[Risk profiling of postoperative complications in 17,644 total knee replacements]

Postoperative complications following primary total knee replacement performed between 2000 and 2002 were assessed to determine perioperative patient- and procedure-related risks associated with the procedure.

For this analysis, the data collected during postoperative hospitalization for 17,644 total knee arthroplasties were assessed. The analysis included two steps. First, using logistic regression, we identified and quantified significant risk factors for the occurrence of general postoperative complications. Second, univariate analysis was utilized to qualitatively and quantitatively analyze the influence of these significant risk factors on the occurrence of major complications (hematoma, cardiovascular complication, deep venous thrombosis, pulmonary embolism, joint infection, and pneumonia).

General postoperative complications were reported in 11.3%. Major postoperative complications occurred in 7.2% with hematoma in 2.9%, cardiovascular complications in 1.8%, deep venous thrombosis in 1.2%, pulmonary embolism in 0.2%, joint infection in 0.8%, and pneumonia in 0.3%. Patient-related risk factors such as age, surgery time, gender, high ASA classification as well as procedure-related risk factors such as allogeneic blood transfusions and lateral release significantly increased the rate of postoperative complications. Males were more prone to hematoma, joint infection, and pneumonia in the immediate postoperative course than females, who were more in danger of developing deep venous thrombosis. Allogeneic blood transfusions increased the risk for postoperative hematoma, infection, and cardiovascular complication. Regional anesthesia was shown to decrease the risk for the occurrence of postoperative deep venous thrombosis and pulmonary embolism.

Postoperative complications in total knee replacement are increased in males and elder patients. Increased time of surgery and allogeneic blood transfusions also represent important risk factors for postoperative complications following primary total knee replacement.