Bone Health

Several diseases can result in defective mineralization of bone in children, including the following:
Rickets
Nutritional rickets
Congenital rickets
Rickets of prematurity
Genetic rickets
Neoplastic rickets
Hypophosphatemic rickets
Drug-induced rickets
Renal causes - Renal osteodystrophy, Fanconi syndrome
Tumor-induced osteomalacia
Other causes
Hypophosphatasia
McCune-Albright syndrome
Osteogenesis imperfecta with mineralization defect (syndrome resembling osteogenesis imperfecta)

Wheeless' Textbook of Orthopaedics Discussion: - this is the most frequently encountered form of rickets and consists of a genetic or acquired fault in the handling of phosphate in the proximal tubule; - patholophysiology: - decreased reabsorpion of phosphate by the renal tubule (causing hypophosphatemia) (otherwise the renal function is normal, ie BUN and Cr are normal); - decreased absorption of calcium and phosphorous from the GI tract;

Wheeless' Textbook of Orthopaedics See: - Osteomalacia: - Vit D Abnormalities: - Discussion: - rickets is an osteomalacic syndrome in which there is an inability to mineralize chondroid and osteoid; - lack of available calcium or phosphorus (or both) for mineralization of newly formed osteoid; - osseous changes in both adults and children reflect the fact that either ionized calcium or phosphate, or both, is insufficient in concentration to mineralize the skeleton fully; - there is less mineralized bone per unit volume of bone; - osseous changes in the rapidly growing skeleton of a young child w/ rickets may result in bowing deformities due to the decreased resistance of the skeleton to bending and shearing moments; - as consequence, stress frxs w/ resultant deformities occur; - note that the classic changes of rickets will typically occur in children younger than 6-7 years of age;

Fact sheet on Vitamin D

Radiology case 438-571

Radiology case 458-571

rickets