Congenital disorders of the MSK System

Question 1

What is skeletal dysplasia?

Answer 1

Medical term for short stature, due to a genetic error resulting in abnormal development of bone and connective tissue.

Question 2

Describe the features of achondroplasia

Answer 2

Autosomal dominant, but 80% sporadic. Disproportionately short limbs with prominent foreheard and widened nose. Lax joints, normal mental development

Question 3

What symptoms can skeletal dysplasia be associated with?

Answer 3

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.

Question 4

What treatment is recommended in achondroplasia, and some skeletal dysplasias?

Answer 4

Genetic testing of child and family. Deformity correction and limb lengthening. Growth HT may be appropriate

Question 5

What are congenital connective tissue disorders due too?

Answer 5

Genetic disorders of collagen synthesis (mainly type 1 found in bone, tendon and ligaments), resulting in joint hypermobility. Often soft tissues affected more than bone in CT disorders

Question 6

What is the inheritance in Marfan’s?

Answer 6

Autosomal dominant or sporadic mutation of the fibrillin gene

Question 7

What are the main features of Marfan’s?

Answer 7

Tall stature with disproportionately long limbs and ligamentous laxity

Question 8

What are the associated features of Marfan’s?

Answer 8

High arched palate, scoiliosis, flattening of chest (pectus excavatum), eye problems (lens dislocation, retinal detachment), aortic aneurysm and cardiac valve incompetence

Question 9

What may cause premature death in a Marfan’s patient?

Answer 9

Cardiac abnormalities

Question 10

What is the treatment of Marfan’s?

Answer 10

Rarely require surgery (scoliosis and bony procedures for joint instability e.g. fusion). Soft tissue stabilisation of dislocating joints usually disappointing as abnormality cannot be corrected

Question 11

What is Ehlers Danlos syndrome?

Answer 11

Heterogenous condition which is often AD inherited with abnormal elastin and collagen formation.

Question 12

What are the clinical features of Ehlers Danlos?

Answer 12

Profound joint hypermobility, vascular fragility with ease of bruising, joint instability and scoliosis.

Question 13

What is the treatment for Ehlers Danlos?

Answer 13

Bony surgery may be required for dislocating joints, bleeding can be problem however and skin healing can be poor-stretched scars or wound dehiscence common.

Question 14

What are the orthopaedic features of Down syndrome?

Answer 14

Short stature, joint laxity with possible recurrent dislocation (especially patella) which may require stabilisation. Atlanto-axial instability in c-spine can also occur

Question 15

What are muscular dystrophies?

Answer 15

Rare and usually X-linked recessive hereditary disorders (male only) resulting in progressive muscle weakness and wasting

Question 16

In what gene is the defect found in Duchenne muscular dystrophy?

Answer 16

Dystrophin gene-involved in calcium transport

Question 17

What happens in Duchenne md?

Answer 17

Gene defect results in muscle weakness which may only be noticed when the boy starts to walk with difficulty standing (Gower’s sign) and going up stairs

Question 18

What occurs around age 10 then 20 in Duchenne md?

Answer 18

At 10 or so the patient can no longer walk, and by 20 progressive cardiac and resp failure develop with death typically in the early 20s.

Question 19

How is Duchenne’s diagnosed?

Answer 19

Confirmed by raised serum creatinine phosphokinase and abnormalities on muscle biopsy

Question 20

What is the treatment of Duchenne’s?

Answer 20

Physiotherapy, splintage and deformity correction may prolong mobility. Severe scoliosis may be corrected by spinal surgery