A novel rodent model of chronic spinal implant-associated infection

Synthesis and evaluation of a novel vancomycin-infused, biomimetic bone graft using a rat model of spinal implant-associated infection

“…Inocula of 1×10 5 methicillin-resistant S. aureus (MRSA) were prepared as previously described [18] . All work with bacteria was performed in Biosafety Level 2 certified fume hoods using aseptic technique.…”

“…Titanium implants that were to be inoculated with either PBS or MRSA were prepared as previously described [18] . A surgical-grade titanium wire (22-AWG/.34 mm 2 , Grade 1, TEMCo, Fremont, CA) was shaped into a staple-like design to mimic pedicle screws and rod fixation in spinal fusion surgeries.…”

“…1 ). Induction of anesthesia and surgical procedures were performed as previously described [ 18 , 22 ]. The L4 and L5 transverse processes (TPs) were exposed, decorticated using a motorized burr, and then cannulated to create a trajectory through rat pedicles into which the titanium implant could be inserted.…”

“…Establishment of infection over the six-week postoperative period was quantitatively evaluated using the Lumina III IVIS system (PerkinElmer, Hopkinton, MA, USA) as previously described [18] . Postoperative scans were performed immediately after the procedure, on the third postoperative day, and each week following the procedure.…”

“…This study proposes a novel tissue engineering approach to intraoperative prophylaxis in instrumented spine surgery. We present a vancomycin infused iteration of our previously described recombinant human bone morphogenetic-2 (rhBMP-2) loaded, biomimetic bone graft, BioMim , tested in our previously described rat model of spinal implant-associated infection [ 18 , 19 ]. We hypothesize that the infusion of vancomycin and rhBMP-2 in BioMim (BioMim-rhBMP-2-VCM) will mitigate infectious colonization of the spinal implant, despite inoculation with MRSA, while also promoting arthrodesis via the prolonged elution of rhBMP-2.…”