In a pediatric patient with an ankle injury and an X‑ray showing open physes where a Salter‑Harris type I fracture cannot be excluded, how should the injury be managed?

Management of Suspected Salter-Harris Type I Ankle Fracture in Pediatric Patients

Treat this injury as a confirmed Salter-Harris type I fracture with immobilization, even when radiographs appear normal, because these physeal injuries are frequently radiographically occult and clinical examination findings (tenderness over the physis with open growth plates) are sufficient for diagnosis. 1, 2

Immediate Management Algorithm

Step 1: Confirm Clinical Diagnosis

• Point tenderness directly over the physis (growth plate) is the key diagnostic finding that distinguishes a Salter-Harris I fracture from a ligamentous sprain in children 3
• Document swelling, bruising, deformity, and inability to bear weight 3
• The diagnosis is clinical when physes are open and standard three-view radiographs (AP, lateral, mortise) show no visible fracture line 4, 2

Step 2: Initial Treatment Without Delay

• Proceed directly to closed reduction (if displaced) and immobilization without waiting for advanced imaging 5, 6
• Salter-Harris I fractures are managed by closed manipulation, reduction, and immobilization in 30-45 days of plaster casting depending on age 6
• These are relatively stable injuries that can be retained by adequate plaster 5
• Perform reduction in the emergency department or operating room under general anesthesia if significant displacement is suspected 6

Step 3: Immobilization Protocol

• Apply plaster immobilization for 30-45 days based on patient age 6
• Weight-bearing restrictions should be maintained during the immobilization period 2
• Critical follow-up radiographs must be obtained between day 7 and day 14 after reduction to detect any loss of position and avoid malunion 6

When to Consider MRI

MRI is rarely necessary for treatment decisions in suspected Salter-Harris I fractures but may be obtained in specific circumstances:

• Persistent pain beyond 1 week despite appropriate immobilization 7
• Uncertainty about diagnosis when clinical findings are equivocal 1, 2
• Need to exclude associated cartilage or ligamentous injuries in high-energy mechanisms 1

The American College of Radiology notes that MRI can help exclude true Salter-Harris I fractures in the pediatric population, though this confirmation is rarely necessary to initiate treatment 1, 2

Common Pitfalls to Avoid

• Do not wait for MRI confirmation before initiating immobilization—clinical diagnosis with physeal tenderness is sufficient 2, 3
• Do not dismiss the injury as a "sprain" simply because radiographs are normal—up to 50% of physeal injuries may be radiographically occult 7
• Do not skip the 7-14 day follow-up radiographs—this is when early malunion or displacement becomes apparent and can still be corrected 6
• Do not order CT as the next study; it adds no value for Salter-Harris I fractures and MRI is superior for detecting physeal injury if advanced imaging is truly needed 1, 7

Prognosis and Complications

• Most Salter-Harris I fractures heal without permanent deformity when properly treated 8, 5
• Potential complications include premature physeal closure, growth disturbance, shortening, and angular deformity 9, 5, 3
• The risk of growth disturbance is lowest with Salter-Harris I fractures compared to other physeal injury types 8, 5
• Regular follow-up is mandatory to monitor for these complications 5

Rehabilitation After Immobilization

• Physical therapy should focus on proprioception, strength, coordination, and functional exercises under supervision 2
• Gradual return to weight-bearing activities with supportive footwear after the immobilization period 2
• Joint mobility typically returns to normal within 3-6 months depending on patient age 6