(28 days)
The GMK® Total Knee System 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 wedges cemented are to be attached to the tibial baseplate with both the fixing cylinders and bone cement.
The GMK HINGE knee prosthesis is designed for cemented use in total knee arthroplasty when the preoperative diagnosis of the joint determines that the bone and stability situation require the implantation of a constrained prosthesis.
The GMK HINGE knee system is indicated in the following cases:
· Severely painful and/or disabled joint as a result of arthritis, traumatic arthritis, rheumatoid arthritis or polyarthritis associated with bone loss and/or severe joint instability
· Considerable loss of function of the knee joint
· High-grade joint destruction requiring additional stabilization with stems and reconstruction of bone defects with metal augmentation
· Failure of a primary prosthesis (e.g. infection, loosening)
· Former revision arthroplasty
· Post traumatic loss of joint configuration
· Avascular necrosis of femoral condyle.
Tibial augmentation are to be screwed to the tibial baseplate with both the two provided fixing screws.
When a GMK HINGE® implant is used it is mandatory to implant both the femoral and tibial components with an extension stem.
The GMK Revision-Femoral Distal Augmentations have been designed to allow the surgeon to selectively fill bone deficiencies and to aid in adjusting the height of the joint line. In addition, these augments can help to achieve a stable fixation between the implant and the bone.
The purpose of this submission is to gain clearance for additional femoral distal augmentation thicknesses of 12 mm, 16 mm, and 20 mm, which can be used with the 5 mm thick posterior wedges. The previously cleared femoral distal augmentation sizes (referred to K102437 as femoral distal wedges) were for 4 mm, 8 mm, and 12 mm.
The subject devices are matched with the GMK Revision STD femoral component, GMK Revision PS femoral component and the GMK Hinge femoral component. The distal wedge is fixed to the femoral component through a thickness-specific titanium alloy screw packaged with it.
The GMK Revision-Femoral Distal Augmentations are manufactured from high nitrogen stainless steel, which is identical to the predicate device GMK Revision and GMK Hinge femoral distal augmentations (also referred to as wedges) which are available in size range 1-6 with thicknesses of 4 mm, 8 mm, and 12 mm.
This document is a 510(k) premarket notification for a medical device called "GMK Revision-Femoral Distal Augmentation." It focuses on demonstrating substantial equivalence to a predicate device, rather than providing a detailed study that defines and proves the device meets specific performance acceptance criteria.
The information provided does not include:
- A table of acceptance criteria and reported device performance in the context of diagnostic or AI-driven performance.
- Sample sizes for test sets, data provenance, or details about training sets.
- Information on experts (number, qualifications, adjudication methods) for establishing ground truth.
- Details about Multireader Multicase (MRMC) comparative effectiveness studies or standalone algorithm performance.
- Specific ground truth types like pathology or outcomes data.
Instead, this document focuses on mechanical and manufacturing characteristics, and a comparison with a predicate device to argue for substantial equivalence.
Here's a breakdown of what is available related to performance and testing:
1. Acceptance Criteria and Reported Device Performance:
The document doesn't present "acceptance criteria" in the typical sense for an AI/diagnostic device (e.g., sensitivity, specificity, accuracy). Instead, it discusses the device's ability to withstand physiological loads and maintain stability.
| Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|
| Withstand physiological loads without breakage. | "The results of the original testing showed that the worst-case product configuration is able to withstand physiological loads without any breakage..." (Page 7) |
| Minimal fretting. | "...and minimal fretting." (Page 7) |
| Stable and fixed connection after dynamic loading conditions. | "The connection was stable and fixed after subjected to dynamic loading conditions." (Page 7) |
| Meet pyrogen limit specifications. | "Limulus Amebocyte Lysate (LAL) testing was evaluated to establish the device meets pyrogen limit specifications." (Page 7) |
| Biocompatibility for permanent implant (>30 days). | "Biocompatibility testing conducted on the predicate device for the same material supports the biological safety of the GMK Revision-Femoral Distal Augmentations." |
| "Implant with permanent >30 day (Equivalency determined)" (Page 7) |
2. Sample Size for Test Set and Data Provenance:
- Sample Size: Not explicitly stated as a numerical sample size of "cases" or "patients." The performance data refers to "worst-case product configuration" for mechanical testing, implying a limited number of physical prototype tests. For LAL testing, no sample size is given.
- Data Provenance: Not specified regarding country of origin or whether it's retrospective/prospective. The testing appears to be lab-based mechanical and biological testing of the device itself (or its material), not clinical trial data.
3. Number of Experts and Qualifications:
- Not applicable. This document does not describe studies involving human readers or expert evaluation as part of device performance assessment.
4. Adjudication Method:
- Not applicable. No expert consensus or adjudication method is described.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study:
- No. This is a premarket notification for a knee implant component, not an AI or diagnostic tool. Therefore, no MRMC study or AI assistance effectiveness is discussed.
6. Standalone (Algorithm Only) Performance:
- No. This is a physical medical device; there is no algorithm or AI component discussed for standalone performance.
7. Type of Ground Truth Used:
- For the mechanical tests (withstanding loads, fretting, stability), the "ground truth" is derived from the physical properties and behavior of the device under simulated physiological conditions.
- For biocompatibility, the "ground truth" is established through standardized biological safety testing (e.g., LAL testing) and material characterization.
8. Sample Size for the Training Set:
- Not applicable. There is no AI component or "training set" in the context of this device.
9. How Ground Truth for the Training Set was Established:
- Not applicable, as there is no training set.
§ 888.3510 Knee joint femorotibial metal/polymer constrained cemented prosthesis.
(a)
Identification. A knee joint femorotibial metal/polymer constrained cemented prosthesis is a device intended to be implanted to replace part of a knee joint. The device limits translation or rotation in one or more planes and has components that are linked together or affined. This generic type of device includes prostheses composed of a ball-and-socket joint located between a stemmed femoral and a stemmed tibial component and a runner and track joint between each pair of femoral and tibial condyles. The ball-and-socket joint is composed of a ball at the head of a column rising from the stemmed tibial component. The ball, the column, the tibial plateau, and the stem for fixation of the tibial component are made of an alloy, such as cobalt-chromium-molybdenum. The ball of the tibial component is held within the socket of the femoral component by the femoral component's flat outer surface. The flat outer surface of the tibial component abuts both a reciprocal flat surface within the cavity of the femoral component and flanges on the femoral component designed to prevent distal displacement. The stem of the femoral component is made of an alloy, such as cobalt-chromium-molybdenum, but the socket of the component is made of ultra-high molecular weight polyethylene. The femoral component has metallic runners which align with the ultra-high molecular weight polyethylene tracks that press-fit into the metallic tibial component. The generic class also includes devices whose upper and lower components are linked with a solid bolt passing through a journal bearing of greater radius, permitting some rotation in the transverse plane, a minimal arc of abduction/adduction. This generic type of device is limited to those prostheses intended for use with bone cement (§ 888.3027).(b)
Classification. Class II.