This 10 month-old male patient of African descent sustained minor trauma. The xray of the left femur shows bowing, an incomplete fracture, cupping and fraying of metaphyses, delay in ossification of the femoral capital epiphysis, and widening of the physes. These findings are typical of rickets.

Rickets may be primary or secondary. Primary rickets is due to vitamin D deficiency, and may be dietary or related to lack of sunshine exposure, or both. Secondary rickets may be due to: malabsorption (gastric, enteric, hepatobiliary or pancreatic disease); primary hypophosphataemia; chronic renal failure or renal tubular acidosis; hypophosphatasia; vitamin-dependant rickets; and certain anticonvulsants (particularly phenytoin). There are also many rarer causes of rickets.

Robinson MJ, Roberton DM. Practical Paediatrics 3rd edition. Churchill Livingstone 1994.
Dähnert W. Radiology Review Manual 5th edition. Lippincott, Williams & Wilkins, 2003.
Chapman S, Nakielny R. Aids to Radiological Differential Diagnosis 4th edition. Saunders, 2003.

Credit: Dr Laughlin Dawes