CLASSIFICATION OF RICKETS & OSTEOMALACIA
1. VIT D DEFICIENCY
* DIETARY DEFICIENCY
* DEFICIENT ENDOGENOUS SYNTHESIS
2. GASTROINTESTINAL DISORDERS
- SMALL INTESTINAL DISEASES WITH MALABSORPTION
- PARTIAL OR TOTAL GASTRECTOMY
- HEPATOBILIARY DISEASES
- CHR PANCREATIC INSUFFICIENCY
3. DISORDERS OF VIT D METABOLISM
- HEREDITARY :
* PSEUDOVITAMIN D DEFICIENCY
* VITAMIN D DEPENDANT RICHET TYPE I ( ABSENCE OF RENAL 25-HYDROXYVITAMIN D-1-ALPHA HYDROXYLASE DEFICIENCY )
* VITAMIN D DEPENDENT RICHET TYPE II ( DEFECTIVE VITAMIN D RECEPTOR )
- ACQUIRED :
* ANTICONVULSANTS
* CHR RENAL FAILURE
* TUMOR ASSOCIATED RICKETS & OSTEOMALACIA
4. ACIDOSIS
- DISTAL RENAL TUBULAR ACIDOSIS
- SECONDARY FORMS OF RENAL ACIDOSIS
- URETEROSIGMOIDOSTOMY
- DRUG INDUCED DISEASE : CHR ACETAZOLAMIDE INGESTION, CHR AMMONIUM CHLORIDE INGESTION
5. CHR RENAL FAILURE
- CAUSING IMPAIRED 1-ALPHA HYDROXYLATION OF 25-HYDROXYVITAMIN D
6. PHOSPHATE DEPLETION
* DIETARY : LOW PHOSPHATE INTAKE PLUS INGESTION OF NON-ABSORBABLE ANTACIDS LIKE ALU HYDROXIDE
- HEREDITARY :
* X-LINKED HYPOPHOSPHATEMIC RICKETS ( VIT D RESISTANT RICKETS )
* ADULT ONSET VIT D RESISTANT HYPOPHOSPHATEMIC OSTEOMALACIA
- ACQUIRED :
* SPORADIC HYPOPHOSPHATEMIC OSTEOMALACIA ( PHOSPHATE DIABETES )
* IMPAIRED RENAL TUBULAR PHOSPHATE REABSORPTION
7. TUMOR ASSOCIATED RICKETS & OSTEOMALACIA
- NEUROFIBOMATOSIS
- FIBROUS DYSPLASIA
8. GENERALISED RENAL TUBULAR DISORDERS ( FANCONI SYNDROME )
* PRIMARY RENAL
- ASSOCIATED WITH SYSTEMIC METABOLIC ABNORMALITY LIKE
CYSTINOSIS
GLYCOGENOSIS
LOWE SYNDROME
- SYSTEMIC DISORDER WITH ASSOCIATED RENAL DISEASE
* HEREDITARY LIKE INBORN ERRORS
WILSON DISEASE
TYROSINEMIA &
NEUROFIBOMATOSIS
* ACQUIRED LIKE MULTIPLE MYELOMA
NEPHROTIC SYNDROME
TRANSPLANTED KIDNEY
9. INTOXICATIONS : CADMIUM , LEAD, OUTDATED TETRACYCLINE
10. PRIMARY MINERALIZATION DEFECTS
* HEREDITARY : HYPOPHOSPHATEMIA
* ACQUIRED: DISODIUM ETIDRONATE TREATMENT , FLUORIDE TREATMENT
11. STATES OF RAPID BONE FORMATION WITH OR WITHOUT A RELATIVE DEFECT IN BONE RESORPTION
- POSTOPERATIVE HYPERPARATHYROIDISM WITH OSTEITIS FIBROSA CYSTICA
- OSTEOPETROSIS
12. DEFECTIVE MATRIX SYNTHESIS : FIBROGENESIS IMPERFECTA OSSIUM
13. MISCELLANEOUS : MAGNESIUM DEPENDANT CONDITIONS LIKE
AXIAL OSTEOMALACIA
PARENTRAL ALIMENTATION
ALUMINIUM INTOXICATION
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DIFFERENTIAL DIAGNOSIS
β’ Osteoporosis
β’ Metastatic bone disease
β’ Primary bone malignancies (lymphoma, myeloma)
OTHER TESTS :
* X-RAY FINDINGS - GROWTH PLATES ARE INCREASED IN THICKNESS, CUPPED, & HAZY AT METAPHYSEAL BORDERS DUE TO DECREASED CALCIFICATION. TRABECULAR PATTERN OF METAPHYSIS IS ABNORMAL, CORTICES OF THE DIAPHYSIS MAY BE THINED & SHAFTS MAY BE BOWED.
* IN VIT D DEFICIENCY - CALCIUM LEVELS ARE LOW OR NORMAL & PHOSPHORUS - LOW DUE TO INCREASED RENAL EXCRETION & 25(OH)D LEVELS ARE CONSISTANTLY LOW
* WHEN VIT D DEFICIENCY IS CHRONIC & SEVERE: S.CALCIUM LEVELS ARE LOW, PTH LEVELS - HIGH, ALK PHOSPHATASE LEVELS - RAISED, URINARY CALCIUM EXCRETION - REDUCED
* VITAMIN D DEPENDANT RICKET TYPE- I : 25-HYDROXYVITAMIN D LEVEL - NORMAL / INCREASED , WHILE 1,25 DIHYDROXYVITAMIN D LEVEL - LOW OR UNDETECTABLE
* VITAMIN D DEPENDANT RICKET TYPE- II : 25-HYDROXYVITAMIN D LEVEL & 1,25 DIHYDROXYVITAMIN D LEVEL - ELEVATED
* HYPOPHOSPHATEMIC RICKET : SERUM PHOSPHATES - LOW, SERUM CALCIUM & PTH LEVELS - NORMAL , SERUM 1,25 DIHYDROXYVITAMIN D LEVELS - INAPPROPRIATELY LOW
IMAGING Radiographic changes are non-specific. Earliest manifestations are thinning of cortical bone. In long-term osteomalacia: bone softening (protrusio
acetabuli), looser lines, stress fractures, and pathologic fractures.
DIAGNOSTIC PROCEDURES Bone biopsy and subsequent histopathologic evaluation deliver the most accurate diagnosis of osteomalacia. The biopsy is usually taken from the iliac crest, and both calcified, and non-calcified studies, as well as special stains (including von Kossaβs stain) are helpful.