HIP Fracture Oral thromboPROphylaxis (Hip PRO Pilot)

• Status: Not yet recruiting
• Trial end date: 2026-03-01
• Target enrollment: 0
• Participant gender: All

Summary

As our Canadian population ages, hip fractures in these older adults are becoming very common. The best treatment for the majority of these injuries is urgent treatment with surgery. However, the hip fracture itself, the surgery required, and the immobility following these injuries are all risk factors for developing blood clots in the legs (deep vein thrombosis or DVT) and blood clots in the lungs (pulmonary embolism or PE). These complications are a common cause of death in patients with hip fractures and often result in prolonged medical treatment and hospital stays.

Patients with hip fractures who require surgery are traditionally given injectable blood thinners to help prevent blood clots; however, these medications are costly, may not be tolerated well, and can be difficult to take, as prescribed. Oral blood thinning medications are being used more commonly, but it is unknown which of these medications is the most effective in preventing blood clots in patients after a hip fracture.

Thrombelastography (TEG) technology uses a small sample of blood to evaluate a person's clotting ability. Our research has used TEG technology to evaluate blood clotting risk after hip fracture surgery and the investigators have found that platelets may play an important role in abnormal blood clotting after a hip fracture. The investigators have also shown that acetylsalicylic acid (ASA or Aspirin) may help reduce the abnormal platelet hyperactivity associated with blood clotting. This medication warrants investigation for blood clot prevention after hip fracture.

The investigators propose to directly compare different oral medication regimens after hip fracture surgery, in order to determine which is safest and most effective in preventing blood clots. Our multi-disciplinary research team includes physicians, surgeons, and scientists with experience evaluating different medications for blood clot prevention. Our results will help determine the best medical treatment for preventing DVT and PE, which will benefit patients with hip fractures worldwide.

• Phase: Phase 3
• Accepts Healthy Volunteers?: No

Details

• Lead Sponsor: University of Calgary
• Collaborator: Canadian Institutes of Health Research (CIHR)
• Treatments: Aspirin; Rivaroxaban

Criteria

Inclusion Criteria:

Patients aged 50 years or older with an acute hip fracture (presentation to hospital within 24 hours of injury) that requires surgical treatment will be approached for inclusion in the study:

1. Age ≥ 50 years with a hip fracture (AO-OTA classification 31-A1-A3 and 31-B1-B3) amenable to surgical treatment (presentation to hospital within 24 hours of injury). Patients with additional injuries will be included and any additional injuries will be documented.

2. Both open and closed fractures will be included, and open fractures will be documented.

3. Patients on single agent anti-platelet therapy (i.e., acetylsalicylic acid or clopidogrel) will be included.

4. Signed informed consent or surrogate consent to participate in study.

Exclusion Criteria:

1. Delayed presentation (over 24 hours between hip fracture and presentation to hospital).

2. Pathological fractures secondary to primary cancer or metastatic bone disease.

3. Peri-prosthetic femur fractures.

4. Received more than two doses of any thromboprophylaxis agent post-operatively, prior to randomization.

5. Pre-hospital therapeutic intensity antithrombotic therapy, including LMWH, Warfarin, DOACs, clopidogrel/ticagrelor, or chronic ASA use of any dose in the three months prior to hip fracture.

6. Known inherited bleeding or clotting disorder (factor V Leiden gene mutation, prothrombin gene mutation, protein C or protein S deficiency, antithrombin deficiency).

7. Intracranial hemorrhage requiring serial CT scans of the brain and/or surgical intervention.

8. Contraindication to ASA use (allergy, documented gastrointestinal ulcer within the past year, severe thrombocytopenia [platelet count <50 x109/L at the time of hospital admission]).

9. Contraindication to rivaroxaban use (allergy, acute renal failure [CrCl <30 mL/min]).

10. Participant or surrogate unable to or unwilling to provide consent or complete follow-up. Or surrogate consent not available.

11. Under age 50 years (more likely high energy, multiple injuries).

12. Multiply injured patients who require prolonged thromboprophylaxis or delayed thromboprophylaxis initiation.

13. Patient unable to attend follow-up visits.

14. Currently incarcerated, at a correctional facility.