## **Core Concept**
A diastatic fracture refers to a type of fracture that occurs along the suture lines of the skull, particularly in infants and young children, due to the skull's greater plasticity and the presence of open sutures. This type of fracture is significant in pediatric patients because their skulls are more prone to deformation and fracture along suture lines.

## **Why the Correct Answer is Right**
The correct answer, **C. Lambdoid suture**, is a common site for diastatic fractures, but actually, the most common suture involved in diastatic fractures is the **sagittal suture**. The sagittal suture is a significant site because it is a common location for diastatic fractures due to its anatomy and the forces applied during trauma. The sagittal suture runs along the midline of the skull, and forces applied to the sides of the head can cause separation along this suture.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is incorrect because, although diastatic fractures can occur at various suture lines, the specific suture mentioned here is not identified. However, based on common knowledge, the coronal suture can be involved but is less commonly associated compared to the sagittal suture.
- **Option B:** This option refers to the coronal suture, which can be a site for diastatic fractures but is not the most common site.
- **Option D:** This option refers to the squamous suture, which is less frequently mentioned in the context of diastatic fractures compared to the sagittal suture.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that diastatic fractures are particularly relevant in pediatric patients due to the open sutures of their skulls. The **sagittal suture** is notably the most common site for diastatic fractures. Recognizing this can help in the assessment and management of head injuries in children.

## **Correct Answer: C. Lambdoid suture**
However, it should be noted the most appropriate answer should reflect that **sagittal suture** is the most common, but given the choices and focusing on accuracy within provided options and explanations:
**Correct Answer: C.**