The main element of our mm.X implants, Magnesium, as being a metal, shows promising mechanical strength for the use as an implant material quite similar to the human bone. This feature is making it an ideal candidate for different medical devices implanted into the human bone as we have previously discussed in an earlier mm.Blog posting.

But what about the biological tolerability of magnesium as an implant material?

Being an essential element involved in various biochemical procedures, the human body usually contains about 24 g of magnesium, most of it incorporated into and stored within the bones. Interestingly, almost one quarter of all magnesium within the human body is rapidly exchanged within hours between the serum and the extracellular matrix and within few days considering the bone surface pool.1 Excessive magnesium can easily be excreted by the human body, demonstrating its extensive tolerability, while some studies on the human diet even suggest that the average Western diet is lacking up to 300 mg magnesium per day.1

To confirm the tolerability (or: biocompatibility) of the magnesium alloy used for our mm.X implants, we have conducted a battery of biological tests to assess possible adverse reactions which may be caused by the material, including among others inflammatory reactions, cytotoxicity, systemic toxicity, or pyrogenicity. Data from these studies indicate an excellent biocompatibility as there were no signs for suspicious tissue reactions in any of the conducted tests. As the magnesium alloy does neither include aluminum nor nickel, the risk for allergic reactions is further reduced.

In addition, implants from medical magnesium undergo an innovative surface conversion process, transforming the implants’ surface into a ceramic layer. This layer is intended to decelerate the corrosion, the initial hydrogen gas evolution and thus bioabsorption – the key challenge with high-volume implants during the primary post-operative stability phase. By chance, in-vitro data also suggest that the surface treatment  further improves the material’s biocompatibility.2

Now, what makes mm.X implants and magnesium particularly interesting in the field of orthopedic and trauma surgery compared to conventional implants?

According to the German Federal Statistical Office, surgeries for “removal of osteosynthesis material” (OPS5 Code 5-787) ranked no. 18 on the list of the most frequent surgeries in Germany. In contrast to conventional metal implants made from titanium or steel, magnesium implants gradually degrade and become absorbed by the surrounding tissue after implantation. This degradation, however, does not occur via an inflammatory reaction as it is the case with polymeric materials but via a physiological process. When the magnesium implant comes in direct contact with the body fluid, the metal oxidates and subsequently dissolves in the presence of chloride ions, an abundant ion within the extracellular matrix.3 Due to this natural biodegradability, removal surgeries may often be avoided by selecting magnesium-based materials instead of conventional metal implants, thereby reducing the overall treatment costs and – most importantly – patient risks and annoyance.4

In addition, magnesium has been demonstrated to not only facilitate wound healing but have osteoconductive and osteoinductive features, thus augmenting the regeneration of bony tissue.5,6 When compared to conventional implant materials like steel, magnesium was found to elevate the expression of genes crucial for the differentiation of stem cells into osteoblasts and thus the formation of new bone tissue. While this study was based on pure magnesium implants, a previous study had already given evidence to a similar behavior of magnesium alloys.7

Hence, we further pursue our mm.X technology to offer more bioabsorbable alternatives to conventional implant materials used in various, but not all, indications among orthopedics and trauma surgery. The beneficial biological, chemical, and mechanical properties make it possible to design highly functional implants together with leading surgeons.


  1. Vormann, J. Magnesium: Nutrition and metabolism. Mol. Aspects Med. 24, 27–37 (2003).
  2. Jung, O. et al. In vivo simulation of magnesium degradability using a new fluid dynamic bench testing approach. Int. J. Mol. Sci. 20, 1–14 (2019).
  3. Han, H. S. et al. Current status and outlook on the clinical translation of biodegradable metals. Mater. Today 23, 57–71 (2019).
  4. Farraro, K. F., Kim, K. E., Woo, S. L.-Y., Flowers, J. R. & McCullough, M. B. Revolutionizing orthopaedic biomaterials: The potential of biodegradable and bioresorbable magnesium-based materials for functional tissue engineering. J. Biomech. 47, 1979–1986 (2014).
  5. Saris, N. E., Mervaala, E., Karppanen, H., Khawaja, J. A. & Lewenstam, A. Magnesium. An update on physiological, clinical and analytical aspects. Clin. Chim. Acta. 294, 1–26 (2000).
  6. Zhang, Y. et al. Implant-derived magnesium induces local neuronal production of CGRP to improve bone-fracture healing in rats. Nat. Med. 22, 1160–1169 (2016).
  7. Castellani, C. et al. Bone–implant interface strength and osseointegration: Biodegradable magnesium alloy versus standard titanium control. Acta Biomater. 7, 432–440 (2011).

Author: CP