The twelfth rib syndrome.

The twelfth rib syndrome appears to be a fairly common and underdiagnosed chronic pain syndrome. It is more common in women than men (3:1) and is usually described as a constant dull ache or sharp stabbing pain that may last from several hours to many weeks. Lateral flexion, rotation of the trunk, and rising from a sitting position classically aggravate the pain. Manipulation of the affected rib and its costal cartilage reproduces it exactly. The diagnosis of this syndrome is clinical, requires exclusion of specific etiologies, and should only be made when the patient's symptoms can be exactly reproduced by manipulation of the affected rib. If symptomatology is complicated, it may be necessary to use an image intensifier for accurate location of the pain locus. Patients with this syndrome can be overinvestigated and have even undergone surgical procedures when this diagnosis has been overlooked. To describe the varied presentation of this syndrome, we describe the clinical manifestations in six patients.