(31 days)
The INFINITY™ Total Ankle System is intended to give a patient limited mobility by reducing pain, restoring alignment and replacing the flexion and extension movement in the ankle joint.
Indications for Use: The INFINITY™ Total Ankle is indicated for patients with ankle joints damaged by severe rheumatoid, post-traumatic, or degenerative arthritis.
The INFINITY™ Total Ankle is additionally indicated for patients with a failed previous ankle surgery.
CAUTION: The ankle prosthesis is intended for cement use only.
The INFINITY® Total Ankle System is a fixed-bearing, bone-sparing total ankle prosthesis that restores mobility to a failing ankle joint. It encompasses three components (i.e., tibial tray, tibial insert, and talar dome) that are assembled together to create a two-piece prosthesis. The device is composed of Titanium Alloy, Cobalt Chrome, Ultra High Molecular Weight Polyethylene and commercially pure Titanium and each component is available in multiple sizes to accommodate variable patient anatomy.
This document describes a 510(k) premarket notification for the WMT INFINITY® Total Ankle System. The document focuses on demonstrating substantial equivalence to a predicate device, rather than providing a study proving performance against acceptance criteria for a novel device. Therefore, much of the requested information regarding acceptance criteria, performance studies, sample sizes, expert ground truth, and comparative effectiveness studies is not applicable or not provided in the given text.
Here's an analysis based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance:
- Acceptance Criteria: Not explicitly defined in terms of measurable performance metrics. The core "acceptance criterion" for this 510(k) submission is demonstrating substantial equivalence to a predicate device.
- Reported Device Performance: The document states that "Through mechanical analysis the subject devices do not represent a new worst-case. Therefore, no additional mechanical testing was performed to support the subject devices." This implies that the performance is considered to be equivalent to the predicate device, which is presumably already proven safe and effective.
| Acceptance Criteria Category | Specific Criteria (Implicit for Substantial Equivalence) | Reported Device Performance |
|---|---|---|
| Mechanical Performance | No new worst-case mechanical behavior compared to predicate. | No new worst-case identified through mechanical analysis. |
| Material Composition | Same materials as predicate. | Composed of Titanium Alloy, Cobalt Chrome, Ultra High Molecular Weight Polyethylene, and commercially pure Titanium (same as predicate). |
| Design Features | Clinically relevant design features maintained; differences do not raise new safety/effectiveness questions. | Maintains clinically relevant design features. Differences are an anterior-posterior (AP) tray length and neutral posterior curvature, which do not raise new safety/effectiveness questions. |
| Intended Use/Indications | Intended use and indications are substantially equivalent to predicate. | Intended use and indications are equivalent to the predicate. |
2. Sample Size for Test Set and Data Provenance: Not applicable. This submission relies on a comparison to a predicate device and mechanical analysis, not a clinical trial with a test set of data.
3. Number of Experts and Qualifications for Ground Truth for Test Set: Not applicable. Ground truth as typically defined for algorithm performance in AI/ML is not established here. The "ground truth" is the established safety and effectiveness of the predicate device.
4. Adjudication Method for Test Set: Not applicable. No test set requiring expert adjudication is described.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study: Not applicable. This is not a study comparing human readers with and without AI assistance.
6. Standalone (Algorithm Only) Performance Study: Not applicable. This device is a physical medical implant, not an algorithm.
7. Type of Ground Truth Used: The "ground truth" in this context is the established safety and effectiveness of the legally marketed predicate device (K123954 INFINITY® Total Ankle System).
8. Sample Size for Training Set: Not applicable. This document describes a medical device, not an AI/ML algorithm that requires a training set. The "training" in a regulatory sense would refer to the historical data and experience with the predicate device.
9. How Ground Truth for Training Set was Established: Not applicable. As above, this is a medical device, not an AI/ML algorithm. The safety and effectiveness of the predicate device would have been established through its own regulatory pathway, which may have included clinical data, mechanical testing, and biocompatibility assessments.
§ 888.3110 Ankle joint metal/polymer semi-constrained cemented prosthesis.
(a)
Identification. An ankle joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace an ankle joint. The device limits translation and rotation in one or more planes via the geometry of its articulating surfaces and has no linkage across-the-joint. This generic type of device includes prostheses that have a talar resurfacing component made of alloys, such as cobalt-chromium-molybdenum, and a tibial resurfacing component made of ultra-high molecular weight polyethylene and is limited to those prostheses intended for use with bone cement (§ 888.3027).(b)
Classification. Class II.