DR: Gehan mohamed

Bones…. What do they need to be strong? calcium/ PO4 Vit D PTH calcitonin

Sources of Vitamen D and importance

VIT D LEVEL IN SERUM - 25 (OH) D3 level ng/ml DEFICIENT < 10 INSUFFICIENT OPTIMAL HIGH TOXIC>90

Vitamin D Deficiency in Saudi Arabia Group mostly affected are: Breast- Fed infants because Human milk contains little vitamin D, Age < 2 years Darked –skin children because darkly pigmented skin, which blocks penetration of ultraviolet light necessary for formation of cholecalciferol (Vit. D3) from cholesterol in the skin. Low socio-economic Class Urban > Rural

PARATHYROID HORMONE Stimulus for its secretion : fall in serum Ca. PTH promotes bone resorption process and is adversely affected by calcitonin. PTH also stimulates the excretion of phosphates by the kidneys; this inhibition of phosphate resorption in turn enables calcium resorption. In GIT - indirectly increases calcium absorption by increasing the synthesis of active vit D 3 by stimulating alpha hydroxylase

CALCITONIN It is produced by para follicular c cells of thyroid. It is a calcium lowering hormone in serum by inhibiting bone resorption by decreasing the no & activity of osteoclasts. So calcitonin acts counter to PTH. Calcitonin inhibits bone resorption thus causing serum calcium levels to fall.

Metabolic bone diseases include: Rickets Osteomalacia osteoporosis

Rickets Disease of growing bones of children(in it epiphyseal plate not closed )in which defective mineralization occurs in both bone and cartilage of epiphyseal growth plate. Osteomalacia Disorder of mature bones in adult (after epiphyseal plate closure )in which mineralization of new osteoid bone is inadequate or delayed

causes of rickets : 1- Nutritional deficiency: commonest cause in the developing countries also Excess of phytate in diet which form insoluble compounds with calcium so prevent its absorption (chapati flour) 2-Malabsorption as in Celiac disease,Pancreatic insufficiency 3-Hepato-biliary disease Biliary Artesia Cirrhosis neonatal hepatitis 4-Drugs Anti-convulsants Phenobartbitone Phenytoin 5-Renal causes : -Renal osteodystrophy - Renal tubular acidosis.

Types of Rickets (1)Vitamin D deficient rickets: there is decrease in vitamin D inside body. (2)Vitamin D dependent rickets: there is defect in the process of vitamen D activation. (3)Vit D resistant rickets: either -Hypophosphatemic rickets - End organ resistance to 1,25 Dihydroxy Vit D3

pathogenesis ofVitamin D deficient rickets The predominant cause of rickets is a deficiency in vitamin D, which is required for normal calcium absorption from the gut. Malabsorption leads to low levels of calcium in the blood. This not only prevents proper bone growth, but can also lead to calcium being released form the bones to increase its blood level.

Hypophosphatemic rickets Nutritional phosphate deficiency Prematurity Decreased intestinal absorption of phosphate Ingestion of phosphate binders (aluminum hydroxide) Renal phosphate wasting

Diagnosis of rickets A-Clinical features of rickets: (1)Skeletal manifestations (2) extraskeletal manifestations B-investigations

(1) Skeletal manifestations The earliest sign of rickets in infant is craniotabes (abnormal softness of skull) Delayed closure of anterior fontanel Frontal and parietal bossing :Rounded prominence of the frontal and parietal bones in an infant’s cranial vault Delayed eruption of primary teeth Enamel defects and caries teeth. Rachitic rosary Swelling of the costo-chondral junction Harrison’s groove Lateral indentation of the chest wall at the site of attachment of diaphragm because the patients lack the mineralized calcium in their bones necessary to harden them; thus the diaphragm, which is always in tension, pulls the softened bone inward. Enlargement of long bones around wrists and ankles Bow legs, knock knees green stick fractures Deformities of spine, pelvis and leg – rachitic dwarfism Growth retardation due to impaired calcification of bone epiphysis.

Rosary beads due to Swelling of the costo-chondral junctions

Costochondral junction

Harrison’s groove Lateral indentation of the chest wall at the site of attachment of diaphragm

Wrist enlargement

Wide ankle

(2)Extra – skeletal manifestations SEIZURES TETANY i.e periodic painful muscular spasms and tremors, caused by faulty calcium metabolism and associated with diminished function of the parathyroid glands. HYPOTONIA AND DELAYED MOTOR DEVELOPMENT Muscle weakness PROTUBERANT ABDOMEN, BONE PAIN, WADDLING GAIT AND FATIGUE. In older children presenting with rickets

Clinical manifestations in rickets

B - Investigations BASIC INVESTIGATIONS TO CONFIRM RICKETS Serum Ca, P and X rays of ends of long bones at knees or wrists Widening, fraying, cupping of the distal ends of shaft.

Abnormal level of calcium Hypocalcemia If Serum Calcium less than 8.0 mg/dl 34

Difference Between Osteoporosis & Osteomalacia Osteoporosis refers to the degeneration of already constructed bone, making them brittle, while osteomalacia is an abnormality in the building process of bone, making them soft.

Osteoporosis DR: Gehan Mohamed

Osteoporotic Vertebra

Osteoporosis The word osteoporosis literally means porous bones. It occurs when rate of degeneration of already constructed bone is rapid and exceed rate of bone building. This lead to loss of an excessive amount of their protein and mineral content. An osteoporotic bone characterized by: Thinning of bone trabecula low bone mass and volume. micro architectural deterioration of the bone tissue Leading to: enhanced bone fragility increase in fracture risk even with any trivial trauma.

WHO Guidelines for Determining Osteoporosis We diagnose Osteoporosis if patient bone density is below the average healthy bone density of the same age by More than 2.5 SD

Factors which decrease risk of osteoporosis in men 1- Men have about 5 percent higher bone density after their growing period than women. 2- Men also tend to have bigger bones, and it's generally harder to break bigger bones. 3- men often have larger muscles than women and may be less likely to fall so not liable for fracture.

Osteoporosis Types of osteoporosis: (A) Idiopathic type which is subclassified into post menopause (Type I) Senile type (Type II) (B) Secondary type : which occur secondary to any other disease, or drug intake.

Idiopathic Osteoporosis - Types Postmenopausal osteoporosis (type I) Caused by lack of estrogen Causes PTH to overstimulate osteoclasts Senile osteoporosis (type II) : as a result of aging

Pathogenesis of Estrogen Deficiency and Bone Loss Estrogen loss triggers increases in InterLeukin-1, IL-6, and Tumor Necrosis factor lead to increased osteoclast development and lifespan. Also estrogen loss stimulate parathormone hormone.

Normal vs. Osteoporotic Bone

Commonest sites affected by osteoporosis

Osteoporosis in vertebra

Investigations: to diagnose degenerative bone diseases as osteoporosis: The primary method of testing is DEXA or dual energy X-ray absorptiometry,This can detect the density of your bones in the most susceptible areas. Sometimes, ultrasound or CT scans are also used to make a diagnosis.

Prevention of osteoporosis good healthy diet containing calcium and vitamen D specially during period of bone growth. Physical activity. Both of them help to reach the optimal bone density during adulthood So form strong and dense bone so become not easy to be affected by any degenerative changes.