Aims. To systematically evaluate whether bracing can effectively achieve curve regression in patients with adolescent idiopathic scoliosis (AIS), and to identify any predictors of curve regression after bracing. Methods. Two independent reviewers performed a comprehensive literature search in PubMed, Ovid, Web of Science, Scopus, and Cochrane Library to obtain all published information about the effectiveness of bracing in achieving curve regression in AIS patients. Search terms included “brace treatment” or “bracing,” “idiopathic scoliosis,” and “curve regression” or “curve reduction.” Inclusion criteria were studies recruiting patients with AIS undergoing brace treatment and one of the study outcomes must be curve regression or reduction, defined as > 5° reduction in coronal Cobb angle of a major curve upon bracing completion. Exclusion criteria were studies including non-AIS patients, studies not reporting p-value or confidence interval, animal studies, case reports, case series, and systematic reviews. The GRADE approach to assessing quality of evidence was used to evaluate each publication. Results. After abstract and full-text screening, 205 out of 216 articles were excluded. The 11 included studies all reported occurrence of curve regression among AIS patients who were braced. Regression rate ranged from 16.7% to 100%. We found evidence that bracing is effective in achieving curve regression among compliant AIS patients eligible for bracing, i.e. curves of 25° to 40°. A similar effect was also found in patients with major curve sizes ranging from 40° to 60° when combined with scoliosis-specific exercises. There was also evidence showing that a low apical vertebral body height ratio, in-brace correction, smaller pre-brace Cobb angle, and daily pattern of brace-wear compliance predict curve regression after bracing. Conclusion. Bracing provides a corrective effect on scoliotic curves of AIS patients to achieve curve regression, given there is high compliance rate and the incorporation of exercises. Cite this article: Bone Joint J 2024;106-B(3):286–292

Adolescent idiopathic scoliosis (AIS), defined by an age at presentation of 11 to 18 years, has a prevalence of 0.47% and accounts for approximately 90% of all cases of idiopathic scoliosis. Despite decades of research, the exact aetiology of AIS remains unknown. It is becoming evident that it is the result of a complex interplay of genetic, internal, and environmental factors. It has been hypothesized that genetic variants act as the initial trigger that allow epigenetic factors to propagate AIS, which could also explain the wide phenotypic variation in the presentation of the disorder. A better understanding of the underlying aetiological mechanisms could help to establish the diagnosis earlier and allow a more accurate prediction of deformity progression. This, in turn, would prompt imaging and therapeutic intervention at the appropriate time, thereby achieving the best clinical outcome for this group of patients.

Cite this article: Bone Joint J 2022;104-B(8):915–921.

Abstract. In the pediatric population, scoliosis is classified into congenital, syndromic, idiopathic, and neuromuscular in aetiology. Syndromic scoliosis represents a wide range of systemic anomalies associated with scoliosis. The primary challenge for a clinician is to think beyond the scoliotic curve, as the underlying pathology is multisystemic. The aim of this review is to identify the systemic anomalies, associated with syndromic scoliosis. MEDLINE, EMBASE, and CINAHL databases were searched, dating from 1990–2020, relevant to the purpose of our study. Keywords used: “scoliosis”+ “syndrome” + “genetic”. Retrospective, prospective studies were included. Case reports that had fewer than 4 patients were not included. Delineating 60 articles, we found a total of 41 syndromes to be associated with scoliosis. Thoracic region was the most common level of scoliosis curve, being noted in 28 syndromes. Mental retardation, seizures, and ataxia were the commonly noticed CNS anomalies. VSD, ASD, and TGA were the anomalies associated with CVS; Hypotonia, rib and vertebral malformations were the most identified neuromuscular anomalies; pulmonary hypoplasia, renal agenesis, and strabismus were other associations. A multidisciplinary approach, involving spinal surgeons, paediatricians, geneticists, anesthesiologists, and allied health professionals, is vital for the best care of patients with syndromic scoliosis. The location of the scoliotic curve reflects the associated anomalies, as thoracic curvature is more closely linked with cardiac anomalies, while lumbosacral curvature is seen to be often linked with genitourinary anomalies. We hope that this article provides a clear overview of the systemic associations in syndromic scoliosis and thus, facilitates and streamlines the management protocol

Objective: To establish a relationship between the scoliotic curve and the centre of gravity during level walking in patients diagnosed with adolescent idiopathic scoliosis. Background data: There is no established aetiology for adolescent idiopathic scoliosis and the reasons for the progression of the curve are still unknown. But there is an agreement regarding multifactorial nature of the aetiology among many authors. One of the interesting factors suggested is asymmetry in the ground reaction forces during walking and their relation to the deformity, indicated by gait analysis studies. Studies have also indicated that the cause and progression of the deformity in idiopathic scoliosis may be due to kinematic differences in the spine, pelvis and lower limb. If a relation could be established between the scoliotic curve and the centre of gravity, it is possible to draw some conclusions regarding the aetiology. There is no method or study till date which looked at the relation of scoliotic curve with the centre of gravity. Materials and Methods: Patients who were diagnosed with adolescent idiopathic scoliosis were selected. Informed consent was taken for gait analysis. 16 Markers were placed over the lower limb and force plate, using modified Helen Hays set. 5 markers were placed over the surface landmarks of selected spinous processes (C7, T6, T12, L3 and S2). Ground reaction forces and motion data were analysed, using APAS gait system and the lines of vectors were developed and correlated with the marker over the second sacral spinous process. Results: With the help of this method we were able to establish a relationship between the scoliotic curve and centre of gravity line. These in turn were expressed in terms of changes in the moment in relation to the midline of the coronal plane. The results indicated that the changes were proportional to the severity of the scoliotic curve. Conclusion: We present a new method of establishing the relation of scoliotic curve with the ground reaction force and the centre of gravity. Initial results obtained from this method indicate the asymmetries in the deviation of the centre of gravity line in relation to the curve, during walking. Ongoing studies based on this method, will help to understand the pathogenesis and aetiology of scoliosis on a biomechanical basis which can help in developing new treatment modalities and efficient management of these patients

Abstract. Purpose. Intracanal rib head penetration is a well-known entity in dystrophic scoliotic curves in neurofibromatosis type 1. There is potential for spinal cord injury if this is not recognised and managed appropriately. No current CT-based classification system is currently in use to quantify rib head penetration. This study aims to propose and evaluate a novel CT-based classification for rib head penetration primarily for neurofibromatosis but which can also be utilised in other conditions of rib head penetration. Materials and methods. The grading was developed as four grades: normal rib head (RH) position—Grade 0, subluxed ext-racanal RH position—Grade 1, RH at pedicle—Grade 2, intracanal RH—Grade 3. Grade 3 was further classified depending on the head position in the canal divided into thirds. Rib head penetration into proximal third (from ipsilateral side)—Grade 3A, into the middle third—Grade 3B and into the distal third—Grade 3C. Seventy-five axial CT images of Neurofibromatosis Type 1 patients in the paediatric age group were reviewed by a radiologist and a spinal surgeon independently to assess interobserver and intraobserver agreement of the novel CT classification. Agreement analysis was performed using the weighted Kappa statistic. Results. There was substantial interobserver correlation with mean Kappa score (k = 0.8, 95% CI 0.7–0.9) and near perfect intraobserver Kappa of 1.0 (95% CI 0.9–1.0) and 0.9 (95% CI 0.9–1.0) for the two readers. Conclusion. The novel CT-based classification quantifies rib head penetration which aids in management planning

Background. Using flexible tethering techniques, porcine models of scoliosis have been previously described. These scoliotic curves showed vertebral wedging but very limited axial rotation. In some of these techniques, a persistent scoliotic deformity was found after tether release. The possibility to create severe progressive true scoliosis in a big animal model would be very useful for research purposes, including corrective therapies. Methods. The experimental ethics committee of the main institution provide the approval to conduct the study. Experimental study using a growing porcine model. Unilateral spinal bent rigid tether anchored to two ipsilateral pedicle screws was used to induce scoliosis on eight pigs. Five spinal segments were left between the instrumented pedicles. The spinal tether was removed after 8 weeks. Ten weeks later the animals were sacrificed. Conventional radiographs and 3D CT-scans of the specimens were taken to evaluate changes in the coronal and sagittal alignment of the thoracic spine. Fine-cut CT-scans were used to evaluate vertebral and disc wedging and axial rotation. Results. After 8 weeks of rigid tethering, the mean Cobb angle of the curves was 24.3 ± 13.8 degrees. Once the interpedicular tether was removed, the scoliotic curves progressed in all animals until sacrifice. During these 10 weeks without spinal tethering the mean Cobb angle reached 50.1 ± 27.1 degrees. The sagittal alignment of the thoracic spine showed loss of physiologic kyphosis. Axial rotation ranges from 10 to 35 degrees. There was no auto-correction of the curve in any animal. A further pathologic analysis of the vertebral segments revealed that animals with greater progression had more damage of the neurocentral cartilages and epiphyseal plates at the sites of pedicle screw insertion. Interestingly, in these animals with more severe curves, compensatory curves were found proximal and distal to the tethered segments. Conclusions. Temporary interpedicular tethering at the thoracic spine induces severe scoliotic curves in pigs, with significant wedging and rotation of the vertebral bodies. As detailed by CT morphometric analysis, release of the spinal tether systematically results in progression of the deformity with development of compensatory curves outside the tethered segment. The clinical relevance of this work is that this tether release model will be very useful to evaluate both fusion and non-fusion corrective technologies in future research. Level of Evidence. Not apply for experimental studies

Aims: The underlying cause of Idiopathic Scoliosis (IS) remains enigmatic. Recently, an increasing number of studies disclosed Central Nervous System (CNS) abnormalities and asymmetries sometimes involving the corticospinal tracts. The present study was designed to investigate the motor system of scoliotic patients with transcranial magnetic stimulation. Methods:21 female patients with right IS (mean age=12.7, scoliotic curves:20û–40û) and 20 normal subjects (mean age=13.8) entered the study. Recordings were made with surface electrodes from 1st dorsal interosseous and abductor hallucis muscles. Corticomotor threshold (LT, UT, MT) was deþned at rest in 1% steps using the method of Mills & Nithi. Central motor conduction time (CMCT) was calculated using the F-wave method. Silent period (SP) measurements were done using a standardized protocol at 130% MT stimulus intensity. Other parameters included cortex to muscle latencies, F- and M-wave latencies, UT-LT range, amplitude and area of MEPs. Electrophysiological data were correlated with several clinical characteristics including handedness, degrees of the scoliotic curve and the Pedriolet and Nash indexes. Normality of data distribution was tested using the Kolmogorov-Smirnov test and thereafter appropriate statistical tests were used. Results: In 14 patients lower limbs were also tested and it was found that asymmetry of facilitated Cx-M was 1.4±0.75ms in IS (vs 0.71±0.47 in controls, p=0.059). It correlated signiþcantly with Nash & Moe and Perdriole indexes (Spearmanñs r=0,554 and 0.575 respectively, p< 0.05) and showed a trend towards signiþcance with degrees of scoliotic curve (Pearsonñs r=0.531, p=0.062). Conclusions: There are no signiþcant asymmetries or pathological alterations in the motor system of patients with IS. However, an increased asymmetry of facilitated

The purpose of the study is to evaluate the outcome of two methods: Posterolateral fusion and instrumentation versus posterolateral fusion, instrumentation and interbody fusion using clinical and radiological criteria in demographically similar groups. This is a prospective cohort study of sixty-four patients randomized to two therapeutic strategies (Level II study). Sixty-four patients were randomized to either instrumented posterolateral fusion (control) or combined instrumented posterolateral and interbody fusion (study) in one level degenerative disorders of the lumbar spine. Demographics of the groups were similar including age, gender and other variables. The demographics of the groups were similar for one level degenerative disorders—disc herniation, spondylolisthesis and spinal stenosis. The primary outcome was measured by the Oswestry Disability Index at two years. There was no statistically significant difference. Secondary outcomes (SF36, VAS, fusion rate, disc height maintenance, maintenance of deformity correction, adjacent segment degeneration) were statistically similar in both groups. In conclusion, no clinical advantage with interbody fusion versus posterolateral fusion alone. Analysis of the correlation between the pedicle shape and the spinal canal anatomy in scoliotic anatomic specimens. S. Parent1, H. Labelle, W. Skalli, J. de Guise,. 13175 Côte Ste-Catherine, Montréal, Québec H3T 1C5. The objective of the present study was to analyze the correlation between the pedicle shape and spinal canal anatomy in scoliotic specimens. Vertebral canal anatomy was evaluated in a series of thirty anatomic scoliotic specimens and compared to thirty normal specimens. Spinal canal enlargement inversely correlated with pedicle width modifications on the concavity of scoliotic curves. These findings suggest that changes in pedicle anatomy are secondary to local changes in spinal cord position. Recent studies have demonstrated the close relationship between the spinal cord and the pedicle on the concavity of the scoliotic curve of patients with scoliotic deformities. The hypothesis of the present study is that changes in spinal canal shape are related to spinal cord position and resulting bone remodeling. This study evaluated the characteristic changes of spinal canal shape in anatomic scoliotic specimens. Posterior elements morphology is closely related to the local spinal cord anatomy and its relationship with the bony architecture. The characteristic posterior element changes seen in scoliosis are likely the result of local bone remodeling. Spinal asymmetry was observed in scoliotic specimens when compared to normal specimens. Spinal canal was enlarged asymmetrically on the concavity of thoracic scoliotic curves (p < 0.01). Overall, canal surface was greater in scoliotic specimens when compared to normal specimens (p < 0.01). These changes were more important at the apex of the curve. Spinal canal characteristic shape was evaluated in thirty scoliotic anatomic specimens and thirty normal anatomic specimens using twelve parameters representing measures of right and left hemi-canal length, width or surface area. The 3-D coordinates of eight points taken at the periphery of each spinal canal were recorded. The results of this study support the hypothesis that spinal canal shape is modified by the spinal cord position and that posterior element changes seen in scoliosis are in part due to bone remodeling in response to local neural anatomy modifications. Funding: Fonds de Recherche en Santé du Québec

Introduction. Previous work has shown that C57BL/6 mice develop scoliosis when rendered bipedal. Our previous work suggested that tamoxifen (TMX) might change the natural course of scoliosis when administered before scoliotic curves develop. We analysed whether the incidence of scoliosis or the magnitude of curves may be decreased by the administration of tamoxifen after curves are observed. Methods. 20 female, 3-week-old C57BL/6 mice underwent amputations of forelimbs and tails at 3 weeks, 18 of which were included in analyses. Posteroanterior scoliosis radiographs were obtained at week 20, and scoliotic curves were recorded. After week 20, all mice received 10 mg TMX per L of daily water supply for 20 weeks. The course of deformities in this group (week 20 group) was compared with that of previous study groups (receiving TMX from week 3; week 3 group). Results. At week 20, overall, upper thoracic (UT), thoraco-lumbar (TL), and double curve scoliosis rates were similar in both groups, but the thoracic (T) scoliosis rate was lower in the week 3 group. At week 40, although T, TL, and double curve scoliosis rates were similar between groups, overall rate and the rates of UT scoliosis were significantly lower in week 3 group (table). We recorded no significant change of curve rates in week 20 group apart from the TL rate, which showed a significant increase (p=0·025). Mean Cobb angles were similar in both study groups (p>0·05) at 20 and 40 weeks. Conclusions. This study has shown that TMX administered after scoliotic changes are observed seems to be less effective compared with prior TMX protocol in C57BL/6 mice model. This information is important for the planning of possible pharmacological intervention in human beings

Objective: To assess early results with the KASS system for scoliosis correction. To assess lateral curvature, rotational correction and complications. Design: The first 22 patients requiring anterior correction of scoliotic curves were retrospectively reviewed. Pre- and post-operative curve measurements were made with a Cobbometer. Topographical assessment (ISIS) scan was used to assess rotation and correction of the rib hump. The notes were reviewed to determine complications and time to discharge. Subjects: Twenty-two patients: 18 idiopathic scoliosis (4 others); average age 15.4 years; 5 King One, 10 King Two, 6 King Three and one non-definable; 5 thoracic curves. Results: Average pre-op scoliosis 54.85 degrees. Average post-op scoliosis 19.4 degrees. Average correction 65%. One patient required second operation for long screws. Four self limiting rninor complications. Average time to discharge eight days. Conclusion: KASS instrurnentation is a safe, effective and reliable method to correct scoliotic curves including rotational deformities. It was not possible to correct the Cobb angle of purely thoracic curves as much as thoracolumbar curves. Cosmetic correction however has been excellent as demonstrated with ISIS. Long term review will be necessary to confirm that correction is maintained

Background: The relation between Adolescent Idiopathic Scoliosis (AIS) and exercising is rather ambiguous. The latter has often been considered both as a therapeutic means as well as a causative factor of the former. Aim of this cross-sectional case-control study was the assessment of the incidence of AIS among athletes and non-athletes in order to determine whether athletic activities play a potential role (positive or not) in the development of AIS. Methods: A group of 2387 adolescents (1177 boys and 1210 girls) was evaluated. Their mean age was 13.4 years (range:12–15 years). All patients completed a detailed questionnaire concerning personal, somatometric and secondary sex characteristics, type, duration and character of daily performed physical activities and existing cases of AIS among their relatives. The patients were classified into 2 groups according to their answers; ‘athletes’ and ‘non-athletes’. The 2 groups were statistically comparable as far as age, height, weight, onset of menstruation and prevalent extremity were concerned. All children underwent physical examination by 3 orthopaedic surgeons that were unaware of their level of athletic activities. Children considered, by all examiners, to be suspicious of suffering from scoliosis underwent further radiographic evaluation. Results: One hundred and seventy seven children (66 boys and 111 girls) were considered as suspicious; in 99 cases (athletes: 48, non-athletes:51) AIS was radiographically confirmed. No statistically significant difference was found between athletes and non-athletes adolescents (p=0.927), athletes and non-athletes boys (p=0.888) and athletes and non-athletes girls (p=0.804), as far as the prevalence of AIS was concerned. There was also no statistically significant difference between male athletes and non-athletes (p=0.899) and female athletes and non-athletes (p=0.311) as far as the mean value of the Cobb angle of the main scoliotic curve was concerned. Conclusions: This study’s results show that systematic exercising is not positively or negatively associated with a higher or lower incidence of AIS. Furthermore, actively participating in sports activities doesn’t seem to correlate with the degree of the main scoliotic curve either

This work was aimed at study the role of paraspinal muscles on spinal tensegrity. Four different models of spinal tensegrity breakage with and without injury of the posterior spinal muscle were investigated. Fifteen minipigs (mean age 6-week) underwent costotransversectomy (CTT) at 5 consecutive vertebral segments. In 4 animals ribs and transverse processes (T7–T11) were removed through a posterior midline approach with complete desinsertion of paraspinal muscles. In other 3 animals, CTT was performed by a posterolateral approach (T6–T10) without detachment of paraspinal muscles. Other 4 minipigs underwent rib resection (T7-T11) throughout a thoracoscopic approach avoiding damage of posterior spinal muscles. A final group of 4 animals, a complete detachment of the paraspinal muscles was performed from T7 to T11 without removing bony structures and leaving in deep surgical wax attached to the spinous and transverse processes to avoid reinsertion of the muscles after surgery. Anatomic specimens were radiologically and macroscopically studied just at sacrifice 5 months after surgery. All 4 animals operated on of CTT by midline posterior approach developed structural spinal deformity with curve convexity at the side of rib removal (mean Cobb angle 34,6°). Animals undergoing CTT by posterolateral approach without paraspinal muscle detachment did not develop any significant spinal deformity. Absence of spinal deformity was also found in those animals in which rib resection was performed by thoracoscopy without injury of the posterior spinal muscles. All 4 animals undergoing detachment of the paraspinal muscles without CTT and application of the surgical wax developed scoliotic curves (mean Cobb angle of 28°). In conclusion, a new insight on the underlying pathogenic mechanisms of scoliotic curves is given by using this spinal tensegrity model. Isolated damage of the posterior muscle-ligamentous structures around the costotransverse joints breaking muscles spine tensegrity seems to be mandatory to induce scoliotic deformity. Rib removal alone appeared to have less scoliotic inductive implication. The finding questions previous knowledge on scoliosis etiopathogeny

Introduction: Although the cell density of the intervertebral disc is low, cells perform a vital role, being responsible for maintaining and remodelling the extracellular matrix. In animal models of scoliosis, cell viability of epiphyseal chondrocytes was found to be adversely affected. Here we examine cell density and viability of surgical disc specimens. Method: A total of 41 discs were removed from 13 consenting patients (3M, 9F, 5–40 yrs) during corrective surgery for scoliosis. Control samples were obtained from 3 non-scoliotic discs. These were further dissected to compare the outer annulus of the disc from the more concave and more convex sides of the quadrant removed at surgery. Cell density was measured using a modified Hoechst’s method. Cell viability was determined microscopically in sections using intracellular fluorescent probes. Results: Cell density was found to be lowest in apical discs, independent of absolute disc level (p< 0.01, Student’s t test). A significantly lower percentage of live cells was found in samples taken from the convex side of the scoliotic curve (p< 0.01, Student’s t test). No significant differences in cell viability were found in either side of control discs. Discussion: Cell viability was seen to be lower on the convex side of the scoliotic curve, suggesting that it is more difficult for cells to survive under the conditions on the convexity compared with the concavity. This may be due to differences in the mechanical conditions or the diffusion distances across the disc. Cell numbers were lowest in the apical disc, where stresses are thought to be maximal. Fewer viable cells may decrease production of matrix macromolecules, and thus compromise matrix integrity. A delicate balance exists between production and breakdown of matrix macromolecules, and any factor that interrupts this equilibrium state has the potential to affect the structure and function of the intervertebral disc

The aim of this study was to report the restauration of the normal vertebral morphology and the absence of curve progression after removal the instrumentation in AIS patients that underwent posterior correction of the deformity by common all screws construct whitout fusion. A series of 36 AIS immature patients (Risser 3 or less) were include in the study. Instrumentation was removed once the maturity stage was complete (Risser 5). Curve correction was assessed at pre and postoperative, before instrumentation removal, just post removal, and more than two years after instrumentation removal. Epiphyseal vertebral growth modulation was assessed by a coronal wedging ratio (WR) at the apical level of the main curve (MC). The mean preoperative coronal Cobb was corrected from 53.7°±7.5 to 5.5º±7.5º (89.7%) at the immediate postop. After implants removal (31.0±5.8 months) the MC was 13.1º. T5–T12 kyphosis showed a significant improvement from 19.0º before curve correction to 27.1º after implants removal (p<0.05). Before surgery, WR was 0.71±0.06, and after removal WR was 0.98±0.08 (p<0.001). At the end of follow-up, the mean sagittal range of motion (ROM) of the T12-S1 segment was 51.2±21.0º. SRS-22 scores improved from 3.31±0.25 preoperatively to 3.68±0.25 at final assessment (p<0.001). In conclusion, fusionless posterior approach using a common all pedicle screws construct correct satisfactory scoliotic main curves and permits removal of the instrumentation once the bone maturity is reached. The final correction was highly satisfactory and an acceptable ROM of the previously lower instrumented segments was observed

Background: The neurocentral junction often has been identified as a potential cause of adolescent idiopathic scoliosis (AIS). Disparate growth at this site has been thought to lead to pedicle asymmetry, which then causes vertebral rotation in the transverse plane and ultimately, the development of scoliotic curves. Objectives:. To develop a model that incorporates pedicle growth and growth modulation into an existing finite element model of the thoracic and lumbar spine already integrating vertebral growth and growth modulation. Using the model to investigate whether pedicle asymmetry, either alone or combined with other deformations, could be involved in scoliosis pathomechanisms. Methods: The model was personalised to the geometry of a non-pathological subject and used as the reference spinal configuration. Left/right asymmetry of pedicle geometry (i.e. initial length) and left/right asymmetry of the pedicle growth rate alone or in combination with other AIS potential pathogenesis (anterior, lateral, or rotational displacement of apical vertebra) were simulated over a period of 24 months. The Cobb angle and local scoliotic descriptors (wedging angle, axial rotation) were assessed at each monthly growth cycle. Results: Simulations with asymmetrical pedicle geometry did not produce significant scoliosis, vertebral rotation or wedging. Simulations with asymmetry of pedicle growth rate did not cause scoliosis independently and did not amplify the scoliotic deformity caused by other initial deformations tested by Villemure (2004). Discussion and Conclusion: The results of this biomechanical model do not support the hypothesis that asymmetrical neurocentral junction growth is a cause of AIS. This concurs with recent animal experiments in which neurocentral junction growth was unilaterally restricted and no scoliosis, vertebral wedging or rotation was noted. With regards to addressing the aetiology of scoliotic curve development, biomechanical modelling represents a powerful tool to investigate cause and affect relationships since AIS patients typically present to the scoliosis clinic well after curves have manifested. Contact person and Presenter: Carl-Éric Aubin, Ph.D., Canada Research Chair “CAD Innovations in Orthopedic Engineering”, Department of Mechanical Engineering, Ecole Polytechnique, Montreal, Canada, Tel: (514) 340-4711, ext. 4437; Fax: (514) 340-5867; E-mail: . carl-eric.aubin@polymtl.ca

Thoracoplasty has been described as primarily a cosmetic resection of the rib hump. The purpose of our study was to investigate whether removal of a normal spine stabilizer affected the correction of the spine, particularly in the sagittal plane. Thirty-eight adolescent idiopathic scoliosis patients who underwent thoracoplasty were compared with eighteen controls in terms of maintenance of correction and patient satisfaction using the SRS questionnaire. Thoracoplasty had no effect on curve correction in the coronal plane. It did show a significant effect on sagittal plane correction of the thoracic hypokyphosis without any significant detractors in terms of patient outcome. To investigate whether thoracoplasty affected spinal correction. We also compared patient outcomes thoracoplasty patients and controls, as well as long-term curve maintenance. Thoracoplasty did increase the correction of thoracic hypokyphosis, without any significant detractors in terms of patient outcome. Current understanding of the scoliotic curve as a three dimensional helix has led to increased recognition of the importance of sagittal contour and balancing the spine’s reciprocal curves to avoid problems such as flat back syndrome. Correction of the scoliotic curve intraoperatively may require the removal of spine stabilizers such as the disc and annulus, posterior facet and capsule, and thoracic cage stabilizers such as the ribs. Thirty-eight patients who had either concave para-median or convex Steel mid-rib thoracoplasty were reviewed and compared to eighteen controls. Prospective patient outcomes using the Scoliosis Research Society instrument with an average of > one year follow-up were available for thirty patients. Degree of curve settle and maintenance of correction was measured on follow-up radiographs. Thoracoplasty had no effect on curve correction in the coronal plane. It did show a significant effect on sagittal plane correction of thoracic hypokyphosis. The paramedian group showed a mean increase of tweleve degrees, the Steel group 8.7 degrees, and, the control group 3.1 degrees. No significant difference between pain, satisfaction, function, and self-image was found. Long-term radiographic follow-up (average three years) showed a mean coronal curve settle of 4.6 degrees (thoracoplasty) versus 3.1 degrees (non-thoracoplasty), and an accompanying improvement in sagittal plane correction of 4.2 and 3.0 degrees, respectively

Classic management of large and stiff thoracic scoliotic curves in the adolescent comprise of anterior release followed by posterior instrumentation. However third generation segmental spinal instrumentations have shown increased correction of thoracic curves. Therefore, the indication for an anterior release may no longer be required. We reviewed our database for cases with thoracic curves with Cobb angle between 70 and 90° that we had only done posterior surgery. We found that with adequate posterior release, and the use of third generation segmental instrumentation there is no need for anterior release even for curves in the 70–90° range. Large and stiff thoracic scoliotic curves in the adolescent represent a classic indication of anterior release before posterior spinal instrumentation. To assess if third generation segmental posterior instrumentation can omit the need of anterior surgery in large and stiff thoracic curves. An independent observer, reviewed in a retrospective fashion our electronic database of adolescent scoliosis surgery (Scolisoft) with the following query: Thoracic curves, Cobb angle between 70 and 90° degrees and posterior surgery only. There was nineteen patients who fit the criteria. Out of these, four were judged to flexible (bends < than 45°) and were not included. Fifteen patients (mean age 13.6) with thoracic scoliosis with average Cobb 78.5° with a flexibility index of 32.5% were analyzed. (mean f/u: twenty-eight months). Postoperatively the thoracic Cobb angle measured on average 34.8° (25° −45°), which represents a correction rate of 54 % (range, 40.0–67.1%) and remained unchanged at the last follow-up (35°). Sagittal alignment improved from an average 11° to 18°. There were two complications (one excessive bleeding and one infection). Coronal balance was improved, as was shoulder balance. All patients reported satisfactory results except the patient with an adding-on phenomena. In the literature most of the results of anterior thora-coscopic release and posterior surgery give a percentage of Cobb angle correction similar or inferior (averaging 50%) to our series for an average initial Cobb angle of less magnitude. With adequate posterior release, and the use of third generation segmental instrumentation there is no need for anterior release even for curves in the 70–90° range

Objective: The development of braces for the non-operative treatment of idiopathic scoliosis has been empirical, based on trial and error. Brace designs have changed periodically over the years, but most modifications have been attempts to improve efficacy and failed to acknowledge the importance, especially to teenagers, of physical appearance. This group resists acting or looking different from their peers, which obviously occurs when a visible brace is worn. Modern materials, lower profiles, and reduced wearing times have been tried, in attempts to reduce resistance and the emotional difficulties encountered with brace wear. A transverse force system, consisting of an anterior progression force counteracted by a posterior force and torque, acts on the vertebrae of a scoliotic spine. The aim of the newly introduced TriaC brace is to reverse this transverse force pattern by externally applied and constantly present orthotic forces. In the frontal plane the force system is in accordance with the conventional braces. However, in the sagittal plane the force system acts only in the thoracic region. As a result, there is no pelvic tilt, and it provides flexibility without affecting the correction forces during body motion. Design: In 1996, when we almost completed the design of the new orthosis, we started a prospective trial in our University Hospital, which we expanded in the year 2000 to a prospective multi-center trial. Subjects: The study included 45 consecutive patients with idiopathic scoliosis treated since 1996 with the newly introduced brace. The group consisted of 40 female and 5 male patients with an average age at the initiation of treatment of 12,6 years. All patients were Risser zero to two and had verified progressive curves (an increase of 5 degrees or more Cobb angle). Results: Three parameters were measured during treatment: the Cobb angle, lateral deviation and axial rotation of the apex of the scoliotic curve. These measurements were conducted on digital X-rays using the Philips Easy Vision Digital Radiographic technique.[. 2. ] Statistical analysis for differences in time for the three measured parameters was performed using the Friedman’s two-way analysis of variance test. Level of significance was reached when the p-value (two-tailed) was less than 0,05. The new brace prevented further progression of the scoliotic curves, except for seven patients, who required surgery. The initial mean Cobb angle before brace treatment, was 26,5 degrees, the mean lateral displacement at the apex 18,5 millimetres, and the initial axial rotation of the apex was 12,3 degrees. Analysis of differences between each successive visit showed that the difference was not statistically significant for the Cobb angle (p=0,71), nor for the other parameters. Conclusions: This presentation shows that the preliminary results of the TriaC brace are very promising, but we acknowledge that our patient number is too small to make definite claims. Our failure rate is comparable with the numbers in literature. But being efficacious is not enough; this brace is reasonable comfortable and cosmetically acceptable so that the teenagers who require this treatment will use it

Combined anterior/posterior scoliosis surgery is the mainstay of scoliosis surgery in large curves with Cobb angle more than 65°, in stiff curves that correct to above 40° only on the pre-operative bending films and in Steersman’s kyphosis greater than 90°. The combined anterior/posterior scoliosis surgery allows better correction of the curve, saving motion segments in the spine and eliminating the occurrence of the crankshaft phenomenon. Video-assisted spinal surgery (VATS) and Mini open thoracotomy, thoracoscopically assisted (MOT-TA) allow for the performing of multi level discectomies and soft tissue release, as an anterior adjunct to posterior spine fusion, through minimal approach to the thoracic spine in scoliosis surgery. During the last year we have begun using the MOT-TA for anterior thoracic spine release and fusion, as the first step in releasing, reducing, and fusing large and stiff scoliotic curves, utilizing standard surgical instrumentation and techniques. Materials and Methods: Mini-Thoracotomy Thoracoscopic Assisted was performed on 15 patients, age 4 to 48 (mean 20 years old) between January 2000 to present. There was a female predominance (12:3). In the group, 13 patients were scoliosis patients and 2 were kyphosis patients. All patients underwent anterior release and discectomy before performing posterior fusion. A mean of 4 discs (range 3 to 5 discs) was excised at surgery. The mean Cobb angle was 62°. No anterior instrumentation was placed in the first 14 cases. In case No. 15 an anterior crew-rod construct was placed through the mini thoracotomy incision. Technique: MOT-TA is performed with the patient positioned in a lateral decubitus with the convex side of the scoliotic curve up through a 5–7 cm skin incision above the apical vertebra obliquely from the posterior to the middle axillary line. Results: There was a short learning curve associated with the technique, which proved to be an easy and straight forward surgical technique. Pre-operative thoracic Cobb angle measured 50°–80° (average 62°) that bends to 30°–66° on the pre-operative thoracic bend films (average 45°). The pot-operative thoracic Cobb angle measured 15°–38° (average 28°). The overall curve correction was 59% on average. The anterior soft tissue releases and discectomies were a quick and relatively “dry” part of the surgery. Estimated blood loss ranged 50–800cc, less than a quarter of the total intra-operative blood loss averaging 220cc out of 1227cc of the total EBL. Anterior surgery time ranged 100 to 170 min averaging 147min for mean of 6.1 discs (range 4 to 9 discs). When compared to the total operative time, the anterior part of the surgery took about a 1/3 of the total surgery time. Discussion: The results of the study show that the mini open thoracotomy, thoracoscopically assisted, for anterior thoracic spine release and discectomies is a fast, easy to learn technique with a short learning curve leading to complete anterior release, short operative time, allowing same day front and back surgery with no difficulty in performing internal thoracoplasty that results in structural and cosmetically superior outcome. In the hands of an experienced surgeon, the usage of VATS could be an effective and beneficial in scoliosis surgery; however, in the case of less experienced surgeon, who has no experience in thoracoscopic surgery, the MOT-TA could be an elegant and useful way to perform the technically demanding anterior discectomies and releases in severely deformed and rigid scoliotic spine. In our last case we have demonstrated the ability to instrument the anterior spine utilizing the same mini thoracotomy incision, this advance will be carried further to more extensive instrumentation in the future. In conclusion: Mini open thoracotomy, thoracoscopically assisted, for anterior thoracic spine release and fusion is a faster, easier, cosmetically superior and surgically justified procedure

Abstract: The effect of a modified Boston Brace with antirotatory blades upon the fate of idiopathic scoliotic (IS) curves, mainly right thoracic with a compensatory left lumbar, is studied. This report refers to curves within the generally accepted range of Cobb angle (20° – 40°) appropriate for conservative treatment. Method and Material: Out of 166 children suffering IS with Cobb angle > 10°, 67 (61 girls, and 6 boys), having a mean follow up 2,3 years (4 months to 7 years), were studied. A brace of Boston type with antirotatory blades was applied in 36 scoliotic children. The curve type was: 18 thoracic (T) right (rt) + Lumbar (L) left (lt) in children with a mean age 13,1 years, 3 T lt + L rt in children with a mean age 16,3 years, 7 T rt in children with a mean age 13 years and 8 thoracolumbar (TL) rt curves in children with a mean age 12,1 years. Full documentation during the FU had 23 out of the 36 children with 14 T rt + L lt, 1 T lt + L rt (15 in total – double curve group), 4 T rt (thoracic group) and 4 TL curves (thora-columbar group). Traditionally deterioration (increase) or improvement (decrease) of a curve is considered a change of 5ï Cobb compared with the initial reading. Results: In the 15 double curve group children the mean FU was 28 months. In this group 5 curves were improved, 6 remained stable and 4 were increased. For the 4 thora-columbar curves with a mean FU 8 months, 3 remained stable and 1 improved. For the 4 thoracic curves with a mean FU 9 months, 2 were stable and 2 improved. During the final FU of the above 23 scoliotic children, when the assessment of Cobb angle was made with children out of the brace, 8 curves were improvement, 11 remained stable and 4 deteriorated (one patient out of 4 (4,3%) was operated upon). All the deteriorated curves were double (T rt + L lt). When the assessment of Cobb angle was made with children in the brace, 10 curves were improved, 12 remained stable and 1 deteriorated. Discussion: The brace treatment affected more the double curves while single curves remained unaffected. Rotation remained unchanged in all curve types except in the lumbar component of double (right thoracic-left lumbar) curves. A composite spiral trunk rotator muscle has been proposed, (consisted of the ipsilateral scapular elevator and rhomboid, the anterior serrated, external oblique and contralateral internal oblique abdominal muscle, (Benninghoff 1985, Wemyss-Holden 1990), which is considered that have an effect on the trunk rotation during gait. Asymmetry of one or more constituent muscles creates scoliosis. These findings are consistent with the view that neuromuscular factors are responsible for the initiation of idiopathic scoliosis. The antirotatory blades of the brace are acting upon the above described composite spiral trunk rotator muscle blocking the deterioration of the scoliotic curve or improving the double curves thus supporting the above aetiologic view. In conclusion the conservative treatment using this brace is beneficially affecting the natural history of the IS in children 12–15 years of age