Abstract

Post-operative spinal infection is a serious and dreaded complication faced by spine surgeons all over the world. Statistically postoperative infections have been decreasing in the last decades. Although infrequent, post-operative spinal infections are still an important source of increased morbidity, mortality and health care cost. Early diagnosis can be challenging. Biopsy sample cultures may be negative due to technical difficulties and perioperative antibiotics. Post-operative biochemical markers may be abnormal, and MRI (Magnetic Resonance Imaging) images (the gold standard for imaging spondylodiscitis) are usually hard to interpret early after surgery and in the presence of implanted hardware. The optimal imaging tool for post-operative spinal infection remains to be established. Molecular metabolic imaging of infection has been the focus of intense interest in preclinical and clinical settings and now plays an important role in the diagnosis of musculoskeletal infections. Ubiquicidin, an antimicrobial 59-amino acid peptide, is part of our immune system. Its cationic fragment, (UBI 29-41) binds preferentially to the anionic membrane of microbial cells. Tc99 Pertechnate is a common technetium radiopharmaceutical used in molecular imaging. Technetium (99mTc) labelled UBI, (99mTec UBI 29-41) can be imaged by Single-Photon Emission Computed Tomography (SPECT), providing anatomic correlation for the metabolic image with clear delineation between structures, potentially differentiating between infectious site and sterile inflammation. The aim of this review is to evaluate the use of this molecular imaging modality in the setting of post-operative spinal infection.

Keywords: Post-operative; Spine infection; Molecular imaging; SPECT; 99mTec; UBI 29-41