(51 days)
The Encore Fully Coated Hip Stem is intended for treatment of patients who are candidates for total hip arthroplasty because the natural head and neck have been affected by osteoarthritis, inflammatory arthritis, traumatic arthritis, rheumatoid arthritis, avascular necrosis or femoral neck fracture, and revision arthroplasty where bone loss is minimal.
The indications for use of the total hip replacement prosthesis include: noninflammatory degenerative joint disease including osteoarthritis and avascular necrosis; rheumatoid arthritis; correction of functional deformity; revision procedures where other treatments or devices have failed; and treatment of nonunion, femoral neck and trochanteric fractures of the proximal femur with head involvement, which is unmanageable using other techniques. This stem is to be pressfit.
The Encore Fully Coated Hip Stem is available in a variety of proximal body, head offset and distal stem diameter and length configurations. When viewed in the mediolateral plane the Encore Fully Coated Hip Stem tapers slightly proximal to distal in the body area only. The proximal body is trapezoidal in cross-sectional geometry and tapers lateral to medial. The distal stem portion is cylindrical and the larger sizes have anterior/posterior flutes to decrease the distal stem stiffness.
The Encore Fully Coated Hip Stem is fabricated from cast CoCrMo that conforms to ASTM F75. The outside surface of the stem is porous coated with CoCrMo beads (ASTM F75) to provide a porous surface for enhanced fixation. The stem is intended to be press-fit.
The Encore Fully Coated Hip Stem is collared and has a Morse type taper to receive modular heads. This stem is available with a standard head/stem offset and a enhanced offset version that provides additional lateralization of the patient's femur without increasing leg length. The stem/neck angle is 135°.
The provided text describes a medical device, the Encore Fully Coated Hip Stem, and its clearance through the FDA 510(k) process. However, it does not contain information about specific acceptance criteria, a study proving device performance against those criteria, or details regarding ground truth establishment, expert involvement, or statistical analysis (like MRMC studies, sample sizes for training/test sets, etc.) typically found in detailed performance studies.
The document is a US FDA 510(k) clearance letter and an "Indications For Use" statement.
Here's a breakdown of what is and isn't present, according to your requested categories:
1. A table of acceptance criteria and the reported device performance
| Acceptance Criteria | Reported Device Performance |
|---|---|
| Not specified in the provided text. | Fatigue Stem Strength: Laboratory testing and finite element analysis were used to determine (but not report specific criteria or results). |
| Morse Type Taper Strength: Laboratory testing and finite element analysis were used to determine (but not report specific criteria or results). |
2. Sample sized used for the test set and the data provenance
- Sample Size for Test Set: Not specified.
- Data Provenance: The "Test Results" section mentions "Laboratory testing and finite element analysis," suggesting these were conducted by Encore Orthopedics, Inc. and are likely internal company data. Given the nature of a 510(k) submission, this would be prospective testing on the physical device and computational modeling, rather than clinical data from human subjects. The country of origin for the data is implicitly the USA, where Encore Orthopedics is located.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
- Number of Experts: Not applicable. The "ground truth" for mechanical testing, like fatigue strength, is determined by established engineering standards and physical measurements, not by expert consensus or interpretation of images/clinical data.
- Qualifications of Experts: Not applicable.
4. Adjudication method for the test set
- Not applicable. Adjudication methods are relevant for subjective interpretations (e.g., image reading) to establish a consensus ground truth. Mechanical testing has objective outcomes.
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
- No MRMC study was done or mentioned. This device is a hip stem implant, not an AI-powered diagnostic or assistive tool for human readers.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
- Not applicable. This is a physical medical implant, not a software algorithm.
7. The type of ground truth used
- The "ground truth" for the tests performed (fatigue stem strength and Morse type taper strength) would be engineering standards and physical measurements demonstrating the device's ability to withstand anticipated mechanical stresses and forces. This is based on objective, quantifiable data derived from laboratory testing and finite element analysis.
8. The sample size for the training set
- Not applicable in the AI/machine learning sense. If "training set" refers to samples used for mechanical testing, it is not specified.
9. How the ground truth for the training set was established
- Not applicable in the AI/machine learning sense. For mechanical testing, the "ground truth" is inherent in the physical properties and performance under controlled conditions as measured during laboratory tests and modeled in finite element analysis.
Summary of Study Information Provided:
The relevant "study" in this context is the pre-market testing required for FDA 510(k) clearance for a physical implant. The document states:
- Study Type: Laboratory testing and finite element analysis.
- Purpose: To determine fatigue stem strength and Morse type taper performance.
- Conclusion (implied by FDA clearance): The device's performance, as demonstrated by these tests, was deemed substantially equivalent to predicate devices, meeting the necessary safety and efficacy standards for its intended use.
- Limitations of Information: The specific acceptance criteria (e.g., "must withstand X cycles at Y load"), the detailed results of the tests, and the exact sample sizes of physical components tested are not disclosed in this public FDA summary document. This information would typically be part of the full 510(k) submission, but not in the public facing clearance letter.
§ 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.