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Five cases were
selected from among individuals who were referred for a neurosurgical
consultation and had previously sustained a work-related injury that
resulted in herniation of a lumbar disc at one or more levels. The
diagnosis in each case was confirmed by magnetic resonance imaging. The
patients chosen were scheduled for percutaneous discectomy. Introduction
of the cannula for the purpose of performing percutaneous discectomy
offered an opportunity to measure pressure changes in the disc prior to
the operative procedure.
The patient was
prepared and a cannula was inserted under local anesthesia into the
nucleus pulposus of the L4-5 intervertebral disc using anteroposterior and
lateral fluoroscopy to position the end. With the cannula in place, the
patient was moved to a VAX-D table.
The tube was
then connected to a pressure monitor using a disposable pressure
transducer. The lines were filled with normal saline. The pelvic harness
designed for this therapy was fastened around the pelvic girdle and
connected to the tensionometer via straps attached to the harness. When
the system was activated the caudal section supporting the lower body
extended slowly, applying a distraction force via the pelvic harness
connected to the tensionometer. The level of tension was preset by the
operator on the control console and observed and plotted on a chart
recorder. The movement of the table was stopped and held when the desired
tension was reached. An average course of therapy consisted of
30‑minute sessions on the table once a day for 10 to 15 days. During
each session the patient undergoes alternating cycles of distraction and
relaxation, the timing and periodicity having been programmed by the
therapist.
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Figure
2
In
this study various distraction tensions ranging from 50 to 100 lbs. were
used for vertebral axial decompression therapy. The distraction tensions
applied were monitored on a digital readout and recorded on a continuous
graph tracing by a chart printer incorporated in the control console. The
resulting changes in intradiscal pressure in the L4-5
nucleus pulposus were observed on a digital readout on the pressure
monitor, and the readings were entered onto the chart recording at the
point when the apex of distraction tension was achieved. The pressure
readings were then applied
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