Abstract: The effect of a modified Boston Brace with antirotatory blades upon the fate of idiopathic scoliotic (IS) curves, mainly right thoracic with a compensatory left lumbar, is studied. This report refers to curves within the generally accepted range of Cobb angle (20° – 40°) appropriate for conservative treatment.

Method and Material: Out of 166 children suffering IS with Cobb angle > 10°, 67 (61 girls, and 6 boys), having a mean follow up 2,3 years (4 months to 7 years), were studied. A brace of Boston type with antirotatory blades was applied in 36 scoliotic children. The curve type was: 18 thoracic (T) right (rt) + Lumbar (L) left (lt) in children with a mean age 13,1 years, 3 T lt + L rt in children with a mean age 16,3 years, 7 T rt in children with a mean age 13 years and 8 thoracolumbar (TL) rt curves in children with a mean age 12,1 years. Full documentation during the FU had 23 out of the 36 children with 14 T rt + L lt, 1 T lt + L rt (15 in total – double curve group), 4 T rt (thoracic group) and 4 TL curves (thora-columbar group). Traditionally deterioration (increase) or improvement (decrease) of a curve is considered a change of 5ï Cobb compared with the initial reading.

Results: In the 15 double curve group children the mean FU was 28 months. In this group 5 curves were improved, 6 remained stable and 4 were increased. For the 4 thora-columbar curves with a mean FU 8 months, 3 remained stable and 1 improved. For the 4 thoracic curves with a mean FU 9 months, 2 were stable and 2 improved. During the final FU of the above 23 scoliotic children, when the assessment of Cobb angle was made with children out of the brace, 8 curves were improvement, 11 remained stable and 4 deteriorated (one patient out of 4 (4,3%) was operated upon). All the deteriorated curves were double (T rt + L lt). When the assessment of Cobb angle was made with children in the brace, 10 curves were improved, 12 remained stable and 1 deteriorated

Discussion: The brace treatment affected more the double curves while single curves remained unaffected. Rotation remained unchanged in all curve types except in the lumbar component of double (right thoracic-left lumbar) curves. A composite spiral trunk rotator muscle has been proposed, (consisted of the ipsilateral scapular elevator and rhomboid, the anterior serrated, external oblique and contralateral internal oblique abdominal muscle, (Benninghoff 1985, Wemyss-Holden 1990), which is considered that have an effect on the trunk rotation during gait. Asymmetry of one or more constituent muscles creates scoliosis. These findings are consistent with the view that neuromuscular factors are responsible for the initiation of idiopathic scoliosis. The antirotatory blades of the brace are acting upon the above described composite spiral trunk rotator muscle blocking the deterioration of the scoliotic curve or improving the double curves thus supporting the above aetiologic view. In conclusion the conservative treatment using this brace is beneficially affecting the natural history of the IS in children 12–15 years of age.

1. Introduction. A significant correlation between handedness and laterality of the curve in scoliotic children is reported in the literature. This correlation is implicating cortical function as an aetiologic factor for scoliosis, (Goldberg and Dowling 1990). The truncal asymmetry expressed as a hump, is the sign at the presence of which there is a suspicion of a scoliotic curve. The above issue stimulated the search of existence of a possible correlation between handedness and the increasing truncal asymmetry, the existence of which represents a risk factor for development of scoliosis. Thus the aim of this study is the appraisal of the correlation of the existence of a truncal asymmetry as it is checked by the use of a scoliometer during the forward bending test and the handedness in schoolmates who were screened at school for scoliosis.

2. Material and Method

2.1 The examined children. 4345 students (2183 girls and 2158 boys), 6 – 18 years of age were examined during the school-screening program for scoliosis.

2.2 The measurements. A protocol with a checklist is filled for each student in which handedness and truncal asymmetry is included. The probability of existence of scoliosis in the child and the recommendation for further clinical and radiological assessment at hospital is based on the amount of the recorded truncal asymmetry. The sitting and standing forward bending test is performed using the Pruijs scoliometer, on which reading ≥7° is a threshold for recommendation for reexamination. Truncal asymmetry was recorded for thoracic, thoracolumbar and lumbar region.

2.3 The statistical analysis. The techniques used for the study of the sample of children included cross tabulation and ÷2.

3. Results. The statistical analysis revealed that there is no statistical difference for handedness between boys and girls therefore the correlation between handedness and truncal asymmetry was performed for both sexes together. 91% children were right-handed (1932 boys and 1996 girls), while 9% left-handed (218 boys and 169 girls) respectively. A significant statistical correlation of truncal asymmetry and handedness was found both in boys and girls at thoracic (p < 0.022) and thoracolumbar (p< 0.027), but not at the lumbar region.

4. Discussion. These findings show that there is significant correlation of truncal asymmetry and the dominant brain hemisphere in terms of handedness, in children who are entitled at risk to develop scoliosis. Thus, the correlation of the handedness and the truncal asymmetry (the scoliosis convex) is present not only at scoliotic children but and at those being at risk that is before the development of the disease. These findings correlate cortical function and the truncal asymmetry, probably as a prodrome state of scoliosis and it is of aetiologic importance.