What is the cause of developmental dysplasia of the hip?

• A. Acetabulum malformation
• B. Proximal femoral fracture
• C. Joint dislocation
• D. Muscle weakness

Answer: (A)

Developmental dysplasia of the hip (DDH) primarily arises from malformation of the acetabulum, which is the hip socket in the pelvis. When the acetabulum is improperly formed, it can't adequately support the femoral head, leading to instability in the hip joint. This instability can progressively cause dislocation or subluxation of the femoral head, resulting in developmental dysplasia.

Malformation of the acetabulum can occur during fetal development due to a combination of genetic and environmental factors. For instance, positioning in utero, particularly in breech births, can contribute to abnormal hip development. Understanding this condition's origin is crucial for early detection and intervention, emphasizing the need for pediatric screenings to avoid complications such as hip arthritis or gait abnormalities later in life.

While proximal femoral fractures and joint dislocation can be associated with hip problems, they are not the foundational causes of DDH. Similarly, muscle weakness can affect hip stability but is secondary to the primary anomaly in acetabular formation.