LEGION COBALT CHROME REVISION KNEE SYSTEM

• K Number: K060742
• Device Name: LEGION COBALT CHROME REVISION KNEE SYSTEM
• Manufacturer: SMITH & NEPHEW, INC.
• Date Cleared: 2006-05-03 ( 44 days)
• Product Code: JWH
• Regulation Number: 888.3560
• Type: Special
• Panel: OR
• Reference & Predicate Devices: K043440 , K041106

Intended Use

Revision Knee System components are indicated for:

1. Rheumatoid arthritis.
2. Post-traumatic arthritis, osteoarthritis, or degenerative arthritis in older patients whose age, weight, and activity levels are compatible with an adequate long-term result.
3. 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 or both of the collateral ligaments (i.e. medial collateral and/or lateral collateral ligament) are absent or incompetent.
   The Revision Knee components are for single use only and are intended for implantation with bone cement.

Device Description

The LEGION Cobalt Chrome Revision femoral component is a modification of the Revision femoral components cleared via K043440. The subject device is identical in design to the predicate, but the material has been changed from Oxinium, an oxidized zirconium alloy, to cobalt chrome.

AI/ML Overview

The provided text describes a medical device, the "LEGION Cobalt Chrome Revision Knee System," and its substantial equivalence determination by the FDA. However, the document does not contain information about acceptance criteria, a specific study proving it meets those criteria, or details related to AI/algorithm performance.

Instead, the document focuses on:

• Device Description: A modification of an existing knee system, changing the material from Oxinium to Cobalt Chrome.
• Classification: Class II device (21 CFR 888.3560).
• Mechanical and Clinical Data: A general statement that a "review" indicated equivalence to clinically used devices and capability to withstand in-vivo loading. There is no specific study described with performance metrics.
• Intended Use: Specific conditions for which the device is indicated (e.g., rheumatoid arthritis, failed osteotomies).
• Substantial Equivalence: Listing similar commercially available devices.
• FDA Determination: The FDA's letter of substantial equivalence (K060742).

Therefore, I cannot populate the requested table and answer many of the questions as the information is not present in the provided text.

Here's a breakdown of what can be extracted and what is missing:

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

   • Not present. The document states a "review of the mechanical and clinical data indicated that the LEGION Cobalt Chrome Revision Knee System is equivalent to devices currently used clinically and is capable of withstanding expected in vivo loading without failure," but no specific acceptance criteria (e.g., specific fatigue life, wear rates, clinical success rates) or quantitative performance data are provided.

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

   • Not present. No specific test set data is described.

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 present. No ground truth establishment is described for a test set.

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

   • Not present. No test set or adjudication method 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 present. This device is a physical knee implant, not an AI or imaging analysis tool. Therefore, MRMC studies and AI assistance comparisons are not applicable.

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

   • Not present. This question is irrelevant as the device is not an algorithm.

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

   • Not present. No specific ground truth is mentioned in relation to performance evaluation. The "review of mechanical and clinical data" is too vague to determine the type of ground truth used, if any specific ground truth was formally established for comparison in a study.

8. The sample size for the training set

   • Not present. No training set is described.

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

   • Not present. No training set or ground truth establishment for a training set is described.

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.