(90 days)
Disposable cement spacer molds with titanium reinforcement stem and prolongation are indicated for use to mold a temporary hemi-hip replacement for skeletally mature patients undergoing a two-stage revision procedure due to a septic process. The temporary prosthesis is molded using low viscosity polymethylmethacrylate bone cement and inserted into the femoral medullary canal and acetabular cavity following removal of the existing femoral and acetabular implants and debridement.
The device is intended for use in conjunction with systemic antimicrobial antibiotic therapy (standard treatment approach to an infection). The hemi-hip prosthesis made from the SpaceFlex Hip disposable cement molds is not intended for use more than 180 days, at which time it must be explanted and permanent devices implanted or another appropriate treatmy performed (e.g. resection arthroplasty, fusion, etc.).
Due to the inherent mechanical limitations of the hemi-hip prosthesis material (low viscosity polymethylmethacrylate), the temporary hemi-hip prosthesis is only indicated for patients who will consistently use traditional mobility assist devices (e.g. crutches, walkers) throughout the implant period.
Disposable cement spacer molds with titanium reinforcement stem and prolongation are indicated for use to mold a temporary hemi-hip replacement for skeletally mature patients undergoing a two-stage revision procedure due to a septic process. The temporary prosthesis is molded using low viscosity polymethylmethacrylate bone cement and inserted into the femoral medullary canal and acetabular cavity following removal of the existing femoral and acetabular implants and debridement.
This document describes the G21 SpaceFlex Hip, a medical device for temporary hemi-hip replacement, and provides information regarding its FDA clearance.
Here's an analysis of the provided text with respect to your questions:
1. A table of acceptance criteria and the reported device performance
The document mentions that the device was tested against "applicable international standards" and that "all results were satisfactory and met all performance specifications." However, it does not provide a specific table of acceptance criteria with corresponding performance outcomes. It lists the types of tests performed:
| Test Type | Reported Performance |
|---|---|
| Fatigue Test | "functioned as intended" and "all results were satisfactory and met all performance specifications." |
| Gentamicin Elution Test | "functioned as intended" and "all results were satisfactory and met all performance specifications." |
| Molding Temperature Analysis | "functioned as intended" and "all results were satisfactory and met all performance specifications." |
| Pyrogen testing (USP 38: NF33 ) | Concluded that the "subject device and packaging is non-pyrogenic." |
2. Sample size used for the test set and the data provenance (e.g., country of origin of the data, retrospective or prospective)
The document mentions "performance testing - mechanical/bench testing," but it does not specify the sample size for any of these tests. It also does not provide information on the country of origin of the data or whether the studies were retrospective or prospective. These were likely benchtop (laboratory) studies, not human or animal studies.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g., radiologist with 10 years of experience)
This question is not applicable to the information provided. The document describes mechanical/bench testing, which typically does not involve human experts establishing ground truth in the same way clinical studies do. The "ground truth" here would be the physical properties and performance characteristics measured by engineering and scientific methods against established standards.
4. Adjudication method (e.g., 2+1, 3+1, none) for the test set
This question is not applicable for the same reasons as point 3. Adjudication methods are relevant for interpretation of clinical data or images, not for objective measurements in bench testing.
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
This question is not applicable. The G21 SpaceFlex Hip is a physical medical device (cement molds for temporary hip replacement), not an AI-powered diagnostic or assistive tool. Therefore, MRMC studies or AI assistance are not relevant.
6. If a standalone (i.e., algorithm only without human-in-the-loop performance) was done
This question is not applicable, as the device is a physical medical product, not an algorithm.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)
For the performance testing mentioned, the "ground truth" would be established by engineering and scientific standards (e.g., ISO, ASTM, USP) for mechanical properties, material properties, and biocompatibility. For instance, the pyrogen testing refers to USP 38: NF33 , which defines the method and acceptance criteria for pyrogenicity.
8. The sample size for the training set
This question is not applicable as the device is a physical product and not an AI algorithm that requires a training set.
9. How the ground truth for the training set was established
This question is not applicable for the same reason as 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.”