AAOS Webinar Surveys the State of Augmented Reality
In an AAOS webinar titled “The Current State of Augmented Reality (AR) in Orthopaedics,” clinicians and representatives from the FDA and from the industry offered information and insights on the use of AR and their perspectives on the benefits and risks of the technology.
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Following an introduction from program director David Jevsevar, MD, MBA, FAAOS, chair of the AAOS Committee on Devices, Biologics, and Technology, Christopher Harner, MD, FAAOS, FAOA, an FDA clinical deputy director in the Office of Orthopedic Devices, said the October webinar—offered free to AAOS members—was intended to “increase awareness of AR technology in orthopaedic stereotaxic—sometimes referred to as 'stereotactic'—navigation systems,” which make use of a three-dimensional coordinate system to locate small targets inside the body and to perform on them some action such as ablation, biopsy, lesion, injection, stimulation, implantation, or radiosurgery. Among the topics to be covered were the clinical and technological challenges associated with orthopaedic AR applications, the scope of possible adverse events and reporting limitations, and the process for implementing adverse-event reporting by surgeons in a timely and accurate way.
The basics
Dr. Harner clarified the distinctions between virtual reality (VR)—“a completely artificial environment accepted as real by users”—and AR, which is “an integrated technique of image processing.” In an AR system, he explained, “Real objects and virtual (computer-generated) objects are combined in a real environment.” Furthermore, in AR, “Real and virtual objects are aligned with each other and run interactively in real-time.”
Currently, VR is not used in surgical practice, Dr. Harner noted; its main orthopaedic use is in training and education for residents, fellows, practicing surgeons, and other allied health professionals.
AR is in active use for surgical procedures (Table 1), he explained, with some 10 AR device submissions having been cleared by the FDA in the past four years. The literature now includes numerous publications on AR, although most studies are smaller clinical trials (<50 patients), and most were conducted outside the United States. Collected data are on device usage, techniques, and accuracy, but not patient-recorded outcomes, and therefore “are not truly clinical studies,” Dr. Harner said. To this point, reported complications are rare, and the most common documented consequence is increased surgical time.
Describing the technological setup for AR (Fig. 1), Dr. Harner said that obtaining an image to be projected in the OR for the end user, the surgeon, requires multiple steps. Failure at any step of the process—from radiographic imaging to visualization, whether due to hardware, software, OR inadequacies, or failure of the user—can adversely affect patient outcomes.
He noted that the Office of Orthopedic Devices has seen a marked increase in the number of stereotaxic “system” submissions over the past five years.
The challenges
Following Dr. Harner was another FDA representative, CDR Michel Janda, MS, of the agency’s Stereotaxic, Bone Growth Stimulators, and Fracture Fixation Devices Team in the Office of Orthopedic Devices. Mr. Janda addressed the “Regulatory Paradigm and Challenges.”
He explained that the product code “OLO” was established to cover stereotaxic guidance during orthopaedic surgery procedures for joints and spine; this code is the current regulatory basis for which limited applications of AR technology are introduced, including robotics and AR systems. Stereotaxic navigation systems, he noted, may use various technologies, including physical, optical, or inertial patient and instrument tracking. From these technologies arrived robotically assisted surgical systems, including robotic arms that connect passively or actively to directly affect the patient.
The FDA, Mr. Janda said, has identified technical and clinical challenges attendant to AR. Among these are technical characteristics, including:
non-rigid patient tracking
lack of continuous patient tracking
completely immersive VR
excessive obstruction of the user’s field of view
soft-tissue navigation/robotics
AR technology expands on these systems, with the simplest iteration using a head-mounted display to replicate the same information as traditionally shown to the user via a TV monitor. Some technical characteristics are considered outside of the governing regulation—including luminance, contrast, temporal and spatial resolution, the field of view, dynamic range, refresh rate, latency, transmission, and optical aberrations such as distortion—as well as acceptance criteria for technical characterization parameters. The limited number of current AR systems and the limited literature on the technology contribute to the challenge. Gauging the accuracy of the displayed information (i.e., the heads-up display) is another aspect of the evaluation process, with the FDA requesting the same validation as it would for a stereotaxic system.
For a system intended to provide an anchored 3D model corresponding to the patient’s anatomy, developers are asked to provide additional quantitative validation of the model’s spatial accuracy.
“Developing this validation protocol for anchored 3D models is challenging, as these virtual models are intended to be observed and interpreted from a user’s perspective,” Mr. Janda said. “Therefore, objective validation requires observation from an independent exterior method that has the same perspective as the user.”
Emerging technical challenges and considerations that the FDA is observing, Mr. Janda said, include user interaction issues with control mechanisms, such as the technician using a mouse on a separate station, foot pedals, hand gestures, vocal commands, and head movements (dwell pointer). “For example, systems that use a commercial off-the-shelf head-mounted display with hand gestures as a control interface may experience difficulties when used in a medical environment,” he said. “This [difficulty] may be due to the required learning curve and also to use of the interface in this environment” versus a commercial setting.
The FDA is also interested in learning about possible negative effects on a user (patient or surgeon), including eye and neck strain, surgery time, and potentially compromised sterility and biocompatibility.
In general, Mr. Janda noted, novel technologies are associated with a training and learning curve, and the FDA expects challenges to arise in this regard.
In the category of higher-level testing, for stereotaxic systems, the FDA reviews quantitative system-level validation testing which compares the accuracy of a planned implant placement and the final implant placement as executed by the system in a cadaver model; this requirement is also applied to AR systems. Additionally, the agency evaluates human factors and usability testing, including adjunctive use versus integral use of the system, as well as “the ability to discontinue use in a convenient way,” Mr. Janda said.
A new FDA request for approval of an AR system, he said, must be accompanied by a submission of a video or step-by-step illustration of the projected imagery to demonstrate what is intended to be seen by the user. Clinical data, or a redefinition of clinically meaningful endpoints, “has not been found to be routinely necessary as of yet but maybe warranted upon future applications of the technology.”
Finally, Mr. Janda summarized the FDA’s protocol and processes for reporting adverse events. The FDA uses post-market surveillance to monitor device performance. Mandatory reporters (i.e., manufacturers, device user facilities, and importers) are required to submit to the FDA certain types of reports for adverse events and product problems that may cause or contribute to adverse events.
“The FDA also encourages healthcare professionals, patients, caregivers, and consumers to submit voluntary reports about serious adverse events that may be associated with a medical device, as well as use errors, product quality issues, and therapeutic failures,” he said. “With regard to AR technology, the agency is interested in using medical device reporting to assess real-world performance.” The FDA looks to monitor medical device reporting directly associated with AR systems, such as that detailing patient reference movement, loss of virtual image registration, and implant malalignment.
The agency is also concerned that adverse effects may be underreported; these may include user fatigue or distraction, surgical delay, and cognitive overload. These occurrences “may not be reported to us because they may not be obviously associated with an adverse effect,” Mr. Janda said. “We encourage those attending this webinar to use the FDA’s online voluntary reporting program to report real-world experience with this technology.”
The other speakers at the webinar were Francesco Siccardi, MS; Barton Sachs, MD, MBA, FAAOS; and Laurence Coyne, PhD. The webinar is accessible to AAOS members at learn.aaos.org.
Why it’s finally time to eliminate all certificate of need laws in Tennessee
By repealing Tennessee’s remaining certificate of need (CON) laws, the state legislature can prevent unelected bureaucrats from further constricting healthcare access and distorting the free market
Jeffrey Mazzella, Guest Columnist
During the 2022 legislative session, Tennessee lawmakers expanded their record of strengthening individual freedoms and fostering a strong economic environment that promotes job creation and growth.
Among numerous accomplishments, Gov. Bill Lee and the legislature passed education reforms putting students first, struck down tax hikes that would have harmed Tennessee businesses, and approved the constitutional ballot initiative protecting workers’ freedom to decide for themselves whether or not to join unions – a right now cemented in our state’s constitution.
This year, as lawmakers seek to build upon last session’s progress, they should begin by fully repealing the remaining “Certificate of Need” (CON) laws that limit healthcare expansion for patients across the state.
CON laws failed to achieve their goals
For readers unfamiliar with CON laws, they require hospitals and other medical providers to obtain special government permission – a costly, difficult and lengthy bureaucratic approval process – by demonstrating a “need” for their services in geographic areas where they propose to build new facilities or offer new care.
States began enacting CON laws in the 1970s, under a heavy-handed mandate by the federal government, with the noble goal of controlling costs and maximizing access to care. That experiment, however, failed. Instead of controlling costs, subjecting the healthcare sector to onerous red tape slowed or prevented private companies from building new facilities or expanding healthcare services to communities in need.
As noted by Mercatus Center Scholars Matthew Mitchell and Christopher Koopman, “Forty years of peer-reviewed academic research...suggests that CON laws have not only failed to achieve their goals but have in many cases led to the opposite of what those who enacted the laws intended.”
Even the federal government recognized the failure of CON laws and repealed its mandate in 1986. Twelve states have subsequently repealed their CON laws completely or allowed them to expire because of the harmful effects.
Here’s how the system is bad for consumers
Here in Tennessee, Governor Bill Lee and the state legislature deserve credit for partially reforming the state’s CON laws during the COVID-19 public health emergency, after recognizing the laws were exacerbating an already dangerous situation.
Hospital systems across the state, especially in major metropolitan areas, operated at or above capacity during the height of the pandemic. The reforms were a way to help expand access and alleviate that pressure on the system.
While those 2021 reforms constitute progress, much work remains. Tennessee still has 26 CON regulations that continue to limit access to care across the Volunteer State.
Tennessee’s remaining CON requirements are governed by 12 government bureaucrats – unelected and unaccountable to everyday Tennesseans – who act as gatekeepers for private companies working to expand healthcare access in the state.
Making matters worse, the process is susceptible to deep-pocketed, insider lobbying whereby entrenched interests like existing hospitals opposed to new competition can block new entrants from receiving CON approval in their geographic region.
Any system that vulnerable to insider influence is bad for consumers and should alarm all Tennesseans. As one CON law critic recently put it, “Imagine if Wendy’s had to get permission from a committee stacked with McDonald’s and Burger King CEOs in order to open up a new franchise.”
Make Tennessee a leader in patient choice and health care access
On a national level, moreover, COVID-19 lockdowns illustrated the harm that unaccountable health officials can cause. Unelected, all-powerful bureaucrats inflicted irreparable damage upon state economies, individual freedoms and school children.
Fully repealing Tennessee’s remaining CON laws will empower patients over government bureaucrats and help the state’s healthcare system be better prepared to handle future public health emergencies.
As someone who relocated to this great state in recent years, I know firsthand how rapidly Tennessee is growing. In future years, that growth will only continue. Over the next decade, Tennessee is expected to grow by approximately 10%, reaching a population of 7.5 million. Accordingly, repealing CON laws is critical to ensuring Tennessee can meet the significant healthcare needs of its growing population – especially in locales where access is already limited.
The 113th General Assembly thus possesses an opportunity to make Tennessee a national leader in patient choice and healthcare access. By fully repealing Tennessee’s remaining CON laws during the 2023 legislative session, the state legislature can prevent unelected bureaucrats from further constricting healthcare access and distorting the free market.
Tennesseans don’t want or need unelected, unaccountable government bureaucrats meddling with their access to care. It’s time to put this issue to rest and fully repeal the state’s CON requirements once and for all.