(28 days)
Total Knee components are indicated for rheumatoid arthritis, osteoarthritis, osteoarthritis, or degenerative arthritis; failed osteotomies, unicompartmental replacement, or total knee replacement.
The Smith & Nephew Legion CR Porous Plus HA Femoral components are indicated for use without bone cement and are single use devices.
The subject of this Special 510(k) is to seek clearance for an additional hydroxyapatite (HA) coating supplier for Smith & Nephew's LEGION CR Porous Plus HA Femoral Components. The LEGION Porous Plus HA Primary Femoral Components were previously cleared for market via premarket notification K091543 (S.E. 12/21/2009). The subject device is used in total knee arthroplasty procedures and is available in sizes 2-8 in both left and right configurations. Like the predicate LEGION Porous Plus HA Primary Femoral Components, the subject device is manufactured from cast cobalt-chrome-molybdenum alloy (ASTM F75) with a cobalt-chromemolybdenum (ASTM F75) sintered bead porous coating (ROUGHCOAT). Additionally, the LEGION CR Porous Plus HA Femoral Components are coated with a thin layer of plasmasprayed hydroxyapatite (HA). There has been no change in femoral size, substrate material, porous coating, or device design as a result of this submission.
The only modification of the previously cleared LEGION CR Porous Plus HA Femoral Components is the addition of an alternate supplier to administer the HA coating process. The device design, principle of operation, substrate material, dimensional characteristics, and indications for use for the subject device will not change as a result of the implementation of an alternate HA coating supplier.
The provided text describes a 510(k) premarket notification for a medical device, specifically the LEGION CR Porous Plus HA Femoral Components. The primary change being cleared is the addition of an alternate supplier for the hydroxyapatite (HA) coating, with no changes to the device's design, materials, or indications for use.
Based on the information provided, here's an analysis of the acceptance criteria and the study that proves the device meets them:
1. A table of acceptance criteria and the reported device performance:
| Acceptance Criteria Category | Specific Acceptance Criterion | Reported Device Performance (with new HA supplier) |
|---|---|---|
| Coating Properties (General) | HA coating characteristics meet or exceed applicable FDA Guidance and ISO Standards. | The new HA coating characteristics meet or exceed the applicable FDA Guidance and ISO Standards. |
| Fatigue Performance | Dual-layer coating (ROUGHCOAT and HA) with the new HA coating supplier performs equivalently to the predicate device. | Fatigue testing demonstrated that the coating properties, via the subject alternate supplier, perform equivalent to the predicate LEGION Porous Plus HA Primary Femoral Components (K091543). |
| Safety and Effectiveness Risks | No new risks related to the safety and effectiveness as a result of the alternate HA coating supplier. | A review of testing has demonstrated that there are no new risks related to the safety and effectiveness of the subject device with the HA coating process performed by the subject alternate HA coating supplier. |
| Substantial Equivalence | Device remains substantially equivalent to the predicate device in terms of intended use, indications for use, design, materials, performance characteristics, and operational principles. | The device is identical in function, design features, intended use, indications for use, operational principles, manufacturing processes, and similar in materials as the commercially available predicate devices. |
2. Sample size used for the test set and the data provenance:
- Sample Size: Not explicitly stated in the document. The text refers to "non-clinical fatigue testing" and "coating characterization" without specifying the number of samples or implants tested for these evaluations.
- Data Provenance: The testing was conducted by Smith & Nephew, the manufacturer. The document doesn't specify the country of origin of the data beyond that it was performed internally. It's retrospective in the sense that it's comparing the performance of the modified device to a previously cleared predicate and its existing data. It's a lab-based, pre-market evaluation rather than a clinical study on patients.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- Not applicable. This submission relies on non-clinical, mechanical, and material characteristic testing. The "ground truth" is established by adherence to engineering standards (FDA Guidance, ISO Standards) and direct comparative performance against the predicate device in a laboratory setting. There were no human experts establishing ground truth in the context of clinical interpretation or diagnosis for this specific clearance.
4. Adjudication method for the test set:
- Not applicable. This information is relevant for studies involving human interpretation (e.g., radiologists reviewing images). Since this is a non-clinical, laboratory-based performance study, adjudication methods for expert consensus are not relevant. The assessment is based on objective measurements and comparison to established benchmarks and predicate device performance.
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:
- No, an MRMC comparative effectiveness study was not done. This type of study is relevant for AI-powered diagnostic or assistive devices involving human interpretation. This submission is for a knee implant component, and its clearance is based on non-clinical performance data.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- Not applicable. This question pertains to AI/algorithm performance. This device is a passive implant component, not an algorithm.
7. The type of ground truth used:
- The "ground truth" for this submission is based on:
- Engineering and Material Standards: Adherence to applicable FDA Guidance and ISO Standards for HA coating characteristics.
- Predicate Device Performance: Direct comparison of the fatigue and coating properties of the device (with the new HA supplier) to the established performance of the legally marketed predicate device (LEGION Porous Plus HA Primary Femoral Components – K091543).
- Objective Measurements: Results from non-clinical fatigue testing and precise HA coating characterizations (static shear, shear fatigue, and HA powder values).
8. The sample size for the training set:
- Not applicable. This question applies to machine learning models that require a training set. This submission is for a medical device component, not an AI/ML product.
9. How the ground truth for the training set was established:
- Not applicable. As stated above, there is no training set for this device.
§ 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.