(30 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 patellofemoral 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 is indicated for cemented use only.
The subject "UNITED" U2 Patella is identical to the legal on-market patellar components in the U2 Total Knee System (available in sizes 26, 29, 32, 35, and 38 mm), except for its larger diameter (available in sizes 41 and 44 mm). The patellar component is machined from extruded UHMWPE bar. It has a three-pegged design for fixation to the host patella and cement groove designed for cemented use only. The radius of dome for the patella components in U2 Patella and U2 Total Knee System are both 23.8 mm. The diameter and length of the pegs of these two systems are 5.0 mm and 4.5 mm, respectively.
The provided text describes the 510(k) summary for the U2 Patella, an orthopedic device, and does not contain information related to software or AI-based devices. Therefore, it is not possible to extract information about acceptance criteria, device performance, sample sizes for test or training sets, expert qualifications, adjudication methods, MRMC studies, standalone performance, or ground truth types as these concepts are not applicable to the information provided.
The document focuses on demonstrating substantial equivalence of the U2 Patella to a predicate device based on its design, materials, and intended use, with only a brief mention of "Performance Data" concerning "patellofemoral contact area and lateral stability testing."
Here's a breakdown of what can be extracted from the document:
1. Acceptance Criteria and Reported Device Performance:
The document states: "Performance testing, including patellofemoral contact area and lateral stability testing of the U2 Patella, completed as part of the design assurance process demonstrated that this device is safe and effective and is substantially equivalent to the predicate device."
- Acceptance Criteria: Not explicitly stated as numerical thresholds. The implicit acceptance criterion is that the performance of the U2 Patella (specifically patellofemoral contact area and lateral stability) is "safe and effective" and "substantially equivalent" to the predicate device.
- Reported Device Performance: No specific numerical results for patellofemoral contact area or lateral stability are provided. The only reported performance is the conclusion that it demonstrated safety, effectiveness, and substantial equivalence to the predicate.
| Acceptance Criteria (Implicit) | Reported Device Performance |
|---|---|
| Device is safe and effective. | Demonstrated through performance testing. |
| Device is substantially equivalent to the predicate device. | Concluded based on identical materials, similar design (except for size), and performance testing (patellofemoral contact area and lateral stability testing). The modification (larger size) does not change intended use or fundamental scientific technology. |
| Patellofemoral contact area testing results are acceptable. | "Performance testing, including patellofemoral contact area... demonstrated that this device is safe and effective and is substantially equivalent to the predicate device." (No specific numerical results provided, only a general qualitative statement of meeting acceptance) |
| Lateral stability testing results are acceptable. | "Performance testing, including... lateral stability testing of the U2 Patella, completed as part of the design assurance process demonstrated that this device is safe and effective and is substantially equivalent to the predicate device." (No specific numerical results provided, only a general qualitative statement of meeting acceptance) |
The following information is NOT available in the provided document:
- Sample size used for the test set and the data provenance: Not applicable/not provided for a physical device substantial equivalence submission where the "test set" would typically refer to clinical data or a statistically significant number of physical tests. The document refers to "Performance testing" without specifying sample sizes for the mechanical tests.
- Number of experts used to establish the ground truth for the test set and the qualifications of those experts: Not applicable. Ground truth as typically defined for AI/software is not relevant here.
- Adjudication method for the test set: Not applicable.
- If a multi-reader, multi-case (MRMC) comparative effectiveness study was done: Not applicable. This is not a study type associated with this kind of device submission.
- If a standalone (i.e., algorithm only without human-in-the-loop performance) was done: Not applicable. This is not an algorithm.
- The type of ground truth used: Not applicable.
- The sample size for the training set: Not applicable. There is no training set for a physical device.
- How the ground truth for the training set was established: Not applicable.
§ 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.