Unity Total Knee System, Unity Knee Cementless CR Femur
Device Facts
| Record ID | K261275 |
|---|---|
| Device Name | Unity Total Knee System, Unity Knee Cementless CR Femur |
| Applicant | Corin, Ltd. |
| Product Code | MBH · Orthopedic |
| Decision Date | Sep 17, 2026 |
| Decision | SESE |
| Submission Type | Traditional |
| Regulation | 21 CFR 888.3565 |
| Device Class | Class 2 |
| Attributes | Therapeutic |
Indications for Use
The Unity Total Knee System is intended for use in total knee arthroplasty in skeletally mature patients, to provide increased mobility and reduce pain by replacing the damaged knee joint articulation where there is evidence of sufficient sound bone to seat and support the components.General total knee arthroplasty indications include:Painful, disabling joint disease of the knee resulting from: degenerative arthritis, rheumatoid arthritis or post-traumatic arthritisPost-traumatic loss of knee joint configuration and functionModerate varus, valgus, or flexion deformity in which the ligamentous structures can be returned to adequate functionRevision of previous unsuccessful knee replacement or other procedure, where soft tissue stability is adequateFracture of the distal femur and/or proximal tibia that cannot be stabilized by standard fracture management techniquesThe posterior stabilized variant is also indicated for PCL instability requiring implant bearing surface geometries with increased anterior-posterior constraint and absent or non-functioning posterior cruciate ligamentThe porous coated CR femoral component may be used for cementless (biological fixation) or cemented use.All other femoral components, tibial trays, patellar components, stem extensions and augmentation blocks are indicated for cemented use only.The Unity Total Knee System is intended for single use only.
Device Story
Unity Total Knee System is a fixed-bearing total knee replacement system for primary or revision arthroplasty. Subject device adds a cementless Cruciate Retaining (CR) femoral component to the existing system. Components include cobalt-chromium (CoCr) femoral component, UHMWPE or Vitamin E-enriched polyethylene (ECiMa) tibial insert, CoCr tibial tray with titanium alloy keel, and optional UHMWPE patellar component. Device is implanted by orthopedic surgeons in a clinical/OR setting. Cementless version utilizes a porous sintered bead coating for biological fixation. Output is a restored knee joint articulation, providing increased mobility and pain reduction. System is single-use.
Clinical Evidence
No clinical data provided. Substantial equivalence is supported by non-clinical bench testing, including coating shear testing (ASTM F1044-25), coating morphology (ASTM F1854-25), microCT assessment, fatigue endurance (ASTM F3210-22e1), and usability testing. Additional data from the original K113060 submission regarding wear, range of motion, contact area/pressure, constraint, and dynamic disassociation were leveraged.
Technological Characteristics
Fixed-bearing knee prosthesis. Materials: Cobalt-chromium alloy (femoral/tray), UHMWPE/ECiMa (insert), titanium alloy (keel/augments). Cementless version features sintered bead porous coating. Standards: ASTM F1044-25 (shear), ASTM F1854-25 (morphology), ASTM F3210-22e1 (fatigue). Single-use, non-active, mechanical device.
Indications for Use
Indicated for skeletally mature patients requiring total knee arthroplasty due to painful, disabling joint disease (degenerative, rheumatoid, or post-traumatic arthritis), post-traumatic loss of function, moderate varus/valgus/flexion deformity, revision of failed knee replacement, or distal femur/proximal tibia fractures. Posterior stabilized variant indicated for PCL instability/absence.
Regulatory Classification
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.
Special Controls
*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.
Predicate Devices
- Apex Knee System Porous Coated Femoral Components (K073602)
- Unity Total Knee System, Unity Knee Cemented CR Femur (K113060)
Submission Summary (Full Text)
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FDA U.S. FOOD & DRUG ADMINISTRATION
September 17, 2026
Corin, Ltd.
Marine De Paoli
Regulatory Affairs Manager
The Corinium Centre
Cirencester, Gloucestershire GL7 1YJ
United Kingdom
Re: K261275
Trade/Device Name: Unity Total Knee System, Unity Knee Cementless CR Femur
Regulation Number: 21 CFR 888.3565
Regulation Name: Knee Joint Patellofemorotibial Metal/Polymer Porous-Coated Uncemented Prosthesis
Regulatory Class: Class II
Product Codes: MBH, JWH
Dated: September 15, 2026
Received: September 15, 2026
Dear Marine De Paoli:
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,
Peter G.
Allen -S
Digitally signed by
Peter G. Allen -S
Date: 2026.09.17
15:22:17 -04'00'
for 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. | K261275 | ? |
| Please provide the device trade name(s). | | ? |
| Unity Total Knee System, Unity Knee Cementless CR Femur | | |
| Please provide your Indications for Use below. | | ? |
| The Unity Total Knee System is intended for use in total knee arthroplasty in skeletally mature patients, to provide increased mobility and reduce pain by replacing the damaged knee joint articulation where there is evidence of sufficient sound bone to seat and support the components.General total knee arthroplasty indications include:Painful, disabling joint disease of the knee resulting from: degenerative arthritis, rheumatoid arthritis or post-traumatic arthritisPost-traumatic loss of knee joint configuration and functionModerate varus, valgus, or flexion deformity in which the ligamentous structures can be returned to adequate functionRevision of previous unsuccessful knee replacement or other procedure, where soft tissue stability is adequateFracture of the distal femur and/or proximal tibia that cannot be stabilized by standard fracture management techniquesThe posterior stabilized variant is also indicated for PCL instability requiring implant bearing surface geometries with increased anterior-posterior constraint and absent or non-functioning posterior cruciate ligamentThe porous coated CR femoral component may be used for cementless (biological fixation) or cemented use.All other femoral components, tibial trays, patellar components, stem extensions and augmentation blocks are indicated for cemented use only.The Unity Total Knee System is intended for single use only.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)? | | |
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K261275 Page 1 of 4
Corin
Connected Orthopaedic Insight
510(k) Notification Submission
Unity Knee Cementless CR Femur
## 510(k) SUMMARY
510(k) #: K261275
Prepared on: 2026-09-17
### Contact Details
Applicant Name: Corin Ltd
Applicant Address: The Corinium Centre, Cirencester, Gloucestershire, GL7 1YJ, United Kingdom
Applicant Contact Telephone: +33456609245
Applicant Contact : Ms. Marine De Paoli
Applicant Contact Email : marine.depaoli@coringroup.com
### Device Name
Device Trade Name: Unity Total Knee System, Unity Knee Cementless CR Femur
Common Name: Total Knee Replacement System
Classification Name: - Knee Joint Patellofemorotibial Metal/Polymer Porous-Coated Uncemented Prosthesis
- Knee Joint Patellofemorotibial Polymer/Metal/Polymer Semi-Constrained Cemented Prosthesis
Regulation Number: - 21 CFR 888.3565
- 21 CFR 888.3560
Product Code(s): - MBH
- JWH
### Legally Marketed Predicate Devices
| Predicate # | Predicate Trade Name (Primary Predicate is listed first) | Product Code |
| --- | --- | --- |
| K073602 | Apex Knee System Porous Coated Femoral Components | MBH, JWH |
| K113060 | Unity Total Knee System, Unity Knee Cemented CR Femur | JWH |
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K261275 Page 2 of 4
Corin
Connected Orthopaedic Insight
510(k) Notification Submission
Unity Knee Cementless CR Femur
## Device Description Summary
The Unity Total Knee System is a fixed bearing total knee replacement system that consists of:
- A cemented or cementless cobalt chromium alloy (CoCr) femoral component,
- A UHMWPE (Ultra-High-Molecular-Weight-Polyethylene) or ECiMa (Vitamin E enriched advanced polyethylene) tibial insert,
- A cemented CoCr tibial tray with a titanium alloy keel extension,
- An all-polyethylene (UHMWPE) cemented patellar component,
for use in primary and revision total knee arthroplasty.
The Unity Total Knee System femoral component is provided in two variants, cruciate retaining (CR) and posterior stabilised (PS).
- The CR femoral component is intended for use in conjunction with the CR tibial insert or Medial Constrained (MC) tibial insert where the posterior cruciate ligament (PCL) is functional or in conjunction with a Condylar Stabilised (CS) tibial insert or MC tibial insert where the PCL is present but is lax or non-functioning or when the PCL is absent. The CR femoral component is available in cemented and cementless versions.
- The PS femoral component is intended for use in conjunction with the PS tibial insert where the posterior cruciate ligament is non-functioning or absent, resulting in joint instability, or in conjunction with the constrained posterior stabilized (PS-C) tibial insert where there is instability of the medial collateral ligament and/or lateral collateral ligament (MCL/LCL). The PS femoral component is available in a cemented version only.
The Unity Total Knee System patellar component is optional and for use with either the CR or PS femoral variants and is intended for use where replacement of the articular surface of the patella is required. The system also provides titanium alloy augment components including femoral augments, tibial augments, stem extensions and offset adapters that are compatible with the PS femoral component and cemented tibial tray only.
The Unity Total Knee System is intended for use in total knee arthroplasty in skeletally mature patients, to provide increased mobility and reduce pain by replacing the damaged knee joint articulation where there is evidence of sufficient sound bone to seat and support the components.
The Unity Total Knee system was originally cleared in K113060. This submission is for the inclusion of an additional range of cementless CR femoral components. The additional range of femoral components has the same intended purpose as those cleared in the original 510(k) submission (K113060).
## Intended Use/Indications for Use
The Unity Total Knee System is intended for use in total knee arthroplasty in skeletally mature patients, to provide increased mobility and reduce pain by replacing the damaged knee joint articulation where there is evidence of sufficient sound bone to seat and support the components.
General total knee arthroplasty indications include:
- 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
- Moderate varus, valgus, or flexion deformity in which the ligamentous structures can be returned to adequate function
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K261275 Page 3 of 4
Corin
Connected Orthopaedic Insight
# 510(k) Notification Submission
Unity Knee Cementless CR Femur
- Revision of previous unsuccessful knee replacement or other procedure, where soft tissue stability is adequate
- Fracture of the distal femur and/or proximal tibia that cannot be stabilized by standard fracture management techniques
- The posterior stabilized variant is also indicated for PCL instability requiring implant bearing surface geometries with increased anterior-posterior constraint and absent or non-functioning posterior cruciate ligament
The porous coated CR femoral component may be used for cementless (biological fixation) or cemented use.
All other femoral components, tibial trays, patellar components, stem extensions and augmentation blocks are indicated for cemented use only.
The Unity Total Knee System is intended for single use only.
# Indications for Use Comparison
The Unity Knee Cementless CR Femur is identical to the Apex Knee Porous Coated Femoral Component (K073602) and the Unity Knee Cemented CR Femur (K113060) in terms of intended use.
The Unity Knee Cementless CR Femur indications for use are similar to the indications for use of the Apex Knee Porous Coated Femoral Component and the Unity Knee Cemented CR Femur; they fall within the intended use of the predicate devices and the differences do not alter the intended therapeutic use of the subject device nor do they affect the safety and effectiveness of the device relative to the predicates.
# Technological Comparison
The Unity Knee Cementless CR Femur is identical to the Apex Knee Porous Coated Femoral Component (K073602) in terms of material and is similar in terms of porous coating. The predicate utilizes a cobalt-chromium alloy sintered bead coating applied to the internal bone-interfacing surfaces of the femoral component. The same coating technology, sintered bead material and sintered bead powder size are used for the subject device.
Whilst the Apex Knee Porous Coated Femoral Component has a larger number of sizes compared to the Unity Knee Cementless CR Femur, they cover approximately the same dimensional range when comparing at the Anterior-Posterior (AP) and Medial-Lateral (ML) dimensions.
The Unity Knee Cementless CR Femur is identical to the Unity Knee Cemented CR Femur (K113060) in terms of raw cast material, connected devices, size range and nominal condyle geometry. The main difference in technological characteristics between the Unity Knee Cemented CR Femur and the Unity Knee Cementless CR Femur is the porous coating applied to the Unity Knee Cementless CR Femur.
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K261275 Page 4 of 4
Corin
Connected Orthopaedic Insight
510(k) Notification Submission
Unity Knee Cementless CR Femur
## Non-Clinical and/or Clinical Tests Summary
Non-clinical testing conducted to demonstrate substantial equivalence includes:
- Coating verification, including static shear testing in accordance with ASTM F1044-25, coating morphology testing in accordance with ASTM F1854-25 and microCT assessment
- Fatigue endurance in accordance with ASTM F3210-22e1
- Usability testing
The Unity Knee Cementless CR Femur is part of the Unity Total Knee System originally cleared in K113060. Some of the previous testing performed for the Unity Total Knee System is applicable to the Unity Knee Cementless CR Femur:
- Wear testing
- Range of motion testing
- Contact area/pressure testing
- Constraint determination
- Dynamic disassociation testing
## Conclusions
The results of the specific mechanical and characterization testing performed on the Unity Knee Cementless CR Femur show that the device is substantially equivalent to the predicate devices. A comparison of intended use and indications for use also demonstrated substantial equivalence.
