(260 days)
U2 Total Knee System - PF+ is indicated in knee arthroplasty for reduction or relief of pain and/or improved knee function in skeletally mature patients with severe knee pain and disability due to rheumatoid arthritis, primary and secondary traumatic arthritis, collagen disorders, avascular necrosis of the femoral condyle or pseudogout, posttraumatic loss of joint configuration, particularly when there is patellofemoral joint surface erosion, dysfunction or prior patellectomy, moderate valgus, varus, or flexion deformities. This device may also be indicated in the salvage or previously failed surgical attempts or for knee in which satisfactory stability in flexion cannot be obtained at the time of surgery. Femoral Component, PF+, Tibial Baseplate, PF+ and Tibial Extension Stem are indicated for both cemented and cementless use.
There are three components included in U2 Total Knee System- PF+ for this 510k, (1)Femoral Component, PF+, (2)Tibial Baseplate, PF+, and (3)Tibial Extension Stem. Both Femoral Component, PF+ and Tibial Baseplate, PF+ can collocate with U2 Total Knee System tibial insert and patellar component (K021657, K051640, K082469, K103733, K131864, K132752, K150829, K152430, K161705, and K210961). This system includes Cruciate Retained (CR) type and Posterior Stabilized (PS) type.
• Femoral Component, PF+
There are two types of Femoral Component, PF+ : Cruciate Retaining type and Posterior Stabilized type. Femoral Component, PF+ is manufactured from cast Co-Cr-Mo alloy conforming to ASTM F75. The inner surface is coated with Co-Cr-Mo beads and Co-Cr-Mo powder (ASTM F75) to provide a porous surface to achieve biological fixation.
• Tibial Baseplate, PF+
Tibial Baseplate, PF+ is manufactured from titanium alloy (ASTM F620) which is forged by titanium alloy bars (ASTM F136). The backside of the subject device is coated with Titanium powder (ASTM F1580).
• Tibial Extension Stem
Tibial Extension Stem is collocated with tibial baseplate. The subject device is made of titanium alloy conforming to ASTM F136.
The provided document (K221705) is a 510(k) summary for a medical device called the "U2 Total Knee System-PF+". This document is a premarket notification to the FDA to demonstrate that the device is substantially equivalent to legally marketed predicate devices.
It is crucial to understand that this document describes a mechanical orthopedic implant (knee replacement components), not an AI-powered or software-based medical device. Therefore, the concepts of acceptance criteria for AI performance, training and test sets for AI models, expert ground truth for imaging, MRMC studies, or standalone algorithm performance are not applicable to this submission.
The document discusses acceptance criteria and proof of meeting them, but these relate to the mechanical and material properties, biocompatibility, and sterilization of the knee implant components, not to the performance of an AI algorithm.
Therefore, I cannot provide the requested information for an AI-powered device based on this document.
However, I can extract information relevant to the device's performance, which is related to its mechanical and material integrity:
Information from the document relevant to the device's "performance" (mechanical/material):
1. A table of acceptance criteria and the reported device performance:
The document broadly states that "the test results indicated that this device is safe and effective" and that "Verification activities on Subject devices demonstrated equivalent safety and effectiveness as compared to the predicate devices."
Specific acceptance criteria (e.g., "fatigue strength must exceed X N at Y cycles") and the exact reported values are not explicitly provided in a table format within this 510(k) summary. The summary typically refers to the fact that these tests were conducted and met the necessary standards for substantial equivalence.
However, the types of performance tests conducted are listed:
| Test Conducted | Performance Indication (Implicit) |
|---|---|
| Femoral component fatigue test | Device meets fatigue life requirements for load-bearing in the knee |
| Tibial baseplate fatigue test | Device meets fatigue life requirements for load-bearing in the knee |
| Articulating surface finish of femoral component | Surface smoothness is adequate for proper articulation and wear resistance |
| Finish of non-articulating surface of tibial baseplate | Surface quality is appropriate for non-articulating areas (e.g., tissue contact, fixation) |
| Microstructure of the modified surface | Material structure is as intended, contributing to mechanical properties and biological fixation |
| Mechanical properties of the modified surface | Material strength, stiffness, etc., are consistent with design and predicate devices |
| Bacteria endotoxin testing | Endotoxin levels are below specified limits (met USP ) ensuring biocompatibility and safety for implantation |
2. Sample sized used for the test set and the data provenance:
- Sample Size: Not explicitly stated for each mechanical test. For mechanical testing of components, samples typically refer to a number of physical units or prototypes tested, not patient data.
- Data Provenance: The tests are performed by the manufacturer, United Orthopedic Corporation (located in Hsinchu City, Taiwan). The testing is primarily laboratory-based mechanical and material characterization, not clinical data. Therefore, concepts like "country of origin of the data" or "retrospective/prospective" in the clinical sense are not applicable.
3. 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 question is not applicable. This device is a mechanical implant, not an AI system interpreting medical images. "Ground truth" in this context would be defined by engineering specifications, material standards (e.g., ASTM F75, F136, F620, F1580), and validated test methodologies (e.g., fatigue testing standards). The "experts" involved would be materials scientists, mechanical engineers, and quality assurance professionals, whose qualifications are implicit in the adherence to recognized standards.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set:
This question is not applicable. Mechanical tests have specific physical or chemical endpoints determined by validated methods and equipment, not human subjective interpretation requiring adjudication.
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:
This question is not applicable. MRMC studies are for assessing diagnostic accuracy of imaging or AI systems with human readers. This device is a mechanical implant.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
This question is not applicable. This device is a mechanical implant.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.):
The "ground truth" for this device's performance is established by:
- Adherence to international and national standards for materials (e.g., ASTM F75, F136, F620, F1580).
- Validated mechanical testing methodologies (e.g., fatigue testing, surface finish measurements).
- Biocompatibility standards (e.g., USP for endotoxin).
- Comparison to the established performance characteristics of predicate devices.
8. The sample size for the training set:
This question is not applicable. There is no AI model or "training set" for this mechanical device.
9. How the ground truth for the training set was established:
This question is not applicable.
§ 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.