We compared thromboembolic events, major haemorrhage and death after knee replacement in patients receiving either aspirin or low-molecular-weight heparin (LMWH). Data from the National Joint Registry for England and Wales were linked to an administrative database of hospital admissions in the English National Health Service. A total of 156 798 patients between April 2003 and September 2008 were included and followed for 90 days. Multivariable risk modelling was used to estimate odds ratios adjusted for baseline risk factors (AOR). An AOR < 1 indicates that risk rates are lower with LMWH than with aspirin. In all, 36 159 patients (23.1%) were prescribed aspirin and 120 639 patients (76.9%) were prescribed LMWH. We found no statistically significant differences between the aspirin and LMWH groups in the rate of pulmonary embolism (0.49% vs 0.45%, AOR 0.88 (95% confidence interval (CI) 0.74 to 1.05); p = 0.16), 90-day mortality (0.39% vs 0.45%, AOR 1.13 (95% CI 0.94 to 1.37); p = 0.19) or major haemorrhage (0.37% vs 0.39%, AOR 1.01 (95% CI 0.83 to 1.22); p = 0.94). There was a significantly greater likelihood of needing to return to theatre in the aspirin group (0.26% vs 0.19%, AOR 0.73 (95% CI 0.58 to 0.94); p = 0.01). Between patients receiving LMWH or aspirin there was only a small difference in the risk of pulmonary embolism, 90-day mortality and major haemorrhage. These results should be considered when the existing guidelines for thromboprophylaxis after knee replacement are reviewed

The optimal regime of antithrombotic prophylaxis for patients undergoing total knee arthroplasty (TKA) has not been established. Many surgeons employ intermittent pneumatic compression while others use low-molecular-weight heparins (LMWH) which were primarily developed for total hip arthroplasty. We compared the efficacy and safety of these two techniques in a randomised study with blinded assessment of the endpoint by phlebography. We randomised 130 patients, scheduled for elective TKA, to receive one daily subcutaneous injection of nadroparin calcium (dosage adapted to body-weight) or continuous intermittent pneumatic compression of the foot by means of the arteriovenous impulse system. A total of 108 patients (60 in the LMWH group and 48 in the mechanical prophylaxis group) had phlebography eight to 12 days after surgery. Of the 47 with deep-vein thrombosis, 16 had received LMWH (26.7%, 95% CI 16.1 to 39.7) and 31, mechanical prophylaxis (64.6%, 95% CI 49.5 to 77.8). The difference between the two groups was highly significant (p < 0.001). Only one patient in the LMWH group had severe bleeding. We conclude that one daily subcutaneous injection of calcium nadroparin in a fixed, weight-adjusted dosage scheme is superior to intermittent pneumatic compression of the foot for thromboprophylaxis after TKA. The LMWH scheme was also safe

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

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. Methods. Through the orthopaedic clinical directors forum, Trusts replacing LMWH with Rivaroxaban for lower limb arthroplasty thromboprophylaxis during 2009 were identified. Prospectively collected Hospital episode statistics (HES) data was then analysed for these units so as to determine rates of 90-day symptomatic deep venous thrombosis (DVT), pulmonary thromboembolism (PTE), major bleed (cerebrovascular accident or gastrointestinal haemorrhage), all-cause mortality, and 30-day wound infection and readmission rates before and after the change to Rivaroxaban. 2752 patients prescribed Rivaroxaban following TKR or THR were compared to 10358 patients prescribed LMWH. Data was analysed using odds ratios (OR). Results. There were significantly more wound infections in the Rivaroxaban group (3.85% vs. 2.81%, OR=0.72; 95% CI 0.58-0.90). There were no significant differences between the two groups for PTE (OR=1.52; 0.77-2.97), major bleed (OR=0.73; 0.48-1.12), all-cause mortality (OR=0.93; 0.46-1.87) and re-admission rate (OR=1.21; 0.88-1.67). There were significantly fewer symptomatic DVTs in the Rivaroxaban group (0.91% vs. 0.36%, OR=2.51; 1.30-4.82). Conclusion. This study is the first to describe the real impact of the use of Rivaroxaban in the NHS. When compared with LMWH in lower limb arthroplasty patients, wound infection rates were significantly higher following Rivaroxaban use whilst providing no reduction in symptomatic PTE or all-cause mortality

Patients who undergo total knee replacement (TKR)are at high risk of venous thromboembolism. Low-molecular-weight heparins (LMWH) are the most suitable chemical prophylactic agents but there are some uncertainties about their safety and effectiveness. The foot pump offers an alternative. We randomised 229 patients undergoing primary, unilateral TKR to receive either the A-V Impulse foot pump or enoxaparin, a LMWH. Ascending venography was undertaken between the sixth and eighth postoperative day in 188 patients without knowledge of the randomisation category. The prevalence of venographic deep-vein thrombosis was 58% (57/99) in the foot-pump group and 54% (48/89) in the LMWH group which was not statistically significant. There were four cases of proximal thrombi and two of fatal pulmonary emboli in the foot-pump group and none in the LMWH group. There were fewer haemorrhagic complications and soft-tissue effects in the foot-pump group. We conclude that the neither method provides superior prophylaxis

INTRODUCTION. We examined whether the introduction of an oral factor Xa inhibitor, increased total blood loss in patients undergoing primary total knee arthroplasty surgery. METHODS. Two groups were studied. The intervention group were prescribed a factor Xa inhibitor 6-10 hours post-surgery, and the control group were prescribed low molecular weight heparin (LMWH) 6-10 hours post-surgery. All other factors were kept constant. Pre- and post-operative haemoglobin levels (post-operative on day 2) were recorded. Any requirement for transfusion was also documented. Actual drop in haemoglobin levels was compared between the two groups. RESULTS. 43 patients were prescribed a factor Xa inhibitor and 37 patients LMWH thromboprophylaxis. Baseline pre-operative haemoglobin were comparable (p=0.91; 13.2 vs 13.2g/dL), however, post-operative blood loss was significantly increased in the factor Xa inhibitor group (p=<0.0001; 3.4 vs 2.6g/dL). More patients required transfusion in the factor Xa inhibitor group (0.07% vs 0.03%). Blood loss was significantly increased in the intervention group in patients who were not on anti-platelet medication, when compared with those on concurrent anti-platelet therapy (p=<0.001). CONCLUSIONS. Oral factor Xa inhibitors significantly increase post-operative blood loss in total knee arthroplasty surgery when compared with LMWH. There is a subsequent increased requirement for blood transfusion and the potential complications related to bleeding and transfusion. These factors must be considered and balanced with the ease of oral anticoagulation when introducing these newer agents in total knee arthroplasty patients. The anticoagulatory effects of oral factor Xa inhibitors are most pronounced in patients not on concurrent anti-platelet therapy

Introduction. There is insufficient data on the trends of anticoagulation after total knee arthroplasty (TKA) in the USA, and the efficacy and safety of rivaroxaban, beyond randomized clinical trials and small cohort studies. Patients and Methods. Using the Truven Health MarketScan database, we retrospectively evaluated new anticoagulation prescriptions after elective TKA from 2010 to 2015. The frequency of deep vein thrombosis (DVT), pulmonary embolism (PE), and adverse events, within 90 days, were then evaluated in 24,856 new users of warfarin and 21,398 new users of rivaroxaban in commercially insured patients (COM), and 15,483 new users of warfarin and 8,997 new users of rivaroxaban in Medicare supplement patients (MED). Data was analyzed by odds ratios using logistic regression models with stabilized inverse probability treatment weighting. Results. Warfarin use decreased from approximately 50% to 17% in COM patients and 60% to 25% in MED patients. Rivaroxaban use increased from 0 to 35% in COM patients and from 0 to 39% in MED patients. Older patients, females, a history of DVT, renal impairment, use of antiplatelet agents or surgery performed as an outpatient had lower odds of getting rivaroxaban. Patients in Western region and having surgery in 2015 had higher odds of getting rivaroxaban. COM patients with capitated insurance plans and a history of PE had lower odds of rivaroxaban initiation. MED patients with atrial fibrillation, cardiovascular disease or hyperlipidemia had lower odds of rivaroxaban initiation. Warfarin users had significantly higher odds ratio of DVT (OR 2.06 in COM patients and OR 2.21 in MED patients) and PE (OR 2.03 in COM patients and OR 2.16 in MED patients) than rivaroxaban users. There were no statistically significant differences in the bleeding risk between the two agents, but warfarin users had a significantly higher odds ratio of periprosthetic infection in both COM (1.57) and MED (1.79) patients. Conclusions. There has been an increase in prophylaxis with rivaroxaban, and a decrease in both warfarin and LMWH use after elective TKA over four years. Rivaroxaban had lower odds ratio of both DVT and PE than warfarin, and bleeding risks were similar. For figures, tables, or references, please contact authors directly

Aims

This study compared patient-reported outcomes of three total knee arthroplasty (TKA) designs from one manufacturer: one cruciate-retaining (CR) design, and two cruciate-sacrificing designs, anterior-stabilized (AS) and posterior-stabilized (PS).

Aims

The optimal management of an infrapopliteal deep venous thrombosis (IDVT) following total knee arthroplasty (TKA) remains unknown. The risk of DVT propagation and symptom progression must be balanced against potential haemorrhagic complications associated with administration of anticoagulation therapy. The current study reports on a cohort of patients diagnosed with IDVT following TKA who were treated with aspirin, followed closely for development of symptoms, and scanned with ultrasound to determine resolution of IDVT.

Aims

Antibiotic-loaded bone cements (ALBCs) may offer early protection against the formation of bacterial biofilm after joint arthroplasty. Use in hip arthroplasty is widely accepted, but there is a lack of evidence in total knee arthroplasty (TKA). The objective of this study was to evaluate the use of ALBC in a large population of TKA patients.

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).

We undertook a prospective randomised controlled trial to investigate the efficacy of autologous retransfusion drains in reducing the need for allogenic blood requirement after unilateral total knee replacement. We also monitored the incidence of post-operative complications. There were 86 patients in the control group, receiving standard care with a vacuum drain, and 92 who received an autologous drain and were retransfused postoperatively. Following serial haemoglobin measurements at 24, 48 and 72 hours, we found no difference in the need for allogenic blood between the two groups (control group 15.1%, retransfusion group 13% (p = 0.439)). The incidence of post-operative complications, such as wound infection, deep-vein thrombosis and chest infection, was also comparable between the groups. There were no adverse reactions associated with the retransfusion of autologous blood.

Based on this study, the cost-effectiveness and continued use of autologous drains in total knee replacement should be questioned.