Osteogenesis imperfecta

Background

• Also called brittle bone disease.
• Most commonly secondary to a genetic defect in type I collagen with autosomal dominant inheritance.
• Presentation age varies by severity and subtype. May be discovered en utero or go undetected until middle age.

Clinical Features

Type I: Osteogenesis imperfecta tarda

• Fragile bones with fractures occurring after minimal trauma.
• Presents in early infancy
• Blue sclera
• Hearing loss (50%)
• Dentinogenesis imperfecta in some (opalescent or yellow-brown discoloration of tooth enamel)

Type II: Osteogenesis imperfecta congenita

• Lethal perinatally or before 1st year of life
• Most common cause of death is pulmonary hypoplasia
• Severe deformity

Type III

• Fragile bones with fractures occurring after minimal trauma.
• Bone deformity (progressive)
• Blue sclera (variable, may fade with age)
• Hearing loss
• Dentinogenesis imperfecta
• Short stature

Type IV

• Fragile bones with fractures occurring after minimal trauma.
• Bone deformity
• Short stature (variable)
• Hearing loss in some
• White or blue sclera
• Dentiogenesis Imperfecta in some

Differential Diagnosis

• Child abuse
• Primary juvenile osteoporosis
• Hypogonadism
• Malignancy

Evaluation

• Family history
• Plain films
• DEXA scan and collagen studies (as outpatient)

Management

• Fracture reduction and splinting
• Physical therapy
• Fracture risk reduction with activity restriction
• Recommendation for genetic counseling

Complications

Cardiopulmonary

• Kyphoscoliosis causing restrictive lung disease
• Pneumonia
• Cor pulmonale
• Tricuspid regurgitation
• Aortic root dilation
• Left ventricular hypertrophy

Neurological

• Hydrocephalus
• Basilar Invagination (headache, dysphagia, ataxia)

Disposition

• Home after splinting
• May admit if surgical fixation is required