Smith and Nephew Legion Hinge Knee System
Device Facts
| Record ID | K151118 |
|---|---|
| Device Name | Smith and Nephew Legion Hinge Knee System |
| Applicant | Smith & Nephew |
| Product Code | KRO · Orthopedic |
| Decision Date | Jul 28, 2015 |
| Decision | SESE |
| Submission Type | Traditional |
| Regulation | 21 CFR 888.3510 |
| Device Class | Class 2 |
| Attributes | Therapeutic |
Indications for Use
The Smith & Nephew Legion Hinge Knee System is indicated for: 1. Rheumatoid arthritis. 2. Post-traumatic arthritis, osteoarthritis, or degenerative arthritis. 3. Failed osteotomies, unicompartmental replacement, or total knee replacement. 4. 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. 5. Constrained 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 ligament) are incompetent. 6. 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 ligament) are absent or incompetent. The Legion Hinge Knee System is for Cemented Use Only.
Device Story
Legion Hinge Knee System is a total knee joint replacement prosthesis. Device treats gross knee instability, bone loss, or comminuted fractures of proximal tibia/distal femur. Components include femoral component (oxidized zirconium alloy/OXINIUM) and tibial tray (titanium alloy Ti-6Al-4V). System is for cemented use only. Used by orthopedic surgeons in clinical/OR settings. Provides mechanical stability to knee joint by replacing articular surfaces. Benefits patient by restoring joint function and stability in cases of severe ligamentous incompetence.
Clinical Evidence
Bench testing only. Provided fatigue testing of OXINIUM hinge knee with hyperextension and varus-valgus loading, anterior/posterior static shear testing, construct fatigue testing at 30° flexion, and torque to failure evaluation of the guided motion lock screw.
Technological Characteristics
Materials: Oxidized zirconium alloy (OXINIUM) for femoral components, Titanium alloy (Ti-6Al-4V) for tibial tray. Design: Constrained hinge knee prosthesis. Energy source: None (mechanical). Connectivity: None. Sterilization: Not specified. Software: None.
Indications for Use
Indicated for patients undergoing primary or revision knee surgery with rheumatoid, post-traumatic, or degenerative arthritis, or failed prior knee procedures. Specifically for hinge systems, indicated where posterior cruciate and one or both collateral ligaments are absent or incompetent.
Regulatory Classification
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).