Biodegradation of a magnesium alloy implant in the intercondylar femoral notch showed an appropriate response to the synovial membrane in a rabbit model in vivo

Abstract

Degradable magnesium alloys are promising biomaterials for orthopedic applications. The aim of this study was to evaluate the potential effects on both the synovial membrane (synovialis) and the synovial fluid (synovia) of the degradation products of a MgYREZr-pin implanted in the intercondylar femoral notch in a rabbit model. Thirty-six animals were randomized into two groups (MgYREZr or Ti6Al4V alloy) of 18 animals each. Each group was then divided into three subgroups with implantation periods of 1, 4, and 12 weeks, with six animals in each subgroup. The initial inflammatory reaction caused by the surgical trauma declined after 12 weeks of implantation, and elucidated a progressive recovery of the synovial membrane. Compared with control Ti6Al4V pins, there were no significant differences between the groups. However, after 12 weeks, recovery of the synovial membrane was more advanced in the titanium group, in which 92% showed no signs of synovitis, than in the magnesium group. A cytotoxicity test with L929 cells and human osteoblasts (HOB) was also conducted, according to EN ISO 10993-5/12, and no toxic leachable products were observed after 24 h of incubation. In conclusion, the MgYREZr alloy seems to be a suitable material for intra-articular degradable implants.

Mg and Mg alloys: How comparable are in vitro and in vivo corrosion rates? A review

“…Of the 50 animal studies (since the first use in 1900 by Pyer [16] until today [17]), 30 were not considered due to lack of quantitative information about the corrosion rate (or insufficient data to calculate the rate). This result already highlights one severe problem: the great variety of possible parameters that are monitored during in vivo trials but not necessarily the corrosion rate.…”

Magnesium inference screw supports early graft incorporation with inhibition of graft degradation in anterior cruciate ligament reconstruction

“…Ezechieli et al . 20 implanted Mg alloy (MgYREZr, which has a composition similar to WE43) pins into the intercondylar femoral notch of a rabbit model and there was no significant inflammatory reaction in the synovial membrane or synovial fluid. Thus, it is essential to determine the influence of biodegradable Mg implants on graft degradation as well as its function in graft fixation during early graft healing process after ACL reconstruction.…”

Alterations in magnetic resonance imaging characteristics of bioabsorbable magnesium screws over time in humans: a retrospective single center study

“…µCT scans in an animal study showed gas liberation being the most prominent four weeks after implantation and significantly decreasing by 24 weeks [ ]. In another study with intraarticularly implanted Mg pins in rabbits, radiographs showed the accumulation of gas most pronounced after four weeks, which decreased after 12 weeks with the explanation of diffusion processes and transportation via the vascular system [ ]. In this study, we observed several gas accumulations at different time points adjacent to the Mg screw.…”