(59 days)
The Axiom Orthopaedics Shoulder Resurfacing System is intended as a hemi shoulder replacement in patients where the humeral head and neck are of sufficient bone stock and the rotator cuff is intact or reconstructable. This device will increase shoulder mobility by reducing pain, restoring alignment, restoring flexion and extension movement, and resisting dislocation.
The Axiom Orthopaedics Shoulder Resurfacing System is indicated for use as a replacement of shoulder joints disabled by
- Rheumatoid arthritis with pain 1.
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- Non-inflammatory degenerative joint disease (i.e. osteoarthritis and avascular necrosis)
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- Correction of functional deformity
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- Fractures of the humeral head
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- Traumatic arthritis.
These components are single use only and are intended for cementless use.
The Axiom Orthopaedics Shoulder Resurfacing System is a series of humeral heads that are designed to articulate with a resurfaced or non-resurfaced Glenoid fossa. The proposed humeral heads are manufactured from cobalt chromium alloy (ASTM F-75) and can be used as either a left or right configuration. The interior surface of the proposed Axiom components contains a pattern of buttressed protrusions that help restrict rotation of the device. In addition to the buttressed protrusion pattern, the interior surface is coated with a plasma spray titanium substrate and a calcium phosphate coating (ASTM 1044 and ASTM 1147, respectively). The proposed humeral heads have been designed to mimic the normal humeral head geometry by employing a non-spherical accurate shape. The shape of the humeral heads does not exceed the radius of curvature of the reamed Glenoid fossa. This helps to maintain contact between the humeral head and the Glenoid fossa throughout the range of motion. The humeral heads are available in 14 sizes.
The provided text describes a 510(k) summary for the "Axiom Orthopaedics Shoulder Resurfacing System," which is a medical device for hemi shoulder replacement. The "study" mentioned here is essentially a performance testing in the form of a Finite Element Analysis (FEA). This is not equivalent to a clinical study with human or animal subjects, but rather an engineering simulation.
Here's an analysis of the acceptance criteria and the study that proves the device meets them, based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria | Reported Device Performance |
|---|---|
| Material Strength (Minimum Factor of Safety) | Factor of Safety: Ranges from 2.6 to 2.1 (for a material strength of 450 MPa). |
| Maximum Tensile Von-Mises Keel Stress | Ranges from 170 to 219 MPa. |
| Compliance with Standards | Complies with ASTM F-75 (cobalt-chromium alloy), F 1044-95, F 1147-99, and F 1160 05. |
| Biocompatibility | Stated that the device is made of biocompatible materials. |
| Functional Similarity | Designed to mimic normal humeral head geometry; fixation features to resist rotation are similar in principle to predicate devices. |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: The "test set" for the Finite Element Analysis (FEA) involved analyzing three sizes of the humeral head system: the smallest, the middle, and the largest.
- Data Provenance: The data is simulated data generated from a Finite Element Analysis, not from human or animal subjects. Therefore, there is no country of origin or retrospective/prospective nature in the traditional sense. It's a computational study.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
Not applicable. For a Finite Element Analysis, the "ground truth" is derived from engineering principles, material properties (e.g., ASTM F-75 material strength of 450 MPa), and simulated load conditions (752 N). There's no mention of human experts establishing a ground truth for the results of this specific engineering analysis in the provided text.
4. Adjudication Method for the Test Set
Not applicable. Since this is an engineering simulation, there is no adjudication method in the context of expert review of clinical cases. The results are based on the FEA model and calculations, which are then compared against predefined engineering acceptance criteria (e.g., factor of safety, stress limits).
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 device is a physical orthopedic implant. The provided document describes engineering performance testing (FEA) and regulatory substantial equivalence, not a study evaluating human reader performance with or without AI assistance. This type of study is relevant for diagnostic imaging AI, not for orthopedic implants.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) was done
Yes, in a way. The Finite Element Analysis (FEA) is a standalone simulation of the device's mechanical performance under specific load conditions. It does not involve human interaction or "human-in-the-loop" performance in the context of the device's function or evaluation during the simulation itself. The simulation is a computational assessment of the device's mechanical integrity.
7. The Type of Ground Truth Used
The "ground truth" for the FEA is based on:
- Engineering Principles and Material Properties: The stress and factor of safety calculations are derived from fundamental physics, mechanics of materials, and the specified properties of the cobalt-chromium alloy (ASTM F-75, with a material strength of 450 MPa).
- Simulated Load Conditions: A simulated 752 N load was applied, representing a defined biomechanical scenario.
8. The Sample Size for the Training Set
Not applicable. A Finite Element Analysis (FEA) is a simulation method that does not involve a "training set" in the machine learning sense. The model is built based on the device's design, material properties, and simulated boundary conditions, not "trained" on data.
9. How the Ground Truth for the Training Set Was Established
Not applicable, as there is no "training set" in this context. The "ground truth" for the model itself (i.e., the accuracy of the FEA simulation) would generally be established by validation against physical testing of similar designs or theoretical derivations, though no such validation against "ground truth" for the FEA model is explicitly mentioned in the provided text (only the results of the FEA are reported and compared to material strength).
§ 888.3690 Shoulder joint humeral (hemi-shoulder) metallic uncemented prosthesis.
(a)
Identification. A shoulder joint humeral (hemi-shoulder) metallic uncemented prosthesis is a device made of alloys, such as cobalt-chromium-molybdenum. It has an intramedullary stem and is intended to be implanted to replace the articular surface of the proximal end of the humerus and to be fixed without bone cement (§ 888.3027). This device is not intended for biological fixation.(b)
Classification. Class II.