By Kimberly D. Young (Originally published by the DRI in For the Defense, Spring 2020)
3D printing is a process by which a three-dimensional object is generated from a digital model. 3D printing, also known as “additive manufacturing,” has countless applications across fields ranging from aerospace and aviation to food and children’s toys. The various applications and innovations offered by 3D printing show no signs of slowing down, with forecasts of revenue from 3D-printing products and services worldwide estimated at $15.8 billion for 2020, climbing to $23.9 billion for 2022, and to $35.6 billion for 2024. Wohlers Report, 3D Printing and Additive Manufacturing: State of the Industry (2019).
The medical field is perhaps the most exciting example of the real-world effect that 3D printing can have on people’s lives. Considered “the fastest-growing innovation in the medical field,” 3D printing offers the potential for bespoke, patient-specific surgical procedures and tools, pharmaceuticals, and medical devices. Anna Aimar, Augusto Palermo, & Bernardo Innocenti, The Role of 3D Printing in Medical Applications: A State of the Art, J. of Healthcare Eng’r, vol. 2019, art. 5340616. However, as with any rapidly evolving technology, the applications can outpace the state of the law and create uncertainty about potential liability. This article will address some of the applications of 3D printing in the medical field, existing industry guidelines and FDA regulations, and best practices for limiting liability in an evolving landscape.
3D Printing in the Medical Field
The potential uses for 3D printing are as varied as health care itself, but its greatest promise is as a precision medical tool to effectively customize treatments to individual patients. J.E. Adamo, W.L. Grayson, H. Hatcher et al., Regulatory Interfaces Surrounding the Growing Field of Additive Manufacturing of Medical Devices and Biological Products, J. of Clinical Translational Sci, vol. 2, 301–04 (2018). The following are some examples of the use of 3D-printing technology in medicine:
3D printing provides the surgeon with a physical, 3D model of a patient’s anatomy to help most accurately plan the best surgical approach. This level of patient-specific surgical planning can reduce the time spent in the operating room and result in fewer complications, shorter hospital days, and fewer revision surgeries. E. Perica & Z. Sun, Patient-Specific Three-Dimensional Printing for Pre-Surgical Planning in Hepatocellular Carcinoma Treatment, Quantitative Imaging in Medicine and Surgery, vol. 7, no. 6, 668–77 (2017).
Customized Surgical Tools and Medical Devices
“For medical devices,” additive manufacturing “has the advantage of facilitating the creation of anatomically-matched devices and surgical instrumentation (called patient-matched devices) by using the patient’s own medical imaging.” Technical Considerations for Additive Manufactured Medical Devices: Guidance for Industry and Food and Drug Administration Staff, Ctr. for Devices & Radiolog. Health & Ctr. for Biologics Eval. & Res. (Dec. 5, 2017).
3D printing allows physicians to use customized surgical implants as well as patient-specific surgical guides and instruments. Just a few examples of the fields in which 3D-printed tools and implants have been used include cardiothoracic surgery, neurosurgery, oral and maxillofacial surgery, orthopedic surgery, plastic surgery, and transplant surgery. S.N. Kurevov, C. Ionita, D. Sammons, & T.L. Demmy, Three-Dimensional Printing to Facilitate Anatomic Study, Device Development, Simulation, and Planning in Thoracic Surgery, J. Thoracic & Cardiovas. Surg., vol. 149, no. 4, 973–79 (2015); M. Randazzo, J.M. Pisapia, N. Singh, & J.P. Thawani, 3D Printing in Neurosurgery; a Systematic Review, Surgical Neurology Int’l, vol. 7, no 34, 9008-09 (2016); H. Lino, K. Igawa, Y. Kanno et al., Maxillofacial Reconstruction Using CustomMade Artificial Bones Fabricated by Inkjet Printing Technology, J. of Artificial Organ, vol. 12, no. 3, 200–05 (2009); F. Auricchio & S. Marconi, 3d Printing: Clinical Applications in Orthopaedics and Traumatology, EFORT Open Rev., vol. 1, no 5, 121–27 (2016); M.P. Chae, W.M. Rozen, P.G. McMenamin et al., Emerging Applications of Bedside 3D Printing in Plastic Surgery, Frontiers in Surgery, vol. 16, no. 2, 25 (2015); N.N. Zein, I.A. Hanouneh, P.D. Bishop et al., Three-dimensional Print of a Liver for Preoperative Planning in Living Donor Liver Transplantation, Liver Transplantation, vol. 19, no. 12, 1304–10 (2013).
The FDA has granted clearance through the 510(k) process for numerous 3D-printed medical devices, including (but certainly not limited to) hearing aids, dental crowns, bone tether plates, skull plates, hip cups, spinal cages, knee trays, facial implants screws, surgical instruments, and Invisalign braces. James Beck & Matthew Jacobson, 3D Printing: What Could Happen to Products Liability When Users (and Everyone Else in Between) Become Manufacturers, 18 Minn. J.L. Sci. & Tech. 143, 182 (2017).
For each of these devices, the company receives patient-specific information, often through a scan of some kind, and prints the medical device to those specifications. Beck & Jacobsen, supra, at 185. Some 3D-printed medical devices, such as Invisalign braces, are printed at a central facility and then shipped to the prescribing dentist in a traditional distribution system. However, point-of-care manufacturing, in which the device is actually printed at the clinic or hospital, adds a new wrinkle that does not fit neatly within the current product liability system. Id. at 183.
Of all of the potential uses of 3D printing in the medical field, bioprinting offers the most radical and exciting prospects. Bioprinting refers to 3D printing of human tissues by depositing cells layer by layer to grow organs. A sampling of the current uses of bioprinting include printing of synthetic skin for transplanting to patients with burn injuries, replicating heart valves using a combination of cells and biomaterials, and replicating human ears using molds filled with a gel containing bovine cartilage cells suspended in collagen. P. He, J. Zhao, J. Zhang et al., Bioprinting of Skin Constructs for Wound Healing, Burns & Trauma, vol. 6, no. 1 (2018); M. Vukievic, B. Mosadegh, J.K. Little, & S.H. Little, Cardiac 3D Printing and Its Future Directions, JACC: Cardiovascular Imaging, vol. 10, no. 2, 171–84 (2017); G. Zhou, H. Jiang, Z. Yin et al., In Vitro Regeneration of PatientSpecific Ear-Shaped Cartilage and Its First Clinical Application for Auricular Reconstruction, EBioMedicine, vol. 28, 287–302 (2018). In addition, researchers are developing biodegradable scaffolds to guide regeneration of damaged and diseased tissues. Adamo, supra, at 302.
One example is a 3D-printed drug tablet used to treat epilepsy. The printing technology allows it to make porous tablets that rapidly disintegrate when taken with water, helping those patients who have trouble taking pills. Beck & Jacobsen, supra, at 186.
Compared with looking at a CT or MRI scan, or having it verbally explained to them by their treating physician, patients can see and touch a 3D model of their own anatomy. This improvement in patient understanding and informed consent would benefit physicians and patients alike.
3D printing offers medical students the opportunity to learn on models with a wider variety of physiologic and pathologic anatomy compared with cadaver dissection. 3D-printed models can use different colors to accentuate anatomical details during the learning process. Surgical trainees can increase their knowledge and confidence in areas of expertise with patient-specific models.
Similar to educating patients, it can be difficult to explain complex medical procedures to a jury. Particularly when a case deals with anatomical abnormalities, a 3D model of a plaintiff’s specific anatomy can go a long way in helping jurors conceptualize key issues in medical malpractice and product liability cases.
Industry Standards and Guidelines
The American Society of the International Association for Testing and Materials (ASTM) implemented its Committee F42 on Additive Manufacturing Technologies in 2009. The ASTM “Committee F42” has adopted standards that focus on several different categories, including general standards (terminology, test methods, safety); process and equipment standards; and application-specific standards (including medical uses). The standards for 3D printing are built off of existing standards to the extent possible and modified for 3D printing when necessary. See Comm. F42, ASTM, http://www.astm.org/Committee/ F42.htm.
The International Organization for Standardization (ISO) also has a committee devoted to 3D printing, the Technical Committee 261 Additive Manufacturing (ISO/TC 261). The United States is one of 22 countries participating in this initiative, which has partnered with ASTM in an effort to develop one set of worldwide standards for 3D printing. See ISO/TC 26, ISO, http://www.iso.org.
In December 2017, the FDA issued a guidance for 3D printing of medical devices. Technical Considerations for Additive Manufactured Medical Devices: Guidance for Industry and Food and Drug Administration Staff, Food and Drug Admin., Editor (Dec. 5, 2017). The purpose of the guidance “is to outline technical considerations associated with AM processes, and recommendations for testing and characterization for devices that include at least one additively manufactured component or additively fabricated step.” Id. at 1. Clearly stating that it contains only guidance and nonbinding recommendations, the document is organized into two topics: (1) design and manufacturing considerations; and (2) device-testing considerations. Id.
The section addressing device-testing considerations includes descriptions of the type of information that should be provided in premarket notification submissions (510(k)) for an additive-manufactured device. However, it is specifically noted that “point-of-care device manufacturing may raise additional technical considerations not addressed in this document,” reflecting the complexities that this non-traditional form of manufacturing introduces to the process. Id. at 2. The author describes the document as “a leapfrog guidance, a type of guidance that serves as a mechanism by which the Agency can share initial thoughts regarding emerging technologies that are likely to be of public health importance early in product development.” Similarly, the guidance “represents the Agency’s initial thinking and [its] recommendations may change as more information becomes available.” Id. While recognizing several advantages to addictive manufacturing, the FDA has identified challenges as well, including the unique aspects of the additive-manufacturing process and the relative lack of experience and clinical history with respect to devices manufactured using additive-manufacturing techniques. Id.
In summary, there is an inherent tension in simultaneously protecting and advancing public health. Adamo, supra, at 302. Protecting public health requires enforcement of consistent regulations, while advancing public health necessitates the development of new regulatory strategies to accommodate the rapidly changing technological landscape. Id.
As the regulatory framework attempts to keep pace with the scientific advancements in 3D printing, the safest route appears to be the 510(k) pathway, because it appears that all 3D-printed medical devices on the market followed the requirements of the Federal Food, Drug and Cosmetic Act’s Section 510(k). Under the 510(k) pathway, applicants must demonstrate that their device is at least as safe and effective as, that is, “substantially equivalent to, a legally marketed or predicate device. If the FDA agrees, the product is cleared for commercial use. Manufacturers will likely continue to favor the 510(k) pathway, at least until the FDA issues similar guidance for the premarket approval (PMA) application process specific to 3D-printed devices.
One of the biggest unknowns related to the growing use of 3D-printing technology is its effect on tort liability, particularly strict product liability. While nuances can vary from state to state, section 402A of the Restatement (Second) of Torts generally represents the modern standard in products liability law. A seller is liable for physical harm caused by a product if it is sold in a defective condition unreasonably dangerous to the user or consumer. The liability is strict because sellers are subject to liability regardless of whether they were negligent. The liability is limited to those engaged in the business of selling the product, and the product must reach the consumer without substantial change in the condition in which it is sold. States typically recognize three types of product defects: defective design, defective manufacture, and defective warnings.
Even from this brief overview of strict liability law, it is apparent that 3D-printed products raise questions about the applicability of the traditional model of strict liability. This is especially true as more hospitals and physicians become comfortable with 3D-printing technology and point-of-care manufacturing becomes more routine. The legal implications include what exactly is a “product,” who is the “manufacturer,” what is the “marketplace,” and who should be liable for a defective 3D-printed product? These questions could be especially difficult for courts to answer for complex products such as pharmaceuticals and medical devices. While a 3D-printed device would almost certainly be considered a “product,” it is less certain that a doctor or hospital which printed the product would constitute a “seller” of the customized device, sufficiently “engaged in the business of selling” such a product. Similarly, is the computer-aided design (CAD) blueprint a sufficiently tangible “product” to implicate the CAD designer under strict liability?
In addition, the introduction of more components and participants into the process of manufacturing a 3D-printed products makes proving causation more difficult. Possible causes of an ultimately defective product include (1) a defect in the original product used to create the digital design; (2) a defect design in the CAD file; (3) a defect introduced into the CAD file when uploaded to a file sharer or downloaded from a file sharer; (4) a defect in the 3D printer itself; (5) a defect in the bulk or raw material used in the 3D printer to create the product; (6) human error in implementing the digital design; and (7) human error in using the 3D printer or raw materials, or both. Beck & Jacobsen, supra, at 162. Currently, there is an open issue pertaining to whether computer-aided design (CAD) files or other software used in the creation of 3D-printed medical devices will be considered “products.” As an analogy, courts have yet to extend product liability theories to bad software, computer viruses, or web sites with inadequate security or defective design. James Henderson, Tort v. Technology: Accommodating Disruptive Innovation, 47 Ariz. St. L.J. 1145, 1165–66 n. 135 (2015). Purely electronic data, such as code, does not constitute a “product” under the Restatement (Third) of Torts, which defines a product as “tangible personal property distributed commercially for use or consumption.” However, at least one case, Corley v. Stryker Corp., may indicate a shift in the law. No. 6:13- CV-02571, 2014 WL 3375596 (W.D. La. May 27, 2014). In Corley, the product was a customized, but non-3D-printed, Class II medical device that also featured electronic files and patient-matched imaging data. The device was a single-use, cutting guide, designed and manufactured from patient-imaging data. The cutting guide was created by a software program from a three-dimensional model of the patient’s anatomy. The court allowed a design-defect product liability claim to survive a motion to dismiss, finding that the software used in creating each cutting guide was a necessary part of the cutting guide. Therefore, the allegation that the software was defective was sufficient to state a strict liability claim. If CAD files used to produce 3D-printed products are considered products, then the companies involved in creating the design files or software may be subject to strict liability type claims. Even if they are not considered products, the FDA could conceivably treat them as “labeling,” in which case the FDA could require CAD files to include the same warnings and other information that must accompany the physical device.
A seller is liable for physical harm caused by a product if it is sold in a defective condition unreasonably dangerous to the user or consumer. The liability is strict because sellers are subject to liability regardless of whether they were negligent.
As for doctors and hospitals participating in point-of-care manufacturing of 3D-printed medical devices, the majority of courts have traditionally viewed doctors and hospitals as services providers, not sellers of products. See e.g., San Diego Hosp. Ass’n. v. Superior Court, 35 Cal. Rptr. 2d 489, 493 (Ca. Ct. App. 1994) (“The fact the hospital provides equipment for the physician’s use is incidental to the overriding purpose of providing medical services.”); Gile v. Kennewick Pub. Hosp. Dist., 296 P.2d 662, 666 (Wash. 1956) (“[T]he contractual relationship between a hospital and a patient is not one of sale but is one of service; that during treatment in the hospital [medical products] for which additional charges are made, may be transferred from the hospital to the patient; and yet the transfer is an incidental feature of the transaction and not a sale.”). However, the distinction between manufacturing and professional services will likely come under pressure as hospitals and doctors’ offices incorporate more on-site 3D-printing centers. Point-of-care manufacturing also could lead to the FDA considering hospitals or physicians “manufacturers,” subjecting these care providers to the inspection, quality control measures, and record-keeping requirements faced by traditional medical device manufacturers. The lines related to who is required to provide warnings regarding 3D-printed medical devices may also become blurry.
To the extent that doctors and hospitals are operating on-site 3D printers and concerned with liability beyond professional negligence, they should consider indemnification agreements or other contractual provisions with those in the supply chain. Medical providers may also consider creating separately incorporated entities to own and operate the 3D printing of the devices, as is often done with discrete medical functions such as anesthesiology. Beck & Jacobsen, supra, at 201.
The tort liability implications of 3D-printed products are still unknown. However, as 3D-printed medical devices become more mainstream, courts will likely be faced with these product liability issues, which will help create a body of law and more predictability going forward. In the meantime, manufacturers of drugs and medical devices developing and selling 3D-printed products can continue to adhere to established and emerging manufacturing and safety standards as well as those guidelines that have been published by the FDA so far. While compliance with such standards is unfortunately not a complete defense in product liability litigation, it at least denies a plaintiff’s attorney the powerful ammunition of non-compliance. In addition, doctors and hospitals taking advantage of the increasing benefits of 3D printing will benefit from discussing with their counsel potential shields to liability, including indemnification agreements.
Kimberly D. Young has been practicing law with Friday, Eldredge & Clark since 2003 and she concentrates her practice in the field of civil litigation, including products liability, intellectual property and premises liability. She has over a decade of experience representing electric and natural gas utilities in Arkansas, including the successful defense of catastrophic injury and wrongful death claims. While she has represented a diverse set of clients in personal injury litigation, most recently her focus has been in the area of products liability, including the defense of pharmaceutical and medical device manufacturers in multi-district litigation.
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