From the Guidelines
MRI is the preferred diagnostic tool over serial X-rays for diagnosing a suspected Salter-Harris type 1 fracture of the distal fibular physis in a 14-year-old male with an invisible growth plate on initial X-ray. This recommendation is based on the highest quality evidence available, which emphasizes the importance of MRI in assessing ligamentous injury and stability, particularly in athletes 1. The study highlights that MRI is the reference standard for evaluating ligamentous injury and assessing stability, which is critical for treatment planning and return to sport assessment.
Key benefits of using MRI in this scenario include:
- Immediate, detailed visualization of the growth plate injury and associated soft tissue damage
- Ability to detect non-displaced Salter-Harris I fractures, which may not be visible on initial X-rays
- Identification of physeal widening, bone marrow edema, and ligamentous injuries that may accompany the fracture
- Comprehensive assessment of the injury, allowing for appropriate treatment planning without delay
- Elimination of radiation exposure concerns associated with repeated X-rays in adolescent patients
As noted in the study, MRI can also help exclude Salter 1 fractures in the pediatric population 1. Furthermore, 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. Therefore, MRI is the most appropriate diagnostic tool for this patient, providing a detailed and comprehensive assessment of the injury, which is essential for proper management and prevention of growth disturbances.
From the Research
Benefits of MRI over Serial X-rays
The use of Magnetic Resonance Imaging (MRI) has several benefits over serial X-rays in diagnosing suspected Salter-Harris type 1 fractures of the distal fibular physis, particularly in cases where the growth plate is invisible on initial X-ray. Some of these benefits include:
- Higher accuracy in diagnosing growth plate injuries, as MRI can detect injuries that are not visible on X-ray 2, 3, 4
- Ability to identify alternative pathologies, such as ligamentous sprains and bony contusions, which are common in children with ankle injuries 2, 3, 4
- Reduced risk of misdiagnosis, as MRI can confirm or rule out the presence of a Salter-Harris type 1 fracture, thereby avoiding unnecessary treatment and potential complications 2, 3, 4
Comparison of MRI and Serial X-rays
Studies have shown that MRI is more effective than serial X-rays in diagnosing Salter-Harris type 1 fractures of the distal fibula. For example:
- A study published in the Journal of Pediatric Orthopedics found that none of the 31 patients with clinically suspected Salter-Harris type 1 fractures of the distal fibula had evidence of the fracture on MRI, suggesting that the diagnosis is often incorrect 3
- Another study published in JAMA Pediatrics found that only 3.0% of children with radiograph-negative lateral ankle injuries had MRI-confirmed Salter-Harris type 1 fractures of the distal fibula, while 80.0% had ligament injuries and 22.0% had isolated bone contusions 4
Clinical Implications
The use of MRI in diagnosing suspected Salter-Harris type 1 fractures of the distal fibular physis has significant clinical implications, including:
- Avoiding unnecessary treatment and potential complications associated with misdiagnosis 2, 3, 4
- Providing a more accurate diagnosis, which can inform treatment decisions and improve patient outcomes 2, 3, 4
- Reducing the need for serial X-rays, which can expose children to unnecessary radiation 2, 3, 4