3D printing, or additive manufacturing, refers to the process whereby a three-dimensional solid object is produced from a digital source. This is done by adding successive layers of a given material to produce the desired object, although several different techniques are available.

Complex shapes and several materials may be utilised in the process, with a wide range of applications.

Although the process of printing itself may be lengthy, the use of this technique shortens the overall time from design to actualisation. The custom production of parts and devices by standard means is typically costly. With 3D printing this can be done in a fraction of the cost. Besides, prior to 3D printing the production of complex, organic shapes was more challenging while, via printing, this is more feasible.

Medicine is a rapidly evolving field, with new advances constantly being made. The use of 3D printing in the medical field is by no means a new event, with the first documented uses dating back to the late 1990s and early 2000s, to produce dental implants and individualised prosthetics. Nowadays, such techniques have vastly expanded, as have the clinical applications for which 3D printing can be applied.

One area which has been transformed via medical 3D printing is orthopaedics, the branch of medicine dealing with injuries and surgery to the musculoskeletal system. Prior to its widespread implementation, any medical prosthesis or orthotic came in a one-size-fits-all configuration, with limited customisation options. 3D printing allows for personalisation of such medical devices, resulting in superior patient outcomes.

Certain surgical procedures tend to be more complex than others, especially if the procedure is not done routinely. Pre-operative planning may be facilitated through the use 3D printed models which are replicas of the actual patient. An example would be producing a replica model of the patient’s knee joint in the case of a complex knee replacement surgery, which would reduce operative time and the risk for potential errors. Another example for the use of such models is to better evaluate a fracture from a replica of the affected bones and to thereby decide the appropriate management.

Patient models may also be used for educational purposes. Another use for 3D printing is the creation of new instruments and drill guides.

A component of personalised medicine is pharmacogenetics, which is the use of a person’s genetic make-up to select the best drug therapy available, since different individuals may respond differently to drugs. The potential role of 3D printing in this regard is to design tailor-made dosage formulations for a patient, as opposed to the pre-defined dosages available on the market. This would be especially useful if an individual is taking several drugs, where the different dosages can be potentially combined into a single dosage. Furthermore, this would also reduce the incidence of adverse drug reactions.

In the near future, patients will have artificial organs as a feasible option

When using 3D printing techniques to produce items which will be in contact with patients, biocompatible materials must be used. Biocompatible materials refer to printing media which do not trigger any allergic or immune reactions when coming into contact with an individual’s skin or after being surgically implanted. This is essential in medical 3D printing, since potential reactions may be severe. When implants are to be placed inside the sterile body site, titanium has been approved.

New research is focusing on 3D bioprinting, which, instead of the traditional filaments, builds an object from living cells or macromolecules. This process, therefore, creates functioning, living tissues. The aim of this approach is to, one day, produce whole working organs for transplantation or to assist in the regeneration of native tissues. As such, the 3D printing of artificial organs and tissues is currently a novel application of this technique.

Currently, synthetic bones, which are 3D printed using biocompatible materials, may be used during surgeries when the removal of native bone is needed. Unfortunately, for the implantation of other artificial organs in humans to be done, a great deal of further research still needs to happen prior to use among the public. However, the successful use of artificial bones is a step in the right direction.

Briefly, the process of bioprinting involves firstly obtaining structural detail from the patient, via radiological imaging techniques. A computerised model is then generated after which printing using bio-functional materials is done layer by layer. Upon completion of the desired tissues or organ, maturation is needed and, finally, implantation is carried out.

It is safe to assume that, in the near future, patients will have artificial organs as a feasible option. Bioprinting is also currently used to produce tissues to be used in research, in a faster manner and also allowing for more manipulation to suit the needs of the researcher.

As such, 3D printing has numerous applications in the medical field, some of which need further research to be widely introduced while others are already in use. Only time will tell how this technique will continue to alter our medical care.

Robert Pisani is a third year medical student and radiographer practitioner.