Osteoporosis

Question 1

Define OP.

Answer 1

Complex skeletal disease, characterised by low bone density and micro-architectural defects in bone tissue resulting in increased bone fragility and susceptibility to fracture.

Question 2

Who is most affected?

Answer 2

White, post-menopausal women.

Question 3

What is the pathophysiology of OP?

Answer 3

· Imbalance in the bone remodelling process&raquo_space;> ‘thinning / less dense bones’.
· Osteocytes play a principal role in the initiation of bone remodelling.
· Osteoclasts resorb bone matrix.
· Osteoblasts synthesise bone matrix.
· Bone remodelling is regulated by hormones including PTH, vitamin D, calcitonin and oestrogen.

Question 4

Bone strength is determined by what 5 factors?

Answer 4

· Bone Mineral Density - BMD. 
· Size and shape of bone. 
· Bone turnover.
· Micro-architecture.
· Bone minerals.

Question 5

List the potential risk factors.

Answer 5

· Prior fragility fracture. 
· Female.
· White. 
· >50 years old for women, and >65 years old for men. 
· Low BMI.
· Post-menopause. 
· Smoking.
· Excessive alcohol use. 
· Prolonged immobilisation. 
· Low calcium intake.
· Vitamin D deficiency. 
· Corticosteroid use. 
· Hyperthyroidism.

Question 6

What are the typical signs and symptoms of OP?

Answer 6

· Vertebral fractures:

• Back pain.
• Kyphosis.

· Pain and swelling at fracture site.

Question 7

What investigations would you request if you suspected a patient had OP?

Answer 7

· DEXA scan.
· X-ray.
· Serum calcium, creatinine, phosphate, 25-hydroxy vitamin D, PTH, TFTs.

Question 8

What DEXA scan T-score diagnoses OP?

Answer 8

T-score of

Question 9

Suggest some differentials.

Answer 9

· Multiple myeloma.
· Osteomalacia. 
· CKD. 
· Primary hyperparathyroidism. 
· Metastatic bone malignancy.

Question 10

How do you treat a patient with OP?

Answer 10

1st - Bisphosphonates, e.g. alendronic acid.

Plus - Calcium and Vitamin D supplementation.

2nd : if oral bisphosphonates not tolerated - debosumab.

Question 11

Complications?

Answer 11

· Hip fractures.
· Rib fractures.
· Wrist fractures.
· Jaw necrosis associated with bisphosphonate treatment.