In scoliosis, most of the deformity is in the disc and occurs during the period of rapid growth. The ring apophyses form the insertion of the disc into the vertebral body, they then ossify and fuse to the vertebrae during that same crucial period. Although this must have important implications for the mechanical properties of the spine, relatively little is known of how this process takes place. This study describes the maturation pattern of the ring apophyses in the thoracic and lumbar spine during normal growth. High-resolution CT scans of the spine for indications not related to this study were included. Ossification and fusion of each ring apophysis from T1 to the sacrum was classified on midsagittal and midcoronal images (4 points per ring) by two observers. The ring apophysis maturation (RAM) was compared between different ages, sexes, and spinal levels. The RAM strongly correlated with age (R = 0.892, p < 0.001). Maturation differed in different regions of the spine and between sexes. High thoracic and low lumbar levels fused earlier in both groups, but, around the peak of the growth spurt, in girls the mid-thoracic levels were less mature than in boys, which may have implications for the development of scoliosis.

Purpose: Adolescent idiopathic scoliosis (AIS) patients are exposed to 9–10 times more radiation and a fivefold increased lifetime cancer risk. Radiation-free imaging alternatives are needed. Ultrasound imaging of spinal curvature was shown to be accurate, however, systematically underestimating the Cobb angle. The purpose of this study is to create and cross-validate an equation that calculates the expected Cobb angle using ultrasound spinal measurements of AIS patients. Methods: Seventy AIS patients with upright radiography and spinal ultrasound were split randomly in a 4:1 ratio to the equation creation (n = 54) or validation (n = 16) group. Ultrasound angles based on the spinous processes shadows were measured automatically by the ultrasound system (Scolioscan, Telefield, Hong Kong). For thoracic and lumbar curves separately, the equation: expected Cobb angle = regression coefficient × ultrasound angle, was created and subsequently cross-validated in the validation group. Results: Linear regression analysis between ultrasound angles and radiographic Cobb angles (thoracic: R² = 0.968, lumbar: R² = 0.923, p < 0.001) in the creation group resulted in the equations: thoracic Cobb angle = 1.43 × ultrasound angle and lumbar Cobb angle = 1.23 × ultrasound angle. With these equations, expected Cobb angles in the validation group were calculated and showed an excellent correlation with the radiographic Cobb angles (thoracic: R² = 0.959, lumbar: R² = 0.936, p < 0.001). The mean absolute differences were 6.5°–7.3°. Bland–Altman plots showed good accuracy and no proportional bias. Conclusion: The equations from ultrasound measurements to Cobb angles were valid and accurate. This supports the implementation of ultrasound imaging, possibly leading to less frequent radiography and reducing ionizing radiation in AIS patients.

Study Design.: Translation and validation of the Early Onset Scoliosis-24 Questionnaire (EOSQ-24). Objective.: To cross-culturally adapt the English version of the EOSQ-24 to the Dutch language and to assess the questionnaire's reliability and validity. Summary of Background Data.: Early-onset scoliosis (EOS) has a profound impact on health-related quality of life. The EOSQ-24 is health-related quality of life questionnaire filled in by parents of children with EOS. The EOSQ-24 was already translated into multiple languages and its application was confirmed in clinical studies. However, the EOSQ-24 is not yet translated and validated for the Dutch population. Methods.: The adaption of the EOSQ-24 for the Dutch population was done in three steps: 1) translation to the Dutch language, 2) cross-cultural adaptation, and 3) cross-cultural validation. To ensure that the Adapted Dutch EOSQ-24 is applicable for clinical use, the measurement properties were tested in four steps: 1) floor and ceiling effects, 2) validation, 3) reliability, and 4) discriminative ability. One hundred three parents completed the Adapted Dutch EOSQ-24, the Child Health Questionnaire (CHQ-28 PF), and the Scoliosis Research Society Questionnaire (SRS-22r). A second EOSQ-24 was completed for test–retest reproducibility. Results.: The EOSQ-24 was successfully translated, adapted, and validated for the Dutch language. Almost all response items showed a normal distribution. The EOSQ-24 showed excellent reliability (Cronbach α of 0.950). The EOSQ-24 was successfully validated against the CHQ-28-PF and the SRS-22r. Test–retest was excellent (ICC ≥ 0.8). Finally, The EOSQ-24 was found capable to discriminate patients with different curve severities (P = 0.003), diagnosis (P = 0.006), and ambulatory status (P < 0.001). Conclusion.: The current Dutch EOSQ-24 proved to be a valid and reliable quality of life assessment tool for patients with EOS. Currently, long follow-up studies using the EOSQ-24, including the Dutch EOSQ-24, are lacking and are needed to fully validate the EOSQ-24 for use in a clinical setting. Level of Evidence: 2

Ultrasound shear wave elastography is a radiation-free and low-cost technique for evaluating the mechanical properties of different tissues. This study systematically reviewed all relevant literature on shear wave elastography of the intervertebral disc. The purpose was twofold: first, to determine the validity of the elastography method, that is, the correlation between elastographically measured shear wave speed and disc mechanical properties, and inter-/intra-operator reliability; and second, to explore if disc elastography is potentially useful in identifying children at risk for idiopathic scoliosis. This systematic review was performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines. A comprehensive search was performed in PubMed and Embase, and study quality was assessed using the AXIS (Appraisal Tool for Cross-sectional Studies) critical appraisal instrument. Seven articles were included. Three animal ex vivo studies reported moderate-to-good correlations between shear wave speed and disc mechanical properties (r = 0.45-0.81). Three studies reported high intra-operator repeatability (intra-class correlation coefficient [ICC] 0.94-0.99) and inter-operator reproducibility (ICC 0.97-0.98). Four clinical studies measured shear wave speed in asymptomatic children. Two studies reported significantly higher shear wave speeds in scoliosis patients compared with healthy controls, measured in discs both inside and outside the scoliotic curve. In conclusion, shear wave elastography appears reliable in assessing intervertebral disc mechanical characteristics. Despite its promising capabilities to distinguish patients with asymptomatic from those with pathological discs, the exact correlation between disc mechanical properties and shear wave speed remains unclear.

Study Design.: Cross-sectional. Objective.: The aim of this study was to analyze the thoracic center of mass (COM) position of children at different ages and evaluate its relation with the previously reported pre-existent rotational pattern of the normal spine. Summary of Background Data.: The normal, nonscoliotic thoracic spine is known to have a rotational pattern that changes direction during growth, a transition from left-sided toward right-sided rotation with increasing age. This matches the changing curve convexity seen when idiopathic scoliosis develops at different ages. Furthermore, the direction of pre-existent rotation was shown to be related to organ orientation; in situs inversus the rotation is opposite to situs solitus. Methods.: Computed tomography (CT) scans of the thorax of infantile (0–4 years, n = 40), juvenile (4–10 years, n = 53), and adolescent (10–18 years, n = 62) children without spinal pathology were included from an existing database. The location of the COM inside the thorax was calculated based on Hounsfield-units, representing tissue mass. The COM offset was defined as the shortest distance to the midsagittal plane. Results.: At the infantile age, the COM was 2.5 ± 2.1 mm on the right side, at juvenile age not significantly deviated, and at adolescent age 3.1 ± 2.3 mm on the left side of the midsagittal plane. The mean COM offset correlated linearly with age (r = 0.77, P < 0.001). Conclusion.: The COM shifts from slightly on the right side of the thorax at the infantile age, to neutral at juvenile age, to the left at adolescent age. This corresponds to the earlier demonstrated change in direction of pre-existent rotation in the normal spine with age, as well as with the well-known changing direction, from left to right, of thoracic curve convexity in scoliosis at different ages. Level of Evidence: N/ A