From the Guidelines
For a 14-year-old male with a suspected Salter-Harris type I fracture of the distal fibular physis, tenderness to palpation over the lateral malleolus, and possible injury to the anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL), plain radiographs should be obtained first as the initial imaging study, as indicated by the American College of Radiology appropriateness criteria 1.
Initial Imaging
Standard ankle radiographs including anteroposterior, lateral, and mortise views are the initial imaging of choice, with a high sensitivity of 92-99% for detecting ankle fractures 1.
- The mortise view is particularly important as it includes the base of the fifth metatarsal bone distal to the tuberosity.
- Weight-bearing radiographs, if possible, provide important information, particularly with fractures of uncertain stability.
Further Evaluation
If these radiographs are negative but clinical suspicion remains high for a physeal injury, an MRI would be the next best step rather than stress views, as MRI is superior for evaluating physeal injuries, especially Salter-Harris type I fractures which may not be visible on plain radiographs, and can simultaneously assess for ligamentous injury to the ATFL and CFL 1.
- MRI is the reference standard for ligamentous injury and assessment of stability, which is particularly important in athletes.
- High-resolution evaluation of the tendons and ligaments allows distinction between tendinopathy, sprain, and partial or complete tears.
Treatment and Follow-up
Early diagnosis is important as missed physeal injuries can lead to growth disturbances.
- Treatment typically involves immobilization with a cast or walking boot for 3-4 weeks, with follow-up radiographs to ensure proper healing and to monitor for growth complications.
- The presence of bone bruise and adjacent soft-tissue edema have shown a higher association with acute ligamentous injuries and tendon abnormalities in patients with negative radiographs 1.
From the Research
Diagnostic Approach for Suspected Salter-Harris Type 1 Fracture
The diagnostic approach for a suspected Salter-Harris type 1 fracture of the distal fibular physis in a 14-year-old male with a right lateral ankle injury involves several considerations:
- Clinical examination and radiographs are essential initial steps, but may not always confirm the diagnosis 2, 3
- Magnetic Resonance Imaging (MRI) can be useful in confirming the diagnosis of a Salter-Harris type 1 fracture, as well as identifying other potential injuries such as ligament sprains or avulsion fractures 2, 3
- The proportion of distal fibula Salter-Harris type 1 epiphyseal fractures in the pediatric population with acute ankle injury is relatively low, with most children having ligamentous lesions, bone contusion, or joint effusion rather than a Salter-Harris type 1 fracture 3
Considerations for Anterior Talofibular Ligament (ATFL) and Calcaneofibular Ligament (CFL) Involvement
- The involvement of the ATFL and CFL should be considered in the diagnostic approach, as these ligaments can be injured in conjunction with a Salter-Harris type 1 fracture 4
- MRI can be useful in identifying injuries to these ligaments, as well as other potential injuries such as avulsion fractures 2
- The treatment approach should take into account the potential for ligamentous injuries, as well as the need for anatomic reduction and fixation of the fracture 4, 5
Treatment Approach
- The treatment approach for a confirmed Salter-Harris type 1 fracture of the distal fibular physis should involve anatomic reduction and fixation, as well as consideration for the potential for ligamentous injuries 4, 5
- Closed reduction and fixation may be possible in some cases, while open reduction and internal fixation may be necessary in others 4, 5
- The goal of treatment should be to achieve anatomic reduction and fixation, while minimizing the risk of complications such as premature physeal closure or growth disturbance 4, 6