MR Imaging of Injury of the Extensor Mechanism of the Fingers.

Extensor mechanism injuries of the hand are common in clinical practice and may lead to significant functional impairment. Understanding the complex anatomy and functional role of different extensor mechanism components in the fingers is critical for accurate imaging interpretation. We provide a brief overview of relevant anatomy and extensor zone injuries classification. Critical points for image acquisition optimization are included. Important imaging findings of extensor tendon injuries and their complications including mallet finger, swan neck and boutonniere deformities, and sagittal band injuries are reviewed. Clinical pearls regarding treatment, potential imaging pitfalls, and mimickers of these injuries are also discussed.