(160 days)
The Symmetric™ Total Knee System consist of single use components intended for total knee arthroplasty with the following indications.
- Osteoarthritis (for cemented use only)
- Rheumatoid Arthritis (for cemented use only)
- Traumatic Arthritis (for cemented use only)
- Where the use of a more conservative procedure has failed or is unacceptable.
The Symmetric™ Total Knee System is intended for the resurfacing of the knee joint. The system consists of metallic femoral and tibial components (including an available metaphyseal stem) and a polyethylene tibial insert and patellar component.
The FEMORAL COMPONENT is designed for left/right orientations. The femoral component is manufactured from cast cobalt chromium/molybdenum (CoCrMo). The femoral component will be available in eight sizes (1-8) and will have a central post (with a 5° valgus angle) and gussets to aid in rotational stability and to increase strength. It will be plasma sprayed with Commercially Pure Titanium (CPTi).
The TIBIAL TRAY is a symmetrically designed component, eliminating the need for left/right orientations. The tibial component is manufactured from wrought titanium alloy (Ti 6Al-4V). The tibial tray features a central post, a pair of gussets, and 2 to 4 pegs on the underside broviding rotational stabilization and increased tray strength. Four screw holes in the tibial tray allow for optional screw fixation. The tibial tray is designed with locking features permitting the UHMWPE tibial insert to be snapped into place. The tibial tray has 8 sizes (1-8) and is plasma sprayed with Commercially Pure Titanium (CPTi).
The TIBIAL INSERT is also a symmetrically designed component manufactured from Ultra-High Molecular Weight Polyethylene (ASTM F648). The inserts' articulating geometry is semiconstrained and is captured in the tibial tray by the mating capture features. The insert is available in nine thicknesses (10, 12, 14, 16, 18, 20, 25, 30, 35mm) and 8 sizes (1-8).
The METAPHYSEAL STEM is designed to be driven onto a tibial tray further increasing the fit and fill of the component allowing for a more stable system.
The REVISION STEM is designed to be driven onto a tibial tray or femoral component further increasing the stability of a revision component.
The PATELLAR COMPONENT is dome shaped and tracks nicely against the femoral component.
Here's a breakdown of the acceptance criteria and the study that proves the device meets them, based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
| Category | Acceptance Criteria (from Predicate Devices) | Symmetric™ Total Knee System Performance (Reported) |
|---|---|---|
| Femoral Component | ||
| Width (mm) | 58-82mm (Beacon), Similar (Profix) | 50-86mm |
| Substrate Material | CoCr (Beacon, Profix) | CoCr |
| Coating | Sintered Beads (Beacon, Profix) | Ti Plasma Spray |
| Tibial Tray | ||
| ML-Width (mm) | 63-88mm (Beacon), Similar (Profix) | 49-84mm |
| Substrate Material | Titanium 6Al-4V (Beacon, Profix) | Titanium 6Al-4V |
| Coating | Sintered Beads (Beacon, Profix) | Ti Plasma Spray |
| Tibial Poly | ||
| Thickness w/ tray (mm) | 10-20mm (Beacon), Similar (Profix) | 10-35mm |
| Standard/Deep | Standard/Deep (Beacon, Profix) | Standard/Deep |
| Material | UHMWPE (Beacon, Profix) | UHMWPE |
| Metaphyseal Stem | ||
| Diameters | NA (Beacon), Similar (Profix) | 18-24mm |
| Lengths | NA (Beacon), Similar (Profix) | 50-63mm |
| Attachment Method | NA (Beacon), Morse Taper (Profix) | Morse Taper |
| Material | NA (Beacon), Titanium 6Al-4V (Profix) | Titanium 6Al-4V |
| Revision Stem | ||
| Diameters | NA (Beacon), Similar (Profix) | 10-26mm |
| Lengths | NA (Beacon), Similar (Profix) | 100-200mm |
| Fixation Method | NA (Beacon), Morse Taper (Profix) | Morse Taper |
| Material | NA (Beacon), Titanium 6Al-4V (Profix) | Titanium 6Al-4V |
| Patella | ||
| Disk Diameter (mm) | 26-41mm (Beacon), Similar (Profix) | 25-40mm |
| Material | UHMWPE (Beacon, Profix) | UHMWPE |
| Intended Use | ||
| Fixation Method | Cemented (Beacon, Profix) | Cemented |
| Indications | Osteoarthritis, Rheumatoid Arthritis, Traumatic Arthritis, Failed conservative procedures (Beacon, Profix) | Osteoarthritis, Rheumatoid Arthritis, Traumatic Arthritis, Failed conservative procedures |
| Overall Performance | Substantially equivalent to or better than predicate devices, with no new questions of safety or effectiveness. | Based on non-clinical testing results. |
2. Sample Size Used for the Test Set and Data Provenance
The document explicitly states: "No clinical data was utilized for the basis of substantial equivalence."
Therefore, there is no clinical test set, sample size, or data provenance related to clinical data. The evaluation was based solely on non-clinical testing.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications
Not applicable, as no clinical test set or ground truth derived from expert opinion on clinical cases was used. The substantial equivalence was determined through non-clinical testing and comparison to predicate devices.
4. Adjudication Method for the Test Set
Not applicable, as no clinical test set requiring adjudication was used.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No MRMC study was performed on human readers as no clinical data was used. The evaluation was based on device performance in non-clinical tests.
6. Standalone (Algorithm Only Without Human-in-the-Loop Performance) Study
This concept is not directly applicable in the context of this traditional medical device (knee implant). The "standalone" performance here refers to the device's physical and mechanical properties as tested in a laboratory setting, without human interaction in a 'use' scenario beyond the testing parameters. The non-clinical testing performed is essentially a standalone evaluation of the device's material and design integrity.
7. Type of Ground Truth Used
The ground truth for proving substantial equivalence was established through:
- Comparison to predicate device specifications: The physical dimensions, materials, and fixation methods were compared to those of the Beacon Cemented and Uncemented Total Knee System (K051510) and the Profix Total Knee System (K933958).
- Non-clinical testing methodologies: Performance was assessed against established engineering standards and guidance documents, specifically "Class II Special Controls Guidance Document: Knee Joint Patellofemorotibial and Femorotibial Metal/Polymer Porous-Coated Uncemented Prostheses; Guidance for Industry and FDA (dated January 16, 2003)."
8. Sample Size for the Training Set
Not applicable, as this is a medical device submission based on substantial equivalence through non-clinical testing and comparison to predicate devices, not an AI/machine learning algorithm that requires a training set.
9. How the Ground Truth for the Training Set Was Established
Not applicable, as no training set was used.
§ 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.