Prophylaxis of infection and effects on osseointegration using a tobramycin‐periapatite coating on titanium implants—An experimental study in the rabbit

Abstract

No options are available for local antibiotic delivery from uncemented implants. By loading a porous titanium implant with a biomimetic HA-coating (PeriApatite, PA) with antibiotics, we could obtain adequate local antibiotic concentrations and reduce infection susceptibility. This study investigated the efficacy of a tobramycin-loaded PA-coated titanium foam implant in preventing infection, as well as the effects on osseointegration. In 72 New Zealand White rabbits, an uncoated (Ti), PA-coated (PA), or Tobramycin-PA-coated (PA-tobra) titanium foam rod was implanted intramedullary in the left tibiae after contamination of the implant bed with none (control), 10 3 , 10 4 or 10 5 CFU Staphylococcus aureus. PA-tobra implants were loaded with 2.4 mg tobramycin. After 28 days analysis was done by bacteriology, histopathology and histomorphometry. Six percent of the contaminated PA-tobra rabbits were infected, whereas this was 53 and 67% for PA and Ti, respectively (p < 0.001). Quantitative cultures were also significantly lower in the PA-tobra group (p ¼ 0.003). None of the control rabbits were infected. Histopathological and histomorphometrical scores were both better for the PA-tobra group, although only significant compared to Ti. No significant differences were observed between PA and Ti rabbits. We conclude that the application of tobramycin to PAcoated titanium foam implants appears to be an effective local antibiotic strategy for uncemented implants for infection prophylaxis and has a beneficial effect on implant fixation, which will result in improved long-term implant survival. ß

A biodegradable gentamicin-hydroxyapatite-coating for infection prophylaxis in cementless hip prostheses

“…With an alpha level of 0.05 and a power of 80 %, sample size needed in each group was 7 animals. The 4-week period is regarded as the time required for initial bone ingrowth and fixation of the pin, while the time point of 12 weeks was added as further data on mediumterm bone integration (Alt et al, 2011;Bobyn et al, 2009;Moojen et al, 2009).…”

“…They showed good results, as infection rates decreased from 88 % for HA-coated K-wires to 0 % for both types of gentamicin-HA-coated K-wires. More recently, Moojen et al (2009) investigated the efficacy of tobramycin-HA coated implants in preventing infection. For a S. aureus challenge in a rabbit model 6 % of the tobramycin-HA-coated titanium foam rods were infected after 28 days, compared to 53 % and 67 % for the HA-coated titanium and uncoated titanium rods, respectively.…”

Prevenzione delle infezioni peri-protesiche mediante rivestimento riassorbibile anti-batterico: un nuovo approccio?

“…Gli studi sull'animale eseguiti finora confermano la capacità di tale prodotto e del rapido rilascio locale di agenti antibatterici di interferire nella "corsa alla superficie" in modo favorevole all'ospite. Da notare che questa è la prima volta che viene sviluppato un dispositivo medico specifico, volto a "truccare" la competizione per la colonizzazione dell'impianto che solitamente si svolge tra cellule dell'ospite ed eventuali batteri contaminanti presenti [10]. Le implicazioni cliniche e scientifiche di tale nuovo approccio sono probabilmente ancora in gran parte da scoprire.…”

The biomimetic apatite-cefalotin coatings on modified titanium

“…Therefore, many studies have addressed this problem with limited success [7][8][9][10][11][12] . Therefore, to solve this problem, local drug delivery system through antibiotic coatings was developed [13][14][15][16][17] . Recently, precipitation coating method was introduced.…”

“…In this biomimetic precipitation method, the titanium implant is immersed into saturated solutions of calcium and phosphate that also contain antibiotics. When the calcium-phosphate crystals were precipitated, the antibiotics were coprecipitated [13][14][15][16] . Antibiotics that contain a carboxylic group, like cefalotin, have strong binding interactions with calcium.…”