A pliable band or hoop that is flexible to normal handling, but cannot
stretch circumferentially once it has reached the limits of its
circumferential length. The band may have a structural portal to be used
for filling, or it may simply be constructed of a fabric-like material
that allows a fill tube to perforate its walls to allow for filling. In
the latter case, the perforated wall tends to self-seal once the fill
tube is withdrawn. The band may be flat or tubular in cross-section.
However, unlike a balloon, the band does not require either a bottom or a
top, as we found that a top and bottom are unnecessary when using a band
or hoop to enclose material injected into a reamed out intervertebral
space.