(118 days)
The DePuy S-ROM® Hip Stem Prosthesis is intended to provide increased patient mobility and reduce pain by replacing the damaged hip joint articulation in patients where there is evidence of sufficient sound bone to seat and support the component.
The DePuy S-ROM® Hip Stem Prosthesis is indicated for uncemented use as the femoral component in total hip arthroplasty (THA) for replacing the hip joints of patients suffering severe pain and disability due to structural damage in the hip joint from rheumatoid arthritis, osteoarthritis, post-traumatic arthritis, collagen disorders, avascular necrosis, and nonunion of femoral fractures. Use of the prosthesis is also indicted for revision of previous hip arthroplasty and for patients with congenital hip dysplasia, protrusion acetabuli, slipped capital femoral epiphysis, and disability due to previous fusion.
The subject DePuy S-ROM® Hip Stem is a line extension to the 36mm S-ROM® titanium stems previously cleared in K961939 and K851422. The line extension adds a +12L option to the previously cleared standard stem sizes 19 x 24 x 175 w/36mm neck and 21 x 26 x 175 w/36mm neck. These two new stems will provide greater lateralization (+12 mm) to the standard stem of comparable diameters. The increased lateralization assists in restoring anatomical biomechanics through adjusting off-set without effecting leg length.
This document describes a 510(k) premarket notification for a hip stem prosthesis, which is a medical device. The information provided is not a study that proves a device meets acceptance criteria in the way one would conduct a clinical trial or algorithm performance study for AI/software. Instead, it's a regulatory submission for substantial equivalence to a previously cleared device. Therefore, the questions about acceptance criteria, performance tables, sample sizes, experts, MRMC studies, standalone performance, and ground truth are not directly applicable in the typical sense of a study proving performance for a software algorithm.
However, I can reframe the information provided to address your questions in the context of a 510(k) submission for a medical device line extension.
Here's how I'll interpret and answer your questions:
- Acceptance Criteria & Reported Device Performance: For a 510(k) submission, "acceptance criteria" generally refers to demonstrating that the new device is as safe and effective as a legally marketed predicate device. "Reported device performance" would relate to how the new device compares to the predicate.
- Study: In a 510(k) for a line extension, the "study" is often an analysis of design, materials, manufacturing, and intended use to show substantial equivalence. It's not usually a clinical performance study with human trial data unless there are significant changes.
- Ground Truth: For device mechanical properties, the "ground truth" would be established through engineering specifications, material testing standards, and design principles.
Reframed Acceptance Criteria and "Study" for a 510(k) for a Hip Stem Prosthesis Line Extension
1. A table of acceptance criteria and the reported device performance
For a 510(k) submission like this, the primary "acceptance criterion" is Substantial Equivalence to a predicate device. The "reported device performance" is the demonstration that the new device shares fundamental characteristics with the predicate.
| Acceptance Criterion (for Substantial Equivalence) | Reported Device "Performance" (demonstration of equivalence) |
|---|---|
| Criterion 1: Same Intended Use | |
| The new device must have the same intended use as the predicate device. | Demonstrated: The DePuy S-ROM® Hip Stem Prosthesis is intended to provide increased patient mobility and reduce pain by replacing the damaged hip joint articulation, which is consistent with the general intended use of hip stem prostheses and implicitly, the predicate DePuy S-ROM® Hip Stem (K961939). |
| Criterion 2: Same Indications for Use | |
| The new device must have the same indications for use as the predicate device. | Demonstrated: The DePuy S-ROM® Hip Stem Prosthesis is indicated for uncemented use as the femoral component in THA for replacing hip joints due to various conditions (rheumatoid arthritis, osteoarthritis, post-traumatic arthritis, etc.), revision, congenital hip dysplasia, etc. The submission explicitly states: "The fundamental scientific technologies of the subject DePuy S-ROM® Hip Prosthesis have not changed from the FDA-cleared DePuy S-ROM® Hip Stem (K961939). They have the same intended use, indications..." |
| Criterion 3: Same Technological Characteristics | |
| If technological characteristics differ, they must not raise new questions of safety or effectiveness. | Demonstrated: The submission states, "The fundamental scientific technologies... have not changed from the FDA-cleared DePuy S-ROM® Hip Stem (K961939). They have the same... sterilization method, packaging, materials, method of manufacture and design." The specific change is a "line extension adds a +12L option to the previously cleared standard stem sizes," providing "greater lateralization (+12 mm)." This type of modification (a dimensional variation within an existing design and material framework) is generally considered to not raise new questions of safety or effectiveness as long as mechanical integrity (e.g., fatigue, strength) is maintained, likely demonstrated through bench testing (though not explicitly detailed in this summary). |
| Criterion 4: Performance Data | |
| Any performance data (e.g., bench, non-clinical, clinical) provided must support substantial equivalence. | Demonstrated: While specific detailed study data (like fatigue testing results) are not included in this summary, the assertion of "same intended use, indications, sterilization method, packaging, materials, method of manufacture and design" implies that engineering analyses and testing (e.g., mechanical, materials, biocompatibility) would have been performed to confirm that the +12L line extension performs equivalently to the predicate devices and meets relevant standards. Such documentation would be part of the full 510(k) submission, substantiating that the dimensional change for increased lateralization does not compromise the device's safety or efficacy. The clearance letter confirms that Substantial Equivalence was found based on the provided information. |
2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)
- Sample Size: This document does not describe a clinical trial or algorithm performance study with a "test set" in the common sense. For a device like a hip stem, a "test set" would typically refer to the number of devices or components tested during bench testing (e.g., fatigue testing, static load testing). This summary does not provide these specific numbers.
- Data Provenance: Not applicable in this summary. The data would primarily be engineering and design specifications, and potentially results from in-house lab testing, not patient-derived data in the typical sense.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience)
- Experts: Not applicable for this type of submission summary. The "ground truth" for hip stem design and performance is established by engineering standards, material science, biomechanical principles, and regulatory requirements, not by expert consensus on interpretive data (like radiology images). Design engineers, materials scientists, and quality assurance personnel would be involved.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
- Adjudication Method: Not applicable. Adjudication methods like 2+1 or 3+1 are used for establishing ground truth in human-interpreted data (e.g., clinical endpoint events, imaging studies). This submission is about a mechanical device.
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
- MRMC Study: No, an MRMC comparative effectiveness study was not done. This type of study is relevant for diagnostic imaging algorithms with human interpretation. This submission is for a physical medical implant (hip stem).
6. If a standalone (i.e. algorithm only without human-in-the loop performance) was done
- Standalone Performance: No, this is not applicable. This is for a physical medical device, not a software algorithm.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)
- Type of Ground Truth: For a hip stem line extension, the "ground truth" for demonstrating substantial equivalence rests on:
- Engineering Specifications and Design Principles: The device must meet established biomechanical and material science principles for an orthopedic implant.
- Material Standards: The materials used must conform to accepted standards for biocompatibility and mechanical properties (e.g., ASTM, ISO standards for titanium alloys).
- Bench Testing Results: Mechanical performance (e.g., fatigue strength, torsional strength, corrosion resistance) would be compared to predicate devices and/or established performance standards through laboratory testing.
- Clinical Outcomes of Predicate Device: The predicate devices (K961939 and K851422) have a history of safe and effective use, and the new device is demonstrated to be structurally and functionally similar enough not to introduce new risks.
8. The sample size for the training set
- Training Set Sample Size: Not applicable. This is not a machine learning or AI algorithm development; there is no "training set."
9. How the ground truth for the training set was established
- Training Set Ground Truth: Not applicable, as there is no training set for this type of device submission.
§ 888.3330 Hip joint metal/metal semi-constrained, with an uncemented acetabular component, prosthesis.
(a)
Identification. A hip joint metal/metal semi-constrained, with an uncemented acetabular component, prosthesis is a two-part 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 includes prostheses that consist of a femoral and an acetabular component, both made of alloys, such as cobalt-chromium-molybdenum. The femoral component is intended to be fixed with bone cement. The acetabular component is intended for use without bone cement (§ 888.3027).(b)
Classification. Class III.(c)
Date PMA or notice of completion of PDP is required. A PMA or a notice of completion of a PDP is required to be filed with the Food and Drug Administration on or before May 18, 2016, for any hip joint metal/metal semi-constrained prosthesis with an uncemented acetabular component that was in commercial distribution before May 28, 1976, or that has, on or before May 18, 2016, been found to be substantially equivalent to a hip joint metal/metal semi-constrained prosthesis with an uncemented acetabular component that was in commercial distribution before May 28, 1976. Any other hip joint metal/metal semi-constrained prosthesis with an uncemented acetabular component shall have an approved PMA or a declared completed PDP in effect before being placed in commercial distribution.