(55 days)
This device is indicated in hip arthroplasty for reduction or relief of pain and/or improved hip function in skeletally mature patients with the following conditions:
For use as a Total Hip Replacement
- Painful, disabling joint disease of the hip resulting from: degenerative arthritis, rheumatoid arthritis, post-traumatic arthritis or late stage avascular necrosis.
- Revision of previous unsuccessful femoral head replacement, cup arthroplasty or other procedure.
- Clinical management problems where arthrodesis or alternative reconstructive techniques are less likely to achieve satisfactory results.
For use as a Bipolar Hip Replacement
- Femoral head/neck fractures or non-unions.
- Aseptic necrosis of the femoral head.
- Osteo-, rheumatoid, and post-traumatic arthritis of the hip with minimal acetabular involvement or distortion.
Cemented stem is designed for cemented use only.
This device manufactured from CoCrMo alloy (ASTM F1537) is an extension of cleared "UNITED" U2 Acetabular Cup and Femoral Head (K022520) and "UNITED" U2 Hip System (K111546). The material, design, safety and effectiveness of this subject are identical to the previously cleared femoral heads except for its offset. The previously cleared femoral head offsets for the U2 Hip System are -3, +0, +5, and +10 mm. This submission adds +7.5 and +2.5 mm offset heads for 28, 32 and 36 mm diameter sizes. This device is intended to be used with the previously cleared U2 Acetabular Cup Liner (K050262), U2 XPE Liner (K111546), U2 bipolar implant (K101670), Revision Stem (K062978), HA/Ti Plasma Spray Stem (K003237), Ti Porous Coated Stem (K003237), UTF Stem (K110245), Press-fit Stem (K111546) and Cemented Stem (K111546) in corresponding size. The differences of femoral head offset do not affect the intended use of the device or alter the fundamental scientific technology of the device.
The provided text describes a Special 510(k) submission for "Femoral Heads, +2.5 and +7.5 mm Offset," which are extensions of previously cleared femoral head prostheses. This submission focuses on the addition of new offset sizes.
Here's an analysis of the acceptance criteria and study information provided:
1. Table of Acceptance Criteria and Reported Device Performance:
| Acceptance Criteria | Reported Device Performance |
|---|---|
| The device must be safe and effective and substantially equivalent to predicate devices. This is established by demonstrating that modifications (new offsets) do not change the indications or fundamental scientific technology, and that mechanical performance meets relevant guidance documents. Specifically, compliance with "Class II Special Controls Guidance Document- Hip Joint Metal Polymer Constrained Cemented or Uncemented Prosthesis" and "Guidance Document for Testing Non-Articulating, 'Mechanically Locked', Modular Implant Components." | "Femoral Head Disassembly loads for the stems, completed as part of the design assurance process, demonstrated that this device is safe and effective and is substantially equivalent to the predicate device." The submission states the material, design, safety, and effectiveness are identical to previously cleared femoral heads except for the new offset sizes. |
2. Sample size used for the test set and the data provenance:
The document does not specify a distinct "test set" in the sense of a clinical or imaging dataset with a specific sample size. The evaluation for this device appears to be based on mechanical testing and design assurance processes, not human clinical data or imaging studies that would typically involve a "test set" of patients or scans.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
Not applicable. The evaluation is based on mechanical testing and engineering principles, not expert interpretation of clinical data or images.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set:
Not applicable. There is no mention of a test set requiring adjudication in the context of this device's evaluation.
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 mechanical implant (femoral head) and does not involve AI or human readers for diagnostic interpretation.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
Not applicable. This device is a mechanical implant, not an algorithm.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.):
The "ground truth" for this device's acceptance stems from established engineering standards and regulatory guidance documents related to the safety and mechanical performance of hip implant components. Specifically, it relies on:
- Design Assurance Process Results: Demonstrating that the new offset configurations maintain the safety and effectiveness established for the predicate devices.
- Compliance with Guidance Documents: Adherence to "Class II Special Controls Guidance Document- Hip Joint Metal Polymer Constrained Cemented or Uncemented Prosthesis" and "Guidance Document for Testing Non-Articulating, 'Mechanically Locked', Modular Implant Components."
- Mechanical Testing Results: "Femoral Head Disassembly loads for the stems" were explicitly mentioned as being completed as part of the design assurance process to show safety and effectiveness.
8. The sample size for the training set:
Not applicable. This device is a mechanical implant and does not involve a "training set" in the context of machine learning or AI.
9. How the ground truth for the training set was established:
Not applicable. As there is no training set for this mechanical device, the concept of establishing ground truth for it does not apply.
§ 888.3358 Hip joint metal/polymer/metal semi-constrained porous-coated uncemented prosthesis.
(a)
Identification. A hip joint metal/polymer/metal semi-constrained porous-coated uncemented prosthesis is a device intended to be implanted to replace a hip 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 has a femoral component made of a cobalt-chromium-molybdenum (Co-Cr-Mo) alloy or a titanium-aluminum-vanadium (Ti-6Al-4V) alloy and an acetabular component composed of an ultra-high molecular weight polyethylene articulating bearing surface fixed in a metal shell made of Co-Cr-Mo or Ti-6Al-4V. The femoral stem and acetabular shell have a porous coating made of, in the case of Co-Cr-Mo substrates, beads of the same alloy, and in the case of Ti-6Al-4V substrates, fibers of commercially pure titanium or Ti-6Al-4V alloy. The porous coating has a volume porosity between 30 and 70 percent, an average pore size between 100 and 1,000 microns, interconnecting porosity, and a porous coating thickness between 500 and 1,500 microns. The generic type of device has a design to achieve biological fixation to bone without the use of bone cement.(b)
Classification. Class II.