Osteogenesis Imperfecta (OI)

OT Dude Academy’s Free NBCOT® Exam Prep Course Pediatric Conditions Osteogenesis Imperfecta (OI)
Contents Hide
1 Introduction
2 Prevalence
3 Cause
4 Types of OI
4.1 Type I (Mild)
4.2 Type II (Most Severe)
4.3 Type III (Severe)
4.4 Type IV (Moderate)
4.5 Type V (Moderate)
4.6 Type VI (Moderate)
4.7 Type VII (Severe) – Recessive Gene Form
4.8 Type VIII (Very Severe) – Recessive Gene Form
5 Complications
6 Treatment
7 Prognosis
8 Outcome Measures
9 Occupational Therapy
9.1 Health Management
9.2 Precautions
10 Additional Reading

Introduction

Osteogenesis imperfecta (OI) is a genetic disorder characterized by fragile bones that break easily leading to associated deformities. It is referred to as brittle bone disease.1 
The severity depends on the type of OI.2 

Prevalence

The exact number is unknown in the US, but estimates suggests 20,000-50,000 people.3 

Cause

OI is caused by dominant genetic defects or recessive mutations. Dominant (classical) OI is due to too little type I collagen or poor quality due to mutation of its genes. Recessive OI is due to mutations in other genes that interfere with collagen production resulting in fragile bones that break easily. Genetic counselors can help people with OI and their families to understand the genetics and possibility of recurrence with offspring.3 

Types of OI

Type I (Mild)

  • Bones are likely to break from mild to moderate trauma.
  • No change or only slight changes to stature.
  • Loose joints and muscle weakness.
  • Blue, purple, or gray tint to the sclera (whites of the eyes).
  • Triangular face.
  • Curved spine with potential for compression of the vertebrae (spine bones) with aging.
  • Mild or no bone deformity.
  • Possible changes to the strength and color of teeth.
  • Possible hearing loss.
  • Normal collagen structure, but less than the normal amount.

Type II (Most Severe)

  • Frequently causes death at birth or shortly after, because of the inability to breathe.
  • Numerous broken bones develop before birth while the baby is still in the womb.
  • Severe bone deformities.
  • Very small stature.
  • Underdeveloped lungs.
  • Blue, purple, or gray tint to the sclera.
  • Improperly formed collagen.

Type III (Severe)

  • Most severe type is among those who survive the neonatal period and usually results in the greatest number of physical disabilities.
  • Easily broken bones with very little trauma over a lifetime.
  • Small stature.
  • Blue, purple, or gray tint to the sclera.
  • Loose joints.
  • Poor muscle development in arms and legs.
  • Barrel-shaped rib cage.
  • Triangular face.
  • Curved spine and compression or collapse of vertebrae.
  • Possible lung problems that worsen with age.
  • Often severe bone deformity.
  • Possible changes to the strength and color of teeth.
  • Possible hearing loss.
  • Improperly formed collagen.

Type IV (Moderate)

  • Bones break easily, sometimes before birth, with most broken bones occurring before puberty.
  • Smaller than average stature.
  • White or blue tint to the sclera.
  • Mild to moderate bone deformity.
  • Vertebra compression or collapse.
  • Barrel-shaped rib cage.
  • Triangular face.
  • Possible changes to strength and color of teeth.
  • Possible hearing loss.
  • Improperly formed collagen.

Type V (Moderate)

  • Clinically similar to Type IV OI in appearance and symptoms.
  • A dense band is seen on X-rays by the cartilage growth plate of the long bones.
  • Unusually large calluses, called hypertrophic calluses, at the sites of fractures or surgical procedures.
  • Calcification of the membrane between the radius and ulna (the bones of the forearm), results in restricted arm movement.
  • Possible loose joints.
  • White sclera.
  • No changes to teeth.
  • “Mesh-like” appearance to bone when viewed under the microscope.
  • Changes in the minerals in the bone.

Type VI (Moderate)

  • Resembles Type IV OI in appearance and symptoms.
  • Not always diagnosed at birth, and symptoms progress over time.
  • “Fish-scale” appearance to the bone when viewed under the microscope.
  • Curved spine.
  • Diagnosed by bone biopsy or genetic studies.
  • Changes in the minerals in the bone.

Type VII (Severe) – Recessive Gene Form

  • Resembles Type II and Type III OI in appearance and symptoms.
  • White sclera.
  • Small stature.
  • Short humerus and short femur.
  • Possible smaller head size.
  • Changes in the process of forming collagen.

Type VIII (Very Severe) – Recessive Gene Form

  • Resembles Type II and Type III OI in appearance and symptoms.
  • White sclera.
  • Small stature.
  • Short humerus and short femur.
  • Possible smaller head size.
  • Changes in the process of forming collagen.4 

Complications

  • Ambulation
  • Spine curves
  • Dental problems
  • Hearing loss
  • Vision problems
  • Cardiac
  • Basilar Invagination (top of the second vertebrae moves upward) 5 

Treatment

  • There is no cure for OI.
  • Treatment is focused on prevention and symptom management.
  • Goals are to maximize independent mobility and develop optimal bone mass and muscle strength.
  • Therapy is often recommended for mobility and function.
  • Rodding is considered by the insertion of metal rods the length of the bone to strengthen them.3 
    • Intramedullary Fixation: surgically fixed length rod that helps fractures to heal and avoid/correct deformities. However, as the child grows, they are at risk for fracturing the leg below the rod.2 
  • Medications: growth hormone
  • Gene therapy3 
  • Spinal fusion for scoliosis6 

Prognosis

  • Varies depending on the number and severity of symptoms.
  • Respiratory failure is a common cause of death.
  • Accidental trauma is the second most common cause of death.

Outcome Measures

  • Brief Assessment of Motor Function (BAMF) 7 
  • OI Pediatric Specific Quality of Life Questionnaire (OI qual) 8 
  • Gross Motor Function Measure (GMFM) 9 
  • Bayley Scales of Infant and Toddler Development
  • Detailed Assessment of Speed of Handwriting (DASH) 10 11 

Occupational Therapy

  • Listen
  • Set goals
  • Address weakness
  • Address the fear of fractures
  • Address and modify the environment
  • Provide adaptive equipment and assistive technology
  • Practice safe handling
  • Use functional assessments
  • Address sports and exercise considerations
  • Provide problem-solving for self-care tasks5 
  • Prevent joint contractures
  • Prevent malalignment
  • Improve function for PADLs, transfers, and ambulation
  • Modify and provide graded activities
  • Encourage and provide problem-solving opportunities12 13 14 
  • Address psychosocial barriers, e.g., depression and anxiety4 

Health Management

  • Exercise to promote muscle and bone strength
  • Swimming and water therapy are good exercise choices (with little risk of fracture).
  • Walking is a good exercise.
  • Children with OI will benefit from maintaining a healthy weight and eating a nutritious diet.
  • Avoid smoking, alcohol, caffeine, and taking steroids as they deplete bone density and make them more fragile.
  • People can lead productive and successful lives with restricted physical activity.3 

Precautions

  • Don’t pull or push on a limb or bend it.
  • Use caution when taking blood pressure; avoid automatic blood pressure cuffs.
  • If a fracture is suspected, minimize handling of the affected limb.
  • Respect the opinions, advice, or instructions provided by parents or family.
  • Do not lift a baby from under the armpits.
  • Do not lift by the ankles to change diaper; slide a hand under the buttocks instead.15 

Additional Reading

  1. New perspectives on osteogenesis imperfecta. Forlino A, Cabral WA, Barnes AM, Marini JC Nat Rev Endocrinol. 2011 Jun 14; 7(9):540-57.[↩]
  2. Novick, N. (2011). Osteogenesis Imperfecta: A Multidisciplinary Approach to Treatment in Children. Retrieved from https://www.hss.edu/conditions_osteogenesis-imperfecta-approach-to-treatment.asp[↩][↩]
  3. Osteogenesis Imperfecta Foundation. (2017). Fast Facts on Osteogenesis Imperfecta. Retrieved from https://oif.org/wp-content/uploads/2019/08/Fast_Facts_About_OI.pdf[↩][↩][↩][↩][↩]
  4. NIH Osteoporosis and Related Bone Diseases National Resource Center. (n.d.). Osteogenesis Imperfecta Overview. Retrieved from https://www.bones.nih.gov/health-info/bone/osteogenesis-imperfecta/overview[↩][↩]
  5. Osteogenesis Imperfecta Foundation. (n.d.). Physical and Occupational Therapists Guide to Treating Osteogenesis Imperfecta. Retrieved from https://oif.org/wp-content/uploads/2019/08/PT_guide_final.pdf[↩][↩]
  6. American Academy of Orthopaedic Surgeons. (2018). Osteogenesis Imperfecta. Retrieved from https://orthoinfo.aaos.org/en/diseases–conditions/osteogenesis-imperfecta[↩]
  7. Brief assessment of motor function: reliability and concurrent validity of the Gross Motor Scale. Cintas HL, Siegel KL, Furst GP, Gerber LH Am J Phys Med Rehabil. 2003 Jan; 82(1):33-41.[↩]
  8. Quality of life in children and adolescents with Osteogenesis Imperfecta: a qualitative interview based study. Hill CL, Baird WO, Walters SJ Health Qual Life Outcomes. 2014 Apr 16; 12():54.[↩]
  9. Reliability of the gross motor function measure for children with osteogenesis imperfecta. Ruck-Gibis J, Plotkin H, Hanley J, Wood-Dauphinee S Pediatr Phys Ther. 2001 Spring; 13(1):10-7.[↩]
  10. Bayley N. Bayley Scales of Infant and Toddler Development. 3rd ed. San Antonio, TX: Pearson Education Limited; 2005.[↩]
  11. Barnett A, Henderson SE, Scheib B, Schulz J. Detailed Assessment of Speed of Handwriting (DASH) San Antonio, TX: Pearson Education Limited; 2007[↩]
  12. Comprehensive rehabilitation of the child with osteogenesis imperfecta. Binder H, Conway A, Hason S, Gerber LH, Marini J, Berry R, Weintrob J Am J Med Genet. 1993 Jan 15; 45(2):265-9.[↩]
  13. Osteogenesis imperfecta: diagnosis and treatment. Biggin A, Munns CF Curr Osteoporos Rep. 2014 Sep; 12(3):279-88.[↩]
  14. Rehabilitation approaches to children with osteogenesis imperfecta: a ten-year experience.
    Binder H, Conway A, Gerber LH Arch Phys Med Rehabil. 1993 Apr; 74(4):386-90.[↩]
  15. Osteogenesis Imperfecta Foundation. (n.d.). Introduction to Osteogenesis Imperfecta: A Guide for Medical Professionals, Individuals and Families Affected by OI. Retrieved from https://oif.org/wp-content/uploads/2019/08/Medical_Guide_revised_2013.pdf[↩]
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