(83 days)
For use as a tool for adjustment of the femoral knee implant to reduce instability from flexion gap asymmetry. The force sensor is sterile, for single patient use.
The device consists of two units, the force sensing unit and an electronic display. The eLIBRATM Force Sensing Tibial Unit is a single use battery powered device designed to transmit an electronic signal to the eLIBRA™ Display Unit. The electronic signal represents the relative medial and lateral compartment forces generated from the soft tissue structures surrounding the knee joint during a total knee arthroplasty (TKA). The LIBRA Dynamic Knee Balancer eLIBRATM Display Unit is a reusable battery powered device designed to receive an electronic signal from the eLIBRATM Force Sensing Tibial Unit. The unit displays a number from 0-19 for both the medial and lateral compartments in the knee joint to aid the surgeon in balancing soft tissue structures during a total knee arthroplasty (TKA).
The provided text describes the eLibra Dynamic Knee Balancer, an orthopedic manual surgical instrument used in total knee arthroplasty (TKA). It outlines the device's description, intended use, and technological characteristics. However, it does not contain specific acceptance criteria, detailed performance metrics, or a comprehensive study plan with the information requested.
Here's an analysis of what can be extracted and what is missing based on your request:
1. A table of acceptance criteria and the reported device performance
- Acceptance Criteria: Not explicitly stated in the provided text. The submission mentions "results were satisfactory and revealed no concerns over safety and effectiveness as compared to predicate devices," but this is a general statement, not quantified acceptance criteria.
- Reported Device Performance:
- Bench Testing: Included "mechanical testing, radio frequency, and sterility testing, including EO residues." The results were deemed "satisfactory."
- Clinical Testing: Performed to determine "adequacy of instructions for use, the range of patient population, performance characteristics, and reliability." The results were "satisfactory."
- Conclusion: "The tests demonstrated that the device is as safe, as effective, and performs in a substantially equivalent manner to the predicate device."
| Acceptance Criteria (Not Explicitly Stated) | Reported Device Performance | Comments |
|---|---|---|
| (e.g., Accuracy of force readings: X% within predicate) | "Satisfactory" for mechanical, radio frequency, sterility tests | No specific quantitative performance metrics are provided for the force sensing or display. |
| (e.g., Clinical reliability: Y% of cases without issue) | "Satisfactory" for clinical testing regarding instructions for use, patient population range, performance characteristics, and reliability | No specific quantitative performance metrics are provided from clinical testing. |
| (e.g., Equivalent safety profile to predicate) | "As safe... as compared to predicate devices" | No specific adverse event rates or safety comparisons are provided. |
| (e.g., Equivalent effectiveness to predicate) | "As effective... as compared to predicate devices" | No specific clinical outcome measures or effectiveness comparisons are provided. |
2. Sample size used for the test set and the data provenance
- Sample Size for Test Set: Not specified. The text only mentions "clinical tests were performed" without detailing the number of patients or cases.
- Data Provenance: Not specified (e.g., country of origin, retrospective or prospective). The text only states "clinical testing was performed."
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
- Number of Experts: Not specified.
- Qualifications of Experts: Not specified. It only mentions aiding "the surgeon in balancing soft tissue structures."
4. Adjudication method (e.g. 2+1, 3+1, none) 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
- MRMC Study: Not applicable. The device is a force-sensing instrument for surgical assistance, not an imaging or diagnostic AI tool that would involve human readers.
- Effect Size: N/A.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
- Not applicable in the typical sense for an AI algorithm. The device itself (eLibra Dynamic Knee Balancer) provides a direct reading (numbers 0-19) for the surgeon to interpret and act upon. It's an instrument providing information to a human operator, not a standalone diagnostic or assistive AI system. Its "standalone" performance would be its accuracy and reliability in measuring force and displaying it. However, no specific details on this are provided beyond "satisfactory."
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)
- Ground Truth: Not explicitly stated or defined. For a force-sensing device, the "ground truth" would likely involve comparison to established methods or calibrated force measurement systems in bench testing, and potentially clinical outcomes or successful soft tissue balancing assessed intra-operatively by surgeons in clinical testing. However, the document does not specify how this "ground truth" was established or measured for the clinical tests.
8. The sample size for the training set
- Not applicable. The device is a hardware instrument with a display, not a machine learning model that undergoes a "training set" in the context of AI.
9. How the ground truth for the training set was established
- Not applicable (see point 8).
Summary of Missing Information:
The provided 510(k) summary focuses on demonstrating substantial equivalence to a predicate device, as well as general safety and effectiveness through satisfactory bench and clinical testing. It lacks detailed quantitative performance data, specific acceptance criteria, sample sizes for testing, and methodologies for ground truth establishment or expert involvement, which are typically found in more comprehensive study reports for AI/diagnostic devices. This is common for predicate-based medical devices that are not complex AI systems.
§ 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).