When you hear the word ‘printing’, you probably think of something that prints documents. It’s quite strange to think of printing a musical instrument, a bikini or a power drill.
Welcome to the brave new world of 3D printing.
What is 3D printing?
3D printing turns a digital file containing 3-dimensional data into a physical object. It means you can create something using a computer-aided design or computer-aided manufacturing program and then print it out.
Normal printers convert your data into a 2-dimensional result – ink on paper. A 3D printer turns your data into a 3D object you can handle or use. It does this by laying down layer upon layer of material to build up the final product.
3D printing has been put to many novel uses, such as:
- Constructing emergency response centre buildings in less than 24 hours
- Printing shoes
- Creating custom-made tooth implants or crowns.
In medicine, 3D printing is used to create products based on the patient’s own anatomy. It’s like wearing a tailor-made suit that fits you perfectly rather than an off-the-shelf model.
How is 3D printing used in orthopaedic surgery?
In orthopaedic surgery, we use numerous implants such as rods, plates, pins or prostheses for procedures such as:
- Hip replacements
- Spinal fixation
- Knee replacements
- Fracture repairs.
No two bodies are ever quite the same though. Your joints and bones have their own subtly different sizes and shapes. Traditionally, we’ve had a choice of sizes and had to pick the closest one. With 3D printing, we can create something made for you that precisely suits the intricacies of your anatomy.
With 3D printing, we scan the relevant part of your body before your operation, generating a model that we can print to make:
- Patient-specific instrumentation – a surgical planning technique using a customised mould that shows us precisely where to cut
- Patient-specific implants – used in joint replacement surgery, for example.
3D printing can also be used to make non-customised implants. Because there are no moulds or specialised equipment, these designs can be rapidly modified and updated when needed.
Bioprinting
Bioprinting takes 3D printing to the next level, adding live cells or growth factors on top of an implant to accelerate the repair of bones and soft tissues.
This is a rapidly evolving field with amazing potential for tissue repair and even organ transplantation. So far, researchers have printed artificial bones, blood vessels and bladders.
Limitations of 3D printing in orthopaedics
By now, you may be thinking that 3D printing could practically solve all medical problems. We could 3D print new heart valves, prosthetic legs, liver tissues, ankle joints and just about everything else, couldn’t we?
Eventually, maybe.
But before we get too excited, it’s worth remembering that 3D printing only began in the 1980s. The first medical use was in the 1990s. The first 3D prosthetic leg was made in 2008 and the first jaw was printed in 2012. The technology is no longer in its infancy but it’s not yet fully grown either.
And it has some limitations that we must consider, including:
- Hygiene – 3D printers can print intricate designs to match your anatomy. But that can mean your perfectly tailored implant or instrument has tiny fissures that can be hard to clean after printing. Cleaning requirements must be built into the planning stages to avoid hygiene risks caused by too much geometric detail.
- Intensive use of resources – 3D printing requires intensive use of plastic and energy.
- Toxicity risks – a 2021 study in mice found that supposedly biocompatible 3D-printable resins used in clear tooth aligners in dentistry could leach compounds into their surroundings, which affected the mice’s fertility.
My view on 3D printing in orthopaedic surgery
I love seeing developments in orthopaedics. That’s why I devote so much time to research. There are techniques we use routinely now that were once new.
Done well (and with an awareness of its limitations), 3D printing offers many benefits. It aids surgeons in pre-op planning and develops customised implants that precisely fit each patient.
That said, we’re not yet at the point where I would use 3D printing by default on every patient. I assess its usefulness during consultations and pre-op planning, in discussion with the patient.
If you would like help to manage a musculoskeletal injury, please book an appointment.
Disclaimer
All information is general and is not intended to be a substitute for professional medical advice. Any surgical or invasive procedure carries risks. Dr Ross Radic can consult with you to determine if a particular treatment or procedure is right for you. A second opinion may help you decide on your options.
