Diagnosis of occult scaphoid fracture with high-spatial-resolution sonography: a prospective blind study.

BACKGROUND

Evaluation of diagnostic accuracy of high-spatial-resolution sonography (HSR-S) in occult scaphoid fractures.

PATIENTS AND

METHODS

HSR-S was performed in 24 patients with clinically suspected fracture and normal radiographs. Three levels of clinical suspicion were considered (high, intermediate, and low). Three levels of sonographic suspicion were defined on the basis of cortical interruption, radiocarpal effusion, and scapho-trapezium-trapezoid effusion. Three positive criteria were interpreted as being highly indicative of fracture. Data from sonograms were compared with computed tomography (CT) scans.

RESULTS

CT scanning demonstrated a fracture of the scaphoid in five patients. The global sensitivity of HSR-S for detection of occult scaphoid fracture was 100% and the specificity 79%. All patients with demonstrated occult fracture had a high sonography index of suspicion. A high sonography index of suspicion was correlated with 100% sensitivity, specificity, positive predictive value, and negative predictive value.

CONCLUSION

HSR-S is a reliable, available, and cost-effective method in early diagnosis of occult fractures of the scaphoid. The presence of three defined criteria is required to assess the diagnosis.