Rheumatoid Arthritis Is Associated With Thromboembolic Complications Following Primary Total Knee Arthroplasty

Recent studies have demonstrated patients with rheumatoid arthritis (RA) have deranged coagulation parameters predisposing them to venous thromboembolisms (VTEs). Therefore, the purpose of this study was to investigate whether patients who have RA undergoing primary TKA have higher rates of (1) VTEs; (2) readmission rates; and (3) costs of care.

Patients who have RA undergoing primary TKA were identified and matched to controls in a 1:5 ratio by age, sex, and comorbidities. Exclusions included patients with a history of VTEs and hypercoagulable states. Primary outcomes analyzed included rates of 90-day VTEs, along with lower extremity deep vein thromboses and pulmonary embolisms, 90-day readmission rates, in addition to day of surgery, and 90-day costs of care. A P-value less than .05 was considered statistically significant.

Patients who have RA were found to have significantly higher incidence and odds (OR) of VTEs (1.9 vs 1.3%; OR: 1.51, P < .0001), deep vein thromboses (1.6 vs 1.1%; OR: 1.55, P < .0001), and pulmonary embolisms (0.4 vs 0.3%; OR: 1.26, P= .0001). Study group patients also had significantly higher incidence and odds of readmissions (21.6 vs 14.1%; OR: 1.67, P < .0001) compared to controls. In addition, RA patients incurred significantly higher day of surgery ($12,475.17 vs $11,428.96; P < .0001) and 90-day costs of care ($15,937.34 vs $13,678.85; P < .0001).

After adjusting for age, sex, and comorbidities, the study found patients who have RA undergoing primary TKA had significantly higher rates of VTEs, readmissions, and costs.