(135 days)
The KneeAlign "M System is a computer controlled system intended to assist the surgeon in determining reference alignment axes in relation to anatomical structures during stereotactic orthopedic surgical procedures. The KneeAlign™ System facilitates the accurate positioning of implants and instrumentation, relative to these alignment axes.
Example orthopedic surgical procedures include but are not limited to:
- . Total Knee Arthroplasty/tibial resection
The KneeAlign " System is an innovative non-invasive computer assisted surgical navigation system for use in knee arthroplasty procedures. The KneeAlign™ System is configured to detect, measure, and display angular measurement changes in a triaxial format.
The KneeAlign " System utilizes a palm-sized computer module and registration instruments 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. In knee arthroplasty procedures, the device assists the surgeon in establishing the mechanical axis of the tibia, determining the varus/valgus angle and the posterior slope angle of the cutting block relative to tibia. The KneeAlign " System comprises a single use computer module and reusable instrumentation.
Here's a breakdown of the acceptance criteria and study information based on the provided text for the K091411 (KneeAlign™ System):
1. Table of Acceptance Criteria and Reported Device Performance
The provided 510(k) summary does not explicitly state specific quantitative acceptance criteria or detailed numerical device performance metrics. Instead, it makes a general statement about validation.
| Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|
| Device met its intended use. | "Bench and cadaver testing confirm that the KneeAlign™ System can be used according to its intended use." |
| Device verified and validated. | "The KneeAlign 100 System has been verified and validated according to OrthAlign's procedures for product design and development." |
| Substantial equivalence to predicates. | "The information provided by OrthAlign in this 510(k) application was found to be substantially equivalent to predicate devices such as the BrainLAB Knee Essential (K073615) and the TOTAL KNEE SURGETICS Navigation System (K060282)." |
| Technological comparison demonstrates substantial equivalence. | "A technological comparison and bench, and cadaver testing demonstrate the substantial equivalence of the KneeAlign™ System to the predicate devices." |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: Not explicitly stated. The text mentions "bench and cadaver testing." The number of cadavers or specific test cases is not provided.
- Data Provenance: Not explicitly stated. "Bench and cadaver testing" generally implies studies conducted by the device manufacturer or a contracted lab. The country of origin is not specified, nor is whether the data was retrospective or prospective.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
- Number of Experts: Not explicitly stated.
- Qualifications of Experts: Not explicitly stated.
4. Adjudication Method for the Test Set
- Adjudication Method: Not explicitly stated. The document simply mentions "bench and cadaver testing" to confirm the system's intended use and performance. There is no information about expert adjudication for establishing ground truth in a test set.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, and the Effect Size of How Much Human Readers Improve with AI vs. Without AI Assistance
- MRMC Study: No, an MRMC comparative effectiveness study is not indicated. The device is a surgical navigation system, not an imaging analysis AI or diagnostic tool that would typically involve human "readers" interpreting output.
- Effect Size: Not applicable.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
- Standalone Performance: The core functionality validated is the "algorithm only" in the sense that the device uses "algorithms to convert sensor outputs into spatial coordinates, providing graphical representation of instruments and anatomy." The "bench and cadaver testing" would evaluate the accuracy and reliability of these algorithmic outputs in a controlled environment, which implicitly assesses its standalone performance in providing accurate measurements and guidance. However, it's not described as a "standalone validation" in the typical sense of comparing an AI's output to ground truth without human intervention in a diagnostic context. The system is designed to assist the surgeon, implying a human-in-the-loop during actual surgery.
7. The Type of Ground Truth Used
- Type of Ground Truth: Not explicitly stated. For bench testing, ground truth would likely be established using precise measurement tools (e.g., goniometers, CMMs) or highly accurate reference systems. For cadaver testing, ground truth might involve post-procedure measurements using specialized tools or dissection to verify alignment relative to anatomical landmarks. The document does not specify how these ground truths were established.
8. The Sample Size for the Training Set
- Training Set Sample Size: Not applicable. This device is a computer-assisted surgical navigation system, and the information provided does not suggest it uses machine learning/AI in a way that would require a separate "training set" for predictive model development as seen in image analysis or diagnostic AI. The algorithms mentioned are likely deterministic (converting sensor outputs to coordinates) rather than machine learning algorithms trained on data.
9. How the Ground Truth for the Training Set Was Established
- Ground Truth for Training Set: Not applicable, as no training set for machine learning is indicated.
§ 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).