Ultrasound as a Primary Evaluation Tool of Bone Stress Injuries in Elite Track and Field Athletes

Background: Little is known about therapeutic ultrasound (TUS) to diagnose bone stress injuries. Hypothesis: Therapeutic ultrasound is an accurate, cost-efficient alternative to other imaging methods for primary assessment of bone stress injuries. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: One hundred thirteen elite track and field athletes (mean age, 20.1 years; range, 17-28 years) underwent TUS and magnetic resonance imaging (MRI) for clinical suspicion of a bone stress injury. A 5-stage MRI grading system was used to classify bone stress injuries. Sensitivity, specificity, accuracy, and positive and negative predictive values of TUS were calculated using MRI as the standard for diagnosis. Results: At MRI, of 113 assessed patients, 3 (2.7%) had grade 0 injuries, 12 (10.6%) had grade 1, 15 (13.3%) had grade 2, 77 (68.2%) had grade 3, and 6 (5.3%) had grade 4. At TUS, no injury was detected in 22 of 113 patients: 2 with grade 0 injury, 8 with grade 1, 8 with grade 2, and 4 with grade 3. Using MRI as the gold standard, TUS showed 81.8% sensitivity, 66.6% specificity, 99.0% positive predictive value, 13.4% negative predictive value, and 81.4% accuracy. Conclusion: Therapeutic ultrasound is a reproducible procedure that is reliable to diagnose bone stress injuries.