(218 days)
The Robotic Arm Interactive Orthopedic System (RIO®) is intended to assist the surgeon in providing software defined spatial boundaries for orientation and reference information to anatomical structures during orthopedic procedures.
The RIO® is indicated for use in surgical knee procedures in which the use of stereotactic surgery may be appropriate, and where reference to rigid anatomical bony structures can be identified relative to a CT based model of the anatomy. These procedures include:
• Total Knee Arthroplasty (TKA)
The Implants systems with which the system is compatible:
• Kinetis Total Knee System (CR/UC)
• Triathlon Total Knee System (CR/CS/PS cemented Primary)
The Robotic Arm Interactive Orthopedic System (RIO) with Total Knee Arthroplasty Application is a stereotactic instrument that includes a robotic arm, an integrated cutting system, an optical detector, a computer, dedicated instrumentation, operating software, a planning laptop, and tools and accessories. RIO uses patient CT data to assist the physician with pre-surgical implant placement planning and intraoperative tracking of the patient's femur and tibia. RIO's robotic arm serves as an "intelligent" tool holder or tool guide used by a surgeon for stereotactic guidance during orthopedic surgical procedures.
The main RIO platform includes an optical detector, computer, dedicated instrumentation, operating software, tools and accessories, cutting system, and a robotic arm. The system's architecture is designed to support total knee procedures. With application specific hardware and software, the system provides stereotactic guidance during orthopedic surgical procedures by using patient CT data to assist a surgeon with pre-surgical planning and interpretive/intraoperative navigation.
RIO's robotic arm, once configured for a specific application, can serve as surgeon's "intelligent" tool holder or tool guide by passively constraining the preparation of an anatomical site for an orthopedic implant with software-defined spatial boundaries.
Here's an analysis of the provided text to extract the acceptance criteria and study details:
1. Table of Acceptance Criteria and Reported Device Performance
The document reports primary and secondary endpoints as part of its clinical study.
| Acceptance Criteria Category | Specific Criteria | Reported Device Performance |
|---|---|---|
| Safety (Primary Endpoint) | No clinically significant increase in the incidence of selected device-related adverse events when using the investigational device relative to manual TKA. This was based on complications identified by the Knee Society TKA Complications Workgroup in 2012, compared against published occurrence rates for manually instrumented TKA. | No subject experienced any of the rare adverse events that comprise the primary composite safety events (0/89). The study met its primary safety study success criterion. |
| Effectiveness (Secondary Endpoint) | Post-operative radiographic limb alignment of the operative knee assessed at 3 months post-operative. Malalignment was defined as a radiographically determined alignment angular deformity in the coronal plane greater than 10° from the mechanical axis. The goal was to demonstrate non-inferiority to TKA with manual instruments. | Independent surgeon reviewer one measured an estimated mean limb alignment deviation from plan of 1.53° (± 1.05°). Independent surgeon reviewer two measured an estimated mean limb alignment deviation from plan of 1.56° (± 1.04°). No subject reported malalignment (i.e., >10° from mechanical axis). |
| Functional Outcome (Supporting Endpoint) | Improvement in post-operative subject function at the three-month interval as compared to the subject's pre-operative function as measured by the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score. A reduction in the WOMAC score from pre-op to 3 months was necessary. | Subjects exhibited a mean 29.6 points reduction in the WOMAC score, indicating improvement over the pre-operative score. |
Non-Clinical Performance Data (Verification/Validation)
| Acceptance Criteria (Purpose) | Reported Device Performance (Results) |
|---|---|
| Verify integration of RIO, Total Knee Application Software, and instrumentation provides adequate functionality to successfully complete a TKA procedure. | Pass |
| Verify overall system accuracy by combining bone registration and bone resection accuracy. | Pass |
| Verify accuracy of bone registration for the TKA 1.0 Application satisfies specified requirements. | Pass |
| Verify RIO resection accuracy for the Total Knee Arthroplasty Application satisfies specified requirements. | Pass |
| Verify RIO perimeter retention accuracy for the Total Knee Arthroplasty Application satisfies specified requirements. | Pass |
| Verify in simulated-use environment integration of RIO with Total Knee Application Software and instrumentation provides adequate functionality and satisfies customer requirements. | Pass |
2. Sample Size Used for the Test Set and the Data Provenance
- Sample Size for Clinical Study (Test Set): 89 implanted subjects (out of 100 consented and enrolled). Two subjects were excluded from the limb alignment assessment.
- Data Provenance: Prospective, non-randomized, multi-center study conducted at three sites in the US.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and the Qualifications of Those Experts
- Safety Assessment: Surgeon assessment of complications intra-operatively and at a short-term follow-up. (Number of surgeons/experts not specified, but implied to be the treating surgeons at the three sites.)
- Limb Alignment Assessment: Two independent reviewers (implied to be surgeons, given the context of medical devices and clinical studies). Their qualifications are not explicitly stated beyond "independent surgeon reviewer."
4. Adjudication Method for the Test Set
- For post-operative radiographic limb alignment, two independent reviewers assessed the outcome. The document reports their measured mean deviations separately (1.53° and 1.56°), implying their individual assessments were presented, rather than an adjudicated consensus. It does not specify an adjudication method like 2+1 or 3+1 if there were discrepancies.
- For adverse events, "Study investigators classified relatedness of all AEs." The number of investigators and their adjudication method are not specified.
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 explicitly described in the provided text.
- The clinical study focused on demonstrating the safety and effectiveness of the RIO system primarily by comparing its outcomes against literature-reported rates for manual TKA, not a direct head-to-head MRMC comparison with human readers/surgeons performing manual TKA in the same study.
- Therefore, an "effect size" of human readers improving with AI vs. without AI assistance cannot be determined from this document.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) was Done
- The document describes the RIO system as a "stereotactic instrument that includes a robotic arm... used by a surgeon for stereotactic guidance." The system "assists the surgeon" and serves as an "intelligent tool holder or tool guide." This indicates a human-in-the-loop system, not a standalone (algorithm only) device.
- The "System Accuracy Test," "Bone Registration Accuracy Test," "RIO 3.0 System Platform Cutting Accuracy Test," and "TKA Perimeter Retention Accuracy Verification" could be considered components of standalone algorithm/system performance tests, but they are integrated within the context of a surgeon-assisted procedure.
7. The Type of Ground Truth Used
- Safety: Surgeon assessment of complications, compared against literature-defined complication rates.
- Effectiveness (Limb Alignment): Post-operative radiographic measurements, compared against a pre-operatively derived subject-specific intended limb alignment. This can be considered a form of objective measurement against a planned target.
- Functional Outcome: Patient-reported outcome measure (WOMAC score).
- Non-Clinical Tests: Pre-defined specified requirements and expected functionalities.
8. The Sample Size for the Training Set
- The document does not explicitly state the sample size for a training set. The clinical study described is the test set for evaluating the final device's performance. For an AI/ML device, a separate training set would typically be used to develop the algorithm before this evaluation.
- The device uses "patient CT data" for pre-surgical planning and intraoperative navigation, implying previous data (potentially a training set) was used to develop the software models for this functionality, but the size and nature of such a set are not provided.
9. How the Ground Truth for the Training Set Was Established
- As the document does not specify a training set, it does not describe how its ground truth was established. For a device like this, which relies on CT data for anatomical modeling and guidance, the "ground truth" for training would likely involve a large dataset of CT images with expert annotations (e.g., bone boundaries, anatomical landmarks) or precise cadaveric/phantom studies to establish known true values for registration and cutting accuracy. The "Performance Data" section describes validation tests that establish accuracy against known targets in a controlled environment, which are analogous to establishing ground truth for individual performance metrics.
§ 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).