Salter-Harris Type IV and V Fractures Have the Worst Prognosis
Salter-Harris Type IV fractures carry the worst prognosis among commonly encountered pediatric physeal injuries, with high rates of premature physeal closure, growth arrest, and angular deformity requiring surgical intervention. Type V fractures (crush injuries to the growth plate) theoretically have equally poor outcomes but are exceedingly rare in clinical practice 1.
Understanding the Prognostic Hierarchy
Type IV Fractures: The Highest Risk Category
- Type IV fractures extend through the articular cartilage, epiphysis, physis, and metaphysis, creating a high risk of premature partial physeal closure 1
- In distal tibial Type IV fractures specifically, 50% (9 of 18 patients) developed premature partial physeal closure resulting in angular deformity or limb-length discrepancy severe enough to require operative treatment (epiphyseodesis, corrective osteotomy, or physeal bar excision) 1
- Type IV fractures are intraarticular, rare, and almost always require surgical reduction to prevent deformity 2
- Even with optimal surgical management achieving <2mm displacement, 8% of patients still demonstrate growth disturbances 3
Type V Fractures: Theoretically Worst, Clinically Rare
- Type V fractures involve crush injuries to the growth plate and theoretically carry the worst prognosis
- However, these are so rare that they lack substantial clinical data and are often only diagnosed retrospectively when growth arrest occurs 1, 4
Types I-III: Better Prognosis
- Type I fractures (through the physis only) generally have excellent prognosis and are managed non-operatively 5, 4
- Type II fractures (through physis and metaphysis) have good outcomes with appropriate immobilization 6
- Type III fractures (through physis and epiphysis) have intermediate risk, though still better than Type IV 7
Critical Management Principles for Type IV Fractures
Surgical Intervention Threshold
- Any Type IV fracture with ≥1mm displacement requires open reduction and internal fixation 7
- Arthrotomy is recommended to achieve anatomical reduction under direct visualization, as fluoroscopy alone is insufficient to evaluate perfect reduction 7
- Surgical reduction to <2mm gap displacement results in fracture union in 100% of cases and prevents osteoarthritis 3
Location-Specific Considerations
- Distal tibial Type IV fractures (medial malleolus) have particularly high complication rates, with the metaphyseal extension often only visible on oblique radiographs 1
- Triplane fractures occurring near skeletal maturity (age 13-15) have lower growth arrest risk due to limited remaining growth 1
Common Pitfalls to Avoid
- Do not rely on standard AP/lateral radiographs alone for Type IV fractures—obtain oblique views to visualize metaphyseal extension 1
- Do not accept >1mm displacement in Type IV fractures—this threshold is lower than the traditional 2mm used for other fracture types 7
- Do not assume closed reduction under fluoroscopy is adequate—arthrotomy provides superior visualization for anatomical reduction 7
- Monitor for physeal bar formation with tomograms in two planes and scanograms during follow-up, as bars may develop despite optimal initial treatment 1