An overview in tendon's physiology, pathomorphology, and treatment options

Tendon degeneration and tendinopathy are common musculoskeletal disorders characterized by chronic pain, impaired function, and structural changes within the tendon. A cascade of pathological changes appears due to several risk factors such as ageing, overuse, obesity, or specific medications. Among these changes are collagen disorganization, neovascularization, altered extracellular matrix composition, and changes in cellular components. Recent studies have highlighted the role of tenocyte apoptosis, matrix metalloproteinase activity, and mechanical stress in the progression of tendinopathy. Biomechanically, a tendon is under elastic and plastic changes in higher amounts of stress. Healing of tendons is divided into three overlapping phases: inflammation, proliferation/repair, and remodeling. Treatment remains challenging, with current strategies ranging from conservative approaches such as eccentric loading and physical therapy to regenerative interventions like platelet-rich plasma (PRP), stem cell therapies, injectable corticosteroids, and low-energy laser therapy. Understanding the underlying biological mechanisms of tendon degeneration is critical for developing targeted therapies and improving long-term outcomes.