What is Osteogenesis Imperfecta?
Osteo-bone Genesis- creation Imperfecta- imperfect.
A disease most commonly caused by a mutation to the
COL1A1 and COL1A2 genes.
It is both a dominant and recessive disorder, however
between 85 and 90 percent of O.I. cases are dominant.
Incidence 1 in 20,000
Abnormal synthesis and structural defects of type 1 collagen
Abnormalities of bones,teeth,ligaments,sclerae and skin
Defining clinical features- osteopenia,
liability to fracture
laxity of ligaments
blue discoloration of sclera
Alteration in structural integrity or reduction in total
amount of type 1 collagen
Bone formation is initiated in the normal way but progresses
abnormally, fully formed tissue consisting of a mixture of
woven and lamellar bone and in worst cases almost entirely
of immature woven bone
Propensity to fracture even with minor trauma, often
without pain and swelling
Fracture recur throughout childhood
Callus formation is florid
New bone is abnl,remains‘plaible’- malunion
By 6yrs-deformities of long bones, vertebral compression #
Blue or grey sclera
Teeth-discolored and carious
In severe cases,infant is stillborn or lives for few weeks
death due to resp failure
intracranial hemorrhage following injury
Symptoms of Osteogenesis Imperfecta
Scoliosis (Curvature of the Spine).
Blue or GrayTint in theWhites (sclera) of the Eye.
May develop hearing loss later in adulthood (Can be as early as 20s or
30s). This is linked to deformities in the inner ear and three small bones
in the middle ear.
Brittle and underdeveloped teeth.
OI patients often bruise easily.
Delays in motor development.
Diagnosis of OI
Fractures occurring with little or no trauma
Short stature or stature shorter than predicted
Progressive, post-pubertal hearing loss.
Thinning of long bones
#s in various stages of healing
Vertebral compression & spinal #
Skull enlarged, presence of wormian bone
Based on well-differentiated pattern of inheritance
Age of presentation
Severity of changes in the bones & extra skeletal tissues
Helps in assessing prognosis and planning treatment
SILLENCE(1981)- four clinical types of OI
OI Type I (mild)
The commonest variety; over 50% of all cases
#s usually appear at 1-2yrs of age
Healing is reasonably good & deformities not marked
Sclera deep blue
Teeth usually normal, some have dentinogenesis imperfecta
Impaired hearing in adults
Quality of life good; normal lfe expectancy
Autosomal dominant inheritance
OI Type II( lethal)
5-10% of cases
Intra-uterine and neonatal #s
Large skull and wormian bones
Rib fractures and respiratory difficulty
Stillborn or survive for only few weeks
Most due to new dominant mutations; some autosomal
OI Type III( severe)
The‘classic’, but not common form
#s often present at birth
Large skull,wormian bones;pinched-looking face
Marked deformities and kyphoscoliosis by 6yrs
Sclera grey,becoming white
Marked joint laxity
Poor quality of life; few survive to adulthood
Sporadic, or autosomal recessive inheritance
OI Type IV
Uncommon; less than 5% cases
Frequent #s during early childhood
Sclera pale blue or normal
Survive to adulthood with fairly good function
Autosomal dominant inheritance
Conservative Rx- preventing #,using light weight orthoses
during physical activity, treating # when they occure
General measures to prevent recurent truma , maintain
movment, encourage social adaptation are very imp
Normal casts would actually harm patients with OI.
Instead specialized casts are used due to the brittle nature of
Fiberglass offers a lighter and more comfortable solution for
The main purpose of casts is to immobilize the broken limbs.
However immobilization should be limited in order to
prevent bone loss.
For less serious breaks, parents are also taught to wrap bones
for their children.
Traction is used to regain alignment of a fracture by applying
force to the body part. It also can relieve muscle spasms
while the bone is healing. Skeletal traction is applied directly
to the bones using pins, wires, or screws.
Exercise and Physical Therapy
Regular exercise helps the patients to become stronger and
Swimming and water exercise is the best way for OI patients
to become more fit because it causes less stress on bones than
any other sport.
Cyclical administration of iv BISPHOSPHONATES are
resently popular in severe OI [ MOA- inhibit bone
Direct effect of bisphosphonate-decrease resoption & turn
over of bone
The resulting deceasing bone pain & # -lead to increase
weight bearing & mobility
It alter the natural course of the disease
Other medical Rx- hgh, vitamines, androgens
Rods are added in order to strengthen bones.
These rods are either non-expandable or expandable. Non-
expandable rods are very versatile but must be changed as the
child grows. Expandable rods grow with the bone, but are
only suitable for larger bones such as the femur.
Spinal rodding is used in severe cases of Scoliosis.
Surgery is also used in order to mend the broken bones.
.Simple undisplased # -plaster cast & splint
Avulsion # olecranon-TBW
Severe cases- Special techniques
IM Rodding of long bone –it allows corection of
deformitoies, put weight bearing line ,along the axis of bone,
allows continous growth
Sofields methods- consist of multiple ostiotomies,
realignment & IM nail fixation,
It is useful for long bones & is indicated for fresh #
&correction of bowing
There is no growth disterbances in this technique
Baily & Duboys – telescopic medullary rod is used which
elongates as growth occurs
Williams- retrograde nailing is done by fixing an extention
to the distal end of the rod and driving the nail through the
Spinal deformity is also common and is difficult to Rx
Bracing is ineffective & progressive curves require operative
instrumentation and spinal fusion
After adolascence, # less common, patient may reasonably