K013385 · Zimmer, Inc. · KRO · Jan 9, 2002 · Orthopedic
Device Facts
Record ID
K013385
Device Name
NEXGEN COMPLETE KNEE SOLUTION ROTATNG HINGE KNEE
Applicant
Zimmer, Inc.
Product Code
KRO · Orthopedic
Decision Date
Jan 9, 2002
Decision
SESE
Submission Type
Traditional
Regulation
21 CFR 888.3510
Device Class
Class 2
Attributes
Therapeutic
Intended Use
This device is indicated for moderate to severe knee instability, significant bone loss and/or ligament deficiencies caused by neoplasms, trauma, rheumatoid arthritis, osteoarthritis, traumatic arthritis, polyarthritis, collagen disorders, avascular necrosis of the femoral condyle, valgus, varus, or flexion deformities and/or for the salvage of previously failed surgical attempts. This device is intended for cemented use only.
Device Story
NexGen Rotating Hinge Knee (RHK) is a constrained total knee prosthesis; provides stability in anterior/posterior and medial/lateral directions while allowing flexion/extension and rotation. Operates via femoral hinge post extension inserted through polyethylene articular surface into tibial baseplate. Used in orthopedic surgery for joint reconstruction; implanted by surgeons. Components include femoral/tibial augments, stem extensions, and variable thickness articular surfaces for soft tissue tensioning. Output is a restored knee joint mechanism; aids in joint stability and function for patients with severe bone/ligament loss.
Clinical Evidence
No clinical data. Bench testing only: included interlock distraction (lift-off) testing, 10 million cycle tibial baseplate fatigue strength testing, and combined load fatigue/pin loosening testing. Contact area comparison performed against predicate. Wear testing not required due to polyethylene thickness > 6 mm.
Technological Characteristics
Constrained metal/polymer knee prosthesis. Materials include metal and polyethylene. Design features femoral hinge post extension and tibial baseplate. Cemented fixation only. Mechanical principle: constrained hinge mechanism allowing rotation and flexion/extension. No software or electronic components.
Indications for Use
Indicated for patients with moderate to severe knee instability, significant bone loss, or ligament deficiencies due to neoplasms, trauma, arthritis (rheumatoid, osteoarthritis, traumatic, polyarthritis), collagen disorders, avascular necrosis, or deformities (valgus, varus, flexion). Also for salvage of failed prior surgeries. Cemented use only.
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).