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Contaminated Screw Caddies: Why We Must Move to Individual Aseptic Packaging of Implantable Medical Devices

There is mounting evidence in academic literature to substantiate that the current practices of reprocessing surgical implants, such as screw caddies, multiple times between patients increases the risk of infection.1,2 Implantable instruments are medical devices that will stay in a body more than 30 days and are intended to become an indefinite or permanent part of a patient’s anatomy (i.e., plates, rods, and screws for orthopedic fixations). Implants are single-use; therefore, once implanted they are not supposed to be placed into another patient, which is why manufacturers make trials to test the area to be implanted and ensure the right size is selected.3

Screw caddies in surgical trays may contain dozens of screws, or even hundreds, depending on the manufacturer and system. It is important that an assortment of sizes and styles of implants are available to the surgeon, who needs to have the right measurements and specifications best suited to the individual anatomical features of unique patients. However, assorted implants in surgical trays are exposed to contaminants from other instruments used on the patient being operated on through various means (i.e., aerosolization of particulates from the surgical site, cross-contamination of used instruments intermingling with implantable devices on the sterile field, and touchpoints from gloves).2,4

Only a small number of the implants available in surgical trays are used at one time, leaving the rest of the implants, which were not used from the operating room, to be reprocessed along with all the instruments from the case. This creates additional opportunities for cross-contamination, such as being subjected to contaminants during transport to the decontamination area, and exposure to contaminants during both the manual cleaning and automatic washer cycles, where intermingling of devices is compounded between multiple patients from cases throughout the day.1,5 Dozens (and in some instances hundreds) of reprocessing cycles occur over the lifetime of a surgical tray containing implants, and while instrument tracking software may store the total number of times an entire tray was reprocessed, the implants themselves are not tracked. This means it is possible for a 20-year-old screw to be next to one that was just restocked (i.e., a screw removed from an unsterile plastic pouch to replace one that was used).

Several research studies conducted by Agarwal and colleagues identified issues contributing to surgical site infection (SSI) risks.1,2,4,5,6 One such study published in the Global Spine Journal entitled “Harboring Contaminants in Repeatedly Reprocessed Pedicle Screws” reported that multiple washing and sterilization cycles were found to break down the surface of implants, inducing stress that creates microfractures for bioburden and other contaminants to adhere within crevices and harbor biofilms.5 Their study revealed that residual chemicals from the washers, such as enzymatic solutions and lubricants, were detected on implants after rinsing, as well as a build-up of layers of residue on intricate surfaces (i.e., crevices between screw threading, and the inner rim of the screw head) of sterile patient-ready pedicle screws, examined by “optical microscopy, scanning electron microscopy with energy dispersive spectroscopy, and Fourier transform infrared spectroscopy.”5

According to Michelle Alfa, in her article entitled “The ‘Pandora’s Box’ Dilemma: Reprocessing of Implantable Screws and Plates in Orthopedic Tray Sets” in the Journal of Biomedical Instrumentation and Technology, contaminated implants from multiple reprocessing cycles “and the role of organic residuals on screws and plates prior to implantation has been…studied for many years [and] suggested as a possible source for antigenic material that may stimulate the inflammatory response,” leading to aseptic loosening, which accounts for 19.4% of implant failures.3 Alfa also questions whether implant manufacturer instructions for use “have validated that screws and plates within orthopedic surgical tray sets can be safely cleaned and steam sterilized hundreds of times” since they are considered single-use devices.3  

Scientific research has also confirmed that delayed and late onset of infections, known as occult infections, are occurring in cases after the 30-day readmission window for Medicare reimbursement, leaving patients to endure pain and suffering, in addition to bearing significant financial burden.1,7 In an article published in Spine Surgery and Related Research entitled “Updates on Evidence-Based Practices to Reduce Preoperative and Intraoperative Contamination of Implants in Spine Surgery: A Narrative Review,” “patients with chronic pain and occult infection had hardware loosening and pseudarthrosis” and is a “condition [which] typically manifests with axial or radicular pain months to years after the index operation. Diagnosis is based on clinical presentation and imaging studies, after other causes of persistent pain are ruled out.”1,8 Studies contrasting the current state reprocessing with individual aseptic packaging of implantable medical devices showed a dramatic reduction in microbial growth of cultured samples. Scotland has banned reprocessing implants since 2007, stating that “repeatedly reprocessing implants in the hospital is a suboptimal practice,” and other countries such as Japan have made similar regulations.3,5

Based on the extensive work of researchers studying the factors involved with implantable hardware contamination and the risk of surgical site infection and implant failure, it is imperative that manufacturers transition away from storing implantable devices in surgical instrument trays. There is strong evidence showing that individually packaged and terminally sterilized implants prevents exposure to cross-contamination and preserves the integrity of the implant. These reasons alone offer hope for better patient outcomes that reduce the risk of infection and implant failure, as well as the additional costs to both patients and healthcare organizations.  


  1. Agarwal, Aakash., Boren Lin, Hossein Elgafy, Vijay Goel, Chris Karas, Christian Schultz, Neel Anand, Steve Garfin, Jeffrey Wang, and Anand Agarwal. 2019. “Updates on Evidence-Based Practices to Reduce Preoperative and Intraoperative Contamination of Implants in Spine Surgery: A Narrative Review.” Spine Surgery and Related Research, Volume 4, Issue 2, pp. 111–116. https://doi.org/10.22603/ssrr.2019-0038.
  2. Agarwal, Akash, Boren Lin, Jeffrey C. Wang, Christian Schultz, Steve R. Garfin, Vijay K. Goel, Neel Anand, and Anand K. Agarwal. 2018. “Efficacy of Intraoperative Implant Prophylaxis in Reducing Intraoperative Microbial Contamination.” Global Spine Journal, Volume 9, Issue 1, pp. 62–66. Retrieved July 25, 2019. https://doi.org/10.1177/2192568218780676.
  3. Alfa, Michelle J. 2012. “The ‘Pandora’s Box’ Dilemma: Reprocessing of Implantable Screws and Plates in Orthopedic Tray Sets.” Biomedical Instrumentation & Technology: Reprocessing, Vol. 46, Issue sp12, pp. 55–59. Retrieved July 25, 2019. https://www.aami-bit.org/doi/full/10.2345/0899-8205-12.1.55.
  4. Agarwal, Akash, Christian Schultz, Vijay K. Goel, Anand Agarwal, Neel Anand, Steve R. Garfin, and Jeffrey C. Wang. “Implant Prophylaxis: The Next Best Practice Toward Asepsis in Spine Surgery.Global Spine Journal, Volume 8, Issue 7, pp. 761–765. Retrieved July 25, 2019. https://journals.sagepub.com/doi/10.1177/2192568218762380.
  5. Agarwal, Akash, Christian Schultz, Anand K. Agarwal, Jeffrey C. Wang, Steve R. Garfin, and Neel Anand. 2018. “Harboring Contaminants in Repeatedly Reprocessed Pedicle Screws.” Global Spine Journal, Volume 9, Issue 2, pp. 173–178. Retrieved July 25, 2019. https://doi.org/10.1177/2192568218784298.
  6. Agarwal, Aakash, Adam MacMillan, Vijay Goel, Anand Agarwal, and Chris Karas. “A Paradigm Shift Toward Terminally Sterilized Devices.” Clinical Spine Surgery, August 2018, Volume 31, Issue 7, pp. 308–311. Retrieved July 25, 2019. https://journals.lww.com/jspinaldisorders/fulltext/2018/08000/A_Paradigm_Shift_Toward_Terminally_Sterilized.9.aspx.
  7. McClelland, Shearwood, Richelle C. Takemoto, Baron S. Lonner, Tate M. Andres, Justin J. Park, Pedro A. Ricart-Hoffiz, John A. Bendo, Jeffrey A. Goldstein, Jeffrey M. Spivak, and Thomas J. Errico. 2016. “Analysis of Postoperative Thoracolumbar Spine Infections in a Prospective Randomized Controlled Trial Using the Centers for Disease Control Surgical Site Infection Criteria.” International Journal of Spine Surgery, Volume 10, Issue 14. https://doi.org/10.14444/3014.
  8. Raizman, Noah M., Joseph R. O’Brien, Kirsten L. Poehling-Monaghan, and Warren D. Yu. 2009. “Pseudarthrosis of the Spine.” Journal of the American Academy of Orthopaedic Surgeons, Volume 17, Issue 8, pp. 494–503. https://doi.org/10.5435/00124635-200908000-00003.

Lisa M. McKown (Wakeman), MBA, CRCST, CIS, CHL, MBTI, is a manager of research and development for Beyond Clean. She graduated with a Bachelor of Science degree in Integrative Leadership and an MBA from Anderson University. Lisa is a doctoral student in the Richard Fairbanks School of Public Health: Global Health Leadership program through IUPUI in Indianapolis, IN. She also holds a certification as a Meyers-Briggs Practitioner, specializing in interpersonal communication. Lisa contributes as an SME volunteer for standards development and other industry-related projects that promote the sterile processing profession, including writing workshops focused on creating and revising questions for the IAHCSMM certification exams. As a healthcare professional driven to influence positive change for patient safety initiatives, Lisa is a catalyst for the advancement of infection prevention within sterile processing. Her passion is education and she is energized when she can use her experience to develop people.

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