In September 2015, a 54-year old Spanish national suffering from chest wall sarcoma (a type of cancerous tumor that grows around the rib cage), received the world’s first 3D printed titanium sternum and ribcage, designed and manufactured in Australia. This was done by the Australia-based company Anatomics in association with CSIRO.
Two years down the line, they have managed to build something even more impressive. The team has now designed and manufactured a 3D printed titanium and polymer sternum (bone, cartilage and tissue) that closely replicates the anatomy of bone, cartilage and soft tissue. All in a single prosthetic implant. In the earlier model, they had done only a 3D printed titanium sternum (just the bones).
When they surgically implanted this advanced titanium and plastic sternum, named PoreStar into a 61-year-old patient, he made a successful recovery!
A 61-year old patient, Edward Evans had a rare infection that required his sternum (a bone in the chest that connects to the ribs) to be removed, leaving his vital organs such as heart and lungs vulnerable and limiting his quality of life. This called for another surgery to implant an artificial sternum.
Conventionally, a prosthetic bone implant is made of hand-molded bone cement (PMMA polymer) together with a porous polymer mesh. In this case though, the surgeons at Heartlands hospital (UK) were looking for a more advanced alternative. They partnered with Anatomics, a company based in Australia that specializes in customized surgical implants, to manufacture a 3D printed implant made from titanium. Titanium is a metal that is biocompatible, strong but lightweight and has the property to integrate with bones.
To prepare the implant, high-resolution CT scans of the patient were sent to Anatomics to design a model of the intended implant that would match the contours of the patient’s anatomy. These computerized models were then sent to CSIRO for 3D printing. Powdered titanium was fed to the printer along with the model design, and the implant was made as layers of titanium were fused together using an electron beam.
The titanium sternum was then processed further at Anatomics and coated with porous polyethylene to mimic the cartilage and soft tissue associated with the bone.
Anatomics had previously prepared a sternum and rib implant in partnership with CSIRO, but it was only made from titanium. This sternum was made with titanium and the polymer mesh that more closely replicates the anatomy of bone, cartilage and soft tissue.
The sternum was successfully implanted in the patient, and he has recovered well after the surgery. Following surgery, motion capture cameras were used to observe his chest movement during breathing. Before surgery, parts of his chest were moving inward while inhaling; however, with the new implant this anomaly was corrected and the co-ordination between his breathing and chest movement has been restored.