Ascertain the corrosion–osteogenesis sequence for small intramedullary Mg implants

Ascertain whether the corrosion of small magnesium implants in the medullary cavity follows the proposed five-step sequence: (i) magnesium degradation products (such as Mg-substituted calcium phosphates) continually replace the magnesium implant; (ii) a hydrogen envelope is formed; (iii) new bone, not rich in magnesium, is formed on the tissue/hydrogen interface; (iv) the hydrogen envelope is slowly replaced by fibrous or non-mineralized tissue; and (v) remaining bone tissue is slowly resorbed and a normal appearance of the medullary cavity is restored.

Background

Based on uCT, histology, and EDS observations, the authors hypothesize a specific sequence linking corrosion products, hydrogen bubble formation, and subsequent osteogenesis around small intramedullary Mg implants. The observed convex and ring-like bone morphologies suggest a structured interaction between corrosion-induced hydrogen and bone tissue formation.

The authors explicitly note insufficient evidence to confirm this mechanism and present it as a motivating question for future work, highlighting a need for targeted in vivo studies to validate or refute the proposed sequence.