(169 days)
The Duracon®, P.C.A.® and Kinemax® Plus Tibial Inserts, All Plastic Tibial Components and Patellar Components (proviously cleared in K915512, K923573, K910235, K922048, K932070, K913188, K872735, K871772 and K921640) are intended to be used with Duracon®, P.C.A.® or Kinemax® femoral components, tibial baseplates and patellar components in primary or revision cemented total knee arthroplasty.
This submission includes wear testing data on UHMWPE Knee Components sterilized by the method previously cleared in 510(k) submission K936292. This data is provided to substantiate claims of improved wear due to the processing of the devices. The submission includes Duracon®, P.C.A.® and Kinemax® Plus Tibial Inserts, All Plastic Tibial Components and Patellar Components which are intended to be used with Duracon®, P.C.A.® or Kinemax® Plus femoral components, tibial baseplates and patellar components in primary or revision cemented total knee arthroplasty.
This submission details the wear testing of Howmedica's Duration™ Stabilized UHMWPE Knee Components to substantiate claims of improved wear. The study compares the wear performance of the stabilized UHMWPE against conventionally gamma sterilized UHMWPE in various in vitro wear tests.
Here is an analysis of the provided information:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria (Implicit) | Reported Device Performance |
|---|---|
| Demonstrate a reduction in volumetric wear of Duration™ Stabilized UHMWPE compared to conventionally gamma sterilized UHMWPE in a ring-on-block test. | A block of Duration™ Stabilized UHMWPE showed a 30% reduction in volumetric wear versus conventionally gamma sterilized UHMWPE. (Test duration: over 5 million cycles) |
| Demonstrate a reduction in volumetric wear of Duration™ Stabilized UHMWPE compared to conventionally gamma sterilized UHMWPE in a pin-on-disk test. | A 9mm thick circular disk of Duration™ Stabilized UHMWPE showed a 68% reduction in volumetric wear versus conventionally gamma sterilized UHMWPE. (Test duration: over 4 million cycles) |
| Demonstrate a reduction in volumetric wear of aged Duration™ Stabilized UHMWPE compared to aged conventionally gamma sterilized UHMWPE in a pin-on-disk test. | An aged (23 days heating in air, simulating 7-9 years of aging) 9mm thick circular disk of Duration™ Stabilized UHMWPE showed a 91% reduction in volumetric wear versus aged conventionally gamma sterilized UHMWPE. (Test duration: over 2.5 million cycles) |
Note: The submission does not explicitly state pre-defined acceptance criteria in numerical terms (e.g., "must show at least X% reduction"). Instead, the reported device performance is the claim being substantiated, implying that any measured reduction in wear would be considered a positive outcome. The FDA's substantial equivalence determination suggests acceptance of these claims.
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: The document refers to "a block" and "a 9mm thick circular disk" for the unaged tests, and "a 9 mm thick circular disk" for the aged test, both for the Duration™ Stabilized UHMWPE and the conventionally gamma sterilized UHMWPE for comparison. This phrasing suggests a sample size of one test article for each condition (stabilized vs. conventional, unaged vs. aged) for each type of test. However, wear testing typically involves multiple samples to ensure reproducibility and statistical significance. The limited detail provided here implies either a single sample per comparison or a simplified reporting of the outcome from multiple samples.
- Data Provenance: The tests were conducted as "in vitro tests" in an "independent laboratory test." The country of origin is not specified but is presumably the USA, given the FDA 510(k) submission. The data is prospective in the sense that these were controlled experiments specifically designed to test the wear properties.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
Not applicable. This study involves in vitro mechanical wear testing, not a clinical study or diagnostic device assessment where expert opinion would establish ground truth. The "ground truth" for wear is established by the measured weight loss or volume displacement during the mechanical tests.
4. Adjudication Method for the Test Set
Not applicable. This is an in vitro mechanical test, not a clinical review requiring adjudication. The measurements of wear are objective.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done
No, an MRMC comparative effectiveness study was not done. This study is an in vitro mechanical wear test of materials, not a diagnostic imaging study involving human readers.
6. If a Standalone (Algorithm Only Without Human-in-the-Loop Performance) was done
Yes, in a way. The tests performed are standalone in the sense that they are material property tests performed in a lab setting, independent of human interaction once initiated. There is no "algorithm" in the context of AI, but the measurements of wear are objective outcomes of the material's performance under simulated conditions.
7. The Type of Ground Truth Used
The ground truth used is measured volumetric wear. This is an objective measurement obtained through laboratory testing (reciprocating ring-on-block wear test and reciprocating pin-on-disk wear evaluations) using established scientific methods (weight loss to calculate volume change, or direct volume measurement if applicable).
8. The Sample Size for the Training Set
Not applicable. This study does not involve a "training set" in the context of machine learning or AI algorithms. It is an in vitro study of material properties.
9. How the Ground Truth for the Training Set Was Established
Not applicable, as there is no training set for an AI algorithm in this context.
§ 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.