Document

Physical Medicine Devices; Reclassification of Non-Invasive Bone Growth Stimulators

The Food and Drug Administration (FDA) is issuing a final order to reclassify non-invasive bone growth stimulators (product codes LOF and LPQ), postamendments class III devices,...

[Federal Register Volume 91, Number 73 (Thursday, April 16, 2026)]
[Rules and Regulations]
[Pages 20352-20362]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2026-07366]


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DEPARTMENT OF HEALTH AND HUMAN SERVICES

Food and Drug Administration

21 CFR Part 890

[Docket No. FDA-2020-N-1053]


Physical Medicine Devices; Reclassification of Non-Invasive Bone 
Growth Stimulators

AGENCY: Food and Drug Administration, HHS.

ACTION: Final amendment; final order.

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SUMMARY: The Food and Drug Administration (FDA) is issuing a final 
order to reclassify non-invasive bone growth stimulators (product codes 
LOF and LPQ), postamendments class III devices, into class II, subject 
to premarket notification. FDA is codifying the reclassification of 
these devices under the new classification regulation, ``non-invasive 
bone growth stimulator.'' FDA is also establishing the special controls 
necessary to provide reasonable assurance of safety and effectiveness 
of these devices.

DATES: This order is effective May 18, 2026.

ADDRESSES: For access to the docket to read background documents or 
comments received, go to https://www.regulations.gov and insert the 
docket number found in brackets in the heading of this final rule into 
the ``Search'' box and follow the prompts, and/or go to the Dockets 
Management Staff, 5630 Fishers Lane, Rm. 1061, Rockville, MD 20852, 
240-402-7500.

FOR FURTHER INFORMATION CONTACT: John Gomes, Center for Devices and 
Radiological Health, Food and Drug Administration, 10903 New Hampshire 
Ave., Bldg. 66, Rm. 4564, Silver Spring, MD 20993, 301-796-5618, 
John.Gomes@fda.hhs.gov.

SUPPLEMENTARY INFORMATION:

I. Background

    The Federal Food, Drug, and Cosmetic Act (FD&C Act), as amended, 
establishes a comprehensive system for the regulation of medical 
devices intended for human use. Section 513 of the FD&C Act (21 U.S.C. 
360c) established three classes of devices, reflecting the regulatory 
controls needed to provide reasonable assurance of their safety and 
effectiveness. The three classes of devices are class I (general 
controls), class II (special controls), and class III (premarket 
approval).
    Devices that were not introduced or delivered for introduction into 
interstate commerce for commercial distribution prior to May 28, 1976 
(generally referred to as postamendments devices) are automatically 
classified by section 513(f)(1) of the FD&C Act into class III without 
any FDA rulemaking process. Those devices remain in class III and 
require premarket approval, unless and until (1) the Food and Drug 
Administration (FDA, the Agency, or we) reclassifies the device into 
class I or II; or (2) FDA issues an order finding the device to be 
substantially equivalent, in accordance with section 513(i) of the FD&C 
Act, to a predicate device that does not require premarket approval. 
FDA determines whether new devices are substantially equivalent to 
predicate devices using the procedures in section 510(k) of the FD&C 
Act (21 U.S.C. 360(k)) and our implementing regulations (21 CFR part 
807, subpart E).
    A postamendments device that has been initially classified into 
class III under section 513(f)(1) of the FD&C Act may be reclassified 
into class I or II under section 513(f)(3) of the FD&C Act, which 
provides that FDA, acting by administrative order, can reclassify the 
device into class I or II on its own initiative, or in response to a 
petition from the manufacturer or importer of the device. To change the 
classification of the device, the new class must have sufficient 
regulatory controls to provide reasonable assurance of safety and 
effectiveness of the device for its intended use.
    FDA relies upon ``valid scientific evidence,'' as defined in 
section 513(a)(3) of the FD&C Act and 21 CFR 860.7(c)(2), in the 
classification process to determine the level of regulation for 
devices. In general, to be considered in the reclassification process, 
the ``valid scientific evidence'' upon which the Agency relies must be 
publicly available and excludes trade secret and/or confidential 
commercial information, such as the contents of a pending premarket 
approval application (PMA) (see section 520(c) of the FD&C Act (21 
U.S.C. 360j(c)). Section 520(h)(4) of the FD&C Act (the ``six-year 
rule'') provides that FDA may use, for reclassification of a device, 
certain information in a PMA 6 years after the application has been 
approved. This includes information from clinical and preclinical tests 
or studies that demonstrate the safety and effectiveness of the device, 
but it does not include descriptions of methods of manufacture and 
product composition and other trade secrets.
    Section 510(m) of the FD&C Act provides that FDA may exempt a class 
II device from the requirements under section 510(k) of the FD&C Act if 
FDA determines that a premarket notification (510(k)) is not necessary 
to provide reasonable assurance of the safety and effectiveness of the 
device.
    On August 17, 2020, FDA published in the Federal Register a 
proposed order \1\ to reclassify non-invasive bone growth stimulators 
intended to promote osteogenesis as an adjunct to primary treatments 
for fracture fixation and spinal fusion or as a treatment for 
established nonunions or failed fusions \2\ (product codes LOF and LPQ) 
3 4 from class III into class II,

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subject to premarket notification (85 FR 49986 (August 17, 2020), the 
``proposed order''). FDA has considered the information available to 
the Agency, including certain information in PMAs in accordance with 
the six-year rule,\5\ peer-reviewed literature, the deliberations of 
the Orthopaedic and Rehabilitation Devices Panel of the Medical Devices 
Advisory Committee convened on September 8-9, 2020 (the ``Panel'') to 
discuss non-invasive bone growth stimulators and the proposed 
reclassification (as discussed in section II of this final order), as 
well as comments from the public docket on the proposed order (as 
discussed in section III of this final order), to determine whether 
there is sufficient information to establish special controls to 
effectively mitigate the risks to health (updated, as discussed in 
section IV of this final order). FDA has also determined based on this 
information that the special controls, together with general controls, 
provide a reasonable assurance of safety and effectiveness when applied 
to these devices.
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    \1\ FDA notes that the ``ACTION'' caption for the proposed order 
was styled as ``Proposed amendment; proposed order; request for 
comments,'' rather than ``Proposed order.'' Beginning in December 
2019, this editorial change was made to indicate that the document 
``amends'' the Code of Federal Regulations. The change was made in 
accordance with the Office of Federal Register's (OFR) 
interpretations of the Federal Register Act (44 U.S.C. chapter 15), 
its implementing regulations (1 CFR 5.9 and parts 21 and 22), and 
the Document Drafting Handbook.
    \2\ The intended use language adopted in this final order adds 
``or as a treatment for established nonunions or failed fusions'' to 
the original intended use language presented in section III of the 
proposed order (85 FR 49986 at 49989).
    \3\ FDA's Center for Devices and Radiological Health (CDRH) uses 
product codes to help categorize and ensure consistent regulation of 
medical devices. A product code consists of three characters that 
are assigned at the time a product code is generated and is unique 
to a product type. The three characters carry no other significance 
and are not an abbreviation.
    \4\ Invasive bone growth stimulators, designated under product 
code LOE, are outside the scope of this reclassification final 
order.
    \5\ In support of this reclassification, FDA, on its own 
initiative, relied on certain data from relevant original PMAs and 
relevant PMA panel-track supplements, available to FDA with product 
code of LOF, in accordance with the six-year rule (see section 
520(h)(4) of the FD&C Act (21 U.S.C. 360j(h)(4))) (See also, https://www.fda.gov/regulatory-information/search-fda-guidance-documents/guidance-section-216-food-and-drug-administration-modernization-act-1997-guidance-industry-and-fda). This includes data from relevant 
original PMAs and relevant PMA panel-track supplements approved 
after November 28, 1990, and before Jan 1, 2020, as noted in section 
VII of the proposed order (85 FR 49986 at 49990). FDA's PMA database 
can be found at https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpma/pma.cfm. For the purpose of this final order, PMA data 
considered in accordance with section 520(h)(4) include only that 
data which was submitted to and therefore considered by FDA at the 
time the PMA was reviewed and approval was issued.
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    Therefore, in accordance with section 513(f)(3) of the FD&C Act, 
FDA, on its own initiative, is issuing this final order \6\ to 
reclassify non-invasive bone growth stimulators intended to promote 
osteogenesis as an adjunct to primary treatments for fracture fixation 
and spinal fusion or as a treatment for established nonunions or failed 
fusions from class III to class II (special controls). Absent the 
special controls identified in this final order, general controls 
applicable to the device type are insufficient to effectively mitigate 
the risks identified for this device type, and therefore insufficient 
to provide reasonable assurance of the safety and effectiveness of 
these devices.
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    \6\ FDA notes that the ``ACTION'' caption for this final order 
is styled as ``Final amendment; final order,'' rather than ``Final 
order.'' (See footnote 1 for explanation of editorial change.)
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    For these class II devices, instead of a PMA, manufacturers may 
submit a premarket notification and obtain FDA clearance of the devices 
before marketing them. This action will decrease regulatory burden on 
industry, as manufacturers will no longer have to submit a PMA for 
these types of devices but can instead submit a 510(k) to the Agency 
for clearance prior to marketing their device. A 510(k) typically 
results in a shorter premarket review timeline compared to a PMA, which 
ultimately provides patients with more timely access to these types of 
devices. FDA expects that the reclassification of these devices would 
enable more manufacturers to develop these types of devices such that 
patients will benefit from increased access to non-invasive bone growth 
stimulators for which there is a reasonable assurance of safety and 
effectiveness.

II. Deliberations of the Panel Meeting

A. Summary of Panel Discussion

    On September 8, 2020, the Panel met to discuss and make 
recommendations regarding the proposed reclassification of non-invasive 
bone growth stimulators from class III into class II (Ref. 1). At the 
Panel meeting, FDA presented the regulatory history,\7\ risks to 
health, mitigations, and special controls described in the proposed 
order (85 FR 49986).
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    \7\ The regulatory history of these devices includes significant 
action around a 2005 petition for reclassification that was referred 
to the Orthopaedic and Rehabilitation Devices Panel of the Medical 
Devices Advisory Committee. In 2006, that panel met to consider the 
petition and its recommendations were published in the Federal 
Register on January 17, 2007 (72 FR 1951). The petitioner 
subsequently withdrew their petition and the action was closed. In 
2015, FDA identified non-invasive bone growth stimulators as a 
potential candidate for reclassification (80 FR 23798) and 
subsequently proposed to reclassify these devices by administrative 
order on its own initiative, taking into account the regulatory 
history of the device type (85 FR 49986).
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    The Panel generally agreed with the risks to health identified by 
FDA and provided recommendations to better qualify and define some of 
the risks to health, as discussed in section II.B of this final order.
    The Panel unanimously agreed that general controls alone are not 
sufficient to provide a reasonable assurance of safety and 
effectiveness for non-invasive bone growth stimulators. The Panel also 
unanimously agreed that non-invasive bone growth stimulators are not 
life-supporting or life-sustaining. The Panel generally agreed with FDA 
that these devices are not of substantial importance in preventing 
impairment of human health, though one Panel member disagreed on the 
grounds that if the device failed to work as intended to treat an 
established nonunion, that failure may have significant health impacts 
rising to the level of substantial importance in preventing impairment 
of human health. The Panel unanimously agreed that non-invasive bone 
growth stimulators do not present a potential unreasonable risk of 
illness or injury.
    The Panel unanimously agreed that sufficient information exists to 
develop special controls for these devices. The Panel deliberated on 
whether the special controls proposed by FDA appropriately mitigate the 
identified risks to health for this device type, and whether additional 
or different special controls should be considered. The Panel generally 
agreed with FDA's proposed special controls and recommended additional 
special controls. The Panel recommended that the special controls 
include specific requirements to ensure a rigorous clinical data set 
and postmarket surveillance as a means of assessing longer-term 
performance. The Panel also recommended that the special controls 
include measures beyond labeling to address risks related to 
interference with other electronic devices.
    In conclusion, while the Panel recommended revisions to the risks 
to health and additional special controls (as discussed in section II.B 
of this final order), it generally agreed that non-invasive bone growth 
stimulators met each of the criteria that would support FDA's proposed 
reclassification of these devices from class III into class II, subject 
to premarket notification and special controls to mitigate the 
identified risks to health for these devices.

B. FDA Responses to Panel Deliberations and Changes in the Final Order

    FDA considered the Panel's comments and recommendations and, as 
described below, either modified the final order in response to Panel 
feedback or explained why we disagreed with the Panel.
1. Risks to Health
    The Panel recommended that FDA clarify the risk of adverse 
interactions with other devices and include additional mitigation 
measures for these risks beyond labeling. Accordingly, FDA

[[Page 20354]]

reevaluated the risks to health and mitigation measures for adverse 
interaction with internal/external fixation devices and electromagnetic 
interference (EMI). FDA made minor revisions in section IV of this 
final order to clarify in the identified risks that tissue damage is a 
result of heating of the fixation device which, in turn, leads to 
heating (damage) of the tissue. FDA also reconsidered mitigations for 
this risk to health and concluded that thermal safety is an important 
consideration, as signal outputs could induce currents in metal 
implants (for modalities that employ electromagnetic fields) or could 
cause deep tissue heating (for ultrasound-based devices). We therefore 
revised the mitigation measures for this risk in section IV of this 
final order to include non-clinical performance testing, which would 
include an evaluation of thermal safety and thermal reliability. FDA 
also revised relevant parts of the non-clinical performance testing 
special control at 21 CFR 890.5870(b)(2) to clarify that thermal safety 
and thermal reliability must be verified and validated. This could be 
demonstrated through non-clinical performance testing, for example, 
using applicable consensus standards (e.g., IEC 60601 series of 
standards for the basic safety and essential performance of medical 
electrical equipment), or other validated methods.
    In addition, we revised the EMI risk in section IV of this final 
order to clarify that patient harms could result from interference 
between non-invasive bone growth stimulators and electrically powered 
implanted devices (i.e., non-invasive bone growth stimulators may 
interfere with implanted devices and vice versa), and also due to 
interference from electronically powered devices in the environment 
(such as radio-frequency emitting household electrical equipment). 
While implanted electrical devices (e.g., pacemakers or nerve 
stimulators) may have been designed to have immunity to certain 
electromagnetic fields, there is potential for the electromagnetic 
fields of non-invasive bone growth stimulators to interfere with 
implanted devices, or for the electromagnetic fields of implanted 
devices to cause electromagnetic interference with non-invasive bone 
growth stimulators. Furthermore, internal/external fixation devices in 
the proximity of non-invasive bone growth stimulators may similarly 
interfere with the treatment signal or lead to heating of the fixation 
device, which could lead to heating and damage of the surrounding 
tissue. We believe the mitigation measures (electromagnetic 
compatibility (EMC) testing and labeling) address these risks, and that 
no further revisions to the mitigation measures for the EMI risk are 
necessary. As a potential method of EMC testing to mitigate EMI risks, 
FDA suggests using FDA-recognized consensus standards \8\ for medical 
electrical equipment safety and electromagnetic compatibility, 
including IEC 60601-1-2 Medical electrical equipment--Part 1-2: General 
requirements for basic safety and essential performance--Collateral 
Standard: Electromagnetic disturbances--Requirements and tests (Ref. 
2). Additional collateral standards within the IEC 60601 series of 
standards may also apply, depending on the technology used in the 
device. Additionally, the labeling special control requires appropriate 
warnings for patients with implantable devices. Consistent with 
aforementioned consensus standards, such warnings in the labeling 
should specify appropriate separation distances, when applicable.
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    \8\ FDA recognizes certain voluntary consensus standards for 
medical devices, which are identified in a database available at 
https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfStandards/search.cfm.
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    The Panel recommended that the risk of adverse biological effects 
either be better defined or otherwise removed from the list of risks to 
health associated with non-invasive bone growth stimulators. FDA 
maintains that this risk should be included, given that signals with 
select characteristics could induce adverse biologic effects outside of 
thermal risks. We have revised the description of this risk to health 
in section IV of this final order to address the Panel's recommendation 
and list the signal characteristics that may lead to adverse biologic 
effects.
    During the Panel's discussion of the risks to health, the Panel 
Chair summarized an additional concern as ``if the signal 
characteristics themselves need to be defined in a way that 
characterized safety and efficacy in a way that was independent from 
the field characteristics'' (Ref. 3 at lines 3135-37). FDA does not 
believe any changes beyond those already detailed in this section are 
necessary to address this concern. The Panel did not identify a 
specific risk to health, and the stated concerns are already captured 
in the risks identified in section IV of this final order such as 
failure or delay of osteogenesis, adverse interaction with internal/
external fixation devices, adverse biologic effects, and burn.
2. Criteria for Classification
    Most of the Panel agreed that non-invasive bone growth stimulators 
met the criteria for classification into class II. The Panel 
unanimously agreed that general controls alone are not sufficient to 
provide reasonable assurance of safety and effectiveness, that non-
invasive bone growth stimulators do not present a potential 
unreasonable risk of illness or injury, and that sufficient information 
exists to establish special controls for non-invasive bone growth 
stimulators. All but one Panel member agreed that non-invasive bone 
growth stimulators are not ``life-supporting or life-sustaining, or of 
substantial importance in preventing impairment of human health.'' This 
Panel member disagreed on the grounds that if the device failed to work 
as intended to treat an established nonunion, that failure may have 
significant health impacts rising to the level of substantial 
importance in preventing impairment of human health. Other Panel 
members responded with the view that the impairment was the nonunion 
and a failure to heal the nonunion was not itself the cause of the 
nonunion. We additionally note that FDA identified (and the Panel 
concurred) that failed or delayed osteogenesis is a risk for this 
device, but measures such as clinical and non-clinical performance 
testing would mitigate the risk of failed or delayed osteogenesis and 
provide a reasonable expectation of the effectiveness of various 
treatment uses. FDA agrees with the majority of the Panel that this 
device type meets all of the criteria for regulation as a class II 
device.
3. Special Controls
    The Panel recommended adding a special control for postmarket 
surveillance to monitor device effectiveness in real-world clinical 
practice. FDA disagrees. Postmarket surveillance as described by the 
Panel is not necessary to demonstrate reasonable assurance of safety 
and effectiveness. The safety profile of non-invasive bone growth 
stimulators is based on a long history of use of these devices and 
supports FDA's position that these devices do not pose sufficient 
safety concerns to warrant postmarket surveillance beyond standard 
postmarket requirements (i.e., medical device reporting (MDR) 
requirements). Consistent with this safety profile, none of the non-
invasive bone growth stimulator devices currently on the market under 
an approved PMA has required or relied on post-approval studies. 
Additionally, FDA's clinical

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data special control will help ensure there is sufficient evidence that 
the device performs as intended without the need to rely upon 
postmarket data for this determination.
    The Panel additionally recommended that the clinical data special 
control include specific requirements to ensure a rigorous data set, 
such as specifying imaging modalities and a follow-up study of at least 
one year to confirm that the device is effective for its intended use. 
As discussed in more detail in our response to comment 2 in section III 
of this final order, the clinical data special control sets the 
expectation that manufacturers will provide robust clinical data to 
demonstrate that the device performs as intended under the anticipated 
conditions of use. FDA disagrees that it is necessary to specify 
prescriptive imaging modalities or the length of follow-up for a 
premarket clinical study. Appropriate timeframes for follow-up studies 
depend on the type of fracture and anatomic site being treated, as the 
timeframes to achieve fusion may vary. As such, the special control for 
clinical performance data has been purposefully written in a way to 
allow for flexibility in the endpoints and measures used to demonstrate 
patient benefits and mitigation of risks for this device type. However, 
to help ensure that clinical data meets appropriate fusion endpoints 
for the device's intended use, we added a requirement in the clinical 
data special control at 21 CFR 890.5870(b)(1) that ``[i]maging data 
must demonstrate fusion at the treatment site.''

III. Comments on the Proposed Order

A. Introduction

    FDA received comments from fewer than 10 commenters on the proposed 
order (85 FR 49986) published in the Federal Register on August 17, 
2020. The comment period on the proposed order closed on October 16, 
2020. Comments received by the close of the comment period were from 
Congressional representatives, a trade organization, an orthopaedic 
scientist-surgeon, and other interested parties. Some of the comments 
contained one or more comments on one or more issues. Some comments 
supported the proposed reclassification, and others recommended against 
reclassification. Various comments included recommendations for special 
controls that commenters believed were necessary to establish 
reasonable assurance of safety and effectiveness.
    We describe and respond to the comments in section III.B of this 
final order. The order of the comments and responses is purely for 
organizational purposes and does not signify the comment's value or 
importance nor the order in which comments were received. To provide 
organized and efficient responses to similar issues, we grouped 
comments by similar subject matter, and, in some cases, we treated 
different subjects presented by the same commenter as distinct 
comments.

B. Description of Comments and FDA Response

    (Comment 1) Various commenters agreed with the proposal to 
reclassify non-invasive bone growth stimulators into class II. These 
comments generally spoke to the importance of patient access and the 
relatively low risk of these devices. They also stated that a lower 
classification (i.e., class II instead of class III) could expedite 
bringing new non-invasive bone growth stimulators to market. Two 
comments, representing multiple interested parties, disagreed with FDA, 
asserting that non-invasive bone growth stimulators should be retained 
in class III because class II controls are insufficient to provide 
reasonable assurance of safety and effectiveness.
    (Response 1) FDA agrees with the comments supporting 
reclassification of non-invasive bone growth stimulators into class II 
and disagrees that these devices should be retained in class III. Based 
on publicly available scientific evidence presented in the proposed 
order and to the Panel, and taking into consideration feedback from the 
Panel and comments received on the proposed order, FDA has determined 
that reclassification of non-invasive bone growth stimulators into 
class II, subject to premarket notification, is appropriate because 
general controls by themselves are insufficient to provide reasonable 
assurance of safety and effectiveness and there is sufficient 
information to establish special controls to provide such assurance. 
The Panel also unanimously agreed that non-invasive bone growth 
stimulators met the criteria for classification into class II.
    Additionally, class III is inappropriate because FDA has 
determined, and a large majority of the Panel agreed, that non-invasive 
bone growth stimulators are not for use in supporting or sustaining 
human life, are not of substantial importance in preventing impairment 
of human health, and do not present a potential unreasonable risk of 
illness or injury.
    We also agree with commenters that this reclassification may have a 
positive impact on bringing new non-invasive bone growth stimulators to 
market more quickly. As discussed in section I of this final order, 
reclassifying non-invasive bone growth stimulators into class II will 
reduce regulatory burdens on industry because instead of submitting a 
PMA, manufacturers may submit a less burdensome 510(k) to obtain FDA 
clearance of the device before marketing it, among other lesser 
regulatory requirements. We expect that this would, in turn, increase 
access to safe and effective therapeutics for which there is still a 
reasonable assurance of safety and effectiveness. The 510(k) pathway is 
less burdensome and generally more cost-effective for industry and FDA 
than the PMA pathway, the most stringent type of device marketing 
application required by FDA. A 510(k) typically results in a shorter 
premarket review timeline compared to a PMA, which ultimately provides 
more timely access of these types of devices to patients.
    (Comment 2) A couple commenters provided recommendations regarding 
the quality of clinical performance data that FDA should require to 
support future marketing submissions for non-invasive bone growth 
stimulators. One commenter suggested that special controls should 
require high-quality clinical data without commenting on whether non-
invasive bone growth stimulators should be reclassified. Another 
commenter stated that non-invasive bone growth stimulators should 
remain a class III device, but if FDA proceeds with reclassification, 
certain data quality standards should apply. These commenters 
emphasized the importance of prospective, randomized clinical trials to 
ensure these submissions include robust clinical evidence. One 
commenter additionally recommended that future clinical studies employ 
similar clinical trial design parameters as those used in pivotal 
studies for currently approved non-invasive bone growth stimulators, 
using clinically relevant endpoints based on imaging data and clinical 
measures of a subject's healing or functioning. The commenter also 
specified that the clinical data should be derived from clinical trials 
rather than citation of published literature.
    (Response 2) While FDA agrees that high-quality clinical data is 
necessary to support 510(k)s for non-invasive bone growth stimulators, 
FDA disagrees that the clinical data special control should 
specifically require prospective, randomized clinical trials to 
demonstrate the effectiveness of new devices brought to the market. FDA 
also agrees that imaging data should be required to demonstrate device 
effectiveness and we have revised the clinical data special control 
accordingly,

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as further described in section II.B.3 of this final order.
    We also note that data supporting approved PMAs for non-invasive 
bone growth stimulators were based on a range of sources that did not 
always include prospective randomized clinical trials. While a 
randomized, controlled clinical study is the highest standard for data 
quality, there are many sources of robust, quality clinical data that 
meet FDA standards for ``valid scientific evidence'' (21 CFR 860.7), 
including non-randomized studies compared to registry data, or other 
sources of real-world evidence. Therefore, the special controls we are 
finalizing for non-invasive bone growth stimulators are intentionally 
flexible and purposefully not intended to limit the types of clinical 
evidence that may support a 510(k) for these devices.
    As discussed in the proposed order, differences in treatment 
waveform and frequency can have unknown effects on the healing pathway, 
resulting in significant effects on reported device effectiveness (85 
FR 49986 at 49991). Therefore, to demonstrate substantial equivalence, 
clinical performance data must demonstrate that the device performs as 
intended in the indicated patient population. FDA recommends that the 
clinical study be sufficiently robust to adequately support the 
proposed indications for use for the device. A randomized prospective 
clinical trial would suffice, however, in certain circumstances, other 
forms of clinical evidence, such as real-world evidence, would also be 
adequately robust to support a substantial equivalence determination. 
Such data should be scientifically valid and include sufficient 
information to demonstrate a clinically meaningful benefit of the 
device and describe the expected safety profile, as defined in section 
513(a)(3) of the FD&C Act and 21 CFR 860.7(c)(2).
    Additionally, to demonstrate that the device performs as intended 
under anticipated conditions of use, the data should represent the 
intended patient population and intended anatomic location of the 
device. The study should include appropriate, clinically relevant 
endpoints. While the endpoint will depend on the device's specific 
indications for use, independent radiographic assessment of bone fusion 
using a clinically recognized scale and validated assessments of 
clinical healing are examples of appropriate endpoints. To support a 
demonstration of substantial equivalence, the study should also include 
sufficient evidence that the device performs equivalently to a legally 
marketed predicate device. If the subject device is not studied in 
conjunction with the predicate device, we recommend that the study 
design demonstrate a clinically meaningful and statistically 
significant improvement compared to an appropriate control (e.g., sham 
device). A side-by-side study could also be used to demonstrate 
substantial equivalence in clinically relevant endpoints (e.g., time to 
radiographic and clinical healing) between the subject device and a 
legally marketed predicate.
    In lieu of using new clinical data to support a 510(k), applicants 
may be able to rely on clinical data from a legally marketed non-
invasive bone growth stimulator with the same intended use and 
indications for use, if the applicant demonstrates that the critical 
signal parameters and operational modality of their device are 
sufficiently similar to those of the legally marketed device. This 
approach is consistent with leveraging publicly available data to 
support approval of a PMA.\9\ Further, we revised the labeling special 
control in this final order to require ``a detailed summary of the 
supporting clinical data'' rather than ``a detailed summary of the 
clinical testing'' as initially proposed to more accurately represent 
the sources of data that may be relied upon for a 510(k). As stated 
above, if the applicant demonstrates that the critical signal 
parameters of their device are sufficiently similar to those of a 
legally marketed predicate device, then the ``supporting clinical 
data'' may include clinical data sets generated using that predicate 
device.\10\
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    \9\ Examples of approved PMAs for non-invasive bone growth 
stimulators that have leveraged publicly available clinical data in 
their submissions since December 2020, in accordance with the 6-year 
rule (see section 520(h)(4) of the FD&C Act), include P190030, 
P210035, P230025, P210016 (Refs. 4-7). While the 6-year rule applies 
only to PMAs, 510(k)s may be able to leverage clinical information 
and data from a sufficiently similar predicate device, assuming the 
sponsor has proper access to such data.
    \10\ Under 21 CFR 807.92(b)(2), when the determination of 
substantial equivalence is based in part on an assessment of 
clinical performance data, the summary should include a brief 
discussion of the clinical tests submitted, referenced, or relied on 
in the premarket notification submission for a determination of 
substantial equivalence. This discussion shall include, where 
applicable, a description of the subjects upon whom the device was 
tested, a discussion of the safety or effectiveness data obtained 
from the testing, with specific reference to adverse effects and 
complications, and any other information from the clinical testing 
relevant to a determination of substantial equivalence.
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    The special controls for non-invasive bone growth stimulators 
include controls for clinical data and non-clinical performance testing 
that could support unique study designs that are appropriate for the 
specific indications for use and technological characteristics for each 
device that would be reviewed in a 510(k).\11\ While every clinical 
study developed to support a premarket submission for non-invasive bone 
growth stimulators should be designed to demonstrate that the device 
performs as intended when used in the intended patient population, the 
final special controls for these devices allow for customized study 
designs tailored specifically for each device considering the device 
technology and indications for use. Reclassification of these devices 
from class III into class II does not exclude the need for device-
specific clinical data and non-clinical performance testing. Rather, 
the special controls establish requirements for such data and testing 
that is necessary to support reasonable assurance of safety and 
effectiveness.
---------------------------------------------------------------------------

    \11\ A manufacturer may seek FDA input on non-clinical or 
clinical study design by utilizing our Q-Submission program, through 
which FDA may provide input on device-specific requirements and 
recommendations for non-clinical and clinical studies intended to 
support device-specific indications for use. Additional information 
regarding the Q-Submission program can be found in FDA's final 
guidance document entitled ``Requests for Feedback and Meetings for 
Medical Device Submissions: The Q-Submission Program'' (Ref. 8). In 
addition, reclassification does not change the regulatory 
requirements related to clinical study oversight and investigational 
device exemptions (IDEs) in 21 CFR part 812 or patient protections 
in 21 CFR part 50 and 56. FDA may provide specific feedback and 
study design considerations for clinical studies as a part of an IDE 
review for significant risk studies.
---------------------------------------------------------------------------

    This flexibility is also important for non-clinical performance 
testing special control requirements, which include validation and 
verification of thermal safety and thermal reliability, that signal 
characteristics are within safe physiologic limits, and that device 
reliability is consistent with the expected use-life. An applicant may 
validate and verify these safety and performance characteristics in a 
variety of ways, as discussed in the following paragraphs. Note that 
the non-clinical performance testing special control also requires 
validation and verification of critical performance characteristics, 
which we discuss in our response to comment 4 in this section of the 
final order.
    Given the potential for devices of this type to cause patient harm 
due to heating from multiple sources, the non-clinical special control 
requires validation and verification of thermal safety and thermal 
reliability. First, as the control units are often worn on a patient's 
belt and are battery powered, excessive heating of the control unit for 
prolonged duration may cause thermal damage to the patient's skin and

[[Page 20357]]

subdermal tissue. Second, the transducer itself may heat up during use, 
causing similar injury at the treatment site if it is patient-
contacting. Finally, the signal itself may cause heating of deep 
tissue. This could be due to the electromagnetic fields generated by 
pulsed electromagnetic field (PEMF) and combined magnetic field (CMF) 
devices inducing currents in nearby metal implants, current leaks in 
capacitive coupling (CC) devices causing electrical burns, or low 
intensity pulsed ultrasound (LIPUS) devices causing deep tissue heating 
due to the mechanical effects of ultrasound signals. Testing results to 
appropriate standards (if applicable) to demonstrate that the device 
does not cause unsafe heating should be included in support of a 
510(k). Literature or other scientific evidence can also be used to 
support the generally accepted thermal safety of the subject device's 
treatment signal.
    Validation and verification that signal characteristics are within 
safe physiologic limits is required to mitigate the potential for 
patient harm from the generated signal, which could be due to various 
factors such as ultrasonic heating or tissue cavitation, excessive 
electrical current which could damage tissue, or electromagnetic fields 
which may interfere with biological function. Applicants should provide 
signal characterization to evaluate the nature of their device and 
provide scientific evidence and rationale demonstrating that the device 
generates a physiologically safe signal, which may include non-clinical 
animal testing,\12\ side-by-side bench testing to demonstrate that the 
device signal falls within the range of a predicate device, or 
literature to demonstrate that similar signals have a history of safe 
use.
---------------------------------------------------------------------------

    \12\ FDA supports the principles of the ``3Rs,'' to replace, 
reduce, and/or refine animal use in testing when feasible. We 
encourage sponsors to consult with us if they wish to use a non-
animal testing method they believe is suitable, adequate, validated, 
and feasible.
---------------------------------------------------------------------------

    Validation and verification that device reliability is consistent 
with the expected use-life of the device is required because these 
devices are generally used daily by patients for several months and may 
be exposed to a large amount of physical wear. A 510(k) should provide 
evidence that the device can perform within specifications throughout 
its labeled use-life. One form this evidence may take is simulated use 
testing of the device. Considerations for the reliability testing 
special control (21 CFR 890.5870 (b)(2)(iv)) should include (as 
applicable), but not be limited to, continued integrity of all 
connection ports, repeated battery connection and disconnection, 
battery performance after repeated charging/discharging, integrity of 
all buttons/switches, performance of components after repeated 
reprocessing, activation of transducer for the full use-life of the 
device, and environmental exposure (e.g., humidity).
    (Comment 3) One commenter expressed concern that, by publishing the 
proposed order in the Federal Register in advance of the Panel meeting, 
``FDA has already prejudged the outcome'' of the meeting and would 
potentially influence the Panel's recommendations.
    (Response 3) FDA complied with all statutory and regulatory 
requirements in its proposal to reclassify non-invasive bone growth 
stimulators under section 513(f)(3) of the FD&C Act, which allows, but 
does not require, FDA to convene a classification panel and does not 
prescribe when the panel meeting and proposed order must occur in 
relation to each other. In the preamble to the final rule updating 
FDA's medical device classification procedures regulations to reflect 
updates made to the FD&C Act in 2012 by the Food and Drug 
Administration Safety and Innovation Act (FDASIA) (Pub. L. 122-144), 
FDA stated its intent to issue a reclassification proposed order under 
section 513(f)(3) before holding the classification panel meeting (83 
FR 64443 at 64451 (December 17, 2018)). FDA's statement was in response 
to comments from interested parties suggesting that Congress intended 
this order when they passed FDASIA (83 FR at 64450). Since then, in 
cases when FDA has elected to convene a classification panel for a 
potential reclassification action under section 513(f)(3) of the FD&C 
Act, FDA has generally issued the proposed order before convening the 
panel.
    (Comment 4) More than one commenter noted the wide range of 
technologies that have been approved as non-invasive bone growth 
stimulators and expressed concern that class II special controls could 
not be established to provide reasonable assurance of safety and 
effectiveness for the generic device type at least in part because of 
this wide range of technologies.
    (Response 4) While we acknowledge that FDA has approved PMAs for 
non-invasive bone growth stimulators with an array of different 
technologies (e.g., PEMF, CMF, CC, and LIPUS), we disagree that special 
controls cannot be established to provide reasonable assurance of 
safety and effectiveness. Furthermore, as discussed in section II.A of 
this final order, the Panel also unanimously agreed with FDA's 
conclusion that sufficient information exists to establish special 
controls.
    In evaluating whether non-invasive bone growth stimulators should 
be reclassified into class II, we considered the risks to health and 
risk mitigations associated with the different technologies of approved 
devices. As part of this assessment, we evaluated peer-reviewed 
literature, MDRs, recalls, and additional information (e.g., the 
Summary of Safety and Effectiveness from PMAs subject to the six-year 
rule \13\). FDA concluded that the risks to health associated with 
approved non-invasive bone growth stimulators, and the appropriate 
mitigations of those risks, are the same across all modalities. For 
this reason, the special controls provide flexibility while still 
requiring manufacturers to account for the critical characteristics of 
their particular technology. While the specific testing necessary to 
mitigate risks for a particular device may differ by technology, the 
special controls are written broadly enough to apply to all non-
invasive bone growth stimulators, regardless of technology.
---------------------------------------------------------------------------

    \13\ See footnote 5 for information regarding the PMAs relied on 
to support this reclassification.
---------------------------------------------------------------------------

    For example, the non-clinical performance data special control (21 
CFR 890.5870(b)(2)) requires validation and verification of critical 
performance characteristics to ensure that intended design outputs are 
delivered to the patient. This particular special control is broadly 
written to allow for flexibility in terms of which specific design 
outputs are relevant based upon the modality of the device. To fully 
describe the specific device and allow for a comparison to the 
predicate, we suggest providing a full and complete characterization of 
both the device and the therapeutic signal in the 510(k). We recommend 
that characterization of the signal waveform include images and a 
sufficiently detailed description to ensure continued treatment 
effectiveness. Because of the wide range of signal modalities 
applicable to non-invasive bone growth stimulators (e.g., PEMF, CMF, 
CC, and LIPUS), it is not possible to list every treatment signal 
parameter that should be assessed; however, in general, we recommend 
including the following (as applicable): output signal shape, 
magnitude, primary frequency, carrier frequency, duty cycle, focal 
depth, magnetic flux, effective radiating area, total average power, 
spatial average-temporal average intensity, beam non-uniformity ratio, 
and any other measure needed to fully characterize the treatment 
signal.

[[Page 20358]]

    Additionally, different treatment signals will pass through human 
tissue and bone in different ways. Consequently, while the device may 
be generating a treatment signal of a specific amplitude or waveform, 
the treatment site may be receiving a different signal. This could be 
caused by signal loss from the transducer/air/skin interface, or due to 
absorption of signal power or certain frequencies as the signal passes 
through soft and hard tissue. Therefore, we recommend applicants 
include results from validation testing to assess the signal reaching 
the treatment site. While it is not possible to consider every 
treatment attenuation scenario, we recommend applicants demonstrate 
that the intended treatment parameters are delivered throughout a 
sufficient volume to encompass the treatment site in the indicated 
patient population. Examples of testing may include measurement of the 
signal in an appropriate surrogate (e.g., phantom model).
    (Comment 5) One commenter requested that FDA issue a special 
controls guidance to outline additional detail regarding ``key 
parameters for clinical studies and other data (labeling comprehension 
and device usability testing) to support marketing of never before-
authorized [non-invasive] bone growth stimulator devices.''
    (Response 5) While we do not intend to issue a guidance document to 
accompany the special controls identified in this final order for non-
invasive bone growth stimulators at this time, the preamble to this 
final order has recommendations and examples for how manufacturers may 
comply with the special controls. In section II.B of this final order, 
in response to Panel feedback, we provide examples of recognized 
consensus standards for EMC testing that would mitigate EMI risks to 
satisfy the performance data special control for EMC. In our responses 
to comments 2 and 4 in this section of this final order, we provide 
examples of the different types of clinical data, clinical studies, and 
non-clinical performance data that could support a 510(k) for non-
invasive bone growth stimulators. FDA reviews the non-clinical and 
clinical data and related valid scientific evidence included in a 
510(k) to assess substantial equivalence to a legally marketed 
predicate device, including, as appropriate, conformance to special 
controls.
    We have also revised the special controls for non-invasive bone 
growth stimulators to provide more detail and clarity on FDA's 
expectations for clinical data and non-clinical performance testing. 
Additionally, as discussed in section II.B.3 and in our response to 
comment 2 in this section of the final order, the clinical data special 
control now requires imaging data to further support device 
effectiveness. Non-clinical performance testing now more clearly 
requires verification and validation of critical performance and safety 
characteristics, which we discuss in our responses to comments 2 and 4 
in this section of the final order.
    (Comment 6) One commenter requested that FDA consider adding a 
requirement for human factors testing and/or a labeling comprehension 
study to the special controls.
    (Response 6) FDA agrees with this comment. Based on literature and 
clinical data from other sources, FDA concurs that user compliance with 
the instructions for use is a significant factor in the effectiveness 
of these devices and maintaining user compliance is a known issue for 
these devices. These devices are used by patients, and the instructions 
for use should be clear and easy to follow. Additionally, labeling 
comprehension testing is currently relied upon to support PMA approvals 
of non-invasive bone growth stimulators. As such, we have added a 
special control to require labeling comprehension testing.
    (Comment 7) One commenter stated that FDA should conduct premarket 
clinical and manufacturing inspections for these devices, even if they 
are reclassified from class III into class II.
    (Response 7) FDA generally does not consider premarket clinical and 
manufacturing inspections to be necessary to provide reasonable 
assurance of safety and effectiveness for class II devices, including 
non-invasive bone growth stimulators. Preapproval inspections conducted 
in the context of a PMA approval allow FDA to assess the firm's 
capability to design and manufacture the device as claimed in the PMA 
and confirm that the firm's Quality Management System is in compliance 
with 21 CFR part 820, Quality Management System Regulation. FDA 
generally does not conduct similar premarket inspections for class II 
devices or when reviewing a 510(k).
    Additionally, the hardware of these devices can generally be 
characterized with well-established methods and standards. The special 
controls identified in this final order establish requirements for 
validating both software and hardware components of these devices 
premarket, including that testing must verify and validate critical 
performance and safety characteristics of the device. The special 
controls also establish requirements relating to electromagnetic 
compatibility, electrical and thermal safety, biocompatibility, and 
software verification, validation, and hazard analysis.
    For class II devices, routine and for cause inspections, which may 
consider compliance with quality management system requirements 
applicable to the manufacturing of the device, allow for appropriate 
postmarket oversight. Mechanisms and procedures for reporting safety 
concerns, such as MDRs and recalls, also provide additional postmarket 
surveillance to help ensure continued safety for marketed devices.
    (Comment 8) One commenter requested that FDA either ``retain 
control over all postmarket [non-invasive bone growth stimulator] 
modifications'' through controls applicable to class III devices, or, 
if non-invasive bone growth stimulators are reclassified, that FDA 
include recommendations in guidance to explain which device 
modifications would be subject to premarket review. The commenter 
highlighted the importance of regulatory oversight of postmarket 
changes to ensure that device performance is not negatively impacted, 
noting that the 2006 Advisory Committee \14\ and FDA previously 
recognized that device modifications that change device output may have 
unknown impacts on clinical response to treatment.
---------------------------------------------------------------------------

    \14\ The commenter is referring to a 2006 meeting of the 
Orthopaedic and Rehabilitation Devices Panel of the Medical Devices 
Advisory Committee, which considered a petition for reclassification 
of non-invasive bone growth stimulators. (See footnote 7 for 
additional information and references.)
---------------------------------------------------------------------------

    (Response 8) FDA disagrees that the requirements applicable to 
modifications of PMA-approved products (i.e., premarket approval or 
annual reporting of changes as required for class III devices) are 
necessary for this device type. Consistent with 21 CFR 807.81(a)(3), a 
new 510(k) is required for any change or modification to a cleared 
device that could significantly affect the safety or effectiveness of 
the device, or for a major change or modification in intended use.\15\ 
Changes and modifications that could significantly affect the safety or 
effectiveness of the device and may require a new 510(k) for

[[Page 20359]]

a non-invasive bone growth stimulator device include:
---------------------------------------------------------------------------

    \15\ In accordance with 21 CFR 807.81(a)(3), a 510(k) is 
required for significant changes or modifications to a device 
including: (1) those that ``could significantly affect the safety or 
effectiveness of the device, e.g., a significant change or 
modification in design, material, chemical composition, energy 
source, or manufacturing process''; or (2) a ``major change or 
modification in the intended use of the device.''
---------------------------------------------------------------------------

      Modifications of the therapeutic signal or modifications 
to the transducer such that there is change to the delivered 
therapeutic signal.
      Changes to the indicated patient population (age range, 
anatomic location, fracture or fusion type, etc.).
    These examples are not exhaustive. Guidance on when device changes 
or modifications may require a new 510(k) can be found in ``Deciding 
When to Submit a 510(k) for a Change to an Existing Device'' (Ref. 9) 
and ``Deciding When to Submit a 510(k) for a Software Change to an 
Existing Device'' (Ref. 10).
    Regardless of whether a new 510(k) is necessary, a modified device 
must continue to comply with the special controls. Additionally, 
manufacturers may wish to use predetermined change control plans 
(PCCPs) as a way to implement future modifications to their devices 
without needing to submit a new 510(k) for each significant change or 
modification \16\ while continuing to provide reasonable assurance of 
device safety and effectiveness. \17\ FDA reviews a PCCP as part of a 
marketing submission for a device to ensure the continued safety and 
effectiveness of the device without necessitating additional marketing 
submissions for implementing each modification described in the PCCP. 
When used appropriately, PCCPs authorized by FDA are expected to be 
least burdensome for manufacturers and FDA.\18\
---------------------------------------------------------------------------

    \16\ For the purpose of this final order reference to 
``modification'' means a significant change or modification that 
would generally require a new premarket notification under 21 CFR 
807.81(a)(3).
    \17\ Section 3308 of the Food and Drug Omnibus Reform Act of 
2022, Title III of Division FF of the Consolidated Appropriations 
Act, 2023, Public Law 117-328 (``FDORA''), enacted on December 29, 
2022, added section 515C ``Predetermined Change Control Plans for 
Devices'' to the FD&C Act. Section 515C has provisions regarding 
PCCPs for devices requiring premarket approval or premarket 
notification. Under section 515C, supplemental applications (section 
515C(a)) and new premarket notifications (section 515C(b)) are not 
required for a change to a device that would otherwise require a 
premarket approval supplement or new premarket notification if the 
change is consistent with a PCCP approved or cleared by FDA.
    \18\ Sections 513 and 515 of the FD&C Act. See also, FDA's 
guidance ``The Least Burdensome Provisions: Concept and 
Principles,'' available at https://www.fda.gov/regulatory-information/search-fda-guidance-documents/least-burdensome-provisions-concept-and-principles.
---------------------------------------------------------------------------

IV. Changes in the Final Order

    As described in sections II and III of this final order, FDA has 
made revisions in this final order in response to Panel feedback and 
comments submitted to the public docket on the proposed order (85 FR 
49986).
    Additionally, as noted in footnote 2, FDA has revised the 
identification language from the proposed order to add the phrase ``or 
as a treatment for established nonunions or failed fusions'' to the 
identification language codified in this final order. (See 21 CFR 
890.5780(a)). This language was included in the proposed order as an 
indication presented to explain the intended use, but FDA has 
determined that for completeness it belongs in the identification 
language as part of the intended use. FDA has also moved the clause in 
the identification language that notes the device is only for 
prescription use from the second sentence of the identification to the 
first sentence of the identification. This change was made for 
consistency with other device types whose classification regulations 
fall into 21 CFR part 890. This change does not have any substantive 
effect.
    Furthermore, in considering the revisions to the final order, FDA 
identified and added two additional risks to health: (i) use error or 
improper device use, and (ii) infection. While the labeling special 
control in the proposed order included cleaning instructions for 
reusable components, we recognize that adding the risk of infection 
clarifies the importance of validated cleaning instructions as a 
mitigation measure to address this risk to health. Accordingly, we 
updated the labeling special control to clarify that cleaning 
instructions must be validated. As discussed in our response to comment 
6, FDA added a risk of use error or improper device use because user 
compliance with the instructions for use is a significant factor in the 
effectiveness of these devices and maintaining user compliance is a 
known issue for these devices. Accordingly, we added a special control 
to require that labeling comprehension testing must demonstrate the 
patient can correctly use the device based solely on reading the 
instructions for use.
    Based in part on Panel feedback and comments on the proposed order, 
FDA revised the list of risks to health, the special controls that FDA 
determined will mitigate these risks, and Table 1, ``Risks to Health 
and Risk Mitigation Measures for Non-Invasive Bone Growth 
Stimulators''.
    FDA has identified the following risks to health associated with 
the use of non-invasive bone growth stimulators:
      Failure or delay of osteogenesis. A patient could receive 
ineffective treatment, contributing to failure or delay of osteogenesis 
that may lead to clinical symptoms (e.g., pain) and the need for 
surgical interventions. Ineffective treatment could be a result of 
various circumstances (e.g., inadequate therapeutic signal output or 
device malfunction).
      Use error or improper device use. Use error or improper 
device use may result from a device design that is difficult to operate 
and/or labeling that is difficult to comprehend, leading to misuse of 
the device resulting in patient harm or ineffective treatment.
      Burn. A patient or health care professional could be 
burned from the use and operation of the device. This could be a result 
of various circumstances including device malfunction (e.g., electrical 
fault) or misuse of the device (e.g., use while sleeping).
      Electrical shock. A patient or health care professional 
could be shocked from the use and operation of the device. This could 
be a result of various circumstances including device malfunction 
(e.g., electrical fault) or misuse of the device (e.g., use of 
alternating current source during treatment).
      Electromagnetic interference (EMI). A patient with 
electrically powered implanted devices (such as cardiac pacemakers, 
cardiac defibrillators, and neurostimulators) could experience harm due 
to device malfunction as a result of electromagnetic interference 
between the implanted device and the non-invasive bone growth 
stimulator. Electronically powered devices in the environment (such as 
radiofrequency emitting household electrical equipment), may similarly 
interfere with the non-invasive bone growth stimulator device.
      Adverse tissue reaction. A patient could experience skin 
irritation and/or allergic reaction associated with the use and 
operation of the device via the use of non-biocompatible device 
materials.
      Infection. A patient could experience an infection if the 
patient-contacting components are not properly cleaned between uses.
      Adverse interaction with internal/external fixation 
devices. The signal output could be impacted by certain metallic 
internal or external fixation devices leading to inadequate treatment 
signals, device malfunction, or tissue heating and damage as a result 
of heating of the fixation device.
      Adverse biologic effects. A patient may experience adverse 
biologic effects resulting from prolonged exposure to the treatment 
signal via biologic interaction with the treatment signal at a cellular 
level. This could be due to various factors such as ultrasonic heating 
or tissue cavitation, excessive electrical current which could damage

[[Page 20360]]

tissue, or electromagnetic fields which may interfere with biological 
function.
    FDA has determined that the following special controls will 
mitigate these risks to health, and that these special controls, in 
addition to general controls, will provide a reasonable assurance of 
safety and effectiveness for non-invasive bone growth stimulators:
      The risk of failure or delay of osteogenesis can be 
mitigated by clinical data that demonstrates that the device performs 
as intended under anticipated conditions of use, including imaging data 
to demonstrate fusion at the treatment site. This risk can also be 
mitigated by non-clinical performance testing which additionally 
demonstrates that the device performs as intended under anticipated 
conditions of use, specifically through verification and validation of 
critical performance characteristics of the device. These include 
ensuring delivery of intended design outputs to the patient, thermal 
safety and reliability, the signal characteristics are within safe 
physiologic limits, and reliability of the device is consistent over 
the expected use-life. Software verification, validation, and hazard 
analysis will also help mitigate the risk of failure or delay of 
osteogenesis by ensuring that any device software performs as intended. 
Finally, labeling will also mitigate this risk by providing appropriate 
instructions for use (e.g., duration, frequency of use) to the end 
user.
      The risk of use error or improper device use can be 
mitigated through labeling, including adequate warnings and 
instructions for use, and labeling comprehension testing that 
demonstrates the patient can correctly use the device based solely on 
reading the instructions for use.
      The risk of burns can be mitigated by non-clinical 
performance testing of the device to verify and validate critical 
performance characteristics, which include ensuring thermal safety and 
reliability, signal characteristics are within safe physiologic limits, 
and reliability of the device is consistent with its expected use-life. 
The risk of burns can be further mitigated by electrical safety testing 
to minimize the risk of thermal burns to the patient, and specific 
instructions regarding proper usage and specific warnings associated 
with the risk of burns.
      The risk of electrical shock can be mitigated by 
electrical safety testing to minimize the risk of shock to the patient. 
This risk can be further mitigated by labeling that includes 
instructions on appropriate usage and maintenance, and specific 
warnings regarding electrical shock.
      The risk of EMI can be mitigated through performance 
testing that demonstrates the EMC of the device and labeling to 
minimize the risk of adverse interaction with other electronic devices, 
such as implanted electronic devices.
      The risk of adverse tissue reaction can be mitigated by a 
biocompatibility evaluation to ensure that the materials used in 
patient-contacting components of the device are safe for skin contact 
and labeling that includes warnings against use on compromised skin or 
when there are known skin sensitivities, as well as validated 
instructions on appropriate cleaning of any reusable components.
      The risk of infection can be mitigated by labeling that 
includes validated instructions for appropriate cleaning of any 
reusable components.
      The risk of adverse interaction with internal/external 
fixation devices can be mitigated through labeling that includes 
appropriate warnings for patients with implanted medical devices, as 
well as non-clinical performance testing, which would include an 
evaluation of thermal safety and thermal reliability.
      The risk of adverse biologic effects can be mitigated by 
non-clinical performance testing to verify and validate critical 
performance characteristics of the device, which include ensuring 
thermal safety and reliability, signal characteristics are within safe 
physiologic limits, and reliability of the device over the expected 
use-life. The risk of adverse biological effects is further mitigated 
by software verification, validation, and hazard analysis, which will 
help ensure the device operates as intended.

 Table 1--Risks to Health and Mitigation Measures for Non-Invasive Bone
                           Growth Stimulators
------------------------------------------------------------------------
       Identified risk to health               Mitigation measures
------------------------------------------------------------------------
Failure or delay of osteogenesis.......  Clinical performance data.
                                         Non-clinical performance
                                          testing.
                                         Software verification,
                                          validation, and hazard
                                          analysis.
                                         Labeling.
Use error or improper device use.......  Labeling comprehension testing.
                                         Labeling.
Burn...................................  Non-clinical performance
                                          testing.
                                         Electrical safety testing.
                                         Labeling.
Electrical shock.......................  Electrical safety testing.
                                         Labeling.
Electromagnetic interference...........  Electromagnetic compatibility
                                          (EMC) testing.
                                         Labeling.
Adverse tissue reaction................  Biocompatibility evaluation.
                                         Labeling.
Infection..............................  Labeling.
Adverse interaction with internal/       Non-clinical performance
 external fixation devices.               testing.
                                         Labeling.
Adverse biological effects.............  Non-clinical performance
                                          testing.
                                         Software verification,
                                          validation, and hazard
                                          analysis.
------------------------------------------------------------------------

V. The Final Order

    In this final order, FDA is adopting relevant findings from the 
August 17, 2020, proposed order (85 FR 49986). FDA has made revisions 
in this final order in response to the Panel deliberations (see section 
II) and comments received (see section III). FDA is issuing this final 
order to reclassify non-invasive bone growth stimulators from class III 
into class II under a new device classification regulation with the 
name non-invasive bone growth stimulator, and to establish special 
controls by revising 21 CFR part

[[Page 20361]]

890 (adding 21 CFR 890.5870). The identification for Sec.  890.5870(a) 
has been revised from the proposed order to provide a more accurate 
description of the devices in this classification regulation.
    Further, in this final order, FDA has identified the special 
controls under section 513(b)(1)(B) of the FD&C Act that, along with 
general controls, provide a reasonable assurance of the safety and 
effectiveness for non-invasive bone growth stimulators. In this final 
order, the Agency has made refinements to the special controls as 
previously described in the proposed order to further mitigate the 
risks to health associated with the use of non-invasive bone growth 
stimulators. Specifically, and among other things, FDA revised certain 
special controls for clarity, added imaging criteria to demonstrate 
effectiveness, and added a new special control for labeling 
comprehension. The clinical data special control now includes a 
requirement for imaging to demonstrate fusion at the treatment site as 
evidence that the device performs as intended. There is a new special 
control for labeling comprehension testing to demonstrate that patients 
can correctly use the devices based solely on the instructions for use. 
We made other minor revisions to several of the special controls for 
clarity.
    Under the FD&C Act, 510(k)s are required to reasonably assure the 
safety and effectiveness of class II devices unless FDA determines that 
the device type should be exempt under section 510(m).\19\ FDA has not 
made this determination for non-invasive bone growth stimulators and, 
therefore, this class II device type is not exempt from 510(k) 
requirements. Thus, under sections 510(k) and 513(f) of the FD&C Act, 
persons who intend to market this device type must submit a 510(k) 
containing information on non-invasive bone growth stimulators that 
they intend to market and must obtain FDA clearance of the device prior 
to marketing.
---------------------------------------------------------------------------

    \19\ In considering whether to exempt class II devices from 
premarket notification, FDA considers whether premarket notification 
for the type of device is necessary to provide reasonable assurance 
of safety and effectiveness of the device. FDA generally considers 
the factors initially identified in 63 FR 3142 (January 21, 1998) 
and further explained in FDA's guidance ``Procedures for Class II 
Device Exemptions from Premarket Notification,'' available at 
www.fda.gov/regulatory-information/search-fda-guidance-documents/procedures-class-ii-device-exemptions-premarket-notification-guidance-industry-and-cdrh-staff, to determine whether premarket 
notification is necessary for class II devices. FDA also considers 
that even when exempting devices from the 510(k) requirements, these 
devices would still be subject to certain limitations on exemptions, 
for example, the general limitations set forth in 21 CFR 890.9.
---------------------------------------------------------------------------

    Under this final order, non-invasive bone growth stimulators are 
prescription use devices under Sec.  801.109 (21 CFR 801.109). 
Prescription devices are exempt from the requirement for adequate 
directions for use for the layperson under section 502(f)(1) of the 
FD&C Act (21 U.S.C. 352(f)(1)) and 21 CFR 801.5, as long as the 
conditions of Sec.  801.109 are met. The device would continue to be 
subject to the submission and device clearance requirements of sections 
510(k) and 513 of the FD&C Act and of part 807, subpart E of FDA's 
regulations (21 CFR part 807).

VI. Effective Date

    This final order is effective 30 days after the date of its 
publication in the Federal Register.

VII. Analysis of Environmental Impact

    The Agency has determined under 21 CFR 25.34(b) that this action is 
of a type that does not normally have a significant effect on the human 
environment. Therefore, neither an environmental assessment nor an 
environmental impact statement is required.

VIII. Paperwork Reduction Act of 1995

    This final order refers to previously approved collections of 
information found in FDA regulations. The previously approved 
collections of information are subject to review by the Office of 
Management and Budget (OMB) under the Paperwork Reduction Act of 1995 
(44 U.S.C. 3501-3521). The collections of information in 21 CFR part 
807, subpart E (Premarket Notification Procedures), have been approved 
under OMB control number 0910-0120; the collections of information in 
21 CFR part 820 (Quality Management System Regulation) have been 
approved under OMB control number 0910-0073; the collections of 
information in 21 CFR part 812 (Investigational Device Exemptions) have 
been approved under OMB control number 0910-0078; the collections of 
information in 21 CFR part 814, subparts A through E (Premarket 
Approval of Medical Devices), have been approved under OMB control 
number 0910-0231; and the collections of information under 21 CFR part 
801 (Device Labeling) have been approved under OMB control number 0910-
0485.

IX. Codification of Orders

    Under section 513(f)(3) of the FD&C Act, FDA may issue final orders 
to reclassify devices. FDA will continue to codify classifications and 
reclassifications in the Code of Federal Regulations (CFR). Changes 
resulting from final orders will appear in the CFR as newly codified 
orders. In accordance with section 513(f)(3) of the FD&C Act, we are 
codifying in this final order the classification of non-invasive bone 
growth stimulators in the new 21 CFR 890.5870, under which these 
devices are reclassified from class III into class II.

X. References

    The following references marked with an asterisk (*) are on display 
at the Dockets Management Staff (see ADDRESSES) and are available for 
viewing by interested persons between 9 a.m. and 4 p.m., Monday through 
Friday; they are also available electronically at https://www.regulations.gov. References without asterisks are not on public 
display at https://www.regulations.gov because they have copyright 
restriction. Some may be available at the website address, if listed. 
References without asterisks are available for viewing only at the 
Dockets Management Staff. Although FDA verified the website addresses 
in this final order, please note that websites are subject to change 
over time.

* 1. FDA, Sept. 8-9, 2020, Meeting of the Orthopaedic and 
Rehabilitation Devices Panel, Meeting Materials: https://www.fda.gov/advisory-committees/advisory-committee-calendar/september-8-9-2020-orthopaedic-and-rehabilitation-devices-panel-medical-devices-advisory-committee.
2. International Electrotechnical Commission, IEC 60601-1-2 Medical 
electrical equipment--Part 1-2: General requirements for basic 
safety and essential performance--Collateral Standard: 
Electromagnetic disturbances--Requirements and tests, 2014. 
(Available at: https://webstore.iec.ch/en/publication/2590.)
* 3. FDA, Sept. 8, 2020, Meeting of the Orthopaedic and 
Rehabilitation Devices Panel Transcript: https://www.fda.gov/media/145159/download.
* 4. FDA, P190030 Summary of Safety and Effectiveness Data, December 
9, 2020. (Available at: https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpma/pma.cfm?id=P190030.)
* 5. FDA, P210035 Summary of Safety and Effectiveness Data, May 3, 
2022. (Available at: https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpma/pma.cfm?id=P210035.)
* 6. FDA, P230025 Summary of Safety and Effectiveness Data, February 
9, 2024. (Available at: https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpma/pma.cfm?id=P230025.)

[[Page 20362]]

* 7. FDA, P210016 Summary of Safety and Effectiveness Data, January 
17, 2025. (Available at: https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpma/pma.cfm?id=P210016.)
* 8. FDA, ``Requests for Feedback and Meetings for Medical Device 
Submissions: The Q-Submission Program; Guidance for Industry and FDA 
Staff,'' May 29, 2025. (Available at: https://www.fda.gov/regulatory-information/search-fda-guidance-documents/requests-feedback-and-meetings-medical-device-submissions-q-submission-program.)
* 9. FDA, ``Deciding When to Submit a 510(k) for a Change to an 
Existing Device; Guidance for Industry and Food and Drug 
Administration Staff,'' October 25, 2017. (Available at: https://www.fda.gov/regulatory-information/search-fda-guidance-documents/deciding-when-submit-510k-change-existing-device.)
* 10. FDA, ``Deciding When to Submit a 510(k) for a Software Change 
to an Existing Device; Guidance for Industry and Food and Drug 
Staff,'' October 25, 2017. (Available at: https://www.fda.gov/regulatory-information/search-fda-guidance-documents/deciding-when-submit-510k-software-change-existing-device.)

List of Subjects in 21 CFR Part 890

    Medical devices.

    Therefore, under the Federal Food, Drug, and Cosmetic Act (21 
U.S.C. 321 et seq., as amended) and under authority delegated to the 
Commissioner of Food and Drugs, 21 CFR part 890 is amended as follows:

PART 890--PHYSICAL MEDICINE DEVICES

0
1. The authority citation for part 890 continues to read as follows:

    Authority:  21 U.S.C. 351, 360, 360c, 360e, 360j, 360l, 371.


0
2. Add Sec.  890.5870 to subpart F to read as follows:


Sec.  890.5870   Non-invasive bone growth stimulator.

    (a) Identification. A non-invasive bone growth stimulator is a 
prescription device that provides stimulation through electrical, 
magnetic, or ultrasonic fields. The device is intended to be used 
externally to promote osteogenesis as an adjunct to primary treatments 
for fracture fixation and spinal fusion or as a treatment for 
established nonunions or failed fusions.
    (b) Classification. Class II (special controls). The special 
controls for this device are:
    (1) Clinical data must demonstrate that the device performs as 
intended under anticipated conditions of use. Imaging data must 
demonstrate fusion at the treatment site.
    (2) Non-clinical performance testing must demonstrate that the 
device performs as intended under anticipated conditions of use. 
Critical performance and safety characteristics of the device, 
considering the operational modality of the device, must be verified 
and validated to ensure:
    (i) Intended design outputs are delivered to the patient;
    (ii) Thermal safety and thermal reliability;
    (iii) Signal characteristics are within safe physiologic limits; 
and
    (iv) Device reliability is consistent with the expected use-life.
    (3) Patient-contacting components of the device must be 
demonstrated to be biocompatible.
    (4) Performance data must demonstrate the electrical safety and 
electromagnetic compatibility of the device.
    (5) Appropriate software verification, validation, and hazard 
analysis must be performed.
    (6) Labeling comprehension testing must demonstrate the patient can 
correctly use the device based solely on reading the instructions for 
use.
    (7) Labeling for the device must include the following:
    (i) Warning against use on compromised skin or when there are known 
skin sensitivities;
    (ii) Appropriate warnings for patients with implanted medical 
devices;
    (iii) A detailed summary of the supporting clinical data, which 
includes the clinical outcomes associated with the use of the device, 
and a summary of adverse events and complications that occurred with 
the device;
    (iv) A clear description of the device;
    (v) Instructions on appropriate usage, duration, and frequency of 
use;
    (vi) Instructions for maintenance and safe disposal;
    (vii) Validated instructions for appropriate cleaning of any 
reusable components;
    (viii) Specific warnings regarding user burns, electrical shock, 
and skin irritation; and
    (ix) The risks and benefits associated with use of the device when 
used as intended.

Grace R. Graham,
Deputy Commissioner for Policy, Legislation, and International Affairs.
[FR Doc. 2026-07366 Filed 4-15-26; 8:45 am]
BILLING CODE 4164-01-P


Legal Citation

Federal Register Citation

Use this for formal legal and research references to the published document.

91 FR 20352

Web Citation

Suggested Web Citation

Use this when citing the archival web version of the document.

“Physical Medicine Devices; Reclassification of Non-Invasive Bone Growth Stimulators,” thefederalregister.org (April 16, 2026), https://thefederalregister.org/documents/2026-07366/physical-medicine-devices-reclassification-of-non-invasive-bone-growth-stimulators.