Differential Diagnosis for a 2-year-old who tripped and is refusing to walk on the leg with tenderness over the anterior tibia and a normal X-ray

• Single most likely diagnosis:
  • Toddler's fracture: This is a common injury in toddlers who are just learning to walk. It typically occurs when the child twists or falls on the leg, causing a small fracture, often in the tibia. The fact that the X-ray is normal does not rule out this diagnosis, as some toddler's fractures may not be visible on initial X-rays.
• Other Likely diagnoses:
  • Soft tissue injury (contusion or bruise): The child could have a soft tissue injury from the fall, which would cause pain and tenderness, especially over the anterior tibia.
  • Shin splint: Although less common in toddlers, shin splints could be a consideration if the child has been active or has recently increased their physical activity.
• Do Not Miss diagnoses:
  • Osteomyelitis: This is an infection of the bone that could present with pain, tenderness, and refusal to bear weight. Although less likely, it is a serious condition that requires prompt diagnosis and treatment.
  • Septic arthritis: If the joint is involved, septic arthritis is a possibility, especially if there are signs of infection such as fever, redness, or swelling.
  • Child abuse: In any case of unexplained injury or inconsistent history, child abuse must be considered and ruled out.
• Rare diagnoses:
  • Bone cyst or tumor: Although rare, a bone cyst or tumor could cause pain and tenderness over the anterior tibia.
  • Rickets or other metabolic bone diseases: These conditions could weaken the bones and make them more susceptible to fractures or pain.