Haller Index Calculator

Historical Background

The Haller Index is a numerical value used to assess the severity of pectus excavatum, a congenital chest wall deformity where the breastbone is sunken into the chest. It was first introduced by Dr. Johannes Haller in 1987 as part of the clinical evaluation of patients with pectus excavatum. The index helps determine whether surgical intervention is necessary.

Calculation Formula

The Haller Index is calculated using the following formula:

\[ \text{Haller Index} = \frac{\text{Transverse Diameter}}{\text{Anteroposterior Diameter}} \]

• Transverse Diameter: The distance across the chest from one side to the other (left to right).
• Anteroposterior Diameter: The distance from the back of the spine to the front of the sternum.

Example Calculation

If a patient has a transverse diameter of 250 mm and an anteroposterior diameter of 50 mm, the Haller Index would be calculated as:

\[ \text{Haller Index} = \frac{250}{50} = 5.0 \]

A Haller Index greater than 3.25 is generally considered an indication for surgery.

Importance and Usage Scenarios

The Haller Index is a vital measurement in diagnosing the severity of pectus excavatum and determining the need for corrective surgery. It is especially important for thoracic surgeons and radiologists to assess patients properly. This index is typically calculated from CT scans or MRI images of the chest.

Common FAQs

1. What does a high Haller Index mean?

   • A high Haller Index, typically above 3.25, indicates a severe case of pectus excavatum and is often used as a surgical criterion.

2. How is the Haller Index measured?

   • The index is calculated by dividing the transverse diameter of the chest by the anteroposterior diameter, usually measured via imaging techniques like CT scans.

3. Can the Haller Index improve over time?

   • Pectus excavatum can worsen as a person grows, and the Haller Index may increase. Surgical correction is often recommended in severe cases.

4. What are normal Haller Index values?

   • A normal Haller Index is generally 2.5 or lower. Values between 2.5 and 3.25 are borderline, while values above 3.25 suggest severe deformity.