What is the appropriate evaluation and management for a 2-year-old presenting with a painless limp in the right leg without a history of trauma?

Evaluation and Management of a 2-Year-Old with Painless Right Leg Limp

Begin with tibia/fibula radiographs of the right leg as your initial imaging study, since spiral tibial fractures (toddler's fractures) are the most common cause of nonlocalized limp in children under 4 years of age, even without a clear history of trauma. 1

Immediate Assessment Priorities

Rule out infection first, even though the child appears painless:

• Check temperature—fever >101.3°F (38.5°C) combined with refusal to bear weight strongly suggests septic arthritis, which requires diagnosis within hours to prevent permanent joint damage 2, 3
• Assess weight-bearing ability—complete refusal raises concern for fracture or septic arthritis 1
• If any fever or systemic symptoms exist, obtain CBC, ESR, and CRP immediately 3

Physical Examination Strategy

Examine systematically from hip to foot, not just where the child seems to favor:

• Two-year-olds cannot verbalize or accurately localize symptoms, and hip pathology refers pain to the thigh, knee, or buttock in up to 30% of cases 1, 3
• Palpate the entire lower extremity for focal tenderness, swelling, or erythema 1
• Observe gait pattern and assess for signs of serious pathology including anxiety, agitation, and high analgesic requirements 3

Initial Imaging Approach

Obtain anteroposterior and lateral radiographs of the right tibia/fibula as the first-line imaging:

• Spiral tibial fractures account for the vast majority of fractures in this age group presenting with limp 1
• Approximately 10% of tibial fractures are initially radiographically occult and only become visible on follow-up films obtained 7-10 days later 1, 3
• If symptoms localize to the hip during examination, obtain hip ultrasound instead to evaluate for joint effusion 2

Management Based on Initial Findings

If Radiographs Are Normal with Improving Symptoms:

• Provide observation and reassurance with follow-up in 1-2 weeks if symptoms persist 3
• Prescribe short-course NSAIDs for analgesia 2

If Radiographs Are Normal with Persistent or Worsening Symptoms:

• Repeat clinical examination and obtain follow-up radiographs in 7-10 days, as toddler's fractures frequently appear only on delayed imaging 1, 2
• Consider hip ultrasound to evaluate for joint effusion, since hip pathology commonly presents with referred symptoms 1
• Obtain MRI of the lower extremity if symptoms worsen or red flags develop (fever, inability to bear weight, systemic symptoms) 1

Critical Pitfalls to Avoid

Never assume normal initial radiographs rule out fracture—41% of toddler's fractures show radiographic evidence only on follow-up films 4, 3

Do not focus only on the right leg—young children frequently mislocalize pain, and hip pathology can present as lower leg symptoms 1, 3

Maintain high suspicion for infection despite painless presentation—septic arthritis can present subtly in young children and requires intervention within hours to prevent permanent joint damage 2, 3