Abstract: Introduction: Incidence of deep vein thrombosis (DVT) (1.9%-3%) and pulmonary embolism (PE) (0.01%) post total knee arthroplasty (TKA) in Asian population is less compared to western population (85% and 1.5%-10% respectively). Hence, routine chemoprophylaxis following Western protocols is debatable in Asia. Wound complications like bleeding, hematoma, blisters, skin necrosis are high with low molecular weight heparin (LMWH) as compared with Aspirin. Aspirin is associated with low rate of DVT and PE (0.008% - 0.35%). The aim is to study the coagulation profile and adverse events like DVT, PE and wound complications in postoperative TKA patients on pharmacological DVT prophylaxis and watch for correlation between coagulation parameters and bleeding complications, and accordingly administer thromboprophylactic agents.
Methods: Prospective observational study.
463 patients undergoing primary unilateral TKA were bifurcated into groups according to thromboprophylaxis given by two surgeons.
1. 271 patients received LMWH
2. 192 patients received Aspirin
Patients were evaluated with coagulation profile preoperatively and postoperatively and observed for wound complications, DVT and PE.
Results: The use of LMWH conferred a significantly higher incidence of wound soakage (p<0.001) and drain volume (p<0.001) than with aspirin. There was no significant difference in the incidence of DVT or PE between the two groups. There was a significant increase in the postoperative aPTT (p<0.001) value over the preoperative value in correlation with drain volume in patients who received LMWH as compared with aspirin.
Conclusion: As wound complications are significant with LMWH, and there is no significant difference in the incidence of DVT/PE with LMWH and aspirin, a balanced view of risk-versus-benefit to be taken when prescribing thromboprophylaxis. Response of aPTT after 1-2 doses of LMWH is useful in identifying those who are likely to develop bleeding complications and LMWH to be switched to aspirin.
