Summary Statement. Pulmonary embolism (PE) after total knee arthroplasty can have a significant impact on patient outcomes and healthcare costs. Efforts to prevent or minimise PE over the last 10 years have not had a significant impact on its occurrence at the national level. Introduction. Pulmonary embolism (PE) is a rare but known potentially devastating complication of total knee arthroplasty (TKA). Significant healthcare resources and pharmaceutical research has been recently focused on preventing this complication but limited data exists regarding the early results of this great effort. The purpose of this study was to assess recent national trends in PE occurrence after TKA and evaluate patient outcomes related to this adverse event. Methods. International Classification of Disease - 9th Revision (ICD-9) procedure codes were used to search the National Hospital Discharge Survey (NHDS) for all patients admitted to US hospitals after primary TKA for each year between 2001 and 2010. ICD-9 diagnosis codes were then used to identify patients from this population who developed an acute PE during the same admission. Data regarding patient demographics, hospitalization length, discharge disposition, deep vein thrombosis, mortality, and hospital size/location were gathered from the NHDS. Trends were evaluated by linear regression with Pearson's correlation coefficient (r) and statistical comparisons were made using Student's t-test, z-test for proportions, and chi-square analysis with a significance level of 0.05. Results. 35,220 patients admitted for a primary TKA were identified. 159 (0.045%) of these patients developed an acute PE during the same admission. After adjusting for fluctuations in annual TKA performed, the development of PE after TKA demonstrated a weak negative correlation with time (r=0.17), insignificantly decreasing from an average rate of 0.049% between 2001–2005 to 0.041% between 2006–2010 (p=0.26). The size of the hospital was found to significantly impact the incidence of PE and primary TKA, with the lowest rate seen in hospitals under 100 beds (0.23%) and the highest rate seen in those with over 500 beds (0.65%, p=0.01). No significant differences in PE incidence were noted based on US region (p=0.38). The mean age of patients with PE was 67.7 years. This group included 54 men and 105 women. The non-PE group had a mean patient age that was insignificantly lower at 66.6 years (p=0.21) and included 12,450 men and 22,611 women. Gender was also not significantly different (p=0.68) between those with PE and those without PE. The number of medical co-morbidities was significantly higher in those with PE (mean 6.42 diagnoses) than those without PE (mean 4.89 diagnoses, p<0.01). Average hospitalization length also varied based on PE status, with significantly longer stays for those with PE (8.2 days, range 2–53) compared to those without PE (3.7 days, range 1–95, p<0.01). The rate of deep vein thrombosis was higher in the PE group (12.7%) versus the non-PE group (0.48%, p<0.01). Mortality was also significantly higher for the PE group (3.9%) compared to the non-PE group (0.09%, p<0.01). Discharge disposition did not significantly vary based on PE status, with 61.5% of PE and 64.0% of non-PE patients able to go directly home (p=0.59) after their inpatient stay. Discussion/Conclusion. This study demonstrates that PE can have a significant impact on patient outcomes and healthcare costs, with an associated 43-fold increase in mortality and a doubling of the inpatient admission duration. Additionally, although the risk of PE after primary TKA remains rare, it still persists. Efforts to prevent or minimise this complication over the last 10 years have not had a significant impact on its occurrence at the national level. This risk of PE appears to be greatest in patients with multiple medical co-morbidities and established DVTs. Interestingly, the PE rate also demonstrated variability based on hospital size. The reasons for this are not clear, but we suspect larger hospitals are more likely to be tertiary-care centers and thus care for more medically-complex patients

Venous Thromboembolism (VTE) prophylaxis is an essential part of orthopaedic surgeries in preventing life-threatening thromboembolic events such as Deep Vein Thrombosis (DVT) and Pulmonary Embolism (PE). Orthopaedic surgery has the highest incidence rate of thromboembolic events as compared to any other surgical specialities, making it an essential component in managing any orthopaedic case. At Queen's Medical Centre (QMC), a major trauma centre in the United Kingdom (UK), sees up to 750 NOF fracture cases annually, making it one of the busiest trauma and orthopaedic centres in the UK. Our study aims to evaluate how VTE Prophylaxis is conducted in a UK Major Trauma Centre for NOF and pelvic fragility fractures and how human factors can improve its efficacy. The Nottingham University Hospitals (NUH) Trust has implemented new guidelines from August 2019 that patients with fragility fractures such as NOF and pelvic fractures are prescribed with 28 days VTE prophylaxis with Enoxaparin, or their own anti-coagulants if risk of thrombosis exceed the risk of bleeding. This is an adaptation from the trust to align their guidelines closer to the NICE 2018 guidelines. We will be evaluating the initial compliance of VTE Prophylaxis, identify and utilise human factors, then re-analyse the department after implementing interventions on the same batch of junior doctors working in the department. Data of 100 patients with fragility fractures were collected, 50 consecutive patients in the pre-intervention window during August 2019 and 50 in the post-intervention window during November 2019. The pre-intervention data had 43 NOF and 7 Pelvic fractures. Our study showed that 93% of NOF fracture and 100% of pelvic fracture received the correct course of VTE prophylaxis. The data was presented at the local department junior doctor academic session. Three simple human factor interventions were implemented over the course of September and October: Education to the trauma and orthopaedic department on the new guideline, extended VTE labels on drug charts for patients with fragility fractures, VTE reminder labels at doctors' stations. Another 50 consecutive patients' data were collected during November 2019. Data shows that 97.8% of NOF (p>0.05) and 60% of pelvic fracture (p>0.05) received the correct course of VTE prophylaxis. Our data has shown an increase in correct VTE prescription for NOF fracture patients, which is the main bulk of our fragility fracture patients whilst we see a drop in pelvic fracture patients. Due to the limited time frame of four months where junior doctors in the UK rotate between specialities, we are only able to collect data during the first month, implement interventions between datasets and collect data on the final month of the four-month rotation. A future bigger study might provide a more significant result on the department. We believe that the key to achieving 100% VTE prophylaxis in the T&O department is optimising human factors, educating junior doctors, who are not orthopaedic trained, with sufficient information of the guidelines, and evidence of the risk and benefits of providing prolonged VTE prophylaxis for orthopaedic patients. In conclusion, we found that QMC, a major trauma centre with high patient volume and turnover, has a high level of compliance with VTE prophylaxis for fragility fractures and it is imperative that utilising human factors will inch the department closer to its goal of 100% VTE compliance

Since the establishment of our department a multi-modal approach to thromboprophylaxis that uses aspirin for chemical prophylaxis was adopted. In accordance with the latest national recommendations, our routine chemical prophylaxis following arthroplasty was changed to rivaroxaban in 2012 and then dalteparin in 2013. This study aimed to compare venous thromboembolism (VTE) rates during the use of the aspirin-based protocol used from 2004 to 2011 with recent, rivaroxaban and dalteparin-based guidelines. Outcome data from ISD Scotland was retrieved and radiology reports performed for CT pulmonary angiograms and lower limb doppler ultrasound scans in our institution were assessed to identify cases of VTE following primary hip or knee arthroplasty. The incidence of pulmonary embolism (PE) and proximal deep venous thrombosis (DVT) was calculated for each year and compared using a Chi-squared test. Additionally, the change in extended thromboprophylaxis regimen was surveyed by recording the discharge prescriptions for consecutive arthroplasty patients for March every year. There were 90 radiologically confirmed cases of DVT or PE between 2004 and 2011 (incidence of 0.71%). The DVT/PE rate was subsequently 0.67% in 2012 and 0.69% in 2013, with a further 29 cases identified. This does not represent a significant change in the venous thromboembolism rates and remains below the national incidence of VTE (1.06%). Aspirin alone was used as chemical thromboprophylaxis in 80.8% of patients from 2004 to 2011, 50.9% in 2012, and 12.1% in 2013. The incidence of VTE at our centre remains favourable to national figures, but the modification of thromboprophylaxis guidelines will incur additional financial costs and has not had a significant reduction on the rate of VTE

Objectives

We have increased the dose of tranexamic acid (TXA) in our enhanced total joint recovery protocol at our institution from 15 mg/kg to 30 mg/kg (maximum 2.5 g) as a single, intravenous (IV) dose. We report the clinical effect of this dosage change.