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