Contaminated pedicle screws are a huge problem in the United States. They cause increased surgical site infections (SSI), causing increased hospitalizations and costing hundreds of thousands of dollars every year. A multicenter group of researchers has proposed a superior standard of care and method of delivery for pedicle screws that completely eliminates this contamination.
12.7% Incidence Rate of Surgical Site Infection
A 2016 study published in the International Journal of Spine Surgery found that surgical site infection occurs at the rate of 12.7% following spinal fusion surgery. The average hospital bill following such infections is $63,000, with hospitalization being necessary in 5.5% of those cases.
Pedicle screws are the most common implant used in spinal fusion surgery. A surgeon will typically have over a hundred screws available for use during surgery, but actually use a very small number of them.
The pedicle screws’ low usage rate leads to these screws being repeatedly reprocessed—or “automated washing with contaminated instruments from theatre and then sterilized without prior inspection by hospital staff” by the sterilization processing department (SPD).
These “sterile” implants, alarmingly, have been found to contain contaminants.
Furthermore, unused pedicle screws are subject to contamination during surgery.
Reprocessing Contamination
Reprocessed pedicle screws have been shown in recent studies to harbor contaminants, even after the automated washing and sterilization process.
One such study by Aakash Agarwal, Ph.D. and colleagues published in the Global Spine Journal, “Harboring Contaminants in Repeatedly Reprocessed Pedicle Screws,” found evidence of corrosion, saccharide, and soap residue on a random selection of pedicle screws that were supposedly sterile and consigned to be used during surgery.
In their study, the researchers selected six pedicle screws from four different trays of cleaned, wrapped, and sterilized implants. The screws were disassembled and sent for optical microscopy, scanning electron microscopy, and Fourier transform infrared spectroscopy. The researchers also reviewed the four major manufacturer’s instructions for reprocessing pedicle screws and compared the steps to the actual procedures that sterilization processing departments (SPDs) used to reprocess a pedicle screw set.
The study found three different types of contaminants on the sterilized pedicles screws: corrosion, saccharide of unknown origin, and soap residue. The study also found that manufacturer’s guidelines recommended 19 hours equivalent of reprocessing, but actual turnaround time was only 1 hour and 17 minutes.
The exact origin of these contaminants is unknown but could range from mucous-like deposits from bacteria, biofilms, fatty tissue residues from reprocessing the implants with other contaminated instruments, and insufficient rinsing after cleansing.
This could be in part due to the fact that pedicle screws are multicomponent with lumens, interfaces, and crevices that range from 0.2 to 1.5mm. These results raise important concerns regarding the practicality and safety of a repeated cleaning and sterilization process being followed in most of the hospitals in United States.
Thank you to the spine surgeons, researchers and scientists for this very important evaluation. As former spine surgeon I try to transfer my new knowledge with regard to the origin of surgical site infections (SSI), resulting from my work for Operating Room (OR) Airflow Standards since several years.
Unfortunately, in the report is nothing written about airborne bacteria respectively microorganisms as origin of SSI. Several well conducted studies show the high importance of the contaminated air of OR for the SSI genesis (e.g. Charnley 1972, Whyte et al. 1982, Lidwell et al. 1987). Charnley (1972) demonstrated the dependence of the SSI rate from the number of air changes in the OR. Lidwell et al. (1987) found a direct relationship between the air contamination and the SSI rate – with a high advantage of laminar airflow (LAF) technology compared to turbulent/dilution airflow technology. Whyte et al. (1982) stated to the origin of bacteria in the surgical wound with regard to the air or patient’s skin: “… the most important and consistent route of contamination was airborne”. Those study results were never corrected by other/later studies. Comparing evaluations of cfu directly in the OR show considerably better results for LAF technology (e.g. Andersson et al. 2014). However, the comparing results in ORs for the different OR airflow technologies didn’t get the required attention. In contrast, primarily register based SSI results influenced even the WHO Global Guidelines for the prevention of SSI (2016). It should be known that register data is not enough sufficient for basic assessments and conclusions (Windeler et al. 2017). Furthermore, several publications from German authors (Brandt et al. 2008, Breier et al. 2011, Gastmeier et al. 2012, Bischoff et al. 2107) comparing the SSI rates of LAF technology and turbulent/dilution airflow technology base upon data for only individual hospital uses (published in an official German document) because of significant bias. Generally, it isn’t clear in most studies comparing different airflow technologies if all sterile instruments, trials, implants are in the protected zone of LAF technology during the complete surgery. Otherwise, there is more danger for SSI.
IN CONCLUSION, the focus to avoid SSI/biofilm should also lie on not contaminated air in the OR and on the right air technology with always LAF for high sensitive surgeries. Furthermore, all influences on air contamination with microorganisms should be known – to undertake everything for the avoidance of air contamination.
PROF. DR. KARIN BÜTTNER-JANZ, MBA
Delegate of Germany for European Standard CEN TC 156 WG 18 (air technology of operating rooms)
Member of DIN Committee 1946-4, Germany (air technology of operating rooms)
Past President of ISASS
buettner-janz@spinefoundation.info
Thank you PROF. DR. KARIN BÜTTNER-JANZ for sharing that.
We were excited to see a comment from you. I still remember reading about you in SNI, especially how you went from Olympics to spine surgery to research, innovation and advocacy in 2009: https://spinalnewsinternational.com/karin-buettner-janz/
This is the question many have asked:
“Interesting results.
I guess the most pressing question is where is the contamination coming from?” for example Dr. Bob Hirschl
I usually comment:
“The current study was only designed to assess the level of contamination using standard-sterile-technique vs two-step-asepsis-technique.
1. However based on everything I have read, researchers cite patient’s own flora as the original source, which then transfers to gloves and then to implants.
2. The quality of air may also not be pristine, as other studies has proven bacterial growth with increase in exposure time (inside the sterile field).
”
So we agree with you 100%. I look forward for the day when the air in the OR (for all countries) is pristine.
Below is my email if you like me involved in any way.
Thank you!
Sincerely
Aakash Agarwal
aakash.agarwal@utoledo.edu
This is common sense, how did we miss it (blatant failure) for so long!
I wonder how many patients have suffered till date due to this negligence, and were consoled saying “it is just bad luck, infection happens, we are just doing our best”.