of mechanical thromboprophylaxis after TKA. Mechanical compression prevents venous stasis and has a fibrinolytic effect. A metaanalysis found that the incidence of asymptomatic deep vein thrombosis (DVT) with routine screening was lowest with mechanical compression alone (17%), compared with warfarin alone (45%), aspirin alone (53%), and low molecular weight heparin alone (29%). Mechanical compression also is low cost and has no increased bleeding risk. Recently, portable mechanical compression devices have become available. Adding mechanical compression to a pharmacologic regimen further decreases the rate of asymptomatic DVT up to 15%.
Mechanical thromboprophylaxis is standard among arthroplasty surgeons, but the choice and duration of chemoprophylaxis remains widely variable. For decades, warfarin and low molecular weight heparin were the standard of practice because most surgeons believe that thromboembolic events occurred via an erythrocyte and coagulant protein based mechanism. However, numerous studies show no significant increase in venous thromboembolic events with the use of antiplatelet medications. Therefore, a risk stratification approach is commonly used, with routine TKA patients receiving aspirin for chemoprophylaxis. Patients at higher risk of venous thromboembolic event (Table 2) are placed on anticoagulant therapy for 3–6 wk postoperatively. However, there was no significant difference in the incidence of venous thromboembolic events in low and high-risk populations using a risk stratification approach.
No studies definitively outline the appropriate duration of thromboprophylaxis after TKA. There is strong evidence that prophylaxis beyond hospital discharge reduces the number of symptomatic deep venous thrombosis. The global arthroplasty registry (GLORY) estimates the mean time to a venous thromboembolic event after TKA was 10 days and 57% of symptomatic deep venous thrombi occurred after hospital discharge. Studies have shown that thromboprophylaxis for 4–6 wk postoperatively can reduce thromboembolic events up to 50% compared with a shorter course of thromboprophylaxis for 10–15 days. Currently, the American Academy of Orthopaedic Surgeons and American College of Chest Physicians guidelines recommend aspirin for 4–6 wk, warfarin for 4–6 wk, or a combination of low molecular weight heparin or a Factor Xa inhibitor for 7–10 days followed by aspirin for a total of 4–6 wk.
Thromboprophylaxis
TKA increases the probability of a venous thromboembolic event. The surgical insult, application of a tourniquet, and postoperative immobility contribute to Virchow's triad (venous stasis, endothelial damage, and hypercoagulability), increasing the risk for a venous thromboembolic event after TKA. The deep venous thrombosis rate after TKA is as high as 88% in untreated patients with I-labeled fibrinogen leg scanning. The incidence of distal deep venous thrombosis with routine screening in treated patients ranges from 7–28%. The sequelae of a deep venous thrombosis after TKA are significant, including proximal propagation of a distal thrombus, postthrombotic syndrome, pulmonary embolism, and increased use of healthcare resources. Thromboprophylaxis is the standard of care after TKA as recommended by the guidelines of the American Academy of Orthopaedic Surgeons and American College of Chest Physicians. A multimodal risk stratified approach to thromboprophylaxis reduces the incidence of symptomatic deep venous thrombosis to approximately 0.5% and symptomatic pulmonary embolism to approximately 0.25%. Routine screening for deep venous thrombosis is not advised in asymptomatic patients.
Early mobilization, periodic dorsiflexion and plantarflexion, and mechanical compressive devices are the mainstay of mechanical thromboprophylaxis after TKA. Mechanical compression prevents venous stasis and has a fibrinolytic effect. A metaanalysis found that the incidence of asymptomatic deep vein thrombosis (DVT) with routine screening was lowest with mechanical compression alone (17%), compared with warfarin alone (45%), aspirin alone (53%), and low molecular weight heparin alone (29%). Mechanical compression also is low cost and has no increased bleeding risk. Recently, portable mechanical compression devices have become available. Adding mechanical compression to a pharmacologic regimen further decreases the rate of asymptomatic DVT up to 15%.
Mechanical thromboprophylaxis is standard among arthroplasty surgeons, but the choice and duration of chemoprophylaxis remains widely variable. For decades, warfarin and low molecular weight heparin were the standard of practice because most surgeons believe that thromboembolic events occurred via an erythrocyte and coagulant protein based mechanism. However, numerous studies show no significant increase in venous thromboembolic events with the use of antiplatelet medications. Therefore, a risk stratification approach is commonly used, with routine TKA patients receiving aspirin for chemoprophylaxis. Patients at higher risk of venous thromboembolic event (Table 2) are placed on anticoagulant therapy for 3–6 wk postoperatively. However, there was no significant difference in the incidence of venous thromboembolic events in low and high-risk populations using a risk stratification approach.
No studies definitively outline the appropriate duration of thromboprophylaxis after TKA. There is strong evidence that prophylaxis beyond hospital discharge reduces the number of symptomatic deep venous thrombosis. The global arthroplasty registry (GLORY) estimates the mean time to a venous thromboembolic event after TKA was 10 days and 57% of symptomatic deep venous thrombi occurred after hospital discharge. Studies have shown that thromboprophylaxis for 4–6 wk postoperatively can reduce thromboembolic events up to 50% compared with a shorter course of thromboprophylaxis for 10–15 days. Currently, the American Academy of Orthopaedic Surgeons and American College of Chest Physicians guidelines recommend aspirin for 4–6 wk, warfarin for 4–6 wk, or a combination of low molecular weight heparin or a Factor Xa inhibitor for 7–10 days followed by aspirin for a total of 4–6 wk.
