Atrophy

Atrophy is the reduction in the volume and mass of an organ, tissue, or cellular population, which may result from a decrease in the size of individual cells, a reduction in their number, or both, leading to a gradual decline in the functional capacity of the affected structure. In the context of orthopedics, atrophy most commonly involves muscle tissue and primarily results from prolonged disuse, as occurs after immobilization due to a fracture or surgical intervention, from chronic pain that limits movement, or from neurological damage that disrupts the innervation of a muscle. Beyond muscle atrophy, orthopedic practice may also involve atrophy of bone tissue, known as osteoporosis or osteopenia, which is associated with reduced bone density and an increased risk of fractures, as well as atrophy of other soft tissues, such as cartilage, in the context of chronic degenerative conditions. Atrophy is classified into physiological, such as that associated with aging, and pathological, which develops as a result of a specific disease, injury, or prolonged immobilization, while its degree of reversibility depends largely on the cause and duration of the underlying condition. Its management is based on the early identification and treatment of the underlying cause, as well as on a targeted physiotherapy program with progressive mobilization and strengthening, aiming, where possible, at restoring the normal mass and function of the affected tissue.