(82 days)
The Pinnacle AltrX Acetabular Cup Liners are indicated for use in total hip replacement procedures.
Total hip replacement is indicated in the following conditions:
- A severely painful and/or disabled joint from osteoarthritis, traumatic arthritis, rheumatoid arthritis, or congenital hip dysplasia.
- Avascular necrosis of the femoral head.
- Acute traumatic fracture of the femoral head or neck.
- Failed previous hip surgery, including joint reconstruction, internal fixation, arthrodesis, hemiarthroplasty, surface replacement arthroplasty, or total hip replacement.
- Certain cases of ankylosis
The Pinnacle AltrX Acetabular Cup Liners are indicated for use with Pinnacle Acetabular Cups in cementless applications.
The subject liner is intended to be used with the DePuy Pinnacle metal acetabular shells, and DePuy metal or ceramic femoral heads to resurface the acetabular socket in cementless total hip arthroplasty. Total hip arthroplasty 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 components.
The DePuy Pinnacle AltrX Acetabular Liner is part of a modular system designed to replace the natural articular surface of the hip joint in total hip replacement. The liner is manufactured from ultra high molecular weight polyethylene (UHMWPE), which locks into a porous coated, hemispherical outer shell component manufactured from titanium alloy (Ti-6A1-4V). The liner component articulates with a metal or ceramic femoral head of an appropriate diameter.
The subject Pinnacle AltrX liners are cross-linked UHMWPE acetabular cup liners that are available in a neutral, lateralized neutral, lipped or lateralized face-changing orientation. The subject liners are intended for use with modular, self-centering (bipolar), M-Spec or ceramic femoral heads within the 28mm-48mm size range.
The provided text describes a 510(k) premarket notification for the DePuy Pinnacle® AltrX™ Acetabular Liners. The submission aims to support a marketing claim regarding reduced wear when these liners are articulated against ceramic femoral heads.
Here's an analysis of the acceptance criteria and study as requested:
1. Table of Acceptance Criteria and Reported Device Performance
The submission does not explicitly state pre-defined acceptance criteria in terms of specific wear rate thresholds for the new claim. Instead, the claim is comparative: "Pinnacle AltrX UHMWPE liners (articulated against ceramic heads) reduce wear by 33% compared to articulation against cobalt-chromium heads."
Therefore, the success criteria for the study would be demonstrating this 33% reduction (or greater statistical significance) with the ceramic head articulation compared to cobalt-chromium heads.
| Acceptance Criteria (Implied by Marketing Claim) | Reported Device Performance | Meets Acceptance Criteria? |
|---|---|---|
| Reduce wear by at least 33% for AltrX liners articulated against ceramic heads compared to articulation against cobalt-chromium heads (control group for this comparison would be AltrX against CoCrMo heads). | AltrX with 36mm CoCrMo femoral head (control for comparison): 4.99 ± 0.66 mg/million cycles (mg/MC) | |
| AltrX with 36mm ceramic femoral head (test group): 3.32 ± 0.38 mg/MC |
Calculation of reduction: ((4.99 - 3.32) / 4.99) * 100% = 33.47% reduction. | Yes |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: The study involved multiple groups of liners and femoral heads. While the exact number of individual devices per group isn't explicitly stated, the text mentions a "12-station orbital bearing hip simulator," which implies a certain capacity for simultaneous testing. The report provides mean and standard deviation for wear rates, indicating multiple samples were tested for each configuration.
- Data Provenance: The study was an in-vitro hip simulator wear study. As such, there is no country of origin for patient data (as it's not patient data) and it is not retrospective or prospective in the clinical sense. It's a laboratory-based study.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications of Those Experts
Not applicable. This is an in-vitro mechanical wear study, not a study requiring expert clinical interpretation or ground truth establishment based on human observational data. The "ground truth" here is the measured wear rate in a standardized laboratory setting.
4. Adjudication Method for the Test Set
Not applicable. As this is an in-vitro mechanical wear study, there is no human adjudication of findings. The wear rates are determined by quantitative laboratory measurements.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
No, an MRMC comparative effectiveness study was not done. This is an in-vitro mechanical wear study, not a clinical study involving human readers or cases.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
Yes, in a conceptual sense, this was a "standalone" performance evaluation of the device's physical properties. The device's wear performance was measured directly in a simulated environment without human intervention influencing the wear measurement itself. It's not an AI algorithm, but rather a physical device being tested.
7. The Type of Ground Truth Used
The ground truth used was quantitative laboratory measurement of wear rates (mg/million cycles) from a standardized in-vitro hip simulator study.
8. The Sample Size for the Training Set
Not applicable. This is not a machine learning or AI-based device, so there is no concept of a "training set" for an algorithm. The "training" for the device's design and manufacturing would involve engineering principles and previous material science studies, not a data-driven training set.
9. How the Ground Truth for the Training Set Was Established
Not applicable, as there is no training set in the context of an algorithm. For material development and design, "ground truth" would be established through material testing, mechanical properties analysis, and prior scientific understanding of UHMWPE behavior under simulated joint loading.
§ 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.