Use of INFIX for managing unstable anterior pelvic ring injuries: A systematic review

Subcutaneous screw rod system which is popularly known as Pelvic internal fixator (INFIX) has emerged as an alternative to external fixators in management of unstable pelvic injuries. INFIX has shown various advantages over external fixation such as reduced infection rate and patient morbidity. However, it has its own set of complications such as lateral femoral cutaneous nerve injury, heterotopic ossification, femoral nerve palsy etc. We intended to conduct a systematic review of the current literature to assess outcomes and complications with INFIX technique of fixation.

A comprehensive search of literature was performed based on Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines and online database of EMBASE, PubMed, Medline and Scopus was searched for all studies in English language till March 2020. Included studies were reviewed for demographic data, fracture type/classification, radiological outcome and functional outcomes. The inclusion criteria were: 1. Studies in English language 2. Clinical studies reporting use of INFIX technique in pelvis fracture where clinical and radiological outcomes were reported.

Twenty-two studies fulfilling inclusion and exclusion criteria were included in this systematic review with total of 619 patients. Radiographic parameters and outcome measures were infrequently reported. Fixation with INFIX in these fractures leads to 87% excellent to good radiological results and 84% excellent to good functional results. Complications include lateral femoral cutaneous nerve irritation (25.3%), heterotopic ossification (24.7%), infection (3%), and femoral nerve palsy (1.6%); which is likely related to placing the bar and screws too deep.

This analysis supports the use of INFIX in management of unstable pelvis fractures where anterior fixation is required.