Venous thromboembolism associated with hip and knee replacement over a ten-year period

Comparison of efficacy and safety between aspirin and oral anticoagulants for venous thromboembolism prophylaxis after major orthopaedic surgery: a meta-analysis of randomized clinical trials

Background: venous thromboembolism (VTE) is one of the most common complications after major orthopaedic surgery. Recent studies have suggested that aspirin may also be effective in preventing VTE, but it is still controversial whether it can be routinely used. Objectives: To compare the efficacy and safety of aspirin against oral anticoagulants in the prevention of VTE following total hip arthroplasty (THA), total knee arthroplasty (TKA) or hip fracture surgery (HFS). Methods: Relevant publications have been obtained using electronic search databases such as PubMed, Embase, Web of Science, Cochrane Library, and Clinical Trials. gov. from inception to 20 July 2023. Only RCTs evaluating the efficacy and safety of aspirin compared with oral anticoagulants undergoing major orthopaedic surgery were included in the meta-analysis. The primary outcome reported was any VTE event (including deep vein thrombosis (DVT) and pulmonary embolism (PE)). Secondary outcomes included mortality, major bleeding (including gastrointestinal bleed, cerebrovascular hemorrhage, or any bleeding requiring a return to the theater), minor bleeding (ecchymosis, epistaxis, hematuria), and wound complications. The risk of bias for all included studies was assessed according to the Cochrane Collaboration's tool. Results: After screening 974 studies, 12 randomized clinical trials (RCTs) were included, involving 5,088 participants, including 2,540 participants in aspirin, 2,205 participants in rivaroxaban, and 323 participants in warfarin. Aspirin was found to be less effective than oral anticoagulants in thromboprophylaxis after major orthopedic surgery (RR = 1.206, 95% CI 1.053-1.383). After subgroup analysis according to the type of oral anticoagulant, the results showed that aspirin was similar to rivaroxaban and inferior to warfarin. Considering that the studies in the warfarin group were all conducted before 2000, our results need to be further confirmed. In addition, the aspirin group had a higher risk of VTE than the control group in other subgroups, including a follow-up time of ≤3 months, type of procedure as TKA, high-dose aspirin (≥650 mg qd), and no combined use of mechanical prophylaxis. In terms of safety events, aspirin did not show significant differences in major bleeding (RR = 0.952, 95% CI 0.499-1.815), all-cause mortality (RR = 1.208, 95% CI 0.459-3.177), and wound-related events (RR = 0.618, 95% CI 0.333-1.145) compared with oral anticoagulants, and aspirin was associated with a reduction in the risk of minor bleeding (RR = 0.685, 95% CI 0.552-0.850) events and total bleeding (RR = 0.726, 95% CI 0.590-0.892). Conclusion: Aspirin reduces bleeding risk after major orthopedic surgery compared with oral anticoagulants, but may sacrifice VTE prevention to some extent. Updated evidence is needed to analyze the thromboprophylaxis effects of aspirin in patients undergoing major orthopedic surgery. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=463481, identifier CRD42023463481.

Aspirin is a safe and effective thromboembolic prophylaxis after total knee arthroplasty: a systematic review and meta-analysis

PURPOSE

Patients undergoing total knee arthroplasty (TKA) are at high risk for thromboembolic events compared to non-surgical patients. Both anticoagulants and antiplatelet agents are used as antithrombotic prophylaxis in TKA. The aim of this review is to understand the role of aspirin in the prevention of thromboembolic events and to compare its efficacy and safety with the main anticoagulants used in antithromboembolic prophylaxis in TKA.

METHODS

A systematic review and meta-analysis was performed according to the PRISMA guidelines. An electronic systematic search was conducted using PubMed, Scopus, and the Cochrane Central Registry to evaluate studies that compared aspirin with other anticoagulants, in terms of deep venous thrombosis and pulmonary embolism after TKA. The meta-analysis compared the rate of complications between aspirin and other anticoagulants.

RESULTS

Thirteen studies were included in the systematic review for a total of 163,983 patients, and 10 studies were included in the meta-analysis. The meta-analysis demonstrated no statistically significant differences between aspirin and other anticoagulants in terms of the rate of deep venous thrombosis (OR 0.93, 95% CI 0.81-1.08, p = 0.35) and pulmonary embolism (OR 0.89, 95% CI 0.56-1.41, p = 0.61).

CONCLUSION

Aspirin is safe, effective, and not inferior to other main anticoagulants in preventing thromboembolic events following TKA.

Incidence of Symptomatic Venous Thromboembolism (VTE) in 8,885 Elective Total Hip Arthroplasty Patients Receiving Post-operative Aspirin VTE Prophylaxis

BACKGROUND

Venous thromboembolism (VTE) is a potentially reducible cause of morbidity and mortality in patients undergoing elective hip arthroplasty surgery. The balance of post-operative VTE prophylaxis and risk of post-operative haemorrhage remains at the forefront of surgeon's mind. The National Institute for Health and Care Excellence (NICE) published updated guidelines in 2018 which recommend the use of both mechanical and pharmacological methods in patients undergoing elective total hip arthroplasty (THA).

OBJECTIVES

The aim of this study was to present the symptomatic VTE incidence in 8,885 patients who underwent THA between January 1998 and March 2018 with Aspirin as the primary agent for pharmacological thromboprophylaxis. Intermittent calf compression stockings are routinely used from the time of surgery until mobilization (usually the following day) with prophylactic doses of low molecular weight heparin (LMWH) during inpatient stay (from 2005 onwards) and then Aspirin 150mg once daily for six weeks on hospital discharge (or Aspirin only prior to 2005), with use of other therapies occasionally as required.

METHODS

Analysis of prospective data collection from consecutive patients at a single institution undergoing THA was performed with the incidence of symptomatic deep vein thrombosis (DVT) and pulmonary embolism (PE) occurring within six months of the index operation as the primary outcome measure. Ninety-day all-cause mortality of this cohort of patients was also analysed.

RESULTS

8,885 patients were reviewed. This included 7230 primary, 224 complex primary and 1431 revision cases. The overall incidence of symptomatic VTE after elective THA was 1.11% (99/8885) - with the incidence of symptomatic DVT of 0.59% (52/8885) and the incidence of symptomatic PE of 0.53% (47/8885). There was no significant difference (χ² test, p=0.239) in the symptomatic VTE incidence between primary (1.20% - 89/7230), complex primary (0.89% - 2/224) and revision cases (0.70% - 10/1431). The 90-day all-cause mortality was 0.88% (78/8885). Cardiovascular and respiratory disease were the main causes of death following surgery. Only 0.03% of deaths (n= 3) within 90 days of index surgery were due to PE. There was no significant difference (p=0.327) in length of stay (and hence amount of pharmacologic prophylaxis with LMWH received by patients before commencement of Aspirin) with the average length of stay for those patients who did not suffer a VTE of 6.8 days compared with 7.6 days for those who did suffer a VTE.

CONCLUSION

Our results support the use of aspirin as an effective form of prophylaxis against symptomatic VTE following THA in contradiction to NICE and American Academy of Orthopaedic Surgery (AAOS) recommendations. It is not associated with an increased incidence in symptomatic DVT, PE or death compared to other published studies. The fact that it is inexpensive, readily available, requires no monitoring and does not pose an increased risk of bleeding are other advantages of using aspirin for VTE prophylaxis.

Enoxaparin Versus Direct Oral Anticoagulants for Venous Thromboembolism in Asians Undergoing Total Knee Arthroplasty: A Meta-Analysis and Systematic Review

BACKGROUND

The introduction of direct oral anticoagulants (DOACs) shows promise for their role as a chemoprophylaxis agent after total knee arthroplasty (TKA) for the prevention of venous thromboembolism (VTE). However, existing studies are largely based on Western populations that do not account for the different risk profiles and lower rates of VTE in Asians. This systematic review and meta-analysis aimed to evaluate the efficacy of DOACs compared with enoxaparin in an Asian-based population study.

METHODS

The review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. All studies that compared outcomes between enoxaparin and DOACs as VTE prophylaxis after TKA in the Asian population were included.

RESULTS

Five studies with 121,153 patients were included. DOACs demonstrated a convincing benefit over enoxaparin in overall VTE prevention (odds ratio [OR] = 0.42, 95% confidence interval [CI]: 0.24-0.74). However, although the OR trended in favor of DOACs for the reduction of deep vein thrombosis events (OR = 0.54, 95% CI: 0.20-1.48) and pulmonary embolism (OR = 0.75, 95% CI: 0.07-8.20), statistical significance was not reached. In terms of bleeding complications, both arms had similar rates of major (0.91% vs 0.20%), clinically relevant nonmajor (3.28% vs 2.94%), and minor bleeding complications (12.8 vs 13.3%). A nonsignificance advantage of enoxaparin over DOACs was revealed in the OR for major bleeding (OR = 3.17; 95% CI: 0.81-12.43), whereas DOACs were favored to reduce risk of clinically relevant nonmajor (OR = 0.82; 95% CI: 0.01-91.51) and minor bleeding (OR = 0.76; 95% CI: 0.11-5.33).

CONCLUSION

DOACs confer a significantly reduced rate of overall VTE compared with enoxaparin in Asians after TKA. No significant differences in deep vein thrombosis, pulmonary embolism, and rates of bleeding complications exist.

Effect of Comorbidity Burden on the Risk of Venous Thromboembolic Events After Total Knee Arthroplasty

Background

Venous thromboembolic events (VTEs) are common after total knee arthroplasty (TKA). The rate of VTEs has improved with early mobilization, mechanical prophylaxis, and appropriate chemoprophylaxis. The aim of this study was to analyze the contribution of medical comorbidities to the risk of VTE after TKA

Method

Medicare claims from 2005 to 2014 were queried. International Classification of Diseases, Ninth revision (ICD-9), and Current Procedural Terminology codes were used to identify the diagnoses, procedures, and complications. 157,200 primary TKAs were age, sex, and Elixhauser Comorbidity Index (ECI) matched with 157,200 osteoarthritis controls. First instances of deep venous thrombosis (DVT) and pulmonary embolism were tracked at 90 days and 2 years. Odds ratios (ORs), confidence intervals, and P-values (p) were calculated and used to investigate the contribution of comorbidities.

Results

90 days after TKA or OA diagnosis, comorbidities were associated with 45% of the DVT risk, 38% of the PE risk. 1 in 92 patients would be expected to be diagnosed with VTE after TKA and 1 in 136 patients after only the diagnosis of osteoarthritis. After 90 days, medical comorbidities were associated with 70% of the DVT risk, 68% of the PE risk.

Conclusion

Nearly 50% of DVTs and 40% of PEs within 90 days of TKA may be related to the baseline health of OA patients. Venous thromboembolic events after TKA are a “never” event according to Center of Medicare and services that appropriate VTE prophylaxis likely cannot be neutralized.

Do We Need Chemoprophylaxis to Prevent Venous Thromboembolism following Medial Open-Wedge High Tibial Osteotomy?

The aim of this study was to investigate the overall incidence of venous thromboembolism (VTE) and to assess the efficacy of chemoprophylaxis to prevent VTE following medial open-wedge high tibial osteotomy (MOWHTO) in Asian patients. A total of 133 patients who consecutively underwent MOWHTO for the treatment of knee osteoarthritis with varus deformity were enrolled. All patients underwent preoperative ultrasonography and computed tomography venography on postoperative day 5 to detect deep vein thrombosis (DVT). Patients were divided into two groups: chemoprophylaxis group included patients (n = 66) who received 2.5 mg fondaparinux for 5 days postoperatively, whereas control group comprised patients (n = 67) who received placebo (67 patients). We evaluated the efficacy and safety outcomes of the treatment. We also assessed the predisposing factors that may affect the occurrence of VTE. The incidence of overall DVT was 14.9% in the control group and 10.6% in the chemoprophylaxis group (p > 0.05). Proximal DVT occurred in one patient in the control group. There was no symptomatic DVT or pulmonary embolism in either group. The patients with DVT had significantly higher mean body mass index (BMI) than the patients without DVT. Multivariate logistic regression showed BMI > 30 kg/m² that was significantly correlated with the development of DVT (odds ratio = 0.8; p = 0.017). There were no cases of major bleeding; however, minor bleeding episodes occurred in four patients in the chemoprophylaxis group. The current study showed that the overall incidence of VTE following MOWHTO was low in Asian patients even without chemoprophylaxis. Therefore, routine chemoprophylaxis following MOWHTO seems to be not necessary in a population with low-VTE incidence. However, selective chemoprophylaxis should be considered in patients with BMI > 30 kg/m².

2021 John N. Insall Award: Aspirin is effective in preventing propagation of infrapopliteal deep venous thrombosis following total knee arthroplasty

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.

METHODS

Among a cohort of 5,078 patients undergoing TKA, 532 patients (695 TKAs, 12.6%) developed an IDVT between 1 January 2014 to 31 December 2019 at a single institution, as diagnosed using Doppler ultrasound at the first postoperative visit. Of the entire cohort of 532 patients with IDVT, 91.4% (486/532) were treated with aspirin (325 mg twice daily) and followed closely. Repeat lower limb ultrasound was performed four weeks later to evaluate the status of IDVT.

RESULTS

Follow-up Doppler ultrasound was performed on 459/486 (94.4%) patients and demonstrated resolution of IDVT in 445/459 cases (96.9%). Doppler diagnosed propagation of IDVT to the popliteal vein had occurred in 10/459 (2.2%) cases. One patient with an IDVT developed a pulmonary embolus six weeks postoperatively.

CONCLUSION

The results of this study demonstrate a low rate of IDVT propagation in patients managed with aspirin. Additionally, no significant bleeding episodes, wound-related complications, or other adverse events were noted from aspirin therapy. Cite this article: Bone Joint J 2021;103-B(6 Supple A):18-22.

Non-Inferiority of Aspirin for Venous Thromboembolism Prophylaxis After Hip Arthroplasty in a Statewide Registry

BACKGROUND

Uncertainty remains surrounding the use of aspirin as a sole chemoprophylactic agent to reduce the risk of venous thromboembolism (deep vein thrombosis or pulmonary embolism) and bleeding after primary total hip arthroplasty.

METHODS

We performed a non-inferiority analysis of a retrospective cohort of patients undergoing total hip arthroplasty from April 1, 2013 to December 31, 2018. Cases were retrieved from the Michigan Arthroplasty Registry Collaborative Quality Initiative database and performed by 355 surgeons at 61 hospitals throughout Michigan. Surgical setting ranged from small community hospitals to large academic and non-academic centers. The primary outcomes were post-operative venous thromboembolism event or death and bleeding event.

RESULTS

Of the 59,747 patients included, 32,878 (55.03%) were female, and the mean age was 64.5. A total of 462 (0.77%) composite venous thromboembolism events occurred. There were 221 (0.71%) and 129 (0.80%) venous thromboembolism events in patients receiving aspirin only and anticoagulants only, respectively. Aspirin was non-inferior to anticoagulants for composite venous thromboembolism events (odds ratio 0.99, 95% confidence interval 0.79-1.26, P < .001). Bleeding events occurred in 767 (1.28%) patients, with 304 (0.97%) and 281 (1.74%) bleeding events in patients receiving aspirin only and anticoagulants only, respectively. Aspirin was non-inferior to anticoagulants for bleeding events (odds ratio 0.62, 95% confidence interval 0.52-0.74, P < .001).

CONCLUSION

Aspirin is not inferior to other anticoagulants as pharmacologic venous thromboembolism prophylaxis with regards to post-operative risk of venous thromboembolism or bleeding. Sole use of aspirin for venous thromboembolism prophylaxis after total hip arthroplasty should be considered in the appropriate patient.

Risk factors for ecchymosis in patients receiving rivaroxaban for thromboprophylaxis after total knee arthroplasty: a retrospective cohort study

WHAT IS KNOWN AND OBJECTIVE

Ecchymosis of the limb is commonly seen after total knee arthroplasty (TKA) when using anticoagulants for thromboprophylaxis, but it is unknown which factors may predispose patients to an increased risk. The aim of this study was to evaluate risk factors for ecchymosis in patients receiving rivaroxaban after TKA.

METHODS

A retrospective, single-centre cohort analysis was conducted. The electronic medical records of patients admitted to the Department of Orthopedics during January 2018 to December 2019 and who received rivaroxaban 10 mg daily after TKA were reviewed for documentation of ecchymosis. Baseline demographics, laboratory values and surgical information were included for analysing their relationship with ecchymosis.

RESULTS AND DISCUSSION

A total of 227 patients were included in the study. Among them, 54 patients (23.8%) developed ecchymosis, and 173 did not. The ecchymosis group had a higher proportion of patients with a body weight >60 kg [83.33% vs. 50.00%, p = 0.0004] and hypertension [61.11% vs 41.46%, p = 0.0304]. The ecchymosis group also had a higher BMI [26.04 ± 2.71 kg/m² vs 24.52 ± 3.18 kg/m² , p = 0.0066] mean arterial pressure (MAP) recorded from post-operation day 1 to day 3 [105.21 mmHg vs 91.52 mmHg, p = 0.0003]. However, serum albumin concentrations before surgery [3.85 g/dL vs. 4.20 g/dL, p = 0.0225] and on post-operation day 3 [3.50 g/dL vs. 3.91 g/dL, p = 0.0370] were lower in the ecchymosis group. Serum haemoglobin on post-operation day 3 was also lower [10.07 g/dL vs. 11.57 g/dL, p = 0.0459]. Five risk factors for ecchymosis were identified by binary logistic regression: mean MAP (from POD1 to POD3) (OR=2.901, 95% CI: 2.522-3.293, p < 0.001), BMI (OR=2.513, 95% CI: 1.929-3.011, p < 0.001), history of hypertension (OR=2.661, 95% CI: 1.272-4.535, p = 0.032), post-surgery serum albumin level (OR=0.848, 95% CI: 0.735-0.977, p = 0.023) and post-surgery serum haemoglobin level (OR=0.943; 95% CI: 0.898-0.990, p = 0.018).

WHAT IS NEW AND CONCLUSION

The present analyses identified that BMI, history of hypertension, mean MAP (POD1 to POD3), post-surgery serum albumin level and post-surgery serum haemoglobin level were independent risk factors for rivaroxaban-related ecchymosis in patients who underwent TKA. These factors should be considered and optimized before starting rivaroxaban therapy.

Multimodal thromboprophylaxis in low-risk patients undergoing lower limb arthroplasty: A retrospective observational cohort analysis of 1400 patients with ultrasound screening

PURPOSE

This study reports the results of a multimodal thromboprophylaxis protocol for lower limb arthroplasty involving risk stratification, intraoperative calf compression, aspirin prophylaxis and early (within 4 h) post-operative mobilisation facilitated by the use of local infiltration analgesia. The study also aimed to identify risk factors for venous thromboembolism (VTE) within a 3-month period following surgery for patients deemed not at elevated risk.

METHODS

Patients undergoing knee/hip arthroplasty or hip resurfacing were preoperatively screened for VTE risk factors, and those at standard risk were placed on a thromboprophylaxis protocol consisting of intraoperative intermittent calf compression during surgery, 300 mg/day aspirin for 6 weeks from surgery and early mobilisation. Patients were screened bilaterally for deep vein thrombosis (DVT) on post-operative days 10-14. If proximal DVT was detected, patients were anticoagulated and outcomes were recorded. Symptomatic VTE within 3 months of surgery were recorded separately. Patient notes were retrospectively collated and cross-validated against ultrasound reports.

RESULTS

At initial screening, the rate of proximal DVT was 0.54% (1.1% for knee and 0.27% for hip), and distal DVT was 6.63% (20.11% for knee and 2.31% for hip). One small, nonfatal pulmonary embolism (PE) was detected within 3 months of surgery (0.28% of total knee arthroplasty patients or 0.07% of total). All proximal DVTs were treated successfully with anticoagulants; however, one patient suffered a minor PE approximately 10 months post-operatively. Regression analysis identified knee implant and advanced age as independent risk factors for VTE in this cohort.

CONCLUSION

Although knee arthroplasty patients remained at higher risk than hip replacement/resurfacing patients, the incidence and outcomes of VTE remained positive compared with protocols involving extended immobilisation, and episodes of PE were extremely rare. Thus, we conclude that patients at standard preoperative risk of VTE may safely be taken through the post-operative recovery process with a combination of intraoperative mechanical prophylaxis, early mobilisation and post-operative aspirin, with closer attention required for older patients and those undergoing knee surgery.

A comparison of aspirin against rivaroxaban for venous thromboembolism prophylaxis after hip or knee arthroplasty: A meta-analysis

PURPOSE

Total knee arthroplasty (TKA) and total hip arthroplasty (THA) patients are at an elevated risk of post-operative venous thromboembolism (VTE). Newer thromboprophylactic agents such as rivaroxaban are increasingly used and effective in preventing thromboembolic events but may worsen bleeding risk. Recent studies have suggested that the more cost-effective aspirin may also be effective in preventing VTE. This systematic review and meta-analysis aimed to compare the efficacy of aspirin against rivaroxaban for the prevention of VTE following TKA and THA.

METHODS

Electronic searches were performed using five databases from their date of inception to August 2018. Relevant studies were identified, with data extracted and meta-analyzed from the studies.

RESULTS

Five studies were included, which consisted of 2257 in the aspirin group and 2337 in the rivaroxaban group. There were no differences between aspirin and rivaroxaban for either VTE (p = 0.48) or its components deep vein thrombosis (p = 0.44) and pulmonary embolism (p = 0.98). Also, there were no differences between groups for either major bleeding (p = 0.17), any bleeding (p = 0.62), readmissions (p = 0.37) or wound complications (p = 0.17).

CONCLUSION

Aspirin was not significantly different to rivaroxaban for prevention of VTE or adverse events after TKA or THA. However, this study was limited by the significant heterogeneity of the included studies. More large randomized studies are needed to add to this body of evidence.

Efficacy and safety of aspirin and rivaroxaban for venous thromboembolism prophylaxis after total hip or knee arthroplasty: A protocol for meta-analysis

BACKGROUND

The purpose of this meta-analysis is to compare the efficacy and safety of aspirin and rivaroxaban in the prevention of venous thromboembolism (VTE) following either total knee arthroplasty or total hip arthroplasty.

METHODS

A comprehensive literature search of several electronic databases (PubMed, Embase, and Web of Science) was conducted to identify relevant studies. Outcomes of interest included VTE rate, deep vein thrombosis (DVT) rate, pulmonary embolism rate, major bleeding events, mortality rate, blood transfusion, and wound complication. Risk ratio (RR) with 95% confidence intervals (95%CIs) were calculated using a fixed-effects model or random-effects model.

RESULTS

A total of 8 studies with 97,677 patients met the inclusion criteria and were included in this meta-analysis. Compared with rivaroxaban, aspirin had a significantly higher incidence of DVT (RR = 1.48, 95%CI: 1.27, 1.72; P < .001), and decreased risk of blood transfusion (RR = 0.94, 95%CI: 0.93, 0.94; P < .001). However, there were no significant differences between the 2 drugs in terms of total VTE rate (RR = 1.39%, 95%CI: 0.94, 2.05; P = .101), pulmonary embolism rate (RR = 1.64, 95%CI: 0.92, 2.92; P = .094), mortality rate (RR = 1.13, 95%CI: 0.15, 8.27; P = .907), major bleeding (RR = 1.00, 95%CI: 0.44, 2.27; P = .995), and wound complication rate (RR = 0.37, 95%CI: 0.07, 1.87; P = .229).

CONCLUSION

Our results suggested that aspirin and rivaroxaban offered similar effect in the prevention of VTE after total knee arthroplasty or total hip arthroplasty. However, rivaroxaban seemed to have better effect than aspirin in reducing the risk of DVT, and aspirin was safer than rivaroxaban in decreasing the blood transfusion rate.

Short-duration chemoprophylaxis might reduce incidence of deep vein thrombosis in Asian patients undergoing total knee arthroplasty

Background

Venous thromboembolism (VTE) is a serious complication that may occur after total knee arthroplasty (TKA), leading to the recommendation of routine chemoprophylaxis by international guidelines. This study aims to determine if short-duration chemoprophylaxis after TKA reduces the incidence of VTE in an Asian population.

Methods

A retrospective study of 316 patients who underwent unilateral primary TKA between 1 January 2011 and 31 December 2013 was conducted. All patients received mechanical prophylaxis. One hundred seventeen patients (37%) received additional chemoprophylaxis, whereas 199 patients (63%) did not. A Doppler ultrasound (DUS) of both lower limbs was conducted for all patients within 6 days after surgery (median = 3 days) to assess for both proximal and distal DVT. Chemoprophylaxis in the form of enoxaparin (low molecular weight heparin; LMWH), aspirin, or heparin was administered until patients had a normal DUS, for a median duration of 4 days. Patients were followed up clinically for a minimum of 6 months to monitor for delayed or recurrent VTE and at least 2 years for patient-reported outcome measures.

Results

Overall, 24 patients (7.59%) developed deep vein thrombosis (DVT): three proximal and 21 distal DVTs. Twenty-three of the 24 patients were asymptomatic. Twenty of 199 patients (10.05%) with only mechanical prophylaxis developed DVT, whereas four of 117 patients (3.42%) with additional chemoprophylaxis developed DVT. Multivariate analysis showed that chemoprophylaxis use was associated with reduced incidence of DVT (odds ratio = 0.19, p value = 0.011). Other factors associated with increased DVT incidence include female gender (odds ratio = 5.45, p value = 0.034), positive history of cancer (odds ratio = 5.14, p value = 0.044), and increased length of stay in hospital (odds ratio = 1.19, p value < 0.001).

Conclusions

Our study has shown that despite the low incidence of DVT in Asian patients undergoing TKA, short-duration chemoprophylaxis might be effective in reducing the incidence of DVT. However, most DVTs observed in our study were distal and may be of limited clinical significance. Further studies are needed to investigate the impact of chemoprophylaxis use on the incidence of PE and overall mortality rates among Asian patients.

Protocolo de prevenção do tromboembolismo venoso: Experiência de 2.000 casos em artroplastia total de joelho*

Objetivo O objetivo do presente estudo é avaliar o impacto de um protocolo institucional em um hospital terciário na prevenção do tromboembolismo venoso em 2.005 pacientes submetidos a artroplastia total primária de joelho.

Métodos Os dados dos prontuários de pacientes submetidos a artroplastia total do joelho antes (n = 1.115) e após (n = 890) a implantação do protocolo institucional, totalizando 2.005 pacientes, foram relatados retrospectivamente. Dados demográficos, comorbidades e desfechos foram analisados.

Resultados Não houve alteração significativa nos casos de trombose venosa profunda (TVP) (1,6% versus 2,4%; p = 0,211). Houve um aumento nos casos de embolia pulmonar (EP) (0,2% versus 0,8%; p = 0,049).

Conclusão Apesar da implementação do protocolo de prevenção, não houve redução nos eventos estudados. A pequena incidência global faz com que novos estudos, com séries maiores, sejam necessários para confirmar ou descartar esses achados.

Venous thromboembolism in patients hospitalized for hip joint replacement surgery

BACKGROUND

Venous thromboembolism (VTE) is a potentially life-threatening disease. Major transient risk factors include trauma, surgery, and immobilization. Patients undergoing hip joint replacement (HJR) are characterized by a high risk of postoperative VTE, but data on the time trends of VTE rates in this population are sparse.

METHODS

In an analysis of the German nationwide inpatient sample, we included all hospitalizations for elective primary HJR in Germany from 2005 to 2016. Time trends of the surgical procedure, overall death rates, and VTE rates were analysed, and predictors of VTE identified.

RESULTS

Overall, 1,885,839 inpatients with elective primary HJR (59.1% women, 51.4% ≥70 years) were included in the analysis. During hospitalization, VTE was documented in 11,554 (0.6%) patients. While total numbers of primary HJR increased from 145,223 in 2005 to 171,421 in 2016 (β-(slope)-estimate 1818 [95%CI 1083 to 2553], P < 0.001), in-hospital VTE decreased from 1288 (0.9%) to 843 (0.5%) cases (β-estimate -0.71 [95%CI -0.77 to -0.65], P < 0.001), and in-hospital death rate from 0.33% (476 deaths) to 0.29% (498 deaths) (β-estimate -0.11 [95%CI -0.20 to -0.02], P = 0.018). Infections during hospitalization were associated with higher VTE risk than cancer and cardiovascular events. VTE events were independently associated with an increased death risk (OR 15.19 [95%CI 14.19-16.86], P < 0.001).

CONCLUSIONS

While total numbers of HJR increased significantly in Germany between 2005 and 2016, in-hospital rates of VTE decreased from 0.9% to 0.5%. Patients with perioperative VTE had a 15-fold increase of in-hospital death. Cancer, cardiovascular disease and perioperative infections were associated with higher risk for VTE.

The changing incidence of arthroscopic subacromial decompression in Scotland

Aims

The aim of this study was to examine the recent trend in delivery of arthroscopic subacromial decompression (ASD) in Scotland and to determine if this varies by geographical location.

Methods

Scottish Morbidity Records were reviewed retrospectively between March 2014 and April 2018 to identify records for every admission to each NHS hospital. The Office of Population Censuses and Surveys (OPCS-4) surgical codes were used to identify patients undergoing primary ASD. Patients who underwent acromioclavicular joint excision (ACJE) and rotator cuff repair (RCR) were identified and grouped separately. Procedure rates were age and sex standardized against the European standard population.

Results

During the study period the number of ASDs fell by 649 cases (29%) from 2,217 in the first year to 1,568 in the final year. The standardized annual procedure rate fell from 41.6 (95% confidence interval (CI) 39.9 to 43.4) to 28.9 (95% CI 27.4 to 30.3) per 100,000. The greatest reduction occurred between 2017 and 2018. The number of ACJEs rose from 41 to 188 (a 3.59-fold increase). The number of RCRs fell from 655 to 560 (-15%). In the year 2017 to 2018 there were four (28.6%) Scottish NHS board areas where the ASD rate was greater than 3 standard deviations (SDs) from the national average, and two (14.3%) NHS boards where the rate was less than 3 SDs from the national average.

Conclusion

There has been a clear decline in the rate of ASD in Scotland since 2014. Over the same period there has been an increase in the rate of ACJE. The greatest decline occurred between 2017 and 2018, corresponding to the publication of epidemiological studies demonstrating a rise in ASD, and awareness of studies which questioned the benefit of ASD. This paper demonstrates the potential impact of information from epidemiological studies, referral guidelines, and well-designed large multicentre randomized controlled trials on clinical practice. Cite this article: Bone Joint J 2020;102-B(3):360–364

Current risk factors for asymptomatic venous thromboembolism in patients undergoing total hip arthroplasty

Objective: A history of venous thromboembolism (VTE) is a risk factor for newly formed VTE after total hip arthroplasty (THA). However, its morbidity and association with postoperative VTE are not clear and, therefore, were investigated in this study. Methods: Four-hundred and nineteen patients scheduled for primary THA were included. We preoperatively identified any VTE factors such as obesity, age, and history of VTE by interviewing and duplex ultrasonography for all patients, and the patients were assigned into 'high-' or 'low-risk' groups, that were the indication whether chemoprophylaxis was administered after surgery. Postoperative VTE was also examined on the day 7 by enhanced computed tomography (CT) for all patients. Results: Preoperative VTE were detected in 48 patients (11.4%), and postoperative VTE were found in 44 (10.5%). Linear and multivariate logistic regression analysis revealed osteonecrosis and preoperative VTE were the independent factors associated with postoperative VTE (Odds ratio (OR) 1.0 e-7 and 5.00, respectively). In the survey of each risk group, only preoperative VTE was recognized as a risk factor for high-risk group, and longer operation time for low-risk group. Conclusion: The present study confirmed high frequency of preoperative VTE which was still the strongest risk factor for postoperative asymptomatic VTE.

Venous thromboembolism prophylaxis after hip preservation surgery: a review and presentation of institutional experience

Venous thromboembolism (VTE) is a serious complication after major orthopedic procedures. The best options for prevention of the VTE are still debated. The most popular evidence-based guidelines for prevention and treatment of VTE in orthopedic surgery addressed the total hip or knee arthroplasty and hip fractures as the major orthopedic surgeries. Majority of studies have evaluated the different modalities of the VTE prophylaxis in patients undergiong hip or knee arthroplasty. Hip preservation surgeries (HPS) including mini-open femoroacetabular osteoplasty, surgical dislocation of the hip, arthroscopic procedures, and periacetabular osteotomy (PAO) are gained popularity in recent two decades. The majority of these patients are young, healthy and active and may not be considered at high risk for VTE. The frequency of VTE in patients undergoing PAO seems to be low between 0 and 5%. There is a paucity of data regarding rates of VTE in young healthy patients undergoing HPS as well as the optimal prevention methods for VTE. Hence current VTE prevention guidelines do not cover HPS adequately. We aimed to review the available literature regarding VTE events and VTE prophylaxis options after HPS. We discussed the available and potential options for prophylaxis of VTE events in these procedures along with our experience in a large cohort of hip preservation surgery.

Early death following revision total hip arthroplasty

INTRODUCTION

The frequency of primary total hip arthroplasty procedures is increasing, with a subsequent rise in revision procedures. This study aims to describe timing and surgical mortality associated with revision total hip arthroplasty (THA) compared to those on the waiting list.

METHODS

All patients from a single institution who underwent revision total hip arthroplasty or were added to the waiting list for the same procedure between 2003 and 2013 were recorded. Mortality rates were calculated at 30 and 90 days following surgery or addition to the waiting list.

RESULTS

561 patients were available for the survivorship analysis in the surgical group. Following exclusion, 901 and 484 patients were available for the 30 and the 90-day analysis in the revision THA waiting list group. 30- and 90-day mortality rates were significantly greater for the revision THA group compared to the waiting list group (excess surgical mortality at 30 days = 0.357%, p = 0.037; odds ratio of 5.22, excess surgical mortality at 90 days = 0.863%, p = 0.045).

CONCLUSIONS

Revision total hip arthroplasty is associated with a significant excess surgical mortality rate until 90 days post-operation when compared to the waiting list population. We would encourage other authors with access to larger samples to use our method to quantify excess mortality after both primary and revision arthroplasty procedures.

The Effect of Age, Sex, Area Deprivation, and Living Arrangements on Total Knee Replacement Outcomes: A Study Involving the United Kingdom National Joint Registry Dataset

Background:

Total knee replacement (TKR) is a common procedure for the treatment of osteoarthritis that provides a substantial reduction of knee pain and improved function in most patients. We investigated whether sociodemographic factors could explain variations in the benefit resulting from TKR.

Methods:

Data were collected from 3 sources: the National Joint Registry for England, Wales, Northern Ireland, and the Isle of Man; National Health Service (NHS) England Patient Reported Outcome Measures; and Hospital Episode Statistics. These 3 sources were linked for analysis. Pain and function of the knee were measured with use of the Oxford Knee Score (OKS). The risk factors of interest were age group, sex, deprivation, and social support. The outcomes of interest were sociodemographic differences in preoperative scores, 6-month postoperative scores, and change in scores.

Results:

Ninety-one thousand nine hundred and thirty-six adults underwent primary TKR for the treatment of osteoarthritis in an NHS England unit from 2009 to 2012. Sixty-six thousand seven hundred and sixty-nine of those patients had complete knee score data and were included in the analyses for the present study. The preoperative knee scores were worst in female patients, younger patients, and patients from deprived areas. At 6 months postoperatively, the mean knee score had improved by 15.2 points. There were small sociodemographic differences in the benefit of surgery, with greater area deprivation (−0.71 per quintile of increase in deprivation; 95% confidence interval [CI], −0.76 to −0.66; p < 0.001) and younger age group (−3.51 for ≤50 years compared with 66 to 75 years; 95% CI, −4.00 to −3.02; p < 0.001) associated with less benefit. Cumulatively, sociodemographic factors explained <1% of the total variability in improvement.

Conclusions:

Sociodemographic factors have a small influence on the benefit resulting from TKR. However, as they are associated with the clinical threshold at which the procedure is performed, they do affect the eventual outcomes of TKR.

Level of Evidence:

Prognostic Level IV. See Instructions for Authors for a complete description of evidence.

Wound Discharge After Pharmacological Thromboprophylaxis in Lower Limb Arthroplasty

BACKGROUND

The benefits vs risk of pharmacological prophylaxis for thromboembolic disease in orthopedic patients remain controversial. Pharmacological thromboprophylaxis regimes are commonly used in this patient group. Few studies specifically examine wound complications attributable to this therapy. In this prospective trial, we investigated the effect of various regimens on postoperative wounds.

METHODS

A prospective, observational, multicenter study involving patients undergoing elective hip or knee arthroplasty was undertaken. Patients were divided into 3 groups depending on thromboprophylaxis: no anticoagulation, aspirin, or low molecular weight heparin (LMWH) (enoxaparin). Surgical wounds were evaluated for each regime using the Southampton Wound Assessment Score.

RESULTS

Over a 12-month period, 327 patients were enrolled with a mean age of 68.1 years (±11.2 years). There were 105 patients in the no anticoagulation group (32.1%), 97 patients in the aspirin group (29.7%), and 125 patients in the LMWH group (38.2%). Wound scores were evaluated for evidence and amount of discharge. The use of LMWH conferred a 4.92 times greater risk and aspirin a 3.64 times greater risk of wound discharge than no pharmacological thromboprophylaxis (P < .0001). There were no significant differences in the incidence of deep vein thrombosis or pulmonary embolus between groups either as an inpatient or postdischarge.

CONCLUSION

There is a significant increase in the risk of wound discharge when aspirin or LMWH is used in arthroplasty patients. As potential complications of wound problems are significant, a more balanced view of risk vs benefit needs to be taken when prescribing thromboprophylaxis for this patient group.

Venous thromboembolism prophylaxis after total knee arthroplasty (TKA): aspirin vs. rivaroxaban

Objectives

To compare the efficacy and safety of aspirin and rivaroxaban in preventing venous thromboembolism (VTE) after total knee arthroplasty (TKA).

Methods

Thirty-two patients with osteoarthritis of the knee and knee arthroplasty indication were selected. The operated patients were randomized into two groups (A and B). Group A received 300 mg of acetylsalicylic acid (aspirin) and Group B received 10 mg of rivaroxaban daily for 14 days. Follow-up was performed weekly for four weeks and evaluated the presence of signs and symptoms of DVT, the healing of the surgical wound, and possible local complications such as hematoma, and superficial or deep infection that required surgical approach.

Results

It was verified that there were no differences between groups (rivaroxaban and aspirin) regarding gender, age, and (p > 0.05). After using the general linear model (GLM) test, it was found that there was a decrease in Hb and Ht levels, preoperatively and at one, three, seven, and 14 days (Hb: p = 1.334 × 10^-30; Ht: p = 1.362 × 10^-28). However, they did not differ as to the type of medication (Hb: p = 0.152; Ht: p = 0.661). There were no identifiable differences in local complications, systemic complications, deep vein thrombosis (DVT), readmission to hospital, reoperation, or death (p > 0.05) between groups (rivaroxaban and aspirin).

Conclusions

Both aspirin and rivaroxaban can be considered useful among drugs available VTE the prevention after TKA.

Aspirin and the prevention of venous thromboembolism following total joint arthroplasty: commonly asked questions

The number of arthroplasties being performed increases each year. Patients undergoing an arthroplasty are at risk of venous thromboembolism (VTE) and appropriate prophylaxis has been recommended. However, the optimal protocol and the best agent to minimise VTE under these circumstances are not known. Although many agents may be used, there is a difference in their efficacy and the risk of bleeding. Thus, the selection of a particular agent relies on the balance between the desire to minimise VTE and the attempt to reduce the risk of bleeding, with its undesirable, and occasionally fatal, consequences.

Acetylsalicylic acid (aspirin) is an agent for VTE prophylaxis following arthroplasty. Many studies have shown its efficacy in minimising VTE under these circumstances. It is inexpensive and well-tolerated, and its use does not require routine blood tests. It is also a ‘milder’ agent and unlikely to result in haematoma formation, which may increase both the risk of infection and the need for further surgery. Aspirin is also unlikely to result in persistent wound drainage, which has been shown to be associated with the use of agents such as low-molecular-weight heparin (LMWH) and other more aggressive agents.

The main objective of this review was to summarise the current evidence relating to the efficacy of aspirin as a VTE prophylaxis following arthroplasty, and to address some of the common questions about its use.

There is convincing evidence that, taking all factors into account, aspirin is an effective, inexpensive, and safe form of VTE following arthroplasty in patients without a major risk factor for VTE, such as previous VTE.

Cite this article: Bone Joint J 2017;99-B:1420–30.

Topically Applied Epsilon-Aminocaproic Acid Reduces Blood Loss and Length of Hospital Stay After Total Knee Arthroplasty

Perioperative blood loss after total knee arthroplasty (TKA) affects postoperative recovery. Tranexamic acid is safe and efficient in reducing blood loss without increasing thromboembolic events. Epsilon-aminocaproic acid (ε-ACA) is less expensive than and as safe as tranexamic acid. Its efficiency when locally applied in TKA is unknown. The authors retrospectively followed 240 consecutive patients treated by 1 surgeon with TKA from January 2012 to August 2016. From January 2013 to May 2015, the authors topically applied 5 g of ε-ACA to the open wound after tourniquet release and before closure (ε-ACA-after-tourniquet-release group). From August 2015 to August 2016, the authors topically applied 5 g of ε-ACA intraoperatively to the open wound 3 minutes before tourniquet release (ε-ACA-before-tourniquet-release group). The last 80 patients not receiving ε-ACA (control group), the 80 patients in the ε-ACA-after-tourniquet-release group, and the 80 patients in the ε-ACA-before-tourniquet-release group were compared regarding blood loss, treatment costs, and thromboembolic complications. The mean±SD calculated blood loss was 1478.8±367.1 mL for the control group, 1424.0±249.3 mL for the ε-ACA-after-tourniquet-release group, and 1052.3±419.1 mL for the ε-ACA-before-tourniquet-release group (P<.05). Using ε-ACA before tourniquet release reduced the length of hospital stay by 0.7 days (P<.05) compared with not using ε-ACA, leading to cost savings of $1547.37 per patient. One patient in the ε-ACA-before-tourniquet-release group and 1 patient in the control group developed a venous thromboembolism in the postoperative period. Epsilon-aminocaproic acid significantly reduces blood loss after TKA when topically applied before tourniquet release. Its application reduced costs by decreasing the length of hospital stay and did not increase thromboembolic events. [Orthopedics. 2017; 40(6):e1044-e1049.].

Elevated d-Dimer Is Not Predictive of Symptomatic Deep Venous Thrombosis After Total Joint Arthroplasty

BACKGROUND

Serum d-dimer is a common screening test for symptomatic deep venous thrombosis (DVT) after total joint arthroplasty. This study characterized the longitudinal resolution of d-dimer measurements after total hip and knee arthroplasty (THA/TKA) over a 6-week period. The authors hypothesized that serum d-dimer would not return to baseline or be below the institutional threshold for a positive test at 6 weeks after uncomplicated total joint arthroplasty, suggesting that quantitative d-dimer has limited clinical utility for postoperative DVT screening.

METHODS

An institutional review board-approved retrospective cohort study was conducted with consecutive patients between January 2013 and June 2015. A total of 177 adult patients aged 40-88 years who underwent a primary hip or knee arthroplasty with a Charlson Comorbidity Index <3 were included in the study. Serum d-dimer was measured at preoperative, perioperative, and postoperative 2- and 6-week time points.

RESULTS

d-dimer measurements peaked 2 weeks postoperatively for both TKA and THA. At the 6-week time point, the peak serum d-dimer measurement resolved by 54.3% and 76.6% for TKA and THA, respectively. At 6 weeks after operation, 92% of THA patient and 100% of TKA patients had serum d-dimer measurements higher than the institutional threshold (0.40 μg/mL) for a "positive" quantitative test. No symptomatic DVTs were reported for the THA and TKA cohorts during the study period.

CONCLUSION

The results suggest that serum d-dimer is an ineffective screening test for the diagnosis of symptomatic DVT in the acute postoperative period. The authors propose that extravascular fibrinolysis, a process essential for wound healing, has a crucial role in the prolonged elevation of serum d-dimer in the postoperative period.

Incidences of Deep Vein Thrombosis and Pulmonary Embolism after Total Knee Arthroplasty Using a Mechanical Compression Device with and without Low-Molecular-Weight Heparin

Purpose

To investigate the incidence of thromboembolic events and complications related to bleeding after total knee arthroplasty (TKA) with a mechanical compression device alone or in combination with low-molecular-weight heparin (LMWH).

Materials and Methods

A total of 489 TKA patients (776 knees) were retrospectively reviewed for the incidence of thromboembolic events and complications related to bleeding. While 233 patients (354 knees) were treated with a mechanical compressive device without LMWH, 256 patients (422 knees) were treated with the mechanical compressive device along with LMWH.

Results

The incidences of deep vein thrombosis (DVT) and pulmonary embolism (PE) were 15 of 375 knees (4.0%) and 5 of 375 knees (1.3%), respectively, in the group that used only a mechanical compressive device, and 14 of 401 knees (3.4%) and 5 of 401 knees (1.2%), respectively, in the group that used the mechanical compressive device with LMWH. There was no significant difference between the two groups (p=0.125 and p=0.146, respectively). The postoperative hemovac drainage amount was 635±57 mL in the group with a mechanical compressive device only and 813±84 mL in the group with the device and LMWH; therefore, the amount of drainage was significantly greater in the latter group (p=0.013).

Conclusions

Mechanical compression alone for prophylaxis against DVT and PE after TKA can be an attractive option in Korean patients.

Development and Validation of a Risk Stratification System for Pulmonary Embolism After Elective Primary Total Joint Arthroplasty

INTRODUCTION

Stratification of patients into different risk categories for pulmonary embolism (PE) after total joint arthroplasty (TJA) may allow clinicians to individualize venous thromboembolism prophylaxis based on an appropriate risk-benefit scale.

METHODS

Patients undergoing primary total hip arthroplasty (THA) or total knee arthroplasty (TKA) as part of the American College of Surgeons National Surgical Quality Improvement Program were identified. Independent risk factors for PE within 30 days of surgery were identified and used to develop a point-scoring system to estimate the relative risk for PE. For validation, the system was tested on patients undergoing TJA at a single institution.

RESULTS

A total of 118,473 patients were identified, including 72,673 (61.3%) undergoing TKA and 45,800 (38.7%) undergoing THA. The incidence of PE within 30 days of the index arthroplasty was 0.50%. The risk factors associated with PE were age ≥70, female gender, higher body mass index (25-30 kg/m(2) and ≥30 kg/m(2)), and TKA (vs THA); anemia was protective. The point scores derived for each of these factors were as follows: anemia: -2; female: +1; body mass index 25-30 kg/m(2): +2; body mass index ≥30 kg/m(2): +3; age ≥70 years: +3; TKA: +5. The point-scoring system was then applied to 17,384 patients from a single institution. Single-institution patients categorized as low risk using the point-scoring system had a 0.44% 90-day risk for PE (95% CI = 0.29%-0.58%); medium risk, 1.51% (95% CI = 1.18%-1.84%); and high risk, 2.60% (95% CI = 2.09%-3.10%).

CONCLUSION

This point-scoring system predicts risk for PE after TJA and may help surgeons to optimize selection of chemical prophylaxis.

Systematic review of aspirin for thromboprophylaxis in modern elective total hip and knee arthroplasty

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.

Materials and Methods

A search of literature published between 2004 and 2014 was performed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A total of 13 studies were eligible for inclusion.

Results

Evidence from one good quality randomised controlled trial (RCT) showed no difference in rates of venous thrombo-embolism (VTE) in patients given aspirin or low molecular weight heparin (LMWH) following TKA. There was insufficient evidence from trials with moderate to severe risk of bias being present to suggest aspirin is more or less effective than LMWH, warfarin or dabigatran for the prevention of VTE in TKA or THA. Compared with aspirin, rates of asymptomatic deep vein thrombosis (DVT) in TKA may be reduced with rivaroxaban but insufficient evidence exists to demonstrate an effect on incidence of symptomatic DVT. Compared with aspirin there is evidence of more wound complications following THA and TKA with dabigatran and in TKA with rivaroxaban. Some studies highlighted concerns over bleeding complications and efficacy of aspirin.

Conclusion

The results suggest aspirin may be considered a suitable alternative to other thromboprophylactic agents following THA and TKA. Further investigation is required to fully evaluate the safety and efficacy of aspirin. Cite this article: Bone Joint J 2016;98-B:1056–61.

Venous thromboembolism after lower limb arthroplasty: is chemical prophylaxis still needed?

BACKGROUND

Venous thromboembolism (VTE) is a significant complication of lower limb arthroplasty. The National Institute for Health and Care Excellence recommends routine use of chemical and mechanical prophylaxis to prevent VTE. Our high-volume, elective, arthroplasty unit adopted this guidance in 2008.

PURPOSE

We examined our incidence of VTE before and after introduction of chemical thromboprophylaxis to determine whether the incidence of VTE reduced.

METHODS

We retrospectively gathered data on 2 cohorts of patients-from January 2004 to August 2007 (Group 1) and January 2010 to December 2012 (Group 2). Patients in Group 1 received mechanical prophylaxis only (unless particularly high risk for VTE), and patients in Group 2 received mechanical and chemical prophylaxis. We recorded VTE occurring within 6 months of surgery. Patients in Group 1 receiving chemical prophylaxis were excluded.

RESULTS

Group 1 had 2320 cases of primary and revision lower limb arthroplasty, and Group 2 had 1430 cases. VTE occurred in 37 cases in Group 1 (1.6 %), and in 17 cases in Group 2 (1.2 %). This difference was not statistically significant (p = 0.26). In Group 1, 1 patient died within 6 months due to pulmonary embolism (0.04 %); there were no VTE-related deaths in Group 2 (0 %). This was also not statistically significant (p = 0.06).

CONCLUSIONS

Although our VTE rate reduced by 0.4 % and our VTE-related mortality reduced by 0.04 % after introduction of chemical thromboprophylaxis, these differences were not statistically significant. Chemical thromboprophylaxis may not be required in all patients undergoing arthroplasty providing appropriate mechanical prophylaxis is used.

Electrical muscle stimulation in thomboprophylaxis: review and a derived hypothesis about thrombogenesis-the 4th factor

INTRODUCTION

Electrical muscle stimulation (EMS) is an FDA-approved thromboprophylactic method. Thrombus pathogenesis is considered to depend on factors related to components of the vessel wall, the velocity of blood, and blood consistency-collectively known as, the Virchow's triad.

OBJECTIVE

The testimony supporting the thromboprophylactic effects of the EMS is reviewed. An emphasis is placed on the fact that, EMS has demonstrated, in certain circumstances, an efficacy rate that cannot be fully explained by the Virchow's triad; also that, in reviewing relevant evidence and the theorized pathophysiological mechanisms, several findings collectively point to a potentially missed point. Remarkably, venous thromboembolic disease (VTE) is extremely more common in the lower versus the upper extremities even when the blood velocities equalize; EMS had synergistic effects with intermittent compressive devices, despite their presumed identical mechanism of action; sleep is not thrombogenic; non-peroperative EMS is meaningful only if applied ≥5 times daily; neural insult increases VTEs more than the degree expected by the hypomobility-related blood stasis; etc. These phenomena infer the presence of a 4th thrombogenetic factor: neural supply to the veins provides direct antithrombic effects, by inducing periodic vessel diameter changes and/or by neuro-humoral, chemically acting factors. EMS may stimulate or substitute the 4th factor. This evidence-based hypothesis is analyzed.

CONCLUSION

A novel pathophysiologic mechanism of thrombogenesis is supported; and, based on this, the role of EMS in thromboprophylaxis is expanded. Exploration of this mechanism may provide new targets for intervention.

Venous Thromboembolism Following Hip and Knee Replacement Arthroplasty in Korea: A Nationwide Study Based on Claims Registry

The aim of this study was to examine the incidence and trends of clinically relevant venous thromboembolism (VTE) including deep vein thrombosis (DVT) and pulmonary embolism (PE) after hip and knee replacement arthroplasty (HKRA) in Korea. Between January 1 and December 31, 2010, 22,127 hip replacement arthroplasty (HRA) patients and 52,882 knee replacement arthroplasty (KRA) patients were enrolled in the analysis using the administrative claims database of the Health Insurance Review and Assessment Service (HIRA). All available parameters including procedure history and clinically relevant VTE during the 90 days after HKRA were identified based on diagnostic and electronic data interchange (EDI) codes. The overall incidence of VTE, DVT, and PE during the 90 days was 3.9% (n=853), 2.7% (n=597), and 1.5% (n=327) after HRA, while the incidence was 3.8% (n=1,990), 3.2% (n=1,699), and 0.7% (n=355) after KRA. The incidence of VTE after HKRA was significantly higher in patients who had previous VTE history (odds ratio [OR], 10.8 after HRA, OR, 8.5 after KRA), chronic heart failure (2.1, 1.3), arrhythmia (1.8, 1.7), and atrial fibrillation (3.4, 2.1) than in patients who did not. The VTE incidence in patients with chemoprophylaxis was higher than that in patients without chemoprophylaxis. The incidence of VTEs revealed in this retrospective review was not low compared with the results of the studies targeting other Asian or Caucasian populations. It may warrant routine prevention including employment of chemoprophylaxis. However, the limitation of the reviewed data mandates large scale prospective investigation to affirm this observation.

Less deep vein thrombosis due to transcutaneous fibular nerve stimulation in total knee arthroplasty: a randomized controlled trial

PURPOSE

It has been known for years that deep vein thrombi (DVT) start to develop during total joint arthroplasty. Previously, we reported effective prevention of venous stasis by transcutaneous electrical nerve stimulation (TENS). It is hypothesized that TENS might be a thromboprophylactic tool for the limb undergoing surgery. The purpose of this study is to clarify the clinical efficacy and safety of TENS in patients during total knee arthroplasty (TKA).

METHODS

Ninety patients undergoing primary TKA were involved and randomly allocated to the TENS or control group. In the TENS group, electrical stimulation of the common fibular nerve, which produced a brisk dorsiflexion of the ankle, was performed for the operated leg during surgery. In the control group, no electrical stimulation was applied. Serum D-dimer and soluble fibrin monomer complex (SFMC) levels were measured before surgery, immediately after surgery, and post-operative day (POD) 1. Ultrasonography was performed on POD 1.

RESULTS

Immediately after surgery, D-dimer and SFMC levels of each group were significantly lower in the TENS group compared with control (p < 0.05). The incidence of DVT was 11 % (five cases) in the TENS group while 31 % (14 cases) in control (p = 0.02). There were no adverse effects related to TENS.

CONCLUSIONS

TENS during TKA showed significant effects on preventing DVT. Sustaining muscle pump activation during surgery prevented not only venous stasis, but also hypercoagulability of blood. Intraoperative TENS is a safe and novel strategy against early post-operative thromboembolism, which is difficult to be completed through existing prophylaxis after total joint arthroplasty.

LEVEL OF EVIDENCE

Randomized controlled trial, Level I.

Improved coding of postoperative deep vein thrombosis and pulmonary embolism in administrative data (AHRQ Patient Safety Indicator 12) after introduction of new ICD-9-CM diagnosis codes

BACKGROUND

Symptomatic venous thromboembolism is a common postoperative complication. The Agency for Healthcare Research and Quality (AHRQ) has developed a Patient Safety Indicator 12 to assist hospitals, payers, and other stakeholders to identify patients who experienced this complication.

OBJECTIVES

To determine whether newly created and recently redefined ICD-9-CM codes improved the criterion validity of Patient Safety Indicator 12, based on new samples of records dated after October 2009.

RESEARCH DESIGN, SUBJECTS, MEASURES

Two sources of data were used: (1) UHC retrospective case-control study of risk factors for acute symptomatic venous thromboembolism occurring within 90 days after total knee arthroplasty in teaching hospitals; (2) chart abstraction data by volunteer hospitals participating in the Validation Pilot Project of the AHRQ.

RESULTS

In the UHC sample, the positive predictive value (PPV) was 99% (125/126) and the negative predictive value was 99.4% (460/463). In the AHRQ sample, the overall PPV was 81% (126/156).

CONCLUSIONS

The PPV based on both samples shows substantial improvement compared with the previously reported PPVs of 43%-48%, suggesting that changes in ICD-9-CM code architecture and better coding guidance can improve the usefulness of coded data.

The incidence of deep vein thrombosis and pulmonary embolism with the elective use of external fixators

Little evidence exists about the incidence of deep vein thrombosis (DVT) and pulmonary embolism (PE) with the use of external fixators. We investigated this in a cohort of 207 consecutive patients undergoing 258 elective frame applications by case note review. Case notes were obtained for 84 % of the sample population. The type of surgery, demographic data, thromboembolic risk factors and the incidence of DVT/PE were recorded. One patient experienced DVT (0.39 %) and one a PE (0.39 %). Both were of high risk and had received mechanical and chemical thromboprophylaxis during their inpatient stay. These complications were identified at least 3 months post-operatively. These findings help to more accurately counsel patients undergoing elective frame surgery on the risks of DVT/PE and also contribute to the discussion between surgeons about whether or not extended course chemical thromboprophylaxis would be of overall benefit.

Early death following primary total hip arthroplasty

This study aims to describe the timing, cause of death, and excess surgical mortality associated with primary total hip arthroplasty when compared to a population awaiting primary total hip arthroplasty. Mortality rates were calculated at cutoffs of 30 and 90 days post-operation or following the addition to the waiting list. Cause of death was recorded from the death certificate. An excess surgical mortality of 0.256% at 30 days (P = 0.002) and 0.025% at 90 days post-operation (P = 0.892), unaffected by age or gender, was seen with myocardial infarction and pneumonia the cause of death in the majority of cases. By using a more appropriate control population, an excess surgical mortality at 30 days post-operation is demonstrated; the effect diminishes at 90 days post-operation.

Evidence-base for aspirin as venous thromboembolic prophylaxis following joint replacement

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.

Pulmonary embolism after total joint arthroplasty: cost and effectiveness of four treatment modalities

Pulmonary embolism (PE) treatment relies on therapeutic anticoagulation and may be associated with severe complications. Inferior vena cava filters (IVCFs) are used as an alternative/adjunct to anticoagulation. In this study we evaluate 4 treatment protocols for clinical efficacy and cost. We reviewed over 27,000 total joint arthroplasty (TJA) patients. We retrospectively identified 294 patients with a documented, symptomatic PE within 90 days of surgery. All patients were treated with warfarin postoperatively. In addition, for the acute management, patients were divided into four treatment groups: (1) IVCF only, (2) IVCF with heparin, (3) heparin only and (4) no treatment. Complication rates, hospital stay and PE recurrence are reported. Among patients who received warfarin, IVCF was associated with fewer complications and lower overall hospital costs compared to the use of heparin for the treatment of PE after TJA.

Administration of enoxaparin 24 h after total knee arthroplasty: safer for bleeding and equally effective for deep venous thrombosis prevention

BACKGROUND

The purpose of this study was to determine the safety and effectiveness, as assessed by risk of bleeding and incidence of deep venous thrombosis (DVT), of administering delayed low-molecular-weight heparin (LMWH) after total knee arthroplasty.

METHODS

A prospective study of 210 consecutive patients undergoing primary unilateral total knee arthroplasty was undertaken. The patients were randomized into two groups: one of which was managed according to a standard LMWH program (LMWH-s group) and the other with delayed LMWH (LMWH-p). LMWH was initiated 12 h after wound closure in the LMWH-s group, and 24 h after wound closure in the LMWH-p group.

RESULTS

The total blood loss in the first three postoperative days was calculated and all complications were recorded. The mean total blood loss was 435 and 387 mL in the LMWH-s group and LMWH-p group, respectively (p < 0.01). No significant difference in the incidence of symptomatic DVT was observed. The mean length of hospital stay was 7.29 days in the LMWH-s group and 6.56 days in the LMWH-p group (p < 0.05).

CONCLUSIONS

After total knee arthroplasty, LMWH-p is safer for bleeding than LMWH-s and equally effective concerning prevention of DVT.

Symptomatic pulmonary embolus after joint arthroplasty: stratification of risk factors

BACKGROUND

Prophylaxis for pulmonary embolism (PE) after total joint arthroplasty (TJA) presents the clinical dilemma of balancing the risk of postoperative thrombotic risk and anticoagulation-related complications such as bleeding, hematoma formation, and infection. Risk stratification of patients undergoing TJA is needed to tailor prophylaxis based on thrombotic and bleeding risk.

QUESTIONS/PURPOSES

The purpose of this study was to identify the preoperative comorbidities that were associated with an increased risk of symptomatic PE after joint arthroplasty in a large group of patients who had TJAs and who were treated with either aspirin or warfarin.

METHODS

We conducted a retrospective study of 26,391 primary and revision TJAs performed at our institution between January 2000 and April 2011. A total of 24,567 patients received warfarin prophylaxis for 6 weeks (targeted international normalized ratio of 1.5-2.0) and 1824 patients received 325 mg aspirin twice daily. Symptomatic patients with decreased oxygen saturation were evaluated for PE using either a ventilation/perfusion scan or multidetector CT scan. Symptomatic PEs occurring in patients within 90 days postoperatively identified with CT or ventilation/perfusion scans were considered complications related to surgery, and fatal PEs were those that occurred in patients who died during the hospital admission owing to cardiopulmonary failure after PE. Using a logistic regression analysis, a nomogram was created to predict postoperative symptomatic PE risk.

RESULTS

Risk of postoperative symptomatic PE after primary and revision TJAs was 1.1%. Risk of postoperative fatal PE was 0.02%. Elevated BMI (p < 0.035), procedures on the knee (p < 0.006), higher Charlson Comorbidity Index (p < 0.015), chronic obstructive pulmonary disorder (p = 0.006), atrial fibrillation (p < 0.001), anemia (p < 0.001), presence of deep vein thrombosis (p < 0.001), and depression (p = 0.012) were independent risk factors for symptomatic PE. Based on these risk factors and derived scoring criteria, patients can be classified into low- (0.35%), medium- (1.4%), and high- (9.3%) risk categories.

CONCLUSIONS

Patients who are obese, undergo knee procedures, have an elevated Charlson Comorbidity Index, chronic obstructive pulmonary disease, atrial fibrillation, anemia, depression, or postoperative deep vein thrombosis are at greater risk of having a postoperative PE develop. These risk factors should be considered when deciding on postoperative anticoagulation prophylaxis.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.

Venous thromboembolism following elbow, wrist and hand surgery: a review of the literature and prophylaxis guidelines

This review summarizes the literature regarding venous thromboembolism and examines the prophylaxis guidelines with relation to hand, wrist and elbow surgery. We performed an extensive literature search identifying any relevant case reports or outcome studies. Of 680 potential articles, only four contained data relevant to thrombosis after elbow, wrist and hand surgery. No isolated deep vein thromboses and only nine pulmonary embolisms were identified suggesting that the rate of venous thromboembolism is extremely low following this subset of upper limb surgery. We identified nine guidelines, of which only two (the British Society for Surgery of the Hand and the National Institute of Health and Clinical Excellence) addressed the upper limb. We present a set of recommendations based on the results of this review.

Changes in blood coagulation-fibrinolysis markers by pneumatic tourniquet during total knee joint arthroplasty with venous thromboembolism

This study investigated changes in blood coagulation-fibrinolysis markers during total knee arthroplasty (TKA). Preoperative 16-row multidetector row computed tomography (MDCT) revealed no asymptomatic venous thromboembolism (VTE) in the 42 patients recruited. Using MDCT postoperatively, patients were divided into thrombus (asymptomatic VTE, 19 patients) and no-thrombus (23 patients) groups. Blood taken at intervals before and after pneumatic tourniquet release revealed increased plasminogen activator inhibitor type-1 (PAI-1) at 30s for both groups and at 90s (both P=0.01) in the thrombus group. D-dimer levels were highest at 30 and 90s for both groups (P = 0.01). PAI-1 and D-dimer levels were strongly correlated at both time points in the thrombus group. Inactivating fibrinolysis due to PAI-1 may lead to asymptomatic VTE after TKA.

Thromboprophylaxis with dabigatran leads to an increased incidence of wound leakage and an increased length of stay after total joint replacement

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.

The necessity of pharmacological prophylaxis against venous thromboembolism in major joint arthroplasty

PURPOSE

Venous thromboembolism (VTE) is a recognised post-operative complication of major lower limb joint arthroplasty. Current National Institute for Health and Clinical Excellence (NICE) guidelines suggest the use of both mechanical and pharmacological prophylaxis following hip and knee replacement. Since the introduction of enhanced recovery programmes following hip and knee arthroplasty the requirement for routine pharmacological VTE prophylaxis has been questioned. The purpose of this study was to assess the efficacy of pharmacological prophylaxis against symptomatic VTE in patients undergoing hip and knee arthroplasty under an enhanced recovery programme.

METHODS

Symptomatic VTE incidence was audited in 1,100 patients undergoing primary or revision total hip or knee arthroplasty at the same hospital with only mechanical prophylaxis from 2007 to 2009. Following addition of chemical prophylaxis (enoxaparin) symptomatic VTE incidence in 522 patients undergoing primary or revision total hip or knee arthroplasty from 2011 to 2012 was re-audited.

RESULTS

In the mechanical prophylaxis group incidence of DVT was 0.73 % [95 % confidence interval (CI) 0.37-1.43 %] and incidence of pulmonary embolism (PE) 0.91 % (95 % CI 0.49-1.67 %). Following addition of pharmacological prophylaxis incidence of DVT was 0.57 % (95 % CI 0.20-1.68 %) and incidence of PE 1.15 % (95 % CI 0.53-2.48 %).

CONCLUSIONS

We found no statistically significant difference in symptomatic VTE incidence following the addition of enoxaparin. We question whether routine pharmacological prophylaxis still has a role following total hip and knee arthroplasty. Peri-operative optimisation, including post-operative analgesia and mobility, with current enhanced recovery programmes may be sufficient. As anticoagulants carry increased risk of post-operative bleeding and wound ooze, in addition to significant cost implications, their role remains controversial.

Can enoxaparin reduce thromboembolism related events after primary TKA in Asian patients?

The purpose of this study was to investigate the efficacy and safety of enoxaparin in preventing venous and arterial thromboembolism related events after primary total knee arthroplasty (TKA) in Asian patients. Four hundred twenty nine patients (621 TKAs) did not receive thromboprophylaxis after TKA and 907 patients (1,336 TKAs) received enoxaparin after the procedure. We assessed clinically significant venous and arterial thromboembolism related events and bleeding complications. Total thromboembolism related events occurred in 13 patients (3.03%) without thromboprophylaxis and 17 patients (1.87%) with enoxaparin (P = 0.183). Our study showed that the incidence of clinically significant thromboembolism related events after TKA was very low in Asian patients. Enoxaparin had no benefits in reducing thromboembolism related events in Asian patients.