Unusual Triggering of the Finger Caused by Distal Flexor Tendinopathy: Successful Treatment With Ultrasound-Guided Prolotherapy

Trigger finger (TF), traditionally viewed as a stenosing tenosynovitis at the A1 pulley, is commonly treated with corticosteroid injections or pulley release. This case report describes a 61-year-old female with a refractory TF who did not respond to a previous corticosteroid injection. Diagnostic imaging revealed insertional tendinopathy of the flexor digitorum superficialis and flexor digitorum profundus with bony spurs, rather than pathology at the A1 pulley. The patient was successfully treated with two sessions of ultrasound-guided prolotherapy directed at the tendon entheses, resulting in complete resolution of triggering and pain. This case challenges the conventional model and suggests that insertional flexor tendinopathy can be a primary cause of TF, warranting a paradigm shift in diagnosis and treatment toward enthesis-focused approaches.