A recent level II clinical study published in Clinical Spine Surgery found that current, standard practices in handling pedicle screws for spinal surgery are leading to preventable bacterial contamination.
Aakash Agarwal, Ph.D., of University of Toledo and esteemed colleagues, including world renowned key opinion leaders like Jeffrey Wang, M.D., Neel Anand, M.D., and Steve Garfin, M.D., found that this bacterial contamination can be avoided by utilizing sterile, prepackaged screws with a preinstalled intraoperative guard.
In 2017, a preliminary study conducted at Parkview Hospital, a state-of-the-art facility in Fort Wayne, Indiana, found positive data outcomes with reduced or zero bacterial transmission with screw-guard usage. This led the Center for Disruptive Musculoskeletal Innovation, a research and innovation collaborative center through the National Science Foundation, to approve this multicenter clinical trial on the subject.
Why It Matters
Dr. Agarwal told OTW that this research was inspired by a 2015 study implicating medical glove transmission of infectious organisms from patient skin to wound site during spinal surgery. Agarwal explained, “Their study showed a dramatic reduction in surgical site infection [SSI] rate by renewing the gloves before handing each implant. Around the same time, I joined Spinal Balance’s team who were at the verge of releasing a pedicle screw with a proprietary intraoperative guard. The benefit of the guard was to avoid the need to change gloves again and again, which would require conscious effort on each member of the surgical staff, and would still fail to avoid exposure to open-air and other surfaces or instruments in the ‘sterile-field’”.
Agarwal’s study is titled “A Multicenter Trial Demonstrating Presence or Absence of Bacterial Contamination at the Screw-Bone Interface Owing to Absence or Presence of Pedicle Screw Guard, Respectively, During Spinal Fusion.” Co-authors of the multicenter study were Boren Lin, Ph.D., Ashish G. Agarwal, M.B.B.S., Hossein Elgafy, M.D., Christian Schultz, M.D., Anand K. Agarwal, M.D., Vijay K. Goel, Ph.D., Von Sigler, Ph.D., Chris Karas, M.D., Sandeep Gidvani, M.D., Jeffrey C. Wang, M.D., Neel Anand, M.D. and Steve R. Garfin, M.D.
The authors summarized data on postoperative infections, which are cited in the literature as occurring at the high end of 2-13%. The researchers pointed out that these numbers are underestimated for various reasons. “It is theoretically impossible to irrigate the bone-screw interface post-implantation” and “[c]onsequently, any contamination of pedicle screws before implantation is permanent, and has the potential to cause deep-bone infection, or hardware loosening due to encapsulation of biofilm between the bone and the screw.” This highlights the value of utilizing any possible preventative approaches. Dr. Agarwal and his team also published a literature review, presenting clinical data on the existence of delayed and late onset infection elucidating the long-term implication and uncertainty that arise from encapsulated bacteria.
