(55 days)
Cobalt™ G HV Bone Cement is indicated for use as bone cement in arthroplasty procedures of the hip, knee and other joints to fix plastic and metal prosthetic parts to living bone when reconstruction is necessary because of revision of previous arthroplasty procedures due to joint infection. The cement is intended for use to affix a new prosthesis in the second phase of a two-stage revision after the initial infection has been cleared.
Cobalt GTM HV Bone Cement is a fast setting polymethylmethacrylate) cement for use in bone surgery. Mixing of the two sterile components, consisting of a powder and a liquid, initially produces a paste that is used to anchor a joint prosthesis or to fill an osseous defect. The hardened bone cement allows stable fixation of the prosthesis and transfers stresses produced on movement to the bone via the large interface. Insoluble zirconium (IV) oxide is included in the cement powder as an x-ray contrast medium. The FD&C Blue No. 2 Aluminum Lake color additive serves as optical marking of the bone cement at the site of the operation. The gentamicin component is a broad-spectrum antibiotic.
This document describes the Cobalt G™ HV Bone Cement, a polymethylmethacrylate (PMMA) bone cement, and its substantial equivalence to predicate devices. It focuses on the non-clinical testing performed to demonstrate this equivalence.
Since no clinical efficacy or diagnostic performance study was conducted, many of the requested sections (e.g., sample size for test set, number of experts, adjudication method, MRMC study, standalone performance) are not applicable. The device relies on non-clinical comparative testing to demonstrate substantial equivalence to a predicate device.
1. Table of Acceptance Criteria and Reported Device Performance
The submission does not explicitly list specific numerical acceptance criteria for each test. Instead, it states that the results of the comparative testing showed that Cobalt G™ HV Bone Cement possesses "chemical, physical, mechanical and handling characteristics necessary to fulfill its intended use" and that it is "equivalent to Palacos® G (with gentamicin) for its primary intended use." The general acceptance criterion was substantial equivalence to the predicate device, Palacos® G Bone Cement.
| Test Category | Acceptance Criteria (Implicit) | Reported Device Performance (Cobalt G™ HV Bone Cement) |
|---|---|---|
| Chemical | To be substantially equivalent to Palacos® G (with gentamicin). | Demonstrated substantial equivalence in chemical composition (primary difference being the color additive FD&C Blue No. 2 Aluminum Lake, which is FDA approved). |
| Physical | To be substantially equivalent to Palacos® G (with gentamicin). | Demonstrated substantial equivalence in physical characteristics. |
| Mechanical | To be substantially equivalent to Palacos® G (with gentamicin). | Demonstrated substantial equivalence in mechanical characteristics. |
| Handling | To be substantially equivalent to Palacos® G (with gentamicin). | Demonstrated substantial equivalence in handling characteristics. |
| Sterilization | Processed and sterilized in an equivalent manner to predicate device. | Processed and sterilized in an equivalent manner to Palacos® G. |
| Packaging | Equivalent to legally marketed devices (Generation 4® Bone Cement, K993836). | Equivalent to Generation 4® Bone Cement. |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size for Test Set: Not specified. The testing was in vitro comparative testing, meaning it was conducted in a laboratory setting using material samples, not a patient-based test set.
- Data Provenance: In vitro laboratory testing.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
- Not applicable. Ground truth for in vitro physical, chemical, and mechanical tests is established by standardized testing methods and measurements, not expert consensus in the diagnostic sense.
4. Adjudication Method for the Test Set
- Not applicable. See point 3.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
- No, a MRMC study was not performed. This device is a bone cement, and its performance is assessed through material properties, not diagnostic accuracy requiring human reader interpretation.
6. Standalone Performance Study
- No, a standalone (algorithm only without human-in-the-loop performance) study was not performed. The "performance" of this device is its material characteristics, which were compared to a predicate, not an AI algorithm.
7. Type of Ground Truth Used
- The "ground truth" for the in vitro comparative testing consisted of established standards for material properties, chemical composition analysis, and physical/mechanical testing protocols. The direct comparison was made against the characteristics of the legally marketed predicate device, Palacos® G Bone Cement.
8. Sample Size for the Training Set
- Not applicable. This device is a medical device (bone cement) and does not involve AI or machine learning algorithms that require a "training set."
9. How the Ground Truth for the Training Set Was Established
- Not applicable. See point 8.
§ 888.3027 Polymethylmethacrylate (PMMA) bone cement.
(a)
Identification. Polymethylmethacrylate (PMMA) bone cement is a device intended to be implanted that is made from methylmethacrylate, polymethylmethacrylate, esters of methacrylic acid, or copolymers containing polymethylmethacrylate and polystyrene. The device is intended for use in arthroplastic procedures of the hip, knee, and other joints for the fixation of polymer or metallic prosthetic implants to living bone.(b)
Classification. Class II (special controls). The special control for this device is the FDA guidance document entitled “Class II Special Controls Guidance Document: Polymethylmethacrylate (PMMA) Bone Cement.”