(24 days)
The GMK knee prosthesis is designed for cemented use in total knee arthroplasty, if there is evidence of sufficient sound bone to seat and support the components. This knee replacement system is indicated in the following cases: Severely painful and/or disabled joint as a result of arthritis, traumatic arthritis, rheumatoid arthritis or polyarthritis. Avascular necrosis of femoral condyle. Post traumatic loss of joint configuration. Primary implantation failure. Tibial augments are to be attached to the tibial baseplate with both the fixing cylinders and bone cement. In case a semi-constrained liner is used, an extension stem must be implanted both on the tibial and on the femoral components.
The GMK Short Stem is a tibial extension stem made of titanium alloy (Ti6-Al4-V) according to ISO5832-3:1996, Implants for Surgery - Metallic materials - Part 3: Wrought titanium 6-aluminum 4-vanadium alloy. The GMK Short Stem has a diameter of 11mm and a length of 30mm. The GMK Short Stem is compatible with the tibial baseplates of the GMK Total Knee System (K090988) and the tibial baseplates of the GMK Sphere Total Knee System (K121416).
This document describes a 510(k) premarket notification for the "GMK Short Stem," a tibial extension stem for total knee arthroplasty. The submission focuses on demonstrating substantial equivalence to predicate devices, primarily through mechanical performance data and comparison of specifications, rather than a clinical study involving human patients or complex AI algorithms that would require extensive acceptance criteria tables and detailed study designs.
Therefore, many of the requested categories (2-9) regarding acceptance criteria for AI/diagnostic devices, sample sizes, expert ground truth, MRMC studies, standalone performance, and training sets are not applicable to this type of submission.
Here's a breakdown of the requested information based on the provided text:
1. A table of acceptance criteria and the reported device performance
| Acceptance Criteria Category | Specific Criteria | Reported Device Performance |
|---|---|---|
| Mechanical Performance | General: Capable of withstanding expected in vivo loading without failure. | |
| Specific (implicitly): Equivalence regarding materials, diameter, and morse taper to the 65mm GMK tibial extension stem (K090988). | ||
| Specific (implicitly): Modular connection to the tibial baseplate equivalent to the connection of the GMK tibial baseplate (K090988). | ||
| Risk Analysis Outcome: No new significant risks identified compared to predicate, and not a "worst case" scenario in terms of modular connection to the tibial baseplate when compared to K090988. | The mechanical data indicates that the GMK Short Stem "is equivalent to devices currently cleared for use and is capable of withstanding expected in vivo loading without failure." | |
| It has "the same specifications (materials, diameter, and morse taper) as the 65mm GMK tibial extension stem cleared under K090988." | ||
| "Since the modular connection to the GMK tibial baseplate (K090988) is the same, the test performed on the tibial modular connection (K090988) is also applicable to the connection when the GMK Short Stem is used and no further tests are needed to prove substantial equivalence." | ||
| Risk analysis identified no new risks, and the GMK Short Stem was determined "not worst case" compared to the K090988 GMK Total Knee component's modular connection. | ||
| Conclusion: Based on this, the device is considered substantially equivalent to its predicate devices. | ||
| Material Composition | Made of titanium alloy (Ti6-Al4-V) according to ISO5832-3:1996. | "Made of titanium alloy (Ti6-Al4-V) according to ISO5832-3:1996, Implants for Surgery - Metallic materials - Part 3: Wrought titanium 6-aluminum 4-vanadium alloy." |
| Design Features | Diameter of 11mm and a length of 30mm. Compatible with GMK Total Knee System (K090988) and GMK Sphere Total Knee System (K121416) tibial baseplates. | "The GMK Short Stem has a diameter of 11mm and a length of 30mm." |
| "The GMK Short Stem is compatible with the tibial baseplates of the GMK Total Knee System (K090988) and the tibial baseplates of the GMK Sphere Total Knee System (K121416)." | ||
| Indications for Use | Must be substantially equivalent to predicate devices. | The indications for use are stated as being for "cemented use in total knee arthroplasty" for conditions like arthritis, avascular necrosis, post-traumatic loss of joint configuration, and primary implantation failure. These are implicitly considered substantially equivalent to predicate devices, as stated in the "Comparison to Predicate Devices" section: "The indications for use, design features and materials of the GMK Short Stem are substantially equivalent to those of the predicate devices." |
2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)
Not Applicable. This submission relies on mechanical testing of medical device components and comparative analysis of specifications, not on clinical data (human patient data) that would involve a "test set" in the context of AI or diagnostic devices. The performance testing mentions "design verification was conducted to written protocols with pre-defined acceptance criteria," which implies lab-based mechanical testing of prototypes or manufacturing samples.
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)
Not Applicable. Ground truth, in the context of expert consensus or clinical outcomes, is not relevant for this type of mechanical device submission. Acceptance criteria were based on "standards, FDA guidance, and comparison to the predicate device system," which are engineering and regulatory benchmarks, not expert clinical interpretation.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
Not Applicable. There was no expert adjudication process for a "test set" in the clinical sense.
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 is a hardware component (a tibial extension stem) for knee arthroplasty, not an AI or imaging diagnostic device.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
Not Applicable. This is a hardware component, not an algorithm.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)
The "ground truth" or basis for evaluation of this device is primarily mechanical engineering standards (e.g., ISO5832-3:1996), FDA guidance documents, and direct comparison of design specifications and materials to previously cleared predicate devices.
8. The sample size for the training set
Not Applicable. This is a mechanical device, not an AI model requiring a training set.
9. How the ground truth for the training set was established
Not Applicable. See above.
§ 888.3560 Knee joint patellofemorotibial polymer/metal/polymer semi-constrained cemented prosthesis.
(a)
Identification. A knee joint patellofemorotibial polymer/metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace a knee joint. The device limits translation and rotation in one or more planes via the geometry of its articulating surfaces. It has no linkage across-the-joint. This generic type of device includes prostheses that have a femoral component made of alloys, such as cobalt-chromium-molybdenum, and a tibial component or components and a retropatellar resurfacing component made of ultra-high molecular weight polyethylene. This generic type of device is limited to those prostheses intended for use with bone cement (§ 888.3027).(b)
Classification. Class II.