A child's skeleton is still growing, so it is softer, more flexible and partly made of cartilage. These differences change how children get injured and how their bones heal.
Growth plates
Long bones lengthen at the growth plates (physes), discs of cartilage near each end of the bone. They close in the late teens, and an injury through a growth plate can disturb future growth.
Softer, bendier bones
Children's bones hold more cartilage and less mineral and are wrapped in a thick, strong periosteum. They often bend or break on one side only, as in buckle (torus) and greenstick fractures.
Fontanelles
An infant's skull bones are joined by flexible sutures with soft spots called fontanelles. The posterior fontanelle closes by about 2 months and the anterior by about 18 months.
Fast healing and red marrow
A rich blood supply lets children's fractures heal quickly and remodel well. Most bones still hold active red marrow, which is why the tibia is a good intraosseous access site in children.
| Feature | Child | Adult |
|---|---|---|
| Bone | More cartilage, more flexible | Fully mineralized, more brittle |
| Growth plates | Open | Closed |
| Typical fractures | Buckle, greenstick, growth plate | Complete fractures |
| Healing | Fast, strong remodeling | Slower |
At the bedside
After an injury, point tenderness over a growth plate is treated as a fracture even when the X-ray looks normal. In an infant, a bulging anterior fontanelle can signal raised intracranial pressure and a sunken one suggests dehydration.
Related guides
Written by Making Synapses. Topic reference: OpenStax, Anatomy and Physiology 2e (no text adapted).