Adolescent Idiopathic Scoliosis Cases Research Articles

Abnormal cerebral cortical thinning pattern in adolescent girls with idiopathic scoliosis

Adolescent idiopathic scoliosis (AIS) is a 3-D spinal deformity with uncertain etiology; abnormalities in brain development represent one of the possible explanatory concepts for its pathogenesis. The objective of this study is to investigate the brain maturation by thickness of cerebral cortex among female adolescents with and without idiopathic scoliosis. Fifty AIS patients with a typical right-thoracic curve pattern were compared with 40 age-matched healthy controls. Based on the T1-weighted magnetic resonance images, the thickness of cortical gray-matter was calculated using a well-validated surface measurement method. Focusing on adolescent participants within the age range with the frequent occurrences of AIS cases (i.e., 12 to 17 years), we observed that the cortical thickness declined significantly in almost all cortical lobes in normal subjects (Spearman correlation<-0.4; P ≤ 0.05) except temporal lobe in LH, while in AIS patients this decline was weakly correlated with age (Spearman correlation>-0.4) and largely insignificant (P ≥ 0.05). Quadratic regression results expressed the detailed difference in the age-related cortical changing pattern between the two groups. In addition, focal cortical thickness was significantly different in AIS patients compared with healthy controls in areas involved in motor and vestibular functions as well as object recognition. The findings from this study imply a different thinning pattern of the cerebral cortex during adolescence in patients with AIS; this may be primary (i.e. etiopathogenetic) or secondary (i.e. adaptation) to the development of scoliosis.

Did the Lenke Classification Change Scoliosis Treatment?

A retrospective review of data prospectively entered into a multicenter database. To evaluate the adherence to classification-specific surgical treatment recommendations for adolescent idiopathic scoliosis (AIS) before and after the Lenke classification system introduction in 2001. The Lenke classification system of AIS was developed in 2001 to provide a comprehensive and reliable means to categorize and guide treatment. The treatment recommendations of the system state that major and structural minor curves are included in the instrumentation and fusion and the nonstructural minor curves are excluded. Surgical AIS cases for each Lenke classification (curve types 1-6) were queried for "Rule-breakers," in which the treatment performed did not follow the recommendations of the Lenke classification system. Each "Rule-breaker" case was individually evaluated to ensure correct Lenke classification and radiographic image verification was performed. "Rule-breaker" patients were expressed as a percentage of the total number of patients for each curve type. The presence of "Rule-breakers" before and after the introduction of the Lenke classification system in 2001 was evaluated for statistical difference using a chi-square analysis. The data for 1310 AIS patients who underwent surgical correction for their deformity were included in this analysis. Overall, treatment of 191 patients did not follow the classification recommendations; the rules are broken 15% of the time. The proportion of "Rule-breakers" (18%) was significantly greater prior to the introduction of the Lenke classification system than it was after (12%) (P=0.001). The introduction of this system has led to a reduction in the variation of treatment approaches; however, our data suggest that 6% to 29% of the time, depending on the curve pattern, there are other aspects of the clinical and radiographic deformity that suggest deviation from the recommendations of the classification system. The outcome of adherence to this system remains yet to be evaluated.

Genetic Variants in Melatonin Synthesis and Signaling Pathway are not Associated with Adolescent Idiopathic Scoliosis

Genetic association study investigating the association of genetic markers of melatonin signaling and biosynthesis with adolescent idiopathic scoliosis (AIS). To determine whether gene polymorphisms related to the melatonin signaling or biosynthesis pathways are associated with AIS. Data have been published on the potential role of gene polymorphisms for melatonin receptor (MTNR) 1B in predicting AIS. Other genes in the melatonin pathways have been tested for association with AIS. The following genes involved in melatonin synthesis were evaluated herein: tryptophan 5-hyroxylase 1 (TPH1), serotonin N-acetyltransferase (SNAT), and hydroxyindoleo-methyltransferase (HIOMT). In addition, proteins involved in melatonin signaling were also included in this study: MTNR1A, MTNR1B, and protein kinase C delta (PKCd). High throughput microarray-based single nucleotide polymorphism (SNP) genotyping was performed for these seven genes using DNA samples from 589 AIS subjects and 1533 ethnically matched controls. Chi-square analyses of allele frequency between AIS cases and controls were performed and odds ratios were calculated for all SNP markers. Three SNPs were tested for both MTNR1A and HIOMT, 4 for TPH1 and SNAT, 12 for PKCd, and 7 for MTNR1B. The minor allele frequencies were not significantly different between AIS cases and controls. No association was thus found between AIS and the investigated SNPs. Genetic polymorphisms associated with either melatonin synthesis or its signaling pathway are unlikely to be commonly associated with AIS.

A Novel Pedicle Channel Classification Describing Osseous Anatomy

Prospective clinical series. To determine how many thoracic scoliotic pedicles have cancellous versus cortical versus absent channels. Although morphologic evaluations of thoracic pedicles have been well reported, the results do not practically reflect clinical findings during actual pedicle screw placement. We propose a novel pedicle channel classification describing the osseous anatomy encountered during pedicle probe insertion. We noted 4 pedicle types in 53 consecutive scoliosis patients. Type A: pedicle probe smoothly inserted without difficulty; the morphology is described as a "Large Cancellous Channel." Type B: pedicle probe inserted snugly with increased force; described as a "Small Cancellous Channel." Type C: pedicle probe cannot be manually pushed but must be tapped with a mallet down the pedicle into the body; described as a "Cortical Channel." Type D: pedicle probe cannot locate a channel thus necessitating a "juxtapedicular" screw position; described as a "Slit/Absent Channel." The average age at time of surgery was 23.4 ± 16.7 years. Diagnoses included idiopathic scoliosis (n = 38) and syndromic scoliosis (n = 15). The average main thoracic Cobb angle was 73° ± 26°. Evaluation of pedicle morphology of the 4 types was also performed in 21 consecutive cases of adolescent idiopathic scoliosis using preoperative computed tomography images. A total of 1021 pedicles with screws placed were evaluated. The average percent per type was as follows: 61.0% type A; 29.2% type B, 6.8% type C, and 3.0% type D. On the convexity, 98.2% of pedicles were type A or B versus 81.5% on the concavity (P < 0.05). There were significant differences between adolescent versus adult idiopathic scoliosis (P = 0.007), and syndromic scoliosis versus adult idiopathic scoliosis (P = 0.017) regarding pedicle morphologic proportions. There was a significant tendency toward a decrease in the proportion of type A pedicles, an increase in the proportion of type B pedicles as the Cobb angle increased (P < 0.0001). Evaluation based on 312 thoracic pedicles in 21 consecutive adolescent idiopathic scoliosis patients using preoperative computed tomography axial images confirmed assumptions of the 4 pedicle types. We propose a classification for pedicle channels describing the osseous anatomy encountered during pedicle probe insertion. Based on the classification, surprisingly, we found during surgery that 90% of thoracic pedicles had a cancellous channel, whereas 7% had a cortical channel and only 3% had an absent channel.

An in vitro study of dynamic cyclic compressive stress on human inner annulus fibrosus and nucleus pulposus cells

Background context Intervertebral disc (IVD) cells exhibit diverse biologic responses to compressive stress depending on the compressive stress type, magnitude, duration, and anatomic zone of IVD cell origin. The previous studies mainly focused on the effects of compressive stress on animal IVD tissue. Few studies have investigated the response of human IVD tissue to compressive stress. Purpose To assess the effect of dynamic cyclic compressive stress on biosynthesis of collagen and glycosaminoglycan of human inner annulus fibrosus (AF) and nucleus pulposus (NP) cells. Study design/setting Observation of moderate and high magnitudes of compressive stress on human IVD cell biosynthesis. Patient sample Human IVD of adolescent idiopathic scoliosis case undergoing thoracoscopic discectomy and fusion was collected. Outcome measures Cell morphology, cell proliferation assay, as well as collagen and glycosaminoglycan content were examined in vitro. Methods Intervertebral discs were cultured under 0.2 or 0.4 MPa of compressive stress at 1 Hz for 2 hours twice a day up to 7 days. These were compared with samples unloaded. The analysis was done via electron microscopy examination, cell proliferation assay, as well as collagen and glycosaminoglycan content analysis. Results Collagen and glycosaminoglycan content in the inner AF and NP cells cultured under 0.2 MPa of compressive stress was significantly higher than that in the control cells but was significantly lower than that in the control cells under 0.4 MPa of compressive stress. The number of endoplasmic reticulum in the inner AF and NP cells cultured under 0.2 MPa of compressive stress was significantly higher than that in the control cells but was significantly lower than that in the control cells under 0.4 MPa of compressive stress. Conclusion These findings imply that biosynthetic characteristics of human inner AF and NP cells may vary under varying degrees of compressive stresses, which may result in varying amounts of extracellular matrix being secreted.

Adolescent idiopathic scoliosis: Retrospective analysis of 235 surgically treated cases

Background:The surgical treatment of adolescent idiopathic scoliosis (AIS) has taken great strides in the last two decades. There have been no long term reported studies on AIS from India with documented long term followup. In this study we review a single surgical team's series of 235 surgically treated cases of AIS with a follow-up from two to six years.Materials and Methods:Pre operative charts, radiographs and MRI scans for 235 patients were collected for this study. The patients were grouped into three groups where anterior correction and fusion (n=47), posterior correction and fusion (n=123) and combined anterior release and posterior instrumentation (n=65) was performed. Each group was divided into two subgroups based on the surgical approach and instrumentation strategy (all screw construct or hybrid construct) used. Patients were followed up for coronal and saggital plane corrections, apical vertebral translation (AVT), trunk balance and back pain. The percentage of correction was calculated in each group as well as sub groups.Results:The incidence of MRI detected intraspinal anomaly in this series is 5.9% with 3.4% of them requiring neurosurgical procedure along with scoliosis correction. Average coronal major curve correction was 66% in the all screw group and 58.5% in the hybrid group. The coronal plane correction was better when the all screw constructs were employed. Also, the AVT and trunk balance was better with the all screw constructs. The anterior corrections resulted in better correction of the AVT and trunk balance as compared to the posterior correction. There were eight (3.4%) complications in this series. The coronal and saggital plane correction paralleled the published international standards.Conclusion:The coronal plane correction was better when all screw constructs were employed. Use of all pedicle screw systems obviated the need for costoplasty in most cases. The increased incidence of intraspinal anomaly may warrant a routine pre operative MR imaging of all adolescent scoliosis needing surgical treatment.

Effects of cyclic dynamic tensile strain on previously compressed inner annulus fibrosus and nucleus pulposus cells of human intervertebral disc-an in vitro study

Our objective was to investigate whether dynamic tensile strain on previously compressed human intervertebral disc (IVD) cells can restore the biosynthetic effects of collagen and glycosaminoglycan. Inner annulus fibrosus (AF) and nucleus pulposus (NP) tissues of adolescent idiopathic scoliosis cases undergoing thoracoscopic discectomy and fusion were cultured on compressive plates. Compressive stress was applied using 0.4 MPa at 1 Hz, for 2 h twice a day for 7 days, to the inner AF and NP tissues, followed by equibiaxial cyclic tensile strain to deform the released cells onto the plate's flexible bottom. With 10% elongation at a rate of 1 Hz, for 2 h twice a day for 7 days, a significant increase in the level of collagen and glycosaminoglycan of the previously compressed inner AF, as well as the level of glycosaminoglycan of the previously compressed NP cells were found. The DNA content and number of endoplasmic reticulum under transmission electron micrograph of the previously compressed inner AF and NP cell were also significantly increased. The results suggested that equibiaxial cyclic tensile strain at a rate of 1 Hz with 10% tensile strain was capable of increasing collagen and glycosaminoglycan synthesis of previously compressed inner AF cells, and glycosaminoglycan synthesis of previously compressed NP cells.

Subjective evaluation of treatment outcomes of instrumentation with pedicle screws or hybrid constructs in Lenke Type 1 and 2 adolescent idiopathic scoliosis: what happens when judges are blinded to the instrumentation?

Superiority of pedicle screws over hybrid/hook instrumentation or vice versa in the treatment of Lenke Type 1 and 2 adolescent idiopathic scoliosis (AIS) remains unresolved for moderate curves. Our objective was therefore to compare the assessment of pedicle screw and hybrid/hooks instrumentation with special attention to cosmesis and uninstrumented spine using novel assessment methods. We carried out a retrospective study of radiographs and clinical photos of 40 cases of thoracic AIS between 40 degrees and 70 degrees of Cobb angle Lenke Type 1 and 2, treated with either pedicle screws or hybrid/hooks. The cases were subjectively assessed by four spine surgeons (SRS Travelling Fellows) for radiographic and operative cosmetic result, shoulder balance, trunk shift, rib hump, and waist asymmetry. Instrumentation in the radiographs was obscured with only the non-instrumented part visible, and the surgeons were asked to guess the instrumentation being used. Eighty photographs of patients before and after surgery were assessed for cosmesis by ten non-medical judges for overall cosmetic score, shoulder balance, waist asymmetry, and shoulder blade prominence. Objective assessment of radiographs and clinical photos was performed for Cobb angle of instrumented and non-instrumented spine, global coronal and sagittal balance, number of unfused vertebrae, disc angulation, tilt of last instrumented vertebra, shoulder balance, waist asymmetry, rib prominence, and percent correction. SRS-24 questionnaire was used to measure health-related quality of life in patients. Subjective assessments by surgeons and non-medical judges showed no significant difference by instrumentation (P > or = 0.05) for all variables. Out of the 160 guesses by surgeons of the cases with instrumentation blocked in the radiographs, they were unable to guess the instrumentation in 92% of the cases. Objective assessment of all variables and SRS-24 scores of all five domains showed no significant difference by instrumentation (P > or = 0.05). In this first-ever conducted study in a blinded-fashion, we conclude that there is no significant difference between the pedicle screw and hybrid/hooks instrumentations used to treat AIS for Lenke Type 1 and 2 curves for moderate curves between 40 degrees and 70 degrees .

Experience with an online prospective database on adolescent idiopathic scoliosis: development and implementation.

Considerable variability exists in the surgical treatment and outcomes of adolescent idiopathic scoliosis (AIS). This is due to the lack of evidence-based treatment guidelines and outcome measures. Although clinical trials have been extolled as the highest form of evidence for evaluating treatment efficacy, the disadvantage of cost, time, lack of feasibility, and ethical considerations indicate a need for a new paradigm for evidence based research in this spinal deformity. High quality clinical databases offer an alternative approach for evidence-based research in medicine. So, we developed and established Scolisoft, an international, multidimensional and relational database designed to be a repository of surgical cases for AIS, and an active vehicle for standardized surgical information in a format that would permit qualitative and quantitative research and analysis. Here, we describe and discuss the utility of Scolisoft as a new paradigm for evidence-based research on AIS. Scolisoft was developed using dot.net platform and SQL server from Microsoft. All data is deidentified to protect patient privacy. Scolisoft can be accessed at www.scolisoft.org. Collection of high quality data on surgical cases of AIS is a priority and processes continue to improve the database quality. The database currently has 67 registered users from 21 countries. To date, Scolisoft has 200 detailed surgical cases with pre, post, and follow up data. Scolisoft provides a structured process and practical information for surgeons to benchmark their treatment methods against other like treatments. Scolisoft is multifaceted and its use extends to education of health care providers in training, patients, ability to mine important data to stimulate research and quality improvement initiatives of healthcare organizations.

Adolescent Idiopathic Scoliosis and Exercising

Cross-sectional observational study. Evaluation and comparison of the prevalence of adolescent idiopathic scoliosis (AIS) among 2 groups of patients (athletes and nonathletes) to determine whether athletic activities are related to the development of AIS. The potential association between AIS and exercising remains uncertain. The latter has often been considered as a therapeutic means and a causative factor of the former. A group of 2387 adolescents (boys: 1177, girls: 1210, mean age: 13.4 years) was evaluated. All completed a questionnaire concerning personal, somatometric, and secondary sex characteristics, type, duration and character of daily-performed physical activities, and existing cases of AIS among relatives. Patients were classified into 2 groups according to their answers; "athletes" and "nonathletes." The groups were comparable as far as age, height, weight, onset of menstruation, family history of scoliosis, and side of handedness were concerned. Children underwent physical examination by 3 orthopedic surgeons who were unaware of their level of athletic activities. Children considered, by all, to be suspicious of suffering from scoliosis, underwent further radiographic evaluation. In 99 cases (athletes: 48, nonathletes: 51), AIS was radiographically confirmed (Cobb angle >10 degrees). No statistically significant difference was found between athlete and nonathlete adolescents (P = 0.842), athlete and nonathlete boys (P = 0.757), and athlete and nonathlete girls (P = 0.705), as far as the prevalence of AIS was concerned. The mean value of the Cobb angle of the main scoliotic curve was not statistically different between male athletes and nonathletes (P = 0.45) and female athletes and nonathletes (P = 0.707). With the Cobb threshold reset at 20 degrees, no statistically significant differences were detected either. Our results demonstrate that systematic exercising is probably not associated with the development of AIS. Actively participating in sports activities doesn't seem to affect the degree of the main scoliotic curve either.

Radiographic evaluation of selective anterior thoracolumbar or lumbar fusion for adolescent idiopathic scoliosis

According to Lenke classification of adolescent idiopathic scoliosis (AIS), patients with type 5 curve in which the structural major curve is thoracolumbar or lumbar curve with nonstructural proximal thoracic and main thoracic curves, could be surgically treated with selective anterior thoracolumbar or lumbar (TL/L) fusion. This study retrospectively analyzed the radiographies of selective anterior TL/L fusion in 35 cases of AIS with Lenke type 5 curve. Segmental fixation with a single rigid rod through anterior thoracoabdominal approach was applied in all patients. Measurements of scoliosis curve in preoperative, immediate postoperative and follow-up radiographies were analyzed. The average follow up time was 36 months (24-42 months). The average preoperative Cobb angle of the TL/L curve was 45.6 degrees and improved into 9.7 degrees immediate postoperatively, with 79.7% curve correction. In addition, the minor thoracic curve decreased from 29.7 degrees preoperatively to 17.6 degrees postoperatively, with a spontaneous correction of 41.5%. During the follow-up, a loss of 4.6 degrees correction was found and the average Cobb angle of TL/L increased to 14.4 degrees . Also, the minor thoracic curve increased to average 20.1 degrees with a loss of 2.4 degrees correction. Trunk shift deteriorated slightly immediate postoperatively and improved at the follow-up. The lowest instrumented vertebra (LIV) tilt was improved significantly and maintained its results at the follow-up. During the follow-up, the coronal disc angle immediately above the upper instrumented vertebra (UIVDA) and below the LIV (LIVDA) aggravated, while the sagittal contours of T5-T12 and T10-L2 were well maintained. The lumbar lordosis of L1-S1 and the sagittal Cobb angle of the instrumented segments were reduced slightly postoperatively and at the follow-up. There were no major complications or pseudarthrosis. The outcomes of this study show that selective anterior thoracolumbar or lumbar fusion with solid rod instrumentation is effective for surgical correction of AIS with Lenke type 5 curve. The TL/L curve, minor thoracic curve, and LIV title can be improved significantly, with good maintenance of sagittal contour. However, the UIVDA and LIVDA aggravate postoperatively when the trunk rebalances itself during follow-up. The degeneration of LIV disc warrants longer-term follow-up.

The Use of Fuzzy Logic to Select Which Curves Need to be Instrumented and Fused in Adolescent Idiopathic Scoliosis

Selection of the appropriate curve fusion levels for surgery in adolescent idiopathic scoliosis (AIS) is a complex and difficult task. Despite numerous publications on this subject, the decision as to which spinal curve, that is proximal thoracic, main thoracic or lumbar, needs to be instrumented and included in the fusion relies mostly on each surgeon's past experience, although recently published data have revealed a high variability of spinal instrumentation configurations among spinal surgeons in AIS. This situation exists because of ambiguity and vagueness in the decision process. Our objective is to capture the proposed rules for the selection of fusion levels and integrate them in a fuzzy logic model to decrease haziness and imprecision in the selection process. Two models have been developed, one for proximal thoracic curves and the other for lumbar curves. These models were constructed using data from a literature review, which allowed the extraction of currently proposed rules and their modeling as inputs in a computer software based on fuzzy logic modeling. Five and four inputs have been respectively chosen for the proximal thoracic and lumbar model. When all input values are entered in the model for a specific subject with AIS, the software calculates the level of suggestion for the indication to perform an instrumentation and fusion of the high thoracic and/or lumbar curves for this particular subject. The usefulness of this approach is demonstrated using illustrative cases. This is the first report on the use of fuzzy logic to assist the decision-making process in the field of spinal deformity surgery and the results suggest that this approach may be useful to facilitate surgical planning in difficult or borderline cases of AIS.

The Reliability of Preoperative Supine Radiographs to Predict the Amount of Curve Flexibility in Adolescent Idiopathic Scoliosis

Retrospective review. To determine the reliability of supine long-cassette radiographs as compared with side-bending films in predicting curve flexibility in operative cases of adolescent idiopathic scoliosis (AIS). The value of side-bending films is important in the classification of AIS, as well as predicting curve flexibility. A total of 675 patients with a diagnosis of operative AIS were evaluated. All curves were classified by the Lenke classification. Coronal parameters included: proximal thoracic (PT), main thoracic (MT), and thoracolumbar/lumbar (TL/L) Cobb measurements; sagittal data including: T2-T5, T5-T12, and TL/L measurements. Curves were divided into Lenke Types 1 (N = 263), 2 (N = 118), 3 (N = 52), 4 (N = 31), 5 (N = 57), and 6 (N = 54). Lenke Types 1 to 4 (Group I-MT Major) were compared with Types 5 and 6 (Group II-TL/L Major). For Group I, MT supine films were highly predictive of MT side-bending while TL/L supine films were highly predictive of TL/L side-bending and standing films. An equation was derived to predict the value of the side-bending radiographs for each part of the curve. For Group II, MT supine films were highly predictive of MT side-bending and standing films. TL/L supine films were highly predictive of TL/L side-bending and standing films. Contingency table analysis for Group I resulted in the supine film providing a strong statistical ability to predict a nonstructural PT curve (sensitivity = 0.952, PPV = 0.864, NPV = 0.865) and also a nonstructural TL/L curve (sensitivity = 0.958, PPV = 0.916). Similarly, in Group II, we found a strong statistical ability to predict a nonstructural PT (sensitivity 1.00, PPV = 0.982, NPV = 1.00) and a nonstructural MT curve (sensitivity 0.789, specificity = 0.842, PPV = 0.833, NPV = 0.80). A single preoperative supine radiograph is highly predictive of side-bending radiographs and can be used as an adjunct to predicting curve type, flexibility, and structurality. Thus, this singular, reproducible, and non-effort-related radiograph can potentially replace the need for dual side-bending films.

Patient Characteristics at the Initial Visit to a Scoliosis Clinic

A cross-sectional study was conducted of all patients referred for an initial visit to the orthopedic outpatient clinic of a metropolitan pediatric hospital in Canada for suspected adolescent idiopathic scoliosis (AIS). To document the appropriateness of current referral patterns for AIS in comparison to those that were prevailing before discontinuation of school screening in Canada. The consequences of the discontinuation of school scoliosis screening programs on the referral patterns of AIS patients remain unknown. The clinical and radiologic charts of the 636 consecutive patients referred for scoliosis evaluation over a 1-year period were reviewed. Patients were classified according to defined criteria of appropriateness of referral based on skeletal maturity and curve magnitude. Of the 489 suspected cases of AIS, 206 (42%) had no significant deformity (Cobb angle <10 degrees ) and could be considered as inappropriate referrals. In subjects with confirmed AIS, 91 patients (32%) were classified as late referrals with regards to brace treatment indications. These findings suggest that current referral mechanisms for AIS are leading to a suboptimal case-mix in orthopedics in terms of appropriateness of referral.

Interobserver and Intraobserver Agreement of Lenke and King Classifications for Idiopathic Scoliosis and the Influence of Level of Professional Training

This is a blinded study of radiographs by observers with different levels of professional training. To determine whether the level of professional training on nonmeasured and premeasured radiographs would affect reliability of Lenke's and King's classifications for adolescent idiopathic scoliosis. Both classification systems have been studied for their reliability, mainly by observers with a high level of experience in orthopedics and scoliosis surgery using premeasured radiographs. Examination of radiographs of 60 operative cases of adolescent idiopathic scoliosis was performed. On 5 occasions, 3 observers with a completely different degree of professional training measured and classified preoperative radiographs according to Lenke's or King's criteria. The results were determined by calculating the interobserver and intraobserver agreement and were quantified using two-rater and multirater kappa statistics. The Lenke and King classifications demonstrated poor to fair interobserver and good intraobserver agreement on nonmeasured radiographs. Both classifications demonstrated good to excellent interobserver agreement on premeasured radiographs. The results confirm that both classifications have a good reliability. On nonmeasured radiographs, the degree of professional training and the measurement process seem to influence the outcome. On premeasured radiographs, the interobserver agreement does not seem to be influenced by the level of professional training.

Reliability of End, Neutral, and Stable Vertebrae Identification in Adolescent Idiopathic Scoliosis

Analysis of radiographic interpretation and vertebral level identification. To assess the intra- and interobserver reliability by observer training level used for selecting the end vertebra (EV), neutral vertebra (NV), and stable vertebra (SV) in adolescent idiopathic scoliosis patients. Various radiographic and clinical factors are important in surgical planning. For adolescent idiopathic scoliosis, an analysis of the end, neutral, and stable vertebrae are of paramount importance for understanding spinal deformity management and determining the distal fusion level. Additionally, the development and comparison of optimal surgical techniques requires reliable, reproducible radiographic parameters. One hundred consecutive radiographs of operative cases of adolescent idiopathic scoliosis were evaluated on three separate occasions by three surgeons (2700 data points) at various levels of training (fellowship-trained spine surgeon, fellow in-training, orthopedic surgery resident). For each iteration, the observers attempted to identify the distal structural Cobb curve EV, NV, and SV. The radiographs included preselected Lenke type 1, 3, and 5 curves in random order. The average main thoracic curve was 53 degrees (range, 30-82 degrees) with a T8-T9 average apex, whereas the average thoracolumbar curve was 33 degrees (range, 18-65 degrees). Intra- and interobserver reliability was assessed by means of Cohen's Kappa correlation coefficient, and raw percentages of agreement were recorded. Intraobserver reliability was good to excellent for determining the EV (kappaa = 0.69-0.88), good for determining the NV (kappaa = 0.65-0.73), and good to excellent for determining the SV (kappaa = 0.74-0.91) with 83.5, 72.2, and 85.6% intraobserver agreement, respectively. A trend was noted towards greater intraobserver reliability with increasing levels of observer experience. Interobserver reliability was poor (kappaa = 0.26-0.39) for each vertebral level, with interobserver agreement for only 48.7% of EV, 41.7% of NV, and 51.0% of SV. However, interobserver agreement increased significantly when concurrence within one vertebral level was assessed, with 91, 73, and 76% agreement for identifying the EV, NV, and SV, respectively. Radiographic determination of the EV, NV, and SV demonstrated good to excellent intraobserver, but poor interobserver, reliability. Interobserver agreement was fair to good when concurrence within one adjacent level was assessed. Observer experience level may be a factor. The difficulties in identifying these vertebral levels represent a potential obstacle to reproducible patient-specific fusion level determination and to the optimization and uniformity of patient care.

The expression of collagen IX in the apical disc of idiopathic scoliosis

To study the distribution of collagen IX gene in the disc and to determine its role in the pathogeny of idiopathic scoliosis (IS). The data included apical disc and intermediate disc from 14 cases of adolescent IS, 26 discs from 13 cases of scoliosis of confirmed pathogeny (CPS), which included 10 cases of congenital scoliosis and neurofibromatosis scoliosis. Six discs were obtained from 3 cases of normal young man served as controls. The distribution of collagen IX was studied in the apical disc of IS by immunohistochemistry and in situ hybridization (ISH) with RNA probe. The figure of collagen IX hybridization in the endplate cartilage was input to the figure analysis system. The mRNA content of collagen IX was compared between each group by SPSS software. Collagen IX was mainly distributed in the inner fibrous annulus, nucleus and endplate cartilage. Collagen IX was secreted by the little round chondrocyte-like cells, which was not expressed in the hypertrophic cells. There was significant difference of collagen IX mRNA content between the concave side of apical disc in the IS and the normal disc(P < 0.05), and also between intermediate vertebrae of CS group and normal. There is no obvious abnormal distribution of collagen IX in the disc of idiopathic scoliosis. Collagen IX may be related to the pathogensis of IS. More investigation such as quantity analysis and protein function determination is needed to confirm its role in the pathogenicity of IS.

Curve Prevalence of a New Classification of Operative Adolescent Idiopathic Scoliosis

A retrospective multicenter consecutive case review of operative adolescent idiopathic scoliosis. To define the curve prevalence of a large consecutive series of cases with operative adolescent idiopathic scoliosis as classified by a new system and to test the ability of this new classification system to correlate with regions of the scoliotic spine to be instrumented/fused. A new comprehensive, two-dimensional classification system, intended to be treatment based, has been developed. However, it has not been tested whether all presenting operative cases of adolescent idiopathic scoliosis are classifiable in a large consecutive series, nor has the prevalence of specific curve types been determined. In addition, it is unknown whether this classification is truly treatment based, as to whether it can correlate with regions of the spine to be instrumented/fused. A multicenter retrospective review of 606 consecutive operative cases of adolescent idiopathic scoliosis was performed. All cases were classified by a new triad classification system, which included the following: a curve type (1-6), a lumbar spine modifier (A, B, C), and a sagittal thoracic modifier (-, N, +). Prevalence of the individual three components of the system and the classification grouping of all three components together were performed. In addition, the authors assessed whether this system could correlate with regions of the spine that should be included in the instrumentation and fusion, based on exactly which regions were fused during the operative procedure. All 606 cases were classifiable by this system. Prevalence of the six curve types noted was as follows: Type 1, main thoracic (n = 305, 51%); Type 2, double thoracic (n = 118, 20%); Type 3, double major (n = 69, 11%); Type 4, triple major (n = 19, 3%); Type 5, thoracolumbar/lumbar (n = 74, 12%); and Type 6, thoracolumbar/lumbar-main thoracic (n = 17, 3%). The five most common curve classifications noted were as follows: 1AN, 1BN, 2AN, 5CN, and 1CN, which accounted for 58% of all curve classifications noted. An average of 90% of the operative cases had surgically structural regions of the spine included in the instrumentation and fusion as predicted by the curve type. A new comprehensive classification system for operative adolescent idiopathic scoliosis found all 606 consecutive cases of adolescent idiopathic scoliosis classifiable, with the Type 1, main thoracic curve pattern, the most common curve type found (51%). This new classification system appears to correlate with treatment of surgically structural regions of the spine fused in 90% of cases by the objective radiographic criteria used.

A new approach to scoliosis.

Despite the advantages that new derotation-based systems have brought to the treatment of scoliosis, the debate continues, especially regarding adolescent idiopathic scoliosis. Problems like decompensation, junctional kyphosis, and insufficient sagittal plane alignment are met with new proposals. We now are using a technique and system, the Ibn-I Sina Spinal System (IBS), that we think is able to overcome these problems. It makes use of sublaminar wires, hooks, screws, and rods for correction. The main innovation is that the major corrective force is a controlled translation force acting simultaneously on all segments of the curve. A retrospective assessment of 25 patients treated with this system showed that besides dealing well with decompensation and junctional kyphosis problems, the technique was superior in sagittal plane adjustments, mainly in that it carried the normal kyphosis to its physiologic location. IBS has proved easy and successful in scoliosis treatment, especially with lordotic rigid curves. We encountered no neurologic injury or instrument failure. In addition to these advantages, ease of preoperative planning and application, decreased operation time, easy removal or revision, and versatility and safety of the system has made the Ibn-I Sina Spinal System (IBS) a treatment of choice, especially for adolescent idiopathic scoliosis cases, in some centers in Turkey.

Prescriptive screening for adolescent idiopathic scoliosis: a review of the evidence.

Published data relating to prevalence, natural history, treatment and prevention adolescent idiopathic scoliosis (AIS) are examined. Screening programmes could lead to about 10% of 11-15 year old schoolchildren being referred for diagnosis, involving, for many, an X-ray of the spine. About 1 in 5 of the children referred would be diagnosed as having AIS; of these 1 in 10 would have treatment, either by the wearing of a brace, or in more severe cases by operation and fusion of the vertebrae. The data suggest that in most cases of AIS the spinal curve regresses or at least does not progress. Treatment, whether by brace or operation, is onerous and not always successful. Very little is known for certain about the causation of AIS and the interplay of various factors in its development and regression. The case for widespread adoption of prescriptive screening programmes is not yet established. There is an urgent need to coordinate and increase research designed to determine the aetiology, incidence, prevalence and course of AIS; to find factors that distinguish a rarer progressive form, commoner in girls than boys, from a more frequent and apparently benign form; to develop reliable and valid screening techniques; and to evaluate different forms of treatment. Some of these studies will have to be carried out by collaboration between a number of centres. Current screening programmes should be rigorously evaluated, all children who are referred for diagnosis and treatment should be examined in designated centres and the findings and details of treatment should be recorded systematically, using agreed definitions and criteria that will ensure that the experience of collaborating centres can be collated.