Magnesium-based implants in an osteoporotic rat modelThursday (27.09.2018) 10:15 - 10:30 S1/03 - 23 Part of:
Osteoporosis is characterized by low peak bone mass, in which bone resorption exceeds bone formation resulting in loss of bone mass and quality. To date, hundreds of millions of predominately post-menopausal women are affected, which additionally raises the economic burden worldwide. Disadvantages of currently used titanium and steinless steel implant materials include “stress-shielding” by reducing loading-induced bone remodeling that may lead to bone loss and increases the risk of peri-implant fractures. Due to the increasing age of the population, it is becoming ever more important to evolve novel strategies to treat and support osteoporosis associated bone fractures. Magnesium (Mg)-based implants are promising due to their biodegradability, biocompatibility and mechanical properties. Therefore, we aimed to investigate a Mg-based implant (Mg-Ca-Zn; ZX00) in ovariectomy-induced osteoporotic rats regarding osseointegration, bone morphology and degradation of the Mg-based implant. Twelve months old Spraque Dawley rats were bilaterally ovariectomized to induce osteoporosis or served as healthy controls. After three months, ZX00 pins were transcortically implanted into the tibiae of osteoporotic animals. To observe osteoporosis progression, in vivo micro-computed tomography was performed before, 4, 8 and 12 weeks after ovariectomy; µCT scans were also performed before, 2, 6, 12 and 24 weeks after ZX00 implantation. After 24 weeks, animals were euthanized and tibiae were excised for Technovit 9100 New embedding, histological analysis and ex vivo high-resolution µCT scans. Here we demonstrated appropriate osseointegration of the ZX00 implant in ovariectomy-induced osteoporotic animals. Hydrogen gas formation did not influence bone in-growth and osseointegration. These results introduce for the first time a rare-earth element free Mg-based implant in a pathological, osteoporotic bone condition. Biodegradable Mg-implants may therefore serve as an extraordinary possibility for osteosynthesis in pathology-associated weakened bone due their biocompatibility and mechanical properties. Whether biodegradable Mg-based implants support or even improve bone morphology will be elucidated in further experiments.