December 13, 2011
We’ve looked at a variety of medical conditions and how they affect emergency evacuations from the school bus, including TBI and near drowning, cerebral palsy, DMD and SMA.
In the fifth edition of the series, we will discuss evacuating students who have osteogenesis imperfecta (OI).
Specifics of OI
OI is a genetic disorder that is commonly called “brittle bone disease.” The disorder is inherited, and both genders are affected. OI is characterized by bones that break easily, often from little to no apparent cause.
It has been found that children who have OI have a problem with the development of collagen in their body. Collagen can be described as the framework upon which bone and tissues are built. If the collagen is defective, bones fracture more easily and muscles lack tone.
There are currently four known types of OI.
Type I OI:
- This is the mildest and most common form.
- These children have half the normal amount of collagen. However, this collagen is structurally normal.
- They may have muscle weakness, joint laxity and flat feet along with dislocations and sprains.
- Life expectancy seems average.
Type II OI:
- This is the most severe form.
- Infants are quite small at birth, and they are born with multiple fractures, an unusually soft skull and an unstable neck.
- Almost all infants with Type II die at or shortly after birth.
Type III OI:
- These children are born with fractures, and X-rays may reveal healed fractures that occurred before birth.
- They may have anywhere from several dozen to several hundred fractures in a lifetime. With these children, surgical correction of long bone bowing and scoliosis is common.
- They may need supplemental oxygen.
- Life expectancy varies.
Type IV OI:
- This is considered the moderate form.
- These children will have frequent fractures that decrease after puberty.
- They have mild to moderate bone malformation.
- Life expectancy appears to be average.
With all four types of OI, fractures decrease after puberty.
Researchers are beginning to identify additional types of OI, namely Type V and Type VI.
The type of OI is determined based on clinical and radiographic data. When working with a student with OI, it is important to focus on his or her particular abilities, strengths and weaknesses rather than the particular OI type.
OI treatment involves caring for fractures, maximizing independent mobility and function, and developing optimal bone mass and muscle strength.
Orthopedic surgery can be done to insert metal rods into the long bones to reduce malformations and control fractures. Medications developed for perimenopausal osteoporosis are currently being tested for OI.
Implications for evacuation
Here are some key factors to keep in mind for evacuating students with OI from the school bus.
1. Just the impact of an accident may cause a fracture for a student with OI. The staff must be extremely careful in how they move and handle the student.
2. When students with OI have to be evacuated from the bus, they will be best protected in their mobility device (unless it is motorized - see No. 3), especially if it is a customized molded seating system. Bus staff must be extremely careful as they move the mobility device out of the bus.
3. If a student with OI is in a motorized mobility device, it will be necessary to remove the student from the device.