Congenital MSK Disorders

Question 1

what is osteogenesis imperfecta

Answer 1

also known as brittle bone disease it is a defect of the maturation and organisation of type 1 collagen (which accounts for most of the organic composition of bone)

Question 2

what are the symptoms of autosomal dominant cases (majority) of osteogenesis imperfecta

Answer 2

multiple fragility fractures of childhood short stature with multiple deformities blue sclerae with loss of hearing

Question 3

what are the symptoms of autosomal recessive cases of osteogenesis imperfecta

Answer 3

fatal in perinatal period or associated with spinal deformity

Question 4

how do the bones tend to be in osteogenesis imperfecta

Answer 4

thin (gracile) with thin cortices and osteopenia

Question 5

what do different types of osteogenesis imperfecta look like

Question 6

how is osteogenesis imperfecta diagnosed

Answer 6

thorough but sensitive history and exam beware of child abuse or ostopenia (result from prematurity and result in low energy fractures)

Question 7

what is treatment of osteogenesis imperfecta

Answer 7

fractures heal with abundant but poor quality callus and treated with splintage, traction or surgical stabilisation

Question 8

some cases of osteogenesis imperfecta develop progressive deformity, how is this treated

Answer 8

may require multiple osteotomies and intramedullary stabilisation for correction (Sofield procedure)

Question 9

what is skeletal dysplasia

Answer 9

medical term for short stature which is due to genetic error (hereditary or sporadic)

Question 10

what is most common type of skeletal dysplasia and what are its features

Answer 10

achondroplasia autosomal dominant but >80% cases sporadic short limbs with prominent forehead and widened nose joints are lax and mental development normal

Question 11

other types of skeletal dysplasia may be associated with what

Answer 11

learning difficulties spine deformity limb deformity internal organ dysfunction craniofacial abnormalities tumour (esp haemangiomas) joint hyper mobility atlanta-axial subluxation spinal cord compression (myelopathy) intrauterine or premature death

Question 12

how is skeletal dysplasia treated

Answer 12

genetic testing orthopedic = deformity correction (eg scoliosis) and limb lengthening growth hormone therapy may be appropriate

Question 13

what are connective tissue disorders associated with

Answer 13

disorders of collagen synthesis (mainly type 1) that affects soft tissues more than just bone

Question 14

what are examples of connective tissue disorders

Answer 14

generalised (familial) joint laxity marfan’s syndrome ehlers-danlos syndrome downs syndrome

Question 15

what is generalised familial joint laxity and what is consequence

Answer 15

autosomal dominant hypermobility more prone to soft tissue injuries (ankle sprains) and recurrent dislocations

Question 16

what is marfans syndrome

Answer 16

autosomal dominant sporadic mutation of fibrillar gene which results in tall stature with disproportionately long limbs and ligamentous laxity

Question 17

what are associated features of marfans

Answer 17

eye problems eg glaucoma high arched palate in mouth spontaneous pneumothorax apical blebs pectus excavatum or carinatum aortic aneurysm, dissection or regurgitation mitral valve prolapse or regurg arachnodactyly (long fingers/toes) scoliosis

Question 18

what is ehlers danlos syndrome

Answer 18

heterogenous condition (often autosomal dominant) where there is abnormal elastin and collagen formation

Question 19

what is clinical features of ehlers danlos

Answer 19

profound joint hypermobility vascular fragility with ease of bruising joint instability scoliosis bony surgery may be required but problem cause bleeding and poor skin healing (wound dishcence and stretched scar)

Question 20

what are the MSK features of down syndrome

Answer 20

short stature joint laxity recurrent dislocation (esp patella) which may require stabilisation atlanto-axial instability in c spine

Question 21

what are muscular dystrophies

Answer 21

rare and usually X linked recessive hereditary disorders (only affecting boys) resulting in progressive muscle weakness and wasting

Question 22

what are the two kinds of muscular dystrophy

Answer 22

duchenne muscular dystrophy becker’s muscular dystrophy

Question 23

what is duchenne muscular dystrophy and what is its sign

Answer 23

defect in dystrophin gene involved in calcium transport may only be noticed when boy start to walk with difficulty standing (Gower’s sign) and going up stairs

Question 24

what is consequence of duchenne muscular dystrophy

Answer 24

progressive muscle weakness and by age 10 he can no longer walk by age 10 progressive cardiac and respiratory failure develop with death typically in early 20s

Question 25

what is beckers muscular dystrophy

Answer 25

similar to DMD but milder so affected boys able to walk into teens and may survive into 30s or 40s

Question 26

although these only occur in boys due to X linked inheritance, can vvvvvvv occasionally happen in girls, when

Answer 26

if gets one faulty gene on one chromosome and the girl lacks a second X chromosome entirely or if the second X chromosome has sustained serious damage

Question 27

how are muscular dystrophies diagnosed

Answer 27

confirmed by raised serum creatinine phosphokinase abnormality on muscle biopsy

Question 28

how is muscular dystrophies treated

Answer 28

physiotherapy, splintage and deformity correction may prolong mobility severe scoliosis may be corrected by spinal surgery