FOUNDATION PLASMA SPRAYED METAL-BACKED PATELLA by ENCORE ORTHOPEDICS, INC.

The Foundation® Plasma Sprayed Metal-backed Patella is intended to be used as a cemented patellar surface replacement in treating patients who are candidates for primary total knee arthroplsty as a result of osteoarthritis, inflammatory arthritis, traumatic arthritis or rheumatoid arthritis with or without varus, valgus, or flexion deformities, or revision arthroplasty where bone loss is minimal. It is intended to aid the surgeon in relieving the patient of knee pain and restoring knee joint function.

Device Description

The Foundation® Plasma Sprayed Metal-backed Patella has a " sombrero" shaped plastic articulating surface and a metal baseplate. The baseplate has three smooth pegs for rotational stability. The plastic component is manufactured from UHMWPe that conforms to ASTM F648. The metal baseplate is fabricated from wrought Ti-6A1-4V (ASTM F136) and is plasma sprayed with commercially pure titanium to provide a roughened surface to enhance cement fixation.

AI/ML Overview

Here's an analysis of the provided text regarding the acceptance criteria and supporting study for K973672:

This 510(k) submission for the Foundation® Plasma Sprayed Metal-backed Patella relies heavily on substantial equivalence to predicate devices rather than a comprehensive clinical study to establish new acceptance criteria. The "study" described is limited to engineering performance testing. As such, many of the requested categories (especially those related to human readers, ground truth for training sets, and multi-reader multi-case studies) are not applicable or not detailed in this type of submission.

Here's the breakdown based on the provided information:

Acceptance Criteria and Reported Device Performance

Acceptance Criteria Category	Specific Acceptance Criteria (Inferred)	Reported Device Performance
Mechanical Integrity	Withstand expected in-vivo loads for the baseplate/plastic assembly attachment mechanism. (No specific quantitative thresholds provided)	"Results indicate that the attachment mechanism is sufficient to withstand the expected in-vivo loads."
Fixation Strength	Sufficient for cement fixation (implied by design feature of roughened surface). (No specific quantitative thresholds provided for adhesion strength)	"plasma sprayed with commercially pure titanium to provide a roughened surface to enhance cement fixation."
Material Conformance	UHMWPe conforms to ASTM F648. Ti-6A1-4V conforms to ASTM F136.	"The plastic component is manufactured from UHMWPe that conforms to ASTM F648." "The metal baseplate is fabricated from wrought Ti-6A1-4V (ASTM F136)..."
Biocompatibility	Materials used are recognized as biocompatible for implantable devices. (Implied by use of standard materials.)	UHMWPe, Ti-6A1-4V, commercially pure titanium plasma spray. No specific studies mentioned.
Sterility	(Not explicitly mentioned in the provided text, but assumed to be met for an implantable device.)	Not detailed.
Design/Geometry	"Sombrero" shaped plastic articulating surface; Three smooth pegs for rotational stability.	"has a 'sombrero' shaped plastic articulating surface and a metal baseplate. The baseplate has three smooth pegs for rotational stability."
Performance Equivalence	Equivalent to predicate devices (Porous Coated Metal-backed patella K932246, Miller/Galante K863805, Natural-Knee K873601) in design, features, and indications.	"The Foundation® Plasma Sprayed Metal-backed Patella is the very same device in regards to articulating geometry, assembly, and indications for usage as the Porous Coated Metal-backed patella approved in K932246." "Equivalent in design and indications to the Miller/Galante (Zimmer) and Natural-Knee (Sulzer Orthopedics) metal-backed patella (Exhibit VII)."

Study Details

Sample size used for the test set and the data provenance:
- Sample Size: Not explicitly stated for the "axial pushout and shear fatigue tests." The number of units tested is not provided.
- Data Provenance: This is an in-vitro engineering test, not a clinical study involving patient data. Therefore, concepts like country of origin or retrospective/prospective do not apply. The tests were performed presumably by or for Encore Orthopedics, Inc.
Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- Not Applicable. The "test set" here refers to physical devices undergoing mechanical tests, not clinical data requiring expert review.
Adjudication method for the test set:
- Not Applicable. As this is mechanical testing, the "ground truth" is determined by the physical outcome of the test (e.g., whether the attachment mechanism failed, or what force it withstood), not by human adjudication.
If a multi reader multi case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance:
- No. This is a medical device (implant), not an AI-powered diagnostic tool. MRMC studies are not relevant here.
If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- No. This is not an algorithmic device.
The type of ground truth used (expert consensus, pathology, outcomes data, etc.):
- Engineering Test Results/Physical Properties: The "ground truth" for the mechanical tests is the quantitative measurement of force/load at failure or the confirmation the device withstood specified loads without failure, compared against internal engineering specifications or industry standards for similar devices. For material conformance, the ground truth is the chemical and physical analysis results compared to ASTM standards.
The sample size for the training set:
- Not Applicable. There is no "training set" in the context of this 510(k) submission, as it does not involve machine learning or AI models.
How the ground truth for the training set was established:
- Not Applicable. As there is no training set.

Summary of the 510(k) Approach:

This 510(k) clearance is primarily based on substantial equivalence to previously cleared predicate devices. The "study" mentioned is limited to engineering bench testing (axial pushout and shear fatigue tests) to demonstrate that the specific modification (plasma sprayed coating) for cement fixation does not negatively impact the critical mechanical integrity of the baseplate-plastic assembly, and that the materials used conform to relevant ASTM standards. The core design, geometry, and intended use are argued to be identical to predicate devices. The FDA's determination letter further emphasizes the "cemented use only" limitation, which is related to the design and testing presented.

Summary

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K973672

DEC 1 8 1997

Summary of Safety and Effectiveness

Encore Orthopedics, Inc.
9800 Metric Blvd.
Austin, TX 78758
(512) 834-6237

Trade Name:	Foundation® Plasma Sprayed Metal-backed Patella
Common Name:	Metal-backed Patella
Classification Name:	patellofemorotibial polymer/metal/polymer semiconstrained cemented prostheses as Class II.

The Foundation® Plasma Sprayed Metal-backed Patella has a " sombrero" shaped Description: plastic articulating surface and a metal baseplate. The baseplate has three smooth pegs for rotational stability. The plastic component is manufactured from UHMWPe that conforms to ASTM F648. The metal baseplate is fabricated from wrought Ti-6A1-4V (ASTM F136) and is plasma sprayed with commercially pure titanium to provide a roughened surface to enhance cement fixation.

Intended Use: The Foundation® Plasma Sprayed Metal-backed Patella is intended to be used as a cemented patellar surface replacement in treating patients who are candidates for primary total knee arthroplsty as a result of osteoarthritis, inflammatory arthritis, traumatic arthritis or rheumatoid arthritis with or without varus, valgus, or flexion deformities, or revision arthroplasty where bone loss is minimal. It is intended to aid the surgeon in relieving the patient of knee pain and restoring knee joint function.

Comparable Features to Predicate Device(s): The Foundation® Plasma Sprayed Metal-backed Patella is the very same device in regards to articulating geometry, assembly, and indications for usage as the Porous Coated Metal-backed patella approved in K932246. The only difference is the coating applied. The Foundation® Plasma Sprayed Metal-backed Patella is equivalent in design and indications to the Miller/Galante (Zimmer) and Natural-Knee (Sulzer Orthopedics) metal-backed patella (Exhibit VII). These devices were cleared for commercial distribution on 510(k)s K863805 and K873601, respectively. Similarities include, metal-backed baseplate with Ti-6A1-4V substrate, " sombrero" shaped articulating surface and three fixation pegs.

Test Results: Testing on this device included axial pushout and shear fatigue tests of the baseplate/plastic assembly. Results indicate that the attachment mechanism is sufficient to withstand the expected in-vivo loads.

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Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850

DEC 18 1997

Ms. Debbie De Los Santos Regulatory/Clinical Specialist Encore Orthopedics, Inc. 9800 Metric Boulevard Austin, Texas 78758

Re : K973672 Foundation® Plasma Sprayed Metal-Backed Patella Requlatory Class: II Product Code: JWH Dated: September 24 ,1997 Received: September 26, 1997
Dear Ms. De Los Santos:

We have reviewed your Section 510(k) notification of intent to market the device referenced above and we have determined the device is substantially equivalent (for the indications for use stated in the enclosure) 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, Druq, and Cosmetic Act (Act). This decision is based on this device being equivalent only to similar devices labeled and intended to be fixed within bone with acrylic "bone cement." You may, therefore, market your device subject to the general controls provisions of the Act and the following limitations :

1. This device may not be labeled or promoted for noncemented use.
1. All labeling for this device, including package label and labeling included within the package, must prominently state that the device is intended for cemented use only.

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Page 2 - Ms. Debbie De Los Santos

Any non-cemented fixation of this device is considered 3. investigational and may only be investigated as a significant risk device in accordance with the investigational device exemption (IDE) regulation under 21 CFR, Part 812. All users of the device for noncemented fixation must receive approval from their respective institutional review boards (IRBs) and the Food and Drug Administration (FDA) to conduct the investigation.
The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practices, labeling, and prohibitions against misbranding and adulteration.

If your device is classified (see above) into either class II (Special Controls) or class III (Premarket Approval), it may be subject to such additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 895. ਕਿ substantially equivalent determination assumes compliance with the current Good Manufacturing Practice requirement, as set forth in the Quality System Regulation (QS) for Medical General requlation (21 CFR Part 820) and that, Devices: through periodic (QS) inspections, the Food and Drug Administration (FDA) will verify such assumptions. Failure to comply with the GMP regulation may result in regulatory In addition, FDA may publish further announcements action. Please note: concerning your device in the Federal Register. 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 begin marketing your device as described in your 510(k) premarket notification immediately. An FDA finding of substantial equivalence of your device to a legally marketed predicate device results in a classification for your device and permits your device to proceed to the market.

If you desire specific advice for your device on our labeling requlation (21 CFR Part 801 and additionally 809.10 for in vitro diagnostic devices), please contact the Office of Compliance at (301) 594-4659. Additionally, for questions on the promotion and advertising of your device, 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

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Page 3 - Ms. Debbie De Los Santos

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,

C. Edwin McWhirter, Ph.D.

ia M. Witten, Ph.D., M.D. Ce Director Division of General and Restorative Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

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510(k) Number (if known): K973672

Device Name:

Indications For Use:

Foundation® Plasma Sprayed Metal-backed Patella Indications For Use

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

oneurrence of CDRH Office of Device Evaluation (ODE)

coeeef

(Division Sign-Off)
Division of General Restorative Devices
510(k) Number K973672

Prescription Use (per 21 CFR 801.109)

Over-The-Counter Use

(Optional Format 1-2-96)_

Regulation Number and Section

§ 888.3560 Knee joint patellofemorotibial polymer/metal/polymer semi-constrained cemented prosthesis.

(a)
Identification. A knee joint patellofemorotibial polymer/metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace a knee 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 a tibial component or components and a retropatellar resurfacing component made of ultra-high molecular weight polyethylene. This generic type of device is limited to those prostheses intended for use with bone cement (§ 888.3027).(b)
Classification. Class II.