How is congenital hip dysplasia typically diagnosed?

• A. X-ray
• B. CT scan
• C. US (ultrasound)
• D. Physical examination

Answer: (C)

Congenital hip dysplasia, or developmental dysplasia of the hip (DDH), is primarily diagnosed using ultrasound, especially in infants. This method is preferred because it allows for the visualization of the soft tissues and cartilaginous structures of the hip joint which are not well seen on X-rays in very young children. Ultrasound can provide real-time imaging, which is crucial for assessing the hip joint's stability during movement.

In infants, physical examination also plays a significant role in the initial assessment for hip dysplasia. However, ultrasound is utilized for a definitive diagnosis and assessment of the hip morphology and the degree of dysplasia.

While X-rays can be useful in diagnosing hip dysplasia in older children, they are not ideal for infants due to their developing bone structure. CT scans, while very detailed, expose the child to unnecessary radiation and are not typically used as a first-line diagnostic tool in this age group. Hence, ultrasound stands out as the best choice for diagnosing congenital hip dysplasia in young patients.