(48 days)
The Arthrex iBalance® TKA System is indicated for use in individuals undergoing surgery for:
- Painful, disabling joint disease of the knee resulting from degenerative arthritis, rheumatoid arthritis or post-traumatic arthritis;
- Post-traumatic loss of knee joint configuration and function;
- Moderate varus, valgus, or flexion deformity in which the ligamentous structures can be returned to adequate function and stability;
- Revisions of previous unsuccessful knee replacement or other procedure.
Additional indications for posteriorly stabilization components:
- Ligamentous instability requiring implant bearing surfaces with increased constraint;
- Absent or non-functioning posterior cruciate ligament.
These devices are single use only and are intended for implantation with bone cement.
The Arthrex iBalance® TKA System consists of femoral components, tibial tray. tibial bearing components and patellar components. All components are available in a range of sizes to fit varying anatomical requirements. Femoral components and tibial bearing components are available in both posteriorly stabilized (PS) and cruciate (CR) configurations. Femoral components are available in left and right versions and are designed to work with the Arthrex dome patella components. Femoral and tibial tray components are manufactured from Cobalt-Chromium Alloy conforming to ASTM F-75. Tibial bearing and patellar components are manufactured from UHMWPE conforming to ASTM F-648.
The provided text describes a 510(k) premarket notification for the Arthrex iBalance® TKA System, specifically addressing a change in the sterilization method for the UHMWPE tibial bearing components from EtO to Gamma Irradiation. The submission focuses on demonstrating substantial equivalence to a predicate device (K081127: Accin™ Total Knee System) despite this change.
Here's an analysis of the acceptance criteria and the study that proves the device meets them, based solely on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|
| Material properties of Gamma-sterilized UHMWPE (adherence to ASTM F648 for Type 2 PE) | "Material properties of the gamma UHMWPE components have been fully characterized per ASTM F2565. Gamma sterilization had minimal effects on the mechanical properties of the PE, and the properties meet those listed in ASTM standard F648 for Type 2 PE." |
| Mechanical strength of Gamma-sterilized UHMWPE (comparison to EtO sterilized) | "The mechanical testing data submitted demonstrates that there is no significant difference in mechanical strength between EtO and Gamma specimens." |
| Substantial equivalence to predicate device (K081127) | "The Arthrex iBalance® TKA System is substantially equivalent to the predicate devices, in which the basic design features and intended uses are the same. Any differences between the Arthrex iBalance® TKA System and the predicates are considered minor and do not raise questions concerning safety and effectiveness." |
2. Sample Size Used for the Test Set and Data Provenance
The document does not specify the exact sample size used for the mechanical testing of the UHMWPE components. It generally refers to "mechanical testing data submitted."
The data provenance is not explicitly stated. However, given that it's a 510(k) submission to the FDA, the testing would typically be conducted according to recognized ASTM standards, implying a controlled laboratory setting. It is a retrospective analysis comparing the properties of gamma-sterilized and EtO-sterilized UHMWPE.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
This information is not provided in the document. The study described is a laboratory-based mechanical testing study, not one requiring expert human interpretation of medical images or clinical outcomes for ground truth establishment.
4. Adjudication Method for the Test Set
This information is not provided and is not applicable to the type of study described (mechanical testing). Adjudication methods are typically used in studies involving human interpretation or clinical outcomes.
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?
No, an MRMC comparative effectiveness study was not done. This submission is for a knee prosthesis and focuses on material properties after a sterilization change, not on AI assistance for human readers or interpretation of data.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
No, a standalone algorithm performance study was not done. This submission is about the physical properties of a medical device, not an algorithm.
7. The Type of Ground Truth Used
The ground truth for this study is based on established material science standards and physical measurements. Specifically, the "ground truth" for the material properties of UHMWPE is defined by ASTM standard F648 for Type 2 PE, and the characterization of material properties after gamma sterilization was conducted per ASTM F2565. The comparison of mechanical strength between EtO and Gamma specimens relies on direct physical measurement of these properties.
8. The Sample Size for the Training Set
This information is not applicable as there is no "training set" in the context of this mechanical testing study. The device is a physical implant, not an AI system that requires training data.
9. How the Ground Truth for the Training Set Was Established
This information is not applicable as there is no "training set."
§ 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.