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Biomedical subjects

K P Singer

Publications and source records attributed to K P Singer.

9 recordsLinked to original sources
PubMed1990

Intra-articular synovial folds of thoracolumbar junction zygapophyseal joints.

Transverse histological sections from T10-11, T11-12, T12-L1, and L1-2 zygapophyseal joints were examined in 32 post-mortem spines, using light microscopy, to record the presence of intra-articular synovial fold inclusions. In addition, three mid-joint sections from each joint were photographed using 35 mm colour film. From these slides, linear dimensions of the extent of intra-articular synovial fold projection between the zygapophyseal joints were measured using computer-aided planimetry. Small, fibrous folds were commonly found at the joint margins extending from the ligamentum flavum and the fibrous joint capsule. Larger, fibro-adipose synovial folds, projecting between the articular surfaces, were also noted, particularly at T12-L1 and L1-2.

Adolescent↗
PubMed1990

A comparison of radiographic and computer-assisted measurements of thoracic and thoracolumbar sagittal curvature.

Sagittal plane curve characteristics of the thoracolumbar spine were evaluated from 286 lateral chest radiographs comparing the Cobb technique with a computer-aided digitizer. Thoracic kyphosis and curve apex were measured from the T3 to T11 segments, and in 120 cases, the level of the thoracolumbar curve inflexion point was determined. An age-related increase in curve magnitude was similar for both measurements, although computer generated kyphosis angles were generally larger. The apex of thoracic kyphosis was consistently located near T7 for males compared with greater variability with age for females. The thoracolumbar inflexion point shifted caudally with increasing years, being most marked for females. The computer method was more reliable, producing a coefficient of variation of 1.4% on repeated measurement. The ability to describe quantitatively the thoracolumbar curve characteristics, calculate angles between selected segments, determine points of inflexion and maximum curvature, indicates that radiographic evaluation of sagittal spinal curvature is improved with the use of computer-aided measurement.

Adolescent↗
PubMed1990

Accessory ossification centres at the thoracolumbar junction.

A survey of 810 thoracolumbar junction CT scans demonstrated several forms of accessory ossification centres and vestigial ribs associated with the posterior element processes. Four examples of short T12 ribs and 15 L1 ribs were identified, in addition to 8 accessory ossification centres at L1, and 3 at T12. Radiographic features of accessory ossification centres were compared with histologic characteristics from cadaver studies. Accessory ossification centres have occasional clinical significance when they may be confused with fractures at the thoracolumbar junction. Differential diagnosis relies on adequate visualization of their cortical margins to distinguish them from recent fractures of the processes.

Adult↗
PubMed1990

Influence of zygapophyseal joint orientation on hyaline cartilage at the thoracolumbar junction.

Hyaline articular cartilage from 102 thoracolumbar junction zygapophyseal joints was examined using light microscopy. One section from the upper, middle and lower third of each joint at the T10-11, T11-12, T12-L1 and L1-2 spinal levels was photographed using 35 mm color film. Hyaline articular cartilage cross-sectional area of the superior and inferior articular processes of each joint pair, at each level, was digitized using computer-aided planimetry. Differences in area were compared with joint orientation (symmetry or tropism) and geometry of each joint pair at each spinal level. Variation in hyaline cartilage cross-sectional area between joint pairs could be attributed to: a) geometric differences, b) the presence of a mortice joint, or c) osteoarthritic changes, with or without tropism. These findings were most frequently demonstrated at the transitional levels of T11-12 and T12-L1.

Adolescent↗
PubMed1990

Manual therapy considerations at the thoracolumbar junction: an anatomical and functional perspective.

Anatomically, the human thoracolumbar junction demonstrates considerable resistance to rotary motion in an effort to decrease torsional stress through an area of marked functional transition. Despite this, rotational manipulation and mobilization procedures have been advocated in the treatment of painful mechanical disorders originating from the thoracolumbar junction. The rationale behind vigorous manipulative techniques, particularly those incorporating extension, is challenged in light of cadaveric histological studies of this region, as well as both in vivo and experimental biomechanical investigations. Judicious use of traction and mobilization procedures are recommended.

Adult↗
PubMed1990

Vertebral body trabecular density at the thoracolumbar junction using quantitative computed tomography. A post-mortem study.

Quantitative computed tomography was used to assess vertebral trabecular density in 26 post-mortem spines from individuals aged between 14 and 80 years. All vertebrae from T10 to L1 were scanned transversely near the mid-vertebral level with calculations of trabecular density in HUs averaged and referenced to a mineral equivalent phantom. An age-related decline in trabecular density was recorded (r = 0.55, p less than 0.0001). Density measures from the anterior aspect of the vertebral body were significantly greater than from postero-lateral regions. From T10 to L1, there was a significant decrease in trabecular density, whereas density measures multiplied by vertebral body cross-sectional area were constant. Predictions of vertebral compressive strength using quantitative computed tomography may become more accurate by increasing the sampling area per scan and including vertebral body cross-sectional area as part of the radiologic assessment.

Adolescent↗
PubMed1989

Radiologic study of the influence of zygapophyseal joint orientation on spinal injuries at the thoracolumbar junction.

The change from coronal to sagittal plane orientation of the zygapophyseal (facet) joints at the thoracolumbar junction, coupled with differences in lumbar and thoracic spine mobility, may predispose the T10 to L2 segments to injury. To test for an association between the level of injury and variations in orientation of the zygapophyseal joints, CT investigations of 44 spinal injured patients were studied. Of these, 28 sustained burst/compression fractures and 16 demonstrated a rotation injury with disruption to one or both zygapophyseal joints. Injuries were examined to determine whether more congruent "mortice" joints localised the segmental level of trauma. The Chi-square statistic was used: to compare the transitional characteristics of 44 clinical cases with a "normal" patient database (n = 630); to examine differences in transition patterns between the "compression" and "rotation" injury groups; and to compare the incidence of mortice joints between the clinical and normal series. A significant difference between the transition patterns of the clinical and normal series (p less than 0.001) appeared to account for the higher frequency of abrupt transitions in the 44 injury cases. No significant differences distinguished the transition patterns of the two injury groups. A higher incidence of mortice joints was demonstrated in the injury group compared with the normal population (p less than 0.02). These findings suggest that individuals with an abrupt transition have a greater predisposition to injuries at the thoracolumbar junction.

Adolescent↗
PubMed1988

Variations in zygapophyseal joint orientation and level of transition at the thoracolumbar junction. Preliminary survey using computed tomography.

Variation in zygapophyseal joint orientation at the thoracolumbar transitional junction was investigated using computed tomography (CT). The study population (N = 214) comprised 176 cases of abdominal scans, 9 thoracolumbar junction referrals and 29 cadaveric vertebral columns. Scans through the superior endplates of T11, T12, L1 and L2 were selected and joint angles calculated using a computer aided digitiser. Analysis revealed 29% of cases presented coronally oriented superior and sagittally orientated inferior joint processes at T12. This pattern occurred in 16% of cases at T11 and 0.5% at L1. A gradual transition occurred in 54% of cases and involved the adjacent inter-segmental joints of T11 and T12. Articular tropism (greater than 20 degrees) was most frequent at T11-12 (21%), followed by T12-L1 (9%).

Adolescent↗