(15 days)
The Lorenz External Mandibular Distractor is an external Fixator used for mandibular bone lengthening. It is used in treatment of mandibular asymmetry and hypoplasia.
The distractor frame is comprised of two threaded rails, a longer straight rail, and a shorter, angled rail to accommodate the anatomic angles of the mandible. These two rails are connected with a locking collar placing the ball joint in the center allowing three-dimensional contouring to match facial curvatures. This biplanar distractor allows for up to 40mm distraction with the straight rail, and up to 30mm distraction with the angled rail.
This document, K031696, is a 510(k) premarket notification for the "Lorenz External Mandibular Distractor." It is a request for clearance to market a medical device, based on substantial equivalence to a predicate device. This type of submission does not typically include studies demonstrating achievement of specific performance acceptance criteria as would be expected for a novel device or software cleared via de novo or PMA pathways.
Instead, the primary "study" involved in a 510(k) submission is a comparison to a legally marketed predicate device to establish substantial equivalence.
Therefore, providing a table of acceptance criteria and reported device performance in the way requested for an AI/software device with specific performance metrics and a dedicated validation study is not directly applicable to this physical medical device's 510(k) submission.
However, I can interpret the request in the context of what is provided in a 510(k) and explain why the other criteria (sample size, experts, ground truth, training set, MRMC) are not found here.
1. Table of Acceptance Criteria and Reported Device Performance
For a 510(k) submission like this one, "acceptance criteria" are generally met by demonstrating substantial equivalence to a predicate device. The performance is assessed against the predicate's known characteristics and intended use.
| Acceptance Criteria (for Substantial Equivalence) | Reported Device Performance (as demonstrated for 510(k) clearance) |
|---|---|
| Intended Use Equivalence: Device has the same intended use as a legally marketed predicate device. | The "Lorenz External Mandibular Distractor" is an external Fixator used for mandibular bone lengthening, treating mandibular asymmetry and hypoplasia. This is stated as substantially equivalent to the predicate device K992873 (which is itself noted as "SAME AS ORIGINAL SUBMISSION K001238"). The FDA's letter (K031696) explicitly states that the device is "substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices." |
| Technological Characteristics Equivalence: Device has the same technological characteristics as the predicate, or if different, the differences do not raise new questions of safety and effectiveness. | The device description ("The distractor frame is comprised of two threaded rails, a longer straight rail, and a shorter, angled rail... These two rails are connected with a locking collar placing the ball joint in the center...") is likely compared against the predicate (K992873/K001238). The submission implicitly argues that its design, materials, and operation are either identical or sufficiently similar to the predicate that no new safety or effectiveness concerns arise. The FDA's clearance indicates agreement. |
| Performance Data (when applicable): Any performance data (e.g., mechanical testing, biocompatibility) submitted demonstrates equivalence or acceptable safety/effectiveness. | While not explicitly detailed in this summary, a 510(k) typically includes reports on mechanical testing (e.g., strength, fatigue of the rails, screws, and ball joint) and biocompatibility for novel materials or designs, compared to the predicate device. The "Possible risks" section indirectly implies these types of assessments were made (e.g., "Bending, loosening of bone screws... fracture of the device," "Nonunion, delayed union... may lead to breakage of the implant"). The absence of specific test results in this summary means we cannot list them here, but they would have been part of the full 510(k) submission. |
Important Note: The concept of "acceptance criteria" for a 510(k) is less about achieving specific numerical performance thresholds (like sensitivity/specificity for AI) and more about demonstrating that the device is as safe and effective as a legally marketed predicate.
Regarding the other requested information (which is not typically found in this type of 510(k) filing for a physical device):
2. Sample size used for the test set and the data provenance (e.g., country of origin of the data, retrospective or prospective)
- This information is not applicable to this 510(k) submission. There is no "test set" of patient data in the context of an AI/software performance study for this physical medical device. The "testing" done for this device would involve engineering verification and validation (e.g., bench testing, material testing) rather than clinical data analysis for performance metrics.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
- This information is not applicable. Since there is no "test set" requiring ground truth establishment by experts, this detail is not present.
4. Adjudication method (e.g., 2+1, 3+1, none) for the test set
- This information is not applicable. There is no "test set" or adjudication process on clinical data in the context of an AI/software evaluation.
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
- This information is not applicable. This device is a physical external mandibular distractor, not an AI software intended to assist human readers (e.g., radiologists). Therefore, an MRMC study is irrelevant.
6. If a standalone (i.e., algorithm only without human-in-the-loop performance) was done
- This information is not applicable. This is a physical device, not an algorithm.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)
- This information is not applicable. There is no ground truth derivation from clinical data in the context of this 510(k) for a physical device. Ground truth for a physical device pertains more to engineering specifications and material properties rather than diagnostic accuracy.
8. The sample size for the training set
- This information is not applicable. This is a physical device, not an AI algorithm requiring a training set.
9. How the ground truth for the training set was established
- This information is not applicable. As above, no training set or ground truth in this context.
§ 872.4760 Bone plate.
(a)
Identification. A bone plate is a metal device intended to stabilize fractured bone structures in the oral cavity. The bone segments are attached to the plate with screws to prevent movement of the segments.(b)
Classification. Class II.