Osteomalacia Flashcards
What causes osteomalacia?
LOW VIT D LEVELS
What are the primary causes of low vit d levels?
Diet
What are 4 secondary causes of osteomalacia?
CKD
Bowel disease
Hypophosphataemia
Anti-convulsants
How can anti convulsants reduce vit d levels?
Can cause chronic acidosis
What step in osteomalacia does low vit d3 levels lead to?
Defective mineralisation of bone
What happens to this unmineralised bone?
Accumulates into a matrix
What is the name of the matrix of unmineralised bone that accumulates in osteomalacia?
Osteoid
What are the levels of bone in osteomalacia?
Normal just not mineralised
What does osteomalacia cause in kids?
Rickets
What is rickets?
Defective mineralisation of the epiphyseal growth plates
What are the signs of rickets?
BOW LEGS
Soft spot on head
“Bony necklace”
Curvy bones
Big lumpy joints
What are the causes of hyperphosphataemia WITHOUT hypercalcuria?
Fanconi’s syndrome
High aluminium ingestion
What is fanconi’s syndrome?
Renal proximal tubule dysfunction
What are the causes of hyperphosphataemia WITH hypercalcuria?
Dents disease
HHRH
What is dents disease?
X linked defective chloride channel
What is HHRH?
Hereditary hyperphosphataemia rickets with hypercalcamia
Neurological signs of osteomalacia?
Hyporeflexia
Parasthesia
Proximal weakness (Late sign)
What can be seen o/e with proximal weakness?
Difficulty rising from chair
What may be seen in the mouth in osteomalacia?
Dental deformity
Diagnosis of osteomalacia?
Bloods
Imaging
Alk phos, PTH, Calcium and phosphate levels?
Alk phos = high
Calcium = low
Phosphate = low (unless hyperphosphataemia)
PTH = high
Why is PTH high?
Negative feedback
What may be seen on wrist x ray in children with osteomalacia?
Champagne glass wrist
