From the Guidelines
For a 14-year-old male with a suspected Salter-Harris type 1 fracture of the dorsal, fibular growth plate physis, MRI is the best diagnostic approach. Initial X-rays often miss these injuries because growth plates appear as radiolucent gaps on radiographs, as noted in the guidelines for acute trauma to the ankle 1. An MRI can clearly visualize both the growth plate injury and assess for associated ligamentous damage to the anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL).
Key Considerations
- The patient's age and the presence of a growth plate make MRI a superior choice for evaluating physeal cartilage and surrounding soft tissues in pediatric ankle injuries.
- CT scanning, while offering better bone detail, is not the preferred initial choice for assessing growth plate injuries and ligamentous damage in this context.
- The guidelines from the Journal of the American College of Radiology 1 support the use of MRI for patients with acute trauma to the ankle and persistent pain, especially when initial radiographs are negative or inconclusive.
Diagnostic Approach
- Given the patient's symptoms and the inconclusive initial X-rays, an MRI without IV contrast is usually appropriate, as it can provide detailed images of the growth plate and surrounding soft tissues.
- If MRI is unavailable, follow-up X-rays in 10-14 days may show periosteal new bone formation or healing callus that wasn't visible on initial imaging, but this should not delay the diagnosis and appropriate management.
Management
- In the interim, the ankle should be immobilized with a removable boot or splint, weight-bearing should be limited as tolerated, and ice, elevation, and appropriate pain management implemented.
- Prompt diagnosis is crucial as missed growth plate injuries can lead to growth disturbances, angular deformities, or premature physeal closure, emphasizing the need for a thorough diagnostic approach like MRI.
From the Research
Diagnostic Approach for Suspected Salter-Harris Type 1 Fracture
- The initial X-rays are inconclusive due to the presence of a growth plate, making it essential to consider alternative diagnostic methods 2.
- A high index of suspicion is crucial for diagnosing physeal injuries, as they may not be initially obvious in children with periarticular trauma 2.
- Differential diagnosis for a Salter-Harris fracture includes ligamentous sprain, acute osteomyelitis, or an extraphyseal fracture such as a Torus fracture 2.
- Musculoskeletal ultrasound (US) can be advantageous in visualizing the nonossified epiphysis and diagnosing growth plate injuries, especially in cases where plain radiographs are inconclusive 3.
Diagnostic Considerations for Salter-Harris Type 1 Fracture
- Radiographic images are essential for prompt diagnosis and minimizing negative health outcomes in patients with suspected Salter-Harris fractures 4, 5.
- MRI can be used in conjunction with radiographs to make a timely diagnosis and minimize patient discomfort 5.
- A thorough physical examination, including assessment of tenderness over the anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL), is crucial in diagnosing Salter-Harris fractures 2.
Management of Salter-Harris Type 1 Fracture
- Salter-Harris I and II growth plate fractures are commonly managed by closed manipulation, reduction, and immobilization 2, 6.
- These injuries are relatively stable and can be retained by adequate plaster, but regular follow-up is necessary to monitor for potential complications such as malunion, bar formation, and posttraumatic arthritis 2, 6.