THE AMERICAN radiological literature and standard textbooks make few references to tetanus as a cause of spinal fractures, a condition first described in 1907 (1). The radiologist familiar with this entity may be the first to suspect its presence on a chest film taken during the acute illness when the fractures are usually asymptomatic (2–5). Patients presenting after the acute illness with back pain, or those in whom the fractures are incidentally discovered, may be spared unnecessary and expensive diagnostic tests if the correct diagnosis is suspected and confirmed with a clinical history of tetanus. It is the purpose of this communication to review the radiographic features of spinal fractures due to muscle spasm in tetanus, to discuss the mechanism of injury, and to briefly consider the differential diagnosis. Material The findings presented are drawn from the author's experience and that of his colleagues at the University College Hospital, Ibadan, Nigeria, where approximately 200 acute cases of tetanus are admitted annually. More complete clinical details of tetanus patients from this hospital have already been reported (6). Incidence Tetanus is a disease of world-wide distribution affecting both sexes and all age groups. Spinal fractures are said to occur in about half the cases (2, 5, 7–9), although there are wide variations in the reported figures; one author noted an incidence as high as 88 per cent (10), while another (11) reporting a large series failed to mention this complication. Spinal fractures are more common in patients under twenty years of age (2, 5, 8, 10, 12) and are also more frequent in males (5, 13). Radiographic Features Multiple consecutive vertebrae are usually involved; most commonly the fourth to the eighth thoracic (T4-T8), with fractures of T5 and T6 being the most frequent and the most severe (2, 5, 7, 9, 12–15) (Fig. 1). It is not unusual to have involvement as high as T3 (5, 9, 15) (Fig. 2) and as low as T9 (5, 14) (Fig. 2). The cervical and lumbar vertebrae are almost never affected, although such fractures have been described (16). The vertebral bodies are flattened in a longitudinal (cranial-caudad) direction with or without anterior wedging and varying degrees of kyphosis (Fig. 4). There may be lateral and/or dorsal-ventral widening of the compressed bodies (13), and anterior chip fractures can also occur (5) (Fig. 3). The bodies never reach the wafer-thin stage of vertebra plana, dislocation does not occur, and the laminae, pedic1es, and other parts of the vertebral arch are not involved. The paravertebral soft-tissue shadows usually remain normal, although widening due to hemorrhage has been described (5,7). Most authors (2, 7, 15) state that the disk spaces remain normal, but we have frequently noted some increase in the biconvex height of the disk spaces (resembling the sagging end-plates of osteoporosis) (Figs. 2 and 4) or localized protrusions into the end-plates of the vertebral bodies (as occurs with Schmorl's nodes) (Fig. 1).