**Developmental Dysplasia of the Hip (DDH)**

**Core Concept**
Developmental dysplasia of the hip (DDH) is a congenital or acquired condition characterized by the abnormal formation or dislocation of the hip joint. It is a significant cause of morbidity in infants and children, potentially leading to chronic hip pain, arthritis, and limited mobility in adulthood.

**Why the Correct Answer is Right**
DDH involves the abnormal relationship between the femoral head and the acetabulum, leading to a shallow or malformed acetabulum. The condition is often bilateral, with a higher incidence in females. The diagnosis of DDH is typically made between 4-12 months of age, with the Ortolani and Barlow maneuvers being key clinical tests for detecting the condition. Early detection and management are crucial to prevent long-term complications.

**Why Each Wrong Option is Incorrect**
**Option A:** DDH is primarily a problem of the femoral head, which is incorrect. DDH involves the abnormal relationship between the femoral head and the acetabulum.
**Option B:** DDH is not a common condition in adults, which is incorrect. DDH can lead to chronic hip pain, arthritis, and limited mobility in adulthood.
**Option C:** DDH is not typically bilateral, which is incorrect. A significant proportion of DDH cases are bilateral.

**Clinical Pearl / High-Yield Fact**
The Ortolani and Barlow maneuvers are essential clinical tests for detecting DDH in infants. The Ortolani maneuver involves gently abducting the hip while applying gentle pressure to the knee, while the Barlow maneuver involves applying gentle pressure to the knee to dislocate the hip.

**Correct Answer:** B. DDH is not a common condition in adults.