1. Congenital Disorders of MSK

Question 1

osteogenesis imperfecta

Answer 1

inherited disorder of type I collagen that results in fragile, low density bones

Question 2

is OI dominant or recessive

Answer 2

dominant

Question 3

osteogenesis imperfecta: majority of cases

Answer 3

multiple fragility fractures of childhood, short state with multiple deformitites, blue sclerae and loss of hearing

Question 4

osteogenesis imperfecta: what can multiple fractures be mistaken for

Answer 4

child abuse/non-accidental injury

Question 5

osteogenesis imperfecta: what can osteopenia result in

Answer 5

low energy fractures

Question 6

osteogenesis imperfecta: what are the bones like

Answer 6

thin cortices and osteopenic

Question 7

osteogenesis imperfecta: how may a mild case present

Answer 7

normal x ray with history of low energy fractures

Question 8

osteogenesis imperfecta: how do fractures tend to heal and how are they treated

Answer 8

tend to heal with abundant but poor quality calus

treated with splintage, traction or sugical stabilisation

Question 9

osteogenesis imperfecta: when Sofield procedure indicated

Answer 9

progressive deformities develop that require multiple osteotomies and intramedullary stabilisation for correction - sofield procedure

Question 10

osteogenesis imperfecta: what is the mildest and most common form

Answer 10

type I

normal life expectancy

Question 11

osteogenesis imperfecta: severe form

Answer 11

type III

recessive

Question 12

skeletal dysplasias

Answer 12

medical term for short stature

due to geneteic error resulting in the abnormal development of bone and connective tissue

may be proportionate or disproportionate

Question 13

skeletal dysplasias: what does dis/proportionate refer to

Answer 13

relative length of limbs and spine

Question 14

achondroplasia

Answer 14

most common type of disproportionate short stature

short limbs with prominent forehead and widened nose

lax joints

normal mental developement

Question 15

skeletal dysplasias: what testing and treatment should be considered

Answer 15

genetic testing of child and family

orthopedic treatment - deformity correction and limb lengthening

growth hormonal therapy may be appropriate

Question 16

connective tissue disorders

Answer 16

genetic disorders of collagen synthesis (mainly type I) resulting in joint hypermobility

tend to affect soft tissue rather than bone (osteogenesis imperfecta)

Question 17

generalised joint laxity

Answer 17

hypermobility present in normal population - ‘double-jointed’

people are more prone to OA, soft tissue injuries and recurrent dislocations

Question 18

inheritance pattern for generalised joint laxity

Answer 18

dominant

Question 19

how is marfans syndrome acquired

Answer 19

AuD or sporadic mutation fibrillin gene resulting in tall stature with disproportionately long limbs and ligamentous laxity

Question 20

what may cause premature death in marfans syndrome

Answer 20

cardiac abnormalities

Question 21

features of marfans syndrome

Answer 21

Question 22

ehlers danlos syndrome

Answer 22

heterogenous condition with abnormal elastin and collagen formation

Question 23

ehlers danlos syndrome: inheritance pattern

Answer 23

dominant

Question 24

ehlers danlos syndrome: clinical features

Answer 24

• profound joint hypermobility
• skin is fragile, poor healing (wound dehiscence common) and easily bruised
• some forms are associated with scoliosis

Question 25

down syndrome

Answer 25

MSK manifestations of trisomy 21 include short stature and joint laxity with possible recurrent dislocation atlanto-axial instability in the C spine can also occur

Question 26

muscular dystrophies

Answer 26

rare **X-linked recessive (only boys)** disorders resulting in progressive muscle weakness and wasting

Question 27

Duchenne Muscular Dystrophy

Answer 27

mutations in **dystrophin gene** involved in Ca transport results in muscle weakness which may only be noticed when the boy starts walking with difficulty standing and going up stairs

Question 28

Duchenne Muscular Dystrophy: gower's sign

Answer 28

Question 29

Duchenne Muscular Dystrophy: course

Answer 29

no abnormaliy noticed at birth progressive muscle weakness follows so by age 10 cant walk by 20 progressive cardiac and resp failure develop typically die in early 20s

Question 30

Duchenne Muscular Dystrophy: diagnosis

Answer 30

raised serum creatinine phosphokinase and abnormalities on muscle biopsy physio, splintage and deformity correction may prolong mobility severe scoliosis corrected by surgery

Question 31

Becker's Muscular Dystrophy

Answer 31

similar to DMD but milder with boys able to walk in their teens sufferers may survive till 30s and 40s