From the Guidelines
For a 14-year-old male with a suspected Salter-Harris type 1 fracture of the distal fibular physis, MRI is the preferred diagnostic imaging modality over spaced x-rays due to its ability to directly visualize the growth plate injury, soft tissue damage, and any displacement that may not be apparent on plain radiographs. When diagnosing potential fractures and displacement in adolescents, it is crucial to consider the limitations of initial x-rays, which often miss Salter-Harris type 1 fractures since these injuries occur through the physis (growth plate) without displacing bone fragments 1. The following key points support the use of MRI in this clinical scenario:
- MRI provides superior visualization of cartilage, bone marrow edema, and ligamentous structures, allowing for comprehensive assessment of both the suspected fracture and associated ankle ligament injuries 1.
- MRI can help exclude Salter 1 fractures in the pediatric population, which is essential for preventing potential growth disturbances 1.
- The ability of MRI to assess stability and determine the grade of ligamentous injury is critical for treatment planning and return to sport assessment, particularly in athletes 1.
- High-resolution evaluation of tendons and ligaments by MRI allows distinction between tendinopathy, sprain, and partial or complete tears, which is vital for accurate diagnosis and treatment 1. In real-life clinical practice, the benefits of MRI in diagnosing and managing Salter-Harris type 1 fractures outweigh its higher cost and reduced availability compared to serial x-rays, especially when considering the potential long-term consequences of misdiagnosis or inadequate treatment on morbidity, mortality, and quality of life.
From the Research
Diagnostic Imaging Modalities
To diagnose a potential fracture and displacement in a 14-year-old male with a suspected Salter-Harris type 1 fracture of the distal fibular physis, where the growth plate is not visible on initial x-ray, the following diagnostic imaging modalities can be considered:
- Spaced x-rays: This modality may not be sufficient to diagnose a Salter-Harris type 1 fracture, as the growth plate is not visible on initial x-ray 2.
- Magnetic Resonance Imaging (MRI): MRI can be used to diagnose Salter-Harris type 1 fractures, especially when the growth plate is not visible on initial x-ray 3, 4.
Advantages of MRI
The advantages of using MRI to diagnose Salter-Harris type 1 fractures include:
- Ability to detect occult growth plate fractures 3, 4
- Ability to detect ligament injuries and bone contusions 3, 4
- Ability to guide nonsurgical treatment 5
Studies Supporting the Use of MRI
Several studies support the use of MRI to diagnose Salter-Harris type 1 fractures:
- A study published in 2016 found that Salter-Harris type 1 fractures of the distal fibula are rare in children with radiograph-negative lateral ankle injuries, and that MRI can detect occult growth plate fractures 3.
- A study published in 2010 found that MRI can detect ligamentous sprains and bony contusions in children with clinically suspected Salter-Harris type 1 fractures of the distal fibula 4.
- A case report published in 2014 found that MRI can guide nonsurgical treatment of McFarland fractures, a type of oblique medial malleolar fracture in children 5.