Effects of Losartan on Musculoskeletal Tissues : Basic Science and Clinical Applications.

BACKGROUND: Fibrosis is a prevalent impediment to musculoskeletal healing, which contributes to poor outcomes across orthopaedic procedures and remains largely underaddressed in orthopaedic care.

PURPOSE: To review the effects of losartan on fibrosis across musculoskeletal tissues, and to evaluate its mechanistic rationale, preclinical outcomes, delivery strategies, and translational potential in orthopaedic practice.

CONTENT SUMMARY: Losartan inhibits transforming growth factor beta 1 signaling by antagonizing the angiotensin II type 1 receptor, thereby reducing myofibroblast activity, limiting extracellular matrix deposition, and preserving regenerative cell populations across musculoskeletal tissues. Preclinical models demonstrate histological and mechanical improvements in models of cartilage injury, joint capsule fibrosis, tendon-bone healing, and skeletal muscle regeneration. Therapeutic efficacy is strongly influenced by timing, delivery route, and the microenvironment of the injury. Biomaterial innovations such as nanofiber scaffolds and injectable angiotensin II receptor blocker (ARB) hydrogels may enhance delivery. Further studies stratifying outcomes by age and sex are warranted. Ongoing clinical trials are evaluating losartan for arthrofibrosis, skeletal muscle disorders, and comparative antifibrotic efficacy among ARBs.

CONCLUSION: Losartan offers a mechanistically targeted, clinically familiar antifibrotic therapy with strong potential to improve surgical and rehabilitative outcomes in orthopaedics.