Abstract. Introduction. The Wells score is commonly used to assess the risk of proximal Deep Vein Thrombosis (DVT) following Knee Arthroplasty (KA). The National Institute for Health and Care Excellence (NICE) guidelines recommend an Ultrasound scan in patients with a Wells score of 2 points or more. We wanted to assess how often this protocol resulted in a scan being done and how many were negative. Methodology. Details of all postoperative Ultrasound scans performed up to 90 days were audited in a high-volume unit between 1st January 2016 and 31st December 2020. This included all Lower Limb Arthroplasty patients. Results. Out of a total of 4955 KA (4506 Total Knee Arthroplasty, 449 Unilateral Knee Arthroplasty), 449 (9.1%) had a total of 561 scans, with 17 (3.0%) scans demonstrating a proximal DVT. Thus 97.0% of Ultrasound scans were negative. Conclusion. The present NICE guidelines with the two-Level DVT Wells score are inappropriate for the management of suspected proximal DVT following KA. We propose that swelling that fails to reduce after 4 hours of elevation, or new swelling after a period of recumbent rest, would be more appropriate indications for a scan and negative scans should not be repeated without a change in symptoms. Unless there are pressing clinical indications, therapeutic anticoagulation should not commence in the absence of a diagnosis

Introduction. The aim of research was estimating risk factors for lower limbs DVT after hip and knee replacement. Material. We reviewed series of 80 patients (58 women and 22 men) who had performed 13 cemented THA, 38 uncemented THA, 19 TKA and 10 revisions after THA. Average patients age was 63 (range 45 to 82). Methods. All patients were preoperatively taken precise history data and examined physically. We noticed their age and BMI. All patients were asked about past DVT, cardiovascular diseases and others, past operations, drug taking, condiments. We examined both lower limbs in suspicion of DVT. All patients were taken laboratory tests, D-dimers test, and two-dimensional and Doppler ultrasonography. During the operation we noticed its time, kind of anaesthesia, amount of blood and other transfusions, loss of blood, time of using the tourniquet (in TKA). After operation we noticed amount of blood and other transfusions, loss of blood, time of patients postoperative tilting to vertical position. All patients were precisely examined physically every day after joint replacement. They were taken laboratory tests in 1st, 4th, 7th and 14th day after operation. In 7th and 14th day we performed two-dimensional and Doppler ultrasonography. In all patients we used the same scheme of DVT prophylaxis. We administered Enoxaparine once a day subcutaneously (first dose 12 hours before operation). Prophylaxis lasted 6 weeks after joint replacement. Results. Average DVT rate was 24,24%. We found the highest rate of DVT after replacement revisions (75%). The lowest rate was after uncemented THA (6,25%). There were no difference in DVT rate between women and men. We found significantly higher DVT rate in patient older than 60 yr. We found significantly higher DVT rate in patient with BMI over 30. We found significantly higher DVT rate in group of smokers. We found the operation was longer the DVT rate was higher. In case of delaying patients tilting to vertical position, DVT rate was higher. We did not find using tourniquet influence DVT rate. Conclusions. The risk factors for DVT after hip and knee replacement are: age over 60 yr, BMI over 30, smoking, long lasting operation, delayed tilting to vertical position, accompanying cardiovascular diseases and past DVT

Stable ankle fractures can be successfully treated non-operatively with a below knee plaster cast. In some European centres it is standard practice to administer thromboprophylaxis, in the form of low molecular weight heparin, to these patients in order to reduce the risk of deep venous thrombosis (DVT). The aim of our study was to assess the incidence of DVT in such patients in the absence of any thromboprophylaxis. We designed a prospective study, which was approved by the local ethics committee. We included 100 consecutive patients with ankle fractures treated in a below knee plaster cast. At the time of plaster removal (6 weeks), patients were examined for signs of DVT. A colour doppler duplex ultrasound scan was then performed by one of the two experienced musculoskeletal ultrasound technicians. We found that 5 patients developed a DVT. Two of these were above knee, involving the superficial femoral vein and popliteal vein respectively. The other three were below knee. None of the patients had any clinical symptoms or signs of DVT. None of the patients developed pulmonary embolism. Of these five patients, four had some predisposing factors for DVT. The annual incidence of DVT in the normal population is about 0.1%. This can increase to about 4.5% by the age of 75. DVT following hip and knee replacement can occur in 40-80% of cases. Routine thromboprophylaxis may be justified in these patients. However, with a low incidence of 5% following ankle fractures treated in a cast, we believe that routine thromboprophylaxis is not justified

According to the National Institute of Clinical Excellence (NICE) Guidelines, some foot and ankle patients are, by definition, at high risk of DVT/PE. Despite NICE guidance, DVT recommendations are still controversial, and are being reviewed by the BOA to be more operation and context specific. One consultant at our institution therefore initiated a 6 week medical DVT prophylaxis regimen for all his post-operative hind–foot surgery patients who were placed in plaster. From January 2007 to February 2008 we audited 97 hind-foot patients to measure their compliance rate, complications and DVT/PE rate. Compliance was excellent (97%) particularly with regard to Low Molecular Weight Heparin (LMWH), but only 70% had medication prescribed for the 6 weeks, and 3% developed a DVT. Self administered LMWH is acceptable and compliance is excellent in post operative orthopaedic patients, but not necessarily effective

Thromboembolic disease (TED) remains as a major concern for orthopaedic surgeons and is a well-known complication of lower extremity joint replacement procedures. While there is voluminous literature on the topic, it is difficult for the average orthopaedic surgeon to keep up with all the advancements in this area as well as the newer pharmacological options for prophylaxis. To address this, the American Academy of Orthopaedic Surgeons (AAOS) has developed a clinical practice guideline (CPG) in this area to provide treatment recommendations based on the best available evidence. Historically, guidelines for TED prophylaxis have been based largely on randomised controlled trials whose outcome measure was venographically documented deep vein thrombosis (DVT). However, many venographically documented DVTs, particularly those distal to the popliteal vein, are of no clinical consequence. Therefore, in the AAOS CPG the systematic review of the literature was focused on those outcomes that have the most clinical relevance: all-cause mortality, symptomatic or fatal pulmonary embolism (PE), proximal DVT, major bleeding and symptomatic DVT rates. Using these as the clinically important endpoints, it is evident that the extant literature is insufficient to provide definitive guidance in this area and to make specific recommendations about optimal pharmacological prophylaxis. Nonetheless, one strong recommendation has emerged from this systematic review: the guideline recommended against routine post-operative duplex ultrasonography screening of patients who undergo elective hip or knee arthroplasty. Only one risk factor – previous history of TED – had evidence demonstrating a higher risk beyond the risk from elective hip or knee arthroplasty itself (weak recommendation). There was not sufficient evidence that other potential risk factors increase the risk of TED, likely because of the relatively high background risk of elective hip or knee arthroplasty. In addition, there is very little evidence defining populations at increased risk for bleeding and bleeding-associated complications associated with pharmacological prophylaxis. However, the panel did come to a consensus that patients with known bleeding disorders or active liver disease are at an increased risk for post-operative bleeding. In these circumstances, it is recommended that mechanical compressive devices be the primary modality of prophylaxis as pharmacologic prophylaxis may increase the risk of bleeding. There was a moderate strength recommendation for the superiority of neuraxial anesthesia to limit blood loss even though there is no demonstrable effect on the incidence of TED. Finally, there was a moderate grade recommendation that pharmacologic agents (including aspirin) and/or mechanical compression devices be utilised for the prevention of VTE in patients that are undergoing elective hip or knee arthroplasty who are not at elevated risk beyond that of the surgery itself for VTE or bleeding. Clearly there is great need for better evidence with appropriately powered studies that examine the most clinically relevant outcomes in TED prophylaxis

Inciting events leading to deep vein thrombosis occur primarily intraoperatively. Therefore, if at all possible, intervention should be performed at the time of the operative procedure. It has been demonstrated in hip replacement surgery that DVT is significantly reduced with epidural hypotensive anaesthesia, which may or not be augmented with intraoperative small doses of heparin (500–1000 units). Reduction of extreme limb position with occlusion of the femoral vein during hip replacement surgery reduces the stasis effect, which promotes clotting. In the hip, overall DVT rates have been reduced to 7% and proximal DVT rates to 2% using these intraoperative techniques. Mechanical devices work by a myriad of mechanisms: 1.) venous turbulence is created in valve pocket areas and this reduces clot formation; 2.) there is an increase release of endothelial relaxing factor (EDRF) which inhibits platelet aggregation; 3.) intermittent compression stimulates fibrinolysis by inducing release of urokinase and tissue plasminogen from the venous endothelium. Randomised trials have demonstrated a reduction in DVT to levels similar to pharmacologic agents (20–27%) without the risk of postoperative haemorrhage. However, compliance with use of these devices is crucia1, as a positive relationship has been demonstrated between time of use and DVT rates. Although plantar pump devices tend to be well tolerated with occasional complaints of foot and skin irritation, calf compression devices with or without sequential foot compression applying at least 50 mmHg of external pressure at a frequency of at least once per minute and an inflation rate of less than 1 second tend to be the ideal device for DVT prophylaxis

Background Elevated plasma levels of D-dimer have been found to be a useful screening tool in the diagnosis of deep venous thrombosis (DVT) in the general population. In the postoperative setting however their role is less clear. In approximately 73% of NHS trusts D-dimer is a prerequisite test prior to radiological imaging to diagnose DVT. This study evaluates the effectiveness of D-dimer as a screening tool for DVT in the postoperative period following total hip and knee arthroplasty. Method Plasma D-dimer levels were measured pre operatively and on post-operative days 1, 3, 5, and 7 in 78 patients undergoing primary total hip or knee arthroplasty. On day 7 patients underwent bilateral duplex ultrasound scanning in order to confirm the absence of DVT. All patients wore pneumatic foot pumps for DVT prophylaxis. Chemical thromboprophylaxis was not used. All patients were under the care of one surgeon with the same postoperative regimen. Results D-dimer levels in the post-operative period were characterized by a double peak, on days 1 and 7. Mean day 1 value 3.63 (sd=2.72, range 0.60–14.34), mean day 7 value 2.83 (sd=1.58, range 1.10–10.30). Mean values on days 3 and 5 were 2.52 (sd=2.26, range 0.50–11.85) and 2.45 (sd=1.41, range 0.91–5.05). Comparing D-dimer levels between hip and knee arthroplasty we found that both groups displayed the same trend in post-operative D-dimer levels (i.e. peaks at days 1 and 7); however levels were significantly higher following knee replacement (At day 7 p< 0.005). We compared D-dimer levels of these patients with a second group of 43 patients who had a confirmed DVT following hip or knee arthroplasty. The mean D-dimer level in this group was 2.20 (sd=0.98 or range 0.80 – 4.46). This group was subdivided into two groups, those with D-dimer samples before (and including) day 7 and those after. We found a significant difference between the groups (p=0.01). Mean ≤ day 7 = 2.70. Mean > day 7 = 1.97. The group of patients with Confirmed DVT on or before day 7 were compared with those free of clot. There was no significant difference found between the D-dimer levels of the two groups. (p=0.37). Conclusion The D-dimer level is never normal (< 0.4mg/l), in the week following total hip or knee replacement and so cannot exclude a DVT. The level it rises to is indistinguishable form that seen in the population with a DVT and so cannot identify those patients in whom further investigation is warranted. Requesting a D-dimer test in this population wastes time and resources and is of no benefit

After decades of clinical experience and hundreds of studies, the ideal method of deep vein thrombosis (DVT) prophylaxis remains controversial. One of the most widely quoted publications on the subject in recent years has been the guidelines published by the American College of Chest Physicians (ACCP). The seventh and eighth ACCP Conference on Antithrombotic Therapy and Prevention of Thrombosis were published in Chest in 2004 and 2008 respectively. The highest level recommendation (1-A) was reserved for Warfarin at a relatively high dose (target international normalised ratio (INR) of 2–3), Low Molecular Weight Heparin (LMWH), or Fondaparinux for a minimum of 10 days for both total hip and total knee replacement. These agents were recommended for all patients, regardless of their relative risk of bleeding or risk of venous thromboembolism (VTE). These recommendations were found to be aggressive by the standards of most orthopaedic surgeons and a number of issues were identified with the methodology and resulting recommendations of the ACCP including: The emphasis on multicentre randomised clinical trials that are enormously expensive and strongly weighted towards pharmaceutical sponsored studies, methodology that prevented inclusion of studies of lower cost, lower tech options such as aspirin or lower dose Warfarin since randomised trials on a large scale are not available due to lack of funding or pharmaceutical company interest in generic low-cost options, lack of consideration of pneumatic compression options such as newly available mobile foot pumps with chips for monitoring compliance, financial conflict of interest of virtually all of the authors of the guidelines and the fundamental problem with utilising asymptomatic DVT as a study endpoint. The concerns with the aggressive nature of these recommendations were confirmed by studies from two academic centres which reported a high incidence of wound and bleeding complications when changing to a 1-A protocol. Recent studies indicate that readmissions following joint replacement are much more likely to be due to wound drainage and bleeding complications than DVT or pulmonary embolism (PE). In response to these concerns, the AAOS released guidelines in 2008 that were updated in 2011. The resulting recommendations represented a dramatic departure from the ACCP guidelines. Clinically crucial endpoints such as PE and death were utilized in the analysis rather than asymptomatic DVT, which was the criteria utilised by the Chest Physicians and the 2011 recommendations also considered symptomatic DVT. The AAOS guidelines consider patient risk category rather than making a uniform recommendation for all patients. Much more discretion is given to surgeons to utilise less aggressive prophylactic strategies including aspirin and foot pumps. In 2012, the ninth edition of the ACCP guidelines was published and many of the concerns previously expressed over prior editions were successfully addressed. Conflict of interest among the authors was much less of an issue, there was more attention placed on symptomatic events and clinically important complications, and a wider scope of literature was considered. The resulting guidelines represented a dramatic departure from previous recommendations. Aspirin and pneumatic compression were elevated to level 1 recommendation status along with potent drug regimens such as injectable drugs (LMWH and Xa inhibitor) as well as the new oral Xa inhibitors and antithrombin agents. When pneumatic compression devices are utilised, the use of a battery powered device capable of recording compliance was recommended. Patient risk status as well as patient preference were also considered. The new ACCP guidelines have successfully addressed many of the concerns previously addressed and are much more in line with the AAOS guidelines. It is anticipated that the federal Surgical Care Improvement Project (SCIP) guidelines for VTE prophylaxis will be released in 2013 and will also embrace the changes recommended by the ACCP. It is further likely that the AAOS and ACCP guidelines are close enough that they may well join forces in the near future and release a single unified document

In his classic monograph entitled Low Friction Arthroplasty of the Hip, which was published in 1979, John Charnley dedicated a chapter to thromboembolic complications. The overall incidence of pulmonary embolism (PE) was approximately 8% and the incidence of death from PE approximately 1%. Surveys of orthopaedic surgeons who undertake total joint replacement conducted by The American Association of Hip and Knee Surgeons (AAHKS), 30 years later, showed that there was still no consensus as to the best form of prophylaxis with a wide variation of methods being used. In the past 3 years, for the first time there is uniformity in the recommendations of the American Academy of Orthopaedic Surgeons (AAOS) and the American College of Chest Physicians (ACCP). Both groups have reached an agreement that the rate of DVT formation is not the ideal endpoint to use when assessing the efficacy of thromboprophylaxis after joint replacement, as had been done in previous drug trials. Most of these DVTs are asymptomatic and of questionable clinical significance. At least one recent study brings into question the association between the rate of DVT formation and that of subsequent symptomatic events. Both groups also focus on minimizing iatrogenic bleeding complications, which can lead to compromised clinical results, including limited movement and pain in the case of knee replacement and increased risk of infection in both knee and hip replacement. To further complete the uniformity of approach in the United States, the Center for Medicare and Medicaid Services (CMS), which administers the Surgical Care Improvement Program (SCIP) that monitors hospital compliance with VTE prophylaxis of hospitalised patients, has also changed their policy. Beginning January 2014, either aspirin or a compression device has been considered as acceptable measures for THR, TKR and hip fracture. The remarkable success reported from many centers with the use of aspirin and/or the use of a mobile compression device in patients without major risk factors, such as a prior history of symptomatic VTE, clearly indicate that aggressive pharmacoprophylaxis is not necessary for the vast majority of patients who undergo joint replacement

Elevated plasma levels of D-dimer have been found to be a useful screening tool in the diagnosis of deep venous thrombosis (DVT) in the general population. In the post operative setting however their role is less clear. The majority of NHS trusts use D-dimer as a prerequisite test prior to radiological imaging to diagnose DVT. Aims and method: This study evaluates the effectiveness of D-dimer as a screening tool for DVT in the postoperative period following total hip and knee arthroplasty. Plasma D-dimer levels were measured pre operatively and on post operative days 1, 3, 5, and 7 in 78 patients undergoing primary total hip or knee arthroplasty. On day 7 patients underwent bilateral duplex ultrasound scanning in order to confirm the absence of DVT. All patients wore pneumatic foot pumps for DVT prophylaxis. Chemical thromboprophylaxis was not used. Results: D-dimer levels in the post operative period were characterized by a double peak, on days 1 and 7. Mean day 1 value 3.63 (sd=2.72), mean day 7 value 2.83 (sd=1.58). Mean values on days 3 and 5 were 2.52 (sd=2.26) and 2.45 (sd=1.41). Comparing D-dimer levels between hip and knee arthroplasty we found that both groups displayed the same trend in post operative D-dimer levels; however levels were significantly higher following knee replacement. We compared D-dimer levels of these patients with a second group of 43 patients who had a confirmed DVT following hip or knee arthroplasty. The mean D-dimer level in this group was 2.20 (sd=0.98 or range 0.80 – 4.46). This group was subdivided into two groups, those with D-dimer samples before day 8 and those after. We found a significant difference between the groups (p=0.01). Mean < day 8 = 2.70. Mean ³ day 7 = 1.97. The group of patients with Confirmed DVT before day 8 were compared with those free of clot. There was no significant difference found between the D-dimer levels of the two groups. (p=0.37). Conclusion: The D-dimer level is never normal (< 0.4mg/l), in the week following total hip or knee replacement and so cannot exclude a DVT. The level it rises to is indistinguishable form that seen in the population with a DVT and so cannot identify those patients in whom further investigation is warranted. Requesting a D-dimer test in this population wastes time and resources and is of no benefit

Our American Academy of Orthopaedic Surgeons (AAOS) and the American College of Chest Physicians (ACCP) have come to a consensus that the use of routine prophylaxis against venous thromboembolism (VTE) is indicated for our patients undergoing total joint arthroplasty. The new guidelines acknowledge differences in efficacy of the various agents and the variable risk of VTE among patients. Agents include warfarin, low molecular weight heparin, aspirin, oral Xa inhibitors, and direct thrombin inhibitors. The use of pneumatic compression devices have been found to be effective in decreasing risk of deep vein thrombosis (DVT) as a stand-alone strategy after total knee arthroplasty (TKA) and is given a level 1C recommendation by ACCP while the data is less strong for use following total hip arthroplasty (THA). Mechanical devices are not associated with an increased bleeding risk, and address the concerns of some surgeons with regard to post-operative bleeding. The availability of mobile compression devices has expanded the indications for use as a result of portability. While the use of mobile pump technology in DVT prophylaxis adds to the armamentarium of tools available for use in VTE risk mitigation, it does not eliminate the need for pharmacologic prophylaxis. While all arthroplasty patients are at elevated risk of VTE, the highest risk is associated with those having a prior history of DVT or pulmonary embolism (PE), having had prior surgery within the preceding three months, or requiring prolonged immobilization post-operatively for any reason. In these patients, thromboprophylaxis with any of a number of agents will play a valuable role in VTE risk reduction. Additionally, not all patients tolerate the use of the pump device. Those individuals with chronic peripheral arterial disease or arterial ulcers in the legs are also poor candidates for mechanical compression strategies which may exacerbate existing vascular compromise and perfusion of the limb. Assessment of the medical comorbidities of the patient may also stratify them to higher risk where the demonstrated benefits of pharmacologic prophylaxis outweigh the considerations of bleeding associated with their use (such as in the morbidly obese/high BMI patients). Mobile pump technology is a valuable adjunct to our VTE reduction strategies, but do not eliminate the need for pharmacologic agents. The judicious selection of DVT prophylaxis strategies based on the totality of the constellation of orthopaedic and medical factors unique to each patient allows us to make clinical decisions tailored to their needs, their risk of VTE, and their reliability in functioning as an active partner in their own post-operative care

Introduction: Several institutes in continental Europe and the US now prescribe low molecular weight heparin for patients with ankle fractures being treated in a below knee plaster cast. Jorgensen et al reported an incidence of deep venous thrombosis (DVT) of up to 20% in patients treated in a cast. However, their study included patients with variable diagnoses, ranging from tendon ruptures to fractures. The aim of our study was to assess the incidence of DVT in patients with ankle fractures that have been treated conservatively in a below knee cast. Method: We performed an ultrasound scan on patients with conservatively ankle fractures at the time of removal of the cast. The same ultrasound technician performed all the scans. The local regional ethics committee had approved this study. Results: So far we have performed an ultrasound scan on 98 patients with ankle fractures. We are likely to complete the study in November 2006 (120 patients). We have encountered only 2 below knee DVTs (2.04 %). None of them involved the popliteal vein. Both patients were completely asymptomatic and were full weight bearing in the cast. A repeat scan showed no evidence of progression. None of the patients had an above knee DVT or a pulmonary embolism. Discussion: The risk of deep venous thrombosis is said to be higher in patients with a plaster cast because of the decreased ability of the calf muscles to pump the venous blood back to the heart. Though some studies have indicated an incidence of up to 20%, the incidence in our population was only about 2%Thus, DVT is a rare event in patients with ankle fractures. Though it is a serious event, its rarity does not justify a blanket prophylaxis regimen for all patients with ankle fractures

Background. In October 2008, CMS instituted a new “No payment for preventable complications“ programme and has released a list of conditions for which it intends to expand the programme in 2009. Although not reimbursing for preventable complications is justifiable, some of the proposed target conditions are lacking in both adequate diagnostic testing accuracy and preventability. Aims. This study examines the effects of imperfect sensitivity and specificity of diagnostic testing, the prevalence of condition, and the rate of surveillance on the ratio of numbers of DVT/PE diagnosed and those that actually occur. Methods. Given that proximal DVT following orthopaedic surgery are not preventable (incidence 4-10% despite prophylaxis), and that the accepted screening test (duplex ultrasonongraphy) has a sensitivity of 96.5% and specificity of 94%, up to 2.5 times as many DVT will be diagnosed as actually occur. Since the new CMS policy would withhold payment when a complication is identified, hospitals would be encouraged to decrease screening for DVT, which would save them lost reimbursement but would result in an increase in incidence of unrecognised – and therefore untreated – DVT after major orthopaedic surgical procedures. The study examines the likely CMS savings in the United States for implementation of this proposed policy (estimated $300M annually), as well as the potential increase in undiagnosed DVT likely to result from implementation of the policy. The overall goal of this study is to provide information to better enable the reader to draw their own conclusions on whether non-payment for DVT after an orthopaedic procedure is a fiscal policy that makes sense and improves the health and healthcare of Americans

We performed a systematic review and meta-analysis to compare the efficacy of intermittent mechanical compression combined with pharmacological thromboprophylaxis, against either mechanical compression or pharmacological prophylaxis in preventing deep-vein thrombosis (DVT) and pulmonary embolism in patients undergoing hip or knee replacement. A total of six randomised controlled trials, evaluating a total of 1399 patients, were identified. In knee arthroplasty, the rate of DVT was reduced from 18.7% with anticoagulation alone to 3.7% with combined modalities (risk ratio (RR) 0.27, p = 0.03; number needed to treat: seven). There was moderate, albeit non-significant, heterogeneity (I. 2. = 42%). In hip replacement, there was a non-significant reduction in DVT from 8.7% with mechanical compression alone to 7.2% with additional pharmacological prophylaxis (RR 0.84) and a significant reduction in DVT from 9.7% with anticoagulation alone to 0.9% with additional mechanical compression (RR 0.17, p < 0.001; number needed to treat: 12), with no heterogeneity (I. 2. = 0%). The included studies had insufficient power to demonstrate an effect on pulmonary embolism. We conclude that the addition of intermittent mechanical leg compression augments the efficacy of anticoagulation in preventing DVT in patients undergoing both knee and hip replacement. Further research on the role of combined modalities in thromboprophylaxis in joint replacement and in other high-risk situations, such as fracture of the hip, is warranted

Study design: In order to evaluate a new CECT (Continuous Enhanced Circulation Therapy) based on protocol for DVT prevention a prospective, randomize, single-blind study was designed to compare the effect of the new protocol to the current standard of care in DCT prophylaxis (LMWH). Objectives: To evaluate and compare the incidence and severity of DVT between the two groups. Background: Total hip and knee replacements are operations particularly prone to thromboembolic complications. Recommendations regarding prophylaxis have changed over the years. A treatment protocol was proposed, based upon the CECT system as the primary DVT prophylaxis method with the addition of low dose aspirin. This protocol is using two very safe treatment modalities with very low risk for adverse effects. The CECT system applies continuous mechanical enhancement of venous blood flow through a miniature, mobile, battery operated system. Methods: 39 patients, who underwent total hip or knee replacement, were prospectively randomized into two groups. In the study group the patients received CECT system starting immediately after the induction of anesthesia and covering the operation and the first 5 postoperative days, within 12 hours after surgery aspirin 100 mg per day was added. In the control group the patients received Enoxaparin 40 mg per day for 5 postoperative days. A venography was performed at the 5th to 8th post-operative day and the DVT prevalence was compared. Results: In the study group 3 patients out of 21 (14.3%) were found to have DVT (1 of them proximal), compared to 8 patients out of 18 (44.4%) in the control group (5 of them proximal). The differences between the two groups are statistically significant for both total and proximal DVT rates (p=0.037). In the study group only 1 patient needed prolonged high dose anticoagulant treatment while 6 patients in the enoxaparin group were treated (p=0.020). The cumulative incidence of adverse events in the study group was significantly lower than that observed in the control group (p=0.000). Average postoperative hospital stay was 8.4 days in the study group and 11.7 days in the control group (p=0.002). The CECT device was very well tolerated by the patients and facilitated early mobilization. Conclusions: The protocol combining CECT and Aspirin was found to be both safe the effective. Comparison to the standard prophylaxis with enoxaparin revealed significant advantage of the proposed protocol with: better DVT prevention, less adverse events and shorter hospital stay. Further research is needed in order to establish the place of this prophylaxis protocol as the treatment of choice in orthopaedic patients

Mechanical methods of deep vein thrombosis (DVT) prophylaxis rely on the prevention of venous stasis – one of Virchow’s triad of cause of DVT. Mechanical methods, such as the A-V Impulse System (Orthofix Vascular Novamedix, Andover, UK) are used widely in orthopaedic surgery for the prevention of DVT, especially after elective orthopaedics. The evidence for the use of the A-V Impulse System in elective orthopaedics is widely accepted and is considered a Grade A Recommendation by the International Consensus Statement. These data are reviewed and critiqued. More recent studies show how mechanical methods can offer benefits to the patient outside of hip and knee replacement surgery. Data are presented on how such devices can effectively reduce swelling, DVT, compartment pressure and pain associated with trauma, based on over 20 years of practical experience. The practical implications of using these devices is discussed

Abstract

Venous thromboembolic (VTE) events including deep vein thrombosis (DVT) and pulmonary embolism (PE) remain a significant concern following total joint arthroplasty. The American Academy of Orthopaedic Surgeons (AAOS) guidelines for VTE prophylaxis have focused on the safety of prophylactic regimens, with the primary endpoint being prevention of symptomatic events while avoiding the risks of hematoma, infection, and re-operation associated with aggressive anticoagulation. In 2007, the AAOS clinical practice guideline recommended “risk stratification” of patients for VTE events and bleeding. Unfortunately, there remains limited evidence as to specific factors that should be used during pre-operative risk stratification.

A prior investigation has demonstrated the effectiveness of using a history of VTE events, active cancer, and hypercoagulable state (i.e. Factor V Leiden) as criteria for high-risk patients undergoing total joint arthroplasty. In addition, large national database systems have been used to identify risk factors for VTE events. Unfortunately, these investigations emphasise different risk factors and their importance in increasing the risk of VTE events. Thus, criteria to be used for risk stratification of patients undergoing total joint arthroplasty remain unclear. What remains clear is that even in healthy patients who are aggressively anticoagulated, a VTE event can still occur.

Venous thromboembolism (VTE) prophylaxis following total joint arthroplasty (TJA) should be individualised in order to maximise the efficacy of prophylactic measures while avoiding the adverse events associated with the use of anticoagulants. At our institution, we have developed a scoring model using the Nationwide Inpatient Sample (NIS) database, which is validated against our institutional data, to stratify patients into low- and high-risk groups for VTE. Low-risk patients are placed on aspirin 81 mg twice daily for four weeks post-operatively, and high-risk patients are placed on either a Vitamin K antagonist (warfarin), low molecular weight heparin, or other oral anticoagulants for four weeks post-operatively. All patients receive sequential pneumatic compression devices post-operatively, and patients are mobilised with physical therapy on the day of surgery. Patients who have a history of peptic ulcer disease or allergy to aspirin are also considered for other types of anticoagulation following surgery.

Risk Stratification Criteria

Major comorbid risk factors utilised in our risk stratification model include history of hypercoagulability or previous VTE, active cancer or history of non-cutaneous malignancy, history of stroke, and pulmonary hypertension. We consider patients with any of these risk factors at elevated risk of VTE and therefore candidates for formal anticoagulation.

Other minor risk factors include older age, bilateral surgery compared with unilateral, inflammatory bowel disease, varicose veins, obstructive sleep apnea, and history of myocardial infarction, myeloproliferative disorders, and congestive heart failure. Each minor criterion is associated with a score. The cumulative score is compared with a defined threshold and the score that surpasses the threshold indicates that the patient should receive post-operative anticoagulation. To facilitate the use of this scoring system, an iOS mobile application (VTEstimator) has been developed and can be downloaded from the app store.