Fig. 1.

The limitations and drawbacks of the existing orthopaedic implants in ACL reconstruction. (A) Representative histological images showing the normal tendon-bone healing with bony ingrowth towards the interface structure of the fibrous tissue or fibrocartilage after reconstruction. Figure adapted from Refs. [38,39]. (B) Representative histological images showing the healing failure between the tendon graft and bone after reconstruction. Figure adapted from Ref. [40]. (C) Representative images of Ti, PLA, PEEK, and Mg based interference screws. (D) Representative radiographic images showing the bone tunnel enlargement in patients after ACL reconstruction with currently used metallic interference screws. Figure adapted from Ref. [41]. (E) The degradation of PLA screws producing a significant amount of oligomers, resulting in aseptic inflammation around them, eventually leading to enlarged tendon-bone interface. Figure adapted from Ref. [42]. (F) Summary of the Young's modulus and tensile yield strength of natural bone, FDA-approved polymers and metals in orthopaedics, along with Mg or its alloys.