Usefulness of gadolinium-enhanced MR imaging in the evaluation of the vascularity of scaphoid nonunions

OBJECTIVE. The objective of this article is to identify the role of gadolinium-enhanced MR imaging in the preoperative evaluation of the vascular status of the proximal fragment in scaphoid nonunions. SUBJECTS AND METHODS. Thirty consecutive patients (27 men and three women; age range, 19-52 years; mean age, 28 years) with nonunion of the scaphoid were prospectively examined with unenhanced and gadolinium-enhanced MR imaging. MR images and surgical findings were classified in four groups according to the vascular status of the proximal fragment (normal bone, moderate ischemic bone, severe ischemic bone, and avascular necrosis). Sensitivity, specificity, and accuracy of unenhanced and gadolinium-enhanced MR studies were calculated. Surgical findings were used as the gold standard. The postoperative rate of union at 12 months was evaluated for each group. RESULT. Unenhanced MR imaging showed a global sensitivity of 36%, specificity of 78%, and accuracy of 68% in the preoperative evaluation of the vascular status of the proximal fragment. Correlation with the surgical findings was not statistically significant (p < 0.149), Global sensitivity, specificity, and accuracy of gadolinium-enhanced MR imaging were 66%, 88%, and 83%, respectively. Correlation with the surgical findings was good (p < 0.0001). Gadolinium-enhanced sequences allowed accurate diagnosis and enabled the creation of prognostic groups having better correlation with surgical findings and postoperative results. CONCLUSION. Gadolinium-enhanced MR imaging is the most reliable imaging method for investigating the vascularity of the proximal pole in scaphoid nonunions.