Showing papers on "Cobb angle published in 1994"

Adult lumbar scoliosis. Epidemiologic aspects in a low-back pain population.

Abstract: The frequency and characteristics of definite lumbar scoliosis in an adult common low-back pain population (n = 671) were assessed by a clinical and radiologic prospective study. The prevalence was 7.5% (N = 50), increasing with age: 2% before 45 years; 15% after 60 years. Scoliosis was revealed by low-back pain in adulthood in 86% of the cases. The mean Cobb angle was 21 +/- 11.4 degrees. A Cobb angle of more than 30 degrees was noted in 16% of the scoliotics, thus 1% of the entire population. The proportion of women increased with the severity of the scoliosis. Right and left side scolioses were equally noted. A correlation between the Cobb angle and age was found (0.3 degrees/yr; P < 0.05). Rotatory olisthesis was noted in 34% of the cases, more often in right side curves (P < 0.01). The lumbar scoliotic patients were distinguished by a more advanced age (62 +/- 12.4 yr vs. 49.6 +/- 15.5 yr; P < 0.001), a greater proportion of women (72% vs. 48%; P < 0.01), and a more likely involvement of L3 and L4 radicular pain (P < 0.05). Radicular thigh pain was related to unstable curves (P < 0.01). The lumbar scoliotic patients thus constitute a subgroup within the low-back pain population.

Variation in Cobb angle measurements in scoliosis.

Abstract: In order to determine the reliability of the Cobb angle measurement as it is used in the clinical management of scoliosis, a methodological survey was carried out. In the measurement of a Cobb angle two phases can be distinguished: (a) the production of a spinal radiograph and (b) the measurement of the angle itself. In respect of the first phase, the variation in production of the radiographs was calculated on Cobb angle measurements made by one investigator on serial radiographs of patients who underwent spinal fusion for scoliosis and therefore had a fixed spinal curvature. For the second phase, the accuracy of Cobb angle measurement was investigated by comparing measurements on the same radiographs of 46 scoliosis patients obtained by three investigators, namely two orthopaedic surgeons and an orthopaedic fellow who was assigned to a school screening project. Results were expressed as a Spearman correlation coefficient and a standard deviation of the differences. The Spearman correlation coefficient was 0.98 for the repeated radiographs (production variation) and also 0.98 for the repeated measurements on one radiograph (interobserver measurement variation). The standard deviation of the differences in Cobb angle for the repeated radiographs amounted to 3.2° and for the repeated measurements on one radiograph it was 2.0°. Although there is a good reproducibility of the Cobb angle measurement between different investigators, the variation in production of a spinal radiograph is an important source of error. This should be taken into account when making decisions in scoliosis management.

Pathophysiology of spinal deformities in neurofibromatosis. An analysis of seventy-one patients who had curves associated with dystrophic changes.

Abstract: The findings in seventy-one patients who had previously untreated spinal deformities associated with dystrophic changes and who had neurofibromatosis were reviewed to identify the risk factors for progression of the curve as well as the natural history of the dystrophic changes and curve patterns. Four different types of curves were evaluated. Two of them had the most severe progression: (1) kyphoscoliosis with angular kyphosis (gibbus) and marked dystrophic changes and (2) so-called kyphosing scoliosis (a scoliosis that has so much rotation [90 degrees] that progression is evident only on the lateral roentgenogram) with a round kyphosis. Risk factors for substantial progression of the curve were an early age of onset, a high Cobb angle at the first examination, an abnormal kyphosis, vertebral scalloping, severe rotation at the apex of the curve, location of the apex of the curve in the middle to caudal thoracic area, penciling of one rib or more on the concave side or on both sides of the curve, and penciling of four ribs or more.

Radiographic changes at the coronal plane in early scoliosis.

Abstract: The development of structural skeletal changes was evaluated on 132 anteroposterior radiographs of spines from three scoliotic groups with a Cobb angle of up to 30 degrees and a reference control group. Significant wedging of the vertebral bodies and disks at the coronal plane was registered in-curves with a Cobb angle of 4 degrees or more. Asymmetry of the rib-vertebra angle was found in curves with a Cobb angle of 8 degrees or more and was most pronounced in the cranial part of the curves. The early simultaneous occurrence of vertebral and disk wedging suggests the involvement of an extraspinal factor rather than growth disturbance of the vertebral body or of the disk in the early pathomechanism of scoliosis.

Computer-assisted curvature assessment and Cobb angle determination of the thoracic kyphosis. An in vivo and in vitro comparison.

Abstract: STUDY DESIGN A retrospective survey of thoracic spinal curvature compared postmortem radiographs with recent clinical films in 22 cases. OBJECTIVES This study was performed to determine whether spinal curvature measured from postmortem radiographs is a valid measure of curvature in vivo. SUMMARY OF BACKGROUND DATA Little quantitative data have been cited on whether sagittal plane thoracic spinal curve characteristics change after death. METHODS Thoracic kyphosis was measured using the Cobb method and the mean radius of curvature from computer-assisted digitizing of the vertebral contour. Thoracic segments visualized on the chest films were referenced to the postmortem radiograph. RESULTS AND CONCLUSIONS The in vivo and in vitro measurements strongly correlated (Cobb angle r = 0.95, curvature r = 0.78). Trends decreased slightly in Cobb angle (1.3%, -2.6%) and increased slightly in curvature (10.7 mm, 4.1%). Differences were not significant, however, supporting the use of spinal curvature analysis with postmortem radiographs.

Scoliosis in Rett syndrome.

Abstract: Scoliosis is the most common orthopaedic problem encountered in Rett syndrome. It is characterized by a long C-shaped thoracolumbar curve of neurologic origin. The occurrence of scoliosis in Rett syndrome is age-dependent, with a reported incidence of 36% to 100%. The onset of scoliosis is usually before age 8 years, and rapid curve progression is usually detected early in the second decade. In Rett syndrome, sagittal deformity with excessive kyphosis can progress and necessitates close observation. Orthotic treatment does not alter the natural history of scoliosis or kyphosis. Indications for surgery are curve progression exceeding a 40 degree or 45 degree Cobb angle or curves that cause pain or loss of function. Anterior discectomy, interbody fusion, and posterior fusion with instrumentation can achieve improved correction in young adolescents with significant curves. Surgical intervention should include fusing the scoliotic and the excessively kyphotic segments.

Vertebral growth after posterior spinal fusion for idiopathic scoliosis in skeletally immature adolescents. The effect of growth on spinal deformity

Abstract: We studied 29 girls and one boy with adolescent idiopathic scoliosis who were at Risser grade 0 at the time of posterior spinal fusion and were followed until maturity (mean 7.8 years). We used serial radiographs to measure the ratio of disc to vertebral height in the fused segments and to detect differential anterior spinal growth and assess its effect on scoliosis, vertebral rotation, kyphosis, and rib-vertebral-angle difference (RVAD). From one year after surgery to the latest review, the percentage anterior disc height decreased by nearly one-half and the percentage posterior disc height by nearly one-third in the fused segments (p < 0.001). There was a 4 degree increase in mean Cobb angle (p < 0.001), 11 patients (37%) having an increase of between 6 degrees and 10 degrees. There was a significant increase in mean apical rotation by 2 degrees (p = 0.003), and four patients (13%) had an increase of between 6 degrees and 16 degrees. There was little change in kyphosis. There was an increase in mean RVAD by 4 degrees (p = 0.003), seven patients (23%) showing a reduction by 1 degree to 7 degrees, and 11 (37%) increases of between 6 degrees and 16 degrees. Spinal growth occurs after posterior fusion in adolescents who are skeletally immature, as a result of continued anterior vertebral growth. There is some progression of scoliosis, vertebral rotation, and RVAD, but little change in kyphosis. The increase in deformity is not enough to warrant the use of combined anterior and posterior fusion. The findings are relevant to the management of progressive curves, the timing and extent of surgery, and the prognosis for progression of deformity in this group of patients.

Left thoracic scoliosis configurations. Why so different

Abstract: Study design Patients in the scoliosis screening database were analyzed with respect to curve convexity, severity, and outcome, using standard statistical methods. Objectives This study assessed whether left thoracic scoliosis is always pathologic and inquired why this is the case. Summary of background data Left thoracic scoliosis is more significant than the usual right thoracic pattern, but evidence in the literature is circumstantial. Methods Prospectively collected data from 1979-1990 was analyzed in the natural history database of the school screening program. Results Right thoracic pattern was observed in 421 girls, and left thoracic pattern was present in 125 girls. The minimum age at diagnosis was 10 years and the Cobb angle was > 4 degrees. Primary left thoracic patterns were statistically smaller and less progressive. Conclusions The left pattern of scoliosis in the absence of overt neuropathology carries a benign prognosis. This contradictory observation is examined in the light of biological asymmetry.

Changes in shape of the adolescent idiopathic scoliosis curve after surgical correction.

Abstract: Study Design The effect of spinal instrumentation in Idiopathic scoliosis was studied in 21 patients who had Harrington instrumentation and 15 who had Wisconsin Drummond instrumentation. Objective Radiographs were analyzed to determine if the frontal and transverse plane shape of the scoliosis curve was changed by surgery, with and without segmental fixation. Summary of Background Data Previous reports were based on frontal plane measurements of the curve (Cobb angle). The study reports correction in the frontal plans (Cobb angle) and transverse plane (apical vertebral rotation), as well as the regional distribution of the correction. Methods Radiographs before surgery, soon after, and between 5 and 48 months after surgery were marked and digitized to measure the regional distribution of the frontal plane shape and transverse plane vertebral rotation. Results Despite improvement in the magnitude of the deformity, the scoliosis curbe shape remained almost constant postoperatively. There was minimal correction of the apical vertabra axial rotation in either group. Conclusion This study documents that although the Harrington and Wisconsin-Drummond instrumentation systems decrease the Cobb angle, they do not change the shape of the curve or correct apical vertebra axial rotation. Newer instrumentation designs need to look beyond the Cobb angle as the only measure of outcome.

Fractures of the dorsolumbar spine with neurological lesions. A comparison of different treatments.

Abstract: Seventy-nine fractures of the dorsolumbar junction with neurological lesions have been studied retrospectively at an average follow up of 29 months. Sixteen patients were treated conservatively and 63 were operated on using the techniques of laminectomy, Harrington rods, supplemented Harrington fixation and the Malaga transpedicular fixator. Both the angle of kyphosis and the percentage of vertebral wedging were comparatively lower when the Malaga fixator was used. Pain and the angle of kyphosis were related statistically, the Cobb angle being greater for those with pain. Surgical treatment allowed patients to sit up earlier, and those with a Malaga fixator spent a shorter time in hospital. No differences were found in neurological improvement.

Clinical use of the simple 3D-calculation in scoliosis

Abstract: In this paper we show the clinical application of a simple method for calculating three-dimensional shape in scoliosis by the use of two tables based on normal standard X-rays in the anteroposterior and lateral projections. The three-dimensional alignment should be considered in both conservative and operative correction. In 57 patients with 87 scoliotic curves we measured the wellknown Cobb angle (a) and determined the vertebral rotation according to the method of Nash and Moe. We compared this information with the results of the calculated three-dimensional angles of scoliosis (angle β between the curvature plane and the sagittal plane, angle σ as the true angle of scoliosis in this curvature plane). In 76 curves (87%) our method was practicable. The true angle σ is always higher than the projected angle α, especially in the clinically relevant range of 20°–40°. Poor correlation is shown between the projected angle a and the true angle σ (r = 0.41 for thoracic curves and r = 0.57 for lumbar curves) and almost no correlation between vertebral rotation and the true angle σ (r = 0.10 for thoracic curves and r = 0.44 for lumbar curves) and the curvature plane (β) (r = 0). The three-dimensional shape of scoliosis cannot be estimated by the well-established projected angles and indices and we recommend the use of our simple method for the radiological investigation of scoliotic patients.

Le traitement de la scoliose idiopathique de l'adolescent par le corset de Chêneau Premiers résultats de l'expérience Lilloise - A propos de 26 cas avec un recul moyen de 16 mois

Abstract: This study aims at presenting the preliminary result of personal experience using the Cheneau-brace in the treatment of idiopathic scoliosis in 26 cases. The average follow-up was 16 months. In every case, wear compliance was perfect ( brace worn 23h out of 24h). At the beginning of the treatment the 19 girls and 7 boys, whose average age was 15 years and 3 months, had a Risser test below 2 in 50% of the cases. At follow-up 69% of the patients had a Risser test higher than 3. In every case but one , the curves were thoracic, lumbar or combined. In frontal plane 73% of the patients were improved and 27% stabilized to within 2 degrees. Initially the average frontal Cobb angle measured 30° at thoracic level and 24° at lumbar level. At follow-up the average improvement was respectively 27% and 37,5%. In sagittal plane a 23% angular loss at dorsal level and a 9% loss at lumbar level were detected at follow-up with brace. We did not notice any effect on vertebral rotation but the movement of translation of the apical vertebra toward the chest wall in the convex side was improved (23%). We confirm that Cheneau-brace is efficient in the conservative treatment of adolescent idiopathic scoliosis but we must point out a decrease of kyphosis and lordosis was detected.