(77 days)
Total knee components are indicated for 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.
Smith & Nephew, Inc. Legion Narrow Oxinium C/R and P/S Femoral Components are indicated for use only with cement and are single use only devices.
The implant devices described in this premarket notification are comprised of Legion Narrow Oxinium Cruciate Retaining (CR) and Posterior Stabilized (PS) Femoral Components. All described implant components are manufactured from oxidized zirconium alloy material (trade name: Oxinium). The subject devices are available in the following configurations and sizes:
| Device Type | Hand | Available Sizes |
|---|---|---|
| Legion Narrow Oxinium CR Femoral Components | Left | 3, 4, 5 and 6 |
| Legion Narrow Oxinium CR Femoral Components | Right | 3, 4, 5 and 6 |
| Legion Narrow Oxinium PS Femoral Components | Left | 3, 4, 5 and 6 |
| Legion Narrow Oxinium PS Femoral Components | Right | 3, 4, 5 and 6 |
Device specific instruments are also described in this premarket notification in select sections and exhibits.
The provided document describes a 510(k) Premarket Notification for a medical device, specifically total knee prosthesis femoral components. This type of filing focuses on demonstrating substantial equivalence to existing legally marketed devices, rather than proving a new device meets specific quantitative acceptance criteria through clinical studies.
Therefore, the input you've provided does not contain the information requested regarding acceptance criteria studies, such as:
- A table of acceptance criteria and reported device performance.
- Sample sizes, data provenance, number of experts for ground truth, or adjudication methods for test sets.
- MRMC comparative effectiveness studies or human reader improvement data.
- Standalone algorithm performance.
- Types of ground truth used.
- Training set sample size or how its ground truth was established.
Instead, the document details:
A. Acceptance Criteria and Study Approach (Implicit through Substantial Equivalence):
- Acceptance Criteria (Implicit): The primary acceptance criterion for a 510(k) submission is demonstrating substantial equivalence to a predicate device. This is achieved by showing that the new device has:
- The same intended use.
- The same technological characteristics, or if there are different technological characteristics, that these differences do not raise different questions of safety and effectiveness.
- The new device is as safe and effective as the predicate device.
- Study That "Proves" Device Meets Criteria: The "study" in this context is a preclinical testing program designed to show that the new device's critical performance aspects are comparable to or better than the predicate devices. This isn't about meeting a specific numerical performance threshold for a new, novel characteristic, but rather confirming that the device performs as expected given its design and materials, and in a manner similar to previously cleared devices.
B. Details from the Provided Document:
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Table of Acceptance Criteria and Reported Device Performance: This information is not explicitly provided in a table format with quantitative thresholds. The document states that the new device shares "very similar or identical Indications of Use, intended use, are manufactured from similar or identical materials, and incorporate very similar technological design characteristics" to its predicates. The preclinical testing described aims to support this similarity rather than report against specific numerical acceptance criteria.
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Sample Size Used for the Test Set and Data Provenance: Not applicable/not provided. The preclinical tests mentioned (Tibiofemoral Constraint, Tibiofemoral Contact Area, Patellofemoral Subluxation Testing) are laboratory mechanical tests, not clinical studies involving human patients or retrospective/prospective data from specific countries. The sample size for these mechanical tests is typically determined by engineering standards and statistical power for material and design performance, but is not specified here.
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Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications: Not applicable/not provided. Mechanical integrity and performance are established through objective physical measurements and engineering analysis, not expert clinical consensus for "ground truth" in the diagnostic sense.
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Adjudication Method for the Test Set: Not applicable/not provided. As this is not a diagnostic device involving human interpretation, an adjudication method is not relevant.
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Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study: No, an MRMC study was not done. This device is a total knee prosthesis, a mechanical implant, not an imaging diagnostic AI or software.
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Standalone Performance Study: The "preclinical testing" mentioned (Tibiofemoral Constraint, Tibiofemoral Contact Area, Patellofemoral Subluxation Testing) represents standalone performance evaluations for the mechanical characteristics of the device. However, this is not a "standalone algorithm performance" in the AI sense.
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Type of Ground Truth Used: For the preclinical tests, the "ground truth" is based on the physical properties and mechanical behavior of the device components as measured by standardized testing methods and engineering principles. There is no pathology, outcomes data, or expert consensus used for ground truth in this context.
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Sample Size for the Training Set: Not applicable/not provided. This is a medical device (implant), not an AI algorithm requiring a training set in the machine learning sense.
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How the Ground Truth for the Training Set was Established: Not applicable/not provided.
In summary: The provided 510(k) summary focuses on demonstrating substantial equivalence of a knee implant to existing devices through comparison of design, materials, intended use, and preclinical mechanical testing. It does not involve the type of clinical trial or AI performance evaluation that would require the specific "acceptance criteria and study" details you've requested.
§ 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.