The P.F.C. Sigma Knee System is indicated for use only with bone cement (PMMA) for patients suffering from severe pain and disability due to permanent structural damage resulting from rheumatoid arthritis, osteoarthritis, post-traumatic arthritis, collagen disorders or pseudogout. This damage may also be the result of trauma or failed prior surgical intervention.

Device Description

The P.F.C. Sigma Inset Patella is a patellar prosthesis intended for use in Total Knee Replacement. The device is constructed of UHMWPE.

AI/ML Overview

The provided documents are a 510(k) premarket notification for a medical device, the P.F.C. Sigma Knee System Inset Patella. This type of submission focuses on demonstrating substantial equivalence to a legally marketed predicate device, rather than providing new clinical study data with acceptance criteria and performance metrics in the way new drug or novel medical device approvals often do.

Therefore, the documents do not contain information regarding a study that proves the device meets specific acceptance criteria in terms of clinical performance or effectiveness, nor do they include details like sample sizes, expert ground truth establishment, or multi-reader multi-case studies as requested in your prompt.

Instead, the "acceptance criteria" here are that the device is substantially equivalent to a predicate device already on the market, meaning it has the same intended use and similar technological characteristics. The "study" is the comparison made in the 510(k) submission itself.

Here's a breakdown of the requested information based on the provided text, highlighting what is not applicable or not present in a 510(k) submission of this nature:

Acceptance Criteria and Study for P.F.C. Sigma Knee System Inset Patella

This submission is a 510(k) premarket notification, which seeks to establish "substantial equivalence" of a new device to a legally marketed predicate device. As such, it does not typically involve clinical trials or studies with performance-based acceptance criteria as would be seen for novel devices or drugs. The "acceptance criteria" discussed below refer to the criteria for demonstrating substantial equivalence.

1. Table of Acceptance Criteria and Reported Device Performance

Acceptance Criteria (for Substantial Equivalence)	Reported Device Performance (vs. Predicate)
Intended Use: Device has the same intended use as legally marketed predicate device.	Matches: Indicated for use only with bone cement (PMMA) for patients suffering from severe pain and disability due to permanent structural damage resulting from rheumatoid arthritis, osteoarthritis, post-traumatic arthritis, collagen disorders or pseudogout, or trauma/failed prior surgical intervention. This intended use is identical to the P.F.C.® Σ Oval Dome Patella and Universal Inset Patella.
Technological Characteristics: Device has similar technological characteristics to legally marketed predicate device.	Similar:
- Bone Removal Method	- P.F.C. Σ Inset Patella: reamed cavity (Matches Universal Inset Patella, differs from P.F.C. Σ Oval-Dome Patella's planar resection)
- Bone Periphery @ Major Diameter	- P.F.C. Σ Inset Patella: yes (Matches Universal Inset Patella, differs from P.F.C. Σ Oval-Dome Patella's no)
- Articulating Surface	- P.F.C. Σ Inset Patella: 1" spherical radius (Matches P.F.C. Σ Oval-Dome Patella, approximately matches the PFC® C/R Femur Patellar Groove 2 which has a 0.8" spherical radius; stated to "Exactly match the PFC® Σ Femur (C/R, C/S & TC3) Patellar Grooves 1")
- Cement Pocket Geometry	- P.F.C. Σ Inset Patella: Dovetail Undercut (Matches both predicate devices)
- Peg Geometry(ies)	- P.F.C. Σ Inset Patella: Round & Clover (Differs from both predicate devices' Round only; potential area of difference that needs to be justified as not raising new safety/effectiveness concerns).
- Material	- P.F.C. Σ Inset Patella: UHMWPE (Matches both predicate devices)
Safety and Effectiveness: Does not raise different questions of safety and effectiveness from the predicate device.	Affirmed by FDA determination: The FDA reviewed the 510(k) and determined the device is substantially equivalent for the stated indications for use, noting specific limitations regarding cemented-use only and investigational use for non-cemented fixation. This implies that the differences in technological characteristics (e.g., bone removal, bone periphery, peg geometry) were deemed not to raise new questions of safety or effectiveness. The FDA's letter explicitly states the device is "substantially equivalent."

2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)

Not Applicable / Not Provided: As this is a 510(k) submission, there isn't a "test set" in the context of a clinical study aimed at proving device performance against efficacy endpoints. The "testing" primarily involves
design comparisons and potentially bench testing (though not detailed here) to ensure equivalence. This documentation does not refer to clinical data from a sample size of patients.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience)

Not Applicable / Not Provided: Ground truth establishment by experts for a test set is relevant for studies measuring diagnostic accuracy or clinical outcomes. A 510(k) submission typically relies on internal engineering and design expertise to compare the new device to the predicate, and FDA reviewers (qualified medical device experts) evaluate this comparison.

4. Adjudication method (e.g. 2+1, 3+1, none) for the test set

Not Applicable / Not Provided: Adjudication methods are used in clinical trials to resolve discrepancies in data interpretation, often by expert panels. This is not part of a 510(k) submission focused on substantial equivalence.

5. 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

Not Applicable / Not Provided: MRMC studies are specific to diagnostic devices (often imaging AI). This device is an orthopedic implant, and the submission does not involve AI assistance or diagnostic interpretation.

6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done

Not Applicable / Not Provided: This device is a passive orthopedic implant, not an algorithm or AI system.

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)

Not Applicable / Not Provided: The "ground truth" for a 510(k) lies in the established safety and effectiveness profile of the predicate device. The new device aims to match or be acceptably similar to this established profile through design and material comparisons, rather than generating new outcomes data for "ground truth."

8. The sample size for the training set

Not Applicable / Not Provided: There is no "training set" as this is not an AI/machine learning device. The design and manufacturing process would involve internal testing and validation, but not in the context of a "training set" for an algorithm.

9. How the ground truth for the training set was established

Not Applicable / Not Provided: No training set, therefore no associated ground truth establishment.

Summary

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

Johnson & Johnson Professional, Inc. 325 Paramount Drive Ravnham. MA 02767-0350

Contact Person: John Ferros Phone: 508.880.8287

Name of Device

Classification Name: Knee joint patellofemorotibial polymer/metal/polymer semi-constrained cemented prosthesis has been placed in Class II by the FDA under 21 CFR 888.3560. This falls under the Orthopaedics panel/87. Common Name: Semi-constrained total knee prosthesis.

Trade Name/Proprietary Name: P.F.C. Sigma Knee System Inset Patella

Performance Standards: No performance standards have been developed for this device.

Predicate Device

P.F.C.® Σ Oval Dome Patella, Universal Inset Patella

Description of Device

The P.F.C. Sigma Inset Patella is a patellar prosthesis intended for use in Total Knee Replacement. The device is constructed of UHMWPE.

Intended Use

The P.F.C.® Sigma Knee System is indicated for use only with bone cement (PMMA) for patients suffering from severe pain and disability due to permanent structural damage resulting from rheumatoid arthritis,

osteoarthritis, post-traumatic arthritis, collagen disorders or pseudogout. This damage may also be the result of trauma or failed prior surgical intervention.

Technological Characteristics Compared to Predicate Device

	P.F.C. ΣInset Patella(subject of this submission)	P.F.C. ΣOval-Dome PatellaK961685	UniversalInset PatellaK933867
Design
Bone Removal	reamed cavity	planar resection	reamed cavity
Bone Periphery @ MajorDiameter	yes	no	yes
Articulating Surface	1" spherical radius¹	1" spherical radius¹	0.8" spherical radius²
Cement Pocket Geometry	Dovetail Undercut	Dovetail Undercut	Dovetail Undercut
Peg Geometry(ies)	Round & Clover	Round	Round
Material	UHMWPE	UHMWPE	UHMWPE

Exactly matches the PFC® Σ Femur (C/R, C/S & TC3) Patellar Grooves 1.

Approximately matches the PFC® C/R Femur Patellar Groove 2.

Image /page/0/Picture/20 description: The image shows the number 10 written in a handwritten style. The number is written in black ink on a white background. The number is slightly tilted to the left.

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

Image /page/1/Picture/1 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo consists of a circular seal with the text "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" around the perimeter. Inside the circle is an abstract symbol that resembles a stylized caduceus or a representation of human figures.

Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850

Mr. John D. Ferros Senior Regulatory Affairs Specialist Johnson & Johnson Professional, Inc. 325 Paramount Drive Raynham, Massachusetts 02767-0350

JUL 16 1997

Re : K971652 P.F.C.® Σ (Sigma) Inset Patella Requlatory Class: II Product Code: JWH Dated: May 5, 1997 Received: May 6, 1997

Dear Mr. Ferros:

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, Drug, 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 non-cemented use.
All labeling for this device, including package 2. label and labeling included within the package, must prominently state that the device is intended for cemented use only.

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

Any non-cemented fixation of this device is 3. considered 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 non-cemented 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 Requlations, Title 21, Parts 800 to 895. A substantially equivalent determination assumes compliance with the Good Manufacturing Practice for Medical Devices: General (GMP) regulation (21 CFR Part 820) and that, through periodic GMP inspections, the Food and Drug Administration (FDA) will verify such assumptions. Failure to comply with the GMP requlation may result in regulatory action. In addition, FDA may publish further announcements concerning your device 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 Regulations.

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.

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

Page 3 - Mr. John D. Ferros

If you desire specific advice for your device on our labeling regulation (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 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,

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

Enclosure

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

510(k) Number (if known): ____________________________________________________________________________________________________________________________________________________

Device Name: P.F.C. Sigma Knee System Inset Patella

Indications for Use:

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

Concurrence of CDRH, Office of Device Evaluation (ODE)

Division Sign Off

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

Prescription Use _x (Per 21 CFR 801.109) OR

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.