K Number
K231975
Manufacturer
Date Cleared
2023-11-21

(141 days)

Product Code
Regulation Number
888.3560
Panel
OR
Reference & Predicate Devices
Predicate For
N/A
AI/MLSaMDIVD (In Vitro Diagnostic)TherapeuticDiagnosticis PCCP AuthorizedThirdpartyExpeditedreview
Intended Use

The PNK Total Knee System is indicated in knee arthroplasty for reduction or relief of pain and/or improved knee function in skeletally mature patients with severe knee pain and disability due to rheumatoid arthritis, primary and secondary traumatic arthritis, avascular necrosis of the femoral condyle, posttraumatic loss of joint configuration. Moderate valgus, varus, or flexion deformity in which the ligamentous structures can be returned to adequate function and stability. This device may also be indicated in correction of unsuccessful osteotomy. arthrodesis, or failure of previous arthroplasty procedure. The PNK Total Knee System is designed for cemented use only.

Device Description

The PNK Total Knee System is of the fixed bearing type with a posterior stabilized design (PS) and cruciate retained design (CR) configurations. It is a Patellofemorotibial, polymer/metal/polymer. semi-constrained, cemented knee prosthesis that consists of a femoral component, tibial tray component, tibial insert component, and patellar component.

The PS version has tibial inserts with posts and femoral components with cams that interact with the posts to help stabilize the knee after the posterior cruciate ligament is removed. The CR version has tibial inserts and femoral components without posts or cams, allowing the posterior cruciate ligament to be "retained" and provide stability to the knee joint.

Femoral Component is fabricated from cast cobalt-chromium-molybdenum alloy, and is intended for cemented application to replace the articulating surface of the distal femur. Total Knee Femoral Component is available in right and left configurations, and eight proportional sizes (sizes 1-8) to accommodate differences in patient anatomy.

The tibial Tray components (tibial baseplate) are made from Ti-6Al-4V titanium alloy, and tibial trays are available in 8 sizes (A-H,) to allow optimal cortical bone coverage of the prepared tibia. The unique stem Diameter for the all 8 sizes.

Tibial Insert components are made from Highly Cross-linked UHMWPE (HXLPE) and are available in 12 proportional sizes that match to corresponding 2 tibial tray components and two femoral components.

Patellar components are made from Highly Cross-linked UHMWPE (HXLPE). The articulating surface of the patellar component is axisymmetric (round) with a flattened sombrero shape and the patella components are available in 6 diameters.

All implant components are provided sterile.

AI/ML Overview

The provided text describes the 510(k) clearance for a medical device called the "PNK Total Knee System." It explicitly states that clinical data were not needed to support the safety and effectiveness of the subject device (PNK Total Knee System).

Therefore, the submission does not include information about acceptance criteria for device performance based on a study of its diagnostic accuracy or clinical outcomes, a test set, expert involvement, adjudication, or human-in-the-loop studies. The focus is on demonstrating substantial equivalence to predicate devices through non-clinical testing.

Here's a breakdown based on the information provided and what is not present:

1. Table of Acceptance Criteria and Reported Device Performance:

Acceptance Criteria CategoryAcceptance Criteria (Not explicitly stated as numerical targets in the text, but implied by regulatory standards and testing protocols)Reported Device Performance (Summary of non-clinical testing results)
Mechanical Performance- Tibial tray fatigue resistance (Implied to meet relevant ISO/ASTM standards)
  • Constraint (Implied to be within acceptable limits for semi-constrained knee prostheses)
  • Contact analysis (Implied acceptable stress distribution)
  • Insert disassembly resistance (Implied to prevent unintended disassembly)
  • Tibial insert post shear strength (Implied to withstand shear forces)
  • Dislocation/jump distance and range of motion (Implied to be comparable to predicate devices and acceptable for function) | "All necessary testing has been performed for the worst-case PNK Total Knee system components to assure substantial equivalence to the predicate device and demonstrate the device performs as intended. All testing was performed on test units representative of finished devices."
    Specific tests performed: tibial tray fatigue testing, constraint test, contact analysis, Insert disassembly test, tibial insert post shear test, and dislocation/jump distance and range of motion. |
    | Material Performance | - Cross-linked UHMWPE mechanical and chemical properties (ASTM F648 and ASTM F2565 requirements) | "Cross-linked UHMWPE testing was done as per ASTM F648 and ASTM F2565 requirements." |
    | Sterilization | - Gamma Sterilization Validation (ISO 11137)
  • Ethylene Oxide Sterilization Validation (ISO 11135)
  • Residuals testing (ISO 10993-7 & ISO 10993-10) | "Gamma Sterilization Validation as per ISO 11137 & Ethylene Oxide Sterilization Validation per ISO 11135 and residuals testing as per ISO 10993-7 & ISO 10993-10 were done." |
    | Biocompatibility | - Biocompatibility (ISO 10993-1) | "Biocompatibility testing has been done as per ISO 10993-1." |
    | Bacterial Endotoxin | - Bacterial Endotoxin (ANSI/AAMI ST72:2011) | "Bacterial Endotoxin Testing (BET) conducted as specified in ANSI/AAMI ST72:2011." |

2. Sample size used for the test set and the data provenance:

  • Not applicable. The submission states, "Clinical data were not needed to support the safety and effectiveness of the subject device." The testing described is non-clinical, involving test units of the device rather than human subjects or patient data.

3. 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" in the context of diagnostic performance or clinical outcomes was used, no experts were involved in establishing ground truth for such a set.

4. Adjudication method (e.g. 2+1, 3+1, none) for the test set:

  • Not applicable. No clinical test set requiring adjudication was utilized.

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 knee joint prosthesis, not an AI-assisted diagnostic or imaging device. No MRMC study was conducted.

6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:

  • Not applicable. This is a physical medical implant, not a software algorithm.

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.):

  • Not applicable. For the non-clinical testing, "ground truth" refers to established engineering and material science standards and benchmarks (e.g., specific forces, deflections, material properties) derived from recognized standards like ASTM and ISO, and performance data from predicate devices.

8. The sample size for the training set:

  • Not applicable. As no AI or machine learning component is described, there is no "training set."

9. How the ground truth for the training set was established:

  • Not applicable. No training set was used.

§ 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.