[Code of Federal Regulations]
[Title 21, Volume 8]
[Revised as of April 1, 2002]
From the U.S. Government Printing Office via GPO Access
[CITE: 21CFR888.3510]

[Page 476]
 
                        TITLE 21--FOOD AND DRUGS
 
CHAPTER I--FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN 
                          SERVICES (CONTINUED)
 
PART 888--ORTHOPEDIC DEVICES--Table of Contents
 
                      Subpart D--Prosthetic Devices
 
Sec. 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 (Sec. 888.3027).
    (b) Classification. Class II.