Establishing the safety of the lateral femoral cutaneous nerve when using the Bridging Infix for anterior pelvic fixation

Background Established subcutaneous internal fixation techniques have shown a better quality of life with reduced pain. However, complications still arise, with the most significant being injury of the lateral femoral cutaneous nerve (LFCN). A novel minimally invasive modified technique, the Bridging Infix, has been proposed; however, the safety of the LFCN during the procedure is currently unknown. The aim of the study, therefore, was to determine the relationship between the Bridging Infix and the LFCN. Method Fifty formalin-fixed cadaveric specimens and two fresh frozen cadaver specimens were utilised in the study. The Bridging Infix was inserted as per the technique guide. Superficial dissection of the surgical site was subsequently conducted. Bilateral measurements of the distance between the LFCN and the implant as well as palpable bony landmarks were taken to determine safe zones for implant placement. Results Overall the LFCN was identified coursing deep to the inguinal ligament. The minimum distance from the LFCN to the most proximal cortical screw was 18.00 mm. The mean distance from the most proximal screw to the LFCN was 37.97 ± 12.20 mm. Conclusion The LFCN was not injured or impinged by the Bridging Infix in any of the cadaver specimens used in this study. Thus, the surgical procedure can be considered safe if layer by layer dissection is employed and the screws are directly inserted on the iliac crest, with no pressure being applied within three finger breadths medial to the anterior superior iliac spine. Level of evidence: Level 3.