(412 days)
The Precice Intramedullary Limb Lengthening System is indicated for limb lengthening, open and closed fracture fixation, pseudarthrosis, malunions, or bone transport of long bones in patients age 18 years and older and indicated for limb lengthening of the femur and tibia in pediatic patients (greater than 12 years old).
The predicate system is designed to achieve limb correction through gradual lengthening or compression and provide intramedullary fixation for fractures of long bones. The purpose of submission is to add the treatment of pediatric patients (greater than 12 years old) to this the Precice Intramedullary Limb Lengthening System indications for use. The Precice Intramedullary Limb Lengthening System includes the same devices as within the predicate Precice System (K172628) : nail, cortical screws, surgical instruments, and remains compatible with the external remote controllers (ERC) (ERC 1, in K113219; ERC 2P, in K131490; or ERC 3P, in K170169; or ERC 4P, in K191336). The configurations of sets and geometry of previously cleared Precice System devices remain unchanged. The following system description is herein repeated from K172628: Precice Nail is available in various designs, lengths, and screw hole configurations to accommodate a variety of patient anatomies and implantation methods. The screws are also available in a variety of different lengths and thread styles. The ERC is available in several compatible models, including the ERC 1, ERC 2P, ERC 3P and ERC 4P. The subject device components are manufactured from medical grade titanium alloy per ASTM F136 Standard Specification for Wrought Titanium-6Aluminum-4Vanadium ELI (Extra Low Interstitial) Alloy for Surgical Implant Applications (UNS R56401). The Precice IMLL nail is implanted using locking screws and reusable surgical instruments.
The provided text describes a 510(k) submission for the Precice Intramedullary Limb Lengthening System, primarily focusing on expanding its indications for use to include pediatric patients (greater than 12 years old). It does not contain information about an AI/ML-driven medical device, an MRMC comparative effectiveness study, or details related to establishing ground truth by a panel of experts for a test set. Therefore, I cannot fully address all the points in your request.
However, I can extract information related to the device's acceptance criteria, study design, and performance data as presented for its 510(k) clearance. The "acceptance criteria" here are not explicitly stated in numerical thresholds, but are demonstrated through substantial equivalence to predicate devices and performance data from clinical literature and a retrospective study.
Here's a breakdown of the available information structured to best fit your request:
Acceptance Criteria and Reported Device Performance
The device's performance is demonstrated through comparison with predicate devices and clinical outcomes from two pediatric datasets (literature review and retrospective study) and one adult literature dataset. The implied acceptance criteria are that the device performs comparably or acceptably for limb lengthening, with acceptable rates of adverse events and bone healing.
Table of Reported Device Performance
Since this is not an AI/ML device with specific classification metrics, the "acceptance criteria" are implied by the comparison to predicate devices and the clinical outcomes themselves. The table below presents the key performance metrics reported in the submission.
| Metric | Pediatric (Literature Review) | Pediatric (Retrospective Study, 13-20 years) | Adult (Literature) |
|---|---|---|---|
| Demographic Information | |||
| N (bones) | 227 (253) | 59 (59) | 136 (189) |
| Age, mean (range) | 14.4 (3-21) | 15.8 (13-20) | 36.1 (21-74) |
| Gender, male/female, % | 52.5/47.5 | 54.2/45.8 | 69.7/30.4 |
| Limb Lengthening Outcomes | |||
| Limb Length Discrepancy, cm | 5.3 | 4.9 | 4.9 |
| Target Length, cm | 6.2 | 4.9 | 4.7 |
| Achieved Length, mean, cm | 5.5 | 4.6 | 5.4 |
| Achieved Length/Target, overall, % | 93.0 | 93.9 | 119.5 |
| Achieved Length/Target, femoral, % | 114.6 | 94.1 | 127.5 |
| Achieved Length/Target, tibial, % | 93.0 | 90.7 | 110.0 |
| Bone Healing Rate, % | 100.0 | 100.0 | 94.3 |
| Adverse Events | |||
| Device-related Adverse Events | 6.7% | 6.8% | 22.2% |
| Lengthening-related Adverse Events | 16.6% | 34.7% | 8.5% |
| Joint Loss of ROM* | 6.2% | 3.4% | 2.9% |
| Joint Subluxation/Dislocation* | 4.0% | 3.4% | 0.0% |
| Angular Malalignment* | 2.8% | 1.7% | 0.0% |
| Radiographic - Premature Consolidation | 1.8% | 3.4% | 2.2% |
| Radiographic - Delayed Union | 2.6% | 16.9% | 8.1% |
| Radiographic - Partial Union | 0.0% | 3.4% | 0.0% |
| Radiographic - Nonunion | 0.9% | 5.1% | 5.1% |
| *Clinically significant events, i.e., those requiring major surgical treatments. |
Study Details
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Sample sizes used for the test set and the data provenance:
- Pediatric Literature Review: 227 patients with 253 lengthened bones (188 femur, 53 tibia, 12 humerus). Data provenance not specified beyond "clinical literature analysis of pediatric patients." It is a retrospective summary of published data.
- Pediatric Retrospective Study: 59 patients (59 bones) treated in the United States with the Precice Intramedullary Limb Lengthening System. This is a retrospective study.
- Adult Literature: 136 patients with 189 bones. Data provenance not specified beyond "clinical literature analysis." This is a retrospective summary of published data.
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Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- This information is not applicable as the study involves a medical device for limb lengthening, not an AI/ML-driven diagnostic or image analysis tool requiring expert ground truth for a test set in the traditional sense of AI/ML validation. The "ground truth" for success/failure or adverse events would be derived from clinical outcomes and medical records.
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Adjudication method (e.g. 2+1, 3+1, none) for the test set:
- Not applicable for the type of device and study described. Clinical outcomes are typically recorded directly from patient follow-ups and medical records, not through an adjudication process of interpretations by multiple experts.
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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 was not done. This type of study is specifically relevant for AI/ML-assisted diagnostic devices, which is not the case for the Precice Intramedullary Limb Lengthening System.
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If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- Not applicable. The device is a physical intramedullary limb lengthening system, not an algorithm. Its performance is directly tied to its use in patients by surgeons.
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The type of ground truth used (expert consensus, pathology, outcomes data, etc.):
- The "ground truth" for the device's performance is based on clinical and radiographic outcomes data from patients treated with the device, derived from both retrospective studies and aggregated literature. This includes achieved limb length, bone healing rates, and the incidence of various adverse events.
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The sample size for the training set:
- Not applicable. This is not an AI/ML device that requires a training set. The "evidence" presented supports the expansion of indications based on existing clinical data and the device's similarity to predicate devices.
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How the ground truth for the training set was established:
- Not applicable as there is no training set for an AI/ML model.
§ 888.3020 Intramedullary fixation rod.
(a)
Identification. An intramedullary fixation rod is a device intended to be implanted that consists of a rod made of alloys such as cobalt-chromium-molybdenum and stainless steel. It is inserted into the medullary (bone marrow) canal of long bones for the fixation of fractures.(b)
Classification. Class II.