A once-daily dose of rivaroxaban 10 mg, an oral, direct Factor Xa inhibitor, was compared with enoxaparin 40 mg subcutaneously once daily for prevention of venous thromboembolism in three studies of patients undergoing elective hip and knee replacement (RECORD programme). A pooled analysis of data from these studies (n = 9581) showed that rivaroxaban was more effective than enoxaparin in reducing the incidence of the composite of symptomatic venous thromboembolism and all-cause mortality at two weeks (0.4% vs 0.8%, respectively, odds ratio 0.44; 95% confidence interval 0.23 to 0.79; p = 0.005), and at the end of the planned medication period (0.5% vs 1.3%, respectively; odds ratio 0.38; 95% confidence interval 0.22 to 0.62; p < 0.001). The rate of major bleeding was similar at two weeks (0.2% for both) and at the end of the planned medication period (0.3% vs 0.2%). Rivaroxaban started six to eight hours after surgery was more effective than enoxaparin started the previous evening in preventing symptomatic venous thromboembolism and all-cause mortality, without increasing major bleeding

Introduction. Air travel and total joint arthroplasty are both established risk factors for development of venous thromboembolism (VTE); accordingly patients are typically counseled against flying in the early postoperative period. The basis for this recommendation may be unfounded, as the risk of VTE associated with flying in the early postoperative period has not been investigated. Methods. This is a case-control study of 1465 consecutive unilateral total hip arthroplasties (THA) and total knee arthroplasties (TKA) performed by a single surgeon over an 18-month period. A multimodal regimen was used for VTE prophylaxis, consisting of early mobilization, mechanical prophylaxis, and chemoprophylaxis according to a risk-stratification model; 96% of patients received aspirin as the sole chemoprophylactic agent. The study population consisted of 220 patients (15.0%) who flew at a mean of 2.9 days after surgery. Patients who elected to fly were encouraged to wear anti-embolic stockings, perform frequent ankle-pump exercises, and move around at least every hour. Mean flight duration was 2.7 hours (range, 1.1 to 13.7 hours). This study population was compared to a control population of 1245 patients (85.0%) who did not fly during this time. Baseline characteristics were similar between the groups, with the exception that the group who flew tended to be older (65.5 vs. 59.5 years, p < 0.001) with a lower body-mass index (28.4 vs. 31.1 kg/m. 2. , p < 0.001). Results. Differences in the rates of DVT, PE, or overall VTE were not statistically significant between the groups. Symptomatic deep vein thrombosis (DVT) occurred in 2 patients (0.91%) in the study group compared with 5 patients (0.40%) in the control group. Symptomatic pulmonary embolism (PE) occurred in 1 patient in the study group (0.45%) compared with 10 patients in the study group (0.80%). Mean flight time among the three patients who developed symptomatic VTE was 2.3 hours (range, 1.4 to 3.7 hours). Conclusion. Using a multimodal approach to prophylaxis with an emphasis on early mobilization, the rate of symptomatic VTE was very low among patients who flew during the early postoperative period following THA and TKA, and was not increased over the control population who did not fly. Although there may be some degree of self-selection bias among patients who choose to fly after surgery, allowing them to do so appears to a safe practice

We welcome letters to the Editor concerning articles which have recently been published. Such letters will be subject to the usual stages of selection and editing; where appropriate the authors of the original article will be offered the opportunity to reply.

Aims. Venous thromboembolism (VTE) is a potential complication of foot and ankle surgery. There is a lack of agreement on contributing risk factors and chemical prophylaxis requirements. The primary outcome of this study was to analyze the 90-day incidence of symptomatic VTE and VTE-related mortality in patients undergoing foot and ankle surgery and Achilles tendon (TA) rupture. Secondary aims were to assess the variation in the provision of chemical prophylaxis and risk factors for VTE. Methods. This was a multicentre, prospective national collaborative audit with data collection over nine months for all patients undergoing foot and ankle surgery in an operating theatre or TA rupture treatment, within participating UK hospitals. The association between VTE and thromboprophylaxis was assessed with a univariable logistic regression model. A multivariable logistic regression model was used to identify key predictors for the risk of VTE. Results. A total of 13,569 patients were included from 68 sites. Overall, 11,363 patients were available for analysis: 44.79% were elective (n = 5,090), 42.16% were trauma excluding TA ruptures (n = 4,791), 3.50% were acute diabetic procedures (n = 398), 2.44% were TA ruptures undergoing surgery (n = 277), and 7.10% were TA ruptures treated nonoperatively (n = 807). In total, 11 chemical anticoagulants were recorded, with the most common agent being low-molecular-weight heparin (n = 6,303; 56.79%). A total of 32.71% received no chemical prophylaxis. There were 99 cases of VTE (incidence 0.87% (95% CI 0.71 to 1.06)). VTE-related mortality was 0.03% (95% CI 0.005 to 0.080). Univariable analysis showed that increased age and American Society of Anesthesiologists (ASA) grade had higher odds of VTE, as did having previous cancer, stroke, or history of VTE. On multivariable analysis, the strongest predictors for VTE were the type of foot and ankle procedure and ASA grade. Conclusion. The 90-day incidence of symptomatic VTE and mortality related to VTE is low in foot and ankle surgery and TA management. There was notable variability in the chemical prophylaxis used. The significant risk factors associated with 90-day symptomatic VTE were TA rupture and high ASA grade. Cite this article: Bone Joint J 2024;106-B(11):1249–1256

Aims. The aim of this study was to evaluate the healthcare costs and benefits of enoxaparin compared to aspirin in the prevention of symptomatic venous thromboembolism (VTE) after total hip arthroplasty (THA) or total knee arthroplasty (TKA) using data from the CRISTAL trial. Methods. This trial-based economic analysis reports value for money as incremental cost per quality-adjusted life-year (QALY) gained in 2022 Australian dollars, compared to a single threshold value of AUD$70,000 per QALY. Event costs were estimated based on occurrence of VTEs and bleeds, and on published guidelines for treatment. Unit costs were taken from Australian sources. QALYs were estimated using CRISTAL six-month follow-up data. Sensitivity analyses are presented that vary the cost of VTE treatment, and extend the analyses to two years. Results. The CRISTAL trial found that enoxaparin was more effective than aspirin in preventing symptomatic VTE within 90 days of THA or TKA (risk difference 1.97% (95% confidence interval (CI) 0.54% to 3.41%; p = 0.007)). The additional cost after a THA or TKA was AUD$83 (95% CI 68 to 97) for enoxaparin, and enoxaparin resulted in an additional 0.002 QALYs (95% CI -0.002 to 0.005). Incremental cost per QALY gained was AUD$50,567 (95% CI 15,513, dominated) for enoxaparin. We can be 60% confident that the incremental cost per QALY does not exceed the willingness-to-pay threshold of AUD$70,000. Increasing the cost of VTE treatment and extension of costs and consequences to two years suggested greater confidence that enoxaparin is good value for money (70% and 63% confidence, respectively). Conclusion. This analysis provides strong evidence that enoxaparin thromboprophylaxis following THA or TKA reduced VTEs, but weak evidence of net economic benefits over aspirin. If the value of avoiding VTEs is high, and there is a strong likelihood of VTE-related health impairments, we can be more confident that enoxaparin is cost-effective compared to aspirin. Cite this article: Bone Joint J 2024;106-B(6):589–595

Introduction. VTE is a possible complication of foot and ankle surgery, however there is an absence of agreement on contributing risk factors in the development of VTE. The primary outcome of this study was to analyse the 90-day incidence of symptomatic VTE following foot and ankle surgery and to determine which factors may increase the risk of VTE. Methods. This was a national, multi-centre prospective audit spanning a collection duration of 9 months (2022/2023). Primary outcomes included incidence of symptomatic VTE and VTE related mortality up to 90 days following foot and ankle surgery and Achilles tendon rupture, and analysis of risk factors. Results. In total 11,363 patients were available for analysis. 5,090 patients (44.79%) were elective procedures, 4,791 patients (42.16%) were trauma procedures (excluding Achilles ruptures), 398 patients (3.50%) were acute diabetic procedures, 277 patients (2.44%) were Achilles ruptures undergoing surgery and 807 patients (7.10%) were Achilles ruptures treated non-operatively. There were 99 cases of VTE within 90 days of admission across the whole group (Total incidence = 0.87%), with 3 cases of VTE related mortality (0.03%). On univariate analysis, increased age and ASA grade showedhigher odds of 90-day VTE, as did previous cancer, stroke, history of VTE, and type of foot and ankle procedure / injury (p<0.05). However, on multivariate analysis, the only independent predictors for 90-day VTE were found to be the type of foot and ankle procedure (Achilles tendon rupture = Odd's Ratio 11.62, operative to 14.41, non-operative) and ASA grade (grade III/IV = Odd's Ratio 3.64). Conclusion. The incidence of 90-day post procedure VTE in foot and ankle surgery in this national audit was low. Significant, independent risk factors associated with the development of 90-day symptomatic VTE were Achilles tendon rupture management and high ASA grade

Aims. The purpose of this article was to review the current literature pertaining to the use of mobile compression devices (MCDs) for venous thromboembolism (VTE) following total joint arthroplasty (TJA), and to discuss the results of data from our institution. Patients and Methods. Previous studies have illustrated higher rates of post-operative wound complications, re-operation and re-admission with the use of more aggressive anticoagulation regimens, such as warfarin and factor Xa inhibitors. This highlights the importance of the safety, as well as efficacy, of the chemoprophylactic regimen. Results. Studies have shown a symptomatic VTE rate of 0.92% with use of MCDs for prophylaxis, which is comparable with rates seen with more aggressive anticoagulation protocols. A prior prospective study found that use of a pre-operative risk stratification protocol based on personal history of deep vein thrombosis, family history of VTE, active cancer, or a hypercoaguable state allowed for the avoidance of aggressive prophylactic anticoagulation in over 70% of patients while maintaining a low incidence of symptomatic VTE. Conclusion. Further investigation is needed into the role of aspirin in VTE prophylaxis as well as the efficacy of MCDs as stand-alone prophylactic treatment. Cite this article: Bone Joint J 2017;99-B(1 Supple A):8–13

Introduction. Total contact casting (TCC) is one of the most commonly utilized modalities in the management of diabetic feet. We undertook a retrospective review to determine the prevalence of symptomatic VTE events in patients treated in a weight bearing TCC in our diabetic foot unit, and to formulate guidelines for VTE prophylaxis. Methods. Electronic records were reviewed to identify all patients treated in a TCC between 2014 and 2021. Data collection included patient demographics, comorbidities, period of immobilization in TCC, the incidence of VTE events, and any VTE prophylaxis prescribed during their period in TCC. Results. 549 patients were identified who had at least one episode of TCC. Mean age was 67 years (range 28 to 94 years) and the mean duration in cast was 10.2 weeks (range 0.3–46 weeks). Only 6 patients (1.1%) were prescribed chemical thrombo-prophylaxis during their period in TCC. Mean body mass index (BMI) for these patients was 32.3 (Range 18.4–58.9). Other significant comorbidities: 81% (n-444) of patients had associated cardio-vascular comorbidities; 54 % (n-296) had renal comorbidities including 22% (n-121) having had dialysis and 4.2% (n-23) with renal transplants. Eight of the 549 patients (1.5%) had suffered a VTE event of which only 2 (0.36%) were during the period of immobilization in TCC. One was a symptomatic DVT (0.18%) and the another was an asymptomatic (incidental) finding of pulmonary embolism (PE). There was no mortality related to the VTE episodes. Conclusion. NICE guidelines state that one should “Consider pharmacological VTE prophylaxis for patients with lower limb immobilization”. Our study finds that patients treated in a weight bearing TCC do not require routine pharmacological VTE prophylaxis, in spite of an extended period of lower limb immobilization and significant medical comorbidities

We report an audit of 208 patients with a mean age of 39 years (16 to 65) attending the Orthopaedic Assessment Unit at the Wellington Hospital between January 2006 and December 2007 with an injury of the tendo Achillis requiring immobilisation in a cast. Information on assessment of venous thromboembolism (VTE) risk, prophylactic measures and VTE events for all patients was obtained from the medical records. A VTE risk factor was documented in the records of three (1%) patients. One of the 208 patients received aspirin prophylaxis; none received low molecular weight heparin. In all, 13 patients (6.3%, 95% confidence interval 3.4 to 10.5) developed symptomatic VTE during immobilisation in a cast, including six with a distal deep-vein thrombosis (DVT), four with a proximal DVT, and three with a confirmed pulmonary embolus. This incidence of symptomatic VTE is similar to that reported following elective hip replacement. We propose that consideration is given to VTE prophylaxis during prolonged immobilisation of the lower limbs in a cast, to ensure that the same level of protection is provided as for patients undergoing elective hip replacement

Prolonged bedrest in hospitalized patients is a major risk factor for venous thromboembolism (VTE), especially in high risk patients with hip fracture. Thrombelastography (TEG) is a whole blood viscoelastic hemostatic assay with evidence that an elevated maximal amplitude (MA), a measure of clot strength, is predictive of VTE in orthopaedic trauma patients. The objective of this study was to compare the TEG MA parameter between patients with hip fracture who were more mobile post-operatively and discharged from hospital early to patients with hip fracture with reduced mobility and prolonged hospitalizations post-operatively. In this prospective cohort study, TEG analysis was performed in patients with hip fracture every 24-hours from admission until post-operative day (POD) 5, then at 2- and 6-weeks post-operatively. Hypercoagulability was defined by MA > 65. Patients were divided into an early (within 5-day) and late (after 5-day) discharge group, inpatient at 2-weeks group, and discharge to MSK rehabilitation (MSK rehab), and long term care (LTC) groups. Two-sample t-test was used to analyze differences in MA between the early discharge and less mobile groups. All statistical tests were two-sided, and p-values < 0.05 were considered statistically significant. In total, 121 patients with a median age of 81.0 were included. Patients in the early discharge group (n=15) were younger (median age 64.0) and more likely to ambulate without gait aids pre-injury (86.7%) compared to patients in the late discharge group (n=105), inpatients at 2-weeks (n=48), discharged to MSK rehab (n=30), and LTC (n=20). At two weeks post-operative, the early discharge group was significantly less hypercoagulable (MA=68.9, SD 3.0) compared to patients in the other four groups. At 6-weeks post-operative, the early discharge group was the only group to demonstrate a trend towards mean MA below the MA > 65 hypercoagulable threshold (MA=64.4, p=0.45). Symptomatic VTE events were detected in three patients (2.5%) post-operatively. All three patients had hospitalizations longer than five days after surgery. In conclusion, our analysis of hypercoagulability secondary to reduced post-operative mobility demonstrates that patients with hip fracture who were able to mobilize independently sooner after hip fracture surgery, have a reduced peak hypercoagulable state. In addition, there is a trend towards earlier return to normal coagulation status as determined by the TEG MA parameter. Post-operative mobility status may play a role in determining individualized duration of thromboprophylaxis following hip fracture surgery. Future studies comparing TEG to clinically validated mobility tools may more closely evaluate the contribution of venous stasis due to reduced mobility on hypercoagulation following hip fracture surgery

Prolonged bedrest in hospitalized patients is a major risk factor for venous thromboembolism (VTE), especially in high risk patients with hip fracture. Thrombelastography (TEG) is a whole blood viscoelastic hemostatic assay with evidence that an elevated maximal amplitude (MA), a measure of clot strength, is predictive of VTE in orthopaedic trauma patients. The objective of this study was to compare the TEG MA parameter between patients with hip fracture who were more mobile post-operatively and discharged from hospital early to patients with hip fracture with reduced mobility and prolonged hospitalizations post-operatively. In this prospective cohort study, TEG analysis was performed in patients with hip fracture every 24-hours from admission until post-operative day (POD) 5, then at 2- and 6-weeks post-operatively. Hypercoagulability was defined by MA > 65. Patients were divided into an early (within 5-day) and late (after 5-day) discharge group, inpatient at 2-weeks group, and discharge to MSK rehabilitation (MSK rehab), and long term care (LTC) groups. Two-sample t-test was used to analyze differences in MA between the early discharge and less mobile groups. All statistical tests were two-sided, and p-values < 0.05 were considered statistically significant. In total, 121 patients with a median age of 81.0 were included. Patients in the early discharge group (n=15) were younger (median age 64.0) and more likely to ambulate without gait aids pre-injury (86.7%) compared to patients in the late discharge group (n=105), inpatients at 2-weeks (n=48), discharged to MSK rehab (n=30), and LTC (n=20). At two weeks post-operative, the early discharge group was significantly less hypercoagulable (MA=68.9, SD 3.0) compared to patients in the other four groups. At 6-weeks post-operative, the early discharge group was the only group to demonstrate a trend towards mean MA below the MA > 65 hypercoagulable threshold (MA=64.4, p=0.45). Symptomatic VTE events were detected in three patients (2.5%) post-operatively. All three patients had hospitalizations longer than five days after surgery. In conclusion, our analysis of hypercoagulability secondary to reduced post-operative mobility demonstrates that patients with hip fracture who were able to mobilize independently sooner after hip fracture surgery, have a reduced peak hypercoagulable state. In addition, there is a trend towards earlier return to normal coagulation status as determined by the TEG MA parameter. Post-operative mobility status may play a role in determining individualized duration of thromboprophylaxis following hip fracture surgery. Future studies comparing TEG to clinically validated mobility tools may more closely evaluate the contribution of venous stasis due to reduced mobility on hypercoagulation following hip fracture surgery

Recent recommendations by the National Institute for Health and Care Excellence (NICE) suggest that all patients undergoing elective orthopaedic surgery should be assessed for the risk of venous thromboembolism (VTE). Little is known about the incidence of symptomatic VTE after elective external fixation. We studied a consecutive series of adult patients who had undergone elective Ilizarov surgery without routine pharmacological prophylaxis to establish the incidence of symptomatic VTE. . A review of a prospectively maintained database of consecutive patients who were treated between October 1998 and February 2011 identified 457 frames in 442 adults whose mean age was 42.6 years (16.0 to 84.6). There were 425 lower limb and 32 upper limb frames. The mean duration of treatment was 25.7 weeks (1.6 to 85.3). According to NICE guidelines all the patients had at least one risk factor for VTE, 246 had two, 172 had three and 31 had four or more. . One patient (0.23%) developed a pulmonary embolus after surgery and was later found to have an inherited thrombophilia. There were 27 deaths, all unrelated to VTE. The cost of providing VTE prophylaxis according to NICE guidelines in this group of patients would be £89 493.40 (£195.80 per patient) even if the cheapest recommended medication was used. . The rate of symptomatic VTE after Ilizarov surgery was low despite using no pharmacological prophylaxis. This study leads us to question whether NICE guidelines are applicable to these patients. . Cite this article: Bone Joint J 2014;96-B:426–30

The aim of this study was to identify factors independently associated with symptomatic venous thromboembolism (VTE) following acute Achilles tendon rupture (ATR), and to suggest a clinical VTE risk assessment tool for patients with ATR. From 2010–2018, 984 consecutive adults (median age 47yrs, 73% male) sustaining an ATR were retrospectively identified. There were 95% managed non-operatively (below-knee cast 52%, n=507/984; walking boot 44%, n=432/984), with 5% (n=45/984) undergoing primary operative repair (<6wks). VTE was diagnosed using medical records and national imaging archives, reviewed at a mean of 5yrs (1–10) post-injury. Regression was performed to identify factors independently associated with VTE. Incidence of VTE within 90 days of ATR was 3.6% (n=35/984; deep vein thrombosis 2.1% [n=21/984], pulmonary embolism 1.9% [n=19/984]). Age ≥50yrs (adjusted OR [aOR] 2.3, p=0.027), personal history of VTE/thrombophilia (aOR 6.1, p=0.009) and family history of VTE (aOR 20.9, p<0.001) were independently associated with VTE. These non-modifiable risk factors were incorporated into a VTE risk assessment tool. 23% of patients developing VTE (n=8/35) had a relevant personal or family history, but incorporating age into the tool identified 69% of patients with VTE (n=24/35). Non weight-bearing ≥2wks after ATR was also independently associated with VTE (aOR 3.2, p=0.026). Age ≥50 years, personal history of VTE/thrombophilia and a positive family history were independently associated with VTE following ATR. Incorporating age into our suggested VTE risk assessment tool enhanced sensitivity in identifying at-risk patients. Early weight-bearing in an appropriate orthosis may be beneficial in VTE risk reduction

Aims. To our knowledge, there is currently no information available about the rate of venous thromboembolism (VTE) or recommendations regarding chemoprophylaxis for patients whose lower limb is immobilized in a plaster cast. We report a retrospective case series assessing the rate of symptomatic VTE in patients treated with a lower limb cast. Given the complex, heterogeneous nature of this group of patients, with many risk factors for VTE, we hypothesized that the rate of VTE would be higher than in the general population. Patients and Methods. Patients treated with a lower limb cast between 2006 and 2018 were identified using plaster room records. Their electronic records and radiological reports were reviewed for details about their cast, past medical history, and any VTE recorded in our hospital within a year of casting. Results. There were 136 episodes of casting in 100 patients. The mean age was 55 years (22 to 91). The mean time in a cast was 45 days (five days to eight months). A total of 76 patients had neuropathy secondary to diabetes. No patient received chemical thromboprophylaxis while in a cast. One VTE (0.7% of casting episodes) was documented. This was confirmed by Doppler scan nine days after removing the cast. Conclusion. The frequency of VTE was higher than that of the general population (0.05%); this is most likely attributable to our patients’ apparent increase in VTE risk as suggested by The National Institute for Health and Care Excellence (NICE). These findings suggest that thromboprophylaxis is not routinely indicated in patients who undergo immobilization of the lower limb in a cast, although the risks of VTE should be assessed. While the cast itself does not pose an increased risk, other pathologies, such as active cancer, mean that each individual case needs to be considered on their merit. Cite this article: Bone Joint J 2019;101-B:691–694

Over a 13-year period we studied all patients who underwent major hip and knee surgery and were diagnosed with objectively confirmed symptomatic venous thromboembolism, either deep venous thrombosis or non-fatal pulmonary embolism, within six months after surgery. Low-molecular-weight heparin had been given while the patients were in hospital. There were 5607 patients. The cumulative incidence of symptomatic venous thromboembolism was 2.7% (150 of 5607), of which 1.1% had developed pulmonary embolism, 1.5% had deep venous thrombosis and 0.6% had both. Patients presented with deep venous thrombosis at a median of 24 days and pulmonary embolism at 17 days after surgery for hip fracture. After total hip replacement, deep venous thrombosis and pulmonary embolism occurred at a median of 21 and 34 days respectively. After total knee replacement, the median time to the presentation of deep venous thrombosis and pulmonary embolism was 20 and 12 days respectively. The cumulative risk of venous thromboembolism lasted for up to three months after hip surgery and for one month after total knee replacement. Venous thromboembolism was diagnosed after discharge from hospital in 70% of patients who developed this complication. Despite hospital-based thromboprophylaxis, most cases of clinical venous thromboembolism occur after discharge and at different times according to the operation performed

Rivaroxaban is a novel, oral, once-daily, direct Factor Xa inhibitor in advanced development for the prevention and treatment of venous thromboembolism (VTE). This study analysed the potential economic benefit attributable to the use of oral rivaroxaban relative to subcutaneous enoxaparin for extended VTE prophylaxis (35±4 days) after total hip replacement (THR). In RECORD1, rivaroxaban reduced the incidence of the composite primary efficacy endpoint (total VTE, including all-cause mortality) by 70%, compared with enoxaparin (p< 0.001). Symptomatic VTE occurred in 0.3% and 0.5% (p=0.22) of patients receiving rivaroxaban and enoxaparin, respectively. Major bleeding was low and similar in both groups: 0.3% and 0.1% (p=0.18), respectively. Potential savings associated with oral rivaroxaban were based on any reduction in the incidence of symptomatic VTE events, and reduced administration and monitoring costs. Analyses for both the US and the UK included only non-drug costs incurred by the healthcare sector. It was assumed that nurses spent 3 minutes/day administering enoxaparin and training patients to self-inject; assumed duration of hospital stay was 5 days. UK costs (based on the 2007 NICE Guidelines) also included full blood counts (FBCs) every 3 days, for up to 14 days, in patients receiving enoxaparin. Two analyses were performed: one assumed no difference in the occurrence of symptomatic VTE between treatments; the other assumed that the observed difference was real, but did not reach statistical significance. In the first analysis, assuming no difference in symptomatic VTE incidence, the total resource cost in the US was $46/patient for enoxaparin and $42.5/patient for rivaroxaban: a saving of $3.5/patient. For the UK, the total resource cost was £33/patient for enoxaparin and £7.5/per patient for rivaroxaban: a saving of £25.5/ patient. Savings were driven by reduced monitoring (FBCs) and administration costs. In the second analysis, assuming the observed difference in symptomatic VTE incidence was real, the US total resource cost was $57/patient for enoxaparin and $42.5/patient for rivaroxaban: a saving of $14.5/patient. For the UK, the total resource cost was £30/patients for enoxaparin and £7.5/patient for rivaroxaban: a saving of £22.5/patient. Savings were again driven by reduced monitoring and administration costs, and also reduced VTE incidence. Over 400,000 US patients undergo THR, and ~60,000 patients in England and Wales undergo THR annually. Thus, the potential cumulative cost savings with rivaroxaban are considerable

Venous thromboembolism (VTE) remains an immediate threat to patients following total hip and knee replacement. While there is a strong consensus that steps should be taken to minimise the risk to patients by utilising some forms of prophylaxis for the vast majority of patients, the methods utilised have been extremely variable. Clinical practice guidelines (CPGs) have been published by various professional organisations for over 25 years to provide recommendations to standardise VTE prophylaxis. Historically, these recommendations have varied widely depending in underlying assumptions, goals, and methodology of the various groups. This effort has previously been exemplified by the American College of Chest Physicians (ACCP) and the American Academy of Orthopaedic Surgeons (AAOS). The former group of medical specialists targeted minimising venographically proven deep vein thrombosis (DVT) (the vast majority of which are asymptomatic) as their primary goal prior to 2012. The latter group of surgeons targeted minimising symptomatic VTE. As a result prior to 2012, the recommendations of the two groups were widely divergent. In the past year, both groups have reassessed the current literature with the principal goals of minimising symptomatic VTE events and bleeding complications. As a result, for the first time the CPGs of these two major subspecialty organisations are in close agreement

Introduction: The standard length of hospital stay after total hip arthroplasty (THA) can be as short as 4 days. However, the risk of venous thromboembolism (VTE) extends beyond this period of hospitalization. A pooled analysis of the RECORD1 and RECORD2 studies evaluated the efficacy, safety, and timing of events with rivaroxaban compared with enoxaparin for the prevention of VTE after THA. Methods: Patients (N=7,050) were randomized to receive oral rivaroxaban 10 mg once daily starting postoperatively (for 31–39 days) or subcutaneous enoxaparin 40 mg once daily starting preoperatively (for 31–39 days in RECORD1, and 10–14 days followed by placebo in RECORD2). The primary efficacy endpoint was the composite of symptomatic VTE and all-cause mortality. The safety endpoints were treatment-emergent major bleeding, major bleeding including surgical-site bleeding, major bleeding plus clinically relevant non-major (CRNM) bleeding, and any bleeding. The primary efficacy endpoint was assessed during treatment. The incidence and timing of the safety endpoints were assessed after the first dose of study medication and up to 2 days after the last dose. Results: Rivaroxaban significantly reduced the incidence of symptomatic VTE and all-cause mortality compared with enoxaparin regimens (0.44% vs 1.01%, respectively; p=0.006), with no significant differences in major bleeding (0.2% vs 0.09%; p=0.219) or the composite of major plus CRNM bleeding (3.23% vs 2.61%; p=0.141). Of the symptomatic VTE and all-cause mortality events, 73% and 86% occurred after day 4 with the rivaroxaban and enoxaparin regimens, respectively. For the composite of major plus CRNM bleeding, 48% and 33% of events occurred after day 4 with the rivaroxaban and enoxaparin regimens, respectively. Conclusion: Rivaroxaban significantly reduced symptomatic VTE and all-cause mortality after THA compared with the enoxaparin regimens, with no significant difference in bleeding events. Major plus CRNM bleeding was more likely to occur earlier than day 4, whereas the majority of symptomatic venous thromboembolic events occurred after day 4. These results highlight the relevance of extended duration of thromboprophylaxis after THA as most VTE events occur post-discharge

Introduction Recent changes in the management of hip fracture surgery patients may have resulted in changes in the epidemiology of venous thromboembolism (VTE). We aimed to determine the incidence of and predictive risk factors for symptomatic VTE and mortality, and the use of VTE prophylaxis, in hip fracture surgery patients. Methods Hip fracture surgery patients were enrolled in 525 hospitals in France between October 1 and November 30, 2002 in this prospective, multicenter, epidemiological study. VTE was assessed by a critical events committee at 3 months. Risk factors were identified using logistic regression. Results Data were from 6860 (97%) of 7019 enrolled patients. Median age was 82 years and 76% were women. 47% were femoral neck and 53% trochanteric or subtrochanteric fractures. All were operated on (osteosynthesis 57%, half prosthesis 35% and THR 8%). Prophylaxis with a low-molecular-weight heparin (LMWH) was administered perioperatively in 97.6% and for at least four weeks in 69.5% (median prophylaxis duration: 6 weeks). The rate of symptomatic VTE at 3 months was 1.34% (95% CI: 1.04– 1.64). There were 16 PE (rate 0.25%) and 3 were fatal. The rate of major bleeding was 1.2%. At 6 months, 1006 patients (14.7%) were dead. Significant risk factors for symptomatic VTE were: history of VTE (OR 2.9), induction of anesthesia until arrival in the recovery room > 2 hrs (OR 2.5), and varicose veins/post-thrombotic syndrome (OR 2.2). LMWH prophylaxis significantly reduced the risk of symptomatic VTE (OR 0.2). Significant predictive factors for mortality were: cancer (OR 2.3), surgical complications requiring re-intervention (OR 1.8), confusion before fracture (OR 1.8), ASA score ≥3 (OR 1.7), BMI ≤18 kg/m2 (OR 1.6), congestive heart failure (OR 1.6), atrial fibrillation (OR 1.6) and age > 80 years (OR 1.1). Conclusions Extended LMWH prophylaxis is applied widely after hip fracture surgery in France. The current rate of postoperative VTE is low. However, a major change in the care of these patients is needed because of the high mortality rate