(270 days)
The R3™ Constrained Liner Acetabular System is an uncemented prosthesis intended to replace a hip joint. The Constrained Liner is intended for primary or revision patients at high risk for hip dislocation due to a history of prior dislocation, bone loss, soft tissue laxity, neuromuscular disease, or intra-operative instability and for whom all other options to constrained acetabular components have been considered. The R3 Constrained Liner is intended for single use only.
Subject of this Traditional premarket notification is the addition of new liner sizes to the Smith & Nephew R3" Constrained Liner Acetabular System. The R3 Constrained Liner Acetabular System currently consists of the R3 Constrained Liner offered in sizes of 52mm to 66/70mm cleared via premarket notification K111635. The proposed devices are additional sizes to the R3 Constrained Liners that were previously cleared. The proposed devices will be offered in sizes of 48mm, 50mm, 72-74mm, and 76-80mm, and will be marketed as part of the R3 Constrained Liner Acetabular System.
The new R3 Constrained Liner sizes are line additions to the primary predicate R3 Constrained Liners cleared via premarket notification K111635. The subject devices are similar to the primary predicate R3 Constrained Liners in that they are a multipiece acetabular component consisting of a bipolar bearing that articulates with a captured outer polyethylene liner, locking ring, and outer poly support ring. The subject devices and the primary predicate R3 Constrained Liners utilize a tripolar design allowing motion at two interfaces: the femoral head with the bipolar bearing and the bipolar bearing with the outer liner. The subject devices are identical in design to the cleared R3 Constrained Liners, with the exception that they are smaller or larger in overall size. The new R3 Constrained Liner sizes are also similar to the following additional predicates: R3 Constrained Liners (K122139), REFLECTION Constrained Liners (K021803, K033442), R3 XLPE Liners (K113848), and DePuy Self-Centering Hip Prostheses (K033273). The subject devices are also similar to reference predicate Osteonics Constrained Acetabular Inserts (P960047). The subject devices utilize seven components manufactured from Ultra High Molecular Weight Polyethylene (UHMWPE), forged Titanium Alloy (Ti-6Al-4V), and Cobalt Chrome (CoCr).
The provided document is a 510(k) premarket notification for a medical device, specifically the Smith & Nephew, Inc. R3TM Constrained Liner. This type of submission is to demonstrate that the new device is "substantially equivalent" to a legally marketed predicate device, rather than proving its safety and effectiveness from scratch through clinical studies. Therefore, much of the information requested in a typical AI/ML medical device study (e.g., sample size for training/test sets, expert qualifications, MRMC studies, standalone performance) is not applicable or not provided in this context.
However, I can extract information related to the acceptance criteria and the type of study conducted to demonstrate equivalence for this specific device.
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria (What was measured) | Reported Device Performance (How the device performed) |
|---|---|
| Attachment loads: Push-in, Pull-out, Shuck-out, Push-out | Met (Demonstrated no new issues) |
| Dislocation resistance | Met (Demonstrated no new issues) |
| Range of Motion (ROM) | Met (Evaluated, demonstrated no new issues) |
| Pyrogen limit specification (≤ 20 EU/device) | Met (Using Limulus Amebocyte Lysate (LAL) test) |
2. Sample size used for the test set and the data provenance:
- Test Set Sample Size: Not explicitly stated as this was mechanical and LAL testing, not a clinical study on a patient population. The document refers to "the subject devices" and "the new R3 Constrained Liner sizes," implying a representative number of physical devices were tested.
- Data Provenance: The testing was conducted internally by the manufacturer, Smith & Nephew, Inc. The document does not specify a country of origin for the data beyond that it's for a US regulatory submission. The studies were prospective in the sense that they were designed and executed to evaluate the new device sizes.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- This information is not applicable. The "ground truth" for mechanical and LAL testing is the established engineering specifications and pyrogen limits, not expert human assessment of images or clinical outcomes.
4. Adjudication method for the test set:
- Not applicable. This device underwent mechanical and LAL testing, not human adjudication of results.
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 is not an AI/ML device, and no MRMC study was performed.
6. If a standalone (i.e., algorithm only without human-in-the-loop performance) was done:
- Not applicable. This is not an AI/ML device. The "standalone" performance here refers to the device's mechanical and biological properties independent of human interaction during testing.
7. The type of ground truth used:
- Mechanical Testing: Engineering specifications and performance standards for hip prostheses.
- Biological Testing: Established pyrogen limits (≤ 20 EU/device).
8. The sample size for the training set:
- Not applicable. As a mechanical medical device, there is no "training set" in the context of AI/ML. The device's design is based on established biomechanical principles and materials science.
9. How the ground truth for the training set was established:
- Not applicable. There is no training set. The "ground truth" for the device's design and manufacturing is derived from engineering design principles, materials science, and compliance with relevant industry standards for orthopedic implants.
Summary:
This 510(k) submission demonstrates substantial equivalence by showing that the new R3 Constrained Liner sizes have equivalent technological characteristics and performance to already legally marketed predicate devices. The "study" here involves mechanical testing (attachment loads, dislocation resistance, range of motion) and biological testing (Limulus Amebocyte Lysate (LAL) test for pyrogens). The primary goal was to ensure that the new, larger/smaller sizes of the liner did not introduce any new issues related to safety or effectiveness compared to the previously cleared sizes and other predicates. Clinical data was explicitly stated as "not needed to support substantial equivalence."
§ 888.3310 Hip joint metal/polymer constrained cemented or uncemented prosthesis.
(a)
Identification. A hip joint metal/polymer constrained cemented or uncemented prosthesis is a device intended to be implanted to replace a hip joint. The device prevents dislocation in more than one anatomic plane and has components that are linked together. This generic type of device includes prostheses that have a femoral component made of alloys, such as cobalt-chromium-molybdenum, and an acetabular component made of ultra-high-molecular-weight polyethylene with or without a metal shell, made of alloys, such as cobalt-chromium-molybdenum and titanium alloys. This generic type of device is intended for use with or without bone cement (§ 888.3027).(b)
Classification. Class II (special controls). The special control for this device is the FDA guidance document entitled “Class II Special Controls Guidance: Hip Joint Metal/Polymer Constrained Cemented or Uncemented Prosthesis.”