(269 days)
- Non-inflammatory degenerative joint disease Including osteoarthritis and avascular necrosis.
- Rheumatoid arthritis.
- Correction of functional deformity.
- Treatment of non-union, femoral neck fracture and trochanteric fractures of the proximal femur with head involvement, unmanageable using other techniques.
- Revision of previously failed total hip arthroplasty.
This device is a single use implant and intended for cementless use only.
Resolve Modular Revision Hip Stem is a modular stem optimized for femoral primary or revision surgery. It consists of three main components:
(1) Resolve Proximal Component (two types: With Hole or No Hole, each available with HA/Ti plasma spray or Ti plasma spray coating)
(2) Resolve Distal Stem (four types: Taper Stem, Clothespin Stem, Clothespin With Hole Stem, and Interlocking Stems. Taper Stem is uncoated; others are available with HA/Ti plasma spray or Ti plasma spray coating. Clothespin With Hole Stem and Interlocking stem provide holes for additional Distal Interlocking Screw fixation.)
(3) Resolve Distal Interlocking Screw (used with Resolve Clothespin With Hole Stem and Interlocking stem)
Resolve Modular Revision Hip Stem can be used with "United" metallic femoral heads (K994078, K022520, K111546, K122504, K152439, K162957, K221675) or ceramic femoral heads (K103497, K112463, K122185).
All components are manufactured from Ti-6Al-4V alloy (ASTM F136). The coatings (HA/Ti plasma spray and Ti plasma spray) comply with ASTM F1580 and ASTM F1185, ISO 13779-6. Proximal components have standard and high offset designs.
Based on the provided FDA 510(k) Clearance Letter for the "Resolve Modular Revision Hip Stem," it's crucial to understand that this document pertains to a physical medical device (an orthopedic implant), not a software-based medical device or AI/ML algorithm.
Therefore, the concepts of "acceptance criteria for an AI/ML algorithm," "test set," "ground truth establishment," "expert adjudication," "MRMC studies," and "standalone performance" do not apply to the information contained within this 510(k) filing.
The 510(k) process for a physical device like this hip stem primarily focuses on demonstrating substantial equivalence to existing legally marketed predicate devices through:
- Indications for Use Comparison: Showing the device is intended for the same medical purposes.
- Technological Comparison: Demonstrating similar fundamental scientific principles, materials, design, and operating conditions.
- Non-Clinical (Bench) Testing: Conducting a series of engineering and materials tests to ensure the device meets specified mechanical and material performance standards, and that it is as safe and effective as the predicate devices.
- No Clinical Studies (unless specifically required): The letter explicitly states "No clinical studies were required or provided," which is common for devices demonstrating substantial equivalence through bench testing.
There is no "AI/ML algorithm" or "software performance" to describe acceptance criteria or study results for in this context.
Instead, I can extract and present the relevant information about the acceptance of this physical medical device based on the given 510(k) letter.
Acceptance Criteria and Study for the Resolve Modular Revision Hip Stem (Physical Device)
The "acceptance criteria" for a physical device in a 510(k) submission are not typically presented as a table of accuracy metrics. Instead, they are demonstrated by meeting various engineering and material standards, and by showing that the device performs similarly (or better) than the predicate devices in specified non-clinical tests. The "study" refers to the non-clinical (bench) testing performed.
1. Table of "Acceptance Criteria" (represented by tests aligned with regulatory standards) and "Reported Device Performance" (implied compliance or successful test outcomes):
| "Acceptance Criteria" (Test Name) | Standard/Guidance Followed | "Reported Device Performance" (Outcome) |
|---|---|---|
| Range of Motion | ISO 21535 | Met standards; device is safe and effective. |
| Pull-out Strength of Morse Taper | ISO 7206-10 | Met standards; device is safe and effective. |
| Neck Fatigue Test | ISO 7206-6 | Met standards; device is safe and effective. |
| Stem Fatigue Test combined with Disassembly Test | ISO 7206-4, ISO 7206-10 | Met standards; device is safe and effective. |
| Fretting Corrosion | ASTM F1875 | Met standards; device is safe and effective. |
| Torsional Testing of Resolve Proximal Screw | ASTM F543 | Met standards; device is safe and effective. |
| Mechanical Testing of Resolve Distal Interlocking Screw | ASTM F543 | Met standards; device is safe and effective. |
| Characterization of HA/Ti Plasma Spray Coating | FDA guidance "510(k) information needed for Hydroxyapatite Coated Orthopedic Implants" | Met standards; device is safe and effective. |
| Characterization of Ti Plasma Spray Coating | FDA guidance "Guidance for Industry on the Testing of Metallic Plasma Sprayed Coatings on Orthopedic Implants..." | Met standards; device is safe and effective. |
| Usability Evaluation | BS EN 62366-1, FDA guidance "Content of Human Factors Information...", "Applying Human Factors and Usability Engineering..." | Met standards; device is safe and effective. |
| Bacteria endotoxin testing | USP<161> | Met the endotoxin limit as specified. |
Explanation of "Reported Device Performance": The document states: "Based on the design rationale of the Subject device, the following tests were conducted to evaluate the safety and effectiveness of the subject device, and the test results indicated that this device is safe and effective." This implies that the device successfully met the requirements and specifications of each listed test and standard, thus demonstrating its safety and effectiveness. Specific numerical performance values are not typically included in the summary letter itself but would be detailed in the full submission.
2. Sample Size and Data Provenance:
- Sample Size: Not explicitly stated for each test (e.g., number of stems tested for fatigue). These are typically engineering bench tests on a representative sample of device components or full devices.
- Data Provenance: The tests are non-clinical (bench tests), meaning they were conducted in a laboratory setting, not with human patient data. The manufacturer, United Orthopedic Corporation, is based in Taiwan.
3. Number of Experts and Qualifications for Ground Truth:
- This concept is not applicable as this is a physical device clearance based on non-clinical bench testing, not an AI/ML algorithm requiring expert review for ground truth establishment.
4. Adjudication Method:
- Not applicable for a physical device and non-clinical bench testing.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study:
- Not applicable. This is a clearance for a physical orthopedic implant. The letter explicitly states: "No clinical studies were required or provided." MRMC studies are typically performed for imaging-based AI/ML devices to assess human reader performance with and without AI assistance.
6. Standalone Performance (Algorithm Only):
- Not applicable as there is no algorithm. The performance documented is the standalone mechanical and material performance of the physical implant itself through a series of bench tests.
7. Type of Ground Truth Used:
- For the physical device, the "ground truth" for acceptance is based on established engineering standards (e.g., ISO, ASTM) and regulatory guidance (FDA guidance documents) for mechanical, material, and biological compatibility properties of orthopedic implants. Compliance with these predetermined, objective standards serves as the "ground truth" for safe and effective performance.
8. Sample Size for Training Set:
- Not applicable. This is not a "training set" in the context of AI/ML. The device's design and manufacturing processes are developed based on extensive engineering principles, materials science, and prior knowledge from predicate devices.
9. How Ground Truth for Training Set was Established:
- Not applicable. As there is no AI/ML training set, the concept of establishing ground truth for it does not apply. The "ground truth" for the device's design and material selection would be established through decades of orthopedic research, biomechanical principles, and clinical experience with similar implants.
U.S. Food & Drug Administration 510(k) Clearance Letter
Page 1
U.S. Food & Drug Administration
10903 New Hampshire Avenue
Silver Spring, MD 20993
www.fda.gov
Doc ID # 04017.07.05
May 1, 2025
United Orthopedic Corporation
Lois Ho
Regulatory Affairs Manager
No 57, Park Ave 2, Science Park
Hsinchu, 30075
Taiwan
Re: K242315
Trade/Device Name: Resolve Modular Revision Hip Stem
Regulation Number: 21 CFR 888.3353
Regulation Name: Hip Joint Metal/Ceramic/Polymer Semi-Constrained Cemented Or Nonporous Uncemented Prosthesis
Regulatory Class: Class II
Product Code: MEH, LZO, KWY
Dated: August 5, 2024
Received: August 5, 2024
Dear Lois Ho:
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.
Page 2
K242315 - Lois Ho
Page 2
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 820.30 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 (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 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.
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-
Page 3
K242315 - Lois Ho
Page 3
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,
Limin Sun -S
Limin Sun, 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
Page 4
K242315 Page 1 of 1
DEPARTMENT OF HEALTH AND HUMAN SERVICES
Food and Drug Administration
Form Approved: OMB No. 0910-0120
Expiration Date: 07/31/2026
See PRA Statement below.
Indications for Use
510(k) Number (if known)
K242315
Device Name
Resolve Modular Revision Hip Stem
Indications for Use (Describe)
- Non-inflammatory degenerative joint disease Including osteoarthritis and avascular necrosis.
- Rheumatoid arthritis.
- Correction of functional deformity.
- Treatment of non-union, femoral neck fracture and trochanteric fractures of the proximal femur with head involvement, unmanageable using other techniques.
- Revision of previously failed total hip arthroplasty.
This device is a single use implant and intended for cementless 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)
CONTINUE ON A SEPARATE PAGE IF NEEDED.
This section applies only to requirements of the Paperwork Reduction Act of 1995.
DO NOT SEND YOUR COMPLETED FORM TO THE PRA STAFF EMAIL ADDRESS BELOW.
The burden time for this collection of information is estimated to average 79 hours per response, including the time to review instructions, search existing data sources, gather and maintain the data needed and complete and review the collection of information. Send comments regarding this burden estimate or any other aspect of this information collection, including suggestions for reducing this burden, to:
Department of Health and Human Services
Food and Drug Administration
Office of Chief Information Officer
Paperwork Reduction Act (PRA) Staff
PRAStaff@fda.hhs.gov
"An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a currently valid OMB number."
FORM FDA 3881 (8/23)
Page 5
Traditional 510(k)
Resolve Modular Revision Hip Stem
510(K) SUMMARY
Traditional 510(k)
[as required by 21 CFR 807.92(c)]
Prepared by date: 2025-0501
Contact Details
| Applicant Name | United Orthopedic Corporation |
|---|---|
| Applicant Address | No. 16, Luke 1st Rd. Luzhu Dist., Kaohsiung 82151 Taiwan |
| Applicant Contact Telephone | +88635773351 |
| Applicant Contact | Ms. Lois Ho |
| Applicant Contact Email | lois.ho@unitedorthopedic.com |
Device Name
| Device Trade Name | Resolve Modular Revision Hip Stem |
|---|---|
| Common Name | Modular Femoral Stem |
| Classification Name | Hip joint metal/ceramic/polymer semi-constrained cemented or nonporous uncemented prosthesisHip joint femoral (hemi-hip) metal/polymer cemented or uncemented prosthesis |
| Regulation Number | 888.3353888.3390 |
| Product Codes | MEH, LZO, KWY |
Predicate Device Information
| 510(k) Number | Predicate Trade Name |
|---|---|
| K090757 | Arcos® Modular Femoral Revision System |
| K022549, K051363, K213129 | Restoration® Modular System |
| K994126 | MODULAR-PLUS REVISION STEM |
| K003237 | U2 Hip Stem, HA/Ti plasma spray |
| K172251 | UTS Stem, Ti plasma spray |
| K050262 | U2 Acetabular Component |
| K110245 | UTF Stem |
| K183312 | Conformity Stem |
Device Description Summary
Resolve Modular Revision Hip Stem is a modular stem optimized for femoral primary or revision surgery. It consists of three main components,
(1) Resolve Proximal Component
Resolve offers two types of proximal components, each available with either HA/Ti plasma spray or Ti plasma spray.
Page 1 of 5
Page 6
Traditional 510(k)
Resolve Modular Revision Hip Stem
| Type | With or without Hole | Coating | Device Name |
|---|---|---|---|
| 1 | With Hole | HA/Ti plasma spray | Resolve Proximal Component |
| With Hole | Ti plasma spray | Resolve Proximal Component, Ti Plasma Spray | |
| 2 | No Hole | HA/Ti plasma spray | Resolve Proximal Component, No Hole |
| No Hole | Ti plasma spray | Resolve Proximal Component, Ti Plasma Spray, No Hole |
(2) Resolve Distal Stem.
Resolve offers four types of distal stems including Taper Stem, Clothespin Stem, Clothespin With Hole Stem, and Interlocking Stems. The Clothespin With Hole Stem and Interlocking stem provide holes for additional Distal Interlocking Screw fixation. The Taper Stem does not have a coating. The other three types of stems are each available with either HA/Ti plasma spray or Ti plasma spray.
| Type | With or without Hole | Coating | Device Name |
|---|---|---|---|
| 1. Taper Stem | No Hole | Without Coating | Resolve Distal Stem, Taper |
| 2. Clothespin Stem | No Hole | HA/Ti plasma spray | Resolve Distal Stem, Clothespin |
| No Hole | Ti plasma spray | Resolve Distal Stem, Ti Plasma Spray, Clothespin | |
| 3. Clothespin With Hole Stem | With Hole | HA/Ti plasma spray | Resolve Distal Stem, Clothespin With Hole |
| With Hole | Ti plasma spray | Resolve Distal Stem, Ti Plasma Spray, Clothespin With Hole | |
| 4. Interlocking Stem | With Hole | HA/Ti plasma spray | Resolve Distal Stem, Interlocking |
| With Hole | Ti plasma spray | Resolve Distal Stem, Ti Plasma Spray, Interlocking |
(3) Resolve Distal Interlocking Screw
It is used with Resolve Clothespin With Hole Stem and Interlocking stem to provide an extra distal fixation and prevent subsidence.
Resolve Modular Revision Hip Stem can be used with "United" metallic femoral heads (K994078, K022520, K111546, K122504, K152439, K162957, K221675) or ceramic femoral heads (K103497, K112463,
Page 2 of 5
Page 7
Traditional 510(k)
Resolve Modular Revision Hip Stem
K122185).
- Resolve Proximal Component
Resolve offers two types of proximal component, with hole and no hole. The hole type provides a hole design on the lateral side of the proximal component. Both types are manufactured from Ti-6Al-4V alloy that complied with ASTM F136. There are two types of coating at the distal part of the proximal component. The first type is plasma spray coated with dual coatings, CP Ti powder (ASTM F1580) for the first layer, and HA powder (ASTM F1185, ISO 13779-6) for the second layer. The second type is plasma spray coated with only CP Ti powder (ASTM F1580). There are also two types of offset design, standard offset and high offset. Resolve Proximal Component are available in various diameters and proximal body heights.
- Resolve Distal Stem, Taper
Resolve Distal Stem, Taper is manufactured from Ti-6Al-4V alloy that complied with ASTM F136. The surface is grit-blasted. Resolve Distal Stem, Taper offers two stem lengths and is available in various diameters.
- Resolve Distal Stem, Clothespin
Resolve Distal Stem, Clothespin offers two types of proximal component, with hole and no hole. It is manufactured from Ti-6Al-4V alloy that complied with ASTM F136. Two types of coating identical to Resolve Proximal Component, HA/Ti dual coating and Ti single coating. All types of Resolve Distal Stem, Clothespins are available in various diameters.
- Resolve Distal Stem, Interlocking
Resolve Distal Stem, Interlocking is manufactured from Ti-6Al-4V alloy that complied with ASTM F136. Two types of coating identical to Resolve Proximal Component, HA/Ti dual coating and Ti single coating. Both types have the hole design to be used with Resolve, Distal Interlocking Screw to provide an extra distal fixation and prevent subsidence. All types of Resolve Distal Stem, Interlocking are available in various diameters.
- Resolve, Distal Interlocking Screw
Resolve, Distal Interlocking Screw is manufactured from Ti-6Al-4V alloy that complied with ASTM F136. It is used with Resolve Clothespin With Hole Stem and Interlocking stem to provide an extra distal fixation and prevent subsidence. It is available in various lengths.
Intended Use/Indications for Use
- Non-inflammatory degenerative joint disease Including osteoarthritis and avascular necrosis.
- Rheumatoid arthritis.
- Correction of functional deformity.
Page 3 of 5
Page 8
Traditional 510(k)
Resolve Modular Revision Hip Stem
- Treatment of non-union, femoral neck fracture and trochanteric fractures of the proximal femur with head involvement, unmanageable using other techniques.
- Revision of previously failed total hip arthroplasty.
This device is a single use implant and intended for cementless use only.
Indications for Use Comparison
The indication for use of the subject device are similar to the predicate devices.
Technological Comparison
The Subject device fundamental scientific principles and technological characteristics, including: material and general design, are the same as, or similar to, the primary predicate and the chosen additional predicate/reference devices.
Summary of the technological characteristics:
- Applied anatomical sites, operating principles, and conditions of use are identical.
- No new risks associated to the Subject device compared to those of the predicate devices.
- Material are similar to the primary predicate.
- Geometry and size: Most of the sizes of the Subject device are bracketed in size by the predicates, except for the diameter of Resolve Distal Stem, Taper and the length of Resolve, Distal Interlocking Screw. The worst-case of Resolve Distal Stem, Taper and Resolve, Distal Interlocking Screw have been demonstrated equivalent safety and effectiveness as compared to the predicate devices.
- Sterilization: identical method as predicates.
The technological characteristics of the Subject device are substantially equivalent to the predicate device(s).
Non-Clinical and/or Clinical Tests Summary & Conclusions
Based on the design rationale of the Subject device, the following tests were conducted to evaluate the safety and effectiveness of the subject device, and the test results indicated that this device is safe and effective.
• Range of Motion (ISO 21535)
• Pull-out Strength of Morse Taper (ISO 7206-10)
• Neck Fatigue Test (ISO 7206-6)
• Stem Fatigue Test combined with Disassembly Test (ISO 7206-4, ISO 7206-10)
• Fretting Corrosion (ASTM F1875)
• Torsional Testing of Resolve Proximal Screw (ASTM F543)
• Mechanical Testing of Resolve Distal Interlocking Screw (ASTM F543)
• Characterization of HA/Ti Plasma Spray Coating (FDA guidance "510(k) information needed for Hydroxyapatite Coated Orthopedic Implants")
• Characterization of Ti Plasma Spray Coating (FDA guidance "Guidance for Industry on the Testing of Metallic Plasma Sprayed Coatings on Orthopedic Implants to Support Reconsideration of Post market Surveillance Requirements")
Page 4 of 5
Page 9
Traditional 510(k)
Resolve Modular Revision Hip Stem
• Usability Evaluation (BS EN 62366-1, FDA guidance "Content of Human Factors Information in Medical Device Marketing Submissions", "Applying Human Factors and Usability Engineering to Medical Devices.")
• Bacteria endotoxin testing was conducted and met the endotoxin limit as specified in USP<l 61 >
No clinical studies were required or provided.
Based upon showing equivalence in the following aspects: intended use, patient population, site of application, conditions of use, operating principles, and the non-clinical performance data, the Subject device has been shown to be safe and effective and to perform equivalently as compared to the legally marketed predicate devices.
Therefore, the Subject device is substantially equivalent to the legally marketed predicate devices.
Page 5 of 5
§ 888.3353 Hip joint metal/ceramic/polymer semi-constrained cemented or nonporous uncemented prosthesis.
(a)
Identification. A hip joint metal/ceramic/polymer semi-constrained cemented or nonporous uncemented prosthesis is a device intended to be implanted to replace a hip joint. This device limits translation and rotation in one or more planes via the geometry of its articulating surfaces. It has no linkage across-the-joint. The two-part femoral component consists of a femoral stem made of alloys to be fixed in the intramedullary canal of the femur by impaction with or without use of bone cement. The proximal end of the femoral stem is tapered with a surface that ensures positive locking with the spherical ceramic (aluminium oxide, A12 03 ) head of the femoral component. The acetabular component is made of ultra-high molecular weight polyethylene or ultra-high molecular weight polyethylene reinforced with nonporous metal alloys, and used with or without bone cement.(b)
Classification. Class II.