(41 days)
The Navio system is intended to assist the surgeon in providing software-defined spatial boundaries for orientation and reference information to anatomical structures during orthopedic procedures.
The Navio system is indicated for use in surgical knee procedures, in which the use of stereotactic surgery may be appropriate, and where reference to rigid anatomical bony structures can be determined. These procedures include unicondylar knee replacement and patellofemoral arthroplasty.
The Navio system is indicated for use with cemented implants only.
The Navio system is a computer-assisted orthopedic surgical navigation and surgical burring system. The system uses established technologies of navigation via a passive infrared tracking camera to aid the surgeon in establishing a bone surface model for the target surgery and to plan the surgical implant location based on predefined bone landmarks and known configuration of the surgical implant. The Navio system then aids the surgeon in executing the surgical plan by using a standard off-the-shelf surgical drill motor and bur (eMax 2 Plus System -K080802), which has been adapted using a tracking system. The surgical bur is located in a handpiece, which allows the bur to move within the handpiece. In the Navio system the software controls the position of the tip of the surgical bur relative to the end of a guard attached to the handpiece and prohibits the bur from cutting bone as it approaches the planned target surface. As the planned surface is reached, the tip of the bur is fully retracted within the guard.
An alternate mode of operation is the speed control mode. In this mode the speed of the bur is controlled and the bur stops as the planned surface is reached. In this mode of operation the bur does not retract into the guard. This mode of operation is useful in shaping surfaces of the condyle as well as placing post holes.
The Navio computer system maintains a log of the patient data and procedure data. Each entry is date and time stamped. Data log entries include date and time stamp for data line entry, patient and procedure ID, implant ID, step in process, and error messages. This data can be archived to a CD upon demand at the end of the procedure.
The provided text describes a 510(k) submission for a device modification to an existing surgical navigation system (Navio). The primary change is the incorporation of a new reflective tracking marker. Therefore, the majority of the testing presented is focused on demonstrating that this modification does not negatively impact the device's safety and effectiveness compared to the predicate device.
Here's an analysis of the acceptance criteria and supporting studies based on the provided text, noting limitations where information is not available:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly state quantitative acceptance criteria in a table format for the device's performance (e.g., accuracy, precision). Instead, the studies aim to demonstrate that the modified device performs "as safe and effective as" the predicate device, K143668.
The nonclinical testing section indicates "bench verification testing," "clinical simulation (usability validation testing)," and "simulated-use testing in simulated knees (sawbones) and cadaver lab testing." The outcome of these tests is stated as "successfully use the Navio system," which implies an acceptable level of performance was achieved, but specific metrics are not provided.
| Acceptance Criteria Category | Specific Acceptance Criteria (Not explicitly stated in quantitative terms) | Reported Device Performance |
|---|---|---|
| New Tracking Marker Design | Ensure the new disk-shaped reflective tracking marker functions equivalently to the spherical markers, maintaining the established accuracy and reliability of the Navio system. | Bench verification testing and simulated-use testing in sawbones and cadaver labs demonstrated that the new tracking marker allowed for successful use of the Navio system, implying equivalent performance to the predicate. No new issues of safety or effectiveness were raised. |
| Biocompatibility | Ensure the new tracking marker material is biocompatible. | Biocompatibility testing was performed. |
| Shelf-Life | Ensure the new tracking marker maintains its properties over its shelf-life. | Shelf-life testing was performed. |
| Labeling Validation | Ensure labeling for the modified device is accurate and appropriate. | Labeling validation was performed. |
| Usability | Ensure surgeons and technical support personnel can successfully use the Navio system with the new marker. | Clinical simulation (usability validation testing) with surgeons and technical support personnel demonstrated successful use of the Navio system. |
2. Sample Size Used for the Test Set and Data Provenance
- Test Set Sample Size:
- For simulated-use testing, "simulated knees (sawbones)" and "cadaver lab testing" were used. The exact number of sawbones or cadavers is not specified.
- For usability validation, "surgeons and technical support personnel" were involved, but the number of participants is not specified.
- Data Provenance: The studies are described as nonclinical bench and simulated-use testing. The origin of the sawbones or cadavers is not specified, but it is implied to be laboratory-controlled since no human clinical tests were conducted. These are retrospective in the sense that they are performed on non-living specimens or models, not on live patients in a prospective clinical trial.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications
- Number of Experts: The document states that "Users included surgeons and technical support personnel who were able to successfully use the Navio system" during clinical simulation. The exact number of surgeons or technical support personnel is not specified.
- Qualifications of Experts: The qualifications are generally stated as "surgeons" (implying orthopedic surgeons given the device's application) and "technical support personnel." Specific details like years of experience or board certifications are not provided.
4. Adjudication Method
The document does not describe a formal adjudication method for establishing ground truth or evaluating performance in the context of multiple expert opinions. The clinical simulation involved "users" (surgeons and technical support personnel) successfully using the system, suggesting a form of consensus or observation-based verification, but an explicit adjudication method (e.g., 2+1, 3+1) is not mentioned. Given the nature of a device modification and non-clinical testing, such a formal adjudication might not have been deemed necessary.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No. The document explicitly states: "No human clinical tests were conducted to determine safety and effectiveness of the Navio system." Therefore, an MRMC comparative effectiveness study involving human readers with and without AI assistance was not performed.
6. Standalone Performance Study
Yes. The nonclinical testing, including bench verification and simulated-use testing (sawbones, cadaver lab), represents standalone performance testing of the device with the new tracking markers. While human "users" were involved in the simulation, the focus was on the device's ability to function correctly and facilitate the surgical procedure with the modification, without a comparison to human performance without the device or without the AI. The goal was to confirm that the device performs as intended.
7. Type of Ground Truth Used
The ground truth for these nonclinical tests appears to be based on:
- Engineered/Simulated Ground Truth: For bench verification testing, the ground truth would be based on engineering specifications and known physical properties, ensuring the new marker functions according to design.
- Simulated Anatomical Ground Truth: For testing in "simulated knees (sawbones)" and "cadaver lab testing," the ground truth would be the known anatomical structures or the planned surgical resections as assessed by the participating surgeons or technical personnel. This is a form of expert-guided assessment of surgical accuracy and outcome in a simulated environment.
8. Sample Size for the Training Set
This 510(k) submission is for a device modification (a new tracking marker) to an existing system. The Navio system itself is a "computer-assisted orthopedic surgical navigation and surgical burring system" that uses "intraoperative data collection (image-free or non-CT data generation) to create a model of the patient's femur and tibia."
The document does not mention a training set in the context of an AI/machine learning algorithm for the new tracking marker. The new marker is a hardware component. The existing Navio system presumably relies on established algorithms and data collected previously for its navigation and planning functions, but details on that training set (if it exists for the core algorithms) are not part of this submission. This submission is focused on demonstrating that the new marker integrates seamlessly with the existing, validated system.
9. How the Ground Truth for the Training Set was Established
As noted above, no training set for a new AI/ML algorithm related to the tracking marker is described in this document. Therefore, information on how such a ground truth would be established for a training set is not applicable/provided in this context.
§ 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).