However, a disc height increase ranging from 0.13 mm to 0.16 mm occurred with the insertion of a 1.85 mm diameter cannula.
There was no statistically significant difference of nucleus pressure or intervertebral disc height with different torsion torques among or between the FSU's and DBU's. The pressure in the nucleus was measured by pulling a pressure probe through the disc along a straight path in the midsagittal plane. Posterior elements were removed and pressure measurements were repeated at the same torsion torques for the disc body unit (DBU).
Nucleus pressure measurements were obtained at 0 Nm, 0.5 Nm, 1.0 Nm and 2 Nm torsion torque. Six human lumbar cadaveric functional spine units (FSU) were loaded in the neutral position with 600 N compression. To test the effects of torsion torques on intradiscal pressure and disc height in human lumbar specimens.
