Trends in Reoperation for Surgical Site Infection After Spinal Surgery With Instrumentation in a Multicenter Study

Kazuyoshi Kobayashi, MD, PhD; Shiro Imagama, MD, PhD; Kei Ando, MD, PhD; Hiroaki Nakashima, MD, PhD; Fumihiko Kato, MD, PhD; Koji Sato, MD, PhD; Tokumi Kanemura, MD, PhD; Yuji Matsubara, MD, PhD; Hisatake Yoshihara, MD, PhD; Atsuhiko Hirasawa, MD, PhD; Masao Deguchi, MD, PhD; Ryuichi Shinjo, MD, PhD; Yoshihito Sakai, MD, PhD; Hidenori Inoue, MD, PhD; Naoki Ishiguro, MD, PhD


Spine. 2020;45(20):1459-1466. 

In This Article

Abstract and Introduction


Study Design: A multicenter retrospective analysis of a prospectively maintained database.

Objective: To examine the characteristics of reoperation for surgical site infection (SSI) after spinal instrumentation surgery, including the efficacy of treatment for SSI and instrumentation retention.

Summary of Background Data: Aging of the population and advances in surgical techniques have increased the demand for spinal surgery in elderly patients. Treatment of SSI after this surgery has the main goals of eliminating infection and retaining instrumentation.

Methods: The subjects were 16,707 patients who underwent spine surgery with instrumentation in 11 hospitals affiliated with the Nagoya Spine Group from 2004 to 2015. Details of those requiring reoperations for SSI were obtained from surgical records at each hospital.

Results: There were significant increases in the mean age at the time of surgery (54.6–63.7 years) and the number of instrumentation surgeries (726–1977) from 2004 to 2015. The incidence of reoperation for SSI varied from 0.9% to 1.8%, with a decreasing trend over time. Reoperation for SSI was performed in 206 cases (115 men, 91 women; mean age 63.2 years). The average number of reoperations (1.4 vs. 2.3, P < 0.05), time from SSI to first reoperation (4.3 vs. 9.5 days, P < 0.05), and the methicillin-resistant Staphylococcus identification rate (20% vs. 37%, P < 0.01) were all significantly lower in cases with instrumentation retention (n = 145) compared to those with instrumentation removal (n = 61).

Conclusion: There were marked trends of aging of patients and an increase in operations over the study period; however, the incidences of reoperation and instrumentation removal due to SSI significantly decreased over the same period. Rapid debridement after SSI diagnosis may have contributed to instrumentation retention. These results can serve as a guide for developing strategies for SSI treatment and for improved planning of spine surgery in an aging society.

Level of Evidence: 3


Recent rapid aging of the population and advances in surgical techniques and anesthesia have increased the demand for spinal surgery in elderly patients and have also increased the number of surgeries performed to improve quality of life.[1–3] There has also been a marked rise in the rate of instrumented spinal surgery.[4] Surgical site infection (SSI) after instrumented spine fusion is a serious adverse event that is difficult to manage. The rate of SSI after posterior spinal fusion and instrumentation is 2% to 10%.[5–11] The standard treatment is surgical debridement and prolonged administration of appropriate antibiotics.[8–10]

Treatment of early SSI after instrumented spine surgery has two main goals of eliminating the infection and retaining the instrumentation. Retention of instrumentation is of paramount importance to avoid a loss of correction or pseudarthrosis due to mechanical instability.[12,13] Adherence of bacteria and formation of a biofilm on the surface of the instrumentation sometimes renders antibiotic treatment insufficient[14] and removal of metal instrumentation may be required to eradicate the infection.[15] To treat a postoperative infection of an instrumented spine, some surgeons recommend removal of the instrumentation if the infection is uncontrolled because the presence of a foreign material could preclude eradication of the infection, whereas others advocate serial wound debridement with retention of stable instrumentation.[12,16–19] Avoidance of instrumentation removal in the early stages of a postoperative infection is preferable because premature removal may result in spinal instability and pseudarthrosis. Epidemiological trends in several reports, however, support instrumentation removal.

In this study, we examine the characteristics and trends of reoperation for SSI after spinal instrumentation in our spine group over 12 years in a cross-sectional study. We also evaluated the efficacy of treatment for SSI, and examined instrumentation retention and surgical debridement. An understanding of changes in SSI treatment after spinal surgery in a society that is a model for aging trends worldwide will allow for improved planning of future directions of spine surgery.