- See addition of antiobiotics to cement discussion

- tobramycin:
- has rapid elution of antibiotics which diminishes quickly after 2 weeks;
- of interest, some bacteria will be able to survive on tobra or vanco beads alone, but generally cannot survive when both
antibiotics are added to cement mixture;
- the addition of 3.6 gm of powered tobramycin / 40 gm of cement should not raise the serum levels above 3 mg / dl;
- some authors routinely add 4.8 gm per 40 gm cement batch;
- note the cost for a 1.2 gm vial is about 250 US dollars;
- in the study by Evans, authors used 4 g of vancomycin and 4.6 g of tobramycin per 40 gm batch of cement in 54
periprosthetic joint infections;
- at 2 year follow up there were no no renal, vestibular, or hearing changes;
- note that the cost for a 1 gm vial is about 40 US dollars;
- in the study by Masri, et al, the authors conclude that at least 3.6 g of tobramycin and 1 g of vancomycin per package of
bone-cement is recommended when antibiotic-loaded cement spacers are used in 2-stage exchange arthroplasty for infected
total hip and TKR;
- there was a statistically significant increase in the elution of vancomycin when dose of tobramycin was increased from at
most 2.4 g to at least 3.6 g;
- references:
- Long-term elution of antibiotics from bone-cement: an in vivo study using the prosthesis of antibiotic-loaded cement
                  - Successful treatment of total hip and knee infection with articulating antibiotic components: a modified treatment method.
- Antibiotic impregnated bone cement in total hip arthroplasty. An in vivo comparison of the elution properties of tobramycin and vancomycin.
- The use of tobramycin-impregnated polymethylmethacrylate beads in the therapy of deep bone and joint infections.
- Effectiveness of bone cement containing tobramycin. An in vitro susceptibility study of 99 organisms found in infected joint arthroplasty.
- Systemic exposure to tobramycin after local antibiotic treatment with calcium sulphate as carrier material
- Acute renal failure associated with vancomycin- and tobramycin-laden cement in total hip arthroplasty
- What is Intraarticular Concentration of Tobra Using Low-dose Tobramycin Bone Cement in TKA: An In Vivo Analysis?

- gentamicin:
- in the report by Springer, et al total antiobiotic load of 10.5 g of vanc and 12.5 g of gent was clinically safe, w/ no evidence of
acute renal insufficiency or other systemic side effects;
- elution falls below the mean inhibitory concentration by 6-8 weeks;
- currently the powered form of genatmicin is not available in the US;
- references:
- Systemic safety of high-dose antibiotic-loaded cement spacers after resection of an infected total knee arthroplasty.
- A comparison of gentamicin-impregnated polymethylmethacrylate bead implantation to conventional parenteral antibiotic therapy in infected total hip and knee arthroplasty.
- Comparison of the clinical efficacy and tolerance of gentamicin PMMA beads on surgical wire versus combined and systemic therapy for osteomyelitis.
- Long-term implantation of gentamicin-polymethylmethacrylate antibiotic beads.
- Audiometric thresholds in osteomyelitis patients treated with gent-impregnated methylmethacrylate beads (Septopal).
- Gentamicin-impregnated polymethylmethacrylate beads compared with systemic antibiotic therapy in the treatment of chronic osteomyelitis.
- The treatment of infected nonunions with gentamicin-polymethylmethacrylate antibiotic beads.
- Reimplantation in infection. Elution of gentamicin from cement and beads.
- Total hip joint arthroplasty with gentamicin-impregnated cement. A clinical study of gentamicin excretion kinetics.
- The release of gentamicin from polymethylmethacrylate beads: an experimental and pharmacokinetic study.
- Palacos gentamicin for the treatment of deep periprosthetic hip infections.
- Role of gentamicin-impregnated cement in total joint arthroplasty.
- Liquid gentamicin in bone cement spacers: in vivo antibiotic release and safety in 2 stage revision of infected HA.
- Does a Prefabricated Gentamicin-impregnated, Load-bearing Spacer Control Periprosthetic Hip Infection?
- Incorporation of large amounts of gentamicin sulphate into acrylic bone cement: effect on handling and mechanical properties, antibiotic release, and biofilm formation.
- Liquid gentamicin and vancomycin in bone cement: a potentially more cost-effective regimen
- Liquid gentamicin in bone cement: a laboratory study of a potentially more cost-effective cement spacer
- Local Antibiotic Therapy in Osteomyelitis