(100 days)
Joint replacement is indicated for patients suffering from disability due to:
- degenerative, post-traumatic or rheumatoid arthritis; .
- avascular necrosis of the femoral condyle; .
- post-traumatic loss of joint configuration, particularly when there is patellofemoral erosion, . dysfunction or prior patellectomy;
- moderate valgus, varus or flexion deformities; .
- treatment of fractures that are unmanageable using other techniques. .
The patient's joint must be anatomically and structurally suited to receive the selected implant(s).
This device may also be indicated in the salvage of previously failed surgical attempts. This system is to be used for cemented applications
The Exprt Revision Knee (ERK) is a tri-compartmental posterior stabilized knee for cemented applications. The system is comprised of three primary components: Femur, Tibial Insert, and Tibial Baseplate. The system is intended to treat patients who are candidates for revision total knee arthroplasty or difficult primary arthroplasty where bone loss may be substantial and the collateral ligaments may be compromised. The design of the knee system is a total condylar design, increasing sagittal conformity and stability. The post and cam of the posterior stabilized design are crucial to inducing femoral rollback and providing resistance to tibial subluxation, substituting the function of the absent PCL. The tibial post, in combination with the femoral cam, provides for greater patient flexion by forcing the femur posteriorly on the tibia.
Here's a breakdown of the acceptance criteria and the study information for the "Exprt Revision Knee" device, as extracted from the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria | Reported Device Performance |
|---|---|
| Not explicitly stated as acceptance criteria in terms of specific thresholds for the revision knee device itself. The primary criterion for FDA clearance in this document is demonstrating substantial equivalence to predicate devices. | Mechanical testing demonstrated substantial equivalence to predicate devices in the following aspects: |
- Static contact area/contact stress testing
- Static testing in anterior-posterior draw
- Static testing in rotary laxity
- Patella subluxation evaluation |
Note: The document does not provide specific numerical acceptance criteria or performance metrics (e.g., minimum load bearing capacity, maximum wear rate) for the device. Instead, the focus is on comparability to existing, cleared devices.
2. Sample Size Used for the Test Set and Data Provenance
No test set was used for clinical evaluation. The document explicitly states "Clinical Testing: None provided." The evaluation of the device for substantial equivalence relied solely on non-clinical (mechanical) testing.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
Not applicable, as no clinical testing with a test set involving human data was performed.
4. Adjudication Method for the Test Set
Not applicable, as no clinical testing with a test set involving human data was performed.
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
Not applicable. This device is a revision knee implant, not an AI-powered diagnostic or assistive tool for human readers. No MRMC study was conducted.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
Not applicable. This device is a physical knee implant, not an algorithm.
7. The Type of Ground Truth Used (expert consensus, pathology, outcomes data, etc.)
For the non-clinical mechanical testing, the "ground truth" or reference for evaluating substantial equivalence was the performance of predicate devices. The specific types of measurements (e.g., force, displacement, stress) during the mechanical tests served as the data points compared against the predicate devices.
8. The Sample Size for the Training Set
Not applicable. This device is a physical knee implant, not a machine learning algorithm that requires a training set.
9. How the Ground Truth for the Training Set Was Established
Not applicable.
Summary of the Study that Proves the Device Meets Acceptance Criteria:
The "Exprt Revision Knee" device's acceptance was based on non-clinical mechanical testing demonstrating its substantial equivalence to legally marketed predicate devices.
- Study Design: The study involved a series of mechanical tests designed to evaluate the physical performance and characteristics of the Exprt Revision Knee.
- Tests Performed:
- Static contact area/contact stress testing
- Static testing in anterior-posterior draw
- Static testing in rotary laxity
- Patella subluxation evaluation
- Acceptance Criteria/Outcome: The device was deemed to have met the acceptance criteria because "All testing has determined that the device is substantially equivalent to the predicate devices." The specific quantitative metrics and thresholds for this equivalence are not detailed in the summary but were presumably part of the full 510(k) submission.
- Absence of Clinical Data: The submission explicitly states "Clinical Testing: None provided," indicating that FDA clearance was granted based solely on the non-clinical mechanical testing and comparison to existing predicate devices.
§ 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.