A Novel Case of Trigger Finger Caused by A1 Pulley Calcification Successfully Treated With Ultrasound-Guided Prolotherapy: A Case Report and Literature Review

Trigger finger is commonly attributed to thickening of the A1 pulley or flexor tendons. Although calcific tendinitis is well recognized in regions such as the shoulder, calcification within the A1 pulley itself is extremely rare and seldom reported as a primary cause of triggering. We describe a 43-year-old woman who presented with painful triggering of the right little finger, accompanied by morning stiffness, snapping, and focal tenderness with warmth over the volar metacarpophalangeal (MCP) joint. Radiographs and high-resolution ultrasonography revealed a calcific deposit in the superficial layer of the A1 pulley, with surrounding hypervascularity on Doppler imaging. The patient underwent three sessions of ultrasound-guided prolotherapy in conjunction with physiotherapy and night splinting, which led to complete resolution of pain, stiffness, and triggering. This case identifies A1 pulley calcification as a rare but distinct etiology of trigger finger and highlights the diagnostic utility of ultrasonography in detecting this lesion. Moreover, it demonstrates that ultrasound-guided prolotherapy can provide an effective, minimally invasive alternative to surgical release, particularly when standard conservative management fails. Ultrasound-guided prolotherapy was selected as the primary intervention, instead of corticosteroid injection (CI), given its potential to promote tissue repair and resorption of calcific deposits, which are less effectively addressed by corticosteroids whose effect is primarily anti-inflammatory. Symptom improvement was observed after each biweekly session, with complete resolution achieved four weeks after the initial intervention. In addition to pain reduction documented by the Visual Analog Scale (VAS), the patient experienced the elimination of morning stiffness and snapping and restoration of full finger range of motion (ROM) following the final prolotherapy session.