Sonographic applications to osteomyelitis, myositis ossificans, tropic pyomyositis, child abuse, synovitis, and slipped capital femoral epiphyses; MR imaging (including gadolinium-enhanced MR scans) in osteomyelitis, the normal and abnormal physis, physeal bars, normal marrow, Gaucher disease, cancer, dysplasia epiphysealis hemimelica, myositis, tenosynovitis, arthritis, and clubfoot; nuclear imaging in osteomyelitis, tibia valga, limp, and unexplained lower extremity pain; and CT in osteomyelitis, are reviewed. Routine long-bone radiography for patients with congenital syphilis is not recommended. Tibia valga after fracture has not been fully explained; tibia valga also follows treatment of renal failure. Nonsupracondylar humerus fractures in infants and femoral shaft fractures in the first year of life may suggest child abuse.