What are the features of rickets?

• Clinical features:

– General features: Failure to thrive, muscle weakness, fractures, increased susceptibility to infections

– Cranial and dental findings: Craniotabes, delayed fontanelle closure, frontal bossing, delayed tooth eruption, poor enamel formation and caries, craniosynostosis

– Musculoskeletal findings: Rachitic rosary–prominence of costochondral junctions, Harrison groove–indentation of the lower anterior thoracic wall with flaring of lower rib cage, pectus carinatum (chest wall deformity with anterior protrusion of sternum and adjacent costal cartilages), scoliosis (lateral curvature of spine), kyphosis (exaggerated thoracic spinal convexity posteriorly), lordosis (exaggerated lumbar spinal convexity anteriorly), enlargement of wrists and ankles, valgus or varus deformities predominantly noted at knees as either lateral bowing of legs or knock knee deformities, limb pain, anterior bowing of the tibia and femur.

– Hypocalcemia symptoms: Tetany, seizures, stridor due to laryngeal spasm

In children younger than 6 years, genu valgum deformity could be physiologic and self-limiting.

• Radiologic features: Osteopenia–lucency of bones, cupping, splaying, fraying of long bone metaphyses, widening of the physis • Histologic features: Disorganized chondrocyte maturation, widened osteoid seams, undermineralization of trabeculae.