Musculoskeletal

Question 1

What is osteomyelitis

Answer 1

an infection of bone

Question 2

What is the most common cause of osteomyelitis and which antibiotic is used to treat it?

Answer 2

Staphylococcus aureus

Flucloxacillin IV is the treatment of choice for
osteomyelitis

Question 3

What is septic arthritis

Answer 3

Inflammatory reaction in joint space (arthritis) caused by infection
Result from direct invasion of the joint
Can be native or prosthetic joints

Question 4

What is the pathogenesis of osteoarthritis?

Answer 4

Chondrocytes produce interleukin-1 – initiates matrix breakdown
Prostaglandin derivatives induces the release of lytic enzymes – prevents matrix synthesis

Question 5

What are the criteria for diagnosis of Rheumatoid arthritis?

Answer 5

Morning stiffness
Arthritis in 3 or more joint areas
Arthritis of hand joints
Symmetric arthritis
Rheumatoid nodules
Serum Rheumatoid factor

4 of the above criteria

Question 6

What are the sero-negative artheritides? (lack rheumatoid factor)

Answer 6

Ankylosing spondylitis
Reiter’s syndrome
Psoriatic arthritis
Enteropathic arthritis

Question 7

What is gout?

Answer 7

End point of a group of disorders producing hyperuricemia
Uric acid is the end product of purine metabolism
Deficiency of the enzymes involved

Question 8

what are tophi?

Answer 8

Tophi = Latin for ‘‘stone’’

A deposit of uric acid crystals

Question 9

What is Paget’s disease of the bone caused by?

Answer 9

osteoclast dysfunction caused by paramyxovirus

Question 10

What is osteomalacia?

Answer 10

Defects in matrix mineralization due to lack of Vit D
Decreases bone density - if too little bone = osteopenia
Skeletal deformities are not seen

Question 11

What is the treatment for a native joint infection with staph. aureus?

Answer 11

Flucloxacillin IV

Question 12

What are the treatments for a prosthetic joint infection with staph. aureus and Coagulase negative Staph. respectively

Answer 12

Flucloxacillin plus rifampicin IV for s. aureus

Vancomycin plus rifampicin IV for CoNS

Question 13

What is osteoporosis?

Answer 13

Osteoporosis is a reduction in bone mass in the presence of normal mineralisation

Question 14

How does chronic renal disease cause renal osteodystrophy?

Answer 14

Inadequate renal tissue - impaired activation of vit D causes osteomalacia

High serum phosphates - inhibit renal enzymes activating vit D and decreases ionised calcium in serum causing hyperparathyroidism

Question 15

What is ankylosis of joints?

Answer 15

Ankylosis (bent, crooked) is a stiffness of a joint due to abnormal adhesion and rigidity of the bones of the joint

Question 16

What is the pathogenesis of Rheumatoid arthritis?

Answer 16

Polypoid fibrovascular thickening of the synovium with synoviocyte hyperplasia, producing a pannus that is eroding into the articular cartilage
Continued growth of the pannus and erosion of the cartilage with penetration into the subchondral bone and cyst formation
Filling of joint space with pannus producing ankylosis of joint space-

Question 17

Which genes increase susceptibility to Rheumatoid arthritis?

Answer 17

(Human Leucocyte antigen) HLA- DR4
and
HLA-DR1

Question 18

What cellular immunological abnormalities occur in rheumatoid arthritis?

Answer 18

A type IV hypersensitivity reaction

CD4 Tcells attract macrophages and synoviocytes which secrete TNF-alpha and IL-1

Question 19

What is Malignant Hyperthermia?

Answer 19

Inherited disease – fast rise in body temperature and severe muscle contraction when the affected person gets general anaesthesia

Question 20

What is Rhabdomyolysis and what are its symptoms?

Answer 20

Destruction of skeletal muscle
Release of muscle fibre content into blood
Myoglobin is released into the blood stream
Filtered through the kidney and enters urine- myoglobinuria- brown urine

Question 21

What is Duchenne muscular dystrophy?

Answer 21

Sex-linked recessive disorder
Mutation of the gene coding for dystrophin
Relentlessly progressive wasting, chair-bound by 12 years
Proximal muscle weakness
Hypertrophy of calves

Question 22

what is Emery-Dreifuss Muscular Dystrophy?

Answer 22

Defects of muscle cell nuclear membrane-related proteins called emerins and lamin A/C

X-linked recessive
Weakness of proximal arm and distal leg muscles
Early contractures
Cardiomyopathy

Question 23

What is Core disease?

Answer 23

Dominantly inherited
The central core is a well demarkated zone in the centre of a muscle fibre, devoid of normal histochemical reactivity (NADH-Tr)
Cores only occur in type I fibres
Not usually detected until child has started walking

Question 24

What is myasthenia gravis?

Answer 24

Autoimmune disease with antibodies, usually IgG, against the acetylcholine receptor

Question 25

Which Inflammatory myopathy is responsible for chronic debilitating disease and associated with a scaly rash?

Answer 25

Dermatomyositis