The value of ultrasound in diagnosis and follow-up of fibrous cortical defect.

Fibrous cortical defects are local disturbances of ossification, most commonly seen in the metaphysis of tubular bones in growing children. These lesions are usually clinically silent, and most of them heal by being replaced with normal bone. Along with typical age, location and absence of clinical symptoms, plain radiographic films allow the diagnosis of fibrous cortical defect to be made. Because of rare but occasionally occurring complications, follow-up examinations are necessary. In a child with fibrous cortical defect the ultrasound examination demonstrated that fibrous cortical defects display a rather typical sonographic image. One finds clearly delineated defects of the bone located in the vicinity of the knee joint, filled with hypo-echogenic soft tissue, also displaying prominent internal vascularisation on colour-Doppler. We followed this patient up with repeated US examinations revealing the lesions to be shrinking in size and becoming shallower. Echogenic foci within the lesions appeared. It could be presumed that these changes represent the healing process and are comparable to the areas of sclerosis seen on CT scans. We believe that ultrasound with all its benefits is a powerful complementary method for the diagnosis and follow-up of fibrous cortical defects in children.