(90 days)
The LINK® MP® Reconstruction Prosthesis is intended for revision hip arthroplasty in patients whose bone stock is of poor quality or inadequate for other reconstruction techniques as indicated by deficiencies of the femoral head, neck, or portions of the proximal femur. The LINK® MP® Reconstruction Hip Prosthesis is indicated for the following conditions:
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Revision arthroplasty due to juxta-articular bone defects.
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Revision of loosened femoral prosthesis components involving extensive bone resorption of the proximal femur and widening of the medullary cavity or marked thinning of proximal femoral cortical bone.
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Revision of loosened femoral prosthesis components by peri- / subprosthetic fracture.
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Deformed proximal femur due to fractures or osteotomies.
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Correction of bone deficiencies, e.g. due to tumors.
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Large post-revision and post-trauma segmental bone defects.
The LINK® MP® Reconstruction Prosthesis is for cementless use only.
The LINK® MP® Reconstruction Prosthesis modular system consists of Prosthesis Heads, Stems, Neck Segments, Proximal Spacers, and Expansion Bolts. The modular components are interchangeable allowing for independent positioning. The Prosthesis Stems are available in a variety of diameters and lengths. Neck Segments are available in a variety of CCD angles and sizes. Proximal Spacers are available in a variety of heights and can be used independently or combined to add leg length. Expansion Bolts are used to secure the Neck Segments and Proximal Spacers, when used, to the modular Prosthesis Stems. Additional features include a tapered stem with a microporous surface. The Prosthesis Stems also include longitudinal fluting.
The MP® Reconstruction Prosthesis Stems (cementless) and Neck Segments are produced of Titanium Aluminum Vanadium alloy (Ti-6Al-4V). Proximal Spacers and Expansion Bolts are made of Cobalt Chromium Molybdenum casting alloy (CoCrMo) materials.
This document is a 510(k) premarket notification decision letter from the FDA to Waldemar Link GmbH and Company, KG, regarding their LINK® MP® Reconstruction Prosthesis.
Based on the provided text, the device in question is a hip joint prosthesis, not an AI/software device. Therefore, the information typically requested for AI/software acceptance criteria and performance studies (such as sample sizes for test and training sets, expert consensus, MRMC studies, etc.) is not applicable to this medical device submission.
The document explicitly states:
- "There was no clinical performance testing required for this device." (Page 5)
- The performance testing conducted was non-clinical (i.e., laboratory-based, mechanical testing) to demonstrate substantial equivalence to a predicate device.
Instead of AI/software metrics, the "acceptance criteria" and "study that proves the device meets the acceptance criteria" for this hip prosthesis are related to its mechanical performance and material characteristics, as outlined in the "Performance Data" section (Page 5).
Here's a breakdown of the relevant information provided, adapted for a mechanical device:
1. A table of acceptance criteria and the reported device performance:
| Acceptance Criteria (Standards/Tests) | Reported Device Performance and Conclusion |
|---|---|
| Guidance Considerations: | |
| * Guidance for Industry and FDA Staff, Non-Clinical Information for Femoral Stem Prosthesis, September 17, 2007 | * Non-clinical performance testing was conducted with consideration to these guidance documents. |
| * Guidance Document For Testing Non-Articulating,"Mechanically Locked", Components, May 1, 1995 | |
| Specific Performance Tests: | |
| * Femoral stem fatigue tests per ISO 7206-4 | * Demonstrated that the device is as safe, as effective, and substantially equivalent to the predicate devices. (Specific numerical results are not provided in this summary, but the FDA's acceptance implies satisfactory performance against the predicate). |
| * Femoral stem fatigue tests per ISO 7206-8 | * Demonstrated that the device is as safe, as effective, and substantially equivalent to the predicate devices. |
| * Femoral neck segment fatigue tests per ISO 7206-6 | * Demonstrated that the device is as safe, as effective, and substantially equivalent to the predicate devices. |
| * ASTM F2068 (presumably related to mechanical properties) | * Demonstrated that the device is as safe, as effective, and substantially equivalent to the predicate devices. |
| * Modular Connections, Fretting, and Corrosion Testing per ASTM F1875-98 | * Demonstrated that the device is as safe, as effective, and substantially equivalent to the predicate devices. |
| Overall Conclusion: | The results of non-clinical performance testing demonstrated that the device is as safe, as effective, and substantially equivalent to the predicate devices. The FDA concludes that the performance testing is sufficient to demonstrate that the subject and predicate devices are substantially equivalent with regard to design. |
2. Sample sized used for the test set and the data provenance:
- Sample Size: Not specified in the provided text. For mechanical testing, this would typically involve a specific number of test articles (e.g., n=5 or n=10 per test condition) rather than patient data.
- Data Provenance: The testing was "Non-Clinical performance testing," meaning it was conducted in a laboratory setting, not on human patients. The manufacturer is located in Hamburg, Germany.
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 mechanical device, and "ground truth" for non-clinical testing is established by adherence to recognized international and national standards (ISO, ASTM) and FDA guidance documents. Expertise would lie in materials science, biomechanics, and engineering, and in conducting accredited laboratory tests.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set:
- Not Applicable. This is not a study involving human readers or subjective interpretations. Mechanical test results are quantitative measurements against established pass/fail criteria defined by the standards.
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. No MRMC study was performed as this is a medical device (hip prosthesis), not an AI/software diagnostic tool.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- Not Applicable. This is a mechanical device, not an algorithm. The "standalone" performance refers to the device's mechanical integrity and functionality on its own.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc):
- Ground Truth Type: For this physical device, the "ground truth" for performance is defined by established engineering and biomechanical standards (ISO 7206 series, ASTM F1875-98, ASTM F2068) and FDA guidance documents for femoral stem prostheses. Successful performance means meeting the acceptance criteria outlined in these standards (e.g., surviving a certain number of fatigue cycles at a specified load, demonstrating acceptable wear/corrosion properties, etc.).
8. The sample size for the training set:
- Not Applicable. There is no "training set" as this is not a machine learning model.
9. How the ground truth for the training set was established:
- Not Applicable. There is no "training set."
In summary: The LINK® MP® Reconstruction Prosthesis underwent non-clinical, laboratory-based performance testing to demonstrate substantial equivalence to a legally marketed predicate device. The "acceptance criteria" were based on compliance with specific ISO and ASTM standards and FDA guidance documents for mechanical and material properties. No clinical studies, AI/software performance evaluations, or human reader studies were deemed necessary for this 510(k) submission.
§ 888.3353 Hip joint metal/ceramic/polymer semi-constrained cemented or nonporous uncemented prosthesis.
(a)
Identification. A hip joint metal/ceramic/polymer semi-constrained cemented or nonporous uncemented prosthesis is a device intended to be implanted to replace a hip joint. This device limits translation and rotation in one or more planes via the geometry of its articulating surfaces. It has no linkage across-the-joint. The two-part femoral component consists of a femoral stem made of alloys to be fixed in the intramedullary canal of the femur by impaction with or without use of bone cement. The proximal end of the femoral stem is tapered with a surface that ensures positive locking with the spherical ceramic (aluminium oxide, A12 03 ) head of the femoral component. The acetabular component is made of ultra-high molecular weight polyethylene or ultra-high molecular weight polyethylene reinforced with nonporous metal alloys, and used with or without bone cement.(b)
Classification. Class II.