(84 days)
This device 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, osteoarthritis, primary and secondary traumatic arthritis, polyarthritis, collagen disorders, avascular necrosis of the femoral condyle or pseudogout, posttraumatic loss of joint configuration, particularly when there is patello femoral erosion, dysfunction or prior patellectomy, moderate valgus, varus, or flexion deformities. This device may also be indicated in the salvage of previously failed surgical attempts if the knee can be satisfactorily balanced and stabilized at the time of surgery.
This device system is designed for cemented use only.
The design of the UKNEE Total Knee System covers both of the cruciate retaining and posterior stabilized types. It is a patellofemorotibia, polymer/metal/polymer, semi-constrained, cemented knee prosthesis, which has a cobalt-chromium-molybdenum (Co-Cr-Mo) alloy femoral component and tibial component composed of a insert, machined from compressed molded UHMWPE flat, mechanical locked with metallic tibial baseplate. There are two types of tibial baseplate component, one is one piece with grooved but without beaded porous coating and the other is modular, with and/or without beaded porous coating, locked with a keeled or round stem by means of Morse Taper. The cruciate retaining type of femoral component has w/ and w/o beaded porous coating design, and the posterior stabilized type has only w/o. The porous coating with two layers of beads has an about 55% of porosity, a 440 um of average pore size, and its thickness is 1.2 +0/+0.3 mm. The patellar components are machined from extruded UHMWPE bar and designed for cemented use only.
Here's an analysis of the acceptance criteria and study information for the UKNEE Total Knee System, based on the provided document:
UKNEE Total Knee System
1. Table of Acceptance Criteria and Reported Device Performance
The provided document describes various tests performed on the UKNEE Total Knee System and compares its performance to predicate devices. It does not explicitly state pre-defined "acceptance criteria" with numerical targets for each test, but rather presents the results and concludes that the device performs "as well or better than the predicate device in all areas tested" and is "substantial equivalent" to the predicate devices.
Here's a table summarizing the reported performance, with the understanding that "acceptance" is implicitly defined by being comparable or superior to the predicate devices:
| Test / Performance Metric | Stated Acceptance Criteria (Implicit) | Reported UKNEE Total Knee System Performance | Comparison to Predicate Devices |
|---|---|---|---|
| Range of Motion | 0° to 115° | 0° to 115° | Satisfies "necessary needs of daily life and general activities." |
| Constraint | N/A (Comparative) | Slightly less constraint | Slightly less constraint than Omnifit® Total Knee System. |
| Femorotibial & Patellofemoral Contact Area | N/A (Comparative) | Similar or greater contact area | Similar or greater contact area than Omnifit® and AMK® (other market products). |
| Morse Taper Pull-off Resistance Strength | N/A (Comparative) | 444 kgf | Substantial to or better than Genesis® (340 kgf). |
| Morse Taper Torsional Resistance Strength | N/A (Comparative) | 4.56 kgf-m | Substantial to or better than Genesis® (1.44 kgf-m). |
| Tibial Insert & Tibial Tray Locking (Anteroposterior Motion at 100N load) | N/A (Comparative) | Average anteroposterior motion is less than the predicated device. | Stronger than &/or similar to Genesis®. |
| Tibial Baseplate Cyclic Fatigue | No fracture after 5M cycles | No fracture after 5 million cycles with compressive cyclic load between 200N and 2.0KN. | (No direct comparison to predicate device explicitly stated for this specific test, but implies passing the fatigue requirement) |
| Patellofemoral Joint Lateral Stability | N/A (Comparative) | Larger stability | Larger stability than Omnifite Total Knee System to prevent lateral dislocation. |
| Beaded Porous Coating Static Tensile Strength | 5000 psi min. | Conformed to endure 5000 psi min. | (No direct comparison to predicate device explicitly stated) |
| Beaded Porous Coating Shear Strength | > 20 MPa | More than 20 MPa | (No direct comparison to predicate device explicitly stated) |
| Beaded Porous Coating Volume Porosity | 30-70 percent | Between 30 and 70 percent | (No direct comparison to predicate device explicitly stated) |
| Beaded Porous Coating Average Pore Size | 100-1000 microns | Between 100 and 1000 microns | (No direct comparison to predicate device explicitly stated) |
| Beaded Porous Coating Thickness | 500-1500 microns | Between 500 and 1,500 microns. (Also mentioned: 1.2 +0/+0.3 mm, which is 1200 +0/+300 microns for a specific type) | (No direct comparison to predicate device explicitly stated) |
2. Sample Size and Data Provenance for Test Set
The document does not explicitly state the sample sizes used for each of the physical tests (e.g., number of components tested for Morse taper strength, number of baseplates for cyclic fatigue). It refers to "test data," but specific N values are not provided.
The data provenance is not explicitly stated. These are in vitro mechanical engineering tests performed on the physical device components, not clinical data from patients. Therefore, terms like "country of origin of the data," "retrospective," or "prospective" are not applicable in the human clinical sense. The tests were likely conducted by the manufacturer, United Orthopedic Corporation, based in Taiwan.
3. Number of Experts and Qualifications for Ground Truth for Test Set
This section is not applicable as the document describes in vitro mechanical testing of physical implants, not diagnostic or clinical performance requiring expert ground truth.
4. Adjudication Method for the Test Set
This section is not applicable as the document describes in vitro mechanical testing of physical implants, not diagnostic or clinical performance requiring adjudication.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study for AI
This section is not applicable. The UKNEE Total Knee System is a physical joint replacement implant (a medical device), not an AI-powered diagnostic or assistive tool. Therefore, an MRMC study comparing human readers with and without AI assistance is irrelevant.
6. Standalone (Algorithm Only) Performance
This section is not applicable. The UKNEE Total Knee System is a physical joint replacement implant, not an algorithm.
7. Type of Ground Truth Used
The "ground truth" for the performance claims are the results of standardized mechanical and physical tests performed on the device components, often compared against established ASTM standards and data from predicate devices. For material properties, the ground truth is the measured property values meeting ASTM standards. For mechanical performance, the ground truth is the measured force, torque, motion, or fatigue response under specified test conditions.
8. Sample Size for the Training Set
This section is not applicable. The UKNEE Total Knee System is a physical medical device. It does not involve machine learning or AI models, and therefore does not have a "training set" in that context. The design and manufacturing process would involve engineering principles and material science, not data training.
9. How the Ground Truth for the Training Set was Established
This section is not applicable, as there is no "training set" for this type of medical device.
§ 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.