Showing papers on "Cobb angle published in 1989"

Ultrasound measurement of vertebral rotation in idiopathic scoliosis.

Abstract: Ultrasound can be used to outline the spinous processes and the laminae, and thus to measure axial rotation. Using our own technique, we measured vertebral rotation in 47 patients with idiopathic scoliosis. There was a strong linear relationship between the Cobb angle and the rotation of the apical vertebra in untreated patients, but this relationship was lost in patients who had had brace treatment. Vertebral rotation can easily be measured by ultrasound. This is a harmless and fairly rapid investigation which can be used at routine follow-up examination of patients with idiopathic scoliosis.

Concordance of back surface asymmetry and spine shape in idiopathic scoliosis.

Abstract: In order to determine why topographic methods have shown a poor correlation with radiographically measured scoliosis in clinical studies, the accuracy of detection of the presence, side, apex, and magnitude of a scoliosis curve was determined topographically (by moire fringe photography and by projected raster photography) in 104 patients attending a scoliosis clinic. The presence or absence of thoracic curves was correctly shown by the topograms in 77% of cases, and in the lower region (lumbar and thoracolumbar curves) in 79% of cases. For correctly identified curves, the greatest back surface rotation was, on average, 1.0 vertebral levels below the skeletal curve apex in the thoracic region and 0.5 levels below the apex in the lower region. The moire fringe with the greatest asymmetry occurred on average at 1.5 and 1.8 vertebral levels above the spinal apex in upper and lower regions, respectively. The magnitude of the Cobb angle was determined to within +/- 5 degrees in 24% of cases by moire measurements, and in 27% by the raster technique. The side of the scoliosis was incorrectly diagnosed by topography in ten patients with minimal or 'nonstandard' vertebral rotation. It was concluded that the presence, level, and side of a scoliosis curvature is well demonstrated by back surface topography in patients with 'standard' rotation, but the magnitude of the scoliosis cannot be determined from topograms sufficiently accurately for most clinical purposes.

Reliability of the Cobb angle index derived by traditional and computer assisted methods.

Abstract: The reliability of the traditional Cobb angle index, which at present exhibits a wide range of reported values, was determined in this study and amounted to a within subject error of +/-4.3 degrees and a between subject error of +/-4.9 degrees. An attempt to pinpoint the source of this variability by investigating the influence of choice of end vertebrae proved inconclusive. The reliability of a computer assisted Cobb angle index, developed to improve measurement accuracy, was also examined and an estimated within subject error of +/-1.5 degrees and a between subject error of +/-1.6 degrees obtained. A comparison of the traditional and computer assisted methods indicates a high correlation between the Cobb angle derived using the two methods when measuring like curves and an improved reliability obtained by the computer method. Such an improvement is worth implementing clinically but of course the availability of a computer and digitizer and a little extra time for an operator to input the X-ray coordinates may be a barrier to its general use.

Biological factors and predictability of bracing in adolescent idiopathic scoliosis

Abstract: Biological factors that could have a predictive value in treating idiopathic scoliosis by brace were studied in 107 patients (102 girls and 5 boys). The mean age of the patients was 14 years 6 months, and the mean Cobb angle of the curves was 36 degrees at start of treatment. The Boston brace was used for an average of 1 year 6 months, and mean follow-up time after weaning was 3 years. Scoliosis with an apex of Th 10-12 proved to be the most favorable for the final result, with a mean correction of 2 degrees. All other curves remained unchanged. Patients who had a period of rapid growth just before or during treatment had a better final result than the others. The final result was also better when treatment was started before menarche.

An analysis of the effect of the Zielke operation on S-shaped curves in idiopathic scoliosis. The use of EVAs showing that correction of the thoracic curve occurs in its lower part: significance of the thoracolumbar spinal segment.

Abstract: This paper analyzes the initial effect of the Zielke VDS operation on S-shaped idiopathic spinal curves in 17 patients with particular reference to the thoracic spine. The curves are evaluated by conventional methods (Cobb angle, apical vertebral rotation, kyphosis, and lordosis) and by a new method using end vertebra angles (EVAs). Three new surgical correction indices are used. In the lower curve, the surgical correction averaged 81%, and it is usually larger than that induced in the thoracic curve by about 48% (surgical correctability index). The lower curve correction is asymmetric, occurring more in its lower part (lower EVA) than in its upper part (upper EVA), a difference that the authors attribute to the restraint imposed by the rib cage on the upper EVA of the lower curve. In the upper (thoracic) curve, the surgically induced correction is variable and averages 33% (range, 6-69%). It is related significantly to preoperative bending film flexibility. The thoracic curve correction also is asymmetric, occurring more in its lower part (lower EVA) than in its upper part (upper EVA), which usually remains stable. The kyphosis angle decreases by an average of 7 degrees. The thoracic apical vertebral rotation shows variable changes. The findings show that the correction of the upper curve occurs mainly in the thoracolumbar spinal segment. It is suggested that this junctional segment of the spine is of importance in determining the limits of both instrumentation and fusion for idiopathic scoliosis.

[Long-term follow-up of lung function and standing height following scoliosis surgery in children and adolescents].

Abstract: Previous investigations have reported conflicting results on the development of lung function and body height after operative correction of scoliosis at young age. Partly the number of patients or the duration of observation were relatively small. 120 patients were followed for at least 10 years (10-14, average 12 years) after surgical correction of scoliosis at the age of 18.2 +/- 6.8 years. Standing height and vital capacity were measured 1, 2, 5 and 10 years after operation. Height was expressed as percentile for age and vital capacity as % expected for actual height. The primary diagnoses were idiopathic scoliosis (n = 84, average Cobb angle 90 degrees), congenital scoliosis (n = 20, 83 degrees), poliomyelitis (n = 10, 128 degrees), neurofibromatosis (n = 6, 101 degrees). We found an initial decrease in lung function after 1 year, which was probably due to post-operative immobilization and increased by the gain in body height achieved by the operation. During the rest of the observation period a significant (p less than 0.05) increase of vital capacity (% of expected for actual height) was observed. The gain was maximal for idiopathic scoliosis (+6%). In congenital scoliosis body height %ile and relative vital capacity appeared fixed at the preoperative level. Interestingly patients with an initial vital capacity below 50% expected (n = 29) or preoperative Cobb angle above 90 degrees showed the best results. They also lacked the initial deterioration of lung function in the first postoperative year and had a significant gain of vital capacity (+14%) over 10 years.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation Of Back Shape Using The ISIS Scanner

Abstract: The Integrated Shape Investigation System (ISIS) is a structured light scanner and shape analysis system, developed as a safe alternative to follow-up radiographs for the clinical assessment of deformities of the human back. The system is described and results presented of several clinic studies. These show a significant correlation between ISIS measures and conventional radiographic measures of spinal curvature, such as the Cobb angle. The development of a predictor for deterioration in adolescent idiopathic scoliosis, based on surface shape weasures, is discussed.© (1989) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.