[Federal Register: February 2, 2000 (Volume 65, Number 22)]
[Notices]
[Page 4981-4982]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr02fe00-85]

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DEPARTMENT OF HEALTH AND HUMAN SERVICES

Food and Drug Administration

[Docket No. 99D-0186]


Medical Devices; Guidance for Industry on the Testing of Metallic
Plasma Sprayed Coatings on Orthopedic Implants to Support
Reconsideration of Postmarket Surveillance Requirements; Availability

AGENCY:  Food and Drug Administration, HHS.

ACTION:  Notice.

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SUMMARY:  The Food and Drug Administration (FDA) is announcing the
availability of a guidance entitled ``Guidance for Industry on the
Testing of Metallic Plasma Sprayed Coatings on Orthopedic Implants to
Support Reconsideration of Postmarket Surveillance Requirements.'' This
guidance is final and is in effect at this time. Metallic plasma spray
coatings, both porous and non-porous, and metallic sintered or
diffusion bonded porous coatings are used to attach artificial joints
to living bone. FDA's Center for Devices and Radiological Health (CDRH)
is issuing this guidance to identify a set of testing methods that can
be used to accurately evaluate the mechanical properties of the various
types of coatings. CDRH will use such data to identify which coated hip
devices should remain subject to postmarket surveillance requirements.

DATES:  Submit written comments at any time.

ADDRESSES:  See the SUPPLEMENTARY INFORMATION section for information
on electronic access to the guidance. Submit written requests for
single copies on a 3.5" diskette of the guidance document entitled
``Guidance for Industry on the Testing of Metallic Plasma Sprayed
Coatings on Orthopedic Implants to Support Reconsideration of
Postmarket Surveillance Requirements'' to the Division of Small
Manufacturers Assistance (HFZ-220), Center for Devices and
Radiological, Food and Drug Administration, 1350 Piccard Dr.,
Rockville, MD 20850. Send two self-addressed adhesive labels to assist
that office in processing your request, or fax your request to 301-443-
8818. Submit written comments on this guidance document to David L.
Daly (address below).

FOR FURTHER INFORMATION CONTACT:  David L. Daly, Center for Devices and
Radiological Health (HFZ-510), Food and Drug Administration, 1350
Piccard Dr., Rockville, MD 20850, 301-594-3674.

SUPPLEMENTARY INFORMATION:

I. Background

    On February 21, 1992, FDA sent a letter order to petitioner,
Richards Medical Co., reclassifying the hip joint, metal/polymer/metal,
semi-constrained, porous-coated uncemented prosthesis from class III
(Premarket Approval) into class II (Special Controls). The
reclassification was published in the Federal Register of January 8,
1993 (58 FR 3227). The reclassification was effective February 21,
1992. On February 15, 1994, CDRH's Orthopedic and Rehabilitation
Devices Branch (ORDB) determined that hip prostheses using plasma
sprayed porous coatings for biological fixation can be substantially
equivalent to the reclassified porous coated hip prosthesis. As part of
the decision, CDRH, using the then existing authority of section
522(a)(1)(C) of the Federal Food, Drug, and Cosmetic Act, required
manufacturers of plasma spray porous coated hip prostheses to conduct
postmarket surveillance of their devices. Postmarket surveillance was
required because of CDRH's concern that reported differences between
the mechanical properties, particularly abrasion resistance, of plasma
sprayed coatings and sintered and diffusion bonded porous coatings
could have an adverse effect on the long-term revision rate of the
plasma sprayed devices. While CDRH has clinical data describing the
long-term revision rate of sintered and diffusion bonded porous coated
hip prostheses, CDRH does not have this type of data on the cementless
use of plasma sprayed hip prostheses. The postmarket surveillance
consisted of prospective, long-term, followup of a population of
patients who have received cementless implantation of the
manufacturer's plasma sprayed porous coated hip prosthesis. The
objective of the patient followup was to determine the long-term
revision rate for each plasma sprayed porous coated hip prosthesis.
    At the time postmarket surveillance was required, CDRH believed
that the term ``plasma spray'' was a single manufacturing technique
that produced a single form of coating, having a single set of
metallurgical and mechanical properties. CDRH now recognizes that
plasma spray manufacturing methods are a subset of the larger ``thermal
spray'' group of metallic coating production methods. CDRH has come to
recognize that thermal spray coating methods can produce coatings with
a wide range of metallurgical and mechanical properties. As an example,
CDRH originally believed that, when used to apply metallic coatings to
hip prostheses, plasma spray manufacturing techniques produced only
porous coatings. CDRH now also recognizes that hip prostheses with non-
porous metallic coatings can be manufactured by plasma spray and other
thermal spray methods.
    Several manufacturers, using a variety of thermal spray coating
methods, have received substantial equivalence decisions for their
coated hips. A number of these manufacturers have sought
reconsideration of CDRH's decision to require postmarket surveillance
of their products. Several of the requests for reconsideration are, in
part, based on claims that manufacturing technology permits the
production of plasma sprayed coatings with mechanical properties,
particularly abrasion resistance, equal to or better than those of the
sintered or diffusion bonded porous coatings upon which the
reclassification was based. In response to the requests for
reconsideration, CDRH, on February 22, 1999, reissued a draft guidance
document describing testing methods that CDRH believed could measure
the mechanical properties of plasma sprayed coatings. Several comments
on the draft guidance document were received. CDRH has considered those
comments and is now issuing this guidance as final guidance that is
effective immediately.
    Some comments on the draft guidance document included mechanical
test data on different thermal spray coatings, both porous and non-
porous. These data indicate that thermal spray coatings can have
mechanical properties greater than, less than, or almost equal to those
of sintered or diffusion bonded porous coatings. CDRH does not believe
that postmarket surveillance is necessary for hip prostheses whose
coatings have mechanical properties, particularly abrasion resistance,
equal to or better than sintered or diffusion bonded porous coatings.
As a result, CDRH is now inviting those manufacturers who have received
postmarket surveillance orders to apply for reconsideration of those
orders. CDRH will, on a case by case basis, reevaluate the need for
manufacturers to conduct postmarket surveillance of their metallic
thermal spray coated hip prostheses.

[[Page 4982]]

II. Significance of Guidance

    This guidance document represents the agency's current thinking on
what data are necessary to support reconsideration of the thermal spray
coated hip prosthesis postmarket surveillance requirements. It does not
create or confer any rights for or on any person and does not operate
to bind FDA or the public. An alternative approach may be used if such
approach satisfies the applicable statute, regulations, or both.
    The agency has adopted Good Guidance Practices (GGP's), which set
forth the agency's policies and procedures for the development,
issuance, and use of guidance documents (62 FR 8961, February 27,
1997). This guidance document is issued as a Level 1 guidance
consistent with GGP's.

III. Electronic Access

    In order to receive ``Guidance for Industry on the Testing of
Metallic Plasma Sprayed Coatings on Orthopedic Implants to Support
Reconsideration of Postmarket Surveillance Requirements'' via your fax
machine, call the CDRH Facts-On-Demand (FOD) system at 800-899-0381 or
301-827-0111 from a touch-tone telephone. At the first voice prompt
press 1 to access DSMA Facts, at second voice prompt press 2, and then
enter the document number (946) followed by the pound sign (#). Then
follow the remaining voice prompts to complete your request.
    Persons interested in obtaining a copy of the guidance may also do
so using the Internet. CDRH maintains an entry on the Internet for easy
access to information including text, graphics, and files that may be
downloaded to a personal computer with access to the Internet. Updated
on a regular basis, the CDRH home page includes ``Guidance for Industry
on the Testing of Metallic Plasma Sprayed Coatings on Orthopedic
Implants to Support Reconsideration of Postmarket Surveillance
Requirements,'' device safety alerts, Federal Register reprints,
information on premarket submissions (including lists of approved
applications and manufacturers' addresses), small manufacturers'
assistance, information on video conferencing and electronic
submissions, Mammography Matters, and other device-oriented
information. The CDRH home page may be accessed at http://www.fda.gov/
cdrh. ``Guidance for Industry on the Testing of Metallic Plasma Sprayed
Coatings on Orthopedic Implants to Support Reconsideration of
Postmarket Surveillance Requirements'' will be available at http://
www.fda.gov/cdrh/postsurv/plasmaspry.pdf.

IV. Comments

    Interested persons may, at any time submit to the contact person
above written comments regarding this guidance. FDA will consider any
comments to determine whether to revise or revoke the guidance.

    Dated: January 16, 2000.
Linda S. Kahan,
Deputy Director for Regulations Policy, Center for Devices and
Radiological Health.
[FR Doc. 00-2242 Filed 2-1-00; 8:45 am]
BILLING CODE 4160-01-F