Editorial Commentary: Biologics Injections for Partial-Thickness Rotator Cuff Tears Show Promise.

Partial-thickness rotator cuff tears (PTRCTs) are difficult to treat. Conservative treatment typically includes physical therapy, nonsteroidal anti-inflammatory drugs, and injectables (e.g., corticosteroid injections, hyaluronic acid, platelet-rich plasma [PRP], stem cells). Recent studies have demonstrated that PRP alone or in combination with other injectables (e.g., PRP + hyaluronic acid) provides a positive short-term therapeutic benefit in patients with PTRCTs. Yet, effects tend to diminish after 1 year. Up to 42% of patients with PTRCTs treated conservatively exhibit tear progression necessitating surgical intervention, and some research shows that PRP may inhibit tendon regeneration. The efficacy and safety of PRP preparations and concentrations can vary, and the optimal biologic injectable and formulation is unknown. Yet, preoperative corticosteroid injections can increase risk of infection after shoulder arthroscopy; thus, continued investigation of biologic injection for rotator cuff tears is indicated.