(100 days)
The OrthAlign Plus® System is a computer-controlled system intended to assist the surgeon in determining reference alignment axes in relation to anatomical and instrumentation structures during stereotactic orthopedic surgical procedures. The OrthAlign Plus® System facilitates the accurate positioning of implants, relative to these alignment axes. The system aids the surgeon in controlling leg length and offset discrepancies in Total Hip Arthroplasty. Ligament balancing is provided by the OrthAlign Plus® System in primary or revision Total Knee Arthroplasty.
Example orthopedic surgical procedures include but are not limited to:
- Total Knee Arthroplasty
- Total Hip Arthroplasty: Anterior/Posterior
- Unicompartmental Knee Arthroplasty: Tibial transverse resection
- Ligament Balancing
The OrthAlign Plus® System is a non-invasive computer assisted surgical navigation system for use in knee and hip arthroplasty procedures. The OrthAlign Plus® System is configured to detect, measure, and display angular and positional measurement changes in a triaxial format. The OrthAlign Plus® System utilizes a palm-sized computer module and reference sensor to generate positional information in orthopedic procedures providing a sequence of steps for registration of anatomical landmarks, calculation of mechanical axes, and positioning of instruments relative to the mechanical axes. The OrthAlign Plus® System comprises a single use computer module and reusable instrumentation.
The OrthAlign Plus® System is a computer-controlled surgical navigation system intended to assist surgeons in determining reference alignment axes during stereotactic orthopedic surgical procedures. It facilitates accurate implant positioning and aids in controlling leg length and offset discrepancies in Total Hip Arthroplasty (THA), and provides ligament balancing in primary or revision Total Knee Arthroplasty (TKA).
Here's an analysis of the provided information regarding acceptance criteria and the study:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly state numerical acceptance criteria for accuracy. However, it does describe the performance testing conducted and concludes that the device performs "as well as the predicate devices." The key performance metric highlighted is accuracy in gap distance and angle measurement.
| Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|
| Gap distance measurement accuracy | Bench testing with mechanical fixtures verified accuracy. |
| Angle measurement accuracy | Bench testing with mechanical fixtures verified accuracy. |
| Software functionality and reliability | Software verification and validation ensured integrity, functionality, and reliability. |
| Instrument mechanical requirements | System hardware verification/validation confirmed instruments meet mechanical requirements. |
| Biocompatibility | Assessed per ISO 10993-1 (2009). |
| Usability and user needs | Validated in simulated use cadaver testing with an advising surgeon. |
2. Sample Size Used for the Test Set and Data Provenance
- Test Set Sample Size: Not explicitly stated with a numerical value. The document mentions "bench testing with mechanical fixtures" and "simulated use testing in cadaver." The number of mechanical tests or cadavers used is not specified.
- Data Provenance: The cadaver testing implies a prospective experimental setting. The location of the test (e.g., country of origin) is not specified.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Their Qualifications
- Number of Experts: One "advising surgeon" was involved in the simulated use cadaver testing.
- Qualifications: "Advising surgeon" is the only qualification provided. Specific experience or subspecialty is not mentioned.
4. Adjudication Method for the Test Set
The document does not describe an adjudication method for the test set in the traditional sense (e.g., 2+1, 3+1). For the cadaver study, an "advising surgeon" was present, suggesting a direct observation and evaluation of the system's performance in a simulated surgical environment. For bench testing, the ground truth would be objectively measured by the mechanical fixtures themselves.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done
No, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not conducted or described. The study focuses on evaluating the device's standalone performance and its equivalence to predicate devices, not on comparing human reader performance with and without AI assistance.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was done
Yes, a standalone performance evaluation was done. "Bench testing with mechanical fixtures to verify gap distance and angle measurement accuracy" specifically evaluates the algorithm's ability to measure accurately without direct human interpretation or intervention affecting the measurement output. The software verification and validation also fall under standalone testing. The "simulated use testing in cadaver" does involve a human surgeon, but the primary focus is on the system's output and meeting user needs, rather than comparing human performance.
7. The Type of Ground Truth Used
- Bench Testing: Objective measurements from mechanical fixtures were used as ground truth for gap distance and angle measurement accuracy.
- Simulated Use Testing: The "advising surgeon" would have implicitly provided a form of expert consensus/observation regarding the system's ability to meet user needs and usability in a simulated surgical environment. However, this is more for usability and functionality validation rather than a quantitative ground truth for accuracy.
8. The Sample Size for the Training Set
The document does not provide any information about a training set since this is a 510(k) summary for a medical device which is largely a hardware and software system, not an AI/Machine Learning model that undergoes "training" in the traditional sense of data-driven learning. While algorithms are involved, they appear to be rule-based or deterministic rather than machine learning algorithms requiring a distinct "training set."
9. How the Ground Truth for the Training Set was Established
As no training set is mentioned or implied for a machine learning model, the method for establishing ground truth for a training set is not applicable to this submission.
§ 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).