Bilateral Lambdoid Synostosis (Clinical Presentation)

Figure kran_10a_n.jpg to kran_10e_n.jpg: Clinical presentation of a bilateral lambdoid synostosis and of the associated radiological and operative findings. In this infant a visible and palpable dent over the always closed posterior fontanel is recognizable besides a flattened back head. This characteristic contour cannot be explained by continual supine position because a pronounced reclination would be necessary for causing it. Compare with the clinical findings of $$kran_2??££a bilateral lambdoid synostosis§§ and with the $$kran_1??nr=5££drawig.§§ Figure kran_10b_n.jpg: The lateral skull x-ray, too, shows a dent over the former posterior fontanel, and in addition, a sclerosis of both borders of the lambdoid suture is visble, and a posteriorly tower-shaped head. Figure kran_10c_n.jpg: In lambdoid synostosis, often a craniotabes of the posterior parietal and of the occipital bones is palpable. The corresponding intraoperative finding is demonstrated in this figure; the elevator depresses the right posterior parietal bone near the bore-hole, which is usually not possible. Figure kran_10d_n.jpg: This craniotabes is due to a focal thinning of the skull due to increased intracranial pressure, as shown in this piece of parietal bone with the light shining through, which was used for transposition of the back of the head. Figure kran_10e_n.jpg: The lambdoid suture behaves rebelliously insofar as pure bony synostoses, as shown in the picture, occur more rarely than functional closures. Often, the suture is visible from the outside, but at the inner surface there is a parasutural bony ridge, and the suture is locally bridged over by bone macroscopically and histologically. These findings explain the often visible sutures on x-rays, as well as the parasutural sclerosis ridge (compare with kran_10b_n.jpg).