- Discussion:
- progression of severe slips after apparently solid in situ arthrodesis has led some to consider reduction and instrumentation for
spondylolithesis;
- another rationale for reduction of the slip is improvement in cosmetic appearance of the trunk;
- slip angle:
- risk factor to predict postop progression is preop slip angle > 35 deg;
- slip angle is measured by drawing line perpendicular to a line drawn along posterior aspect of first sacral vertebral body and
measuring angle between that & line parallel to inferior end plate of L-5;
- complications of reduction: neurologic injury;
- nerve root injuries not only occur at level of spondylolisthesis but may also occur throughout the lumbosacral plexus because of the
trunk lengthening that occurs w/ reduction;
- most studies of spondylolisthesis reductions report new L-5 root deficits, some of which are permanent;
- Technique of Reduction:
- reduction of forward translation & of lumbosacral kyphosis that accompanies severe slips is performed w/ serial casting, traction, external
fixators, or w/ posterior implants (pedicle screws, plates, & rods)
Treatment of severe spondylolisthesis by reduction and pedicular fixation. A 4-6-year follow-up study.
Passive reduction of spondylolisthesis on the operating room table: a prospective study.