Biology of Injury and Repair of Soft Tissues of the Shoulder

Soft tissue injuries in the shoulder, especially to the rotator cuff tendons, are a common source of shoulder pain and dysfunction. Intrinsic pathological changes in the rotator cuff tendon often lead to diminished tendon quality and eventual rotator cuff tendinosis and tearing. Understanding the native biology of the rotator cuff, the effect of aging on tendon quality, the intrinsic and extrinsic factors that may play a role in tendon degeneration, and the biology of tendon healing is critically important for a comprehensive approach to the management of rotator cuff disease. Specifically, common hormones, proteins, and growth factors that affect degeneration and healing of the rotator cuff may offer potential targets for biological treatments. The current chapter provides an in-depth review of the biological processes during injury and repair of the soft tissues about the shoulder joint with a special emphasis on the rotator cuff.