Manubrium sterni in patients with diastrophic dysplasia--radiological analysis of 50 patients.

BACKGROUND: Patients with diastrophic dysplasia (DD) have many typical and some peculiar radiological findings in their skeleton. Currarino reported recently that 6 of his 12 patients with DD had accessory ossification centers of the manubrium sterni.

OBJECTIVES: This study analyzed abnormalities of the manubrium sterni in patients with DD to find out more about the prevalence and natural history.

MATERIALS AND METHODS: A total of 50 patients with DD (22 male, 28 female) were included in this retrospective analysis. The average age of patients at the time of the first radiograph,was 7.1 years (range: newborn-34.7 years). Lateral radiographs of the spine or the chest were included. Follow-up was of 20 patients (40%) with an average age of 8 years (range: 1-24 years). The number, location, and time of the radiological fusion of accessory ossification centers were analyzed. Additionally, the form of the manubrium was evaluated using an arbitrary scale with three grades.

RESULTS: Accessory ossification centers were seen in the first radiograph of 16 (32%) patients. The first radiographs of 16 patients were taken before the age of 18 months; 13 (81%) of them had accessory ossification centers. The most common finding was an accessory ossification center located ventral to the cranial part of the manubrium (a double-layered manubrium). In older patients, the manubrium was usually bulging anteriorly, resembling an asymmetric club. It was as if there had been an accessory ossification center that had fused with the main part of the manubrium.

CONCLUSIONS: The manubrium sterni is abnormal in almost all patients with DD. The prevalence of accessory ossification centers in childhood is high. The presence of an accessory ossification center ventral or cranial to the manubrium in radiographs may help in making the diagnosis of DD.