(63 days)
The iTotal® Posterior Stabilized (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 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 Posterior Stabilized Retaining Knee Replacement System (hereafter referred to as the "iTotal PS KRS") is a patient specific tricompartmental faceted, cruciate sacrificing knee replacement system. The iTotal PS KRS is a semi-constrained, fixed bearing, cemented knee implant which consists of a femoral, tibial and patellar component.
Using patient imaging (CT scan) 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 cobalt chromium molybdenum alloy and a polyethylene insert that is manufactured from ultra-high molecular weight polyethylene (UHMWPE). The patellar component is 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 PS KRS, patient specific accessory orthopedic manual surgical instruments designed for use with the modified iTotal PS KRS are provided to assist in the positioning of the total knee replacement components intraoperatively and in guiding the cutting of bone. These instruments are single use only and may be provided sterile. 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 K152704, K142404 and K142161.
The provided text is a 510(k) summary for the ConforMIS iTotal® Posterior Stabilized Knee Replacement System (iTotal PS KRS). The purpose of this summary is to demonstrate substantial equivalence to previously cleared predicate devices, not to establish performance against acceptance criteria for a new device. Therefore, much of the requested information regarding acceptance criteria, sample sizes, ground truth establishment, expert involvement, and comparative effectiveness studies for an AI/device performance study is not present in this document.
The document discusses a modification to an existing device, specifically "adding the option of automating the generation of the iTotal PS iView using the proprietary software module iTotal PS iView v1.0." The relevant "study" for this modification is primarily software verification and validation.
Here's the information that can be extracted or inferred:
1. Table of Acceptance Criteria and Reported Device Performance
This document does not provide a table of acceptance criteria for device performance in the typical sense of accuracy, precision, sensitivity, specificity, etc., as it is a 510(k) summary focused on demonstrating substantial equivalence of a modified manufacturing process of a medical device, not a new AI diagnostic or prognostic device's performance.
The "performance" criteria for the software modification are related to its functionality and reliability in automating the generation of the iTotal PS iView, which would be assessed through software verification and validation. No quantitative performance metrics are reported in this summary.
| Acceptance Criteria (Implied for software) | Reported Device Performance (Implied from substantial equivalence) |
|---|---|
| Software functions as intended for iTotal PS iView generation | Software verification and validation testing completed; demonstrated substantial equivalence to predicate device where iView generation was manual. |
| Automation of iView generation maintains design, materials, and methods of manufacture equivalency | No changes to design, materials, methods of manufacture, packaging, or sterilization of the iTotal PS KRS itself. |
| The modified process does not impact the safety and effectiveness of the device compared to the predicate | The device is considered substantially equivalent to the predicate device for the intended use. |
2. Sample size used for the test set and the data provenance
- Test Set Sample Size: Not applicable in the context of an AI performance study. The testing performed was "Detailed software description and software verification and validation testing of proprietary software iTotal PS iView v1.0." The number of test cases or data points used during this software testing is not specified.
- Data Provenance: Not applicable in the context of an AI performance study. The document refers to patient imaging (CT scans) being used to design the patient-specific implant, but this is part of the original design process, not a test set for the "iView v1.0" software. The source or nature of data used for software testing is not detailed (e.g., synthetic, real patient scans, number of scans).
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
Not applicable. This document does not describe a study involving expert-established ground truth for a test set. The modification is about software automation in the manufacturing process, not expert interpretation of outputs.
4. Adjudication method for the test set
Not applicable. As there is no described test set involving expert ground truth, no adjudication method is mentioned.
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 done. The document focuses on demonstrating substantial equivalence of a manufacturing process modification (software automation), not on human reader performance with or without AI assistance.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
This document describes "Software verification and validation testing of proprietary software iTotal PS iView v1.0." This testing would inherently be assessing the algorithm's performance in generating the iView, so it can be considered a standalone assessment of the software module. However, specific performance metrics are not provided. The entire ConforMIS iTotal PS KRS system requires human-in-the-loop (surgeon) for implantation, but the iView generation itself is an automated step.
7. The type of ground truth used
For the software verification and validation of the iTotal PS iView v1.0, the ground truth would likely be established by comparing the automatically generated iViews to manually generated iViews (the predicate process) or to predefined specifications/requirements for the iView output. The document doesn't explicitly state the type of ground truth, but for software testing, it would involve functional correctness and adherence to design specifications.
8. The sample size for the training set
Not applicable. The document does not describe a machine learning model that requires a training set in the conventional sense. The "iTotal PS iView v1.0" is described as a "proprietary software module" for automating a process, implying it's a rule-based or algorithmic system rather than a deep learning model trained on a large dataset.
9. How the ground truth for the training set was established
Not applicable, as no training set for a machine learning model is mentioned.
§ 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.