Implant-Associated Infection of Long-Segment Spinal Instrumentation: A Retrospective Analysis of 46 Consecutive Patients

Abstract

Study Design: This single-center retrospective study analyzed patients with an implant-associated infection of spinal instrumentation (four or more segments) treated between 2010 and 2018.Purpose: This study aimed to investigate the treatment of implant-associated infections of long-segment spinal instrumentation and to define risk factors for implant removal.Overview of Literature: Implant-associated infection occurs in 0.7%–20% of spinal instrumentation. Significant blood loss, delayed reoperation, and use of effective antibiotics are reported risk factors for implant removal.Methods: Patients with superficial infections not involving the implant were excluded. All patients received surgical and antibiotic treatments according to our interdisciplinary osteomyelitis board protocol. An infection was considered healed if a patient showed no signs of infection 1 year after termination of treatment. The patients were divided into an implant retention group and implant removal group, and their clinical and microbiological data were compared.Results: Forty-six patients (27 women, 19 men) with an implant-associated infection of long-segment spinal instrumentation and mean age of 65.3±14.3 years (range, 22–89 years) were included. The mean length of the infected instrumentation was 6.5±2.4 segments (range, 4–13 segments). Implant retention was possible in 21 patients (45.7%); in the other 25 patients (54.3%), a part of or the entire implant required removal. Late infections were associated with implant removal, which correlated with longer hospitalization. Both groups showed high postoperative complication rates (50%) and high mortality rates (8.7%). In 39 patients (84.8%), infection was eradicated at a mean follow-up of 18.9±11.1 months (range, 12–60 months). Three patients (6.5%) were lost to follow-up.Conclusions: Implant-associated infections of long-segment spinal instrumentations are associated with high complication and mortality rates. Late infections are associated with implant removal. Treatment should be interdisciplinary including orthopedic surgeons and clinical infectiologists.