The inhalation effects of by-products from chlorination of heated indoor swimming pools on spinal development in pup mice.

INTRODUCTION: It has been postulated that swimming in heated indoor swimming pools in the first year of life is associated with the development of spinal deformity in children. We explored in pup mice whether exposure to certain disinfection by-products resulting from chlorination of heated pools would affect the future development of the spinal column. METHODS: Mice, from birth and for 28 consecutive days, were exposed to chemicals known to be created by disinfection by-products of indoor heated swimming pools. The study made use of a body fluid analogue and a chlorine source to recreate the conditions found in municipal pools. A cohort of 51 wild-type C57B6 mice, male and female, were divided into two groups: experimental (n = 29) and controls (n = 22). 24 mice were observed for 8 months (32 weeks), with 27 culled at 4 months (16 weeks). Serial CT scanning was used to assess the spines. RESULTS: Exposure to disinfection by-products resulted in an increase in the normal thoracic kyphotic spinal angle of the mice when compared with their controls at 10 weeks; experimental mice kyphosis range 35-82° versus 29-38° in controls. At 14 weeks the kyphosis of the experimental mice had reduced in size but never to that of the control group. CONCLUSION: We have demonstrated the ability to influence spinal development in pup mice through environmental factors and shown that the developmental deformity became evident only after a significant latent period.

Does an Internal Thoracoplasty Correct and Prevent a Reassertion of the Rib Cage Deformity After Spine Surgery for an Adolescent Idiopathic Thoracic Scoliosis Greater Than 70 Degrees.

STUDY DESIGN: Prospective observational study. OBJECTIVE: To evaluate the effect of internal thoracoplasty and anterior spine release combined with posterior spinal instrumentation in correcting and preventing a reoccurrence of the rib cage deformity in adolescent idiopathic thoracic scoliosis >70 degrees. SUMMARY OF BACKGROUND DATA: The rib cage deformity rather than the lateral curvature of the spine is usually the major cosmetic deformity in severe adolescent idiopathic thoracic scoliosis. This can be difficult to treat and assess the effect of surgery. METHODS: The Integrated Shape Imaging System was used to assess rib cage deformity before surgery and during follow-up for more than 2 years in 37 patients with an adolescent idiopathic thoracic scoliosis (Lenke 1) >70° (mean 81°) treated by internal thoracoplasty and anterior spine release combined with posterior spinal instrumentation using a hybrid construct. RESULTS: The mean Cobb angle was reduced from 81° to 30° (63% correction). The rib cage deformity was improved in 30 patients (81%) because of a combination of both a reduction of the convex rib hump and an elevation of the concave rib depression. However, the effect on patients with an angle of thoracic inclination <16° was not as reliable. One year after surgery, additional improvement of the chest deformity had occurred in 9 patients. In none of the 37 patients was there any further progression of the rib cage deformity. CONCLUSION: An internal thoracoplasty was effective in improving and/or stabilizing the rib cage deformity as well as achieving good correction of the scoliosis in patients with adolescent idiopathic thoracic scoliosis and severe deformity.

Erratum to: Physical activities of Patients with adolescent idiopathic scoliosis (AIS): preliminary longitudinal case-control study historical evaluation of possible risk factors.

[This corrects the article DOI: 10.1186/s13013-015-0029-8.].

Physical activities of Patients with adolescent idiopathic scoliosis (AIS): preliminary longitudinal case-control study historical evaluation of possible risk factors.

To our knowledge there are no publications that have evaluated physical activities in relation to the etiopathogenesis of adolescent idiopathic scoliosis (AIS) other than sports scolioses. In a preliminary longitudinal case-control study, mother and child were questioned and the children examined by one observer. The aim of the study was to examine possible risk factors for AIS. Two study groups were assessed for physical activities: 79 children diagnosed as having progressive AIS at one spinal deformity centre (66 girls, 13 boys) and a Control Group of 77 school children (66 girls, 11 boys), the selection involving six criteria. A structured history of physical activities was obtained, every child allocated to a socioeconomic group and examined for toe touching. Unlike the Patients, the Controls were not X-rayed and were examined for surface vertical spinous process asymmetry (VSPA). Statistical analyses showed progressive AIS to be positively associated with social deprivation, early introduction to indoor heated swimming pools and ability to toe touch. AIS is negatively associated with participation in dance, skating, gymnastics or karate and football or hockey classes, which might suggest preventive possibilities. There is a significantly increased independent odds of AIS in children who went to an indoor heated swimming pool within the first year of life (odds ratio 3.88, 95% CI 1.77-8.48; p = 0·001). Furthermore fourteen (61%) Controls with VSPA compared with 9 (17%) Controls without VSPA had been introduced to the swimming pool within their first year of life (P < 0.001). Early exposure to indoor heated swimming pools for both AIS and VSPA, suggests that the AIS findings do not result from sample selection.

Prognosis for congenital scoliosis due to a unilateral failure of vertebral segmentation.

BACKGROUND: Congenital scoliosis due to a unilateral failure of vertebral segmentation usually has a poor prognosis. However, not all curves progress to the same degree or develop the same spinal deformity. METHODS: The medical records and spine radiographs of 171 patients with a scoliosis due to unilateral unsegmented bar were reviewed retrospectively. The mean patient age at diagnosis was 9.3 years. Thirty-six patients had immediate surgery, 103 immature patients were followed untreated or before surgery for a mean duration of 3.6 years, twenty-eight patients were seen untreated at skeletal maturity, and four patients had no follow-up. RESULTS: The unsegmented bar occurred at all levels; the mean extent was three vertebrae (range, two to eight vertebrae). Before the age of ten years, patients had a mean rate of scoliosis progression without treatment for all regions of the spine of 2° to 3° per year. By the age of ten years, seventy-three patients who had been seen untreated or prior to treatment had a mean scoliosis of 50° (range, 18° to 100°). After the age of ten years, these patients had an increase in the mean rate of scoliosis progression, but this rate varied per year depending on the affected region of the spine: 7° for the thoracolumbar curve, 5° for the midthoracic curve, and 4° for the upper thoracic curve. Spine surgery was performed on seventy-four patients who had a mean age of 12.2 years and a mean scoliosis of 78° for thoracolumbar curves, 66° for midthoracic curves, and 54° for upper thoracic curves. Of the patients with midthoracic congenital scoliosis, 24% developed a lower structural compensatory curve, which became larger and more deforming than the congenital curve, 22% had congenital rib fusions, and 16% had occult intraspinal anomalies. CONCLUSIONS: Prognosis depends on growth imbalance at the site of the unsegmented bar as well as the location and extent of the bar, age at diagnosis, and spinal growth remaining. LEVEL OF EVIDENCE: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Heated indoor swimming pools, infants, and the pathogenesis of adolescent idiopathic scoliosis: a neurogenic hypothesis.

BACKGROUND: In a case-control study a statistically significant association was recorded between the introduction of infants to heated indoor swimming pools and the development of adolescent idiopathic scoliosis (AIS). In this paper, a neurogenic hypothesis is formulated to explain how toxins produced by chlorine in such pools may act deleteriously on the infant's immature central nervous system, comprising brain and spinal cord, to produce the deformity of AIS. PRESENTATION OF THE HYPOTHESIS: Through vulnerability of the developing central nervous system to circulating toxins, and because of delayed epigenetic effects, the trunk deformity of AIS does not become evident until adolescence. In mature healthy swimmers using such pools, the circulating neurotoxins detected are chloroform, bromodichloromethane, dibromochloromethane, and bromoform. Cyanogen chloride and dichloroacetonitrile have also been detected. TESTING THE HYPOTHESIS: In infants, the putative portals of entry to the blood could be dermal, oral, or respiratory; and entry of such circulating small molecules to the brain are via the blood-brain barrier, blood-cerebrospinal fluid barrier, and circumventricular organs. Barrier mechanisms of the developing brain differ from those of adult brain and have been linked to brain development. During the first 6 months of life cerebrospinal fluid contains higher concentrations of specific proteins relative to plasma, attributed to mechanisms continued from fetal brain development rather than immaturity. IMPLICATIONS OF THE HYPOTHESIS: The hypothesis can be tested. If confirmed, there is potential to prevent some children from developing AIS.

Indoor heated swimming pools: the vulnerability of some infants to develop spinal asymmetries years later.

Evidence reported in an earlier paper suggests that infants introduced to indoor heated swimming pools in the first year of life show an association with spinal asymmetries including progressive adolescent idiopathic scoliosis (AIS) and in normal subjects vertical spinous process asymmetry. Indoor heated swimming pools may contain a risk factor that predisposes some infants to develop such spinal asymmetries years later. What the risk factor(s) may be and its possible portal of entry into the infant's body are unknown and possibilities are examined. New teenage controls were obtained after mothers of AIS patients mentioned that they had taken their child to an infant swim class. In a further group of 18 normal teenagers introduced to an indoor heated swimming pool in the first year of life, 15 had vertical spinous process asymmetry. This prevalence of 83% of those at risk confirms our previous observation of vertical spinous process asymmetry in 61% of teenagers who were introduced to indoor heated swimming pools in the first year of life. Subject to confirmation of our observations consideration should be given to chemical risk factors, possible portals of entry, toxicology, environmental epigenomics and disease susceptibility to altered spinal development. If the risk factor is confirmed there may ultimately be a place for the prevention of AIS in some subjects.