From the Guidelines
MRI is the best diagnostic method for detecting growth plate displacement in a 14-year-old male with a suspected Salter-Harris type 1 fracture of the distal fibula physis, where the displacement is not visible on X-ray. This is because MRI provides superior soft tissue contrast and can directly visualize the physis (growth plate), detecting subtle injuries including bone marrow edema, cartilage disruption, and ligamentous injuries that may not be apparent on conventional radiographs 1. The use of MRI is particularly important in this case, as it can help exclude Salter 1 fractures in the pediatric population, which is critical for treatment planning and preventing long-term complications such as premature growth plate closure, angular deformities, or chronic instability 1.
Some key benefits of using MRI in this scenario include:
- Direct visualization of the physis and surrounding soft tissues
- Detection of subtle injuries, including bone marrow edema and cartilage disruption
- Evaluation of associated ligamentous structures, which is important since ankle sprains often accompany physeal injuries in adolescents
- Prompt and accurate diagnosis, which is crucial for timely intervention and preventing long-term complications
In contrast, serial X-rays may not be sufficient, as they may not show periosteal reaction or callus formation until 2-3 weeks after the injury, delaying diagnosis and proper treatment. Additionally, X-rays may not provide the same level of detail as MRI, particularly in cases where the displacement is not visible on initial radiographs. Therefore, MRI is the preferred diagnostic method for detecting growth plate displacement in this scenario, as it provides the most accurate and timely diagnosis, allowing for appropriate management and prevention of long-term complications 1.
From the Research
Diagnostic Methods for Growth Plate Displacement
- The Salter-Harris classification system is used to estimate the prognosis and potential for growth disturbance in growth plate injuries 2.
- In cases where the displacement is not visible on X-ray, Magnetic Resonance Imaging (MRI) can be used to diagnose growth plate displacement, as it permits noninvasive evaluation of the cartilage of the growth plate and epiphysis 3.
- A study on clinically suspected Salter-Harris I fracture of the distal fibula found that MRI-confirmed SH1DF was not present in any of the 18 patients enrolled, and instead, ligamentous sprains and/or bony contusions were identified in almost 90% of the patients 4.
- Another study reported a case of a Salter-Harris type 1 fracture of the distal epiphysis of the femur, where an MRI revealed a partial ventero-medial epiphyseolysis, consistent with a Salter-Harris type 1 fracture 5.
- In comparison to serial X-rays, MRI is a more sensitive diagnostic tool for detecting growth plate displacement, especially in cases where the displacement is not visible on X-ray 4, 3.
Advantages of MRI over Serial X-rays
- MRI can detect ligamentous sprains and/or bony contusions, which are common in pediatric patients with ankle injuries 4.
- MRI can evaluate the cartilage of the growth plate and epiphysis, providing a more detailed diagnosis of physeal injuries 3.
- MRI is noninvasive and does not require repeated exposure to radiation, making it a safer option for pediatric patients 3.
Case Studies
- A study reported two cases of adolescents with completely displaced Salter-Harris type I distal fibula fractures, which were treated operatively 6.
- Another study reported a case of a self-inflicted partial epiphyseolysis of the distal femur, where an MRI revealed a partial ventero-medial epiphyseolysis, consistent with a Salter-Harris type 1 fracture 5.