OSTEOGENESIS IMPERFECTA

Nama Kelompok:

1. Putu Agung Wirahadi Sanjaya

2. I Made Oka Mahendra

3. Putu Feryawan Meregawa

PROGRAM PENDIDIKAN DOKTER SPESIALIS

ORTHOPAEDI DAN TRAUMATOLOGI

BAGIAN/SMF ORTHOPAEDI DAN TRAUMATOLOGI FK UNUD/RSUP

SANGLAH DENPASAR

2014

Osteogenesis Imperfecta

History

Osteogenesis Imperfecta (OI) is one of the common form of skeletal dysplasioa. OI

is geneticaly congenital osteoporosiswhich result in weakness and fragility of the

bones (Salter,1999). In patient with osteogenesis imperfecta (OI) there is

abnormality of synthesis and structural of type I collagen(Salter,1999).. This result

some defect in several organ such as ones, teeth, ligaments, sclerae and skin.APP

Pathological fractures are common in patient with OI(Salter,1999).

Prevalence

Osteogenesis imperfecta (OI) is one of the commonest of the genetic disorders of

bone, with an estimated incidence of 1 in 20 000(Salter,1999). Type I is the most

commonest (Dietz, 2003)

Clinical features

Clinical features of patient with OI have some variation. The most severe is the

propensity to fracture generally after minor trauma and often without much pain or

swelling(Solomon et al, 2010). The pathological fracture usually start to occur

during infancy and less frequent after puberty. In the classic case fractures are

discovered during infancy and they recur frequently throughout

childhood(Solomon et al, 2010). Callus formation is florid, so some practitioner

difficult to distinguish OI with osteosarcoma(Solomon et al, 2010). Fracture

healing result in abnormal bone and it remains pliable for a longtime, thus

predisposing to malunion and pathological fracture. When the children with OI is 6

years old usually there are severe deformities of long bone and vertebrae.

Compression fracture of vertevbrae lead to kyphoscoliosis (Solomon et al, 2010).

Patients with OI have thinner skin and hypermobile joints. They usually have blue

and grey sclera because uveal pigment showing through the hypertranslucent

cornea (Solomon et al, 2010). They also have discoloured teeth. In milder cases

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pathological fractuyre usually aoccur when the children begin to walk. Some

children have less pathological fracture but obvious deformity. In severe cases

fractures may be occur before birth and the infants is ether stillborn or lives only

for a few weeks. The infant with OI usually die in a few weeks due to respiratory

failure, basilar indentation or intracranial haemorrhage following injury (Solomon

et al, 2010).

Simple classification of clinical feature of OI divided into 4 type (Dietz,2003) .

Type Clinical Features

I Osseous fragility 9mild tomoderate)

Blue Sclera

Mixed hearing loss

Mitra valve prolapsed

II Osseouse fragilitry (very severe)

Short calvarium

Shortr trunk and limbs

Small chest and protuberant abdomen

Early lethaly

III Osseous fragility (severe)

Progressive deformity

Short stature

Normal sclera

IV Osseous fragility

Normal sclera

Dentinogenesis imperfect

Occasional severe deformity

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X-ray finding in baby with Osteogenesis Imperfecta (Dietz,2003)

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Pathology

Genetic factor as a basic pathology of OI has made an alteration in structural

intergrity and reduction in total amount of type I collagen (Solomon, 2010). Type I

collagen is one of the major components of fibrillar connective tissue in

skin,ligament and bone(Solomon, 2010). Bone formation is initiated in the normal

way but it progresses abnormally. The initial tissue form a mixture of woven and

lamellar bone. In worst cases the newly foring bone only consist of woven bone.

There is thinning of the dermis, laxity of ligaments, increased corneal translucency

and (in some cases) loss of dentin leading to tooth decay (Solomon, 2010)

Genetics

Osteogensis imperfect is autosomal dominant. Autosomal recessive was confirmed

by biochemical and molecular level. Chromosomal defect locations are on

17q21.31-q22 and 7q22.1. Gene involved are COLIAI (collagen type I alpha1

chain) and COLIA2 (collagen type I alpha 2chain). Almost OI caused by

heterozygous mutation in type I collagen. Type I collagen is trimer. It is made of

two chain pro alpha 1 and pro alpha 2 encoded by COL1A1 and COL1A2. The end

result of mutation is failure of synthesis a chain or inability to be incorporated into

trimeric molecule result in mild OI. The amount of collagen type I is reduced but

the quality is normal (Dietz, 2003).

Management

The Goal of conservative treatment are preventing and treating fracture. Splintage

should not be overdone because this lead to osteopenia(Solomon,2010). The most

important is to prevent trauma, balance movement and good social interaction.

Biphosphonat increase bone mineral density and reduce pathological fracture in

severe cases. The most difficult problem are encountered in type III and IV.

Immobilization must be kept to a minimum (Solomon 2010). Severe long bone

deformity are common because malunion and recurrent pathological fracture

(Solomon,2010). Operative correction is very important on these cases usually at 4

or 5 years old. The operator will perform multiple osteotomy and then

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intramedulary rod will be applied to realigned the bone fragment. Telescoping nail

will facilitate the growing bone. Deformity in vertebral bone is common and

difficult to treat. Brace application does not prevent progressive curve growth.

Operative instrumentation and spinal fusion are required on these cases (Solomon,

2010).

REFERENCES

1. Dietz, F. R. (2003). Genetics for Orthopedic Surgeons: The Molecular Genetic Basis of Orthopedic Disorders. The Journal of Bone & Joint Surgery, 85(11), 2273-2273.

2. Salter, R. B. (1999). Textbook of disorders and injuries of the musculoskeletal system: an introduction to orthopaedics, fractures and joint injuries, rheumatology, metabolic bone disease, and rehabilitation. Williams & Wilkins.

3. Solomon, L., Warwick, D. J., & Nayagam, S. (2010). Apley's system of orthopaedics and fractures. CRC Press.

NAMA KELOMPOK:

1. Putu Agung Wirahadi Sanjaya

2. I Made Oka Mahendra

3. Putu Feryawan Meregawa

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