Vascular Disease Prevention, 2007, 4, 171-175 171 1567-2700/07 $50.00+.00 © 2007 Bentham Science Publishers Ltd. Overview of Current Trends and the Future of Thromboprophylaxis in Orthopaedic Surgery Francois Tudor*, Chris Hee, Anika Singh, Kemi Akinola and Alexander T. Cohen Vascular Diseases Research Group, Department of Surgery, King’s Denmark Hill Campus, London SE5 9PJ, UK Abstract: Venous thromboembolic disease (VTE) is a well known risk in orthopaedic and trauma surgery. There is no unified opinion on the best method of prophylaxis and so most orthopaedic departments use very different regimes. We provide an overview of the best prophylactic methods available at present and an insight into the future of VTE preven- tion. Keywords: Thromboprophylaxis, orthopaedic surgery, deep vein thrombosis (DVT), Low-Molecular Weight Heparin (LMWH). INTRODUCTION There is a high prevalence of venous-thromboembolism (VTE) in hospitalised patients and surgery is one of the most important risk factors for its development [1]. Moreover, such patients often have multiple other risk factors associ- ated with the primary disorder, including age, immobilisa- tion, trauma, malignancy, varicose veins and oestrogen treatment [2-3]. The type of surgery bears significance and orthopaedic joint replacement is regarded as high risk. Spe- cific operations carry different risks, with deep vein throm- bosis (DVT) rates being higher in total knee replacements than total hip replacements, and patients with hip fractures representing one of the highest risk groups. Without thromboprophylaxis, the incidence of fatal pul- monary embolus (PE) varies from 1.7% after elective hip replacement to 4.0% after surgical hip fracture repair [4] and in both these operations, the DVT risk is 40-60% [5]. VTE is often silent and poorly diagnosed. Acutely, one third of deaths post orthopaedic surgery are due to PE at post-mortem and one third of hospital re-admissions are due to DVT or PE. Chronically, the cumulative recurrence of DVT after 8 years is 30.3% while post-thrombotic syndrome after 8 years is 29.1%. The occurrence of VTE can signifi- cantly reduce quality of life, with patients requiring pro- longed treatment and follow-up along with possible in- creased morbidity. VTE contributes a great financial burden to the NHS, with the primary diagnosis and treatment of DVT or PE in 44,850 patients between 1999-2000 costing £42,500,000. For comparison, in this period, 44,486 patients were diagnosed and treated for stroke, costing £95,300,000 [6]. We can as- sume that orthopaedic surgery has resulted in a proportion of these VTE events and thus contributes to this massive bill. In view of this it is important to reiterate that thromboprophy- laxis significantly reduces mortality due to PE [1]. *Address correspondence to this author at the Vascular Diseases Research Group, Department of Surgery, King’s Denmark Hill Campus, Bessemer Road, London SE5 9PJ, UK; Tel: +44 (0) 020 7346 3015/3036; Fax: +44 (0) 020 7346 3927/3866; E-mail: francoistudor@yahoo.co.uk Up until recently, low-molecular weight heparins (LMWH) were thought to be the most effective agents rou- tinely used in clinical practice to prevent VTE in the ortho- paedic patient. Compared with placebo, the relative risk re- duction for all thrombi is approximately 70% with LMWH [7]. Despite this, many improvements are possible in the thromboprophylactic regimes used in modern practice, with new drugs leading the way. In particular, specific clotting factor inhibitors, such as thrombin inhibitors and activated factor X inhibitors. In developing new antithrombotic treat- ments, it is important to establish a balance between a good efficacy of the drug and an acceptable bleeding risk. CURRENT PRACTICES OF VTE PROPHYLAXIS AMONG ORTHOPAEDIC SURGEONS A recent survey of British orthopaedic surgeons doing total hip replacements showed some concerning results. In total, 15% used mechanical prophylaxis only, 20% used as- pirin without other pharmacological prophylaxis and 65% used pharmacological prophylaxis without aspirin. Of the 941 surgeons who replied (of 1308), only 74% have a de- partmental policy for DVT prophylaxis [8]. It is important therefore to continue education, discuss the best methods available at present and determine the path that future thera- pies may follow. Thromboprophylaxis can be either mechanical or phar- macological or both. Modalities in use at present include Thrombo-Embolic Deterrent Stockings (TEDS), aspirin, low-dose un-fractionated Heparin (UFH), Low-molecular weight Heparin (LMWH) and Vitamin K antagonists. Stud- ies that compared these prophylactic regimes after elective total hip replacement, showed a DVT rate of 15% in the LMWH group, as opposed to 20% in the vitamin K antago- nist group, 34% in UFH patients and 56% in aspirin only patients. Patients with compression stockings only had a 38% DVT rate and those not receiving any prophylaxis had a 51% DVT rate. DVT rates in patients undergoing elective total knee replacement and hip fracture surgery were also shown to be lowest in the patients receiving LMWH post operatively [9]. There is limited data on the effect of com-