(28 days)
This device is indicated for patients with severe knee pain and disability due to:
• Rheumatoid arthritis, osteoarthritis, traumatic arthritis, polyarthritis.
• Collagen disorders, and/or avascular necrosis of the femoral condyle.
· Post-traumatic loss of joint configuration, particularly when there is patellofemoral erosion, dysfunction or prior patellectomy.
· Moderate valgus, varus, or flexion deformities. · The salvage of previously failed surgical attempts or for a knee in which satisfactory stability in flexion cannot be obtained at the time of surgery.
Specific uses with LPS-Flex femorals: · Provides increased flexion capability for patients who have both the flexibility and desire to increase their flexion range. · The LPS-Flex femoral, when used with the LPS-Flex articular surfaces, is designed for use with both cruciate ligaments excised and when load bearing ROM is expected to be less than or equal to 155 degrees.
The LPS-Flex Fixed Bearing Knee is a semiconstrained, condylar system for use without the cruciate ligaments when additional stability is required to prevent anterior subluxation of the femur relative to the tibia in flexion.
This document is a 510(k) premarket notification for a medical device modification, specifically for the NexGen® Complete Knee Solution Legacy® Posterior Stabilized (LPS)-Flex Fixed Bearing Tivanium® Ti-6Al-4V Alloy Femoral Components. It seeks to demonstrate substantial equivalence to a predicate device.
Here's an analysis of the provided information concerning acceptance criteria and supporting studies:
-
A table of acceptance criteria and the reported device performance
This document does not explicitly list quantitative acceptance criteria in a table format in the way one might expect for a software or diagnostic device. Instead, the "acceptance criteria" are implicitly met by demonstrating substantial equivalence through non-clinical (laboratory) performance testing. The main criterion is that the modified device performs comparably to the predicate device and meets safety and effectiveness standards for its intended use.
Acceptance Criteria (Implicit) Reported Device Performance Device is safe and effective. The results of non-clinical (laboratory) performance testing demonstrate that the device is safe and effective. Device is substantially equivalent to the predicate device (NexGen® Complete Knee Solution Legacy® Posterior Stabilized (LPS)-Flex Fixed Bearing Femoral and Articular Surface Components, K991581). The results of non-clinical (laboratory) performance testing demonstrate that the device is substantially equivalent to the predicate device. The modifications (change in material and surface hardening processing) do not change the intended use or the fundamental scientific technology. Device is packaged using the same materials and processes. -
Sample sizes used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)
The document states: "The results of non-clinical (laboratory) performance testing demonstrate that the device is safe and effective and substantially equivalent to the predicate device."
- Sample Size for Test Set: The document does not specify the sample size for the non-clinical (laboratory) performance testing.
- Data Provenance: The data provenance is "non-clinical (laboratory) performance testing." There's no information about the country of origin or whether it was retrospective or prospective, as these terms typically apply to clinical data.
-
Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience)
This is not applicable. The study conducted was non-clinical (laboratory) performance testing of a mechanical device (femoral components for a knee replacement). There was no "ground truth" to be established by human experts in the context of interpreting medical images or data. Performance was likely evaluated against engineering specifications and comparison to the predicate device's characteristics.
-
Adjudication method (e.g. 2+1, 3+1, none) for the test set
This is not applicable. Adjudication methods like 2+1 or 3+1 are used for establishing ground truth in studies involving human interpretation or clinical outcomes, typically for diagnostic devices or AI algorithms. This submission pertains to a mechanical orthopedic implant, where "adjudication" in this sense is not relevant.
-
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
This is not applicable. An MRMC study is relevant for evaluating the impact of an AI algorithm on human reader performance, particularly in diagnostic imaging. The device in question is a knee implant component, not a diagnostic AI tool.
-
If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
This refers to a mechanical device, not an algorithm. Therefore, "standalone algorithm only" testing is not applicable. The "standalone performance" was the non-clinical laboratory testing of the physical components.
-
The type of ground truth used (expert consensus, pathology, outcomes data, etc)
This is not explicitly stated in terms of a "ground truth" as it would be for a diagnostic device. For a mechanical implant, "ground truth" generally relates to adherence to design specifications, material properties, mechanical strength, wear characteristics, and biocompatibility, as confirmed through laboratory testing. The implicit ground truth would be that the modified device's performance characteristics (e.g., strength, durability, wear resistance) are equivalent or superior to the predicate device, and meet a predefined set of engineering and biocompatibility standards.
-
The sample size for the training set
This is not applicable. This device is a mechanical implant, not an AI/ML algorithm that requires a "training set."
-
How the ground truth for the training set was established
This is not applicable, as there is no training set for a mechanical implant.
§ 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.