(106 days)
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 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 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.
The system is intended to treat patients who are candidates for total knee arthroplasty where the collateral ligaments are intact. Use of the iTotal PS KRS is usually based on surgeon preference, but it may be also used when total knee replacement is indicated and the posterior cruciate ligament is compromised, absent, or surgically excised.
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 CoCrMo 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, ancillary orthopedic manual surqical instruments designed for use with the iTotal PS KRS are provided to assist with implantation. The ancillary instruments are made from biocompatible nylon, and similar to the implants, 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 intended use and function of the patient specific ancillary instruments remain similar to those described in the predicate 510(k)s (K140833).
This document describes a 510(k) premarket notification for the ConforMIS iTotal Posterior Stabilized (PS) Knee Replacement System (KRS). It focuses on demonstrating substantial equivalence to a predicate device, rather than proving performance against specific acceptance criteria in the way a clinical trial or AI performance study would.
Therefore, many of the requested categories for AI/medical device performance evaluation are not applicable or cannot be extracted from this document, as it concerns a medical implant that has undergone non-clinical laboratory testing for substantial equivalence, not a diagnostic AI algorithm.
Here's an attempt to address your request based on the provided text, noting where information is not applicable:
1. A table of acceptance criteria and the reported device performance
The document does not present explicit "acceptance criteria" in terms of clinical performance metrics with target values. Instead, it relies on demonstrating substantial equivalence to a previously cleared predicate device through non-clinical laboratory testing. The "performance" reported are the results of these tests, which support the claim of substantial equivalence.
| Acceptance Criteria Category (Implied by Substantial Equivalence to Predicate) | Reported Device Performance (via Non-Clinical Tests) |
|---|---|
| Mechanical Strength/Durability: | |
| Femoral Component Fatigue | Testing demonstrated substantial equivalence. (Specific numerical criteria not provided, but implies meeting predicate's performance or relevant standards.) |
| Tibial Insert Spine-Femoral Cam Fatigue | Testing demonstrated substantial equivalence. (Specific numerical criteria not provided, but implies meeting predicate's performance or relevant standards.) |
| Functional/Biomechanical: | |
| Range of Motion | Analysis demonstrated substantial equivalence. (Specific methods or numerical results not detailed, but implies similar range of motion to predicate.) |
| Cadaveric Evaluation | Evaluation demonstrated substantial equivalence. (Specific outcomes not detailed, but implies similar fit, function, and surgical approach to predicate.) |
| Overall Safety and Effectiveness | The determination of substantial equivalence was based on a detailed device description and non-clinical laboratory testing, demonstrating the device is safe for its intended use and substantially equivalent to the predicate devices. Clinical data was deemed not necessary. |
2. Sample size used for the test set and the data provenance
- Sample size for test set: Not applicable in the context of human data or a "test set" for an AI algorithm. The "test set" here refers to the physical devices and materials used in the non-clinical laboratory tests. The document does not specify the number of components or constructs tested for each non-clinical test (e.g., how many femoral components were fatigued).
- Data provenance: Not applicable. The "data" comes from physical laboratory testing of the device components, not from patient data (retrospective or prospective).
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
Not applicable. There is no human "ground truth" establishment in this context, as it's mechanical and functional testing of an implant rather than diagnostic assessment.
4. Adjudication method (e.g., 2+1, 3+1, none) for the test set
Not applicable. Adjudication methods like 2+1 or 3+1 are used for establishing consensus among experts for ground truth in diagnostic cases. This document describes non-clinical laboratory tests, which would follow established testing protocols and standards, not expert adjudication.
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 applicable. This is not an AI-assisted diagnostic device, and therefore no MRMC study with human readers was conducted or is relevant.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
Not applicable. This is not an algorithm, but a physical knee implant.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)
Not applicable. For the non-clinical tests, the "ground truth" would be established engineering standards, material properties, and biomechanical principles against which the device's performance is measured or compared to the predicate's known performance.
8. The sample size for the training set
Not applicable. This device is a physical knee implant, not an AI model requiring a training set. The design of the implant is patient-specific based on imaging, but this is a manufacturing process, not a machine learning training process.
9. How the ground truth for the training set was established
Not applicable for the same reason as above.
§ 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.