The Journal of Bone and Joint Surgery, Vol 63, Issue 1 62-70, Copyright © 1981 by Journal of Bone and Joint Surgery, Inc
Stability of the upper lumbar spine following progressive disruptions and the application of individual internal and external fixation devices
DA Nagel, TA Koogle, RL Piziali and I Perkash
Five fresh human cadavera were tested to determine range-of-motion
measurements at the interspace of the first and second lumbar vertebrae
after progressive disruption of the joint followed by internal and external
stabilization. The disruption progressed from posterior to anterior,
leaving the anterior longitudinal ligament and anterior part of the annulus
fibrosus intact. Flexion-extension range of motion was most sensitive to
progressive disruptions and was significant following disruption of the
facets. The Taylor-Knight brace was effective for limiting lateral motion,
fair for limiting flexion-extension, and not effective for rotation. The
three-point hyperextension brace was fairly effective for flexion-extension
only. The body cast was effective in limiting all motions. Wire loops
partially cut through the spinous processes in all cases with extreme
flexion. Harrington distraction rods were effective in limiting motion if
under proper tension, but they dislodged in three of the five specimens.
CLINICAL RELEVANCE: Data from this study show that flexion of the second
lumbar vertebra on the first of 20 degrees or a lateral bend of 10 degrees
seen on a routine roentgenogram without vertebral fracture indicates that
all posterior ligaments and at least part of the annulus fibrosus must be
disrupted. Because internal fixation failed on occasion, we strongly urge
the use of external fixation and careful mobilization of the patient to
prevent flexion and rotation if internal stabilization is used for
disruptions of the upper lumbar spine. The body cast was the most effective
in limiting motion of the external fixation devices tested.