Total Joint Arthroplasty (TJA) is a successful orthopaedic procedure allowing dramatic clinical and functional improvements. Globally, there's been an increase in demand and performed cases associated with an increase in complications. Subsequently, focus on the prevention of complications has become important worldwide. The incidence of venous-thrombolic events (VTE) despite great attention has not diminished despite much investigation. A balance between efficacy and safety from the available agents is essential. Low molecular weight heparin (LMWH) has been commonly used, but oral anti-coagulants have become more popular. The aim of this study was to assess the adherence LMWH and the effectiveness and safety of preventing VTE in post-operative arthroplasty patients in a South African setting. We conducted a prospective cohort study that included hip and knee, primary and revision, arthroplasty patients who received thromboprophylaxis with one daily injection of LMWH for 14 days post discharge. Patients who omitted 1 or more doses during the follow up period were classified as “non adherent”. A questionnaire was used at follow up visits at least 6 weeks post-operatively. 100 consecutive patients were followed up. The mean age of patients was 63.45 years. There were 68 % female patients. There was a 92% compliance rate. 60 % of patients had the injection administered by a family member, 38 % administered it themselves and 2 % had the injection administered by health professionals. Venous thromboembolic events were confirmed in 5 % at 7.86 days after surgery. Three patients had persistent wound drainage after surgery, however, none required reoperation or readmission. Compliance with LMWH is high and is comparable with oral agents. It is effective in preventing VTE and safe with regards to bleeding and wound complications in a South African setting. Patient education regarding medications may improve compliance of the medication

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

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

Introduction. Deep venous thrombosis (DVT) is a potentially serious complication after total hip (THA) and knee (TKA) arthroplasty, traditionally justifying aggressive prophylaxis with low molecular weight heparin (LMWH) or direct oral anticoagulants (DOA) at the cost of an increased risk of bleeding. However, fast-track procedures might reduce the DVT risk and decrease the cost-benefit ratio of the current recommendations. The objective of this study was to compare thrombotic and bleeding risk in an unselected population of elective THA and TKA with a fast-track procedure. MATERIAL - METHODS. A series of 1,949 patients were analyzed prospectively. There were 1,136 women and 813 men, with a mean age of 70 years. In particular, 16% were previously treated by antiplatelet agents and 8% by anticoagulants. All patients followed a fast-track procedure including early walking within 24 hours of surgery, and 80% of patients returned home after surgery, with a mean length of stay of 3 days (THA) or 4 days (TKA). The occurrence of a thromboembolic event or hemorrhagic complication has been identified. Results. Out of the 1,110 THAs, 5 thromboembolic events were identified (0.4%): 2 non-fatal pulmonary embolism and 3 DVTs. There was no impact of these complications on the final result. 19 hemorrhagic complications were identified (1.7%): 10 significant haematomas (3 of which were complicated by infection), 9 anemias (with 4 transfusions). Out of the 839 TKAs, 9 thromboembolic events were identified (1.0%): 4 non-fatal pulmonary embolism and 5 DVTs. There was no impact of these complications on the final result. 14 hemorrhagic complications were identified (1.7%): 8 haematomas including 4 reoperations, 6 anemias (with 5 transfusions). Discussion. Thromboembolic complications after elective THA and TKA have virtually disappeared, with a rate of 0.7%. On the other hand, bleeding complications are now more frequent, with a rate of 1.7%. This suggests that the cost-benefit ratio of preventive treatments with LMWH or DOA should be reassessed. Prescribing LMWH or DOA after elective THA and TKA with fast-track procedures exposes the patient to a much higher risk of bleeding than thrombotic risk. The use of aspirin may represent an acceptable compromise in these patients

Background. The National Institute for Health and Clinical Effectiveness recommends both low molecular weight heparin (LMWH) and Rivaroxaban for venous thromboembolic (VTE) prophylaxis following lower limb arthroplasty. Despite evidence in the literature that suggests Rivaroxaban reduces VTE events, there are emerging concerns from the orthopaedic community regarding an increase in wound complications following its use. Methods. Through the orthopaedic clinical directors forum, Trusts replacing LMWH with Rivaroxaban for lower limb arthroplasty thromboprophylaxis during 2009 were identified. Prospectively collected Hospital episode statistics (HES) data was then analysed for these units so as to determine rates of 90-day symptomatic deep venous thrombosis (DVT), pulmonary embolism (PE), major bleed (cerebrovascular accident or gastrointestinal haemorrhage), all-cause mortality, and 30-day wound infection and readmission rates before and after the change to Rivaroxaban. 2752 patients prescribed Rivaroxaban following TKR or THR were compared to 10358 patients prescribed LMWH. Data was analysed using odds ratios (OR). Results. There were significantly more wound infections in the Rivaroxaban group (3.85% vs. 2.81%, OR=0.72; 95% CI 0.58–0.90). There were no significant differences between the two groups for PE (OR=1.52; 0.77–2.97), major bleed (OR=0.73; 0.48–1.12), all-cause mortality (OR=0.93; 0.46–1.87) and re-admission rate (OR=1.21; 0.88–1.67). There were significantly fewer symptomatic DVTs in the Rivaroxaban group (0.91% vs. 0.36%, OR=2.51; 1.30–4.82). Discussion. This study is the first to describe the real impact of the use of Rivaroxaban in the NHS. When compared with LMWH in lower limb arthroplasty patients, there were fewer DVTs in the Rivaroxaban group. However, wound infection rates were significantly higher following Rivaroxaban use whilst providing no reduction in symptomatic PE or all-cause mortality

Patients with hip fracture are at high risk of venous thromboembolism (VTE). Chemical thromboprophylaxis with low molecular weight heparin (LMWH) is associated with a risk of major bleeding in certain patient groups, such as those with renal failure. In these patients, unfractionated heparin should be used. Our aim was to determine the practice of VTE risk assessment in patients admitted with hip fracture against the national guidance, which states that all should have VTE risk assessment on admission. We also assessed the impact of introducing the VTE risk assessment form on prescribing practice of chemical thromboprophylaxis in patients with renal failure. Prospective audit of patients of 50 patients admitted with hip fracture from 4/8/10 with re-audit of 50 patients admitted from 17/2/2011 after introducing the VTE risk assessment form into the hip fracture admissions proforma. Retrospective analysis was undertaken to determine chemical thromboprophylaxis prescribing in patients with eGFR <30ml/min/1.73m. 2. . Patient demographics were comparable in both audit loops, with the mean age being equal (84 years) and an equal majority of female patients (76%). There were similar numbers of patients with eGFR <30ml/min/1.73m. 2. in both audit loops with 8% (n=4) in the initial audit, and 10% (n=5) in the re-audit. Frequency of VTE risk assessment significantly increased from 16% to 86% after including the VTE risk assessment form in the hip fracture proforma (p<0.0001). Despite this, there was no significant reduction in prescribing of LMWH in patients with renal failure with eGFR <30ml/min/1.73m. 2. , (P=0.52). Documentation of VTE risk assessment in patients admitted with hip fracture can be improved by simple measures such as inclusion of the VTE risk assessment form in the admissions proforma. However, this did not result in a reduction of LMWH prescribed in patients with significant renal failure and risk of major bleeding

The selection of venous thromboembolism (VTE) prophylaxis after total joint arthroplasty (TJA) has been controversial. Although the aspirin controversy is presumably resolved, there is no medical evidence for the “optimal” VTE prophylaxis regime for individual patients. A risk-stratified multi-modal VTE prophylaxis protocol was developed and adopted by consensus. VTE risk factors and bleeding risk factors were categorised into six VTE/bleeding risk levels: (1) pre-operative vitamin K antagonists (VKA) use, (2) bleeding risk factors, (3) hypercoagulable state, (4) pre-operative anti-platelet therapy [clopidogrel use], (5) VTE risk factors, (6) no VTE or bleeding risk factors. The pharmacologic agents used for each risk level were: (1) resume VKA with low molecular weight heparin (LMWH) bridge, (2) pharmacologic agents contra-indicated and mechanical prophylaxis only, (3) VKA for 90 days with LMWH bridge, (4) resume anti-platelet therapy, (5) LMWH in hospital and discharge on aspirin for 90 days, (6) aspirin for 90 days (starting in hospital). In addition to pharmacologic treatment, all patients received multi-modal prophylaxis including early mobilisation, mechanical foot pumps, and neuraxial anesthesia when not contra-indicated. Prior to surgery, a VTE/bleeding risk factor checklist was completed determining the risk level. The intervention cohort included all TJA patients from January 1, 2010 to December 31, 2012. The comparison cohort included all TJA patients from the year prior to implementation of the protocol at the same community hospital. Thirty day all-cause non-elective re-admissions, 30 day same-site re-operations, 90 day VTE events, and protocol compliance were abstracted from the electronic medical record. The intervention group consisted of 2679 patients (1075 hip arthroplasty patients and 1604 knee arthroplasty patients). The comparison group consisted of 1118 patients (323 hip arthroplasty patients and 795 knee arthroplasty patients). The 30 day all cause non-elective re-admission rate was 2.72% (73/2679) in the intervention group and 4.29% (48/1118) in the comparison group (p=0.0148). The 30 day same-site re-operation rate was 1.38% (37/2679) in the intervention group and 1.25% (14/1118) in the comparison group (p=0.8773). The 90 day VTE event rate was 1.57% (42/2679) in the intervention group and 3.40% (38/1118) in the comparison group (p=0.0007). The VTE rate was higher for knee arthroplasty patients 2.00% (32/1604) than for hip arthroplasty patients 0.93% (10/1075) (p=0.0379). The rate of VTE events was higher for patients that deviated from the VTE protocol 5.03% (10/199) than for all risk groups treated per the protocol 1.29% (32/2481) (p=0.0007). The risk-stratified multi-modal VTE prophylaxis protocol simultaneously reduced 30 day all-cause non-elective re-admissions and 90 day VTE events. The possible causes for reducing 30 day re-admissions and reducing 90 day VTE events are: (1) reducing bleeding events by using aspirin for VTE prophylaxis in more than 80% of patients, (2) extending VTE prophylaxis to 90 days, and (3) using multi-modal prophylaxis. The risk-stratified multi-modal VTE prophylaxis protocol for total joint arthroplasty is consistent with 9 of the 10 recommendations in the AAOS Clinical Practice Guideline. The risk-stratification checklist provides a standardised tool to assess risks, discuss risks, and make shared decision with patients. Patient treatment that deviated from the protocol had a significantly higher VTE rate (5.03%). Protocol compliance increased each year from 91.1% in 2010 to 94.2% in 2012

Introduction. We investigated the incidence of venous thromboembolism (VTE) and pulmonary embolism (PE) after total knee arthroplasty (TKA) and assessed the efficacy and complications of three different chemical prophylactic regimens. Materials and Methods. From May, 2011 to November 2013, 268 patients, 330 knees were randomly allocated to three groups, low molecular weight heparin (LMWH) 5000IU for 2 days followed by aspirin 100mg for 5 days (Group HA, 110 knees), rivaroxaban 10mg for 7 days (Group X7, 110 knees), or for 10 days (Group X10, 110 knees) postoperatively. Intermittent pneumatic compression device was applied on all patients. The multidetector row computed tomography (MDCT) was done at postoperative 10 days to evaluate VTE (PE & DVT separately), and MDCT was rechecked to evaluate the changes of VTE at postoperative 3 months in VTE patients. Additionally, major and minor bleeding complications, amounts of bleeding, and bruise around wound were checked. Results. The incidence of VTE was 42 (38.2%) in Group HA, 22 (20.0%) in Group X7, 11 (10.0%) in Group X10. Deep vein thrombosis (DVT) was revealed 39 (35.5%) in Group HA, 17 (15.5%) in Group X7, 8 (7.3%) in Group X10. Group HA showed statistically higher prevalence in VTE and DVT than rivaroxavan groups. PE was detected 21 (19.1%) in Group HA, 11 (10.0%) in Group X7, 3 (2.7%) in Group X10. Group X10 was statistically significantly lower PE incidence than Group HA (p=0.0001) and Group X7 (p=0.027). Asymptomatic distal DVT was completely resolved in 88.8% with no specific treatment. There was no major or minor bleeding complications and bleeding amounts were not statistically different in 3 groups. Conclusion. Rivaroxaban has better prophylactic efficacy with no increasing bleeding complications than LMWH followed by aspirin. Ten days rivaroxaban was more effective for PE and VTE prevention than 7 days rivaroxavan. However, most of reduced VTEs were asymptomatic and distal DVTs

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

NICE technology appraisal guidance 157 suggests that the oral anticoagulation medication Dabigatran etexilate can be used for the primary prevention of venous thromboembolic events (VTE's) in adult patients who have undergone elective total hip or knee replacement surgery. The NICE guidance reports that 13.8% of patients receiving recommended doses of Dabigatran experienced adverse bleeding events. In the pivotal hip and knee VTE trial, wound secretion only accounted for 4.9% of patients treated with Dabigatran (cf 3.0% of patients treated with Enoxaparin). We report our wound secretion experience after Dabigatran use at Warwick Hospital from March 2009 to March 2010. Of the 788 lower-limb arthroplasties performed, 55 patients (6.9%) had oozing wounds after discharge (Mean=8 days, Range=1-39 days). This resulted in 226 extra home-visits by discharge nurses, 26 positive microbiology cultures and 5 confirmed wound infections needing antibiotic treatment and/or surgical intervention. Incidentally, there were also 2 known cases each of deep vein thrombosis and pulmonary embolus in this cohort. The number of complications was markedly increased from previous years when LMWH was the VTE prophylaxis used. This data suggests that the use of Dabigatran in Warwick Hospital may significantly increase surgical site morbidity and resource output after lower limb arthroplasty

Background. Current treatments for the prevention of thromboembolism include heparin and low-molecular weight heparins (LMWHs). A number of studies have suggested that long term administration of these drugs may adversely affect osteoblasts and therefore, bone metabolism. Xarelto(tm) (Rivaroxaban) is a new anti-thrombotic drug for the prevention of venous thromboembolism in adult patients undergoing elective hip and knee replacement surgery. The aim of this in vitro study was to investigate the possible effects of rivaroxaban on osteoblast proliferation, function, matrix mineralisation and gene expression compared to enoxaparin, a commonly used LMWH. Methods. Primary human osteoblast cultures were treated with varying concentrations of rivaroxaban (0.013, 0.13, 1.3 and 13 μg/ml) or enoxaparin (0.1, 1.0 and 10 international units/ml). The effect of each drug on osteoblast function and matrix mineralisation was evaluated by measuring alkaline phosphatase activity and calcium deposition, respectively. The MTS assay was used to assess the effect of drug treatments on cell proliferation. Changes in osteocalcin, Runx2 and BMP-2 messenger RNA (mRNA) expression following drug treatments were measured by real-time polymerase chain reaction (PCR). Results. Rivaroxaban and enoxaparin treatment did not adversely affect osteoblast proliferation. However, both drugs caused a significant reduction in osteoblast function, as measured by alkaline phosphatase activity, with a moderate reduction in calcium deposition also observed. This reduction in osteoblast function was associated with a reduction in the mRNA expression of the bone marker, osteocalcin, the transcription factor, Runx2, and the osteogenic factor, BMP-2. Conclusion. These data show that rivaroxaban treatment may negatively affect bone through a reduction in osteoblast function. The increased duration of recommended Rivaroxaban therapy (2 and 5 weeks) post-arthroplasty compared to Enoxaparin therapy (average one week) may have a more pronounced effect on bone homeostasis

Introduction. Oral factor Xa inhibitors have recently been licensed for use as thromboprophylaxis in arthroplasty surgery. Phase IV trials have proven there efficacy in DVT/PE prevention with comparable rates in major adverse events, including major bleeding. We examined whether the introduction of rivaroxoban, an oral factor Xa inhibitor, increased total blood loss in patients undergoing primary arthroplasty surgery. Methods. Two groups were studied. The intervention group were prescribed rivaroxoban thrombophrophylaxis 6–10 hours post-surgery, and the control group were prescribed low molecular weight heparin (daltaparin 5,000u) 6–10 hours post-surgery. All other factors were kept constant. Pre- and post-operative haemoglobin levels (post-operative day 2) were recorded. Any requirement for transfusion was also documented. Actual drop in haemoglobin levels was compared between the two groups. Results. 91 patients were prescribed rivaroxoban (48 THR and 43 TKR), and 71 were included in the control group (34 THR and 37 TKR). Baseline pre-operative haemoglobin were comparable (p=0.43; 13.0 vs 13.2g/dL), however, post-operative blood loss was significantly increased in the rivaroxoban group (p=< 0.0001; 3.6 vs 2.8g/dL). Total knee replacements had a significant increase in post-operative blood loss in the rivaroxoban group (p=< 0.0001; 3.4 vs 2.6g/dL). Total hip replacement surgery had an increase in total blood loss in the rivaroxoban group, but this did not reach statistical significance (p=0.33; 3.8 vs 3.3g/dL). More patients undergoing TKR required transfusion in the rivaroxoban group (0.07% vs 0.03%). Conclusions. Oral factor Xa inhibitors significantly increase post-operative blood loss in total knee arthroplasty surgery when compared with LMWH. There is a subsequent increased requirement for blood transfusion and the potential complications related to bleeding and transfusion. These factors must be considered and balanced with the ease of oral anticoagulation when introducing these newer agents in arthroplasty patients

Background. Current UK NICE guidelines on the prevention of thromboembolism state that all patients undergoing elective Hip or Knee Replacement surgery should be offered combined mechanical and pharmacological VTE prophylaxis. Methods. The original audit was performed between October 1999 and January 2009, totaling 7,532 patients. Updated to the full 10 years, a total of 8,140 patients underwent hip or knee replacement surgery (revision and primary) in our unit. Using a targeted thromboprophylaxis policy 83% of patients received mechanical A-V foot pumps only until mobile. High risk patients (12%) received in addition LMWH or fondaparinux, with only very high risk patients continuing on chemical prophylaxis post-discharge. All data are collected and stored on our own joint registry database with patients being assessed pre-operatively to determine their level of VTE risk. Results. Overall DVT rate was 1%, PE rate 0.5% and fatal PE rate 0.06%. The rates were slightly higher in the targeted Chemical thromboprophylaxis group (DVT 1.6%, PE 0.95%, fatal PE 0.1%) as expected as these patients were identified as being high risk. 5% of patients failed to receive any prophylaxis and in these patients the rates were the lowest of all (DVT 0.8%, PE 0.3% and fatal PE 0%). All p-values were >0.05. These rates are similar to those published in recent trials involving the oral anticoagulants Dabigatran and Rivaroxaban, given to all patients, (RE-NOVATE, RECORD 1,2,3,4, RE-MOBILISE Trials) with all p values again > 0.05. Complications however were ten times less using a targeted approach. Conclusion. We recommend the use of a targeted approach, only chemically treating those patients who are at high risk for thromboembolism, along with a rapid recovery programme. This has not only been shown to be safe but cuts costs and has ten times fewer complications than treating all patients with both chemical and mechanical prophylaxis as suggested by NICE

Introduction. Peak incidence of pulmonary embolism (PE) typically occurs weeks after total hip (THA) or knee (TKA) arthroplasty, long after hospital discharge. We investigated risk factors for acute PE occurring during index hospitalisation. Methods. Retrospective review of an IRB-approved database identified 329 arthroplasties performed by a single surgeon between 2002 and 2007 at two University teaching hospitals. Warfarin (goal INR 2.0) was standard venous thromboembolism prophylaxis. Results. There were 126 (38.6%) primary THA, 86 (26.1%) primary TKA and 117 (35.3%) revision arthroplasties. Seven patients (7/329; 2.1%) experienced clinically evident non-fatal pulmonary embolism, including 5 after TKA (5/128; 3.9%) and 2 after THA (2/194; 1.0%). In-hospital PE occurred in 4 (1.2%) patients (3 TKA, 1 THA) at a mean 2.7 days (range 2-4 days) after operation, compared with 3 symptomatic events (2 TKA, 1 THA) occurring after discharge (mean 19.3 days; range 8-27 days). Three of four patients suffering acute in-hospital PE were on pre-operative warfarin for chronic atrial fibrillation. Among all patients on pre-operative warfarin, 3 (12.5%) sustained an early PE, with a relative risk of 38.1 times that of controls not on chronic warfarin therapy (p=0.001). Body mass index greater than 30 kg/m2, a history of previous venous thromboembolism, coronary artery disease, ASA score, and type of operation were all found to not be associated with increased risk of in-hospital PE. Conclusion. Acute symptomatic in-hospital pulmonary embolism was correlated with chronic pre-operative warfarin anticoagulation. Compared to historical controls, time to PE was shorter in patients on chronic warfarin. Rebound hypercoagulability after discontinuation of chronic warfarin in preparation for total joint arthroplasty represents a greater hazard than excessive bleeding; we advocate bridging anticoagulation with LMWH in these patients

Patients with pelvic and acetabular fractures have a high risk of developing thromboembolic complications. Despite routine screening, the risk of PE remains high and may develop in patients with negative DVT screening. The search for a means to identify the patient ‘at risk’ has been elusive. 537 consecutive patients, referred to Royal Adelaide Hospital over a 20 year period for treatment of pelvic and acetabular fractures, were evaluated prospectively for pulmonary embolus (PE). 352 patients referred directly to the author were treated with variable dose heparin as prophylaxis to venous thromboembolic (VTE) disease. 184 patients primarily admitted under the general surgeons or to ITU, prior to referral to the author, were treated with fixed dose heparin or Enoxaparin. All patients were followed prospectively to determine the rate of pulmonary embolus. The heparin dosage requirements of those who developed pulmonary emboli were compared to those who did not. Patients were also identified for whom a clinical diagnosis of deep venous thrombosis (DVT) was made during the study and their heparin dosage requirements were determined. 7 of 352 patients treated with variable dose heparin developed PE (1.98%). 13 of 184 patients treated with fixed dose heparin, Enoxaparin, or combinations, developed PE (7.06%). An incidental finding of DVT was made in 36 patients. Of these, 10 patients (2.8%) were treated with variable dose heparin and 26 patients (14.1%) with fixed dose heparin or Enoxaparin. The average Injury Severity Score was higher in patients treated with variable dose heparin than those treated with fixed dose regimes. Patients treated with variable dose heparin who developed PE showed a progressively increasing heparin requirement. The majority of patients who did not develop PE (72%) showed a progressively decreasing heparin requirement (suggesting reversal of a prothrombotic state). 21% showed an initial increasing heparin requirement followed by a decreasing requirement (suggesting a prothrombotic state that was reversed, e.g. a DVT successfully treated by the increasing heparin dose provided by a variable dose regime). 4% manifested a static heparin requirement (suggesting maintenance of a prothrombotic state). 8 patients treated with variable dose heparin developed DVT. 6/8 patients manifested a phase of progressively increasing heparin requirement, followed by a decreased requirement, and 2/8 patients manifested a sustained level of heparin requirement. Patients with pelvic and acetabular fractures treated with variable dose heparin showed a rate of PE (1.98%). This is remarkably low compared with published rates of PE in such patients, and particularly compared with those patients treated only with chemoprophylaxis. The rate of PE was 3.5x higher and the rate of DVT was 5x higher in patients treated with fixed dose heparin or Enoxaparin. Patients who developed PE or DVT manifested an increasing heparin requirement. An increasing dosage of heparin may protect the ‘at risk’ patient from venous thromboembolism. Fixed dose unfractionated heparin/LMWH may be insufficient to treat the ‘at risk’ patient. An increasing heparin requirement may identify the patient ‘at risk’

Drug therapy forms an integral part of the management of many orthopaedic conditions. However, many medicines can produce serious adverse reactions if prescribed inappropriately, either alone or in combination with other drugs. Often these hazards are not appreciated. In response to this, the European Union recently issued legislation regarding safety measures which member states must adopt to minimise the risk of errors of medication.

In March 2014 the Medicines and Healthcare products Regulatory Agency and NHS England released a Patient Safety Alert initiative focussed on errors of medication. There have been similar initiatives in the United States under the auspices of The National Coordinating Council for Medication Error and The Joint Commission on the Accreditation of Healthcare Organizations. These initiatives have highlighted the importance of informing and educating clinicians.

Here, we discuss common drug interactions and contra-indications in orthopaedic practice. This is germane to safe and effective clinical care.

Cite this article: Bone Joint J 2015;97-B:434–41.

We performed a systematic review and meta-analysis to compare the efficacy of intermittent mechanical compression combined with pharmacological thromboprophylaxis, against either mechanical compression or pharmacological prophylaxis in preventing deep-vein thrombosis (DVT) and pulmonary embolism in patients undergoing hip or knee replacement. A total of six randomised controlled trials, evaluating a total of 1399 patients, were identified. In knee arthroplasty, the rate of DVT was reduced from 18.7% with anticoagulation alone to 3.7% with combined modalities (risk ratio (RR) 0.27, p = 0.03; number needed to treat: seven). There was moderate, albeit non-significant, heterogeneity (I² = 42%). In hip replacement, there was a non-significant reduction in DVT from 8.7% with mechanical compression alone to 7.2% with additional pharmacological prophylaxis (RR 0.84) and a significant reduction in DVT from 9.7% with anticoagulation alone to 0.9% with additional mechanical compression (RR 0.17, p < 0.001; number needed to treat: 12), with no heterogeneity (I² = 0%). The included studies had insufficient power to demonstrate an effect on pulmonary embolism.

We conclude that the addition of intermittent mechanical leg compression augments the efficacy of anticoagulation in preventing DVT in patients undergoing both knee and hip replacement. Further research on the role of combined modalities in thromboprophylaxis in joint replacement and in other high-risk situations, such as fracture of the hip, is warranted.

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 risk of venous thromboembolism in patients following arthroplasty may be reduced by continuing chemical thromboprophylaxis for up to 35 days post-operatively. This prospective cohort study investigated the compliance of 40 consecutive consenting patients undergoing lower limb arthroplasty with self-administration of a recommended subcutaneous chemotherapeutic agent for six weeks after surgery. Compliance was assessed by examination of the patient for signs of injection, number of syringes used, and a self-report diary at the end of the six-week period. A total of 40 patients, 15 men and 25 women, were recruited. One woman was excluded because immediate post-operative complications prevented her participation. Self-administration was considered feasible in 87% of patients (95% confidence interval (CI) 76 to 98) at the time of discharge. Among this group of 34 patients, 29 (85%) were compliant (95% CI 73 to 97). Patients can learn to self-administer subcutaneous injections of thromboprophylaxis, and compliance with extended prophylaxis to six weeks is good.

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.