Ultrasound-Guided Interphalangeal Injection (US-IPI) of Mucoid Cysts as a Non-Surgical Option: Technical Notes and Clinical Efficacy

Abstract

Digital mucous cysts (DMCs) are common soft tissue tumors affecting interphalangeal joints. Various treatment options exist, with surgical excision being the standard. Ultrasound-guided cortisone (CC) injection into the distal interphalangeal (DIP) joint has been proposed as a therapeutic alternative. This study aims to assess the technical success and clinical efficacy of US-IPI in terms of swelling resolution and pain control. Fifty-two patients with DMCs underwent CCs DIP joint ultrasound-guided infiltration. Eighty-three percent of patients exhibited a positive response to US-IPI, with a significant reduction in NRS pain scores (p < 0.01). Persistent pain in 17% of patients was effectively managed with marked improvement after a secondary infiltration. Joint swelling was reduced in 68% of patients within 1 month, with complete resolution by 3 to 6 months. No recurrence was reported at the 6-month follow-up. Pain assessment using the Numeric Rating Scale and joint swelling evaluation were conducted at follow-ups of 2 weeks, 1, 3, and 6 months. Statistical analysis was performed to compare pre- and post-procedure NRS pain scores. Here, we show that US-IPI of DMCs is an effective therapeutic option that provides immediate pain relief and long-term aesthetic improvement, resulting in an alternative option to surgical excision.