Antibiotics and Bone Cements:Experimental and Clinical Long-Term Observations

Abstract

Comparing several antibiotics and different bone cements, the mixture of Palacok R (polymethylmethacrylate, PMMA) with gentamicin proved to be the most suitable one as far as a high and sustained release of the antibiotic from the artificial resin is concerned. A antinuous leaching of gentamicin was observed for more than 5 years. w t a m i c i n proved to be stable in Palacos R for the whole period of time. The release of 12 antibiotics from Palaas R was evaluated in witro. Four other bone cements were included in this itudy as well, in order to evaluate the leaching of gentamicin from these materials. The combination Gentamicin-Palacos R (GP) showed a 2-3 fold higher and much more prolonged release than did the other mixtures. From this investigation, which also included studies of commercially available antibiotic bone cement mixtures, it is quite obvious that there exist distinct differences in the various bone cements as well as in the various antibiotics as regards their qualification for use in alloarthroplasty. Pharmacokinetic studies in patients after implantation of G P showed low gentamicin concentrations in serum (on average 1.8 pg/ml) and urine. However, in wound exudate, derived directly from the vicinity of the implanted cement, gentamicin concentrations up to 150 pg/ml were observed. Also in tissue samples from the vicinity of the implant, high concentrations were measurable for a long period of time (up to 5+ years).

Antimicrobial Release From Prefabricated Spacers Is Variable and the Dose Is Low

“…We found that gentamicin release from both the prefabricated ALBC spacers and the hand-mixed ALBC was highest initially but then slowed after the first day. Our findings are consistent with previously reported release data from ALBC [12,23]. The amount of gentamicin that is released from the prefabricated ALBC spacer surfaces is more than we measured from 1 g/batch ALBC, but less than we measured from higher antimicrobial loads of 5 g or 10 g per batch of hand-mixed ALBC.…”

Influence on Mitochondria and Cytotoxicity of Different Antibiotics Administered in High Concentrations on Primary Human Osteoblasts and Cell Lines

“…With the exception of ticarcillin, antibiotic concentrations in the granulation tissue surrounding the beads exceeded 30 g/ml even 28 days after implantation. In pharmacokinetic studies in patients after implantation of gentamicin-impregnated PMMA, concentrations of up to 150 g/ml active gentamicin were observed in wound exudates derived directly from the vicinity of the implanted cement (49). Besides the nonbiodegradable PMMA, numerous biodegradable materials have been studied for use as local drug delivery systems for antibiotics (27).…”

Vascularized versus Nonvascularized Bone Grafts: What Is the Evidence?

“…The first of the two [21] does not study or reference graft lengths, and the second [57] recommends VBGs for greater than 6-cm grafts based on an additional three articles [22,25,48]. A look at those three articles finds that one [25] also recommends VBGs for greater than 6-cm grafts and cites a case series of eight VBGs for tibial defects [13] and subsequently references numerous sources of low relevance [2,10,11,30,32,45,47,[51][52][53][54]. Another of the three articles [22] is a case series of 14 VBGs used for tibial defects, although only four grafts exceed 3 cm.…”