Characteristics

• Rickets is inadequate mineralisation of osteoid in the immature skeleton.

• Osteomalacia (softened bone) is the same inadequate mineralisation of bone, but occurring in the adult skeleton without the growth disturbances of rickets.

• Rickets occurs secondary to vitamin D deficiency/dysfunction, and with inadequate intake of calcium and phosphorus.

• Associated with sunlight deficiency, renal disease, liver disease and malabsorption, because of the effect on vitamin D synthesis.

Clinical features

• Infants may present with convulsions, tetany or failure to thrive.

• Craniotabes (skull deformity) develops early.

• Muscular hypotonia is common.

• Wrist, ankle and knee swelling.

• ‘Rickety rosary’ – costochondral junction enlargement.

• Harrison's sulci – lateral chest-wall gutters secondary to muscular action on weakened ribs.

• Leg bowing and knock-knees become more prominent on weight bearing.

• Spinal involvement and long-bone fractures are late manifestations.

Radiological features

• Metaphyses of long bones subjected to stress are particularly involved (wrists, ankles, knees).

• Irregular widened epiphyseal plates – due of the failure of mineralisation.

• Cupping and fraying of metaphyses – best seen where growth is maximal.

• Coarse trabecular pattern.

• Long-bone bowing.

• Periosteal reaction may be present.

Management

• Identify and treat underlying cause.

• Most deformities will correct with growth once the condition is treated.

• Corrective surgery for severe deformities may be required.