Osteogenesis Imperfecta: When Bones Break Too Easily

Dr Bonita S Pradhan

Imagine being told that something as ordinary as a fall, a bump, or sometimes even an everyday movement could result in a broken bone.

For most of us, bones are something we rarely think about. They support us, protect our organs and allow us to move through life without much consideration. But for people living with osteogenesis imperfecta, the bones themselves can be unusually fragile.

Osteogenesis imperfecta, commonly known as OI or brittle bone disease, is a rare genetic disorder in which bones fracture more easily than normal. But describing OI simply as “bones that break easily” does not tell the whole story.

It is a condition that can affect much more than the skeleton.

What is osteogenesis imperfecta?

The name itself comes from Latin: osteogenesis means bone formation, while imperfecta means imperfect.

OI is a group of inherited disorders that primarily affect the strength and quality of connective tissue, particularly bone. In many people, the underlying problem involves changes in genes responsible for producing or processing type I collagen, an important structural protein found throughout the body.

Think of collagen as part of the framework that gives tissues their strength and flexibility. When that framework is altered, bones can become less resistant to fracture.

However, OI is not one single disease with one predictable presentation.

There are different types and varying degrees of severity. Some individuals may experience frequent fractures beginning in infancy or childhood, while others may have relatively mild disease and remain undiagnosed until adulthood.

It is not always obvious at birth

One of the misconceptions about OI is that it must be immediately apparent in a newborn.

That is not necessarily the case.

In severe forms, fractures can occur before birth or shortly afterwards, and the condition may be recognized very early in life. In milder forms, however, a child may appear completely healthy and simply seem to fracture bones more often than expected.

A history of repeated fractures after relatively minor trauma may eventually prompt further investigation.

Other features can provide clues as well. Depending on the type and severity, people with OI may have short stature, abnormal curvature of the spine, joint hypermobility or characteristic changes in the shape of the bones.

One particularly recognizable feature in some individuals is blue or greyish sclerae — the whites of the eyes appearing bluish because of the relative thinness of the connective tissue beneath them.

Dental problems can also occur, particularly dentinogenesis imperfecta, in which the teeth may be unusually fragile or discolored.

Hearing loss is another possible feature, particularly in some adults with OI.

The important point is that these features vary considerably. Someone with OI may have several of them, only one or two, or none that are immediately noticeable.

Why do the bones fracture?

Normal bone is not simply a hard, lifeless structure.

It is a living tissue that is constantly being formed and broken down. Its strength depends on a combination of minerals and an organized structural framework, including collagen.

In many forms of OI, alterations in type I collagen affect the quality or quantity of this framework.

The result is bone that may be less able to withstand mechanical stress.

This is why fractures in OI can sometimes occur after injuries that would not normally be expected to cause a fracture.

But there is an important distinction here:

Fragile bones do not mean a fragile person.

People with OI may have significant physical limitations, but many lead active, independent and fulfilling lives.

Is OI inherited?

Yes, most forms of osteogenesis imperfecta are genetic.

Many cases are caused by a change in a single copy of a gene and are inherited in an autosomal dominant pattern. However, other inheritance patterns exist, and some cases occur because of a new genetic change in a child without either parent having the condition.

This is one reason genetic counselling can be valuable for individuals and families affected by OI.

A diagnosis is not simply about understanding what caused a person’s fractures. It can also help families understand the likelihood of OI occurring in future pregnancies and what testing options may be appropriate.

How is it diagnosed?

There is no single test that identifies every case of OI.

Doctors usually begin with the person’s history and examination, paying particular attention to fracture history, family history and associated features.

X-rays can provide important clues, particularly when there are characteristic changes in bone structure or evidence of previous fractures.

Depending on the circumstances, genetic testing can help identify disease-causing variants and may establish the specific form of OI.

Sometimes, however, genetic testing does not identify a mutation even when the clinical picture strongly suggests OI.

This is where specialist assessment becomes particularly important.

Can osteogenesis imperfecta be treated?

There is currently no treatment that simply makes the underlying genetic change disappear.

But that does not mean that nothing can be done.

Fractures need appropriate treatment, but care goes beyond treating each broken bone as it occurs. Physiotherapy and carefully planned physical activity can help maintain muscle strength, mobility and independence.

In children, orthopedic interventions may sometimes be used to correct significant deformities or improve mobility.

Medications such as bisphosphonates are used in some people with OI, particularly children with more significant bone fragility. They can increase bone mineral density and may reduce fracture burden in selected patients, although treatment needs to be individualized and monitored by specialists.

Dental care, hearing assessment, nutritional support and attention to spinal and respiratory health may also form part of long-term management.

The goal is not simply to prevent every possible fracture.

It is to help a person move, function and live as independently as possible while protecting their bones and overall health.

What about exercise?

For someone unfamiliar with OI, the instinct might be to think that people with brittle bones should avoid physical activity altogether.

In reality, complete inactivity can create its own problems.

Muscle weakness and reduced mobility can make daily life more difficult and may further compromise physical function. Appropriate physical activity, usually planned with healthcare professionals familiar with OI, can help maintain strength, coordination and independence.

The type and intensity of activity must be individualized.

The message is not “don’t move.”

It is move safely and intelligently.

Growing up with OI

For a child, living with OI can involve much more than medical appointments.

There may be missed school days, repeated hospital visits, restrictions on certain activities and the constant concern of sustaining another fracture.

Parents can also find themselves living with a difficult balance: wanting to protect their child without making them feel incapable.

This is where good medical care extends beyond prescriptions and procedures.

Children with OI should be supported in developing independence, participating in education and social activities, and understanding their own bodies.

They are not defined by their fractures.

The adult with OI

OI is not something that necessarily disappears when childhood ends.

Adults with OI may continue to experience fractures, chronic pain, joint problems, spinal abnormalities or hearing difficulties. Some may also face challenges related to mobility, employment and accessibility.

At the same time, many adults with OI have careers, relationships, families, hobbies and completely ordinary lives.

The severity of the condition varies enormously, and it is important not to assume what a person can or cannot do simply from their diagnosis or appearance.

A condition that deserves understanding, not pity

Perhaps one of the most important things we can change is the way we think about rare diseases.

Someone with OI may look perfectly healthy while living with a condition that requires considerable planning and adaptation.

They may need to think carefully about how they move, travel, exercise or manage everyday environments.

That does not make them weak.

And it certainly does not mean that their lives should be defined by limitations.

Osteogenesis imperfecta reminds us that medicine is not always about finding a cure. Sometimes it is about understanding a condition deeply enough to reduce its impact, prevent avoidable complications and help a person live as fully as possible.

For someone with OI, a broken bone may be part of their medical history.

It should never become the entirety of their story.