Showing papers on "Cobb angle published in 2001"
TL;DR: The LPR angle, the association between the thoracic curve vertebral tilt angles and the amount of in-brace correction of the Cobb angle, were significant predictors of outcome and a patient’s reported wear schedule significantly influenced outcome.
Abstract: STUDY DESIGN A retrospective review of 51 patients with adolescent idiopathic scoliosis (AIS) treated with a Boston brace for curves ranging from 36 degrees to 45 degrees. OBJECTIVES To determine what radiographic or clinical observations may be predictive of outcome. SUMMARY OF BACKGROUND DATA Patients with AIS who are braced for curves >35 degrees are less likely to respond to conservative treatment than patients of similar maturity with smaller curves. METHODS Skeletally immature patients with AIS with no history of prior treatment were treated with a Boston brace. Cobb angles, vertebral tilt angles, coronal decompensation, apical vertebral translation(s), apical vertebral rotation, lateral trunk shift, rib vertebral angle difference, pelvic tilt, and the lumbar pelvic relationship (LPR) were measured at brace prescription, initial in-brace, brace discontinuation, and follow-up. RESULTS At the time of brace discontinuation, 31 patients (61%) were judged treatment successes. With follow-up observation, an additional eight patients progressed beyond 5 degrees, and a total of 16 patients (31%) required surgical correction. Only patients with double curves were found to have radiographic values predictive of outcome. The LPR angle, the association between the thoracic curve vertebral tilt angles and the amount of in-brace correction of the Cobb angle, were significant predictors. A patient's reported wear schedule significantly influenced outcome. CONCLUSIONS Patients with a double curve pattern in which the thoracic curve is >35 degrees and the LPR angle is >12 degrees are significantly more likely to demonstrate curve progression. In-brace correction for double curves of at least 25% and a patient's ability to wear the orthosis >18 hours/day significantly increased the likelihood of success.
203 citations
TL;DR: It is unlikely that topography will supplant radiography for the ascertainment of Cobb angles, because the error margins of both are wide, and the two are not measuring the same aspect of the deformity.
Abstract: Study design Preliminary analysis of the clinical value of surface topography in a spinal deformity clinic. Objectives The Cobb angle is the gold standard for the monitoring of scoliosis. This study was designed to determine whether surface topography would reflect Cobb angle status with sufficient reliability to permit its safe use as an alternative means of documentation in some circumstances. Summary of background data Surface topography offers the possibility of describing spinal deformity more fully than radiographic measures alone. To be useful, it must ignore changes due to varying posture and reliably detect differences that are clinically significant, while broadening the ability to assess deformity. Methods Surface topography using Quantec () was obtained routinely in all patients attending a spinal deformity unit. Intrasubject variation was reduced by taking the mean for each parameter of four repositioned scans, which gives a smallest detectable change on all measures of approximately 10 U. Fifty-nine patients with two sets of radiographs and topography scans were studied to determine the ability of the different measurements to detect significant change. Results There was a significant correlation between Cobb angle and Quantec spinal angle. A significant change in Cobb angle could be identified by associated change in at least one topographic measure in a significant proportion of cases. Conclusions It is unlikely that topography will supplant radiography for the ascertainment of Cobb angles, because the error margins of both are wide, and the two are not measuring the same aspect of the deformity. The Quantec system is useful in patient monitoring as an alternative to radiography, without diminishing the standard of care.
188 citations
TL;DR: Although more than 20 years had passed since completion of the treatment, most of the curves did not increase and the surgical complication rate was low: Pseudarthrosis occurred in three patients, and flat back syndrome developed in four patients.
Abstract: STUDY DESIGN This study is a follow-up investigation for a consecutive series of patients with adolescent idiopathic scoliosis treated between 1968 and 1977. In this series, 156 patients underwent surgery with distraction and fusion using Harrington rods, and 127 were treated with brace. OBJECTIVES To determine the long-term outcome in terms of radiologic findings and curve progression at least 20 years after completion of the treatment. SUMMARY OF BACKGROUND DATA Radiologic appearance is important in comparing the outcome of different treatment options and in evaluating clinical results. Earlier studies have shown a slight increase of the Cobb angle in brace-treated patients with time, but not in fused patients. METHODS Of 283 patients, 252 attended a clinical and radiologic follow-up assessment by an unbiased observer (91% of the surgically treated and 87% of the brace-treated patients). This evaluation included chart reviews, validated questionnaires, clinical examination, and full-length standing frontal and lateral roentgenographs. Curve size was measured by the Cobb method on anteroposterior roentgenograms as well as by sagittal contour and balance on lateral films. The occurrence of any degenerative changes or other complications was noted. An age- and gender-matched control group of 100 individuals was randomly selected and subjected to the same examinations. RESULTS The mean follow-up times were 23 years for surgically treated group and 22 years for brace-treated group. The deterioration of the curves was 3.5 degrees for all the surgically treated curves and 7.9 degrees for all the brace-treated curves (P < 0.001). Five patients, all brace-treated, had a curve increase of 20 degrees or more. The overall complication rate after surgery was low: Pseudarthrosis occurred in three patients, and flat back syndrome developed in four patients. Eight of the patients treated with fusion (5.1%) had undergone some additional curve-related surgical procedure. The lumbar lordosis was less in the surgically treated than in the brace-treated patients or the control group (mean, 33 degrees vs 45 degrees and 44 degrees, respectively). Both surgically treated and brace-treated patients had more degenerative disc changes than the control participants (P < 0.001), but no significant differences were found between the scoliosis groups. No statistically significant difference in terms of radiographically detectable degenerative changes in the unfused lumbar discs was found between patients fused below L3 or those fused to L3 and above (P = 0.22). A study on intra- and interobserver measurements of kyphosis, lordosis, and sagittal vertical axis on two films for each patient demonstrated that the repeatability of measuring sagittal plumbline on two different lateral radiographs, with patients moving between radiograms, was unreliable for comparison. CONCLUSIONS Although more than 20 years had passed since completion of the treatment, most of the curves did not increase. The surgical complication rate was low. Degenerative disc changes were more common in both patient groups than in the control group.
169 citations
TL;DR: Patients treated by posterior fusion or a brace gradually increase their pulmonary function up to 25 years after treatment, and lung volumes did not correlate with pretreatment or post-treatment Cobb angles or smoking habits.
Abstract: BACKGROUND—Pulmonary function in patients with adolescent idiopathic scoliosis many years after posterior spinal surgery or brace treatment has not been documented.
METHODS—A consecutive group of patients treated by posterior fusion or a brace at least 20 years previously was investigated. 90% attended a clinical follow up. Lung volumes were determined before treatment in 251 patients, 1.4 years after surgery in 141 patients, and 25 years after surgery or start of brace treatment in 110patients. Vital capacity (VC) was calculated as percentage predicted according to height and age and the results were corrected for loss of height due to scoliosis. Scoliosis angles were measured and smoking habits were recorded. An age and sex matched control group was also examined with the same questionnaire and pulmonary function tests.
RESULTS—VC increased from 67% predicted immediately before surgery to 73% (p<0.001) after surgery and to 84% (p<0.001) at the present follow up, mean change 10.8% (95% CI 9.5 to 12.1). In the brace treated patients VC increased from 77% predicted before treatment to 89% (p<0.001) 25 years after start of treatment, mean change 12.3% (95% CI 10.5 to 14.1). The mean Cobb angle at the present follow up study was 40° in both surgically and brace treated patients. The present results of lung volumes did not correlate with pretreatment or post-treatment Cobb angles or smoking habits.
CONCLUSIONS—Patients treated by posterior fusion or a brace gradually increase their pulmonary function up to 25 years after treatment. Smoking and curve size are not risk factors for reduced pulmonary function.
141 citations
TL;DR: Thirty-three structural curves of 25 patients with adolescent idiopathic scoliosis were evaluated using computed tomography (CT) scans and plain radiography, finding measurements obtained from the scanograms by the Perdriolle method in the supine position are very similar to those obtained by CT.
Abstract: Thirty-three structural curves of 25 patients with adolescent idiopathic scoliosis were evaluated using computed tomography (CT) scans and plain radiography. The average Cobb angle on standing radiographs was 55.72 degrees and was observed to be corrected spontaneously to 39.42 degrees while the patients were in supine position (29.78% correction). Average apical rotation according to Perdriolle was 22.75 degrees on standing radiographs and 16.78 degrees on supine scanograms. The average rotation according to Aaro and Dahlborn on CT scans was 16.48 degrees. Radiographic measurements were significantly different from axial CT slice or scanogram measurements (p = 0.000), but the two latter measurements, both obtained in the supine position, did not appear to be different (p = 0.495). Deformities on the transverse plane as well as on the coronal plane are influenced by patient positioning. If the patient lies supine, the scoliosis curve corrects spontaneously to some degree on both planes. Measurements obtained from the scanograms by the Perdriolle method in the supine position are very similar to those obtained by CT. Perdriolle's is a simple, convenient, and reliable method to measure rotation on standing radiograms.
128 citations
TL;DR: Perioperative halo-gravity traction improves trunk balance and frontal and sagittal alignment in children with severe spinal deformity and surgical fusion was enhanced by the improved alignment, and neurologic injury was avoided.
Abstract: SUMMARY Perioperative halo traction was used in the treatment of severe scoliosis in 19 children. Diagnoses included neuromuscular, idiopathic, and congenital scoliosis. Traction was transferable between the bed and a walker or wheelchair. Thirteen patients had prior spinal surgery, and most required osteotomy. Traction was used for 6 to 21 weeks. All patients underwent spinal fusion surgery after traction, with instrumentation used in 15 patients. Improvement was achieved in all patients. The Cobb angle improved 35% from an average 84 degrees before traction (range 63 degrees -100 degrees ) to 55 degrees preceding fusion. Trunk decompensation improved in all patients. Trunk height increased 5.3 cm in traction. Response to traction did not correlate with diagnosis, patient age, or prior surgery. There were no neurologic complications. Perioperative halo-gravity traction improves trunk balance and frontal and sagittal alignment in children with severe spinal deformity. Surgical fusion was enhanced by the improved alignment, and neurologic injury was avoided.
125 citations
TL;DR: A new magnetic resonance imaging procedure showing the whole spine in a coronal and sagittal plane, which can reveal relevant clinical data without radiation exposure is introduced, and idiopathic thoracic scoliosis was identified by a reduced sagittal Cobb angle.
Abstract: The purpose of the present study was to introduce a new magnetic resonance imaging (MRI) procedure showing the whole spine in a coronal and sagittal plane, and to study the assessment of sagittal Cobb angle measurements using this technique. Prospectively we studied 32 patients (average age 14.8 years) with idiopathic scoliosis (mean thoracic Cobb angle 33° on radiograph) and 18 patients (average age 14.5 years) without scoliosis. The MRI investigation was carried out in a standard supine position. The cervical and upper thoracic spine and the lower thoracic and lumbar spine were measured on a 1.5-T Gyroscan ACS-NT Powertrak 6000 system. An algorithm was developed to combine the results of the cranial and caudal scans into a coronal and a sagittal image of the whole spine (MR total spine imaging). Measurement of the sagittal Cobb angle conducted ten times by four independent investigators revealed an intraobserver variance of 1.6° and an interobserver variance of 1.8°. In the group with scoliosis the mean sagittal Cobb angle from T4 to T12 was 12° (range –3° to 24°) and in the group without scoliosis 22° (range 16° to 30°), which was a significant difference. MR total spine imaging makes it possible to image scoliosis in the sagittal plane. On these MR projections, idiopathic thoracic scoliosis was identified by a reduced sagittal Cobb angle. MR total spine imaging would allow monitoring of scoliosis in the sagittal plane, which can reveal relevant clinical data without radiation exposure.
98 citations
TL;DR: Long-term follow-up evaluation of Harrington rod fusion for adolescent idiopathic scoliosis showed no important impairment of health-related quality of life, as measured by patient-oriented evaluation.
Abstract: Study design A retrospective study was performed, using the Short Form-36 Health Survey and the Roland and Morris Disability Questionnaire, to investigate patient outcomes after fusion for adolescent idiopathic scoliosis using Harrington rod instrumentation. Objective To evaluate health-related quality of life and low back pain in a long-term follow-up study of surgery for adolescent idiopathic scoliosis. Summary of background data The commonly accepted surgical treatment for idiopathic evolutive scoliosis is vertebral fusion. It has been suggested that this procedure may cause low back pain and a poor quality of life over the long term. Outcome measures after surgery for adolescent idiopathic scoliosis have focused mainly on objective parameters such as radiographic measures. However, this information has proved to be correlated only weakly with outcomes that are more relevant to patients, such as functional status and symptoms. Until recently, only a few long-term outcome studies have used standardized and validated patient-oriented tools to evaluate surgically treated patients with scoliosis. Methods In this study, 70 patients treated with a standard Harrington technique were recontacted and evaluated by means of self-administered questionnaires (Short Form-36 Health Survey and Roland and Morris Disability, clinical examination, and radiographic analysis. Preoperative and follow-up radiographic findings were registered. Relations between radiographic and patient-oriented data were evaluated. Results A comparison between the current sample and the Italian age-matched normative data for the Short Form-36 Health Survey showed them to have a similar pattern. Findings showed the patient-oriented outcome to be correlated inversely with the extension of vertebral fusion and the preoperative Cobb angle. Conclusion Long-term follow-up evaluation of Harrington rod fusion for adolescent idiopathic scoliosis showed no important impairment of health-related quality of life, as measured by patient-oriented evaluation.
83 citations
TL;DR: On average, the relative amount of vertebral and disc wedging did not differ significantly between initial and follow-up radiographs made after progression of the scoliosis, and did not appear to differ by diagnosis.
Abstract: A retrospective longitudinal radiographic study of patients with progressive scoliosis was conducted to determine the relative amount of wedging between vertebrae and discs as a function of progression of the scoliosis curve, cause of the scoliosis, and anatomic curve region. Posteroanterior radiographs of 27 patients with idiopathic scoliosis and of 17 patients with scoliosis associated with cerebral palsy were studied. The amount of wedging of vertebrae and discs at the curve apex was measured by the Cobb method and expressed as a proportion of the curve's Cobb angle. On average, the relative amount of vertebral and disc wedging did not differ significantly between initial and follow-up radiographs made after progression of the scoliosis. In both groups of patients, the mean vertebral wedging was more than the disc wedging in the thoracic region; the converse was found in curves in the lumbar and thoracolumbar regions. The patients with scoliosis associated with cerebral palsy had curves that were longer and more commonly in the thoracolumbar and lumbar regions. The relative wedging did not change significantly with curve progression and did not appear to differ by diagnosis. In the management of scoliosis, including small curves, it should be recognized that both the vertebrae and discs have a wedging deformity.
81 citations
TL;DR: The mean preoperative sitting Cobb angle was 84 degrees (10 to 150) and the mean postoperative angle 40 degrees (52% correction) as discussed by the authors, and most patients (96%) were able to discard their braces and there was a high level of patient satisfaction.
Abstract: We have treated 101 patients with scoliosis secondary to muscular dystrophy over a 13-year period; 64 had Duchenne's muscular dystrophy, 33 spinal muscular atrophy and four congenital muscular dystrophy. The patients underwent a modified Luque (87) or Harrington-Luque instrumentation (14) combined with a limited Moe fusion in all except 27 cases. A mean of 13 levels was instrumented. The mean preoperative sitting Cobb angle was 84 degrees (10 to 150) and the mean postoperative angle 40 degrees (52% correction). Most patients (96%) were able to discard their braces and there was a high level of patient satisfaction (89.6%). Less correction was seen for severe curves, and there was a greater recurrence of postoperative pelvic tilt in those patients not instrumented to the sacrum. Although the incidence of minor or temporary complications was high, these occurred chiefly in the early high-risk patients with very severe curves and considerable pre-existing immobility.
66 citations
TL;DR: Neural-network analysis of full-torso scan imaging shows promise to accurately estimate scoliotic spinal deformity in a variety of patients.
Abstract: STUDY DESIGN Correlation of torso scan and three-dimensional radiographic data in 65 scans of 40 subjects. OBJECTIVES To assess whether full-torso surface laser scan images can be effectively used to estimate spinal deformity with the aid of an artificial neural network. SUMMARY OF BACKGROUND DATA Quantification of torso surface asymmetry may aid diagnosis and monitoring of scoliosis and thereby minimize the use of radiographs. Artificial neural networks are computing tools designed to relate input and output data when the form of the relation is unknown. METHODS A three-dimensional torso scan taken concurrently with a pair of radiographs was used to generate an integrated three-dimensional model of the spine and torso surface. Sixty-five scan-radiograph pairs were generated during 18 months in 40 patients (Cobb angles 0-58 degrees ): 34 patients with adolescent idiopathic scoliosis and six with juvenile scoliosis. Sixteen (25%) were randomly selected for testing and the remainder (n = 49) used to train the artificial neural network. Contours were cut through the torso model at each vertebral level, and the line joining the centroids of area of the torso contours was generated. Lateral deviations and angles of curvature of this line, and the relative rotations of the principal axes of each contour were computed. Artificial neural network estimations of maximal computer Cobb angle were made. RESULTS Torso-spine correlations were generally weak (r < 0.5), although the range of torso rotation related moderately well to the maximal Cobb angle (r = 0.64). Deformity of the torso centroid line was minimal despite significant spinal deformity in the patients studied. Despite these limitations and the small data set, the artificial neural network estimated the maximal Cobb angle within 6 degrees in 63% of the test data set and was able to distinguish a Cobb angle greater than 30 degrees with a sensitivity of 1.0 and specificity of 0.75. CONCLUSIONS Neural-network analysis of full-torso scan imaging shows promise to accurately estimate scoliotic spinal deformity in a variety of patients.
TL;DR: The back surface image study is a method for providing a quantitative assessment of mild spinal deformity, allowing evaluation of patients by integrated three-dimensional parameters with no reference to radiographs.
Abstract: Study design A stepwise discriminant analysis was used to define a spinal deformity score based on three-dimensional measurements by the Quantec spinal image system (raster stereophotograph). Objective To provide functional classification of spinal deformity in patients with mild idiopathic scoliosis without using radiographs. Summary of background data Most studies classify the degree of spinal deformity in terms of coronal plane radiograph without analyzing transverse rotation. To the authors' knowledge, no studies investigating classification of spinal deformity in idiopathic scoliosis using Quantec system measurements have been documented. Methods In this study, 129 patients with a single curve and 119 patients with a double curve were divided into three groups according to Cobb angle: Group 1 (less than 10 degrees ), Group 2 (10-20 degrees ), and Group 3 (greater than 20 degrees ). Results The patients were assigned to the group with the highest scores after application of a stepwise discriminant analysis. The accuracy of the classification system by functional scores for the patients with a single curve was 85% for Group 1, 63.5% for Group 2, and 71.7% for Group 3. The accuracy of classification by functional scores for the patients with a double curve was 87.1% for Group 2 and 76.1% for Group 3. Conclusion The back surface image study is a method for providing a quantitative assessment of mild spinal deformity, allowing evaluation of patients by integrated three-dimensional parameters with no reference to radiographs.
TL;DR: A mathematical formula is constructed that accurately provides the roentgenographic T4-T12 kyphosis angle in adolescents using only the Debrunner kYphometer with a deviation of less than 3 degrees that will reduce the cost of school screening programs, overdiagnoses, and unnecessary exposure of adolescents to irradiation.
Abstract: The Debrunner kyphometer is an accepted tool for detecting and evaluating thoracic kyphosis. This prospective study was conducted to create a mathematical formula that provides, with high approximation, the roentgenographic angle of thoracic kyphosis (T4-T12) using only the kyphometer. Several clinical (kyphometer value, age, and sex) and radiographic (Cobb angle [T4-T12]) parameters from 90 consecutively screened adolescents (44 male and 46 female) were correlated using simple and multiple linear regression analyses. The reliability of measurement using the Debrunner kyphometer was high. The kyphometer value was strongly correlated with the roentgenographically measured thoracic Cobb angle (simple linear regression analysis; probability range, 0.0026 to 0.0002). There was no correlation between age or sex and thoracic kyphosis. The predicted kyphosis angle using the kyphometer and the mathematic formula was 44.66 degrees +/- 2.68 degrees, (range 27 to 62 degrees), and the real roentgenographic kyphosis angle was 47.5 degrees +/- 3.53 degrees, (range, 24 to 70 degrees). The kyphometer and formula were more reliable and accurate when kyphosis less than 50 degrees was measured. In this study, the authors constructed a mathematical formula that accurately provides the roentgenographic T4-T12 kyphosis angle in adolescents using only the Debrunner kyphometer with a deviation of less than 3 degrees. The authors recommend that all physicians engaged in kyphosis screening programs use the kyphometer combined with the recently constructed simple mathematic formula. This method will reduce the cost of school screening programs, overdiagnoses, and unnecessary exposure of adolescents to irradiation.
TL;DR: Spinal stabilization with the ISOLA system was found to be a suitable treatment for scoliosis owing to Duchenne muscular dystrophy and should be carried out after loss of ambulation as soon as a progressive curve of more than 20 degrees is documented.
Abstract: The aim of this study was to report results of prophylactic spinal stabilization in patients with Duchenne muscular dystrophy. There is still debate regarding the ideal instrumentation. A prospective study of a consecutive series of 31 patients stabilized with the ISOLA system from D2 to S1 will be presented. The mean follow-up was 22 months (range, 1-60 months). The evaluation of the Cobb angle and pelvic obliquity revealed the following: 1) Cobb angle: preoperation, 48.6 degrees (range, 22-82 degrees); postoperation, 12.5 degrees (range, 0-30 degrees); follow-up, 12.5 degrees (range, 0-42 degrees); and 2) pelvic obliquity: preoperation, 18.2 degrees (range, 3-40 degrees); postoperation, 3.8 degrees (range, 0-13 degrees); follow-up, 5.1 degrees (range, 0-14 degrees). Spinal stabilization with the ISOLA system was found to be a suitable treatment for scoliosis owing to Duchenne muscular dystrophy. It should be carried out after loss of ambulation as soon as a progressive curve of more than 20 degrees is documented. The complication rate was found to be high.
TL;DR: Using a shoe lift resulted in acute postural adaptations which specifically affected the spine and the three-dimensional position and orientation of the pelvis and shoulder girdle.
Abstract: The objective of this study was to identify acute spinal and three-dimensional postural adaptations induced by a shoe lift in a population of idiopathic scoliosis (IS) patients. Forty-six IS patients (mean age: 12±2 years) were evaluated radiologically and with a stereovideographic system for pelvic obliquity. Based on the initial postural and radiological evaluation, a pertinent shoe lift height was chosen for each with the result that 12 patients were tested with 5-mm (S5) lifts, 20 patients were tested with 10-mm (S10) lifts, and 14 patients with 15-mm (S15) lifts. The posture for all 46 patients was then re-evaluated and a spinal radiograph obtained for 14 patients. The implementation of a shoe lift independent of the type of curve and amplitude significantly decreased the Cobb angle. As expected there was a change in the vertical height of the left tibial plateau and greater trochanter that induced a change in pelvic tilt. There was also a significant increase in the vertical height of S1 and T1. There was a significant change in the left and right iliac bone version, as well as a decrease in the difference in version between these two bones. The implementation of the shoe lifts also changed the lateral shift of the pelvis. A relative change between the shoulders and pelvis for tilt and anteroposterior shift was also found to be significant. In conclusion, using a shoe lift resulted in acute postural adaptations which specifically affected the spine and the three-dimensional position and orientation of the pelvis and shoulder girdle.
TL;DR: No single factor can predict the severity of impairment in scoliotic patients' pulmonary function, however, uppermost vertebra, scoliosis angle, and patient's age may play important roles influencing pulmonary function in both groups.
TL;DR: Results indicate that even in the very young neuromuscular patient, acceptable amounts of curve correction can be achieved and maintained with posterior-only unit rod instrumentation and fusion, and seemed to prevent the crankshaft phenomenon in the majority of those patients at risk.
Abstract: Study Design. A retrospective study to determine the efficacy of posterior-only unit rod instrumentation and fusion in a skeletally immature neurornuscular scoliosis population. Objective. To determine whether the posterior-only approach to this population adequately addresses the concerns of correction of scoliosis and pelvic obliquity, maintenance of that correction over time, and the inci dence of crankshaft phenomenon. Summary of Background Data. Controversy exists regarding the need for anterior release to improve curve flexibility and the need to obtain an anterior arthrodesis in those skeletally immature petients at risk for crankshafting with continued anterior growth Methods. From 1992 through 1997, 28 consecutive skeletally immature patients with neuromuscular scoliosis underwent posterior-only unit rod instrumentation and fusion for the treatment of progressive, symptomatic spinal deformities. Preoperative, immediate postopera tive, and final follow-up radiographs were analyzed with respect to scoliosis and pelvic obliquity correction, maintenance of that correction over time, and the development of the crankshaft phenomenon as evidenced by loss of correction and/or increased rib-vertebral angle difference. The average age of the patients was 12.8 years and the average follow-up was 58 months with a minimum of 2 years. Results. Twenty-six patients were available for final follow-up. The initial Cobb angle correction averaged 66%, with 75% of the pelvic obliquity corrected. These corrections were maintained over time. Before surgery 27 of 28 patients were Risser 0, 1, or 2. The triradiate cartilage was open in nine patients, and five patients were ≥ 10 years of age. At the final follow-up 22 of the 26 patients were Risser 5 and 4 were Risser 4. There was one patient with increased rib-vertebral angle difference over the length of follow-up, with no loss of frontal or sagittal plane atignment. Conclusions These results indicate that even in the very young neuromuscular patient, acceptable amounts of curve correction can be achieved and maintained with posterior-only unit rod instrumentation and fusion. The biomechanical stiffness of this construct seemed to be able to prevent the crankshaft phenomenon in the majority of those patients at risk.
TL;DR: Segmental vertebral translation measurements most strongly correlate with segmental angle of trunk inclination measurements during follow-up, which is best explained by unwinding of the thoracic cage tensioned by surgery rather than through relative anterior spinal overgrowth.
Abstract: Study Design. Analysis of preoperative, 8-week, 1-year, and 2-year data from patients with right thoracic adolescent idiopathic scoliosis treated by posterior Universal Spine System (Stratec Medical, Oberdorf, Switzerland). Objective. Report 2-year results and the association between back surface and radiographic assessments. Summary of Background Data. Few longitudinal studies have related surface and radiographic data in the follow-up of surgical patients. Methods. Of 34 patients with right thoracic adolescent idiopathic scoliosis having posterior Universal Spine System instrumentation, 27 had complete prospective back surface and radiographic appraisal. Results. Cobb angle corrected from 58° to 34° (41%), apical vertebral rotation from 26° to 20° (23%), apical vertebral translation from 4.5 to 2.4 cm (47%), and maximum angle of trunk inclination from 17° to 13° (22%) (preoperative to 2 years). Rib-hump reassertion occcurred between 8 weeks and 1 year, regardless of age, and correclated with changes in vertebral translation (for 10 vertebral levels corresponding to 10 back surface levels between C7 and S1, P = 0.001 MANOVA). Preoperative frontal tilt of L1 with concave fifth rib(spinal angle predicted the percentage correction of maximum angle of trunk inclination, and the concave ninth rib-spinal angle predicted reassertion of maximum angle of trunk inclination. Conclusions. Almost half of initial back surface correction is lost by 2 years. Segmental vertebral translation measurements most strongly correlate with segmental angle of trunk inclination measurements during follow-up. Rib-hump reassertion is best explained by unwinding of the thoracic cage tensioned by surgery rather than through relative anterior spinal overgrowth. Spine and thoracic cage factors determine rib-hump correction, so surgical disruption of the latter by costoplasty may prevent rib-hump reassertion. Results of scoliosis surgery should include surface data.
TL;DR: Preliminary spinal fusion alone with unit rod instrumentation is adequate treatment to control crankshaft deformity in skeletally immature children with neuromuscular scoliosis due to cerebral palsy.
Abstract: Radiographs and charts were reviewed for all children with cerebral palsy who underwent posterior-only spinal fusion with the unit rod for neuromuscular scoliosis by the senior author from 1989 through 1996. Fifty patients were found to have an open triradiate cartilage at the time of fusion. A single observer obtained measurements of the preoperative, postoperative, and most recent spine films using the standard Cobb angle. Amount of change was calculated over the respective periods. Forty-three patients had at least 2 years of clinical follow-up. Twenty-nine patients had more than 2 years of both radiographic (mean, 4.6 years) and clinical follow-up (mean, 4.8 years) with a closed triradiate cartilage on their most recent films. In this group, the mean absolute curve change over the length of radiographic follow-up was 0.6 degrees (range, -9-14). None of the 43 patients with at least 2 years of clinical follow-up (mean, 4.5 years) had any radiographic change that was clinically significant on chart review. Therefore posterior spinal fusion alone with unit rod instrumentation is adequate treatment to control crankshaft deformity in skeletally immature children with neuromuscular scoliosis due to cerebral palsy.
TL;DR: Gender, direction of the convexity, the level of the apex and the kyphotic angle were determined more by genetic factors than the lateral Cobb angle of the scoliotic curve, which suggests that variations in the environment may affect the curve patterns in monozygotic twins.
Abstract: Most authors state that there is strong evidence for a genetic origin of adolescent idiopathic scoliosis (AIS). This conclusion is mainly based on the fact that the rate of concordance for AIS in monozygotic twins is significantly higher than that in dizygotic twins. However, it is of interest to determine whether all elements of scoliosis formation are genetically predetermined. If this were the case, there would perhaps be less place for closed treatment. We surveyed the literature for monozygotic twin pairs in which both members suffered from idiopathic scoliosis and added 3 pairs from our own patient group. The total group consisted of 32 twin pairs. We found that gender, direction of the convexity, the level of the apex and the kyphotic angle were determined more by genetic factors than the lateral Cobb angle of the scoliotic curve. This suggests that variations in the environment may affect the curve patterns in monozygotic twins.
TL;DR: In Scheuermann kyphosis, the flexible cervical and lumbar spine is linked by the intermediate rigid thoracic segment, and lordosis of the cervical spine increases as the patient strives to maintain a forward visual gaze.
Abstract: The sagittal profiles of the cervical and lumbar spine have not been studied in Scheuermann kyphosis. The purpose of this study was to investigate these profiles. Standing lateral radiographs of the spine in 34 children with Scheuermann kyphosis were reviewed. Cervical lordosis, lumbar lordosis, thoracic kyphosis, sagittal vertebral axis, and sacral inclination were measured. The relations between these variables were explored using the Pearson correlation. The average patient age was 15.5 +/- 1.8 years, thoracic kyphosis was 65 degrees +/- 12 degrees, lumbar lordosis 71 degrees +/- 13 degrees, and cervical lordosis 4 degrees +/- 15 degrees (Cobb angle), and 9 degrees +/- 14 degrees (posterior vertebral body angle [PVBA]). No correlations were noted between cervical lordosis and thoracic kyphosis. Correlations were noted between cervical lordosis and lumbar lordosis (r2 = 0.17, Cobb angle; r2 = 0.16, PVBA) and between cervical lordosis and the residual sagittal difference (thoracic kyphosis minus lumbar lordosis; r2 = 0.32, p = 0.001 [Cobb angle], and r2 = 0.19, p = 0.01 [PVBA]). In Scheuermann kyphosis, the flexible cervical and lumbar spine is linked by the intermediate rigid thoracic segment. As the residual sagittal difference becomes more kyphotic, lordosis of the cervical spine increases as the patient strives to maintain a forward visual gaze.
TL;DR: Thoracic volume was calculated in 50 adolescent patients operated on for severe idiopathic thoracic scoliosis using anterior instrumentation and posterior instrumentation in 25 patients, and the best correlation was found between the volume increase and the sagittal parameters.
Abstract: Thoracic volume was calculated in 50 adolescent patients operated on for severe idiopathic thoracic scoliosis. In 25, anterior instrumentation was used (group 1), and posterior instrumentation in the other 25 patients (group 2). Calculation of thoracic volume was made from measurements of pre-operative and post-operative radiographs. The mean spinal curvature in group 1 was 73±12.4° before the operation, and 19±15° after the operation, and in group 2 the curvature was 75±13° before the operation and 37±10° after the operation. The calculated thoracic volume in the group with anterior instrumentation increased from 5234 ml pre-operatively to 6043 ml post-operatively, while with posterior instrumentation it increased from 5155 ml to 5489 ml. The correlation between the change in the Cobb angle and the thoracic volume change was poor for both groups. To determine the role in the thoracic volume increase of the frontal, sagittal and vertical thoracic diameters, further correlation tests were made between these and the thoracic volume increase in each diameter. The best correlation was found between the frontal and vertical increase of diameters in group 1, whereas in group 2 the best correlation was found between the volume increase and the sagittal parameters.
TL;DR: The measurements performed on human cadavers showed that the isolated transection of the anterior longitudinal ligament leads to a sufficient anterior release of the thoracic spine, allowing a correction of the kyphotic deformity.
Abstract: With a custom-made measuring unit, two separate experiments, involving six and five cadaveric torsos with intact rib cages and sternums, respectively, were carried out to determine the effect of the transection of the anterior longitudinal ligament with and without osteodiscectomy and its influence on the thoracic kyphosis. The open or thoracoscopically assisted anterior release, as part of the operative treatment of scoliosis or kyphosis, usually consists of a transection of the anterior longitudinal ligament (ALL) and an additional discectomy. A complete osteodiscectomy, however, is not always possible with a minimally invasive approach. As part of our biomechanical research, we attempted to quantify the amount of correction achievable with a defined force prior to and following the isolated transection of the anterior longitudinal ligament. The aim of the study was to clarify whether or not an isolated transection of the anterior longitudinal ligament is sufficient to obtain an adequate anterior release of the spine. In the surgical treatment of kyphotic deformities, anterior release of the spine is performed in the form of a transection of the ALL and discectomy. Recently, video-assisted thoracic surgery has become increasingly popular in spine surgery. As part of this change in surgical technique, the question has arisen as to what extent an isolated transection of the ALL provides an adequate release of the thoracic spine. Eleven human spines were retrieved from fresh cadavers, dissected, and attached to a specially constructed apparatus. The spine was attached to the construct at the twelfth vertebral body. C6 and C7 were fixed in synthetic resin. We installed the instruments in such a manner as to reproducibly apply a torsional moment of 10 Nm to the spine. Motion was only permitted in the sagittal plane. Segmental transections of the ALL were carried out from T3 to T7. For comparison, the sagittal Cobb angle was also documented following an anterior release combined with an osteodiscectomy. With the isolated transection of the ALL, an average correction of the sagittal Cobb angle of 4° in each functional spinal motion segment was recorded. In comparison, the additional osteodiscectomy led to a further average increase of only 2° per level. The measurements performed on human cadavers showed that the isolated transection of the ALL leads to a sufficient anterior release of the thoracic spine, allowing a correction of the kyphotic deformity. The release with a concomitant osteodiscectomy represents a more time-consuming and more invasive procedure resulting in only a slightly greater amelioration of the sagittal Cobb angle, while being associated with a greater patient morbidity.
TL;DR: The study concluded that the translation maneuver, especially when used with the cantilever technique, resulted in high correction rates in the frontal plane, and was also successful in obtaining normal sagittal contours and correcting balance values.
Abstract: Since the definition of three-dimensional components of the scoliotic deformity, there have been important improvements in the surgical treatment of the problem. A derotation maneuver was proposed as a treatment option with CD instrumentation, but the reports of imbalance and decompensation with this system repopularized sublaminar wiring and translation as a corrective maneuver. Isola spinal instrumentation is one of the modern systems that utilizes vertebral translation instead of rod rotation. This study analyzes the results of 24 patients with idiopathic scoliosis who had been followed up for at least 2 years, and were surgically treated with titanium Isola Spinal Instrumentation in the Department of Orthopaedics and Traumatology, Ankara Social Security Hospital. Patients were grouped according to the King-Moe classification. Patients with type III, IV or V curves received only posterior instrumentation while this procedure followed anterior release and discectomy in the same session in patients with type I or II curves. A translation maneuver was utilized in the correction of scoliotic curves using the cantilever technique, either alone or supplemented by sublaminar wiring with Songer multifilament titanium cables. This study aimed to elucidate the effects of this technique in the frontal and sagittal plane curves and the trunk balance. The balance was analyzed clinically and radiologically by measurement of the lateral trunk shift (LT), shift of stable vertebra (SS), and shift of head (SH) in vertebral units (VU). The postoperative correction was significant in the frontal plane for all types of curves (p < 0.05). The postoperative correction was 80.9% ± 9.5% in type III curves. Overall, the mean Cobb angle of the major curve value in the frontal plane was 66.9°± 18.8°, and it was corrected by 62.8% ± 20.1%. The correction loss of Cobb angles in the frontal plane was 5.4°± 5.5° at the last follow-up visit. A normal physiologic thoracic contour (30°–50°) was achieved in 83.3% of the patients and normal lumbar contour (40°–60°) in 66.7% of the patients in the sagittal plane. The correction was found to be significant in all balance values (p < 0.05). The postoperative correction in LT values correlated with the correction of the Cobb angle values in the frontal plane. All patients had complete balance (SH: 0 VU and SS: 0 VU) or balanced curves (0 VU < SH, SS < 0.5 VU).Finally, the study concluded that the translation maneuver, especially when used with the cantilever technique, resulted in high correction rates in the frontal plane. Additionally, the technique was also successful in obtaining normal sagittal contours and correcting balance values.
TL;DR: MR total spine imaging could be a useful tool for studying the brace effect in scoliosis in two planes, and is found to find reduced sagittal Cobb angles for the thoracic kyphosis with brace.
TL;DR: In this article, the effect of multisegmental spinal fusion on the long-term functional and radiological outcome in patients with scoliosis was investigated, and the authors compared these patients both with those whose spine had not been fused, and with a control group.
Abstract: We have investigated the effect of multisegmental spinal fusion on the long-term functional and radiological outcome in patients with scoliosis. We compared these patients both with those whose spine had not been fused, and with a control group. We studied 68 patients with idiopathic scoliosis (34 operative and 34 non-operative) who had been followed up for a minimum of five years after treatment. They were matched for age (mean 44 years) and Cobb angle (mean 54°) at follow-up. An age- and gender-matched control group of 34 subjects was also recruited. All participants completed a questionnaire to assess spinal function and to grade the severity of back pain using a numerical rating scale. Radiographs of the spine were taken in the patients with scoliosis and lumbar degenerative changes were recorded. The spinal function scores for the patients with scoliosis who had had a fusion were similar to those who had not. Both scoliosis groups, however, had lower scores than the control group (p < 0.001). The frequency and severity of back pain were lower for patients with scoliosis and fusion than for those without, but higher for both scoliosis groups compared with the control group. Radiographs showed similar degenerative changes in both scoliosis groups.
TL;DR: The results suggest that one should investigate the neuraxis with MRI before contemplating orthopaedic surgical correction of severe idiopathic scoliosis, because the findings may lead to a change of procedure.
Abstract: The use of magnetic resonance imaging (MRI) in the preoperative investigation of children with idiopathic scoliosis is controversial. Syringomyelia and other intraspinal lesions may be risk factors for neurological injury during surgical correction. Our purpose was to investigate whether pathology of the neuraxis is associated with scoliosis and to detect lesions which may threaten neurological sequelae during distraction and instrumented correction. We obtained T1- and T2-weighted images of 40 children (28 girls, 12 boys), mean age 12.7 years with severe idiopathic scoliosis (Cobb angle 50-70 degrees) obtained in coronal, sagittal and axial planes from the posterior cranial fossa to the sacrum, and these were assessed by two neuroradiologists and an orthopaedic surgeon prior to further treatment planning. Abnormalities of the neuraxis were found in 24 patients (60%); five (12%) had two or more lesions. No abnormalities of the neuraxis were found in 16 patients (40%). There were 15 patients (38%) with intraspinal abnormalities who deteriorated clinically and nine (22%) who showed no clinical changes. We transferred 16 patients (40%) from the orthopaedic to the neurosurgical department for further assessment. Our results suggest that one should investigate the neuraxis with MRI before contemplating orthopaedic surgical correction of severe idiopathic scoliosis, because the findings may lead to a change of procedure.
TL;DR: Thirty-two patients with adolescent idiopathic scoliosis underwent anterior fusion with rigid single rod (third generation instrumentation) and titanium mesh cages and cages were used in all the lumbar procedures and at the cranial and caudal ends of the instrumented area in thoracic cases.
Abstract: Thirty-two patients with adolescent idiopathic scoliosis underwent anterior fusion with rigid single rod (third generation instrumentation) and titanium mesh cages. The mean follow-up was 31 (24–45) months and the mean age was 14.9 years. There were 8 patients with King type I, 10 with type II, 6 with type III, 4 with type IV and 4 with lumbar curves. Titanium mesh cages were used in all the lumbar procedures and at the cranial and caudal ends of the instrumented area in thoracic cases. All the patients were immobilized in an orthosis for 3–6 months postoperatively. Mean preoperative primary coronal Cobb angle of 56° was improved to 8.6°. Average correction rate was 84%. Sagittal balance was restored with a mean thoracic kyphosis of 28° and a mean lumbar lordosis of 38°. Spontaneous secondary curve decompensation did not occur and postoperative thoracolumbar junctional kyphosis was not seen. One case had to be revised due to proximal screw pull out and loss of correction.
TL;DR: The results demonstrate the influence of rotation over frontal plane deformity and is more apparent at curves >30 degrees.
Abstract: To analyze the effect of rotation on frontal plane deformity in idiopathic scoliosis, 44 patients with idiopathic scoliosis aged 11 to 18 years were examined using standing anteroposterior and true AP radiographs. Axial rotation was measured by computed tomography. Patients were divided into two groups according to Cobb angle: patients with angles 30 degrees comprised group 2. Cobb angle increased with true-AP projection a mean of 21.2% in group 1 and 16.7% in group 2. Rotation degree was significantly correlated with increasing degree of frontal plane deformity (P .05). These results demonstrate the influence of rotation over frontal plane deformity and is more apparent at curves >30 degrees.
TL;DR: In the case of a wedge-shaped deformation of a vertebral body, the relative increase of the flexion moment is a function of the wedge angle and of the original position of the centre of gravity of the upper body.
Abstract: Kyphosis is a dorsally convex curvature of the spine in the sagittal plane. A pathological kyphosis of the thoracic spine has a Cobb angle greater than 50 degrees. It occurs when the anterior and/or posterior load-transferring elements of the spine are overloaded or damaged. Wedge-shaped vertebral bodies may be found at one or several levels. A wedge-shaped vertebral body increases the curvature of the spine and moves the centre of gravity of the body parts above of the corresponding vertebral body in a ventral direction. This increases the flexion-bending moment acting on the spine. In the case of a wedge-shaped deformation of a vertebral body, the relative increase of the flexion moment is a function of the wedge angle and of the original position of the centre of gravity of the upper body.