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The Alloclassic SL Offset Femoral Stem is intended for prosthetic replacement without bone cement in treatment of the following:

• patient conditions of noninflammatory degenerative joint disease (NIDJD); e.g., avascular . necrosis, osteoarthritis and inflammatory joint disease (IJD), e.g., rheumatoid arthritis.
• those patients with failed previous surgery where pain, deformity, or dysfunction persists. .
• revision of a previously failed hip arthroplasty. .
• patients who require a total hip replacement. .

The Alloclassic Zweymüller SL Offset Femoral Stem is very similar to the previously cleared Alloclassic Zweymüller SL Femoral Stem in that it is:

• a conically shaped straight stem with a rectangular cross section (for rotational stability). 1.
• the same design, distal to the line of resection. 2.
• manufactured from wrought Ti-Al-Nb titanium alloy (Protasul-100™, ISO 5832-11/ASTM 3. F1295).
• grit blasted, below the neck, to enhance the bone-prosthesis interface. 4.
  In contrast, this stem provides an additional 6.25mm of offset (per size) and has a CCD/neck angle of 121° (vs. 131° for SL stem). Overall, this new design provides a higher offset sometimes needed for:
• 1. correcting insufficient soft tissue balancing,
• 2. restoration of leg length, and
• sufficient joint stability following total hip arthroplasty. 3.

The provided text is a 510(k) summary for a medical device called the "Alloclassic™ Zweymüller™ SL Offset Femoral Stem." This type of document is a submission to the FDA to demonstrate substantial equivalence to an existing legally marketed device. It typically focuses on design, materials, and intended use comparison rather than clinical study data proving performance against specific acceptance criteria in the way a diagnostic AI device would.

Therefore, many of the requested points, especially those related to clinical studies, diagnostic performance, ground truth, and expert evaluation, are not applicable to this type of regulatory submission for a prosthetic hip stem. The document does not describe a study to prove the device meets acceptance criteria in a quantitative sense of diagnostic accuracy or clinical outcomes assessed by a clinical trial. Instead, it argues for substantial equivalence based on design and material similarities to a predicate device.

Here's a breakdown based on the available information:

1. A table of acceptance criteria and the reported device performance

• Acceptance Criteria: The document does not explicitly state quantitative acceptance criteria in terms of performance metrics (like sensitivity, specificity, accuracy) that a diagnostic device would have. The "acceptance criteria" for a 510(k) submission for a hip stem are typically related to demonstrating substantial equivalence in terms of:
  • Same indications for use.
  • Similar design principles (shape, material, mechanism of action).
  • Similar materials of construction.
  • Similar manufacturing processes.
  • No new questions of safety or effectiveness.
• Reported Device Performance: The document does not report performance data from a clinical study for the new device itself. Instead, it highlights design differences and their intended benefits:
  • Provides an additional 6.25mm of offset (per size).
  • Has a CCD/neck angle of 121° (vs. 131° for the SL stem).
  • These design changes are intended for:
    • Correcting insufficient soft tissue balancing.
    • Restoration of leg length.
    • Sufficient joint stability following total hip arthroplasty.
  • The document implies that the performance (safety and effectiveness) is substantially equivalent to the predicate device due to shared fundamental characteristics.

2. Sample size used for the test set and the data provenance (e.g., country of origin of the data, retrospective or prospective)

• Not Applicable. This document describes a 510(k) submission based on design and material comparison, not a clinical study with a test set of patient data.

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)

• Not Applicable. No test set or ground truth determination by experts is described in this document.

4. Adjudication method (e.g., 2+1, 3+1, none) for the test set

• Not Applicable. No test set or adjudication process is described.

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 a hardware orthopedic implant, not an AI-assisted diagnostic device.

6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done

• Not Applicable. This is a hardware orthopedic implant, not an algorithm.

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)

• Not Applicable. No ground truth is described as there is no diagnostic study. The "ground truth" for the substantial equivalence argument is the established safety and effectiveness of the predicate device (K030373), which is assumed to be safe and effective based on its own prior regulatory clearance.

8. The sample size for the training set

• Not Applicable. There is no "training set" in the context of an AI/diagnostic device. For a hip stem, this would refer to design validation and verification activities (e.g., mechanical testing, fatigue testing) often done on prototypes, but these are not clinical "training sets."

9. How the ground truth for the training set was established

• Not Applicable. As above, no training set or ground truth in the AI/diagnostic sense is applicable here. The "ground truth" for design validation is typically engineering specifications and performance standards established through biomechanical testing, material science, and established surgical principles.

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