Postoperative Spinal Implant Infections (PSII)—A Systematic Review: What Do We Know So Far and What is Critical About It?

STUDY DESIGN: Systematic review. OBJECTIVES: Postoperative spinal implant infections (PSII) are an increasing challenge in the daily clinical routine. This review summarizes existing knowledge in the field of PSII, including definitions, epidemiology, classifications, risk factors, pathogenesis, symptoms, diagnosis, and treatment. METHODS: A systematic review was performed using a structured PubMed analysis, based on the PRISMA criteria. The search terminology was set as: "spinal implant associated infection OR spinal implant infection OR spinal instrumentation infection OR peri spinal implant infection." PubMed search was limited to the categories randomized controlled trials (RCT), clinical trials, meta-analysis and (systematic) reviews, whereas case reports were excluded. Studies from January 2000 to December 2020 were considered eligible. A total of 572 studies were identified, 82 references included for qualitative synthesis, and 19 for detailed sub analysis (12 meta-analysis, 7 prospective RCT). RESULTS: Structural problems in the field of PSII were revealed, including (1) limited level of evidence in clinical studies (missing prospective RCT, metanalyzes), (2) small patient numbers, (3) missing standardized definitions, (4) heterogeneity in patient groups, and (5) redundancy in cited literature. CONCLUSION: Evidence-based knowledge about spinal implant-associated infections is lacking. All involved medical fields should come together to define the term PSII and to combine their approaches toward research, training, and patient care.