Replacement of tibial ostectomies in sheep by a titanium scaffold associated to a poliaxial locking plate

Abstract

The development of customised implants for bone regeneration in sheep represents a significant advance in the field of experimental orthopaedic surgery. In this study, implants with a porous scaffold adapted to the anatomy of the sheep tibia were designed and manufactured with the aim of promoting osseointegration and bone regeneration. Two implant models were used, one located on the lateral side and the other on the caudal side of the tibia, which were fixed using locked and unlocked screws, respectively. Four rams underwent surgery and were subjected to clinical and radiological follow-up during the postoperative period. The formation of new bone tissue was evaluated using radiographic images, as well as the stability of the implants and the functionality of the operated limb. The results showed progressive bone regeneration around the scaffold, especially in implants placed in areas of greater bone density and better fixation, which promoted adequate functional recovery. Key aspects such as the influence of scaffold porosity, biomechanical load distribution, and implant design on osteogenesis were discussed, comparing them with previous studies. The limitations of the current model were also analysed, highlighting the need to improve fixation systems and optimise the protocol and surgical approach. This work provides preliminary evidence on the feasibility and efficacy of customised porous implants in sheep models, laying the foundations for future improvements in orthopaedic implants adapted to the specific biomechanical characteristics of bone.