(22 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.
Bone screws (or K-wire) are inserted percutaneously into the bone and attached to the distractor frame with a clamp.
The frame is locked by set screws which tighten and thereby lock the ball joint and rails in place. Adjustments can be made intra-operatively or post-operatively.
Due to the detailed nature of your request and the specific information needed from the provided text, it's important to note that the provided document is a 510(k) summary for the Lorenz External Mandibular Distractor. This type of submission focuses on demonstrating substantial equivalence to a predicate device rather than presenting a full clinical study with acceptance criteria and detailed performance data as one might find in a Premarket Approval (PMA) application or a dedicated clinical trial report.
Therefore, many of the requested items, particularly those related to rigorous statistical studies, multi-reader multi-case analyses, or
extensive ground truth establishment, are not typically present or required in a 510(k) submission for a device like an external mandibular distractor. The focus is on comparing the new device's design, materials, and intended use against a legally marketed predicate device to establish that it is as safe and effective.
Here's an analysis based on the provided text, with explanations where information is not available:
# Summary of Safety and Effectiveness
Device Name: Lorenz External Mandibular Distractor
Predicate Device: Lorenz Mandibular Distractor, 510(k) number [K955640](https://510k.innolitics.com/search/K955640)
Classification Name: External Mandibular Fixator and/or Distractor
Device Product Code and Regulation Number: MQN, 21 CFR 872.4760
#### Intended use:
The Lorenz External Mandibular Distractor is an external fixator used for mandibular bone lengthening. It is used in treatment of mandibular asymmetry and hypoplasia.
1. Table of acceptance criteria and the reported device performance
As a 510(k) submission for a mechanical device undergoing modifications to materials and design, explicit "acceptance criteria" and "reported device performance" in the sense of statistical endpoints from a clinical trial are not provided in this document. The "performance" is implicitly demonstrated through the comparison to the predicate device and the design changes.
The document highlights the capabilities of the device:
| Feature | Reported Device Performance (Modified Distractor) | Implied Acceptance Criteria (relative to Predicate) |
|---|---|---|
| Distraction Capability | Up to 40mm (straight rail), Up to 30mm (angled rail) | Maintain or improve distraction range |
| Distraction Mechanism | Biplanar distraction with ball joint | Provide multi-directional control |
| Screw Type/Pitch | 6mm screw (rail) M6 x 1 thread (1mm pitch) | Maintain or improve mechanical advantage |
| Bone Fixation Screws/K-wire | 3.0/2.5mm taper & 2.5/2.0mm taper trocar tipped bone fixation screws; 1.6 & 2.0mm K-wire | Provide secure bone attachment |
| Frame Design | Two threaded rails (longer straight, shorter angled), locking collar with ball joint in center | Accommodate anatomic angles, 3D contouring |
| Loading/Fatigue | (Not specified in this document) | (Implicit: withstand anticipated physiological loads without failure) |
| Biocompatibility | Stainless steel, Ti-6Al-4V, 316 LVM Stainless Steel, hard coat anodized aluminum | (Implicit: materials are known to be biocompatible for intended use) |
The acceptance criteria are generally to demonstrate that the modified device is "substantially equivalent" to the predicate device in terms of safety and effectiveness, meaning it performs similarly and does not raise new questions of safety or effectiveness. This is achieved by showing that the materials, design, and mechanisms of action are comparable or improved, and that any potential risks are understood and managed.
2. Sample size used for the test set and the data provenance
Not applicable/Not provided. This is a 510(k) submission primarily based on design and material changes and a comparison to a predicate device. It does not describe a clinical evaluation with a "test set" of patients in the way a clinical trial would. The assessment of "performance" here is largely based on engineering design analysis and comparison.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
Not applicable/Not provided. Since there isn't a "test set" of patient data requiring ground truth establishment, this information is not relevant to this submission.
4. Adjudication method (e.g., 2+1, 3+1, none) for the test set
Not applicable/Not provided. No test set or expert adjudication process is described in this 510(k) summary.
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
Not applicable. This device is a mechanical surgical distractor, not an imaging or diagnostic device that would involve "human readers" or "AI assistance." Therefore, an MRMC study is not relevant.
6. If a standalone (i.e. algorithm only without human-in-the loop performance) was done
Not applicable. This is a mechanical device, not an algorithm.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)
Not applicable/Not provided. For a 510(k) of this nature, the "ground truth" is fundamentally the understanding of biomechanical principles, material science, and prior clinical experience with similar devices, specifically the predicate device. The changes are evaluated against these established engineering and medical principles to ensure equivalence. There is no specific "ground truth" for a study as there is no specific study described.
8. The sample size for the training set
Not applicable/Not provided. There is no "training set" as this is not a machine learning algorithm or a clinical trial in that sense.
9. How the ground truth for the training set was established
Not applicable/Not provided. As there is no training set, this is not relevant.
In summary: The provided document is a 510(k) summary, which is a premarket notification to the FDA demonstrating substantial equivalence to a predicate device. It relies on comparisons of design, materials, and intended use rather than presenting comprehensive clinical study data with detailed acceptance criteria, sample sizes, and ground truth establishment as would be found for a novel device or a clinical trial for a PMA. The "study" proving the device meets criteria is primarily the engineering analysis and comparison to the predicate device, K955640.
§ 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.