(114 days)
The CONSENSUS® KNEE SYSTEM Primary Knee is designed as a system and is not intended for substitution of components from other systems.
- A. Primary intervention of rheumatoid arthritis, osteoarthritis, post-traumatic arthritis, or degenerative arthritis.
- B. Failed osteotomy or unicompartmental replacements.
- C. Replacement of unsatisfactory cemented or press-fit knee components when sufficient bone stock exists.
- D. The porous coated (CoCr beads with Titanium) femoral and tibial components may be used with or without cement.
The Consensus Total Knee System (CKS) is a primary fixed-bearing total knee system that has been on the market since 1990's.
The CKS has been designed to replicate the natural anatomy of the knee in order to restore knee function. It has been developed to preserve and utilize healthy ligamentous structures. For cases where the soft tissues are not functional, the PCL substituting tibial inserts or the posterior stabilized system are available for increased stability.
The CKS incorporates femoral, tibial, and patellar components and all associated instrumentation needed for implantation. The CKS can be used for total knee replacement with posterior cruciate ligament (PCL) retaining or substituting.
The femoral components are provided in left and right side versions and are designed to replicate natural kinematic motion between the femur, tibia and patella. The Consensus femoral component is designed to provide uniform contact zones in the coronal plane throughout the range of motion when the knee is properly aligned. The femoral component is also designed with a large distal radius to optimize contact areas and reduce contact stress. The trochlear groove in the femur is designed to allow the load from the patella to be evenly distributed on the femur with adequate lateral constraint.
Here's an analysis of the provided text, focusing on acceptance criteria and the study proving device performance:
Acceptance Criteria and Device Performance for Consensus® Knee System (K102927)
This submission (K102927) is primarily to expand the indications for the already cleared Consensus® Knee System (CKS) porous-coated components to allow for uncemented use. The non-clinical performance data provided specifically addresses the porous coating's mechanical and chemical properties, demonstrating its suitability for this expanded use.
1. Table of Acceptance Criteria and Reported Device Performance
The provided document includes a clear table outlining the specifications, acceptance criteria, and verification results for the modified surface (porous CoCr bead with Ti coating).
| Specification | Acceptance Criteria | Verification Results |
|---|---|---|
| Microstructure of the modified surface | N/A | Bead to Bead Neck Diameter: 0.33 mm |
| Pore Size: 0.432 mm | ||
| Volume % Porosity: 37% | ||
| Coating Thickness: 0.889 mm | ||
| Corrosion of the modified surface (shall be equal or less than that measured in a legally marketed device) | Equal to or improved corrosion resistance when compared with CoCr beads using ASTM F746 & G61 | Critical Potential (CoCr Beads): 1290 mV; Breakdown Potential: 1200 mV |
| Critical Potential (Ti Coated CoCr Beads): 1315 mV; Breakdown Potential: 1200 mV | ||
| Modified surface shall exhibit adequate static tensile strength | The static tensile strength will exceed 20 MPa. | Static Tensile Strength: 58.32 MPa |
| Modified surface shall exhibit adequate static shear strength | The static shear strength will exceed 20 MPa. | Static Shear Strength: 58.32 MPa |
| Modified surface shall exhibit adequate shear fatigue strength | The shear fatigue strength will exceed 10 million cycles. | 10 million cycles achieved with a strength of 13.78 MPa |
| Modified surface shall exhibit adequate rotating beam fatigue strength | The rotating beam fatigue strength will exceed 10 million cycles. | 10 million cycles achieved with a strength of 206.7 MPa |
| Modified surface shall not exhibit excessive abrasion | N/A | 200N load: Avg. mass loss 0.006 g, Avg. thickness loss 6% |
| 1500N load: Avg. Mass loss 0.179 g, Avg. thickness loss 23% |
Note: For microstructure and abrasion, the "Acceptance Criteria" are listed as "N/A" in the table, indicating these are descriptive measurements rather than pass/fail thresholds in this summary. However, the reported values are provided as verification results. For corrosion, the results for both CoCr beads and Ti Coated CoCr Beads demonstrate a comparable or improved resistance against the breakdown potential.
2. Sample Size Used for the Test Set and Data Provenance
The document describes non-clinical performance data which typically involves laboratory testing of materials and components, not clinical data from patients. Therefore, terms like "test set" in the context of patient data, "country of origin of the data," or "retrospective/prospective" studies are not applicable here.
The sample sizes for the mechanical and corrosion tests are not explicitly stated in this summary. It's common in such submissions for the detailed test reports (which would include sample sizes, testing methodologies, and raw data) to be referenced but not fully reproduced in the 510(k) summary. These tests are performed on material coupons or device components in a laboratory setting.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications
This question is not applicable to this submission. The "test set" here refers to material samples or device components tested in a lab. The "ground truth" is established by direct physical and chemical measurements (e.g., measuring dimensions, applying forces, assessing corrosion) using standardized test methods (like ASTM standards mentioned). Therefore, human expert consensus on image interpretation or clinical outcomes is not relevant for this type of non-clinical data.
4. Adjudication Method for the Test Set
This question is not applicable. Adjudication methods (like 2+1, 3+1) are used for resolving disagreements among human experts when establishing ground truth, typically in clinical studies or image review. Since this involves non-clinical laboratory testing, there is no human adjudication process of this nature.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No MRMC study was done. This type of study assesses how human readers' diagnostic performance changes with and without AI assistance, which is irrelevant for a submission concerning the material properties and expanded uncemented use of a knee implant.
6. Standalone (Algorithm Only Without Human-in-the-Loop Performance) Study
No standalone algorithm performance study was done. This typically refers to the performance of an AI algorithm on its own. The Consensus® Knee System is a medical device (a knee implant), not an AI algorithm.
7. Type of Ground Truth Used
The ground truth used for this non-clinical performance data is direct physical and chemical measurement against predefined specifications and ASTM standards. This includes:
- Physical dimensions and morphology (e.g., bead neck diameter, pore size, coating thickness).
- Electrochemical properties (e.g., critical potential, breakdown potential for corrosion resistance).
- Mechanical properties (e.g., static tensile strength, static shear strength, shear fatigue strength, rotating beam fatigue strength, mass and thickness loss from abrasion).
8. Sample Size for the Training Set
This question is not applicable. There is no AI model or algorithm being trained within the scope of this 510(k) submission. The data presented are for validating the material properties of the porous coating.
9. How the Ground Truth for the Training Set Was Established
This question is not applicable, as there is no training set mentioned or implied in the context of this device submission.
§ 888.3565 Knee joint patellofemorotibial metal/polymer porous-coated uncemented prosthesis.
(a)
Identification. A knee joint patellofemorotibial metal/polymer porous-coated uncemented 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 is designed to achieve biological fixation to bone without the use of bone cement. This identification includes fixed-bearing knee prostheses where the ultra high molecular weight polyethylene tibial bearing is rigidly secured to the metal tibial base plate.(b)
Classification. Class II (special controls). The special control is FDA's guidance: “Class II Special Controls Guidance Document: Knee Joint Patellofemorotibial and Femorotibial Metal/Polymer Porous-Coated Uncemented Prostheses; Guidance for Industry and FDA.” See § 888.1 for the availability of this guidance.