No Difference Between Low- and Regular-dose Aspirin for Venous Thromboembolism Prophylaxis After THA

The Use of Aspirin for Venous Thromboembolism Prophylaxis in Patients Who Have Morbid Obesity Undergoing Primary and Revision Total Joint Arthroplasty

BACKGROUND

Venous thromboembolism (VTE) poses a major clinical concern due to its life-threatening nature, and obese and morbidly obese patients are thought to be at an increased risk for VTE. The aims of this study were twofold; first, to explore VTE rates in patients who have a body mass index (BMI) > 40 undergoing primary and revision total joint arthroplasty, and second, to investigate aspirin (ASA) efficacy and safety.

METHODS

We identified all patients (n = 4,672) who had a BMI > 40 who underwent primary and revision total joint arthroplasty from 2016 to 2022 at a single academic tertiary care center. Patients were stratified by BMI groups: 40 to 44.9 (n = 3,462), 45 to 49.9 (n = 935), and 50+ (n = 275). The primary outcome was any VTE event within 90 days postoperatively. The secondary outcome consisted of wound complications within 90 days postoperatively.

RESULTS

The total VTE rate was 0.4% (n = 21) and did not differ statistically between the BMI groups (0.4 versus 0.4 versus 0.7%, P = .669). The VTEs consisted of 6 deep venous thromboses (DVTs), 14 pulmonary embolisms, and one concomitant deep venous thrombosis and pulmonary embolism. The VTE rates were not statistically different between patients who received aspirin 325 mg 0.5% (n = 9), aspirin 81 mg 0.2% (n = 1), aspirin + anticoagulant (AC) 0.5% (n = 6), and AC alone 0.4% (n = 5) (P = .954). In addition, wound complications did not differ significantly between patients who received ASA 325 mg, ASA 81mg, ASA + AC, or AC alone (1.6 versus 1.0 versus 1.8 versus 1.1%, P = .351).

CONCLUSIONS

The use of aspirin 325 and 81 mg was found to have similar VTE rates as aspirin + ACs and ACs alone, with no significant increase in wound complications. In patients who have a BMI > 40, the use of aspirin is a safe option for VTE prophylaxis and should be prescribed in the context of the patient who has other risk factors for VTE.

Venous Thromboembolism Chemical Prophylaxis in Patients Undergoing Shoulder Arthroscopy

» Venous thromboembolism (VTE) after shoulder arthroscopy is rare (0.01%-0.38%) but impacts a significant number of patients because of the high procedure volume.» Studies found no significant benefit in reducing VTE risk with aspirin or low-molecular-weight heparins.» Current guidelines for thromboprophylaxis in shoulder arthroscopy lack consensus and need patient-specific considerations.» Further research is required to develop evidence-based thromboprophylaxis guidelines for shoulder arthroscopy.

The efficacy and safety of aspirin in preventing venous thrombosis in major orthopedic surgery: An updated meta-analysis of randomized controlled trials

BACKGROUND

Major orthopedic surgery, including hip and knee replacement and lower extremity trauma fractures surgery, is associated with a high risk of venous thromboembolism (VTE), especially proximal deep vein thrombosis (DVT), and pulmonary embolism (PE), and is linked with high morbidity and mortality rates. Chemical anticoagulation is routinely used to prevent VTE, with previous meta-analyses reporting on the efficacy and safety of aspirin and other anticoagulants, however, opinions are divided. In the past 2 years, several large randomized controlled trials have been published, therefore, we reanalyzed aspirin efficacy and safety when compared with other anticoagulants in preventing VTE in major orthopedic surgery.

METHODS

Using PubMed, The Cochrane Library, Embase, and Web of Science databases, we conducted a RCT search in August 2023. The main outcomes included VTE, proximal DVT or PE. Additional outcomes included bleeding events, wound complications, wound infections, blood transfusions, and death events.

RESULTS

In total, 17 eligible articles, involving 29,522 patients (15,253 aspirin vs 14,269 other anticoagulant cases), were included. Primary outcomes showed that VTE incidence was more high in the aspirin group when compared with other anticoagulants (risk ratio [RR] = 1.45, 95% confidence interval [CI] = 1.18-1.77, P = .0004) and proximal in the aspirin group the DVT and/or PE incidence was significantly higher in the aspirin group when compared with other anticoagulants (RR = 1.19, 95% CI = 1.02-1.39, P = .03). No significant secondary outcome differences were identified in the aspirin group when compared with other anticoagulants (bleeding events [RR] = 0.83, 95% CI = 0.63-1.10, P = .20); wound complications (RR = 0.45, 95% CI = 0.20-1.04, P = .06); wound infection (RR = 1.08, 95% CI = 0.85-1.38, P = .53); blood transfusion events (RR = 1.00, 95% CI = 0.84-1.19, P = 1.00) and death events (RR = 1.11, 95% CI = 0.78-1.57, P = .55).

CONCLUSIONS

Our updated meta-analysis showed that aspirin was inferior to when compared with other anticoagulants in VTE-related orthopedic major surgery, including proximal DVT and/or PE, and was more likely to form VTE. No differences between groups were identified for bleeding, wound complications, wound infections, transfusion, or death events.

Role of aspirin in the prevention of heterotopic ossification following total hip replacement: a systematic review and meta-analysis

BACKGROUND

To systematically investigate if aspirin (ASA), used as venous thromboembolism (VTE) prophylaxis, plays a role in the prevention of heterotopic ossification (HO) following total hip arthroplasty (THA) and if ASA dosage impacted the rate of HO.

METHODS

Eligible studies published from January 2000 to July 2022 were identified from the computerized searching of PubMed, Scopus and Web of Science. HO was defined according to Brooker Classification. Pooled risk ratios (OR) and 95% confidence interval (CI) were estimated under a random-effect model. Additionally, combined HO incidences were compared according to ASA dosage (a regular dose of 325 bid vs. a low dose of 81 mg bid/162 mg qd).

RESULTS

Thirteen studies were included. ASA administered for VTE prophylaxis was significantly associated with a reduced risk of all-grade HO following THA (univariate, OR: 0.50, 95% CI: 0.34-0.74, P < 0.001; multivariate, OR: 0.60, 95% CI: 0.49-0.73, P < 0.001). Similar results could be observed for high-grade HO (univariate, OR: 0.57, 95% CI: 0.36-0.89, P = 0.015; multivariate, OR: 0.50, 95% CI: 0.27-0.92, P = 0.026). There was a non-significant trend towards a higher incidence of HO formation for low-dose ASA (31%, 95% CI: 29-34%), compared with regular-dose ASA (21%, 95% CI: 11-33%) (P = 0.069 under test of interaction).

CONCLUSIONS

ASA can be an effective option for HO prophylaxis. More well-designed trials with long-term follow-ups are encouraged to confirm the current findings and to investigate the effect of ASA dosage on HO reduction.

Trends of Venous Thromboembolism After Total Hip Arthroplasty in the United States: Analysis From 2011 to 2019

BACKGROUND

In 2011, the American Academy of Orthopaedic Surgeons released a Clinical Practice Guideline` that recommended routine venous thromboembolism (VTE) prophylaxis after total joint arthroplasty. The purpose of this study was to examine (1) the change in the incidence of 90-day VTE, deep vein thrombosis, and pulmonary embolism, (2) the change in the utilization of antithrombotic agents; and (3) the change in the economic burden associated with VTE after total hip arthroplasty (THA) from 2011 to 2019.

METHODS

National, administrative claims data from 2011 to 2019 were used to identify patients who underwent primary THA for osteoarthritis. Exclusions entailed liver pathology, coagulopathy, malignancy, or those on prior prescribed blood thinners before THA. Multivariable regression was used, controlling for age and Charlson Comorbidity Index for all years, with 2011 as the reference year.

RESULTS

From 2011 to 2019, there was a significant reduction in 90-day VTE rates after THA, with a significant reduction in deep vein thrombosis and pulmonary embolism during this time frame as well. Of the antithrombotic agents prescribed after THA, the utilization of prescribed aspirin significantly increased and that of nonaspirin anticoagulants significantly decreased. Among nonaspirin anticoagulants, the utilization of direct factor Xa inhibitors and direct thrombin inhibitors significantly increased. The added reimbursements associated with VTE after THA significantly decreased during this period.

CONCLUSION

Since 2011, the incidence and economic burden associated with VTE after THA have significantly declined. In addition, there has been an increase in prescription aspirin and direct oral anticoagulants.

LEVEL OF EVIDENCE

Therapeutic, III.

Low-Dose NSAIDs Efficacy in Orthopedic Applications

Non-steroidal anti-inflammatory drugs (NSAIDs) [cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) inhibitors] and COXIBs (the COX-2 selective inhibitors) may induce several potentially severe and life-threatening issues especially in elderly patients. The use of low-dose NSAIDs is associated with lower risk of side effects compared to the standard dosage. Low-dose NSAIDs could minimize the side effects of these drugs while maintaining their clinical efficacy and effectiveness. The present study evaluates the effectiveness and safety of low-dose NSAIDs in musculoskeletal applications.

Incidence and risk factors associated with venous thromboembolism following primary total hip arthroplasty in low-risk patients when using aspirin for prophylaxis

AIMS

The primary aim was to assess the incidence of venous thromboembolism (VTE) following total hip replacements (THR) in a low-risk patient group when using 150 mg aspirin as the pharmacological component of VTE prophylaxis on discharge. The secondary aim was to identify factors associated with an increased risk of a VTE event in this low-risk group.

PATIENTS AND METHODS

Retrospective review of a consecutive cohort of patients undergoing THR during a 63-month period. Patient demographics, socio-economic status, ASA grade, type of anaesthetic, length of surgery and BMI were recorded. A diagnosis of VTE was assigned to symptomatic patients with positive imaging for a deep vein thrombosis (DVT) and/or a pulmonary embolism (PE) within 8 weeks of surgery. Multivariate logistic regression modeling was used to identify factors associated with VTE after THR.

RESULTS

3880 patients underwent THR during the study period, of which 2740 (71%) were low risk and prescribed aspirin for VTE prophylaxis. There were 34 VTE events, of which 15 were DVTs and 18 were PEs, with 1 patient diagnosed with both. The incidence of VTE was 1.2%, with no VTE-related deaths. Patients incurring a VTE postoperatively were more likely to be male (odds ratio [OR] 2.06, p = 0.022), of older age (OR 0.43, p = 0.047) and were more likely to be socially deprived (OR 0.32, p = 0.006). There was no significant difference with patients given low-molecular-weight heparin (LMWH) as an inpatient prior to discharge on aspirin (p = 0.806), nor any difference with the type of anaesthetic used during surgery (p = 0.719).

CONCLUSIONS

Aspirin is a relatively safe and effective choice for VTE prophylaxis in low-risk patients undergoing THR. Male sex and age >70 years were twice as likely to sustain a VTE and patients from the most deprived socio-economic background are 3 times as likely.

Is aspirin still relevant as a single pharmacological agent for venous thromboembolism prophylaxis post hip and knee arthroplasty surgery: A retrospective review

Introduction: Aspirin is widely used for the prevention of venous thromboembolism (VTE) after total hip arthroplasty (THA) and total knee arthroplasty (TKA). It is well-established that the bleeding and wound complication risk for aspirin is low or equivalent to the other anticoagulant agents, but there is still ongoing controversy regarding the efficacy of aspirin for VTE prophylaxis. The current HSE (2012) guideline suggests 72 h of enoxaparin and 4 weeks of Aspirin therapy. But is this practice still relevant with more recent guidelines, NICE (2021) and SIGN (2014) suggesting that Aspirin is not recommended as a single pharmacological agent for VTE prophylaxis. Method: A Retrospective review was performed of a single centre, between January 2016 and May 2021 assessing for symptomatic VTE post-THA and TKA. All the patients received enoxaparin and aspirin as per the HSE guidelines. Using NIMIS we assessed which patients received a workup for potential symptomatic VTE and who had a confirmed VTE within 3 months post-surgery. The secondary outcome was mortality within 3 months post-surgery. Results: A total of 1178 patients (721 undergoing THR and 457 undergoing TKR) were included in the study. The number of patients who received a workup for potential symptomatic VTE was 124 of 1178 (10.53%). VTE occurred in 13 of 721 patients (1.80%) of the THR patients and 1 of 457 (0.22%) of the TKR patients, and a total of 14 of 1178 patients (1.19%). Of these 7 (0.59%) patients developed a DVT and 7 (0.59%) a PE. No patients suffered a fatal pulmonary embolism within 90 days of index surgery nor any other cause of mortality. Conclusion: Aspirin is not only still relevant but can be considered as one of the most optimal pharmacological agents in preventing VTE after THA and TKA.

Morbidly Obese Patients Undergoing Primary Total Joint Arthroplasty May Experience Higher Rates of Venous Thromboembolism When Prescribed Direct Oral Anticoagulants vs Aspirin

BACKGROUND

Morbidly obese (body mass index [BMI] >40 kg/m²) patients undergoing total joint arthroplasty (TJA) are at high risk for postoperative venous thromboembolism (VTE); however, there is debate surrounding the optimal pharmacologic agent for prevention of VTE after TJA in this patient subset. Current guidelines recommend against direct-acting oral anticoagulants (DOACs) in patients of BMI >40 kg/m² due to low quality evidence justifying their use. We evaluated whether patients of BMI >40 kg/m² undergoing primary unilateral TJA would have increased risk of postoperative VTE if prescribed DOACs compared to non-DOAC agents such as aspirin.

METHODS

This retrospective study analyzed 897 patients of BMI >40 kg/m² undergoing primary unilateral TJA. Demographic and comorbidity-related variables were collected. The association between postoperative VTE and prophylactic pharmacologic agent prescribed was evaluated by multivariate logistic regression.

RESULTS

After controlling for comorbidities, we found that the sole use of DOACs, specifically apixaban, for VTE prophylaxis was associated with an increased risk of developing VTE compared to prophylaxis with aspirin alone in patients of BMI >40 kg/m² (odds ratio 2.962, P = .016). Regardless of VTE prophylactic agent, patients with BMI >40 kg/m² undergoing TKA had at least 4.5-fold increased odds of developing VTE compared to patients undergoing THA (OR 4.830, P = .019).

CONCLUSION

In our retrospective study of a large sample size of patients with BMI >40 kg/m², we found that the use of DOACs, specifically apixaban, for VTE prophylaxis following TJA was associated with increased odds of a VTE complication compared to the use of aspirin alone.

Prophylaxis for Venous Thromboembolic Events in Elective Total Hip and Total Knee Arthroplasty

Venous thromboembolism (VTE) is a serious complication after major orthopaedic operations, such as a total hip (THA) and knee (TKA) arthroplasty. Therefore, perioperative VTE prophylaxis is recommended; a multitude of modern options are available, including both pharmacologic (aspirin, unfractionated and lowmolecular-weight heparin, vitamin K antagonists, and novel oral anticoagulants) and/or mechanical interventions (early mobilization, graduated compression stockings, intermittent pneumatic compression devices, and venous foot pumps). However, because of the abundance of these possibilities, it is crucial to understand the benefits and drawbacks of each VTE prophylaxis option to ensure that the optimal treatment plan is developed for each patient. The American College of Chest Physicians (AACP) and the American Academy of Orthopaedic Surgeons (AAOS) have both published individual guidelines on VTE prophylaxis regimens, alongside numerous studies evaluating the efficacy and outcomes of the different prophylaxis modalities. The purpose of this review is to provide a summary of the evidence on VTE prophylaxis after elective total hip and knee arthroplasty based on current guidelines and highlight the major concerns and potential complications.

Weight-Based Aspirin Dosing May Further Reduce the Incidence of Venous Thromboembolism Following Primary Total Joint Arthroplasty

BACKGROUND

Obesity poses a challenge to thromboembolic prophylaxis following total joint arthroplasty (TJA). The purpose of this study is to evaluate a weight-based aspirin dosing regimen for prevention of venous thromboembolism (VTE) following TJA.

METHODS

This is a retrospective observational study of 2403 patients who underwent primary total hip or knee arthroplasty at one institution. A weight-based aspirin dosing regimen for VTE prophylaxis was administered to 1247 patients: patients weighing ≥120 kg received 325 mg aspirin twice daily (BID) and those weighing <120 kg received 81 mg aspirin BID for 4 weeks. In total, 1156 patients in the comparison cohort received 81 mg aspirin BID. VTE and gastrointestinal bleeding events were identified through chart review at 42 days and 6 months postoperatively. A multivariable logistic regression was performed to adjust for covariates.

RESULTS

The weight-based aspirin cohort had a significantly lesser incidence of VTE at 42 days (P = .03, relative risk [RR] 0.31, 95% confidence interval 0.12-0.82) and 6 months (P = .03, RR 0.38, 95% confidence interval 0.18-0.80). There was no difference in VTE incidence between total hip arthroplasty and total knee arthroplasty cases (P = .8). There was no difference in gastrointestinal bleeding events between the cohorts at 42 days (P = .69) or 6 months (P = .92). Subanalysis of patients weighing ≥120 kg demonstrated a significant difference between the cohorts with a VTE incidence of 3.48% and 0% in the 81 mg and weight-based cohorts, respectively (P = .02).

CONCLUSION

Patients prescribed a weight-based aspirin regimen had significantly fewer VTEs after TJA compared to historical controls with an RR reduction of 69% at 6 weeks and 62% at 6 months postoperatively. This suggests the need to factor patient weight when determining postoperative VTE prophylaxis with aspirin.

Hypercoagulable Disorders in Orthopaedics: Etiology, Considerations, and Management

»

Hypercoagulable disorders (HCDs) can be inherited or acquired. An HCD of either etiology increases the chance of venous thromboembolic events (VTEs).

»

Patients with an HCD often have the condition discovered only after surgical complications.

»

We recommend that patients with a concern for or a known HCD be referred to the appropriate hematological specialist for workup and treatment.

»

Tourniquet use in the orthopaedic patient with an HCD is understudied and controversial. We recommend that tourniquets be avoided in the surgical management of patients with an HCD, if possible. When tourniquets are applied to patients with unknown HCD status, close follow-up and vigilant postoperative examinations should be undertaken.

Postoperative venous thromboembolism event increases risk of readmissions and reoperation following total joint arthroplasty: a propensity-matched cohort study

PURPOSE

The clinical impact of postoperative venous thromboembolism (VTE) following total joint arthroplasty (TJA) remains unclear. In this study, we evaluate the effect of VTE following TJA on postoperative outcomes including discharge disposition, readmission rates, and revision rates.

METHODS

We retrospectively reviewed all patients over the age of 18 who underwent primary, elective THA or TKA between 2013 and 2020. Patients were stratified into two cohorts based on whether or not they had a VTE following their procedure. Baseline patient demographics and clinical outcomes such as readmissions and revisions were collected. Propensity score matching was performed to limit significant demographic differences, while independent sample t-tests and Pearson's chi-squared test were used to compare outcomes of interest between the groups.

RESULTS

After propensity score matching, there were 109 patients in each cohort, representing a total of 218 patients for the matched comparison. Prior to matching, the VTE cohort was noted to have a significantly higher BMI than the non-VTE cohort (32.22 ± 6.27 vs 30.93 ± 32.04 kg/m², p = 0.032). All other patient demographics were similar. Compared to the non-VTE cohort, the VTE cohort was less likely to be discharged home (66.1% vs 80.7%; p = 0.021), had a higher rate of 90-day all-cause readmissions (27.5% vs 9.2%, p = 0.001), and a higher two-year revision rate (11.0% vs 0.9%, p = 0.003).

CONCLUSION

Patients with postoperative VTE were less likely to be discharged home and had higher 90-day readmission and two-year revision rates. Therefore, mitigating perioperative risk factors, initiating appropriate long-term anticoagulation, and maintaining close follow-up for patients with postoperative VTE may play significant roles in decreasing hospital costs and the economic burden to the healthcare system.

LEVEL OF EVIDENCE III

Retrospective Cohort Study.

Low-Dose vs Regular-Dose Aspirin for Venous Thromboembolism Prophylaxis in Primary Total Joint Arthroplasty

BACKGROUND

Consensus on whether low-dose (81 mg) or regular-dose (325 mg) aspirin (ASA) is more effective for venous thromboembolism (VTE) chemoprophylaxis in primary total joint arthroplasties (TJAs) is not reached. The goal of this study is to evaluate the efficacy of low-dose and regular-dose ASA for VTE chemoprophylaxis in primary total hip arthroplasties and total knee arthroplasties.

METHODS

We retrospectively identified 3512 primary TJAs (2344 total hip arthroplasties and 1168 total knee arthroplasties) with ASA used as VTE chemoprophylaxis between 2000 and 2019. Patients received ASA twice daily for 4-6 weeks after surgery with 961 (27%) receiving low-dose ASA and 2551 (73%) receiving regular-dose ASA. The primary endpoint was 90-day incidence of symptomatic VTEs. Secondary outcomes were gastrointestinal (GI) bleeding events and mortality. The mean age at index TJA was 66 years, 54% were female, and mean body mass index was 31 kg/m². The mean Charlson Comorbidity Index was 3.5. Mean follow-up was 3 years.

RESULTS

There was no difference in 90-day incidence of symptomatic VTEs between low-dose and regular-dose ASA (0% vs 0.1%, respectively; P = .79). There were no GI bleeding events in either group. There was no difference in 90-day mortality between low-dose and regular-dose ASA (0.3% vs 0.1%, respectively; P = .24).

CONCLUSION

In 3512 primary TJA patients treated with ASA, we found a cumulative incidence of VTE <1% at 90 days. Although this study is underpowered, it appears that twice daily low-dose ASA was equally effective to twice daily regular-dose ASA for VTE chemoprophylaxis, with no difference in risk of GI bleeds or mortality.

LEVEL OF EVIDENCE

III, retrospective cohort study.

Aspirin Use for Venous Thromboembolism Prevention Is Safe and Effective in Overweight and Obese Patients Undergoing Revision Total Hip and Knee Arthroplasty

BACKGROUND

Venous thromboembolism (VTE), defined as pulmonary embolism or deep venous thrombosis, is a rare but serious complication following revision total hip arthroplasty (RTHA) and revision total knee arthroplasty (RTKA). Previous studies show that obesity may be associated with an increased risk for pulmonary embolism, wound complications, and infection. With no current universal standard of care for VTE prophylaxis, we sought to determine whether aspirin prescribed (ASA) is safe and effective in obese patients undergoing RTHA/RTKA.

METHODS

A retrospective review of 1578 consecutive RTHA/RTKA cases (751 RTHAs and 827 RTKAs) was conducted identifying patients prescribed 325 or 81 mg ASA. Ninety-day postoperative VTE rates, bleeding, wound complications, deep infections, and mortality were collected. Cohorts were stratified according to body mass index (BMI): normal (18-24.9 kg/m²), overweight (25-29.9 kg/m²), obese (30-34.9 kg/m²), severely obese (35-39.9 kg/m²), and morbidly obese (≥40 kg/m²).

RESULTS

The cohort comprised of 335 patients with a normal BMI, 511 were overweight, 408 obese, 232 severely obese, and 92 morbidly obese. Total VTE rates were statistically similar between BMI groups (0.90% vs 0.78% vs 0.74% vs 0.43% vs 0%, P = .89). There were no differences in bleeding rates (0.90% vs 0% vs 0% vs 0.43% vs 0%, P = .08), wound complications (0.30% vs 0.20% vs 0.25% vs 0% vs 0%, P = .93), infection (1.49% vs 1.57% vs 0.98% vs 1.29% vs 1.09%, P = .66), or mortality (0% vs 0.20% vs 0% vs 0% vs 0%, P = .72).

CONCLUSION

ASA is safe and effective for VTE prevention in obese patients with similar complication rates to nonobese patients undergoing RTHA/RTKA.

A Retrospective Analysis Comparing Post-Operative Bleeding with Various Doses of Aspirin after Lower Extremity Joint Arthroplasty or Revision

STUDY OBJECTIVE

Previous studies have shown that aspirin is noninferior to other anticoagulation therapies in preventing postoperative venous thromboembolism following lower extremity arthroplasty or revision; however, its optimal dosing for this indication is less clear. This study aims to compare the odds of bleeding between different aspirin dosages following lower extremity joint arthroplasty or revision.

DESIGN

This is a 3-year retrospective multi-center cohort study across the United States and its territories.

SETTING

This study included patients admitted for total hip or knee arthroplasty or revision and were treated with prophylactic aspirin.

PATIENTS, INTERVENTION, MEASUREMENTS

Patients were assigned to groups based on a total daily aspirin dose of 81, 162, 325, or 650 mg. Data were analyzed for postsurgical bleeding and thromboembolism events occurring during the initial admission and up to 40 days following surgery. Other exploratory variables included type of surgery, hip or knee arthroplasty, length of stay, and patient demographic data.

MAIN RESULTS

Among 53,848 patients receiving aspirin, 3922 received a total daily dose of 81 mg, 19,341 received a total daily dose of 162 mg, 5256 received a total daily dose of 325 mg, and 25,329 received a total daily dose of 650 mg. Bleeding occurred in 466 (0.87%) patients and venous thromboembolism (VTE) in 209 patients (0.39%). The odds of bleeding were compared using logistic regression, with the 650-mg dose as the reference group. None were statistically significant for bleeding between all studied aspirin doses: 81 mg (OR 1.12, 95% CI 0.83-1.51, p = 0.451), 162 mg (OR 0.83, 95% CI 0.67-1.03, p = 0.097), and 325 mg (OR 0.83, 95% CI 0.59-1.13, p = 0.245). The odds of VTE were also not statistically significant: 81 mg (OR 0.71, 95% CI 0.40-1.17, p = 0.181), 162 mg (OR 0.75 95% CI 0.54-1.03, p = 0.072), and 325 mg (OR 1.00, 95% CI 0.64-1.53, p = 0.989).

CONCLUSIONS

There were no significant differences in the odds of bleeding or venous thromboembolism among all studied aspirin dosages in patients receiving aspirin for thromboprophylaxis following lower extremity joint arthroplasty or revision.

Fibula Musculo-Osteocutaneous Flap with Full Thickness of Flexor Hallucis Longus Muscle

BACKGROUND

Fibula flap has been a gold standard method for reconstruction of the mandible. It has been used for reconstruction of maxilla as well as long bones, effectively. Fibula flap in selected cases has been used as a pedicled flap. The flexor hallucis longus muscle has been used to obliterate the dead space during the reconstruction. With a wide range of indications, the use of flexor hallucis muscle has studied for the reconstruction.

METHODS

In a retrospective case record analysis study, 38 subjects were enrolled, included 32 patients with reconstruction of mandible, 1 patient with reconstruction of maxilla, 4 patients with 3 free flaps and 1 pedicled flap with reconstruction of the tibia.

RESULTS

The success rate was 89%, with 4 flap failures. The muscle was used for reconstruction of the tongue, floor of the mouth, antrum, and to cover the fibula graft.

CONCLUSION

Flexor hallucis longus muscle harvested with the flap could decrease the operative time, ease the harvest, and fill the dead space during reconstruction.

One Size Does Not Fit All: Venous Thromboembolism Prophylaxis in Colorectal Cancer

Background and Objectives

Venous thromboembolisms (VTEs) in patients who have undergone a colorectal cancer operation increases morbidity and mortality, lengthens recovery time, and are costly. The current common standard is a 28-day prophylactic regimen of 40 mg enoxaparin daily. This study aims to examine the variability in prophylaxis discharge prescriptions at one institution, report 30-day postoperative incidence of venous thromboembolisms and bleeding, and to offer a new protocol for VTE prophylaxis in postoperative patients.

Methods

This retrospective case series occurred at Abington-Jefferson Health Hospital in Abington, PA. The electronic medical record was searched for patients who underwent an operation for colorectal cancer from October 2019 to mid-March 2020 and all discharge prophylaxis regimens were recorded and patient demographics were analyzed. Outcomes were measured by rate of VTEs and postoperative complications such as bleeding, transfusions, re-admission, and intensive care admission in the 30-day postoperative period.

Results

Eighteen of 57 patients received a medication besides 40 mg of enoxaparin daily. These 18 patients were divided into six different sub-groups of various prophylaxis regimens. No patients developed a venous thromboembolism. Four of 18 patients experienced postoperative bleeding complications.

Conclusions

Patients with similar pre-operative comorbidities have various venous thromboembolism perioperative prophylaxis regimens prescribed. Despite prescription variations, VTE rates remain negligible. Patients with different comorbid conditions may require alterations to the traditionally prescribed 40 mg enoxaparin daily. Upon discharge, aspirin 81 mg with 40 mg of enoxaparin daily for high-risk patients shows benefits, but requires further investigation.

An Update on Venous Thromboembolism Rates and Prophylaxis in Hip and Knee Arthroplasty in 2020

Patients undergoing total hip and knee arthroplasty are at high risk for venous thromboembolism (VTE) with an incidence of approximately 0.6-1.5%. Given the high volume of these operations, with approximately one million performed annually in the U.S., the rate of VTE represents a large absolute number of patients. The rate of VTE after total hip arthroplasty has been stable over the past decade, although there has been a slight reduction in the rate of deep venous thrombosis (DVT), but not pulmonary embolism (PE), after total knee arthroplasty. Over this time, there has been significant research into the optimal choice of pharmacologic VTE prophylaxis for individual patients, with the objective to reduce the rate of VTE while minimizing adverse side effects such as bleeding. Recently, aspirin has emerged as a promising prophylactic agent for patients undergoing arthroplasty due to its similar efficacy and good safety profile compared to other pharmacologic agents. However, there is no evidence to date that clearly demonstrates the superiority of any given prophylactic agent. Therefore, this review discusses (1) the current prevalence and trends in VTE after total hip and knee arthroplasty and (2) provides an update on pharmacologic VTE prophylaxis in regard to aspirin usage.

Incidence of Heterotopic Ossification in Direct Anterior Approach to Total Hip Arthroplasty with use of Aspirin as Thromboembolic Prophylaxis

CONTEXT

Heterotopic ossification (H.O.) is a common occurrence after total hip arthroplasty (THA) with significant potential clinical ramifications. Controversy still exists regarding the exact etiology of the disorder, including possible risk factors. Surgical technique, surgical approach, postoperative medication protocols and even thromboembolic prophylaxis have been implicated in the formation of H.O. Our study looked at one institution with a single surgeon performing direct anterior THA (DAA THA) in patients who received aspirin (ASA) as monotherapy for thromboembolic prophylaxis.

METHODS

Patients at a single institution who underwent DAA THA between 2015 and 2019 were identified by CPT code. 45 patients ultimately met inclusion criteria. Postoperative radiographs were analyzed retrospectively for H.O. according to the Brooker classification. Several patient characteristics and comorbidities were statistically analyzed using Chi-square tests, Fisher Exact tests, Wilcox rank sum tests, and Pearson correlation.

RESULTS

12 patients (26.7%) were found to have heterotopic ossification (67% Class 1, 8% Class 2, 25% Class 3, and 0% Class 4); with a median follow up of 35 weeks (range: 12-96). 25% of these patients received ASA 325mg BID while 75% received ASA 81 BID. No statistical differences in development of H.O. were detected among age, gender, BMI, sex, race, diabetes, or NSAID use in the post-operative interval. There were significantly more smokers in the H.O. group (50% vs. 9%, p<0.006).

CONCLUSIONS

Our analysis aimed to quantify the incidence of H.O. with consistency in surgical approach and post-operative protocol. There have been few studies on this topic, and we believe it is very relevant with the increasing use of aspirin in the post-operative protocol for thromboembolic prophylaxis. Our retrospective analysis identified H.O. at rates similar to previous studies in DAA.

Stratifying Venous Thromboembolism Risk in Arthroplasty: Do High-Risk Patients Exist?

BACKGROUND

While there are many possible complications associated with total joint arthroplasty (TJA), venous thromboembolism (VTE) is both frequent and potentially severe. Despite this importance, there are inconsistent recommendations for prophylaxis based on patient risk factors.

METHODS

A predictive model was constructed to compare low-molecular-weight heparin(LMWH) and aspirin (ASA) for prevention of VTE-associated complications following TJA.The model used risks from prior prophylaxis studies to estimate the risk of developing a symptomatic deep vein thrombosis, pulmonary embolism, thrombocytopenia, and operative or nonoperative site bleeding. We also evaluated the progression to 4 possible final health states: postphlebitis syndrome, intracranial hemorrhage, death, or baseline health. Within published ranges, we selected assumptions that were favorable to LMWH such that these analyses represent a best case scenario for LMWH or an alternative more aggressive low-molecular-weight heparin alternative (LMWHA). Events and outcomes were assigned quality-adjusted life-year (QALY) losses according to prior studies to determine the effect on patients' outcomes for ASA and LMWHA prophylaxis.

RESULTS

Assessing VTE risk populations from 0.2% to 2% with life expectancies ranging from 5 to 40 years postoperatively, patients with a risk ratio less than 3.7 showed increased expected QALY with ASA compared to LMWHA. For patients with a baseline VTE risk of 1% and a 15 year life expectancy, a risk ratio of 13.4 was needed to identify patients that would benefit from LMWHA. With life expectancy increased to 30 years, the risk ratio needed to idetify these patients was 7.4.

CONCLUSION

Patients undergoing TJA should receive ASA chemoprophylaxis in nearly all situations, unless the patient has a significantly increased VTE risk compared to the baseline population and a long life expectancy.

Have Venous Thromboembolism Rates Decreased in Total Hip and Knee Arthroplasty?

BACKGROUND

Venous thromboembolism (VTE) is a major cause of morbidity, mortality, and healthcare costs in arthroplasty patients. In an effort to reduce VTEs, numerous strategies and guidelines have been implemented, but their impact remains unclear. The purpose of this study is to compare annual trends in 30-day VTE, deep vein thrombosis (DVT), pulmonary embolism (PE), and all-cause mortality in (1) total hip arthroplasty (THA) and (2) total knee arthroplasty (TKA).

METHODS

The American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database identified 363,530 patients who received a TKA or THA from 2008 to 2016. Bivariate analysis was performed to assess the association between the year in which surgery was performed and demographics and comorbidities. Bimodal multivariate logistic regression models for THA and TKA were developed for 2009-2016 using 2008 as a reference.

RESULTS

Overall incidence of VTE, DVT, PE, and mortality for THA were 0.6%, 0.4%, 0.3%, and 0.2%, respectively. Based off of multivariate regression VTE, DVT, PE, and mortality rates have shown no significant (P > .05) change from 2008 to 2016 in THA patients. Overall incidence of VTE, DVT, PE, and mortality for TKA were 1.4%, 0.9%, 0.6%, and 0.1%, respectively. Multivariate regression revealed reductions when compared to 2008 for VTEs and DVTs from 2009 to 2016 (P < .05) for TKA patients. A significant reduction in PEs (P = .002) was discovered for 2016, while no significant change was observed in mortality (P > .05).

CONCLUSION

Approximately 1 in 71 patient undergoing TKA, and 1 in 167 undergoing THA developed a VTE within 30 days after surgery. Our study demonstrated that VTE incidence rates have decreased in TKA, while remaining stable in THA over the past 8 years. Further research to determine the optimal prophylaxis algorithm that would allow for a personalized, efficacious, and safe thromboprophylaxis regimen is needed.

LEVEL OF EVIDENCE

III.