Case of the Week: January 16-January 23, 2003
2 year old Boy with Limp and Leg Pain
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Diagnosis: TODDLER'S FRACTURE
There is a faintly visible lucent line crossing the mid-distal tibia obliquely. This is characteristic of the "toddler's fracture" of the tibia, a common accidental injury seen in young children.
This fracture occurs in the age group of approximately 9 months to 3 years. The child is typically irritable and refuses to bear weight on the affected extremity. There is usually no definite preceding trauma observed by the parent. The fracture results from a twisting or torque force on the tibia which occurs during one of the frequent accidental falls that are so common in this age group. Because of the frequency of such accidental falls, it is difficult or impossible to pinpoint a single traumatic event that precedes the symptoms.
Radiographs of the tibia may reveal an oblique, nondisplaced hairline fracture of the mid to lower shaft of the tibia, which may be very subtle and often visible on only one view. In some cases, the fracture may not be visible at all on the initial radiographs, and only soft tissue swelling may be evident. When a toddler's fracture is strongly suspected, but not visible on radiographs, a radionuclide bone scan may be helpful to confirm the abnormality. Alternatively, the leg may be immobilized and repeat follow-up radiographs may show the fracture more clearly. This patient's subsequent radiograph shows the fracture line to be more easily visible at follow-up than on the initial films:
It is important to recognize this injury as a common accidental injury, and to be aware that usually the child's parents are unable to provide a clear history of trauma. Such recognition will avoid unnecessary and unjustified concern about the possibility of nonaccidental trauma. Remember, however, that a similar fracture in a very young infant who is not yet a "toddler" cannot be ascribed to accidental falls and therefore would be suspicious for abuse.
Differential diagnosis is very limited due to the characteristic appearance of the faint fracture line. When the fracture is not initially visualized, osteomyelitis could be considered but should be distinguished by other clinical evidence of infection. Neoplasm could also be considered but rarely presents with the sudden onset of symptoms that is typical of the toddler's fracture.
Other "toddler's" type fractures have been described, involving the bones of the feet, particularly the calcaneus and cuboid bone. These are more easily recognized by radionuclide bone scanning, and are usually not visible on radiographs until healing results in a zone of sclerosis. These injuries usually are fairly self-limited, with symptoms resolving spontaneously; the frequent, minor accidental injuries of childhood are presumably the etiology of these fractures as well.
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