Promotion of tendon growth into implant through pore-size design of a Ti-6Al-4 V porous scaffold prepared by 3D printing

At present, no suitable method exists for tendon fixation after artificial prosthetic implantation. Researching and determining the optimal factors for biological fixation between the tendon and prosthesis is the crux for restoring limb function. In order to increase the growth of tendon fibers into the scaffold and reduce the formation of cicatricial tissue, selective laser melting (SLM) three-dimensional (3D) printing was used to prepare four types of cylindrical scaffold. The actual pore sizes of cuboids, which were used as the monomers, were 657.65, 527.15, 348.68, and 169.20 μm. Cell experiments showed that the greatest number of fibroblasts became adhered to and grew into the scaffold with an actual pore size of 527.15 μm. Each group of scaffolds was surgically implanted into a rabbit model of acute injury to the supraspinatus tendon. Micro-computed tomography (micro-CT) and hard tissue section staining were used to analyze the growth of tendon tissue in each group. We concluded that 527.15 μm is the best pore size for a titanium alloy surface to promote tendon ingrowth. The current study provides a reference for the clinical design of the pore size of tendon attachments onto the surfaces of tumor prostheses.