(40 days)
The iTotal Cruciate Retaining (CR) Knee Replacement System (KRS) is intended for use as a total knee replacement in patients with knee joint pain and disability whose conditions cannot be solely addressed by the use of a prosthetic device that treats only one or two of the three compartments, such as a unicondylar, patellofemoral or bicompartmental prosthesis.
The Indications for Use include:
• Painful joint disease due to osteoarthritis, traumatic arthritis, rheumatoid arthritis or osteonecrosis of the knee.
• Post traumatic loss of joint function.
• Moderate varus, valgus or flexion deformity in which the ligamentous structures can be returned to adequate function and stability.
• Failed osteotomies, hemiarthroplasties, and unicondylar, patellofemoral or bicompartmental implants.
• Revision procedures provided that anatomic landmarks necessary for alignment and positioning of the implant are identifiable on patient imaging scans.
This implant is intended for cemented use only.
The iTotal CR Knee Replacement System (hereafter referred to as the "iTotal CR KRS") is a patient-specific, tricompartmental, faceted posterior cruciate ligament (PCL) retaining knee replacement system. The iTotal CR KRS is a semi-constrained, cemented knee implant which consists of a femoral, tibial, and patellar component.
Using patient imaging and a combination of proprietary and offthe-shelf software, a patient-specific implant is designed that best meets the geometric and anatomic requirements of the specific patient. The femoral implant is manufactured from cobalt chromium molybdenum (CoCrMo) alloy. The tibial component includes a metal tray manufactured from CoCrMo alloy and either one or two polyethylene inserts. The polyethylene inserts may be manufactured from either UHMWPE or iPoly® XE (a highly cross-linked vitamin E infused polyethylene) The patellar component may also be manufactured from either UHMWPE or iPoly® XE.
For user convenience, and similar to the predicate iTotal CR KRS, single-use, patient-specific ancillary orthopedic manual surgical instruments designed for use with the proposed iTotal CR KRS are provided to assist in the positioning of the total knee replacement components intraoperatively and in guiding the cutting of bone. In addition, reusable orthopedic manual surgical instruments are provided separately.
The function and general design features of the patient-specific implants and ancillary instruments remain similar to those described in the predicate 510(k), K161366.
This document does not contain the detailed acceptance criteria or a study that proves the device meets specific performance criteria in the way typically expected for an AI/ML device.
The provided text is a 510(k) summary for the Conformis iTotal Cruciate Retaining (CR) Knee Replacement System. This document focuses on demonstrating substantial equivalence to a previously cleared predicate device (K161366) rather than establishing new performance metrics.
Here's a breakdown based on your requested information, highlighting what is and is not present in the provided text:
1. A table of acceptance criteria and the reported device performance
- Not present in this document. This document does not establish specific performance acceptance criteria (e.g., accuracy, precision) for a medical image analysis algorithm or AI component in the typical sense. Instead, it focuses on demonstrating that the updated software produces results comparable to the predicate software and that the overall device design and materials remain unchanged.
2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)
- Not present in this document. There is no mention of a test set sample size or data provenance as this 510(k) is not presenting a clinical performance study. The "test set" in this context refers to the software verification and validation testing, but no details on the data used are provided.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience)
- Not present in this document. Ground truth for clinical performance is not discussed as there is no clinical performance study being presented. For software verification, ground truth would likely be based on engineering specifications or comparisons to output from the previous software version.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
- Not present in this document. Adjudication methods are typically relevant for clinical studies where expert consensus is needed to establish ground truth for ambiguous cases. This is not applicable to the type of submission described.
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 present in this document. This device is a knee replacement system, and the software components are for patient-specific implant design and surgical planning. It is not an AI-assisted diagnostic tool for human readers, so an MRMC study is not relevant here.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
- The document states "Software verification and validation testing of proprietary software" was performed. This implies standalone testing of the algorithm (software modules) to ensure they function as intended and produce expected outputs for implant design and surgical planning. However, no specific details of this testing are provided. The software's output (implant design and surgical plan) is ultimately used by human surgeons during the procedure.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)
- For the "Software verification and validation testing," the ground truth would likely be based on:
- Engineering specifications: The software should produce designs that meet predefined geometric and functional requirements.
- Comparison to predicate software outputs: The updated software (iTotalWorks 6.0, iTotalFem CR 1.0, iTotalTib CR 5.0, iTotal CR iView 4.0) should produce designs and plans that are equivalent or demonstrate appropriate improvements compared to the predicate software (iTotalWorks 5.1, iTotal FemJigs 3.0, iTotalTib CR 4.3, iTotal CR iView 3.0). The purpose of the changes is to improve manufacturing efficiencies through automation, implying the output should remain consistent with the validated predicate.
- No clinical "ground truth" (pathology, outcomes data) is mentioned as it's not a diagnostic device.
8. The sample size for the training set
- Not applicable/Not present. This document discusses a change in software versions (i.e., v5.1 to v6.0 for iTotalWorks, etc.) for a workflow that custom designs existing implants. It is not describing a machine learning model that was specifically "trained" on a dataset in the way an AI diagnostic algorithm would be. The "proprietary and off-the-shelf software" uses patient imaging to design a patient-specific implant based on pre-defined algorithms and rules, not necessarily a training phase with a distinct training set.
9. How the ground truth for the training set was established
- Not applicable/Not present. As there's no explicitly defined "training set" in the context of an AI/ML model for this device, there's no discussion of how ground truth for such a set was established.
In summary:
This 510(k) pertains to a knee replacement system where the software is used for patient-specific implant design and surgical planning. The submission is a modification to an already cleared device and focuses on demonstrating that changes to the software modules for CAD manufacturing processes do not alter the substantial equivalence of the device to its predicate. The "study" mentioned is "Software verification and validation testing of proprietary software," which ensures the new software performs as intended and produces results consistent with the previously cleared versions. This is a technical (engineering) validation rather than a clinical performance study with human readers or AI diagnostic capabilities.
§ 888.3560 Knee joint patellofemorotibial polymer/metal/polymer semi-constrained cemented prosthesis.
(a)
Identification. A knee joint patellofemorotibial polymer/metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace a knee joint. The device limits translation and rotation in one or more planes via the geometry of its articulating surfaces. It has no linkage across-the-joint. This generic type of device includes prostheses that have a femoral component made of alloys, such as cobalt-chromium-molybdenum, and a tibial component or components and a retropatellar resurfacing component made of ultra-high molecular weight polyethylene. This generic type of device is limited to those prostheses intended for use with bone cement (§ 888.3027).(b)
Classification. Class II.