Paeds- Congenital Disorders Flashcards
Osteogenesis Imperfecta
known colloquially as brittle bone disease, osteogenesis imperfect is a defect of the maturation and organization of type 1 collagen (which accounts for most of the organic composition of bone).
Osteogenesis Imperfecta signs & symptoms
majority are autosomal dominant with multiple fragility fractures of childhood, short stature with multiple deformities, blue sclerae and loss of hearing.
Rarer cases are autosomal recessive and are either fatal in the perinatal period or associated with spinal deformity.
Osteogenesis Imperfecta investigation
Multiple fractures can be mistaken for child abuse / Non‐Accidental Injury (NAI).
Osteopenia can also result from prematurity and result in low energy fractures.
Thorough but sensitive history and examination.
Bones tend to be thin (gracile) with thin cortices and osteopenic.
Mild cases may have relatively normal xrays with history of low energy fractures.
Osteogenesis imperfects treatment
Fractures tend to heal with abundant but poor quality callus and are treated with splintage, traction or surgical stabilization.
Some cases develop progressive deformity which may require multiple osteotomies and intramedullary stabilization for correction (Sofield procedure).
Skeletal dysplasia
medical term for short stature (dwarfism is no longer used) and is due to genetic error (hereditary or sporadic mutation) resulting in abnormal development of bone and connective tissue.
short stature may be proportionate (limbs and spine proportionally short) or disproportionate (limbs propotionally shorter or longer than spine).
more than 300 types
Most common type skeletal dysplasia
commonest and most recognized type is achondroplasia which may be autosomal dominant, however over 80% of cases are sporadic.
Achondroplasia results in disproportionately short limbs with a prominent forehead and widened nose.
Joints are lax and mental development is normal.
Skeletal dysplasia symptoms
associated with learning difficulties, spine deformity, limb deformity, internal organ dysfunction, craniofacial abnormalities, skin abnormalities, tumour formation (especially haemangiomas), joint hypermobility, atlanto‐axial subluxation, spinal cord compression (myelopathy) and intrauterine or premature death.
Skeletal dysplasia investigation & treatment
Genetic testing of the child and family should be considered and orthopaedic treatment comprises of deformity correction (including severe scoliosis correction) and limb lengthening.
Growth hormone therapy may be appropriate.
Connective Tissue Disorders
due to genetic disorders of collagen synthesis (mainly type 1 found in bone, tendon and ligaments) resulting in joint hypermobility.
Osteogenesis imperfecta predominantly affects the type 1 collagen of bone whereas the connective tissue disorders affect soft tissues more than bone.
Types of connective tissue disorders
Generalised (Familial) Joint Laxity
Marfan’s syndrome
Ehlers‐Danlos syndrome
Down syndrome
Generalised (Familial) Joint Laxity
Around 5% of normal people have hypermobility of the joints which usually runs in families and is inherited in a dominant manner. Patients may describe themselves as “double‐jointed” and be able to perform tricks as a party piece (eg voluntary dislocation of the shoulder).
People with generalized ligamentous laxity are more prone to soft tissue injuries (ankle sprains) and recurrent dislocations of joints (especially shoulder and patella) which may be painful.
Marfan’s syndrome
autosomal dominant or sporadic mutation of the fibrillin gene resulting in tall stature with disproportionately long limbs and ligamentous laxity.
Associated features include a high arched palate, scoiliosis, flattening of the chest (pectus excavatum), eye problems (lens dislocation, retinal detachment), aortic aneurysm and cardiac valve incompetence.
Cardiac abnormalities may result in premature death.
Patient’s rarely require orthoapedic surgery (scoliosis and bony procedures for joint instability eg fusions) and soft tissue stabilization of dislocating joints usually has disappointing results as the biological abnormality cannot be corrected
Ehlers‐Danlos syndrome
heterogeneous condition which is often autosomal dominantly inherited with abnormal elastin and collagen formation.
Clinical features include profound joint hypermobility, vascular fragility with ease of bruising, joint instability and scoliosis.
Bony surgery may be required for dislocating joints however bleeding can be a problem and skin healing can be poor with stretched scars or wound dehiscence common.
Down Syndrome
Musculoskeletal manifestations of Trisomy 21 include short stature and joint laxity with possible recurrent dislocation (especially patella) which may require stabilization.
Atlanto‐axial instability in the c‐spine can also occur (see later).
Muscular Dystrophies
rare and usually X‐linked recessive hereditary disorders (therefore only affecting boys) resulting in progressive muscle weakness and wasting.
