(59 days)
The Apex Knee System is intended for use as a primary or revision total knee replacement. This prosthesis may be used for the following conditions, as appropriate:
- Non-inflammatory degenerative joint disease, including osteoarthritis and avascular necrosis:
- Rheumatoid arthritis: .
- Correction of functional deformity: .
- Revision procedures where other treatments or devices have failed. .
The porous coated femoral component may be used cemented or uncemented (biological fixation). The porous coated tibial baseplate component may be used uncemented (biological fixation). All other femoral, tibial baseplate, and patellar components are indicated for cemented use only.
The Apex Knee System Porous Coated Tibial Components are part of the Apex Knee System for primary or revision total knee replacement. These cobalt chrome tibial components have a plasma sprayed CP titanium porous coating (ASTM F1580) with a plasma sprayed overcoat of hydroxyapatite (ASTM F1185), and are intended for use without bone cement. Fixation of the porous coated tibial component is achieved by biological fixation via tissue ingrowth into the porous coating. The Apex Knee System includes a tibial component option with two holes for supplemental fixation using cancellous bone screws, and the same porous coating. The Apex Knee System consists of a range of sizes of femoral components with a deep patellar groove, dome shaped UHMWPE patella resurfacing components, UHMWPE tibial inserts, cobalt chrome tibial trays, and a titanium alloy bolt for locking the tibial insert to the tibial tray. This modular configuration allows the surgeon user to choose a combination of femoral and tibial tray component sizes to appropriately fit the anatomy of the patient, and to use a tibial insert with a size-for-size match to the femoral component. There are two different articular geometries for the tibial insert, a cruciate retaining ("CR") design, which allows retention of the posterior cruciate ligament, and an ultra-congruent posterior cruciate substituting ("Ultra") design. For each tibial insert, a range of UHMWPE thicknesses are available to aid in obtaining the proper soft tissue balance across the knee joint.
Acceptance Criteria and Study Details for Apex Knee System Porous Coated Tibial Components
The provided document describes a 510(k) premarket notification for the Apex Knee System Porous Coated Tibial Components. This type of submission relies on demonstrating substantial equivalence to a legally marketed predicate device, rather than conducting a de novo clinical study with specific acceptance criteria and performance metrics against those criteria. Therefore, the device "meets the acceptance criteria" by demonstrating substantial equivalence to the predicate device through a comparison of intended use, design, and materials, supported by material and design testing.
This document does not outline specific acceptance criteria in terms of clinical performance metrics (e.g., patient outcomes, reduction in pain scores, mobility improvements) and a study explicitly proving the device meets those criteria. Instead, the "acceptance criteria" are the FDA's requirements for demonstrating substantial equivalence.
Here's an analysis based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
As this is a 510(k) submission based on substantial equivalence, the "acceptance criteria" are primarily focused on demonstrating similarities and justifying differences from legally marketed predicate devices. The "reported device performance" is the demonstration of these similarities and the safety/effectiveness of the new features through material and design testing, rather than clinical performance outcomes.
| Acceptance Criterion (Implicit for 510(k)) | Reported Device Performance (Demonstrated Equivalence) |
|---|---|
| Intended Use Equivalence: Same or very similar intended use as predicate. | Same: The Apex Knee System Porous Coated Tibial Components share the same intended use as the predicate Apex Knee System (K060192 and K073602) for primary or revision total knee replacement for non-inflammatory degenerative joint disease, rheumatoid arthritis, correction of functional deformity, and revision procedures. The key difference is the option for uncemented use of the porous coated tibial baseplate, which is supported by the materials and design of the porous coating. |
| Technological Characteristics Equivalence (Design): Similar design features or minor differences that do not raise new questions of safety/effectiveness. | Similar Design (Apex Knee System): The new tibial components maintain the "Anatomic (asymmetric) tibial tray," "Metal-backed UHMWPE tibial component," "CR and Ultra tibial insert designs," and "Central post and 2 keels" distal features, identical to the predicate Apex Knee System. |
| Minor Differences Justified: The addition of a porous coating to the tibial tray and an option for two screw holes for supplemental fixation are the principal design changes. These are addressed by the material equivalence to K043123. | |
| Technological Characteristics Equivalence (Materials): Same or clinically equivalent materials, especially for new features. | Similar Materials (Apex Knee System): The core tibial component material remains "Cobalt chrome," consistent with the predicate Apex Knee System. |
| Equivalent Material (Apex Modular™ HA Hip Stem): The "Plasma sprayed CP titanium with HA overcoat" for the porous coating on the tibial tray is explicitly stated to be identical to the porous coating on the predicate Apex Modular™ HA Hip Stem (K043123), which has already been cleared for uncemented use and biological fixation in a load-bearing application. | |
| Performance Data (Non-Clinical): Bench testing, material characterization, and/or design verification to support safety and effectiveness of new features. | While not explicitly detailed in the provided summary, a 510(k) for a device with a new porous coating for uncemented fixation would typically include: |
- Porous coating characterization: Adhesion strength, porosity, pore size, chemical composition (HA content).
- Biocompatibility testing: To ensure the new materials (HA overcoat system) are safe for implantation.
- Mechanical testing: To demonstrate the structural integrity of the porous coated components, especially for the screw holes if present, and to ensure the coating does not compromise mechanical performance.
- It is stated that the "porous coating is identical to... K043123," implying that the safety and effectiveness of this specific coating for biological fixation has already been established and accepted by the FDA. |
2. Sample Size Used for the Test Set and Data Provenance
Given this is a 510(k) submission based on substantial equivalence, there is no "test set" in the context of clinical data with human subjects as typically understood for a novel device. The "test set" would refer to bench testing samples (e.g., specific numbers of components subjected to mechanical tests, material analysis samples). This information is not provided in the summary.
Data Provenance: The primary "data provenance" for demonstrating substantial equivalence is the prior FDA clearance of the predicate devices:
The data used to support these previous clearances would have included a range of non-clinical (bench) and potentially limited clinical data (for K043123 regarding biological fixation), but this document doesn't detail their original provenance (e.g., country of origin, retrospective/prospective).
3. Number of Experts Used to Establish Ground Truth and Qualifications
Not applicable. This type of premarket notification does not involve establishing ground truth from experts on clinical data. The "expertise" involved is that of the FDA reviewers who assess the substantial equivalence claim based on engineering, material, and regulatory principles.
4. Adjudication Method for the Test Set
Not applicable. No clinical test set with human data requiring an adjudication method is described.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No. An MRMC study is typically used for diagnostic or imaging devices to assess reader performance. This is a submission for an implantable orthopedic device, not a diagnostic tool.
6. Standalone (Algorithm Only) Performance Study
Not applicable. This is a physical prosthetic device, not a software algorithm.
7. Type of Ground Truth Used
The "ground truth" for this 510(k) determination is the established safety and effectiveness of the legally marketed predicate devices, specifically:
- The overall design and intended use of the Apex Knee System (K060192 and K073602).
- The specific plasma-sprayed CP titanium with HA overcoat for biological fixation, as proven safe and effective in the Apex Modular™ HA Hip Stem (K043123).
8. Sample Size for the Training Set
Not applicable. There is no "training set" in the context of machine learning or AI algorithms for this device. The development of the device relied on engineering design principles, biomaterials science, and regulatory compliance, drawing from established knowledge and testing of the predicate devices.
9. How the Ground Truth for the Training Set Was Established
Not applicable. As there is no training set for an algorithm, this question is not relevant. The basis for the acceptability of the design and materials is the extensive regulatory and scientific background supporting the predicate devices.
§ 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.