(119 days)
For use as a tool for adjustment of the femoral knee implant to reduce instability from flexion gap asymmetry. The Knee Balancer is sterile, for single patient use.
OrthoSensor Knee Balancer provides a means to dynamically balance the knee during knee replacement surgery intra-operatively. The system includes an instrumented trial tibial insert comprising an array of load sensors that measure the forces applied on its surface and angular positional information after insertion into the space between the tibia and the femur.
The provided text describes a Special 510(k) submission (K130380) for the OrthoSensor Knee Balancer. This submission is specifically for removing the "qualitative reference only" designation from the angular positional information previously associated with the device. It explicitly states that "This results in no change to the device itself as it has the same intended use, operating principles, and physical, operational specifications as compared to the predicate device." Therefore, the focus of this submission is not on demonstrating new performance criteria for the device as a whole, but rather on validating the angular positional data as quantitative without altering the fundamental scientific technology.
Given this, the provided document does not contain details about acceptance criteria or a study proving the device meets general performance criteria for its intended use as a whole. Instead, it refers to design control activities and verification/validation testing specifically for the change made.
However, based on the information provided, here's what can be extracted and inferred regarding the "study" related to the change:
1. Table of Acceptance Criteria and Reported Device Performance:
| Acceptance Criteria (Related to the change) | Reported Device Performance |
|---|---|
| No new risks associated with the modification | "The results of risk analysis have determined that there are no new risks associated with the modification on the device." |
| Verification of angular positional data | "bench top performance verification testing as well as design validation and usability testing performed in a cadaver lab setting." (Specific performance metrics are not provided in this document). |
| Device maintains substantial equivalence | "The proposed updated submission has the same intended use as the predicate and same technological characteristics that do not raise different types of questions of safety and effectiveness." |
2. Sample size used for the test set and the data provenance:
- Sample size for test set: Not specified in the provided text.
- Data provenance: "cadaver lab setting" is mentioned for design validation and usability testing. This implies a prospective study using cadaveric tissue. The country of origin is not specified.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- Not specified. The document only mentions "design validation and usability testing performed in a cadaver lab setting," without detailing the involvement or qualifications of experts for establishing ground truth within that testing.
4. Adjudication method for the test set:
- Not specified.
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:
- No, a multi-reader multi-case comparative effectiveness study is not mentioned. The device is a physical intraoperative tool, not an AI diagnostic algorithm.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- Not applicable in the context of an intraoperative physical device. The device's "algorithm" (its measurement capabilities) is inherently used with a human (surgeon) who interprets the data. However, the benchtop and cadaveric testing would effectively be "standalone" in verifying the accuracy of the device's measurements themselves, independent of a surgeon's interpretation of those measurements for decision-making. The document states "bench top performance verification testing."
7. The type of ground truth used:
- For the cadaver lab testing, the "ground truth" would likely involve direct physical measurements or established anatomical references against which the device's angular positional information is compared. The document doesn't explicitly state the specific ground truth method.
8. The sample size for the training set:
- Not applicable. The document describes a medical device, not an AI/ML algorithm that requires a "training set" in the conventional sense. The "training" of the device would be its initial design and calibration for which no sample size is provided.
9. How the ground truth for the training set was established:
- Not applicable for this type of device.
In summary, this 510(k) submission focuses on a minor change (redefining the status of existing angular data) and relies on prior validations and risk analysis, along with limited specific verification and validation testing for the change itself. It does not present a comprehensive study demonstrating new performance criteria for the device as a whole.
§ 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).