(87 days)
The MILESTONE Knee System Primary Knee is designed as a system and is not intended for substitution of components from other systems.
- A. Primary intervention of rheumatoid arthritis, osteoarthritis, post-traumatic arthritis, or degenerative arthritis.
- B. Failed osteotomy or unicompartmental replacements.
- C. Replacement of unsatisfactory cemented or press-fit knee components when sufficient bone stock exists.
All MILESTONE Knee components are intended for cemented use only.
The MILESTONE Knee System (MKS) is a primary, fixed-bearing, total knee system designed to replicate the natural anatomy of the knee in order to restore knee function. It was developed to preserve and utilize healthy ligamentous structures, and to restore stability to the knee.
The MKS incorporates femoral, tibial, and patellar components and all associated instrumentation needed for implantation. The femoral and tibial components are provided in left and right configurations. The femoral component is made from CoCr and is offered in a posterior stabilizing (PS) configuration. The tibial component comprises an asymmetric tibial baseplate made from CoCr alloy and an asymmetric PS tibial insert made from UHMWPE. The baseplate is designed to maximize metaphyseal bone coverage on the tibia. The baseplate employs a cruciate type keel to enhance implant fixation and torsion resistance. The tibial insert attaches to the baseplate via a mechanical locking mechanism. All MKS metallic components are available in uncoated variants for cemented use. The patellar component is an all-poly round patella made from UHMWPE, also intended for cemented use.
The provided document describes the TGM Medical, Inc. MILESTONE Knee System (MKS) and its substantial equivalence to a legally marketed predicate device, the Consensus Knee System (CKS). It is a traditional 510(k) premarket notification.
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 | Reported Device Performance |
|---|---|
| Equivalence in Materials | MKS components employ identical materials as their respective predicate CKS components. |
| Equivalence in Design Features | MKS components employ identical geometry and design features as their respective predicate CKS components. |
| Biomechanical Performance (Safety & Effectiveness) | Biomechanical testing of predicate CKS components validated the safety and effectiveness for MKS. |
| Indicated Uses | Indications for Use are identical to the predicate device. |
Note: The document does not explicitly state quantitative "acceptance criteria" for performance metrics in a pass/fail sense, but rather establishes equivalence through material, design, and prior testing of predicate devices.
2. Sample Size Used for the Test Set and Data Provenance
- Test Set (for the MKS itself): Not applicable in the traditional sense of a clinical trial with a "test set" of patients.
- Data Provenance: The "testing" referred to is non-clinical bench testing and analyses performed on predicate CKS components. The document does not specify the sample size for these predicate tests, nor does it mention a specific country of origin or whether the data was retrospective or prospective.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications
- Not applicable. This submission is based on substantial equivalence to a predicate device, relying on prior regulatory clearances and non-clinical bench testing of the predicate. There is no mention of a human expert-based ground truth establishment for a "test set" in the context of this 510(k) summary.
4. Adjudication Method for the Test Set
- Not applicable. As there is no clinical trial with a "test set" requiring expert ground truth or adjudication described.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
- No. An MRMC study was not done. The submission relies on establishing substantial equivalence to a predicate device through non-clinical testing and material/design comparisons, not comparative effectiveness studies with human readers or AI.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
- No. This device is a total knee prosthesis, a physical implant, not an algorithm or AI software. Therefore, standalone algorithm performance is not applicable.
7. The Type of Ground Truth Used
- The "ground truth" for demonstrating the safety and effectiveness of the MKS is established through:
- Prior Regulatory Clearance of Predicate Devices: The FDA's clearance of the predicate CKS components (K954818, K110950, K932837, K001456, K945589) serves as the primary "ground truth" for their safety and effectiveness.
- Biomechanical Testing of Predicate Devices: The non-clinical bench testing performed on the predicate CKS components validates their safety and effectiveness.
8. The Sample Size for the Training Set
- Not applicable. This submission is for a physical medical device (knee prosthesis), not an AI algorithm that requires a "training set."
9. How the Ground Truth for the Training Set Was Established
- Not applicable. As a training set is not relevant for this type of device submission.
Summary of Acceptance Criteria and Evidence from the Document:
The MILESTONE Knee System demonstrates meeting what could be interpreted as "acceptance criteria" by establishing substantial equivalence to existing, legally marketed predicate devices. The key argument is that the MKS components employ identical materials, geometry, and design features as corresponding components of the Consensus Knee System (CKS). Therefore, the non-clinical bench testing and analyses previously conducted for the CKS components are considered sufficient to validate the safety and effectiveness of the MKS. No new clinical or non-clinical testing unique to the MKS components was deemed necessary because of this identity with the predicate.
§ 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.