Direct Thrombin Inhibitor (Dti) vs. Aspirin in Primary Total Hip and Knee Replacement Using Wound Ooze as the Primary Outcome Measure. A Prospective Cohort Study

The latest NICE guidance dictates that all patients undergoing lower-limb arthroplasty should be prescribed potent venous thromboembolic (VTE) prophylaxis. However, use of potent anti-thrombotics is likely to lead to increased post-operative wound ooze. Postoperative wound ooze is associated with increased risk of infection.

This study used a prospective, consecutive, multi-surgeon sample of 110 patients undergoing primary total hip replacement (THR) and total knee replacement (TKR) prescribed either direct thrombin inhibitor (DTI) (n=51, 26 males: 25 females, age 69 ±18) or aspirin (n=59, 25 males: 34 females, age 69 ± 19). Hospital stay, body mass index (BMI), wound length and patient demographics were documented along with a daily assessment of wound ooze.

The use of DTI’s was associated with a significant increase in mean days to dryness in both THR (6.2 ± 0.98, 95% C.I. 5.2–7.1) and TKR (6.6 ± 1.89, 95% C.I. 4.7–8.5) compared to aspirin in THR (3.0 ± 1.03, 95% C.I 1.9–4.0) and TKR (3.4 ± 1.21, 95% C.I 2.2–4.6) with p-values of <0.0001 and 0.0024 for THR and TKR respectively. Age, gender and wound length were not found to be significant confounding variables. DTI’s proven benefit in lowering venous thromboembolism when compared with aspirin needs to be balanced with their increased cost and increased duration of wound ooze.