“Trigger finger at the wrist” due to anomalous flexor digitorum superficialis muscle belly within the carpal tunnel

Abstract

"Triggering of the fingers at the wrist" is a relatively unusual condition. It consists in a triggering at the wrist produced by finger motion. Its etiology and presentation may vary. This condition should be clearly differentiated from the other clinical entity called "trigger wrist", occurring on wrist movement. In the present article, we report the case of an anomalous flexor digitorum superficialis muscle belly, arising from the right ring finger at the carpal tunnel, in a 47-year old female patient, causing triggering of the right ring finger at the wrist and a carpal tunnel syndrome. Surgical excision of the muscle mass and carpal tunnel release relieved patient's symptoms and has led to the disappearance of the triggering phenomenon. To date, few cases of trigger finger at the wrist have been reported in the literature. These reported cases were reviewed. The clinical entity of "true trigger wrist" and its etiology are also discussed.