Bionic design and verification of 3D printed PEEK costal cartilage prosthesis

Chest wall reconstructions are mainly needed after surgical treatment of tumors or trauma. The costal cartilage is part of the chest wall, connecting sternum and ribs. The currently existing rib prostheses made of Titanium or PEEK were found lacking the costal cartilage portion, causing unsatisfactory functional rehabilitation of breath. This study proposed a newly bionic methodology for designing a costal cartilage prosthesis using a wavy elastic structure. By changing the design parameters, the mechanical properties can be accurately adjusted. Finite element analysis was carried out for the optimization of the prostheses. Then the prostheses were fabricated by fused deposition modelling manufacturing technology, using PEEK. Mechanical tests were carried out to determine the elastic modulus of the prostheses. The equivalent modulus ranged 0.5-17.3 MPa, and the tensile strength ranged 0.7-8.3 MPa. The results indicated that the mechanical behavior of the designed prostheses were close to those of the natural costal cartilage and that the wavy elastic structure was a reasonable choice for designing a costal cartilage prosthesis. Therefore, the designed PEEK costal cartilage prostheses have the potential as replacement of the natural costal cartilage with better breathing function for the patient undergoing chest wall reconstruction.