Trunk rotation in scoliosis. The influence of curve type and direction in 150 children

Morphological differences in scoliosis curvatures as a cause of difficulties in its early detection based on angle of trunk inclination

INTRODUCTION

The three dimensional deformation of the spine in scoliosis is specific for a given child with regard to the number and length of curvatures, their degree of rotation and the size of the curvature angle. Early diagnosis of scoliosis in a clinical examination according to the Adams test depends on the correlation between the angle of trunk inclination (ATI) and the Cobb angle and the adopted diagnosis criterion. The aim of the study was to demonstrate the need to adopt different diagnostic criteria for ATI depending on the age and location of scoliosis. Moreover, the observed differences in the ATI/Cobb correlation became the basis for the proposal to introduce the concept of low, medium and high-rotated of curvature to the clinical description of scoliosis.

MATERIALS AND METHODS

The group consisted of 229 children who were first examined, aged 6 to 17 years, with an average age of -11.57 years (SD ± 3.26), with symptoms of idiopathic scoliosis. The correlation of the criteria for the diagnosis of scoliosis in the ATI 7° clinical trial with a Cobb angle of 10° three dimensional in the X-ray image was used to distinguish three types of curvature/scoliosis, i.e., low, medium and high rotation. The frequencies of each type were compiled for three age groups and three scoliosis locations. Moreover, the degree of vertebral rotation according to the Perdriolli (AVR) of curvature was correlated with the Cobb angle and ATI. A one-way logistic regression model was used to assess the effectiveness of scoliosis detection in children based on the measurement of the ATI angle alone and the measurement of both ATI and Cobb angles.

RESULTS

Low-rotated curves were most often found in the age groups of 6-9 and 10-12 years in 65.6% and 71.4% of patients, respectively (p < 0.05). Medium-rotated curvatures were most common in the age group of 13-17 years - 51.6%. With regard to the localization of scoliosis, the low-rotated curvatures were significantly more frequently (p < 0.05) found in the lumbar and thoracolumbar spine. Moreover, the univariate regression model for ATI showed that we could detect scoliosis best by taking the cut-off point of 5° and the mathematically determined Cobb angle was 9.5°. Patients with ATI ≥ 7° had significantly higher AVR values ​​than those with ATI < 7°, and the ATI/AVR correlation was of average strength.

CONCLUSION

The specific morphology of the scoliotic curvature of the child's spine may be manifested by the difference in the ATI/Cobb correlation depending on the location of the scoliosis and change with age. The curvatures of the scoliosis that form can be low, medium and high-rotated, and the low-rotated curvatures were most often found in the 6-9- and 10-12-year-old groups and in the lumbar and thoracolumbar section. To increase the rate of early diagnosis of scoliosis, the results suggest the need to adopt two ATI criteria for the diagnosis of scoliosis at screening, 5° for age of 6-12 years, and when asymmetry affects the lumbar and thoracolumbar section, and 7° for the remaining children.

Magnetically controlled growing rods in the management of early onset scoliosis: a systematic review

Background

Early onset scoliosis (EOS) presents in patients younger than 10 years. Magnetically controlled growing rods (MCGR) were developed as an outpatient distraction system for EOS, allowing to avoid multiple surgeries. This systematic review investigated the efficacy and feasibility of MCGR in EOS.

Methods

This systematic review was conducted according to the PRISMA guidelines. PubMed, Google scholar, Embase, and Scopus were accessed in May 2022. All the clinical trials which investigate the role of MCGR for early onset scoliosis were accessed. Only studies reporting data in patients younger than 10 years with a preoperative Cobb Angle greater than 40° were eligible. The following data was extracted at baseline and at last follow-up: mean kyphosis angle, overall mean Cobb angle, mean T1–S1 length. Data from complication were also collected.

Results

Data from 23 clinical studies (504 patients) were included in the present study. 56% (282 of 504) were females. The average length of the follow-up was 28.9 ± 16.0 months. The mean age of the patients was 8.7 ± 1.9 years old. The mean BMI was 17.7 ± 7.6 kg/m². The mean kyphosis angle had reduced by the last follow-up (P = 0.04), as did the overall mean Cobb angle (P < 0.0001), while the overall T1–S1 length increased (P = 0.0002). Implant-associated complications, followed by spinal alignment failure, wound healing ailments, pulmonary complications, progressive trunk stiffness, persistent back pain, and fracture.

Conclusion

The management of EOS remains challenging. The current evidence indicates that MCGR may be effective to distract the spine and model the curve in EOS.

The importance of the size of the trunk inclination angle in the early detection of scoliosis in children

BACKGROUND

Early detection of idiopathic scoliosis is one factor in determining treatment effectiveness. Therefore, the aim of this study was to assess the importance of the size of the trunk inclination angle (ATI) for the early detection of scoliosis in preschool- and school-age children, taking into account the location and size of the spine curvature.

METHODS

The study included a group of 216 children (mean age 11.54 years, standard deviation ± 3.05), who had previously untreated idiopathic scoliosis and a Cobb angle of ≥ 10°. The ATI values were compared with the corresponding Cobb angle values. The results of the ATI-Cobb correlation were compared to the ATI thresholds of 5° and 7°.

RESULTS

In the age groups 6-9, 10-12 and 13-17 years, the method sensitivity for the ATI ≥ 7° criterion was low at 33.90%, 27.69% and 51.29% (p < 0.05), respectively, while for the ATI ≥ 5° criterion, it was 67.8%, 69.23% and 93.48% (p < 0.05), respectively. With respect to location, significantly more frequent misdiagnoses (p < 0.05) were related to the lumbar and thoracolumbar (regions) sections of the spine in the groups aged 6-9 and 10-12 for ATI ≥ 7°; while no significant relationship was found at ATI ≥ 5°. For both ATI levels, the most frequent cases of mis- or undiagnosed scoliosis were observed among children with a Cobb angle of 10°-14° (p = 0.004).

CONCLUSION

A low predictive ATI value was demonstrated regarding scoliosis detection for the ATI 7° criterion in children aged 6-9 and 10-12 years, particularly for the lumbar and thoracolumbar locations. Adoption of the threshold of ATI 5° in screening tests for children aged 6-12 years, as well as for lower locations of scoliosis, may be more effective in the early detection of scoliosis.

TRIAL REGISTRATION

This study was approved by the Jan Dlugosz University in Czestochowa Ethics Committee KE-U/7/2021, and conducted under the Declaration of Helsinki.

The Postural Control Indexes during Unipodal Support in Patients with Idiopathic Scoliosis

Proper posture provides the best balance and body stability at minimal muscular effort. It is constantly controlled by the central nervous system, which integrates the stimuli from the proprioceptors (deep feeling sensors), vision receptors, and balance receptors through the subcortical structures. The main purpose of the study was to describe single stance stability and its correlation with the degree of scoliosis and trunk rotation among patients suffering from idiopathic scoliosis and in the control group without scoliosis. The study included 80 patients (69 girls and 11 boys) and 40 healthy children without scoliosis (21 girls and 19 boys). The Cobb angle technique was used to determine the magnitude of the deformity. All subjects were divided into three subgroups according to Bogdanov's classification. Single stance stability with eyes open and eyes closed was assessed with an electronic postural station-Delos Postural Proprioceptive System (DPPS). In case of multiple group comparisons for variables with normal distribution ANOVA with Scheffe, post hoc test was used or Kruskal-Wallis test was used as the nonparametric equivalent. The relationship between the two continuous variables was investigated using either Pearson product-moment correlation or Spearman's rank correlation. In all these calculations, the statistical significance level was set to p < 0.05. The single stance test showed a significant difference between the stability index with eyes open and stability index with eyes closed in study and control groups. The character of these alterations is influenced by the degree of trunk rotation. The degree of scoliosis according to Bogdanov classification does not determine the decrease in stability indexes. In summary, significantly lower values of the stability index during one-leg standing with eyes closed indicated balance impairment, which is mainly connected with inadequate functioning of the proprioceptive system.

Evaluation of balance in young adults with idiopathic scoliosis

Objectives

This study aims to evaluate the relation of scoliosis with coronal and sagittal balance parameters and the effect of postural balancing in young adults with idiopathic scoliosis.

Patients and methods

Between April 2017 and June 2017, a total of 24 patients (7 males, 24 females; mean age 20.3±2 years; range 17 to 24) who were diagnosed with scoliosis and 65 age- and sex-matched healthy controls (20 males, 45 females; mean age 20.3±1.6 years; range 19 to 25) were included in the study. The Cobb angle, sagittal balance, coronal balance, and truncal shift were measured with radiographs in the patient group. The Biodex Balance System (BBS) was used to assess the general stability index, anterior- posterior and medial-lateral stability index, and fall risk.

Results

All balance parameters were significantly worse in the patient group than in the control group (p<0.05). The static balance was mostly associated with sagittal balance, followed by coronal balance. In the patients with left scoliosis, sagittal balance was 93% negative and 67% of the patients gave their weight to the back. Coronal balance was negative in 60% of the patients and 93.3% of the patients were weighted to the right side. In 89% of the patients with right scoliosis, sagittal balance was negative and 89% of the patients gave their weight to the back. Coronal balance was 44% neutral and 78% of the patients gave their weight to the right side.

Conclusion

In patients with scoliosis, the static balance is worse than healthy individuals. Static balance is mostly related to sagittal balance and also to coronal balance. While the coronal balance tends to be in the direction of the curve, both right and left scoliosis give more weight to the right.

3D Markerless asymmetry analysis in the management of adolescent idiopathic scoliosis

BACKGROUND

Three dimensional (3D) markerless asymmetry analysis was developed to assess and monitor the scoliotic curve. While the developed surface topography (ST) indices demonstrated a strong correlation with the Cobb angle and its change over time, it was reported that the method requires an expert for monitoring the procedure to prevent misclassification for some patients. Therefore, this study aimed at improving the user-independence level of the previously developed 3D markerless asymmetry analysis implementing a new asymmetry threshold without compromising its accuracy in identifying the progressive scoliotic curves.

METHODS

A retrospective study was conducted on 128 patients with Adolescent Idiopathic Scoliosis (AIS), with baseline and follow-up radiograph and surface topography assessments. The suggested "cut point" which was used to separate the deformed surfaces of the torso from the undeformed regions, automatically generated deviation patches corresponding to scoliotic curves for all analyzed surface topography scans.

RESULTS

By changing the "cut point" in the asymmetry analysis for monitoring scoliotic curves progression, the sensitivity for identifying curve progression was increased from 68 to 75%, while the specificity was decreased from 74 to 59%, compared with the original method with different "cut point".

CONCLUSIONS

These results lead to a more conservative approach in monitoring of scoliotic curves in clinical applications; smaller number of radiographs would be saved, however the risk of having non-measured curves with progression would be decreased.

Correlation Between Hump Dimensions and Curve Severity in Idiopathic Scoliosis Before and After Conservative Treatment

STUDY DESIGN

Prospective study in 150 consecutive outpatients affected by adolescent idiopathic scoliosis (AIS).

OBJECTIVES

The purposes were to (1) identify a correlation between hump dimensions and the severity of scoliotic curve, and (2) evaluate how the treatment influenced the main parameters of scoliosis.

SUMMARY OF BACKGROUND DATA

The existence of a relationship between clinical deformities and curve severity in AIS is still debated. Furthemore, only a few studies have investigated the effectiveness of conservative treatment for idiopathic scoliosis taking into account both clinical and radiologic factors.

METHODS

150 consecutive outpatients (mean age 12.8 ± 1.9 years) affected by AIS were subjected to conservative brace-based treatment. 134 participants completed the treatment protocol. Two parameters were considered to evaluate the treatment progress: the hump and the Cobb angle. Measurements were determined at the beginning and the end of treatment. Statistical analyses were performed in the whole sample and after dividing the study participants into 4 subgroups: patients with lumbar (n = 66) or thoracic curves (n = 68), patients ranging in age between 6 and 13 years (n = 89) and patients ≥ 14 years of age (n = 45).

RESULTS

A positive correlation was detected between the hump dimension and curve severity at the beginning and the end of treatment, except for lumbar curves at baseline. The deformity was effectively corrected by the orthotic treatment (Cobb angle: 29.4 ± 8.5° at baseline and 19.3 ± 9.8° at the end of treatment; hump severity: 11.6 ± 5.6 mm at baseline and 6.2 ± 4.6 mm at the end). In addition, our data indicate that the hump correction is more evident than that of the curve registered in Cobb degrees.

CONCLUSION

A significant correlation exists between the hump dimension and curve severity both at the beginning and the end of treatment, except for lumbar curves at baseline. The brace treatment confirmed its effectiveness in arresting the deformity progression and inducing a remodeling both of the scoliotic curve and the hump.

2016 SOSORT guidelines: orthopaedic and rehabilitation treatment of idiopathic scoliosis during growth

BACKGROUND

The International Scientific Society on Scoliosis Orthopaedic and Rehabilitation Treatment (SOSORT) produced its first guidelines in 2005 and renewed them in 2011. Recently published high-quality clinical trials on the effect of conservative treatment approaches (braces and exercises) for idiopathic scoliosis prompted us to update the last guidelines' version. The objective was to align the guidelines with the new scientific evidence to assure faster knowledge transfer into clinical practice of conservative treatment for idiopathic scoliosis (CTIS).

METHODS

Physicians, researchers and allied health practitioners working in the area of CTIS were involved in the development of the 2016 guidelines. Multiple literature reviews reviewing the evidence on CTIS (assessment, bracing, physiotherapy, physiotherapeutic scoliosis-specific exercises (PSSE) and other CTIS) were conducted. Documents, recommendations and practical approach flow charts were developed using a Delphi procedure. The process was completed with the Consensus Session held during the first combined SOSORT/IRSSD Meeting held in Banff, Canada, in May 2016.

RESULTS

The contents of the new 2016 guidelines include the following: background on idiopathic scoliosis, description of CTIS approaches for various populations with flow-charts for clinical practice, as well as literature reviews and recommendations on assessment, bracing, PSSE and other CTIS. The present guidelines include a total of 68 recommendations divided into following topics: bracing (n = 25), PSSE to prevent scoliosis progression during growth (n = 12), PSSE during brace treatment and surgical therapy (n = 6), other conservative treatments (n = 2), respiratory function and exercises (n = 3), general sport activities (n = 6); and assessment (n = 14). According to the agreed strength and level of evidence rating scale, there were 2 recommendations on bracing and 1 recommendation on PSSE that reached level of recommendation "I" and level of evidence "II". Three recommendations reached strength of recommendation A based on the level of evidence I (2 for bracing and one for assessment); 39 recommendations reached strength of recommendation B (20 for bracing, 13 for PSSE, and 6 for assessment).The number of paper for each level of evidence for each treatment is shown in Table 8.

CONCLUSION

The 2016 SOSORT guidelines were developed based on the current evidence on CTIS. Over the last 5 years, high-quality evidence has started to emerge, particularly in the areas of efficacy of bracing (one large multicentre trial) and PSSE (three single-centre randomized controlled trials). Several grade A recommendations were presented. Despite the growing high-quality evidence, the heterogeneity of the study protocols limits generalizability of the recommendations. There is a need for standardization of research methods of conservative treatment effectiveness, as recognized by SOSORT and the Scoliosis Research Society (SRS) non-operative management Committee.

Scapular kinematics in adolescent idiopathic scoliosis: A three-dimensional motion analysis during multiplanar humeral elevation

The scapula plays a critical role in supporting shoulder function. Considering the closed anatomical relationship between the scapula and the thoracic cage, the presence of postural disturbances could be linked to alterations in the scapular position and orientation in adolescent idiopathic scoliosis (AIS). However, currently there is a lack of descriptive research and detailed assessment of scapular kinematics in AIS. The aim of this study was to investigate the three-dimensional scapular kinematics in AIS. Nineteen AIS patients and fourteen healthy controls participated in this study. Bilateral shoulder kinematics were measured with an electromagnetic tracking device during shoulder elevation in the sagittal, scapular, and frontal planes. Data for the scapular orientation were analyzed in the resting position and at 30°, 60°, 90°, and 120° of humerothoracic elevation. Scapular behavior was different in participants with AIS, compared to healthy controls, with different patterns observed on convex and concave sides. While examining all three planes of elevation, the scapula was more internally and anteriorly tilted on the convex side, while the scapula was more externally, downwardly rotated, and posteriorly tilted on the concave side in participants with AIS. Furthermore, there was a decreased peak humerothoracic elevation and altered scapular posterior tilt in participants with AIS in the resting position. These findings increase our knowledge and understanding of scapular alterations and the reported scapular alterations can be considered as adaptive compensation strategies in AIS.

Scoliosis epidemiology is not similar all over the world: a study from a scoliosis school screening on Chongming Island (China)

Background

School scoliosis screening has been carried out around the world. The screen program has never been performed on Chongming Island, the third largest island in China and characterized less population exchange with the rest of China. This study was designed to examine scoliotic parameters in children from Chongming Island and determine whether the parameters differed from those of the published data.

Methods

A total of 6824 children (3477 boys and 3347 girls) aged from 6 to 17 were recruited. The screen included Adam’s test and scoliometer measurements. Posteroanterior radiographic evaluation was performed if trunk rotation was 5° or more.

Results

One hundred seventy two were confirmed with Cobb angle of 10° or more; the prevalence was 2.52 %, higher in girls (3.11 %) than in boys (1.96 %) (p < 0.05). There was a weak positive correlation between prevalence and age. Majority curves were minor (from 10 to 19°). The most common thoracic curve was right curve (60.3 % of all thoracic curves), while the most common thoracolumbar (75.5 %) and lumbar curves (64.7 %) were left curves.

Conclusions

The prevalence of scoliosis on Chongming Island was 2.52 %. This study indicates that epidemiology of scoliosis has regional variation, and genetic differences may contribute such difference.

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-016-1140-6) contains supplementary material, which is available to authorized users.

Swimming and spinal deformities: a cross-sectional study

OBJECTIVE

To compare the prevalence of spinal deformities and low back pain (LBP) in adolescent competitive swimmers and normal controls.

STUDY DESIGN

This was a cross-sectional study with convenience sample of 112 adolescent competitive swimmers (62 females) compared with 217 students (106 females) of the same age (12.5 years). We designed a questionnaire to collect data on LBP and measured the angle of trunk rotation with a Bunnell scoliometer to screen for scoliosis, along with the plumbline distances for kyphosis and lordosis. Clinical cutoffs defined in the literature for detection of spinal deformities were applied. Analyses were performed using the t test and χ(2) test, and ORs and 95% CIs were calculated.

RESULTS

Swimming was found to increase the risk of trunk asymmetries (OR, 1.86; 95% CI, 1.08-3.20). Swimming also increased the risk of hyperkyphosis (OR, 2.26; 95% CI, 1.35-3.77) and hyperlordosis (OR, 2.24; 95% CI, 1.06-4.73), and increased LBP in females by 2.1-fold (95% CI, 1.08-4.06).

CONCLUSION

Swimming is associated with an increased risk of trunk asymmetries and hyperkyphosis. Although swimming has been considered a complete sport and a treatment option for scoliosis, our data contradict that approach, and also show a higher prevalence of LBP in females.

Validity and reliability of the iPhone to measure rib hump in scoliosis

STUDY DESIGN

This was a prospective blinded validity and reliability analysis.

OBJECTIVE

The aim of this study was validation and reliability evaluation of the Scoligauge iPhone app.

BACKGROUND

The scoliometer is used to clinically measure the rib hump in scoliosis as a means to evaluate the axial trunk rotation. The increasing availability of smartphone with built-in accelerometer led to the development of a vast number of applications to measure angles. Of these, the Scoligauge mimics a scoliometer. The aim of this study was to compare the validity of the Scoligauge iPhone application without an associated adapter with the traditional scoliometer and to test the reliability of the application in a clinical setting.

METHODS

Two observers measured the rib hump deformity on 34 consecutive patients with idiopathic scoliosis with an average Cobb angle of 24.2 ± 13.5 degrees (range, 4 to 65 degrees). Measurements were made with an iPhone without the adapter and with a scoliometer. The validity as well as the interobserver and intraobserver reliability were calculated using the intraclass coefficient (ICC) and the Bland-Altman test.

RESULTS

The mean difference between the scoliometer and the Scoligauge application was 0.4 degrees [95% confidence interval (CI) of ± 3.1 degrees] with an ICC of 0.947 (P < 0.001). The intraobserver and interobserver ICC were 0.961 (P < 0.001) and 0.901 (P < 0.001), respectively. The mean intraobserver difference was 0.0 degrees (95% CI of ± 2.7 degrees) and the mean interobserver difference was 0.1 degrees (95% CI of ± 4.4 degrees).

CONCLUSIONS

The intraobserver and interobserver reliability of the Scoligauge iPhone app, as well as its validity compared with the scoliometer, are excellent. The mean differences between measurements are small and clinically not significant. Thus, the Scoligauge application is valid for clinical evaluation even without special adapter.

LEVEL OF EVIDENCE

Level I (Diagnostic Study).

Scoliosis detection, patient characteristics, referral patterns and treatment in the absence of a screening program in Norway

BACKGROUND

Early diagnosis of idiopathic scoliosis allows for observation and timely initiation of brace treatment in order to halt progression. School scoliosis screening programs were abolished in Norway in 1994 for lack of evidence that the programs improved outcome and for the costs involved. The consequences of this decision are discussed.

OBJECTIVES

To describe the detection, patient characteristics, referral patterns and treatment of idiopathic scoliosis at a scoliosis clinic during the period 2003-2011, when there was no screening and to compare treatment modalities to the period 1976-1988 when screening was performed.

METHODS

Patient demographics, age at detection, family history, clinical and radiological charts of consecutive patients referred for scoliosis evaluation during the period 2003-2011, were prospectively registered. Patients were recruited from a catchment area of about 500000 teenagers. Maturity was estimated according to Risser sign and menarcheal status. Severity of pain was recorded by a verbal 5-point scale from no pain to pain at all times. Physical and neurological examinations were conducted. The detector and patient characteristics were recorded. Referral patterns of orthopedic surgeons at local hospitals and other health care providers were recorded. Patient data was obtained by spine surgeons. Treatment modalities in the current period were compared to the period 1976-1988.

RESULTS

We registered 752 patients with late onset juvenile and adolescent idiopathic scoliosis from 2003-2011. There were 644 (86%) girls and 108 (14%) boys. Mean age at detection was 14.6 (7-19) years. Sixty percent had Risser sign ≥ 3, whilst 74% were post menarche with a mean age at menarche of 13.2 years. Thirty-one percent had a family history of scoliosis. The mean major curve at first consultation at our clinic was 38° (10°-95°). About 40% had a major curve >40°. Seventy-one percent were detected by patients, close relatives, and friends. Orthopaedic surgeons referred 61% of the patients. The mean duration from detection to the first consultation was 20(0-27) months. The proportion of the average number of patients braced each year was 68% during the period with screening compared to 38% in the period without screening, while the proportion for those operated was 32% and 62%, respectively ( p=0.002, OR 3.5, (95%CI 1.6 to 7.5).

CONCLUSION

In the absence of scoliosis screening, lay persons most often detect scoliosis. Many patients presented with a mean Cobb angle approaching the upper limit for brace treatment indications. The frequency of brace treatment has been reduced and surgery is increased during the recent period without screening compared with the period in the past when screening was still conducted.

Pelvis morphology, trunk posture and standing imbalance and their relations to the Cobb angle in moderate and severe untreated AIS

Adolescent idiopathic scoliosis (AIS) is the most common form of scoliosis and usually affects young girls. Studies mostly describe the differences between scoliotic and non-scoliotic girls and focus primarily on a single set of parameters derived from spinal and pelvis morphology, posture or standing imbalance. No study addressed all these three biomechanical aspects simultaneously in pre-braced AIS girls of different scoliosis severity but with similar curve type and their interaction with scoliosis progression. The first objective of this study was to test if there are differences in these parameters between pre-braced AIS girls with a right thoracic scoliosis of moderate (less than 27°) and severe (more than 27°) deformity. The second objective was to identify which of these parameters are related to the Cobb angle progression either individually or in combination of thereof. Forty-five scoliotic girls, randomly selected by an orthopedic surgeon from the hospital scoliosis clinic, participated in this study. Parameters related to pelvis morphology, pelvis orientation, trunk posture and quiet standing balance were measured. Generally moderate pre-brace idiopathic scoliosis patients displayed lower values than the severe group characterized by a Cobb angle greater than 27°. Only pelvis morphology and trunk posture were statistically different between the groups while pelvis orientation and standing imbalance were similar in both groups. Statistically significant Pearson coefficients of correlation between individual parameters and Cobb angle ranged between 0.32 and 0.53. Collectively trunk posture, pelvis morphology and standing balance parameters are correlated with Cobb angle at 0.82. The results suggest that spinal deformity progression is not only a question of trunk morphology distortion by itself but is also related to pelvis asymmetrical bone growth and standing neuromuscular imbalance.

Prediction of scoliosis progression with serial three-dimensional spinal curves and the artificial progression surface technique

Adolescent idiopathic scoliosis (AIS) progression is clinically monitored by a series of full spinal X-rays. To decrease radiation exposure, an artificial progression surface (APS) is proposed to predict progression. Fifty-six acquisitions (posteroanterior radiographs, 0° and 20°) were obtained from 11 AIS patients (29.8 ± 9.6° Cobb angle). Three-dimensional curves were constructed through vertebral pedicle centers. Three previous serial spinal curves (6-month intervals) were used to construct an APS with a Non-uniform Rational B-Spline surfacing technique. Future progression was achieved by aligning the curves on the APS using the generalized cross-validation extrapolation technique. With three and four previous serial spinal curves, the prediction accuracies of future progression at the next 6-month interval were 4.1 ± 3.3° for Cobb angles and 3.6 ± 3.5 mm for apex lateral deviations. Apex locations and Cobb regions varied within one vertebral level. The proposed technique shows potential as an accurate three-dimensional prediction method for AIS progression and could help pediatricians make decisions about treatment. However, it could only be applied once before more radiographic data would be needed.

Impaired dynamic balance control in adolescents with idiopathic scoliosis and abnormal somatosensory evoked potentials

BACKGROUND

Both balance control dysfunction and dysfunction of the central nervous system have been proposed as being causative factors in adolescent idiopathic scoliosis (AIS), yet the relationship between these factors has not been investigated in detail. An intergroup comparative study was conducted to investigate the effect of abnormal somatosensory function on the dynamic balance parameters of girls with AIS.

METHODS

The relationship between dynamic balance control and abnormal somatosensory function seen in AIS patients was examined by studying the dynamic balance parameters in normal controls, in AIS patients with normal posterior tibial nerve somatosensory cortical evoked potentials (PTN-SCEPs), and in AIS patients with abnormal PTN-SCEPs. Gait parameters were recorded in 18 AIS girls (8 showing abnormal PTN-SCEPs and 10 showing normal PTN-SCEPs). Eight healthy age-matched volunteers served as a control group.

RESULTS

No significant left-right asymmetry of gait parameters was found for the controls or the AIS patients with normal PTN-SCEPs, whereas significantly higher gait parameters were found on the side of the curvature in the AIS patients with abnormal PTN-SCEPs.

CONCLUSIONS

Somatosensory dysfunction in AIS patients shows to have an impact on dynamic balance control. Further studies to examine the association between somatosensory dysfunction and balance control and how they may be related to the etiology of AIS are recommended.

LEVEL OF EVIDENCE

Diagnostic study, level IV (case-control study).

The effect of growth on the correlation between the spinal and rib cage deformity: implications on idiopathic scoliosis pathogenesis

BACKGROUND

Numerous studies have attempted to quantify the correlation between the surface deformity and the Cobb angle without considering growth as an important factor that may influence this correlation. In our series, we noticed that in some younger referred children from the school-screening program there is a discrepancy between the thoracic scoliometer readings and the morphology of their spine. Namely there is a rib hump but no spinal curve and consequently no Cobb angle reading in radiographs, discrepancy which fades away in older children. Based on this observation, we hypothesized that in scoliotics the correlation between the rib cage deformity and this of the spine is weak in younger children and vice versa.

METHODS

Eighty three girls referred on the basis of their hump reading on the scoliometer, with a mean age of 13.4 years old (range 7-18), were included in the study. The spinal deformity was assessed by measuring the thoracic Cobb angle from the postero-anterior spinal radiographs. The rib cage deformity was quantified by measuring the rib-index at the apex of the thoracic curve from the lateral spinal radiographs. The rib-index is defined as the ratio between the distance of the posterior margin of the vertebral body and the most extended point of the most projecting rib contour, divided by the distance between the posterior margin of the same vertebral body and the most protruding point of the least projecting rib contour. Statistical analysis included linear regression models with and without the effect of the variable age. We divided our sample in two subgroups, namely the younger (7-13 years old) and the older (14-18 years old) than the mean age participants. A univariate linear regression analysis was performed for each age group in order to assess the effect of age on Cobb angle and rib index correlation.

RESULTS

Twenty five per cent of patients with an ATI more than or equal 7 degrees had a spinal curve under 10 degrees or had a straight spine. Linear regressions between the dependent variable "Thoracic Cobb angle" with the independent variable "rib-index" without the effect of the variable "age" is not statistical significant. After sample split, the linear relationship is statistically significant in the age group 14-18 years old (p < 0.03).

CONCLUSION

Growth has a significant effect in the correlation between the thoracic and the spinal deformity in girls with idiopathic scoliosis. Therefore it should be taken into consideration when trying to assess the spinal deformity from surface measurements. The findings of the present study implicate the role of the thorax, as it shows that the rib cage deformity precedes the spinal deformity in the pathogenesis of idiopathic scoliosis.

Selective screening for scoliosis

Scoliosis screening has been practiced for nearly 50 years and has provided valuable knowledge about the prevalence and natural history of scoliosis. Early diagnosis allows for nonoperative treatment, like wearing an orthosis that has been shown to be effective by numerous outcome studies. Challenges in scoliosis screening include the low prevalence rate of clinically significant scoliosis, the inverse relationship of sensitivity and specificity in the screening process because of the poor correlation of clinical deformity and radiographic abnormality, and the inflated cost of these programs because of overreferral. Recommendations for improvement include redefinition of what actually constitutes a "significant" scoliosis for screening, diagnostic, and outcome purposes; selective screening of only immature females; the use of objective referral criteria; and re-screening patients rather than referring those who have borderline cases.

Prediction of Cobb angle in idiopathic adolescent scoliosis

We did a prospective study of 291 children and adolescents with idiopathic scoliosis to identify possible correlations between clinical (scoliometer value, age, height) and radiographic (Cobb angle, Nash-Moe rotation, Risser iliac apophysis classification) parameters to predict the curve angle. There was a statistically significant correlation between thoracic, thoracolumbar, and lumbar scoliometer values and the thoracic, thoracolumbar, and lumbar Cobb angles, respectively (Pearson's r-0.685, 0.572, and 0.677, respectively). There was a statistically significant correlation between Cobb angle in the thoracic, thoracolumbar, and lumbar spine and the patients' age and height. Mathematical formulas that predict the Cobb angle of thoracic, thoracolumbar, and lumbar scoliosis using the scoliometer measurements are reported.

Relations between standing stability and body posture parameters in adolescent idiopathic scoliosis

STUDY DESIGN

A retrospective study of standing imbalance and body posture in 71 able-bodied girls and subjects with adolescent idiopathic scoliosis was conducted.

OBJECTIVE

To test the hypothesis that postural parameters are related to standing stability parameters.

SUMMARY OF BACKGROUND DATA

Spinal deformity not only modifies the shape of the trunk, but also changes the relations between body segments affecting posture in scoliotic children. These postural adaptations to the scoliotic curve progression could be linked in part to increased body sway in upright standing. This has not yet been related to specific postural parameters involving the head, trunk, and pelvis in nontreated idiopathic scoliosis.

METHODS

The head, trunk, and pelvis orientations of each subject were measured by a Flock of Bird system. An AMTI force platform was used to assess quiet standing stability and to monitor the position and displacement of the center of pressure (COP). The center of mass (COM) excursion was estimated from a biomechanical model using force plate information only. Analyses of variance (ANOVAS) were performed to determine the statistical differences between the scoliotic and nonscoliotic subjects, and backward stepwise multiple regression analyses were performed to identify any correlation between measures of quiet standing stability and body postural parameters

RESULTS

The scoliotic group was characterized by a decrease in standing stability. There was an increase in the sway areas measured by the variations of the COP and COM. From the backward stepwise multiple regression analysis, it appears that for the able-bodied girls, the body posture parameters were correlated only with the mean anteroposterior center of pressure (COP(AP)) position. For the scoliotic group, the sway areas and the mean position of the centers of pressure and the COP(AP)-COM(AP) were correlated significantly with body posture parameters. The higher COP-COM differences for the scoliotic group were attributed to a greater neuromuscular demand to maintain standing balance. The coefficients of correlation of the multiple regression analyses ranged from 0.64 to 0.85 for the nonscoliotic group and from 0.55 to 0.72 for the scoliotic group.

CONCLUSIONS

The use of backward stepwise multiple correlations highlighted the interaction between several body parameters and their relation to standing stability in both able-bodied girls and scoliotic subjects. The scoliotic group displayed a much larger number of correlations between standing stability and body posture parameters than the nonscoliotic group. Standing imbalance was related to altered body posture parameters measured in the frontal and horizontal planes only. Although the correlation coefficients were relatively high, factors other than body posture parameters appeared related to standing imbalance in adolescent idiopathic scoliosis. These findings support the concept of either a primary or a secondary dysfunction in the postural regulation system of scoliotic subjects.