Classification principles
This categorization system describes specific injuries affecting the growth plate (physis) in pediatric patients. The five types are based on the direction of the fracture line relative to the epiphysis, metaphysis, and the growth plate itself.
Simple and frequent injuries (Types I and II)
These types of injuries are characterized by the absence of epiphyseal involvement in the fracture line.
- Type I — Slipped. Occurs in approximately 5% of cases. It is an isolated injury of the growth plate with separation of the epiphysis (epiphysiolysis). Important imaging feature: fractures of the adjacent bone tissue are completely absent. The fracture line passes exclusively through the hypertrophic layer of the growth plate (physis).
- Type II — Above. The absolute leader in frequency — about 75% of all cases. The fracture line first splits the growth plate and then extends "above" into the metaphysis, separating a small bone fragment. As a rule, this is the result of shearing (shearing) or avulsive (avulsive) forces. The most typical patient age is 10 to 16 years.
Epiphyseal involvement (Types III and IV)
In these types, the fracture line directly involves the epiphysis, requiring careful evaluation of the articular surfaces.
- Type III — Below. Accounts for about 10% of cases. The fracture line begins in the epiphysis ("below" the growth plate), passes through it, and then horizontally crosses the growth plate. Radiologists most often encounter this pattern when examining the distal tibia (tibia). At-risk age group — children 10–15 years old.
- Type IV — Through. Also occurs in 10% of situations. This is a complex vertically oriented fracture. The fracture line involves both the epiphysis and the metaphysis simultaneously, crossing the growth plate completely. Typical localization — distal humerus (humerus) and tibia (tibia).
Compression injuries (Type V)
Type V — Ruined. The rarest (less than 1% of cases) but extremely insidious variant. It results from a powerful compressive force that literally crushes the growth plate. The danger lies in the fact that the initial imaging findings may be non-obvious. The diagnosis is often made retrospectively at later stages when a clinically significant bone growth arrest and subsequent deformity are detected.
Imaging examples
Various projections and research methods are used to make an accurate diagnosis:
- In Type II injuries of the distal right radius (radius) and ulna (ulna), standard anteroposterior (AP) and lateral radiographs are evaluated.
- To detail a Type III injury (e.g., fracture of the distal tibial epiphysis), computed tomography (CT) is extremely informative in addition to the anteroposterior radiograph.
- For a Type IV injury in the distal tibia, a comprehensive approach is required: anteroposterior and several variations of lateral radiographs for a precise spatial understanding of the fracture line course.
Briefly: answers to topical questions
What English mnemonic is used to remember the five main types of Salter-Harris fractures?
The sources do not provide a specific mnemonic abbreviation, but the following English terms are used to remember the five main fracture types.
- Type I — Slipped — isolated injury of the growth plate where the fracture line passes through the hypertrophic layer of the growth plate (physis).
- Type II — Above — the fracture line splits the growth plate and extends into the metaphysis.
- Type III — Below — the fracture line passes through the epiphysis and then horizontally crosses the growth plate.
- Type IV — Through — vertically oriented fracture involving the epiphysis and metaphysis, commonly found in the distal humerus (humerus) and tibia (tibia).
- Type V — Ruined — occurs as a result of a compressive force that crushes the growth plate.
Easy to remember by their English names: I — Slipped, II — Above into the metaphysis, III — Below into the epiphysis, IV — Through all layers, V — Ruined by compression.
Class and exam questions
Which type of Salter-Harris fracture is most common?
Type II is the most frequent (about 75% of cases), where the fracture line passes through the growth plate and extends into the metaphysis.
What is the main danger of a Type V fracture?
Due to compression crushing of the growth plate, it is often invisible on initial scans, but subsequently leads to growth arrest and bone deformity.
What methods are used to diagnose Type III fractures?
Anteroposterior radiography is performed first, but computed tomography (CT) may be used for a more detailed assessment of epiphyseal injury.
What else to study on this topic
- Radiological signs of isolated epiphysiolysis (Type I)
- Biomechanics of shearing and avulsion forces in long bone injuries
- Application features of CT in intra-articular fractures in children
- Retrospective diagnosis of bone growth arrest
Master the entire topic in the "Diagnostic Radiology" course
This is a summary. The course covers everything tested in classes and exams.
- Complete study guide on "Salter-Harris Fracture Classification" and 2,199 more pages of the subject
- Assignments and quizzes after every topic — just like in a colloquium
- AI tutor answers questions on the topic anytime
- 10 video lessons on the subject
Other Topics in "Pediatric Diagnostic Radiology"
Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.