(78 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, 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 proposed iTotal CR Knee Replacement System (hereafter referred to as the "iTotal CR KRS") is a patient specific tri-compartmental 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), a patient-specific implant is designed that best meets the geometric and anatomic requirements of the specific patient. The device 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.
This document is a 510(k) Summary for the ConforMIS iTotal CR Knee Replacement System. It focuses on demonstrating substantial equivalence to a previously cleared predicate device, rather than providing "acceptance criteria" and "device performance" in the traditional sense of a study with numerical performance metrics.
Here's a breakdown of the requested information based on the provided text:
1. A table of acceptance criteria and the reported device performance
The document does not specify "acceptance criteria" and "reported device performance" in terms of numerical thresholds or metrics. Instead, "substantial equivalence" is the overarching acceptance criterion, demonstrated by comparing the modified device's characteristics and performance to a predicate device.
| Characteristic | Modified iTotal CR KRS (This submission) | Predicate iTotal CR KRS (K094050) | "Acceptance Criteria" (Substantial Equivalence) | "Reported Device Performance" (Comparison Result) |
|---|---|---|---|---|
| Indications for Use | Same as predicate | Total knee replacement for painful joint disease, post-traumatic loss of function, moderate deformity, failed osteotomies, hemiarthoplasties, unicondylar, patello-femoral or bi-compartmental implants. Intended for cemented use only. | Must be the Same | Same |
| Intended for Cement Use Only | Yes | Yes | Must be the Same | Same |
| Components | Femoral Component, Metal Backed Tibial Component, Patellar Component | Same | Must be the Same | Same |
| Materials | Femoral Implant- CoCrMo; Metal-Backed Tibial Components: Tibial tray- CoCrMo; Tibial Insert-UHMWPE; Patellar Component: UHMWPE | Same | Must be the Same | Same |
| Design - Knee joint type | Patellofemorotibial semi-constrained cemented prosthesis | Same | Must be the Same | Same |
| Design - Configuration | ||||
| Femoral Implant | Constant coronal curvature, Femoral cuts (distal, anterior, anterior chamfer, posterior, posterior chamfer) | Same | Must be the Same | Same |
| Tibial Implant | Metal Backed Tibial Implant; Single or Dual inserts; Insert sizes: 6-16mm; Articulating Surface: Curved; Profile: patient specific; Tray interlock: Interference fit Anterior lip Tray undercut design | Metal Backed Tibial Implant; Single or Dual inserts; Insert sizes: 6-16mm; Articulating surface: Curved; Profile: patient specific; Tray interlock: Interference fit No Anterior lip Tray pocket design | Must be substantially equivalent | Minor difference in tray interlock design, deemed substantially equivalent |
| Patellar Implant | Symmetrical, sizes 32, 35, 38, 41 mm; heights 6, 7, 8.5, 10 mm | Same | Must be the Same | Same |
| Principle of Operation | Cemented use, Fixed Bearing Design | Same | Must be the Same | Same |
| Posterior Cruciate Ligament (PCL) Sparing | Yes | Yes | Must be the Same | Same |
| Patient-Matched | Yes | Yes | Must be the Same | Same |
| Packaging | Device components individually double pouched using Tyvek/film pouches, sealed and labeled | Same | Must be the Same | Same |
| Non-clinical Performance | Tibiofemoral contact area/contact stress testing, Modular assembly and disassembly testing, Constraint testing | Not explicitly detailed for predicate, but testing performed to establish equivalence. | Safe and equivalent to predicate | Demonstrated through non-clinical testing |
2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)
The document mentions "non-clinical laboratory testing" but does not specify a "test set sample size" in terms of patients or a specific dataset. It also does not provide information on data provenance (country of origin, retrospective/prospective) as the submission relies on engineering and material testing rather than clinical data.
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)
This information is not applicable to this 510(k) submission. The "ground truth" here is the established safety and effectiveness of the predicate device, and the "experts" involved would be the engineers and scientists conducting the non-clinical tests to compare the new device to the predicate. There's no mention of medical experts establishing ground truth for a test set in the context of this submission.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
This is not applicable. Adjudication methods are typically used in clinical studies involving human readers or evaluators, which is not the primary focus of this substantial equivalence submission.
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
There is no mention of an MRMC comparative effectiveness study, AI assistance, or human readers in this document. The device is a physical knee replacement system, not an AI-driven diagnostic tool.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
This is not applicable. The device is a knee implant, not an algorithm.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)
The "ground truth" for this substantial equivalence submission is the established safety and effectiveness of the predicate device (iTotal CR KRS K094050) through its prior FDA clearance. The modified device's equivalence is demonstrated through engineering and material testing, showing "design, material intended use and function" are either identical or appropriately similar to the predicate.
8. The sample size for the training set
This is not applicable. There is no "training set" in the context of an AI/algorithm. For the physical device, manufacturing processes would be validated, but that's different from a "training set."
9. How the ground truth for the training set was established
This is not applicable as there is no training set mentioned in the document.
§ 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.