Abstract
In two-stage revision surgery of infected joint prosthesis, temporary bone cement spacers have been used for several years. By adding antibiotics to the cement, high local antibiotic concentrations that exceed the minimum inhibiting and bactericidal concentration of the respective pathogen during the first days after surgery, are achieved. Currently, aminoglycosides (e.g. gentamicin and tobramycin), as well as glycopetides (e.g vancomycin) are used as antibiotic agents and mixed into the acrylic cement. In order to increase the quantity of active antibiotic substances, we established a novel surgical technique of additional superficial vancomycin coating (SVC) of temporary bone cement spacer. The aim of this study was to analyze the safety of this method by measuring postoperative joint and serum vancomycin concentrations, as well as the creatinine levels.
We reviewed prospectively collected data on all patients, which were treated by explanting the prosthetic components, following temporary spacer implantation and SVC between 05/2013 and 04/2015 at the Department of Orthopedic Surgery, Medical University of Graz. In total 13 patients were treated by addition SVC during the study period. Before hardening, vancomycin powder (2 grams) was pressed manually onto the surface of the bone cement. Vancomycin levels were obtained from drains and blood samples on postoperative days 1 to 5. Forty-six blood serum samples and 52 drain fluid samples were available for further
On postoperative day one to five, a median serum vancomycin level of < 2.0 μg/mL was present (range <2.0 – 3.9). The highest median vancomycin level from the drain was documented on postoperative day 1 with a value of 388.0 μg/mL (range 44.4–1650.0), continually decreasing until postoperative day 4. After SVC, neither an anaphylactic reaction nor side effects such as a red man syndrome, fever and chills were observed. Furthermore, no patient complained about subjective hearing loss. No serum creatinine increase of 0.5 mg/dL from creatinine baseline value or a ≥50% increase from baseline was detected. After a median of 64 days (range 18–82), the temporary cement spacer was explanted followed by prosthesis implantation. During this time no reinfection occurred. One patient suffered from a dislocation of the spacer with a distal femur fracture and was therefore re-operated after 18 days.
Powdered vancomycin as an additional superficial coating of bone cement spacer results in much higher local antibiotic concentrations than in conventional spacers. The newly introduced method is feasible, safe and promising to enhance local inhibiting concentrations of vancomycin.
