Comparison of DOACs and LMWH for Thromboprophylaxis After Total Knee Arthroplasty

NCT07869615 | Recruiting

• 1 other identifier: DOLOTHROK-2026
• Study Type: interventional
• Target: 138
• Locations: 1 country
• Sites: 1

Brief Summary

Yes. For these two fields, I would enter the following in English, based on your study protocol. 1\. Brief Summary Copy and paste: This study aims to compare three thromboprophylaxis regimens in adults undergoing primary total knee arthroplasty: rivaroxaban 10 mg once daily, apixaban 2.5 mg twice daily, and low-molecular-weight heparin (LMWH) once daily. The study will assess venous blood flow in the lower limbs using Doppler ultrasound and determine whether blood flow differs between the three treatment groups. Participants will be randomly assigned to one of the three treatment groups and followed for 28 days after surgery. Doppler ultrasound examinations will be performed at baseline and on Days 7, 15, 21, and 28. Additional assessments will include rehabilitation progress, postoperative bleeding, suspected venous thromboembolism, cardiovascular complications, and other postoperative complications. The study is being conducted at the Department of Anesthesiology, Principal Military Hospital of Instruction of Tunis.

Conditions

Venous Thromboembolism Prevention After Total Knee Arthroplasty

Keywords

Total Knee Arthroplasty; Thromboprophylaxis; Venous Blood Flow; Doppler Ultrasound; Rivaroxaban; Apixaban; Low-Molecular-Weight Heparin; Venous Thromboembolism

Outcome Measures

Primary Outcomes (1)

• Peak Systolic Velocity (PSV) of Major Lower-Limb Veins

  Peak systolic velocity (PSV) of major lower-limb veins measured by duplex Doppler ultrasound and compared between participants receiving apixaban twice daily, rivaroxaban once daily, or LMWH.

  Within 28 days after total knee arthroplasty

Secondary Outcomes (8)

• Time-Averaged Mean Velocity (TAMEAN)

  Within 28 days after surgery

• Venous Flow Volume

  Within 28 days after surgery

• Respiratory Phasicity

  Within 28 days after surgery

• Distal Augmentation

  Within 28 days after surgery

• Visible Intraluminal Sludging

  Within 28 days after surgery

Study Arms (3)

Apixaban

EXPERIMENTAL

Participants receive apixaban 2.5 mg twice daily for 14 days.

Drug: Apixaban

Rivaroxaban

EXPERIMENTAL

Participants receive rivaroxaban 10 mg once daily for 14 days.

Drug: Rivaroxaban

LMWH

ACTIVE COMPARATOR

Participants receive enoxaparin 40-60 mg once daily, weight-adjusted, for 14 days.

Drug: Enoxaparin (LMWH)

Interventions

Apixaban DRUG

Apixaban 2.5 mg twice daily, starting 24 hours after surgery, for 14 days. Participants receive initial LMWH prophylaxis 6 hours after surgery before starting the assigned regimen.

Apixaban

Rivaroxaban DRUG

Rivaroxaban 10 mg once daily, starting 24 hours after surgery, for 14 days. Participants receive initial LMWH prophylaxis 6 hours after surgery before starting the assigned regimen.

Rivaroxaban

Enoxaparin (LMWH) DRUG

Enoxaparin 40-60 mg once daily, weight-adjusted, starting 6 hours after surgery, for 14 days.

LMWH

Eligibility Criteria

• Age: 18 Years - 80 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Adults aged 18 years or older undergoing elective primary unilateral total knee arthroplasty.
• Able to provide informed consent.

You may not qualify if:

• Allergy or contraindication to the study medications.
• Requirement for long-term therapeutic anticoagulation.
• Requirement for antiplatelet therapy.
• Pregnancy or lactation.
• Active cancer or cancer treatment.
• Documented previous venous thromboembolism in the target limb.
• Hypercoagulable state.
• BMI \>40 kg/m².
• Severe inflammatory disease.
• Age \>80 years.
• Inability to comply with follow-up.
• Incomplete data.

Sponsors & Collaborators

• Military Hospital of Tunis: lead

Study Sites (1)

Principal Military Hospital of Instruction of Tunis

Tunis, Tunis Governorate, Tunisia

RECRUITING

MeSH Terms

Conditions

Venous Thromboembolism

Interventions

apixaban; Rivaroxaban; Enoxaparin; Heparin, Low-Molecular-Weight

Condition Hierarchy (Ancestors)

Thromboembolism; Embolism and Thrombosis; Vascular Diseases; Cardiovascular Diseases

Intervention Hierarchy (Ancestors)

Thiophenes; Sulfur Compounds; Organic Chemicals; Morpholines; Oxazines; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds; Heparin; Glycosaminoglycans; Polysaccharides; Carbohydrates

Central Study Contacts

Haythem Elaskri

CONTACT

54015050; haythem.elaskri@fmt.utm.tn

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Masking Details: The Doppler specialist performing the ultrasound assessments will be blinded to the participant's anticoagulation regimen.
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Participants will be randomly assigned to one of three parallel thromboprophylaxis groups following primary total knee arthroplasty: rivaroxaban 10 mg once daily, apixaban 2.5 mg twice daily, or LMWH once daily. Participants will be followed for 28 days, with Doppler ultrasound assessments performed at baseline and on Days 7, 15, 21, and 28.

Study Record Dates

• First Submitted: October 4, 2026
• First Posted: October 9, 2026
• Study Start: September 15, 2026
• Primary Completion (Estimated): April 15, 2027
• Study Completion (Estimated): April 15, 2027
• Last Updated: October 9, 2026

Record last verified: 2026-10

Data Sharing

• IPD Sharing: Will not share

Locations

TU (1)