The intended use of the modified tibial bearing inserts is identical to that of the unmodified tibial bearing inserts. As with the predicate tibial bearing inserts, the modified tibial bearing inserts are single use devices. They are intended for mating with commercially available Osteonics® Tibial Trays and corresponding posteriorly stabilized femoral and patellar components. The Osteonics® Scorpio™ Posteriorly Stabilized Total Knee Components are intended for cemented fixation. Specific indications for use are as follows:

Painful, disabling joint disease of the knee resulting from: degenerative arthritis, . rheumatoid arthritis or post-traumatic arthritis.
Post-traumatic loss of knee joint configuration and function.
Moderate varus, valgus, or flexion deformity in which the ligamentous structures can be returned to adequate function and stability.
Revision of previous unsuccessful knee replacement or other procedure.
Ligamentous instability requiring implant bearing surface geometries with increased constraint.
Absent or non-functioning posterior cruciate ligament.

Device Description

The Osteonics® Scorpio™ Total Knee Relaxed Back P/S Tibial Bearing Insert is a modification of the predicate Osteonics® Scorpio™ Total Knee Posteriorly Stabilized Tibial Bearing Insert. The modification involves increasing the posterior radius of the tibial bearing insert to a value of six inches as compared to three inches for the standard Scorpio™ family of tibial bearing inserts. This modification is designed to allow the femur to reach deeper flexion angles by further resisting femoro-tibial distraction and increase ligament tension in the deep flexion range. All other design features of the modified Scorpio™ design tibial bearing insert will remain unchanged. The sizes and UHMWPE thicknesses of the modified tibial bearing inserts will be identical to the predicate tibial bearing insert design.

AI/ML Overview

The provided document describes a medical device modification (K991461 Osteonics® Scorpio™ Total Knee Relaxed Back P/S Tibial Bearing Insert) and its substantial equivalence to a predicate device, rather than a study with acceptance criteria and performance metrics in the way one would typically quantify for AI/software-as-a-medical-device (SaMD).

Therefore, many of the requested elements (sample sizes, expert qualifications, MRMC studies, standalone performance, training set details) are not applicable to this type of device modification submission. This document focuses on demonstrating that a physical modification to an existing, cleared device does not raise new questions of safety or effectiveness.

Here's a breakdown of the available information, highlighting what is present and what is not applicable:

1. Table of Acceptance Criteria and Reported Device Performance

The document does not present quantitative acceptance criteria or performance metrics in a tabular format as would be seen for a diagnostic or AI device. Instead, it relies on demonstrating substantial equivalence to a predicate device.

Acceptance Criterion (Implicit for Substantial Equivalence)	Reported Device Performance (as demonstrated by the modification)
Safety and Effectiveness maintained: The modified device should be as safe and effective as the predicate device.	"All other design features of the modified Scorpio™ design tibial bearing insert will remain unchanged." "The sizes and UHMWPE thicknesses of the modified tibial bearing inserts will be identical to the predicate tibial bearing insert design." "A Risk Analysis and R & D Testing have been performed to demonstrate the substantial equivalence of this tibial bearing insert design to the predicate tibial bearing insert design."
Intended Use maintained: The modification should not change the intended use of the device.	"The intended use of the modified tibial bearing inserts is identical to that of the unmodified tibial bearing inserts."
Technological Characteristics (except the specified modification) are equivalent: Materials, manufacturing, and other design features should remain substantially similar.	"All features of the Osteonics® Scorpio™ Total Knee Relaxed Back P/S Tibial Bearing Insert are unchanged with the exception of 1) the change posterior radius of the tibial bearing insert from three inches to six inches. All other design features, materials and manufacturing methods will remain unchanged."

2. Sample size used for the test set and the data provenance

Not Applicable. This is a physical device modification, not a software or diagnostic algorithm undergoing testing on a "test set" of data. The "testing" referred to ("R & D Testing") would be mechanical, material, or bench testing rather than performance on a clinical data set.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts

Not Applicable. See point 2.

4. Adjudication method for the test set

Not Applicable. See point 2.

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. This is a physical implant, not an AI or diagnostic device that requires human interpretation.

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

Not Applicable. This is a physical implant, not a standalone algorithm.

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

Not Applicable. The "ground truth" for this device modification is assessed through engineering principles, material compatibility, biomechanical testing, and comparison to the predicate device's established safety and performance profile over time. The document states a "Risk Analysis and R & D Testing" were performed to demonstrate substantial equivalence.

8. The sample size for the training set

Not Applicable. This is not an AI/ML device requiring a training set.

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

Not Applicable. This is not an AI/ML device requiring a training set.

Summary of the Study (Device Modification)

The "study" in this context is the submission for a Special 510(k), which is specifically for modifications to a manufacturer's own legally marketed device. The goal is to demonstrate that the change does not significantly affect the safety or effectiveness of the device.

Device Modification:

Description: The modification involves increasing the posterior radius of the tibial bearing insert from three inches (predicate) to six inches.
Purpose of Modification: To allow the femur to reach deeper flexion angles by further resisting femoro-tibial distraction and increasing ligament tension in the deep flexion range.
Unchanged Features: All other design features, sizes, UHMWPE thicknesses, materials, and manufacturing methods remain identical to the predicate device.
Intended Use: Remains identical to the predicate device.

Proof of Meeting (Implicit) Acceptance Criteria (Substantial Equivalence):

The manufacturer performed a Risk Analysis and R&D Testing to demonstrate substantial equivalence. While details of these tests are not provided in this summary, they would typically involve bench testing (e.g., wear testing, fatigue testing, mechanical strength) to ensure the modified design performs comparably or better than the predicate, especially regarding the changed radius.
The FDA's decision to clear the device implies they accepted these demonstrations of substantial equivalence, ensuring the modified device meets the general controls provisions of the Act for safety and effectiveness. The limitations imposed by the FDA (cemented use only, minimum polyethylene thickness) indicate specific areas they wanted clarified and restricted to ensure continued safety.

Summary

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

MAY 17 999

K99 1461

Special 510(k) - Device Modification Summary of Safety and Effectiveness for the Osteonics® Scorpio™ Total Knee Relaxed Back P/S Tibial Bearing Insert

Submission Information

Name and Address of the Sponsorof the 510(k) Submission:	Howmedica Osteonics Corp.59 Route 17Allendale, NJ 07401-1677
Contact Person:	Marybeth NaughtonRegulatory Affairs Team Member
Date of Summary Preparation:	April 16, 1999
Device Identification:
Proprietary Name:	Osteonics® Scorpio™ Total KneeRelaxed Back P/S Tibial BearingInsert
Common Name:	Knee Prosthesis
Classification Name and Reference:	Knee Joint, Patellofemorotibial,Polymer/Metal/Polymer, Semi-Constrained, Cemented Prosthesis21 CFR §888.3560

Predicate Device Identification

The modified features of the Osteonics® Scorpio™ Total Knee Relaxed Back P/S Tibial Bearing Inserts are substantially equivalent to features of the following Osteonics® predicate device, which has been cleared for marketing via the 510(k) process:

Osteonics® Scorpio™ Total Knee Posteriorly Stabilized Tibial Bearing Insert ● (#K962152)

Device Description

The Osteonics® Scorpio™ Total Knee Relaxed Back P/S Tibial Bearing Insert is a modification of the predicate Osteonics® Scorpio™ Total Knee Posteriorly Stabilized Tibial Bearing Insert.

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

The modification involves increasing the posterior radius of the tibial bearing insert to a value of six inches as compared to three inches for the standard Scorpio™ family of tibial bearing inserts. This modification is designed to allow the femur to reach deeper flexion angles by further resisting femoro-tibial distraction and increase ligament tension in the deep flexion range. All other design features of the modified Scorpio™ design tibial bearing insert will remain unchanged. The sizes and UHMWPE thicknesses of the modified tibial bearing inserts will be identical to the predicate tibial bearing insert design.

Intended Use:

Painful, disabling joint disease of the knee resulting from: degenerative arthritis, . rheumatoid arthritis or post-traumatic arthritis.
Post-traumatic loss of knee joint configuration and function.
Moderate varus, valgus, or flexion deformity in which the ligamentous structures can be returned to adequate function and stability.
Revision of previous unsuccessful knee replacement or other procedure.
Ligamentous instability requiring implant bearing surface geometries with increased constraint.
Absent or non-functioning posterior cruciate ligament.

Performance Data:

A Risk Analysis and R & D Testing have have been performed to demonstrate the substantial equivalence of this tibial bearing insert design to the predicate tibial bearing insert design.

Statement of Technological Comparison:

All features of the Osteonics® Scorpio™ Total Knee Relaxed Back P/S Tibial Bearing Insert are unchanged with the exception of 1) the change posterior radius of the tibial bearing insert from three inches to six inches. All other design features, materials and manufacturing methods will remain unchanged.

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

Public Health Service

Image /page/2/Picture/2 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo is circular and contains the text "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" around the perimeter. In the center of the circle is an abstract symbol that resembles a stylized human figure or a bird in flight. The logo is black and white.

MAY 1 7 1999

Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850

Ms. Marybeth Naughton Requlatory Affairs Howmedica Osteonics Corporation 59 Route 17 Allendale, New Jersey 07401-1677

Re: K991461 Osteonics® Scorpio™ Total Knee Relaxed Back P/S Tibial Bearing Insert II Requlatory Class: Product Code: JWH Dated: April 22, 1999 Received: April 27, 1999

Dear Ms. Naughton:

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 system being equivalent only to similar device systems labeled and intended to be fixed within bone with acrylic "bone cement." You may, therefore, market your device subject to the qeneral controls provisions of the Act and the following limitations:

The thinnest tibial insert available is the nominal "size 1. 3″ insert, which has a minimum polyethylene thickness under the condyles of 6.25mm.
1. This device system may not be labeled or promoted for non-cemented use.
1. All labeling for this device system, including package label and labeling included within the package, must prominently state that the device is intended for cemented use only.

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

Page 2 - Ms. Marybeth Naughton

Any non-cemented fixation of this device system is 4 . 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 system 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 requlations 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 current Good Manufacturing Practice requirement, as set forth in the Quality System Regulation (QS) for Medical Devices: General regulation (21 CFR Part 820) and that, 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. 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.

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 requlation entitled, "Misbranding by reference to premarket notification" (21 CFR 807.97). Other general information on your responsibilities under the Act may be

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

Page 3 - Ms. Marybeth Naughton

obtained from the Division of Small Manufacturers Assistance at its toll-free number (800) 638-2041 or (301) 443-6597 or at at feb corr rroc namble (p://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

{5}------------------------------------------------

510(k) Number (if known): K99146)

Device Name: Osteonics® Scorpio™ Total Knee Relaxed Back P/S Tibial Bearing Insert

Indications For Use:

The indications for the use of the Osteonics® Scorpio™ Total Knee Relaxed Back P/S Tibial Bearing Insert , in keeping with those of other legally marketed Osteonics® total knee components, are as follows:

Indications

Painful, disabling joint disease of the knee resulting from: degenerative arthritis, ● rheumatoid arthritis or post-traumatic arthritis.
Post-traumatic loss of knee joint configuration and function. ●
Moderate varus, valgus, or flexion deformity in which the ligamentous structures can ● be returned to adequate function and stability.
Revision of previous unsuccessful knee replacement or other procedure. ●
Ligamentous instability requiring implant bearing surface geometries with increased ● constraint.
Absent or non-functioning posterior cruciate ligament. ●

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

Prescription Use X (Per 21 CFR 801. 109) OR

Over-The-Counter Use

(Optional Format 1-2-

Picollela

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

Regulation Number and Section

N/A