Soft Tissue Injuries of the Finger and Thumb.

Soft tissue digital injury of the hand is a common presenting complaint in the emergency setting. Although initial work-up requires physical examination and radiographs, many of these entities may be radiographically occult and solely appreciated on ultrasound (US) or magnetic resonance imaging (MRI). If undiagnosed, these conditions may lead to sequela of untreated disease including early osteoarthritis, pain, permanent deformity, and immobility. Soft tissue finger injuries that may not be readily apparent without the use of MRI or US are discussed. The key imaging features of radiolucent foreign bodies in addition to tendon, collateral ligament, sagittal band, and pulley injuries on MRI and US are discussed.