The Reading Room: Salter-Harris Classification of Fractures

Let’s take a break for a second and take a crack at explaining the importance of understanding Salter-Harris fractures. They are the perfect example of how children are not tiny adults. Salter-Harris fractures only occur in children due to the differences in bone anatomy. The growth plate (or physis) of growing bone is cartilaginous and sits between the distal epiphysis and the metaphysis and is responsible for lengthening as children grow. Compared to other parts of the bone, the physis is the weakest, causing it to be more easily injured. More significant Salter-Harris injuries can lead to permanent growth arrest so correct classification is essential.

Describing the Fracture

With all fractures, describing them is the first step in management. Residents – when describing the fracture to your attending try to categorize using these terms and look at the image together before deciding to call orthopedics.

Things to ask yourself:

Is it open or closed?
- Is there a visible wound? Remember, the bone can pop through the skin and then retract back in.
What type of fracture is it?
- Salter-Harris? Complete? Incomplete?
Where on the bone is it located?
- Epiphysis, Physis, Metaphysis, Diaphysis
- Is it displaced? (Describe the distal portion compared to the proximal)
- Angulated, rotated, translated, impacted?

Salter-Harris Fracture Classification

Check out the excellent infographic at the end of this post for a visual description of all of these fracture types.

Type I

Extend through the entirety of the growth plate (physis)
May NOT be visible on x-ray, so a physical exam is key
Tenderness along the entirety of the physis = fracture present
If there is minimal displacement, splint and refer to a pediatric orthopedic physician in 1 week for casting
Though uncommon, significantly displaced SH Type I fracture will require an emergent reduction

Type II

Through the growth plate (physis) and extend into the metaphysis
Most common of the Salter-Harris fractures
Minimal displacement requires splinting and referral to a pediatric orthopedic physician in 1 week for definitive casting
If SH II fracture is significantly displaced, then they will require an emergent reduction

Type III

Extend from the growth plate (physis) into the epiphysis and intra-articular space
Any displacement requires urgent to emergent pediatric orthopedic evaluation
Appropriately splint if transferring to a tertiary care hospital to prevent further displacement
Management of non-displaced SH Type III fractures are a case by case discussion with a pediatric orthopedist

Type IV

Extend from the metaphysis, through the growth plate (physis), and into the epiphysis (intra-articular space)
Considered an unstable fracture and require emergent pediatric orthopedic care
High risk for growth arrest of injured bone
Will need to be seen by a pediatric orthopedic physician ASAP, if not available, splint and transfer

Type V

Crush injury of the germinal matrix and vascular supply leading to damage of the entire growth plate
More commonly occur in the ankle or knee
Can be difficult to see on X-ray, consider obtaining non-injured side for comparison
History of a ramming type injury and severe pain should increase suspicion
Nearly all lead to growth arrest and need immediate pediatric orthopedic care
If pediatric orthopedist is not available, splint and transfer