3D Printing for Orthopaedic Prostheses

Modern 3D printing technology, also known as Additive Manufacturing (AM), allows for the production of previously virtually impossible items.

The innovation and development in recent years in 3D printing, therefore, make it possible to produce complex orthopaedic elements that can provide additional functionality to joint prostheses and spinal and craniomaxillofacial implants. This article has already shown the importance of 3D printing in the dental and medical fields.

This is why medical device manufacturers worldwide are increasingly exploiting the possibility of 3D printing to work with metals such as titanium or chromium to produce implants and prostheses that can have a long life span and guarantee a much better quality of life for patients.

Medicine, particularly orthopaedics, benefits from this epoch-making change and the innovation this technology brings. Therefore, many companies have decided to invest time and resources in 3D printing projects. Patients will increasingly be able to obtain great benefits from this new technology.

But what is 3D printing? By this technique, we mean a precise process that allows a project to be realised in three dimensions by placing several material layers (chosen according to the type of use of the object) on top of each other to create a final object that develops vertically. This process remains unchanged even in 3D printing for prostheses, supporting doctors before and after orthopaedic surgery.

3D printing for prostheses and orthoses

More doctors and researchers rely on 3D printing for various functions, from prototyping new products to designing customised guides.

Modern 3D printing technology and materials significantly improve patient care, allowing doctors to produce more effective results.

There is no perfect size for prosthetics and orthotics. Doctors may face individual situations, organs, and specific bone fractures and diseases. In these cases, applicable solutions and surgical interventions are particularly complex and require direct knowledge of the patient’s needs.

However, thanks to 3D printing, new opportunities are opening in this area, thanks to exact technologies and materials that are becoming increasingly realistic.

Therefore, 3D printing in prostheses and orthoses allows for a reduction in complexity through customisation. New technologies make it possible to create customised components based on data obtained from the patient’s X-rays.

Unlike standard prostheses and orthoses, those created through 3D printing are designed for the patient’s specific body and significantly reduce complications. This new approach also allows for building parts that do not exist to carry out specific and complex surgeries.

3D printing for human prostheses: a new future for medicine?

3D printing already represents an area of significant innovation for medicine in general and, specifically, for human prosthetics. Research never stops and travels fast. Recently, a US research team has been developing a new 3D printing technology that aims to be up to 50 times faster than current standards. This kind of growth could further revolutionise the medical world in prosthetics.

This result shows how 3D printing, despite being a recent technology, is developing rapidly. This growth is also driven by promising results for patients’ quality of life. Experiments in prosthetics are evolving most rapidly and fruitfully.

Also increasing the interest in this technology is the considerable reduction in the cost of producing a prosthesis, which in standard models can run into the thousands of euros; with 3D technology, on the other hand, this expense is reduced to a few hundred euros.

One aspect developers are trying to implement is the durability of 3D-printed materials. Indeed, traditional prostheses currently have a longer life, but the new materials being tested promise to exceed these standards.

Another aspect that points to a bright future for 3D printing in the medical and prosthetic sector is customisation. Indeed, perfect solutions will be found for specific and complex cases.

The future is also about cutting time. Indeed, studies are leading 3D technology to reduce the time it takes to print a prosthesis. A recent test showed that printing a life-size human hand in under 20 minutes is possible. This is a gigantic step forward and a hope for the future of this industry, which will see more and more human organs and tissues made using 3D printing technology.

Alongside this reality, which will continually be improved in the future, is the field of Artificial Intelligence. Researchers are working to create technologies that can make prostheses controlled by thought. The focus of the work at the moment is on people who have lost the use of their limbs.

Thus, with these developments that will make prostheses increasingly democratic, 3D printing will allow millions of people to benefit from this technology in the future.

However, one future development that could further disrupt the world of 3D printing is prostheses with touch. In addition to simulating the movements of the reproduced body part, these will give the patient the sensation of feeling, touching, and hearing.

In this regard, scientific research is heading towards creating synthetic and bright skin (with many sensors inside) that can give the tactile sensations of human skin. This will allow the patient to feel pressure, humidity and even temperature.

Recent studies have been working on powering these sensors embedded inside this synthetic skin prototype. The solution tested involves a technology that uses the sun’s rays to power the skin.

This artificial skin could be more effective than other materials powered by batteries because it obtains energy from a natural source.

What are the advantages of the 3D-printed prosthesis?

As many experts in the field point out, the first and obvious advantage of 3D-printed prostheses is their ability to overcome the significant limitations of standard ones.

Research in this field, in fact, never stops and, on the contrary, always travels fast, achieving more and more breakthroughs, innovations and novelties. That is why this development has led 3D printing to provide a considerable advantage, namely the possibility of choosing the most suitable prosthesis for the individual case.

Printing a prosthesis customised to the patient guarantees the creation of an exclusive implant. To achieve this, 3D technology also uses other advanced tools and specific examinations, such as CT or MRI, allowing a much more accurate and precise assessment of the patient’s needs, analysing every detail.

Thanks to modern and innovative 3D prostheses, overcoming complications is another possible advantage. This technology allows the patient to avoid the pain and inflammation following surgery, usually when an unstable or unsuitable prosthesis is inserted.

Therefore, post-operative recovery is much faster and safer, allowing patients to return to their usual quality of life quickly.

Another aspect to consider when discussing the advantages of 3D-printed prostheses is the apparent cost reduction. Many patients experience unpleasant situations that can drastically worsen their quality of life.

In this context, one cannot overlook the economic aspect of relying on expensive specialist interventions. Thanks to 3D printing, on the other hand, even better results can be achieved, but at a much lower cost than with standard prostheses.

3D printing, therefore, is a technology that makes it possible to reduce the number of steps needed to create a prosthesis, thereby reducing costs. Researchers are working to ensure high-quality products can be manufactured rapidly to meet the high demand.

The prosthesis construction process

The study behind the construction of prostheses is a centuries-long activity that allows doctors to help patients with functional loss.

In addition to the technical aspect and design, efforts have been made to intervene in the different rehabilitation and patient acceptance phases.

One of the most common applications of 3D-printed prostheses is in the upper limbs. In these cases, loss of function can be due to various causes, mainly pathologies, traumas, and genetic malformations.

Trauma is one of the main reasons for amputation worldwide. In the case of the upper limbs, amputation occurs when the hand’s functionality is compromised. Amputation is usually carried out below the elbow. Preserving the elbow joint makes it easier for the patient to accept a 3D prosthetic arm and integrate it into their activities.

The opposite case, complete amputation above the elbow, is the most complex to adapt to a prosthesis. This is caused by the larger and more significant joints to be replaced.

Generally, upper limb prostheses consist of three components: a possible elbow joint, the socket and the terminal device.

The first component, the elbow joint, is a hinge that allows the forearm to be bent and lengthened so that the terminal device or the hand can lead objects to the body or mouth.

One can bend the elbow by pulling or helping with the other arm. Using a locking system, the elbow can be held precisely while the patient uses the hand.

The socket, on the other hand, plays a crucial role. It is the element that connects the prosthesis and the skin. For this reason, it must be comfortable; otherwise, the patient cannot use the prosthesis properly.

Constructing these and other prostheses requires an exact process. They are usually produced after careful patient morphology analysis and study.

Different techniques for manufacturing prostheses vary depending on the type of technology, material, and budget. A traditional process involves the following steps: The first is measurement using plaster casts. Next, a provisional prosthesis is made.

The second stage is the construction of the definitive prosthesis, after which the patient’s fitting phase occurs.

This type of work is characterised by repeatability. Depending on the patient’s biological changes or the wear of the prosthesis, this process can be repeated over time.

Currently, 3D scanners or photometry can be used to take measurements. During this phase, it is essential to do a static and dynamic analysis, i.e., under stress.

Measurements can be made digitally using specific CAD software, facilitating the realisation and repeatability of this process.

The different production steps of the prosthesis are realised by adapting existing parts or using 3D technology for some of them.

3D printing has been used in this field for several years, allowing prostheses to be manufactured. Compared to other techniques, it guarantees high precision and allows for the easy creation of unique parts adapted to the patient’s needs.

In some cases, electromechanical components are integrated to provide additional functionality, which differentiates such prostheses from static prostheses.

In our country, the point of reference in the manufacture of prostheses is the INAIL prosthesis centre. This facility uses traditional and more advanced and innovative techniques to guarantee the production of prostheses for 11,000 Italian patients.

Final Thoughts on 3D Printing for Prosthetics

As this article shows, the development of 3D techniques and materials has enabled considerable progress in the prosthesis sector in recent years, the area that has benefited most from these innovations.

3D printing technology has been available for several years now. However, it was characterised by high management costs that limited its application in many areas. Fortunately, recently, thanks in part to lower costs, its widespread use has increased markedly, especially in the medical and orthopaedic fields.

From the future of this technology, we expect the applicability of biologically customised support for the patient. This will make 3D printing revolutionary in the medical field. This is a very complex challenge to accomplish. This difficulty is prompting more medical and orthopaedic professionals to focus on research and experimentation in prosthetics. This area is very attractive from a market perspective.

In general, it will also be crucial to rely on professional, competent, and experienced 3D printing companies such as Fama 3D, which use the best technology and have more than 140 years of experience manufacturing industrial components.