(88 days)
The Natural-Knee II Unicompartmental Knee is intended for use in:
- Unicompartmental noninflammatory degenerative joint disease (NIDJD), e.g., avascular necrosis, osteoarthritis and arthritis secondary to a variety of diseases and anomalies;
- Passively correctable valgus-varus deformity and moderate flexion contracture;
- Those patients with failed previous surgery where pain, deformity or dysfunction persists.
The N-K II Unicompartmental All-Poly Tibia is intended to be used only with bone cement. The modular metal/polymer N-K II Unicompartmental Tibia and Femur are intended for use with or without bone cement.
The Natural-Knee II Unicompartmental Knee System is a conservative, cost-effective alternative to total knee replacement for patients with osteoarthritis primarily confined to one compartment. The N-K II Unicompartmental Knee System is intended for resurfacing of one side of the knee joint.
The N-K II Unicompartmental Modular Metal-backed Tibia is similar to the previously cleared N-K II Unicompartmental Tibia (K955778). The wrought titanium alloy tibial baseplate is a symmetrically designed component, eliminating the need for left/right orientations. The baseplate features three smooth pegs on the underside which aid in positioning and rotational stability. A smooth surface finish is provided on the inner surface of the tibial tray to minimize the potential for polyethylene wear. A screw hole is placed in the center of the baseplate for optional screw fixation. The baseplate is available in either a porous or non-porous version.
The all-poly tibia is designed with a single keel to position the component on the tibia and increase stability. Cement grooves on both the medial and lateral side of the keel increase the anchoring effect of the keel, while a dovetail cement channel around the perimeter of the distal surface, along with a T-pattern dovetail cement channel, act to resist movement in all directions. It is to be used only with bone cement for application directly onto the patient's resected proximal tibia.
The metal-backed and the all-poly tibias are both available in 6 sizes (1-6). The modular metal-backed tibia will be offered in 3 thicknesses (9, 11, and 13 mm). The insert thickness reflects the total amount of bone to be resected. The all-poly insert will be available in 4 thicknesses (7, 9, 11, and 13mm), in which the thickness is measured at the thinnest point from the distal to the proximal surface of the component.
The design of the femoral component of the proposed N-K II Unicompartmental Knee System will not change. This premarket notification only seeks to obtain clearance for the addition of cementless use of the previously cleared porous-coated femur (K955778).
The provided text is a 510(k) summary for a medical device (Natural-Knee® II Unicompartmental Knee System). It describes the device, its intended use, and its substantial equivalence to predicate devices. However, this document does not contain information about acceptance criteria or a study proving that the device meets such criteria.
The 510(k) summary focuses on demonstrating "substantial equivalence" to already cleared predicate devices based on design features, indications for use, materials, and labeling. It does not include:
- A table of acceptance criteria and reported device performance.
- Details about sample sizes for a test set or data provenance for performance evaluation.
- Information about experts for ground truth establishment.
- Adjudication methods.
- A multi-reader multi-case (MRMC) comparative effectiveness study.
- A standalone algorithm performance study.
- Details about the type of ground truth used for performance evaluation.
- Sample size for a training set or how ground truth was established for training.
Therefore, I cannot fulfill your request for this specific information based on the provided text. The document's purpose is to establish substantial equivalence for regulatory clearance, not to report on specific performance criteria derived from clinical or technical studies that would typically be associated with AI/software-as-a-medical-device performance claims.
§ 888.3530 Knee joint femorotibial metal/polymer semi-constrained cemented prosthesis.
(a)
Identification. A knee joint femorotibial metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace part of 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 consist of a femoral component made of alloys, such as cobalt-chromium-molybdenum, and a tibial component made of ultra-high molecular weight polyethylene and is limited to those prostheses intended for use with bone cement (§ 888.3027).(b)
Classification. Class II.