(30 days)
TMINI™ Miniature Robotic System is indicated as a stereotaxic instrumentation system for total knee replacement (TKA) surgery. It is to assist the surgeon by providing software-defined spatial boundaries for orientation and reference information to identifiable anatomical structures for the accurate placement of knee implant components.
The robotic device placement is performed relative to anatomical landmarks as recorded using the system intraoperatively and based on a surgical plan determined preoperatively using CT based surgical planning tools.
It includes a handheld robotic device, an optical sensor navigation system and accessories, software system, surgical instruments and accessories.
The targeted population has the same characteristics as the population that is suitable for the implant(s) compatible with the TMINI™ Miniature Robotic System. The TMINIM Miniature Robotic System is to be used with the following knee replacement systems in accordance with the indications and contraindications:
- · Enovis™ EMPOWR Knee System®
- · Ortho Development® BKS® and BKS TriMax® Knee System
- · Total Joint Orthopedics Klassic® Knee System
- · United® U2™ Knee Total Knee System
Like its predicate, the TMINI™ Miniature Robotic System consists of three primary components: a three-dimensional, graphical, Preoperative Planning Workstation (TPLAN Planning Station), an Optical Tracking Navigation Console (TNav) and a Robotically Controlled Hand-held Tool (TMINI Robot) that assists the surgeon in preparing the bone for implantation of TKA components.
The TPLAN Planning Station uses preoperative CT scans of the operative leg to create 3D surface models for case templating and intraoperative registration purposes. The Planning Workstation contains a library of 510(k) cleared knee replacement implant(s). The surgeon can select an implant model from this library and manipulate the 3D representation of the implant in relation to the bone model to place the implant. Once the surgeon is satisfied with the implant location and orientation, the data is written to a file that is used to guide the robotically controlled hand-held tool.
The handheld robotic tool is optically tracked relative to optical markers placed in both the femur and tibia and articulates in two degrees-of-freedom, allowing the user to place bone pins in a planar manner in both bones. Mechanical guides are clamped to the bone pins, resulting in subsequent placement of cut slots and drill quide holes such that the distal femoral and proximal tibial cuts can be made in the pre-planned positions and orientations, and such that the implant manufacturer's multi-planer cutting block can be placed relative to drilled distal femoral pilot holes.
The provided text describes the TMINI™ Miniature Robotic System (Additional Knee Systems) and its substantial equivalence to a predicate device (K230202) for total knee replacement (TKA) surgery. The primary modification in this submission is the addition of compatibility with three new knee implant systems.
Here's an analysis of the acceptance criteria and the study that proves the device meets them, based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly list quantitative acceptance criteria in a table format with specific thresholds (e.g., "Accuracy must be within +/- X mm"). Instead, it states that performance testing was conducted and passed. The performance criteria are implicitly linked to the "cutting accuracy" and "cadaver lab validation testing."
| Acceptance Criteria Category | Specific Acceptance Criteria (Inferred from text) | Reported Device Performance |
|---|---|---|
| Cutting Accuracy Verification | Device must meet all test criteria and specifications for cutting accuracy, similar to the predicate. | Passed (All test criteria and specifications met) |
| Cadaver Lab Validation Testing | Device must meet all test criteria in simulated surgical testing in a cadaver model, similar to the predicate. | Passed (All test criteria met) |
| Biocompatibility | Materials must pass standard biocompatibility tests (Cytotoxicity, Sensitization, Intracutaneous Reactivity, Acute Systemic Toxicity, Pyrogenicity). | Passed (All 5 tests passed the acceptance criteria of the test protocol) |
| Risk Assessment | The addition of new implant systems must not introduce new clinical hazards or increase the likelihood/severity of existing hazards. | Passed (No new clinical hazards identified; existing risks unchanged) |
2. Sample Size Used for the Test Set and Data Provenance
- Test Set Sample Size: The document does not explicitly state the sample size for the "cutting accuracy verification" or the "cadaver lab validation testing." It mentions "simulated surgical testing in a cadaver model," implying a limited number of cadavers were used, but the exact count is not given.
- Data Provenance: The document does not specify the country of origin for the data. The "cadaver model" likely refers to ex vivo testing in a lab setting, not human clinical data. The review is for a 510(k) submission to the US FDA, so the data would have been submitted to support this application. It is implicitly a pre-market study, and given the nature of a 510(k) (seeking substantial equivalence), it would be considered prospective for the purpose of demonstrating the device's performance for this specific submission, even if the methods were established previously.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
The document does not provide any information regarding the number of experts, their qualifications, or how they established ground truth for the performance testing.
4. Adjudication Method for the Test Set
The document does not provide any information regarding an adjudication method for the test set. Given the "cutting accuracy" and "cadaver lab validation" descriptions, the "ground truth" likely involves precise physical measurements rather than subjective expert interpretations requiring adjudication.
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 done. This type of study is typically used for diagnostic or screening devices where human interpretation of images is a key component, often comparing human readers with and without AI assistance. The TMINI™ Miniature Robotic System is a surgical assistance device, and the testing described focuses on its mechanical accuracy and safety, not diagnostic interpretation. Therefore, there is no mention of human readers or an effect size of AI assistance on their performance.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) was Done
The performance testing described ("cutting accuracy verification" and "cadaver lab validation testing") can be interpreted as standalone performance of the robotic system in achieving its intended surgical goal. While the system "assists the surgeon," the testing focuses on the robot's precision in placing bone pins and enabling cuts, which is an intrinsic performance characteristic of the algorithm and hardware. It demonstrates the direct output of the robotic system.
7. The Type of Ground Truth Used
The ground truth for "cutting accuracy verification" would likely be:
- Precise Physical Measurements: Using highly accurate measurement tools (e.g., CMM, optical tracking systems, or specialized gauges) to quantify the deviation of the cuts or pin placements from the pre-planned surgical model.
The ground truth for "cadaver lab validation testing" would similarly involve:
- Physical Measurements Post-Procedure: Assessing the accuracy of implant component placement or bone cuts on the cadaveric specimens against the pre-operative plan. This might involve post-procedure imaging (e.g., CT scans) and subsequent measurement analysis.
The biocompatibility testing ground truth is based on standard chemical and biological assay results.
8. The Sample Size for the Training Set
The document does not directly address or mention a "training set" in the context of an AI/ML algorithm. The TMINI™ system uses "software-defined spatial boundaries" and "preoperative CT scans" for planning. While there's software involved, the description doesn't suggest a machine learning model that undergoes a training phase with a large dataset. It appears to be a deterministic robotic system guided by a surgical plan created from CT data.
9. How the Ground Truth for the Training Set Was Established
As no "training set" for an AI/ML algorithm is explicitly mentioned or seems applicable to this device as described, the question of how its ground truth was established is not relevant based on the provided text. The "TPLAN Planning Workstation" has a "library of 510(k) cleared knee replacement implant(s)," and surgeons use this to manipulate 3D representations for planning, which then guides the robot. This implies a rules-based or model-based system rather than a machine learning one requiring a distinct training phase.
§ 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).