OSTEOMALACIA

DEFINITION

Osteomalacia is the disorder in adults leading to softening of the bones caused by defective bone mineralization secondary to prolonged deficiency of Vitamin D,  phosphate and calcium or due to excessive resorption of calcium from the bone. This can lead to weakening of bones that result in easy bending and break (fracture) of the bone

Osteomalacia in children is known as rickets.

ETIOLOGY:

• Vitamin D deficiency : As there is decrease GI absorption of calcium
• Insufficient Nutritional quantities or faculty metabolism of vitamin D or phosphorus
• Renal tubular acidosis: which involves accumulation of acid in the body due to failure of the kidneys which causes increased calcium excretion in urine
• Malnutrition: especially during pregnancy results in decreased stores of calcium and phosphorus in the body which results in decreased mineralization of bone
• Malabsorption syndrome: it is disease of GI the system which causes decreased absorption of calcium and there by decreases the bone formation
• Hypophospahatemia: Decreased phosphorus level in the blood results increased osteoclastic activity and calcium shifts to the blood
• Chronic kidney failure: This results in impaired tubular regulation of calcium resulting in demineralization of the bone as increased phosphate excretes in urine and resorption of calcium occurs in bones.
• Tumor-induced osteomalacia: Formation of tumor cells can cause increased uptake of calcium from the bones resulting in osteomalacia
• Long term anti convulsants therapy: This causes binding of calcium and decreased osteoblastic activity.
• Celiac Disease: It is auto immune disorder of the GI tract which causes decreased GI absorption of calcium
• Cadmium poisoning: It is a toxic metal found in industrial work places, exposure to cadmium can cause softening of the bones and lead to osteomalacia
• Hyperparathyroidism: It Causes increased resorption of calcium from bones.

PATHOPHYSIOLOGY

Due to deficiency of vitamin D and calcium

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Decreased GI absorption of calcium

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Low Systemic levels of calcium & Vitamin D

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Impaired mineral Ion homeostasis

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Hypo mineralization (Decreased mineralization) of the bones

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Decreased Bone Density & rigidity

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Softening or weakening of the bones (Osteomalacia)

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Prone for pathologic Fractures

CLINICAL MANIFESTATIONS

• Diffuse joint and bone pain in spine, pelvis and legs and pain increased while standing, walking & running
• Muscle weakness & cramps
• Difficulty in walking with waddling gait
• Chvostek sign positive (When the facial nerve is tapped at the angle of the jaw the facial muscle in the same side of the face will contract momentarily
• Compressed vertebrae and diminished stature
• Pelvic falttening
• Weak soft bones
• Easy fracturing & looser Zone’s Fracture (Partial break in the bone)
• Binding of bones
• Lower back pain radiating to thighs
• Difficulty in climbing upstairs and getting up from squatting position
• Lordosis due to tri radiate pelvis. (Excessive curative of the lower back or saddle back)
• Waddling gait
• Chronic fatigue and bone aches

DIAGNOSTIC FINDINGS

• History & Physical Examination to identify the cause and severity of Osteomalacia
• Laboratory Serum Biochemical Analysis show Low serum calcium less than 9mg/dl and low Phosphate levels less than 3mg/dl
• Vitamin Assays determines Low serum vitamin <25mcg/ml
• Urinary Examination denotes Low urinary calcium levels
• Serum Alkaline Phosphatase levels increased due to increased in compensatory osteoblast activity
• Hormonal Assays shows Increased Parathormone levels elevated more than 60pg/ml
• Bone scan with Technetium radio nucleide isotope shows the bone mineral density that is the amount of calcium and other minerals present in the bone segment
• Radiologic X-rays shows the presence of pseudo fractures and bone loss
• Renal function test to assess the function of kidneys
• CT scan of spine show changes in the vertebrae
• Bone biopsy indicates the presence of soft and weak bony tissue.

COLLABORATIVE CARE:

• Identify and treat the underlying cause like treating the renal, digestive & hormonal disorders
• Careful exposure to the sun for short periods (10-15 minutes) to increase vitamin D
• Use of braces and splint to realign the bones, in case of deformity
• Advice to avoid Alcoholism and Smoking
• Encourage the client to maintain a healthy body weight
• Exercise helps to strengthen the bones especially weight bearing exercise like walking or running is adviced. Heavy and intense exercise are avoided to prevent fracture

NUTRITIONAL THERAPY

• Advice to Increase sources of calcium in diet include enriched or fortified milk and milk products, Green leafy vegetables, Soya beans, Nuts,  salmon, shrimp, sardines, cod liver oil and egg yolks
• Advice to intake foods rich in Vitamin D sources like Fish, red meat, Fortified cereals, butter and spreads
• Encourage to take phosphorous rich foods like Oats, lentils, bran cereals, nuts etc

SUPPLEMENTAL THERAPY

• Administer Calcium supplements like calcium carbonate & calcium citrate 500-1000mg/day and Advice calcium intake of 750mg/day in diet
• Administer Vitamin D supplement (calcitriol 25-50mcg/day is administered for mineralisation of the bone
• Administer other forms of vitamin D like vitamin D2 and D3 are also administered along with multi vitamin tablets to enhance bone formation.