(177 days)
TrueBalance™ Surgical System is indicated for any medical condition in which primary or revision Total Knee Arthroplasty (TKA) would be indicated.
For use as a tool to measure implant alignment of the femoral knee implant to reduce instability from flexion gap asymmetry. TrueBalance™ Surgical System is completely reusable with the exception of the Ultra-Thin Force Sensor which is single use.
TrueBalance™ Surgical System provides a means to measure implant alignment and dynamically balance the knee during primary or revision Total Knee Arthroplasty (TKA).
TrueBalance™ Surgical System consists of seven components and one optional component:
- Electronic Module, 1.
-
- Ultra-Thin Force Sensor,
- Multifunction Alignment Handle, 3.
-
- Sensor Covers (8 sizes),
-
- Alignment Rod,
- Sterilization Tray, and 6.
-
- TrueBalance™ Software Application (TSA) and Display (iPad)
-
- (Optional) Off-the-shelf Tablet Floor Stand for iPad
The TrueBalance™ Surgical System Electronic Module and hardware components are steam sterilizable via autoclave and reusable via a Sterilization Tray. TrueBalance™ Surgical System Ultra-Thin Force Sensor is single use, packaged non-sterilizable via autoclaye. The TrueBalance™ Surgical System Electronic Module is steam sterilizable via autoclave in either the Sterilization Tray or standard autoclavable pouches.
TrueBalance™ Surgical System measures dynamic loads in the medial and lateral compartments of the knee and static angular measurements for the alignment functionality. The data from the Ultra-Thin Force Sensor and embedded accelerometer is wirelessly transmitted to the TrueBalance™ Software Application (TSA) and Display (iPad) which is located outside the sterile field in the operating room.
Here's a breakdown of the acceptance criteria and study information for the TrueBalance™ Surgical System, based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
The document provides specific performance specifications for Load/Force and Alignment, comparing them to previous predicate devices (K193580 and K180459). The acceptance criteria are implicit in these reported performance specifications, as stated "with results demonstrating that acceptance criteria were met."
| Performance Metric | Acceptance Criteria (Subject Device, TrueBalance™ Surgical System) | Reported Device Performance (Subject Device, TrueBalance™ Surgical System) | Predicate Device (K193580) Performance | Predicate Device (K180459) Performance |
|---|---|---|---|---|
| Load/Force Balancing | ||||
| Operating Range | 0 - 160 LBF (per condyle) | 0 - 160 LBF | 0 - 160 LBF | 5 - 40 LBF (reported as operating range) |
| Load Accuracy | ± 3.0 LBF or ± 7.5% (whichever is greater) | ± 3.0 LBF or ± 7.5% (whichever is greater) | ± 3.5 LBF | ± 3.5 LBF |
| Load Values Displayed for Reference | >160 LBF | >160 LBF | >160 LBF | 41-70 LBF (reported for reference) |
| Maximum Safe Load | 160 LBF (per condyle) | 160 LBF (per condyle) | 70 LBF | |
| A-P Condylar Position & M-L Distribution Accuracies | Equal to or better than ± 25% | Equal to or better than ± 25% | COL for Reference Only | COL for Reference Only |
| Alignment | ||||
| Tibia Varus/Valgus | ± 0.9° (95% Confidence) | ± 0.9° (95% Confidence) | Range ± 7°, accuracy ± 3° | N/A (this predicate doesn't specify alignment directly) |
| Femur Varus/Valgus | ± 1.2° (95% Confidence) | ± 1.2° (95% Confidence) | N/A | N/A |
| Posterior Slope | ± 1.0° (95% Confidence) | ± 1.0° (95% Confidence) | N/A | N/A |
| Mechanical Axis | ± 1.5° (95% Confidence) | ± 1.5° (95% Confidence) | N/A | N/A |
2. Sample Size for the Test Set and Data Provenance
The document states that "Load/Force Performance Testing" and "Alignment Performance Testing" were conducted using "Internal Protocol." However, specific sample sizes for the test sets are not provided. The data provenance (e.g., country of origin, retrospective/prospective) is also not explicitly stated beyond being "Internal Protocol." Given the nature of the device (surgical system), it is likely that these tests were conducted in a laboratory setting or on cadaver models, but this is not explicitly detailed.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
The document mentions "Usability Engineering / Cadaver Labs" as a safety and performance test. While this implies involvement of surgical experts, the number of experts and their qualifications (e.g., radiologist with 10 years of experience) are not specified.
4. Adjudication Method for the Test Set
The document does not explicitly state an adjudication method (e.g., 2+1, 3+1, none) for the test set results. The internal protocols for Load/Force and Alignment performance testing would typically detail how results are evaluated and confirmed, but these details are not provided in this summary.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, and the Effect Size
No MRMC comparative effectiveness study is mentioned. The document explicitly states:
- "Performance Testing - Animal: N/A (Animal performance testing was not required to demonstrate substantial equivalence)"
- "Performance Testing - Clinical: N/A (Clinical performance testing was not required to demonstrate substantial equivalence)"
Therefore, no effect size of human readers improving with AI vs. without AI assistance can be determined from this document as it's not an AI-assisted diagnostic device in the traditional sense, but a measurement tool.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
The device is described as a "measurement tool to provide the surgeon with quantifiable data." It relies on "Electronics and sensors to measure load/force pressure" and an "accelerometer to measure coronal plane alignment." The "TrueBalance™ Software Application (TSA)" processes this data and "displays both numerically and pictorially load data along with angular measurements (alignment data)."
This indicates that the algorithm operates in a standalone capacity to process sensor input and generate measurements, which are then presented to the human user (surgeon). The performance specifications listed in the table (Load Accuracy, Tibia Varus/Valgus, etc.) are a direct measure of this standalone algorithmic performance.
7. The Type of Ground Truth Used
For the Load/Force and Alignment Performance Testing, the ground truth would have been established through highly precise mechanical measurement systems and/or calibrated physical models/phantoms designed to simulate the knee joint under various loading and alignment conditions. This is implied by the nature of the reported accuracy metrics (e.g., LBF, degrees). For the Usability Testing Cadaver Labs, the ground truth would likely be established by observing surgical procedures, expert assessment of outcomes, and possibly comparative measurements against established surgical references.
8. The Sample Size for the Training Set
The document does not mention a training set or its sample size. This is common for devices that rely on established physical principles and calibrated sensors for measurement, rather than machine learning models that require extensive training data.
9. How the Ground Truth for the Training Set Was Established
Since no training set is mentioned for a machine learning model, this information is not applicable/provided. The device operates based on sensor readings and algorithms derived from engineering principles.
§ 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).