(268 days)
Painful, disabling joint disease of the knee resulting from: degenerative arthritis, rheumatic arthritis.
Post-traumatic loss of knee joint configuration and function.
Moderate varus, valgus, or flexion deformity in which the ligamentous structures can be returned to adequate function and stability.
Revision of previous unsuccessful uni-knee replacement or other procedure.
The system components are intended for cemented use only.
The XN Knee Prosthesis System is a knee implant developed by Beijing Chunlizhengda Medical Instruments Co. Ltd. The subject system includes femoral condyle, tibial tray, tibial insert and patella. The fixation method of the system is bone cement fixation. It is mainly used in total knee replacement to repair the diseased or injured knee joint, improve the range of motion of the knee joint and reduce the pain of the patient. The XN Knee Prosthesis System is a Posterior Stabilized (PS) total knee replacement system.
This document is a 510(k) clearance letter from the FDA for a medical device (XN Knee Prosthesis System). It confirms that the device is substantially equivalent to a previously marketed predicate device. For devices seeking 510(k) clearance based on substantial equivalence, the "study that proves the device meets the acceptance criteria" is typically a series of non-clinical performance tests and engineering analyses that demonstrate the new device performs as safely and effectively as a legally marketed predicate device.
It's important to understand that a 510(k) submission generally does not involve large-scale clinical trials or studies akin to those for drug approvals. Instead, the focus is on demonstrating equivalence through comparison to an existing device, primarily via bench testing, material characterization, and engineering simulations.
Based on the provided text, here's a breakdown of the "acceptance criteria" and the "study" (non-clinical testing) that proves the device meets them:
1. Table of Acceptance Criteria and Reported Device Performance
The document states: "Testing and engineering analyses showed that the subject components met the pre-determined acceptance criteria identified in the Bench Testing Summary, demonstrating that the subject components are substantially equivalent compared to the predicate components."
While explicit numerical acceptance criteria for each test are not detailed in this summary (they would be in the full submission, which is not provided), the document lists the types of performance tests conducted. The "reported device performance" is implicitly that the device passed these tests and was found substantially equivalent.
| Acceptance Criterion (Implied) | Reported Device Performance |
|---|---|
| Sufficient Component Interlocking Strength | Met acceptance criteria (demonstrated acceptable mechanical performance) |
| Acceptable Fatigue Performance Under High Flexion | Met acceptance criteria (demonstrated acceptable mechanical performance) |
| Acceptable Tibial Insert Constraint | Met acceptance criteria (demonstrated acceptable mechanical performance) |
| Acceptable Surface Roughness | Met acceptance criteria (demonstrated acceptable mechanical performance) |
| Acceptable Patella Contact Pressure | Met acceptance criteria (demonstrated acceptable mechanical performance) |
| Acceptable Patella Constraint | Met acceptance criteria (demonstrated acceptable mechanical performance) |
| Acceptable Static Contact Stress | Met acceptance criteria (demonstrated acceptable mechanical performance) |
| Acceptable Dynamic Fatigue | Met acceptance criteria (demonstrated acceptable mechanical performance) |
| Acceptable Wear Performance | Met acceptance criteria (demonstrated acceptable mechanical performance) |
| Acceptable UHMWPE Characterization | Met acceptance criteria (demonstrated acceptable mechanical performance) |
| Mechanical performance for intended use | Acceptable mechanical performance demonstrated for intended use |
| Equivalence to predicate device in intended use, materials, and fundamental technology | Substantially equivalent to predicate device |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: The document does not specify exact sample sizes for each test. For non-clinical bench testing, sample sizes are typically determined by relevant ASTM or ISO standards for testing medical devices (e.g., often N=3 or N=5 for certain mechanical tests, depending on variability and statistical power needs). This information would be in the detailed test protocols within the full 510(k) submission.
- Data Provenance: The testing was non-clinical (bench testing and engineering analysis) and performed by the manufacturer, Beijing Chunlizhengda Medical Instruments Co. LTD. The location of primary testing would likely be China, where the manufacturer is based. It is retrospective in the sense that the data was collected and analyzed for this specific submission.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications of those Experts
- This question is not applicable in the context of a 510(k) non-clinical bench testing submission. "Ground truth" for these tests is established by engineering specifications, accepted industry standards (e.g., ISO, ASTM), and comparison to the predicate device's known performance characteristics. There are no human "experts" establishing a "ground truth" for each individual test sample in the way a clinical trial might use radiologists for image interpretation. The expertise lies in the engineers performing and reviewing the tests, and the FDA reviewers assessing the data against regulatory standards.
4. Adjudication Method for the Test Set
- This question is not applicable as the "test set" consists of physical devices undergoing mechanical and material property testing, not subjective human assessments that would require adjudication.
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
- This question is not applicable. The XN Knee Prosthesis System is a mechanical orthopedic implant, not an AI/software device used for diagnostic imaging or a human-in-the-loop system. The clearance is based on substantial equivalence to a predicate device through non-clinical performance data.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
- This question is not applicable. As stated, this is a mechanical implant, not an algorithm.
7. The Type of Ground Truth Used
- For this device, the "ground truth" for substantial equivalence is primarily established through:
- Engineering specifications and design requirements: The device must meet predefined mechanical and material properties that ensure safety and efficacy.
- Comparison to the predicate device: The new device's performance is measured against the known and accepted performance of the legally marketed predicate device (Stryker Triathlon® Total Knee System). The standard is "substantially equivalent," meaning it performs as safely and effectively as the predicate.
- Relevant industry standards (e.g., ISO, ASTM): These standards often define the specific tests and acceptable ranges for performance for orthopedic implants.
8. The Sample Size for the Training Set
- This question is not applicable. This is a mechanical device, not a machine learning or AI model that requires a "training set" of data.
9. How the Ground Truth for the Training Set Was Established
- This question is not applicable for the same reason as point 8.
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Image /page/0/Picture/0 description: The image shows the logo of the U.S. Food and Drug Administration (FDA). On the left is the Department of Health & Human Services logo. To the right of that is the FDA logo, with the letters "FDA" in a blue square. To the right of the blue square is the text "U.S. FOOD & DRUG ADMINISTRATION" in blue.
June 28, 2024
Beijing Chunlizhengda Medical Instruments Co. LTD % Dave Mcgurl VP, Orthopedic Regulatory Affairs Mcra, LLC 803 7th St NW. Floor 3 Washington, District of Columbia 20001
Re: K232175
Trade/Device Name: XN Knee Prosthesis System Regulation Number: 21 CFR 888.3560 Regulation Name: Knee Joint Patellofemorotibial Polymer Semi-Constrained Cemented Prosthesis Regulatory Class: Class II Product Code: JWH
Dear Dave Mcgurl:
The Food and Drug Administration (FDA) is sending this letter to notify you of an administrative change for your device cleared on April 14, 2024. Specifically, FDA is updating this SE Letter because FDA inadvertently indicated that the SE determination also included review and clearance of a predetermined change control plan (PCCP). However, your 510(k) submission did not include a PCCP, so FDA is providing this administrative correction. Please see the attached revised clearance letter.
Please note that the 510(k) submission was not re-reviewed. For questions regarding this letter please contact Lixin Liu, OHT6: Office of Orthopedic Devices, 301-796-3480, Lixin.Liu@fda.hhs.gov.
Sincerely.
Lixin Liu -S
Lixin Liu, Ph.D. Assistant Director DHT6A: Division of Joint Arthroplasty Devices OHT6: Office of Orthopedic Devices Office of Product Evaluation and Quality Center for Devices and Radiological Health
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Image /page/1/Picture/0 description: The image shows the logo of the U.S. Food and Drug Administration (FDA). The logo consists of two parts: the Department of Health & Human Services logo on the left and the FDA text logo on the right. The FDA text logo is in blue and includes the acronym "FDA" followed by "U.S. FOOD & DRUG ADMINISTRATION" in a stacked format.
June 28, 2024
Beijing Chunlizhengda Medical Instruments Co. LTD % Dave Mcgurl VP. Orthopedic Regulatory Affairs MCRA, LLC 803 7th St NW, Floor 3 Washington, District of Columbia 20001
Re: K232175
Trade/Device Name: XN Knee Prosthesis System Regulation Number: 21 CFR 888.3560 Regulation Name: Knee Joint Patellofemorotibial Polymer Semi-Constrained Cemented Prosthesis Regulatory Class: Class II Product Code: JWH Dated: July 21, 2023 Received: July 21, 2023
Dear Dave Mcgurl:
The Food and Drug Administration (FDA) is sending this letter to notify you of an administrative change for your device cleared on April 14, 2024.
We have reviewed your section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food. Drug, and Cosmetic Act (the Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. Although this letter refers to your product as a device, please be aware that some cleared products may instead be combination products. The 510(k) Premarket Notification Database available at https://www.accessdata.fda.gov/scripts/cdrb/cfdocs/cfpmn/pmn.cfm identifies combination product submissions. The general controls provisions of the Act include requirements for annual registration. listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.
If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of
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Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.
Additional information about changes that may require a new premarket notification are provided in the FDA guidance documents entitled "Deciding When to Submit a 510(k) for a Change to an Existing Device" (https://www.fda.gov/media/99812/download) and "Deciding When to Submit a 510(k) for a Software Change to an Existing Device" (https://www.fda.gov/media/99785/download).
Your device is also subject to, among other requirements, the Quality System (QS) regulation (21 CFR Part 820), which includes, but is not limited to, 21 CFR 820.30, Design controls; 21 CFR 820.90, Nonconforming product; and 21 CFR 820.100, Corrective and preventive action. Please note that regardless of whether a change requires premarket review, the QS regulation requires device manufacturers to review and approve changes to device design and production (21 CFR 820.70) and 21 CFR 820.70) and document changes and approvals in the device master record (21 CFR 820.181).
Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801); medical device reporting of medical device-related adverse events) (21 CFR Part 803) for devices or postmarketing safety reporting (21 CFR Part 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safety-reportingcombination-products); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820) for devices or current good manufacturing practices (21 CFR Part 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR Parts 1000-1050.
Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to https://www.fda.gov/medical-devices/medical-device-safety/medical-device-reportingmdr-how-report-medical-device-problems.
For comprehensive regulatory information about mediation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medicaldevices/device-advice-comprehensive-regulatory-assistance) and CDRH Learn (https://www.fda.gov/training-and-continuing-education/cdrh-learn). Additionally, you may contact the Division of Industry and Consumer Education (DICE) to ask a question about a specific regulatory topic. See the DICE website (https://www.fda.gov/medical-device-advice-comprehensive-regulatoryassistance/contact-us-division-industry-and-consumer-education-dice) for more information or contact DICE by email (DICE@fda.hhs.gov) or phone (1-800-638-2041 or 301-796-7100).
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Sincerely,
Lixin Liu -S
Lixin Liu, PhD Assistant Director DHT6A: Division of Joint Arthroplasty Devices OHT6: Office of Orthopedic Devices Office of Product Evaluation and Quality Center for Devices and Radiological Health
Enclosure
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Indications for Use
510(k) Number (if known) K232175
Device Name XN Knee Prosthesis System
Indications for Use (Describe)
Painful, disabling joint disease of the knee resulting from: degenerative arthritis, rheumatic arthritis.
Post-traumatic loss of knee joint configuration and function.
Moderate varus, valgus, or flexion deformity in which the ligamentous structures can be returned to adequate function and stability.
Revision of previous unsuccessful uni-knee replacement or other procedure.
The system components are intended for cemented use only.
| Type of Use (Select one or both, as applicable) |
|---|
| ------------------------------------------------- |
Prescription Use (Part 21 CFR 801 Subpart D)
Over-The-Counter Use (21 CFR 801 Subpart C)
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510(k) Summary
| Device Trade Name: | XN Knee Prosthesis System |
|---|---|
| Manufacturer: | Beijing Chunlizhengda Medical Instruments Co. LTDNo. 10 Xinmi West 2nd Road, Southern District of TongzhouEconomic Development Zone, Tongzho Beijing 101112 China |
| Contact: | Mr. Xie FengbaoDirector, Research and DevelopmentBeijing Chunlizhengda Medical Instruments Co. LTDNo. 10 Xinmi West 2nd Road, Southern District of TongzhouEconomic Development Zone, Tongzho Beijing 101112 ChinaPhone: +1 861080561677xiefengbao@clzd.com |
| Prepared by: | Mr. Dave McGurlVP, Regulatory Affairs - OrthopedicsMCRA LLC803 7th Street NW, Floor 3Washington, DC 20001Office: 202.552.5797Cell: 215.275.4786dmcgurl@mcra.com |
| Date Prepared: | April 12, 2024 |
| Classification: | 21 CFR 888.3560, Knee joint patellofemorotibiapolymer/metal/polymer semi-constrained cemented prosthesis. |
| Common Name: | Total Knee Replacement Prosthesis |
| Class: | II |
| Product Code: | JWH |
| Primary Predicate: | Stryker Triathlon® Total Knee System (K053514) |
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Reference Devices: Klassic Knee System - Klassic Knee PS-Post Femur; Klassic Knee Tibial Insert, PS-Post, Std Poly; Klassic Knee Tibial Insert, PS-Post, E-Link Poly (K183596)
Klassic Knee System (K112906)
Madison Total Knee System (K192084)
Indications for Use:
- 0 Painful, disabling joint disease of the knee resulting from: degenerative arthritis, rheumatoid arthritis or post-traumatic arthritis.
- Post-traumatic loss of knee joint configuration and function. 0
- Moderate varus, valgus, or flexion deformity in which the ligamentous structures can be ● returned to adequate function and stability.
- Revision of previous unsuccessful uni-knee replacement or other procedure.
The system components are intended for cemented use only.
Device Description:
The XN Knee Prosthesis System is a knee implant developed by Beijing Chunlizhengda Medical Instruments Co. Ltd. The subject system includes femoral condyle, tibial tray, tibial insert and patella. The fixation method of the system is bone cement fixation. It is mainly used in total knee replacement to repair the diseased or injured knee joint, improve the range of motion of the knee joint and reduce the pain of the patient. The XN Knee Prosthesis System is a Posterior Stabilized (PS) total knee replacement system.
Performance Testing:
Engineering simulation, rationales and testing of the worst-case constructs demonstrates acceptable mechanical performance for the intended use. The complete battery of non-clinical testing, including component interlocking strength, range of motion, wear rationale, and contact area/stress testing, were conducted.
Non-clinical testing and engineering analysis conducted to demonstrate substantial equivalence was as follows:
- o Component Interlocking Strength
- 0 Fatigue Under High Flexion
- Tibial Insert Constraint Test ●
- Surface Roughness Test ●
- Patella Contact Pressure Test ●
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- o Patella Constraint Test
- Static Contact Stress o
- Dynamic Fatigue ●
- Fatigue Performance ●
- Wear Evaluation ●
- UHMWPE Characterization ●
Substantial Equivalence:
The ChunLi XN Knee Prosthesis System is substantially equivalent to the legally marketed predicate, Triathlon® Total Knee System marketed by Stryker Orthopaedics (K053514) with respect to intended use, materials, and fundamental technology.
The subject and predicate systems are both indicated for use in total knee replacement for pathologies, including degenerative joint diseases, post-traumatic loss of configuration and function, deformities and revision procedures. Both systems can be used for posterior stabilized (PS) total knee replacement.
Technological Comparison:
The subject and predicate system designs consist of the same components in left and right configurations in various sizes to accommodate varying patient anatomy, including femoral condyles, tibial trays, tibial inserts, and dome-shaped patella components. The components have similar design features, where the construct replaces and repairs the knee joint and provides a fixed-bearing connection between the tibial component and the PE-insert. The components are provided in a similar size range and the component fixation method is equivalent between the subject and predicate systems: cemented fixation. The subject and predicate are not identical with respect to design, however, both systems are highly similar in that they are cemented fixation, posterior stabilized (PS) for cemented total knee replacement. Both systems include the same component types and materials.
Conclusions:
Testing and engineering analyses showed that the subject components met the pre-determined acceptance criteria identified in the Bench Testing Summary, demonstrating that the subject components are substantially equivalent compared to the predicate components.
§ 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.