Purpose of the study: The cervical spine is the most mobile portion of the spinal column. Trauma raises a high risk of bone and ligament injury. Several cervical collars are used in adults with variable efficacy. For children the problem is the availability of adapted collars, although the issue has not been examined in the literature. The purpose of this work was to evaluate the efficacy of paediatric collars widely used for stabilising the cervical spine in children.

Material and method: Thirty asymptomatic patients aged 6 to 12 years participated in this study. Four types of paediatric cervical collars were used (Philadelphia, Miami Jr, Neloc, and the conventional stiff collar). The medium size, proposed for children aged 6 to 12 was used. A standard protocol was applied with the Vicon^® system to analyse movement. Mobility of the neck was recorded with and without collars: flexion, extension, lateral inclination and axial rotation. The mobilities recorded without a collar were compared with the values obtained when the children wore each collar. The degree of mobility reduction was calculated for each collar. Seventeen children participated in a reproducibility study. ANOVA and Student’s t test were used for the statistical analysis.

Results: There was no statistically significant difference between the collars for efficacy in the saggital plane, though apparent stability was better with the Neloc. The degree of reduction was smaller with the Philadelphia than with the other collars in the frontal plane. Miami Jr and Neloc were more effective than the Philadelphia and the conventional collar in the axial plane.

Discussion: This study provide an assessment of the efficacy of paediatric collars to limit mobility of the cervical spine. Although a limited number of collars are proposed, those available on the market appear to ensure optimal stability, particularly the Miami Jr and the Neloc. The stabilisation problem, could be resolved by adapting the collars, particularly the height.

Purpose: Parent worry about torsional or angular anomalies of the lower limbs of their children is widespread. The relationship between a child’s postural habits and torsional anomalies of the lower limbs is often mentioned in the literature despite the lack of a single study demonstrating solid evidence. Active treatment of such anomalies is exceptionally necessary. Postural education is undoubtedly provided by parents. The purpose of this study was not to establish a cause and effect relationship between postural habits and torsional anomalies but rather to determine whether children who exhibit a preferential nocturnal and diurnal posture have torsional anomalies of the lower limbs.

Material and methods: This retrospective analysis included all patients consulting one paediatric orthopaedist for in-toeing during a period of six years. Patients with a neurological disorder, bone and joint disease, or a congenital malformation as well as those with a history of orthesis use for fracture or surgery of the lower limbs were excluded. The cohort was composed of 463 children aged 1.5 to 15 years. Five habitual postures were studied: sitting cross-legged, sitting on knees feet under the buttocks, laying on knees with buttocks upward and feet inward, laying on belly knees extended and feet inward, and indifferent sitting and reclining positions. Abnormal torsion was determined clinically. Internal hip rotation greater than 70 (Staheli) observed in the ventral decubitus position with knees flexed 90° was considered to indicate excessive femoral anteversion (EFAV). Internal tibial torsion (ITT) was considered to be present when the thigh-foot angle was 0 measured in the ventral decubitus position or sitting on the table legs hanging. We searched for correlations between habitual posture and abnormal torsion as well as the influence of gender and age using the chi-square test and 95% confidence intervals. Patients with both EFAV and ITT were stratified by group using the Woolf method associated with the Mantel-Haenszel test.

Results: Abnormal torsion was found more often in children aged less than 4 years with no difference between boys and girls. Among the children in this study presenting in-toeing, 31% did not have a preferred sitting or reclining position and only 7% presented clearly abnormal torsion. There was a significant direct correlation between EFAV and sitting crosslegged and a significant inverse correlation between EFAV and the other habitual postures. Conversely, there was no significant correlation between ITT and the habitual postures studied.

Discussion and conclusion: This study provided objective information concerning widely accepted but poorly documented notions. There were two limitations: 1) the lack of a control group not presenting in-toeing, 2) the absence of precise goniometric measurements, a problem encountered in most studies using clinical methods. Although the presence of abnormal torsion of the lower limb appears to significantly influence the gait pattern in children, it does not appear to affect habitual postures. A significant relationship was found only between habitual posture and EFAV, and not ITT. These results should be taken into consideration when planning treatment.

Purpose: Ligament laxity is a common feature of trisomy 21 and is incriminated in most of the orthopaedic disorders observed. Early diagnosis and management is essential. C1-C2 instability is a recognised manifestation in trisomy 21 and is associated, at least theoretically, with significant risk of cord complications. The purpose of this work was to provide a descriptive analysis of the C1-C2 joint in trisomy 21 and to analyse instability factors in order to determine the tolerable C1-C2 distance.

Material and methods: Within the framework of a French national epidemiology survey of trisomy 21, we focused on the C1-C2 joint. A total of 472 children with trisomy 21 were identified; 458 who were examined were included in this study. Careful history taking and a detailed physical examination with neurological tests (search for even minimal signs of neurological disorders) was conducted. The Carter and Wilkinson method was used to assess joint laxity. The same specialist searched for other orthopaedic disorders. Patients were divided into two groups depending on the presence or absence of neurological signs. Two groups were also distinguished according to the presence or absence of generalised laxity (Carter and Wilkinson). Lateral x-rays centred on C1-C2 were performed by the same technician on the same machine with the patient in a neutral position, hyperflexion and hyperextension. The same technique inspired by the method described by Singer et al. and modified for simplification was used in all cases. The same observer interpreted the images using a single-blinded protocol to search for congenital malformations and signs of degeneration, measure the C1-C2 distance the minimal sagittal diameter and the C1-C2 angle (not reported in the literature and described for this study). These measures were then compared with data in the literature as available and correlated by age, gender, presence of neurological signs and joint laxity. Seven patients were excluded from the study due to insufficient cooperation for the x-rays and nine because of incomplete clinical or radiological data. The statistical analysis was performed on data from 442 patients. Quantitative variables were compared with the Pearson test and parameteric ANOVA was used to search for correlations of quantitative and qualitative variables. Significance was set at p< 0.05.

Results: Mean patient age was 13.8 years. There were 184 girls and 258 boys. Minor neurological anomalies were found in 42% of the patients. There were no cases of major motor deficit. Generalised laxity as defined by Carter and Wilkinson was observed in 24% of patients. Other orthopaedic problems, basically of the foot, were found in 85%. The radiograms revealed a very wide range of measures were thus expressed as means. The C1-C2 distance was greater than 4 mm in 34 patients on the flexion films (limit established in the literature for instability in trisomy 21). The maximal C1-C2 distance in the neutral position was 8 mm, 9.6 mm in flexion. The lowest minimal sagittal distance was 8 mm in flexion and 10 mm in the neutral position (the lower limit reported in the literature before considering the cord to be threatened in 14 mm). The greatest variability was found for the C1-C2 angle. Ligament laxity and atlantoaxial distance were inversely proportional to patient age, but there was no significant correlation between atlantoaxial instability (C1-C2 distance > 4 mm) and gender or generalised hyperlaxity. There was no significant correlation between C1-C2 instability or laxity and neurological signs.

Discussion and conclusion: Compared with earlier publications, our series offers the advantage of a large unselected population providing epidemiological data on trisomy 21. A standard radiography protocol was used. The large majority of the radiographic measures reported in the literature do not take into account the magnification effect nor position variability between patients. Our findings confirm certain data in the literature and also provide new information suggesting it could be useful to revisit certain pathogenic hypotheses about C1-C2 instability and its neurological consequences in trisomy 21. Two important observations were the absence of a correlation between general laxity and C1-C2 instability and the absence of correlation between C1-C2 instability and the presence of neurological signs.