(227 days)
Significantly impaired joints resulting from rheumatoid, osteo, and post-traumatic arthritis. Revision of failed femoral head replacement, hip arthroplasty or other hip procedures.
A. Proximal femoral fractures.
B. Avascular necrosis of the femoral head.
C. Non-union of proximal femoral neck fractures.
D. Other indications such as congenital dysplasia, arthrodesis conversion, coxa magna, coxa plana, coxa vara, coxa valga, developmental conditions, metabolic and tumorous conditions, osteomalacia, pseudarthrosis conversion, and structural abnormalities.
UNISYN stems used with roughened and plasma coated bodies are intended for cemented or uncemented use. UNISYN stems used with plasma/HA or HA coated bodies are intended for uncemented use only.
The UniSyn Hip System was originally cleared as a modular hip system for Hayes Medical under the name "Triton", modifications to the system were cleared in a subsequent submission by Hayes under the UniSyn name. Hayes Medical changed its name to Consensus Orthopedics in 2008. This system consists of three primary components: the neck, the body, and the stem. This submission is to addition of a set of modified ("Plus") stems.
These minor modifications in body thickness are designed to allow for better contact between the implant and the inner surface of the medullary canal during revision surgery. The sizes of stems offered with the modified design are within the ranges previously cleared for the UniSyn system. The Plus stems are offered in neutral or +1 mm styles, short or long, in 10 to 20 mm diameters, and lengths from 110 to 210 mm. There is no change to the manufacturing, packaging, or sterilization processes. This change will not affect the indications for use nor any of the labeling.
The provided text describes a 510(k) premarket notification for the UNISYN Plus stem, which is part of the UNISYN Hip System. The submission aims to demonstrate substantial equivalence to previously cleared predicate devices, rather than establishing new safety and effectiveness through a comprehensive study with acceptance criteria and performance metrics in the way a novel device might.
Here's an analysis based on the provided document:
1. Table of Acceptance Criteria and Reported Device Performance:
For this type of 510(k) submission, the "acceptance criteria" and "reported device performance" are primarily focused on demonstrating that the modified device (UNISYN Plus stem) maintains the same fundamental characteristics and performance as its predicate devices. The document does not present a table with specific quantitative acceptance criteria (e.g., accuracy, sensitivity, specificity) and corresponding performance results. Instead, it relies on the concept of substantial equivalence.
The key "criteria" for this submission are that the new "Plus" stems for the UniSyn hip systems employ the:
- Same materials
- Basic design features
- Manufacturing processes
- Packaging
- Indications as the predicate stems for the UHS.
The "reported device performance" is implicitly that these criteria are met, leading to the conclusion of substantial equivalence.
Specific Performance Data Mentioned:
- Distal fatigue performance: "Distal fatigue performance of the UniSyn Plus grit blasted stem was evaluated per ISO 7206-4 on a worst case example."
- Acceptance Criteria (Implied): The fatigue performance must be equivalent to, or better than, the predicate device and meet the standards set by ISO 7206-4.
- Reported Performance: Not explicitly stated with a numerical result, but the conclusion is that "No other nonclinical bench testing was deemed necessary over that used in support of the predicates based on identical design and materials," implying satisfactory performance.
2. Sample Size for Test Set and Data Provenance:
- Sample Size for Test Set: The document explicitly states "a worst case example" was evaluated for distal fatigue performance. This means the sample size for this specific test was very small, likely N=1 or a limited number of test articles representing the worst-case scenario. It is a bench test, not a clinical test involving human subjects.
- Data Provenance: The data comes from non-clinical bench testing conducted by the manufacturer (Consensus Orthopedics, Inc.). It is not from human subjects, so concepts like "country of origin" or "retrospective/prospective" do not apply.
3. Number of Experts Used to Establish Ground Truth for Test Set and Qualifications:
Not applicable. The "ground truth" for a device like a hip stem is typically established through engineering specifications, material science standards, and established biomechanical performance criteria (e.g., ISO standards). There are no "experts" in the sense of clinicians establishing a diagnostic ground truth for a test set.
4. Adjudication Method for the Test Set:
Not applicable. This is a non-clinical bench test, not a clinical study involving human assessment or adjudication of results.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study:
No. This type of study is typically done for diagnostic imaging devices or AI-assisted diagnostic tools. The UNISYN Plus stem is a physical orthopedic implant, making an MRMC study irrelevant. There is no human reader improvement with AI assistance discussed as there is no AI component.
6. Standalone (Algorithm Only Without Human-in-the-Loop Performance) Study:
Not applicable. There is no algorithm or AI component in the UNISYN Plus stem. Performance assessment is based on physical material and design testing.
7. Type of Ground Truth Used:
The ground truth used for evaluating the UNISYN Plus stem's performance relies on engineering specifications, material properties, and adherence to recognized international standards such as ISO 7206-4 for fatigue testing. It is not expert consensus, pathology, or outcomes data in the clinical sense, but rather a demonstration of compliance with established biomechanical and material science criteria.
8. Sample Size for the Training Set:
Not applicable. This device does not involve a "training set" in the context of machine learning or algorithms. Its development and testing are based on traditional engineering design and physical performance verification.
9. How the Ground Truth for the Training Set Was Established:
Not applicable, as there is no training set. The "ground truth" for the overall design and performance of the hip system is established through a combination of biomechanical design principles, material science knowledge, and adherence to relevant ISO standards, accumulated over years of orthopedic implant development.
§ 888.3360 Hip joint femoral (hemi-hip) metallic cemented or uncemented prosthesis.
(a)
Identification. A hip joint femoral (hemi-hip) metallic cemented or uncemented prosthesis is a device intended to be implanted to replace a portion of the hip joint. This generic type of device includes prostheses that have a femoral component made of alloys, such as cobalt-chromium-molybdenum. This generic type of device includes designs which are intended to be fixed to the bone with bone cement (§ 888.3027) as well as designs which have large window-like holes in the stem of the device and which are intended for use without bone cement. However, in these latter designs, fixation of the device is not achieved by means of bone ingrowth.(b)
Classification. Class II.