DURATION II ACETABULAR COMPONENTS-ETHYLENE OXIDE STERILIZATION by HOWMEDICA CORP.

The intended use of this additional style of System 12® acetabular inserts is identical to that of previously released System 12® inserts: they are intended to be used with Osteolock/Vitalock acetabular shells in primary or revision total hip arthroplasty.

Device Description

The purpose of this submission is to describe an additional style of System 12® acetabular Inserts which are stabilized/sterilized using a process called Duration® II Stabilization. The purpose of the Duration® If process is to crosslink all of the free radicals found in the UHMWPE rod stock by exposure to gamma radiation followed by a stabilization process in a heated oven. During this radiation/stabilization period, the UHMWPE is exposed to a very low oxygen concentration. The stabilized rod stock is then machined to its final configuration. The acetabular insert is packaged in air, and terminally sterilized by the ethylene oxide sterilization process. The System 12® Acetabular Inserts produced by this method conform to the requirements for Ultra High Molecular Weight Polyethylene specified in ASTM Specification F-648, and the FDA guidance document on UHMWPE used in Bearing Surfaces for Orthopedic Devices.

These System 12® inserts are identical in design to the previously cleared System 12® inserts: they are available in a range of outer diameter sizes to mate with the respective acetabular shell, and 22.0, 22.2, 26, 28, and 32mm inner diameters to mate with Howmedica femoral heads. These inserts are available in a neutral, 10°, and 15° hooded design. The locking mechanism of this style of acetabular insert is identical to the previously released System 12® acetabular inserts.

AI/ML Overview

The manufacturer, Howmedica, sought to introduce an additional style of System 12® acetabular inserts, the Duration® II, which are stabilized/sterilized using a process involving gamma radiation, heated oven stabilization, and ethylene oxide sterilization. The main purpose was to demonstrate substantial equivalence to previously cleared System 12® acetabular inserts.

Here's an analysis of the provided information regarding acceptance criteria and the supporting study:

1. Table of Acceptance Criteria and Reported Device Performance

Acceptance Criteria / Marketing Claim	Reported Device Performance
Material Properties:
1. Duration® II products meet all ASTM F 648 specified standards.	Met: The summary explicitly states, "The acetabular insert is packaged in air, and terminally sterilized by the ethylene oxide sterilization process. The System 12® Acetabular Inserts produced by this method conform to the requirements for Ultra High Molecular Weight Polyethylene specified in ASTM Specification F-648."
2. Duration® II products have no detectable oxidation as measured by FTIR up to 30 days of accelerated aging at 80°C in air.	Met: The summary states, "Duration® II products have no detectable oxidation as measured by FTIR up to 30 days of accelerated aging at 80° C in air." This is a direct claim made by the manufacturer as a result of their testing.
3. Duration® II products have a higher gel content (cross-linking) than air irradiated UHMWPE measured in accordance with modified ASTM D2765-90 standard.	Met: The summary states, "Duration® II products have a higher gel content (cross-linking) than air irradiated UHMWPE measured in accordance with modified ASTM D2765-90 standard." This is a direct claim made by the manufacturer as a result of their testing.
4. Duration® II has a lower tensile modulus than air irradiated UHMWPE. This lower stiffness has demonstrated an increase in contact area and a decrease in contact stress.	Met: The summary states, "Duration® II has a lower tensile modulus than air irradiated UHMWPE. This lower stiffness has demonstrated an increase in contact area and a decrease in contact stress." This is a direct claim made by the manufacturer as a result of their testing.
5. No free radicals are detected in the Duration® II material when analyzed by the ESR technique of the final product.	Met: The summary states, "No free radicals are detected in the Duration® II material when analyzed by the ESR technique of the final product." This is a direct claim made by the manufacturer as a result of their testing.
Wear Performance:
6. Duration® II has a lower wear rate, as measured by hip wear simulator than air irradiated UHMWPE.	Met: The summary reports significantly lower wear. "Duration® II has a lower wear rate, as measured by hip wear simulator than air irradiated UHMWPE (an average total wear of 198.60 ± 31.9 mm³ instead of 310 ± 40.8 mm³)."

Details of the Study Proving Device Meets Acceptance Criteria:

The provided document describes a bench testing and material characterization study to support the substantial equivalence of the Duration® II Acetabular Inserts.

Sample Size Used for the Test Set and Data Provenance:
- Test Set Sample Size: Not explicitly stated for each specific test (e.g., number of samples for FTIR, ESR, tensile modulus). However, for the hip wear simulator, multiple samples would have been run to generate the reported average and standard deviation (198.60 ± 31.9 mm³ and 310 ± 40.8 mm³). The "an average total wear" suggests multiple iterations, but the exact number of tested inserts is not specified.
- Data Provenance: The study was conducted by Howmedica, implying retrospective, in-house laboratory testing within the United States (the contact address is Rutherford, NJ). It is not clinical data.
Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts:
- Not applicable. This was a laboratory-based material science and mechanical performance study, not a clinical study requiring expert ground truth for diagnostic accuracy. The "ground truth" here is the physical measurement of material properties and wear rates using established scientific methods and standards.
Adjudication Method for the Test Set:
- Not applicable. As a laboratory study, results are based on instrumental measurements and adherence to specified test protocols (e.g., ASTM standards). There is no "adjudication" in the sense of reconciling human expert opinions.
Multi Reader Multi Case (MRMC) Comparative Effectiveness Study:
- No, an MRMC comparative effectiveness study was not done. This device is a component of a medical implant, and the study focused on material and mechanical performance, not a diagnostic or treatment effectiveness study requiring human reader assessment.
Standalone Performance (Algorithm Only without Human-in-the-Loop Performance):
- Yes, the described study assesses the "standalone" performance of the Duration® II material and its components in a laboratory setting. This means the device's inherent properties and performance (wear rate, strength, cross-linking, oxidation) were evaluated directly, without human interaction influencing the measurement results or interpretation in a real-world clinical scenario. The hip wear simulator, for example, tests the device's mechanical wear performance independent of a human's input or interpretation.
Type of Ground Truth Used:
- The "ground truth" used for this "device" (material) is based on standardized physical and chemical measurements and comparative laboratory testing against a predicate device or control. This includes:
  - Material properties: Adherence to ASTM F-648, FTIR for oxidation, ESR for free radicals, modified ASTM D2765-90 for gel content, and tensile modulus measurements.
  - Mechanical performance: Hip wear simulator testing provides quantitative wear rate data.
Sample Size for the Training Set:
- Not applicable. There is no explicit "training set" in this context. The study describes the characterization and testing of the final product material. While manufacturing process parameters are optimized, the document does not detail a separate "training" phase for the material itself in the way an AI algorithm has a training set.
How the Ground Truth for the Training Set Was Established:
- Not applicable, as there was no "training set" in the conventional sense of machine learning. The "ground truth" for the material's properties (e.g., meeting ASTM F-648 standards) is established by the specifications defined by the standard itself and verified through appropriate analytical and mechanical testing methods.

Summary

{0}------------------------------------------------

K980926

DEC 16 1998

510(k) Summary

Duration® II System 12® Acetabular Inserts - Ethylene Oxide Sterilization Device:

These inserts are substantially equivalent to the other System 120 acetabular liners which are already in distribution by Howmedica.

Testing was performed in accordance with the draft FDA guidance on UHMWPE.

The following marketing claims will be made for the product:

1. Duration® II products meet all ASTM F 648 specified standards.
Duration® II products have no detectable oxidation as measured by FTIR up to 2. 30 days of accelerated aging at 80° C in air.
1. Duration® II products have a higher gel content (cross-linking) than air irradiated UHMWPE measured in accordance with modified ASTM D2765-90 standard.
Duration® II has a lower tensile modulus than air irradiated UHMWPE. This যঁ lower stiffness has demonstrated an increase in contact area and a decrease in contact stress.

{1}------------------------------------------------

No free radicals are detected in the Duration® II material when analyzed by 5. the ESR technique of the final product.
Duration® II has a lower wear rate, as measured by hip wear simulator than air 6. irradiated UHMWPE (an average total wear of 198.60 ± 31.9 mm³ instead of 310 ± 40.8 mm³). Testing was performed in a multiaxial hip joint simulator for five million cycles using a 32 mm CoCr head articulating counterface and bovine calf serum as a lubricant. The results of in vitro tests have not been shown to correlate with clinical wear mechanisms.

Frank Maas For information contact: Manager, Regulatory Affairs Howmedica Osteonics 359 Veterans Boulevard Rutherford, NJ 07070 (201) 507-7875

{2}------------------------------------------------

Image /page/2/Picture/1 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo features a stylized eagle or bird design with three curved lines representing the bird's body and wings. The text "DEPARTMENT OF HEALTH & HUMAN SERVICES-USA" is arranged in a circular pattern around the bird. The logo is black and white and has a simple, clean design.

Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850

DEC 1 6 1998

Ms. Margaret Crowe Manager, Requlatory Affairs Howmedica Inc. Pfizer Medical Technology Group 359 Veterans Boulevard Rutherford, New Jersey 07070-2584

Re : K980925 Duration® II Tibial Inserts - EtO Trade Name: Sterilization K980926 Duration® II Acetabular Components - EtO Trade Name: Sterilization Requlatory Class: II Product Codes: JWH and JDI Dated: October 7, 1998 Received: October 8, 1998

Dear Ms. Crowe:

We have reviewed your Section 510(k) notifications of intent to market the devices referenced above and we have determined these devices are substantially equivalent (for the indications for use stated in the enclosures) to devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act). You may, therefore, market the devices, subject to the general controls provisions of the Act. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration.

If your devices are classified (see above) into either class II (Special Controls) or class III (Premarket Approval), they may be subject to such additional controls. Existing major regulations affecting your devices can be found in the Code of Federal Requlations, Title 21, Parts 800 to 895. ਬ substantially equivalent determination assumes compliance with the current Good Manufacturinq Practice requirement, as set forth in the Quality System Requlation (QS) for Medical Devices: General requlation (21 CFR Part 820) and that, through periodic (QS) inspections, the Food and Drug Administration (FDA) will verify such assumptions. Failure to

{3}------------------------------------------------

Paqe 2 - Ms. Margaret Crowe

In addition, FDA may publish further announcements action. concerning your devices in the Federal Register. Please note: this response to your premarket notification submission does not affect any obligation you might have under sections 531 through 542 of the Act for devices under the Electronic Product Radiation Control provisions, or other Federal laws or requlations.

This letter will allow you to beqin marketing your devices as described in your 510(k) premarket notification. The FDA finding of substantial equivalence of your devices to legally marketed predicate devices results in a classification for your devices and thus, permits your devices to proceed to the market.

If you desire specific advice for your devices on our labeling regulation (21 CFR Part 801 and additionally 809.10 for in vitro diaqnostic devices), please contact the Office of Compliance at (301) 594-4659. Additionally, for questions on the promotion and advertising of your devices, please contact the Office of Compliance at (301) 594-4639. Also, please note the regulation entitled, "Misbranding by reference to
premarket notification" (21 CFR 807.97). Other general information on your responsibilities under the Act may be obtained from the Division of Small Manufacturers Assistance at its toll-free number (800) 638-2041 or (301) 443-6597 or at its internet address "http://www.fda.gov/cdrh/dsmamain.html".

Sincerely yours,

lia M. Witten, Ph.D., M.D. Director Division of General and Restorative Devices Office of Device Evaluation Center for Devices and Radioloqical Health

Enclosures

{4}------------------------------------------------

Indications for Use

510(k) Number (if known): K980926

Device Name: Duration® II System 12® Acetabular Inserts, Ethylene Oxide Sterilization

Indications for Use:

The intended use of this additional style of System 12® acetabular inserts is identival The Intention use of this additional or to of of of of of of the need with to that of provided foremously of evision total hip arthroplasty.

(PLEASE DO NOT WRITE BELOW THIS LINE - CONTINUE ON ANOTHER PAGE IF NEEDED)

Concurrence of CDRH, Office of Device Evaluation (ODE)

OR Prescription Use (Per 21 CFR 801.109)

Over-The-Counter Use_

(Optional Format 1-2-96)

Division Sign Org.

eneral Restorative Devic

Regulation Number and Section

§ 888.3350 Hip joint metal/polymer semi-constrained cemented prosthesis.

(a)
Identification. A hip joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace a hip joint. The device limits translation and rotation in one or more planes via the geometry of its articulating surfaces. It has no linkage across-the-joint. This generic type of device includes prostheses that have a femoral component made of alloys, such as cobalt-chromium-molybdenum, and an acetabular resurfacing component made of ultra-high molecular weight polyethylene and is limited to those prostheses intended for use with bone cement (§ 888.3027).(b)
Classification. Class II.