November 13, 2009

Osteogenesis Imperfecta

Steogenesis Imperfecta (OI), also known as brittle-bone disease, is a genetic (inherited) disorder characterized by bones that break easily without a specific cause. An estimated 20,000 to 50,000 people in the US have this disease.

The disorder occurs in one out of 20,000 to one out of 60,000 live births. OI can affect males and females of all races.

What causes osteogenesis imperfecta?
The cause of OI is believed to be due to a genetic defect that causes imperfectly-formed, or an inadequate amount of, bone collagen - a protein found in the connective tissue.

What are the types and symptoms of OI?
The following are the most common symptoms for osteogenesis imperfecta. However, each individual may experience symptoms differently. Although symptoms may vary, generally they are used to classify the four forms of OI, each of which represents the severity of the condition.

According to the Osteoporosis and Related Bone Diseases National Resource Center, part of the National Institutes of Health (NIH), the types of OI and their symptoms include the following:

Type I:

  • most common
  • bones fracture easily
  • can usually be traced through the family
  • near normal stature or slightly shorter
  • blue sclera (the normally white area of the eye ball)
  • dental problems
  • hearing loss beginning in the early 20s and 30s
  • most fractures occur before puberty; occasionally women will have fractures after menopause
  • triangular face
  • tendency toward spinal curvatures
Type II:
  • newborns severely affected; frequently fatal
  • usually resulting from a new gene mutation
  • very small stature with extremely small chest and under developed lungs
Type III:
  • tend to be isolated family incidents
  • very small in stature - some only 3 feet tall
  • fractures at birth very common
  • x-ray may reveal healing of in utero fractures
  • severe early hearing loss
  • loose joints and poor muscle development in arms and legs
  • barrel-shaped rib cage
Type IV:
  • can frequently be traced through the family
  • bones fracture easily - most before puberty
  • normal or near normal colored sclera
  • problems with teeth - more than Type I
  • spinal curvatures
  • loose joints

The symptoms of osteogenesis imperfecta may resemble other medical conditions or problems. Always consult your physician for a diagnosis.

How is osteogenesis imperfecta diagnosed?
In addition to a complete medical history and physical examination, diagnostic procedures for osteogenesis imperfecta may include a skin biopsy to evaluate the amount and structure of collagen. However, this test is complicated and not many qualified facilities are available to perform the procedure. It is not unusual for results of the biopsy to take up to six months.

Additional diagnostic tests may include:
  • x-ray - a diagnostic test which uses invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs onto film
  • an examination of the ear, nose, and throat (to detect hearing loss)

Treatment for Osteogenesis Imperfecta
Specific treatment for osteogenesis imperfecta will be determined by your physician based on:

  • your age, overall health, and medical history
  • extent of the disease
  • your tolerance for specific medications, procedures, or therapies
  • expectations for the course of the disease
  • your opinion or preference
To date, there is no known treatment, medicine, or surgery that will cure osteogenesis imperfecta (OI). The goal of treatment is to prevent deformities and fractures and allow the child to function as independently as possible. Treatments for preventing or correcting symptoms may include:
  • care of fractures
  • surgery
  • rodding - a procedure to insert a metal bar the length of a long bone to stabilize it and prevent deformity
  • dental procedures
  • physical therapy
  • assistive devices, such as wheelchairs, braces, and other custom-made equipment
Management of Osteogenesis Imperfecta (OI)
Management of the disease includes focusing on preventing or minimizing deformities, and maximizing the individual's functional ability at home and in the community. Management of OI is either non-surgical or surgical. Non-surgical interventions may include one or more of the following:
  • physical therapy
  • positioning aids (to help sit, lie, or stand)
  • braces and splints (to prevent deformity and promote support or protection)
  • medications
  • psychological counseling
Surgical interventions may be considered to manage the following conditions:
  • fractures
  • bowing of bone
  • scoliosis - a lateral, or sideways curvature and rotation of the back bones (vertebrae), giving the appearance that the person is leaning to one side.
  • heart problems
Surgery may also be considered to maintain the ability to sit or stand. Long-Term Outlook for an Individual with Osteogenesis Imperfecta (OI)
Osteogenesis imperfecta (OI) is a progressive condition that needs life-long management to prevent deformity and complications. The interdisciplinary healthcare team helps the family to improve the functional outcomes and to provide support. The Osteogenesis Imperfecta Society can also be an important resource.