Musculo-Skeletal Pathology Non-Neoplastic 02/10/18

Question 1

What are the 4 non-neoplastic causes of MSK disease?

Answer 1

Connective tissue diseases
Metabolic diseases
Fractures
Degenerative Disease

Question 2

What are the basics of the 4 Hypersensitivity reactions?

Answer 2

1 - Immediate IgE
2 - Antibody mediated
3 - Immune complex mediated
4 - Delayed/Cell mediated

Question 3

Are connective tissue diseases autoimmune?

Answer 3

yes

Question 4

The presence of what characterises a connective tissue disease?

Answer 4

Autoantibodies

Question 5

What percentage of the population have a connective tissue disease?

Answer 5

1-2%

Question 6

Give 2 conditions and their autoantibodies

Answer 6

Rhematoid arthritis - rheumatoid factor
Lupus - often structural parts of DNA
Scleroderma - Anti-centromere
Dermatomyositis - Anti Jo

Question 7

What is Rheumatoid arthritis?

Answer 7

Inflammation of the joints

Question 8

What autoantibodies are present in reumatoid arthritis?

Answer 8

Rheumatoid factor

Autoantibody agains Fc IgG

Question 9

Can rheumatoid arthritis be systemic?

Answer 9

Yes

Question 10

What is formed in the acute phase of RA?

Answer 10

Pannus

Inflammatory granulation tissue at the edges and over the articular surfaces of joints

Question 11

What happens to the cartilage in RA?

Answer 11

It is destroyed

Question 12

What occurs in the chronic phase of RA?

Answer 12

Fibrosis

Deformity

Question 13

What kind of condition is SLE?

Answer 13

Prototypic systemic auto-immune condition

Question 14

What are the autoantibodies directed at in SLE?

Answer 14

DNA

Question 15

ANA is +ve in what percentage of lupus patients?

Answer 15

95%

Question 16

What are some other antibodies found in SLE?

Answer 16

Anti double stranded DNA
\+ve anti-sm 
RNP
SS-A
SS-B

Question 17

What cells are present in chronic inflammation?

Answer 17

Lymphocytes and plasma cells

Question 18

What are the acute histological signs in inflammatory conditions?

Answer 18

Oedema
Fibrin
Reactive features in synovial cells

Question 19

What are 3 metabolic diseases?

Answer 19

Pagets
Osteomalacia
Crystal arthropathies

Question 20

What is an example of a crystal arthropathy?

Answer 20

Gout

Question 21

What is the end product of purine synthesis?

Answer 21

Uric acid

Question 22

What 2 DNA bases are purine based?

Answer 22

Adenine and Guanine

Question 23

When is urate formed?

Answer 23

DNA replication

Question 24

What are the two reasons for Hyperuricaemia?

Answer 24

Increased production of Uric acid

Reduced excretion

Question 25

Why does increased production of uric acid occur?

Answer 25

Usually idiopathic HGPRT deficiency Increased cell turnover - Psoriasis, Leukamia

Question 26

What is a reason for reduced excretion of uric acid?

Answer 26

Drugs - Thiazide diuretics

Question 27

What are the clinical manifestations of hyperuricaemia?

Answer 27

``` Precipitation of crystals Usually in joints Elicit acute inflammatory reaction Gouty tophus Renal disease ```

Question 28

What are the pathological findings of hyperuricaemia?

Answer 28

Long thin needle shaped crystals | Amorphous eosinophillic debris and inflammation

Question 29

What can Calcium pyrophosphate deposition cause?

Answer 29

Common crystal arthropathy | Psuedogout or chondrocalcinosis

Question 30

What are the symptoms of pseudogout?

Answer 30

Usually none | May have joint pain

Question 31

What is seen on investigations for psuedogout?

Answer 31

Large Rhombus shaped crystals

Question 32

What is paget's disease?

Answer 32

Abnormality of bone turnover | Increased osteoclastic activity but not normally structured

Question 33

What causes Pagets disease?

Answer 33

Not sure Genetic? Viral infection

Question 34

What are the three stages of Paget's disease?

Answer 34

Osteolytic Mixed Burnt Out

Question 35

Are the reversal lines normal in pagets?

Answer 35

No they are mosaic like

Question 36

When can pagets cause pain?

Answer 36

Microfracture or nerve compression

Question 37

What does pagets do to bones?

Answer 37

``` Enlargement and abnormal shape Leontiasis Ossea Platybasia Sabre tibia ```

Question 38

What is the malignancy that pagets can cause?

Answer 38

Osteosarcoma

Question 39

What metabolic affects can pagets have?

Answer 39

Heat Warm skin AV shunt Cardiac failure

Question 40

What is osteomalacia?

Answer 40

Abnormal Vitamin D metabolism

Question 41

What is osteomalacia related to?

Answer 41

Sun exposure

Question 42

What does osteomalacia cause?

Answer 42

``` Rickets Bowed legs Square heads Pigeon chest Rickety rosary ```

Question 43

What is a pathological fracture?

Answer 43

Where the fracture is outkeeping with the level of trauma | E.g. Osteoporitic fractures, Tumours

Question 44

What are the initial phases of trauma?

Answer 44

Haematoma Influx of inflammatory cells Cytokine release After a week - callus, organised haematoma, early remodelling at bone ends

Question 45

What occurs during weeks 2-3 of bone repair?

Answer 45

Maximum girth of callus Woven bone deposited perpendicular to cortical bone Cartilage deposition at fracture site which undergoes endoochondral ossification Bridging with bony callus

Question 46

What causes bony lesions?

Answer 46

Malignant proliferation of plasma cells

Question 47

What is the difference between osteosclerotic and osteolytic lesions?

Answer 47

Sclerotic - appear as areas of opacity (prostate) | Lytic - Bone is resorbed and appear as radiolucent

Question 48

What is Avascular necrosis?

Answer 48

Bone infarction

Question 49

What causes avascular necrosis?

Answer 49

Alcohol Trauma Steroids

Question 50

What shape is the infarct in avascular necrosis?

Answer 50

Wedge shaped | Subcortical

Question 51

What is an example of a degenerative disease?

Answer 51

Osteoarthritis

Question 52

What are the stages involved in joint changes?

Answer 52

``` Early - small cracks in cartilage Fibrillation Cartilage is worn away Bone on Bone Surface becomes polished - eburnation Cortical bone thickens greatly to cope with load Leakage of synovial fluid forming small cysts Rapid bone remodelling Mistakes are made and osteophytes form ```

Question 53

What is eburnation?

Answer 53

Subchondral sclerosis

Question 54

What is a subchondral cyst?

Answer 54

Synovial fluid accumulation

Question 55

What is an osteophyte?

Answer 55

Disorganised bone remodelling