Metabolic bone disorders Flashcards
What causes high calcium and high PTH levels? (primary hyperparathyroidism)
Duye to:
Presence of adenoma (one or more benign tumours)
Hyperplasia of one or more parathyroid glands
What causes high calcium and low PTH levels?
Malignancy
Excess calcium intake
Granulomatous disease
Medications
What causes low calcium and low PTH levels?
Idiopathic
Neck surgery
Radiotherapy
Severe magnesium deficiency
What causes low calcium and high PTH levels? (secondary hyperparathyroidism)
Vitamin D deficiency
Renal failure
what is primary hyperparathyroidism caused by?
Overactive parathyroid gland due to a problem within the PT gland itself.
what is secondary hyperparathyroidism caused by?
overactive parathyroid gland secondary to some other reason and not due to problem in PT gland
What are osteomalacia and rickets caused by, and what is the difference between the two?
Vitamin D deficiency, resulting in Inadequate mineralisation in bone.
Osteomalacia = adults Rickets = children
What is osteogenesis imperfects also known as? Describe it. What sign is indicative of it?
brittle bone disease
Defective type 1 collagen
Prone to breaking and fractures
Slight blueness in the sclera
what is Paget’s disease ? what problems can it cause?
Excessive breakdown and formation (turnover) of bone which causes bones to weaken. This leads to bone pain, fractures, arthritis and misshapen/deformed bones.
Other problems include: hearing loss and high output cardiac failure
What effect does renal disease have on bone turnover?
Reduces bone turnover
If hypercalcemia is detected what steps should be taken for further diagnosis?
Check PTH levels
If they are undetectable = malignancy
If they are detectable or high = primary hyperparathyroidism (usually an adenoma)
list some clinical X-ray features of hyperparathyroidism
Bone resorption
Decrease in bone density
Calcium deposits (chondrocalcinosis)
Brown tumours: significant erosion of cortex
what is osteoPETrosis and what effect does it have on bones?
Osteopetrosis:
Excessive bone formation
High bone mass
Makes bones prone to breaking
what is fluorosis?
Fluoride instead of calcium due to abnormal matrix mineralisation
what are clinical features of osteomalacia ?
Bone tenderness
Bone pain
Proximal muscle weakness without atrophy (waddling gait)
How do CALCIUM levels compare in those with Osteoporosis, Osteomalacia and 1ry Hyperparathyroidism?
OP: normal
OM: normal or LOW
PH: high
How do PHOSPHATE levels compare in those with Osteoporosis, Osteomalacia and 1ry Hyperparathyroidism?
OP: normal
OM: normal or LOW
PH: normal or LOW
How do ALKALINE PHOSPHATASE levels compare in those with Osteoporosis, Osteomalacia and 1ry Hyperparathyroidism?
OP: normal (high after fracture)
OM: normal or HIGH
PH: Normal or HIGH
How do 25OH vitamin D levels compare in those with Osteoporosis, Osteomalacia and 1ry Hyperparathyroidism?
OP: normal or LOW
OM: Low
PH: Normal or Low
How do PTH levels compare in those with Osteoporosis, Osteomalacia and 1ry Hyperparathyroidism?
OP: normal
OM: High
PH: high
