From the Guidelines
The best way to diagnose a suspected Salter-Harris type 1 fracture of the distal fibula physis in this 14-year-old male is to obtain an MRI, as it is the reference standard for ligamentous injury and assessment of stability, and can help exclude Salter 1 fractures in the pediatric population. Since the growth plate is not visible on X-ray and there is tenderness to palpation at the lateral malleolus, anterior talofibular ligament (ATFL), and calcaneofibular ligament (CFL), further investigation is warranted. According to the American College of Radiology 1, MRI is the preferred imaging modality for assessing ligamentous injuries and stability, particularly in athletes.
Key Points to Consider
- MRI can directly visualize physeal cartilage and detect bone marrow edema indicative of injury, making it a crucial diagnostic tool in this case 1.
- The presence of bone bruise and adjacent soft-tissue edema have shown a higher association with acute ligamentous injuries and tendon abnormalities, which can be assessed using MRI 1.
- CT scanning may help identify subtle fractures but is less sensitive than MRI for physeal injuries.
- Early orthopedic consultation is recommended as proper diagnosis and management are crucial to prevent growth disturbances and long-term complications in this skeletally immature patient.
Initial Management
In the interim, the ankle should be immobilized with a removable boot or brace, weight-bearing as tolerated with crutches if needed, and RICE therapy (rest, ice, compression, elevation) should be implemented to reduce pain and inflammation.
Importance of Accurate Diagnosis
Accurate diagnosis and management of Salter-Harris type 1 fractures are critical to prevent long-term complications, such as growth disturbances and chronic ankle instability. The use of MRI as the preferred imaging modality can help ensure accurate diagnosis and guide appropriate treatment, as recommended by the American College of Radiology 1.
From the Research
Diagnostic Approach for Suspected Salter-Harris Type 1 Fracture
- The diagnosis of a Salter-Harris type 1 fracture of the distal fibula physis can be challenging, especially when the growth plate is not visible on X-ray 2, 3, 4, 5.
- In cases where the X-ray does not show a clear fracture, magnetic resonance imaging (MRI) can be a useful diagnostic tool to confirm the presence of a Salter-Harris type 1 fracture 3, 4, 5.
- Studies have shown that a significant proportion of children with clinically suspected Salter-Harris type 1 fractures of the distal fibula do not actually have this type of fracture, but rather ligamentous sprains or bone contusions 3, 4, 5.
- In one study, only 3.0% of children with clinically suspected Salter-Harris type 1 fractures of the distal fibula were found to have MRI-confirmed fractures, while 80.0% had ligament injuries and 22.0% had isolated bone contusions 4.
- Another study found that none of the patients with clinically suspected Salter-Harris type 1 fractures of the distal fibula had evidence of a fracture on MRI, and instead had ligamentous lesions, bone contusion, or joint effusion 5.
Clinical Presentation and Diagnostic Criteria
- The clinical presentation of a suspected Salter-Harris type 1 fracture of the distal fibula physis may include tenderness to palpation at the lateral malleolus, anterior talofibular ligament (ATFL), and calcaneofibular ligament (CFL) 2.
- The diagnosis of a Salter-Harris type 1 fracture is typically made based on a combination of clinical and radiographic findings, including tenderness and swelling at the growth plate, and abnormal radiographic findings such as widening of the growth plate or displacement of the epiphysis 2, 6.
- However, as noted above, the absence of radiographic findings does not rule out the possibility of a Salter-Harris type 1 fracture, and further diagnostic evaluation with MRI may be necessary to confirm the diagnosis 3, 4, 5.