LOW-DOSE ASPIRIN VERSUS LOW-MOLECULAR-WEIGHT HEPARIN FOR PREVENTION OF DEEP VEIN THROMBOSIS AFTER TOTAL KNEE ARTHROPLASTY

Abstract

Background: Deep vein thrombosis (DVT) remains a concern after total knee arthroplasty (TKA), particularly in resource-constrained settings where the optimal pharmacological prophylaxis is debated. This study compared the efficacy and safety of low-molecular-weight heparin (LMWH) versus low-dose aspirin following primary unilateral TKA. Material and Methods: A quasi-experimental, non-randomized prospective comparative study was conducted at Sharif Medical City Hospital, Lahore, using consecutive non-probability sampling. Ninety-two standard-risk patients undergoing primary unilateral TKA received either enoxaparin 40 mg subcutaneously (Group A) or aspirin 75 mg orally daily (Group B). Symptomatic DVT, ease of administration, compliance, adverse events, and direct drug costs were assessed at 30 days. Categorical variables were analyzed using the chi-square or Fisher’s exact test, and continuous variables using the independent t-test or Mann-Whitney U test. A p-value <0.05 was considered statistically significant. Results: No symptomatic DVT occurred in either group. Aspirin had greater ease of use (84% vs. 48%, p=0.01) and compliance (92% vs. 76%, p=0.04). Minor bruising occurred in 12% of the LMWH group versus none in the aspirin group (p=0.03), while gastritis occurred in 8% of the aspirin group versus none in the LMWH group (p=0.12). Aspirin had a lower direct drug cost (PKR 500 vs. PKR 12,000, p=0.001). Conclusion: Low-dose aspirin provided comparable short-term DVT prophylaxis, with better ease of use, compliance, and lower direct drug cost in standard-risk TKA patients