The weakened ribs pulled by muscles also produce flaring over the diaphragm known as Harrison groove. The sternum may be pulled into a pigeon-breast deformity. In more severe instances in children older than 2 years, vertebral softening leads to kyphoscoliosis. The ends of the long bones show that same knobby thickening. Because the softened long bones may bend, they may fracture one side of the cortex, a greenstick fracture.
Weight bearing produces deformities such as bowlegs and knock-knees.
Some deformity occurs before weight bearing from strong dorsal muscle pull. Acute infection or fever, producing catabolic release of phosphate from cells, occasionally precipitates hypocalcemia and tetany as a presenting manifestation. Failure to calcify osteoid in the adult is called osteomalacia. Rickets occurs when the metabolites of vitamin D are deficient. Less commonly, dietary deficiency of calcium or phosphorus may produce rickets.