High-yield overview
5 types (I–V)classified by fracture path through physis, epiphysis, metaphysis
Type II most commonapproximately 75 percent of all physeal fractures
Types III–IVintra-articular — demand anatomic reduction
Higher type, higher riskgrowth arrest risk rises with type number
Critical Must-Knows
- Salter-Harris classifies fractures through the physis in children by the path of the fracture line through the epiphysis, physis, and metaphysis. Higher types carry progressively worse prognosis for growth disturbance.
- Type II (through physis and metaphysis) is by far the most common and generally has an excellent prognosis. Types III and IV cross the articular surface and therefore demand anatomic reduction.
- Type V is a crush injury to the physis — often diagnosed only in retrospect when growth arrest becomes apparent. It carries the worst prognosis among all five types.
- The key exam rule: higher type number means higher risk of growth arrest. Types III and IV are intra-articular and almost always need open reduction and internal fixation.
What examiners want you to say
Examiners expect you to classify the fracture, state the prognosis, and justify your management in one breath. For types III and IV the phrase is "intra-articular fracture requiring anatomic reduction, usually open, to restore joint congruity and minimise growth arrest." For type V, emphasise "often unrecognised at presentation; managed expectantly with serial monitoring for growth disturbance."
The Salter-Harris Classification
The classification is based on the fracture line's relationship to the physis, epiphysis, and metaphysis.
| Type | Fracture Path | Articular? | Frequency | Growth Arrest Risk |
|---|---|---|---|---|
| I | Through physis only | No | 5–7% | Low |
| II | Through physis then metaphysis | No | ~75% | Low (under 2%) |
| III | Through physis then epiphysis | Yes | 8–10% | Moderate |
| IV | Through epiphysis, physis, and metaphysis | Yes | 8–12% | High |
| V | Crush or compression of physis | No | Under 1% | Very high |
Mnemonic
S — A — L — T — RSALTR — the five types
Clinical Pearl
The direction of the metaphyseal or epiphyseal extension matters for types II and III. In type II the Thurston-Holland fragment (metaphyseal spike) confirms the diagnosis on radiograph. In type III the epiphyseal fragment may be displaced and the joint incongruous — this is why CT is often needed for surgical planning.
Clinical Implications and Management
Management is guided by whether the fracture is intra-articular and the risk of growth arrest.
| Type | Reduction | Fixation | Prognosis |
|---|---|---|---|
| I | Closed reduction if displaced | Rarely needed | Excellent — growth disturbance uncommon |
| II | Closed reduction | Percutaneous K-wires if unstable | Excellent — growth arrest under 2 percent at most sites |
| III | Open if greater than 2 mm displacement | Internal fixation (screws in epiphysis) | Good if anatomic reduction achieved |
| IV | Open reduction and internal fixation | Screws in epiphysis and metaphysis, avoiding transphyseal pins | Guarded — significant growth arrest risk |
| V | N/A — diagnosed retrospectively | Protected weight-bearing initially | Poor — high rate of growth arrest |
Caution
Types III and IV are intra-articular fractures. Accepting greater than 2 mm of displacement risks post-traumatic arthritis and growth arrest. Anatomic reduction — usually open — is the standard of care. Do not accept non-anatomic reduction in any Salter-Harris type III or IV fracture.
Mnemonic
Higher type equals higher arrest riskThree exam rules for Salter-Harris
Pitfalls and Imaging Considerations
- Type V is often missed on initial radiographs. The physis may appear normal or only slightly widened. Diagnosis is frequently retrospective, made when asymmetric growth or angular deformity develops over months. A high index of suspicion is needed in crush mechanisms — for example a child's ankle caught between bicycle spokes, or a fall from height with axial loading.
- MRI can identify occult physeal injury when plain films are normal but clinical suspicion is high. MRI is the gold standard for detecting physeal disruption and can demonstrate type V injuries acutely, showing oedema within the physis even when the radiograph is unrevealing.
- CT is the preferred modality for surgical planning in types III and IV — it delineates articular step-off, fragment size, and the plane of physeal involvement far better than plain radiographs.
- Growth arrest occurs via physeal bar formation. A bony or fibrous bridge across the physis tethers growth on one side, producing angular deformity (partial arrest) or limb-length discrepancy (complete arrest). The distal femoral and distal tibial physes contribute the most to lower-limb length and are therefore the highest-stakes sites.
- Timing of surgery matters. In adolescents nearing skeletal maturity the consequences of growth arrest are modest because little growth remains. In younger children the same physeal injury can produce devastating deformity. Always relate the classification to the child's remaining growth potential.
Mnemonic
Scan — Compare — MeasureGrowth arrest monitoring
Evidence Base
Evidence
Distribution of physeal and nonphyseal fractures in 2,650 long-bone fractures in children aged 0-16 years
Mann DC, Rajmaira S • J Pediatr Orthop (1990)
Key Findings:
- Among 2,650 long-bone fractures in children, approximately 30% involved the physis
- Type II Salter-Harris fractures were by far the most common physeal injury across all anatomical sites
- The distal radius and distal tibia were the most frequently fractured physis sites
Clinical implication: Large series confirming the relative frequencies of physeal fracture types and sites, validating the Salter-Harris distribution.
Limitation: Retrospective review from a single institution; includes only long-bone fractures.
Source: J Pediatr Orthop 1990;10(6):713-6
Evidence
Physeal fractures: part 1. Epidemiology in Olmsted County, Minnesota, 1979-1988
Peterson HA • J Pediatr Orthop (1994)
Key Findings:
- Population-based epidemiology: physeal fractures accounted for approximately 15 to 30 percent of all childhood fractures
- Type II was overwhelmingly the most common, comprising roughly three-quarters of physeal injuries
- Distal radius was the most frequently injured physis, followed by distal tibia
Clinical implication: Provided the epidemiological foundation for understanding which physeal fractures are common and therefore high-yield for exams.
Limitation: Single geographic population; may not reflect global patterns.
Source: J Pediatr Orthop 1994;14(4):423-30
Evidence
Statistical analysis of the incidence of physeal fractures
Mizuta T, Benson WM, Foster BK, Paterson DC, Morris LL • J Pediatr Orthop (1987)
Key Findings:
- Confirmed type II as the dominant pattern across all anatomical sites
- Type V injuries were the rarest but carried the highest growth arrest rate
- Peak incidence in early adolescence coinciding with the growth spurt
Clinical implication: Validated the Salter-Harris distribution across sites and reinforced the age-related vulnerability of the physis during rapid growth.
Limitation: Retrospective review from a single tertiary centre.
Source: J Pediatr Orthop 1987;7(5):518-23
Evidence
Growth disturbance after distal femoral growth plate fractures in children: a meta-analysis
Basener CJ, Mehlman CT, DiPasquale TG • J Orthop Trauma (2009)
Key Findings:
- Distal femoral physeal fractures carried a significantly higher rate of growth disturbance than physeal fractures at other sites
- Overall growth disturbance rate for distal femoral physeal fractures approached 40-50% in the meta-analysis
- The distal femoral physis contributes the most to lower-limb length and is particularly vulnerable
Clinical implication: Not all type II fractures are benign — the distal femur demands extra vigilance and close follow-up regardless of classification type.
Limitation: Meta-analysis of heterogeneous studies; variable follow-up durations across included series.
Source: J Orthop Trauma 2009;23(9):663-7
Evidence
Premature physeal closure following distal tibia physeal fractures: a new radiographic predictor
Barmada A, Gaynor T, Mubarak SJ • J Pediatr Orthop (2003)
Key Findings:
- The distance between the fracture line and the physis on initial radiographs predicted premature physeal closure in distal tibia fractures
- Salter-Harris type III and IV fractures at the distal tibia had significantly higher rates of growth arrest than type I and II
- Residual displacement after reduction was a strong independent predictor of premature physeal closure
Clinical implication: Provides a practical radiographic method for early risk stratification of growth arrest after distal tibial physeal fractures.
Limitation: Retrospective design; limited to distal tibia fractures only.
Source: J Pediatr Orthop 2003;23(6):733-9
Exam Viva
Practise clinical reasoning and management decisions out loud
Viva scenarioStandard
Clinical prompt
“A 12-year-old boy falls on an outstretched hand and presents with a painful, swollen wrist. Radiographs show a fracture through the distal radial physis with a small metaphyseal spike on the volar side. Classify this fracture and outline your management.”
Practical approach
This is a Salter-Harris type II fracture of the distal radius — the fracture traverses the physis and exits through the metaphysis, producing the characteristic Thurston-Holland fragment. Type II is the most common physeal fracture pattern. I would perform a gentle closed reduction under appropriate sedation or anaesthesia, aiming to restore alignment. If the fracture is stable post-reduction I would immobilise in an above-elbow cast for four to six weeks. If unstable, I would consider percutaneous K-wire fixation. The prognosis is generally excellent with a growth arrest rate of under 2 percent at this site. I would arrange follow-up radiographs at one to two weeks to confirm maintenance of reduction, and at six to twelve weeks to ensure ongoing physeal growth, comparing with the contralateral wrist.
Key clinical points
Correctly identify the Thurston-Holland fragment as indicating type II
Closed reduction under sedation or anaesthesia is the standard
Growth arrest is rare at the distal radius for type II, but monitoring is still essential
Common pitfalls
Confusing type II (metaphyseal spike) with type III (epiphyseal involvement)
Assuming all physeal fractures carry high growth arrest risk — type II at the distal radius has an excellent prognosis
Failing to arrange follow-up to confirm physeal growth continues
Further questions
“How would your management differ if this were a type III fracture?”
“What is a Thurston-Holland fragment and why does it matter?”
“How long would you follow this child for growth disturbance?”
Viva scenarioAdvanced
Clinical prompt
“A 10-year-old girl sustains a twisting injury to her ankle. CT shows a fracture extending from the medial malleolar articular surface through the epiphysis, across the physis, and into the metaphysis. The articular step-off is 3 mm. Classify the fracture, explain the prognosis, and describe your operative plan.”
Practical approach
This is a Salter-Harris type IV fracture of the distal tibia — the fracture line traverses the epiphysis, the physis, and the metaphysis. It is an intra-articular injury with a 3 mm articular step-off, which exceeds the acceptable threshold. Type IV fractures carry a high risk of physeal bar formation and subsequent growth arrest, particularly at the distal tibia which contributes significantly to lower-limb length. I would perform open reduction and internal fixation through an anteromedial approach. The epiphyseal fragment would be reduced anatomically under direct vision and fixed with smooth K-wires or a cannulated screw placed parallel to the physis, avoiding transphyseal fixation that could itself cause a growth bar. I would confirm reduction with intra-operative fluoroscopy and a post-operative CT scan if needed. Post-operatively I would immobilise in a non-weight-bearing cast for four to six weeks. Long-term follow-up is essential — I would monitor with serial radiographs for at least 12 to 18 months, watching for Park-Harris growth arrest lines, physeal bar formation, or angular deformity. If a physeal bar is detected and significant growth remains, bar excision with interposition material would be considered.
Key clinical points
Identify type IV by the fracture crossing all three zones: epiphysis, physis, and metaphysis
Emphasise the intra-articular nature requiring anatomic open reduction
Internal fixation parallel to the physis — not transphyseal
High growth arrest risk at the distal tibia — prolonged monitoring essential
Common pitfalls
Accepting less than anatomic reduction in an intra-articular fracture
Placing transphyseal hardware that could itself create a growth bar
Underestimating growth arrest risk at the distal tibial physis
Confusing with a Tillaux fracture or triplane fracture pattern
Further questions
“How does the remaining growth potential affect your management?”
“What is a physeal bar and how is it managed surgically?”
“How would you distinguish this from a triplane fracture?”
Exam day cheat sheet
Salter-Harris — Exam Cheat Sheet
Classification (SALTR)
- Type I: through physis only (Slipped) — rare, good prognosis
- Type II: through physis and metaphysis (Above) — most common at approximately 75 percent, good prognosis
- Type III: through physis and epiphysis (Lower) — intra-articular, needs anatomic reduction
- Type IV: through epiphysis, physis, and metaphysis (Through) — intra-articular, high surgical urgency
- Type V: crush of physis (Rammed) — rarest, worst prognosis, often diagnosed retrospectively
Management principles
- Types I and II: closed reduction; fix only if unstable
- Types III and IV: open reduction and internal fixation for greater than 2 mm displacement
- Type V: protected weight-bearing; monitor for growth arrest
- Fixation should be parallel to the physis — avoid transphyseal hardware in a growing child
High-yield exam points
- Higher type number equals higher growth arrest risk
- Thurston-Holland fragment equals type II
- Distal femoral physis is the highest-stakes site (contributes roughly 10 mm per year of growth)
- Monitor for at least 12 to 18 months with serial radiographs after any physeal fracture