Paediatric musculoskeletal radiologyOther disorders
Frostbite in children
The manifestations of frostbite that are different in children in adults are growth disturbances due to growth plate damage. The first affected areas are the distal phalanges of the hand or foot the resultant do sure of the affected growth plates and resultant deformity and shortening of these bones. A characteristic pattern may be seen in the hand with the distal phalanges of the fingers affected but with sparing of the distal phalanx of the thumb. This is due to the fact that the thumb has better circulation and it is often clasped within the hand. Other phalanges and even
a
|
Figure 70.
Langerhans cell histiocytosis (histiocytosis X).
|
b
|
|
c
|
|
metacarpals may be affected in severe cases. Bums can similarly cause growth plate closure.
Langerhans cell histiocytosis
Previously known as histiocytosis X, Langerhans cell histiocytosis includes the entities known as eosinophilic granuloma, Hand-Shüller-Christian disease, and Letterer-Siwe disease. This condition has variable manifestations. In the skeleton there are areas of bone destruction usually with sharply defined lucent lesions without a cortical rim. However, a variety of other manifestations may be present (Fig. 70). During healing sclerotic areas may be present. In the pelvis there may be sclerotic changes mimicking Ewings. Langerhans cell histiocytosis should be considered in the differential diagnosis of all bone tumors and in almost any type of bone destruction in the skeleton. Flattening of vertebrae bodies sometimes with disk-like vertebra plana may be seen. In the skull the lesions are usually sharply defined round or geographic (Fig. 70 b). Occasional target like lucencies may be seen in the skull due to different
 | Figure 71.
Myofibromatosis (congenital fibromatosis) in a 5-month-old boy. There are sharply circumscribed lytic defects in the fibula. Other similar lesions were present in other parts of the skeleton. These lucencies are similar to what may be seen in histiocytosis X, but they occur at a very early age; often at birth. |
degrees of destruction in the outer and inner tables. The lesions of Langerhans cell histiocytosis may clear up spontaneously leaving no visible residual.
Myofibromatosis
This is also known as congenital fibromatosis. This condition which affects bone in the neonate with sharply defined lucent lesions and sometimes soft tissue tumors as well (Fig. 71). It is the most likely diagnosis in the neonate with sharply defined lucencies. Langerhans cell histiocytosis does not usually appear at this age. The lesions usually disappear spontaneously unless there is visceral involvement.
Sickle cell disease in childhood
In toddlers one of the important findings of sickle cell disease is the so called hand-foot syndrome which presents as swelling and pain in the fingers and toes. It represents areas of infarction within the metacarpals, metatarsals, or phalanges. There may be periosteal elevation and focal areas of destruction usually involving several but not all digits. Generally in the United States only the tubular bones of the hands and feet are affected. In Africa involvement of other bones may also occur. The important differential if only one or two bones are affected is the possibility of osteomyelitis, which also can occur in these children. The handfoot syndrome is difficult to separate from osteomyelitis. Bone marrow scans and bone scintigraphy have been used to try to differentiate osteomyelitis from infarcts of the hand foot syndrome but this effort is often unsuccessful. The areas of infraction may damage growth plates causing growth alteration resulting in coned epiphyses and short metacarpals or other bones.
Other skeletal manifestations of sickle cell disease occur in older children. These include aseptic necrosis of the hips and spine changes. In the spine there may be a squared off indentation of the end plates which represents a growth disturbance.
Andrew K. Poznanski