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Guidance Document For the Preparation of Premarket |
This guidance was written prior to the February 27, 1997 implementation of FDA's Good Guidance Practices, GGP's. It does not create or confer 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 requirements of the applicable statute, regulations, or both. This guidance will be updated in the next revision to include the standard elements of GGP's.
D R A F T
January 10, 1995
PLEASE FORWARD YOUR COMMENTS TO:
Orthopedic Devices Branch
Division of General and Restorative Devices
Center for Devices and Radiological Health
U.S. Food and Drug Administration
9200 Corporate Blvd
Rockville, MD 20850
301-594-2036
CONTENTS
PREFACE
The FDA has reclassified the hip joint metal/ceramic/polymer semi- constrained cemented or non-cemented prosthesis (referred to in this document as ceramic ball hip system) from class III (premarket approval) into class II (performance standards) (see Federal Register, vol. 53, No. 103). A premarket notification (510k) must be submitted by all distributors of ceramic balls and hip stems labeled for use with a ceramic ball.
The purpose of this document is to recommend to the device manufacturer or sponsor of premarket notifications (510(k)), Investigational Device Exemption (IDE), Premarket Approval (PMA), reclassification petition, or master file important information that should be submitted to FDA in order for FDA to determine the substantial equivalence and/or safety and effectiveness of hip systems which may include a ceramic ball. The development of this guidance document was based on data in a reclassification petition filed by PROTEK, Inc., Indianapolis, IN, and on the evaluation of the literature concerning ceramic ball hip systems by the Division of Surgical and Rehabilitation Devices (DSRD) . It suggests some important evaluation criteria, test procedures, and end points that FDA feels are necessary to provide reasonable assurance of substantial equivalence and/or safety and effectiveness of ceramic ball hip systems. Although this guidance document contains certain administrative requirements, it does not replace the requirements of the 21 CFR 801 or 807 or the statue.
FDA may require information in addition to what is contained in this document if circumstances require it. In other instances, the sponsor may be able to sufficiently justify the omission of some tests. Suggestions and recommendations presented in this document are not mandatory requirements, but reflect data and methodologies which ORDB has determined to be acceptable. Therefore, the words "should", "must" and "shall" are not used in a regulatory sense and should not be construed as such. They express FDA's current feeling as to what constitutes good scientific decision making.
The guidance document should be viewed as a living document. As scientific knowledge changes and scientific techniques are improved, FDA will revise the document. Nonetheless, the basic objectives will remain the same.
IDENTIFICATION OF THE STEM
The following must be tabulated for each stem having the cone design and ceramic balls specified below:
CONE DESIGN
A table or dimensioned engineering design drawings must be provided which include tolerances for the following dimensions:
The table or dimensioned engineering design drawings must include all:
IDENTIFICATION OF THE BALL
The following should be tabulated for the ceramic balls identified above:
The following must be provided regarding surface engravings:
The following information on radioactive isotopes must be provided:
A letter of access from the ball manufacturer must be submitted to FDA for all ceramic balls which were not previously approved or found substantially equivalent. The letter of access must give FDA permission to examine data in the master file pertaining to the ceramic balls identified in the labeling of the stem.
BALL DESIGN
Dimensioned engineering drawings and tolerances for the following parameters must be provided for all ceramic balls which were not previously approved or found to be substantially equivalent. The values in parentheses are the boundaries of the reclassified ceramic ball hip system. A system does not have to be within these bounds to be determined substantially equivalent if the mechanical test results are adequate.
The following must be provided for alumina balls:
The following must be provided for zirconia balls:
A description of the critical manufacturing methods, QC tests and pass/fail criteria must be provided.
MECHANICAL TESTING
Each hip stem cone with a unique set of dimensions and tolerances, materials and design must be mechanically tested with either:
Once a particular cone with a specified set of dimensions and tolerances has been cleared for use with a particular ball, other stems from the same manufacturer with the same set of cone dimensions and tolerances will not require mechanical testing.
A statement should be provided to the effect that the balls and cones which were mechanically tested, were representative of the design tolerances of the product shipped for clinical use and that ceramic test specimens had the same composition and structure (e.g., grain size, density) as the ball. All deviations from this statement must be listed and explained. The test result for each specimen must be provided and all specimens chosen for testing must be identified.
FDA may require additional mechanical tests for cone and ball designs whose mechanical performance can not be adequately predicted from the design specifications and mechanical tests listed in this document.
STATIC COMPRESSION
A random sample of at least 5 balls of each combination shall be loaded axially in compression to failure following ISO 7206-5. The load may be applied to the ball through a copper ring or an equivalent method of loading (e.g., an appropriate copper ring to load a 32 mm ball would have a 1" O.D., 0.800" width and 0.055" thickness).
A detailed test report on static compression to failure must be provided. A copy of the entire report should be included in the 510k even if the same cone and ball designs were cleared in other documents. Each data point must identify the manufacturer and model numbers of each ceramic ball which was tested on the stem. The cone trunions mechanically tested must be identified as outlined above under CONE DESIGN.
The average fracture strength of the balls shall exceed 46 KN. No ball shall fail at less than 20 kN.
NEW BALL MECHANICAL TESTING
A ceramic ball made of a new material or manufacturing process or produced by a new manufacturer may require the following mechanical test data in addition to static compression to failure:
LABELLING
The labeling for each stem must identify the manufacturer and model or catalogue numbers of each ceramic ball to be used with the stem. The labeling for the ball must state that the ball will be used only with stems labeled for use with the ball and that the stem labeling should be consulted to determine which stems are compatible with the ceramic ball. This allows the use of future hip stems with a ceramic ball without altering the ball labeling. It would also be appropriate to include the following in the ball labeling:
Zirconia balls must contain the following labeling:
OTHER INFORMATION
FDA may require additional testing for cone and ball designs whose performance can not be adequately predicted from the design specifications and tests listed in this document.
Clinical data may be accepted in support of but not in place of mechanical data since the mechanical properties of a stem-ball system may be inferior to that approved in the petition, yet still not demonstrate ball fracture or wear in clinical studies.
TEST REPORT CONTENT
Detailed reports should be organized and subdivided into separate sections (some sections may be combined to enhance clarification) having (if applicable) the following headings:
Can you provide the following?:
clinical fracture rate (number fractured/number implanted) of each type of ceramic ball (material, diameter, neck length)
evidence that a smaller ball is normally used in a lighter patient
copy of iso 6474
cracking or phase changes due to surface engraving
methods of evaluating radioactive isotopes
a list of material requirements for zirconia balls
Uploaded on August 13, 1998
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