Current controversies in deep vein thrombosis prophylaxis after orthopaedic surgery.

As a result of easy measurable perioperative bleeding and a high number of subclinical deep vein thromboses after surgery, total hip replacement has become a benchmark for antithrombotic drug development. Today, a nonscientific evidence-based transatlantic view on thromboprophylaxis in orthopaedic surgery exists. Efforts should be taken to bridge these divergent opinions. We need to standardize study designs that allow unbiased comparison and aggregation of data to get insight in rare complications like the cauda equina syndrome associated with spinal analgesic techniques and anticoagulation and to optimize thromboprophylaxis in homogeneous groups of patients. Dosage, timing of initiation in relation to surgery, and duration of prophylaxis seems a crucial and open question for all homogeneous groups of orthopaedic patients. A definition on surgical bleeding, which allows practical measurement procedures and quantification, is lacking. Clinical studies on vascular endpoints are warranted to achieve relevant basic data for health economic analyses, which also lack scientific standardized procedures. An intercontinental close cooperation is needed to solve these issues.