LOCO1

Question 1

Briefly explain why a DEXA scan is used to measure bone mineral density 2 marks

Answer 1

DEXA scans use two low energy x-rays beams (1 mark) this increases the sensitivity of the scan in measuring bone density (1 mark)

Question 2

What type of bone is most susceptible to developing osteoporosis and explain why?
2 marks

Answer 2

Trabeculae bone 1 mark
Because it turns over quicker and more often than cortical bone.

Question 3

What biochemical changes are observed in the osteoarthritic articular cartilage?
(2 marks)

Answer 3

Reduced proteoglycan content
Change from collagen type 2 to type 1

Question 4

What is the mode of action of the alendronate and what is long term potential side effect for patients taking this drug?
2 marks

Answer 4

It inhibits osteoclast mediated bone resorption 1 mark
Osteonecrosis of the jaw or pathological femoral fractures as a result of low bone turnover 1 mark
 

Question 5

Explain pathophysiology of OA [4]

Answer 5

 pathology of the entire unit of a synovial joint

 Imbalance between the cartilage being worn down and the chondrocytes repairing it leading to structural issues in the joint.

 A failure in maintaining the homeostatic balance of the cartilage matrix synthesis and degradation, resulting from reduced formation or increased catabolism.

 Severe OA the cartilage is so thin that no longer covers the thickened bone joints

 The loss of cartilage, the wearing of bone, and the bony overgrowth at the edges can change the shape of the joint.

Question 6

Describe a common complication of OA [1]

Answer 6

 A common complication is where chalky deposits of calcium crystals form in the cartilage (a process called calcification or chondrocalcinosis).

• These calcium crystals can shake loose from the cartilage, irritate the synovium and cause the joint to become hot, red and swollen (pseudogout).

Question 7

Hand signs of OA? [5]

Answer 7

• Heberden’s nodes (in the DIP joints)
• Bouchard’s nodes (in the PIP joints)
• Squaring at the base of the thumb at the carpo-metacarpal joint
• Carpo-metacarpal joint commonly effected
• Weak grip
• Reduced range of motion

Question 8

Describe diagnostic process for OA [3]

Answer 8

 The diagnosis of osteoarthritis is largely clinical based on the presence of characteristic symptoms:

o Is 45 or over and
o Has activity-related joint pain and
o Has either no morning joint-related stiffness or morning stiffness that lasts no longer than 30 minutes.

Question 9

Non-pharmological therapy for OA? [4]

Answer 9

• Exercise & manual therapy
• **Weight loss **
• Electrotherapy: Transcutaneous electrical nerve stimulation (TENS)
• Aids & devices
  o Appropriate footwear
  o Bracing / joint supports
  o Walking sticks

Question 10

Describe the 4 lines of pane management for OA [4]

Answer 10

• 1st line:
  o Topical analgesia

* 2nd line:
o Topical analgesia & paracetamol

* 3rd line
o NSAID + paracetamol + topical capsaicin

* 4th line
o opioid + NSAID + paracetamol + topical capsaicin

Question 11

Name a PPI given with NSAIDs (for OA) [1]

Answer 11

• omeprazole

Question 12

Name a topical treatment used for OA [1]

Answer 12

o Capsaicin topical
o diclofenac topical:
o ketoprofen

Question 13

Name an intra-articular joint injection used to treat OA [[1]

Answer 13

methylprednisolone acetate

Question 14

Describe pathophysiology of OP

Answer 14

Question 15

Name 5 risk factors for OP

Answer 15

 Older age – menopause
 Female
 White ethnicity
 Reduced mobility and activity
 Low BMI (< 18.5 kg/m2)
 Rheumatoid arthritis
 Alcohol and smoking
 Long term corticosteroids. NICE suggest the risk increases significantly with the equivalent of more than 7.5mg of prednisolone per day for more than 3 months)
 Other medications such as SSRIs, PPIs, anti-epileptics and anti-oestrogens

Question 16

Which DEXA scores (Z or T) are used in clinical diagnosis of OP? [1]

Answer 16

T score

Question 17

Where do you conduct a OP DEXA scan from? [1]

Answer 17

• Hip measurement is used for OP diagnosis

Question 18

Where do you conduct a OP DEXA scan from? [1]

Answer 18

• Hip measurement is used for OP diagnosis

Question 19

Name two results in blood that would indicate OP diagnosis [2]

Answer 19

• 25(OH)D blood test – good indicator – hers is below in the scenario
• Phosphate levels

Question 20

What DEXA scan scores would indicate: [3]

Normal
Osteopenia
Osteoporosis

Answer 20

• Normal: a T-score > -1
• Osteopenia: a T-score of -1 to -2.5
• Osteoporosis: a T-score of ≤ -2.5

Question 21

Name a bisphosphinate drug used to treat OP [1]

Describe the MoA

Answer 21

Alendronate:
* prevents inhibition of osteoclast formation, bone resorption, and kinase activation in vitro.

Question 22

Describe the MoA of Denosumab [1]

Answer 22

o is a monoclonal antibody that works by blocking the activity of osteoclasts.

Question 23

Describe the MoA of Raloxifene [1]

Answer 23

It is a selective oestrogen receptor modulator that stimulates oestrogen receptors on bone but blocks them in the breasts and uterus.

Question 24

Which foods should be targeted for OP patients

Answer 24

• Salmon and mackerel
• Maintain a healthy weight
• Adequate calcium intake
• Adequate vitamin D
  o Ergocalciferol (Vit D)
• Stop smoking
• Reduce alcohol consumption

Question 25

Explain the results table

Answer 25

Explain results table: ALP raised osteoblasts are making more of enzyme. Low 25 (OHD) suggests that not absorbing much calcium from gut, so increased extraction from bones. Ca is normal so PTH is also normal