(29 days)
The ACCIN UNI-Knee System components are for use in Unicompartmental knee arthroplasty as a result of: Moderately disabling joint disease of the knee resulting from painful osteoarthritis or post traumatic arthritis; Correction of functional deformities: Revision of previous unsuccessful unicompartmental knee replacement or other procedure; As an alternative to tibial osteotomy in patients with unicompartmental osteoarthritis. These components are single use only and are intended for implantation with bone cement.
The ACCIN UNI-Knee System consists of Cobalt Chrome femoral component and tibial tray and a polyethylene tibial insert.
This document describes a Special 510(k) submission for a line extension to the ACCIN UNI-Knee System. The modification is the addition of new tibial bearing components with thicknesses of 11mm, 13mm, and 14mm, expanding the thickness range from 8mm-10mm to 8mm-14mm. No other changes were made.
The submission focuses on demonstrating substantial equivalence to a legally marketed predicate device (Accin UNI-Knee System - K060670 and Zimmer Unicompartmental Knee System - K033363) rather than proving general safety and effectiveness through extensive clinical trials. Therefore, the information provided does not align with a typical AI/software device evaluation.
Here's an analysis based on the provided text, highlighting what is present and what is absent:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|
| Mechanical properties and design for tibial bearing components | Equivalent to currently marketed Accin UNI-Knee tibia bearing components with the exception of thickness. |
| Thickness range for tibial bearing components | Extended from 8mm-10mm to 8mm-14mm (in 1mm increments). |
| Material composition (Cobalt Chrome, polyethylene) | Unchanged from existing components. |
| Intended use | Unchanged from existing components; for unicompartmental knee arthroplasty due to osteoarthritis, post-traumatic arthritis, functional deformities, revision, or as an alternative to tibial osteotomy. |
| Substantial Equivalence to Predicate Device (K060670, K033363) | Determined by FDA. |
Explanation: For a device modification of this nature (a line extension adding different sizes), the "acceptance criteria" are implied to be that the new components perform equivalently to the existing ones and the predicate device in terms of mechanical properties, biocompatibility, and manufacturing quality, and that the new sizes do not introduce new safety or effectiveness concerns. The "study" proving this is often through bench testing, material characterization, and comparison to design specifications and predicate devices, demonstrating that the change in thickness does not alter the fundamental safety and effectiveness. The FDA's substantial equivalence determination confirms that these criteria were met to their satisfaction for market clearance.
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: Not explicitly stated as a "test set" in the context of clinical data. For mechanical testing or design verification in medical devices, the sample size would refer to the number of components tested to ensure their performance meets specifications. This information is not detailed in the provided summary.
- Data Provenance: Not applicable in the context of clinical "data provenance" as this is not a study relying on patient data. The provenance for the device modification would be the manufacturing process and design documentation for the new components.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications
- Experts and Qualifications: Not applicable. This submission is for a device modification (size extension) rather than a diagnostic or AI device requiring expert consensus for ground truth on patient data. The "ground truth" here is based on engineering specifications, material science, and manufacturing standards for the knee implant components. The FDA reviewers and the manufacturer's internal team would be the "experts" assessing this.
4. Adjudication Method for the Test Set
- Adjudication Method: Not applicable. There is no "test set" in the context of diagnostic performance or clinical outcomes that would require adjudication by multiple experts. The approval process is regulatory in nature.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
- MRMC Study: No. This is not an AI or diagnostic imaging device; it is a physical implant. Therefore, an MRMC study is not relevant or performed for this type of device modification.
6. If a Standalone (Algorithm Only Without Human-in-the-Loop Performance) Was Done
- Standalone Performance: Not applicable. This is not an algorithm or AI device.
7. The Type of Ground Truth Used
- Ground Truth: For this device modification, the "ground truth" would be established by:
- Engineering Specifications: Mechanical properties (e.g., strength, wear resistance, fatigue life) designed for the new components.
- Material Standards: Conformance to established standards for cobalt chrome and polyethylene used in implantable devices.
- Bench Testing: Results from laboratory tests demonstrating the physical performance of the new components meet established safety and effectiveness benchmarks, often comparing them directly to the predicate devices.
- Design Rationale: Justification that the increased thickness does not negatively impact performance or safety, based on biomechanical principles.
8. The Sample Size for the Training Set
- Training Set Sample Size: Not applicable. There is no AI algorithm being "trained" in this context.
9. How the Ground Truth for the Training Set Was Established
- Ground Truth for Training Set Establishment: Not applicable. There is no training set for an AI algorithm.
In summary: The provided document is a regulatory submission for a medical device line extension, not an AI or diagnostic performance study. The "acceptance criteria" and "study" refer to the demonstration of substantial equivalence to predicate devices through engineering, material, and manufacturing standards, as reviewed and approved by the FDA. The questions posed are primarily relevant to AI/diagnostic device evaluations and are mostly not applicable to this type of medical implant modification.
§ 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.