(32 days)
The Klassic" Knee Tibial Stem Extension is intended for use with the Klassic" Knee System. The Klassic" Knee System is intended for prosthetic replacement with the use of bone cement in treatment of the following:
- Patient conditions of non-inflammatory degenerative joint disease (NIDJD): avascular necrosis and osteoarthritis
- Patient conditions of inflammatory joint disease (IJD): rheumatoid arthritis
- Patients with failed previous surgery where pain. deformity, or dysfunction persists
- Correctable varus-valgus deformity and moderate flexion contracture
- Revision of a previously failed knee arthroplasty
- Patients who require a total knee replacement
The Klassic Knee Tibial Stem Extension is a modular component designed for use with the Klassic Knec System Tibial Baseplate to provide the user with options for stemming the Tibial Baseplate where additional distal fixation is desired. The Stem Extension is fully compatible with the predicate Klassic Knee System and offered in lengths up to 150mm. The Klassic Knee Tibial Stem Extension is manufactured from titanium alloy and features a threaded connection which allows for attachment to the Klassic Knee System Tibial Baseplate.
Here's an analysis of the provided text regarding the Klassic™ Knee Tibial Stem Extension:
Acceptance Criteria and Device Performance Study
The review document for the Klassic™ Knee Tibial Stem Extension details non-clinical bench testing to demonstrate substantial equivalence to predicate devices, rather than a clinical study evaluating diagnostic accuracy.
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria Category | Specific Test/Standard | Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|---|---|
| Mechanical Performance | Cantilever Bending Fatigue Testing | Meet or exceed performance of predicate devices and relevant ASTM standards (F2083, F1800) for cyclic fatigue with worst-case geometry. | "All bench testing demonstrates the Klassic Knee Tibial Stem Extension is equivalent in regards to safety and efficacy, is suitable for use in Total Knee Replacement and is substantially equivalent to predicate devices." This implies the device met the performance requirements for fatigue. |
| Modular Connection Integrity | Post Fatigue Fretting-Corrosion Analysis | Demonstrate acceptable levels of fretting and corrosion after fatigue loading, comparable to predicate devices. | "All bench testing demonstrates the Klassic Knee Tibial Stem Extension is equivalent in regards to safety and efficacy, is suitable for use in Total Knee Replacement and is substantially equivalent to predicate devices." This implies the modular connection integrity was acceptable. |
| Material/Design Equivalence | Analysis of the Integrity of the Modular Connection | Maintain structural and functional integrity of the modular connection under applied loads. | "All bench testing demonstrates the Klassic Knee Tibial Stem Extension is equivalent in regards to safety and efficacy, is suitable for use in Total Knee Replacement and is substantially equivalent to predicate devices." This implies the connection was integral. |
| Overall Equivalence | Comparison to Predicate Devices (Technological Characteristics) | Similar in device design, material of manufacture, sterilization, size offerings, and non-clinical performance. | "The Klassic Knee Tibial Stem Extension is similar in device design, material of manufacture, sterilization and size offerings... Any differences in the technological characteristics between the devices do not raise any new issues of safety or effectiveness." |
Important Note: The document states that the testing was based on guidance from specific ASTM standards:
- ASTM F2083-12 Standard Specification for Knee Replacement Prosthesis
- ASTM F1814-97(2009) Standard Guide for Evaluating Modular Hip and Knee Joint Components
- ASTM F1800-12 Standard Practice for Cyclic Fatigue Testing of Metal Tibial Tray Components of Total Knee Joint Replacements
The acceptance criteria are therefore implicitly tied to meeting the performance requirements outlined in these standards and demonstrating equivalence to the predicate devices. The document does not provide specific numerical thresholds for acceptance, but rather a general statement of equivalency and suitability for use.
2. Sample Size for the Test Set and Data Provenance
- Sample Size: The document does not specify the exact number of Klassic Knee Tibial Stem Extension units tested for each benchmark. It refers to "bench testing" and evaluations using the "worst case geometry."
- Data Provenance: The data is from non-clinical bench testing conducted by the manufacturer, Total Joint Orthopedics. It is not patient or human data; therefore, country of origin or retrospective/prospective classification is not applicable in the human study sense.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications
This section is not applicable. The "ground truth" for this type of device (a knee prosthesis component) is established through engineering and materials science principles, industry standards (ASTM), and comparison to the known performance of predicate devices. There is no assessment requiring expert interpretation of images or patient data to establish ground truth in the context of diagnostic accuracy.
4. Adjudication Method for the Test Set
This section is not applicable. As it's non-clinical bench testing, there is no adjudication of findings by multiple human readers/reviewers in the sense of a clinical or image-based study. The results of the physical tests would be measured and analyzed by engineers.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
This section is not applicable. No MRMC study was performed as this is a physical medical device (implant component) and the evaluation was non-clinical bench testing, not a diagnostic imaging or human-reader performance study.
6. Standalone (Algorithm Only) Performance
This section is not applicable. The Klassic™ Knee Tibial Stem Extension is a physical medical device, not an algorithm or AI software. Therefore, standalone algorithm performance is not relevant.
7. Type of Ground Truth Used
The "ground truth" in this context is based on:
- Established engineering principles and material science: Ensuring the device's design and materials are appropriate for its intended use.
- Industry standards (ASTM): Performance benchmarks set by organizations like ASTM for knee replacement components (e.g., fatigue strength, mechanical integrity).
- Performance of predicate devices: The "known good" performance of existing, legally marketed devices that the new device aims to be substantially equivalent to.
8. Sample Size for the Training Set
This section is not applicable. There is no "training set" in the context of a physical medical device undergoing bench testing for regulatory submission. Training sets are typically used for machine learning models.
9. How the Ground Truth for the Training Set Was Established
This section is not applicable for the same reasons as #8.
§ 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.