{"id":4069,"date":"2010-08-09T12:01:41","date_gmt":"2010-08-09T16:01:41","guid":{"rendered":"http:\/\/insidesurgery.com\/?p=4069"},"modified":"2010-08-08T23:08:06","modified_gmt":"2010-08-09T03:08:06","slug":"rickets","status":"publish","type":"post","link":"https:\/\/insidesurgery.com\/2010\/08\/rickets\/","title":{"rendered":"Rickets"},"content":{"rendered":"
Pathophysiology<\/strong><\/p>\n 1)<\/strong> functional vitamin D deficiency causing inadequate mineralization of bones and the matrix of growth plates 2)<\/strong> two forms – type 1 (vitamin D dependent) and type 2<\/p>\n Signs and Symptoms<\/strong><\/p>\n 1)<\/strong> type 1 – usually presents in first year of life 2)<\/strong> type 2 – usually presents early in life but not uncommon for first signs to appear in childhood up to puberty 3)<\/strong> bowed legs 4)<\/strong> slipped capital femoral epiphysis 5)<\/strong> short stature 6)<\/strong> patients dit in a Buddha-like posture 7)<\/strong> flattened skull 8)<\/strong> prominent forehead (frontal bossing) 9)<\/strong> classic rachitic rosary chest (knobs on costochondral cartilage) 10)<\/strong> pectus carinatum 11)<\/strong> potbelly 12)<\/strong> weak muscles 13)<\/strong> irritability 14)<\/strong> apathetic 15)<\/strong> difficulty in focusing on tasks 16)<\/strong> severe dental caries<\/p>\n Characteristic Test Findings<\/strong><\/p>\n Laboratory<\/em> – 1)<\/strong> type 1 – increased serum PTH and alkaline phosphatase, hypocalcemia, hypophosphatemia 2)<\/strong> type 2 – increased 1,25-(OH)2D\u00c2\u00a0 Radiology – 3)<\/strong> flared and cup-shaped epiphysis<\/p>\n Histology\/Gross Pathology<\/strong><\/p>\n hypertrophy of growth plate (5-15) times thicker than normal) as osteoclasts do not resorb this plate<\/p>\n Associated Conditions<\/strong><\/p>\n increased incidence secondary to – 1)<\/strong> phenytoin use 2)<\/strong> phenobarbital use 3)<\/strong> hypoparathyroidism 4)<\/strong> tumor-induced osteomalacia 5)<\/strong> chronic renal disease<\/p>\n Biochemistry<\/strong><\/p>\n 1)<\/strong> vitamin D can be ingested in food or synthesized from 7-dehydrocholesterol in the skin by exposure to the UV component of sunlight 2)<\/strong> type 1 – deficiency in renal 1-alpha-hydroxylase, which prevents conversion from precursor form 3)<\/strong> type 2 – defect in vitamin D receptor, making end organs functionally resistant to 1,25-(OH)2D<\/p>\n Inheritance\/Epidemiology<\/strong><\/p>\n 1)<\/strong> virtually eliminated in developed nations by addition of vitamin D to foodstuffs and generally improved nutrition 2)<\/strong> vitamin D-dependent rickets is autosomal recessive<\/p>\n Treatment<\/strong><\/p>\n 1)<\/strong> type 1 – 1,25-(OH)2D 2)<\/strong> type 2 – repeat IV calcium<\/p>\n Tips for USMLE<\/strong><\/p>\n 1)<\/strong> if rachitic rosary chest is mentioned, think rickets 2)<\/strong> if bowed legs are mentioned think rickets 3)<\/strong> if anything about deficient vitamin D functioning is mentioned, think rickets<\/p>\n","protected":false},"excerpt":{"rendered":" Pathophysiology 1) functional vitamin D deficiency causing inadequate mineralization of bones and the matrix of growth plates 2) two forms – type 1 (vitamin D dependent) and type 2 Signs and Symptoms 1) type 1 – usually presents in first year of life 2) type 2 – usually presents early in life but not uncommon […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_exactmetrics_skip_tracking":false,"_exactmetrics_sitenote_active":false,"_exactmetrics_sitenote_note":"","_exactmetrics_sitenote_category":0,"_genesis_hide_title":false,"_genesis_hide_breadcrumbs":false,"_genesis_hide_singular_image":false,"_genesis_hide_footer_widgets":false,"_genesis_custom_body_class":"","_genesis_custom_post_class":"","_genesis_layout":"","footnotes":""},"categories":[1],"tags":[2658,2656,2660,2657,2659],"yoast_head":"\n