Orthopaedics

Question 1

What are some risk factors for the development of osteoporosis?

Answer 1

• Non-modifiable - age, female, FHx, thin frame, Caucasian/Asian
• Modifiable - smoking, BMI, low sun exposure, drugs, alcohol/coffee/protein excess, insufficient exercise

Question 2

Describe some secondary causes of osteoporosis

Answer 2

• Drugs: glucocorticoids, heparin, loop diuretics, GnRH agonists, phenytoin
• Disease states: hyper-PTH, hyperthyroidism, hypogonadism, Cushing’s, malabsorption, metastatic bone disease, multiple myeloma, RA, chronic renal failure

Question 3

What is the difference between a T-score and a Z-score on bone densitometry?

Answer 3

• T-score - compared to 30y/o healthy adult (# of standard deviations)
• Z-score - compared to age and sex-matched adult (SDs) - may be a flag for secondary causes
• Sclerotic conditions like osteoarthritis might falsely increase lumbar spine scores