Pathology

An excess of unmineralised osteoid is characteristic of both rickets and osteomalacia. Normally, this accounts for less than a quarter of trabecular bone but in osteomalacia and rickets it may approach 100%.

Additionally in rickets there is failure of normal mineralisation of the cartilage matrix in the growth plate. There is an overgrowth of chondrocytes producing a greatly thickened growth plate. Both vascularisation and calcification are impaired in the underlying zone of maturation.

Reference

1. Chesney RW. Bone structure, growth, and hormonal regulation. In: Behrman RE, Kliegman RM, Jenson HB, eds. Nelson textbook of paediatrics, 17th ed. Philadelphia, PA: Saunders; 2004.