Physeal Zones and Abnormalities

Courtesy: Prof Nabil Ebraheim, University of Toledo, Ohio, USA
This video describes the different physeal zones & their abnormalities.

Growth plate has 3 zones-
Reserve zone, proliferative zone & hypertrophic zone.

Hypertrophic zone is again divided into zone of maturation , zone of degeneration & zone of provisional calcification.

Reserve zone is the area where lipids, glycogen & proteoglycans are stored. Gaucher’s disease & diastrophic dwarfism are the common abnormalities that affect this zone

Gaucher’s disease is due to the deficiency of B- glucocerebrosidase which leads to the accumulation of sphingolipids. Avascular necrosis of femoral head can be seen in Gaucher’s disease

In Diastrophic dwarfism , Hitchhiker thumb $ cauliflower ear are seen; it is due to the deficiency of sulfate transfer protein causing undersulfation of proteoglycans.

Proliferative zone is the region with higher activity. Disproportionate short dwarfism and gigantism are diseases that affect this zone
Disproportionate dwarfism is caused by fibroblast growth factor receptor3 mutation leading to spinal stenosis & champagne glass outlet of pelvis. Gigantism is the increased height & length above average.

Ricket, slipped capital femoral epiphysis , Salter Harris type 1 fractures, mucopolysaccharidosis & scurvy are the abnormalities that affect the Hyperotrophic zone

Mucopolysaccharidosis occurs due to the inability to metabolise one of the glycoproteins ( accumulation of keratin sulphate- Morquio syndrome)
In Scurvy , there is deficiency of vitamin c causing decrease in the amount of chondroitin & collagen.