(132 days)
Moderately disabling joint disease of the knee resulting from painful osteo- or post traumatic arthritis.
Revision of previous unsuccessful unicompartmental knee replacement or other procedure.
As an alternative to tibial osteotomy in patients with unicompartmental osteoarthritis.
This device consists of a distal femoral resurfacing component and a proximal tibial resurfacing component. It is intended to be used to replace the medial or lateral compartments of the knee joint, specifically the femorotibial joint damaged as a result of inflammatory and non-inflammatory joint disease or trauma. These components are intended for cemented use only. The femoral component is manufactured from a cobalt-chromium alloy, which conforms to ASTM F-75. The tibial component is manufactured from ultra-high molecular weight polyethylene, which conforms to ASTM F-648.
This is a K99 Summary for a medical device called the "First Step Unicompartmental Knee System." It is a 510(k) submission, which means it evaluates the device's substantial equivalence to existing, legally marketed predicate devices, rather than requiring a full clinical trial for safety and effectiveness. Therefore, it does not contain the typical "acceptance criteria" and "study that proves the device meets the acceptance criteria" in the way a clinical trial submission would for a novel device.
The "study" in this context is the demonstration of substantial equivalence to predicate devices, focusing on design, materials, and intended use, rather than a clinical performance study with specific acceptance criteria like accuracy, sensitivity, or specificity.
Here's an analysis based on the provided document and the typical content of a 510(k) summary:
1. Table of Acceptance Criteria and Reported Device Performance
As mentioned, a 510(k) summary for a device like this does not typically present a table of quantitative "acceptance criteria" and "reported device performance" in the way one would for an AI diagnostic device. Instead, the "acceptance criteria" for a 510(k) submission are met by demonstrating substantial equivalence to predicate devices.
The "performance" is implicitly deemed equivalent to the predicate devices if substantial equivalence is successfully demonstrated. The document states:
"The substantial equivalence of this device is based on equivalence in intended use, materials, design and operational principles to other predicate devices indicated for unicompartmental knee surgery. These devices include Howmedica Osteonics Corp.'s Duracon Unicompartmental Knee and SCR Uni Knee Systems."
Therefore, the "acceptance criteria" are qualitative comparability to the predicate devices across these aspects. There are no reported numerical performance metrics for the First Step Unicompartmental Knee System in this document.
2. Sample Size Used for the Test Set and Data Provenance
This document does not describe a "test set" in the context of an AI study. The "test set" for a 510(k) in this case is the comparison of the new device to existing predicate devices. The "provenance" is the existing knowledge and performance of the specified predicate devices already on the market (Howmedica Osteonics Corp.'s Duracon Unicompartmental Knee and SCR Uni Knee Systems).
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications of Those Experts
Not applicable. There is no "ground truth" establishment in the context of an AI study or a diagnostic test in this document. The assessment is based on engineering and design comparisons to predicate devices.
4. Adjudication Method for the Test Set
Not applicable. There is no "adjudication method" as this is not a diagnostic performance study requiring expert consensus on outputs.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done
No, an MRMC comparative effectiveness study was not done. This device is a mechanical implant, not an AI-assisted diagnostic tool.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) was done
No, a standalone performance study was not done. This is a mechanical implant.
7. The Type of Ground Truth Used
Not applicable. As this is a mechanical implant seeking substantial equivalence to predicate devices, there isn't a "ground truth" in the sense of a medical outcome or diagnosis that an AI algorithm would be evaluated against. The "truth" in this context is the established safety and effectiveness of the predicate devices.
8. The Sample Size for the Training Set
Not applicable. There is no "training set" for an AI algorithm in this context.
9. How the Ground Truth for the Training Set Was Established
Not applicable. There is no "ground truth" or "training set" for an AI algorithm in this context.
§ 888.3520 Knee joint femorotibial metal/polymer non-constrained cemented prosthesis.
(a)
Identification. A knee joint femorotibial metal/polymer non-constrained cemented prosthesis is a device intended to be implanted to replace part of a knee joint. The device limits minimally (less than normal anatomic constraints) translation in one or more planes. It has no linkage across-the-joint. This generic type of device includes prostheses that have a femoral condylar resurfacing component or components made of alloys, such as cobalt-chromium-molybdenum, and a tibial component or components made of ultra-high molecular weight polyethylene and are intended for use with bone cement (§ 888.3027).(b)
Classification. Class II.