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Among the causes of gait abnormality in children, those that should be kept in mind in acute settings include infection, trauma, and malignancy. Children who develop a limp acutely should be evaluated carefully with a detailed history and physical examination, appropriate radiographs and laboratory studies, and timely subspecialty evaluation in order to exclude these potentially worrisome causes. When infection is suspected, the workup should be conducted in either an observation or inpatient status until the diagnosis is confirmed or excluded. An age-based approach to diagnosis can help the clinician focus his or her approach.
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A thorough history will point the clinician toward the correct diagnosis in most cases. Factors to note are the onset and duration of symptoms, the presence and location of pain, the presence of fever or malaise, or any history of witnessed injury. Although trauma is far more common in children than is infection or malignancy, it is less commonly the source of an unexplained limp. The history is consistent with injury, without suggestion of fever or malaise. The clinician must maintain a high index of suspicion for nonaccidental injury when objective findings point toward trauma but the history is inconsistent. Physical findings often demonstrate bruising or swelling without erythema. Trauma may be reported as an antecedent event in approximately 35% of children with infection. In these circumstances, the physician should be mindful of subtle details in the history and physical examination. One should ask about the timing of the injury with respect to the onset of symptoms, the mechanism of injury, and the presence of fever.
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Gait should be observed by having the child walk and run while distracted. Antalgic gait is characterized by shortening the stance phase to minimize weight bearing on a painful limb. Limp with a nonantalgic gait pattern is less likely the result of an infectious or traumatic etiology.
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The lower extremities should be observed for symmetry, noting any areas of swelling or deformity. Range of motion of the hips, knees, and ankles should be assessed. Keep in mind that hip disorders may present with knee pain, but movement of the hip may exacerbate the pain. Affected areas should be palpated for swelling or tenderness. Sites that are painful with range of motion or tender to palpation may warrant radiographic evaluation.
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Discrepancy in the length of the legs should be assessed with the patient standing and the examiner’s hands on the iliac crests. Discrepancy can be further evaluated by observing the heights of the knees with the patient supine and the hips and knees flexed (Galeazzi sign), followed by prone observation of length of the lower leg.
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The child stands on 1 leg with ...