(27 days)
- Rheumatoid arthritis.
- Post-traumatic arthritis, osteoarthritis, or degenerative arthritis.
- Failed osteotomies, unicompartmental replacement, 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.
- Constrained knee systems are designed for use in patients in primary and revision surgery, where the posterior cruciate ligament and one or both of the collateral ligaments (i.e. medial collateral ligament) are incompetent.
- Hinge knee systems are designed for use in patients in primary and revision surgery, where the posterior cruciate ligament and one or both of the collateral ligaments (i.e. medial collateral collateral ligament) are absent of incompetent.
The LEGION Knee System - Finned Tibial Wedges are for single use only and are intended for implantation with bone cement.
Smith & Nephew has also developed the subject LEGION Knee System - Finned Tibial Wedges for tibial bone deficiency. The tibia augments (wedges) are line additions to the augments currently included as part of the Legion Revision and Legion Hinge Knee Systems. The LEGION Finned Tibial Wedges are asymmetrically shaped to match the perimeter profile of Legion Revision and Legion Hinge tibia bases. The Legion Finned Tibia Wedges will be offered in sizes 2-8, in left and right hand configurations, with 10mm, 15mm, and 20mm height increments. The subject wedges will consist of grit blasted tibia augments that are intended to address defects in the proximal tibia.
The subject LEGION Finned Tibial Wedges are full wedges with a similar general design and fundamental scientific technology to the existing predicate LEGION Revision Hemi-Stepped Tibia Augments (K043440 (S.E. 02/18/2005)) in the Smith & Nephew LEGION Knee System Portfolio. The subject LEGION Finned Tibial Wedges mate with the LEGION Tibial Baseplates via screws and interface with host bone to replace tibial bone loss in complex knee surgeries. The top and bottom surface of the LEGION Finned Tibial Wedges will have a grit-blasted surface for cement adhesion. The LEGION Finned Tibial Wedges are an extension of the LEGION portfolio of wedges consisting of a modified small fin to the underside of a full wedge. The subject LEGION Finned Tibial Wedges replicate the fins on the tibial baseplate that are covered when a standard Smith & Nephew full tibial wedge is used. The small fins on the tibial baseplate and on the subject LEGION Finned Tibial Wedges are designed to provide additional rotational stability of the final tibial implant construct.
The subject LEGION Finned Tibial Wedge consists of a Ti-6A1-4V alloy wedge with a gritblasted surface identical to that of Smith & Nephew's current LEGION Revision Hemi-Stepped Tibia Augment (K043440 (S.E. 02/18/2005)). The use of a wedge is intended to add thickness to the total knee construct when the surgeon determines the need for additional construct height. The subject LEGION Finned Tibial Wedges is designed to interface with Smith & Nephew LEGION Tibial Trays and host bone along with bone cement.
The purpose of this 510(k) submission is to add additional tibial wedge components to the Smith & Nephew Legion Knee System of implants.
The provided text is a 510(k) premarket notification for the Smith & Nephew LEGION Knee System - Finned Tibial Wedges. This type of submission focuses on demonstrating substantial equivalence to a legally marketed predicate device, rather than proving the device meets specific acceptance criteria through a clinical or performance study in the way one might expect for a novel AI device.
Therefore, the information requested in your prompt regarding acceptance criteria, study details, sample sizes, expert ground truth, adjudication methods, MRMC studies, standalone performance, and training set information is largely not applicable to this type of regulatory document.
However, I can extract the information that is present and explain why the other criteria are not addressed.
Here's a breakdown based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria (What was tested against) | Reported Device Performance (How did it perform) |
|---|---|
| Biocompatibility: In accordance with FDA's Draft Guidance "Use of International Standard ISO-10993, Biological Evaluation of Medical Devices Part 1" and classified as permanent, >30 day body contact. | Biocompatibility evaluation completed; summary rationale provided. Material (Ti-6Al-4V alloy) is identical to predicate device, which has established biocompatibility. |
| Mechanical: Finite Element Analysis (FEA) and engineering rationale to demonstrate mechanical performance. | FEA and engineering rationale demonstrated substantial equivalence to predicate devices. Subject devices met the acceptance criteria for all outputs. |
| Sterility: Bacterial Endotoxin Testing per FDA Guidance "Submission and Review of Sterility Information..." and ANSI/AAMI ST72. | Met acceptable endotoxin limits. Identical gamma sterilization method to predicate device. |
| Risk Assessment: No new risks compared to predicate devices (for additional thicknesses). | Part of design control activities; additional thickness wedges have been shown to not create any new risks. |
Explanation: The "acceptance criteria" here refer to the criteria for demonstrating substantial equivalence as required for a 510(k) submission, not necessarily a pre-defined performance threshold for a primary outcome in a clinical trial. The device "performance" is primarily shown through a comparison to a predicate device and engineering analyses rather than direct human usability or clinical efficacy studies.
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. This document describes a medical device (knee implant components) and its 510(k) submission, which relies on engineering testing and comparison to predicate devices, not human subject testing or data sets in the context of an AI/software device. There is no "test set" in the sense of patient data for evaluating a diagnostic or AI algorithm.
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. As above, there is no "ground truth" established by experts for a test set of patient data, as this is not an AI/software device undergoing such validation.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
- Not Applicable. No test set or expert adjudication is described.
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 medical implant, not an AI device. No MRMC study was performed.
6. If a standalone (i.e. algorithm only without human-in-the loop performance) was done
- Not Applicable. This is a physical medical implant, not an AI or standalone software algorithm.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)
- Not Applicable. No "ground truth" in the context of patient data or clinical outcomes is used for this specific 510(k) submission. The "truth" considered here is in relation to engineering principles, material properties, and established performance of predicate devices.
8. The sample size for the training set
- Not Applicable. This is a physical device, not an AI model, so there is no "training set."
9. How the ground truth for the training set was established
- Not Applicable. There is no training set for this device.
§ 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.