Since the introduction of the National Institute for Health and Care Excellence (NICE) guidelines on thromboprophylaxis and the use of extended thromboprophylaxis with new oral agents, there have been reports of complications arising as a result of their use. We have looked at the incidence of wound complications after the introduction of dabigatran for thromboprophylaxis in our unit.

We investigated the rate of venous thromboembolism and wound leakage in 1728 patients undergoing primary joint replacement, both before and after the introduction of dabigatran, and following its subsequent withdrawal from our unit.

We found that the use of dabigatran led to a significant increase in post-operative wound leakage (20% with dabigatran, 5% with a multimodal regimen; p < 0.001), which also resulted in an increased duration of hospital stay. The rate of thromboembolism in patients receiving dabigatran was higher (1.3%) than in those receiving the multimodal thromboprophylaxis regimen, including low molecular weight heparin as an inpatient and the extended use of aspirin (0.3%, p = 0.047). We have ceased the use of dabigatran for thromboprophylaxis in these patients.

Cite this article: Bone Joint J 2014;96-B:122–6.

Thromboprophylaxis for venous thromboembolism (VTE) after elective arthroplasty remains controversial. Previous surveys have shown considerable variation amongst orthopaedic surgeons, and the topic is still being debated. Chest physicians recently advocated that randomised data demonstrating a risk reduction with long- established thromboprophylaxis have been ignored by orthopaedic surgeons. We present the current thromboprophylaxis practice amongst AOA members performing elective hip and knee replacements and discuss its rationale. All orthopaedic surgeons in the AOA were asked to complete a one page postal questionnaire asking for information regarding: whether they performed elective hip or knee arthroplasty, which methods of mechanical and/or chemical prophylaxis were routinely used, the time frame in ceasing thromboprophylaxis, the motive in using thromboprophylaxis, and whether thromboprophylaxis guidelines released by the AOA or RACS would be helpful in their orthopaedic practice. Responses from the survery are currently being collected and analysed. These results will be ready for presentation at the AOA conference. The results of the survey will be presented in addition to a discussion of the rationale behind current use of post-operative thromboprophylaxis for elective hip and knee arthroplasty and a need for clinical guidelines

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

Thromboprophylaxis is of particular interest to the NHS due to the number of deaths from preventable hospital-acquired venous thrombo-embolism, considerable treatment cost and related long-term morbidities. In compliance with current NICE guidelines, our departmental protocol for chemical thromboprophylaxis changed from aspirin to clexane. We present a review of the use of both these chemical agents in our hip fracture patients; assessing duration of wound ooze, incidence of symptomatic PE and DVT and thrombocytopaenia. Prospective study of surgically treated hip fractures patients on chemical thromboprophylaxis postoperatively over a 7 month period. Of 224 patients reviewed, 110 fitted our inclusion criteria; 78 on Clexane and 32 on aspirin. Mean patient age: 82.6 years(48–100). Mean hospital stay: 30d ays(6–80). Female predominance (3:1). Mean duration of wound ooze: 6.9 days (1–24) for aspirin and 5.6 days (0–15) for clexane. Symptomatic DVTs: 1(3%) for aspirin and 3(3.8%) for clexane. Symptomatic PE: 0 for aspirin and 1(1.3%) for clexane. Thrombocytopenia: 0 for both groups. Mean duration of wound ooze for both groups was approximately 1 week. Low but significant incidence of thrombo-embolism. Thromboembolism-deterrent-stockings were observed to be unreliable mainly due to skin problems and compliance

We performed a meta-analysis of the English literature to assess the efficacy of four common regimes for thromboembolic prophylaxis after total knee arthroplasty: aspirin, warfarin, low-molecular-weight heparin (LMWH) and pneumatic compression. We reviewed 136 articles and abstracts published between January 1980 and December 1997. Papers not using routine venography and a lung scan or angiography to detect deep-venous thrombosis (DVT) and pulmonary emboli (PE) respectively, were excluded. Of the 136 studies, 23 with 6001 patients were selected. The incidence of DVT was 53% (1701/3214) in the aspirin group, 45% (541/1203) in the warfarin group, 29% (311/1075) in the LMWH group, and 17% (86/509) in the pneumatic compression device group. Intermittent pneumatic compression devices and LMWH were significantly better than warfarin (p < 0.0001) or aspirin (p < 0.0001) in preventing DVT. The incidence of asymptomatic PE was 11.7% in the aspirin group (222/1901), 8.2% (101/1229) in the warfarin group and 6.3% (24/378) in the pneumatic compression group. No studies with LMWH used routine lung scans. Warfarin and pneumatic compression were significantly better than aspirin in preventing asymptomatic PE (p < 0.05). The incidence of symptomatic PE was 1.3% (23/1800) in the aspirin group, 0.4% (2/559) in the warfarin group, 0.5% (2/416) in the LMWH group and 0% (0/177) in the pneumatic compression group. No statistically significant difference was noted between the above prophylatic regimes due to the very small incidence of symptomatic PE. Prophylaxis for thromboembolic disease in TKA may have to include a combination of some of the above regimes to incorporate their advantages

Purpose: Thromboprophylaxis is recommended for at least 10 days and up to 35 days following total hip replacement (THR). Rivaroxaban is an oral, direct Factor Xa inhibitor in advanced clinical development that showed promise in early clinical trials. The purpose of this randomized, double-blind, double-dummy, phase III study was to compare the efficacy and safety of oral rivaroxaban with subcutaneous enoxaparin for 5 weeks, to prevent venous thromboembolism (VTE) in patients undergoing primary THR. Method: Patients received 10 mg rivaroxaban orally 6–8 hours after surgery and once daily thereafter, or 40 mg enoxaparin subcutaneously the evening before surgery (restarting 6–8 hours after surgery), and continued once daily. Thromboprophylaxis was administered for 35±4 days, and mandatory, bilateral venography was conducted the next day. The primary efficacy endpoint was the composite of any deep vein thrombosis (DVT), non-fatal pulmonary embolism (PE), and all-cause mortality. The primary efficacy analysis was a test for non-inferiority, followed by a test for superiority. Safety endpoints included major and non-major bleeding during the active treatment period. Results: A total of 4541 patients were randomized to receive rivaroxaban or enoxaparin. Rivaroxaban significantly reduced the incidence of the composite of DVT, PE, and all-cause mortality compared with enoxaparin (1.1% vs 3.7%, respectively; p< 0.001; relative risk reduction [RRR] 70%). Rivaroxaban also significantly reduced the incidence of major VTE compared with enoxaparin (0.2% vs 2.0%, respectively; p< 0.001; RRR 88%). There were no significant differences in the incidence of major bleeding (0.3% vs 0.1%; p=0.178) or non-major bleeding (5.8% vs 5.8%; p=1.000) between rivaroxaban and enoxaparin, respectively. There was no evidence of cardiac or liver safety issues. Conclusion: Oral, once-daily rivaroxaban was significantly more effective than subcutaneous, once-daily enoxaparin for extended thromboprophylaxis following THR. Rivaroxaban was not associated with an increased risk of bleeding and had a similar safety profile to enoxaparin. This trial demonstrated the efficacy and safety of a fixed, unmonitored dose of an oral, direct Factor Xa inhibitor – rivaroxaban – for extended thromboprophylaxis after THR

Background: Prophylaxis against thromboembolic complications has become routine after major trauma and major orthopaedic surgery. In contrast, it remains an issue for debate whether prophylaxis after minor surgery and immobilization is necessary, even though these treatments are well-known risk factors for deep vein thrombosis (DVT). Objectives: The objective of this study was to evaluate the efficacy of Dalteparin (5,000 U given subcutaneously once daily for six weeks) during lower limb immobilization after surgical treatment of Achilles tendon rupture. Methods: After surgery, 105 consecutive patients were randomized to a placebo-controlled double-blind study to evaluate the efficacy of given thromboprophylaxis. DVT screening using validated color duplex sonography was performed three weeks and six weeks after surgery, and all DVTs were confirmed with phlebography. Results: Primary endpoint analysis was available for 91 patients. DVT was diagnosed in 16/47 patients (34%) in the Dalteparin group and in 16/44 patients (36%) in the placebo group. These figures are not significantly different (p=0.8). Proximal DVT was diagnosed in one patient (2%) in the Dalteparin group and in three patients (6%) in the placebo group (p=0.6). No pulmonary emboli or major bleeding occurred in either of the groups. Conclusions: DVT is common after surgical treatment of Achilles tendon rupture and therefore effective thromboprophylaxis is desirable. Thromboprophylaxis with Dalteparin however, does not affect the incidence of DVT during the immobilization after Achilles tendon rupture surgery. Long-term effects of immobilization, such as the risk for post-thrombotic syndrome, need to be investigated further

Introduction: After total hip replacement (THR), thromboprophylaxis for at least 10 days and for up to 35 days is recommended – yet a convenient, oral anticoagulant is not currently available. Rivaroxaban – a once-daily, oral, direct Factor Xa inhibitor with a predictable clinical profile – is in advanced clinical development. RECORD1, a multinational, randomized, double-blind, double-dummy, phase III study, compared once-daily oral rivaroxaban with subcutaneous enoxaparin for 5 weeks following THR. Methods: In total, 4541 patients were randomized to receive oral rivaroxaban 10 mg (6–8 hours after surgery and once daily thereafter), or 40 mg enoxaparin (administered subcutaneously the evening before surgery, resumed 6–8 hours after surgery, and continued once daily). Thromboprophylaxis was administered for 35±4 days; mandatory, bilateral venography was conducted the next day. The primary efficacy endpoint was the composite of any deep vein thrombosis (DVT), nonfatal pulmonary embolism (PE), and all-cause mortality. Safety endpoints included major and non-major bleeding during the active treatment period. Results: The incidence of the composite of DVT, PE, and all-cause mortality was significantly lower for rivaroxaban compared with enoxaparin (1.1% vs 3.7%, respectively; p< 0.001; relative risk reduction [RRR] 70%). The incidence of major VTE was also significantly lower for rivaroxaban compared with enoxaparin (0.2% vs 2.0%, respectively; p< 0.001; RRR 88%). There were no significant differences in the incidence of major bleeding (0.3% vs 0.1%; p=0.178) or non-major bleeding (5.8% vs 5.8%; p=1.000) between rivaroxaban and enoxaparin, respectively. There was no evidence of cardiac or liver safety issues. Conclusions: Following THR, thromboprophylaxis with once-daily, oral rivaroxaban was shown to be significantly more effective than subcutaneous, once-daily enoxaparin – without an increased risk of bleeding. This trial demonstrates the efficacy and safety of oral rivaroxaban using a fixed, unmonitored, once-daily dose for extended thromboprophylaxis after THR

Aim. Thromboprophylaxis in total hip replacement (THR) and total knee replacement (TKR) remains controversial, conspicuous by absence of consensus. Because of protracted and variable mobilisation, there is an extended risk of Venous Thromboembolism (VTE). We hypothesised that a combination of low molecular weight heparin and miniwarfarin would minimise the initial and extended risk. Therefore we evolved a protocol of enoxaparin sodium 40 mgs for 5 days starting preoperatively and miniwarfarin 1-2mg for 6 weeks following surgery. We undertook a retrospective study of total hip and knee replacements in a District General Hospital between January 2000 and December 2005 to determine the effectiveness of the protocol. Methods. We analysed the incidence of symptomatic VTE in 1307 patients, of who 681 underwent THR and 626 TKR. We evaluated the incidence of symptomatic DVT and PE between 0-6 weeks, 6 weeks-3months and 3-6 months following surgery. Results. Total incidence of VTE in the study group as a whole including both total hip and knee arthroplasty in 6 months following surgery was 29/1307 (2.22%), after THR 12/681 (1.76%) and after TKR 17/626 (2.72%). VTE at 6 weeks following TKR was 12/626 (1.92%) and THR 4/681(0.59%); between 6 weeks-3 months following TKR 1/626 (0.16%) and THR 6/681 (0.88%); between 3- 6 months 4/626 (0.64%) following TKR and 2/681 (0.29%) after THR. DVT following TKR was 12/626 (1.92%) at 6 months and following THR 7/681 (1.03%). PE at 6 months after TKR was 5/626 (0.80%) and THR 5/681(0.73%) with no attributable mortality. Conclusions. The incidence of VTE using our thromboprophylaxis protocol - low molecular weight heparin (LMWH) and very low dose warfarin - in THR and TKR not only compares favourably with other modes of thrombo-prophylaxis in literature, but also is cheap and cost effective

Introduction

The use of intramedullary lengthening devices is becoming increasingly popular. There are no published data regarding the incidence of venous thromboembolism following intramedullary lengthening and no reports or guidance for current practices on use of thromboprophylaxis. Following a case of post-operative deep vein thrombosis in our institution, we felt that it is important to assess best practice. We conducted this survey to collect data that would describe current practice and help guide consensus for treatment.

Rivaroxaban is a novel, oral, once-daily, direct Factor Xa inhibitor in advanced clinical development. RECORD1 was a multinational, randomized, double-blind, double-dummy, phase III study investigating the efficacy and safety of extended thromboprophylaxis with rivaroxaban compared with subcutaneous enoxaparin following THR. Patients (N=4541) were randomized to receive oral rivaroxaban 10 mg (6–8 hours after surgery and once daily thereafter) or subcutaneous enoxaparin 40 mg (administered the evening before surgery, 6–8 hours after surgery, and once daily thereafter) for 35±4 days. The primary efficacy outcome was the composite of deep vein thrombosis (DVT: symptomatic or detected by mandatory, bilateral venography if asymptomatic), non-fatal pulmonary embolism (PE), and all-cause mortality up to day 36±6. Major venous thromboembolism (VTE), the composite of any DVT, non-fatal PE and VTE-related death, was a secondary outcome. Safety endpoints included major and non-major bleeding while receiving study medication. Rivaroxaban significantly reduced the incidence of the primary efficacy outcome compared with enoxaparin (1.1% vs 3.7%, respectively; p< 0.001; relative risk reduction [RRR] 70%). Rivaroxaban also significantly reduced the incidence of major VTE compared with enoxaparin (0.2% vs 2.0%, respectively; p< 0.001; RRR 88%). There were no significant differences in the incidence of major bleeding (0.3% vs 0.1%; p=0.178) or non-major bleeding (5.8% vs 5.8%; p=1.000) between rivaroxaban and enoxaparin, respectively. There was no evidence of liver safety issues associated with rivaroxaban. Thromboprophylaxis with once-daily, oral rivaroxaban was significantly more effective than subcutaneous enoxaparin following THR without an increased risk of bleeding. This trial demonstrates the efficacy and safety of a fixed, unmonitored, once-daily dose of oral rivaroxaban for extended thromboprophylaxis after THR

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.

We report preliminary results from the first, multicenter prospective study designed to define the incidence of symptomatic (Venous Thromboembolism) VTE in patients with isolated leg fractures distal to the knee. Eight hundred and twenty-six enrolled patients have completed three months of follow up. By three months, only seven patients had sustained a symptomatic VTE with no fatal PE. Symptomatic and fatal VTE were infrequent complications after isolated leg fractures distal to the knee without thromboprophylaxis. Routine thromboprophylaxis may not be warranted in isolated leg fractures distal to the knee. To report results from the first, multicenter prospective study designed to define the incidence of symptomatic Venous Thromboembolism (VTE) in patients with isolated leg fractures distal to the knee. Symptomatic and fatal VTE are infrequent complications after isolated leg fractures distal to the knee without thromboprophylaxis. Routine thromboprophylaxis may not be warranted in isolated leg fractures distal to the knee. From August 2002 to April 2004, one thousand eight hundred and eight consecutive patients with isolated leg fractures distal to the knee were screened for entry at five hospitals in Ontario. Patients with major trauma, active cancer and previous VTE were excluded. Thromboprophylaxis was not allowed. Patients were followed prospectively for three months, with telephone calls at fourteen days, six weeks and three months. Suspected DVT and PE were investigated in a standardized manner. Eight hundred and twenty-six enrolled patients have completed three months of follow up. The mean age was forty-five years (range sixteen to ninety-three) and 59.5% of this cohort was female. 99% of these fractures were unilateral and 97% were closed. Fractures included: fibula (38%), metatarsal (29%), phalanges (13%), calcaneus, talus or tarsal (10%), tibia (10%) and patella (7%). Only 11% of fractures were surgically treated. 88% of fractures received a cast or splint for a mean duration of 41+/− 20 days. Complete follow-up was available for 97.5% of this cohort. By three months only seven patients had sustained a symptomatic VTE (2 proximal DVT, 3 calf DVT, 2 PE) with no fatal PE-an incidence of 0.9% (95% CI 0.3 to 1.8%). Funding: This study was funded by a research grant from Pharmacia

Venous thromboembolism (VTE) is the second most common complication and pulmonary embolism (PE) is the fourth most common cause of death after a hip fracture. Despite thromboprophylaxis, deep vein thrombosis (DVT) is detected in up to 45% of hip fracture patients. Thrombelastography (TEG) is a whole-blood, point of care test capable of providing clinicians with a global assessment of the clotting process, from fibrin formation to clot lysis. Maximal amplitude (mA) from TEG analysis is a measure of clot strength. Elevated admission mA values of >65mm and >72mm have been determined to be independent predictors of in-hospital PE. The coagulation index (CI) is calculated based on TEG parameters and defines hypercoagulable state as CI >3. This study aimed to use serial TEG analysis to determine the duration of hypercoagulable state after hip fracture.

A prospective cohort of hip fracture patients >50 years of age amenable to surgical treatment (AO 31A1–A3 & 31B1–B3) were enrolled at a Level I trauma centre. Serial TEG analysis (TEG 6S) was performed every 24-hours from admission until 5-days post-operatively and at 2- and 6-week follow-up visits. All patients received a minimum of 28 days of thromboprophylaxis. Descriptive statistics and single sample t-tests were used for comparison of mA to the 65mm threshold.

Thirty-five patients (26 female) with a median age of 83 (range = 71–86) years were included. On admission, 31.4% and 82.9% of patients were hypercoagulable based on mA >65mm and CI, respectively. At 2 weeks, all patients remained hypercoagulable, however, mA >72mm showed that 16 patients (47.1%) were at even higher risk for VTE. At 6-weeks, 65.7% and 97.1% of patients were hypercoagulable based on mA >65mm and CI, respectively. When compared with the mA >65mm threshold, patients were hypocoagulable at the time of admission (mA = 62.2 (±6.3), p = 0.011), but became significantly more hypercoagulable at 2-weeks (mA = 71.6 (±2.6), p < 0 .001), followed by continued hypercoagulability at 6-weeks, however not significantly elevated above the 65mm threshold (mA = 66.2 (±3.8), p = 0.058). One patient developed a symptomatic DVT at 2-weeks and had a mA = 72.9 and a CI of 5.9.

This is the first study to demonstrate that >50% of hip fracture patients remain hypercoagulable 6 weeks post fracture despite thromboprophylaxis, and there are individual hypercoagulable responses. This is critical, as guidelines only recommend 28 to 35 days of thromboprophylaxis in this high-risk population. Previously determined mA thresholds may be a more sensitive test for risk-stratifying patients' VTE risk than the CI threshold. Additionally, assessing ΔmA using serial TEG may better predict VTE risk.

Purpose: We conducted the first, multicentre, prospective cohort study to define the incidence of symptomatic venous thromboembolism (VTE) in patients with tibia and ankle fractures treated conservatively and relatively minor lower leg fractures. The reported incidence of deep vein thrombosis (DVT) using routine venography in patients with lower leg injury requiring cast immobilization is approximately 20–40%, which has lead to the routine use of anticoagulant prophylaxis for several weeks in many such patients. However the vast majority of venographically-detected DVTs are asymptomatic, distal thrombi whose clinical relevance is uncertain. Therefore venography is not the best outcome measure to assess the burden of clinically important VTE. Method: Consecutive patients with tibia and fibula fractures (treated non-operatively) and patella and foot fractures, (treated operatively or conservatively) were assessed for eligibility at 5 Ontario hospitals. Patients were enrolled after informed consent within 96 hours of injury and were followed prospectively, by telephone, at 2, 6 and 12 weeks. Those with major trauma, active cancer, and previous VTE were excluded. Thromboprophylaxis was not allowed. Education regarding symptoms of VTE was provided at study entry and patients were asked about VTE symptoms at follow up. Suspected VTE was investigated in a standardized manner. Results: From August 2002 to June 2005, 1200 patients were enrolled from 2446 consecutively screened patients. 98% of patients completed 3-month follow-up. The mean age was 45 years (16 to 93) and 60% were female. The most common fractures were fibular (39%) and most injuries were caused by falls (75%). 99 % of these fractures were unilateral. Most fractures did not require surgical repair (93%), and 82% of patients were immobilized by cast or splint for an average of 42 ±32 days. Overall, 7 patients had symptomatic, objectively confirmed VTE (2 proximal DVT, 3 calf DVT, 2 PE) with no fatal PE – an incidence of 0.6 % (95% CI 0.2 to 1.2). Conclusion: Symptomatic VTE is an infrequent complication after these fractures without thromboprophylaxis. Therefore routine thromboprophylaxis is neither warranted, nor likely to be cost-effective in these patients. This study also highlights the significant discrepancy between clinical endpoint studies and studies using venography

Aims

The aims of this study were to compare the efficacy of two agents, aspirin and warfarin, for the prevention of venous thromboembolism (VTE) after simultaneous bilateral total knee arthroplasty (SBTKA), and to elucidate the risk of VTE conferred by this procedure compared with unilateral TKA (UTKA).

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

We studied the safety and efficacy of multimodal thromboprophylaxis (MMP) in patients with a history of venous thromboembolism (VTE) undergoing total hip arthroplasty (THA). MMP includes discontinuation of procoagulant medications, VTE risk stratification, regional anesthesia, an intravenous bolus of unfractionated heparin before femoral work, rapid mobilization, the use of pneumatic compression devices, and chemoprophylaxis tailored to the patient's risk.

British national guidelines recommend agents which antagonise factor Xa or warfarin as prophylaxis of venous thromboembolism (VTE) in lower limb arthroplasty. However, they discourage the use of aspirin prophylaxis.

We conducted a prospective, multi-centre audit between two national centres, Ninewells Hospital in Dundee and the Royal Infirmary in Edinburgh to compare bleeding and VTE risk. Only Edinburgh routinely uses aspirin as VTE prophylaxis. The study comprises a number of cycles from 2013 to 2015. Consecutive groups of patients were identified prospectively using elective theatre data and information extracted from their case-notes on type of VTE prophylaxis, VTE occurrence, wound complications and length of hospital stay for a period of nine weeks post-operatively.

262 Edinburgh patients and 92 Dundee patients were included. Most Edinburgh patients were prescribed aspirin in hospital and on discharge (188/262, 71.8%), in line with local protocol. In Dundee, dalteparin was most commonly prescribed in hospital (68/92, 73.9%) and rivaroxaban on discharge (57/92, 62.0%).

The Edinburgh group had a 1.5% incidence of pulmonary embolus (PE) and a 1% rate of deep venous thrombosis (DVT), 2% had problems with wound haematoma and one patient (0.4%) required a transfusion; no wound washouts were required. In Dundee there was 0% PE, 2% DVT, 5% had problems with haematoma, 3% required transfusion and 2% required washout. There was no difference in length of hospital stay, with a mode of 4 days for both centres.

Non-fatal PE was prevented in Dundee patients but possibly at the cost of greater incidence of wound complications.

Background: Aetiology of venous thromboembolism is multifactorial and thromboprophylaxis includes mechanical and chemical agents. There is no clear consensus on the choice of chemical agent in elective total hip arthroplasty (THA), although National Institute of Clinical Excellence (NICE) recommends low molecular weight heparin or fondaparinux to all patients.

Aim: The aim of our study was to define the efficacy and safety of various chemical agents currently used for venous throboprophylaxis – namely aspirin, warfarin and low molecular weight heparin in primary THA.

Methods: We retrospectively reviewed 905 consecutive patients with primary THA during an 18 month period. Medical notes were reviewed to record demographic data, inpatient and outpatient thromboprophylactic agents, total hospital stay, readmission, incidence of DVT, pulmonary embolism and death following surgery. Post-operative mobility, transfusion requirements and complications were noted. Suspected thromboembolic events were investigated with venous Doppler ultrasound scanning and CTPA.

Results: 417 (46%) patients received aspirin, 253 received enoxaparin, 190 patients had low dose warfarin and 45 patients had none or multiple agents for inpatient thromboprophylaxis. 615 patients had cemented and 290 patients received uncemented total hip arthroplasty. Patients predominantly received aspirin (61%) as outpatient prophylactic agent. 41 patients were investigated for a suspected thromboembolic event. 2 patients had DVT and 2 patients had PE. There were 3 deaths within 6 weeks, one each due to PE, sepsis and unknown cause. All 4 patients with thromboembolism were on enoxaparin for prophylaxis.

Conclusion: In our study aspirin was the preferred choice for thromboprophylaxis following total hip arthroplasty. We found that aspirin was most effective with no complications and enoxaparin was least effective. We advise the use of aspirin as the first choice drug for thromboprophylaxis as reiterated by some recent studies.

Introduction: In April 2007, NICE published guidance on reducing the risk of venous thromboembolism. Immobilization of a limb in plaster was identified as a risk factor for thromboembolism. NICE recommend that all orthopaedic patients with risk factors are offered low molecular weight heparin (LMWH) whilst an inpatient. There was no cost effective evidence to continue treatment as an outpatient in foot and ankle patients. Foot and ankle surgery often requires prolonged periods of immobilization postoperatively. This study aims to provide a snapshot of current practice amongst foot and ankle surgeons in the UK, highlighting any differences between current practice and NICE guidelines.

Materials and Methods: A random sample of the 267 members of the British Foot and Ankle Surgery Society listed in the 2007 BOA Handbook was obtained. In order to have a 90% confidence level, the sample size was calculated to be 71. The specialist teams identified were contacted by telephone and questioned on their use of thromboprophylaxis for elective patients in plaster. The results were collated and compared to NICE guidelines.

Results: 94% of foot and ankle surgeons prescribe LMWH to post operative elective inpatients in plaster. 65% of specialists continue thromboprophylaxis for out-patients. The duration and agent of thromboprophylaxis varied markedly. The commonest agents were LMWH and aspirin. The length of treatment ranged from ten days to the duration of plaster immobilization.

Discussion: The results highlight a trend amongst foot and ankle surgeons to exceed current NICE guidelines for thromboprophylaxis, continuing treatment for an extended outpatient period. Although there was shown to be no cost effective evidence to continue treatment, the practice continues.

Conclusion: The vast majority of UK foot and ankle surgeons fulfill the NICE recommendations on thromboprophylaxis. There is a clear need for a policy statement from BOFAS on the extended use of thromboprophylaxis for outpatients immobilized in plaster.

Venous Thromboembolism (VTE) is the most common complication following major joint surgery. While attention has focused on VTE following joint arthroplasty their exists a gap in the literature examining the incidence of VTE in spinal surgery; with a shortage of epidemiological data, guidelines for optimal prophylaxis are limited.

This survey, undertaken at the 2009 BASS Annual Meeting, sought to examine prevailing trends in VTE thromboprophylaxis in spinal surgery and to compare selections made by Orthopaedic and Neurosurgeons.

We developed a questionnaire based around eight clinical scenarios. Participants were asked to supply details on their speciality (orthopaedics or neurosurgery) and level of training (grade) and to select which method(s) of thromboprophylaxis they would employ for each scenario. Thirty-nine participants provided responses to the eight scenarios; complete details, including speciality and grade of those surveyed, were complied for 27 of the 39 questionnaires completed.

LMWH was the preferred pharmacological method of thromboprophylaixs selected 31% and 72% of the time by orthopaedic and neurosurgeons respectively. For each of the eight clinical scenarios LMWH and BK TEDS were selected more frequently by neurosurgeons than orthopaedic surgeons who elected to employ early mobilisation and mechanical prophylaxis. Neurosurgeons were more likely to employ more than method of thromboprophylaxis.

Thromboprophylactic selections differed between the two groups; Neurosurgeons preferred LMWH and BK TEDS whilst Early Mobilisation and Mechanical prophylaxis were the preferred methods of thromboprophylaxis amongst orthopaedic surgeons. Based on the results of this survey neurosurgeons more closely adhered to guidelines outlined by NICE/BASS.

It is widely recognised that pelvic disruption in association with high-energy trauma is a life-threatening injury. The potential morbidity and mortality associated with acetabular injuries are less well understood. Due to chronic underfunding and the absence of a comprehensive and coordinated national approach to the management of acetabular trauma throughout the UK, patients can incur prolonged recumbency. Prompt and appropriate referral for specialist management, thromboprophylaxis and venous thrombosis surveillance are important issues for the referring centre. We performed a postal questionnaire to establish the current clinical practice in the specialist centres throughout the UK in pelvic and acetabular trauma, with respect to time to surgery, thromboprophylaxis, and surveillance.

We identified twenty-one units and thirty-seven surgeons in the NHS who deal with pelvic and acetabular injuries. The mean time to surgery from injury in the UK is 8.5 days (range 2-19 days). The larger units that accept and treat patients from outside their region experience the greatest delay to surgery. Mechanical thromboprophylaxis was used in 67% (14) of the units. 24% (5) use arterio-venous boots, 19% (4) use calf pumps, and 52% (11) use TEDS stockings. No unit routinely use prophylactic IVC filters in acetabular trauma. Chemical thromboprophylaxis is routinely used in 100% (21) of the units. 95% (20) used prophylactic doses of unfractionated heparin or low molecular weight heparin. Clinical surveillance alone for thromboembolism is employed in 90% (19) of the units. Only 2 (10%) units routinely perform radiological surveillance with ultrasound Doppler on its acetabular fracture cases pre-operatively.

Currently there is no published directory of dedicated pelvic and acetabular surgeons in the UK. There is no general consensus on the approach to thromboprophylaxis and surveillance in acetabular trauma in the UK. There is no consensus approach to thromboprophylaxis and surveillance in the literature.

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.

We prospectively studied the outcome of a protocol of prophylaxis for deep vein thrombosis (DVT) in 103 consecutive patients undergoing surgical stabilisation of pelvic and acetabular fractures. Low-molecular-weight heparin (LMWH) was administered within 24 hours of injury or on achieving haemodynamic stability. Patients were screened for proximal DVT by duplex ultrasonography performed ten to 14 days after surgery.

The incidence of proximal DVT was 10% and of pulmonary embolus 5%. Proximal DVT developed in two of 64 patients (3%) who had received LMWH within 24 hours of injury, but in eight of 36 patients (22%) who received LMWH more than 24 hours after the injury (p < 0.01). We conclude that LMWH, when begun without delay, is a safe and effective method of thromboprophylaxis in high-risk patients with major pelvic or acetabular fractures.

Identification of the paediatric orthopaedic patient at high risk of venous thromboembolism (VTE) can allow a targeted approach to thromboprophylaxis. There is currently no national consensus on the correct method of risk assessment in this patient group. The Royal National Orthopaedic Hospital has developed a guideline using the evidence available to allow stratification of risk for the paediatric orthopaedic patient.

A list of departments offering specialist paediatric orthopaedic surgery was obtained from the member list of the British Society of Paediatric Orthopaedic Surgeons (BSCOS). These hospitals were contacted via telephone interview to determine if they have a specific guideline or risk assessment proforma for paediatric VTE risk.

A total of 74 hospitals were identified with a specialist paediatric orthopaedic practice in the United Kingdom. A response rate was gained from 100% of these hospitals. Only 3/74 of these hospitals had a guideline or protocol in place for the formal assessment of VTE risk in the paediatric patient (Royal National Orthopaedic Hospital, Stanmore; Sheffield Children's Hospital; Barts & the London NHS Trust). All three hospitals were able to provide details of their guideline. Both the RNOH and Barts & the London commented that their guideline was based on that of the Sheffield group, with adaptations for their own requirements.

The majority of hospitals in the UK with a paediatric orthopaedic interest do not have guidance available for the management of VTE risk. Presented here is the outcome of using the limited evidence available, in combination with expert opinion, to develop a guideline suitable for the requirements of a paediatric unit in an orthopaedic hospital. This may be of benefit to other units producing their own guidelines, producing thought and discussion as to the specific requirements of paediatric patients undergoing orthopaedic procedures.

The recommendation that patients having a total hip replacement should receive pharmacological thromboprophylaxis is based on the belief that fatal pulmonary embolism is common, and that prophylaxis will decrease the death rate. To investigate these assumptions we performed a meta-analysis of all studies on hip replacement which included information about death or fatal pulmonary embolism. A total of 130 000 patients was included. The studies were so varied in content and quality that the results of our analysis must be interpreted with some caution.

The fatal pulmonary embolism rate was 0.1% to 0.2% even in patients who received no prophylaxis. This is an order of magnitude lower than that which is generally quoted, and therefore the potential benefit of prophylaxis is small and may not justify the risks. To balance the risks and benefits we must consider the overall death rate. This was 0.3% to 0.4%, and neither heparin nor any other prophylactic agent caused a significant decrease.

Our study demonstrates that there is not enough evidence in the literature to conclude that any form of pharmacological thromboprophylaxis decreases the death rate after total hip replacement. For this reason guidelines which recommend their routine use to prevent death after hip replacement are not justified.

Nice guidelines recommend VTE prophylaxis to patients in below knee casts following foot and ankle surgery following risk assessment. The guidelines are controversial and BOFAS recommendations reiterate the risk factors but highlight poor evidence to support these guidelines. Implementation has been variable dependent on interpretation.

58 patients who underwent hindfoot procedures and were immobilised in a cast were identified. These patients were under the care of two consultants, one of whom anticoagulates with daily enoxaparin and one who does not, providing a de facto case-control design. The patients were followed up to identify those who subsequently suffered a DVT or PE, and the clinical circumstances.

2 cases of VTE events were noted in 58 patients undergoing foot and ankle surgery. Both were elective cases managed postoperatively in cast and treated with prophylaxic enoxaparin. Both of these presented to hospital with signs of VTE greater than 6 weeks following surgery after cast removal and discontinuation of enoxaparin. No patients were considered high risk according to NICE guidelines. None of the patients who received no thromboprophylaxis had a clinical DVT.

Within our study group we found that VTE thromboprophylaxis does not influence clinically evident VTE rates. Patients who developed VTE were not considered high risk by definition of NICE guidelines but only at increased risk due to their immobility. The VTE events were initiated while the patients were receiving thromboprophylaxis. The effectiveness of the guidelines in predicting patients who would benefit from chemoprophylaxis is questionable from this study.

NICE guidelines on VTE thromboprophylaxis have been received with some concerns. Although this investigation studied only a relatively small number of patients, it raises issues about the clinical effectiveness of the guidelines in foot and ankle patients.

Stable ankle fractures can be successfully treated non-operatively with a below knee plaster cast. In some European centres it is standard practice to administer thromboprophylaxis, in the form of low molecular weight heparin, to these patients in order to reduce the risk of deep venous thrombosis (DVT).

The aim of our study was to assess the incidence of DVT in such patients in the absence of any thromboprophylaxis. We designed a prospective study, which was approved by the local ethics committee. We included 100 consecutive patients with ankle fractures treated in a below knee plaster cast. At the time of plaster removal (6 weeks), patients were examined for signs of DVT. A colour doppler duplex ultrasound scan was then performed by one of the two experienced musculoskeletal ultrasound technicians.

We found that 5 patients developed a DVT. Two of these were above knee, involving the superficial femoral vein and popliteal vein respectively. The other three were below knee. None of the patients had any clinical symptoms or signs of DVT. None of the patients developed pulmonary embolism. Of these five patients, four had some predisposing factors for DVT.

The annual incidence of DVT in the normal population is about 0.1%. This can increase to about 4.5% by the age of 75. DVT following hip and knee replacement can occur in 40-80% of cases. Routine thromboprophylaxis may be justified in these patients. However, with a low incidence of 5% following ankle fractures treated in a cast, we believe that routine thromboprophylaxis is not justified.

The National Institute for Clinical Excellence, UK published guidelines in 2007 encouraging the use of low molecular weight heparin (LMWH) joint replacement surgery. Subsequently, our hospital adopted these guidelines in the treatment of total hip replacements. This study is based on our prospective database of total hip replacements between 2005 and 2009 and compares the complication and mortality rates pre- and post institution of the NICE guidelines.

We analysed prospectively collected data on 686 patients who underwent a primary total hip replacement done by a single surgeon between January 2005 and April 2009. We compared the incidence of mortality, pulmonary embolism, myocardial infarction and intracranial bleeding between the two groups. Prior to the guidelines, all patients were treated for the duration of their admission with 75mg aspirin followed by 4 weeks after discharge. Subsequent to the guidelines, the treatment changed to 40mg of LMWH (Clexane) while an inpatient with aspirin being prescribed for 4 weeks on discharge. Patients unable to tolerate aspirin were treated with low molecular weight heparin. High risk patients (previous pulmonary embolism, previous deep vein thrombosis, family history) were treated with 6 weeks of warfarin. Each patients was reviewed at 8 weeks and 6 months following surgery, and adverse incidents were documented at each review or incident.

Results: 686 patients were identified from the study – 328 pre and 358 post implementation of the NICE guidelines. In the pre-guideline group the mortality was 0.6%, with the incidence of pulmonary embolism being 0.3%, myocardial infarction 0.9% and intracranial bleed 0.3%. Both complications of myocardial infarction occurred early in the post-operative stage and were fatal. The post-guideline group had a mortality rate of 0.2%, with the incidence of pulmonary embolism being 0.2% and intracranial bleeding 0.2%. No myocardial infarctions were noted in this group. The single death was as a result of an intracranial bleed. The was no significant statistical difference in the incidence of mortality, pulmonary embolism, myocardial infarction or intracranial bleeding between the two groups (p value > 0.05, 95% confidence interval). There were no complications in the warfarinised patients of which there were equal numbers in both groups (16).

Conclusion: This study has shown that the change in thromboprophylaxis has not had a significant effect on complication rates in primary total hip replacements and that our mortality rate (0.4%) compares favourably with recent literature. The lack of complications in the war-farinised group probably reflects that high risk patients were identified in the screening process and commenced on warfarin early in the post operative period. Note must be made of the single death due to an intracranial bleed while on low molecular weight heparin.

Introduction

Rivaroxaban, an oral factor Xa inhibitor, has been approved by USFDA for prophylaxis of deep vein thrombosis (DVT) and pulmonary embolism (PE) in hip and knee arthroplasties. Its indication in hip fracture surgery has been recently recommended in Asian venous thromboembolism (VTE) guidelines. Phase II dose-ranging study demonstrated that 5 mg rivaroxaban is as effective as enoxaparin for VTE prophylaxis with lower incidence of bleeding complication than the recommended 10 mg dose. Rivaroxaban is recommended to be given 6–8 hours after operation. However, many surgeons are hesitated to follow this guideline since it might increase post-operative blood loss and wound complication. Elderly patients, such as hip fracture patients, are generally at more risk of bleeding and wound complications. These patients may benefit from using the delayed and reduced-dose regimen.

Introduction

Recent UK national guidelines advocate using a combination of mechanical and pharmacological VTE prophylaxis in patients undergoing lower limb arthroplasty. We compared the results from our two series of patients: one treated with clexane and the other treated with rivaroxaban.

Background

There are multiple documented advantages of undertaking total knee arthroplasty (TKA) without tourniquet, however, increased rates of blood loss and transfusion are often cited as contraindications to this approach. The aim of this study was to examine the effect of intra-operative TA administration on blood loss and transfusion rates in TKA without pneumatic tourniquet, using Rivaroxaban as thrombo-embolic prophylaxis.

Introduction: Rivaroxaban is a novel, oral, direct Factor Xa inhibitor in advanced clinical development for the prevention and treatment of thromboembolic disorders. In this phase III trial, the efficacy and safety of thromboprophylaxis with rivaroxaban was compared with enoxaparin in patients undergoing total knee replacement (TKR).

Methods: In RECORD3 – a randomized, double-blind trial – patients received rivaroxaban 10 mg 6–8 hours after surgery and once daily (od) thereafter, or enoxaparin 40 mg od beginning the evening before surgery; both were continued for 10–14 days. The primary efficacy outcome was the composite of any deep vein thrombosis (DVT), non-fatal pulmonary embolism (PE) and all-cause mortality. Secondary efficacy outcomes included major venous thromboembolism (VTE; the composite of proximal DVT, PE and VTE -related death) and symptomatic VTE. The primary safety outcome was major bleeding, and other safety outcomes included any on-treatment bleeding and haemorrhagic wound complications (the composite of excessive wound haematoma and surgical-site bleeding).

Results: A total of 2531 patients were randomized; 2459 were eligible for inclusion in the safety population and 1702 for the modified intention-to-treat population. The primary efficacy outcome was reported in 9.6% of patients receiving rivaroxaban and 18.9% of patients receiving enoxaparin. This equated to a relative risk reduction of 49% (p< 0.001) with rivaroxaban compared with enoxaparin. The incidence of major VTE was also significantly reduced with rivaroxaban compared with enoxaparin (relative risk reduction 62%, p=0.016). The incidence of symptomatic VTE was significantly lower in the rivaroxaban group than in the enoxaparin group (p=0.005). Major bleeding rates were 0.6% and 0.5% in the rivaroxaban and enoxaparin groups, respectively, and rates of any on-treatment bleeding were 4.9% and 4.8%, respectively. The incidence of haemorrhagic wound complications was 2.1% in the rivaroxaban group and 1.9% in the enoxaparin group.

Conclusions: Rivaroxaban was significantly more effective than enoxaparin for the prevention of VTE after TKR, with a similar safety profile. The oral, direct Factor Xa inhibitor rivaroxaban, given as a fixed, unmonitored dose, may have the potential to change clinical practice for thromboprophylaxis after TKR.

Introduction

Reported incidence of DVT after spinal surgery ranges from 0-15% and PE 0.5-2.7%. Theoretically, manipulation of the vessels and venous stasis caused by retraction during anterior lumbar inter-body fusion may increase the propensity for thrombosis. The reported incidence of DVT and PE following major abdominal and pelvic surgery are high (up to 23%) and all these patients routinely receive chemical prophylaxis.

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.

Hip and knee arthroplasty has been associated with relatively high rates of thromboembolic events and the majority of UK orthopaedic surgeons use at least one form of prophylaxis. Of the many different subgroups of thromboembolic rates that are commonly presented in the literature, symptomatic proximal deep vein thrombosis (spDVT) and fatal pulmonary embolism (fPE) are perhaps the most important clinical outcomes.

To determine the effectiveness of common chemical and mechanical prophylactic methods in preventing spDVT and fPE in patients undergoing primary hip and knee arthroplasty. A systematic review of the literature from 1981 to December 2002 was performed. Predetermined inclusion and exclusion criteria were applied. Studies where more than one method of prophylaxis was used were excluded from analysis. For each individual method of prophylaxis, data was extracted, combined and converted to give estimates of the rates of spDVT, fPE and major bleeding events. Absolute risk reduction estimates for spDVT, fPE and major bleeding events were calculated by comparing the thromboembolic rates for each method of prophylaxis with using no prophylaxis of any kind.

992 studies were identified of which 162 met the inclusion criteria. No method of prophylaxis was statistically significantly more effective at preventing spDVT and fPE than using nothing. There were at least as many major bleeding complications as spDVTs. The number of fPEs prevented was very small.

When complications such as major bleeding are considered, the evidence behind the use of any prophylaxis is unconvincing.

Aims

We studied the safety and efficacy of multimodal thromboprophylaxis in patients with a history of venous thromboembolism (VTE) who undergo total hip arthroplasty (THA) within the first 120 postoperative days, and the mortality during the first year. Multimodal prophylaxis includes discontinuation of procoagulant medications, VTE risk stratification, regional anaesthesia, an intravenous bolus of unfractionated heparin prior to femoral preparation, rapid mobilization, the use of pneumatic compression devices, and chemoprophylaxis tailored to the patient’s risk of VTE.

Introduction

Recent UK national guidelines advocate using a combination of mechanical and pharmacological VTE prophylaxis in patients undergoing lower limb arthroplasty but do not recommend one particular pharmacotherapy over another.

Objective

Assess patient compliance with self-administration of subcutaneous low-molecular-weight-heparin (enoxaparin) injections for 14 days following knee replacement surgery.

Purpose of the study

To determine the effectiveness, complications and side effects of Rivaroxaban when used for extended thromboprophylaxis in patients undergoing primary and revision knee arthroplasty.

Introduction

Venous thromboembolism (VTE) is an uncommon complication of foot and ankle surgery but has the potential for significant morbidity and mortality. The incidence, risk factors and prevention of VTE in foot and ankle surgery is not clear.

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.

Aim: To investigate the incidence and type of venous thromboembolic event (VTE) diagnosed in patients undergoing total knee arthroplasty (TKA) and the trends over time following the introduction of a rigorously enforced thromboprophylaxis protocol.

Methods: Data from all 3260 TKAs performed in our unit between April 1996 and March 2003 were prospectively collected by the Scottish Arthroplasty Project (SAP). The SAP data identified 84 of these patients as having being admitted with or died from a VTE episode. A unified thromboprophylaxis protocol was introduced in 1999, from 2001 it was included as part of the integrated care pathway. We retrospectively reviewed all available casenotes of these patients to identify the assessment and thromboprophylaxis given, the precise diagnosis of VTE, the treatment and adverse outcomes.

Results: Of the 84 VTEs identified, 29 had pulmonary emboli (PE), 12 had above knee deep vein thrombosis (DVT), 24 had calf DVT and 10 had no evidence of VTE though were coded as such (but not treated) by physicians elsewhere. Data were unavailable for the remaining 9 but these were assumed to have had VTE for the purposes of this study. Of the 24 patients with calf only DVT, 16 were given therapeutic anticoagulation of whom five developed haemorrhagic complications. From 2001 the thromboprophylaxis protocol was followed in 100% of patients. The rate of VTE in our unit has fallen steadily from 2.26% in 1996–7 to 1.05% in 2002–3.

Conclusions: There has been a steady decline in the rate of venous thromboembolism in our unit over the seven years of the study. A thromboprophylaxis protocol has been successfully introduced in our unit and consistently applied since 2001. There is considerable overdiagnosis and treatment of calf DVT with significant resultant morbidity.

Introduction and Aims: Venous Thromboembolism is a common complication following a hip replacement. Recently the pulmonary embolism prevention study was published. It reported that aspirin decreased the fatal pulmonary embolism rate in patients admitted with a fracture neck of femur. In addition, new products (synthetic factor X inhibitor-Fondaparinux, and a direct thrombin inhibiter-Desirudin) have been reported to be more effective than low molecular weight heparin in preventing asymptomatic deep vein thrombosis. We felt it was important to repeat a survey, done in 1997, on the use of thromboembolism prophylaxis among British Orthopaedic Surgeons.

Method: A single page questionnaire was sent out to all 1308 consultants – orthopaedic surgeons who were members of the British Orthopaedic Association. Those who did not respond were sent a reminder letter.

Results: We achieved a 72% response rate. All surgeons use some form of prophylaxis. Eighty-five percent of surgeons use pharmacological prophylaxis. Low molecular weight heparin is used by 55% of surgeons. Twenty percent of surgeons use aspirin as their only form of pharmacological prophylaxis. Less than 1% (five consultants) use early mobilisation alone and nearly 2% (13 consultants) use graded stockings and early mobilisation as their only form of prophylaxis. Seventy-four percent of surgeons have a unit policy. Thirty percent have changed their regime in the last three years.

Conclusion: The majority of British orthopaedic surgeons still use pharmacological thromboprophylaxis. There has been a significant increase in the use of Aspirin, from 5% to 30%. Aspirin is often combined with a mechanical prophylaxis. This has led to an increase in the use of intermittent calf compression (3% to 22%), and foot pumps (12% to 19%). Low molecular weight heparin use has fallen by 10%.

Venous thrombo-embolism is a common complication following hip replacement. The recently-published pulmonary embolism prevention study reported that aspirin decreased the fatal pulmonary embolism rate in patients with femoral neck fractures. In addition, new products (synthetic factor X-inhibitor Fondaparinux and direct thrombin-inhibiter Desirudin) have been reported to be more effective than low-molecular-weight heparin in preventing asymptomatic DVT. We thought it important to update the 1997 survey on thrombo-embolism prophylaxis by British Orthopaedic Surgeons.

A single page questionnaire was sent to 1308 members of the British Orthopaedic Association who are consultant orthopaedic surgeons. Those who did not respond received a reminder. We had a 72% response rate.

All surgeons use some form of prophylaxis, with 85% using pharmacological agents. Low-molecular-weight heparin is used by 55% of surgeons, while 20% use only aspirin. Fewer than 1% (five consultants) use early mobilisation and nearly 2% (13 consultants) use graded stockings and early mobilisation as their only prophylactic measures. Unit policies govern 74% of surgeons. In the last 3 years, 30% have changed their regime.

Most British orthopaedic surgeons still use pharmacological thromboprophylaxis. The use of aspirin has increased from 5% to 30%. Aspirin is often combined with a mechanical prophylactic. The use of intermittent calf compression has increased from 3% to 22% and of foot pumps from 12% to 19%. The use of low-molecular-weight heparin has fallen by 10%.

Purpose

To investigate the incidence of deep vein thrombosis (DVT) and pulmonary embolism (PE) with external fixator use and to help establish whether current guidelines are appropriate.

The 2007 National Institute for health and Clinical Excellence (NICE) thromboprophylaxis guidelines concerning hip arthroplasty remain contentious. A survey among British Hip Society members was performed to investigate the impact of these guidelines. Information on thromboprophylactic measures before and after guideline publication was gathered in the three categories of Total Hip Replacement (THR), hip fracture and high-risk patients as defined by NICE. The response rate was 185/250 (74%). All responders used thromboprophylaxis, but only 44%, 22% and 7% indicated they were currently acting in accordance with guidance for THR, high risk and hip fracture groups respectively. 19%, 14% and 14% had changed their practice since publication of the guidance in THR, high risk and hip fracture groups respectively. The effects of the NICE guidance in influencing the responders’ thromboprophylactic protocols have been very limited. These results do not appear to endorse the authority of NICE in decisions made in this area.

Introduction: Thromboembolic complications are common in both elective and trauma orthopaedic practice. Despite the many studies reported in the literature, there remain a number of unanswered questions regarding the use of thrombophylaxis. The aim of this study was to establish the current practice amongst Irish consultant orthopaedic surgeons regarding thromboprophylaxis.

Materials and Methods: A detailed confidential written questionaire was sent to all consultant orthopaedic surgeons in the republic of Ireland. Surgeons were asked to indicate the type of mechanical and chemothromboprophylaxis in the setting of total hip arthroplasty, knee arthroplasty and hip fracture. They were also questioned regarding 1) time of commencement of therapy 2) duration of therapy 3) method of diagnosis of DVT 4) Estimated incidence of mortality from pulmonary embolism in the last five years 5) Whether there was established protocol for DVT prophylaxis in their unit. 6) Reason for not using chemothromboprophylaxis if not used and 7) whether their method of treatment was influenced by anaesthetic concerns.

Results: The response rate was seventy percent. Over ninetyfive percent of surgeons used a combination of physical and chemical modalities. There was a wide variation between type of therapy, commencement time and duration of prophylaxis. There was a higher rate of intervention and duration of therapy in elective practice. A unit policy regarding thromboprophylaxis existed in a majority of hospitals (54.7%). Forty-seven per cent of respondents felt that there had been no post-operative mortality in their practice in the previous five years from pulmonary embolism. Twenty-six percent of respondents felt that anaesthetists influenced the type of prophylaxis used. The results of this survey shows that venous thromboembolism is regarded as a significant complication of orthopaedic surgery and that most orthopaedic surgeons take active steps to try and prevent its occurrence. There was a higher rate of intervention in this groug of surgeons compared to previous surveys of British orthopaedic surgeons. This may reflect a higher standard of care or a concern regarding the high rate of litigation in the republic of Ireland. However there is no consensus as to the optimum therapy which reflects the conflicting evidence available in the many publications on this subject.

The incidence of venous thromboembolism (VTE) is unknown in elective foot and ankle surgery. In March 2010 we surveyed the current practice in VTE prophylaxis in elective foot and ankle surgery amongst members of the British Orthopaedic Foot and Ankle Society (BOFAS).

The response rate was 53%. The total the number of elective foot and ankle operations performed by the surveyed group was 33,500 per annum. The perceived incidence of DVT, PE and fatal PE was 0.6%, 0.1% and 0.02%. In our study the number of patients needed to treat to prevent a single fatal PE is 10,000 although this figure is open to significant bias.

The National Institute for Health and Clinical Excellence (NICE) recently published guidelines on reducing the risk of venous thromboembolism in surgical patients. These guidelines cover all surgical inpatients and uses data extrapolated from other groups of patients. We question the applicability of these guidelines to patients undergoing elective foot and ankle surgery. We consider that this data justifies the prospective study of the incidence of VTE in patients undergoing elective foot and ankle surgery, without the use of chemical thromboprophylaxis.

Background: Patients undergoing elective Lower limb arthroplasty are at increased risk of deep vein thrombosis (DVT). On reviewing the literature, there is a lack of evidence about the best time to administer anticoagulants post-operatively - recommended between 6 and 12 hours. In addition the recent American College of Chest Physicians guidelines recommends that postoperative DVT prophylaxis is given for a minimum of 10 days.

The principal aim of this audit was to assess the timing and duration of thromboprophylaxis post-arthroplasty in our unit.

Methods: Data was collected prospectively. We recorded the timing of the first post operative dose of Fragmin following closure of the wound along with duration of treatment. 5 months of data were analysed; changes were suggested and implemented. This included 2 post operative Fragmin ward rounds. The first at 6pm for patients undergoing surgery in morning and a second at 10pm for those in the afternoon. All patients now receive prophylaxis for 10 days. If they were discharged before 10 days they were sent home on Fragmin. A further analysis was carried out six months later for a further five months.

Results: Initial Audit – 330 patients – primary hip or knee replacement

The timing from finishing surgery to receiving Fragmin ranged from 0:31 to 8:37. 11% received Fragmin less than 2 hours post operatively, 12% 2–4 hours post operatively, 27% 4–6 hours and 49% 6–8 hours

The Duration of prophylaxis ranged from 3 to 32 days. 54% received prophylaxis for less than 7 days.

Second Audit – 337 patients – primary hip or knee replacements

The delay from completing surgery to receiving Fragmin ranged from 2:05 to 9:38. Now only 2% received Fragmin less than 4 hours post operatively. Only 51%, however received Fragmin 6–10 hours post op.

All patients received Fragmin for a minimum of 10 days in the second audit

Discussion: The initial audit highlighted potentially dangerous practice in our venous throboprophylaxis regime. Changes were instituted.

The new protocol for post-operative Fragmin administration had little impact on the percentage of patients receiving Fragmin within 6 hours of surgery. The results, however, show that only 8 of these patients received anti-coagulation within 4 hours, a definite improvement on the initial audit.

Following the changes to Fragmin continuation at discharge, inpatient stay is now not an indicator of duration of Fragmin therapy. All patients now receive 10 days of Fragmin, either as inpatients or in the community.

Conclusion: The change in protocol has reduced the number of patients receiving anti-coagulation less than 4 hours after surgery. However there are still a significant number of patients who receive Fragmin under the recommended 6 hours post-operative.

Introduction: Though underutilized, there are currently several pharmacological options available for the prevention of venous thromboembolism (VTE) following major orthopedic surgery. The use of different agents depends on the orthopedic surgeon’s perception of the benefit in prevention of thrombosis versus the risk of bleeding, as well as the bleeding origin (surgical or not). Here we report the results of an international survey assessing the orthopedic surgeon’s perception of the importance of different types of bleeding and how these relate to the bleeding endpoints used in clinical trials.

Methods: Orthopedic surgeons from Germany, Spain, France, USA, and the UK were invited to participate in this survey. Each responder was asked 13 questions. The answers provided by the first 100 responders from each country were used in subsequent analyses. Once 100 surveys had been completed in each country, no further data were collected. Only in France, the physicians invited to participate also included anesthetists, therefore data from this country were obtained from 50 orthopedic surgeons and 50 anesthetists. In all other countries the physicians invited were exclusively orthopaedic surgeons.

Results: In total, 5303 physicians from across Germany, Spain, France, USA, and the UK were invited to participate in the survey. Of these, 789 responded to the invitation. Surgical site bleedings were a great concern in 50–71% of surgeons across participating countries whereas a lower proportion of surgeons appeared to be concerned regarding extra surgical bleeding (2–11%). Importantly, up to 79% and 71% of surgeons across participating countries considered an increase in surgical site bleeding to be very likely associated with a longer hospital stay and delay or difficulty in postoperative rehabilitation, respectively. When asked to decide between anticoagulant A with reduced bleeding risk (versus current agents with similar efficacy) and a second agent (anticoagulant B), which was associated with increased prophylactic efficacy (versus current agents with similar bleeding rate), 52–67% of responders reported that they would select anticoagulant A.

Conclusions: Our survey suggests that surgical site bleedings are of major concern among surgeons across different countries. Up to approximately 80% of surgeons consider that an increase in surgical site bleedings has an impact on patients’ duration of hospitalization and rehabilitation process. Reduced risk for bleeding may be considered a more important factor compared with an increase in efficacy among orthopedic surgeons, when determining the choice of anticoagulant prophylaxis.

The introduction of direct thrombin inhibitors in arthroplasty surgery has reignited the debate on the risk of wound complications when using chemical thromboprophylaxis. It has been suggested that direct thrombin inhibitors might lead to an increased risk of systemic and operative site bleeding and wound sepsis when compared to low molecular weight heparin.

In July 2009, departmental thromboprophylaxis policy for patients undergoing hip and knee replacement surgery (including revision) was changed from subcutaneous enoxaparin for the duration of inpatient stay to dabigatran for 10 days (knees) or 28 days (hips) unless contraindicated. In the 2 years prior to policy change, 1091 patients underwent hip or knee arthroplasty (Group A), with 1150 patients undergoing the same procedures in the 2 years following July 2009 (Group B). A minority of patients were already on warfarin (2% in group 1, 3% in group 2).

This study presents a retrospective analysis of all patients who returned to theatre within 30 days of joint replacement surgery to assess whether the change in unit policy caused any discernible increase in bleeding-related complications.

In group A, 20 / 1091 patients (1.8%) returned to theatre within 30 days. 9 were for reasons unrelated to thromboprophylaxis (mainly dislocated hips), 4 for gastrointestinal bleeding and 7 for wound complications (haematoma, wound breakdown, or infection).

In group B, 22 / 1150 patients (1.9%) returned to theatre within 30 days. 13 were for unrelated reasons, 4 for gastrointestinal bleeding, and 5 for wound complications. One patient with a wound complication was on warfarin and therefore did not receive dabigatran.

The lower wound complication rate in group B was not statistically different.

This study, in a large heterogeneous group of patients, suggests that a change from enoxaparin to dabigatran does not increase the incidence of early infection, or the risk of bleeding at the operative site or the gastrointestinal tract.

The introduction of direct thrombin inhibitors in arthroplasty surgery has reignited the debate on the risk of wound complications when using chemical thromboprophylaxis. It has been suggested that direct thrombin inhibitors might lead to an increased risk of systemic and operative site bleeding and wound sepsis when compared to low molecular weight heparin.

In July 2009, departmental thromboprophylaxis policy for patients undergoing hip and knee replacement surgery (including revision) was changed from subcutaneous enoxaparin for the duration of inpatient stay to dabigatran for 10 days (knees) or 28 days (hips) unless contraindicated. In the 2 years prior to policy change, 1091 patients underwent hip or knee arthroplasty (Group A), with1150 patients undergoing the same procedures in the 2 years following July 2009 (Group B). A minority of patients were already on warfarin (2% in group 1, 3% in group 2).

This study presents a retrospective analysis of all patients who returned to theatre within 30 days of joint replacement surgery to assess whether the change in unit policy caused any discernible increase in bleeding-related complications.

In group A, 20/1091 patients (1.8%) returned to theatre within 30 days. 9 were for reasons unrelated to thromboprophylaxis (mainly dislocated hips), 4 for gastrointestinal bleeding and 7 for wound complications (haematoma, wound breakdown, or infection).

In group B, 22/1150 patients (1.9%) returned to theatre within 30 days. 13 were for unrelated reasons, 4 for gastrointestinal bleeding, and 5 for wound complications. One patient with a wound complication was on warfarin and therefore did not receive dabigatran.

The lower wound complication rate in group B was not statistically different.

This study, in a large heterogeneous group of patients, suggests that a change from enoxaparin to dabigatran does not increase the incidence of local or systemic complications of sufficient severity to warrant return to theatre.

In a prospective study of 205 consecutive patients undergoing surgical stabilisation of acute pelvic and/or acetabular fractures, the incidence of proximal deep vein thrombosis (DVT) was 9.2%, pulmonary embolism (PE) was 1.9% and fatal PE 0.5%.

Use of a DVT prophylaxis protocol, using a low molecular weight heparin (LMWH), administered within 24 hours of injury or achieving haemodynamic stability, was associated with a significantly lower incidence of thromboembolism (p=0.036). Increased rates of thromboembolism were associated with longer delays to surgery (p=0.013), delays to mobilisation of the patient post-operatively (p=0.017), delay in starting chemoprophylaxis (p=0.039) and higher injury severity scores (p=0.042).

Patient age, sex, Glasgow Coma Scale and fracture classification were not associated with the development of thromboembolic complications.

One hundred and thirty four patients had a pre-operative venous Doppler, seven patients had a proximal DVT identified of which six patients had a preoperative inferior vena caval filter applied and underwent successful surgical fracture stabilisation. Five filters were unable to be removed postoperatively and the patients remain on lifelong warfarin.

A DVT prophylaxis protocol using LMWH is reported that is safe and effective.

The introduction of direct thrombin inhibitors in arthroplasty surgery has reignited the debate on the risk of wound complications when using chemical thromboprophylaxis. It has been suggested that direct thrombin inhibitors might lead to an increased risk of systemic and operative site bleeding and wound sepsis when compared to low molecular weight heparin.

In July 2009, departmental thromboprophylaxis policy for patients undergoing hip and knee replacement surgery (including revision) was changed from subcutaneous enoxaparin for the duration of inpatient stay to dabigatran for 10 days (knees) or 28 days (hips) unless contraindidated. In the 2 years prior to policy change, 1091 patients underwent hip or knee arthroplasty (Group 1), with1150 patients undergoing the same procedures in the 2 years following July 2009 (Group 2). A minority of patients were already on warfarin (2% in group 1, 3% in group 2).

This study presents a retrospective analysis of all patients who returned to theatre within 30 days of joint replacement surgery to assess whether the change in unit policy caused any discernible increase in bleeding-related complications.

In group 1, 23/1091 patients (2.1%) returned to theatre within 30 days. 8 were for reasons unrelated to thromboprophylaxis (mainly dislocated hips), 5 for gastrointestinal bleeding (mainly upper GI endoscopy) and 10 for wound complications (haematoma, wound breakdown, or washout of early infection). In group 2, 22 / 1150 patients (1.9%) returned to theatre within 30 days. 12 were for unrelated reasons, 5 for GI bleeding, and 5 for wound complications. The lower return to theatre rate in the second group was not statistically different.

This study, in a large heterogeneous group of patients, suggests that a change from enoxaparin to dabigatran does not increase the incidence of early infection, or the risk of bleeding at the operative site or the gastrointestinal tract.

Venous thromboembolism (VTE) is a potentially fatal complication after total hip replacement (THR) and may be associated with a considerable economic burden. In many centres, thromboprophylaxis using a subcutaneous (sc) anticoagulant in patients undergoing THR is restricted to 14 days or less. Rivaroxaban is a once-daily, oral, direct Factor Xa inhibitor in advanced clinical development for thromboprophylaxis after major orthopaedic surgery; it does not require monitoring or dose adjustment. In a phase III study, RECORD2, oral rivaroxaban 10 mg, given once daily for 35±4 days, significantly reduced the incidence of the primary endpoint (deep vein thrombosis, pulmonary embolism and all-cause mortality), compared with 40 mg sc enoxaparin, given for 14 days (2.0% vs 9.3%, respectively; relative risk reduction 79%; p< 0.001). The incidence of bleeding was low and similar in both groups, despite extended thromboprophylaxis with rivaroxaban. This analysis demonstrates the economic impact of extended thromboprophylaxis with oral rivaroxaban. The effect of rivaroxaban on healthcare costs was based on the primary efficacy results, and the associated reduced administration and monitoring costs, and includes non-drug costs only. The cost of symptomatic VTE was taken from published sources in the US and the UK 2007 NICE Guidelines. It was assumed that nurses spent 3 mins/day administering enoxaparin and training patients to self-inject for outpatient use. Hospital duration was 5 days. In the UK, full blood counts should be taken every 3 days when receiving enoxaparin. The total US health-care resource cost was $192/patient for enoxaparin and $39 for rivaroxaban (excluding drug costs). This saving of $153 was driven by reduced hospital costs associated with fewer VTEs when using rivaroxaban. In the UK, the total healthcare cost/patient was £44 with enoxaparin and £2 with rivaroxaban – savings driven equally by reduced hospitalization and monitoring costs with rivaroxaban prophylaxis. The different cost savings in the US and UK are due to higher US hospital costs. The costs of post-thrombotic syndrome (PTS) were excluded in this analysis. PTS has an estimated 5-year rate of 21% after asymptomatic VTE and 30% after symptomatic VTE, at a total cost/patient of more than $11,000 in the US and £4000 in the UK. Given the reduction in all VTE events with rivaroxaban, there are potential further healthcare cost savings due to reduced PTS. The RECORD2 study showed that extended prophylaxis (35 days) with rivaroxaban was significantly more effective than short-term enoxaparin (14 days) for the prevention of VTE, and was not associated with an increased risk of bleeding. This analysis illustrates an additional benefit of once-daily, oral rivaroxaban in the reduction in healthcare costs related to administration and monitoring.

Purpose: Rivaroxaban is a novel, oral, direct Factor Xa inhibitor in advanced clinical development for the prevention and treatment of thromboembolic disorders. RECORD3 was a phase III trial conducted to compare the efficacy and safety of oral rivaroxaban with subcutaneous enoxaparin for the prevention of venous thromboembolism (VTE) in patients undergoing total knee replacement (TKR).

Method: In this randomized, double-blind trial, patients received rivaroxaban 10 mg once daily (od), or enoxaparin 40 mg od. Enoxaparin was initiated the evening before surgery, and rivaroxaban 6–8 hours after surgery; therapy continued for 10–14 days. The primary efficacy outcome was the composite of any deep vein thrombosis (DVT), pulmonary embolism (PE), and all-cause mortality. Secondary efficacy outcomes included major VTE (the composite of proximal DVT, PE, and VTE-related death) and symptomatic VTE. Major bleeding was the primary safety outcome. Other safety outcomes included any on-treatment bleeding and hemorrhagic wound complications (the composite of excessive wound hematoma and surgical-site bleeding).

Results: A total of 2531 patients were randomized; 2459 were eligible for inclusion in the safety population and 1702 for the modified intention-to-treat population. The incidence of the primary efficacy outcome was significantly reduced with rivaroxaban compared with enoxaparin (relative risk reduction 49%, p< 0.001). Major VTE occurred in 1.0% and 2.6% of patients receiving rivaroxaban and enoxaparin, respectively (relative risk reduction 62%, p=0.016). The incidence of symptomatic VTE was significantly lower in the rivaroxaban group than in the enoxaparin group (p=0.005). Major bleeding rates were 0.6% and 0.5% in the rivaroxaban and enoxaparin groups, respectively, and rates of any on-treatment bleeding were 4.9% and 4.8%, respectively. The incidence of hemorrhagic wound complications was 2.1% in the rivaroxaban group and 1.9% in the enoxaparin group.

Conclusion: Rivaroxaban was significantly more effective than enoxaparin for thromboprophylaxis after TKR. Importantly, the incidence of bleeding was low and similar in both groups. This is the first trial to demonstrate the efficacy and safety of a fixed, unmonitored regimen of an oral, direct Factor Xa inhibitor – rivaroxaban – for thromboprophylaxis after TKR.

Purpose of Study

To investigate current practice of thromboprophylaxis in major UK spinal centres for both trauma and elective surgery, and to asses compliance with NICE guidelines

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.

In a double-blind, randomised study of thromboprophylaxis in patients undergoing total hip replacement, we compared a low-molecular-weight heparin with a placebo. Of the 120 patients enrolled, 112 completed the trial; 58 in the treatment group and 54 in the placebo group. Nine (16%) patients in the treatment group and 19 (35%) in the placebo group developed deep venous thrombosis, diagnosed by the 125I-fibrinogen uptake test (p < 0.02). Verification was obtained by phlebography in 86% of the patients. Prolonged surgery increased the risk of thrombosis in the placebo group but not in the treatment group (p < 0.05). There were significantly more cases of deep venous thrombosis in the placebo group during the first four postoperative days (p < 0.02). The groups did not differ with respect to peroperative and postoperative bleeding. Low-molecular-weight heparin offers safe and easily administered thromboprophylaxis in total hip replacement.

Rivaroxiban is a factor Xa inhibitor and is a newer oral alternative for thromboprophylaxis after joint replacements. Its major advantage is its oral administration and hence better patient compliance. However there are some doubts about its efficacy compared to dalteparin/heparin. We have recently changed over from using dalteparin injections to rivaroxiban tablets for thromboprophylaxis after hip replacements. We assessed our results to find efficacy and specificity of its action in patients undergoing THR.

504 patients underwent hip replacement in last 2 years. 316 were treated with dalteparin injections (fragmin) for thromboprophylaxis while 189 patients were treated with oral rivaroxiban for 35 days after their hip replacement.

Average haemoglobin drop at 24 hours postop was 2.79 in Rivaroxiban group compared to 3. 10 in dalteparin group. 19 patients (of 189 i.e. 10.05%) required postop blood transfusion in rivaroxiban group as against 60 (of 315 i.e. 19.04%) in Dalteparin group. This difference was statistically significant. Incidence of DVT was no different in either groups, but the number of patients was too small to compare this.

Rivaroxiban appears to be more specific in its action and our results suggest a significant reduction in postop blood transfusion following hip replacements without any increase in rate of Deep Vein Thrombosis. We would like to present our findings and discuss role of oral thromboprophylaxis after joint replacements.

Aims

The aim of this study was to present data on 11 459 patients who underwent total hip (THA), total knee (TKA) or unicompartmental knee arthroplasty (UKA) between November 2002 and April 2014 with aspirin as the primary agent for pharmacological thromboprophylaxis.

Low molecular weight heparin (LMWH) is frequently used as thromboprophylaxis after major orthopaedic surgery. Varying levels of non-adherence (5% to 45%) with outpatient LMWH has been reported. Oral direct thrombin inhibitors have been recommended by industry due to ease of administration. We aim to audit the compliance rate with outpatient LMWH treatment following primary total hip arthroplasties (THA) in our district general hospital (DGH).

Using the ORMIS computer system, we identified all primary THA performed in Monklands Hospital between July 2011 and August 2012. Patients’ case notes were analysed retrospectively, looking at operating surgeon's postoperative thromboprophylaxis instructions. We then conducted a telephone interview on patients discharged with outpatient LMWH to assess compliance.

There were 58 primary THAs performed during the audit period. 33 patients were discharged on outpatient LMWH, whilst 15 patients and 3 patients were discharged on aspirin and warfarin respectively. Seven patients were excluded as their discharge prescriptions were missing.

We successfully contacted 20 of the 33 patients discharged with outpatient LMWH. All respondents showed 100% compliance to the full course of treatment. 50% of patients self-administered; 30% were administered by district nurses and 20% by family members. 35% of patients preferred an oral tablet alternative, for its perceived ease of administration. Bruising and skin irritation were the reported problems in some patients, but these did not affect compliance.

Contrary to the previous published non-adherence rates, the compliance rate with outpatient LMWH after THA was high in our DGH. The patient counseling, and family/district nurse involvement in may have contributed to this. However, our numbers of patients are low but data collection continues.

Aims: In major orthopedic surgery, fondaparinux provided a major benefit over enoxaparin, with an overall venous thromboembolsim (VTE) risk reduction of > 50% and similar safety profile regarding clinically relevant bleeding (leading to death or reoperation, or occurring in critical organ). The aim of the present study was to analyze this superior efficacy according to patients and surgery characteristics. Methods: In four phase III trials, the primary efficacy outcome was the VTE incidence up to day 11, defined as deep-vein thrombosis (DVT) detected by mandatory bilateral venography or documented symptomatic DVT or pulmonary embolism. Primary efficacy was further analyzed according to predefined categorical covariates using a logistic regression model. Results: Fondaparinux was more effective than enoxaparin irrespective of age, gender, obesity, the use of cement or surgery duration (odds reduction from −46.9% to −59.7% in favor of fondaparinux. Clinically relevant bleeding did not differ between the two groups according to predefine covariates. Conclusions: For VTE prevention in major orthopaedic surgery, the superiority of fondaparinux over enoxaparin was consistent irrespective of patient or surgery characteristics.

INTRODUCTION

We examined whether the introduction of an oral factor Xa inhibitor, increased total blood loss in patients undergoing primary total knee arthroplasty surgery.

Introduction

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.

Background

Hip fracture in the elderly has high morbidity and mortality. National guidelines have recommended low molecular weight (LMW) heparin or aspirin for thromboprophylaxis in hip fracture. Unlike other types of major surgery, there is a lack of trial evidence for graduated elasticated compression (GEC) stockings in hip fracture patients.

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.

Purpose: Thromboembolic events, such as deep vein thrombosis (DVT) and pulmonary embolism (PE), are a serious risk after major orthopaedic surgery. BAY 59-7939 is a novel, oral, direct Factor Xa inhibitor in clinical development for the prevention and treatment of thromboembolic disorders. The efficacy and safety of BAY 59-7939 for thromboprophylaxis have been determined relative to enoxaparin in two clinical trials, one after elective total hip replacement surgery, and one after elective total knee replacement surgery. This pre-specified analysis combines data from two multicenter, multinational, double-blind, dose-ranging studies; the hip surgery trial was performed in Europe, and the knee surgery trial in North America.

Methods: Patients (N=1343) were randomized to oral BAY 59-7939 at 2.5, 5, 10, 20, or 30 mg twice daily (bid), or subcutaneous enoxaparin (40 mg once daily starting 12 hours before hip surgery, or 30 mg bid starting 12 hours after knee surgery), continuing until mandatory bilateral venography was performed 5–9 days after surgery. The primary efficacy endpoint was a composite of DVT, PE, and all-cause mortality. The primary safety endpoint was major, post-operative bleeding.

Results: The primary efficacy endpoint occurred in 21.6%, 22.9%, 16.1%, 24.4%, and 19.3% of patients receiving BAY 59-7939 2.5, 5, 10, 20, and 30 mg bid, respectively, and 27.8% receiving enoxaparin (n=914). No significant dose–response relationship for efficacy was observed with BAY 59-7939 (P=0.39); this was potentially due to the efficacy achieved with the lower BAY 59-7939 doses. A significant dose–response relationship was observed for major, post-operative bleeding with BAY 59-7939 (P< 0.001), which occurred in 0.9%, 1.3%, 2.1%, 3.9%, and 7.0% of patients receiving BAY 59-7939 2.5, 5, 10, 20, and 30 mg bid, respectively, and 1.7% of patients receiving enoxaparin (n=1317).

Conclusions: This analysis showed that BAY 59-7939 has a wide therapeutic window for the prevention of VTE following major orthopaedic surgery, and, at doses of 2.5–10 mg bid, has similar efficacy and safety to the enoxaparin regimens.

Funding : Commerical funding

Funding Parties : This study was sponsored by Bayer HealthCare AG

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.

Aims: To assess whether there was a relationship between the timing of the first administration of fondaparinux and its efficacy and safety in preventing venous thromboembolism (VTE) in orthopaedic surgery. Methods: Overall, 3616 patients received fondaparinux in 4 randomized, double-blind studies in this setting. We performed a post-hoc analysis of the effect of this timing on VTE up to day 11 (primary efficacy) and bleeding with a bleeding index (BI) ≥2, using logistic regression. These 2 parameters were also analyzed according to whether fondaparinux started before 6 hours or at 6 hours or later postoperation. Results: Logistic regression showed that the efficacy of fondaparinux was not affected by the timing of its first administration (p=0.67). However, there was a statistically significant relationship between this timing and bleeding with a BI ≥2 (p=0.008). The table gives the incidence of VTE and bleeding with a BI ≥2 according to the interval between skin closure and the first fondaparinux injection. Conclusions: The efficacy of fondaparinux in preventing VTE in orthopaedic surgery was not related to the timing of its first administration. In addition, a significant reduction in the incidence of bleeding with a BI ≥2 was observed when the first fondaparinux injection took place between 6 and 9 hours after skin closure.

Ximelagatran is an oral direct thrombin inhibitor intended for the prophylaxis and treatment of thrombo-embolic complications. Purpose: The efficacy and safety of ximelagatran, and its subcutaneous (sc) form melagatran, were evaluated in patients undergoing total hip or knee replacement (THR, TKR). Study 1 was a randomised, double-blind, controlled, dose–response study in which patients received 2-6 doses of sc melagatran (1, 1.5, 2.25, or 3 mg bid) followed by oral ximelagatran (8, 12, 18, or 24 mg bid), or sc dalteparin (5000 IU od). Melagatran treatment was initiated immediately before surgery. Study 2 was a randomized, double-blind, controlled study in which patients received 1–5 doses of sc melagatran (3 mg bid) initiated 4–12 h after surgery followed by oral ximelagatran (24 mg bid), or sc enoxaparin (40 mg od). In both studies, low-molecular-weight heparin (LMWH) was started the evening before surgery, and all treatment regimens were continued for 8–11 days. Bilateral venography was performed on the final day of treatment.

Results: In Study 1, 1876 patients underwent THR (n=1270) or TKR (n=606). A significant dose-dependent reduction in venous thromboembolism (VTE) was seen with melagatran + ximelagatran for both THR (P< 0.0001) and TKR (P=0.0014). The rate of VTE was significantly lower with the highest dose of melagatran + ximelagatran (15.1%) when compared with dalteparin (28.2%) (P< 0.0001). In Study 2, 2788 patients underwent THR (n=1923) or TKR (n=865). The VTE rate was 31% in the melagatran + ximelagatran group and 27% in the enoxaparin group (P=0.053). Total bleeding volume was not significantly different between treatment groups. Conclusion: Fixed-dose sc melagatran followed by oral ximelagatran are efficacious and well tolerated for the prophylaxis of VTE following THR or TKR.

Objectives

We aimed to examine the characteristics of deep venous flow in the leg in a cast and the effects of a wearable neuromuscular stimulator (geko; FirstKind Ltd) and also to explore the participants’ tolerance of the stimulator.

According to the 2004 ACCP guidelines on antithrombotic and thrombolytic therapy general extended prophylaxis with low molecular weight heparins, vitamin K antagonists, or fondaparinux is recommended after major orthopedic surgery. This recommendation is based on a number of placebo controlled, clinical studies using venographic screening for deep vein thrombosis (DVT), as a surrogate end-point for pulmonary embolism (PE), other vascular thrombotic events were not considered. In a recent meta-analysis on these studies the overall event rate of symptomatic venous thromboembolism 30–42 days after a joint arthroplasty was 2.7% DVT and 0.6 % PE in patients having short-term prophylaxis and it was significantly reduced by extended prophylaxis. Bleeding episodes were seen in 4% of cases having extension. Taking into consideration the risk benefit for the individual patient do these findings justify that extended prophylaxis is used on a general basis? To answer this question also compliance, adverse event profile, and cost of the prophylactic regimens have to be addressed. It would be very attractive to be able to individualize the duration of the prophylactic period by assessing the thrombotic potential of every patient in order to balance the risks and benefits of continued prophylaxis.

Knee arthroscopy is the most commonly performed orthopaedic operation world wide. There is however little data on the incidence of DVT and consequently there is no consensus regarding the need for periopeartive thromboprophylaxia. Hoppener et al,2003 reported a high incidence of 11% DVT without the use of thromboprophylaxis.

The aim of our study was to establish the incidence of venous thromboembolic complications in day case knee arthroscopy without any thromboprophylaxis

A retrospective review of 458 consecutive knee arthroscopies done in our unit between Feb 1998 to May 2007 were carried out. They were all day cases and did not receive any chemical thromboprophylaxis. All the case notes were carefully scrutinized for any readmissions for symptoms of venous thromboembolism(VTE). The clinical signs documented were pain, tenderness, swelling or redness of the legs, dyspnoea, chest pain and haemoptysis leg pains or redness following the surgery.

There were 278 males and 180 females. The age group ranged from 15 to 88 years. The average age group was 57.7years. The primary out come of the study was the incidence of symptomatic and asymptomatic venous thromboembolic complications after the knee arthroscopy during the 2 week and 8 week followup period. Our study showed there were no cases of symptomatic deep vein thrombosis in any of the patients.

The pooled overall estimate of the incidence of all VTE, without the use of thromboprophylaxis was 7.4%, symptomatic 2% and asymptomatic 5.4%. This is not in agreement with our study. The limitation of our study, it is a retrospective analysis and no investigative tools were used.

We conclude that until more extensive studies have been performed, it seems justified to withhold thromboprophylaxis in patients undergoing uncomplicated knee arthroscopic procedures in a daycare setting..

Aims: To investigate the efficacy and safety of a new dosage regimen of the oral direct thrombin inhibitor ximelagatran, and its subcutaneous (sc) form melagatran, started in close proximity to surgery. Methods: In a randomised, double-blind, parallel-group study, duration 8–11 days, patients undergoing total hip or knee replacement (THR, n= 1856; TKR, n= 908) received either sc melagatran 2 mg immediately before surgery followed by sc 3 mg in the evening after surgery, and then by oral ximelagatran 24 mg bid as a fixed dose (the ximelagatran group), or sc enoxaparin 40 mg od, started the evening before surgery. Bilateral venography was performed on the final day of treatment. Results: The rate of proximal deep vein thrombosis plus pulmonary embolism was 2.3% in the ximelagatran group vs. 6.3% in the enoxaparin group (p< 0.000002; RRR 63.2%). The total rates of venous thromboembolism (VTE) were 20.3% vs. 26.6%, respectively (p< 0.0003; RRR 23.6%). Cases with symptomatic VTE were rare: 8 in the ximelagatran group and 12 in the enoxaparin group. Bleeding events were more common in the ximelagatran group compared with the enoxaparin group (3.3% vs. 1.2%) as were the transfusion rates (66.8% vs. 61.7%). Importantly, there were no differences in fatal bleeding, critical organ bleeding or bleeding requiring re-operation. Conclusion: Pre-operatively initiated sc melagatran followed by oral ximelagatran was superior in efficacy to enoxaparin in preventing VTE in patients undergoing THR or TKR.

RECORD3 was a multicentre, phase III study designed to investigate the efficacy and safety of rivaroxaban – a novel, oral, once-daily, direct Factor Xa inhibitor – compared with subcutaneous enoxaparin for thromboprophylaxis in patients undergoing total knee arthroplasty (TKA).

Patients scheduled to undergo TKA (N=2,531) were randomized to receive either rivaroxaban 10 mg once daily (initiated 6–8 hours after surgery) or enoxaparin 40 mg once daily (initiated the evening before surgery, then given 6–8 hours after surgery), and daily thereafter for 10–14 days.

The primary efficacy outcome was the composite of any deep vein thrombosis (DVT; symptomatic or asymptomatic detected by mandatory, bilateral venography), non-fatal pulmonary embolism (PE) and all-cause mortality within 13–17 days after surgery.

Rivaroxaban significantly reduced the incidence of the primary efficacy outcome compared with enoxaparin (9.6% vs 18.9%, respectively; p< 0.001; relative risk reduction [RRR] 49%). Rivaroxaban significantly reduced the incidence of major VTE (the composite of proximal DVT, non-fatal PE and VTE-related death) compared with enoxaparin (1.0% vs 2.6%, p=0.01; RRR 62%), and the incidence of symptomatic VTE (0.7% vs 2.0%, p=0.005; RRR 66%). The incidence of bleeding events was similar in both groups (major bleeding: 0.6% and 0.5% in the rivaroxaban and enoxaparin groups, respectively; any on-treatment bleeding: 4.9% and 4.8%, respectively; haemorrhagic wound complications [the composite of excessive wound haematoma and surgical-site bleeding]: 2.0% and 1.9%, respectively). There were no deaths or PEs in the rivaroxaban group during the treatment period, and two deaths and four PEs in the enoxaparin group.

Rivaroxaban was significantly more effective than enoxaparin for the prevention of VTE after TKA, with a similar rate of bleeding. The oral, direct Factor Xa inhibitor rivaroxaban, given once daily as a fixed, unmonitored dose of 10 mg, has the potential to change clinical practice for thromboprophylaxis after TKA.

Aims: Whether the use of elastic stockings (ES) on top of pharmacological thromboprophylaxis is beneficial remains debated. In a worldwide phase III program including 7344 patients in major orthopaedic surgery, fondaparinux, the first synthetic selective factor Xa inhibitor, demonstrated a substantial benefit over enoxaparin in preventing venous thromboembolism (VTE); risk reduction > 50% without increasing clinically relevant bleeding. The aim of this study was to evaluate the influence of ES on this superior efficacy of fondaparinux. Methods: In all four randomized, double-blind trials, comparing a once daily 2.5 mg s.c. injection of fondaparinux to enoxaparin, the primary efficacy outcome was VTE up to day 11, defined as deep-vein thrombosis (DVT) detected by mandatory bilateral venography, or documented symptomatic DVT or pulmonary embolism. A post-hoc analysis on primary efficacy was performed according to the use of ES. Results: The table shows VTE incidences by day 11 without and with ES. Conclusions: In major orthopaedic surgery, fondaparinux showed a similar superior efficacy over enoxaparin in patients with and without ES, indicating that ES did not influenced the major benefit of this new agent. An additive effect of ES in enoxaparin-treated patients cannot be excluded but the effect is insufficient compared with fondaparinux alone.

We present the 12 month data on the relatively novel drug Dabigatran Etexilate (Pradaxa), a new oral anticoagulant which was introduced to combat the risk of post operative venous-thromboembolic disease (VTED) in orthopaedic surgery. This drug was introduced at our hospital in March 2010 and we present our modified protocol of: using 5000u subcutaneous Dalteparin whilst in hospital and giving Dabigatran only on discharge, and at a lower dose (150mg compared to 220mg).

We carried out a retrospective analysis of the notes and imaging of every patient who underwent elective hip and knee arthroplasty over 12 months since the drug was introduced. We evaluated the rate of VTED complications and the rate of transfusion and bleeding post operatively.

The case series of 370 patients showed a 1% risk of deep vein thrombosis with no pulmonary emboli and 1 death due to an unrelated cause. There was a transfusion rate of 11% with 0.5% patients taken back to theatre for evacuation of haematomas. There were no reported adverse effects of Dabigatran.

We argue that our modified protocol for this novel drug should be followed as it is both safe and effective for postoperative anticoagulation.

Introduction: Pharmacological and mechanical methods are recommended to prevent venous thromboembolism (VTE) following hip replacement (THR). However, data on mechanical methods such as graduated compressive stockings (GCS) are limited. This study examined the efficacy and safety of GCS when added to fondaparinux.

Methods: The randomised treatments were 2.5 mg fondaparinux for 5–9 days starting postoperatively alone or with GCS for 42±7 days. The primary efficacy outcome was VTE or sudden death prior to Day 42±7. All patients were to have duplex USS at day 42 + 7. VTE was defined by verified symptomatic VTE or asymptomatic proximal DVT. The main safety outcomes were major and minor bleeding and VTE death.

Results: 856 patients were randomised, of which 799 were THR patients. Of these 756 (95%) were evaluable, 377 in the fondaparinux and 379 in the fondaparinux plus GCS groups. Risk factors for thrombosis were recorded (age > 75 in 20%, history of obesity in 21%, cancer in 6% and VTE in 3%). Compliance with GCS was high, with 85% wearing them continuously. The primary efficacy outcome of VTE or sudden death in THR patients was similar in each treatment group, the results were 5.5% in the fondaparinux only group and 5.3% in the fondaparinux with GCS group; odds ratio was 0.96, 95% confidence interval 0.50–1.83, p=0.91. Outcomes were not different for long-length and short-length stockings. Major bleeding occurred in one patient (< 1%), minor bleeding in 6.7%. No VTE deaths were reported.

Discussion: The addition of GCS to fondaparinux showed no benefit in thromboprophylaxis over fondaparinux alone in this large study of THR patients. Therefore GCS may not be indicated in patients receiving fondaparinux. Graduated compression stockings are time consuming to measure and fit, inconvenient and expensive; therefore we recommend a reconsideration of this current and commonly used practice in THR.

Aims

There is uncertainty regarding the optimal means of thromboprophylaxis following total hip and knee arthroplasty (THA, TKA). This systematic review presents the evidence for acetylsalicylic acid (aspirin) as a thromboprophylactic agent in THA and TKA and compares it with other chemoprophylactic agents.

Aims

The place of thromboprophylaxis in arthroplasty surgery remains controversial, with a challenging requirement to balance prevention of potentially fatal venous thrombo-embolism with minimising wound-related complications leading to deep infection. We compared the incidence of fatal pulmonary embolism in patients undergoing elective primary total hip arthroplasty (THA) between those receiving aspirin, warfarin and low molecular weight heparin (LMWH) for the chemical component of a multi-modal thromboprophylaxis regime.

Purpose: Venous thromboembolism (VTE) is a common, potentially fatal complication of major orthopaedic surgery. Pharmacologic thromboprophylaxis is recommended following total hip replacement (THR) for a minimum of 10 days, and up to 35 days. However, its extended use is not accepted universally – an effective, safe and convenient, oral anticoagulant would improve implementation of these recommendations. This study was conducted to compare short-term thromboprophylaxis with enoxaparin and extended thromboprophylaxis with the novel, oral, direct Factor Xa inhibitor rivaroxaban after THR. This was the largest, prospective, randomized clinical trial conducted to date for the evaluation of the risk/benefit of extended duration thromboprophylaxis.

Method: In this global, double-blind trial, 2509 patients undergoing THR were randomized to receive either subcutaneous enoxaparin 40 mg once daily (od), beginning the evening before surgery and continued for 10–14 days, followed by placebo until day 35±4 (short-term prophylaxis); or oral rivaroxaban 10 mg od beginning 6–8 hours after surgery and continuing for 35±4 days (extended prophylaxis). Mandatory, bilateral venography was conducted on day 36±4. The primary efficacy endpoint was the composite of any deep vein thrombosis (DVT), non-fatal pulmonary embolism (PE), and all-cause mortality. The main secondary efficacy endpoint was major VTE; the composite of proximal DVT, non-fatal PE, and VTE-related death. Safety endpoints included the incidence of major and non-major bleeding.

Results: Extended thromboprophylaxis with rivaroxaban significantly reduced the incidence of both the primary efficacy endpoint (2.0% versus 9.3%, respectively; p< 0.001; relative risk reduction [RRR] 79%) and major VTE (0.6% versus 5.1%, respectively; p< 0.001; RRR 88%), compared with short-term enoxaparin. The incidence of major bleeding was 0.1% in patients receiving either extended or short-term thromboprophylaxis. Non-major bleeding was reported in 6.5% of patients receiving extended prophylaxis with rivaroxaban and 5.5% of those receiving short-term enoxaparin.

Conclusion: Extended duration thromboprophylaxis with rivaroxaban was significantly more effective than short-term enoxaparin for the prevention of VTE in patients undergoing THR. Both regimens were associated with a similar incidence of bleeding. Extended thromboprophylaxis provides substantial benefits for patients undergoing THR and rivaroxaban provides a safe and effective option for this strategy.