Venous thromboembolic prophylaxis in orthopedic surgery: knee surgery

Knee replacement surgery is associated with a high risk of venous thromboembolic complications, and the risk appears to be highest during the 7 days following surgery. Meta-analysis of a number of randomized, controlled trials has conclusively established the efficacy and safety of low molecular weight heparin (LMWH) prophylaxis in knee replacement surgery. It is clear that LMWHs exhibit distinct physico-chemical, biological, and pharmacodynamic properties, and recently the United States Food and Drug Administration has concluded that these are noninterchangeable drugs. The clinical experience with each LMWH varies widely, and the paucity of data on thromboprophylaxis with LMWHs other than enoxaparin limits relevant comparisons of efficacy and safety. Further clinical trials with different LMWHs are indicated and will help resolve the issue of LMWH inequivalence currently at the center of debate.