Misdiagnosis of trigger finger? Flexor seed ganglion masquerading as closed FDS rupture

Abstract

The authors present the case of a 25-year-old right-handed female warehouse worker who presented to the emergency department complaining of an inability to flex her left index finger and an associated painful lump on the volar surface of her left index finger over the metacarpal–phalangeal joint following a hyperextension injury. Clinical examination suspected a closed flexor digitorum superficialis (FDS) injury; however, on surgical exploration, the FDS tendon to the left index finger was intact. A flexor sheath seed ganglion was identified. This case, although rare, identifies the modality of specialist ultrasound scan (USS) by those with an interest in musculoskeletal radiology to be used in cases where the history is unclear or diagnosis in doubt.