(70 days)
The Arthrex iBalance® TKA System is indicated for use in individuals undergoing surgery for:
• Painful, disabling joint disease of the knee resulting from degenerative arthritis, rheumatoid arthritis or post-traumatic arthritis:
• Post-traumatic loss of knee joint configuration and function
• Moderate varus, valgus, or flexion deformity in which the ligamentous structures can be returned to adequate function and stability:
• Revisions of previous unsuccessful knee replacement or other procedure.
Additional indications for posteriorly stabilized components:
• Ligamentous instability requiring implant bearing surfaces with increased constraint;
• Absent or non-functioning posterior cruciate ligament.
These devices are single use only and are intended for implantation with bone cement.
The Arthrex iBalance® TKA System consists of femoral components, tibial tray, tibial bearing components and patellar components. All components are available in a range of sizes to fit varying anatomical requirements. Femoral components and tibial bearing components are available in both posteriorly stabilized (PS) and cruciate retaining (CR) configurations. Femoral components are available in left and right versions and are designed to work with the Arthrex dome patella components. Femoral and tibial tray components are manufactured from Cobalt-Chromium Alloy conforming to ASTM F-75. Tibial bearing and patellar components are manufactured from UHMWPE conforming to ASTM F-648.
The CR Plus line of tibial bearing components are comparable to the system's current tibial bearing components with the exception of having dimensional specifications modification in order to offer a taller anterior lip for each size of the tibial bearing component.
The provided text describes the Arthrex iBalance® TKA System, specifically a line extension (CR Plus tibial bearing components), and its clearance via a 510(k) premarket notification. The submission focuses on demonstrating substantial equivalence to a predicate device rather than presenting a detailed study with specific acceptance criteria and performance data in the format of AI/ML device studies.
Therefore, many of the requested elements for an AI device study (such as sample sizes for test/training sets, ground truth establishment methods, number of experts, adjudication, MRMC studies, or standalone performance) are not applicable or cannot be extracted from this document, as it pertains to a mechanical medical device (knee prosthesis).
However, I can extract the information related to the demonstration of substantial equivalence, which serves a similar purpose to meeting acceptance criteria in the context of a 510(k) submission.
Acceptance Criteria and Device Performance (Demonstration of Substantial Equivalence)
In the context of the 510(k) submission, the "acceptance criteria" are implicitly understood as demonstrating substantial equivalence to a predicate device. This involves showing that the new device is as safe and effective as a legally marketed device and does not raise new questions of safety or effectiveness. For mechanical devices, this is often achieved through comparative mechanical testing.
| Acceptance Criteria (Implicit for Substantial Equivalence) | Reported Device Performance (Arthrex iBalance® TKA System CR Plus) |
|---|---|
| No significant difference in performance between the proposed and predicate devices regarding contact stress. | "The contact stress... information submitted demonstrates that there is no significant difference in performance between the proposed and predicate devices." |
| No significant difference in performance between the proposed and predicate devices regarding constraint. | "The... constraint... information submitted demonstrates that there is no significant difference in performance between the proposed and predicate devices." |
| No significant difference in performance between the proposed and predicate devices regarding interlock. | "The... interlock... information submitted demonstrates that there is no significant difference in performance between the proposed and predicate devices." |
| No significant difference in performance between the proposed and predicate devices regarding range of motion. | "The... range of motion testing information submitted demonstrates that there is no significant difference in performance between the proposed and predicate devices." |
| Technological characteristics (e.g., material, use, size range, thickness at sulci for CR Plus tibial bearing components) are equivalent to the predicate tibial bearing components. | The CR Plus tibial bearing components are "equivalent to the currently available predicate tibial bearing components in size range, thickness at the sulci, material, use and performance with the exception that the CR Plus tibial bearing components have a dimensional specifications modification to provide a taller anterior lip." The modifications are considered minor and do not raise questions concerning safety and effectiveness. The predicate device is the Arthrex iBalance® TKA System (K081127: Accin™ Total Knee System is the further predicate for the entire system). |
| Indications for Use for the new device align with the predicate device. | The Arthrex iBalance® TKA System, including the CR Plus line extension, has the same stated indications for use as the predicate Arthrex iBalance® TKA System (which is the predicate for this specific line extension, though K081127 is listed as the overall predicate). These indications include painful, disabling joint disease of the knee from various arthritides, post-traumatic loss of configuration/function, moderate deformities where ligaments can be restored, revisions, and for PS components, ligamentous instability and absent/non-functioning PCL. |
Since this is a submission for a mechanical device and not an AI/ML device, the following points are not applicable or cannot be answered from the provided text.
- Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective): Not applicable for mechanical device testing where physical samples are used for mechanical tests, not a "test set" of patient data. The document does not specify the number of physical samples tested.
- 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): Not applicable. Ground truth as typically understood in AI/ML is not established for mechanical device testing.
- Adjudication method (e.g. 2+1, 3+1, none) for the test set: Not applicable.
- 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: Not applicable, as this is not an AI-assisted diagnostic or therapeutic device.
- If a standalone (i.e. algorithm only without human-in-the-loop performance) was done: Not applicable.
- The type of ground truth used (expert consensus, pathology, outcomes data, etc): Not applicable in the AI/ML sense. "Ground truth" for a mechanical device is based on established engineering principles, material science, and mechanical testing standards (e.g., ASTM F-75 for Cobalt-Chromium Alloy, ASTM F-648 for UHMWPE), demonstrating properties like strength, wear, and biomechanical compatibility.
- The sample size for the training set: Not applicable. There is no concept of a "training set" for a mechanical device in this context.
- How the ground truth for the training set was established: Not applicable.
§ 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.