Disc cell viability detected by fluorescence microscope (200 times magnification).

<p>AF-annulus fibrosus, NP- nucleus pulposus. Under fluorescence microscope, the living cells were shown in green and the dead cells in orange. The cell survival rate  =  the number of green-stained cells/the total number of stained cells.</p

Values of the biomechanical test (mean ± SD; axial force, N; torsional torque, N.mm).

<p>Values of the biomechanical test (mean ± SD; axial force, N; torsional torque, N.mm).</p

Representative photographs of the gross morphology of Beagle's grafted discs.

<p>Grade 1 was a normal disc with a bulging NP and clear demarcation between AF and NP. Grade 2 was the mild disc degeneration which had fibrous tissue or mucinous material peripherally. However, the transplanted disc did not display Grade 1 or Grade 2 degeneration in this study. Grade 3 presented slight narrowing of disc height and unclear demarcation between AF and NP. Grade 4 had consolidated fibrous tissue in the segment, loss of AF-NP demarcation, and early chondrophytes. Grade 5 presented horizontal clefts in NP, disruptions in AF, irregularities in the endplates, usually with small osteophytes. Grade 6 showed no visible NP, destruction of the endplate, and scar tissue, usually with larger osteophytes. Pseudoarthrosis was also regarded as Grade 6 disc degeneration.</p

Method of measuring alignment using the cephalic endplate of the upper vertebrae and the caudal endplate of the lower vertebrae of the involved segment.

<p>ROM of the segment can be calculated by the difference between extension (A) and flexion (B) angles.</p

Biomechanical test for IVD.

<p>Discs were fixed to the fixture by special tapered screws penetrating vertebral bodies, and tested by Mechanical Testing & Simulation Machine (MTS 858 mini bionix-2, Eden Prairie).</p

ROM of the transplanted segment in various time points (degree).

<p>*: P<0.05;</p><p>**: P<0.01 (compared with pre-op, <i>t</i> test).</p>#<p>: Because four beagles in each group were already sacrificed three-months postoperatively, so the average value of the two residual samples was not analyzed statistically.</p

Classified transplanted disc degeneration at 3-month postoperatively (n).

<p>Correlation analysis showed that disc degeneration related significantly to the dose of irradiation (<i>X ²</i> test, P<0.01).</p

DHI of the transplanted segment in various time points,

<p>*: P<0.05;</p><p>**: P<0.01 (compared with pre-op, <i>t</i> test).</p>#<p>: Because four beagles in each group were already sacrificed three-months postoperatively, so the average value of the two residual samples was not analyzed statistically.</p

X-rays of the disc allografts in different groups (three months postoperatively).

<p>A: AP view, B: lateral view, C: extention-lateral view, D: flexion-lateral view.</p

Radiographic measurement of DHI.

<p>Heights of the vertebral body and disc were measured using the middle vertebral line. DHI = a/A.</p