The sonographic Ottawa Foot and Ankle Rules study (the SOFAR study)

Area of Science:

• Emergency Medicine
• Musculoskeletal Radiology
• Diagnostic Imaging

Background:

• Foot and ankle injuries are prevalent in Emergency Departments (ED).
• Approximately 22% of patients with Ottawa Foot and Ankle Rules-positive injuries have fractures.
• Ultrasound is emerging as a rapid, cost-effective tool for musculoskeletal assessment, visualizing both soft tissue and bony structures.

Purpose of the Study:

• To evaluate the efficacy of ultrasound in detecting acute bony foot and ankle injuries.
• To determine the diagnostic accuracy of ultrasound compared to radiography for fractures in Ottawa Rules-positive patients.

Main Methods:

• A diagnostic cohort study involving 110 Ottawa Rules-positive patients over 16 years old.
• Ultrasound scans (USS) were performed by trained ED personnel, blinded to radiographic findings.
• Radiographic reporting was also blinded to USS results, with management decisions based on radiographs.

Main Results:

• Ultrasound detected 10 out of 11 significant fractures, achieving a sensitivity of 90.9% (95% CI 65.7 to 98.3).
• The specificity of ultrasound was 90.9% (95% CI 88.1 to 91.7), with a negative predictive value of 98.9% (95% CI 0.959 to 0.998).
• One fracture was initially missed due to inadequate scanning depth but was visible upon review.

Conclusions:

• Ultrasound demonstrates significant potential for the sensitive detection of foot and ankle fractures.
• This imaging modality may improve the efficiency of identifying patients requiring radiographic evaluation for bony injuries.