SK Knee System
Device Facts
| Record ID | K253961 |
|---|---|
| Device Name | SK Knee System |
| Applicant | Just Medical Devices (Tianjin) Co., Ltd. |
| Product Code | JWH · Orthopedic |
| Decision Date | Sep 1, 2026 |
| Decision | SESE |
| Submission Type | Traditional |
| Regulation | 21 CFR 888.3560 |
| Device Class | Class 2 |
| Attributes | Therapeutic |
Indications for Use
The SK Knee System is indicated for cemented use only as a total knee replacement in patients with a painful or disabled knee joint resulting from osteoarthritis, rheumatoid arthritis, post-traumatic arthritis, or a failed previous total knee joint procedure.
Device Story
Total knee replacement system; includes posterior stabilized (PS) and cruciate retaining (CR) femoral components, tibial base plates, modular UHMWPE tibial bearings, and patellar components. Designed for cemented fixation to replace damaged knee joint articulation; intended to increase patient mobility and reduce pain. Surgically implanted by orthopedic surgeons in hospital settings using reusable general and device-specific instruments. System components replace the patellofemorotibial joint; provides semi-constrained articulation. Clinical benefit derived from mechanical restoration of joint function.
Clinical Evidence
No clinical data. Substantial equivalence supported by extensive pre-clinical bench testing including patellofemoral subluxation, contact area/pressure (ISO 21536), tibial tray fatigue (ISO 14879-1), disassembly forces (ASTM F1814), tibio-femoral constraint (ASTM F1223-20), PS post shear testing (ASTM F1814-22), femoral fatigue (ASTM F3210-22e1), range of motion (ISO 21534/21536), wear testing (ISO 14243-1/2), MRI compatibility, biocompatibility (ISO 10993-1), and sterilization/shelf-life validation.
Technological Characteristics
Semi-constrained total knee prosthesis. Materials: Cast Co-Cr-Mo alloy (ISO 5832-4) for femoral/tibial components; UHMWPE (ISO 5834-2) for patellar/tibial bearings. Fixation: Cemented. Design: CR and PS options, asymmetric femoral components, symmetrical tibial base plates. Sterilization: Gamma radiation (ISO 11137).
Indications for Use
Indicated for patients with painful or disabled knee joints due to osteoarthritis, rheumatoid arthritis, post-traumatic arthritis, or failed previous total knee replacement, requiring cemented total knee arthroplasty with sufficient bone stock.
Regulatory Classification
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).
Predicate Devices
- Vanguard Complete Knee System (K113550)
- Vanguard Complete Knee System (K183583)
- DePuy Attune Knee System (K101433)
Submission Summary (Full Text)
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FDA U.S. FOOD & DRUG ADMINISTRATION
September 1, 2026
Just Medical Devices (Tianjin) Co., Ltd.
Robert Poggie
President
BioVera, Inc.
65 Promenade Saint Louis
Notre-Dame-De-L'Île-Perrot, QC J7W3J6
Canada
Re: K253961
Trade/Device Name: SK Knee System
Regulation Number: 21 CFR 888.3560
Regulation Name: Knee Joint Patellofemorotibial Polymer/Metal/Polymer Semi-Constrained Cemented Prosthesis
Regulatory Class: Class II
Product Code: JWH
Dated: July 31, 2026
Received: July 31, 2026
Dear Robert Poggie:
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/cdrh/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 Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.
U.S. Food & Drug Administration
10903 New Hampshire Avenue
Silver Spring, MD 20993
www.fda.gov
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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 Management System Regulation (QMSR) (21 CFR Part 820), which includes, but is not limited to, ISO 13485 clause 7.3 (Design controls), ISO 13485 clause 8.3 (Nonconforming product), ISO 13485 clause 8.5.2 (Corrective action), and ISO 13485 clause 8.5.3 (Preventative action). Please note that regardless of whether a change requires premarket review, the QMSR requires device manufacturers to review and approve changes to device design and production (ISO 13485 clause 7.3 and ISO 13485 clause 7.5) and document changes and approvals in the Medical Device File (ISO 13485 clause 4.2.3).
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 (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-reporting-combination-products); good manufacturing practice requirements as set forth in the Quality Management System Regulation (QMSR) (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.
All medical devices, including Class I and unclassified devices and combination product device constituent parts are required to be in compliance with the final Unique Device Identification System rule ("UDI Rule"). The UDI Rule requires, among other things, that a device bear a unique device identifier (UDI) on its label and package (21 CFR 801.20(a)) unless an exception or alternative applies (21 CFR 801.20(b)) and that the dates on the device label be formatted in accordance with 21 CFR 801.18. The UDI Rule (21 CFR 830.300(a) and 830.320(b)) also requires that certain information be submitted to the Global Unique Device Identification Database (GUDID) (21 CFR Part 830 Subpart E). For additional information on these requirements, please see the UDI System webpage at https://www.fda.gov/medical-devices/device-advice-comprehensive-regulatory-assistance/unique-device-identification-system-udi-system.
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-reporting-mdr-how-report-medical-device-problems.
For comprehensive regulatory information about medical devices and radiation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medical-devices/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-devices/device-advice-comprehensive-regulatory-
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assistance/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).
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
Enclosure
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| Indications for Use | | |
| --- | --- | --- |
| Please type in the marketing application/submission number, if it is known. This textbox will be left blank for original applications/submissions. | K253961 | ? |
| Please provide the device trade name(s). | | ? |
| SK Knee System | | |
| Please provide your Indications for Use below. | | ? |
| The SK Knee System is indicated for cemented use only as a total knee replacement in patients with a painful or disabled knee joint resulting from osteoarthritis, rheumatoid arthritis, post-traumatic arthritis, or a failed previous total knee joint procedure. | | |
| Please select the types of uses (select one or both, as applicable). | ☑ Prescription Use (21 CFR 801 Subpart D) ☐ Over-The-Counter Use (21 CFR 801 Subpart C) | ? |
K253961 Page 1 of 1
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| 510(k) #: K253961 510(k) Summary Prepared on: 2026-08-31 | | |
| --- | --- | --- |
| Contact Details | | 21 CFR 807.92(a)(1) |
| Applicant Name | Just Medical Devices (Tianjin) Co., Ltd. | |
| Applicant Address | No. 27, Ziyang Road, Nankai District Tianjin 300190 China | |
| Applicant Contact Telephone | +86-022-2339950 | |
| Applicant Contact | Ms. Wendy Zhang | |
| Applicant Contact Email | zhangyuan-zc@justmedical.cn | |
| Correspondent Name | BioVera, Inc. | |
| Correspondent Address | 65 Promenade Saint Louis Notre-Dame-de-L'Ile-Perrot QC J7W3J6 Canada | |
| Correspondent Contact Telephone | 514 349 7226 | |
| Correspondent Contact | Dr. Robert Poggie | |
| Correspondent Contact Email | orthobob@biovera.ca | |
| Device Name | | 21 CFR 807.92(a)(2) |
| Device Trade Name | SK Knee System | |
| Common Name | Total Knee Replacement System | |
| Classification Name | Knee joint patellofemorotibial polymer/metal/polymer semi-constrained cemented prosthesis | |
| Regulation Number | 888.3560 | |
| Product Code(s) | JWH | |
| Legally Marketed Predicate Devices | | 21 CFR 807.92(a)(3) |
| Predicate # | Predicate Trade Name (Primary Predicate is listed first) | Product Code |
| K113550 | Vanguard Complete Knee System | JWH |
| K183583 | Vanguard Complete Knee System | JWH |
| K101433 | DePuy Attune Knee System | JWH |
| Device Description Summary | | 21 CFR 807.92(a)(4) |
| The Just Medical SK Knee System is a total knee system that includes posterior stabilized (PS) and cruciate retaining (CR) total knee replacement options for cemented fixation. The SK Knee System includes CR and PS femoral components with left and right options (asymmetric), tibial base plates with a central stem (symmetrical), modular ultra-high-molecular-weight polyethylene (UHMWPE) tibial bearing components (two types of CR bearings and one PS type), and symmetrical, single-radius-domed UHMWPE patellar bearing | | |
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components. The femoral and tibial baseplate components are made of cast Co-Cr-Mo alloy per ISO 5832-4, and the patellar and tibial bearing components are made of UHMWPE per ISO 5834-2.
The SK Knee System includes Femoral Condyle (Cruciate Retaining-CR Type (Left & Right) and Posterior Stabilized-PS Type (Left & Right)), Tibial Tray (two types of stem/keel), Tibial Bearing (CR, AS and PS Type) and patella which are designed to achieve total reconstructive replacement of the knee joint, and intended for cement fixation.
The SK Knee System is indicated for use as a cemented total knee replacement in patients with a painful or disabled knee joint resulting from osteoarthritis, rheumatoid arthritis, post-traumatic arthritis, or a failed previous total knee replacement procedure. The subject device is intended to provide increased patient mobility and reduced pain by replacing the damaged knee joint articulation in patients where there is evidence of sufficient sound bone to support the components. The implant components of the SK Knee System are surgically implanted with reusable instruments that include a mix of general surgical instruments and device-specific instruments.
## Intended Use/Indications for Use
21 CFR 807.92(a)(5)
The SK Knee System is indicated for cemented use only as a total knee replacement in patients with a painful or disabled knee joint resulting from osteoarthritis, rheumatoid arthritis, post-traumatic arthritis, or a failed previous total knee joint procedure.
## Indications for Use Comparison
21 CFR 807.92(a)(5)
The indications for use of the subject device and the predicate device (K101433) are the same.
## Technological Comparison
21 CFR 807.92(a)(6)
The subject and predicate devices have similar technological characteristics; the minor differences do not raise any different issues of safety and effectiveness. Specifically, the following characteristics are similar for the subject and predicate devices:
- Indications for Use
- Materials of manufacture (cast CoCrMo for the femoral and tibial components)
- Fixation method (cemented)
- Principle of operation (total knee replacement)
- Size options (tibial, femoral, and patellar components)
- Design (CR and PS options); asymmetric; semi-constrained
- Level of semi-constraint of tibiofemoral articulation
- Sterilization methods for implants and instruments
Minor differences with the predicate devices exist with respect to:
- The subject device includes an anterior stabilized tibial insert
- Materials of manufacture (cast CoCrMo for the femoral and tibial components)
- The subject device patellar component is offered in 8 or 9 mm thickness while the primary predicate ranges from 6.2 to 10.0 mm thickness
- The primary predicate offers nine sizes of the tibial component while the subject device offers seven sizes (similar range of sizes)
- The primary predicate includes cemented and cementless options while the subject device is for cemented use only
The minor differences in design and performance characteristics discussed herein were confirmed via pre-clinical bench testing and therefore do not raise different issues of safety and effectiveness.
## Non-Clinical and/or Clinical Tests Summary & Conclusions
21 CFR 807.92(b)
Pre-clinical performance testing was performed for the SK Knee System per the FDA Guidance Document "Class II Special Controls Guidance Document: Knee Joint Patellofemorotibial and Femorotibial Metal/Polymer Porous-Coated Uncemented Prostheses; Guidance for Industry and FDA", ASTM, and ISO consensus standards, and publicly available information. The performance data presented in this 510(k) notification show the SK Knee System to meet the specified acceptance criteria that are specified in the test reports and/or relative to the consensus and industry standards for total knee replacement devices. Therefore in terms of biomechanical performance, the subject device was determined to be substantially equivalent to the predicate devices or in compliance with performance criteria set forth in FDA guidance documents and consensus standards.
- Patellofemoral subluxation, contact area, and contact pressure testing per ISO 21536:2023.
- Tibial tray fatigue per ISO 14879-1
- Disassembly forces for tibial tray and bearing per ASTM F1814
- Tibio-femoral constraint per ASTM F1223-20
- Shear testing of the post for the PS tibial insert per ASTM F1814-22
- Fatigue strength of the femoral component per ASTM F3210-22e1
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- Range of motion analyses per ISO 21534 and ISO 21536
- Tibio-femoral contact stress per ISO 21536-23
- Wear testing and analysis per ISO 14243-1:2009 and ISO 14243-2:2009
- MRI compatibility testing per FDA Guidance Document: Testing and Labeling Medical Devices for Safety in the Magnetic Resonance (MR) Environment: Guidance for Industry and FDA Staff (2023), ASTM standards F2503-23, F2182-19, F2052-21, F2213-17, and F2119-24.
- Biocompatibility testing per ISO 10993-1
- Bacterial Endotoxin Testing (BET) conducted as specified in ANSI/AAMI ST72:2011
- For CoCrMo and UHMWPE components: Gamma Sterilization Validation per ISO 11137
- Validation studies of sterility of implants and reusable instruments, packaging, cleaning of reusable instruments, and shelf life testing.
The results of pre-clinical bench testing and analyses met acceptance criteria and published standards of performance and in turn demonstrated substantial equivalence to the predicate devices.
