(96 days)
This system is to be used to treat gross knee instability resulting from loss of collateral ligament function, gross bone loss possibly including the insertion points of the collateral ligaments or patella tendon, or comminuted fractures of the proximal tibia or distal femur. Patients requiring hinged knees typically fall into one of four categories; 1) revision knee procedure 2) oncology 3) trauma or 4) severe varus/valgus primary knees.
- Rheumatoid arthritis.
- Post-traumatic arthritis, ostecarthritis, or degenerative arthritis in older patients whose age, weight, and activity level are compatible with an adequate long-term result.
- Failed osteotomies, unicompartmental replacement, or total knee replacement.
- Posterior stabilized knee systems are designed for use in patients in primary and revision surgery, where the anterior and posterior cruciate ligaments are incompetent and the collateral ligaments remain intact.
- Constrained and hinge knee systems are designed for use in patients in primary and revision surgery, where the posterior cruciate ligament and one or both of the collateral ligaments (i.e. medial collateral and/or lateral collateral ligament) are absent or incompetent.
The Legion Hinge Knee System is for Cemented Use Only.
Subject of this pre-market notification is the LEGION Hinge Knee system. This is an extension to the LEGION Revision system. This system broadens the complexity of cases which can be addressed with LEGION by offering a hinged option which can be used in cases of inadequate ligament stability of the knee or gross femoral/tibial bone loss. Instrumentation is to be minimized by using many of the LEGION Revision instruments. This system is to include femoral and tibial revision components, tibial inserts, distal femoral and proximal tibial segments, stems, cones and wedges as well as the instruments and trials required to implant the components. The tibial component includes a rotating platform option.
This document is a 510(k) premarket notification for the Smith & Nephew Legion Hinge Knee system. It is a submission to the FDA to demonstrate substantial equivalence to existing legally marketed devices, not a study evaluating the performance of the device against specific acceptance criteria. Therefore, the requested information regarding acceptance criteria and a study proving the device meets those criteria is not present in this document.
The document focuses on:
- Intended Use and Indications for Use: Describing the conditions for which the device is designed.
- Device Description: Outlining the components and functionality of the knee system.
- Substantial Equivalence Information: Comparing the device to predicate devices already on the market. This is the primary method used to "prove" the device's safety and effectiveness in a 510(k) submission – by demonstrating it is as safe and effective as a legally marketed device, not by presenting new performance data against specific acceptance criteria.
- FDA Clearance Letter: Indicating that the device has been cleared for market based on the substantial equivalence argument.
Therefore, I cannot provide the requested table of acceptance criteria, reported device performance, or details about a study evaluating these criteria from the provided text. The 510(k) process relies on demonstrating equivalence to predicate devices, not on proving performance against a set of new acceptance criteria through a specific study as would be seen for a novel device or in a clinical trial setting.
§ 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.