Custom-made kneecaps being printed by the surgeon as the patient lies on the operating table. It sounds like someone's pulling your leg, right?
Wrong. According to St Vincent's Hospital's Mark Cook this is the future; a new frontier that has opened up for researchers and clinicians, thanks to the rapidly advancing capabilities of 3D printing.
St Vincent's and University of Wollongong researchers are already building a hand-held gun for doctors to print body parts on demand, while the patient is in theatre.
Professor Cook believes that within years, a patient's own cells will be one of the key ingredients in a solution fed into a 3D printer like ink.
A kneecap could be made by growing the patient's cells in advance and adding them to a polymer solution that is placed in a syringe, heated to 37 degrees to keep the cells at their resting temperature.
Hovering over a metal plate chilled to 10 degrees, the syringe is stationary as the plate moves and the thin ''bio-thread'' lands. As layers build up, it soon starts to resemble the dimensions of the kneecap pictured on the computer screen. The cartilage is ''set'' with a blast of UV light and then ready to be implanted.
''It's not science fiction, not at all,'' Professor Cook said. ''These are things we are already working on. We're seeing if they integrate properly, what are the best ways to do it and what are the best cells.''
The same team has already manufactured scaffolding capable of supporting and growing cartilage, muscle cells and cells of the nervous system.
Custom-made pieces of skull bone have also been implanted into thousands of patients. Queensland University of Technology's Dietmar Hutmacher developed the technique while working in Singapore. Designed for patients such as former F1 driver Michael Schumacher, who have had skull sections removed during neurosurgery, the replacement bone grows on a 3D printed scaffold that later dissolves.
Loaded with a growth factor, the scaffold is modelled on the proportions of the missing piece of bone using CT and MRI scans.
Since the first human implant in 2004, thousands of patients in America, Europe and parts of Asia have had the procedure, although it does not have approval from the Australian Therapeutic Goods Administration.
But it's not just body parts that can be printed. A neurologist, Professor Cook said 3D-printed ''bio-parts'' could also be used to deliver medication. Already, animal trials to test ways to manage epilepsy seizures have shown promising results.