Salter-Harris fractures

Written by the X-Ray Atlas editorial team from the sources listed below · Medical review pending · Updated 24 October 2026 · Level: Beginner

A Salter-Harris fracture is a fracture that involves the physis (growth plate) of a growing bone. The physis is cartilage, so it is weaker than the bone and ligaments around it, and in children it often fails before a ligament tears. That makes physeal injuries a routine part of paediatric trauma. They matter because a damaged growth plate can stop growing, or grow unevenly, leaving a short or angled limb years later. The Salter-Harris system (Salter and Harris, 1963) sorts these injuries into five types that broadly predict how they behave and how they are treated.

1. The growing bone: the words you need

A long bone in a child has four zones. Learn them first, because the whole classification is described in these terms.

Zone	What it is	How it looks on X-ray
Epiphysis	The end of the bone beyond the growth plate, forming the joint surface.	An ossification centre whose size and shape change with age. In infants it may be entirely cartilage and invisible.
Physis	The growth plate: a disc of cartilage where length is added.	A lucent (dark) band between epiphysis and metaphysis, usually with smooth, slightly undulating edges.
Metaphysis	The flared part of the shaft next to the physis.	Wider, with thinner cortex. Most childhood fractures and many bone lesions sit here.
Diaphysis	The shaft.	Thick cortex and a tubular medullary cavity.

The physis is visible on X-ray only as a gap. You cannot see the cartilage itself, which is why a pure growth plate injury can look normal. See the glossary for these and related terms.

2. How to look

• Two orthogonal views (usually AP and lateral) are the minimum, as with any fracture. Include the joint above and below for a shaft injury. See how to describe a fracture.
• Follow each cortex from the shaft into the metaphysis, across the physis and round the epiphysis. A tiny metaphyseal corner fragment may be the only clue.
• Measure the physis by eye. Is it the same width all the way across? Is it wider than the corresponding physis elsewhere in the same film? Asymmetric widening suggests a type I injury.
• Check epiphyseal alignment. The epiphysis should sit squarely on its metaphysis. Even a small step or tilt is significant.
• Look at the soft tissues. Swelling over a physis, or a joint effusion (for example a raised elbow or knee fat pad), raises suspicion even when the bones look normal.
• Comparison views of the other side are not routine. They are reserved for when you are genuinely unsure whether an appearance is normal for age.

3. The five types: SALTR

The mnemonic SALTR assumes the epiphysis is drawn at the bottom of the picture, as at the distal radius or distal tibia.

Type	SALTR	Path of the fracture	X-ray clues and notes
I	Straight across (slipped)	Through the physis only.	The film may be normal, or show a widened physis or a displaced epiphysis. A slipped upper femoral epiphysis is a type I injury (see SUFE, Perthes and DDH).
II	Above	Through the physis and out through the metaphysis.	The most common type, about 75%. The triangular metaphyseal piece is the Thurston-Holland fragment. The distal radius is the classic site.
III	Lower (below)	Through part of the physis and down through the epiphysis into the joint.	Intra-articular. A step in the joint surface matters. Example: the juvenile Tillaux fracture.
IV	Through	Through metaphysis, physis and epiphysis in one line.	Intra-articular, and the fracture crosses the growth zone, so there is a risk of growth arrest. Lateral condyle fractures of the elbow behave like this.
V	Rammed (crushed)	Compression of the physis without a visible line.	Rare, and the initial film is often normal. It is usually recognised in retrospect, when growth stops. The worst prognosis.

Some authors add further types (for example Rang's type VI, an injury to the edge of the physis), but types I–V are the ones used in everyday reporting and in exams.

Type I in practice

A child with point tenderness over a growth plate and a normal-looking film may still have a type I injury. In many departments this is managed as a presumed type I fracture, with immobilisation and review, rather than being labelled "normal". The decision is clinical, guided by local protocol. A normal film does not exclude a physeal injury.

Type II in practice

Look for the small triangle of metaphysis that stays attached to the epiphysis. On a distal radius the epiphysis and that fragment usually displace dorsally, and the rest of the physis may look subtly widened. Most type II injuries do well after reduction if needed. See distal radius fractures for the adult equivalents and how they differ.

4. Special patterns: Tillaux, triplane and beyond

The distal tibia closes in a predictable order during adolescence, and that produces two patterns worth knowing.

• Juvenile Tillaux fracture: a type III injury of the anterolateral distal tibial epiphysis, the last part of the physis to fuse. The fragment is pulled off by the anterior tibiofibular ligament. On the AP view you see a vertical line through the lateral epiphysis.
• Triplane fracture: a fracture in three planes that looks like type III on the AP and type II on the lateral. Plain films underestimate it, so CT is used to plan treatment. See ankle fractures.
• Distal femur and proximal tibia: physeal fractures around the knee are less common but more likely to disturb growth, and a displaced proximal tibial or distal femoral injury can threaten the popliteal vessels. Treat these with respect. See knee fractures.
• Elbow: lateral condyle fractures are effectively type IV injuries and are often subtle. See the paediatric elbow.

5. Why the type matters

The classification is popular because it is simple and roughly prognostic. As a rule of thumb:

• Types I and II do not cross the joint surface or the deep germinal layer of the physis, and usually heal without growth problems. Closed reduction is often enough.
• Types III and IV are intra-articular and cross the physis. They usually need anatomical reduction, sometimes surgical fixation, to restore a smooth joint and reduce the risk of a physeal bar (a bridge of bone across the growth plate).
• Type V carries the highest risk of growth arrest.

This is a guide, not a rule. The bone involved, the child's remaining growth, the amount of displacement and the energy of injury all affect the outcome. Even a type II fracture can cause growth disturbance, particularly around the knee. Growth arrest shows later as a leg length difference or an angular deformity if only part of the physis stops growing. Follow-up is arranged by the treating team.

6. Pitfalls and mimics

• Normal physes and ossification centres: a growth plate, an apophysis or an accessory ossification centre can look like a fracture to the inexperienced eye. Physes are smooth, have corticated (white) edges and appear where you expect them. A fracture line is usually sharper and non-corticated. Use an atlas of normal variants.
• Physiological physeal widening: physes are wider in younger children and during growth spurts. Compare with other physes on the same film before calling widening abnormal.
• Satisfaction of search: a forearm with an obvious radial injury may also have an ulnar styloid or ulnar physeal injury. Check both bones.
• Classic metaphyseal lesions are different: the corner and bucket-handle fractures of infants are planar fractures through the metaphysis, not Salter-Harris injuries. In a non-ambulant infant they should prompt a safeguarding assessment. See non-accidental injury.
• Rickets and other metabolic disease widen and fray the physes, and can mimic or coexist with injury. See metabolic bone disease.
• Undercalling the joint: a type III or IV line can be hair-thin. If a vertical line runs into the epiphysis, look closely at the joint surface on both views.

Red flags: act now

What to focus on, by role

Role	Priorities
Medical student	Know the four zones of a growing bone, SALTR and the fact that type II is most common. Be able to say that types I and V can look normal.
Nurse / ENP	Point tenderness over a growth plate is significant even with a "normal" X-ray. Check circulation and sensation distal to the injury and escalate changes. Recognise when the history does not fit the child's age.
Junior doctor	Describe which zones the line crosses, decide whether the joint surface is involved, and refer displaced or intra-articular injuries promptly. Document neurovascular status before and after any manipulation.
Radiographer	True orthogonal views centred on the joint, and an extra oblique where the protocol allows for subtle distal tibial or elbow injuries. Flag suspected physeal injuries through your preliminary clinical evaluation process.
Advanced / FRCR	Tillaux and triplane fractures, lateral condyle fractures as type IV injuries, physeal bars on follow-up imaging, and separating physeal injury from classic metaphyseal lesions and metabolic disease.

Practise on paediatric X-rays →

References

1. Salter RB, Harris WR. Injuries involving the epiphyseal plate. J Bone Joint Surg Am 1963;45(3):587–622.
2. Radiopaedia. Salter-Harris classification. radiopaedia.org
3. Radiology Masterclass. Paediatric musculoskeletal imaging. radiologymasterclass.co.uk
4. National Institute for Health and Care Excellence. Fractures (non-complex): assessment and management (NG38). nice.org.uk
5. Don't Forget the Bubbles. Paediatric emergency medicine education. dontforgetthebubbles.com
6. Royal College of Radiologists. iRefer: making the best use of clinical radiology. irefer.org.uk

For education only. Not a substitute for a formal report, senior review or your local policy. Never use this page to make decisions about a real patient.