Ankylosing spondylitis (AS) is a chronic inflammatory disease that causes deterioration in the function of the spine and peripheral
joints. In addition to history and examination, imaging is important in diagnosing this disease. Pelvic X-rays in particular may show
pseudo widening, erosion, and sclerosis sacroiliac joint. Spinal X-rays may also identify syndesmophytes. In more advanced stages,
the spine may also be involved, forming a specific type of disease called “bamboo spine”. The New York criteria, which includes
radiologic and clinical criteria, are used to diagnose AS. The distribution of involvement in joints and bones in AS varies, but
classically, it is ascending from the sacroiliac joint, lumbar, and thoracic region.
Herein, we report a case of AS that was undiagnosed for 5 years. Despite the normal appearance of the sacroiliac joint, severe
involvement of the spinal column in the thoracic region known as “bamboo spine” was observed. The time order of bone
involvement in this patient is contrary to what is usually seen.
Based on the New York criteria for AS, the case under discussion is not included in the AS definition; however, the patient had
clinical symptoms of AS, bamboo spine, and showed a dramatic response to treatment of AS.
Heeding the course of the AS as well as the clinical signs and imaging results of various areas (heart, lumbar spine, and sacroiliac
joint) will help physicians diagnose AS accurately and in a timely manner. Also, the radiologic manifestation of a rheumatologic
disease may occur without any predictable order.