There are a lot of diseases and factors that affect the growth plate. Growth plate or physis is the region between the epiphysis and metaphysis of a growing bone. Injury to this physeal region may lead to several complications.
Here, we enumerate these factors for your information
- Diastrophic dysplasia
- Kniest dysplasia
- Physeal fracture
1. Gaucher disease. It occurs due to deficiency of enzyme beta-glucocerebrosidase. It affects the reserve zone.
2. Diastrophic dwarfism. In diastrophic dwarfism or dysplasia patient present with characteristic features like cauliflower ear, hitchhiker’s thumb and cherubic face. This disease also affects the reserve zone.
3. Pseudoachondroplasia. There is an abnormality of both metaphysis and epiphysis due to mutation of COMP in chromosome 19. This disorder also affects the reserve zone.
4. Kniest syndrome. This is an autosomal dominant disorder of type II collagen. Kniest dysplasia also affects reserve zone.
Diseases that affect the proliferative zone of physis
Achondroplasia and gigantism are two main diseases that affect the proliferative zone of the physis.
Thus, growth hormone, obviously, affects this zone. One important fact about this zone is that increase in oxygen tension and proteoglycans inhibit calcification here.
Diseases and factors that affect the hypertrophic zone of growth plate
Hypertrophic zone has three sub-zones. These are maturation, degeneration, and provisional calcification.
Mucopolysaccharidoses and its various forms, rickets, osteomalacia and physeal fracture occur through this zone.
Similarly, Slipped Capital Femoral Epiphysis (SCFE) affects this zone.
Coming to the factors, parathyroid hormone (PTH), inhibits chondrocyte maturation. Similarly, the Indian hedhehog gene regulates the expression of PTHrp.
Additionally, decrease in oxygen tension and proteoglycan aid bone scaffold formation.
Tabulating diseases and factors that affect the growth plate
|Gaucher Disease Diastrophic dwarfism Pseudoachondroplasia Kniest syndrome
|Growth hormone acts sIncreased O2 tension and increased proteoglycans inhibit calcification
|Hypertrophic zone `
|Mucopolysaccharidoses Rickets, osteomalacia and physeal fracture through this zone SCFE
|PTH — > inhibits chondrocyte maturation Indian hedgehog — > regulates expression of PTHrpLow O2 tension and decreased proteoglycan aid for bone scaffold formation
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