About the authors
Dr Jenny Ault
Professor David Sillence
Ms Verity Pacey
Download full article (.pdf 108kB)
What is osteogenesis imperfecta?
Osteogenesis imperfecta, commonly abbreviated as OI, refers to a group of disorders with increased likelihood to fracture throughout life. There are many different genetic types of OI.
Due to the fractures, students with osteogenesis imperfecta may have their schooling and learning disrupted at times. Support and assistance and flexibility with learning programs can be very important. The tendency to fracture will vary in children with osteogenesis imperfecta. Within a year, fractures may occur occasionally or multiple times.
Fractures can occur in any bone. Finger, arm and leg fractures occur more often than rib or skull fractures. Crush fractures may occur in the vertebral bones in the spine. The increased likelihood of fractures results from children with osteogenesis imperfecta having:
Osteoporosis can be documented in children by bone densitometry using a machine calibrated for children. Fortunately the osteoporosis in osteogenesis imperfecta can now be treated very effectively with medication.
All children in New South Wales can be referred by their general practitioner for assessment to the centre of expertise (eg the Connective Tissue Dysplasia Clinic at The Children’s Hospital at Westmead, or similar) and most children with osteogenesis imperfecta are referred.
The different types of osteogenesis imperfecta are numbered in Roman numerals and, for practical purposes, types I, III, IV, and V are encountered in school-aged children. The numerals do not correspond to severity but to the order in which each disorder was named.
There are also several other very rare types of osteogenesis imperfecta with specific names, eg Bruck type, Cole-Carpenter type and several types in which the child has a visual impairment as well as a tendency to fracture.
A classification for grading severity, eg mild, moderate, and severe osteogenesis imperfecta, has been adopted. This can be a useful tool to assist communication between health professionals, parents and school staff.
Associated features in some, but not all, children with osteogenesis imperfecta include:
In some children with osteogenesis imperfecta, the teeth are a yellowish colour due to affected dentine (dentinogenesis imperfecta), and wear or chip much more easily. Present practice is to crown the molar teeth with stainless steel and/or coat the teeth with a hard plastic (composite).
These children need extra dental care and may need time off school for dental appointments.
Many children with osteogenesis imperfecta are shorter than their peers. If the child’s trunk is very short adjustments may be needed, eg attending to the height of the school desk and other working benches. Adjustments can include ‘common sense’ adaptations such as a step to reach the bubblers or toilets.
Back pain in children with osteogenesis imperfecta should be taken seriously and teachers need to report concerns about pain to the parent/carer as this can interfere with concentration and may affect school academic performance.
All varieties of osteogenesis imperfecta are heritable. Many children with osteogenesis imperfecta have a parent with OI, but a proportion of school-aged children with OI are the first ones affected in their family (sporadic inheritance).
The extent of bone fragility is hard to predict as it varies in any child depending on his or her underlying type of osteogenesis imperfecta, mobility, activities, personality (adventurous or cautious), treatment stage and age. The frequency of fractures appears to increase in the first year or two after preschool or school entry. Generally, there are fewer fractures after puberty.
Children in this group may also have joint hypermobility (very flexible joints) and a tendency to bruising.
Several medications are used and these are given either intravenously in hospital or as tablets which can be taken at home.
Where the bone density is very low, intravenous infusions of bisphosphonates (Pamidronate or Zometa) given every 1–3 months in hospital, may significantly improve bone density, activity levels, and energy, although the tendency to fracture is still present. There are very few side effects.
Once the fracture has been set and the student is ready to attend school again he or she may need to take an analgesic for pain. The procedures for the administration of prescribed medication in schools in schools should be followed.
Deformity in arms, legs and spine may develop and become more marked during childhood. The osteogenesis imperfecta management team, including orthopaedic surgeons, makes every effort to prevent deformity occurring.