Design, Manufacturing, and Implementation of an Implant Through Additive Manufacturing as an Alternative for Future Implants

Implants have a fundamental role in medicine as a temporal or permanent substitute for the bone structure of living beings. Current solutions, although effective, have certain limitations with the material from which they are manufacture, which doesn’t allow a complete osteoinduction and osteogenesis in the fracture, and even it can cause wear in the bone cause of the continuous friction. Another limitation they present is the discomfort patients in occasions feel for the presence of the implant and the need to have another surgery to replace the worn implant after a certain time. These negative consequences present an opportunity to develop new materials that fit better to the bone structure and allow that the natural process of bone regeneration happens without losing the structural support implants provide.

Hereby, this research work focuses on eliminating the limitations in osteointegration that current solutions present by manufacturing implants through 3D printing, using a compound biomaterial that accomplishes the four conditions – osteoconduction, osteoinduction, osteogenesis, and structural support – to be used as a graft. At the same time, the implant, as time goes by, will stimulate the natural grown of the bone while it is degrading, allowing that space once occupied by the implant fills with the new bone structure. 

For experimentation of the devised product, a TTA implant was designed to treat the rupture of the anterior cruciate ligament in canines because it is one of the most common clinical conditions in these patients. The material was tested in three different canines patients. In the first patient, the intramedullary subcutaneous reaction of the material in living bone was tested grafting five filaments – two intramedullary, two horizontal to the femur, and one between the bone and the muscular tissue – in the femur of the patient. Four days after the surgery the patient didn’t reveal any rejection symptomatology – inflammation or swelling in the patient´s leg – of the material and it didn’t show symptoms of infection.

In the second patient treated, and implant manufacture exclusively using the 3D printing technology was tested. The first positive sign of acceptance of the implant and its correct functioning as a structural support that he presented was that, twenty-four hours after being operated, he was already walking without a limp. During the recovery period, regeneration of bone tissue was evident around the edges of the implant, which had some expected degradation. On the other hand, there were no symptoms of rejection of the material or infection in the post-operatory, recovery process, and sixty days after the surgery

In the third patient treated, an implant was tested using another manufacturing methodology that combines 3D printing technology and CNC machining. As in the second patient, the regeneration of bone tissue was evident around the edges of the implant, which had some expected degradation. On the other hand, there were no symptoms of rejection of the material or infection in the post-operatory and recovery process.

Keywords: implant, osteosynthesis, osteoconduction, osteoinduction, 3D printing, biomaterial.