(60 days)
Wright's PROPHECY® Preoperative Navigation Alignment Guides are intended to be used as patient-specific surgical instrumentation to assist in the positioning of total ankle replacement components intra-operatively and in quiding the marking of bone before cutting. The PROPHECY® Preoperative Navigation Alignment Guides are intended for use with Wright's INBONE® and INFINITY™ Total Ankle Systems and their cleared indications for use, provided that anatomic landmarks necessary for alignment and positioning of the implant are identifiable on patient imaging scans. The PROPHECY® Preoperative Navigation Alignment Guides are intended for single use only.
PROPHECY® Preoperative Navigation Alignment Guides are patient-specific quides created to fit the contours of the patient's distal tibial and proximal talar anatomy. The quides are designed and manufactured from patient imaging data (CT) and are made from biocompatible nylon. The PROPHECY® Guides serve as an alternative to traditional alignment instrumentation used with Wright's INBONE® and INFINITY™ Total Ankle Systems, and thereby reduce the overall number of surgical steps reguired during total ankle arthroplasty. The quides serve to position and align the implants comparable to that attainable with traditional instrumentation.
1. Acceptance Criteria and Reported Device Performance
The provided document does not explicitly state numerical acceptance criteria in a table format. However, the study aims to demonstrate that the PROPHECY® INFINITY™ Preoperative Navigation Alignment Guides achieve comparable placement and alignment to traditional instrumentation. The conclusion across all evaluations was that the subject alignment guides are "substantially equivalent to the predicates."
| Acceptance Criteria Category | Reported Device Performance |
|---|---|
| Guide Design Repeatability | Concluded to be substantially equivalent to predicates. |
| Guide Placement Repeatability | Concluded to be substantially equivalent to predicates. |
| Placement Location and Orientation (Cadaver Evaluation) | Concluded to be substantially equivalent to predicates. |
| Software Validation | Concluded to be substantially equivalent to predicates. |
2. Sample Size and Data Provenance
The document does not specify the exact sample sizes for the "Guide design repeatability," "Guide placement repeatability," and "Software validation" tests.
For the cadaver evaluation, the sample size is not explicitly stated. The data provenance is implied to be experimental, likely conducted in a lab setting, which would be considered prospective. The country of origin is not specified but is presumably the US, where Wright Medical Technology is located.
3. Number of Experts and Qualifications
For the cadaver evaluation, the document states "Cadaver evaluation by end users analyzing placement location and orientation." It does not specify the number of end users or their exact qualifications beyond being "end users," which implies surgical professionals who would typically use such alignment guides.
For the guide design repeatability, it mentions "Guide design repeatability across design engineers." It does not specify the number or qualifications of these design engineers.
4. Adjudication Method
The document does not describe an explicit adjudication method (e.g., 2+1, 3+1) for any of the evaluations. The evaluations conclude with a general statement of "substantial equivalence to the predicates," suggesting a consensus or qualitative assessment rather than a formal adjudication process with multiple independent reviewers and a defined conflict resolution mechanism.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No multi-reader multi-case (MRMC) comparative effectiveness study is mentioned. The evaluations focus on the performance of the alignment guides themselves, not on the improvement of human readers with AI assistance.
6. Standalone Performance (Algorithm Only)
The device described is a physical patient-specific alignment guide manufactured based on imaging data, not solely an algorithm. The "Software validation" was done as part of the overall device evaluation, but it is not presented as a standalone algorithm performance study. The device is intended to be used by a human surgeon in the operating room.
7. Type of Ground Truth Used
- Guide design repeatability: The ground truth would likely be established by comparing multiple designs generated from the same patient imaging data against a predetermined set of design specifications or against each other for consistency.
- Guide placement repeatability: The ground truth would involve comparing repeated placements of the guide on a model or cadaver to a known, ideal placement or to each other.
- Cadaver evaluation: The ground truth for placement location and orientation would be established by direct anatomical measurement or imaging of the implant and guide placement relative to anatomical landmarks on the cadavers, likely verified by surgical experts.
- Software validation: The ground truth would involve comparing software outputs (e.g., guide design, measurements) against known correct values or established benchmarks.
8. Sample Size for the Training Set
The document does not provide information about a "training set" in the context of an algorithm. The alignment guides are designed and manufactured from individual patient imaging data (CT), implying a real-time process for each patient rather than a pre-trained algorithm in the typical sense.
9. How the Ground Truth for the Training Set Was Established
As there is no mention of a traditional "training set" for an algorithm, this question is not applicable in the context of the provided document. The patient-specific nature of the guides means each guide's design is based on the individual patient's CT scan, not a pre-trained model on a large dataset.
§ 888.3110 Ankle joint metal/polymer semi-constrained cemented prosthesis.
(a)
Identification. An ankle joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace an ankle joint. The device limits translation and rotation in one or more planes via the geometry of its articulating surfaces and has no linkage across-the-joint. This generic type of device includes prostheses that have a talar resurfacing component made of alloys, such as cobalt-chromium-molybdenum, and a tibial resurfacing component made of ultra-high molecular weight polyethylene and is limited to those prostheses intended for use with bone cement (§ 888.3027).(b)
Classification. Class II.