Ankylosing spondylitis is a chronic inflammatory rheumatic disease belonging to the group of seronegative spondyloarthropathies. It primarily affects the sacroiliac joints and the spine, causing progressive inflammation of the vertebrae, intervertebral discs, and spinal ligaments.
Persistent inflammation gradually leads to ossification of the ligaments and the formation of bony bridges between adjacent vertebrae, known as syndesmophytes. This process results in progressive fusion and stiffness of the spine, particularly in advanced stages of the disease.
The condition occurs most commonly in young adults, especially men, and is strongly associated with genetic predisposition, particularly the presence of the HLA-B27 histocompatibility antigen.
The main symptoms include chronic lower back pain and stiffness, which are typically more severe in the morning or after prolonged periods of inactivity and improve with movement. As the disease progresses, reduced spinal mobility may develop.
Ankylosing spondylitis may also affect peripheral joints, such as the hip and shoulder, as well as extra-articular structures, including the eyes (uveitis) and, less commonly, the heart or lungs.
Diagnosis is based on clinical history, physical examination, imaging studies (such as X-rays or magnetic resonance imaging of the sacroiliac joints), and laboratory investigations. Treatment includes physical therapy with targeted mobility and posture exercises, non-steroidal anti-inflammatory drugs (NSAIDs), and, in more severe cases, biological agents aimed at controlling the underlying inflammatory process.