in the name of god. osteomalacia mohsen mardani-kivi assistant professor, orthopedic department,...
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In the name of God
Osteomalacia
Mohsen Mardani-KiviAssistant Professor, Orthopedic Department, Guilan University of Medical Sciences
Case• 33 year old Asian lady• Presents with 3 /12 months history of
generalised bony pain• PMH depression• D/Hx sertraline• P/Ex generalised bony tenderness• Joints normal ROM, no inflammation
Investigations• Hb 12.9 (11.5-16.5) Calcium 2.18 (2.2-2.6)
• WBC 4.7 (4.9-11.0) Phosphate 0.79 (0.85-
1.45)
• Plt 253 (150-400) Albumin 39 (35-50)
• ESR 12 Alk Phos 172 (25-96)
• Clotting Normal Total protein 72 (60-80)
• Urea 4.2 (3.0-6.5) LFTs normal
• Creat 85 (35-120)
• Diagnosis?
Definition• Osteomalacia is the general term for the
softening of the bones due to defective bone mineralization.
Definition• Osteomalacia in children is
known as rickets, and because of this, it is often restricted to the milder, adult form of the disease.
• It may show signs as diffuse body pains, muscle weakness, and fragility of the bones.
General characteristics
• Osteomalacia is derived from Greek: – osteo bone– malacia softness
• most commonly found in:– dark-skinned– diet-disbalanced subjects (mainly lactating females).
• Age: adults• Site: WEIGHT-BEARING BONES such as vertebral
bodies and femoral neck
General characteristics
Physiology Normal bone metabolism: CA
• CALCIUM 99% in bone. • Main functions muscle /nerve function, clotting.• Plasma calcium 50% free, 50% bound to albumin. • Dietary needs:
– Kids: 600mg/day– Adolescent 1300mg/day,– Adult: 750mg/day– Pregnancy: 1500mg/day, – Breastfeeding: 2g/day,– Fractures: 1500mg/day
• Absorbed in duodenum (active transport) and jejunum (diffusion), 98% reabsorbed in kidney prox. tubule, may be excreted in stool.
Physiology Normal bone metabolism: PHOSPHATE
• PHOSPHATE 85% in bone.• Functions: metabolite and buffer in enzyme systems.• Plasma phosphate mainly unbound.
Daily requirement: 1-1.5g/day
Physiology Regulation of Calcium & Phosphate Metabolism:Peak bone mass at 16-25 years.Bone loss 0.3- 0.5% per year (2-3% per year after 6 th decade).1. Parathyroid Hormone (PTH)2. Vitamin D33. Calcitonin4. Other Hormones:
Estrogen: Prevents bone loss Corticosteroids: Increases bone loss Thyroid hormones: Leads to osteoporosis Growth hormones: Cause positive calcium balance Growth factors
Physiology
Physiology
Physiology • Serum Ca & Phosphate in equilibrium with Ca & Phosphate
in bone.
Physiology
Patho physiology
Kidney disease
Defect in phosphateexecration
No hydroxylation of Vit.D3
Patho physiology
Hypocalcaemia So,Stimulation of PTH
Bone..Relase of Ca.
Kidney Ca absorption
Etiology• Calcium deficiency
– Hypo-phosphataemia– Defect in Vitamin D metabolism
• Nutritional– Diet: oily fish, eggs, breakfast cereals– Antacid abuse, causing reduced dietary phosphate
binding
• underexposure to sunlight– Elderly individuals with minimal sun exposure– Dark skin, skin covering when outside
Etiology• Calcium deficiency
– Hypo-phosphataemia– Defect in Vitamin D metabolism
• intestinal mal-absorption– Coeliac– Intestinal bypass– Post-Gastrectomy– Chronic pancreatitis– Biliary disease (reduced absorption of Vitamins)– Small bowel disease
• Calcium deficiency– Hypo-phosphataemia– Defect in Vitamin D metabolism
• liver & kidney diseases – Fat mal-absorption syndromes – Kidney failure: RTA, Renal osteodystrophy
• Epilepsy: phenytoin, phenobarbitorate• Genetic disease
Etiology
• Other Etiologies:– Receptor Defects– Altered phosphate homeostasis
Etiology
Pathology
Symptoms & Signs• Bone pain , backache• Muscle weakness• Vertebral collapse: kyphosis• loss of height• Deformities & stress fractures
• Osteomalacia in adults starts insidiously as aches and pains in the lumbar region and thighs, spreading later to the arms and ribs.
• Pain is non-radiating, symmetrical, and accompanied by tenderness in the involved bones.
• Proximal muscles are weak, and there is difficulty in climbing up stairs and getting up from a squatting position
Symptoms & Signs
• Physical signs include deformities like lordosis.• Pathologic fractures due to weight bearing may develop.• Most of the time, the only alleged symptom is chronic and
bony ache which is only revealed by pressure or shocks.
Symptoms & Signs
• Rickets – Tetanus , convulsions, failure to thrive– restlessness, muscular flaccidity– Flattening of skull (craniotabes)– Thickening of wrists from epiphyseal overgrowth, Stunted growth,
Rickety rosary, spinal curvature, Coxa vara, bowing, – Fx of long bones
• Osteomalacia– Aches and pains– muscle weakness loss of height– stress fx
Symptoms & Signs
1.Hypo-calcaemia
2.Hypo-calcuria
3.High alkaline phosphatase
biochemistry
Work up for OsteomalaciaWork up for Osteomalacia
Ca , P , Alk ph 24 h urinary Ca 25 (OH) Vit-D 1 , 25 (OH) Vit-D PTH Bone Biopsy
biochemistry
1- ca P = Nl Alk ph2- ca = Nl P Alk ph3- ca P Alk ph
24 h Urinary ca < 100 mg / 24 h24 h Urinary Hydroxyproline Excretion
biochemistry
*Rickets - Growth plate widening & thickening
- Metaphyseal cupping
- Diaphyseal deformities
*Osteomalacia - Looser zone , biconcave vertebra , protrusio acetabuli
- Spontaneous fractures
*Signs of secondary hyperparathyroidism
X-ray
Loosers zones – incomplete stress Fx with
healing lacking calcium, on compression side of long bones.
Codfish vertebrae due to pressure of discs
Trefoil pelvis, due to indentation of acetabulae stress fx
X-ray
Loosers zones
X-ray
X-ray
X-ray
Depends on the cause
Nutritional Vitamin D deficiency Dietary chelators of calcium
Phytates
Oxalates Phosphorus deficiency (unusual)
Antacid abuse
Treatment
Depends on the causeGastro-intestinal absorption defects
Post-gastrectomy Biliary disease Enteric absorption defects
Short bowel syndrome Rapid onset (gluten-sensitive enteropathy)
Inflammatory bowel disease Crohns Celiac
Treatment
Depends on the causeRenal tubular defects
Vitamin D dependant type I type II Treatment; High levels of vit D
Vitamin D resistant (familial hypophosphatemic rickets) Treatment; Phosphate 1-3 gm daily, Vit D3 high dose
Fanconi syndrome I, II, III Renal tubular acidosis
Treatment
Depends on the cause
Renal Osteodystrophy – in chronic renal failure
Miscellaneous Hypophosphatasia Anticonvulsant therapy
SURGERY
For deformities
Treatment
Treatment
• Natural sources cheese, sardines, salmon, dark leafy vegetables & sesame seeds.
Treatment