Showing papers on "Cobb angle published in 2009"

Correlation of scoliosis curve correction with the number and type of fixation anchors.

Abstract: Study Design. Clinical and radiologic assessment derived from a prospective multicenter data base of adolescent idiopathic scoliosis (AIS) patients. Objective. We investigated if "implant density" or the number of screws correlated with the major curve (thoracic or lumbar) correction at 2 years in patients with AIS. We also investigated the effect of implant density on the change in sagittal contour before surgery to after surgery. Summary of Background Data. Controversy exists regarding number and type of spinal anchors and the mumber of implant sites used that result in improved correction in AIS. Methods. A prospective database of patients with AIS treated by posterior instrumentation between 1995 and 2004 was analyzed. The major curve correction expressed as % correction (from preoperative to 2 years postoperative) was correlated with the percentage of implants relative to the number of available implant sites within the measured Cobb angle. Correlation of % correction to the number of hooks, wires, and screws was also performed. We also analyzed the change in sagittal contour T2-T12, T5-T12, and T10-L2 before surgery and after surgery. This absolute change was then correlated with implant density, as was the number of hooks, wires, and screws. Results. There were 292 patients included with all 6 Lenke curve types represented (250 with major thoracic curves and 42 with major lumbar curves). The overall % coronal Cobb correction was 64% (range: 11%-98%). The implant density within the major curve averaged 61% (range: 6%-100%). There was a significant correlation between implant density and % curve correction (r = 0.31, P < 0.001). The number of each implant type (hooks, wires, and screws) in the construct did not correlate with the % correction; however, the average % correction of the major curve was greater when the Cobb levels were instrumented only with screws (64%) compared to hooks alone (55%), P < 0.01. The greatest % correction 78% was achieved when bilateral segmental screws were used (100% screw density). The higher the implant density within the major thoracic curve, the greater the postoperative loss of kyphosis at T2-T12 (r= -0.13, P< 0.01) and T5-T12 (r = -0.16, P < 0.001). At T10-L2, increasing screw implant density correlated with decreasing kyphosis (r = -0.40, P < 0.001 whereas increasing hook implant density correlated with increasing kyphosis (r = 0.33, P < 0.001 ). Conclusion. Major curve correction at 2 years correlates most with the implant density that is correction increases with the number of implants used within the measured Cobb levels. Although the absolute number of screws used did not correlate with correction, there was an advantage in lumbar and thoracic curves to using screws compared to hooks. Sagittal contour in the thoracic spine became less kyphotic than the higher the implant density.

Radiographic restoration of lumbar alignment after transforaminal lumbar interbody fusion

Abstract: Objective Restoration of lumbar lordosis is a critical factor in long-term success after lumbar fusions. Transforaminal lumbar interbody fusion (TLIF) is a popular surgical technique in the lumbar spine, but few data exist on change in spinal alignment after the procedure. Methods Eighty patients who underwent TLIF surgery were retrospectively reviewed (minimum follow-up period, 2 years). Standing x-rays were assessed for changes in focal and segmental kyphosis, and restoration of lumbar lordosis. Improvement in spondylolisthesis, sagittal balance, and scoliosis were also assessed. Fusion was assessed as well. Results Eighty operations were performed at 107 levels. Mean presenting lumbar Cobb angle measurement (L1-S1) was 36.3 +/- 4.5 degrees (range, 12-77 degrees). Forty patients (50%) had sagittal imbalance. Mean postoperative Cobb angle (L1-S1) was 55.1 +/- 6.6. Thirty-three of 36 patients with segmental kyphosis (92%) had restoration of lordosis. Improvement in alignment was most prominent at the surgical level (mean increase in lordosis, 20.2 +/- 4.2 degrees). The improvement in lumbar lordosis among patients undergoing multilevel TLIFs (27.3 +/- 3.4 degrees) was significantly higher compared with patients undergoing single-level operations (17.4 +/- 4.4) (Student's t test, P = 0.0004). Thirty of the 40 patients with sagittal imbalance (75%) achieved immediate restoration of normal sagittal balance. The ability to restore normal sagittal balance was correlated with a sagittal imbalance of less than 10 cm (P = 0.0001). Spondylolisthesis was completely corrected at the TLIF site in 90 of 99 levels (91%). Three patients (4%) required reoperation, 2 for implant disengagement and 1 for worsening kyphoscoliosis above the original surgical levels. Two of the 80 patients had pseudoarthrosis; hence, the rate of pseudoarthrosis was 2.5%. Conclusion The TLIF operation is highly effective in improving spinal alignment in patients with degenerative spinal disorders when the appropriate surgical technique is implemented.

Hemivertebra resection and osteotomies in congenital spine deformity.

Abstract: Study design Retrospective study of posterior hemivertebra resection and osteotomies with transpedicular instrumentation in very young children. Objective Assessment of early intervention in congenital scoliosis with almost complete correction of the main deformity. Summary of background data There is a trend to early correction of congenital deformities, however, there is a lack of long-term follow-up. Methods Forty-one children aged 1 to 6 years with congenital scoliosis were operated on by hemivertebra resection by a posterior only approach with transpedicular instrumentation. Mean age at time of surgery was 3 years 5 months. They were retrospectively studied with a mean follow-up of 6 years 2 months. Results In group 1 (patients without bar formation), the average Cobb angle of the main curve was 36 degrees before surgery and 7 degrees after surgery. Compensatory cranial curve improved spontaneously from 15 degrees to 3 degrees, compensatory caudal curve from 17 degrees to 4 degrees. The angle of kyphosis was 22 degrees before surgery and 8 degrees after surgery. In group 2 (patients with bar formation) the main curve improved from 69 degrees to 23 degrees, cranial curve from 27 degrees to 11 degrees, caudal curve from 34 degrees to 14 degrees, and kyphosis from 24 degrees to 9 degrees. Conclusion Posterior hemivertebra resection, in case of bar formation with osteotomy of the bar, allows for excellent correction in both the frontal and sagittal planes, with a short segment of fusion. Early surgery in young children prevents the development of severe local deformities and secondary structural curves, thus allowing for normal growth in the unaffected parts of the spine.

Three-dimensional classification of thoracic scoliotic curves.

Abstract: STUDY DESIGN: Three-dimensional (3D) characterization of the thoracic scoliotic spine (cross-sectional study). OBJECTIVES: To investigate the presence of subgroups within Lenke type-1 curves by evaluating the thoracic segment indices extracted from 3D reconstructions of the spine, and to propose a new clinically relevant means (the daVinci representation) to report 3D spinal deformities. SUMMARY OF BACKGROUND DATA: Although scoliosis is recognized to be a 3D deformity of the spine its measurement and classification have predominantly been based on radiographs which are 2D projections in the coronal and sagittal planes. METHODS: Thoracic segment indices derived from 3D reconstructions of coronal and sagittal standing radiographs of 172 patients with right thoracic adolescent idiopathic scoliosis, reviewed by the 3D Classification Committee of the Scoliosis Research Society, were analyzed using the ISOData unsupervised clustering algorithm. Four curve indices were analyzed: Cobb angle, axial rotation of the apical vertebrae, orientation of the plane of maximum curvature of the main thoracic curve, and kyphosis (T4-T12). No assumptions were made regarding grouping tendencies in the data nor were the number of clusters predefined. RESULTS: Three primary groups were revealed wherein kyphosis and the orientation of the PMC of the main thoracic curve were the major discriminating factors with slight overlap between groups. A small group (G1) of 22 patients having smaller, nonsurgical (minor) curves was identified. Although the remaining patients had similar Cobb angles they were split into 2 groups (G2: 79 patients; G3: 71 patients) with different PMC (G2: 65 degrees -81 degrees ; G3: 76 degrees -104 degrees ) and kyphotic measures (G2: 23 degrees -43 degrees ; G3: 7 degrees -25 degrees). CONCLUSION: Two distinct subgroups within the surgical cases (major curves) of Lenke type-1 curves were found thus suggesting that thoracic curves are not always hypokyphotic. The ISOData cluster analysis technique helped to capture inherent 3D structural curve complexities that were not evident in a 2D radiographic plane. The daVinci representation is a new clinically relevant means to report 3D spinal deformities.

Efficacy and safety of posteromedial translation for correction of thoracic curves in adolescent idiopathic scoliosis using a new connection to the spine: the Universal Clamp

Abstract: Correction of adolescent idiopathic scoliosis (AIS) has been reported with various systems. All-screw constructs are currently the most popular, but they have been associated with a significant decrease in thoracic kyphosis, with a potential risk of junctional kyphosis, not observed with hybrid constructs in the literature. In addition, it is important to weigh potential advantages of pedicle screw fixation against risks specific to its use. Because hybrid constructs are associated with a lower risk of complications and better sagittal correction than all-screw constructs, at present we use lumbar pedicle screws combined with a new sublaminar connection to the spine (Universal Clamps) at thoracic levels. The purpose of this study was to determine the efficacy and safety of the Universal Clamp (UC) posteromedial translation technique for correction of AIS. Seventy-five consecutive patients underwent posterior spinal fusion and hybrid instrumentation for progressive AIS. Correction was performed at the thoracic level using posteromedial translation. At the lumbar level, correction was performed using in situ contouring and compression/distractions maneuvers. A minimum 2-year follow-up was required. Medical data and radiographs were prospectively analyzed and compared using a paired t test. The average age at surgery was 15 years and 4 months (±19 months). The average number of levels fused was 12 ± 1.6. The mean follow-up was 30 ± 5 months. The average preoperative Cobb angle of the major curve was 60° ± 20°. The immediate postoperative major curve correction averaged 66 ± 13%. The average loss of correction of the major curve between the early postoperative assessment and latest follow-up was 3.5° ± 1.4°. The mean Cincinnati correction index was 1.7 ± 0.8 postoperatively, and 1.57 ± 1 at last follow up. The mean rotation of the apical vertebra was corrected from 23.3° ± 9° preoperatively to 7.3° ± 5° at last follow up (69% improvement, P < 0.0001). In the sagittal plane, the mean thoracic kyphosis improved from 23.8° ± 14.2° preoperatively to 32.3° ± 7.3° at last follow up. For the 68 patients who had a normokyphotic or a hypokyphotic sagittal modifier, thoracic kyphosis increased from 20.5° ± 9.9° to 31.8° ± 7.4°, corresponding to a mean kyphosis correction of 55% at last follow up. No intraoperative complication occurred and none of the patients developed proximal junctional kyphosis during the follow up. The principal limitation of the UC technique was the rate of proximal posterior prominence (14.6%), leading us to recommend the use of conventional claws at the upper extremity of the construct. The technique was safe, and reduced operative time, radiation exposure, and blood loss. While achieving correction of deformity in the coronal and axial planes equivalent to the best reported results of all-screw or previous hybrid constructs, the UC hybrid technique appears to provide superior correction in the sagittal plane. The excellent outcome in all three planes was maintained at 2 year follow up.

Effect of cervical dynamics on adjacent segment degeneration after anterior cervical fusion with cages

Abstract: The objective of this study is to evaluate the effect of anterior cervical discectomy and fusion (ACDF) on the motion of the cervical spine and dynamic stress (tendency to kyphosis) on adjacent segments and on the overall spinal alignment which may predispose to symptomatic disc diseases at other levels. Twenty consecutive patients underwent ACDF with a mean follow-up of 28 months (range 13–38). Preoperative and postoperative clinical assessments were done by using the neck disability index (NDI) and the Japanese Orthopedic Association (JOA) score. In all cases, at the last follow-up control, a neuro-radiographic assessment [cervical spine static and dynamic X-ray and magnetic resonance imaging (MRI)] was done. The angle of the operated disc space, the disc space angle of contiguous segments, and their range of motion (ROM) and the kyphotic Cobb angle (C2-7) were measured by computer software. The study was done at Sant’Andrea Hospital, Rome, Italy in the period from November 2003 to November 2005. We observed that: the mean Cobb angle improved significantly (p < 0.001) from 3.4° (kyphosis) to postoperative 14.5°. This normalization of angle showed a direct effect on improvement of myelopathic patients, but it had a statistically nonsignificant effect on adjacent segments degeneration (ASD). The mean segmental ROM of adjacent segments did not show significant instability. The mean was 11.1° at upper and 10.2° at lower levels (close to normal). In six cases, the ROM was higher than normal: five of these patients demonstrated symptomatic adjacent segment pathology. Postoperative improvement of mean JOA and NDI scores was statistically significant (p < 0.001). Anyway, symptomatic ASD was observed in five patients (20%): in four of them, the higher disc spaces and in one, the lower disc spaces were involved. In four cases, the preoperative MRI showed slight and asymptomatic disc degeneration at the same levels involved subsequently. This ASD was significantly related to the increased ROM at the segments involved. Follow-up X-rays showed solid fusion with absence of movement in all but one case (at 13-month follow-up), who showed slight movement in the operated level in spite of clinical improvement. The follow-up MRI showed, in all cases, good decompression in the treated levels. Compensatory increase in ROM of the contiguous motion segments in patients subjected to ACDF may lead to ASD especially in those cases with asymptomatic adjacent subclinical degenerative disease. If these preliminary results will be confirmed by larger series, it could be reasonable in young selected patients with soft disc herniation to adopt total disc arthroplasty instead of fusion after cervical micro-discectomy.

Curve Progression in Idiopathic Scoliosis : Follow-up Study to Skeletal Maturity

Abstract: Study design This is a follow-up study to skeletal maturity on a cohort of students screened for a 1-year prospective epidemiological prevalence study for scoliosis. Objectives This study aims to identify the prognostic factors for curve progression to a magnitude of 30 degrees at skeletal maturity in skeletally immature patients with adolescent idiopathic scoliosis. Summary of background data The natural history of idiopathic scoliosis is not well understood. Previous reports have focused on the characteristics of curve progression where progression has been predefined at specific angles of 5 degrees to 6 degrees. However, the absolute curve magnitude at skeletal maturity is more predictive of long-term curve behavior rather than curve progression of a defined magnitude over shorter periods of skeletal growth. It is generally agreed that curves less than 30 degrees are highly unlikely to progress after skeletal maturity. Hence, defining the factors that influence curve progression to an absolute magnitude of more than 30 degrees at skeletal maturity would more significantly aid clinical practice. Methods One hundred eighty-six patients who fulfilled the study criteria were selected from an initial 279 patients with idiopathic scoliosis detected by school screening, and who were followed-up till skeletal maturity. The initial age, gender, pubertal status, and initial curve magnitude were used as risk factors to predict the probability of curve progression to more than 30 degrees at skeletal maturity. Results Curve magnitude at first presentation was the most important predictive factor for curve progression to a magnitude of more than 30 degrees at skeletal maturity. An initial Cobb angle of 25 degrees had the best receiver-operating characteristic of 0.80 with a positive predictive value of 68.4% and a negative predictive value of 91.9% for curve progression to 30 degrees or more at skeletal maturity. Conclusion Initial Cobb angle magnitude is the most important predictor of long-term curve progression and behavior past skeletal maturity. We suggest an initial Cobb angle of 25 degrees as an important threshold magnitude for long-term curve progression. Initial age, gender, and pubertal status were less important prognostic factors in our study.

Computed tomography evaluation of rotation correction in adolescent idiopathic scoliosis: a comparison of an all pedicle screw construct versus a hook-rod system

Abstract: STUDY DESIGN: Retrospective review with historical cohort OBJECTIVE: Our study measures axial rotation of the apical vertebral bodies of patients with adolescent idiopathic scoliosis treated with an all pedicle screw (APS) construct versus a hook-rod (HR) construct using computed tomography (CT) SUMMARY OF BACKGROUND DATA: Ecker et al (Spine 1988;13:1141-4) observed a 22% derotation of the apical vertebrate of the thoracic spine and 33% of the apical vertebra of the lumbar spine when using an HR system (CD instrumentation) More recently Lee et al (Spine 2004;29:343-9) reported 425% derotation of the apical vertebra (both thoracic and lumbar) in a series of APS constructs Currently, there is no comparison series reported between the 2 types of constructs METHODS: From a database of 193 patients with adolescent idiopathic scoliosis and posterior spinal fusions, 32 patients were identified as having all APS constructs with pre- and postoperative CT scans This cohort of patients was compared with a historical published cohort of patients treated with HR constructs by Ecker et al (Spine 1988;13:1141-4) Comparison of the groups showed no statistically significant differences for age and preoperative Cobb angle of the main curve (P > 005); however, there was a statistically significant difference (P < 005) in postoperative correction values The apical vertebral rotation for the major curve was measured from the pre- and postoperative axial CT using the methods described by Aaro and Dahlborn (Spine 1981;6:460-7) RESULT: The average preoperative rotation was similar between the 2 groups (thoracic: HR = 226, APS = 213, P = 06; lumbar: HR = 194, APS = 206, P = 07) The postoperative correction had a significant difference (thoracic: HR = 16, APS = 85, P = 0015; lumbar: HR = 134, APS = 70, P = 0032) The percent correction of the apical vertebrae showed a significant difference, with 22% correction in the HR group and 60% in APS group (P < 0001) CONCLUSION: Our study finds axial rotation correction using APSs and a direct vertebral body derotation technique was significantly greater than that obtained with the HR construct

Arthrodesis to L5 versus S1 in long instrumentation and fusion for degenerative lumbar scoliosis.

Abstract: There is a debate regarding the distal fusion level for degenerative lumbar scoliosis. Whether a healthy L5-S1 motion segment should be included or not in the fusion remains controversial. The purpose of this study was to determine the optimal indication for the fusion to the sacrum, and to compare the results of distal fusion to L5 versus the sacrum in the long instrumented fusion for degenerative lumbar scoliosis. A total of 45 patients who had undergone long instrumentation and fusion for degenerative lumbar scoliosis were evaluated with a minimum 2 year follow-up. Twenty-four patients (mean age 63.6) underwent fusion to L5 and 21 patients (mean age 65.6) underwent fusion to the sacrum. Supplemental interbody fusion was performed in 12 patients in the L5 group and eleven patients in the sacrum group. The number of levels fused was 6.08 segments (range 4–8) in the L5 group and 6.09 (range 4–9) in the sacrum group. Intraoperative blood loss (2,754 ml versus 2,938 ml) and operative time (220 min versus 229 min) were similar in both groups. The Cobb angle changed from 24.7° before surgery to 6.8° after surgery in the L5 group, and from 22.8° to 7.7° in the sacrum group without statistical difference. Correction of lumbar lordosis was statistically better in the sacrum group (P = 0.03). Less correction of lumbar lordosis in the L5 group seemed to be associated with subsequent advanced L5-S1 disc degeneration. The change of coronal and sagittal imbalance was not different in both groups. Subsequent advanced L5-S1 disc degeneration occurred in 58% of the patients in the L5 group. Symptomatic adjacent segment disease at L5-S1 developed in five patients. Interestingly, the development of adjacent segment disease was not related to the preoperative grade of disc degeneration, which proved minimal degeneration in the five patients. In the L5 group, there were nine patients of complications at L5-S1 segment, including adjacent segment disease at L5-S1 and loosening of L5 screws. Seven of the nine patients showed preoperative sagittal imbalance and/or lumbar hypolordosis, which might be risk factors of complications at L5-S1. For the patients with sagittal imbalance and lumbar hypolordosis, L5-S1 should be included in the fusion even if L5-S1 disc was minimal degeneration.

Cobb angle progression in adolescent scoliosis begins at the intervertebral disc.

Abstract: STUDY DESIGN Longitudinal radiographic study of patients with progressive idiopathic scoliosis. OBJECTIVE To determine the relative contributions of vertebral and disc wedging to the increase in Cobb angle during 3 phases of adolescent skeletal growth and maturation. SUMMARY OF BACKGROUND DATA Both disc wedging and vertebral body wedging are found in progressive scoliosis, but their relative contribution to curve progression over time is unknown. Which occurs first is important for understanding how scoliosis progresses and for developing methods to halt progression. Previous studies have not properly identified maturity, and provide conflicting results. METHODS Eighteen girls were followed through their adolescent growth spurt with serial spine and hand skeletal age radiographs. Each Cobb angle was divided into disc wedge angles and vertebral wedge angles. The corresponding hand radiographs provided a measure of maturity level, the Digital Skeletal Age (DSA). The disc versus bone contributions to the Cobb angle were then compared during 3 growth phases: before the growth spurt, during the growth spurt and after the growth spurt. Significance of relative changes was assessed with the Wilcoxon 2-sided mean rank test. RESULTS Before the growth spurt, there was no difference in relative contributions of the disc and the bone (3 degrees vs. 0 degrees, P = 0.38) to curve progression. During the growth spurt, the mean disc component progressed significantly more than that of the vertebrae (15 degrees vs. 0 degrees, P = 0.0002). This reversed following the growth spurt with the vertebral component progressing more than the disc (10 degrees vs. 0 degrees, P = 0.01). CONCLUSION Adolescent idiopathic scoliosis initially increases through disc wedging during the rapid growth spurt with progressive vertebral wedging occurring later.

Is spine deformity surgery in patients with spastic cerebral palsy truly beneficial?: a patient/parent evaluation.

Abstract: Study design Retrospective clinical outcome study. Objective To evaluate the clinical outcomes and satisfaction associated with the surgical treatment of neuromuscular spinal deformity secondary to cerebral palsy. Summary of background data Controversy still exists regarding whether spinal deformity surgery is truly a beneficial surgery for patients with cerebral palsy (CP) since there is limited functional benefit and higher perioperative complications rates in this patient population. Methods Neuromuscular patient evaluation questionnaires were answered retrospectively by 84 patients/families of spastic CP patients undergoing spinal fusion. The average follow-up was 6.2 years (range: 2-16). The questionnaires were designed to assess expectation, cosmesis, function, patient care, quality of life, pulmonary function, pain, health status, self-image, and satisfaction. Questionnaire results, complications, and radiographic data were divided into "satisfied group" and "less satisfied group" and we analyzed reasons of satisfaction and dissatisfaction. Results The overall satisfaction rate was 92%. Ninety-three percent reported improvement with sitting balance, 94% with cosmesis, and 71% in patient's quality of life. Functional improvements seemed limited, but 8% to 40% of the patients still perceived the surgical results as improvement. The postoperative complication rate was 27%. The mean preoperative Cobb angle of the major curve was 88 degrees (range: 53 degrees-141 degrees), which corrected to 39 degrees (range: 5 degrees-88 degrees) after surgery. The less satisfied group had a significantly higher late complication rate, less correction of the major curve, greater residual major curve, and hyperlordosis of the lumbar spine after surgery. Conclusion Despite the perioperative difficulties seen with CP patients, the majority of the patient/parents were satisfied with the results of the spinal deformity surgery. Functional improvements were limited but 8% to 40% of the patients still perceived the results as improved. The reason for less than optimal satisfaction appears to be due to less correction of the major curve, greater residual major Cobb angle, hyperlordosis of the lumbar spine after surgery, and late postoperative complications.

Automatic Cobb Measurement of Scoliosis Based on Fuzzy Hough Transform with Vertebral Shape Prior

Abstract: To reduce variability of Cobb angle measurement for scoliosis assessment, a computerized method was developed. This method automatically measured the Cobb angle on spinal posteroanterior radiographs after the brightness and the contrast of the image were adjusted, and the top and bottom of the vertebrae were selected. The automated process started with the edge detection of the vertebra by Canny edge detector. After that, the fuzzy Hough transform was used to find line structures in the vertebral edge images. The lines that fitted to the endplates of vertebrae were identified by selecting peaks in Hough space under the vertebral shape constraints. The Cobb angle was then calculated according to the directions of these lines. A total of 76 radiographs were respectively analyzed by an experienced surgeon using the manual measurement method and by two examiners using the proposed method twice. Intraclass correlation coefficients (ICC) showed high agreement between automatic and manual measurements (ICCs > 0.95). The mean absolute differences between automatic and manual measurements were less than 5 degrees . In the interobserver analyses, ICCs were higher than 0.95, and mean absolute differences were less than 5 degrees . In the intraobserver analyses, ICCs were 0.985 and 0.978, respectively, for each examiner, and mean absolute differences were less than 3 degrees . These results demonstrated the validity and reliability of the proposed method.

A three-dimensional retrospective analysis of the evolution of spinal instrumentation for the correction of adolescent idiopathic scoliosis

Abstract: This is a clinical radiographic study, spanning over three decades, analyzing the three-dimensional (3-D) changes in spine geometry after corrective surgery for adolescent idiopathic scoliosis (AIS) using four generations of instrumentation systems. The objective of this study was to retrospectively evaluate the evolution of spinal instrumentation over time by measuring the 3-D changes of spinal shape before and after surgical correction of subjects with AIS using Harrington/Harrington-Luque (H/HL) instrumentation, original and recent generations of Cotrel-Dubousset Instrumentation (CDI) with rod rotation maneuvers, as well as third generation systems using thoracic pedicle screws and direct vertebral derotation (DVD) manoeuver in order to determine if the claims for improved 3-D correction from generation to next generation could be substantiated. The 3-D shape of the thoracic and lumbar spine was recorded from a pair of standing radiographs using a novel 3-D reconstruction technique from uncalibrated radiographs in 128 adolescents with AIS undergoing surgery by a posterior approach. Changes in coronal Cobb angles, kyphosis, lordosis, as well as in a series of 3-D parameters computed from the spine reconstructions before and after surgery were used to compare the four groups. Results demonstrate statistically significant differences (P = 0.05) between generations with regards to the correction of the coronal Cobb angle, and different loss of physiological lordosis. More importantly, significant differences in the 3-D correction of the spine based on the orientation of the planes of maximal curvature were observed (20/−6% H/HL vs. 39/39% CDI vs. 42/18% DVD for the thoracic/lumbar regions, respectively), confirming that recent CDI and third generation instrumentations coupled with DVD can bring the deformity significantly closer to the sagittal plane. An increased correction in apical vertebra axial rotation was observed with the DVD manoeuver (74%), while fewer notable differences were found between DVD and recent CDI systems in terms of 3-D correction. This is the first quantitative study to clearly demonstrate that the rod derotation and DVD maneuvers can significantly improve 3-D correction of scoliotic deformities, thereby supporting the transition towards these more elaborate and costly instrumentation technologies in terms of 3-D assessment.

Methodology of evaluation of morphology of the spine and the trunk in idiopathic scoliosis and other spinal deformities - 6th SOSORT consensus paper

Abstract: Background Comprehensive evaluation of the morphology of the spine and of the whole body is essential in order to correctly manage patients suffering from progressive idiopathic scoliosis. Although methodology of clinical and radiological examination is well described in manuals of orthopaedics, there is deficit of data which clinical and radiological parameters are considered in everyday practise. Recently, an increasing tendency to extend scoliosis examination beyond the measure of the Cobb angle can be observed, reflecting a more patient-oriented approach. Such evaluation often involves surface parameters, aesthetics, function and quality of life.

Gait in adolescent idiopathic scoliosis: energy cost analysis.

Abstract: Walking is a very common activity for the human body. It is so common that the musculoskeletal and cardiovascular systems are optimized to have the minimum energetic cost at 4 km/h (spontaneous speed). A previous study showed that lumbar and thoracolumbar adolescent idiopathic scoliosis (AIS) patients exhibit a reduction of shoulder, pelvic, and hip frontal mobility during gait. A longer contraction duration of the spinal and pelvic muscles was also noted. The energetic cost (C) of walking is normally linked to the actual mechanical work muscles have to perform. This total mechanical work (W(tot)) can be divided in two parts: the work needed to move the shoulders and lower limbs relative to the center of mass of the body (COM(b)) is known as the internal work (W(int)), whereas additional work, known as external work (W(ext)), is needed to accelerate and lift up the COM(b) relative to the ground. Normally, the COM(b) goes up and down by 3 cm with every step. Pathological walking usually leads to an increase in W (tot) (often because of increased vertical displacement of the COM(b)), and consequently, it increases the energetic cost. The goal of this study is to investigate the effects of scoliosis and scoliosis severity on the mechanical work and energetic cost of walking. Fifty-four female subjects aged 12 to 17 were used in this study. Thirteen healthy girls were in the control group, 12 were in scoliosis group 1 (Cobb angle [Cb] or = 40 degrees). They were assessed by physical examination and gait analysis. The 41 scoliotic patients had an untreated progressive left thoracolumbar or lumbar AIS. During gait analysis, the subject was asked to walk on a treadmill at 4 km h(-1). Movements of the limbs were followed by six infrared cameras, which tracked markers fixed on the body. W(int) was calculated from the kinematics. The movements of the COM(b) were derived from the ground reaction forces, and W(ext) was calculated from the force signal. W(tot) was equal to W(int) + W(ext). Oxygen consumption VO2 was measured with a mask to calculate energetic cost (C) and muscular efficiency (W(tot)/C). Statistical comparisons between the groups were performed using an analysis of variance (ANOVA). The external work (W(ext)) and internal work (W(int)) were both reduced from 7 to 22% as a function of the severity of the scoliosis curve. Overall, the total muscular mechanical work (W(tot)) was reduced from 7% to 13% in the scoliosis patients. Within scoliosis groups, the W(ext) for the group 1 (Cb > or = 20 degrees) and 2 (20 or = 40 degrees). No significant differences were observed between scoliosis groups for the W(int). The W(tot) did not showed any significant difference between scoliosis groups except between group 1 and 3. The energy cost and VO2 were increased by around 30%. As a result Muscle efficiency was significantly decreased by 23% to 32%, but no significant differences related to the severity of the scoliosis were noted. This study shows that scoliosis patients have inefficient muscles during walking. Muscle efficiency was so severely decreased that it could be used as a diagnostic tool, since every scoliosis patient had an average muscle efficiency below 27%, whereas every control had an average muscle efficiency above 27%. The reduction of mechanical work found in scoliotic patients has never been observed in any pathological gait, but it is interpreted as a long term adaptation to economize energy and face poor muscle efficiency. With a relatively stiff gait, scoliosis patients also limit vertical movement of the COM(b) (smoothing the gait) and consequently, reduce W(ext) and W(int). Inefficiency of scoliosis muscles was obvious even in mild scoliosis (group 1, Cb < 20 degrees) and could be related to the prolonged muscle contraction time observed in a previous study (muscle co-contraction).

Thoracic pedicle subtraction osteotomy for fixed sagittal spinal deformity.

Abstract: STUDY DESIGN.: A retrospective clinical study. OBJECTIVE.: To find the corrective capacity of a thoracic pedicle subtraction osteotomy (PSO), determine if segmental correction is dependent on level, and to compute the impact of thoracic PSO on regional and global spinal balance. SUMMARY OF BACKGROUND DATA.: PSO is a technique popularized in the lumbar spine primarily for the correction of fixed sagittal imbalance. Despite several studies describing the clinical and radiographic outcome of lumbar PSO, there is no study in literature reporting its application in the thoracic spine. METHODS.: We retrospectively analyzed patients with fixed thoracic kyphosis who underwent thoracic PSOs for sagittal realignment. Segmental pedicle screw instrumentation and intraoperative neurophysiologic monitoring was used in all patients. Data acquisition was performed by reviewing medical charts and radiographs to determine sagittal correction (segmental/regional/global) and complications. Clinical outcome using the Scoliosis Research Society-22 (SRS-22) instrument was determined by interview. RESULTS.: A total of 25 thoracic PSOs were performed (mean: 1.7 PSOs/patient, range: 1-3) in 15 patients (9 M/6 F). The study population had an average age of 56 years (range, 36-81 years) and was followed up after surgery for a mean of 3.5 years (range, 24-75 months). The osteotomies were carried out in the proximal thoracic spine (T2-T4, n = 6), midthoracic spine (T5-T8, n = 12), and distal thoracic spine (T9-T12, n = 7). Mean correction at the PSO for all 25 levels was 16.3 degrees +/- 9.6 degrees . Stratified by region of the spine, thoracic PSO correction was as follows: T2-T4 = 10.7 degrees +/- 15.8 degrees , T5-T8 = 14.7 degrees +/- 4.6 degrees , and T9-T12 = 23.9 degrees +/- 4.1 degrees . Mean thoracic kyphosis (T2-T12 Cobb angle) was improved from 75.7 degrees +/- 30.9 degrees to 54.3 degrees +/- 21.4 degrees resulting in a significant regional sagittal correction of 21.4 degrees +/- 13.7 degrees (P < 0.005). Global sagittal balance was improved from 106.1 +/- 56.6 to 38.8 +/- 37.0 mm yielding a mean correction of 67.3 +/- 54.7 mm (P < 0.005). One patient, in whom there was segmental translation during osteotomy closure, had a decline in intraoperative somatosensory-evoked potentials. No patient sustained a temporary or permanent neurologic deficit after surgery. The mean SRS-22 Questionnaire score at final follow-up was 82.4 +/- 10.2. CONCLUSION.: Thoracic PSO can be performed safely. Segmental sagittal correction appears to vary based on the region of the thoracic spine the PSO is performed. The distal thoracic segments, which more closely resemble lumbar segments in morphology, rendered the greatest sagittal correction after PSO, approximately 24 degrees . There was no case of neurologic injury associated with thoracic PSO, and clinical outcomes according to the SRS-22 instrument were generally favorable.

A porcine model for progressive thoracic scoliosis.

Abstract: Study design An IACUC-approved study to create a scoliotic deformity representative of adolescent idiopathic scoliosis. Objective The goal of this study was to develop a reliable porcine scoliosis model and to evaluate the three-dimensional progression of the deformity. Summary of background data Optimal development of nonfusion techniques for treatment of adolescent idiopathic scoliosis requires a reliable large animal model that achieves a progressive three-dimensional (frontal, sagittal, axial) deformity. Limitations in previous work have led our team to the development of a porcine model. Methods This IACUC-approved study included 18 Yorkshire pigs, obtained at 11 weeks old. Scoliosis was induced through unilateral posterior ligament tethering of the spine via pedicle screw fixation, and ipsilateral ribcage tethering. Progressive deformity was documented with biweekly radiographs. Frontal, sagittal, and axial modifications were assessed using the Cobb method. Animals were observed until severe deformity (>50 degrees) developed, then killed. Results Animals were observed for a mean 11 weeks. The mean coronal Cobb angle was 25 degrees immediately postoperatively and 55 degrees at 11 weeks. The mean lordosis increased from 4 degrees postoperative to 24 degrees at final follow-up. Apical axial rotation (posterior elements into concavity) increased from 4% postoperative to 27% at 11 weeks. Rate of coronal curve progression was significantly correlated with the initial Cobb index. Conclusion This study establishes a porcine scoliosis model. With placement of a unilateral ligamentous spinal tether combined with concave ribcage ligament tethering a three-dimensional (frontal, sagittal, and axial) spinal deformity can be obtained. The speed of the progressive deformity leaves significant remaining skeletal growth to assess growth modulating therapies for correction. This work forms the basis for a number of investigative efforts at developing new fusionless therapies for patients suffering from adolescent scoliosis.

The Vertical Expandable Prosthetic Titanium Rib in the treatment of spinal deformity due to progressive early onset scoliosis.

Abstract: The Vertical Expandable Prosthetic Titanium Rib (VEPTR) is a technique developed for the treatment of progressive early onset scoliosis. This vertically placed device uses distraction to indirectly elongate the spine and chest, stabilizing the progression of the spinal deformity while preserving spinal growth. Thoracic spine and chest wall deformity are usually correlated; therefore, elongation of the chest wall will increase the space available for the lung and improve respiratory mechanics in patients with early onset scoliosis. We conducted a retrospective study of 17 patients with early onset scoliosis treated with the VEPTR technique. The medical records, imaging studies, and follow-up physical examinations were evaluated. The patient population consisted of 17 primary VEPTR implantations and 33 expansion surgeries with a mean follow-up of 25 months. Our results show that there was an improvement in the coronal plane deformity between the presurgical and postsurgical Cobb angles, preoperative Cobb angle of 59 degrees (range 38-77) to postoperative 35 degrees (range 10-70), resulting in an average decrease of 59% in the Cobb angle (P<0.001). The thoracic kyphosis was maintained at anatomically normal values. The surgical technique preserved the space available for the lung. The complication rate was 13%, which includes infection, device migration, and rib fracture. The analysis of the data shows that the natural history of the progressive spinal deformity was improved in all patients. This preliminary report reaffirms that the VEPTR implantation is a safe and efficient method for the treatment of early onset scoliosis.

Comparison of vertebral rotation corrected by different techniques and anchors in surgical treatment of adolescent thoracic idiopathic scoliosis.

Abstract: Study design Evaluation of radiographs and computed tomography in patients undergoing different surgical interventions for adolescent idiopathic scoliosis (AIS). Objective To compare the correction of vertebral rotation by different surgical techniques and/or anchors in the treatment of AIS. Summary of background data The technique and the technology used in the surgical treatment of AIS continue to evolve; there is little information about the comparison of the vertebral rotation correction of thoracic scoliosis by different surgical techniques and/or anchors. Methods A retrospective study was performed on 106 consecutive patients with AIS, who underwent selective thoracic fusion with different surgical techniques and/or anchors, including hooks, wires, and pedicle screws on the periapical concave side from a posterior approach and an anterior approach using screws. The selection criteria were as follows: younger than 20 years of age, thoracic scoliosis (Lenke type 1, 2, and 3), selected thoracic fusion, and a minimum 2-year follow-up period, whereas thoracic hyperkyphosis was excluded. The patients were classified into group A (anterior approach, n=27), group H (hooks, n=39), group S (screws, n=25), and group W (wires, n=15). The Cobb angle and apical vertebral rotation were evaluated by plain radiography and computed tomography, respectively, before and after surgery and after 2 years of follow-up. Results All 4 groups were matched for age, sex, preoperative major curve, and curve flexibility. In all groups, the coronal Cobb angle was significantly improved after surgery, without any significant differences between the 4 groups. The Rotation Angle midline values in group A, group H, and group S were significantly improved after 2 years of follow-up (P 0.5 and 0.5. Conclusions Compared with the use of hooks and the wires, vertebral rotation in AIS is effectively corrected by either the anterior approach or posterior pedicle screw fixation, especially in patients with more flexible scoliosis (a flexibility index >0.5).

Long-term results of thoracolumbar and lumbar burst fractures after short-segment pedicle instrumentation, with special reference to implant failure and correction loss.

Abstract: Objective: To assess the long-term results of short-segment pedicle instrumentation for thoracolumbar and lumbar burst fractures. Methods: From February 1987 to June 1995, 89 patients with thoracolumbar or lumbar burst fracture were treated with short-segment pedicle instrumentation, and 68 (76.4%) of them were followed up for an average of 8.0 years (range, 5–13 years). Radiographs were taken pre- and post- operatively, before implant removal and at final follow-up. Computerized tomography (CT) scans of the fractured vertebrae were done on 18 patients, with their consent, at final follow-up. Results: At final follow-up, neurological status had improved at least one grade in the Frankel Grading system in 90.8% patients who had presented incomplete paralysis preoperatively, and low back pain was evaluated as Denis' P1 in 60.3%, P2 in 35.3% and P3 in 4.4% of patients. An average of 2.5 mm (range, 0–6.5 mm) of implant deformation was recorded before implant removal, and implant failure was noted in 11 (16.2%) patients. At final follow-up, loss of correction of the anterior vertebral body height and Cobb angle averaged 1.9% and 12.1°, leaving residual correction rates of 30.5% and 5.8°, respectively. The loss of correction occurred mainly at adjacent disc spaces, and collapse of the vertebral body was more severe at its center. CT scan revealed an obvious gap, which communicated with the adjacent disc space, in the vertebral body of 16 of the 18 patients scanned. Local kyphosis of more than 20° existed in five patients and three of them had low back pain. Conclusion: Short-segment pedicle instrumentation provides satisfactory reduction for thoracolumbar and lumbar burst fractures. The relatively high incidence of implant failure and the loss of correction may be caused by various factors, and more adequate fusion is recommended.

The effect of a modified Boston brace with anti-rotatory blades on the progression of curves in idiopathic scoliosis: aetiologic implications.

Abstract: The effect of a modified Boston brace with anti-rotatory blades on idiopathic scoliotic curves, mainly right thoracic with a compensatory left lumbar, was studied. Method and Material: Twenty-eight scoliotic children divided into three sub-groups according to the curve type were included in the study. Cobb angle and rotation was measured on posteroanterior spinal radiographs taken during the first examination and also during the follow-up with the children in and out of the brace. Results: Ten curves improved, 13 remained stable and 5 increased (Cobb angle change >5° compared with the initial measurement). The brace treatment had more affect on 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. Discussion: These findings indicate that in curves with a compensatory component (e.g. main thoracic with compensatory lumbar curve), a deforming rotatory force, which is blocked by ...

Shoulder balance after surgery in patients with Lenke Type 2 scoliosis corrected with the segmental pedicle screw technique.

Abstract: Object The authors evaluated the effectiveness of Lenke Type 2 criteria in scoliosis correction with the segmental pedicle screw (PS) technique, with emphasis on shoulder balance. Methods Twenty-five consecutive patients with Lenke Type 2 scoliosis (structural double thoracic curves, sidebending Cobb angle > 25°, or T2–5 kyphosis > 20°) who underwent segmental PS instrumentation were included in this study. At surgery, the patients were an average of 14.1 years of age, and the average duration of follow-up was 2.9 years. For radiological evaluation of the patients, preoperative, postoperative, and the latest available follow-up radiographs were used. The difference between right and left shoulder heights was determined to assess shoulder balance. All patients were treated with fusion of both the proximal and distal curves. Results The mean preoperative proximal thoracic curve of 43° was corrected to 21° postoperatively, a 51.2% correction. The preoperative lower thoracic curve of 61° was corrected to 23°,...

Accuracy and repeatability of a new method for measuring scoliosis curvature.

Abstract: STUDY DESIGN A prospective diagnostic clinical trial. OBJECTIVE To evaluate the accuracy, repeatability of a new method for measuring spinal curvature in patients with scoliosis, the axis-line-distance technique (ALDT), in comparison with the Cobb method. SUMMARY OF BACKGROUND DATA Timely and accurate determination of the degree of lateral curvature of the spine is essential for deciding the appropriate treatment method for scoliosis. Although the Cobb method has been accepted as the clinical standard for 60 years, many investigators have reported a high degree of variance in the measurements of spinal curvature obtained using this method. Therefore, the development of an alternative method that incorporates the advances in imaging technology and assessment is needed. METHODS Sixty-five scoliosis patients were evaluated by 6 physician observers. The spinal curves were measured on 2 separate occasions using the Cobb method and the ALDT on a picture archiving and communication system workstation. The time interval between the 2 measurements was 3 weeks, and the data were analyzed by a paired-sample Student t test and Pearson correlation method using SPSS 12.0 software package. RESULTS Intraobserver variance of the 2 measurements, the minimum variance, the maximum variance, and the mean and standard deviation values were 0 degrees, 26 degrees, and 5.14 degrees +/- 0.69 degrees for the Cobb method, and 0 mm, 20 mm, and 2.55 +/- 0.38 mm for the ALDT, respectively. There was a significant intraobserver difference in the Cobb angle measurements among 3 of the 6 observers (P < 0.05). No significant intraobserver variance in ALDT measurements was detected. The mean interobserver measurement variance for the Cobb method was 6.54 degrees +/- 1.35 degrees, significantly greater than that for the ALDT (3.58 +/- 0.93 mm; P < 0.05). There were significant positive correlation between the ALDT and the Cobb measurements (r = 0.73, P < 0.05). CONCLUSION The ALDT is more reliable, reproducible, and straightforward, and less error-prone than the Cobb method for measurements of spinal curvature.

The surgical treatment of congenital kyphosis.

Abstract: Study design Retrospective study with clinical and radiologic evaluation of 15 patients with congenital kyphosis or kyphoscoliosis who underwent anterior instrumented spinal fusion for posterolateral or posterior hemivertebra (HV). The management of congenital kyphosis has been described in the literature using a variety of techniques. The presentation of patients at diagnosis is discussed. The question of when to begin treatment is reviewed. The pitfalls in the management and how to avoid these are discussed. The different published techniques are reviewed. We present our own techniques and our results of treatment of congenital kyphosis in very young children. Objective To evaluate the safety and efficacy of early surgical anterior instrumented fusion with partial preservation of the HV in the treatment of progressive congenital kyphosis in children below the age of 3. We discuss the management of patients presenting with neurologic compromise. We aim to systematically review the literature and to present our own experience in the management of these deformities, so that the issues common to treating physicians may be explored. Summary of background data A variety of treatments have been described in the literature for the treatment of congenital kyphosis due to HV. We report the results of our technique. Methods Between 1997 and 2005 we have treated 15 consecutive patients with progressive congenital kyphosis with anterior instrumented fusion and strut grafting. Thirteen patients had a single posterolateral HV and 2 patients had a single posterior HV. Of the 15 patients in the study, 5 were girls and 10 boys. Mean age at surgery was 22 months (range, 8-33). Mean follow-up period was 6.8 years. Thirteen HV were located in the thoracolumbar junction (T10-L2) and 2 in the thoracic spine. Results The average operating time of procedure was 150 minutes (range, 130-210 minutes). The average blood loss was 180 mL (range, 100-330 mL), equivalent to a mean external blood volume loss of 15% (range, 11%-24%).Preoperative segmental Cobb angle averaging 34 degrees at last follow-up. Compensatory coronal cranial and caudal curves were corrected by 50%. The angle of segmental kyphosis averaged 39 degrees (range, 20 degrees-80 degrees) before surgery and 21 degrees (range, 11 degrees-40 degrees) at last follow-up. This represents a 43% of improvement of the segmental kyphosis, and a 64% of improvement of the segmental scoliosis at last follow-up. One case with initial kyphosis of 80 degrees continued to progress and required revision anterior and posterior surgery. There were no neurologic complications.

Quality of life in patients treated surgically for scoliosis: longer than sixteen-year follow-up.

Abstract: Study design A retrospective study. Objective To evaluate the long-term quality of life (QOL) of patients treated surgically for scoliosis. Summary of background data Measures of long-term outcome after surgery for scoliosis have focused mainly on radiologic changes. However, QOL issues such as working status and marital status are the subjects of greatest concern for patients who will undergo surgical treatment for scoliosis. Methods Thirty-two patients treated surgically for scoliosis between 1976 and 1989 were included in this study. The mean duration of follow-up was 21.1 years. Eighteen patients had adolescent idiopathic scoliosis, 8 congenital scoliosis, and 6 symptomatic scoliosis. We evaluated long-term outcome by direct interview with patients. Working status, marital status, and childbearing were determined in addition to clinical and radiologic evaluation. Patients were also asked to fill out the short form (SF)-36 and Scoliosis Research Society (SRS)-22 questionnaires. Results Twenty-seven patients (84.4%) were or had been engaged in various occupations without marked difficulty. Although none of the male patients was married, 62.5% of the female patients were married. Half of the female patients had delivered babies after surgery, and the mean number of such children was 1.83. On the SF-36, none of the scores for subjects with idiopathic or congenital scoliosis were markedly different from those for age-matched healthy controls. Multivariate logistic regression analysis revealed that marked preoperative Cobb angle and positive sagittal balance at the most recent follow-up were significantly associated with increased odds ratio for poor scores on the SRS-22. Conclusion We evaluated long-term QOL in patients treated surgically for scoliosis, and found that it was not impaired, particularly in the case of patients with idiopathic or congenital scoliosis. Larger preoperative Cobb angle and positive sagittal balance at the most recent follow-up were related to poor outcome in QOL as assessed by the SRS-22.

Bilateral use of the vertical expandable prosthetic titanium rib attached to the pelvis: a novel treatment for scoliosis in the growing spine.

Abstract: Object Few options exist for the treatment of severe, early onset scoliosis. Goals of treatment include stabilizing curve progression while allowing for normal spine, chest, and lung growth. The vertical expandable prosthetic titanium rib (VEPTR) is a novel device designed to control the spine deformity while permitting lung and spine growth. In this paper the authors report their experience with using bilateral VEPTRs from the ribs to the pelvis for children with severe, early onset scoliosis. Methods Eleven children were identified who had been treated with bilateral VEPTRs from the ribs to the pelvis. The authors conducted a retrospective review and collected the following data: clinical diagnosis, age at surgery, number of lengthening procedures, and complications. In addition, pre- and postoperative radiographs were reviewed to measure maximum Cobb angle (both thoracic and lumbar), thoracic height, total spine height as measured from T-1 to S-1, thoracic kyphosis (T2–12), and lumbar lordosis (L1–S1)....

Conservative management of idiopathic scoliosis--guidelines based on SOSORT 2006 Consensus.

Abstract: Background Idiopathic scoliosis, defined as a lateral curvature of the spine of above 10 degrees (Cobb angle), is seen in 2-3% of the growing age population, while curves above 20 degrees , requiring conservative treatment, are found in 0.3-0.5%. In our observation, both under-treatment of progressive curves and over-treatment of stable cases are common during conservative management of scoliosis. Material and methods A model of therapeutic management is presented based on the experience of Polish clinicians specialising in the treatment of scoliosis as well as the effects of work of a panel of experts of SOSORT (Society on Scoliosis Orthopaedic and Rehabilitation Treatment). The model comprises the indications for conservative treatment according to age, curve type and size and Risser grading. The aetiology, classifications, usefulness of the Lonstein and Carlson factor of progression and other methods of determining the probability of scoliosis progression, as well as the psychological aspects of conservative management are presented. Results Based on the knowledge of the natural history of idiopathic scoliosis, factors of progression and on the SOSORT experts' opinion, guidelines are proposed for clinicians treating children and adolescents with idiopathic scoliosis, including the timing and course of brace treatment and the types of exercises. Conclusions Uniform practical guidelines developed by experts may represent an essential step towards establishing standards of conservative scoliosis care in our country.

Pediatric tethered cord syndrome: response of scoliosis to untethering procedures. Clinical article.

Abstract: Object Tethered cord syndrome (TCS) is frequently associated with scoliosis in the pediatric population. Following spinal cord untethering, many patients continue to experience progression of spinal deformity. However, the incidence rate, time course, and risk factors for scoliosis progression following tethered cord release remain unclear. The aim of this study was to determine factors associated with scoliosis progression and whether tethered cord release alone would halt curve progression in pediatric TCS. Methods The authors retrospectively reviewed 27 consecutive pediatric cases of spinal cord untethering associated with scoliosis. The incidence rate and factors associated with scoliosis progression (> 10° increased Cobb angle) after untethering were evaluated using the Kaplan-Meier method. Results The mean age of the patients was 8.9 years. All patients underwent cord untethering for lower-extremity weakness, back and leg pain, or bowel and bladder changes. Mean ± SD of the Cobb angle at presentatio...