Ankylosing Spondylitis is a chronic inflammatory disease characterised by pain and progressive stiffness. It involves spine and proximal large joints such as hips and shoulders. It is part of a group of rheumatic diseases termed seronegative spondyloarthropathies. Ankylosing spondylitis is seronegative because a rheumatoid factor is not detected in the patient’s blood. Ankylosing spondylitis is considered to be hereditary, although environmental factors have been suggested. HLA-B27 antigen may be positive in theses patients.

Onset typically occurs between the ages of 15 and 45. In the early stages of the disease, the sacroiliac joints become inflamed and painful. As the disease progresses, ossification is triggered by the body’s defense mechanism. Ossification causes new bone to grow between vertebrae eventually fusing them together increasing the risk for fracture. Patients develop deformity called kyphosis. Their vision may get restricted due to the deformity in spine. The breathing capacity is also restricted due to involvement of joints of rib cage.

Plain radiographs show fusion of the spine due to new bone formation. It is called as “bamboo spine”. The hips may show ankylosis.

This condition is treated with physiotherapy, exercises, non-steroidal anti-inflammatory drugs and disease modifying drugs.  Newer drugs which modify immune responses have shown to be beneficial in these patients. Patients with severe deformity may need corrective surgery called spinal osteotomy. Fractures in Ankylosing Spondylitis need internal fixation as they do not heal well.