(160 days)
- Patient conditions of non-inflammatory degenerative joint disease (NIDJD), e.g., 1. avascular necrosis, osteoarthritis and inflammatory joint disease (IJD), e.g., rheumatoid arthritis.
- Those patients with failed previous surgery where pain, deformity, or dysfunction 2. persists.
- Revision of previously failed arthroplasty. 3.
The Natural-Hip™ System Porous Stem with HA/CSTi™ is intended only for use without bone cement.
The Natural-Hip System Porous Stem with HA/CSTi is a straight stem manufactured from Ti-6Al-4V alloy conforming to ASTM F-136. The stem is available in both a collared and collarless design. The proximal anterior surface of the stem employs anterior angulation or build-up to match the anatomic angulation of a natural femur. The superior portion of the stem has a built-in anteversion of nine degrees to match the anatomic anteversion of the femur. Circumferential hydroxylapatite coated Cancellous Structured Titanium™ (CSTi™) porous coating provides biological fixation in a cementless application. The distal portion of the Natural-Hip System Porous Stem with HA/CSTi employs ribs and flutes on the anterior and posterior sides to enhance cortical contact, thereby providing rotational stability to the hip stem. In addition, the distal portion of the stem has a flared coronal slot which reduces stiffness of the stem.
This 510(k) submission describes a hip implant device, not an AI/ML-enabled medical device. Therefore, the information typically requested for AI/ML device acceptance criteria and studies (such as sample sizes for test and training sets, expert qualifications, ground truth methods, MRMC studies, and standalone performance) is not applicable in this context.
The document focuses on demonstrating substantial equivalence to predicate devices based on product description, diagnostic indications, and material composition. The FDA's letter (K970300) confirms this substantial equivalence but places limitations on labeling and promotional claims.
Here's an attempt to interpret the request within the context of a traditional medical device submission, focusing on "acceptance criteria" as related to the device's intended use and substantial equivalence:
1. Table of Acceptance Criteria and Reported Device Performance
For traditional medical devices like this hip implant, "acceptance criteria" are typically met by demonstrating that the device is substantially equivalent to legally marketed predicate devices in terms of intended use, technological characteristics, and safety and effectiveness. The "reported device performance" is essentially the determination of substantial equivalence by the FDA.
| Criterion | Reported Device Performance (FDA's Determination) |
|---|---|
| Intended Use Equivalence: The device is intended for the same uses as legally marketed predicate devices. | Met: The Natural-Hip™ System Porous Stem with HA/CSTi™ is intended "to replace the anatomy of the femur in cases of total hip or hemi-hip replacement," and for "cementless (press-fit) application" for conditions like non-inflammatory degenerative joint disease (NIDJD), inflammatory joint disease (IJD), failed previous surgery, and revision. These indications are consistent with the predicate devices listed. (Refer to pages 1 and 5). |
| Technological Characteristics Equivalence: The device has similar technological features (e.g., design, materials, manufacturing). | Met: The device is described as "a straight stem manufactured from Ti-6Al-4V alloy conforming to ASTM F-136." It features "hydroxylapatite coated Cancellous Structured Titanium™ (CSTi™) porous coating" for biological fixation. The submission explicitly states the device is substantially equivalent to other Intermedics Orthopedics, Inc. products (Natural-Hip System Porous Stem, APR Universal Hip System) and competitive systems (Howmedica Precision Osteolock, Osteonics Omnifit with HA). The FDA's decision is "based on consideration of the specific design of stem and coating composition detailed in this application." (Refer to pages 1 and 2). |
| Safety and Effectiveness Equivalence: The device is as safe and effective as legally marketed predicate devices. | Met (with limitations): The FDA determined the device is substantially equivalent, allowing marketing. However, a significant limitation was placed: "You may not label or in any way promote these devices for enhanced clinical or radiographic performance, enhanced biological fixation and/or long-term stable fixation. The data presented support equivalence with no additional claims over a conventional porous-coated uncemented hip prosthesis (i.e., biological fixation, only)." This indicates the device meets the baseline safety and effectiveness of its predicates for biological fixation but cannot claim superiority or augmented performance. (Refer to page 2). |
Study that Proves the Device Meets the Acceptance Criteria:
The "study" in this context is the 510(k) Premarket Notification itself, which presents information to the FDA to demonstrate substantial equivalence to predicate devices. This typically involves:
- Comparison to Predicate Devices: A detailed comparison of the new device's intended use, technological characteristics (materials, design, manufacturing process), and performance data (if applicable, e.g., mechanical testing for implants) to one or more legally marketed predicate devices.
- Performance Data (Non-Clinical): For an implant, this generally involves engineering tests, material characterization, and biocompatibility assessments to ensure the device performs as intended and is safe. The document implies such data were submitted, as the FDA based its decision on "the specific design of stem and coating composition." However, specific test results are not detailed in this summary.
Regarding your specific numbered points (which are more applicable to AI/ML devices):
- Sample size used for the test set and the data provenance: Not applicable in the AI/ML sense. Mechanical testing or biocompatibility studies would use specific samples of the device and materials, but this isn't "test set" data for an algorithm.
- Number of experts used to establish the ground truth for the test set and the qualifications of those experts: Not applicable. Ground truth for an implant isn't established by experts in this manner. Its performance is evaluated through engineering standards and clinical observation (post-market, often).
- Adjudication method: Not applicable.
- If a multi reader multi case (MRMC) comparative effectiveness study was done: Not applicable. This is not an imaging or diagnostic device that would involve human readers.
- If a standalone (i.e. algorithm only without human-in-the-loop performance) was done: Not applicable. This is a physical implant.
- The type of ground truth used: For a physical implant, "ground truth" relates to its conformity to engineering specifications, material properties, biocompatibility, and mechanical performance under simulated physiological conditions. Ultimately, long-term clinical outcomes (post-market surveillance) provide the most significant "ground truth" regarding its effectiveness in patients.
- The sample size for the training set: Not applicable.
- How the ground truth for the training set was established: Not applicable.
In summary, for a traditional medical device like a hip implant, the "acceptance criteria" are fundamentally about demonstrating substantial equivalence to pre-existing, legally marketed devices. The "study" is the 510(k) submission itself, supported by non-clinical performance data (e.g., material properties, mechanical testing) rather than clinical studies or AI algorithm performance metrics.
§ 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.