Is an MRI appropriate for ongoing ankle and lower extremity pain with swelling after an injury and negative x-rays?

From the Guidelines

An MRI is appropriate for ongoing ankle and lower extremity pain with swelling after an injury and negative x-rays, as it can detect soft tissue injuries such as ligament tears, tendon damage, and bone bruises that X-rays cannot visualize. According to the American College of Radiology Appropriateness Criteria for acute trauma to the ankle 1, MRI is the reference standard for ligamentous injury and assessment of stability, particularly important in athletes. The study highlights that ligament and tendon injuries can occur without fracture on radiography, and MRI can help exclude Salter 1 fractures in the pediatric population.

When considering an MRI, it's essential to first try conservative management, including the RICE protocol (Rest, Ice, Compression with an elastic bandage, and Elevation above heart level), along with over-the-counter pain relievers like ibuprofen 400-600mg three times daily or naproxen 500mg twice daily, and possibly physical therapy 1. If symptoms persist for more than 1 week but less than 3 weeks despite these measures, an MRI may be necessary to identify the underlying cause of continued symptoms and guide appropriate treatment. Key points to consider include:

• MRI can detect soft tissue injuries, including ligament tears, tendon damage, and bone bruises
• Conservative management should be tried first, including RICE protocol and over-the-counter pain relievers
• If symptoms persist, an MRI can help identify the underlying cause and guide treatment
• The American College of Radiology Appropriateness Criteria support the use of MRI in acute trauma to the ankle with persistent pain and negative radiographs 1.

From the Research

Ongoing Ankle and Lower Extremity Pain after Injury

• Ongoing ankle and lower extremity pain with swelling after an injury and negative x-rays can be challenging to diagnose and manage.
• The patient's history and physical examination are crucial in making an accurate diagnosis and providing effective treatment 2.

Role of MRI in Diagnosis

• MRI is highly sensitive and can detect early signs of stress injuries, such as periosteal edema and bone marrow signal abnormality 3, 4.
• MRI is the preferred imaging modality for evaluating stress fractures, especially in cases where plain radiographs are negative 3, 4.
• MRI can help diagnose other conditions that may cause chronic ankle and lower extremity pain, such as medial tibial stress syndrome, chronic exertional compartment syndrome, and functional popliteal artery entrapment syndrome 5.

Diagnostic Approach

• A detailed patient history and physical examination are essential in making an accurate diagnosis and providing effective treatment 5, 2.
• Imaging recommendations for evaluating stress fractures include initial plain radiographs followed by MRI, if necessary 3, 4.
• MRI and MR angiography are the primary investigative tools for functional popliteal artery entrapment syndrome and other conditions that may cause chronic ankle and lower extremity pain 5.

Treatment Options

• Treatment for ongoing ankle and lower extremity pain after an injury and negative x-rays depends on the underlying diagnosis.
• Unloading strategies, conservative therapy, and surgery may be considered for treating bone stress injuries, medial tibial stress syndrome, and other conditions that may cause chronic ankle and lower extremity pain 5.