What sign would indicate an underlying problem in a 4 year old child presenting after falling on an outstretched hand?

• A. Crescent sign
• B. Risser sign
• C. Sulcus sign
• D. Posterior fat pad sign

Answer: (D)

The presence of a posterior fat pad sign is indicative of potential underlying injury, particularly in a child who has fallen on an outstretched hand. In pediatric patients, such as a 4-year-old, a fall of this nature can lead to significant injuries like an occult fracture, especially in the elbow region.

When imaging is conducted, particularly X-rays, the presence of a posterior fat pad that is visible on the lateral view can suggest an intra-articular fracture, even if the fracture isn't visibly apparent on the X-ray. This sign often corresponds with injury to the distal humerus and indicates that further evaluation and possibly treatment may be required.

In contrast, other options listed do not specifically apply to evaluating injuries in this scenario. For instance, the crescent sign often relates to osteonecrosis and is more typical in older populations. The Risser sign is used to assess skeletal maturity in adolescents and is not applicable in this context. The sulcus sign is typically associated with shoulder instability, which is not relevant in the case of falling on an outstretched hand.

The posterior fat pad sign is critical in clinical practice as it guides the clinician toward recognizing possible fractures that might not yet be visible, ensuring timely and appropriate intervention.