What Is the Best Surgical Treatment for Ulnar Styloid Impaction Syndrome? - A Systematic Review

Background: Ulnar styloid triquetrum impaction syndrome (USTI) is a rare cause of ulnar-sided wrist pain resulting from a mechanical conflict between an elongated ulnar styloid and the carpal bones. Despite various surgical options, there is no consensus on the optimal treatment. This study aims to systematically review and synthesise the available literature on the surgical treatment of USTI, focussing on clinical presentation, surgical techniques, outcomes and complications. Methods: A systematic review was conducted in accordance with PRISMA guidelines. Four databases (PubMed, Medline, Embase and Ovid) were searched for publications through May 2025 using terms related to USTI. Inclusion criteria were studies in English, French or German reporting surgically treated cases in adult patients. Outcomes assessed included pain, range of motion, grip strength, patient-reported outcome measures (PROMS) and patient satisfaction. Study quality was rated using OCEBM Levels of Evidence. Results: Twelve studies (two cohort, five case series and five case reports) were included. The majority were retrospective and of low methodological quality (Level 4 or 5). Surgical techniques included partial ulnar styloid resection (n = 8), complete resection (n = 2) and osteotomies (n = 2), with variable approaches to triangular fibrocartilage complex (TFCC) management. Postoperative outcomes generally showed pain relief, although data on range of motion, grip strength and PROMS were inconsistently reported. Complication rates were generally low, and patient satisfaction was high (when recorded). Conclusions: Surgical treatment of USTI yields good clinical outcomes in selected patients; however, the literature is limited by methodological weaknesses and heterogeneity in surgical technique and outcome reporting. Prospective studies with standardised measures are needed to optimise management strategies. Level of Evidence: Level III (Therapeutic).