Risk Factors for Venous Thromboembolism Following Total Knee Arthroplasty: An Analysis of 3,052 Pulmonary Emboli

Identifying risk factors for pulmonary embolism (PE) and deep vein thrombosis (DVT) following primary total knee arthroplasty (TKA) may improve risk stratification and guide surgeons in prophylaxis selection. This study aimed to identify factors associated with postoperative venous thromboembolism (VTE) following TKA.

A national healthcare database was queried for adults who underwent primary, elective TKA from January 1, 2015 to December 31, 2020. Patients who developed PE or DVT within 90 days postoperatively were compared with patients who did not. Demographics, comorbidities, hospital factors, perioperative medications, and blood transfusion needs were assessed. A multivariate model was used to identify independent risk factors for VTE. Overall, 847,496 patients were identified, of whom 8,002 (0.94%) developed a VTE postoperatively (3,052 PE, 5,294 DVT).

After controlling for confounders, an elevated risk of VTE was associated with increased age (adjusted odds ratio [aOR]: 1.01, 95% confidence interval [CI] = 1.01-1.01, P < 0.001), Black patients (aOR: 1.30, 95% CI=1.28-1.47, P < 0.001), and patients enrolled in Medicare (aOR: 1.18, 95% CI = 1.13-1.24, P < 0.001) or Medicaid (aOR: 1.24, 95% CI = 1.12-1.37, P < 0.001). Independent risk factors for PE included obesity (aOR: 1.25, 95% CI = 1.16-1.35, P < 0.001), pulmonary hypertension (aOR: 3.64, 95% CI = 3.05-4.35, P < 0.001), and history of VTE (aOR: 1.71, 95% CI = 1.54-1.91, P < 0.001). Risk factors associated with an increased risk of DVT included iron deficiency anemia (aOR:1.38, 95% CI = 1.14-1.66, P < 0.001) and abnormal weight loss (aOR: 1.67, 95% CI = 1.07-2.60, P = 0.023).

Increasing age, Black race, Medicare, or Medicaid insurance were associated with increased risk of VTE. Obesity, history of VTE, and pulmonary hypertension were risk factors for both PE and DVT. These data can assist surgeons in the selection of a prophylactic regimen after TKA.