(30 days)
SpaceFlex Knee disposable cement spacer molds are indicated for use to mold a temporary Total Knee Replacement (TKR) for skeletally mature patients undergoing a two-stage procedure due to a septic process. The molded temporary knee prosthesis is indicated for an implantation period of 180 days or less. Because of inherent mechanical limitations of the device material (G3A Bone Cement), the molded temporary prosthesis is only indicated for patients who will consistently use traditional mobility assist devices (e.g. crutches, walkers) throughout the implant period.
G21 SpaceFlex Knee system are disposable cement spacer molds made of polypropylene (PP) intended to be filled with low-viscosity polymethyl methacrylate bone cement directly in the operating room. Once the bone cement has hardened, the SpaceFlex Knee system creates a polymethyl methacrylate based bone cement spacer for patients undergoing a two-stage procedure following a periprosthetic joint infection. The device can be used in either the left or right knee joint. The SpaceFlex Knee molds are single-use and cannot be re-used or re-sterilized.
This document is a 510(k) summary for a medical device called "SpaceFlex Knee - 80mm Size." It aims to demonstrate that this new device is substantially equivalent to existing predicate devices.
1. Acceptance Criteria and Reported Device Performance:
| Acceptance Criteria (Performance Specification) | Reported Device Performance |
|---|---|
| Device functions as intended post-testing. | Functioned as intended. |
| All results are satisfactory. | All results were satisfactory. |
| Meets all performance specifications. | Met all performance specifications. |
| Passed Dimensional and Visual Characterization | Test passed. |
| Passed Rupture Test | Test passed. |
| Passed Fatigue Test | Test passed. |
| Passed Elution Test | Test passed. |
2. Sample Size Used for the Test Set and Data Provenance:
The document does not explicitly state the sample size for the test set. It mentions "The mechanical properties of the SpaceFlex knee System 80mm size were tested in accordance with applicable international standards," implying that a sufficient number of samples were tested to meet the requirements of those standards.
The provenance of the data is directly from the manufacturer, G21 S.r.l., whose address is in Italy. The testing described appears to be prospective performance testing conducted on the device itself, rather than retrospective analysis of patient data.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications of Those Experts:
This type of study does not involve establishing ground truth through expert review in the way a diagnostic AI study would. The performance data presented here relates to mechanical and material properties of the device, not clinical diagnostic accuracy. Therefore, the concept of "experts" establishing ground truth in this context is not applicable. The "ground truth" for these tests would be the established international standards and engineering specifications.
4. Adjudication Method for the Test Set:
Adjudication methods like 2+1 or 3+1 are typically used in clinical studies involving interpretation of medical images or patient outcomes, where there might be disagreements among expert reviewers. This document describes laboratory-based mechanical and material performance testing of a physical device. Therefore, adjudication methods are not applicable here. The results of these tests are objective measurements against predefined standards.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done:
No, an MRMC comparative effectiveness study was not done. This study is focused on the mechanical and material performance of a physical medical device (a cement spacer mold for knee replacement), not on the diagnostic accuracy or effectiveness of an AI algorithm interpreted by human readers.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was done:
No, a standalone (algorithm only) performance study was not done. This document is about the physical characteristics and performance of a medical device, not an AI algorithm.
7. The Type of Ground Truth Used:
The "ground truth" for this study is based on predefined international standards and engineering specifications for the mechanical properties and material characteristics of medical devices, specifically those for knee joint prostheses and bone cement. The tests (Dimensional and Visual Characterization, Rupture Test, Fatigue Test, Elution Test) verify that the device meets these established physical and material requirements.
8. The Sample Size for the Training Set:
This document describes the performance testing of a physical medical device, not the development or training of an AI algorithm. Therefore, the concept of a "training set" and its sample size is not applicable.
9. How the Ground Truth for the Training Set was Established:
As this study does not involve an AI algorithm with a training set, the question of how ground truth for a training set was established is not applicable.
§ 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.”