[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: 21CFR888.6]

[Page 464]
 
                        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 A--General Provisions
 
Sec. 888.6  Degree of constraint.

    Certain joint prostheses provide more constraint of joint movement 
than others. FDA believes that the degree of constraint is an important 
factor affecting the safety and effectiveness of orthopedic prostheses. 
FDA is defining the following standard terms for categorizing the degree 
of constraint.
    (a) A ``constrained'' joint prosthesis is used for joint replacement 
and prevents dislocation of the prosthesis in more than one anatomic 
plane and consists of either a single, flexible, across-the-joint 
component or more than one component linked together or affined.
    (b) A ``semi-constrained'' joint prosthesis is used for partial or 
total joint replacement and limits translation and rotation of the 
prosthesis in one or more planes via the geometry of its articulating 
surfaces. It has no across-the-joint linkage.
    (c) A ``non-constrained'' joint prosthesis is used for partial or 
total joint replacement and restricts minimally prosthesis movement in 
one or more planes. Its components have no across-the-joint linkage.