Disc degeneration in the thoracolumbar junctional region. Evaluation by radiography and discography in autopsy.

Disc dimensions and lengths of spondylophytes in the thoracolumbar junctional region (T 10-L 1) of 37 male cadaveric spines were measured from conventional radiographs. The disc degeneration was assessed by discography. The surface areas of the spondylophytes at vertebral body margins were recorded directly from the bones of 24 of the spines. Disc degeneration and the largest spondylophytes at corresponding levels measured from radiographs were related at T10-11 and at T11-12 (r = 0.41 and r = 0.43; p less than 0.01), but not at T12-L1 (r = 0.14). In the individual discs, however, only large spondylophytes in radiographs (actual length over 4 mm) were related to signs of disc degeneration. In addition, 'traction spurs' and Scheuermann's changes were more often associated with severe disc degeneration than 'claw-type' spondylophytes. The intervertebral disc space height correlated poorly with disc degeneration except, to some extent, at T11-12. Thus, the assessment of disc degeneration from conventional radiographs seems unreliable at this region of the spine.