• Clinical science

Osteomalacia and rickets

Summary

Osteomalacia is a disorder of impaired mineralization of the osteoid; rickets is a disorder of impaired mineralization of cartilaginous growth plates. Adults have fused growth plates so they are only affected by osteomalacia. In children, whose growth plates are open, the disorders can occur simultaneously. The most common cause of both osteomalacia and rickets is vitamin D deficiency resulting from inadequate intake, malabsorption, or lack of exposure to sunlight. Patients with osteomalacia usually present with bone pain and tenderness, while patients with rickets exhibit bone deformities and impaired growth. Over time, both conditions may lead to bending of the long bones or even pathologic fractures. Treatment consists of administering vitamin D and ensuring sufficient calcium intake.

Etiology

Vitamin D‑dependent forms

Vitamin D‑independent forms (rare)

References:[1][2][3][4][5][6]

Pathophysiology

For more information on calcium metabolism, see calcium homeostasis.

References:[2][7]

Clinical features

Osteomalacia

Rickets

References:[8][9]

Diagnostics

Laboratory tests

Calcium
Phosphate
Alkaline Phosphatase
Parathyroid hormone

(See laboratory evaluation of bone disease.)

X‑ray

Osteomalacia

  • Low bone mineral density
  • Thin cortices
  • Looser zones (pseudofractures): transverse bands of radiolucency indicating defective calcification of osteoid

Rickets

References:[8][9]

Differential diagnoses

References:[8]

The differential diagnoses listed here are not exhaustive.

Treatment

  • Vitamin D deficiency: administration of Vitamin D
    • Also indicated in infants who are exclusively breastfed
    • The healing of both osteomalacia and rickets requires adequate daily intake of calcium.
  • Defective vitamin D metabolism or vitamin D‑independent forms
    • Treatment of underlying disease

References:[2][8]