[Sonographic follow-up of secondary fracture healing. Initial experiences with morphologic and semiquantitative assessment of periosteal callus formation].

We report on the contribution of real-time sonography in comparison to plain radiographs to the assessment of fracture healing of 121 patients suffering fractures of the long bones of the lower limbs. Sonographic morphology of periosteal callus metamorphosis shows basically a persistent increase of echogenicity representing the temporal range from fracture haematoma to the "woven bone". Further criteria are the homogeneity of structure and the development of a marginal interface. Nonunion radiologically classified into hypertrophic and atrophic types may also be differentiated by sonographic criteria and may influence proper orthopaedic management. Regarding sonographic methods using an A-mode amplitude signal, the morphologic assessment of callus metamorphosis is more likely to be translated into clinical practice. Although it yields a variety of information, sonography will be unable to replace radiography due to methodical limitations.