Baastrup's disease (kissing spines syndrome): a pictorial review

Excessive lordosis is a common finding and may produce mechanical pressure that causes repetitive strains of the interspinous ligament with subsequent degeneration and collapse. Baastrup's disease (kissing spine syndrome) is a term referring to close approximation of adjacent spinous processes due to degenerative changes of the spine. Baastrup's disease usually affects the lumbar spine, with L4-L5 being the most commonly affected level. There is higher occurrence at ages over 70 and no gender predilection. Symptoms include back pain with midline distribution that worsens during extension, is relieved during flexion and is exaggerated upon finger pressure at the level of interest. Diagnosis rests on clinical examination and imaging studies. The hallmark of imaging findings is the close approximation and contact of adjacent spinous processes, with all the subsequent findings including oedema, cystic lesions, sclerosis, flattening and enlargement of the articulating surfaces, bursitis and occasionally epidural cysts or midline epidural fibrotic masses. Proposed therapies include conservative treatment, percutaneous infiltrations or surgical therapies such as excision of the bursa or osteotomy. The purpose of this study is to illustrate the spectrum of imaging findings in Baastrup's disease and to emphasise upon including the syndrome in the list of potential causes of lowback pain. Teaching Points Baastrup's disease refers to close approximation of adjacent spinous processes. Diagnosis of Baastrup's disease is verified with clinical examination and imaging studies. Contact of adjacent spinous processes results in oedema, sclerosis, flattening and enlargement. Proposed therapies include conservative treatment, percutaneous infiltrations or surgical therapies.