Growth Plates (Epiphyseal Plates)
Growth plates (epiphyseal plates) are found in the bones of children but not adults. They are the area at the ends of long bones that allow the bones to grow in length. They are made of hyaline cartilage and sit between the epiphysis and the metaphysis. Once the epiphysis and the metaphysis fuse during the teenage years, the growth plates become the epiphyseal lines.
The growth plate is generally stronger than the rest of the bone.
Bones in Children versus Adults
Children have growth plates, whereas adults do not. Children have more cancellous bone, which is the spongy, highly vascular bone in the centre of long bones. Adults have more cortical bone, which is the compact, hard bone around the outside. This makes children’s bones are more flexible but less strong. This makes children prone to “greenstick” fractures, where one side of the bone breaks whilst the other stays intact. Bones in children have very good blood supply and are able to heal much more quickly with less long term deformity compared with adults.
Fractures in Children versus Adults
The younger the child, the better and faster the healing of fractures. When bones fracture in children, they are more likely to break cleanly in two compared with adults.
Children are more likely to have greenstick fractures, where only one side of the bone breaks whilst the other side of the bone stays intact.
Children are more likely to have a buckle fracture (or torus fracture), due to less strength against compression.
Bone remodelling is the process where bone tissue is taken from areas of low tension and deposited in areas of high tension. This allows bone to change to the optimum shape for function. Bones in children have a high capacity for remodelling, which means that even if they are set at an incorrect angle, they will remodel over time to return to the correct shape.
Types of Fracture
- Buckle (torus)
- Salter-Harris (growth plate fracture)
Fractures at the Growth Plate
Fractures through the growth plate can cause issues with growth in that bone. Growth plate fractures are graded using the Salter-Harris classification. The higher the Salter-Harris grade, the more likely the fracture is to disturb growth.
Use the SALTR mnemonic to remember the types:
- Type 1: Straight across
- Type 2: Above
- Type 3: BeLow
- Type 4: Through
- Type 5: CRush
Principles of Management
Always keep safeguarding in mind when children present with fractures. Does the story make sense? Has this happened before? When there is doubt, discuss the case with a senior and consider a safeguarding referral.
The first principle is to achieve mechanical alignment of the fracture by:
- Closed reduction via manipulation of the joint
- Open reduction via surgery
The second principle is provide relative stability for a period of time, to allow healing. This can be done by fixing the bone in the correct position while it heals. There are various ways the bone can be fixed in position:
- External casts
- K wires
- Intramedullary wires
- Intramedullary nails
- Plate and screws
Pain management in children is slightly different than adults. The World Health Organisation have a pain ladder for children that has only two steps:
- Step 1: Paracetamol or ibuprofen
- Step 2: Morphine
If a child requires morphine they generally need admission for a serious illness.
TOM TIP: Examiners like to test your knowledge on the pain medications that are not used in children. Codeine and tramadol are not used in children as there is unpredictability in their metabolism, so the effects vary too greatly to make them safe and effective options. Aspirin is contraindicated in children under 16 due to the risk of Reye’s syndrome (except in certain circumstances such as Kawasaki disease).
Last updated January 2020