Additive manufacturing solutions for orthopedic applications
Industrial 3D printing by EOS delivers tailor-made, flexible solutions for orthopedics applications, with quick and cost-effective production of high-quality patient-specific implants and disposable surgical instruments.
Orthopedics companies have increasingly come to rely on EOS Additive Manufacturing (AM) solutions to produce implants and disposable surgical instruments. This solves present-day challenges: even though no human body is exactly like another, implants must fit perfectly and be quickly tolerated by the body so they can bring about a long-term improvement in the patient’s quality of life. Standard products are inadequate here. Instead, products must be tailor-fitted to the patient, with an added need for fast availability at a reasonable price.
Compared to conventional implant production methods, EOS AM offers multiple benefits. Based on 3D CAD data for example, patient-specific parts can be generated without using tools, using high-quality, medically compatible materials. Lattice structures can help to accelerate post-operative healing significantly. In addition, a definable degree of surface roughness
helps bones and implants fuse better. Improved implant fit also makes the surgeon’s job easier. EOS AM ensures that production costs remain economically viable, even for highly individualized products. Implant manufacturers are able to optimize 3D CAD data-based models quickly and benefit from maximum flexibility. The use of AM optimizes patient treatment, shortens hospital stays and minimizes unpleasant side effects.
For complicated operations, surgeons are increasingly using patient-specific disposable surgical instruments. These enable more precise implant positioning, increasing the success rate of operations for patients, surgeons and hospitals. Additive Manufacturing methods can also be used to produce such individualized instruments. The surgeon receives a high-quality, precise product that fulfils the stringent requirements for medical applications. Compared to non-disposable instruments, hospitals save sterilisation and storage costs and benefit from increased productivity. EOS systems are able to manufacture medical devices. However, EOS cannot offer any guarantee that these devices meet all requirements.
EOS Additive Manufacturing technology – Orthopedic best-practice examples
Medical: Alphaform – Production of hip implant by using Additive Manufacturing
15-Year-Old Cancer Patient Receives the Perfect Implant and Renewed Hope for the Future
For anyone affected by it, a cancer diagnosis always comes as a shock. In the case of a boy from Croatia this was partic
rue as an aggressive form of bone cancer had destroyed the teenager’s hip. The only option for the doctors treating him was a complete reconstruction of the hip bone. Once again, the 3D printing experts at Alphaform, a company with extensive experience in the medical sector, placed its trust in EOS’ technology to successfully produce the implant.
A primary bone tumor (meaning one not formed by metastasis), is a cancer lying directly on the bone – a serious illness. The malignancies generally grow destructively, meaning that the original tissue must be removed. This was the case with a 15-year-old patient from Croatia. A complete arthroplasty of the hip was the fundamental prerequisite for ensuring the cancer cells did not continue to spread in the boy’s body. An intervention of this type limits the mobility of the joint, and thus the mobility of the patient. Particularly in young people it is important to find solutions that limit, or even prevent, any negative consequences further down the line.
With a precision implant, a patient’s motor skills can largely remain unaffected in the future. In the hip area, the precise shaping of the replacement bone is particularly important. The femoral neck functions as the central joint for the leg and is thereby fundamental to walking and running. It requires a perfect connection to the body in order to function correctly. What is important is not so much the fit of the hip bone in the joint. Rather, the complete artificial hip should correspond as precisely as possible to the original so that the entire positioning and all of the angles match one another again.
The manufacture of such an implant is of course no simple undertaking. However, the cancer in the body of the boy was a powerful adversary. In addition to its pure destructive force, the illness was also causing the doctors concern because of the speed with which it was spreading – time was of the essence. Furthermore, the new implant had to meet the doctors’ weight specifications. Lightweight, precision, fast – these were the three requirements with which the Croatian surgical team brought to Alphaform with their request for a corresponding metal bone part.
The German Additive Manufacturing expert has made a name for itself in the production of implants. It utilises a process whereby a powdered material is hardened with a laser, layer by layer, to create artificial bone parts. Having studied the available information it was quickly established that the boy could be helped. According to Christoph Erhardt, Director of Additive Manufacturing at Alphaform AG, “The design process was a real challenge. We received the complete 3D data including the cavities from Instrumentaria. Based on this we were able to start with the precise manufacture of the implant.”
This is where the advantages of EOS’ innovative production processes came into full effect. In order to keep the weight of the artificial hip to a minimum, Instrumentaria built in a large number of cavities. Such recesses in otherwise solid parts can only be achieved through Additive Manufacturing. Precision casting or conventional milling cannot achieve such a complex shape. The challenge with the integration of the empty spaces was to find the correct mix of stability and weight reduction because the implant also needed to withstand a high degree of physical stress.
Within one week the component was produced with the EOSINT M 280 using a stable yet light titanium alloy. The process, from the initial computer sketches to the final implant, took only six weeks. This period included the sophisticated finishing of the artificial bone. “We were making something that would be placed inside a human body. Even the slightest contamination, residues, or unevenness could have catastrophic consequences”, explains Erhardt. The high level of experience of the 3D service provider also had a positive effect here. The cleaned implant fulfilled the highest medical requirements and arrived in Croatia within an impressively short time.
To the delight of everyone involved, the subsequent operation in May 2014 was a great success. First the team of doctors completely removed all of the parts affected by the cancer and then the new artificial hip was inserted, complete with the integrated joint. What’s more, a part of the young patient’s thigh was replaced so that both joint parts fit within one another perfectly. The precision, lightweight implant fulfilled all of the medical requirements and the foundation was laid for the patient’s successful recovery.
Besides the short duration of the planning and construction, the finishing process, which was developed by Alphaform and has subsequently proven its value on many occasions, was a further component of the overall success. Amongst other factors, the multi-step cleaning process facilitates the utilisation of the part for medical applications. It also guarantees over the long term, that the body and the implant harmonise with one another. In addition, depending on the growth rate of the young patient, it will also be possible to replace the hip with a larger one in a relatively simple procedure.
Atif Cakor is R&D Design Manager for Custom Implants at Instrumentaria and had a leading role in the joint project. He underlines the importance of Additive Manufacturing in the medical sector: “The team that carried out the operation with Prof. Dr. Robert Kolundžić and Dr. Sc. Srećko Sabalić did a fantastic job. Together with the knowledge of the doctors it was the high quality of the implant that served as a guarantee for the enduring success of the procedure. The fact that these advantages do not come at an exorbitant cost is better still. The signs are that this technology will go on to help many more patients in the future.”
“We have not only contributed to saving the life of a 15-year-old boy, but also to making his life significantly more pleasant – what more could you hope to say about the advantages of an innovative solution? Both the Additive Manufacturing and the finishing have proven to be a great success. We are all very happy that the operation went well. It is a prime example of the way in which EOS technology can help people.”
Christoph Erhardt, Director, Additive Manufacturing at Alphaform AG
“In recent years we have been able to gain a great deal of knowledge and experience in the area of custom implants. Each new patient benefits from this expertise. The technical foundation is provided by Additive Manufacturing. It has been important that technology pioneers such as EOS were able to establish metal-based processes in this field. The result of their innovation is that we are able to offer people consistently better implants.”
Atif Cakor, R&D Design Manager for Custom Implants at Instrumentaria Co.
Medical: FHC – EOS Technology for Manufacturing of Stereotactic Platforms for Neurosurgery
Additive Manufacturing of customized surgical tools achieved high precision
Brain surgery requires devices and instrumentation that are manufactured to the highest levels of precision. Deep Bra
in Stimulation (DBS), which treats acute symptoms of various diseases, targets areas of the brain that are measured in millimetres. Yet every person’s brain geometry is unique. FHC – a worldwide leader in innovative neuroscience products for more than 40 years—collaborated with a leading neurosurgeon to transform traditional stereotaxy using a 3D-modelling process based on each patient’s anatomical coordinates. The first application of this new STarFix technology is the award-winning, patient-matched, frameless microTargeting™ Platform, which offers greater patient comfort, increased accuracy and time savings in the operating room (OR). Using the FORMIGA P 100 to laser sinter the Platform, FHC achieves precision results at reduced costs within record delivery times.
Neurologists with patients who suffer from Parkinson’s disease, essential tremor or dystonia that are not well-controlled by medication have increasingly been referring them for DBS surgery. Some 8,000 such surgeries are now performed each year. However, to prevent movement during the procedure, traditional stereotactic frames fix the patient’s head in place for many gruelling hours of awake imaging, target identification and electrode implantation within brain tissues. The FDA-cleared Platform, developed in the late 1990s and now in use in hospitals around the world, provides a custom mounting interface between patient and device that allows for the surgical plan to be built directly into the geometry of the fixture in advance of the OR. Patients enjoy movement and relative comfort, neuronal targeting and lead placement are more efficient, and OR time is reduced to an average of two hours in a bilateral procedure. Although FHC had been using various additive manufacturing technologies to produce the Platform before, as demand for the new device grew they wanted to reduce production turnaround times, lower costs, and more easily accommodate surgeon’s special designs—all while increasing the precision of their finished products. “We are also looking to expand development of enabling products into other surgical specialties such as orthopaedics,” said Fred Haer, FHC CEO and STarFix President. “Laser sintering from EOS offers a solution to these multiple needs.”
“We’re very pleased with the advancements in additive manufacturing we’ve seen since the STarFix technology was patented in 2001,” says Haer. “To meet our most exacting standards, we moved our primary production of the fixture to an EOS system in 2011.” Unlike traditional, large, universal stereotactic frames, each STarFix device is both patient- and procedure-customized in advance from MRI and CT data. FHC planning software locates 3 or 4 anchor attachment points in the skull and then allows the surgeon to input a selected target and trajectory. These inputs create a custom-formed stereotactic guide that attaches precisely to the anchors, aligning the microdrive for recording and DBS lead placement. This same “growing to a desired shape” customization is reflected in the design flexibility and precision provided by laser sintering. Following the parameters of an intelligent, independent solid model provided by the planning software, the fixture is “grown” inside the FORMIGA P 100 in only a matter of hours using PA 2201 polyamide powder.
The switch to manufacturing the Platform with EOS technology has provided numerous benefits to FHC. “Our new machine is smaller, lighter and more accurate than what we were using previously,” says STarFix Chief Technology Officer Ron Franklin. “Plus, we’ve been able to add new features to the Platform while reducing materials and processing costs.” Parts consolidation enabled by laser sintering has allowed FHC to fine-tune the STarFix design, reducing assembly time in the OR. “We’re now able to build more of the parts right into the Platform with additional features that simplify the mounting of various devices so it’s more precise,” says Franklin. One example is a metal indexing ring that was formerly screwed onto the platform by the surgeon during the surgery. “Now we can incorporate that function within the finished fixture,” says Franklin. “This saves us the effort of having to provide that machined part separately and saves the hospital OR time because they don’t have to sterilize the part and keep track of small, loose screws during surgery.” Materials savings are another benefit of additive manufacturing. “We found it was more economical to use EOS’ high-quality polyamide,” says Franklin. “Another thing we like about the FORMIGA P 100 is that there is no overflow material needed in the build envelope.” Since all material added to the system is used, there is less material consumption. Response time to the doctor’s needs is a key driver at FHC. “We typically receive a patient file during the working day, consult with the physician as needed to confirm the design, start manufacturing that afternoon and can send back the finished Platform the next day,” notes Haer. “This means about a 48-hour turnaround in the US, 72 to Europe.”
“We anticipate even greater product improvement opportunities from the switch to laser sintering as we go forward. Having the flexibility of a technology that can create patient-specific solutions rather than one-size-fits-all can result in both hospital econom
ies and better patient outcomes,”
Fred Haer, FHC CEO and STarFix President
“The trend in medical devices is to create customized products. EOS technology provides us with patient-specific product manufacturing while enabling us to control costs as we speed delivery to our surgical customers.”
Ron Franklin, Chief Technology Officer, STarFix
FHC’s commitment to Innovation through Collaboration has supported the neuroscience community for more than 40 years through the design and manufacture of unique microelectrodes and a broad range of research and clinical instrumentation, including
micro-positioning devices for acute and chronic recording/ stimulating preparations.