Normal metaphyses in infants contain a step-off not to be confused with child abuse. Extension of physeal lucency into the metaphyses can be a sign of healing child-abuse fracture of experimental physeal fracture, as well as deferoxamine overdose. Sonography can reveal costochondral dislocation, the pattern of healing fracture callus, the patellar tendon in jumper's knee, synovium of rheumatoid arthritis, sequestrum in advanced osteomyelitis, the unossified dislocated patella, and, even after 2 years of age, the dislocated femoral head. Further developments concern bone scanning, MR imaging, CT, and plain films of specific trauma, tumor, and infectious, metabolic, and orthopaedic conditions. Ultrasound has been proven useful for radiologist removal of soft tissue foreign bodies, whereas CT can be helpful for osteoid osteoma nidus removal under imaging control.