K Number
K210961
Date Cleared
2021-04-21

(21 days)

Product Code
Regulation Number
888.3560
Panel
OR
Reference & Predicate Devices
AI/MLSaMDIVD (In Vitro Diagnostic)TherapeuticDiagnosticis PCCP AuthorizedThirdpartyExpeditedreview
Intended Use

The U2 Total Knee system is indicated in knee arthroplasty for reduction or relief of pain and/or improved knee function in skeletally mature patients with severe knee pain and disability due to rheumatoid arthritis, osteoarthitis, primary and secondary traumatic arthritis, polyarthritis, collagen disorders, avascular necrosis of the femoral condyle or pseudogout, posttraumatic loss of joint configuration, particularly when there is patellofemoral erosion, dysfunction or prior patellectomy, moderate valgus, varus, or flexion deformities. This device may also be indicated in the salvage of previously failed surgical attempts if the knee cannot be satisfactorily balanced and stabilized at the time of surgery.

For cemented femoral components, patellar components, tibial baseplate components and tibial inserts components: This device is a single use implant and intended for cemented use only.

For porous coated femoral component: This device is a single use implant and intended for cementless use only.

Device Description

The U2 Total Knee System include femoral components, patellar components, tibial baseplate components and tibial inserts components which are designed to be used together to achieve total replacement of the knee joint. This system includes Cruciate Retained (CR) type, Posterior Stabilized (PS) type and Ultracongruent (UC) type. The subject device, U2 Total Knee System, XPE Tibial Insert, Posterior Stabilized PLUS (PS PLUS), belongs to U2 Total Knee System PS type.

U2 Total Knee System, XPE Tibial Insert, PS PLUS (Subject device) is a constrained design insert mechanically locked with metallic tibial baseplate. It is manufactured from Gamma irradiated UHMWPE which conform to ASTM F2565-13, while the UHMWPE raw material is in accordance with ASTM F648-14 and ISO 5834-1:2005.

The Subject device is used with the Posterior Stabilized (PS) type Femoral Component. In comparison to the marketed predicate devices, the Subject device has slightly modified width and height of the post, the height of the anterior lip. The Subject device provides constraint in varus/valgus and internal/external rotation to enhance joint stability and resist paradoxical anterior femoral slide.

Except for the differences of the post and anterior lip, the size distribution the Subject device is identical to the previously cleared Tibial Inserts of U2 Total Knee System predicates. The Subject device is available in eight proportional sizes (#0~ #7) and ten thicknesses (thicknesses of poly insert + tibial baseplate: 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm and 18mm). The minimum thickness of poly insert of Subject device is 6 mm on the bearing surface, identical to the primary predicate.

Surgical procedures with the use of the Subject device shall be performed with the support of orthopedic instrumentation, to facilitate their proper insertion and removal from the patient. The surgical instruments have been previously cleared as part of the predicate devices.

AI/ML Overview

This document describes the FDA's decision regarding the substantial equivalence of the "U2 Total Knee System, XPE Tibial Insert, PS PLUS" to a predicate device. It does not contain information about the acceptance criteria or study results in the context of an AI/ML medical device.

Therefore, I cannot provide the requested information about acceptance criteria, reported device performance, sample sizes, ground truth, expert qualifications, adjudication methods, or MRMC studies, as these details are not present in the provided text.

The document is purely a regulatory clearance notice for a knee implant, focusing on its manufacturing, materials, and intended use as compared to existing, legally marketed predicate devices.

§ 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.