Biomedical subjects
A Malmivaara
Publications and source records attributed to A Malmivaara.
[Morton's symptoms--but which?].
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The value of the axial view in assessing discograms. An experimental study with cadavers.
The clinical value of discography is controversial. An axial view of a discogram such as could be obtained with CT scans should increase the structural information regarding disc pathology, and clarify the relationship to disease of the facet joints as well. To evaluate this concept, 103 intervertebral levels in 23 cadaver specimens were studied by anteroposterior, lateral, and axial roentgenographic views. From these three views, a new classification for interpreting discograms was developed. The correlations between the three different views were good, confirming the potential value of CT axial views. However, in one fourth of the discs there were pathologic anatomic findings that could be seen only in the axial views. There were more severe osteoarthritic changes in the right than the left facet joint, and a discrepancy between facet arthritis and disc disease was also noted.
Plain radiographic, discographic, and direct observations of Schmorl's nodes in the thoracolumbar junctional region of the cadaveric spine.
The perceivability of Schmorl's nodes in plain radiographs and discograms in the thoracolumbar junctional region (T10-L1) of the cadaveric spine was assessed by comparing the radiologic measurements with bone measurements. Schmorl's nodes in bone specimens were encountered in 19 of 24 spines studied. They were more than two times as common between vertebrae T10-11 and T11-12 as between T12 and L1 (P less than 0.01). When the areas of actual Schmorl's nodes exceeded 0.5 cm2 (corresponding to an aperture with a diameter of 0.8 cm), 47% of the nodes were seen in plain lateral radiographs and 68% in discograms. When the area measured 0.5 cm2 or less, only 24% could be perceived in plain lateral radiographs and 23% in discograms. The clinical significance of Schmorl's nodes remains uncertain as long as they are difficult to detect in vivo.
Facet joint orientation, facet and costovertebral joint osteoarthrosis, disc degeneration, vertebral body osteophytosis, and Schmorl's nodes in the thoracolumbar junctional region of cadaveric spines.
The disc degeneration in the thoracolumbar junctional region (T10-L1) of 37 male cadaveric spines was recorded with the use of discography. From 24 of these spines the facet joint orientation and degenerative findings of the facet and costovertebral joints, vertebral bodies (osteophytosis) and discs, and Schmorl's nodes were recorded directly from bones. At T11-12, the most common site for the transitional zone between thoracic and lumbar facet type, there was a marked variation in the orientation of facets. The occurrence of degenerative findings and Schmorl's nodes at the three levels in the region differed. At T10-11, disc degeneration, vertebral body osteophytosis, and Schmorl's nodes were most common (anterior degeneration). At T12-L1, facet and costovertebral joint degeneration were dominant (posterior degeneration). At T11-12, disc degeneration, vertebral body osteophytosis, Schmorl's nodes, and facet and costovertebral joint degeneration all occurred (anterior and posterior degeneration). The results point to a pathoanatomic association between degenerative changes and facet orientation.
Radiographic vs. direct measurements of the spinal canal of the thoracolumbar junctional region (T10-L1) of the spine.
Midsagittal diameter (MSD) and interpedicular distance (IPD) in the thoracolumbar junctional region (T10-L1) of 24 male cadaveric spines were measured both from radiographs and directly from bones after removal of the soft tissues in order to assess the accuracy of plain radiographs. In addition surface areas of the vertebral canals were measured also from bone samples. It was found that the mean difference between bone and radiographic measurements in the IPD on different vertebral levels was 1.0 mm (r = 0.98). The MSD was a more difficult measurement, but the correlation coefficient was still 0.70, the mean difference being 0.7 mm or less. The sum of the MSD and IPD showed good relationship with the cross sectional area of the spinal canal, and the correlation coefficient was 0.77 (P less than 0.001).
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.