2.  lack of vitamin D, calcium, orphosphate, which leads to softening and weakening of the bones. Defective mineralization of bone matrix –excessive unmineralised osteoid
3.  Vitamin D helps the body properly controlcalcium and phosphate levels in the body.When the body is deficient in vitamin D, it isunable to properly control calcium andphosphate levels calcium and phosphorous are found in milk andgreen vegetables.
4.  Defective Vitamin D metabolism – lowering of calcitriol - intestinal malabsorption of calcium - reduction of serum calcium – Parathyroid stimulation – normalised S.calcium at the expense ofreduced S.Phosphate
6. ultraviolet rays 7-DihydrocholesterolCholecalciferol (Vitamin D3)- in dermisVit D2 absorbed thru small intestineTransport in serum- binds with X-globulin25-Hydroxylation in Liver1,25- Dihyroxylation in Kidney – active form
8.  Decrease in effect & amount of Sunlight Bread/Chapathi rich in Phytate bind dietarycalcium – reduced absorption Infants who are exclusively breastfed maydevelop vitamin D deficiency. Poor Dietary intake of Ca & Vit D Malabsorption disorders – Coeliac d/s, hepaticosteodystrophy, lactose intolerance
9.  Renal – Renal osteodystrophy, Nephrectomy,renal failure, hypoparathyroidism,X-linked hypophosphatemia/Vit D resistantricketsVitamin dependant Type I (Inability to hydroxylate)Vitamin dependant Type II (Receptor insensitivity) Anticonvulsant therapy( 25OH in liver)
10.  Failure of deposition of Ca along maturecartilage cell columns Disorderly invasion of cartilage by bloodvessels Lack of reabsorption at the zone ofprovisional calcification Increased thickness of epiphyseal plate
11.  Abundant osteoid with Defective mineralization No resorption of uncalcified osteoid byosteoclasts Normal osteoblast – laid irregularly Abnormal arrangement of collagen bundles incompact bone
12.  Long bones bent when child startscrawling/walking
16.  Bone pain or tendernessArms Legs Spine Pelvis Skeletal deformitieso Bowlegso pigeon chesto rachitic rosaryo Frontal bossingo Spine deformities (spine curvesabnormally, including scoliosis orkyphosis )o Pelvic deformities
17.  Increased tendency toward bonefractures Dental deformitieso Delayed formation of teetho Defects in the structure of teeth, holes inthe enamelo Increased incidence of cavities in theteeth ( dental caries )o Decreased muscle tone (loss of musclestrength) Muscle cramps Impaired growth Short stature
19.  Epiphysis Mottled & irregular Metaphysis ragged & broader Periosteal thickening disappears
20.  Dense shadow Dense line at the end of metaphysis-deposition of Ca Stage of repair
21.  Increase in breadth of metaphysis Clearly defined bone Normal content of Ca salts Bone completely repaired
22.  Serum Ca low or normal.o Tetany -prolonged muscle spasm.o Chvosteks sign may be positive (a spasm offacial muscles occurs when the facial nerveis tapped) S.Phosphorus may be low. S.ALP may be high. ABG may reveal metabolic acidosis Urinary Ca may be low .
23.  24-hydroxylase assay – for vitamin Ddependency rickets Serum 25-OH vitamin levels A bone biopsy is rarely performed but willconfirm rickets.
25.  Goals - relieve symptoms andcorrect the cause of the condition. Underlying cause must be treated to preventrecurrence.
26.  Medical treatment Prevention of deformity Treatment of existing deformity
27.  Dietary sources of vitamin D include fish, liver,milk and cheese. Exposure to moderate amounts of sunlight isencouraged. Reduce cereal containing phytates Supplemention of Calcium andVitamin D – 3000 i.u./day
28. Before treatment and 2 years after treatment with calcium
29.  Control of movements – reduced pressure uponlimbs (soft bones easily bent by pressure / musclestrain) Positioning or bracing with ‘rickets’ splints may beused.
30.  Correction by splinting In young children below 4 yrs Useful in lower limbs Continuous supervision needed to preventsores
31.  Correction by osteotomy When deformity is near a joint At least stage 3 in radiograph
32.  Chronic skeletal pain Skeletal deformities Skeletal fractures, may occur without cause
33.  Rickets of prematurity Very premature infants at risk Risk factors- hepatobiliary d/s, TPN, Diuretic therapy, chest percussion therapy Pathologic # in NICU Readily heal with treatment
34.  Antiepileptic medications Induce microsomal P-450 enz Decreased Vit D Should be suspected in neurologic patientshaving seizures Start having frequent #
35.  Familial hypophosphatemic rickets X-linked dominant (MC)- Mutn in PEX gene Aut dominant 12p13 – phosphatonins – fgf23 – cause phosphaturia Aut recessive
36.  Renal tubule unable to retain PO4 End organ insensitivity to vit D (AR) Kidney unable to perform 2nd hydroxylation Renal tubular acidosis (kidney excretes fixedbase and wastes bicarbonate) Ca ppt – renal calcinosis
38.  Surgery not efficacious – multilevel osteotomyto correct mechanical axis Recurrent deformity common Surgery when - gait compromised/severepain
39.  Oncogenic hypophosphatemicosteomalacia Asso with Neurofibromatosis, fibrousdysplasia Osteoblastoma, hemangiopericytoma ofbone, skin tumors (disrupts renal tubular abs of po4) Secrete phosphatonins Resolve with excision of tumor
40.  C/C pyelonephritis Congenital Abnormalities Polycystic kidney d/s Secondary hyperparathyroidism Leads to actvn of osteoclast and resorption ofbone (high turn over d/s)
41.  Glomerulus unable to excrete Phosphorus Vit D prodn reduced Ca abs from S.Intestine reduced PTH triggered Increased S.Ca – bone demineralization Precipitate in cornea, skin, blood vessels
42.  C/F similar to Nutritional. Angular deformity, SCFE, AVN Radiography – cuppping of physis notpresent Subperiosteal resorption in phalanges, MCand ulna (feature of Hyperparathyroidism) Osteosclerosis of skull, rugger jersey spine Lytic areas in long bones (Brown tumors) Treat underlying d/s- Ca, Vit D, growthhormone, osteotomy, Ilizarov
43.  Ca Normal or low in all Phosphate is reduced in all except RenalOsteodystrophy ALP and PTH high in all 25 OH Vit D N or high in all exceptnutritional (decreased) 1,25 (OH)2 N or low in all except Vit Ddependent typeII (receptor insensitivity)
44.  Maintain an adequate intake of calcium,phosphorus, and vitamin D. This may require dietary supplements inpeople who have gastrointestinal or otherdisorders Renal causes of vitamin D should be treatedpromptly.
45.  Levels of calcium and phosphorus should bemonitored regularly in people who have renaldisorders . Genetic counseling may help people with a familyhistory of inherited disorders that can causerickets.