Osteogenesis Imperfecta (OI) is a group of hereditary disorders of type I collagen synthesis characterized by extremely fragile bones with a propensity to fracture. Often patients will present with multiple fractures at various stages of healing, which can be confused with non-accidental trauma. The underlying osteopenia and the fact that OI fractures tend to involve the diaphysis rather than the metaphyseal corners can help to distinguish the two entities.

Two major types:

1. Congenita (develops at or before birth) - autosomal recessive with frequency of 1:60,000
2. Tarda (develops later, less severe) - autosomal dominant with frequency of 1:30,000

Radiographic characteristics of OI:

• demineralization of the diaphyses of long bones with deformity/bowing and multiple fractures
• wormian bones of the skull
• vertebral bodies that are shallow, radiolucent, and bi-concave

Osteogenesis Imperfecta, congenital form. Radiograph of the left upper extremity in a child reveals a pathologic fracture with healing resulting in a thick tubular bone.

Osteogenesis Imperfecta Tarda in a 15-year-old male. Lateral radiograph of the right knee demonstrates marked cortical thinning with undertubulation of the long bones (gracile bones).