(52 days)
- Components with CSTi porous coating are indicated for uncemented or cemented use in skeletally mature individuals with intact medial and lateral ligaments undergoing primary surgery for rehabilitating knees damaged as a result of Noninflammatory Degenerative Joint Disease (NIDJD) or Inflammatory Joint Disease (IJD).
- Components without CST porous coating are indicated for cemented use in skeletally mature individuals with intact medial and lateral collateral ligaments with conditions of Noninflammatory Degenerative Joint Disease (NIDJD) or Inflammatory Joint Disease (IJD), correctable varus-valgus deformity and moderate flexion contracture, or failed previous surgery where pain, deformity or dysfunction persists.
- The N-K Flex femoral provides increased flexion capability for patients who have both the flexibility and desire to increase their flexion range. When used with N-K Flex articular surfaces, it is designed for use when load bearing ROM is expected to be less than or equal to 155 degrees.
The Gender Solutions Natural-Knee Flex System is a semiconstrained, nonlinked condylar knee prosthesis that is designed to have a maximum active flexion of 155 degrees. The system includes GSM and GSF femoral components; these designations indicate that the design of the femoral components has been modified to address specific anatomical features of the distal femur that can be seen in patients of either gender, but are more typical of male and female patients, respectively.
Components with CSTi porous coating are indicated for uncemented or cemented use in skeletally mature individuals with intact medial and lateral collateral ligaments undergoing primary surgery for rehabilitating knees damaged as a result of Noninflammatory Degenerative Joint Disease (NIDJD) or Inflammatory Joint Disease (IJD).
Components without CSTi porous coating are indicated for cemented use in skeletally mature individuals with intact medial and lateral collateral ligaments with conditions of Noninflammatory Degenerative Joint Disease (NIDJD) or Inflammatory Joint Disease (IJD), correctable varus-valgus deformity and moderate flexion contracture, or failed previous surgery where pain, deformity or dysfunction persists.
The N-K Flex femoral provides increased flexion capability for patients who have both the flexibility and desire to increase their flexion range. When used with N-K Flex articular surfaces, it is designed for use when load bearing ROM is expected to be less than or equal to 155 degrees.
Except for minor geometrical and material modifications, the proposed components are identical to the predicate devices.
The provided document describes the Zimmer Gender Solutions™ Natural-Knee® Flex System, which is a total knee prosthesis. It details the device's description, indications for use, and a comparison to predicate devices. However, it explicitly states:
"Clinical data and conclusions were not needed for this device."
This type of submission (510(k)) relies on demonstrating substantial equivalence to a legally marketed predicate device rather than conducting new clinical studies to prove safety and effectiveness from scratch. Therefore, the information you've requested regarding acceptance criteria based on a clinical study, sample sizes, expert ground truth, adjudication methods, MRMC studies, or standalone algorithm performance does not exist within this document for this specific device.
The document primarily focuses on:
- Substantial Equivalence: The approval is based on the device being substantially equivalent to the NexGen® Complete Knee Solution Knee Gender Solutions Female (GSF) Femoral Components and Natural-Knee II System with Cancellous-Structured Titanium™ (CSTi™) Porous Coating.
- Non-Clinical Performance: "Mechanical testing and Finite Element Analysis of the proposed device demonstrates that it is substantially equivalent to the predicate devices." This likely covers aspects like strength, wear, and other physical properties.
Summary of Requested Information (Based on the Provided Document):
Since no clinical study was needed or performed for this device's 510(k) clearance, most of the requested fields cannot be filled.
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Table of acceptance criteria and the reported device performance:
- Acceptance Criteria: Not explicitly stated as performance metrics from a clinical study for this device, but implied to be "substantially equivalent" to predicate devices based on non-clinical testing.
- Reported Device Performance: Not reported from a clinical study for this device. Mechanical testing and Finite Element Analysis indicated substantial equivalence to predicate devices.
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Sample sized used for the test set and the data provenance: Not applicable as no clinical test set was used for this 510(k) submission.
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Number of experts used to establish the ground truth for the test set and the qualifications of those experts: Not applicable as no clinical test set was used for this 510(k) submission.
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Adjudication method for the test set: Not applicable as no clinical test set was used for this 510(k) submission.
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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 physical knee prosthesis, not an AI-assisted diagnostic tool for human readers.
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If a standalone (i.e. algorithm only without human-in-the-loop performance) was done: Not applicable. This device is a physical knee prosthesis, not an algorithm.
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The type of ground truth used (expert consensus, pathology, outcomes data, etc): Not applicable as no clinical ground truth was established for this device's 510(k) submission. The "ground truth" for clearance was the established safety and effectiveness of the predicate devices.
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The sample size for the training set: Not applicable as no training set (in the context of machine learning or clinical trials) was used for this 510(k) submission.
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How the ground truth for the training set was established: Not applicable as no training set was used for this 510(k) submission.
In essence, the "study that proves the device meets the acceptance criteria" in this case is the non-clinical mechanical testing and Finite Element Analysis that demonstrated the device's substantial equivalence to already cleared predicate devices. The acceptance criteria were met by showing that the new device performs similarly in terms of its mechanical properties and design to devices already established as safe and effective.
§ 888.3565 Knee joint patellofemorotibial metal/polymer porous-coated uncemented prosthesis.
(a)
Identification. A knee joint patellofemorotibial metal/polymer porous-coated uncemented 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 is designed to achieve biological fixation to bone without the use of bone cement. This identification includes fixed-bearing knee prostheses where the ultra high molecular weight polyethylene tibial bearing is rigidly secured to the metal tibial base plate.(b)
Classification. Class II (special controls). The special control is FDA's guidance: “Class II Special Controls Guidance Document: Knee Joint Patellofemorotibial and Femorotibial Metal/Polymer Porous-Coated Uncemented Prostheses; Guidance for Industry and FDA.” See § 888.1 for the availability of this guidance.