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Although radiography is often considered the mainstay of fracture
diagnosis, two orthopedic principles must be kept in mind when evaluating
patients with extremity trauma:
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A fracture is a clinical, not a radiographic, diagnosis
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A fracture is a soft tissue injury with skeletal involvement
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Radiographic studies serve to confirm the clinical diagnosis
of a fracture and define its anatomy. Over-reliance on radiography
is a potential pitfall in patient care. In some cases, a fracture
may be present without apparent radiographic abnormality, i.e.,
an occult fracture. Second, soft tissue injuries (neurovascular
and ligamentous) can be of greater consequence than the fracture
itself and are in general not visible on the radiographs.
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The clinical diagnosis of a fracture is based on:
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(1) the mechanism of injury,
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(2) the findings on physical examination, and
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(3) the age of the patient.
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Some physical examination findings are highly predictive of a
fracture. Definite signs of a fracture include gross deformity,
abnormal mobility at the injury site, and crepitus on palpation
of the injured part. In the pre-radiographic era, these findings
served as diagnostic criteria for a fracture. Bone tenderness is
also characteristic of a fracture, although soft tissue tenderness
is usually difficult to distinguish from bone tenderness. Other
physical examination findings are less specific for a fracture because
they are also seen with soft tissue injuries such as sprains, strains,
and contusions. These include soft tissue swelling, ecchymosis,
pain on motion of the involved joint, limitation of range of motion,
and pain on weight bearing.
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There are a number of important instances in which a fractures
may be difficult or impossible to detect radiographically (see Table
4). When such an injury is suspected based on clinical examination,
but is not seen radiographically, a fracture should presumed to
be present and the patient managed with adequate immobilization
and follow-up care. Examples of fractures that have serious consequences
if missed include scaphoid fractures and femoral neck fractures.
Such fractures may have normal radiographs (“occult fractures”)
or have subtle radiographic findings that must be sought when examining
the radiographs.
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