Baastrup's Disease: a poorly recognised cause of back pain.
A 56-year-old male complained about progressive mechanical back pain for more than 10 years, which worsened with prolonged orthostatism and spine extension and improved in fetal position. His lumbar spine radiography revealed enlargement and sclerosis of the spinous processes which was confirmed by computed tomography, suggesting Baastrup's disease. This condition is characterized by enlargement, close approximation and impingement of one spinous process on another ("kissing spines"). There are few studies on Baastrup´s disease epidemiology and their results are inconsistent. Patients often complain of back pain, typically increased with extension and relieved by flexion. Radiographically, spinous process impingement leads to reactive sclerosis, enlargement, flattening, and remodeling of the involved vertebral spines. Physicians frequently miss it on radiographs due to lack of knowledge and overexposure of spinous processes in most X rays. Both conservative and surgical options are available for treatment. Baastrup's disease should be considered in differential diagnosis of back pain, although one must be aware the typical radiographic changes appear to be common with aging and may not be the cause of patient's symptoms.