(128 days)
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.
This 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 is designed that best meets the geometric and anatomic requirements of the specific patient. The femoral component is manufactured from cobalt chromium molybdenum (CoCr) alloy. The tibial component includes a metal tray manufactured from CoCr 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 ancillary instruments remain similar to those described in the predicate iTotal CR 510(k)s (K131467, K131019 and K122870).
The provided text is a 510(k) summary for the ConforMIS iTotal® Cruciate Retaining Knee Replacement System. This document focuses on demonstrating substantial equivalence to previously cleared predicate devices, rather than establishing acceptance criteria and performance against those criteria as would be done for a novel device.
The "study" in this context is a series of non-clinical laboratory tests designed to show that changes to the manufacturing process (specifically, using additive manufacturing for the femoral component) do not negatively impact the device's safety and effectiveness compared to the predicate devices. Therefore, the "acceptance criteria" discussed here are implicitly related to the performance benchmarks set by the predicate devices, and the "reported device performance" is the demonstration that the new device meets those benchmarks through direct testing.
Here's the breakdown of the requested information based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria (Implicit from Predicate Devices & Regulations) | Reported Device Performance (as demonstrated by testing) |
|---|---|
| Material Properties (CoCr alloy) | Material properties tests demonstrated that the device is safe and can be considered substantially equivalent to the predicate device. |
| Mechanical Properties | Mechanical properties testing demonstrated that the device is safe and can be considered substantially equivalent to the predicate device. |
| Biocompatibility | Biocompatibility Testing of implants manufactured by the additive manufacturing process demonstrated that the device is safe and can be considered substantially equivalent. |
| Contact Stress/Area | Contact stress/area testing demonstrated that the device is safe and can be considered substantially equivalent to the predicate device. |
| Fatigue Resistance | Fatigue testing of femoral implant demonstrated that the device is safe and can be considered substantially equivalent to the predicate device. |
| Safety for Intended Use | All testing has demonstrated the device is substantially equivalent to the predicate devices, and is safe for its intended use. |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: The document does not specify exact sample sizes for each non-clinical test (material properties, mechanical properties, biocompatibility, contact stress/area, fatigue). It generally refers to "testing on the femoral components" and "biocompatibility testing of implants."
- Data Provenance: The data is from non-clinical laboratory testing conducted by the submitter (ConforMIS Inc.). The country of origin is not explicitly stated, but it is implied to be internal testing or contracted testing laboratories. The data is prospective in the sense that the tests were conducted specifically for this 510(k) submission to demonstrate equivalence of the new manufacturing process.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
Not applicable. This is a medical device 510(k) involving non-clinical (laboratory) testing of physical and mechanical properties, not an AI/diagnostic imaging study requiring human expert ground truth.
4. Adjudication Method for the Test Set
Not applicable. This is a medical device 510(k) involving non-clinical (laboratory) testing, not an AI/diagnostic imaging study requiring adjudication of expert interpretations.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, and Effect Size
No, a multi-reader multi-case (MRMC) comparative effectiveness study was not done. This 510(k) is for a total knee replacement system and relies on non-clinical laboratory testing to demonstrate substantial equivalence, not human reader performance with or without AI assistance.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
Not applicable. This device is a physical knee implant, not an algorithm or AI system for standalone performance evaluation. The "proprietary and off-the-shelf software" mentioned is used for patient-specific implant design, but its performance is not assessed in a standalone capacity in this document; rather, the safety and effectiveness of the resulting physical implant are evaluated through non-clinical tests.
7. The Type of Ground Truth Used
The "ground truth" in this context is the established performance characteristics and safety profile of the predicate devices (iTotal CR KRS, K131467, K131019, and K122870), as well as general regulatory standards for knee joint prostheses (e.g., ISO standards for material and mechanical testing, biocompatibility standards). The purpose of the testing was to demonstrate that the new device, with its additive manufactured femoral component, meets these established benchmarks and is substantially equivalent.
8. The Sample Size for the Training Set
Not applicable. There is no concept of a "training set" in this 510(k) submission, as it focuses on non-clinical testing of a physical medical device, not the development of a machine learning algorithm.
9. How the Ground Truth for the Training Set Was Established
Not applicable for the same reasons as #8.
§ 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.