This study evaluates the long-term survival of
spinal implants after surgical site infection (SSI) and the risk
factors associated with treatment failure. A Kaplan-Meier survival analysis was carried out on 43 patients
who had undergone a posterior spinal fusion with instrumentation
between January 2006 and December 2008, and who consecutively developed
an acute deep surgical site infection. All were appropriately treated
by surgical debridement with a tailored antibiotic program based
on culture results for a minimum of eight weeks. A ‘terminal event’ or failure of treatment was defined as implant
removal or death related to the SSI. The mean follow-up was 26 months
(1.03 to 50.9). A total of ten patients (23.3%) had a terminal event.
The rate of survival after the first debridement was 90.7% (95%
confidence interval (CI) 82.95 to 98.24) at six months, 85.4% (95%
CI 74.64 to 96.18) at one year, and 73.2% (95% CI 58.70 to 87.78)
at two, three and four years. Four of nine patients required re-instrumentation
after implant removal, and two of the four had a recurrent infection
at the surgical site. There was one recurrence after implant removal
without re-instrumentation. Multivariate analysis revealed a significant risk of treatment
failure in patients who developed sepsis (hazard ratio (HR) 12.5
(95% confidence interval (CI) 2.6 to 59.9); p <
0.001) or who
had >
three fused segments (HR 4.5 (95% CI 1.25 to 24.05); p = 0.03).
Implant survival is seriously compromised even after properly treated
surgical site infection, but progressively decreases over the first
24 months. Cite this article:
