(200 days)
The Sigma High Performance Unity Knee Resurfacing System is intended to provide increased patient mobility and reduced pain by replacing the damaged knee joint articulation in patients where there is evidence of sufficient sound bone to seat and support the components.
The Sigma High Performance Unity Knee Resurfacing System is indicated for single or multicompartmental knee replacement in skeletally mature individuals with osteoarthritis, posttraumatic arthritis of the tibiofemoral and/or patellofemoral articular surfaces or a history of gout or pseudogout. All Sigma High Performance Unity Knee Resurfacing System components are intended for CEMENTED USE ONLY.
The Sigma High Performance Unity Knee Resurfacing System is composed of unicompartmental femoral components, patellofemoral trochlear components, unicompartmental tibial components and patellar components. These components may be used in various combinations to create: a single unicompartmental femorotibial replacement for either the medial or lateral side of the knee; two unicompartmental femorotibial replacements for both the medial and lateral sides of the knee; a patellofemoral replacement; a bicompartmental patellofemorotibial replacement for the medial or lateral side of the knee; or a tricompartmental patellofemorotibial replacement for the medial and lateral sides of the knee.
This submission adds metal-backed unicompartmental tibial components to the previously cleared GCK System. The Sigma High Performance Unity Knee Resurfacing System metalbacked unicompartmental tibial components consist of wrought forged Co-Cr-Mo unicompartmental tibial trays and XLK cross-linked UHMWPE unicompartmental tibial inserts. The trays and inserts are available in 6 sizes and in left medial / right lateral and right medial / left lateral configurations. Each tibial insert is available in 5 thicknesses. The Sigma High Performance Unity Knee Resurfacing System metal-backed unicompartmental tibial components are intended for use with the previously cleared GCK unicompartmental femoral components.
The document provided describes a 510(k) premarket notification for a medical device, the Sigma High Performance Unity Knee Resurfacing System metal-backed unicompartmental tibial components. This type of submission aims to demonstrate that a new device is "substantially equivalent" to a legally marketed predicate device, rather than proving its safety and effectiveness through extensive clinical trials as would be required for a PMA (Premarket Approval).
Therefore, the concept of "acceptance criteria" and "study that proves the device meets the acceptance criteria" in the traditional sense of a performance study with well-defined metrics, thresholds, and clinical outcomes, is not applicable here.
Instead, the submission focuses on demonstrating substantial equivalence through:
- Comparison to predicate devices: Showing the new device has the same intended use, similar design, and materials as previously cleared devices.
- Non-clinical testing: Engineering analysis, wear simulator testing, and mechanical testing to support the substantial equivalence claim.
Here's an analysis based on the provided text, addressing your points where information is available or indicating its absence due to the nature of a 510(k) submission:
Analysis of Device Acceptance and Supporting Studies
1. A table of acceptance criteria and the reported device performance
- Acceptance Criteria: No explicit "acceptance criteria" are provided in the document in terms of performance metrics (e.g., accuracy, sensitivity, specificity, or specific clinical outcomes). For a 510(k) for an orthopedic implant, acceptance is typically based on demonstrating substantial equivalence to a predicate device in terms of design, materials, indications for use, and performance under non-clinical testing (mechanical, wear).
- Reported Device Performance: The document states that "Engineering analysis, wear simulator testing and mechanical testing were performed to demonstrate the substantial equivalence of the Sigma High Performance Unity Knee Resurfacing System mctal-backed unicompartmental tibial components to the predicate devices." However, specific performance data (e.g., precise wear rates, fatigue strength results, or other mechanical test values) and the acceptance thresholds for these tests are not detailed in this 510(k) summary. The conclusion is that these tests demonstrated substantial equivalence, implying they met unstated internal or recognized standard-based criteria.
2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)
- This information is not applicable/provided as no clinical test set (i.e., human subject data) was used. The testing described is non-clinical (engineering, wear simulation, mechanical). Therefore, there is no provenance or sample size related to human data.
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 information is not applicable/provided. No clinical test set requiring expert ground truth establishment was conducted. The "truth" in this context is based on engineering principles and established material and mechanical testing standards.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
- This information is not applicable/provided. No clinical test set requiring adjudication was conducted.
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 information is not applicable/provided. This device is a knee prosthesis, not an imaging analysis AI or a diagnostic tool that involves "human readers" or "AI assistance." Therefore, an MRMC study is irrelevant to this device.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
- This information is not applicable/provided. This device is an orthopedic implant, not an algorithm.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)
- The "ground truth" for demonstrating substantial equivalence for this device would be based on engineering standards, material specifications, and biomechanical principles. For example, wear simulator testing would follow specific ISO or ASTM standards, with "ground truth" being the established scientific understanding of material wear in the physiological environment, and the results compared against predicate device performance or accepted thresholds.
8. The sample size for the training set
- This information is not applicable/provided. There is no "training set" in the context of an orthopedic implant 510(k) submission.
9. How the ground truth for the training set was established
- This information is not applicable/provided. There is no "training set" or associated ground truth establishment for this type of device submission.
In summary, the provided text describes a 510(k) premarket notification for an orthopedic implant. This submission pathway relies on demonstrating substantial equivalence to a legally marketed predicate device primarily through non-clinical testing (engineering, mechanical, wear simulation). It explicitly states, "Clinical testing was not necessary to determine substantial equivalence between the subject Sigma High Performance Unity Knee Resurfacing System Tibial Components and the predicate devices." Therefore, many of the typical clinical study parameters (sample size, ground truth experts, MRMC, etc.) are not relevant or provided in this document.
§ 888.3530 Knee joint femorotibial metal/polymer semi-constrained cemented prosthesis.
(a)
Identification. A knee joint femorotibial metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace part of 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 consist of a femoral component made of alloys, such as cobalt-chromium-molybdenum, and a tibial component made of ultra-high molecular weight polyethylene and is limited to those prostheses intended for use with bone cement (§ 888.3027).(b)
Classification. Class II.