Bottom Line: Take the Implant Out
Surgeons may feel reluctant to assume the risks of implant removal or replacement. “The challenge with implant removal (in addition to other post-operative procedures to eliminate or reduce SSI) is the possibility of spinal instability in the absence of fusion resulting in clinical symptoms, such as back/leg pain, or neurologic deficits.”
“There was never a consensus or appreciation for the inherent risk involved with spinal implants in the presence of bacterial contaminants,” continued Agarwal. “These risks should be considered even when choosing to retain or replace implants for delayed onset infection also, which isn’t a standard as of now (and there is a lot of debate around it).”
Furthermore, argues Agarwal, “debridement alone without implant removal could easily hinder eradication of infection because bacterial organisms always grow on metal surfaces and produce biofilm, to embed themselves into it. This matrix of extracellular polymeric substance (biofilm) makes the bacterial species resistant to further antibiotic administration.”
“In addition, recent evidence points toward another mode of failure when biofilm is left undetected on the implants; ‘aseptic’ screw loosening! Thus, the cascade of spinal instability begins even when the implants are not removed/replaced. Therefore, implant removal/replacement (replacing the implants would avoid any instability in cases with premature fusion) is necessary in such cases.”
Bottom line: “The evidence we have gathered and presented from the literature is clear and suggests implant replacement is the most prudent choice for delayed and late onset SSI.”
And Stop Reprocessing Implants
A number of countries (not the U.S., yet) have implemented new clinical practices to prevent implant infection including ceasing the practice of reprocessing implants. Agarwal said, “the least we can do now is stop reprocessing implants just like Scotland did 10 years ago (hospitals in The Netherlands and Japan are already halfway there), and also avoid any touching and exposure of implants in the ‘sterile’ field as a preventative measure.”
85% Likelihood You Won’t See Your Late SSI Patient
Agarwal and his colleagues found that few authors in the literature review focused specifically on late onset SSI. When the researchers conducted a poll asking surgeons about how many of their post-operative patients were their own, they found that only 15% were. This would imply that 85% of patients end up seeing a surgeon other than their original surgeon for late onset surgical infection.
Agarwal said, the “obvious question here is, who is keeping track of such SSI incidences? So, if a surgeon has 2% infection in the short term, it may mean he or she actually had 13% infection rate altogether, when accounting for the loss in patient follow-up. Therefore, the only way to really know the true infection rate and consequences of using contaminated implants is to find out what these long-term studies such as the one cited above recorded. Thus, I had to conduct this review.”
The researchers look forward to further evidence supporting what is already known, and hope for concrete clinical practice change that will help patients.
Implications for You and Your Practice
When OTW asked about the implications of the study, Agarwal said, “The conclusions of this and previous studies are very clear and correlated. We know what we have to do to prevent post-operative infection and implant loosening. And we also know that incidences are high and anecdotal experiences carry zero value in decision making.”
He continued, “Some other questions that hospitals and clinicians should further ponder upon are: Is it clinically more dangerous to implant reprocessed and exposed/touched implants when replacing implants for surgical management of SSI? As the patient is already susceptible to infection, and the risk of recurrent infection has increased, why should he/she be given a reprocessed or exposed implant? I just hope manufacturers, FDA, and hospitals would take this seriously and implement the known solution, which has no side effects and reduces U.S. healthcare costs.”
