From the Guidelines
No, an ultrasound is not required for the diagnosis of an ankle sprain. The diagnosis of an ankle sprain is primarily clinical, based on a thorough history and physical examination, as supported by the most recent and highest quality study 1. Typically, a healthcare provider will ask about the mechanism of injury, assess for pain, swelling, bruising, and tenderness over the affected ligaments, and evaluate the stability of the ankle joint through specific maneuvers like the anterior drawer test.
Key Points to Consider
- For most uncomplicated ankle sprains, imaging studies are unnecessary, with the exception of cases where there is concern for a fracture, in which case X-rays may be ordered based on specific clinical decision rules like the Ottawa Ankle Rules 1.
- Ultrasound might occasionally be used in certain situations to evaluate the integrity of specific ligaments or to assess for associated injuries like tendon tears, but it is not considered standard or necessary for diagnosing typical ankle sprains.
- The sensitivity and specificity of physical examination using the anterior drawer test are optimized if clinical assessment is delayed for between 4 and 5 days post injury, making it a reliable method for diagnosis without the need for ultrasound 1.
- Treatment typically involves rest, ice, compression, elevation (RICE), pain management with medications like NSAIDs, and progressive rehabilitation exercises, regardless of whether imaging was performed.
Considerations for Imaging
- While ultrasound has similar sensitivity to physical examination, it lacks specificity and depends on the availability of an experienced technician and equipment, making it less ideal for routine diagnosis of ankle sprains 1.
- MRI can be performed in cases of suspicion of high-grade ligament injuries, osteochondral defects, syndesmotic injuries, and occult fractures due to its excellent sensitivity and specificity, but its use is limited by availability and cost 1.
From the Research
Diagnosis of Ankle Sprain
- Ankle sprains are typically diagnosed through physical examination and medical history, with diagnostic ultrasound sometimes used to confirm ligamentous injuries 2.
- The use of ultrasound in diagnosing ankle sprains is not always necessary, as physical examination alone can be sufficient in many cases 3.
Role of Ultrasound in Ankle Sprain Diagnosis
- Ultrasound has been shown to be accurate in diagnosing ligamentous injuries, but its use is often excluded from management algorithms that rely on physical examination alone 2.
- A comprehensive, evidence-based diagnostic ankle ultrasound protocol can be used in conjunction with thorough history and physical examination to improve diagnostic accuracy 2.
Treatment of Ankle Sprains
- The treatment of ankle sprains typically involves rest, ice, compression, and elevation, with casting and orthotics sometimes used to facilitate healing 3.
- Ultrasound therapy is sometimes used in the treatment of ankle sprains, but its effectiveness is not well supported by scientific evidence 4, 5, 6.
- Several studies have found that ultrasound therapy does not significantly improve outcomes for patients with acute ankle sprains, and its use is not recommended as a standard treatment 5, 6.