Rheumatoid arthritis.
Post-traumatic arthritis, osteoarthritis, or degenerative arthritis in older patients whose age, weight, and activity levels are compatible with an adequate long-term result.
Failed osteotomies, unicompartmental replacement, or total knee replacement.
The constrained knee systems are designed for use in patients in primary and revision surgery, where the posterior cruciate ligament and one on both of the collateral ligaments (i.e. medial collateral and/or lateral collateral ligament) are absent or incompetent.

Device Description

The subject stems are revision stems manufactured from titanium alloy which feature distal fixation holes. The stems will be available in a variety of lengths and diameters, and they will be used in conjunction with currently marketed femoral and tibial components of the Legion Revision Knee System.

AI/ML Overview

The provided text is a 510(k) summary for the Smith & Nephew Legion Stems with Holes. This document focuses on demonstrating substantial equivalence to predicate devices for a knee prosthesis component, not on presenting a study with acceptance criteria for device performance as would be expected for an AI/ML medical device.

Therefore, the information required for your request, such as a table of acceptance criteria, device performance, sample sizes, expert qualifications, ground truth establishment, or specific study types like MRMC or standalone performance, is not present in the provided text.

The closest information available that might relate to "acceptance criteria" is the Indications for Use, which defines the patient populations and conditions for which the device is intended. The device's "performance" in this context is implicitly considered acceptable through its substantial equivalence to existing, legally marketed devices.

Here's how I can address your request based only on the provided text, highlighting what is missing:

1. A table of acceptance criteria and the reported device performance

Acceptance Criteria (Implied)	Reported Device Performance (Implied)
Substantial equivalence to predicate devices in Indications for Use, material, method of manufacture, and basic design principles.	The device is substantially equivalent to the predicate devices (Smith & Nephew Legion Press-Fit Stem and TriGen Knee Nail) in the specified aspects.
Distal fixation mechanism is substantially equivalent to the TriGen Knee Nail.	The distal fixation mechanism is substantially equivalent to the TriGen Knee Nail.

Missing: Specific numerical performance metrics (e.g., accuracy, sensitivity, specificity, mechanical strength tolerances) that would be common for AI/ML or other performance-based device studies are not available in this document. The "performance" here is regulatory compliance through substantial equivalence.

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

Missing: The document does not describe a "test set" in the context of device performance evaluation (e.g., clinical study data). The substantial equivalence determination is based on comparative analysis of device characteristics and intended use, not clinical trial data with a test set.

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)

Missing: Not applicable for this type of submission. There is no "test set" in the sense of clinical images or patient data requiring expert ground truth.

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

Missing: Not applicable for this type of submission.

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

Missing: Not applicable. This is not an AI/ML device, and no MRMC study is mentioned.

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

Missing: Not applicable. This is not an AI/ML device.

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

Missing: Not applicable. The "ground truth" for this submission is regulatory compliance based on the documented characteristics of the device and its predicate.

8. The sample size for the training set

Missing: Not applicable. This is not an AI/ML device, and no "training set" is mentioned.

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

Missing: Not applicable. This is not an AI/ML device, and no training set is mentioned.

Summary based on the provided text:

The 510(k) submission for the Legion Stems with Holes primarily relies on demonstrating substantial equivalence to predicate devices (Smith & Nephew Legion Press-Fit Stem and TriGen Knee Nail) rather than presenting data from a clinical performance study with acceptance criteria. The "proof" is the detailed comparison of the new device's features (such as indications for use, material, method of manufacture, and basic design principles, including the distal fixation mechanism) to those of the already-marketed predicate devices. The FDA's issuance of the 510(k) clearance signifies agreement with this claim of substantial equivalence.

Summary

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K072531/

510(k) Summary Smith & Nephew

DEC 0 6 2007

Submitter's Name: Submitter's Address: Submitter's Telephone Number: Contact Person: Date Summary Prepared: Trade or Proprietary Device Name: Common or Usual Name: Classification Name:

Smith & Nephew, Inc., Orthopaedic Division 1450 Brooks Road, Memphis, TN 38116 901-399-5340 Megan Bevill September 6, 2007 Legion Stems with Holes Knee Prosthesis 21 CFR 888.3560 Knee joint patellofemorotibial polymer/metal/polymer semi-constrained cemented prosthesis Class II Orthopaedics/87/JWH

Device Description

Device Class: Panel Code:

Intended Use and Indications

Intended Use:

The subject Legion Stems with Holes are intended to be used with femoral and tibial components of the Legion Revision Knee System.

Indications:

The Revision Knee System Components are indicated for:

1. Rheumatoid arthritis.
1. Post-traumatic arthritis, osteoarthritis, or degenerative arthritis in older patients whose age, weight, and activity levels are compatible with an adequate long-term result.
1. Failed osteotomies, unicompartmental replacement, or total knee replacement.
The constrained knee systems are designed for use in patients in primary and revision ধ: surgery, where the posterior cruciate ligament and one or both of the collateral ligaments (i.e. medial collateral and/or lateral ligament) are absent or incompetent.

Substantial Eguivalence

Predicate stems:

Smith & Nephew Legion Press-Fit Stem Smith & Nephew TriGen Knee Nail

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The subject stems are substantially equivalent to the above named stems in indications for use, material, method of manufacture, and basic design principles. The distal fixation mechanism is substantially equivalent to the TriGen Knee Nail listed above

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Image /page/2/Picture/1 description: The image is a circular seal for the Department of Health & Human Services - USA. The seal features the department's emblem, which is a stylized caduceus, a symbol often associated with medicine and healthcare. The text "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" is arranged around the emblem in a circular fashion.

Public Health Service

DEC 0 6 2007

Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850

Smith & Nephew, Inc. Orthopaedic Division % Megan Bevill Regulatory Affairs Specialist 1450 Brooks Road Memphis, Tennessee 38116

Re: K072531

Trade/Device Name: Legion Stem with Holes Regulation Number: 21 CFR 888.3560 Regulation Name: Knee joint patellofemorotibial polymer semi-constrained cemented prosthesis Regulatory Class: Class II Product Code: JWH Dated: September 6 2007 Received: September 7, 2007

Dear Ms. Bevill:

We have reviewed your Section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate 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) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, 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 device is classified (see above) into either class II (Special Controls) or class III (PMA), 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 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.

Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801); good manufacturing practice requirements as set

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Page 2 - Ms. Megan Bevill

forth in the quality systems (OS) regulation (21 CFR Part 820); and if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050. This letter will allow you to begin marketing your device as described in your Section 510(k) premarket notification. The FDA finding of substantial equivalence of your device to a legally marketed predicate device results in a classification for your device and thus, permits your device to proceed to the market.

If you desire specific advice for your device on our labeling regulation (21 CFR Part 801), please contact the Center for Devices and Radiological Health's (CDRH's) Office of Compliance at 240-276-0120. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR Part 807.97). For questions regarding postmarket surveillance, please contact CDRH's Office of Surveillance and Biometric's (OSB's) Division of Postmarket Surveillance at 240-276-3474. For questions regarding of device adverse events (Medical Device Reporting (MDR)), please contact the Division of Surveillance Systems at 240-276-3464. You may obtain other general information on your responsibilities under the Act from the Division of Small Manufacturers, International and Consumer Assistance at its toll-free number (800) 638-2041 or (240) 276-3150 or at its Internet address http://www.fda.gov/cdrh/industry/support/index.html.

Sincerely yours,

Mark N. Mulhausen

Mark N. Melkerson Director Division of General, Restorative and Neurological Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

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Indications for Use

510(k) Number (if known): _ K07253 |

Device Name: Legion Stems with Holes

The Revision Knee System Components are indicated for:

1. Rheumatoid arthritis.
1. Post-traumatic arthritis, osteoarthritis, or degenerative arthritis in older patients whose age, weight, and activity levels are compatible with an adequate long-term result.
1. Failed osteotomies, unicompartmental replacement, or total knee replacement.
1. The constrained knee systems are designed for use in patients in primary and revision surgery, where the posterior cruciate ligament and one on both of the collateral ligaments (i.e. medial collateral and/or lateral collateral ligament) are absent or incompetent.

Prescription Use × (Part 21 CFR 801 Subpart D)

AND/OR

Over-The-Counter Use (21 CFR 801 Subpart C)

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

Concurrence of CDRH, Office of Device Evaluation (ODE)

Cukave Buchm
(Division Sign-Off)

Division of General, Restorative, and Neurological Devices

510(k) Number 072531

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.