Regenerative properties of bone marrow mesenchymal stem cell derived exosomes in rotator cuff tears

In recent years, the growing prevalence of physical exercise and fitness has been accompanied by an escalating risk of musculoskeletal injuries. Consequently, tendon-bone injuries have become increasingly common, particularly in sports and other high-intensity physical activities. Among these, rotator cuff injuries (RCI) represent the most prevalent form of tendon-bone trauma. In the United States alone, approximately 200,000 rotator cuff repairs are performed annually, underscoring the widespread impact of this condition [ 1 , 2 , 3 , 4 , 5 , 6 ]. Current clinical treatment protocols for RC usually follow a graded treatment strategy with conservative treatment followed by surgical intervention if necessary. Initial management of RC usually includes conservative measures aimed at reducing pain and inflammation while promoting healing and maintaining function. Examples include rest and activity modification, physical therapy, nonsteroidal anti-inflammatory drugs (NSAIDs), and corticosteroid injections, where patients may face complications such as cardiovascular disease, gastrointestinal disorders, or diabetes mellitus when using NSAIDs or corticosteroids for long periods of time [ 7 , 8 , 9 ]. Conservative treatment of RC has the advantage of being non-invasive, avoids the risk of surgery, and is indicated for mild to moderate injuries, with gradual restoration of function, primarily through therapeutic physics, medications, and injections. However, patients vary from person to person, and severe tears or chronic injuries additionally have limited recovery and higher risk [ 10 , 11 ]. Surgery may be necessary for patients who do not respond to conservative treatment within 6 to 12 months, or for patients with complete tears. Clinically RC enthesis injuries are usually treated surgically with tendon/ligament reconstruction, which involves inserting a tendon graft into a bone tunnel in order to establish tendon-to-bone healing. In spite of that, re-injuries after surgical reconstruction are extremely high, and 94% of repaired RCs re-tear after surgery [ 12 , 13 ].