Aims. Current guidelines recommend surgery within 48 hours among patients presenting with hip fractures; however, optimal surgical timing for patients on oral anticoagulants (OACs) remains unclear. Individual studies are limited by small sample sizes and heterogeneous outcomes. The aim of this study was to conduct a systematic review and meta-analysis to summarize the effect of pre-injury OACs on time-to-surgery (TTS) and all-cause mortality among older adults with hip fracture treated surgically. Methods. We searched MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL) from inception to 14 October 2019 to identify studies directly comparing outcomes among hip fracture patients receiving direct oral anticoagulants (DOACs) or vitamin K antagonists (VKAs) prior to hospital admission to hip fracture patients not on OACs. Random effects meta-analyses were used to pool all outcomes (TTS, in-hospital mortality, and 30-day mortality). Results. A total of 34 studies (involving 39,446 patients) were included in our systematic review. TTS was 13.7 hours longer (95% confidence interval (CI) 9.8 to 17.5; p < 0.001) among hip fracture patients on OACs compared to those not on OACs. This translated to a three-fold higher odds of having surgery beyond the recommended 48 hours from admission (odds ratio (OR) 3.0 (95% CI 2.1 to 4.3); p = 0.001). In-hospital mortality was higher (OR 1.4 (95% CI 1.0 to 1.8); p < 0.03) among anticoagulated patients. Among studies comparing anticoagulants, there was no statistically significant difference in time-to-surgery between patients taking a DOAC compared to a VKA. Conclusion. Patients presenting with a hip fracture who were taking OACs prior to injury experience a delay in time-to-surgery and higher mortality than non-anticoagulated patients. Patients on DOACs may be at risk of further delays. Evaluating expedited surgical protocols in hip fracture patients on OACs is an urgent priority, with the potential to decrease morbidity and mortality in this group of high-risk patients. Cite this article: Bone Joint J 2021;103-B(2):222–233

Direct oral anticoagulant (DOAC) use is becoming more widespread in the geriatric population. Depending on the type of DOAC, several days are required for its anticoagulant effects to resorb, which may lead to surgical delays. This can have an important impact on hip fracture patients who require surgery. The goal of the current study is to compare surgical delays, mortality and complications for hip fracture patients who were on a DOAC to those who were not. A retrospective cohort study was conducted at a university hospital in Sherbrooke. All hip fracture patients between 2012 and 2018 who were on a DOAC prior to their surgery were included. These patients were matched with similar patients who were not on an anticoagulant (non-DOAC) for age, sex, type of fracture and date of operation. Demographic and clinical data were collected for all patients. Surgical delay was defined as time of admission to time of surgery. Mortality and complications up to one year postoperative were also noted. Each cohort comprised of 74 patients. There were no statistically signification differences in Charleson Comorbidty Index and American Society of Anesthesiologists scores between cohorts. Surgical delay was significantly longer for DOAC patients (36.3±22.2 hours vs. 18.6±18.9 hours, p < 0 .001). Mortality (6.1%) and overall complication (33.8%) rates were similar between the two cohorts. However, there were more surgical reinterventions in DOAC patients than non-DOAC ones (16.2% vs. 0.0%, p < 0 .001). Among DOAC patients, mortality was greater for those operated after 48 hours (23.1% vs. 3.3%, p < 0 .05) and complications were more frequent for those operated after 24 hours (52.0% vs. 37.5%, p < 0 .05). Direct oral anticoagulant (DOAC) use in hip fracture patients is associated with longer surgical delays. Longer delays to surgery are associated with higher mortality and complication rates in hip fracture patients taking a DOAC. Hip fracture patients should have their surgery performed as soon as medically possible, regardless of anticoagulant use

Direct oral anticoagulant (DOAC) use is becoming more widespread in the geriatric population. Depending on the type of DOAC, several days are required for its anticoagulant effects to resorb, which may lead to surgical delays. This can have an important impact on hip fracture patients who require surgery. The goal of the current study is to compare surgical delays, mortality and complications for hip fracture patients who were on a DOAC to those who were not. A retrospective cohort study was conducted at a university hospital in Sherbrooke. All hip fracture patients between 2012 and 2018 who were on a DOAC prior to their surgery were included. These patients were matched with similar patients who were not on an anticoagulant (non-DOAC) for age, sex, type of fracture and date of operation. Demographic and clinical data were collected for all patients. Surgical delay was defined as time of admission to time of surgery. Mortality and complications up to one year postoperative were also noted. Each cohort comprised of 74 patients. There were no statistically signification differences in Charleson Comorbidty Index and American Society of Anesthesiologists scores between cohorts. Surgical delay was significantly longer for DOAC patients (36.3±22.2 hours vs. 18.6±18.9 hours, p < 0 .001). Mortality (6.1%) and overall complication (33.8%) rates were similar between the two cohorts. However, there were more surgical reinterventions in DOAC patients than non-DOAC ones (16.2% vs. 0.0%, p < 0 .001). Among DOAC patients, mortality was greater for those operated after 48 hours (23.1% vs. 3.3%, p < 0 .05) and complications were more frequent for those operated after 24 hours (52.0% vs. 37.5%, p < 0 .05). Direct oral anticoagulant (DOAC) use in hip fracture patients is associated with longer surgical delays. Longer delays to surgery are associated with higher mortality and complication rates in hip fracture patients taking a DOAC. Hip fracture patients should have their surgery performed as soon as medically possible, regardless of anticoagulant use

Most of current literatures advise on thromboprophylaxis with injectable LMWH for trauma patients. Injectable anticoagulants have got inherent problems of pain, bruising and difficulty in administering the drug, which leads to low compliance. Clexane is derived from a pig's intestinal mucosa, hence could be objectionable to certain proportion of patients because of their religious beliefs. Oral anticoagulants have been used as thromboprophylactic agents in hip and knee arthroplasty. However there is not enough literature supporting their use as thromboprophylactic agent in ambulatory trauma patients with ankle fracture being managed non-operatively as out-patient. This study looks into the efficacy of oral anticoagulant in preventing VTE in ambulatory trauma patients requiring temporary lower limb immobilisation for management of ankle fracture. The end point of this study was symptomatic deep vein thrombosis (either proximal or distal) and pulmonary embolism. Routine assessment with a VTE assessment risk proforma for all patients with temporary lower limb immobilisation following lower limb injury requiring plaster cast is done in the fracture clinic at this university hospital. These patients are categorised as low or high risk for a venous thromboembolic event depending on their risk factor and accordingly started on prophylactic dose of oral anticoagulant (Rivaroxaban - Factor Xa inhibitor). Before the therapy is started these patients have a routing blood check, which includes a full blood count and urea and electrolyte. Therapy is continued for the duration of immobilisation. Bleeding risk assessment is done using a proforma based on NICE guideline CG92. If there is any concern specialist haematologist advice is sought. A total of 200 consecutive patients who presented to the fracture clinic with ankle fracture, which was managed in plaster cast non-operatively, were included in this study. They were followed up for three months following injury. This was done by checking these patients’ radiology report including ultrasound and CT pulmonary scan (CTPA) test on hospital's electronic system. Fracture of the lateral malleolus which include Weber-A, Weber-B and Weber-C fractures were included in the study. Also included were bimalleolar fractures and isolated medial malleolus fractures. Complex pilon fractures, polytrauma and paediatric patients were excluded from the study. Only one case of plaster associated isolated distal deep vein (soleal vein) thrombosis was reported in this patient subgroup. There was no incidence of proximal deep vein thrombosis or pulmonary embolism. No significant bleeding event was reported. Injectable low molecular weight heparin (LMWH) rather than oral anticoagulant has been recommended by most of the studies and guidelines as main thromboprophylactic agent for lower limb trauma patients

Abstract

The April 2024 Trauma Roundup. 360. looks at: The infra-acetabular screw in acetabular fracture surgery; Is skin traction helpful in patients with intertrochanteric hip fractures?; Reducing pain and improving function following hip fracture surgery; Are postoperative splints helpful following ankle fracture fixation?; Biomechanics of internal fixation in Hoffa fractures: a comparison of four different constructs; Dual-plate fixation of periprosthetic distal femur fractures; Do direct oral anticoagulants necessarily mean a delay to hip fracture surgery?; Plate or retrograde nail for low distal femur fractures?

Rivaroxaban was introduced for thromboprophylaxis at the Royal Cornwall Hospital for hip and knee arthroplasty surgery in October 2009. We identified 140 patients from theatre logbooks who underwent elective joint replacement between October 2009 and March 2010. Patient notes, computer and DVT clinic records and WebPacs data were collected to determine the uptake of the new drug and the incidence of wound problems, DVTs and any other post-operative complications. In our sample 55.7% [78/140] patients received rivaroxaban. 10.3% [8/78] of patients on rivaroxaban suffered wound complications compared with 6.6% [4/62] of patients on alternative anticoagulation. Three patients suffered DVT's, 1 of whom was taking rivaroxaban. There were a further 6 patients, 4 on rivaroxaban, with leg swelling severe enough to merit investigation, all of whom had negative doppler scans. Bleeding events included 4 patients with postoperative haematemesis of which 2 were taking rivaroxaban. Five patients, all under different surgical operators of which 3 had taken rivaroxaban, developed stiff total knee replacements and were offered MUA or physiotherapy.

BACKGROUND: Oral DVT prophylaxis not requiring monitoring is an advantage in orthopaedic patients. Dabigatran etexilate is an oral direct thrombin inhibitor undergoing evaluation for the prevention of venous thromboembolic events (VTE) following orthopaedic surgery.

METHODS: In a phase III, multicenter, non-inferiority, double-blind study, patients undergoing total knee replacement were randomized to 3 treatments. The patients received 8±2 days of oral dabigatran etexilate, 150 or 220 mg once daily starting with a half dose (i.e.75 or 110 mg) 1–4 hours after surgery, or subcutaneous enoxaparin 40 mg once daily starting 12 hours prior to surgery. The primary efficacy outcome was the composite of total VTE and all causes of mortality during the treatment period. All efficacy and safety outcome events were adjudicated by blinded independent committees.

RESULTS: Efficacy could be evaluated for 1541 (75%) treated and operated patients. Total VTE and death occurred in 40.5%, 36.4% and 37.7% of patients assigned to dabigatran etexilate 150 or 220mg once daily or enoxaparin, respectively. Proximal DVT and/ or PE occurred in 3.8%, 2.6% and 3.5% of patients receiving dabigatran 150 or 220mg or enoxaparin, respectively. Three deaths occurred during the treatment period, one in each of the treatment groups. Safety was evaluated for all 2076 patients receiving study treatment. The rate of major bleeding was 1.3%, 1.5% and 1.3% of patients receiving dabigatran 150 or 220mg or enoxaparin. Elevated LFTs (ALT > 3xULN) occurred in 3.7%, 2.8% and 4.0% of the patients treated with 150 and 220 mg dabigatran or enoxaparin during the study. A temporary rise in LFTs was observed during the follow-up period in 0.5% of the patients who had received dabigatran and in 0.4% of the patients who had received enoxaparin.

CONCLUSIONS: Non-inferiority for the primary efficacy endpoint was met for both doses of dabigatran etexilate compared to enoxaparin. There was no difference in bleeding rates between the treatment groups. Oral administration of dabigatran etexilate once daily, given early in the postoperative period, was effective and safe for the prevention of total VTE in patients undergoing total knee replacement surgery.

Aim. Prosthetic joint replacement is more commonly done in the elderly group of patients due to an increase pathology related to joint degeneration that comes with age. In this age group is also more frequent having underling condition that may predispose to a prosthetic joint infection. Also, the pharmacological intervention in those patients may play an important role as a risk factor for infection after joint replacement surgery. The use of oral anticoagulants seems to be particularly increased in elderly patients but there aren't enough data published to support an association between prosthetic joint infection and the use of oral anticoagulants. Identifying risk factors in elderly patients age >75 years old with a special focus on the oral anticoagulation therapy is the aim of the study. Methods. In a retrospective study from 2011 till 2018 all the patients >75 years old with knee and hip replacement surgery have been review looking for acute prosthetic infection and risk factors that may be predispose to it. Patients with previous surgery or any other mechanical complication that needed intervention on the same area have been excluded. Results. A total of 1220 patients have been included (801 knee replacement surgery and 419 hip replacement surgery). The mean age was 79.5 ± 3.44 years and most of the patients were women (72,6%). The infection rate was 2,5%. Several factors have been identified to be associated with acute infection. (Table.1.). The patients receiving oral anticoagulants had an increased risk of infection (OR 3.63 (1.60–7.74), p=0.002). Conclusions. Even all the risk factors associated with risk infection have been described previously, the relevant aspect is the increased risk of prosthetic joint infection in patients receiving oral anticoagulants

The December 2023 Hip & Pelvis Roundup. 360. looks at: Early hip fracture surgery is safe for patients on direct oral anticoagulants; Time to return to work by occupational class after total hip or knee arthroplasty; Is there a consensus on air travel following hip and knee arthroplasty?; Predicting whether patients will achieve minimal clinically important differences following hip or knee arthroplasty; High-dose dual-antibiotic-loaded cement for hip hemiarthroplasty in the UK (WHiTE 8): a randomized controlled trial; Vitamin E – a positive thing in your poly?; Hydroxapatite-coated femoral stems: is there a difference in fixation?

In recent years, many changes have taken place regarding agents used for chemical thromboprophylaxis in elective joint replacement. Enoxaparin, Rivaroxaban, Dabigatran and Apixaban are all now recommended in NICE CG92 and their use varies nationally. Whilst data exists comparing oral anticoagulants to Enoxaparin, there is little data on the comparative efficacy of the individual oral anticoagulants. This study analyses data from Warrington Hospital, where each of the above oral anticoagulants was used trustwide in 3 successive years following hip and knee arthroplasty. We analysed similar 4–5 month periods in 2010(Rivaroxiban), 2011(Dabigatran) and 2012(Apixaban). The study was done prospectively and data was collected contemporaneously. The total sample size was 475 patients. Data was collected through electronic hospital patient records. Patients were excluded if data was incomplete. We defined our primary outcome as any complication requiring the drug to be omitted or stopped. We found that for Rivaroxaban, 7 of 129 patients had the drug omitted or stopped (5.4%, 95% confidence interval 1.0–9.8), for Dabigatran 19 of 150 patients, (12.7%, 95% confidence interval 6.4–19.0) and for Apixaban 10 of 196 patients (5.1%, 95% confidence interval 0.9–9.3). For Rivaroxaban and Apixaban, there were no confirmed thromboembolic events; however, for Dabigatran, there were six VTEs. All three had bleeding complications, which were well below the figures published for Enoxaparin. Apixaban registered the lowest rate in our study (5.1%). This data suggests that Apixaban is a safe oral anticoagulant in elective total knee and hip replacement

In recent years, many changes have taken place regarding agents used for chemical thromboprophylaxis in elective joint replacement. Enoxaparin, Rivaroxaban, Dabigatran and Apixaban are all now recommended in NICE CG92 and their use varies nationally. While data exist comparing oral anticoagulants to Enoxaparin, there is little data on the comparative efficacy of the individual oral anticoagulants. This study analyses data from Warrington Hospital, where each of the above oral anticoagulants was used trustwide in 3 successive years following hip and knee arthroplasty. We analysed similar 4–5 month periods in 2010 (Rivaroxiban), 2011 (Dabigatran) and 2012 (Apixaban). The study was done prospectively and data was collected contemporaneously. The total sample size was 475 patients. Data was collected through electronic hospital patient records. Patients were excluded if data was incomplete. We defined our primary outcome as any complication requiring the drug to be omitted or stopped. We found that for Rivaroxaban, 7 of 129 patients had the drug omitted or stopped (5.4%, 95% confidence interval 1.0–9.8), for Dabigatran 19 of 150 patients, (12.7%, 95% confidence interval 6.4–19.0) and for Apixaban 10 of 196 patients (5.1%, 95% confidence interval 0.9–9.3). For Rivaroxaban and Apixaban, there were no confirmed thromboembolic events; however, for Dabigatran, there were six VTEs. All three had bleeding complications, which were well below the figures published for Enoxaparin. Apixaban registered the lowest rate in our study (5.1%). This data suggests that Apixaban is a safe oral anticoagulant in elective total knee and hip replacement

Novel oral anticoagulant (NOAC) use in Australia has increased significantly since their introduction to the Pharmaceutical Benefits Scheme (PBS). Currently, there are no specific guidelines regarding recommencement of NOAC therapy post-operatively for patients concurrently on a NOAC and undergoing arthroplasty. To address this gap in the literature, the aim of this study was to compare the clinical and patient-reported outcomes in a patient cohort recommencing a therapeutic dose of NOAC within 24 hours of total hip or knee arthroplasty. Data was retrieved from a prospective registry (ACTRN1262000079698) containing hip and knee arthroplasties. Cases were labelled based on whether they presented on a therapeutic dose of NOAC prior to surgery or not. Descriptive statistics were used to summarise patient outcomes. Of 291 patients undergoing 331 primary arthroplasties, 9.3% were undertaking NOAC therapy prior to their surgery. In the NOAC cohort, there was a 34.5% adverse event rate, however on closer analysis of each event, it was found that none of these events were complications in relation to NOAC use. This was compared to 15.6% of the comparison cohort who experienced a range of complications, some involving bleeding events. PROMs improved to a similar degree amongst both groups. This study showed that recommencing therapeutic doses of NOACs in patients post hip and knee arthroplasty within 24 hours was safe. These findings will help guide larger scale analysis to better inform clinical guidelines pertaining to hip and knee arthroplasty

To compare the incidence of Bone Cement Implantation Syndrome (BCIS), perioperative thromboembolic events and mortality in patients with a femoral neck fracture (FNF) treated with a hybrid total hip arthroplasty (THA) without intraoperative unfractioned heparin (UFH) (control) versus a group of patients who received intraoperative UFH before femoral cementation. We retrospectively reviewed 273 patients who underwent hybrid THA due to a FNF between 2015 and 2020. We compared a group of 139 patients without intraoperative administration of UFH (group A) with 134 patients who underwent THA with intraoperative administration of 10 UI/kg UFH (group B). UFH indication was dependent on surgeon´s preference. We assessed the advent of BCIS and 30-day thromboembolic events, as well as 90-day and 1-year mortality. BCIS was observed in 51 cases (18%), defined as Grade 1 (O2% < 94% or fall in systolic blood pressure of 20% to 40%) in 37 cases (13%) and Grade 2 (O2% < 88% or fall in systolic blood pressure of > 40%) in 14 cases (5%). Forty-seven BCIS (35%) were observed in the group that received UFH and 4 BCIS (3%) in the control group (p <0.001). Multivariate regression model showed that intraoperative UFH (OR=18, CI95% 6–52) and consumption of oral anticoagulants (OR=3.3, CI95% 1–10) had an increased risk of developing BCIS. Five patients developed a pulmonary embolism in the UFH group while 2 patients presented this complication in the non UFH group (p=0.231). Mortality was 1% for both groups at 90 days PO (p= 0.98), 2% at 1 year for group A and 3% for group B (p =0.38). BCIS in our series was 18%. We found a paradoxically 17-fold significant increase of BCIS with the use of UFH. Heparin did not prevent BCIS, thromboembolic events and mortality in this group of patients

Aims. NICE recommends oral anticoagulants after lower limb arthroplasty, as they are thought to lead to better outpatient compliance than injected anticoagulants. Having prescribed self-administered Dalteparin for many years, we began using oral Dabigatran in December 2010. The change afforded an opportunity to compare compliance and acceptability of the two treatments. Methods. Patients were recruited at discharge and telephoned at 28 days. Left over doses were counted to assess compliance. Side-effects, complications and patient views were also recorded. Results. 47 patients were discharged on dalteparin, 59 on dabigatran. Total compliance rates were 81% and 56% respectively (p<0.001). However, the mean pain score associated with dalteparin was 2.4 out of 10, and 31% of patients experienced significant bruising. No patient suffered pain or bruising with dabigatran (p<0.001), but two experienced dyspepsia and four suffered wound problems. Two thromboembolic events and one gastrointestinal bleed occurred in the dalteparin group. Conclusions. Our outpatient compliance is higher for injected anticoagulants than for oral anticoagulants. This runs contrary to some of the marketing for oral agents. However, Dabigatran offers better patient acceptability than Dalteparin. While not designed or powered to show statistically significant differences in complication rates, our study has prompted closer investigation of wound problems with both treatments

Study Aim. To assess the impact of two oral thromboprophylaxis agents against Clexane with regard to range of movement (ROM) following TKR with or without haemostasis following tourniquet release. Methods & Results. Thromboprophylaxis choice following total knee replacement (TKR) has become of interest with the introduction of oral anticoagulants and support for these by NICE. Specific concerns with oral agents include a perceived elevated level of anti-coagulation and soft tissue complications. The population (n=264) was subclassified into cohorts regarding thromboprophylaxis cover: Clexane, Rivaroxaban and Dabigatran. Each subgroup was subdivided into whether surgery was performed with or without haemostasis following tourniquet release. This study demonstrates Clexane is associated with a better and earlier return of ROM post-operatively as compared to oral the thromboprophylaxis agents. This effect was more obvious when combined with haemostasis following early tourniquet release (p< 0.05). The oral thromboprophylaxis agents Rivaroxaban and Dabigatran had a relative negative effect on ROM as compared against Clexane. This was independent of whether the surgery was performed with or without haemostasis following tourniquet release. There was no different between the subgroups with repect to change of serum haemoglobin, symptomatic venous thromboembolism or rate of return to theatre. Conclusions. This study demonstrates Clexane to have a beneficial effect over the oral anticoagulants, Rivaroxaban and Dabigatran, on ROM and speed of recovery post TKR. This effect was significant (p< 0.05) when combined with genicular vessel haemostasis following early tourniquet release. We hypothesise independent of intra-operative haemostasis of genicular vessels after torniquet release, elevated small vessel ooze secondary to the oral thromboprophylaxis has a detrimental impact on ROM post TKR

Financial impact and patient satisfaction with four different anticoagulants for hip and knee arthroplasty in patients with a previous history of VTE- A prospective randomised trial. Introduction. New generation oral anticoagulants (dabigatran/rivaroxaban) have recently become available for the prevention of venous thromboembolism (VTE) following hip and knee arthroplasty. Traditional therapies (warfarin/low molecular weight heparins) are less costly, but have several limitations. The aim of this study was to evaluate the financial impact of substituting enoxaparin and warfarin with newer therapies dabigatran and rivaroxaban. A secondary objective was to investigate patient satisfaction with these treatments. Methods. A randomised prospective study was conducted over a 12 month period. Patients with a history of VTE undergoing hip or knee replacement were randomised to receive one of four anticoagulants for five weeks post surgery. Information was gathered during the hospital stay and then post discharge, by telephone, for five weeks(35 days)to determine costs. The costs included cost of drug, nursing time, blood monitoring and transport costs. The patients were also asked to complete the Duke Anticoagulation Satisfaction Scale (DASS). The DASS is a 26 item questionnaire which has 7 responses for each question. Results. Although dabigatran and rivaroxaban had higher drug acquisition costs, warfarin and enoxaparin were financially more costly overall. These additional costs were mainly due to increased blood monitoring and time for training and administration which is not required for newer therapies. DASS scores were significantly better with dabigatran (38.5±5.1) and rivaroxaban (38.6±8.3) compared to warfarin (71.8±16.2) and enoxaparin (68.5±14.2) (p< 0.001). This indicates more satisfaction for patients prescribed dabigatran or rivaroxaban compared to traditional therapies. Conclusion. The use of new generation oral anticoagulants has the potential to significantly reduce the financial burden of thromboprophylaxis on the NHS with an additional benefit of better patient satisfaction when compared to traditional therapies

Considerable debate exists regarding which agent(s) should be preferred for venous thromboembolism (VTE) chemical prophylaxis following joint replacement. We assessed the practice of surgeons regarding VTE chemical prophylaxis for primary THR and TKR, pre and post issuing of updated NICE guidance in 2018. A survey, circulated through the British Hip Society and regional trainee networks/collaboratives, was completed by 306 UK surgeons at 187 units. VTE chemical prophylaxis prescribing patterns for surgeons carrying out primary THR (n=258) and TKR (n=253) in low-risk patients were assessed post publication of 2018 NICE recommendations. Prescribing patterns before and after the NICE publication were subsequently explored. Questions were also asked about surgeon equipoise for participation in future RCTs. Following the new guidance, 34% (n=87) used low-molecular weight heparin (LMWH) alone, 33% (n=85) aspirin (commonly preceded by LMWH), and 31% (n=81) direct oral anticoagulants (DOACs: with/without preceding LMWH) for THR. For TKR, 42% (n=105) used aspirin (usually monotherapy), 31% (n=78) LMWH alone, and 27% (n=68) DOAC (with/without preceding LMWH). NICE guidance changed the practice of 34% of hip and 41% of knee surgeons, with significantly increased use of aspirin preceded by LMWH for THR (before=25% vs. after=73%;p<0.001), and aspirin for TKR (before=18% vs. after=84%;p<0.001). Significantly more regimens were NICE guidance compliant after the 2018 update for THR (before=85.7% vs. after=92.6%;p=0.011) and TKR (before=87.0% vs. after=98.8%;p<0.001). Support from surgeons for future RCTs was dependent on the clinical question, ranging from 48% participation in trials (effectiveness of aspirin vs. a DOAC) to 79% (effectiveness of 14 days LMWH vs. 28 days LMWH). Over one-third of surveyed surgeons changed their VTE chemical prophylaxis in response to 2018 NICE recommendations, with more THR and TKR surgeons now compliant with latest NICE guidance. The major change in practice was an increased use of aspirin for VTE chemical prophylaxis. Furthermore, there is an appetite amongst UK surgeons for participating in future RCTs, with a trial comparing standard versus extended duration LMWH likely feasible in current practice

Objectives. Venous thromboembolism (VTE) is a major potential complication following orthopaedic surgery. Subcutaneously administered enoxaparin has been used as the benchmark to reduce the incidence of VTE. However, concerns have been raised regarding the long-term administration of enoxaparin and its possible negative effects on bone healing and bone density with an increase of the risk of osteoporotic fractures. New oral anticoagulants such as rivaroxaban have recently been introduced, however, there is a lack of information regarding how these drugs affect bone metabolism and post-operative bone healing. Methods. We measured the migration and proliferation capacity of mesenchymal stem cells (MSCs) under enoxaparin or rivaroxaban treatment for three consecutive weeks, and evaluated effects on MSC mRNA expression of markers for stress and osteogenic differentiation. Results. We demonstrate that enoxaparin, but not rivaroxaban, increases the migration potential of MSCs and increases their cell count in line with elevated mRNA expression of C-X-C chemokine receptor type 4 (CXCR4), tumor necrosis factor alpha (TNFα), and alpha-B-crystallin (CryaB). However, a decrease in early osteogenic markers (insulin-like growth factors 1 and 2 (IGF1, IGF2), bone morphogenetic protein2 (BMP2)) indicated inhibitory effects on MSC differentiation into osteoblasts caused by enoxaparin, but not by rivaroxaban. Conclusions. Our findings may explain the adverse effects of enoxaparin treatment on bone healing. Rivaroxaban has no significant impact on MSC metabolism or capacity for osteogenic differentiation in vitro. Cite this article: Dr H. Pilge. Enoxaparin and rivaroxaban have different effects on human mesenchymal stromal cells in the early stages of bone healing. Bone Joint Res 2016;5:95–100. DOI: 10.1302/2046-3758.53.2000595

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