Most discussions concerning the prophylaxis of Deep Vein Thrombosis usually end up with the resolution stating ‘we agree to disagree.’ The confusion persists and that is what makes this topic extremely exciting and challenging. The book is a result of multispecialty contribution to put together this manual with multispecialty contribution from vascular surgeon, anesthesiologist, physiotherapists, orthopedicians and most critically anatomists. The importance of venous thromboembolism (VTE) cannot be over empathized. Many questions may still be unanswered. Venous thromboembolism is a common disease; it includes both deep vein thrombosis (DVT) and pulmonary embolism (PE). It is a common, lethal disorder that affects hospitalized and nonhospitalized patients, recurs frequently, and is often overlooked, under-diagnosed, with an average annual incidence of more than 1 case per 1000 persons. We however hope that we have once again lit a fire of inquisitiveness in your mind.

Venous thromboembolism is a common and potentially lethal disease. Patients who have pulmonary embolism are at especially high risk for death. Sudden death is often the first clinical manifestation. Only a reduction in the incidence of venous thromboembolism can reduce sudden death owing to pulmonary embolism and venous stasis syndrome owing to deep vein thrombosis. Improvement in the incidence of venous thromboembolism will require (i) better recognition of persons at risk, (ii) improved estimates of the magnitude of risk, (iii)avoidance of risk exposure when possible, (iv)more widespread use of safe and effective prophylaxis when risk is unavoidable, and (v) targeting of prophylaxis to those persons who will benefit most. Early and timely diagnosis and management of deep vein thrombosis and pulmonary embolism considerably reduces the subsequent morbidity and mortality.

This book reviews the main topics in thromboprophylaxis around orthopedic surgery, from a general scope of the problems with the disease highlighting them in orthopedics to the new specific protocols involving, for example, new oral anticoagulants. The prevalence of the venous thromboembolism in each procedure (from “easy” to “hard” surgeries, with different rates of related thrombosis) and the risk factors to bear in mind in each one (related and non-related with the orthopedic procedure) are also revised. A chapter focus on the diagnosis and treatment of venous thromboembolism, which is commonly “forgotten” in many books addressed to orthopedic surgeons and anaesthesiologists. The methods for thromboprophylaxis have three specific chapters: the most common drugs used and recommended when pharmacological prophylaxis is needed, new drugs which are arising day by day and which management will be of main importance in a close near future, and mechanical methods, recommended both as additional when possible and for sole indications when the risk of bleeding could move us to minimize the real risk of thrombosis. Anaesthetic implications for thromboprophylaxis and, also, main implications of the application of antithrombotic protocols in the anaesthetic practice are covered by another chapter. In our opinion it was very important to divide the orthopedic procedures according to their own thrombotic risk, so having their own protocols for thromboprophylaxis: high risk, day surgery procedures and “special” surgical procedures are included in three different chapters, from three different authors with complementary views. Finally, in a last chapter, we review the problems involving the perioperatory management of antiaggregated and anticoagulated patients, with a special part in hip fracture surgery.

"Venous Thromboembolism Prophylaxis in Orthopedic Surgery: Main Report" (see also "Venous Thromboembolism Prophylaxis in Orthopedic Surgery: Appendices") - Major orthopedic surgery (total hip replacement, total knee replacement or hip fracture surgery) carries a high risk of venous thromboembolism. Pulmonary embolism following orthopedic surgery is reported to be rare. However, without prophylaxis, historical data suggest that hospital acquired deep venous thrombosis has been estimated to occur in 40 to 60 percent of cases in the 7 to 14 days following surgery compared with 10 to 40 percent among medical or general surgical patients. While asymptomatic deep vein thrombosis is identified more frequently than symptomatic deep vein thrombosis in clinical trials due to routine screening, there is disagreement as to the clinical relevance of asymptomatic cases. While certain patient characteristics (i.e. age, immobility, comorbidities) have been suggested to increase the risk of venous thromboembolism regardless of the clinical setting, major orthopedic surgery contributes additional factors such as use of general anesthesia which may prolong immobility and surgical involvement of the femoral vein. A variety of strategies to prevent venous thromboembolism are available and with routine use, the rate of symptomatic venous thromboembolism in patients within 3 months of surgery is 1.3 to 10 percent. The main limitation of pharmacologic venous thromboembolism prophylaxis is the risk of bleeding. Based on historical data major bleeding following total hip replacement and total knee replacement is estimated to be 1 to 3 percent. Determining the incidence of major bleeding with pharmacologic thromboprophylaxis is complicated by the variability in the definitions used in published literature and paucity of data in control patients. Following removal of an infected prosthesis and extended intravenous antibiotic treatment further surgery may be required to either implant a new prosthesis or perform an arthrodesis of the joint. There are many unknowns that need to be explored in a comparative effectiveness review. In contemporary practice, the risk of venous thromboembolism, pulmonary embolism, and deep vein thrombosis, and the causal link between deep vein thrombosis and pulmonary embolism has not been well established. Previous observations of the incidence of pulmonary embolism in patients who have undergone orthopedic surgery with confirmed deep vein thrombosis suggests that pulmonary embolism and deep vein thrombosis are related disorders. However, whether the presence of deep vein thrombosis affects the risk of pulmonary embolism and to what degree if so remains unclear in the literature. Widespread use of anticoagulants to treat venous thrombomebolism for many decades along with the evolution of diagnostic strategies have limited the availability of literature regarding the natural history of venous thromboembolism. In addition to major orthopedic surgery, there are a variety of other orthopedic surgeries in which the impact of venous thromboembolic prophylaxis has not been well evaluated. These orthopedic surgeries of interest include knee athroscopy, surgical repair of lower extremity injuries distal to the hip, and elective spine surgery. While prophylactic strategies may decrease the risk of venous thromboembolism, pulmonary embolism, and deep vein thrombosis, the magnitude of benefit in contemporary practice using rigorous definitions of endpoints and the impact of duration of prophylaxis on outcomes is not well delineated. Whether dual prophylactic strategies are superior to a single modality is not well defined. In addition, in order to determine comparative effectiveness, both the benefits and harms need to be appreciated. Finally, several previous meta-analyses and guidelines allowed the use of medications or devices that are not available for use in the United States reducing their applicability.

BACKGROUND: Major orthopedic surgeries, such as total knee replacement (TKR), total hip replacement (THR), and hip fracture (HFx) surgery, carry a high risk for venous thromboembolism (VTE)--deep vein thrombosis (DVT) and pulmonary embolism (PE). METHODS: Updating a 2012 review, we compare interventions to prevent VTE after TKR, THR, and HFx surgery. We searched four databases and other sources through June 3, 2016, for randomized controlled trials (RCTs) and large nonrandomized comparative studies (NRCSs) reporting postoperative VTE, major bleeding, and other adverse events. We conducted pairwise meta-analyses, Bayesian network meta-analyses, and strength of evidence (SoE) synthesis. RESULTS: Overall, 127 RCTs and 15 NRCSs met criteria. For THR: low molecular weight heparin (LMWH) has lower risk than unfractionated heparin (UFH) of various VTE outcomes (moderate to high SoE) and major bleeding (moderate SoE). LMWH and aspirin have similar risks of total PE, symptomatic DVT, and major bleeding (low SoE). LMWH has less major bleeding (low SoE) than direct thrombin inhibitors (DTI), but DTI has lower DVT risks (moderate SoE). LMWH has less major bleeding than vitamin K antagonists (VKA) (high SoE). LMWH and factor Xa inhibitor (FXaI) comparisons are inconsistent across VTE outcomes, but LMWH has less major bleeding (high SoE). VKA has lower proximal DVT risk than mechanical devices (high SoE). Longer duration LMWH has lower risk of various VTE outcome risks (low to high SoE). Higher dose LMWH has lower total DVT risk (low SoE) but more major bleeding (moderate SoE). Higher dose FXaI has lower total VTE risk (low SoE). For TKR: LMWH has lower DVT risks than VKA (low to high SoE), but VKA has less major bleeding (low SoE). FXaI has lower risk than LMWH of various VTE outcomes (low to moderate SoE), but LMWH has less major bleeding (low SoE) and more study-defined serious adverse events (low SoE). Higher dose DTI has lower DVT risk (moderate to high SoE) but more major bleeding (low SoE). Higher dose FXaI has lower risk of various VTE outcomes (low to moderate SoE). For HFx surgery: LMWH has lower total DVT risk than FXaI (moderate SoE). CONCLUSIONS: VTE prophylaxis after major orthopedic surgery trades off lowered VTE risk with possible adverse events--in particular, for most interventions, major bleeding. In THR, LMWH has lower VTE and adverse event risks than UFH, LMWH and aspirin have similar risks of VTE and major bleeding, DTI has lower DVT risk than LMWH but higher major bleeding risk, and higher dose LMWH has lower DVT risk but higher major bleeding risk than lower dose. In TKR, VKA has higher DVT risk than LMWH but lower major bleeding risk, and higher dose DTI has lower DVT risk but higher major bleeding risk than lower dose. In HFx surgery and for other intervention comparisons, there is insufficient evidence to assess both benefits and harms, or findings are inconsistent. Importantly, though, most studies evaluate "total DVT" (an outcome of unclear clinical significance since it includes asymptomatic and other low-risk DVTs), but relatively few studies evaluate PE and other clinically important outcomes. This limitation yields a high likelihood of selective outcome reporting bias. There is also relatively sparse evidence on interventions other than LMWH.

Venous Thromboembolism in Orthopaedic Surgery.