Destructive vertebral lesions in ankylosing spondylitis

Destructive lesions of the vertebrae in ankylosing spondylitis have been described over the years (Guest and Jacobson, 1951; Baggenstoss, Bickel and Ward, 1952; Romanus and Ydén, 1952; Rivelis and Freiberger, 1969; Ball, 1971) and are important in both the early diagnosis and follow-up of these cases. The radiological incidence of these lesions varies widely (Strĕda, 1964; Jacqueline, 1965; Schulitz, 1968). This variation is dependent upon the extent of the spinal survey, duration of the disease when reviewed radiologically and the lack of agreed diagnostic criteria. The destructive lesion can affect the vertebral margins in two ways (Fig. 1). The first is by producing a localized destructive lesion at the edges of the vertebrae. Two types are seen, differing in aetology and pathogenesis—the Romanus lesion and the vertebral rim lesion. The second way is by a destructive lesion involving the whole disc/vertebral border (Fig. 2). The cause of most of these lesions has been considered in the past to be an inflammatory process in the vertebral end plate and intervertebral discs. Recent work has thrown new light on these lesions and the overwhelming evidence is that with the exception of the Romanus lesion, they are not part of an inflammatory process but are related to focal osteoporosis and associated trauma.