Printing Bone: How Should Orthopaedic Surgery Practices React to Advancements in 3D Printing?
3D printing technology has made significant advancements in the past few years. Can 3D printing be used in orthopaedics? Is this technology ready for surgery? How could orthopaedic practices best position themselves?
A surgeon’s ability to understand the intricacies of a patient’s musculoskeletal system has largely been determined by that surgeon’s ability to read medical imaging. 3D printing can shift the reliance away from radiological expertise and enable more personalized solutions for patients.
This process involves converting a CT or MRI into a format recognizable by a 3D printers using programs such as Osirix and Mimics (Figure 1).[1] These programs allow surgeons to create a printable file from their own desktop. 3D printing can improve the understanding of a patient’s precise anatomy with a physical model. This physical model can be used to improve preoperative surgical planning, thereby increasing implant placement precision and surgical outcomes. 3D printing can also allow for the creation of customized implants specific to a patient’s anatomy (Figure 2).[1][2]
Figure 1. A 3D representation in Mimics planning a hip replacement with a customized implant.
Figure 2. 3D printed model of a patient’s hip along with the customized implant.
3D printing has only recently begun to be utilized in orthopaedic surgery. While there are some critics of its reliability for clinical usage, there is tremendous excitement about its future potential, especially in the field of regenerative medicine. 3D printing can allow for bioprinting, which combines cells, growth factors and supporting material. In orthopedics, artificial cartilage and bone scaffolds are two critical tissues that can be bioprinted.[3] Often materials used to mimic these tissues such as hydrogels and polymers are unable to fully demonstrate these tissue’s properties.[4] Bioprinting can be especially useful when an autologous bone graft would not suffice or additional support is required, in cases such as congenital abnormalities, bone tumors and complex fractures.[5]
CURRENT STATE OF ORTHOPAEDIC PRACTICES
Orthopaedic surgery practices have primarily reacted to this innovation by reviewing research findings and technological capabilities. The research driving this adoption is primarily being conducted by large academic centers with strong engineering and computer science departments. These researchers have used 3D printing for preliminary planning, simulation of procedures, fracture repair, bone tumor removal and fixing congenital deformities.
Customized orthopaedic implants are now manufactured by third party vendors. Knee replacement manufacturers have already popularized patient specific cutting blocks.[6] While outsourcing customized implants can be useful to familiarize a practice with new technologies, it does not necessarily take advantage of the complete purpose of additive manufacturing – to be able to efficiently and cost effectively create in-house prototypes.
While 3D printing has gained traction in many practices, some respected physicians do not trust the reliability of 3D printing for clinical applications.[7] Recent studies have more robustly evaluated these models. Studies have assessed the degree of similarity between models and true anatomical parameters. In a recent systemic study, 3D model dimensions were found to be reliable and precise.[8]
Considering the initially mixed reception within the orthopaedic community, many practices have been slow to buy 3D printers or begin learning to use the programs. The cost of 3D printers has significantly dropped in the last few years and therefore 3D printers already available at many large academic practices. Most practices are still waiting for the technology to advance further and for the development of a strong consensus in the field.
RECOMMENDATIONS
For an orthopedic practice, a short term recommendation would be to download and become more comfortable with the software programs that allow 3D visualization of CTs and MRIs. Many programs are free and can both provide an additional perspective on patient anatomy, and position a practice to become facile with visualization tools that are becoming increasingly important.
While printer and building materials are relatively inexpensive, the cost associated with hiring staff to operate these machines represents a significant impediment to implementation. This begs the question: Should orthopaedic practices or device manufacturers lead the creation and iteration of 3D printed models?
Understandably, practices without the support of a larger institution do not want to take on these additional costs. These practices could visit a practice with 3D printers to better understand the technology. A potential solution to the cost of staffing would be to initially outsource the printing to a third party. With technological advances, the 3D printers may eventually be able to automate the process from MRI or CT to creation of a prototype.[9] This could ultimately allow even resource constrained practices to take advantage of 3D printing. With the continued advancements and the increasing popularity of 3D printing, its use for surgical planning, implant customization and tissue engineering is likely to become widespread in the near future.
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References
[1] Wang et al. 3D printing technology used in severe hip deformity. Experimental and Therapeutic Medicine 14: 2017, 2595-2599
[2] Wong TM, Jin J, Lau TW, et al. The use of three-dimensional printing technology in orthopaedic surgery: a review. J Orthop Surg. 2017 Jan;25(1).
[3] You F, Eames BF, Chen X. Application of extrusion-based hydrogel bioprinting for cartilage tissue engineering. Int J Mol Sci. 2017 Jul 23;18(7).
[4] Vaibhav Bagaria et al. 3D printing- creating a blueprint for the future of orthopaedics: Current concept review and the road ahead. Journal of Clinical Orthopaedics and Trauma 9, 2018 207e212.
[5] Hitesh Lal et al. 3D printing and its applications in orthopaedic trauma: A technological marvel. Journal of Clinical Orthopaedics and Trauma 9 2018 260e268.
[6] Boonen B, Schotanus MG and Kort NP. Preliminary experience with the patient-specific templating total knee arthroplasty. Acta Orthop; 2012, 83: 387.
[7] Barrack RL, Ruh EL, Williams BM, et al. Patient specific cutting blocks are currently of no proven value. J Bone Joint Surg Br; 2012, 94: 95. 14.
[8] Zou Y, Han Q, Weng X, et al. The precision and reliability evaluation of 3- dimensional printed damaged bone and prosthesis models by stereolithography appearance. Medicine. 2018 Feb;97(6).
[9] Vaish A, Vaish R. 3D printing and its applications in Orthopaedics. J Clin Orthop Trauma. 2018 Mar 1;9:S74eS75.
3D Printing has potential to play significant role in global healthcare sector, especially in orthopedic surgery. Customization of implant bone, tissue, or even joints can be undertaking and therefore improve quality of life for patients after the treatment. However, even though cost of 3D printing has gone down significantly in accordance with the technology improvement, the cost of 3D printing in healthcare is unlikely to follow the trend. Considered as matter of life and death for patients, the printed bones or tissue required close attention from orthopedists and specialists which therefore driven up the cost. It seems an on-going debate with never-ending solution when it comes to tension between advance healthcare technology and cost to patients.
Jordan – thanks for a great read; very informative piece. Out of curiosity, have you come across Gartner’s latest hype cycle for 3D printing (https://www.sculpteo.com/blog/2017/08/01/the-3d-printing-hype-cycle-by-gartner-what-does-the-2017-edition-say/)? It seems like a lot of the medical applications of 3D printing are on the rise in the hype cycle (or at their peak, as for medical devices). Overall, I strongly agree with your assessment that achieving widespread buy-in from doctors / key opinion leaders in orthopedic medicine will be one of the biggest barriers / catalysts to mass adoption. The challenge I see is that there’s a circular / chicken-and-egg type of issue at play here – medical leaders aren’t willing to test this new 3D printing method out until it’s proven, but this method can’t really be proven out on a large scale without more buy-in from more medical leaders. Do you think it’s possible to start by addressing certain less invasive / less critical procedures with 3D printed implants to get more doctors comfortable with the process and results before trying to tackle more intense procedures like hip replacements?
Curious to know what specific surgeries/repairs are prime for this type of technology. Is it simply any sort of implant? Or are specific areas where customization may be particularly useful and/or is a step change in performance and comfort compared to what’s done today.
It always frustrates me when great technologies are slow to reach patients because of implementation barriers. I agree with you that many of the “legitimate” concerns with 3D printing orthopedics have been addressed. The challenge with breakthrough treatments for complex conditions (such as a broken hip) is that nobody wants to bear the risk associated with being the first to adopt the new technology, should something go wrong. In pharmaceutical development the approach is generally to find the easiest, safest path to approval for a drug first, then as doctors and payers become more comfortable with the new drug conduct follow up studies to pursue more difficult diseases. Like Mike, I wonder if the same approach could be used here in applying 3D printing for less complex joints than the hip first.
Great paper. I totally see the potential of 3-d manufacturing in orthopaedics. My question is whether — given the flexibility of additive manufacturing — we can use this technology not just to replace human bones but to augment them. Could we make bouncier feet? Stronger hips? Is this something that we as humans should even be trying to do?
Great paper to learn about the real life-saving applications of 3D printing! My concerns are more on the commercialization of the technology or equipment. Does it require very high technical design knowledge or capability of the physicians? If yes, then the whole process of technology education for physicians might take a very long time?
Dr. Jordan — this article is outstanding and I’m incredibly hopeful about the potential for bio-printing (especially for cartilage) to address limitations currently facing the field – i.e., arthritis. Given that the top-end orthopedic surgeons that I know or have been seen by carry tremendous case loads, I’d be curious to get your thoughts on what you think the uptake would be with respect to using 3-D printed models for pre-surgery planning? Additionally, are the imaging methodologies precise enough for 3-D printing to generate models with sufficient accuracy?
It’s interesting to read own the internal autonomy of patients can vary so much. But does a physical 3D printed replica really provide that much more value during pre-op surgical planning than an MRI image that is also 3D? It’s also interesting to think about the bio-printing of implants and how these can actually be used in surgery. I’d be curious to better understand how these implants are created today, and how a lack of customization is impacting patients. It seems like 3D printing has had trouble gaining a foothold in many industries. Knowing how slow the healthcare industry is in adopting new technologies, does it seem realistic that 3D printing will be adopted at all in the near term? Great post!
Great article! It was interesting that you highlighted the resistance to adoption from physicians (especially respected ones) despite the benefits of this 3D printing application. I’m interested to see if such applications are already included in medical education (both in medical school and continuing education programs)/explore when the best time is for practitioners to be exposed to this technology. Since such applications are still in nascency, I also wonder if risks around lawsuits also act as a barrier to adoption.
Love this–found it to be a very exciting application of 3D printing. In general, I’m curious if doctors feel that having a 3D print versus a 2D image will improve or change what they will do? I’m guessing it would improve, but there are ego barriers to adoption for doctors, especially experienced ones. Do you think there are other risks to this method that we aren’t seeing, or is this the way of the future and it is just a matter of time before almost every doctor is using additive manufacturing?
Thanks for sharing such an interesting read! Its great to know that bio-printing has such a high potential to address limitations facing the field. However, I’d be interested to know about the application of this technology to other areas. To give an example based on my limited understanding, our precision with imaging all body parts is spread across a large spectrum. What are the key improvements that would aid the spread of this to other areas? Additionally, what are your thoughts around the adoption of this by surgeons, given the already stretched bandwidth?
Great read, thank you. I’m just curious about why a doctor should want to use a 3D-printed model rather than continuing to read the image. Does the 3D model really provide that much more information to a well-trained physician than the image? Does the model better tap into the physician’s intuition about how to proceed, resulting in better outcomes? Does not having to know how to translate an image into a diagnosis free up the physician to focus on higher-value-add tasks? Intuitively it seems straightforward that a 3-D model would be easier and faster for a physician to understand, but I’m just trying to figure out what the exact value proposition is over the status quo.
Jordan thanks for sharing a very interesting and important piece! It’s great to see how 3D printing is having an impact on the healthcare industry particular in your case being used for orthopedic surgery practices. With its application, I’m quite curious to know more about the scale and adoption of the technology, what’s the patients point of view, how they perceive the technology? And also, get a better understanding of how this can be applied to other areas in healthcare.