ENhanced Recovery and ABbreviated LEngth of Anticoagulation for Thromboprophylaxis After Primary Hip Arthroplasty
Surgical hip replacement (total hip arthroplasty, THA) is associated with a high risk of venous thromboembolism, but the appropriate duration of postoperative medical thromboprophylaxis (anticoagulation) remains highly controversial. The international randomized controlled trial (RCT) ENhanced recovery and ABbreviated LEngth of Anticoagulation for Thromboprophylaxis after primary Hip Arthroplasty (ENABLE-Hip) will enroll patients undergoing elective THA that are eligible for early mobilization after surgery. The trial will compare a regimen of short-duration (10-day) postoperative anticoagulation (experimental group) to standard-duration (35-day) postoperative anticoagulation (control group) using the direct oral anticoagulant Rivaroxaban (brand name: Xarelto) at the recommended dose. Thus, ENABLE-Hip will be the first major RCT to directly test an overall reduction in the duration of post-THA thromboprophylaxis instead of replacing one antithrombotic drug or regimen by another. Follow-up visits after hospital discharge will be on day 35 and on day 90 after surgery. The primary outcome is acute symptomatic proximal deep vein thrombosis, or symptomatic or fatal pulmonary embolism, within 90 days after surgery. If ENABLE-Hip will demonstrate 'non-inferiority' of the experimental intervention, its benefits will be obvious, as patients are spared many days of unnecessary (and potentially harmful in terms of bleeding risk) anticoagulation.
• Written informed consent
• Age between 18 and 85 years
• Scheduled to undergo elective unilateral primary THA and eligible for perioperative management based on the ERAS protocol
• Baseline Timed Up and Go (TUG) test scoring \< 20 seconds, corresponding to a good mobility status before surgery
• Capability to understand and comply with the protocol requirements (e.g., sufficient knowledge of German language to answer the questionnaires, ability to swallow intact capsules).
• Pregnancy and contraception:
‣ Pregnancy test: Negative serum pregnancy test at screening for women of childbearing potential (WOCBP).
⁃ Contraception: WOCBP and men who are able to father a child, willing to be abstinent or use highly effective methods of birth control that result in a low failure rate of less than 1% per year when used consistently and correctly beginning at informed consent, for the duration of drug treatment and allowing for a safe wash out period of at least 5 days for female or for male subjects after the last dose of trial medication. This is a very conservative estimate, considering the 'worst case scenario' of a substantially prolonged half-life up to 13 hours (e.g., in older patients and/or those with renal dysfunction) (28), and calculating for at least 8 half-lives to ensure practically non-detectable levels and effects of rivaroxaban.