A Phase 4 interventional study of Losartan and Placebo in ACL Injury, ACL Reconstruction and Scar Formation, sponsored by Rush University Medical Center. Not yet recruiting at 1 site in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-12-15.
Sponsored by Rush University Medical Center · Phase 4, Interventional, and Other
The purpose of this study to investigate the effect of using losartan (a blood pressure lowering drug with anti-scarring properties) on preventing primary postoperative arthrofibrosis (formation of abnormal scar tissue) in the knees in participants undergoing anterior cruciate ligament (ACL) repair surgery of their knee.
Losartan, an angiotensin-II receptor blocker (ARB), approved by the Food and Drug Administration (FDA) for the treatment of hypertension and diabetic nephropathy, has garnered recent interest in the field of orthopedic surgery as an anti-fibrotic (anti-scarring) agent. Losartan's primary mechanism of action as an anti-hypertensive involves acting as a receptor antagonist for angiotensin II, a peptide produced by the liver which causes vasoconstriction, release of anti-diuretic hormone from the pituitary gland, and release of aldosterone from the adrenal glands, among other functions. Losartan secondary function is to act as a TGF-β1 blocker. TGF-β1 has been implicated in pro-fibrotic pathways in multiple organs systems. Losartan, initially as a treatment for hypertension and diabetic nephropathy, was found to have benefits against fibrosis in the renal system. As a result, the use of losartan has gained interest in several other fields in medicine, including plastic surgery for wound healing and keloid prevention, in ophthalmology to prevent corneal scarring, and orthopedic surgery. The potential use of losartan presents an attractive anti-fibrotic prophylaxis candidate against the formation of postoperative arthrofibrosis following ACLR.
512 studies on the registry are indexed under Anterior Cruciate Ligament Injuries; 164 are open to participants now.
This study's planned enrollment of 144 is above the median of 56 across 373 interventional studies indexed under Anterior Cruciate Ligament Injuries.
Browse Anterior Cruciate Ligament Injuries studies →Rush University Medical Center is the lead sponsor of 394 studies on the registry; 61 are open to participants now.
Of its 30 completed or terminated interventional studies of FDA-regulated products, 25 (83%) have results posted.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
The experimental arm (Arm 1) will receive 25mg losartan daily for 3 days followed by 50 mg losartan daily for 25 days.
Drug: Losartan
The placebo arm (Arm 2) will receive a placebo tablet with the same appearance and frequency to that of the losartan group.
Other: Placebo
Two types of losartan capsules will be compounded by combining a broken-up 25mg or 50mg losartan tablet and microcrystalline cellulose placebo filler to eliminate rattling of the broken tablet inside of the capsule. The 25mg losartan capsules will be yellow and the 50 mg losartan capsules will be blue.
The placebo capsules will consist of microcrystal cellulose and will come in yellow and blue to appear identical to the losartan capsules.
Range of Motion
Range of motion measured from baseline to 12 months
Time frame: 12 months
Documents are hosted by the registry — open the source record to download them.
This study is not yet recruiting, as verified in Dec 2025. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Anterior Cruciate Ligament Injuries→
Rush University Medical Center