Etiology of the So-Called Idiopathic Scoliosis from Birth to Aging Seen from a Clinician Side : The Biomechanical Importance of the Horizontal Plane

The biomechanical etiology of the so-called idiopathic scoliosis (Adolescent Idiopathic Scoliosis [AIS]) is described in years 1995-2007. In article are presented the etiological factors, the new classification, and the methods of therapy and principles of causal prophylaxis. The etiology of AIS is strictly biomechanical and it is connected with the asymmetry of the movement of the hips and with function-“standing” and “gait”. The new knowledge about scoliosis is important for doctors and nurses. Materials: In the years 1984-2018, more than 2500 patients with scoliosis have been observed and treated. This group included children in 80% in age 4 to 18 and in 20% older patients in age of 40-70. In this group of patients there were children endangered or with first or advanced symptoms of “so-called idiopathic scoliosis”. The patients with various syndromes or congenital scoliosis were excluded in the statistic of research.

The biomechanical etiology of the so-called idiopathic scoliosis [Adolescent Idiopathic Scoliosis (AIS)] has been the subject of the author’s research since 1984. In the period from 1984 till 2020 many children with scoliosis have been observed (N-2500). During this time all information about etiology, classification, new therapy and causal prophylaxis has been provided. The principle information about the subject was found in the years 1995-2007. The etiology of AIS is strictly biomechanical and is connected with asymmetry of the hips movements and next with the function of the hips and the spine. Scoliosis develops because of “permanent standing ‘at ease’ on the right leg” and in some types connected with “gait”. As causative influence: “standing” and “gait” is in “S” scoliosis in the 1st etiopathological group (epg), only “standing” in “C” 2nd / A epg and “S” 2nd / B epg group / type, in “I” 3 rd epg type of scoliosis only “gait”.

The so-called idiopathic scoliosis [adolescent idiopathic scoliosis-AIS] is very common in Poland (till 8%) and in every county in Europe and in America. Many children are operated, mostly because of cosmetic reasons and curve more that 40 degree. The study presents an example of so called idiopathic scoliosis and the principles of treatment. According to our knowledge the cause of deformities in children, youth and pain syndromes in adults are connected not with “Weak muscles” but with 1/ the wrong position of joints of the lower or upper extremities, in the spine, in the whole trunk, 2/ with limited movement of joints, 3/ even connected with pathological position of joint, with contractures in the spine, in the hips, in the knees and in the feet. The study observations confirm that without any doubt the “weak muscles” are not the cause of deformations of children and youth as well, pain syndromes in adults. Unfortunately, the diagnosis of “weak muscles” is very often given / stated by Polish physiotherapist and rehabilitations doctors.

Vestibular dysfunction has been reported as a potential cause in adolescent idiopathic scoliosis (AIS). However, it remained unclear how stochastic galvanic vestibular stimulation (GVS) affected kinetic performance of patients with AIS. This study aimed to investigate the effect of stochastic GVS on ground reaction forces (GRF) measures during obstacle negotiation among patients with AIS. Fifteen patients with AIS and 15 age/sex-matched healthy controls (HC) participated in this study. Stochastic GVS was applied via electrodes placed over bilateral mastoid process with the intensity of 80% of individual sensory thresholds. Six walking trials including 2 types of GVS (stochastic GVS/sham stimulation) and 3 obstacle conditions (Level/Low/High) were randomly allocated to each participant, and each trial was repeated 3 times. Four AMTI force plates were used to measure GRF peaks and impulses in anterior-posterior (AP1/AP2), medial-lateral (ML1/ML2), and vertical (V1/V2) directions. Significant interactions were observed in AP1 (F2,56=3.537, p = 0.036), V1 (F2,56=4.118, p = 0.021), ML1 (F2,56=3.313, p = 0.044) and medial-lateral impulses (F2,56=4.386, p = 0.017) for the step negotiating obstacles. Post-hoc comparisons showed that in comparison to sham stimulation, the application of stochastic GVS significantly (1) increased AP1 (Low: p = 0.038) and V1 (Low: p < 0.001; High: p = 0.035) in two groups; (2) decreased ML1 of two groups (AIS: ps < 0.01; HC: ps < 0.05) and medial-lateral impulses in patients with AIS (Low: p = 0.013; High: p = 0.015) during obstacle negotiation. Additionally, the rates of change in ML1 and medial-lateral impulses among patients with AIS were significantly higher than that of HC, indicating that stochastic GVS demonstrated a greater effect of decreasing ML1 and medial-lateral impulses in AIS. Stochastic GVS ameliorated kinetic performance of patients with AIS during obstacle negotiation, and its potential mechanism may involve the induction of stochastic resonance phenomenon to enhance vestibular perception. Our study offered stochastic GVS as a novel approach to target vestibular-related postural instability in AIS.

In first article the author (T. Karski) described the biomechanical causes of development of the so-called idiopathic scoliosis. It this article is given basic information for new screening for scoliosis, and for new proper conservative therapy. We are given also examples of “wrong, incorrect therapy in the past”. The article underlined necessity of causal prophylaxis.

So-called idiopathic scoliosis – disfiguring deformity in children, pain problems in adults. Information about biomechanical etiology, classification and therapy

Pathophysiology of Adolescent Idiopathic Scoliosis (AIS) is not yet completely understood. This exploratory study aims to investigate two aspects neglected in clinical practice: a defective postural central nervous system control in AIS, and alterations of body schema due to scoliosis spinal deformities. We recorded EEG data and balance data in four different standing positions in 14 adolescents with AIS and in 14 controls. A re-adaptation of the Image Marking Procedure (IMP) assessed body schema alterations on the horizontal (Body Perception Indices (BPIs)) and vertical direction (interacromial and bisiliac axes inclinations). Our results revealed no differences in balance control between groups; higher EEG alpha relative power over sensorimotor areas ipsilateral to the side of the curve and a significant increase of theta relative power localized over the central areas in adolescents with AIS. The difference in BPI shoulder and BPI waist significantly differed between the two groups. The inclinations of the perceived interacromial axes in adolescents with AIS was opposite to the real inclination. Increased theta activity and alpha lateralization observed may be a compensatory strategy to overcome sensorimotor dysfunction mirrored by altered body schema. Scoliosis onset might be preceded by sensorimotor control impairments that last during curve progression.

This paper reports a retrospective review of 91 patients with idiopathic thoracic scoliosis corrected by Zielke VDS instrumentation. The results were analysed to demonstrate the correction in all three planes. Satisfactory correction was obtained, and was particularly good in the sagittal and horizontal planes. There were no disadvantages from the thoracotomy.

Scoliosis is a multifaceted three-dimensional deformity that significantly affects patients' balance function and walking process. While existing research primarily focuses on spatial and temporal parameters of walking and trunk/pelvic kinematics asymmetry, there remains controversy regarding the symmetry and regularity of bilateral lower limb gait. This study aims to investigate the symmetry and regularity of bilateral lower limb gait and examine the balance control strategy of the head during walking in patients with idiopathic scoliosis. The study involved 17 patients with idiopathic scoliosis of Lenke 1 and Lenke 5 classifications, along with 17 healthy subjects for comparison. Three-dimensional accelerometers were attached to the head and L5 spinous process of each participant, and three-dimensional motion acceleration signals were collected during a 10-meter walking test. Analysis of the collected acceleration signals involved calculating five variables related to the symmetry and regularity of walking: root mean square (RMS) of the acceleration signal, harmonic ratio (HR), step regularity, stride regularity, and gait symmetry. Our analysis reveals that, during the walking process, the three-dimensional motion acceleration signals acquired from the lumbar region of patients diagnosed with idiopathic scoliosis exhibit noteworthy disparities in the RMS of the vertical axis (RMS-VT) and the HR of the vertical axis (HR-VT) when compared to the corresponding values in the healthy control (RMS-VT: 1.6±0.41 vs. 3±0.47, P<0.05; HR-VT: 3±0.72 vs. 3.9±0.71, P<0.05). Additionally, the motion acceleration signals of the head in three-dimensional space, including the RMS in the anterior-posterior and vertical axis, the HR-VT, and the values of step regularity in both anterior-posterior and vertical axis, as well as the values of stride regularity in all three axes, are all significantly lower than those in the healthy control group (P<0.05). The findings of the analysis suggest that the application of three-dimensional accelerometer sensors proves efficacious and convenient for scrutinizing the symmetry and regularity of walking in individuals with idiopathic scoliosis. Distinctive irregularities in gait symmetry and regularity manifest in patients with idiopathic scoliosis, particularly within the antero-posterior and vertical direction. Moreover, the dynamic balance control strategy of the head in three-dimensional space among patients with idiopathic scoliosis exhibits a relatively conservative nature when compared to healthy individuals.

We studied the brace effect on the spinal profile in idiopathic scoliosis, using a MR procedure visualising the complete scoliotic spine in any vertical plane, while rotating it 180 degrees on the longitudinal axis of the patient. Thirty-eight female patients (mean age, 14.5 years) were included in the study. Inclusion criteria were an idiopathic scoliosis, a Cobb angle greater than 20 degrees , age of 10-17 years and bracing with a Cheneau brace. The brace effect was studied in 38 thoracic curves. The MR examinations were carried out in direct sequences, with and without brace. A reconstruction algorithm allows visualising the whole spine in vertical projections, with rotational steps of 2 degrees , from -90 degrees to 90 degrees , referred to as MR animation. In various vertical MR projections, the changes of the curves were evaluated by measuring the Cobb angle. Additionally, a translation angle of the apical vertebra was determined, representing the lateral deviation of the apical vertebra from a defined midline. Testing the reproducibility of the Cobb angles, the standard deviation of the intra-individual differences was 1.7 degrees and of the inter-individual differences, 2.1 degrees . For the translation angles, the standard deviation of the intra-individual differences was 0.8 degrees and of the inter-individual differences, 0.9 degrees . With brace the mean Cobb angle of the thoracic curves was significantly reduced in the various vertical MR projections. The mean translation angle was also reduced. MR analysis showed that the brace effect is a translation process, straightening the profile of the scoliotic spine in all vertical planes. MR animation allows visualising the brace effect on the spine in scoliosis based on a 3D data set, without additional radiation exposure. It showed the straightening effect of the brace leading to a flattening of the sagittal spinal profile.

To examine whether the sacro-femoral-pubic (SFP) angle could estimate pelvic tilt (PT) in scoliotic and normal subjects. One hundred nine subjects including 38 patients with adolescent idiopathic scoliosis (AIS), 35 patients with congenital scoliosis (CS), and 36 healthy individuals were studied. PT, as the angle between the lines connecting the midpoint of the sacral plate to the centroid of one acetabulum and the vertical plane, and the SFP angle, as the angle between the midpoint of the upper sacral endplate, the centroid of one acetabulum, and the upper midpoint of the pubic symphysis, were calculated on full-length lateral and anteroposterior radiographs, respectively. Correlations between PT and the SFP angle were investigated in each group. The three groups were comparable in terms of age, sex, and the mean SFP angle. The mean PT, however, was significantly lower in healthy subjects compared to that in patients with AIS and CS. Significant and reverse correlations were present between PT and the SFP angle in all three groups (AIS: r = -0.32, p = 0.04, PT = 82.5 - average SFP angle; CS: r = -0.48, p = 0.003, PT = 95.41 - average SFP angle; healthy: r = -0.33, p = 0.04, PT = 88.95 - average SFP angle). Unlike two previous reports, the SFP angle correlated poorly to PT in this study, limiting its use as a suitable surrogate for PT in scoliotic and healthy subjects.

A retrospective study of standing imbalance and body posture in 71 able-bodied girls and subjects with adolescent idiopathic scoliosis was conducted. To test the hypothesis that postural parameters are related to standing stability parameters. 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. 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 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. 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.

Adolescent idiopathic scoliosis (AIS) is a complex three-dimensional (3D) deformity, and the plane of maximum curvature (PMC) is proposed to reflect these clinical features, which refers to a vertical plane presenting the maximum projected spinal curvature and its parameters include the PMC Cobb and orientation (angle between PMC and sagittal planes). This study aimed to develop a computational method (CM) for PMC estimation. Twenty-nine patients with AIS and computed tomography (CT) images were recruited. For CT, PMC was determined by rotating a vertical plane about its vertical axis with 5°increment until the maximum Cobb angle was measured. For CM, PMC was estimated via identifying the eight points (the corner points of the superior and inferior endplates of the upper and lower end-vertebrae respectively) in the coronal and lateral CT images. Two experienced raters repeated the PMC estimation three times with one-week interval. The intra-class correlation coefficient (ICC) and Bland-Altman method were used for statistical analysis. Twenty-seven right thoracic curves (RTs) (mean Cobb: 46.1°±12.4°) and 23 left thoracolumbar/lumbar (LTLs/LLs) (mean Cobb: 30.6°±11.1°) were analysed. The intra- and inter-rater ICC values were >0.91 and 0.84 in RTs and LTLs/LLs, respectively. The PMCs obtained from the CM and CT were showed good agreement was also observed between the PMCs obtained from the two methods according to ICC (>0.90) and Bland-Altman method assessments. This purpose-design computational method could provide reliable and valid estimation of PMCs for AIS, which has potential to be used as an alternative for 3D assessment.

PurposeFree-hand pedicle screw insertion methods are widely used for screw insertion during scoliosis surgery. Preoperative knowledge about the pedicle size helps to maximize screw containment and minimize the risk of pedicle breach. Radiographs taken by a biplanar low-dose X-ray device (EOS) have no divergence in the vertical plane. The criterion validity and reliability of preoperative EOS images for pedicle size measurements in patients with idiopathic scoliosis (IS) was investigated in this study.MethodsSixteen patients who underwent surgical treatment for IS were prospectively included. Intra- and extracortical pedicle height and width measurements on EOS images were compared with reconstructed intra-operative 3D images of the isthmus of included pedicles. Secondly, intra- and interobserver reliability of pedicle size measurements on EOS images was determined.ResultsThe total number of analyzed pedicles was 203. The correlation between the EOS and 3D scan measurements was very strong for the intra- and extracortical pedicle height and strong for the intra- and extracortical pedicle width. There are, however, significant, but likely clinically irrelevant differences (mean absolute differences < 0.43 mm) between the two measure methods for all four measurements except for extracortical pedicle height. For pedicles classified as Nash–Moe 0, no significant differences in intra- and extracortical pedicle width were observed. Both intra- and interobserver reliability was excellent for all pedicle size measurements on EOS images.ConclusionThe results of this study indicate a good validity and reliability for pedicle size measurements on EOS radiographs. Therefore, EOS radiographs may be used for a preoperative estimation of pedicle size and subsequent screw diameter in patients with IS.

So-Called Idiopathic Scoliosis in New Classification. Prophylactics and Therapeutic Aims for Orthopedic Surgery and for General Medicine