MSK 4

Question 1

What is osteogenesis imperfecta?

Answer 1

brittle bone disease
a group of disorders of collagen metabolism causing bone fragility, with bowing and frequent fractures
3 most common forms
leading cause of lethal short limbed dwarfism
Autosomal dominant
• Diagnosis is mostly done prenatal but milder forms may not be picked up until much later

Question 2

What is type 1 osteogenesis imperfecta?

Answer 2

Childhood fractures, blue sclerae and some develop hearing loss
dilated aortic root and thin heart valves
may be hyperboility of the joints and the teeth can be affected
Treated with bisphosphonates

Question 3

What is type 2 osteogenesis imperfecta?

Answer 3

• This is the severe and lethal form, with multiple fractures already present before birth- many affected infants are still born
• Inheritance is variable, but mostly autosomal dominant or due to new mutations
• Scleral discolouration may be minimal

Question 4

What is type 3 osteogenesis imperfecta?

Answer 4

• This is a severely progressive form- the child will have various amounts of immature woven bone
• The child may be born with fractures and, as age increases, there is a noticeable short stature and impaired dentition

Question 5

What are the associated syndromes of polydactyly?

Answer 5

More than 5 digits on the hands or feet. 1 in 1000
o	Trisomy 13
o	Trisomy 21
o	Tibial hemimelia
o	Ellis-van Creveld syndrome

Question 6

What are the associated syndromes of syndactyly?

Answer 6

Fusion of two or more digits and occurs in 1 in 2500
o Apert syndrome
o Poland syndrome

Question 7

What is skeletal dysplasia?

Answer 7

characterised by abnormal growth of bones & cartilage resulting in abnormal shape and size of the skeleton and disproportion of the long bones, spine & head
broadly involves the growth plate and most commonly the zone of proliferation- this usually results in impaired strength
• They can be classified according to the region of bone involved or by their genotype

Question 8

What is achondroplasia?

Answer 8

Autosomal dominant (50% new mutations)
o	Short stature- from marked shortening of the limbs
o	A large head
o	Frontal bossing
o	Depression of the nasal bridge
o	Short & broad hangs
o	Marked lumbar lordosis
o	Hydrocephalus- sometimes occurs

Question 9

What is thanatophoric dysplasia?

Answer 9

results in still birth- the infants have a large head, extremely short limbs and a small chest
• The appearance of the bones on x-ray is characteristic
• The importance of the correct diagnosis of this disorder is that its inheritance is sporadic
• It may be identified on antenatal ultrasound

Question 10

What is cleidocranial dysostosis?

Answer 10

Autosomal dominant
absence of part or all of the clavicles and delay in closure of the anterior fontanelle and of ossification of the skull
• The child is often able to bring the shoulder together in front of the chest to touch each other as a ‘party trick’
• Short stature is usually present- intelligence is normal

Question 11

What is arthrogryposis?

Answer 11

Hetergenous group of congenital disorders in which there is stiffness and contracture of joints
association with oligohydramnios, widespread congenital anomalies or chromosomal disorders- it is usually sporadic
• Marked flexion contractures of the knees/elbows/wrists, dislocation of the hips & other joints, talipes equinovarus and scoliosis are common
• The skin in thin, subcutaneous tissue is reduced and there is marked muscle atrophy around the affected joints- intelligence is usually unaffected
disorder may be localised to the upper or lower limbs

Question 12

What is the management for arthrogryposis?

Answer 12

Physiotherapy and correction of deformities- where possible, by splints, plaster casts or surgery, walking is impaired in the more sever forms of the disorder

Question 13

How does osteopetrosis present?

Answer 13

stone/marble bone disease’- rare disorder, with bones being dense, but brittle
Autosomal recessive 
bone marrow transplant is curative 
o	FTT
o	Recurrent infection
o	Hypocalcaemia
o	Anaemia
o	Thrombocytopenia

Question 14

What is SLE?

Answer 14

• SLE is a complex, multisystem autoimmune disorder affecting adolescents
is rare in younger children female:male is 20:1 commoner and more severe in Afro-Caribbean, Hispanic and Far Eastern girls

Question 15

How is SLE diagnosed?

Answer 15

If 4 of the 11 features present simultaneously or serially
o Malar rash
o Discoid rash
o Photosensitivity
o Mouth ulcers
o Arthritis- non-erosive
o Serositis- pleurisy or pericarditis
o Renal disease- persistent proteinuria >0.5g/24hr or cellular casts
o Neurological disorders-psychosis or seizures in absence of known precipitants
o Haematological abnormality- haemolytic anaemia or leucopenia <4x109 on 2 or more occasions or thrombocytopenia <100x109/L
o Immunological- raised anti-DNA binding antibody, anti-Smith antibody and/or +ve anti-phospholipid antibodies
o Anti-nuclear antibody

Question 16

What are the clinical features of SLE?

Answer 16

o	Low grade fever
o	Weight loss
o	Fatigue
o	Anorexia
o	Lymphadenopathy
•	Mucocutaneous problems
o	Hair loss
o	Mouth ulcers
o	Photosensitivty  50%
o	Raynaud’s phenomenon  90%
o	Butterfly rash over nose
o	Discoid lesions
o	Livido reituclaris
o	Urticarial rashes
o	Purpuric rashes
•	Cardiovascular
o	Pericarditis
o	Myosititis
o	Valvulitis with endocarditis
•	Pulmonary
o	Pleurisy
o	Pleural effusion
o	Haemoptysis from pulmonary vascultitis
o	Intersitial fibrosis
o	Pneumonitis
•	Haematological
o	Anaemia
o	Leucopenia
o	Lymphopenia
o	Thrombocytopenia
•	Neurological
o	Migraine
o	Mood disorders
o	Psychoses
o	Seizures

Question 17

What are the msk features of SLE?

Answer 17

o	Polyarthritis- resembling RA
o	Tendonitits
o	Arthralgia
o	Myalgia
o	Myositis- 5%
o	Aseptic necrosis