Although bones are not well imaged by US this imaging modality can be helpful in the assessment of bone surface and can be complementary to standard radiographs. A focal irregularity of the hyperechoic cortical line indicates a fracture, a cortical avulsion, a local bulging of the cortex or a foreign body related or not to previous surgery. Subperiosteal collections either purulent or hemorrhagic are easily detected and can be aspirated under US guidance if an infection is suspected. US also allows diagnosis of epiphyseal fractures when involving the distal epiphysis of the metatarsals, radial head, humeral head (Hill-Sachs fracture) growing cartilages… US examination of joints can detect osteophytes and marginal erosions (allowing early diagnosis of rheumatoid arthritis together with visualization of hyperaemic pannus and joint effusion) Cortical continuity in a location where in normal conditions a joint space is found indicates a synostosis. In children US, by directly visualizing the cartilaginous component of the non ossified bones, allows detection and serial follow-up of many congenital malformation (pes equinus…). US may be obtained in all patients where standard radiographs are not diagnostic because of it is efficient, non-invasive and relatively inexpensive.