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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.

Ask a specific question about this device

The iTotal 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 knee 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 off the shelf software a patient specific implant is designed, that best meets the geometric and anatomic requirements of the specific patient. The femoral component 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 is also manufactured from either UHMWPE or iPoly XE.

For user convenience, and similar to the predicate iTotal CR KRS, patient specific accessory 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), K160025.

The provided document is a 510(k) summary for the ConforMIS iTotal® Cruciate Retaining (CR) Knee Replacement System (iTotal CR KRS). It focuses on establishing substantial equivalence to a predicate device, specifically for an additional sterilization method (Ethylene Oxide) for certain components.

The information requested, which typically relates to the acceptance criteria and study data for device performance in relation to its intended clinical use (e.g., accuracy, sensitivity, specificity, or effects on human readers for AI/diagnostic devices), is not present in this document. This submission primarily deals with changes in manufacturing (sterilization methods) and material properties, rather than clinical efficacy or diagnostic performance. Therefore, the requested information about device performance against acceptance criteria for a "study that proves the device meets the acceptance criteria" in a clinical/diagnostic sense cannot be extracted from this text.

However, I can provide information on the acceptance criteria and supporting "study" (validation testing) related to the sterilization process as outlined in the document:

Here's the information regarding the sterilization validation:

1. Table of Acceptance Criteria and Reported Device Performance (related to sterilization)

Ask a specific question about this device

The iTotal 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 knee compartments, such as a unicondylar, patellofemoral or bicompartmental prosthesis: The Indications for Use include:

• · Painful joint disease due to osteoarthritis, traumatoid arthritis, rheumatoid arthritis or osteonecrosis of the knee
• · Post traumatic loss of joint function.
• · Moderate varus, valgus or flexion deformity in which the ligamentous structurs 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 off the shelf software a patient specific implant is designed, that best meets the geometric and anatomic requirements of the specific patient. The femoral component 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 a highly cross-linked Vitamin E infused polyethylene (iPoly XE™) The patellar component is also manufactured from either UHMWPE or from a highly cross-linked Vitamin E infused polyethylene (iPoly XE™).

For user convenience, and similar to the predicate iTotal CR KRS, patient specific accessory orthopedic manual surgical instruments designed for use with the modified 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)s K142161 and K152704.

The provided text describes a 510(k) premarket notification for a medical device called the ConforMIS iTotal Cruciate Retaining (CR) Knee Replacement System (KRS). The core of this submission is to demonstrate substantial equivalence to previously cleared predicate devices.

Here's an analysis of the acceptance criteria and the "study" that proves the device meets them, based on the provided document:

1. Table of Acceptance Criteria and Reported Device Performance

It's important to note that this document does not present acceptance criteria in the traditional sense of numerical thresholds for a new device's performance against a gold standard. Instead, the "acceptance criteria" are implied by the demonstration of substantial equivalence to predicate devices, focusing on the functionality and safety of the modifications made.

The primary "performance" being evaluated is the proper functioning of the updated CAD software used in the manufacturing process.

2. Sample Size Used for the Test Set and Data Provenance

• Test Set Sample Size: Not explicitly stated in terms of a number of patient cases or specific outputs. The testing was focused on software verification and validation testing of proprietary software iFit iTotalTib CR, and not on clinical patient data.
• Data Provenance: Not applicable in the context of patient data. The "data" being tested would be internal software outputs and comparisons, rather than external patient cases. The software itself is proprietary to ConforMIS.

3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts

• Number of Experts: Not specified.
• Qualifications of Experts: Not specified. Given that this is software verification and validation, the ground truth would typically be established based on engineering specifications, mathematical models, and perhaps manual expert review of CAD outputs to confirm their correctness against design requirements.

4. Adjudication Method for the Test Set

• Adjudication Method: Not specified. For software verification and validation, adjudication would involve comparing software outputs with expected results (ground truth defined by specifications or manual calculations/reviews).

5. Multi Reader Multi Case (MRMC) Comparative Effectiveness Study

• Was an MRMC study done? No, an MRMC comparative effectiveness study was not done. The submission explicitly states: "Clinical data is not necessary to demonstrate substantial equivalence." This is a software and device modification submission, not a new clinical efficacy claim requiring human-in-the-loop performance evaluation.
• Effect size of human readers improve with AI vs without AI assistance: Not applicable, as no MRMC study was performed and AI assistance for human readers is not the subject of this submission. The "AI" here refers to automated CAD processes, not decision support for human readers.

6. Standalone (Algorithm Only Without Human-in-the-Loop Performance) Study

• Was a standalone study done? Yes, in essence. The "software verification and validation testing of proprietary software iFit iTotalTib CR" constitutes a standalone evaluation of the algorithm's performance in generating the customized implant designs. Although not framed as a "study" in a clinical sense, this testing evaluates the algorithm's functional correctness without human intervention in the design generation phase itself (though humans define parameters and review outputs).

7. Type of Ground Truth Used

• Type of Ground Truth: The ground truth for the software verification and validation would be based on engineering specifications, design requirements, and potentially known correct outputs from previous versions of the software or manual calculations. It's likely a combination of:
  • Specification-based: Does the software produce outputs that meet predefined engineering specifications for implant geometry and fit?
  • Comparison-based: Are the outputs from the new automated CAD processes consistent with those generated by the predicate device's CAD processes or manual processes for similar inputs?

8. Sample Size for the Training Set

• Training Set Sample Size: Not applicable. This document describes a submission for a medical device (knee replacement system) with updated manufacturing software, not an AI/ML model that requires a training set of data in the common sense. The "training" for the software would be its initial development and programming based on engineering principles and design rules, not data-driven machine learning.

9. How the Ground Truth for the Training Set Was Established

• How Ground Truth for Training Set Was Established: Not applicable. As noted above, this is about software verification and validation for a manufacturing process, not an AI/ML model for which a "training set" with established ground truth is required. The software's "knowledge" is encoded during its development from established biomechanical, anatomical, and engineering principles used in knee replacement design.

Ask a specific question about this device

The iTotal 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 knee compartments, such as a unicondylar, patellofemoral or bicompartmental prosthesis: The Indications for Use include:

• Painful joint disease due to osteoarthritis, traumatoid arthritis, rheumatoid arthritis or osteonecrosis of the knee
• Post traumatic loss of joint function.
• Moderate varus, valgus or flexion deformity in which the ligamentous structurs 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 aligmment and positioning of the implant are identifiable on patient imaging scans.
  This implant is intended for cemented use only.

The iTotal PS 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 knee compartments, such as a unicondylar, patellofemoral, or bicompartmental prosthesis. The Indications for Use include:

• Painful joint disease due to osteoarthritis, traumatic arthritis, rheumatoid arthritis, polyarthritis or osteonecrosis of the knee.
• Post traumatic loss of joint function.
• Moderate varus, valgus or flexion deformity.
• Failed osteotomies, hemiarthroplasties, and unicondylar, patellofemoral 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® Knee Replacement Systems (hereafter referred to as the "iTotal KRS") are patient specific tricompartmental faceted knee replacement systems. The iTotal® KRS are semi-constrained, cemented knee implants which consist of femoral, tibial, and patellar components.
Using patient imaging and a combination of proprietary and off the shelf software a patient specific implant is designed, that best meets the geometric and anatomic requirements of the specific patient. The femoral component is manufactured from cobalt chromium molybdenum ("CoCrMo") alloy. The tibial component includes a metal tray manufactured from CoCrMo alloy and either single or dual-piece (CR only) polyethylene inserts. The polyethylene inserts may be manufactured from either UHMWPE, or for iTotal CR KRS, a highly cross-linked Vitamin E infused polyethylene (iPoly XE) The patellar component is also manufactured from either UHMWPE or from a highly cross-linked Vitamin E infused polyethylene (iPoly XE).
For user convenience, and similar to the predicate iTotal KRS, accessory orthopedic manual surgical instruments designed for use with the modified iTotal KRS are provided to assist with implantation. The ancillary instruments may be provided sterile or non-sterile to be sterilized by the end-user and are for single-use only.
The purpose of this submission is to propose dimensional modifications to the iTotal KRS implants and changes to the ancillary instrumentation.
The function and general design features of the patient specific implants and ancillary instruments remain similar to those described in the predicate 510(k)'s K142161, K142404 and K152704.

The provided text describes a 510(k) submission for the ConforMIS iTotal Cruciate Retaining Knee Replacement System and ConforMIS iTotal Posterior Stabilized Knee Replacement System. This submission focuses on demonstrting substantial equivalence to predicate devices through non-clinical testing, rather than studies that generate new clinical performance data with acceptance criteria that would typically be reported for software products.

Therefore, the following information cannot be extracted from the provided text: acceptance criteria, device performance, sample size for test set, data provenance, number of experts for ground truth, expert qualifications, adjudication method, MRMC study effect size, standalone algorithm performance, ground truth type for test set, sample size for training set, and how ground truth for the training set was established.

Here's the information that can be extracted regarding the comparison and testing performed:

1. A table of acceptance criteria and the reported device performance:

No specific numerical acceptance criteria or device performance metrics in terms of clinical outcomes are reported in the provided document. The submission focuses on demonstrating substantial equivalence through non-clinical testing.

2. Sample size used for the test set and the data provenance:

Not applicable. The reported tests are non-clinical laboratory tests, not tests on a clinical dataset with a "test set" in the context of AI/software performance.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:

Not applicable. Ground truth, in the context of expert review for clinical data, is not mentioned for these non-clinical tests.

4. Adjudication method (e.g. 2+1, 3+1, none) for the test set:

Not applicable. Adjudication methods are typically used for establishing ground truth from expert reviews of clinical data, which is not described here.

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:

No. An MRMC comparative effectiveness study was not performed or referenced.

6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:

Not applicable. This is a knee replacement system, not an AI algorithm. The performance evaluation is based on the physical device's characteristics and its comparison to predicate devices, not algorithm-only performance.

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.):

Not applicable in the context of clinical ground truth. The evaluation is based on engineering principles and performance testing against established standards or predicate device characteristics.

8. The sample size for the training set:

Not applicable. This is a physical medical device, not an AI/ML system that utilizes training sets.

9. How the ground truth for the training set was established:

Not applicable. See above.

Summary of the Study that Proves the Device Meets Acceptance Criteria (as described for this 510(k) submission):

The device, ConforMIS iTotal Cruciate Retaining Knee Replacement System and ConforMIS iTotal Posterior Stabilized Knee Replacement System, underwent non-clinical laboratory testing to demonstrate substantial equivalence to legally marketed predicate devices (ConforMIS iTotal CR Knee Replacement System K142161, K142404, K152704 and ConforMIS iTotal PS Knee Replacement System K142161, K142404, K152704).

The study involved the following non-clinical laboratory tests:

• Tibial Insert Spine-Femoral Cam Fatigue Testing: This test likely evaluates the durability and resistance to wear and tear of the tibial insert component under repeated stress, simulating physiological loading conditions.
• Range of Motion Analysis: This test would assess the range of movement permitted by the knee replacement system, ensuring it allows for an appropriate and functional range of motion for the patient.
• Cadaveric Evaluation: This type of evaluation uses cadaveric specimens to assess the device's fit, alignment, and potentially the surgical procedure in a simulated anatomical environment.

The conclusion drawn from these tests was that the present device is substantially equivalent to the predicate devices for their intended use. This implies that the performance in these non-clinical tests met the established performance characteristics or standards for the predicate devices, thereby demonstrating that the modified device is as safe and effective as the previously cleared devices. Clinical data was deemed not necessary to demonstrate substantial equivalence for this submission.

Ask a specific question about this device

The iTotal 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 knee 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 PS 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, polyarthritis or osteonecrosis of the knee.
• Post traumatic loss of joint function.
• Moderate varus, valgus or flexion deformity.
• 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® Knee Replacement Systems (hereafter referred to as the "iTotal® KRS") are patient specific tricompartmental faceted knee replacement systems. The iTotal® KRS are semi-constrained, cemented knee implants which consist of femoral, tibial, and patellar components.

Using patient imaging and a combination of proprietary and off the shelf software a patient specific implant is designed, that best meets the geometric and anatomic requirements of the specific patient. The femoral component is manufactured from cobalt chromium molybdenum ("CoCrMo") alloy. The tibial component includes a metal tray manufactured from CoCrMo alloy and either one or two (CR only) polyethylene inserts. The polyethylene inserts may be manufactured from either UHMWPE, or for iTotal CR KRS, a highly cross-linked Vitamin E infused polyethylene (iPoly XETM) The patellar component is also manufactured from either UHMWPE or from a highly cross-linked Vitamin E infused polyethylene (iPoly XETM).

For user convenience, and similar to the predicate iTotal KRS, accessory orthopedic manual surgical instruments designed for use with the modified iTotal® KRS are provided to assist with implantation. The ancillary instruments are provided sterile and for single-use only. These patient specific instruments are provided to assist in the positioning of total knee replacement components intra-operatively and in guiding the cutting of bone.

The function and general design features of the patient specific implants and ancillary instruments remain similar to those described in the predicate 510(k)'s K140423 and K140833.

The provided text describes a 510(k) premarket notification for the ConforMIS iTotal Cruciate Retaining Knee Replacement System (iTotal CR KRS) and ConforMIS iTotal Posterior Stabilized Knee Replacement System (iTotal PS KRS). It is a submission to establish "substantial equivalence" to legally marketed predicate devices, rather than a study demonstrating a novel device's performance against specific acceptance criteria.

Therefore, many of the requested elements about acceptance criteria, device performance metrics, sample sizes for test and training sets, expert qualifications, and adjudication methods are not applicable or explicitly stated in this type of regulatory document. The focus here is on demonstrating that the modified device is as safe and effective as a previously cleared device, rather than proving performance against new, quantitative acceptance criteria.

However, I can extract information related to the changes made and the testing performed to demonstrate substantial equivalence.

Here's a breakdown of the information available in the document, framed to address your questions where possible:

1. Table of Acceptance Criteria and Reported Device Performance

This document does not specify "acceptance criteria" in the sense of quantitative performance metrics for the device itself (e.g., accuracy, sensitivity, specificity). Instead, it aims to demonstrate "substantial equivalence" to a predicate device. The "performance" being evaluated is that the modified device, particularly its manufacturing software, retains the same functionality and characteristics as the predicate.

2. Sample Size for the Test Set and Data Provenance

• Test Set Sample Size: Not applicable. This submission focuses on demonstrating substantial equivalence through non-clinical testing, particularly software verification and validation, rather than a clinical test set of patients or anatomical data. The "test set" here refers to the software's internal testing of its CAD manufacturing process. No specific numbers of "cases" or "patients" are mentioned for this software testing.
• Data Provenance: Not applicable in the context of patient data. The "data" being evaluated is the software's output and internal workings.

3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications of those Experts

• Number of Experts: Not applicable. This document is about software updates for a medical device's manufacturing process, not expert review of medical images or patient outcomes.
• Qualifications of Experts: Not applicable.

4. Adjudication Method for the Test Set

• Adjudication Method: Not applicable. As there are no human readers or diagnostic interpretations being evaluated, there is no need for an adjudication method.

5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study

• MRMC Study Done: No. This is a 510(k) submission for a knee replacement system, specifically focusing on updates to its proprietary software for manufacturing. MRMC studies are typically used for evaluating diagnostic imaging systems or AI-assisted diagnostic tools by comparing human reader performance.

6. Standalone (i.e., algorithm only without human-in-the-loop performance) Study

• Standalone Study Done: Yes, in a sense, as the software's performance is evaluated independently of a human operator during the manufacturing process. The "non-clinical testing" involves "Software verification and validation testing of proprietary software" (SegSurf, iTotal FemJigs, iTotalTib, iTotal TibJigs, iTotal iView). This evaluates the algorithm's functional output (e.g., consistency of design generation) for its intended purpose in manufacturing. However, this is not a "standalone performance" in the context of, for example, an AI algorithm diagnosing disease from images.

7. Type of Ground Truth Used

• Type of Ground Truth: For the software verification and validation, the "ground truth" would be the expected and validated outputs of the software based on engineering specifications and existing design principles for knee replacement systems. This is an internal engineering "ground truth" rather than a clinical ground truth like pathology or patient outcomes. The software is expected to accurately translate patient imaging data into a patient-specific implant design that meets established anatomical and design requirements.

8. Sample Size for the Training Set

• Training Set Sample Size: Not explicitly stated, nor is the concept of a "training set" directly applicable in the same way it would be for an AI algorithm that learns from data. The software mentioned (SegSurf, iTotal FemJigs, etc.) appears to be rule-based or algorithmic software for CAD manufacturing, rather than a machine learning model that undergoes "training" on a dataset.

9. How the Ground Truth for the Training Set Was Established

• Ground Truth for Training Set: Not applicable in the context of an AI training set. If the software involves any machine learning components (which is not explicitly stated but implied by "proprietary software modules" being updated for "increasing automation"), the "ground truth" for its development would be based on expertly defined anatomical landmarks, surgical principles, and biomechanical requirements of knee replacement design. This would be established by engineers, orthopedic surgeons, and domain experts during the software's initial development and refinement.

Ask a specific question about this device

The iTotal® 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 knee 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 (either CT or MR scans) and a combination of proprietary and off the shelf software a patient specific implant is designed, that best meets the geometric and anatomic requirements of the specific patient. The femoral component 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 a highly cross-linked Vitamin E infused polyethylene (iPoly XE™) The patellar component is also manufactured from either UHMWPE or from a highly cross-linked Vitamin E infused polyethylene (iPoly XE™).

For user convenience, and similar to the predicate iTotal CR KRS, accessory orthopedic manual surgical instruments designed for use with the modified iTotal CR KRS are provided to assist with implantation. The ancillary instruments are provided sterile and for single-use only. These patient specific instruments are provided to assist in the positioning of total knee replacement components intra-operatively and in guiding the cutting of bone.

The function and general design features of the patient specific implants and ancillary instruments remain similar to those described in the predicate 510(k)'s K131467 and K131019.

Here's an analysis of the acceptance criteria and study information for the ConforMIS iTotal® CR Knee Replacement System (K140423), based on the provided text:

Acceptance Criteria and Device Performance for ConforMIS iTotal® CR Knee Replacement System (K140423)

It's important to note that this 510(k) summary primarily focuses on demonstrating substantial equivalence to a predicate device, rather than defining specific numerical performance acceptance criteria in the way one might see for a diagnostic AI device. The "performance" here is demonstrating that the modified device is as safe and effective as the predicate device.

1. Table of Acceptance Criteria and Reported Device Performance

Given the nature of this submission (a 510(k) for a modified knee replacement system), the acceptance criteria are largely qualitative, centered around demonstrating equivalence and safety. The performance is assessed through verification and validation of changes.

2. Sample Size Used for the Test Set and Data Provenance

The provided document does not specify a distinct "test set" in the context of typical AI/ML model evaluation with granular sample sizes.

• Software Verification and Validation: Performed for specific software versions (iTotalWorks v5.0, iTotal FemJigs v2.0, iTotalTib v2.0, iTotal TibJigs v1.0, iTotal iView v2.0). The sample size for these tests is not explicitly stated in terms of patient cases or specific data points, but rather implies a thorough testing regimen for the software itself.
• Cadaveric Testing: This typically involves a very small number of specimens. The exact number of cadavers used is not specified, but this is a common method for validating surgical instrument fit and implant placement.
• Data Provenance: Not applicable in the context of patient data for model training/testing as this is a medical device (knee replacement system) and associated software for design and implantation, not a diagnostic AI algorithm analyzing patient data. The "data" here relates to the software itself and the physical device.

3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications of Those Experts

Not applicable for this submission. The ground truth for this device revolves around established engineering principles, biomechanical performance, and surgical accuracy. The "ground truth" for cadaveric testing would be the precise fit and alignment of the implant components as assessed by experts (e.g., orthopedic surgeons, biomedical engineers), but the specific number or qualifications are not detailed.

4. Adjudication Method for the Test Set

Not applicable. There's no indication of multiple readers reviewing outputs that would require an adjudication method. Verification and validation are typically performed against pre-defined specifications and expected outcomes.

5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study

No, a multi-reader multi-case (MRMC) comparative effectiveness study was not performed. This type of study is more common for diagnostic imaging AI systems where human readers interpret medical images with and without AI assistance. This submission is for a knee replacement system and its associated planning software, not a diagnostic AI.

6. Standalone (Algorithm Only) Performance Study

Yes, in a sense, standalone performance was assessed through the "Software verification and validation testing of proprietary software" for each component of the iTotal CR KRS system (iTotalWorks, iTotal FemJigs, iTotalTib, iTotal TibJigs, iTotal iView). This means the algorithms within these software packages were tested for their intended function (e.g., design generation, jig creation, surgical planning) independent of human intervention in the evaluation process. The cadaveric testing also validates the output of these algorithms in a realistic, non-human patient setting prior to clinical use.

7. Type of Ground Truth Used

• Software Verification and Validation: The "ground truth" is defined by the software's functional requirements, design specifications, and expected outputs. This includes accuracy of calculations, proper generation of designs, and adherence to engineering principles.
• Cadaveric Testing: The "ground truth" is the optimal anatomical fit and alignment of the implant components, typically measured against surgical goals and expected outcomes derived from anatomical studies and surgical best practices.

8. Sample Size for the Training Set

Not applicable. This device is not an AI/ML system that "learns" from a training set in the typical sense. The software involved in designing patient-specific implants is based on algorithms and models derived from extensive anatomical data and biomechanical principles, but there is no explicitly defined "training set" of patient data in the context of machine learning. The software uses patient-specific imaging (CT or MR scans) to design the implant, rather than being "trained" on a large dataset of patient images to develop its core functionality.

9. How the Ground Truth for the Training Set Was Established

Not applicable, as there wasn't a "training set" in the machine learning sense. The underlying principles for the software's algorithms would have been established through biomechanical research, anatomical studies, engineering design principles, and clinical experience, not through a labeled dataset for AI model training.

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The iTotal 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 knee 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 (either CT or MR scans) and a combination of proprietary and off the shelf software a patient-specific implant is designed, that best meets the geometric and anatomic requirements of the specific patient. The femoral component is manufactured from cobalt chromium molybdenum ("CoCrMo") alloy. The tibial component indudes a metal tray manufactured from CoCrMo alloy and either one or two polyethylene inserts. The polyethylene inserts may be manufactured from either UHMWPE or a highly cross-linked Vitamin E infused polyethylene (iPoly XE™) The patellar component is also manufactured from either UHMWPE or from a highly cross-linked Vitamin E infused polyethylene (iPoly XE).

For user convenience, and similar to the predicate iTotal CR KRS, accessory orthopedic manual surgical instruments designed for use with the modified iTotal CR KRS are provided to assist with implantation. The ancillary instruments are provided sterile and for single-use only. These patient specific instruments are provided to assist in the positioning of total knee replacement components intra-operatively and in guiding the marking of bone before cutting.

The function and general design features of the patient specific ancillary instruments remain similar to those described in the predicate 510(k) K122870.

This device is not an AI/ML device, and therefore the acceptance criteria and study information is not applicable in the requested format.

The ConforMIS iTotal® CR Knee Replacement System (iTotal CR KRS) is a traditional medical device (a knee replacement system) and not an AI/ML powered device. The document describes a 510(k) summary for a modified version of an already cleared device, focusing on demonstrating substantial equivalence to the predicate device.

The "testing" mentioned is non-clinical laboratory testing to establish substantial equivalence for the modified device, specifically:

• Patella fixation testing
• Steam Sterilization Validation and Product Performance for metal implants and iJig Instrumentation post steam sterilization to support instructions provided for sterilization of components in case of a loss of sterility.

These are standard engineering and sterilization validation tests for physical implants and instruments, not performance metrics for an AI/ML algorithm. Therefore, the requested information about acceptance criteria, sample sizes for test/training sets, experts for ground truth, adjudication methods, MRMC studies, or standalone algorithm performance are irrelevant to this submission.

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The iTotal® CR Knee Replacement System 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 knee 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.
  The implant is intended for cemented use only.

The iTotal Cruciate Retaining 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 (either CT or MR scans) and a combination of proprietary and off the shelf software a patient-specific implant and related instrumentation are designed, that best meet the geometric and anatomic requirements of the specific patient. The femoral component 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 that are manufactured from UHMWPE. The patellar component is also manufactured from UHMWPE.
ConforMIS is proposing a line extension of the current iTotal CR Knee Replacement System. The proposed line extension consists of providing tibial inserts and patellae made from a highly cross linked Vitamin E infused polyethylene (iPoly XE) similar to the predicate Biomet E-Poly™ Tibial Bearings (K080528) and the DJO Surgical Highly Cross-Linked Vitamin E UHMWPE Tibial Insert and Patella (K113756, K103223, K091956).
The iPoly XE tibial inserts and patellae will be manufactured from ultra high molecular weight polyethylene (UHMWPE) that is blended with Vitamin E (alpha-tocopherol), compression molded and then highly crosslinked. Other than the material, the iPoly XE Tibial inserts are identical in design to those cleared for the iTotal CR KRS via K120316. The iPoly XE patellae are also identical in design to those cleared via K112780.
For user convenience, and similar to the predicate iTotal CR KRS, accessory orthopedic manual surgical instruments designed for use with the modified iTotal CR KRS are provided to assist with implantation. The ancillary instruments are provided sterile and for single-use only. These patient specific instruments are provided to assist in the positioning of total knee replacement components intra-operatively and in guiding the cutting of bone.

The acceptance criteria and study details for the ConforMIS iTotal® Cruciate Retaining Knee Replacement System with iPoly XE™ Tibial Inserts and patellae are outlined below, based on the provided 510(k) summary (K122870).

1. Table of Acceptance Criteria and Reported Device Performance

The submission focuses on demonstrating substantial equivalence to predicate devices through non-clinical laboratory testing. The "acceptance criteria" are implied by the successful performance of these tests, indicating that the device's material properties and performance characteristics are comparable to or improved over the predicates, particularly regarding wear reduction.

• Other Performance Tests: Tibiofemoral Contact Area/Stress, Strength of Tibial interlock, Patella Shear Test, Patella Tensile Test, Patellofemoral Contact Area/Stress Test, Wear Testing under abrasive conditions, Analysis of wear debris were conducted and results supported substantial equivalence. |
  | Electromagnetic Compatibility | Compatibility with MRI environments, ensuring patient safety and device integrity during MRI scans. | Evaluation demonstrated the safety and compatibility of the iTotal CR Knee Replacement System within the MRI Environment. |

The study concluded that: "All testing has demonstrated the device is substantially equivalent to the predicate devices." and specifically, "Test results demonstrated that the device is safe and can be considered substantially equivalent to the predicate device for the intended use."

2. Sample Size Used for the Test Set and Data Provenance

The provided summary does not explicitly state the specific sample sizes for each non-clinical laboratory test (e.g., number of samples for wear testing, mechanical testing). These are typically detailed in the full test reports, which are not included in the 510(k) summary.

• Data Provenance: The data is retrospective in the sense that it's laboratory testing conducted on the manufactured device components. The data origin is from the manufacturer's (ConforMIS Inc.) internal testing or contracted testing laboratories. There is no mention of country of origin for the data provided directly in this summary.

3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts

This type of information is not applicable to this submission. The device is a medical implant (knee replacement system), and the testing performed is non-clinical laboratory testing (material properties, mechanical performance, wear simulation, biocompatibility). Clinical performance is not evaluated in this submission for substantial equivalence. "Ground truth" in the context of expert consensus or pathology is typically relevant for diagnostic AI/imaging devices.

4. Adjudication Method for the Test Set

This is not applicable as the evaluation is based on objective laboratory data against predefined engineering and material standards, not expert adjudication of subjective assessments.

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 is not applicable. This is a submission for a knee implant, not an AI-assisted diagnostic or clinical decision support device. Therefore, no MRMC studies or AI-related effectiveness studies were part of this 510(k).

6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was done

This is not applicable. This submission is for a knee implant. While the device utilizes patient-specific design based on imaging (CT or MR scans) and "proprietary and off the shelf software" for design, the submission does not describe this software as an "algorithm" in the context of standalone diagnostic or assistive AI performance. The focus is on the physical implant's material and mechanical properties, not the performance of the design software as a medical device in itself.

7. The Type of Ground Truth Used

The "ground truth" for the non-clinical laboratory testing is established by:

• Known material specifications and standards: e.g., for UHMWPE, Vitamin E content, CoCrMo alloy properties.
• Industry standards and test methods: e.g., ISO 14243 for wear testing, ISO 10993 for biocompatibility.
• Pre-defined engineering and design requirements: Ensuring the device meets its functional criteria (e.g., interlock strength, contact stress).
• Comparisons to predicate devices: The "ground truth" for determining substantial equivalence is largely the established safety and effectiveness of the legally marketed predicate devices through comparable test results.

8. The Sample Size for the Training Set

This is not applicable. There is no "training set" in the context of AI/machine learning for this submission. The device design process involves using patient imaging data, but that's for individual patient-specific device creation, not for training a generalizable AI model described in this summary.

9. How the Ground Truth for the Training Set was Established

This is not applicable for the same reasons as point 8.

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The iTotal® CR Knee Replacement System 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 knee 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. The 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. The product design incorporates a bone preserving approach with minimal bone resection of the tibia and femur for the treatment of severe pain and/or disability of a knee damaged by osteoarthritis or trauma. Using patient imaging (either CT or MR scans) and a combination of proprietary and off the shelf software a patientspecific implant and related instrumentation are designed, that best meet the geometric and anatomic requirements of the specific patient. The femoral component 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 manufactured from UHMWPE of identical configuration. The patellar component is manufactured from UHMWPE For user convenience, and similar to the predicate iTotal CR KRS, accessory orthopedic manual surgical instruments designed for use with the modified iTotal CR KRS are provided to assist with implantation. The ancillary instruments are provided sterile and for single-use only. These patient-specific instruments are provided to assist in the positioning of total knee replacement components intra-operatively and in guiding of the cutting of bone.

Here's an analysis of the provided text regarding the acceptance criteria and supporting study for the ConforMIS iTotal CR Knee Replacement System:

1. Table of Acceptance Criteria and Reported Device Performance:

The provided document does not explicitly state numerical acceptance criteria for the device's performance in a clinical or analytical study. Instead, the submission focuses on demonstrating substantial equivalence to existing predicate devices.

The "acceptance criteria" here are implicitly that the modified device performs similarly to or no worse than the predicate devices across various characteristics. The "reported device performance" is a confirmation that these characteristics are maintained or improved.

2. Sample Size Used for the Test Set and Data Provenance:

• The submission does not mention a traditional "test set" in the context of clinical or analytical performance data from patient samples. The substantial equivalence is primarily based on device description, materials, design, and software verification/validation.
• Data Provenance: Not applicable in the sense of clinical patient data, as the study relies on software testing and device characteristic comparison.

3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications:

• Not applicable. This submission focuses on validating software and demonstrating equivalent physical/design characteristics to a predicate device, rather than assessing a device's diagnostic or clinical performance against expert-established ground truth from patient data.

4. Adjudication Method for the Test Set:

• Not applicable. No clinical test set requiring expert adjudication is described in the provided text.

5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done:

• No, an MRMC comparative effectiveness study was not done. The document explicitly states: "Clinical data is not necessary to demonstrate substantial equivalence."

6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was done:

• While not a standalone clinical performance study, the submission does refer to "Software verification and validation testing of proprietary software iTotalWorks" and "Software verification and validation testing of proprietary software iTotalTib." This testing confirms the functionality and accuracy of the algorithms as they relate to the design and manufacturing of the patient-specific implants and instruments. This can be considered a form of standalone software validation, demonstrating the algorithm's performance in its specific intended function (designing the implant and instrumentation based on patient imaging).

7. The Type of Ground Truth Used:

• For the software verification and validation, the ground truth would have been established through design specifications, requirements documents, and potentially comparison to known good outputs or established engineering principles and measurements. For example, the software would be validated to ensure it accurately translates imaging data into the geometric specifications for the patient-specific implants and instruments within specified tolerances.

8. The Sample Size for the Training Set:

• Not applicable. The document does not describe a machine learning model that would require a "training set" in the typical sense of AI/ML-based diagnostic devices. The proprietary software mentioned (iTotalWorks and iTotalTib) likely refers to CAD/CAM software used for design and manufacturing, which does not typically undergo "training" with patient data in the same way an AI diagnostic algorithm would.

9. How the Ground Truth for the Training Set was Established:

• Not applicable. (See point 8).

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The iTotal® CR Knee Replacement System 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 knee compartments, such as a unicondylar, patello-femoral or bi-compartmental 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, hemiarthoplasties, and unicondylar, patello-femoral or bi-compartmental implants.

The implant is intended for cemented use only.

The iTotal Cruciate Retaining 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. The product design incorporates a bone preserving approach with minimal bone resection of the tibia and femur for the treatment of severe pain and/or disability of a knee damaged by osteoarthritis or trauma.

Using patient imaging (either CT or MR scans) and a combination of proprietary and off the shelf software, a patient-specific implant and related instrumentation are designed that best meet the geometric and anatomic requirements of the specific patient. The femoral component 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 manufactured from UHMWPE of identical configuration. The patellar component is manufactured from UHMWPE.

For user convenience, and similar to the predicate iTotal CR KRS, accessory orthopedic manual surgical instruments designed for use with the modified iTotal CR KRS are provided to assist with implantation. The ancillary instruments are provided sterile and for single-use only. These patient-specific instruments are provided to assist in the positioning of total knee replacement components intra-operatively and in quiding the marking of bone before cutting.

The function and general design features of the patient-specific ancillary instruments remain similar to those described in the predicate 510k i.e. K094050, K103117, K112780, K120068, K113378 and K120316.

Here's an analysis of the provided text regarding the ConforMIS iTotal CR Knee Replacement System, focusing on acceptance criteria and supporting studies:

This document is a 510(k) summary for a medical device (ConforMIS iTotal CR Knee Replacement System) seeking clearance from the FDA. In the context of a 510(k) submission, the primary "acceptance criterion" is demonstrating substantial equivalence to a legally marketed predicate device. The "study" proving this is typically a set of non-clinical tests and comparisons.

1. Table of Acceptance Criteria and Reported Device Performance

For a 510(k) submission, the "acceptance criteria" are demonstrating that the new device shares similar indications for use, technological characteristics, and performance (safety and effectiveness) as the predicate device(s). The "reported device performance" is the evidence presented to support this similarity.

2. Sample Sizes Used for the Test Set and Data Provenance

• Test Set Sample Size: The document does not specify a "test set" in the traditional sense of a clinical or analytical study with a defined number of patient cases. The primary testing method described is software verification and validation testing of proprietary software (iTotal iView). This usually involves testing the software against a set of predefined requirements, scenarios, and potentially a dataset of patient images, but the exact number of "samples" or cases used for this internal testing is not disclosed in this summary.
• Data Provenance: Not specified for the software V&V. It's likely internal data or simulated data used for engineering validation. Given the nature of patient-specific implants, the input for the software would be patient imaging (CT or MR scans), but the origin of these scans for testing purposes is not explicitly stated. The submission is focused on demonstrating equivalence to an existing product, not on new clinical claims.

3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications

• Number of Experts: Not applicable/not specified. The detailed software verification and validation would typically involve software engineers, developers, and potentially expert clinicians (e.g., orthopedic surgeons) in defining requirements and evaluating software output (e.g., implant designs generated by the software), but the document does not outline a formal ground truth adjudication process by external experts with specific qualifications for a test set. The ground truth for the software's performance would be its ability to accurately and precisely process patient imaging data to generate the patient-specific implant and instrumentation designs according to predefined specifications.

4. Adjudication Method for the Test Set

• Adjudication Method: Not applicable/not specified. Since there isn't a defined "test set" requiring human interpretation or classification against a ground truth, an adjudication method like 2+1 or 3+1 is not mentioned. Software verification and validation is typically internal and relies on internal quality control processes and predefined acceptance criteria for software functionality and output accuracy.

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

• MRMC Study: No, an MRMC comparative effectiveness study was not done. The device (ConforMIS iTotal CR KRS) is a knee replacement system and its associated patient-specific software and instruments used for implantation. It's not an AI diagnostic or assistive tool for image interpretation by human readers. The software assists in designing the implant and instruments based on patient imaging.
• Effect Size: Not applicable.

6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was done

• Standalone Performance: The core of the new technology described is the "proprietary software iTotal iView" which generates the patient-specific surgical plan and designs the implants/instrumentation. The document states "Software verification and validation testing of proprietary t software iTotal iView" was performed. This implies testing of the algorithm itself, without a human in the loop for the design generation process. However, the outcome (the physical implant and instruments) is intended for human surgical use, and a surgeon is in the loop for the final implantation. The document doesn't explicitly detail "standalone performance" in terms of how the algorithm's output compares to a physician's manual planning, but rather focuses on verifying the software's functionality and accuracy in generating designs.

7. The Type of Ground Truth Used

• Type of Ground Truth: For the software verification and validation, the ground truth would likely be established through:
  • Engineering specifications and design requirements: The software's output (implant dimensions, bone cut guides) would be compared against the target design parameters derived from the patient's anatomy as interpreted by design engineers and surgeons, often using CAD models or reference anatomical data.
  • Clinical expertise and anatomical models: The accuracy of the software's interpretation of patient imaging (CT/MR scans) and its subsequent design generation would be assessed against established anatomical principles and clinical requirements for knee replacement.
  • Comparison to predicate device's design principles: Since this is a 510(k) for a modified device, the "ground truth" also heavily relies on demonstrating that the software-generated designs maintain the established safety and effectiveness characteristics of the predicate devices.

8. The Sample Size for the Training Set

• Training Set Sample Size: Not applicable/not specified. The document describes "proprietary software" for designing the patient-specific implant and instruments. It does not explicitly state that this software utilizes machine learning or AI models that require a "training set" in the conventional sense. If it's a rule-based or conventional algorithmic software (common for CAD/CAM in medical devices at the time of this filing), a distinct "training set" might not exist. If it incorporates machine learning (which is not explicitly stated but possible even in 2012 for aspects like image segmentation or anatomical landmark identification), the training data details are not provided.

9. How the Ground Truth for the Training Set Was Established

• Ground Truth Establishment for Training Set: Not applicable/not specified, as a "training set" and its ground truth are not mentioned for this device's software. If machine learning were involved, the ground truth for training data would typically be established by expert annotation of medical images (e.g., outlining anatomical structures) or precise measurements performed by qualified personnel.

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