The Risk of Venous Thromboembolism is Not Equal for all Patients Who Undergo Total Joint Replacement

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.

Prevention of venous thromboembolism with aspirin following knee surgery: A systematic review and meta-analysis

Venous thromboembolism (VTE) is a well-known complication following orthopaedic surgery. The incidence of this complication has decreased substantially since the introduction of routine thromboprophylaxis. However, concerns have been raised about increased bleeding complications caused by aggressive thromboprophylaxis.Attention has grown for aspirin as a safer thromboprophylactic agent following orthopaedic surgery.A systematic review using MEDLINE, Embase and Web of Science databases was undertaken to compare the effectiveness of aspirin prophylaxis following knee surgery with the current standard prophylactic agents (low molecular weight heparin [LMWH], vitamin K antagonists and factor Xa inhibitors).No significant difference in effectiveness of VTE prevention was found between aspirin, LMWH and warfarin. Factor Xa inhibitors were more effective, but increased bleeding complications were reported.As evidence is limited and of low quality with substantial heterogeneity, further research with high-quality, adequately powered trials is needed. Cite this article: EFORT Open Rev 2021;6:892-904. DOI: 10.1302/2058-5241.6.200120.

The Incidence of Venous Thromboembolism Following Pelvic and Lower Extremity Trauma Despite Adherence to Modern Prophylactic Protocols

OBJECTIVES

Describe the incidence of venous thromboembolism (VTE) in patients with pelvic and lower extremity long bone trauma in the setting of modern prophylaxis.

DESIGN

Retrospective health-system database study.

SETTING

Multi-center health care system.

PATIENTS

Database query from 2010 to 2017 identified 11,313 adult trauma patients who received open reduction internal fixation of pelvic, acetabular, femoral neck, or intertrochanteric fractures, or received intramedullary nailing (IMN) of the femoral or tibial shaft. Patients with incomplete prophylaxis, prior history of VTE, coagulopathy, or concomitant lower extremity fracture were excluded.

INTERVENTION

Mechanical and chemical VTE prophylaxis following pelvic or lower extremity fracture fixation.

MAIN OUTCOME MEASUREMENTS

VTE rates.

RESULTS

The overall VTE rate was 0.82% [0.39% deep venous thromboses (DVT); 0.43% pulmonary emboli (PE)]. By procedure, pelvic open reduction and internal fixation (ORIF) and femoral IMN had the highest VTE rates 1.70% (0.98% DVT; 0.78% PE) and 1.33% (0.75% DVT; 0.58% PE), whereas tibial IMN had the lowest incidence of VTE 0.34% (0.17% DVT; 0.17% PE). Among hip fractures, femoral neck ORIF had a VTE rate of 0.98% (0.59% DVT; 0.39% PE), whereas intertrochanteric ORIF had lower rates of 0.59% (0.20% DVT; 0.39% PE).

CONCLUSIONS

Despite adherence to modern VTEp protocols, nonpreventable VTE occur in 0.82% of pelvic and lower extremity orthopaedic trauma patients. Incidence ranged between 0.34% and 1.70% depending on injury/fixation method with the highest rate observed in pelvis ORIF followed by femoral IMN. In the era of pay for quality performance, it is important for health systems and auditing agencies to reconcile the difference between preventable and nonpreventable VTEs.

LEVEL OF EVIDENCE

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