The number of arthroplasties being performed increases each year. Patients undergoing an arthroplasty are at risk of venous thromboembolism (VTE) and appropriate prophylaxis has been recommended. However, the optimal protocol and the best agent to minimise VTE under these circumstances are not known. Although many agents may be used, there is a difference in their efficacy and the risk of bleeding. Thus, the selection of a particular agent relies on the balance between the desire to minimise VTE and the attempt to reduce the risk of bleeding, with its undesirable, and occasionally fatal, consequences. Acetylsalicylic acid (aspirin) is an agent for VTE prophylaxis following arthroplasty. Many studies have shown its efficacy in minimising VTE under these circumstances. It is inexpensive and well-tolerated, and its use does not require routine blood tests. It is also a ‘milder’ agent and unlikely to result in haematoma formation, which may increase both the risk of infection and the need for further surgery. Aspirin is also unlikely to result in persistent wound drainage, which has been shown to be associated with the use of agents such as low-molecular-weight heparin (LMWH) and other more aggressive agents. The main objective of this review was to summarise the current evidence relating to the efficacy of aspirin as a VTE prophylaxis following arthroplasty, and to address some of the common questions about its use. . There is convincing evidence that, taking all factors into account, aspirin is an effective, inexpensive, and safe form of VTE following arthroplasty in patients without a major risk factor for VTE, such as previous VTE. Cite this article: Bone Joint J 2017;99-B:1420–30

Venous thromboembolism (VTE) is a preventable cause of morbidity and mortality in patients undergoing elective hip arthroplasty surgery. The balance of post-operative VTE prophylaxis and risk of post-operative haemorrhage remains at the forefront of surgeon's mind. The National Institute for Clinical Excellence (NICE) has altered their prophylaxis guidance in the setting of total hip arthroplasty (THA). The aim of this study was to present the VTE incidence in 8,890 patients who underwent total hip arthroplasty between January 1997 and March 2018 with Aspirin as the primary agent for pharmacological thromboprophylaxis. Analysis of prospective data collection from consecutive patients undergoing THA was performed with the incidence of deep vein thrombosis (DVT) and pulmonary embolism (PE) occurring within 6 months of the index operation as the primary outcome measure. 90-day all-cause mortality of this cohort of patients was also analysed. 8890 patients were reviewed. This included 7235 primary, 224 complex primary and 1431 revision cases. The incidence of DVT was 0.64% after elective THA and the incidence of PE was 0.54%. There was no difference in the incidence between primary and revision cases. The 90-day all-cause mortality was 0.88%. Cardiovascular and respiratory disease were the main causes of death following surgery. Only 0.03% of deaths (n= 3) within 90 days of index surgery were due to VTE. Our results support the use of aspirin as an effective form of prophylaxis against VTE following THA. It is not associated with an increased incidence in symptomatic DVT, PE or death compared to other published studies. The fact that it is inexpensive, readily available, requires no monitoring and does not pose an increased risk of bleeding are other attractive advantages of using aspirin for VTE prophylaxis

Purpose: The objective of this study was to examine the relationship between aspirin and other non-steroidal anti-inflammatory drugs (NSAIDS) on postoperative blood loss following Total Knee Arthroplasty. Methods: We prospectively examined the pre-operative consumption of aspirin and NSAIDS and haematological parameters of 50 consecutive patients undergoing Total Knee Arthroplasty. 22 (44%) patients were on aspirin only, 17 (34%) patients on aspirin and another NSAID and 11 (22%) patients were taking neither aspirin nor a NSAID. (All patients received 150mg of aspirin the evening before surgery as DVT prophylaxis). Results: The average pre-operative haemoglobin of the group taking aspirin and a NSAID, aspirin only and neither aspirin nor NSAID group was 12.9g/dl, 13,8g/dl and 13.49g/dl respectively. The drop between their pre-operative level and Day 3 Haemoglobin level was 3.788g/dl, 4.45g/dl and 4.28g/dl respectively. The same trend was reflected in the PCV drops of 0.111, 0.133 and 0.1273 respectively. Transfusion rates for the three groups showed that those on aspirin and another NSAID had the highest rate with an average of 0.235 units per patient compared to 0.136 for those on aspirin only and 0.10 for those on neither aspirin nor NSAID. Discussion: These findings indicate that the ingestion of aspirin or a NSAID preoperatively does not increase the amount of blood loss following total knee arthroplasty (TKA). The higher transfusion rates in the aspirin and NSAID group is because of the lower preoperative haemoglobin as compared to the other groups studied. Conclusion: Observation of transfusion trends within our unit has shown a transfusion rate of 18% in patients with a preoperative Haemoglobin level of greater than 13.0g/dl as compared to 48% with a haemoglobin level of 13.0g/dl or less (review of 180 consecutive patients undergoing Total Knee Arthroplasty). The ingestion of aspirin and NSAID does not increase blood loss following TKA but significantly have a lower preoperative Hb level. We feel that pre-operative Haemoglobin levels are the best predictors of transfusion requirements following total knee arthroplasty

Background. Few studies have compared aspirin with DOACs (direct oral anticoagulants = direct thrombin inhibitors and factor Xa inhibitors) for venous thromboembolism (VTE) prophylaxis following total hip and knee replacement (THR and TKR). We assessed the efficacy and safety of aspirin compared with DOACs for VTE prophylaxis following THR and TKR using the world's largest joint replacement registry. Methods. We studied the National Joint Registry linked to English hospital inpatient episodes for 218,650 THR and TKR patients. Patients receiving aspirin were matched separately to (1) direct thrombin inhibitors, and (2) factor Xa inhibitors using propensity scores. Outcomes assessed at 90 days included VTE, length of stay, and adverse events. Results. Following THR, the risk of VTE was significantly lower in patients receiving direct thrombin inhibitors (0.44%; odds ratio (OR)=0.69, 95% confidence interval (CI)=0.55–0.87, p=0.002) and factor Xa inhibitors (0.37%; OR=0.63, CI=0.47–0.85, p=0.003) compared with aspirin (0.63%). Following THR, direct thrombin inhibitors (coefficient=−0.37, CI=−0.43 to −0.31, p<0.001) and factor Xa inhibitors (coefficient=−0.80, CI=−0.87 to −0.74, p<0.001) reduced length of stay compared with aspirin. Similar findings for both outcomes were observed following TKR. Compared with aspirin, DOACs did not increase the risk of short-term revision surgery; reoperation; major haemorrhage; wound disruption; surgical site infection; and mortality. Conclusions. Following THR and TKR, the risk of VTE was lower in patients receiving DOACs compared with aspirin. DOACs were associated with a reduced length of stay, and DOACs did not increase the risk of further surgery, wound problems, bleeding complications, or mortality compared with aspirin

Aims. Thromboprophylaxis following Total Hip Replacement (THR) surgery remains controversial, balancing VTE prevention against wound leakage and subsequent deep infection. We analysed the 90 day cause of death post THR in our institution after the implementation of new thromboprophylactic policy of low dose aspirin for low risk patients, as part of a multimodal regime. Those at high risk were anticoagulated. Patients and methods. The PAS database was used to identify patients undergoing primary THR between January 2012 and June 2017 at The Royal Derby Hospital, and all deaths within 90 days. Trauma cases were excluded. Case note review and Coroner's verdict were utilised to ascertain cause of death. Results were compared to a previous study at the same institution prior to the introduction of the new policy, where thromboprophylaxis was decided upon by surgeon preference for either LMWH, aspirin or warfarin. Results. During this period 4021 THRs were performed. The rate of mortality was 0.22% at 90 days. This compares to 0.58% in the previous study with the only other factor changing being the rapidity of post op mobilization. Of the 9 deaths, only one was due to fatal pulmonary embolism. None of the deaths were at high risk of VTE. This compared to 5 fatal pulmonary embolism deaths in1838 patients in the previous study in the LMWH group. The leading causes of death were heart failure and lower respiratory tract infection. Conclusion. Our institution reports a similar 90 day (0.22%) mortality using aspirin to that in the last 5 years on the NJR (0.3%) in which over 80% use LMWH. We confirm that fatal PE following elective THR with a multi-modal prophylaxis regime is rare. Changing to low dose aspirin in low risk patients is a safe option

Venous thromboembolism (VTE) is a serious complication after total hip and knee arthroplasty. There is still no consensus regarding the best mode of thromboprophylaxis after lower limb arthroplasty. The aim of this study was to ascertain the efficacy, safety profile and rate of adverse thromboembolic events of aspirin as extended out of hospital pharmacological anticoagulation for elective primary total hip and knee arthroplasty patients and whether these rates were comparable with published data for low molecular weight heparin (LMWH). Data was extracted from a prospective hospital acquired thromboembolism (HAT) database. The period of study was from 1st Jan 2013-31st Dec 2016 and a total of 6078 patients were treated with aspirin as extended thromboprophylaxis after primary total hip and knee arthroplasty. The primary outcome measure of deep vein thrombosis and pulmonary embolism within 90 days postoperatively was 1.11%. The secondary outcome rates of wound infection, bleeding complications, readmission rate and mortality were comparable to published results after LMWH use. The results of this study clearly show that Aspirin, as part of a multimodal thromboprophylactic regime, is an effective and safe regime in preventing VTE with respect to risk of DVT or PE when compared to LMWH. It is a cheaper alternative to LMWH and has associated potential cost savings

Introduction. Patients undergoing total knee arthroplasty (TKA) are at high risk of post operative venous thromboembolism (VTE). Edoxaban, the oral direct and selective factor Xa inhibitor, is available for preventing VTE after TKA. Recently, patients often take antiplatelet drugs including aspirin for their past illness. In our hospital, patients, in general, undergoing TKA receive edoxaban, but patients with aspirin for past illness receive only aspirin for preventing VTE. The aim of this study was to compare edoxaban and aspirin for preventing VTE in patients undergoing TKA. Materials and methods. From April 2012 to March 2014, 137 patients underwent primary TKA under general anesthesia with epidural anesthesia or femoral/ sciatic nerve block. Patients were excluded following; (1) renal dysfunction, (2) have taken anticoagulants such as warfarin for past illness. Finally, a total of 120 patients were enrolled. At the surgery, tourniquet was inflated and mid-vastus approach was used. After prosthesis implantation, tourniquet was deflated and drain tube was inserted. Intra and after operation, an intermittent pneumatic compression device was used. At postoperative day 2, edoxaban or aspirin started after removal of epidural anesthesia or drainage tube. Ninety-seven patients were assigned to receive edoxaban once daily (group E), and the rest of 23 received aspirin again same as before (group A). Edoxaban were scheduled to continue for 10 days. DVT diagnosis. At postoperative day 7, compression and colored Doppler imaging was taken for bilateral common femoral veins, superficial veins, popliteal veins and calf veins by skilled clinical technologist. Augmentation by calf squeezing and by dropped lower leg down were included. Diagnosing DVT criteria was loss of vein compressibility, presence of intraluminal echogenicity and absence of venous flow. D-dimer levels. At preoperative, postoperative days 7 and 14, plasma D-dimer levels were measured. Statistical analysis. Data were compared using independent t-test or the chi-square test. A significant difference was set at p<0.05. Results. Patients’ characteristics were shown in table 1. Age in the group A was significantly higher than in the group E. The total incidence of DVT was 40%. The incidence of DVT was significantly decreased in group E compared to group A at day 7 (group E: 34% versus group A: 65%, p<0.01) (table 2). The D-dimer level in group E was significantly decreased at postoperative day 7 (13.2 ± 6.8 (mean ± SD) vs 17.0 ± 9.1, p<0.05). At day 14, there were no significant differences (Figure 1). Discussion. In this study, edoxaban decreased the incidence of DVT after TKA compared to aspirin. The result of D-dimer supported the efficacy of edoxaban. Results showed that edoxaban is effective for preventing DVT following TKA. Recently, TKA patients often take antiplatelet drugs including aspirin for their past illness. It is still controversial to add an antithrombotic drug for preventing VTE. The incidence of DVT with aspirin was higher than that with edoxaban. Thus, patients received only aspirin might be needed not only to pay attention to VTE, but also to add anticoagulants as edoxaban for preventing VTE

The National Institute for Health and Clinical Excellence (NICE) has thus far relied on historical data and predominantly industry-sponsored trials to provide evidence for venous thromboembolic (VTE) prophylaxis in joint replacement patients. We argue that the NICE guidelines may be reliant on assumptions that are in need of revision. Following the publication of large scale, independent observational studies showing little difference between low-molecular-weight heparins and aspirin, and recent changes to the guidance provided by other international bodies, should NICE reconsider their recommendations?. Cite this article: Bone Joint Res 2014;3:146–9

Thromboembolic disease is associated with a high degree of morbidity and mortality. There is increasing pressure for elective orthopaedic patients, including those undergoing foot and ankle surgery, to be prescribed chemical thromboprophylaxis post-operatively in order to reduce the risk of a thromboembolic event. The risks of chemical thromboprophylaxis in terms of increased bleeding, wound problems and HIT are well documented. The aim of this study was to determine the incidence of clinically significant thromboembolic events in patients undergoing elective foot and ankle surgery with and without the use of aspirin. We audited a consecutive series of 1625 patients undergoing elective foot and ankle surgery between 2003 and 2010. Between 2003 and 2006 inclusive, aspirin was used post operatively as chemical thromboprohylaxsis. Between 2007 and 2010, no chemical thromboprohylaxsis was used. The follow-up period for all patients was at least three months post-operatively. Most patients were reviewed at 3 months by the senior surgeon. Those who were reviewed less than 3 months (patients undergoing minor procedures) were contacted via telephone to confirm whether a thromboembolic event had been diagnosed. There was no loss to follow up. Of the 1625 patients, 555 patients received aspirin and 1070 patients received no chemical thromboprohylaxsis. 5 of 1625 (0.31%) patients developed a clinically significant thromboembolic event. 3 patients developed a DVT at an average time of 5 weeks post operatively. 2 patients developed non-fatal PE at an average time of 7 weeks post operatively. 3 of the 5 thromboembolic events occurred in the aspirin group (all DVT's) whereas 2 of the 5 (all PE) developed in the non aspirin group. The incidence of clinically significant thromboembolic events is low in elective orthopaedic foot and ankle surgery. We suggest that the benefit of chemical thromboprophylaxis does not outweigh its potential risks in foot and ankle surgery

Introduction: The recent BOA blue book on blood conservation in elective orthopaedic surgery highlighted the need for blood saving strategies to be implemented. Perioperative management guidelines of oral anti-coagulation and anti-thrombosis medication have to date concentrated on warfarin use. Information and guidelines on aspirin usage in elective orthopaedics and its effects post operatively are limited. Methods: Data was collected prospectively from 1936 patients who underwent 2024 primary unilateral total hip replacement in a single institution. All patients were treated with the same postoperative transfusion regime and thromboembolic prophylaxis. Preoperative medication, haemoglobin levels and patient demographics were recorded by a standard assessment. Post op transfusion requirements and haemoglobin levels were noted throughout the postoperative period. Results: Multivariate analysis revealed that preoperative aspirin use was a significant independent predictor of postoperative transfusion requirement (p< 0.001). Discussion: Expanding indications for the use of aspirin for primary and secondary cardiovascular disease prevention have meant that large numbers of our patients undergoing total hip replacement are concurrently taking the drug. With increasing and emerging evidence of the risks involved in blood transfusion, including vCJD transmission and immune related reactions coupled with reduced supplies of donor blood further measures to reduce transfusion requirement are needed. We recommend that in the absence of absolute contraindications to stopping aspirin therapy, it should be omitted for 1 week prior to total hip replacement

Introduction: Venous thromboembolism is a major cause of morbidity and mortality in hospitalised patients and patients undergoing major orthopaedic surgery are at high risk from venous thromboembolism. Thromboprophylaxis, both mechanical and chemical, is commonly administrated to reduce fatality from thromboembolism after surgery. However, there is no convincing evidence in the literature demonstrating that routine chemothromboprophylaxis reduces death rates from pulmonary embolus. Furthermore, it is unclear from the literature which thromboprophylactic agent, if any, should be used. Recent NICE guidelines have recommended that heparin should be routinely administered to patients under-going THR to prevent thromboembolism, although it is unclear from the existing evidence if heparin is the most effective. However, research has suggested that aspirin, which is a low cost prophylactic agent, is effective in preventing DVT and PE after orthopaedic surgery. The aim of this study was to determine the 90-day mortality rate after THR using aspirin as a prophylactic agent. Patients and Methods: Between 2003–2006, 2,286 patients underwent primary THR and 372 patients underwent revision hip replacement (RHR). Routine chemothromboprophylaxis consisting of aspirin 75mg daily for 6 weeks. In addition all patients were treated with anti-thromboembolic stockings. 40mg of subcutaneous clexane, in lieu of aspirin, was given daily to all patients who had previously suffered from a pulmonary embolus or deep venous thrombosis. Patients who died within 90 days of surgery had their death certificates examined. Retrieval at 90 days with regard to death was 100%. Results:. Primary THR. One patient (0.04%) died within 30 days of surgery and a further 3 (0.13%) died between day 30 and day 90, giving a total mortality at 90 days of 0.17% (4/2,286). One patient (0.04%) died from PE and the other 3 patients (0.13%) died from non-vascular causes. Revision hip replacement. One patient (0.27%) died within 30 days of surgery and a further 1 patient (0.27%) died between day 30 and day 90, giving a total mortality at 90 days of 0.54% (2/367). Both patients died from non-vascular causes. Discussion: This study found that the 30-day mortality rate for primary THR and RHR was 0.08% and the 90-day mortality rate was 0.23%. In this study, there was only one death from PE and no deaths from arterial complications. Therefore, although NICE guidelines suggest the use of heparin, this study found that routine aspirin administration is beneficial in protecting against early death after THR because of both thromboembolism and adverse arterial events

Background: Percutaneous compression plating (PCCP) is used for the fixation of intertrochanteric hip fractures by a minimally invasive technique. While offering several advantages compared to classic open reduction and internal fixation, the technique does not allow direct hemostasis. We aimed to assess the effect of regular aspirin use on blood loss, transfusion requirements and wound complications in patients undergoing urgent fixation using this technique. Methods: The study involved 326 patients who presented to our hospital with an intertrochanteric fracture. Parameters recorded included time to surgery, blood loss (assessed by pre and post operative hemoglobin concentrations), and transfusion requirements. The status of wound healing was evaluated, with specific reference to hematoma formation. The influence of regular pre-operative aspirin use was analyzed with respect to these outcome measures. Results: 32% of patients were regular aspirin users, and were comparable to the non aspirin group. There was no significant difference between the aspirin and non aspirin groups in terms of preoperative hemoglobin concentrations, perioperative changes in hemoglobin levels, and transfusion requirements. The severity of wound hematoma and the number of drainage procedures was not significantly different between the two groups. In a multivariate logistic regression analysis (composite complications. *. versus no complications as the dependent variable. R. 2. =0.108, P< 0.001), only delay to surgery was associated with a higher complication rate. *. Composite complications defined as transfusion ≥3 units, abnormal wound hematoma and length of stay ≥ 10 days. Conclusion: Regular aspirin use pre-operatively is not associated with increased blood loss, transfusion requirements and wound complications in patients treated with this percutaneous fixation technique. Rather, it is the delay to surgery that is associated with a composite bad outcome. Our data suggest that patients on aspirin can safely undergo urgent non-delayed fracture fixation using the PCCP

The Pulmonary Embolism Prevention (PEP) Trial was designed to assess the effects of a 35 day course of aspirin (160 mg daily) on the risks of thromboembolic events, other cardiovascular outcomes and bleeding among individuals undergoing surgery for hip fracture or joint replacement. From 1992 to 1998, 148 hospitals in Australia, New Zealand, South Africa, Sweden and the United Kingdom randomised 13,356 hip fracture patients, and 22 hospitals in New Zealand randomised 4,088 elective arthroplasty patients. Among hip fracture patients, aspirin produced proportional reductions in PE of 43% (95% confidence interval [CI] 18% to 60%; 2P=0.002) and symptomatic DVT of 29% (95% CI 3% to 48%; 2P=0.03). PE or DVT was confirmed in 105 (1.6%) of 6679 patients allocated aspirin versus 165 (2.5%) of 6677 allocated placebo, representing an absolute reduction of 9±2 per 1000 and a proportional reduction of 36% (95% CI 19% to 50%; 2P=0.0003). Aspirin prevented 4±1 fatal pulmonary emboli per 1000 treated (18 aspirin vs 43 placebo deaths), representing a proportional reduction of 58% (95% CI 27% to 76%; 2P=0.002), with no apparent effect on deaths from other vascular (hazard ratio 1.04; 95% CI 0.86 to 1.26) or non-vascular cause (1.01; 95% CI 0.84 to 1.23). Deaths due to bleeding were rare (13 aspirin vs 15 placebo), but there was an excess of 6±3 post-operative transfused bleeds per 1000 allocated aspirin (2P=0.04). Among elective arthroplasty patients, venous thromboembolism rates were lower but the proportional effects of aspirin appeared similar to those among hip fracture patients

Background. The most appropriate form of chemical thromboprophylaxis following knee replacement is a contentious issue. Most national guidelines recommend the use of low molecular weight Heparin (LMWH) whilst opposing the use of aspirin. We compared thromboembolic events, major haemorrhage and death after knee replacement in patients receiving either aspirin or LMWH. Methods. Data from the National Joint Registry for England and Wales was linked to an administrative database of hospital admissions in the English National Health Service. A total of 156 798 patients undergoing knee replacement between April 2003 and September 2008 were included and followed up for 90 days. Multivariable risk modelling was used to estimate odds ratios adjusted for baseline risk factors (AOR). An AOR < 1 indicates that risk rates are lower with LMWH than with aspirin. Results. In all, 23.1% of patients were prescribed aspirin and 76.9% LMWH. We found no statistically significant differences in the rate of pulmonary embolism (aspirin 0.49%, LMWH 0.45%, AOR 0.88; 95% confidence intervals (CI) 0.74 to 1.05), 90-day mortality (0.39% versus 0.45%, AOR 1.13; 95% CI 0.94–1.37) and major haemorrhage (0.37% versus 0.39%, AOR 1.01; 95% CI 0.83–1.22). There was a significantly greater likelihood of requirement for return to theatre in the aspirin group (0.26% versus 0.19%, AOR 0.73; 95% CI 0.58–0.94). Discussion. Between patients receiving LMWH or aspirin, there was no difference in the risk of pulmonary embolus, 90-day mortality and major haemorrhage. These results should be considered when the existing guidelines for thromboprophylaxis after knee replacement are reviewed

Current orthopedic practice requires consideration of apparently contradictory recommendations regarding VTE prevention among THR/TKR patients. American College of Chest Physicians (ACCP) 8th Clinical Practice Guidelines for the Prevention of Venous Thromboembolism recommend against aspirin for VTE prophylaxis in any patient. 1. The American Academy of Orthopedic Surgeons (AAOS) Guideline recommends pulmonary embolism risk stratification, then implementation of one of many possible courses including the use of aspirin. 2. . We conducted a prospective observational study among consecutive patients presenting for total hip or knee arthroplasty. Pre-operative PE risk stratification was performed at the discretion of the surgeon. Patients identified as usual risk for PE received aspirin. Patients considered being at elevated risk for PE received warfarin. This observational study protocol called for one year of data collection. At approximately 8 months 656 patients were enrolled, and the surgeon principally implementing PE risk stratification and administration of aspirin chose to stop enrolling patients due to a high incidence of pulmonary emboli. One hundred fifty five patients received thromboprophylaxis with aspirin 600 mg PR in the PACU, then 325 mg BID for one month (reduced to 81 mg daily if GI symptoms were present). The remaining 501 patients received an ACCP-based warfarin protocol managed by a pharmacist anticoagulation management service. Our hypothesis is the null hypothesis; that an AAOS-based approach to hromboembolism prevention is not inferior to an ACCP-based approach. The a priori primary endpoints of the AVP Study are clinically overt VTE, DVT, PE, major bleeding, and death. All patients will receive a 90 day follow-up questionnaire in person or by telephone. Additionally, the electronic medical record of Intermountain Healthcare will be interrogated for ICD-9 codes germane to the outcomes of interest. Ninety day follow-up has been completed for approximately 140 patients. The dataset will be locked upon completion of the 90 day follow-up among those patients who last received PE risk stratification and aspirin therapy (data lock early June, 2009). We anticipate preliminary data available for report by July, 2009

Following the outcomes of the RECORD trials the protocol of extended thromboprophylaxis in patients undergoing elective primary total hip or knee arthroplasty has been changed in our institution. Between June 2008 and May 2009 patients were offered extended thromboprophylaxis with 150mg of aspirin daily, commencing preoperatively on admission and continuing for a total of six weeks. From June 2009 onwards patients were treated with 10mg of rivaroxaban once daily for two weeks following total knee and five weeks following total hip arthroplasty commencing 4 to 6 hours postoperatively. Our cohorts were 700 patients before and after the introduction of the new regimen. The two groups were matched for age, sex and type of operation. All patients with no contraindication to treatment with aspirin or rivaroxaban respectively undergoing elective primary total hip or knee arthroplasty were included in the study. Patients receiving warfarin on admission were treated with warfarin postoperatively and were excluded. We have compared the two treatment protocols in terms of safety and efficacy. Results focus on 4 safety outcome measures including mortality, haemorrhagic complications, transfusion requirements and infection rates and 2 efficacy outcome measures including thromboembolic complications and length of inpatient stay. Rates of DVT were equal in the two cohorts (P< 0.005) as were the mortality rates. Transfusion requirements post-operatively were not affected by the introduction of the new regimen however there was a significant increase in both return to theatre rates and prolonged wound ooze (P< 0.005). Infection rates were slightly higher in the cohort treated with rivaroxaban but this was not statistically significant. We conclude that further trials need to be done to confirm the suitability of routine use of rivaroxiban

Upper gastrointestinal (GI) bleeding in patients who undergo hip and knee arthroplasty tends to be associated with NSAID use, steroid intake, pre-existing peptic ulcers and smoking. The use of Aspirin for thromboprophylaxis is an added risk for the occurrence of GI Bleed. The aim of this study was to determine if the use of peri-operative oral Ranitidine reduces the incidence of GI bleeding when Aspirin thromboprophylaxis is used for hip and knee arthroplasty. Data from 1491 consecutive patients who underwent Hip and knee replacements at the James cook university hospital (Group 1) and 886 patients who underwent Hip and Knee replacements at the Friarage hospital, Northallerton (Group 2) was analysed to determine the incidence of Gastro intestinal Bleeding. All patients received 150 mg of Aspirin per day for a period of six weeks from the day of surgery. Additionally patients operated at the Friarage Hospital received 300 mg of oral Ranitidine per day, for three postoperative days. Patients with clinically symptomatic GI bleeding were evaluated by the Upper GI team. We observed that patients in Group 1 had a higher incidence of overt upper GI haemorrhage (n=14), which was statistically significant (p < 0.014) compared with patients in group 2(n=1). From the pooled data of both groups, there were 18 reported patients with symptomatic pulmonary embolism (0.75%) 3 of which were fatal (0.12%), phlebitis of deep leg veins in 31 patients (1.3%), deep vein thrombosis in 34 patients (1.43%), 5 of whom had embolic episodes, post operative infection in 22 patients (1.13%), and postoperative haemorrhage in 5 patients (0.2%). Thromboembolic phenomenon and pulmonary embolism was confirmed by autopsy in the three cases. Based on this experience, we recommend the use of peri-operative gastric protection when aspirin is used for thromboprophylaxis in hip and knee arthroplasty

Introduction. Venous thromboembolism (VTE), defined as either pulmonary embolism (PE) or deep venous thrombosis (DVT), is a rare, but serious complication following total hip arthroplasty (THA). Current VTE guidelines recommend pharmacologic agents with or without intermittent pneumatic compression devices (IPCDs). At our institution, both 81mg aspirin (ASA) twice a day (BID) and portable IPCDs were prescribed to THA patients at standard risk for VTE. The aim of this study is to determine if discontinuing the use of portable outpatient IPCDs is safe and does not increase the rate of VTE in patients undergoing THA. Methods. A retrospective review of 1,825 consecutive THA cases was conducted identifying patients with a VTE 90-days postoperatively. Patients were divided into two separate consecutive cohorts. Cohort one consisted of THA patients who received outpatient IPCDs for a period of 14 days (control). Cohort two consisted of THA patients without outpatient IPCDs (experimental). Patients were non-randomized to 81mg ASA BID for 28 days for VTE chemoprophylaxis. An interim power analysis was performed to determine the proper sample size. Results. A total of 748 patients were discharged with outpatient IPCDs while 1,077 patients were discharged without IPCDs. There were no VTE events found in control group (0%). The total VTE rate of the experimental group was 0.2% (2 PE and 1 DVT). There was no statistical difference between these rates (p=0.24). A binary logistic regression did not detect any significant associations for any VTE outcomes even after accounting for demographic differences. Conclusion. Our findings suggest that discontinued use of outpatient portable IPCDs is safe and does not increase the rate of VTE in standard risk patients undergoing THA while using 81mg ASA BID as VTE prophylaxis

Dabigatran etexilate (Pradaxa^®) is an oral direct thrombin inhibitor that was recently approved in Europe and Canada for the prevention of venous thromboembolism (VTE) in patients undergoing total knee arthroplasty (TKA) or total hip arthroplasty (THA) surgery. In the phase III studies, concomitant administration of selective nonsteroidal anti-inflammatory drugs (NSAIDs with t½≤12 hours) and acetylsalicylic acid (ASA; < 160 mg/day) was allowed during treatment with dabigatran etexilate or enoxaparin. Due to the potential additional anticoagulant activity of these concomitant therapies a separate post hoc analysis was conducted to investigate the bleeding risk in these patients. We analysed the pooled study population (8,135 patients) from the three phase III trials in THA and TKA surgery (RE-MOBILIZE, RE-MODEL and RE-NOVATE) for major bleeding events (MBE). All MBE, which included surgical site bleeds, were assessed by an independent, expert adjudication committee. We report the rates of MBE and odds ratios (with 95% confidence intervals [CI]) for comparison of the subgroup concomitantly treated with NSAID (or ASA) versus the subgroup of patients without concomitant antithrombotically active medication. The overall rate of MBE (with and without NSAIDs and ASA) was 1.4% [CI 1.0–1.9], 1.1% [0.7–1.5] and 1.4% [1.0–2.0] with dabigatran etexilate 220 mg, 150 mg, and enoxaparin, respectively. Of the total population, 57.4% of patients received concomitant antithrombotic treatment: 54.1% received NSAID and 4.7% received ASA. The MBE rate in patients receiving dabigatran etexilate or enoxaparin plus NSAIDs was similar to the rate in patients taking only dabigatran etexilate or enoxaparin; 1.5% vs. 1.4% [OR 1.05; 0.55–2.01] for dabigatran etexilate 220 mg, 1.1% vs. 1.0% [OR 1.19; 0.55–2.55] for dabigatran etexilate 150 mg, and 1.6% vs. 1.2% [OR 1.32; 0.67–2.57] for enoxaparin. A similar pattern was seen in patients concomitantly receiving ASA; in this small group only a few patients with MBE were observed: 2 (1.6%) in the dabigatran etexilate 220 mg group, 2 (1.6%) in the 150 mg group, and 4 (3.0%) in the enoxaparin group. No relevant differences in risk for MBE were detected between treatments by co-medication subgroup or within treatment groups when comparing patients receiving dabigatran etexilate or enoxaparin only versus those concomitantly receiving NSAIDs or ASA. In conclusion, patients concomitantly receiving dabigatran etexilate and NSAIDs (with t½ ≤12 hours) or ASA (< 160 mg/day) have a similar risk of MBE to patients taking only dabigatran etexilate. These data support the use of dabigatran etexilate for the prevention of VTE in patients after THA or TKA, when concomitant use of NSAIDs or ASA (< 160 mg/day) is required.

Aims. It is common practice for patients to have postoperative blood tests after total joint replacement (TJR). However, there have been significant improvements in perioperative care with arthroplasty surgery, and a drive to reduce the length of stay (LOS) and move towards day-case TJR. We should reconsider whether this intervention is necessary for all patients. Methods. This retrospective study included all patients who underwent a primary unilateral TJR at a single tertiary arthroplasty centre during a one-year period. Electronic medical records of 1,402 patients were reviewed for patient demographics, LOS, and American Society of Anesthesiologists (ASA) grade. Blood tests were examined to investigate the incidence of postoperative anaemia, electrolyte abnormalities, and incidence of acute kidney injury (AKI). Results. For total knee arthroplasties, preoperative (R = −0.22) and postoperative haemoglobin (R = 0.2) levels were both negatively correlated with LOS (p < 0.001). For all patients who had undergone a TJR, 19 patients (0.014%) required a blood transfusion postoperatively due to symptomatic anaemia. Risk factors identified were age, preoperative anaemia, and long-term aspirin use. Significant abnormal sodium levels were found in123 patients (8.7%). However, only 36 patients (2.6%) required intervening treatment. Risk factors identified were age, preoperative abnormal sodium level, and long-term use of non-steroidal anti-inflammatory drugs, angiotensin receptor blockers, and corticosteroids. Similarly, abnormal potassium levels were evident in 53 patients (3.8%), and only 18 patients (1.3%) required intervening treatment. Risk factors identified were preoperative abnormal potassium level, and long-term use of angiotensin-converting enzyme inhibitors and diuretics. The incidence of AKI was 4.4% (61 patients). Risk factors identified were age, increased ASA grade, preoperative abnormal sodium, and creatinine level. Conclusion. Routine blood tests after primary TJR is unnecessary for most patients. Blood tests should only be performed on those with identifiable risk factors such as preoperative anaemia and electrolyte abnormalities, haematological conditions, long-term aspirin use, and electrolyte-altering medications. Cite this article: Bone Jt Open 2023;4(5):357–362