The Radiograph of the Pelvis as a Window to Skeletal Dysplasias.

Skeletal dysplasias are disorders of bone formation. There are many dysplasias that have been identified and studied over the years and long lists of radiological features have been documented; it is not possible to remember all of them, most of which are common to more than one dysplasia. This article is about a practical approach to the radiological diagnosis of skeletal dysplasias by viewing only a few radiographs rather than the entire skeletal survey. The radiographs that are to be studied are AP view of the pelvis, dorsolumbar spine- AP and lateral view and both hands PA view, in that order. The skull lateral view and both knees AP view are sometimes required. The authors advice to set out with the pelvis that provides information of not only the pelvic bones but also parts of the lumbar spine and the upper ends of the femur including their epiphyses, metaphyses and a part of the diaphyses. Sometimes the diagnosis is reached with only this one radiograph, as in achondroplasia or it may indicate a group like mucopolysaccharidoses which can be sorted out with radiographs of the spine and hands or the upper part of the femur can provide a cue to epiphyseal and metaphyseal dysplasias. Gamuts and atlases can be consulted for the rare dysplasias.