(30 days)
The ConforMIS Unicondylar Knee Repair System (iUni KRS) with curved tibial insert is intended for use in one compartment of the osteoarthritic knee to replace the damaged area of the articular surface in patients with evidence of adequate healthy bone sufficient for support of the implanted components.
Candidates for unicondylar knee repair include those with:
- joint impairment due to osteoarthritis or traumatic arthritis of the knee
- previous femoral condyle or tibial plateau fracture, creating loss of function and
- valgus or varus deformity of the knee.
This implant is intended for cemented use only.
The ConforMlS Unicondvlar Knee Repair System (iUni KRS) with curved tibial insert is composed of individually packaged femoral and tibial components. The femoral component is manufactured of cobalt chromium molybdenum (CoCrMo) alloy. The tibial implant is offered in two configurations; an all polymer (UHMWPE) configuration and metal-backed configuration. The Metal-backed Tibial implant consists of two components: a CoCrMo tibial tray and an ultra-high molecular weight polyethylene (UHMWPE) tibial trav insert.
The outline bone contacting and articular surfaces of the femoral component as well as the outline of both tibial components are personalized to match the patient's femoral and tibial anatomy. The design of the implant is derived from an analysis, using proprietary software, of images obtained by MRI or CT Scan. In this manner, the implant is personalized on its bone contact and articular surfaces to match a patient's anatomy, thus becoming patient specific.
The provided text is a 510(k) summary for the ConforMIS® Unicondylar Knee Repair System (iUni® KRS). This document focuses on demonstrating substantial equivalence to previously cleared devices rather than establishing specific performance acceptance criteria and proving them through a new study with a statistical design. Therefore, much of the requested information (like specific acceptance criteria values, sample sizes for test and training sets, expert qualifications, and detailed study types) is not present in this regulatory document.
However, I can extract information related to the device and its regulatory submission.
Device Description and Purpose:
The ConforMIS Unicondylar Knee Repair System (iUni KRS) with a curved tibial insert is designed to replace damaged articular surfaces in one compartment of an osteoarthritic knee. The device is personalized to the patient's anatomy using proprietary software analysis of MRI or CT scan images. It comprises femoral and tibial components. The femoral component is CoCrMo alloy. The tibial implant comes in two configurations: all UHMWPE or metal-backed (CoCrMo tray with UHMWPE insert).
Substantial Equivalence Claims:
The submission asserts substantial equivalence to existing, legally marketed iUni Unicondylar Knee Repair Systems (reference K043570, K063432, K072368, and K072586).
I. Table of Acceptance Criteria and Reported Device Performance:
This document does not contain a table of explicit acceptance criteria with numerical targets or specific performance metrics derived from a new study designed to prove these criteria. Instead, it relies on a determination of substantial equivalence to predicate devices. The "performance" mentioned is in the context of safety.
| Feature/Criterion (Implied) | Reported Device Performance |
|---|---|
| Safety | Non-clinical laboratory testing was performed demonstrating that the device is safe. |
| Material Composition | Femoral: Cobalt Chromium Molybdenum (CoCrMo) alloy. Tibial: Ultra-high molecular weight polyethylene (UHMWPE) or CoCrMo tibial tray with UHMWPE insert. (Matches predicate material usage). |
| Intended Use | For use in one compartment of the osteoarthritic knee to replace damaged articular surface in patients with adequate healthy bone. Candidates: joint impairment due to osteoarthritis/traumatic arthritis, previous femoral condyle/tibial plateau fracture, valgus/varus deformity. (Matches predicate intended use). |
| Personalization Method | Design derived from analysis of MRI or CT images using proprietary software to match patient's femoral and tibial anatomy. (This is a key characteristic of the iUni system, indicating consistency with previous iUni clearances). |
| Cemented Use | Intended for cemented use only. (Consistent with predicate). |
II. Sample Size Used for the Test Set and Data Provenance:
The document states: "Non-clinical laboratory testing was performed demonstrating that the device is safe and can be considered substantially equivalent to the predicate device for the proposed intended use."
- Sample Size for Test Set: Not specified. As this is a 510(k) summary for substantial equivalence, it likely refers to various materials, mechanical, and perhaps wear testing, rather than a clinical "test set" in the sense of patient data.
- Data Provenance: Not specified, but "non-clinical laboratory testing" generally implies in-vitro or bench testing, not human subject data.
III. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications:
Not applicable. The submission is based on non-clinical laboratory testing and comparison to predicate devices, not on a study requiring expert-established ground truth on a test set (e.g., for diagnostic accuracy).
IV. Adjudication Method for the Test Set:
Not applicable. No clinical test set with adjudicated ground truth is described.
V. If a multi-reader multi-case (MRMC) comparative effectiveness study was done:
No, an MRMC comparative effectiveness study is not mentioned. This device is a surgical implant, not an imaging AI diagnostic tool, so an MRMC study would be out of scope for this type of submission.
VI. If a standalone (i.e., algorithm only without human-in-the-loop performance) was done:
Not applicable in the context of a medical device implant. The "proprietary software" is used to design the implant, which is then surgically implanted by a human. There is no "algorithm only" performance metric in this context.
VII. The type of ground truth used:
For the non-clinical testing, the "ground truth" would be established engineering standards, material properties, biomechanical test methods, and potentially wear simulation protocols that are considered acceptable for demonstrating the safety and performance of orthopedic implants.
VIII. The sample size for the training set:
Not applicable. This is not a machine learning submission in the sense of training a diagnostic algorithm on a dataset. The "proprietary software" analyzes individual patient images to design personalized implants, but there's no mention of a "training set" for the software in the context of this 510(k). The clinical data comes from predicate devices.
IX. How the ground truth for the training set was established:
Not applicable for the reasons stated above.
§ 888.3520 Knee joint femorotibial metal/polymer non-constrained cemented prosthesis.
(a)
Identification. A knee joint femorotibial metal/polymer non-constrained cemented prosthesis is a device intended to be implanted to replace part of a knee joint. The device limits minimally (less than normal anatomic constraints) translation in one or more planes. It has no linkage across-the-joint. This generic type of device includes prostheses that have a femoral condylar resurfacing component or components made of alloys, such as cobalt-chromium-molybdenum, and a tibial component or components made of ultra-high molecular weight polyethylene and are intended for use with bone cement (§ 888.3027).(b)
Classification. Class II.