(156 days)
The iKnee Distal Femoral Cutting Guide is indicated for use as a stereotaxic accessory instrument that acts as a cutting guide for the distal femur during a total knee arthroplasty using computer navigation. The iKnee Distal Femoral Cutting Guide requires the use of a Stryker Smart Instrument navigation tracker in conjunction with a compatible Stryker navigation system.
The Operativ iKnee Distal Femoral Cutting Guide is a device used to cut the distal femur during a computer navigated total knee arthroplasty. The iKnee Distal Femoral Cutting Guide can control all three plains (varus/valgus, flexion/extension and depth) independently to allow for easy adjustments to ensure accuracy and ease of use. The iKnee Distal Femoral Cutting Guide is used with the Stryker Navigation Unit and associated stereotaxic Smart Instruments (K010204) to cut the distal femur during a total knee arthroplasty.
Here's a breakdown of the acceptance criteria and the study that proves the device meets them, based on the provided text.
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly state quantitative acceptance criteria (e.g., "accuracy must be within X mm" or "error must be less than Y degrees"). Instead, the acceptance criterion for each test is consistently described as the subject device exhibiting "no significant error" or being "as accurate as" the predicate device system.
| Acceptance Criteria (Implicit) | Reported Device Performance |
|---|---|
| Test #1: Navigation of cutting blocks at 15° femoral hyperextension (end limit of device flexion) (SW 3.0) should show no loss of accuracy compared to the predicate. | "This test provided consistent information with no significant error between the two devices. This test showed that the iKnee Distal Femoral Cutting Guide is an accurate alternative to the Stryker cutting system and can be used during a navigated total knee arthroplasty with no loss in accuracy." |
| Test #2: Toggle Test (SW 3.0) at 0° femoral flexion should show equivalent accuracy to the predicate with a similar rotation of the tracker assembly. | "This test provided consistent information with no significant error between the two devices. This showed that the iKnee Distal Femoral Cutting Guide is an accurate alternative to the Stryker cutting system and can be used during a navigated total knee arthroplasty with no loss in accuracy." |
| Test #3: Navigation of cutting blocks at 0° femoral flexion (SW 3.1) should be as accurate as the predicate cutting block system. | "This test provided consistent information with no significant error between the two devices. This test showed that the iKnee Distal Femoral Cutting Guide is an accurate alternative to the Stryker cutting system and can be used during a navigated total knee arthroplasty with no loss in accuracy." |
| Test #4: Linear measurement of depth of medial and lateral femoral condyles (SW 3.1) should show consistency with the predicate and no increased error. | "This test provided consistent information with no significant error between the two devices. This test showed that the iKnee Distal Femoral Cutting Guide is an accurate alternative to the Stryker cutting system and can be used during a navigated total knee arthroplasty with no loss in accuracy." |
2. Sample Size Used for the Test Set and Data Provenance
- Test Set Sample Size: The document does not specify a numerical sample size for any of the bench tests. It describes comparative testing against the predicate device system.
- Data Provenance: The data is retrospective, as it comprises bench tests performed by the manufacturer (Evergreen Orthopedic Research Lab d/b/a Operativ) to demonstrate substantial equivalence. The tests compare the subject device to existing predicate devices (Stryker and Zimmer). The country of origin for the data is not explicitly stated but can be inferred as the USA, given the manufacturer's location and the FDA submission.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of those Experts
Not applicable. This was a bench test evaluating the physical and functional accuracy of a surgical cutting guide in conjunction with a navigation system, not a study requiring expert interpretation of medical images or outcomes to establish ground truth. The "ground truth" was established by direct physical measurements and the performance of the predicate device's established accuracy.
4. Adjudication Method for the Test Set
Not applicable. As a bench test comparing instrumental accuracy, an adjudication method for reconciling expert opinions is not relevant.
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
Not applicable. The document describes a bench test of a surgical cutting guide, not an AI-powered diagnostic device or an MRMC study.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was Done
This scenario is partially applicable in the sense that the device's inherent accuracy and communication with the navigation system are tested, representing its "standalone" functional capability as a tool. However, it's crucial to understand that this is a surgical instrument, not an AI algorithm. Its performance is evaluated mechanically/electronically in conjunction with a navigation unit, not as an autonomous decision-making system. The tests evaluate the instrument's ability to accurately translate the navigation system's guidance into a physical position for cutting.
7. The Type of Ground Truth Used (expert consensus, pathology, outcomes data, etc.)
The ground truth for these bench tests was the established accuracy and performance of the legally marketed predicate devices (Stryker and Zimmer cutting guide systems in conjunction with their respective navigation units). The subject device's performance was measured against the established and expected performance of these predicate systems, essentially using the predicate's known characteristics as the benchmark for "ground truth" in terms of accuracy and function. This inherently relies on the previously validated performance standards of the predicate devices.
8. The Sample Size for the Training Set
Not applicable. This is a physical medical device (surgical cutting guide), not a machine learning or AI algorithm that requires a "training set."
9. How the Ground Truth for the Training Set was Established
Not applicable. See point 8.
§ 882.4560 Stereotaxic instrument.
(a)
Identification. A stereotaxic instrument is a device consisting of a rigid frame with a calibrated guide mechanism for precisely positioning probes or other devices within a patient's brain, spinal cord, or other part of the nervous system.(b)
Classification. Class II (performance standards).