(23 days)
The Ascent™ All-Poly PS Tibial Bearings are for the painful and disabled knee joint resulting form osteoarthritis, theumatoid arthritis, traumatic arthritis where one or more compartments are involved; the correction of varus, valgus, or posttraumatic deformity; and the correction or revision of unsuccessful osteotomy, arthrodesis, or failure of previous joint replacement procedure. This device is for use with bone cement.
The Ascent™ All-Poly PS Tibial Bearings are manufactured from ArCom®, an ultra-high molecular weight polyethylene (UHMWPE). The one-piece posterior stabilized (PS) tibial components are available in varying thicknesses and widths. The Ascent™ All-Poly PS Tibial Bearings are used in conjunction with the Ascent™ Femoral Components (K982869).
This document describes a 510(k) premarket notification for the Ascent™ All-Poly PS Tibial Bearing. For this type of device, substantial equivalence is typically established through non-clinical testing and comparison to a predicate device, rather than through clinical trials with specific acceptance criteria and detailed performance metrics as one might find for a novel therapeutic device.
Therefore, the requested information regarding acceptance criteria and a study proving the device meets them cannot be entirely filled out in the conventional sense for a clinical study.
Here's a breakdown based on the provided document:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria Category | Specific Criteria (Implicitly Met) | Reported Device Performance (Summary) |
|---|---|---|
| Material Properties | Equivalent to predicate device (UHMWPE, ArCom®) | Manufactured from ArCom®, an ultra-high molecular weight polyethylene (UHMWPE). |
| Design | Similar to predicate devices (one-piece, PS, varying thicknesses/widths) | One-piece posterior stabilized (PS) tibial components available in varying thicknesses and widths. |
| Sizing | Similar to predicate devices | Similar to predicate devices. |
| Indications for Use | Aligned with predicate devices | Indications for use are similar or identical to predicate devices. |
| Biomechanical Safety | No new risks identified compared to predicate device. | Determined through Engineering Justifications and Finite Element Analysis (FEA) that the device presented no new risks. |
| Substantial Equivalence | Demonstrates equivalence to a legally marketed predicate device (Kirschner Performance Total Knee System K934589) based on design, materials, and indications for use. | FDA's finding of substantial equivalence based on the provided information. |
2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)
- Sample Size: Not applicable. No clinical test sets were used for this 510(k) submission. The evaluation was primarily based on non-clinical engineering justifications.
- Data Provenance: Not applicable.
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)
- Number of Experts: Not applicable. No ground truth was established by external experts in a clinical study context for this submission. The "ground truth" for substantial equivalence was based on engineering analysis and comparison to a legally marketed predicate device, reviewed by the FDA.
- Qualifications of Experts: Not applicable for a clinical test set. The review and approval were conducted by the FDA, including the Division of General, Restorative and Neurological Devices.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
- Adjudication Method: None. No clinical test set requiring adjudication was performed.
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
- MRMC Study: No. This is a medical device (knee implant component), not an AI-assisted diagnostic or imaging device. Therefore, MRMC studies are not relevant.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
- Standalone Performance: Not applicable. This is a physical medical device, not a software algorithm.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)
- Ground Truth: For the purpose of this 510(k) submission, the "ground truth" was established by demonstrating that the device is substantially equivalent to a legally marketed predicate device (Kirschner Performance Total Knee System K934589) in terms of materials, design, sizing, and indications for use, and that non-clinical testing (engineering justifications and Finite Element Analysis) showed no new risks. This is a regulatory "ground truth" rather than a clinical one derived from patient data.
8. The sample size for the training set
- Sample Size: Not applicable. No training set was used as this is a physical medical device and not an AI/machine learning system.
9. How the ground truth for the training set was established
- Ground Truth Establishment: Not applicable. No training set was used.
Summary of the Study that Proves the Device Meets Acceptance Criteria:
The "study" that proves the Ascent™ All-Poly PS Tibial Bearing meets its "acceptance criteria" (which in this context are the requirements for demonstrating substantial equivalence to a predicate device) is defined by the Non-Clinical Testing described in the document:
- Engineering Justifications: This involves a detailed analysis of the device's design, materials, and manufacturing processes, comparing them to the predicate device. This would include assessing mechanical properties, wear characteristics, and biocompatibility.
- Finite Element Analysis (FEA): This is a computational method used to predict how a product reacts to real-world forces, vibration, heat, fluid flow, and other physical effects. For a tibial bearing, FEA would be used to model stress distribution, deformation, and potential failure points under various loading conditions representative of human activity.
The conclusion from these non-clinical tests was that "the Ascent™ All-Poly PS Tibial Bearings presented no new risks and were, therefore, substantially equivalent to the predicate device." This finding, along with the device's similar "materials, design, sizing, and indications" to existing devices, formed the basis for the FDA's determination of substantial equivalence. The document explicitly states: "No clinical testing was provided as a basis for substantial equivalence."
§ 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.