Hypophosphataemic rickets and osteomalacia

Occurs impaired renal tubular reabsorption

of phosphateCalcium levels normal, no

hyperparathyroidism defective of bone mineralization

Familial hypophosphaetamic rickets◦Commonest form, X-linked◦Infancy looks normal, with genu valgum/varus◦Adult heterotopic bone formation

Treatment◦Phosphate (up to 3 gr/day) and large

dose of vitamin D◦Bony deformities may require

bracing or osteotomy

• Hyperparathyroidism–Primary : adenoma,hiperplasia–Secondary : persistent hypocalcemia–Tertiary : when secondary hyperplasia

leads to autonomous activityStimulating tubular absorption,intestinal

absorption,bone resorption calcinosis, stone formation, recurrent infection, impaired function(kidney)

Severe cases : osteoclastic hyperactivity produces subperiosteal erosion,endosteal cavitation,and replacementof marrow spaces by vascular granulationand fibrous tissue (osteitis fibrosa cistica)

1. Primary hyperparathyroid- Middle age, women:man = 2:1- Clinical features : due to hypercalcemia, chronic hypercalciuria, chondrocalcinosis- Xray : subperiosteal cortical resorption of middle phalanges(pathognomonic)- Biochemical : hypercalcemia, hypophosphatemia, serum PTH↑- Diagnosis : exclusions of other causes hypercalcemia in which PTH level decreased- Treatment : conservatives (adequate hydration and dietary Ca restriction)

#parathyroidectomy indication:- unremitting hypercalcemia, recurrent renal calculi, progressive nephrocalcinosis ,severe osteoporosis#post operative hungry bone syndrome, treated with one of the fast acting vit D metabolites

2. Secondary hyperparathiroidismeas response of chronic hypocalcemia (rickets,osteomalacia)

Renal osteodistrophy

- Diffuse bone changes which are variable combination of rickets or osteomalacia, secondary hyperparathyroidism, osteoporosis, osteosclerosis

- Children clinically more severely affected, they are stunted, pasty faced, rachitic deformities

Xraywidened and irregular epiphyseal platesosteosclerosis in axial skeletonrugger jersey in lateral xray of spine

Treatment hemodyalisis or renal transplatation

vit d 500.000 IU daily1,25 DHCC in resistant cases

Scurvy

Causes failure of collagen syntesis and osteoid formation

Clinical : -infant irritable,-anemic,-gum spongy and bleeding-subperiosteal bleeding-->pain & tenderness near large joint

Xray : bone rarefaction, most in long bone metaphysis

Treatment : large dose vit c

Hypervitaminosis Hypervitaminosis A

◦Children : excessive dosage◦Clinical : bone pain, headache,

vomiting (↑intracranial pressure)◦Xray: ↑density in metaphysis and

subperiosteal calcification

Hypervitaminosis D◦PTH like effect◦Ca is withdrawn from bones◦Treatment :

Vit D dose regulated Low ca diet, plentiful fluids (infants)

Fluorosis

Fluorine stimulates osteoclast activity

Clinically: • subperiosteal new bone accretion

and osteosclerosis (vertebra,ribs,pelvis,forearm, and leg)

• Backache,bone pain,joint stiffness• Stress fracture (sometimes)

- Xray :osteosclerosis,osteophytosis, and ossification of ligamentous and fascial attachment

Paget disease (osteitis deformans)- Enlargement and thickening of bone

but internal architecture is abnormal and the bone is unusually brittle

Clinical :• Pelvis and tibia the commonest site• Asimptomatic;pain,deformity• Limb looks bent and thick,skin

undully warm