(207 days)
The Crosstrees® PVA Pod device is intended to provide surgeons with a percutaneous means to deliver bone cement to painful pathologic compression fractures of the vertebral body in levels T4-L5 of the thoracic and lumbar spine. Pathologic fractures of the vertebral body may be caused by osteoporosis. It is intended to be used in combination with Crosstrees Fortibrae® Bone Cement when delivered by the Crosstrees CDrive® Bone Filler Delivery System.
The Crosstrees® PVA Pod device is designed to deliver bone cement to the fractured vertebral body in a controlled manner without the need for an additional permanent implant other than the bone cement. The device consists of a shaft assembly for delivery of PMMA cement to a fabric barrier. Following cement delivery, the fabric barrier is opened and withdrawn from the vertebral body. The Crosstrees® PVA Pod device is made from a variety of materials commonly used in orthopedic and radiological procedures including stainless steel and polymers. The device is available in either a 2.0 mL or 3.0 mL fill capacity. The device is provided with a number of class I tools that are used for surgical access and delivery of the Pod to the surgical site, as well as preparation and delivery of bone cement.
Here's a breakdown of the acceptance criteria and the study details for the Crosstrees® PVA Pod device, based on the provided 510(k) summary:
Acceptance Criteria and Device Performance
| Acceptance Criteria (Primary Endpoints) | Reported Device Performance (6-month) | Reported Device Performance (12-month) |
|---|---|---|
| Clinically significant improvement in pain (≥2 cm VAS from baseline) | 94.5% of subjects | 89.6% of subjects |
| Freedom from cement leakage | 85.0% (based on core lab assessment) | (Not explicitly stated for 12 months, but likely improved from 6 months due to overall effectiveness claim) |
| Absence of device-related adverse events | No serious device-related adverse events, most related to asymptomatic cement extravasation | No serious device-related adverse events |
| Absence of device-related reoperations or revisions | None at the index level | None at the index level |
Note: The leakage rate reported at 6 months by the radiographic core laboratory (15.0% extravasation) implies an 85.0% freedom from cement leakage. The intra-operative assessment by investigators reported 9.0% extravasation (91.0% freedom from leakage).
Study Details
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Sample size used for the test set and the data provenance:
- Total Enrollment: 135 subjects
- Analysis Population: 133 subjects
- Data Provenance: Prospective, single-arm, IDE clinical trial.
- Country of Origin: Included 111 U.S. subjects, implying the study was conducted internationally with a significant U.S. component. The specific countries are not detailed beyond "U.S. subjects."
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Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- The document mentions a "radiographic core laboratory" for assessing cement leakage and "Investigator" for intra-operative observations.
- The number of experts within the core lab is not specified.
- The qualifications of the experts (e.g., specific specialties, years of experience) are not specified for either the core lab personnel or the investigators.
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Adjudication method for the test set:
- The document implies a separate assessment by a "radiographic core laboratory" and "Investigator" for cement leakage, suggesting some level of independent review. However, it does not detail a formal adjudication method (e.g., 2+1, 3+1 consensus process) for discrepancies between these assessments. The core lab's assessment is described as "conservative."
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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:
- No, an MRMC comparative effectiveness study involving AI assistance for human readers was not conducted or reported. This study evaluated the device's performance directly, not its interaction with AI.
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If a standalone (i.e., algorithm only without human-in-the-loop performance) was done:
- No, a standalone algorithm performance study was not done. The Crosstrees® PVA Pod is a medical device for cement delivery, not an AI algorithm.
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The type of ground truth used (expert consensus, pathology, outcomes data, etc.):
- Pain Improvement: Patient-reported Visual Analog Scale (VAS) scores, considered a form of patient-reported outcomes data.
- Cement Leakage: Assessed by a "radiographic core laboratory" (imaging interpretation by experts) and "Investigator" (clinical observation during the procedure). This is a form of expert assessment/imaging review.
- Adverse Events/Reoperations: Clinical observation and reporting, considered outcomes data.
- New Fractures: Post-operative radiographic review, implying expert assessment/imaging review.
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The sample size for the training set:
- Not applicable / Not explicitly reported. This device is a physical medical device, not a machine learning model, so there isn't a "training set" in the conventional AI sense. The study described is a clinical trial to evaluate the device itself.
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How the ground truth for the training set was established:
- Not applicable. As mentioned above, there is no AI training set for this device. The clinical trial established the ground truth for the device's performance based on the methods described in point 6.
§ 888.3027 Polymethylmethacrylate (PMMA) bone cement.
(a)
Identification. Polymethylmethacrylate (PMMA) bone cement is a device intended to be implanted that is made from methylmethacrylate, polymethylmethacrylate, esters of methacrylic acid, or copolymers containing polymethylmethacrylate and polystyrene. The device is intended for use in arthroplastic procedures of the hip, knee, and other joints for the fixation of polymer or metallic prosthetic implants to living bone.(b)
Classification. Class II (special controls). The special control for this device is the FDA guidance document entitled “Class II Special Controls Guidance Document: Polymethylmethacrylate (PMMA) Bone Cement.”