K Number
K200407
Date Cleared
2020-03-13

(23 days)

Product Code
Regulation Number
888.3560
Panel
OR
Reference & Predicate Devices
AI/MLSaMDIVD (In Vitro Diagnostic)TherapeuticDiagnosticis PCCP AuthorizedThirdpartyExpeditedreview
Intended Use

Total Knee components are indicated for rheumatoid arthritis, osteoarthritis, osteoarthritis, or degenerative arthritis; failed osteotomies, unicompartment, or total knee replacement. Posterior stabilized knee systems are designed for use in patients in primary and revision surgery, where the anterior and posterior cruciate ligaments are incompetent and the collateral ligaments remain intact.

The Smith & Nephew Legion Inserts with JRNY Lock are single use devices.

Device Description

The subject of this Special 510(k) is the LEGION Inserts with JRNY Lock (LEGION Inserts). The subject LEGION Inserts are tibia insert components, and a line extension of the LEGION CR High Flex and Deep Dish inserts cleared under premarket notification K071071. The subject devices were modified by incorporating the identical JOURNEY II locking mechanism from the JOURNEY II CR and JOURNEY II BCS inserts, cleared under premarket notifications K121443 and K111711 respectively.

The subject LEGION Inserts have a size range of 1-2, 3-4, 5-6, 7-8mm with thicknesses of 9, 10, 11, 12, 13, 15, 18, 21mm, and come in cruciate-retaining high flexion (CR HF) and Deep Dish varieties. The LEGION Inserts are manufactured from 7.5MRad Cross-linked Polyethylene (XLPE) conforming to ASTM F648 and ISO 5834-2, as the predicate LEGION CR Inserts cleared under a premarket notification K071071.

AI/ML Overview

This document describes a 510(k) premarket notification for LEGION Inserts with JRNY Lock, which are tibial insert components for total knee replacement. The submission argues for substantial equivalence to existing predicate devices based on technological characteristics and mechanical performance testing.

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

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

The document does not explicitly state quantitative acceptance criteria in a table format. Instead, it relies on the concept of "substantial equivalence" to predicate devices. The performance testing section mentions the types of tests performed and concludes that the subject device is "substantially equivalent" to the predicate devices.

Acceptance Criteria (Implied)Reported Device Performance
Mechanical Performance: Equivalent to predicate devices in:- Range of Motion and Constraint: Performed
- Range of Motion and Constraint- Tibiofemoral Contact Area Analysis: Performed
- Tibiofemoral Contact Area Analysis- Component Interlock Strength Testing: Performed
- Component Interlock Strength Testing- Substantially equivalent to predicate devices based on leveraged non-clinical bench (mechanical) testing.
Biocompatibility/Sterility: Meet acceptable endotoxin limits.- Bacterial endotoxin testing: Completed and met acceptable endotoxin limits as stated in FDA guidance and ANSI/AAMI ST72.
Function, Intended Use, Indications for Use, Material Composition, Overall Design: Identical/very similar to predicate devices.- Identical in function, intended use, indications for use, and material composition.
  • Very similar in overall design. |
    | No new issues related to safety and effectiveness. | - No new issues related to the safety and effectiveness of the subject devices demonstrated by review of technological characteristics and testing. |

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

The document mentions "leveraged non-clinical bench (mechanical) testing." This indicates the use of physical samples or models for mechanical tests, not human data. The specific sample size for each test (e.g., number of inserts tested for range of motion) is not specified.
There is no information about the country of origin of the data as it's non-clinical bench testing, and it's not applicable to human data (retrospective or prospective).

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)

This is not applicable as the study is non-clinical bench testing of a medical device (knee inserts) and does not involve establishing ground truth from expert readings of patient data. The "ground truth" for these tests would be the design specifications and performance characteristics of the predicate devices and relevant industry standards (ASTM, ISO).

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

This is not applicable as the study is non-clinical bench testing. Adjudication methods are typically used in clinical studies or studies involving expert interpretation of medical data to resolve discrepancies.

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

No, an MRMC comparative effectiveness study was not done. This submission is for a knee implant component and relies on non-clinical mechanical testing and comparison to predicate devices, not AI assistance or human reader evaluations.

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

No, a standalone algorithm-only performance study was not done. This is not an AI-enabled device.

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

The "ground truth" for this submission is based on:

  • Established performance of predicate devices: The comparison standard for substantial equivalence.
  • Industry Standards: ASTM F648 and ISO 5834-2 for material properties (XLPE), and FDA Guidance/ANSI/AAMI ST72 for bacterial endotoxin testing.
  • Design Specifications: The documented design and intended function of both the subject device and the predicate devices.

8. The sample size for the training set

Not applicable. This submission is not for an AI/ML device that requires a training set.

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

Not applicable. (See point 8).

§ 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.