The Pelvic INFIX Technique for Unstable Anterior Pelvic Ring Fractures: Clinical Outcomes, Radiographic Results, and Complications.

Background: Unstable pelvic ring injuries often require surgical stabilization to restore pelvic ring integrity. The anterior subcutaneous internal fixator, or pelvic INFIX, has emerged as an alternative to external fixation and open anterior fixation. This study evaluated the functional, radiographic, and complication-related outcomes of INFIX fixation for unstable anterior pelvic ring injuries. Methods: We retrospectively reviewed 21 adult patients treated with anterior pelvic INFIX for unstable anterior pelvic ring fractures, with or without posterior fixation, at a Level 1 Trauma Center between 2017 and 2024. Fractures were classified according to the AO/OTA system. Functional outcomes were assessed using the Iowa Pelvic Score and Short Form-12 questionnaire. Radiographic outcomes were evaluated according to Tornetta and Matta criteria. Complications were recorded throughout follow-up. The INFIX device was routinely removed 6 months postoperatively. Results: The cohort included 15 males and six females, with a mean age of 42.5 ± 11.1 years. Mean Injury Severity Score was 25.3 ± 9.6, and mean follow-up after implant removal was 31 (IQR 28-34) months. The mean Iowa Pelvic Score was 80.2 ± 7.4, indicating an overall good functional outcome. Mean SF-12 physical and mental scores were 49.2 ± 3.5 and 48.3 ± 7.9, respectively. Radiographic outcomes were excellent in eight patients, good in 11, and fair in two. Complications included postoperative hemorrhage, implant loosening, heterotopic ossification, and three cases of lateral femoral cutaneous nerve (LFCN) injury. Conclusions: INFIX fixation appears to be a reliable minimally invasive option for unstable anterior pelvic ring injuries, providing satisfactory mid-term functional and radiographic outcomes with an acceptable complication profile.