Potent anticoagulants are associated with a higher all-cause mortality rate after hip and knee arthroplasty

Fatal pulmonary embolism following elective total hip arthroplasty

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.

Patients and Methods

A prospective audit database was used to identify patients who had died within 42 and 90 days of surgery respectively between April 2000 and December 2012. A case note review was performed to ascertain the causes of death.

Results

During this period 7983 THAs were performed. The rate of mortality was 0.43% and 0.58% at 42 and 90 days respectively. The groups comprised 1571 patients (19.7%) on warfarin, 1838 (23.0%) on LMWH and 4574 (57.3%) on aspirin. The 90-day mortality for these three groups was 0.38%, 1.09% and 0.43% respectively. The higher mortality rate for LMWH was significant (p < 0.05). There were six fatal pulmonary emboli (PEs) (0.08%). A total of three occurred within 42 days, all in the LMWH group. A total of three occurred between 42 and 90 days; one on warfarin, two on LMWH. The leading causes of death in all three groups were lower respiratory tract infections and myocardial infarction.

Conclusion

We confirmed that fatal PE following elective THA with a multi-modal prophylaxis regime is rare. We further found that LMWH conferred no benefit over aspirin in this context, and is associated with a higher all-cause rate of mortality. Take home message: This study proposes that aspirin may be an appropriate thromboprophylaxis agent when used as part of a multi-modal regimen, suggesting current guidelines should be reviewed. Cite this article: Bone Joint J 2016;98-B:585–8.

One-Year All-Cause Mortality of Patients Diagnosed as Having In-Hospital Pulmonary Embolism After Modern Elective Joint Arthroplasty Is Low And Unaffected By Radiologic Severity

BACKGROUND

We studied the 1-year complication rate of patients diagnosed as having a pulmonary embolism (PE) after elective total hip arthroplasty (THA) and total knee arthroplasty (TKA) surgery and the distribution of emboli in the pulmonary circulation, and determined if a relationship exists between the location of the PE and age, gender, body mass index, preoperative predisposing factors, American Society of Anesthesiology classification, type of surgery, prophylaxis, hospital stay, transfer to a higher level of care, and mortality.

METHODS

Two hundred sixty-nine patients who developed an in-hospital PE proved by computed tomography pulmonary angiography after elective THA or TKA between 2005 and 2012 were studied.

RESULTS

The most proximal location of the emboli was central in 62, segmental in 139, and subsegmental in 68. Nineteen patients (7%) developed a bleeding complication during PE treatment. Twenty-nine patients (11%) were readmitted during the first year. Two patients (0.74%) died: one had a segmental PE after TKA. He died 11 months after surgery due to an autopsy-proven sepsis. The second patient developed a segmental PE after THA. She was anticoagulated, developed an intracranial bleed, and died 8 months after surgery. Multivariate analysis showed that demographic variables, American Society of Anesthesiology class, preoperative comorbidities (with the exception of arrhythmia), and the presence of preoperative predisposing factors had no effect in the location of the PE.

CONCLUSION

The 1-year mortality rate of these patients is low. Death can be caused by bleeding complications secondary to anticoagulation or by unrelated conditions. This information may aid clinicians while counseling patients who developed a PE after surgery, particularly those with small subsegmental emboli.

Timing of Symptomatic Pulmonary Embolism with Warfarin Following Arthroplasty

The purpose is to determine the incidence and timing of pulmonary embolism for patients receiving warfarin for thrombo-prophylaxis following total joint arthroplasty (TJA). Current guidelines for duration of prophylaxis are nonspecific. Chemical prophylaxis carries the risk of bleeding and associated periprosthetic joint infection. We retrospectively studied 26,415 primary and revision TJA cases performed at our institution between 2000 and 2010. The overall 90-day rate of symptomatic PE was 1.07%. Fatal PE rate was 0.02%. Out of 283 documented symptomatic PE cases, 81% occurred within three postoperative days, 89% within one postoperative week, and 94% within two postoperative weeks. The risk of symptomatic PE appears to be highest during the first week after TJA. Efforts must be made to minimize risk during this period.

Prophylactic effect of fondaparinux and enoxaparin for preventing pulmonary embolism after total hip or knee arthroplasty: A retrospective observational study using the Japanese Diagnosis Procedure Combination database

OBJECTIVES

The aim of this study was to estimate the effect of fondaparinux and enoxaparin combined with mechanical prophylaxis (MP) after total hip arthroplasty (THA) and total knee arthroplasty (TKA). We also investigated the occurrence of pulmonary embolism (PE) and its associated risk factors.

METHODS

Data were retrospectively collected on patients who underwent THA or TKA between 2008 and 2010 from the Japanese Diagnosis Procedure Combination database (n = 49,678). We extracted information on sex, age, main diagnosis, types of anesthesia, duration of anesthesia, comorbidities, hospital volume, the use of MP, and the use of anticoagulant drugs.

RESULTS

The overall occurrence of PE was 0.41%. Multivariate logistic regression analysis showed that the occurrence of PE was significantly higher in females (odds ratio, 2.17; p < 0.001, compared with males), TKA (1.47; p = 0.039, compared with THA), and longer-duration anesthesia (2.63; p = 0.008 in the ≥ 240-min. group compared with the ≤ 119-min. group). Compared with the MP-alone group, the occurrence of PE was significantly reduced in the fondaparinux group (0.58; p = 0.025) and the enoxaparin group (0.59; p = 0.046).

CONCLUSIONS

Fondaparinux or enoxaparin combined with MP decreased the occurrence of PE. The risk factors for PE were female patients, TKA, and longer-duration anesthesia (≥ 240 min.).

Total hip replacement due to primary osteoarthritis in relation to cumulative occupational exposures and lifestyle factors: a nationwide nested case-control study

OBJECTIVE

To investigate the risk of total hip replacement (THR) due to primary osteoarthritis in relation to cumulative occupational mechanical exposures and lifestyle factors.

METHODS

Using register information, we identified first-time THR cases within the Danish working population in 2005-2006. For each case, 2 age- and sex-matched controls were drawn. Persons within 2,500 randomly selected case-control sets received a questionnaire about job history, weight at age 25 years, present weight and height, smoking, and sports activities at age 25 years. The job history was combined with a job exposure matrix. Cumulative exposure estimates were expressed according to the pack-year concept of smoking (e.g., cumulative lifting was expressed as ton-years). We used conditional logistic regression for statistical analyses.

RESULTS

In total, 1,776 case-control sets (71%) were available for analysis. The adjusted odds ratio (OR) for exposure to ≥20 ton-years was 1.35 (95% confidence interval [95% CI] 1.05-1.74) for men and 1.00 (95% CI 0.73-1.41) for women. Standing/walking and whole body vibration showed no associations. The adjusted OR for body mass index (BMI) ≥30 kg/m(2) at age 25 years was 2.44 (95% CI 1.38-4.32) for men and 5.12 (95% CI 2.30-11.39) for women. The corresponding adjusted ORs for an increase in BMI of ≥10 kg/m(2) since age 25 years were 2.16 (95% CI 1.25-3.70) and 2.46 (95% CI 1.47-4.13). Sports participation showed weak positive associations, while pack-years of smoking showed no associations.

CONCLUSION

The results indicated a modest increase in risk of THR in relation to cumulative lifting among men and an increased risk in relation to a high BMI at age 25 years and to a gain in BMI in both sexes.

Postoperative venous thrombotic events in Asian elderly patients with surgically treated hip fractures with and without chemoprophylaxis

BACKGROUND AND PURPOSE

Chemothromboprophylaxis for hip fracture surgery has been under-practiced in Asia. We investigate the postoperative incidence of venous thrombotic events (VTE) in elderly Asian patients with hip fractures.

PATIENTS AND METHODS

Patients over 60 years old with surgically treated hip fractures were reviewed. All patients followed a hip fracture protocol, which included a post-operative ultrasound Doppler venous scan of both lower limbs five days after injury to detect any deep vein thrombosis (DVT). All patients were given mechanical prophylaxis. Patients who had additional chemoprophylaxis were included.

RESULTS

From 2010 to 2012, 454 patients were reviewed. The overall incidence of DVT was 6.4% (29 patients). The incidence of PE was 1.3% (six patients). There was no significant correlation between DVT and age, gender, race, hypertension, diabetes mellitus, end stage renal failure, type of fracture and operation, preoperative haemoglobin, platelet count or urea and creatinine levels. Sixteen DVTs (55.2%) were on the ipsilateral side as the fracture, eight (27.6%) were on the contralateral side and five (17.2%) were bilateral. Chemoprophylaxis was not given to 399 patients, of which 27 (6.8%) developed DVT. Ten (2.5%) were proximal DVTs in which four (1%) developed PE. One (0.25%) patient developed PE without DVT. Fifty-five patients were on chemoprophylaxis, of which two (3.6%) developed DVT. Both were proximal DVTs with one subsequently developing PE.

CONCLUSIONS

The incidence of VTE in Asian patients may be lower compared to Western populations when mechanical prophylaxis is used. Chemoprophylaxis may assist in reducing the rates of DVT but not PE. The low incidence may not justify the use of routine chemoprophylaxis.

Preoperative comorbidities as potential risk factors for venous thromboembolism after joint arthroplasty: a systematic review and meta-analysis of cohort and case-control studies

The purpose of this study was to examine the effect of preoperative comorbidities on the risk of VTE after joint arthroplasty surgery. Of 2235 citations identified for screening, 16 studies reporting 7,395,847 patients were eligible. The results showed that patients with cardiovascular disease, previous VTE history, neurologic disease and high anesthetic ASA rating had significantly higher VTE risk than those with no such preexisting medical comorbidities after joint arthroplasty. The presence of respiratory disease, urinary and kidney disease, coronary artery disease, endocrine disease, cancer and malignant disease, hematological disease and comorbidities index did not increase the risk of VTE in our study. The data suggest that risk assessment of patients may further reduce the overall incidence of DVT and PE from VTE prophylaxis.

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.

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.

Aspirin: an alternative for pulmonary embolism prophylaxis after arthroplasty?

BACKGROUND

The most effective agent for prophylaxis against venous thromboembolic disease after total joint arthroplasty (TJA) remains unknown. The paucity of literature comparing different methods of pulmonary embolism (PE) prophylaxis and fear of litigation make it difficult for surgeons to abandon the use of aggressive chemical prophylaxis.

QUESTIONS/PURPOSES

We compared the (1) overall frequency of symptomatic PE, (2) risk of symptomatic PE after propensity matching that adjusted for potentially confounding variables, and (3) other complications and length of stay before and after propensity matching in patients undergoing TJA at our institution who received either aspirin or warfarin prophylaxis.

METHODS

A total of 28,923 patients underwent TJA between January 2000 and June 2012 at our institution, had either aspirin (325 mg twice daily; 2800 patients) or warfarin prophylaxis (26,123 patients), and were registered in our institutional electronic database. The incidence of symptomatic PE, symptomatic deep vein thrombosis (DVT), hematoma formation, infection, wound complications, and mortality up to 90 days postoperatively was collected from the database. We performed multivariate analysis and 3:1 and 5:1 propensity score matching for comorbid and demographic variables.

RESULTS

The overall symptomatic PE rate was lower (p < 0.001) in patients receiving aspirin (0.14%) than in the patients receiving warfarin (1.07%). This difference did not change after matching. The aspirin group also had significantly fewer symptomatic DVTs and wound-related problems and shorter hospital stays, which did not change after matching.

CONCLUSIONS

After publication of the American Academy of Orthopaedic Surgeons' guidelines, some surgeons have utilized aspirin as thromboprophylaxis after TJA. Based on our findings from a large institutional database, aspirin offers suitable prophylaxis against symptomatic PE in selected patients.

Complications of perioperative warfarin therapy in total knee arthroplasty

Patients presenting for knee replacement on warfarin for medical reasons often require higher levels of anticoagulation peri-operatively than primary thromboprophylaxis and may require bridging therapy with heparin. We performed a retrospective case control study on 149 consecutive primary knee arthroplasty patients to investigate whether anti-coagulation affected short-term outcomes. Specific outcome measures indicated significant increases in prolonged wound drainage (26.8% of cases vs 7.3% of controls, P<0.001); superficial infection (16.8% vs 3.3%, P<0.001); deep infection (6.0% vs 0%, P<0.001); return-to-theatre for washout (4.7% vs 0.7%, P=0.004); and revision (4.7% vs 0.3%, P=0.001). Management of patients on long-term warfarin therapy following TKR is particularly challenging, as the surgeon must balance risk of thromboembolism against post-operative complications on an individual patient basis in order to optimise outcomes.

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.

DVT prophylaxis after TKA: routine anticoagulation vs risk screening approach - a randomized study

The American College of Chest Physicians (ACCP) recommended routine anticoagulation for thromboprophylaxis in patients undergoing lower limb arthroplasty. We compared results of routine anticoagulation Vs risk stratified approach for Deep Venous Thrombosis (DVT) prophylaxis after TKA in terms of symptomatic DVT and wound complications. Nine hundred TKAs done in 673 patients were randomized after DVT risk screening to routine anticoagulation (n = 450) or to risk stratification (n = 450) and selective anticoagulation. 194 patients in the risk screening group received only Aspirin. Primary outcome was symptomatic DVT and wound complication. This randomized study showed that the symptomatic DVT rates after TKA were similar whether patients were routinely anticoagulated or selectively anticoagulated after risk screening. However there was a significantly higher incidence of wound complications (P < 0.014) after routine anticoagulation.

Clinical Venous Thromboembolism Following Joint Surgery

We describe annual incidences and 6-month postoperative patterns of clinical venous thromboembolism (VTE) in 9078 patients undergoing major joint surgery in a Scandinavian hospital. In cohort I (1989-1999), low-molecular-weight heparin thromboprophylaxis for 7 to 10 days was uniformly introduced, 5-week thromboprophylaxis becoming routine after total hip replacement (THR), partially applied after hip fracture surgery (HFS), but not used after total knee replacement (TKR) thereafter (2003-2011; cohort II). Mean annual VTE incidence was lower in cohort II than in cohort I after THR and HFS but not after TKR. In cohort I, the cumulative VTE incidence increased sharply during the first 5 postoperative weeks in all groups, subsequently plateauing up to 6 months postsurgery. In cohort II, this incidence remained low and stable during 5 weeks post-THR, rising gradually up to 6 months, with a comparable but less pronounced pattern following HFS but not TKR. In conclusion, the VTE risk after major joint surgery seems to persist after 5- and 1-week prophylaxis in patients undergoing hip surgery and TKR, respectively.

Thromboprophylaxis for deep vein thrombosis and pulmonary embolism after total joint arthroplasty in a low incidence population

Postoperative venous thromboembolism is one of the most serious complications following total joint arthroplasty. Pharmacological and mechanical prophylaxis methods are used to reduce the risk of postoperative symptomatic deep vein thrombosis and pulmonary embolism. Use of pharmacological prophylaxis requires a fine balance between the efficacy of the drug in preventing deep vein thrombosis and the adverse effects associated with the use of these drugs. In regions with a low prevalence of deep vein thrombosis such as Korea, there might be a question whether the benefits of using pharmacological prophylaxis outweigh the risks involved. The current article reviews the need for thromboprophylaxis, guidelines, problems with the guidelines, pharmacological prophylaxis use, and the current scenario of deep vein thrombosis, and discusses whether the use of pharmacological prophylaxis should be mandatory in low incidence populations.

Safety and efficacy of multimodal thromboprophylaxis following total knee arthroplasty: a comparative study of preferential aspirin vs. routine coumadin chemoprophylaxis

Multimodal thromboprophylaxis encompasses preoperative VTE risk stratification, regional anesthesia, mechanical prophylaxis, and early mobilization. We determined if aspirin can be safely used for adjuvant chemoprophylaxis in patients who have a low thromboembolic risk. 1016 consecutive patients undergoing TKA received multimodal thromboprophylaxis. Aspirin was used in 67% of patients and Coumadin 33% (high risk patients, or who were on Coumadin before surgery). This study group was compared to 1001 consecutive patients who received multimodal thromboprophylaxis and routine Coumadin chemoprophylaxis. There was no significant difference in rates of VTE, PE, bleeding, complications, readmission and 90-day mortality between the two groups. There was a significantly higher rate of wound related complications in the control group (p=0.03). Multimodal thromboprophylaxis with aspirin given to the majority of patients at a low VTE risk is safe and effective in patients undergoing primary TKA.

Is venous foot pump effective in prevention of thromboembolic disease after joint arthroplasty: a meta-analysis

The goal of this meta-analysis was to evaluate the efficacy of venous foot pumps in prevention of venous thromboembolism following joint arthroplasty. Using different databases, we found 13 prospective clinical trials published meeting our inclusion criteria. In total, 1514 patients were included in the final analysis. Venous foot pump devices are effective in prevention of venous thromboembolic disease after total hip and knee arthroplasty compared to chemoprophylaxis. This was especially significant in prevention of major deep vein thrombosis and pulmonary emboli rate. The use of mechanical devices like venous calf or foot pump, either alone or in combination with less potent chemical prophylaxis, on the other hand can reduce the rate of venous thromboembolism and complications of potent chemoprophylaxis like wound hematoma.

Important variations in the content of care pathway documents for total knee arthroplasty may lead to quality and patient safety problems

AIM

Reducing variations by standardizing the key interventions in clinical processes is an effective tool to minimize the probability of medical errors. Thus, we determined whether variations exist in the key interventions included in care pathway documents (CPDs) of different organizations and in the timing of these interventions during the care process.

METHODS

We invited members of the Belgian Dutch Clinical Pathway Network to send their CPDs for external review. We analysed 19 CPDs for total knee arthroplasty. International guidelines were consulted for definition of key interventions. Documentation of these interventions in the pathway documents was checked.

RESULTS

From the 19 CPDs analysed, we retrieved 18 key interventions. Nine of these key interventions appeared in at least 80% of the care pathways. Only two key interventions appeared in all pathway documents. Nine out of 12 interventions that appeared in at least 80% of the pathway documents showed a variation of 1 day in the timing of care from the median timing.

CONCLUSION

We conclude that important variation exists in the included interventions and in their timing. The results of this study suggest that, before use in daily patient care, CPDs should be reviewed by peers and checked to ensure that all evidence-based key interventions are included and properly planned. Only in this way can pathways documents be used interprofessionally during the entire perioperative period in the search for optimal quality and patient safety.

Aspirin for the Prophylaxis of Venous Thromboembolic Events in Orthopedic Surgery Patients: A Comparison of the AAOS and ACCP Guidelines with Review of the Evidence

BACKGROUND

The American Academy of Orthopaedic Surgeons (AAOS) and the American College of Chest Physicians (ACCP) have both developed evidence-based guidelines to prevent venous thromboembolism (VTE) in high-risk orthopedic surgery patients. Recent changes to these documents have brought them into agreement as to the inclusion of aspirin as an appropriate option for VTE prophylaxis in this patient population.

OBJECTIVE

To evaluate the appropriateness of aspirin to prevent VTE in high-risk orthopedic surgery patients.

DATA SOURCES

Guidelines published by the AAOS in 2011 and the ACCP in 2012 were compared regarding their recommendations on the use of aspirin for the prevention of VTE. A literature search was also conducted to identify clinical trials that evaluated the use of aspirin for the prevention of VTE in this patient population. Search terms included the MeSH terms venous thromboembolism; venous thrombosis; pulmonary embolism; aspirin; arthroplasty, replacement, knee; arthroplasty, replacement, hip; and hip fractures/surgery.

STUDY SELECTION AND DATA EXTRACTION

Any study that evaluated aspirin, even in combination with another method of prophylaxis (such as pneumatic compression devices), and had been published during or after 1985 was included.

DATA SYNTHESIS

Randomized controlled trials, meta-analyses, and other large pooled and retrospective reviews have failed to consistently arrive at similar conclusions regarding the efficacy and safety of aspirin as an option for VTE prophylaxis in patients undergoing total knee arthroplasty (TKA), total hip arthroplasty (THA), or hip fracture surgery (HFS). Disagreements in the appropriateness of surrogate markers for safety and efficacy have resulted in differing recommendations from the ACCP and AAOS. The primary argument lies in the appropriateness of deep vein thrombosis as a surrogate marker for more serious outcomes such as pulmonary emboli.

CONCLUSIONS

Recent changes to both the ACCP and AAOS guidelines are in agreement for those who choose to use aspirin for chemoprophylaxis of VTE. Current surgical care improvement project measures do not include aspirin as an appropriate sole option for the prevention of VTE, but in patients undergoing elective TKA or who have a contraindication to pharmacologic prophylaxis and undergo a THA or HFS, aspirin in conjunction with compression devices as part of a multimodal approach would meet these measures. Data do not support the hypothesis that aspirin is less likely to cause adverse bleeding events than more potent anticoagulants.

Intermittent pneumatic compression for venous thromboembolism prophylaxis in total knee arthroplasty

Venous thromboembolism (VTE) prophylaxis in total knee arthroplasty (TKA) is controversial. The purpose of this study was to evaluate the efficacy of bilateral intra- and postoperative intermittent pneumatic compression without major anticoagulation as prophylaxis for VTE in TKA.This retrospective study involved 157 consecutive patients undergoing TKA performed by 1 surgeon who were treated with bilateral intra- and postoperative intermittent pneumatic compression stockings. All patients were followed for at least 6 weeks postoperatively. Postoperative color duplex ultrasound imaging with compression by certified vascular technologists was obtained for 120 patients 2 to 3 days postoperatively. During hospitalization, 2 (1.7%) patients had acute deep vein thrombosis (DVT) diagnosed, 2 (1.7%) had DVT of indeterminate age, and 4 (3.3%) had chronic DVT. During follow-up, 1 (0.8%) patient had an acute DVT diagnosed at 5 weeks postoperatively and 1 (0.8%) had a superficial phlebitis and subsequently had a nonfatal pulmonary embolism 23 days postoperatively. The predominant chemoprophylaxis used was aspirin alone in 107 (89.2%) patients. Epidural anesthesia was used in the majority (n=96; 80%) of patients.The results of this study support the use of a multimodal approach to VTE prophylaxis in TKA, using bilateral intra- and postoperative intermittent pneumatic compression, epidural anesthesia, early mobilization, and postoperative aspirin without the use of major anticoagulation as an effective, safe VTE prophylactic protocol for patients undergoing elective TKA. The study suggests that the protocol is highly effective, has low morbidity, and is cost effective.

Inpatient enoxaparin and outpatient aspirin chemoprophylaxis regimen after primary hip and knee arthroplasty: a preliminary study

Our institution has used a thromboprophylaxis regimen consisting of inpatient enoxaparin and outpatient aspirin for patients at standard risk for venous thrombosis after hip and knee arthroplasty. We reviewed 500 cases using this protocol. Inpatient treatment with enoxaparin averaged 2.75 days, followed by a 28-day course of aspirin. The overall thrombosis rate was 0.6% (1 deep venous thrombosis and 2 pulmonary emboli). Bleeding requiring transfusion of 3 or more units of packed red blood cells occurred in 1.8% of the cases. Fifteen infections were noted, 14 superficial and 1 deep. This compared favorably with a control group of 500 patients using a 14-day course of enoxaparin followed by 14 days of aspirin. We believe that a brief course of inpatient enoxaparin and outpatient aspirin is a safe and effective form of thromboprophylaxis.

Fast-track hip and knee arthroplasty: clinical and organizational aspects

Fast-track hip and knee arthroplasty aims at giving the patients the best available treatment at all times, being a dynamic entity. Fast-track combines evidence-based, clinical features with organizational optimization including a revision of traditions resulting in a streamlined pathway from admission till discharge – and beyond. The goal is to reduce morbidity, mortality and functional convalescence with an earlier achievement of functional milestones including functional discharge criteria with subsequent reduced length of stay and high patient satisfaction. Outcomes are traditionally measured as length of stay; safety aspects in the form of morbidity/mortality; patient satisfaction; and – as a secondary parameter – economic savings. Optimization of the clinical aspects include focusing on analgesia; DVT-prophylaxis; mobilization; care principles including functional discharge criteria; patient-characteristics to predict outcome; and traditions which may be barriers in optimizing outcomes. Patients should be informed and motivated to be active participants and their expectations should be modulated in order to improve satisfaction. Also, organizational aspects need to be analyzed and optimized. New logistical approaches should be implemented; the ward ideally (re)structured to only admit arthroplasties; the staff educated to have a uniform approach; extensive preoperative information given including discharge criteria and intended length of stay. This thesis includes 9 papers on clinical and organizational aspects of fast-track hip and knee arthroplasty (I–IX). A detailed description of the fast-track set-up and its components is provided. Major results include identification of patient characteristics to predict length of stay and satisfaction with different aspects of the hospital stay (I); how to optimize analgesia by using a compression bandage in total knee arthroplasty (II); the clinical and organizational set-up facilitating or acting as barriers for early discharge (III); safety aspects following fast-track in the form of few readmissions in general (IV) and few thromboembolic complications in particular (V); feasibility studies showing excellent outcomes following fast-track bilateral simultaneous total knee arthroplasty (VI) and non-septic revision knee arthroplasty (VII); how acute pain relief in total hip arthroplasty is not enhanced by the use of local infiltration analgesia when multi-modal opioid-sparing analgesia is given (VIII); and a detailed description of which clinical and organizational factors detain patients in hospital following fast-track hip and knee arthroplasty (IX). Economic savings following fast-track hip and knee arthroplasty is also documented in studies, reviews, metaanalyses and Cochrane reviews – including the present fast-track (ANORAK). In conclusion, the published results (I–IX) provide substantial, important new knowledge on clinical and organizational aspects of fast-track hip and knee arthroplasty – with concomitant documented high degrees of safety (morbidity/mortality) and patient satisfaction. Future research strategies are multiple and include both research strategies as efforts to implement the fast-track methodology on a wider basis. Research areas include improvements in pain treatment, blood saving strategies, fluid plans, reduction of complications, avoidance of tourniquet and concomitant blood loss, improved early functional recovery and muscle strengthening. Also, improvements in information and motivation of the patients, preoperative identification of patients needing special attention and detailed economic studies of fast- track are warranted.

A meta-analysis of total hip arthroplasty and hemiarthroplasty outcomes for displaced femoral neck fractures

BACKGROUND

Total hip arthroplasty or hemiarthroplasty are used to treat displaced femoral neck fractures. However, the optimal treatment of these fractures remained controversial.

OBJECTIVE

To assess the effects that compare total hip arthroplasty with hemiarthroplasty for the treatment of femoral neck fractures in the elderly.

METHODS

We searched MEDLINE (January 1980 to 2010), EMBASE (January 1980 to 2010), and the Cochrane Library 2010; issue 1. Only prospective randomized controlled trials (RCTs) that compare total hip arthroplasty with hemiarthroplasty for the treatment of femoral neck fracture in the elderly were included. The analysis was performed with software RevMan5.0 from the Cochrane Collaboration.

RESULTS

We identified seven relevant randomized controlled trials with a total of 828 participants. The meta-analysis showed relative risk of re-operation was 0.40 (95% CI = 0.24-0.67, P = 0.0004), the dislocation was 2.02 (95% CI = 1.26-3.25, P = 0.002), the mobility as functional outcome was 1.70 (95% CI = 1.21-2.38, P = 0.002). It was reported that the average operating room times and blood loss volumes in total hip arthroplasty were more than in hemiarthroplasty (P < 0.001). Other results were not significantly different.

CONCLUSIONS

Total hip arthroplasty is associated with better functional outcome and lower reoperation rate than hemiarthroplasty in treatment of displaced femoral neck fractures in the elderly patients.

Risk Factor Analysis for 30-Day Mortality After Primary THA in a Single Institution

The purpose of this study was to determine the prevalence of, and associated risk factors for, 30-day perioperative death following primary total hip arthroplasty (THA). Data of all the patients were compiled from the computerized total joint registry at a single institution. Between May 1993 and May 2006, 3,232 consecutive primary THA (2,453 elective and 779 nonelective) were performed. Eleven deaths occurred during the first month after surgery (0.34 %). Thirty-day mortality rate after elective THA was 0.08 % (two of 2,453 IC 95 %(0-0.4)). The 30-day mortality rate after nonelective THA was 1.15 % (nine of 779 IC 95 %(0.7-2.4). To analyze the factors that could have contributed with death, we conducted a 4-to-1 nested case-control study. Control cases were strictly matched by sex, age, surgeon, prosthesis fixation mode, and date of surgery. Conditional logistic regression was used to evaluate the association of risk factors with mortality. Elective surgery was associated with a lower risk of mortality with an odds ratio (OR) of 0.07 (95 % CI 0.008-0.6);p = 0.015. American Society of Anesthesiologists (ASA) score III-IV increased the mortality risk 13 times (OR 13.7; 95 % CI 1.6-114.8). Cardiovascular disease increased the risk for mortality eight times (OR 8.83 (95 % CI 1.78-43.6). Time delay before surgery showed a trend towards significance (p = 0.06). Aggressive vs. nonaggressive thromboembolism prophylaxis and the amount of blood transfusions required were not associated with a higher risk of death. Patients undergoing a THA due to fractures, patients with high ASA score, and those with cardiovascular disease were the highest risk factors for 30-day mortality after primary THA.

Aspirin for elective hip and knee arthroplasty: a multimodal thromboprophylaxis protocol

PURPOSE

Multimodal thromboprophylaxis includes preoperative thromboembolic risk stratification and autologous blood donation, surgery performed under regional anaesthesia, postoperative rapid mobilisation, use of pneumatic compression devices and chemoprophylaxis tailored to the patient's individual risk. We determined the 90-day rate of venous thromboembolism (VTE), other complications and mortality in patients who underwent primary elective hip and knee replacement surgery with multimodal thromboprophylaxis.

METHODS

A total of 1,568 consecutive patients undergoing hip and knee replacement surgery received multimodal thromboprophylaxis: 1,115 received aspirin, 426 received warfarin and 27 patients received low molecular weight heparin and warfarin with or without a vena cava filter.

RESULTS

The rate of VTE, pulmonary embolism, proximal deep vein thrombosis (DVT) and distal DVT was 1.2, 0.36, 0.45 and 0.36 %, respectively, in patients who received aspirin. The rates in those who received warfarin were 1.4, 0.9, 0.47 and 0.47 %, respectively. The overall 90-day mortality rate was 0.2 %.

CONCLUSIONS

Multimodal thromboprophylaxis in which aspirin is administered to low-risk patients is safe and effective following primary total joint replacement.

Meta-analysis of cause of death following total joint replacement using different thromboprophylaxis regimens

We performed a meta-analysis of modern total joint replacement (TJR) to determine the post-operative mortality and the cause of death using different thromboprophylactic regimens as follows: 1) no routine chemothromboprophylaxis (NRC); 2) Potent anticoagulation (PA) (unfractionated or low-molecular-weight heparin, ximelagatran, fondaparinux or rivaroxaban); 3) Potent anticoagulation combined (PAC) with regional anaesthesia and/or pneumatic compression devices (PCDs); 4) Warfarin (W); 5) Warfarin combined (WAC) with regional anaesthesia and/or PCD; and 6) Multimodal (MM) prophylaxis, including regional anaesthesia, PCDs and aspirin in low-risk patients. Cause of death was classified as autopsy proven, clinically certain or unknown. Deaths were grouped into cardiopulmonary excluding pulmonary embolism (PE), PE, bleeding-related, gastrointestinal, central nervous system, and others (miscellaneous). Meta-analysis based on fixed effects or random effects models was used for pooling incidence data. In all, 70 studies were included (99 441 patients; 373 deaths). The mortality was lowest in the MM (0.2%) and WC (0.2%) groups. The most frequent cause of death was cardiopulmonary (47.9%), followed by PE (25.4%) and bleeding (8.9%). The proportion of deaths due to PE was not significantly affected by the thromboprophylaxis regimen (PA, 35.5%; PAC, 28%; MM, 23.2%; and NRC, 16.3%). Fatal bleeding was higher in groups relying on the use of anticoagulation (W, 33.8%; PA, 9.4%; PAC, 10.8%) but the differences were not statistically significant. Our study demonstrated that the routine use of PA does not reduce the overall mortality or the proportion of deaths due to PE.

The Australian arthroplasty thromboprophylaxis survey

Previous surveys of orthopedic surgeons have shown considerable variation in thromboprophylaxis for venous thromboembolism after joint arthroplasty. This survey aimed to determine the current practice among Australian orthopedic surgeons. A questionnaire regarding the duration, reasons, and methods of chemical and mechanical prophylaxis for hip and knee arthroplasty patients was sent to the 1082 surgeons identified; 593 (55%) members completed the questionnaire. The survey revealed that 98% of surgeons used chemical thromboprophylaxis, mainly low-molecular-weight heparin (84% hip and 79% knee). Those who use low-molecular-weight heparin were more likely to prescribe anticoagulants in fear of litigation (19.2% vs 10.1%, P = .04) and more likely to rely on protocols or guidelines (32.2% vs 17.2%, P = .004) instead of basing their decision on their own reading (52.4% vs 71.3%, P = .001). Most orthopedic surgeons in our survey have indicated that they would welcome guidelines from their association or college regarding thromboprophylaxis in arthroplasty.

Does international normalized ratio level predict pulmonary embolism?

BACKGROUND

Preventing pulmonary embolism is a priority after major musculoskeletal surgery. The literature contains discrepant data regarding the influence of anticoagulation on the incidence of pulmonary embolism after joint arthroplasty. The American College of Chest Physicians guidelines recommend administration of oral anticoagulants (warfarin), aiming for an international normalized ratio (INR) level between 2 and 3. However, recent studies show aggressive anticoagulation (INR > 2) can lead to hematoma formation and increased risk of subsequent infection.

QUESTIONS/PURPOSES

We asked whether an INR greater than 2 protects against pulmonary embolism.

PATIENTS AND METHODS

We identified 9112 patients with 10,122 admissions for joint arthroplasty between 2004 and 2008. All patients received warfarin for prophylaxis, aiming for an INR level of 2 or lower. We assessed 609 of 10,122 admissions (6%) for pulmonary embolism using CT, ventilation/perfusion scan, or pulmonary angiography, and 163 of 10,122 admissions (1.6%) had a proven pulmonary embolism.

RESULTS

Fifteen of 163 admissions (9%) had an INR greater than 2 before or on the day of workup compared to 35 of 446 admissions (8%) who were negative. We observed no difference between the INR values in patients with or without pulmonary embolism.

CONCLUSIONS

We found no clinically relevant difference in the INR values of patients who did or did not develop pulmonary embolism. The risk of bleeding should be weighed against the risk of pulmonary embolism when determining an appropriate target INR for each patient, as an INR less than 2 may reduce the risk of bleeding while still protecting against pulmonary embolism.

LEVEL OF EVIDENCE

Level III, therapeutic study. See Instructions to Authors for a complete description of levels of evidence.

Risk factors for pulmonary embolism and the effects of fondaparinux after total hip and knee arthroplasty: a retrospective observational study with use of a national database in Japan

BACKGROUND

Clinical evidence demonstrating the effectiveness of pharmacological and mechanical thromboprophylaxis for the prevention of pulmonary embolism is limited because the prevalence of postoperative pulmonary embolism following total hip and knee arthroplasty is very low. Our purposes were to characterize a patient population with in-hospital pulmonary embolism, to identify perioperative risk factors associated with pulmonary embolism, and to analyze the effect of combining fondaparinux with mechanical prophylaxis on the prevalence of pulmonary embolism following total hip and knee arthroplasty.

METHODS

We retrospectively identified 27,542 patients who underwent total hip or knee arthroplasty at 793 hospitals, using data from the Diagnosis Procedure Combination database, collected from July 1 to December 31 in 2007 and 2008. We extracted data on patient sex, age, primary diagnoses, and comorbidities that could potentially affect the prevalence of pulmonary embolism. The dates of pharmacological and mechanical thromboprophylaxis were identified for each patient. Logistic regression analysis was performed to analyze the concurrent effects of various factors on the prevalence of postoperative pulmonary embolism.

RESULTS

The mean age (and standard deviation) of the patients at the time of arthroplasty was 69.9 ± 10.3 years, and 23,783 patients (86.4%) were diagnosed as having osteoarthritis. The overall mean duration of anesthesia was 159 ± 84 minutes. The overall prevalence of postoperative pulmonary embolism was 0.55% (151 of 27,542). Significant risk factors for postoperative pulmonary embolism included age, number of comorbidities, diagnosis of rheumatoid arthritis, type of anesthesia, and duration of anesthesia. Multivariate analysis found that the prevalence of postoperative pulmonary embolism was significantly reduced when fondaparinux was used in combination with mechanical prophylaxis, compared with the use of mechanical prophylaxis alone (0.40% versus 0.66%; odds ratio, 0.60; 95% confidence interval, 0.42 to 0.84; p = 0.003).

CONCLUSIONS

These findings could help to identify patients at higher risk of postoperative pulmonary embolism after total hip or knee arthroplasty. Our results demonstrate the effectiveness of fondaparinux in combination with mechanical prophylaxis for the prevention of postoperative pulmonary embolism after total hip or knee arthroplasty.

Apixaban and rivaroxaban safety after hip and knee arthroplasty: a meta-analysis

Direct experimental safety comparisons of Xa coagulation factor direct inhibitors, apixaban and rivaroxaban, on their approved therapeutic indications have not been identified. Due to recently raised safety concerns, a meta-analysis was carried out pooling data from studies identified on a Medline and Cochrane Library search in order to better evaluate the safety profile of both drugs. Abstracts from scientific meetings were also searched from 2003 to 2011. Primary and secondary outcome measures were major bleeding and total bleeding, respectively. Relative risks (RRs) were estimated using random effects models and statistical heterogeneity was estimated with I(2) statistics. Of the 160 screened publications, 12 clinical trials were included in which enoxaparin was the active control. For knee arthroplasty, apixaban was associated with significantly fewer major bleeding events (6496 patients, RR 0.56, 95% confidence interval [CI] 0.32-0.96) and fewer total bleeding events (6496 patients, RR 0.81, 95% CI 0.67-0.97). There were no significant differences in the incidence of major bleeding events (5699 patients, RR 1.40, 95% CI 0.56-3.52) or in the incidence of total bleeding events for rivaroxaban (5699 patients, RR 1.09, 95% CI 0.91-1.30). No differences were found when thromboprophylaxis after hip replacement was the case. Apixaban seems to be associated with a lower risk of the incidence of hemorrhagic events after total knee arthroplasty. For hip arthroplasty, no differences were found between the studied drugs.

A study of thromboprophylactic practices of Scottish orthopaedic surgeons in patients undergoing total hip replacements. Should practice change with new guidelines?

Despite increasing scientific investigation, the best method for preventing postoperative thromboembolism in patients undergoing a total hip replacement (THR) remains unclear. National Institute for Health and Clinical Excellence (NICE) and Scottish Intercollegiate Guidelines Network (SIGN) guidelines on the prevention of thromboembolism have caused much controversy. We surveyed Scottish surgeons regarding their thromboprophylaxis prescribing after THR. Questionnaires were sent to all Scottish orthopaedic consultants. They were asked about routine pharmacological and mechanical prophylaxis in patients undergoing a THR. Comparison was made with a previous survey done in 2003. The response rate was 75%. The survey showed an increased use of pharmacological prophylaxis from 93% to 100%. This was due to the increased use of aspirin from 51% to 64%. The use of low molecular weight heparin has remained constant at 51%. No surgeons routinely use warfarin, un-fractionated heparin or fondaparinux. Use of graded compression stockings has increased from 59% to 70%. In conclusion, there is increasing evidence that patients undergoing THR should receive extended prophylaxis for up to 35 days. Oral agents such as dabigatran and rivaroxaban have offered a new option for oral extended prescribing. The results in change of practice must be closely audited.

Predictive blood coagulation markers for early diagnosis of venous thromboembolism after total knee joint replacement

Pulmonary embolism development may be prevented if asymptomatic venous thromboembolism (VTE) can be predicted and treated preoperatively or soon after total knee arthroplasty (TKA). The purpose of this study was to evaluate whether asymptomatic VTE can be predicted by blood coagulation markers preoperatively or early after TKA. This prospective single-centre study enrolled 68 patients (6 men, 62 women; mean age: 71 years) who underwent TKA between September 2004 and August 2009. Sixteen-row multidetector computed tomography was performed 4 days before and after surgery for diagnosis of asymptomatic VTE. Blood samples were taken to measure the plasma levels of soluble fibrin monomer complex (SFMC), D-dimer and cross-linked fibrin degradation products by leukocyte elastase (e-XDP) at 4 days preoperatively, and at 1 hour, 1 day and 4 days postoperatively. The preoperative SFMC, D-dimer and e-XDP levels did not differ significantly between the thrombus (n=36) and no-thrombus (n=32) groups. D-dimer and e-XDP levels showed the most significant increases at days 4 and 1, respectively, after surgery in the thrombus group. With cut-off points of 7.5 μg/ml for D-dimer and 8.2 U/ml for e-XDP, the sensitivities were 75% and 75%, and the specificities were 63% and 59%, respectively. By multiple logistic regression analysis, D-dimer at day 4 and e-XDP at day 1 postoperatively were independent markers for early diagnosis of VTE (odds ratio=1.61 and 1.19, P=0.01 and 0.04, respectively). The postoperative occurrence of new asymptomatic VTE may be predicted by D-dimer at day 4 and e-XDP at day 1 after TKA.

Patient-reported history of leg ulceration 12-16 years after total primary knee or hip replacement

BACKGROUND AND PURPOSE

Deep vein thrombosis is common after total joint replacement. It is frequently asymptomatic, and it is unclear whether this leads to longer-term problems such as post-thrombotic syndrome and leg ulceration. We investigated whether the postoperative prevalence of ulceration in patients who had undergone primary total hip replacement (THR) or total knee replacement (TKR) was higher than that found in a control group who had not undergone total joint replacement.

METHODS

The study group consisted of patients who had undergone THR or TKR at one orthopedic center 12-16 years previously without routine chemothromboprophylaxis, and who had not undergone revision surgery. The control group was recruited via primary care. All participants were recruited by post and asked to complete a questionnaire. Age- and sex-adjusted prevalence of self-reported leg ulceration was calculated, and logistic regression was used to determine whether there were any associations between THR or TKR and leg ulceration.

RESULTS

Completed questionnaires were received from 441 THR patients (54% response rate), 196 TKR patients (48%) and 967 control participants (36%). No statistically significant differences in age- and sex-adjusted prevalence of ulceration were found between the groups, for either lifetime prevalence or prevalence over the previous 15 years.

INTERPRETATION

Patients who undergo THR and TKR without chemothromboprophylaxis are unlikely to be at a higher risk of long-term venous ulceration than the normal population.

[Evidence-based update in hip arthroplasty]

The present manuscript provides an overview of current evidence-based data and new clinically relevant developments in the field of hip arthroplasty. A multitude of current clinical trials have focussed on tribology with special interest on metal-on-metal implants. Large trials from implant registries have defined specific risk factors for early implant failure and pseudotumors in surface replacement. Furthermore, new ceramic liners and femoral head implants have been investigated in randomized trials. Apart from other very interesting studies, the results of large meta-analyses are now available for laboratory values in periprosthetic infection, antibiotic prophylaxis, regional anesthesia, prevention of thromboembolism, implant fixation, navigation and clinical pathways to prevent complications.

Incidence of deep vein thrombosis following total hip arthroplasty: a Doppler ultrasonographic study

PURPOSE

To investigate the incidence of deep vein thrombosis (DVT) following total hip arthroplasty (THA) in Singaporean patients.

METHODS

197 patients (mean age, 60 years) underwent primary THA (n=155) or revision procedure (n=42) without receiving routine chemoprophylaxis. There were 149 Chinese, 25 Malays, 19 Indians, and 4 Eurasians. Duplex ultrasonography to detect DVT was performed on both lower limbs on postoperative day 5.

RESULTS

15 (8%) patients developed DVT, which was proximal in 6 and distal in 9. Only one patient had pulmonary embolism. The presence of DVT did not correlate to age, gender, race, presence of diabetes mellitus, history of malignancy, smoking habit, fixation type, primary versus revision type of surgery, or operating time.

CONCLUSION

The incidence of DVT following THA in Singaporean patients is low, and routine chemoprophylaxis may not be indicated.

Markers of thrombin generation during resurfacing and noncemented total hip arthroplasty: a pilot study

BACKGROUND

Hip resurfacing arthroplasty (HRA) could be associated with an increased risk of deep vein thrombosis (DVT) compared to traditional noncemented THA because it involves greater dissection, increased kinking and distortion of the femoral vessels, takes longer to perform, and involves insertion of some cement into the femur.

QUESTIONS/PURPOSES

Does HRA lead to greater risk of thromboembolism compared with noncemented THA?

METHODS

We prospectively studied 20 patients receiving HRA and 20 receiving THA. All patients were younger than 67 years old and were similar in height, weight, American Society of Anesthesiologists status, and gender mix. Patients undergoing HRA were younger (mean, 50 versus 59 years), their surgery was longer (mean, 87 versus 65 minutes), and they required more crystalloid during surgery (mean, 2160 versus 1662 mL). Radial artery blood samples were taken at six events during surgery and assayed for prothrombin fragment F1 + 2 and thrombin-antithrombin III complex (TAT) using enzyme-linked immunosorbent assays.

RESULTS

We observed no differences in the intraoperative increases in F1 + 2 and TAT between the two groups and no differences in surgical events.

CONCLUSION

Based on these data, HRA and THA should have similar risk of thromboembolism as THA based on the parameters we measured.

LEVEL OF EVIDENCE

Level I, diagnostic study. See Guidelines for Authors for a complete description of levels of evidence.

Venous thromboembolism and bleeding after total knee and hip arthroplasty. Findings from the Spanish National Discharge Database

The impact of venous thromboembolism (VTE) and bleeding in patients undergoing major joint surgery has not been thoroughly studied. The Spanish National Discharge Database during the years 2005-2006 was used to assess the frequency and clinical impact of VTE and bleeding after elective total knee (TKA) or hip (THA) arthroplasty. Of 58,037 patients undergoing TKA, 0.18% (95% confidence interval [CI]: 0.15-0.22) were diagnosed with pulmonary embolism (PE), 0.57% (95% CI: 0.51-0.63) with deep-vein thrombosis (DVT), 1.20% (95% CI: 1.12-1.30) had bleeding complications, and 0.09% (95% CI: 0.07-0.12) died. Of 54 patients who died, 20.4% (95% CI: 10.7-35.4) had been diagnosed with PE, 3.70% (95% CI: 0.63-11.7) with DVT, and 13.0% (95% CI: 5.67-25.6) had bled. Of 31,769 patients undergoing elective THA, 0.23% (95% CI: 0.18-0.29) were diagnosed with PE, 0.44% (95% CI: 0.37-0.52) with DVT, 1.21% (95% CI: 1.10-1.34) bled, and 0.16% (95% CI: 0.12-0.21) died. Of 52 patients who died, 13.5% (95% CI: 6.08-24.8) had been diagnosed with PE, and 9.61% (95% CI: 3.52-21.3) had bled. On multivariable analysis, PE (odds ratio [OR]: 157; 95% CI: 75-328), DVT (OR: 6.3; 95% CI: 1.5-27) and bleeding (OR: 8.5; 95% CI: 3.6-20) were independent predictors for death after TKA. After THA, only PE (OR: 65; 95% CI: 26-160) and bleeding (OR: 6.4; 95% CI: 2.3-17) predicted the risk for death. Bleeding, DVT, and PE, arising after TKA were all independent predictors for death. Their increase in risk was, however, substantially higher for PE. After THA, only PE and bleeding independently predicted death.

Venous thromboembolic prophylaxis for hip fractures

Patients with hip fractures are at very high risk for the development of venous thromboembolism (VTE). To provide an overview of cause, risk factors, current treatment strategies, and complications associated with VTE prophylaxis, we reviewed the most current, best available evidence on VTE prophylaxis for patients with hip fractures. We comprehensively reviewed the literature to assess the efficacy of VTE prophylaxis in patients with hip fractures, including the most recent published guidelines by national medical and surgical health organizations from the UK, USA, and Canada. Mechanical devices are effective in reducing the risk of VTE for hip fracture, but poor patient compliance is common and the devices are not recommended for sole VTE prophylaxis. Aspirin reduces the risk of VTE but does not provide optimal protection compared with other chemical agents; therefore, it is not recommended for sole VTE prophylaxis. Fondaparinux, warfarin, low-molecular-weight heparin, and unfractionated heparin reduce the risk of venographic deep vein thrombosis, but there is insufficient evidence that they reduce fatal pulmonary embolism or all-cause mortality. Fondaparinux is considered to be cost effective and more efficacious than low-molecular-weight heparin. At present, most major health organizations advocate at least 28 days of postoperative chemical prophylaxis. Chemical VTE prophylaxis should be administered to all patients with hip fractures unless contraindicated. Additional research is required to establish an agent that has a significant impact on fatal pulmonary embolism and all-cause mortality, without increasing bleeding complications, in this group of patients.

DVT prophylaxis: better living through chemistry: opposes

The association between total hip arthroplasty and subsequent postoperative deep venous thrombosis is of particular concern because it can lead to symptomatic venous thromboembolic events. However, controversy remains about the optimal approach to prophylaxis. Some authors recommend the use of various chemoprophylactic agents, while others advocate the use of mechanical devices or combinations. The ideal method of prophylaxis should be effective and easy to administer, have a predictable onset and duration, have minimal interaction with food or other drugs, be easily reversible, be cost effective, and have a low risk of side effects. While available chemoprophylactic agents address some of these attributes, all have substantial drawbacks. Among the most concerning effects for orthopedic surgeons is the increased risk of bleeding and hematoma formation, which can be associated with periprosthetic infections. These typically lead to additional surgical procedures and significant patient morbidity, and can adversely impact clinical outcomes. An alternative to chemoprophylaxis is the use of pneumatic intermittent compression devices. Modern compression devices are portable and easy to use, and have a high rate of patient compliance. Several studies have demonstrated the efficacy of these devices in reducing the risk of symptomatic venous thromboembolic disease, in some cases resulting in lower mortality when compared to pharmacological agents. Additionally, these devices significantly reduce the risk of postoperative bleeding.

Is deep vein thrombosis a good proxy for pulmonary embolus?

It is assumed that prevention of deep venous thrombosis (DVT) is likely to lead to a reduction in the incidence of pulmonary embolus (PE). This study examines the association between symptomatic DVT and PE in patients undergoing orthopedic procedures. We reviewed medical records of 1495 patients who underwent evaluation for DVT or PE within 90 days of an index orthopedic procedure at our institution between 2004 and 2008. Only 27 cases were positive for both DVT and PE (1.7% of the total cohort, 10.8% of cases scanned for both DVT and PE). Tests of association, performed across the entire cohort and within specific subsets of patients, did not demonstrate that patients were more likely to have both DVT and PE than to have either DVT or PE. The high association between DVT and PE that is assumed to exist does not seem to hold true for orthopedic surgery patients.

Meta-analysis of low molecular weight heparin versus placebo in patients undergoing total hip replacement and post-operative morbidity and mortality since their introduction

OBJECTIVES

1) To establish the clinical validity for in-patient low molecular weight heparin (LMWH) following total hip replacement (THR) through a meta-analysis of peer reviewed and published randomised placebo controlled trials (RCTs). 2) To establish whether modern peri-operative practices were associated with changes in rates of clinical venous thromboembolic (VTE) and all-cause mortality after THR by review of series of patients receiving in-patient LMWH published between 1985 and 2000. DATASOURCES: Medline and Embase (from 1980 to 2005), Datastar and Proquest databases were searched and references from bibliographies traced.

REVIEW METHODS

Studies of adult patients receiving in-patient LMWH following elective primary or revision THR were sought and data abstracted. The first part of our analysis included only randomised placebo controlled trials. For the second part, randomised control trials were included and divided by their year of completion into three groups.

RESULTS

We found no difference between LMWH and placebo in the risk of fatal pulmonary embolism (PE), other deaths, all cause mortality or major bleeding. LMWH reduced non-fatal PE (OR=0.14, 95%CI 0.03 to 0.74, p=0.029) at the expense of haematoma formation (7/147 vs 0/149, p=0.015). 35 studies were included in the second part of our analysis. Point estimates of rates of fatal and non-fatal pulmonary embolism and other deaths suggest a decline over time but fell short of statistical significance.

CONCLUSION

Clinically relevant VTEs are a rare complication following THR. The lower risk of VTE narrows the risk benefit of potent pharmacological thromboprophylaxis. We do not support their use in patients undergoing THR without additional thromboembolic risk factors.