Fig. 1.

(A) The MRI of one patient with cast shows the local folded soft tissue (patient give consent to use this image). (B) The local paratenon could be constricted by the folded soft tissue. (C) The regeneration process of the collagen fibrils might be negatively influenced by the constricted paratenon. (D, E) The 3D printed clasp was applied in the CP group, while cast immobilization was utilized for both groups. (F, G) The rabbit common calcanean tendon was severed leaving a 4 mm gap. (H) The paratenon and incision were closed. (I) A 3D printed clasp was applied in the CP group; no skin necrosis was documented