Osteogenesis Imperfecta
Osteogenesis Imperfecta: Excerpt from The 5-Minute Pediatric Consult
John P. Dormans, MD
Osteogenesis Imperfecta - BASICS
Osteogenesis Imperfecta - description
Osteogenesis imperfecta (OI) is a group of genetically and clinically heterogeneous connective tissue disorders affecting bone and soft tissue, causing abnormal fragility of bone, resulting in recurring fractures and deformity.
Osteogenesis Imperfecta - epidemiology
Osteogenesis Imperfecta - prevalence
~1 in 20,000
Osteogenesis Imperfecta - risk factors
Osteogenesis Imperfecta - genetics
- Sillence classification:
- Type 1: Autosomal dominant, blue sclera, onset preschool:
- A: Teeth involved
- B: Teeth not involved
- Type II: Autosomal recessive, lethal, blue sclera
- Type III: Autosomal recessive, severe, normal sclera
- Type IV: Autosomal dominant, normal sclera, mild form:
- A: Teeth involved
- B: Teeth not involved
- Some cases of OI occur as spontaneous mutations.
Osteogenesis Imperfecta - pathophysiology
- In general, both enchondral and intramembranous bone formation are disturbed:
- Osteoid seams are wide and crowded by osteoblasts (woven bone).
- Osteoclasts are normal.
- Collagen fibrils are disorganized (by electron microscope).
- Physis broad and irregular:
- Osteopenia
- Long bones are slender and smaller.
- Fractures (recent or healed)
- Deformities
- Spine: Scoliosis, compression fractures, kyphosis, upper cervical spine instability
- Skull: Multiple centers of ossification, wormian bones, basilar invagination/platybasia
Osteogenesis Imperfecta - etiology
- Abnormality of collagen production and organization
- Failure of maturation of procollagen to type 1 collagen and failure of normal collagen cross-linking
Osteogenesis Imperfecta - DIAGNOSIS
Osteogenesis Imperfecta - signs & symptoms
- Severe congenital forms:
- Multiple fractures
- Limbs deformed and short
- Skull soft
- Mild and moderate forms:
- General: Short stature, hernias
- Extremities: Bowing, coxa vara deformity, cubitus varus, hypermobility of joints: Subluxations and dislocations
- Pelvis: Trefoil pelvis, protrusio acetabuli
- Spine (cause: Osteoporosis, compression fractures, and ligamentous laxity): Kyphoscoliosis (30–40%), platybasia
- Skin: Thin skin, subcutaneous hemorrhages, wide surgical scars
- Eyes: Blue sclera caused by thin collagen layer, Saturn ring (white sclera immediately) hyperopia, embryotoxon or arcus juvenilis occasionally, retinal detachment occasionally
- Teeth: Dentinogenesis imperfecta, enamel normal, both deciduous and permanent teeth affected, teeth easily broken, discoloration
- Deafness: Either conduction or nerve type
Osteogenesis Imperfecta - history
Osteogenesis Imperfecta - tests
Osteogenesis Imperfecta - lab
- Serum calcium and phosphorus levels:
- Alkaline phosphatase:
- No widely available specific diagnostic laboratory test
- Collagen testing is becoming more available.
Osteogenesis Imperfecta - imaging
- Osteopenia
- Fractures:
- New, healing, or healed
- Malunions
- Deformity
- Metaphyseal ends of long bones:
- Honeycomb appearance of ends of long bones, popcorn calcifications, Erlenmeyer flask appearance, acetabular protrusio
- Spine:
- Atlantoaxial subluxation, spondylolisthesis, scoliosis, compression fractures
Osteogenesis Imperfecta - differencial diagnosis
- Severe:
- Congenital hypophosphatasia
- Achondroplasia
- Camptomelic dwarfism
- Mild:
- Cystinosis
- Pyknodysostosis
- Child abuse
- Leukemia
- Idiopathic juvenile osteoporosis
- Steroid treatment
- Rickets in very-low-weight infants
- Menkes kinky hair syndrome (newborn male [X-linked recessive] with failure to thrive)
- Metaphyseal corner fractures
- Abnormal hair
- Hyperplastic callus formation may be confused with osteogenic sarcoma.
Osteogenesis Imperfecta - TREATMENT
Osteogenesis Imperfecta - initial stabilization
Emergency care:
- For unstable fractures, such as femur fractures, spine instability
- Depends on location of fracture and details of individual situation
Osteogenesis Imperfecta - general measures
- Fracture treatment:
- Fractures heal at a normal rate; splinting, orthoses, casting, operations (intramedullary rod)
- Scoliosis:
- Seen in ~50%
- Orthoses usually ineffective
- Spinal fusion for curves >50°
- Correction of deformities (e.g., realignment osteotomies with intramedullary fixation most common for long bone deformity)
Osteogenesis Imperfecta - medication
- Bisphosphonates are being used currently in clinical trials for children with severe involvement (gene therapy possibly in future).
- Sex hormones, fluoride, magnesium oxide, and calcitonin
Osteogenesis Imperfecta - FOLLOW UP
Osteogenesis Imperfecta - prognosis
- In general, the earlier the fractures occur, the more severe the disease.
- For moderate and mild types, there is a gradual tendency to improvement, with the incidence of fractures decreasing after puberty.
- Depends on severity of OI
- Moderate and mild types:
- Gradual tendency to improvement, with incidence of fractures decreasing after puberty
Osteogenesis Imperfecta - bibliography
- Antoniazzi F, Zamboni G, Lauriola S, et al. Early bisphosphonate treatment in infants with severe osteogenesis imperfecta. J Pediatr. 2006 Aug;149(2):174–179.
Dormans JP, Flynn JM. Pathologic fractures associated with tumors and unique conditions of the musculoskeletal system. In: Beaty JH, Kasser JR, eds. Rockwood and Wilkins’ Fractures in Children. 6th ed. Philadelphia: Lippincott Williams & Wilkins; 2006:133–222.
Dormans JP. Pediatric Orthopaedics: Core Knowledge in Orthopaedics. Philadelphia, PA: Elsevier Mosby; 2005:393–394.
- Gertner JM, Root L. Osteogenesis imperfecta. Orthop Clin North Am. 1990;21:151–162.
- Minch CM, Kruse RW. Osteogenesis imperfecta: A review of basic science and diagnosis. Orthopedics. 1998;21:558–567, 568–569 (quiz).
- Sillence DO. Osteogenesis imperfecta: An expanded panorama of variants. Clin Orthop. 1981;159:11.
- Spranger JW, Cremin B, Beighton P. Osteogenesis imperfecta congenita. Pediatr Radiol. 1982;12:21.
- Tosi LL. Osteogenesis imperfecta. Curr Opin Pediatr. 1997;9:94–99.
Zaleske DJ. Metabolic and endocrine abnormalities. In: Morrissy RT, Weinstein SL, eds. Lovell and Winter’s Pediatric Orthopaedics. 5th ed. Philadelphia: Lippincott Williams & Wilkins; 2001:177–242.
Osteogenesis Imperfecta - CODES
Osteogenesis Imperfecta - icd9
756.51 Osteogenesis imperfecta
Osteogenesis Imperfecta - PATIENT TEACHING-MED
Education and fracture and injury prevention are important.
Book Source Details
- Book Title: The 5-Minute Pediatric Consult
- Author(s): M. William Schwartz MD; et al.
- Year of Publication: 2008
- Copyright Details: The 5-Minute Pediatric Consult, Copyright © 2008 Lippincott Williams & Wilkins.
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Copyright notice for book excerpts: Copyright © 2008 Lippincott Williams & Wilkins. All rights reserved.
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More About This Book:
Title: The 5-Minute Pediatric Consult
Authors: M. William Schwartz MD; et al.
Publisher: Lippincott Williams & Wilkins
Copyright: 2008
ISBN: 0-7817-7577-9
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