National Trends in Deep Vein Thrombosis following Total Knee and Total Hip Replacement in the United States.

BACKGROUND: Total knee replacement (TKR) and total hip replacement (THR) are associated with an increased risk of deep vein thrombosis (DVT). Advances in DVT prophylaxis over the past decade have led to a decrease in DVT-related morbidity, but gender, racial, and other demographic factors that contribute to a higher risk of DVT are incompletely characterized. This study aimed to determine the incidence of DVT over the past decade and identify factors that were associated with an increased risk of DVT.

METHODS: Patients who underwent TKR or THR between 2001 and 2011 were identified using the National Inpatient Sample. For patients who developed a DVT, their demographics (including age, gender, and race), comorbidities, and subsequent outcomes (including length of stay [LOS] and mortality) were determined. Differences between patients who developed a DVT and those who did not were determined using multivariate regression analysis. A Mann-Kendall analysis was done to evaluate all trends.

RESULTS: Between 2001 and 2011, a total of 1.1 million patients underwent TKR, and 550,000 underwent THR. The overall incidence of DVT decreased for TKR from 0.86% in 2001 to 0.45% in 2011 and decreased for THR from 0.55% to 0.24% for the same period. Patients who developed a DVT after TKR were older (67.7 vs. 66.8, P < 0.001); more likely to be African American (P < 0.001); and more likely to have significant comorbidities including congestive heart failure, peripheral artery disease, and end-stage renal disease. Findings were similar for patients who developed a DVT after THR. Mortality was significantly greater for patients who developed a DVT (0.4% for TKR and 1.7% for THR), with an almost double LOS.

CONCLUSIONS: A focus on DVT prophylaxis may have decreased national rates of DVT after TKR and THR. Older patients, African Americans, and patients with more comorbidities appear to be especially at risk for DVT. Mortality is almost 4 to 8 times higher for patients with DVT, and LOS is double. A focus on DVT prophylaxis and perhaps more aggressive management of the at-risk population may further help decrease the rate of DVT.