End Vertebra Research Articles

Retrospective analysis of anterior correction and fusion for adolescent idiopathic thoracolumbar/lumbar scoliosis: the relationship between preserving mobile segments and trunk balance

The objective of this paper was to investigate the surgical strategy of the selection of the lowest instrumented vertebrae (LIV) in anterior correction for adolescent idiopathic scoliosis (AIS) and to discuss the relationship between the LIV and trunk balance. From 1998 to 2004, 28 patients with thoracolumbar/lumbar AIS (Lenke 5 type) were treated by anterior correction and fusion with a mean follow-up of 1.5 years. Specific radiographic parameters were observed respectively and the correlation between disc wedging immediately below the LIV and these parameters was analysed. The mean corrective rate of major curves was 74.84%. The preoperative disc angle distal to LIV was 2.96 +/- 1.43 degrees and postoperatively it was -3.60 +/- 1.75 degrees . The postoperative disc wedging was most correlated with LIV obliquity. The postoperative LIV-CSVL (centre sacral vertical line) distance, which reflects regional balance, was correlated with various preoperative parameters. LIV determination was correlated with multiple preoperative radiographic parameters. Disc wedging distal to LIV occurs most often when a short fusion excluding the lower end vertebra (LEV) and the subjacent disc are nearly parallel.

Change of Deformity due to Position and Anesthesia in Adolescent Idiopathic Scoliosis

Purpose: To determine changes in the end vertebra and neutral vertebra as well as in the magnitudes of coronal and rotational deformities according to position and anesthesia in patients with adolescent idiopathic scoliosis. Materials and Methods: Sixty-two structural curves in 31 patients were evaluated using standing, supine, side bending, post-anesthesia, and postoperative anteroposterior plain radiographs. Cobb angles and rotation angles by perdriolle torsionmeter were measured, and the end vertebra and neutral vertebra were identified in each radiograph. Results: Coronal cobb angles decreased significantly with correction rates of 25.0%, 31.7%, 59.5%, and 74.0%, and rotational deformities decreased with correction ratesof 6.1%, 24.5%, 6.2%, and 25.7% by supine position, anesthesia, side bending and surgery, respectively.The end vertebrae changed in 18 patients (58.1%) in both supine and post-anesthesia radiographs, and the neutral vertebrae changed in 10 patients (32.3%) in supine radiographs and in 20 patients (64.5%) in post-anesthesia radiographs. Conclusion: Coronal deformities are significantly corrected by supine position and anesthesia. Anesthesia significantly corrects axial rotation, but more correction cannot be achieved by rod derotation. The end vertebra and neutral vertebra have a tendency to vary by position and anesthesia, which gives rise to confusion in the determination of fusion level.

Cobb Angle Measurement of Scoliosis Using Computer Measurement of Digitally Acquired Radiographs-Intraobserver and Interobserver Variability

Study DesignWe evaluated computer assisted digital measurement of radiographic parameters in patients with idiopathic scoliosis.PurposeTo assess the reliability of digital measurements.Overview of LiteratureVarious authors analyzed scoliotic deformities by conventional radiographs, but very few studies have addressed the reliability of digital radiographic measurement using computer software.MethodsThree independent, blinded observers measured 318 whole spine pre-operative antero-posterior radiograms of children with varying degrees of idiopathic scoliosis. Only one curve per radiograph was measured. Each observer measured the Cobb angle three times with a 1-week gap between each measurement. The computer system, picture archiving and communication system (PACS, PiViewSTAR version 5) was used in all cases. The end vertebrae were pre-selected to avoid this as a potential source of error. The results were statistically analyzed for intraobserver and interobserver reliability and variability.ResultsThe 95% confidence intervals for intraobserver and interobserver variability were ±1.30 and ±1.260, respectively. There was better reliability in larger curves.ConclusionsMeasurement using a digitized system may help to minimize measurement discrepancies by eliminating an intrinsic cause of error.

Changes in Vertebral Axial Rotation after Thoracoscopic Scoliosis Correction

Purpose: In this study, we investigated whether thoracoscopic anterior correction can effectively derotates the scoliotic spine and we also evaluated the patterns of derotational changes inside the instrumented area and at the junction between the instrumented and uninstrumented area. Materials and Methods: Preoperative and postoperative MR images with single axial cuts through each vertebral level were obtained in 20 patients who underwent thoracoscopic anterior instrumentation. Each vertebral rotation was measured by the use of Aaro's method. Vertebral axial derotation of the apical zone (AZ), upper instrumented zone (UIZ), lower instrumented zone (LIZ) and junctional segment were compared. The amount of segmental rotation and segmental derotation in each zone was calculated. Statistical analysis was performed by the use of by 2-way ANOVA and the Wilcoxon signed ranks test. Results: The average axial rotations at AZ were 10.1 o preoperatively and 5.3 o postoperatively with an average correction rate of 48%. Derotation of the AZ was greater than the UIZ and LIZ. For the LIZ derotation was not significant (p=0.023) while for the UIZ there was a significant derotation (p<0.001). Postoperatively, the first uninstrumented vertebra rotated significantly in the direction of rotation of the instrumented end vertebra. Preoperative and postoperative segmental rotation was higher in the UIZ and LIZ than in the AZ. However, segmental derotation occurred uniformly in the instrumented area. At the junctional segment, preoperative segmental rotation was same as that of the UIZ and LIZ and segmental derotation was not significant. Conclusion: Thoracoscopic scoliosis correction can achieve effective axial correction by causing dero- tation of each of the vertebral bodies and segmental derotation.

Histomorphological study of the spinal growth plates from the convex side and the concave side in adolescent idiopathic scoliosis

Asymmetrical growth of the vertebrae has been implicated as one possible etiologic factor in the pathogenesis of adolescent idiopathic scoliosis. The longitudinal vertebral growth derives from the endochondral ossification of the vertebral growth plate. In the present study, the growth plates from the convex and concave side of the vertebrae were characterized by the method of histology and immunohistochemistry to evaluate the growth activity, cell proliferation, and apoptosis. Normal zoned architectures were observed in the convex side of the growth plate and disorganized architectures in the concave side. The histological grades were significantly different between the convex and the concave side of the growth plate in the apex vertebrae (P < 0.05). The histological difference was also found significant statistically between end vertebrae and apex vertebrae in the concave side of vertebral growth plates (P < 0.05). The proliferative potential indexes and apoptosis indexes of chondrocytes in the proliferative and hypertrophic zone in the convex side were significantly higher than that in the concave side in the apex vertebral growth plate (P < 0.05). There was a significant difference of the proliferative potential index (proliferating cell nuclear antigen, PCNA index) between convex side and concave side at the upper end vertebra (P < 0.05). The difference of the proliferative potential index and apoptosis index were found significant statistically in the concave side of the vertebral growth plate between end vertebrae and apex vertebrae (P < 0.05). The same result was also found for the apoptosis index (terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphate biotin nick end labeling assay, TUNEL index) in the convex side of vertebral growth plate between end vertebrae and apex vertebrae (P < 0.05). Some correlation were found between radiographic measurements and proliferation and apoptosis indexes. The difference in histological grades and cellular activity between the convex and concave side indicated that the bilateral growth plate of the vertebrae in AIS patients have different growth kinetics which may affect the curve progression.

Comparative analysis of pedicle screw versus hybrid instrumentation in posterior spinal correction of adolescent idiopathic scoliosis

To compare the effect of posterior correction and fusion between segmental pedicle screw instrumentation with hybrid constructs in adolescent idiopathic scoliosis (AIS). Study the clinical data of 40 AIS patients retrospectively. They were underwent posterior fusion and be distributed into two group, group A was hybrid instrumentation (20 cases) and group B was pedicle screw instrumentation (20 cases). Compared therapy effect, operative time, intraoperative blood loss. The average major curve correction was 82.4% in the screw group and 71.8% in the hybrid group (P = 0.004). After one to three years follow-up, major curve correction was 77.0% and 62.5% respectively (P = 0.001). Average apical vertebral derotation showed 63% correction in the screw group and 32% in the hybrid group (P = 0.001). There was no statistical significance between two group in thoracic sagittal correction, the lowest instrumented vertebra below the lower end vertebra, trunk shift, operative time, and average estimated blood loss. There were no neurologic complications related to hybrid or pedicle screw instrumentation. Pedicle screw instrumentation was significantly better than hybrid constructs.

Inter- and intraobserver reliability assessment of the Cobb angle: manual versus digital measurement tools

The objective of this study is to determine the intraobserver and interobserver reliability of end vertebra definition and Cobb angle measurement using printed and digital radiographs of 48 patients with scoliosis. The Cobb angle and the end vertebra were assessed by six observers in 48 patients with scoliosis using printed and digital radiographs. Definition of end vertebra and measurement of the Cobb angle was repeated three times with a 3 week interval. Intraclass correlation coefficients (ICC) were used to determine the interobserver and intraobserver reliabilities. 95% prediction limits for the errors in measurements are provided. For the Cobb angle a mean ICC of 0.97 was determined for intra- and interobserver reliability measurement of the printed radiographs. For the electronic radiographs a mean ICC value of 0.93 was determined for interobserver reliability and a mean ICC value of 0.96 for intraobserver reliability. Intraobserver ICC for definition of end vertebrae was 0.8 for both methods. Interobserver ICC was 0.83 for the manual and 0.74 in the digital method. One pitfall in angle measurement implies the Cobb method itself which measures in two dimensions. Until we develop a proper tri-dimensional measuring system an error is introduced. For the Cobb angle measurement the definition of end vertebrae introduces the main source of error. Digital radiography does not improve the measurement accuracy.

Posterior spinal shortening for paraparesis following vertebral collapse due to osteoporosis

Retrospective case series. To assess the efficacy of posterior spinal shortening for paraparetic patients following vertebral collapse owing to osteoporosis, especially on instrumentation loosening. Department of orthopaedic surgery, Jichi Medical University Hospital and Omiya Medical Center in Japan. The clinical records and radiographs of 13 patients with paraparesis following vertebral collapse owing to osteoporosis treated with posterior spinal shortening were retrospectively reviewed to evaluate the usefulness of this method. Assessment of the clinical course was done by direct examination in all cases. Ambulatory ability was divided into four categories. Upon final observation, nine cases were able to walk with a cane or crutch, one case remained in gait training, two cases remained unable to stand and one case with urinary incontinence improved in urinary function. In one case, paralysis deteriorated. Vertebral compression fracture of the end vertebrae that were fixed occurred in three cases complicated with rheumatoid arthritis. The posterior spinal shortening can be a choice for treating delayed paraparesis following vertebral collapse owing to osteoporosis.

Selective posterior fusion of single thoracic curve adolescent idiopathic scoliosis: experience in 72 cases

To prospectively evaluate the strategy of surgery and choice of the fusion segments in thoracic adolescent idiopathic scoliosis (AIS) treatment. Selective posterior fusion was used on 72 AIS patients, 13 male and 59 female, aged 14.3 (12 - 18), 50 being of Lenke-type IA, 8 Lenke-type IB, and 14 Lenke-type IC. In principle the upper neutral vertebrae were selected as upper instrumented vertebrae. The lower neutral vertebrae, the vertebrae 1 level proximal to the neutral vertebrae, or stable vertebrae were chosen as the lower instrumented vertebrae based on the analysis of the correlation among the lower end vertebrae, neutral vertebrae and stable vertebrae's locations. Standing anteroposterior and lateral and side-bending radiographs were taken preoperatively, postoperatively and during the follow-up. The coronal and sagittal Cobb angle, translation and rotation of apical vertebrae, and trunk translation were evaluated to observe the curve correction and trunk balance. The patients underwent spinal fusion of 7.3 segments (4 - 10 segments) on average. Follow-up was conducted for 15.9 months (12 - 39 months). The thoracic curves' coronal Cobb angle before the operation was 56.7 degrees +/- 14.5 degrees (40 degrees - 98 degrees), and was 18.5 degrees +/- 8.3 degrees (3 degrees - 40 degrees) after the operation. The lumbar curves' coronal Cobb angle before operation was 33.9 degrees +/- 10.4 degrees (25 degrees - 69 degrees), and was 11.1 degrees +/- 6.4 degrees (0 degrees - 30 degrees ) after operation. The spontaneous correction rate was 66.9% +/- 16% (44% - 100%). The trunk translation before operation was 16.1 +/- 10.2 mm (4 - 43 mm), and was 8.2 +/- 6.1 mm (0 - 25 mm) after operation. Two patients were found with slight trunk decompensation postoperatively, but with no progression during a 2-year follow-up. Determination of the fusion levels based on the analysis of the correlation among the end vertebrae, neutral vertebrae and stale vertebrae's location helps obtain the satisfying curative effect in the management of single thoracic curve AIS.

Reliability of Radiographic Parameters in Neuromuscular Scoliosis

Retrospective review of radiographic data. This study sought to define interobserver and intraobserver variability to further delineate reliable means by which radiographs of patients with neuromuscular scoliosis can be examined. Previous studies analyzed the use of Cobb angles in the measurement of idiopathic and congenital scoliosis, but no study until now describes a critical analysis of measurement in evaluating neuromuscular scoliosis. Forty-eight patients with neuromuscular scoliosis radiographs were reviewed. These were evaluated for Cobb angle, end vertebrae selection, Ferguson angle, apex of the curve, C7 balance, pelvic obliquity, Risser sign, status of the triradiate cartilage, kyphosis Cobb angle, endplate selection for kyphosis, and kyphotic index. Interclass and intraclass variability was examined with statistical analysis. Cobb angle had an intraobserver variability was 5.7 degrees and the interobserver variability was 14.8 degrees . The intraobserver and interobserver variability for Ferguson angle was 6.8 degrees and 20.6 degrees, respectively. The kyphotic Cobb angle intraobserver variability was found to be 17.4 degrees, and the interobserver variability was 24.01 degrees . Neuromuscular scoliosis radiographs can be reliably analyzed with the use of Cobb angle. Other forms of analysis, such as Ferguson angle, are not as reliable. Pelvic obliquity should be measured from the horizontal, as other methods are not as reliable. Kyphosis is best evaluated with the use of the kyphotic Cobb angle. Finally, it is felt that a separate anteroposterior pelvis radiograph should be used to assess skeletal maturity, as scoliosis films often truncate the vital anatomy necessary to determine skeletal maturity.

Comparison of Short Fusion versus Long Fusion for Degenerative Lumbar Scoliosis

Purpose: To compare the results of short fusion versus long fusion for degenerative lumbar scoliosis. Materials and Methods: Forty-seven patients undergoing short fusion (n=28) and long fusion and instrumentation (n=19) were evaluated. Short fusion was defined as fusion within the deformity, not exceeding the upper end vertebra. Long fusion was defined as fusion extended above the upper end vertebra. The number of levels fused in the short and long fusion groups was 3.14 and 6.89 segments, respectively. Results: Before surgery, the Cobb angle was 16.3o in the short fusion group and 22o in the long fusion group, which changed to 10.1o and 8.47o, respectively, at the last visit. The correction of coronal imbalance was better in the long fusion group. In contrast, the correction of sagittal imbalance was similar in both groups. The mean estimated blood loss in the short and long fusion groups was 1,671 ml and 2,742 ml, respectively. Early perioperative complications developed frequently in the long fusion group. Adjacent segment disease occurred more frequently in the short fusion group. Conclusion: Long fusion and instrumentation for degenerative lumbar scoliosis was better at correcting the coronal deformity and imbalance than short fusion but was ineffective in correcting the sagittal imbalance.

Comparison of Cobb Angle Measurement of Scoliosis Radiographs With Preselected End Vertebrae

Prospective study. To compare variability in Cobb angle between digitally and traditionally acquired scoliosis radiographs. Previous studies have shown that the 95% confidence interval for Cobb angle can vary from 2.6 degrees to 8.8 degrees. No study directly comparing Cobb angles measured from traditional and digitally acquired radiographs has been reported. A spine model simulating 25 single right thoracic curves (range, 20 degrees-60 degrees) was imaged using traditional and digital techniques. Traditional films and miniaturized printed digital films were each measured twice manually. Digital films were also measured twice using computer imaging software. Overall mean angle and (95% confidence interval) were 41.7 degrees (39.1 degrees-44.3 degrees) for traditional, 40.6 degrees (37.4 degrees-43.8 degrees) for digital, and 39.7 degrees (36.3 degrees-43.1 degrees) for computer measurements. Overall correlation was 0.994 for traditional and digital, 0.987 for traditional and computer, and 0.993 for digital and computer. Fixed effect model analysis demonstrated that, although a statistically significant difference existed between the 3 methods of measuring the Cobb angle (P < 0.0001), the difference between methods was less than 2 degrees. Any of the 3 evaluated methods of measurement can be used to measure Cobb angles. Additionally, the methods can be used interchangeably.

Distribution and expression of collagen type II, transforming growth factor beta1 and basic fibroblast growth factor in articular process cartilages of scoliosis

To look into the character of the expression of collagen type II and transforming growth factor beta1 (TGF-beta1), basic fibroblast growth factor (bFGF) in the apical articular process cartilages of adolescent idiopathic scoliosis (AIS) and congenital scoliosis (CS) patients. The articular processes of 22 AIS and 18 CS were collected. The techniques of HE staining, immunohistochemistry and in situ hybridization were adopted in this research. By comparing the apical processes with the end processes, the convex processes with the concave processes, the AIS processes with CS processes, the pathological changes of the articular process cartilages of these patients and the distribution of collagen type II and TGF-beta1, bFGF in them were studied. The images of immunohistochemistry and in situ hybridization were input into the image analysis system and were analyzed semi-quantitatively. The SAS software (8.01) was adopted, and P < 0.05 was defined as the significant level. The expression of collagen type II and TGF-beta1, bFGF in AIS was similar to CS: the concave sides of apexes were higher than the convex sides. The comparisons had statistical significance. There was no statistical significance between upper and lower end vertebrae in convex and concave sides, between convex and concave sides in upper and lower end vertebrae. The apical vertebrae were significantly higher than the ipsilateral sides of upper or lower end vertebrae for collagen type II. There was no statistical difference of the expression at the concave, convex, upper, lower end vertebrae between AIS and CS. The cartilages of the apical processes show some signs of regression and hypoplasia in scoliosis. The concave side is more severe than the convex side. Increase of collagen type II and TGF-beta1, bFGF in the concave sides of apical processes in scoliosis may be the results of reconstruction of extracellular matrix and the compensation reactions which are caused by abnormal biomechanical forces such as compressive stresses. Compressive stress on the concave sides has more influences on the expression of collagen type II than tensile stress on the convex sides.

Comparison of the Lowest Instrumented, Stable, and Lower End Vertebrae in “Single Overhang” Thoracic Adolescent Idiopathic Scoliosis: Anterior Versus Posterior Spinal Fusion

A retrospective multicenter study. To investigate the relationship between the lowest instrumented, stable, and lower end vertebrae in patients with "single overhang" thoracic (main thoracic) curves treated with anterior or posterior spinal fusion. Previous studies have shown "saving" fusion levels with anterior spinal fusion, as opposed to posterior spinal fusion; however, to our knowledge, none of these studies evaluated the relative position to the lower end vertebra to compare study groups accurately. For clarification, "single overhang" includes Lenke 1A and 1B curves. For these thoracic curves, the lumbar curve does not cross the midline. A retrospective multicenter study of adolescent idiopathic scoliosis was performed to identify specifically patients with "single overhang" thoracic (Lenke 1A and 1B) curves with more than a 2-year follow-up. To analyze relative fusion levels, the differences were computed as follows: (1) the difference between the vertebra position for the stable vertebra of the main thoracic (MT) curve and the lowest instrumented vertebra, as noted on postoperative radiographs, or [equation: see text] (2) the difference between the vertebra position for the lower end vertebra of the main thoracic (MT) curve and the lowest instrumented vertebra, as noted on postoperative radiographs, or [equation: see text]. A total of 298 "single overhang" thoracic curves (148 Lenke 1A, 150 Lenke 1B) were identified, of which 293 had either an anterior spinal fusion or posterior spinal fusion; 5 patients underwent a combined anterior-posterior spinal fusion. Anterior spinal fusion was performed in 70 patients (23.9%) and posterior spinal fusion in 223 (76.1%). While comparing the lowest instrumented vertebra to the stable vertebra with anterior spinal fusion, the lowest instrumented vertebra was identified either at the level of the stable vertebra or above in 97% of 1A/B curves (P < 0.001). Using posterior spinal fusion techniques, the lowest instrumented vertebra was identified either at the stable vertebra or above in 65% of the 1A/B curves (P < 0.05). These data confirm that anterior spinal fusion techniques result in a mean shorter fusion of 1.5 vertebral segments/patient when compared to posterior spinal fusion techniques with respect to the position of the lowest instrumented and stable vertebrae for "single overhang" thoracic (Lenke 1A/B) curves. However, because this is a retrospective multicenter study over 10 years, it represents various posterior spinal fusion techniques that do not include all pedicle screw constructs.

Expression of transforming growth factor-beta1 and basic fibroblast growth factor in articular process cartilages of adolescent idiopathic scoliosis

To investigate the characteristics of the expression of transforming growth factor-beta(1) (TGF-beta(1)) and basic fibroblast growth factor (bFGF) in the apical articular process cartilages of adolescent idiopathic scoliosis (AIS) patients. The specimens of articular processes of 22 AIS patients and 18 congenital scoliosis (CS) patients were collected during operation. The pathology of the processes was observed with H.E staining. Immunohistochemistry and in situ hybridization were adopted to detect the expression of TGF-beta(1) and bFGF. The differences in the pathological changes, and expression of TGF-beta(1) and bFGF between the apical processes and the end processes, the convex processes and the concave processes, and the AIS processes and CS processes. The images of immunohistochemistry and in situ hybridization were input into the image analysis system and were analyzed semi-quantitatively. The SAS (8.01) software was adopted and (128.1 +/- 50.6 vs 165.4 +/- 59.2, 126.5 +/- 47.0 vs 168.3 +/- 46.8; 76.6 +/- 29.9 vs 96.4 +/- 28.4, 73.7 +/- 31.6 vs 101.8 +/- 39.4; 77.1 +/- 52.2 vs 114.4 +/- 59.4, and 69.5 +/- 40.1 vs 109.8 +/- 51.0 (P < 0.05) was defined as the significant levels. The expression of TGF-beta(1) and the expression of bFGF were not significantly different between the AIS patients and the CS patients. The TGF-beta(1) expression in the concave side of the apical vertebrae of the AIS group was 165.4 +/- 59.2, significantly higher than that in the convex sides (128.1 +/- 50.6, P = 0.03), and the TGF-beta(1) expression in the concave side of the apical vertebrae of the CS group was 168.3 +/- 46.8, significantly higher than that of the convex side (126.5 +/- 47.0, P = 0.02). However, there was no statistically significant differences in the TGF-beta(1) expression between the concave and convex sides of the upper and lower end vertebrae and between the upper and lower end vertebrae. The bFGF expression in the concave side of the apical vertebrae of the AIS group, and the bFGF expression in the concave side of the apical vertebrae of the CS group was 101.8 +/- 39.4, significantly higher than that of the convex side (73.7 +/- 31, P = 0.02). However, there were no statistically significant differences in the bFGF expression between the concave and convex sides of the upper and lower end vertebrae and between the upper and lower end vertebrae. The cartilages of the apical processes show some signs of regression and hypoplasia in AIS patients, especially at the concave side in comparison with the convex side. Increase of TGF-beta(1) and bFGF in the concave sides of apical processes in AIS may be the results of reconstruction of extracellular matrix and the compensation reactions which are caused by abnormal biomechanical forces, especially compressive stresses.

Comparative Analysis of Pedicle Screw Versus Hybrid Instrumentation in Posterior Spinal Fusion of Adolescent Idiopathic Scoliosis

A retrospective matched cohort study. To comprehensively compare the 2-year postoperative results of posterior correction and fusion with segmental pedicle screw instrumentation versus with hybrid (proximal hooks and distal pedicle screws) constructs in adolescent idiopathic scoliosis (AIS) treated at a single institution. Despite the reports of satisfactory correction and maintenance of scoliotic curves by pedicle screw instrumentation, there have been no reports on the comprehensive comparison of AIS treatment after segmental pedicle screw instrumentation versus hybrid instrumentation. A total of 58 AIS patients that underwent posterior fusion with hybrid instrumentation (29) or pedicle screw (29) instrumentation at a single institution were sorted and matched according to four criteria: similar patient age, fusion levels, identical Lenke curve type, and identical operative methods. Patients were compared at 2-year follow-up according to radiographic changes, operative time, intraoperative blood loss, pulmonary function tests, and SRS-24 outcome scores. The two cohorts were well matched. The preoperative major Cobb angle averaged 62 degrees in the screw group and 60 degrees in the hybrid group. Average major curve correction was 70% in the screw group and 56% in the hybrid group (P = 0.001). At 2-year follow-up, major curve correction was 65% and 46%, respectively (P < 0.001). At 2-year follow-up, thoracic sagittal Cobb angle changes between T5 and T12 were 9.0 degrees decrease in the screw group and 2.4 degrees decrease in the hybrid group compared with preoperative (P = 0.024). There were no differences in the lowest instrumented vertebra below the lower end vertebra (P = 0.56), operative time (P = 0.14), and average estimated blood loss (P = 0.54). Two years following surgery, the screw group demonstrated improved percent predicted pulmonary function values compared with that of the hybrid group (FVC; 81% --> 81% in screw group vs. 85% --> 79% in hybrid group P = 0.08, FEV1; 73% --> 79% in screw group vs. 79% --> 75% in hybrid group, P = 0.006). Postoperative total SRS-24 scores were similar in both groups (hybrid group: 99 vs. screw group: 95) (P = 0.19). There were no neurologic complications related to hybrid or pedicle screw instrumentation. Pedicle screw instrumentation offers a significantly better major curve correction and postoperative pulmonary function values without neurologic problems compared with hybrid constructs. Both instrumentation methods offer similar junctional change, lowest instrumented vertebra, operative time, and postoperative SRS-24 outcome scores in the operative treatment of AIS.

Geometric and Electromyographic Assessments in the Evaluation of Curve Progression in Idiopathic Scoliosis

The natural history of patients with idiopathic scoliosis was analyzed radiographically and electromyographically in a prospective longitudinal study. To identify changes in geometric variables and the sequence in which these changes occur during curve progression in the natural history of patients with idiopathic scoliosis. In addition, to study the relationship between several geometric variables and electromyographic (EMG) measurements to determine their predictive value as risk factors to curve progression of the scoliotic deformity. The main area of concern in treating children with adolescent idiopathic scoliosis is the unpredictability of curve progression during the early development of the deformity. The changes in radiographic geometric and EMG variables between the first presentation and consecutive 4-6-month follow-up periods were analyzed in 105 patients with idiopathic scoliosis. Statistical analyses were performed to elucidate in more detail how spinal geometry evolves during curve progression. Curve severity was associated with remaining growth potential expressed as an increasing spinal growth velocity (SGV). With increasing SGV, an enhanced EMG activity at the lower part on the convex side of the curve expressed as EMG ratio was found. High EMG ratio was associated with increased axial rotation and diminished kyphosis before the rapid increase in Cobb angle. Lateral deviation, wedge angle, and axial rotation all increased during periods of progression. Changes in tilt angle and lordosis were not associated with curve progression. In the natural history of idiopathic scoliosis, SGV and EMG ratio at the lower end vertebra are prominent risk factors of curve progression. The asymmetric muscle activity is associated with increased axial rotation, which in its turn is associated with increasing Cobb angle and diminishing kyphosis. The combination of these variables provides insight in the physiologic and 3-dimensional biomechanical evolution of the natural history of curve progression in idiopathic scoliosis.

Expression of calmodulin in the articular process of vertebrae of adolescent idiopathic scoliosis patients

To investigate the expression of calmodulin in the articular process of vertebrae of adolescent idiopathic scoliosis (AIS) patients and congenital scoliosis (CS) patients and its possible effects on the pathogenesis of AIS. Nine AIS patients aged 13 - 17, and 10 patients of CS, aged 11 - 18, underwent orthopedic surgery. Specimens of the inferior articular process from the apical vertebrae and upper end vertebrae discarded during operation were collected from the AIS patients and specimens of the. Inferior articular process from the upper end vertebrae wee collected from the CS patients. Immunohistochemistry was used to detect the protein expression of calmodulin, and in situ hybridization was adopted to examine the mRNA expression of calmodulin. Calmodulin were expressed in the bone cells. There was no difference between the expression of calmodulin at the concave side and convex side, or between the apical vertebrae and end vertebrae. The expression of calmodulin of the AIS group was significant lower than that of the CS group (P < 0.05). The result of immunohistochemistry and that of in situ hybridization corresponded with each other. The expression of calmodulin in the articular process of vertebrae of AIS patients is low, suggesting that it plays a role in the development and progression of AIS.

The expression of collagen type I, II and TGF-beta1 in the articular processes of scoliosis patients

To look into the characteristic of the expression of collagen type I, II and transforming growth factor-beta(1) (TGF-beta(1)) in the processes of scoliosis patients. The articular processes of 9 IS patients and 10 CS patients were collected. The techniques of HE staining and immunohistochemistry were adopted in this research. The images of immunohistochemistry were analyzed semi-quantitatively. For collagen type I: The expression at the concave side of the apical vertebrae of both IS and CS patients is significantly higher than that of the convex side, 193 +/- 64 vs 151 +/- 45 and 199 +/- 86 vs 179 +/- 78, P < 0.05, and the apical vertebrae higher than the end vertebrae. In the lower end vertebrae of the IS patients, the expression at the concave side is significantly higher than that of the convex side; and the convex side of the apical vertebrae of IS patients is lower than that of CS patients. For collagen type II: The expression at the concave side in the lower end vertebrae of CS patients is higher than that of convex side; and for both IS and CS patients, the apical vertebrae is higher than the end vertebrae. For TGF-beta(1): The expression at the concave side of the apical vertebrae of both IS and CS patients is significantly higher than that of the convex side, 145 +/- 43 vs 112 +/- 50 and 120 +/- 61 vs 89 +/- 32, P < 0.05. For IS patients, the lower end vertebrae at the concave side is higher than concave side; the apical vertebrae is higher than the end vertebrae. For CS patients, the concave side of the apical vertebrae is higher than the end vertebrae; while for the apical vertebrae, IS patients higher than CS patients. Articular processes cartilage of the apical vertebrae of scoliosis patients shows degenerative sign. The expression of collagen type I, II and TGF-beta(1) is significantly higher at the concave side and the apical vertebrae of both IS and CS patients. Abnormal press and stress power may play a very important role.

Expression of Transforming Growth Factor and Basic Fibroblast Growth Factor and Core Protein of Proteoglycan in Human Vertebral Cartilaginous Endplate of Adolescent Idiopathic Scoliosis

To compare the expression of cytokines and core protein of proteoglycan in the scoliotic concave and convex cartilaginous endplate using immunohistochemical staining. To define the possible role of transforming growth factor beta 1 (TGFbeta1), basic fibroblast growth factor (bFGF), and core protein of proteoglycan in the development of adolescent idiopathic scoliosis. Changes in the endplate composition have been implicated as possible etiologic factors in the pathogenesis of adolescent idiopathic scoliosis. Cytokines have exclusive effects on cartilage. Thus comparing the expression of the cytokines and matrix on the convex and concave sides of scoliotic endplate tissues may help to understand the role of endplate tissues in the induction and/or progression of idiopathic scoliosis. The convex and concave half of cartilage endplate was collected at the apex and end vertebrae from 12 patients. The expression of TGFbeta1, bFGF, and core protein on both sides was examined with the immunohistochemistry method, and results were analyzed with the image analysis system. TGFbeta1, bFGF, and core protein of proteoglycan were all expressed in the cytoplasm of chondrocytes in the cartilaginous endplate. The area density and quantity density of TGFbeta1 and bFGF on the concave side are expressed in an even significantly higher level than that on the convex side (P > or = 0.05). The expression of the core protein of proteoglycan on the convex side is higher than that on the concave side, the difference is not significant (P > 0.05). There was a significantly higher expression of TGFbeta1 and bFGF, although a lower expression of the core protein on the concave side, which suggests a possible etiological factor or a secondary change in the development of adolescent idiopathic scoliosis.