Antibiotic cement nails manufactured with threaded rods or cannulated intramedullary nails are better than those made with guidewires and do not debond.

Abstract

The purpose of this study was to comparatively evaluate cement debonding at the time of removal of antibiotic cemented coated nails (ABNs) with cores made with a guidewire ($120), a regular intramedullary nail ($1100) or a threaded rod from a circular frame external fixator set ($60). A retrospective study was performed on 32 ABNs that had been implanted for long bone infections after intramedullary nailing. All ABNs were manufactured intraoperatively by the treating surgeon using 2 grams of vancomycin and single package of Tobramycin Simplex Cement (Stryker, Kalamazoo, MI). The powder, antibiotics, and polymer were mixed and then injected into an ABN cement mold (Bonesetter Holdings USA). Debonding was assessed at time of removal by the operating surgeon. Rates of cement debonding between the 3 groups were statistically compared. Debonding occurred in 0/12 of the cement nails manufactured with an intramedullary nail, 0/7 threaded rod ABNs, and 6/13 guidewire ABNs. There was a significant difference in the rate of debonding between the 3 groups (P < 0.01). Removal of the remnant cement was accomplished with thin osteotomes, long pituitary rongeurs, or reamers. The canal was visualized using an arthroscope to ensure complete removal of the cement. ABNs fabricated with standard intramedullary nails or threaded rods did not lead to any debonding. Debonding of the cement from the inner core of an antibiotic nail often requires significant effort to remove the remnant cement. Given that threaded rods are often cheaper than guidewires, we recommend that ABNs be fabricated with either threaded rods or interlocking nails, but not guidewires, depending on the level of stability required.