K Number
K034028
Device Name
ATH FEMORAL STEM
Date Cleared
2004-03-11

(73 days)

Product Code
Regulation Number
888.3350
Reference & Predicate Devices
N/A
Predicate For
N/A
AI/MLSaMDIVD (In Vitro Diagnostic)TherapeuticDiagnosticis PCCP AuthorizedThirdpartyExpeditedreview
Intended Use

The ATH Femoral Stem is indicated for use in total hip arthroplasty for reduction or relief of pain and/or improved hip function in skeletally mature patients with the following conditions:

    1. non-inflammatory degenerative joint disease such as osteoarthritis, avascular necrosis, ankylosis, protrusio acetabuli, and painful hip dysplasia;
    1. inflammatory degenerative joint discase such as rheumatoid arthritis;
    1. correction of functional deformity;
    1. revision procedures where other treatments or devices have failed; and,
    1. treatment of fractures that are unmanageable using other techniques.
Device Description

The design features for Wright Medical Technology's ATH Femoral Stem are as follows:

  • Sizes range from 4mm to 13mm .
  • Wright Medical Technology's standard 12/14 SLT taper .
  • . Grit blast surface finish
  • Proximal body with double wedge shape .
  • Proximal body has rounded off rectangular cross-section .
  • Tapered distal stem with rounded off rectangular cross-section .
  • Dimple on lateral shoulder .
AI/ML Overview

This document is a 510(k) summary for the ATH Femoral Stem, submitted by Wright Medical Technology, Inc. It describes the device, its intended use, and states that it is substantially equivalent to predicate devices. This type of regulatory submission does not typically include a detailed study proving device meets acceptance criteria in the manner you've outlined for performance studies (e.g., specific acceptance criteria, sample sizes, expert ground truth).

Instead, "acceptance criteria" in this context refers to the FDA's regulatory requirements for demonstrating substantial equivalence to a legally marketed predicate device. This is achieved through comparisons of technological characteristics, intended use, and performance data from internal testing or literature, rather than a clinical study with an AI device.

Therefore, for the provided document, I cannot fill out the requested table regarding acceptance criteria and device performance as if it were an AI performance study. However, I can extract information relevant to the substantial equivalence determination.

Here's an analysis of the provided text in the context of your request:

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

The document does not present acceptance criteria and device performance in the format of a clinical or AI performance study. Instead, it relies on demonstrating substantial equivalence to predicate devices. This regulatory pathway means that the device is considered safe and effective if its intended use and technological characteristics are similar to those of a legally marketed predicate device, and any differences do not raise new questions of safety or effectiveness.

The "device performance" in this context is implied by its similarity to existing, approved devices. The summary states:

"The safety and effectiveness of the ATH Femoral Stem is established by the substantial equivalent information, materials data, and testing results provided within this Premarket Notification."

The specific "acceptance criteria" are not quantitative thresholds like sensitivity or specificity. Instead, they are the qualitative and quantitative similarities to the predicate device in terms of:

Acceptance Criteria (Implied by Substantial Equivalence)Reported Device Performance (as per document)
Intended Use (Must be the same as or very similar to predicate)The ATH Femoral Stem is indicated for use in total hip arthroplasty for reduction or relief of pain and/or improved hip function in skeletally mature patients with conditions such as: 1) non-inflammatory degenerative joint disease (e.g., osteoarthritis, avascular necrosis); 2) inflammatory degenerative joint disease (e.g., rheumatoid arthritis); 3) correction of functional deformity; 4) revision procedures; and 5) treatment of unmanageable fractures.
Technological Characteristics (Must be similar to predicate)- Sizes range from 4mm to 13mm.
  • Wright Medical Technology's standard 12/14 SLT taper.
  • Grit blast surface finish.
  • Proximal body with double wedge shape.
  • Proximal body has rounded off rectangular cross-section.
  • Tapered distal stem with rounded off rectangular cross-section.
  • Dimple on lateral shoulder.
  • Classification: 21 CFR 888.3358 Prosthesis, hip, semi-constrained, metal/polymer, porous uncemented- Class II; 21 CFR 888.3350 Prosthesis, hip, semi-constrained, metal/polymer, cemented- Class II. |
    | Performance Data (Must demonstrate equivalent safety and effectiveness; typically non-clinical for 510(k), e.g., material testing, mechanical testing) | The document explicitly states: "The safety and effectiveness... is established by the substantial equivalent information, materials data, and testing results provided within this Premarket Notification." (Specific types or results of these tests are not detailed in this summary, but would have been part of the full 510(k) submission.) |

2. Sample size used for the test set and the data provenance

The document does not describe a "test set" in the context of an AI performance study, nor does it mention a specific sample size of patients or images. The "testing results" mentioned in the summary refer to non-clinical tests (e.g., mechanical, material) that demonstrate the device's characteristics are comparable to the predicate. The FDA letter confirms the device is "substantially equivalent... to legally marketed predicate devices."

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts

Not applicable. This is a medical device 510(k) submission, not an AI performance study involving expert ground truth labeling.

4. Adjudication method for the test set

Not applicable. This is a medical device 510(k) submission, not an AI performance study involving adjudication of expert opinions.

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 medical device 510(k) submission for an implantable orthopedic device, not an AI diagnostic or assistive technology.

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

Not applicable. This is for a physical medical device.

7. The type of ground truth used

For a 510(k) submission for a physical implant, the "ground truth" for demonstrating safety and effectiveness relies on established engineering principles, material science, biomechanical testing standards, and the successful clinical history of the predicate device. It's not about expert consensus on an image or pathology from a dataset.

8. The sample size for the training set

Not applicable. This is a medical device 510(k) submission, not an AI development project.

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

Not applicable. This is a medical device 510(k) submission.

§ 888.3350 Hip joint metal/polymer semi-constrained cemented prosthesis.

(a)
Identification. A hip joint metal/polymer semi-constrained cemented 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 includes prostheses that have a femoral component made of alloys, such as cobalt-chromium-molybdenum, and an acetabular resurfacing component made of ultra-high molecular weight polyethylene and is limited to those prostheses intended for use with bone cement (§ 888.3027).(b)
Classification. Class II.