Showing papers on "Cobb angle published in 1999"

Ten-year follow-up evaluation of a school screening program for scoliosis. Is the forward-bending test an accurate diagnostic criterion for the screening of scoliosis?

Abstract: Study design A 10-year follow-up evaluation of the effectiveness of school screening for scoliosis performed in a closed island population Objectives To evaluate the diagnostic accuracy of methods used for screening scoliosis and to re-examine the long-term effectiveness of the school scoliosis screening program Summary of background data The diagnostic accuracy of the forward-bending test and the long-term efficacy of the screening programs have not been clearly established Methods In 1987, 2700 pupils aged 8 to 16 years from the island of Samos were screened for scoliosis The Adams forward-bending test, Moire topography, the scoliometer, and the humpometer were used Radiologic evaluation of the spine was available for each pupil and the number of false-negative and false-positive results of the screening methods was calculated Subsequently, sensitivity, specificity, and positive and negative predictive values were estimated for each screening technique Pupils found positive for spinal deformity were then followed up regularly at yearly intervals In 1997, all positive subjects attended a 10-year clinical and radiologic follow-up, and the remaining subjects were re-evaluated by a postal questionnaire and were clinically examined if necessary Results Spinal deformity was found in 153 (566%) pupils Scoliosis (defined as a spinal curvature > or = 10 degrees) was found in 32 pupils, for a prevalence of 118% For scoliosis, the Adams forward-bending test showed a number of false-negative results (in five cases), for a sensitivity of 8437% and specificity of 9344% The sensitivities of Moire topography, the humpometer, and the scoliometer were 100%, 9375%, and 9062%, respectively, and specificity was 8538%, 7811%, and 7976% respectively The negative predictive value of the forward-bending test was inferior to those of the other methods During this scoliosis screening program, if cutoff limits for referral had been used, such as the asymmetry of two Moire fringes, a humpogram deformity of (D + H) = 10 mm, and 8 degrees of scoliometer angle, it would have been possible to reduce radiologic examination by 894% Three (011%) pupils aged between 12 and 14 years with scoliotic deformities greater than 20 degrees underwent satisfactory nonoperative treatment with Boston braces One pupil with a 40 degrees thoracic curvature, underwent satisfactory surgical treatment because of progression 1 year later Of the 121 spinal deformities with an initial Cobb angle less than 10 degrees, 44 (358%), and of the 29 scoliotic deformities with an initial Cobb angle between 10 degrees and 20 degrees, 14 (483%) progressed (a Cobb angle difference of at least 5 degrees in more than one examination) Observation and physiotherapy were the only treatments applied to all except one of the pupils in these groups Conclusions The Adams forward-bending test cannot be considered a safe diagnostic criterion for the early detection of scoliosis (especially when it is used as the only screening tool) because it results in an unacceptable number of false-negative findings For the early detection of scoliosis, a combination of back-shape analysis methods can be safely used with the introduction of cutoff limits for referral being a useful procedure The incidence of significant scoliosis is low, and its natural history seems to be independent of early detection The wide-spread use of school scoliosis screening with the use of the forward-bending test must be questioned

Luque trolley and convex epiphysiodesis in the management of infantile and juvenile idiopathic scoliosis.

Abstract: STUDY DESIGN Retrospective analysis of 5-year follow-up data from patients instrumented with Luque trolley with or without convex epiphysiodesis for management of progressive infantile and juvenile idiopathic scoliosis. OBJECTIVE To assess results, establish predictors of outcome, and suggest more effective surgical interventions. SUMMARY OF BACKGROUND DATA Initial results have been reported. There are no long-term follow-up studies. METHODS Luque trolley instrumentation was used in eight patients with idiopathic scoliosis between 1983 and 1984. Luque trolley with convex epiphysiodesis was used in 18 patients between 1984 and 1990. RESULTS Changes in Cobb angle from 8-week to 5-year follow-up are as follows. For Luque trolley alone, Cobb angle worsened for all patients. For progressive infantile scoliosis managed with Luque trolley and convex epiphysiodesis, Cobb angle worsened in seven, remained unchanged in four, and improved in two patients. Mean age at operation was 3.1 years (range, 1.5-7.4 years), and instrumented spinal growth was 32% of expected growth. Preoperation Cobb angle was 65 degrees (range, 40-95 degrees). Cobb angle at 5-year follow-up was 32 degrees (range, 0-86 degrees), which is predicted by preoperation apical concave rib-spinal angle (P = 0.002) and upper end vertebral tilt (P = 0.04). For juvenile idiopathic scoliosis managed with Luque trolley and convex epiphysiodesis, Cobb angle worsened in three patients and improved in one. CONCLUSIONS Luque trolley instrumentation alone does not prevent curve progression. Additional convex epiphysiodesis results in curve resolution in some patients, which suggests a growth effect. Both spine and rib factors predict Cobb angle at 5-year follow-up.

Brace treatment in neuromuscular spine deformity.

Abstract: We reviewed 90 consecutive patients with various neuromuscular diseases and a progressive spine deformity treated with a prefabricated Boston-type underarm corrective brace. Of these, 38 patients had spastic tetraplegia; seven, syndrome-related muscular hypertonia; 24, muscular hypotonia; and 21, myelomeningocele. The mean age at the treatment start was 9.2 years (range, 1.4-17.7 years). Twenty-four were ambulating and 66 wheelchair-bound. Hypotonia was the dominant type of muscle involvement in 49, spasticity in 28, and athetosis in 13 patients. The mean pretreatment Cobb angle was 47 degrees, with a range from 23 to 95 degrees. The mean brace-induced Cobb-angle correction was 60%, thus well comparable to that in idiopathic scoliosis. However, this did not predict favorable treatment results. At the follow-up, on average 3.1 years (range, 1-5.5 years) after weaning from the brace, the brace treatment was successful in 23 patients. Successful was defined as <10 degrees curve progression during the observation time and a good brace compliance. Forty-one patients discontinued the brace treatment, and 19 progressed despite adequate brace wear. Five patients are still in treatment, and two have died. Successful treatment was seen in ambulating patients with muscle hypotonia and short thoracolumbar/lumbar curves measuring <40 degrees as well as in nonambulating patients with spastic short lumbar curves. These types of neuromuscular scoliosis may be the only ones to respond to brace treatment. In other cases, the brace treatment cannot be expected to have a lasting corrective effect although it can be used as sitting support.

Pelvic obliquity after fusion of the spine in Duchenne muscular dystrophy

Abstract: Spinal fusion, ending caudally at L5 rather than at the sacrum, is recommended for selected patients with scoliosis due to Duchenne muscular dystrophy. We present a retrospective review of 48 patients operated on for this condition. Patients having spinal curvature with a Cobb angle of less than 40° and with less than 10° between a line tangential to the superior margins of both iliac crests and a line perpendicular to the spinous processes of L4 and L5, were fused to L5 (38 patients); patients not meeting these criteria were fused to the sacrum (10 patients). Spinal and sitting obliquity increased in patients fused to L5, rather than to the sacrum, but the severity of the worsening obliquity was significantly greater in patients in whom the apex of the curve was below L1. Two of the ten latter patients required revision procedures for worsening obliquity when their pulmonary function deteriorated to less than 25% of predicted values. We recommend fusion to the sacrum for scoliosis in Duchenne muscular dystrophy, especially for patients with an apex to their curve below L1.

The effects of melatonin therapy on the development of scoliosis after pinealectomy in the chicken.

Abstract: The mechanism underlying the development of scoliosis after pinealectomy in young chickens is unknown. However, since the main product of the pineal gland is melatonin, melatonin remains an obvious focus in studies designed to discover this mechanism. One confounding factor is that serum melatonin levels are close to zero after pinealectomy but scoliosis does not develop in all chickens that have had this procedure. Therefore, the role of melatonin in the development of scoliosis in chickens after pinealectomy remains controversial. In the current investigation, two pilot studies demonstrated that a physiological therapeutic dose of melatonin (2.5 milligrams per kilogram of body weight) restored the circadian rhythm of melatonin, as measured by serum assay. In the main study, this dose was administered daily starting either immediately after the pinealectomy or two weeks after it, when scoliosis had developed. Scoliosis was assessed on weekly radiographs, and the Cobb angle was determined for all chickens in which scoliosis developed. Overall, scoliosis developed in only 56 percent (fifty) of the eighty-nine chickens that had had a pinealectomy; this rate was consistent throughout all experimental groups. Scoliosis did not develop in any of the control chickens, which did not have a pinealectomy. On the basis of the average Cobb angles in the chickens in which scoliosis had developed, it was determined that neither the prevalence nor the pattern of the scoliosis was affected by the therapy in any of the experimental groups. It was thus concluded that melatonin therapy after pinealectomy in young chickens has no effect on the development or progression of scoliosis. These results raise doubts regarding the role of melatonin in the development of scoliosis after pinealectomy in the young chicken. CLINICAL RELEVANCE: Although scoliosis has been produced in some animal studies, none of these models has proved to be entirely satisfactory. Consequently, research regarding adolescent idiopathic scoliosis has been hampered. Recently, it was shown that scoliosis with many characteristics similar to those seen in patients who have adolescent idiopathic scoliosis can be produced consistently in chickens after pinealectomy. This finding encourages the development of this model. An understanding of the mechanism involved in the development of scoliosis after pinealectomy in chickens might provide new insights into adolescent idiopathic scoliosis and aid in the development of novel treatment methods.

The selection of fusion levels using torsional correction techniques in the surgical treatment of idiopathic scoliosis.

Abstract: Study Design. This is a retrospective, consecutive case series, with the index patient included. Objectives. To evaluate the evolution and effectiveness of instrumentation techniques designed to untwist the scoliosis deformity. Summary of Background Data. Three-dimensional studies of the idiopathic scoliosis deformity are consistent with the theory that the deformity or deformities evolve as an imperfect torsion or torsions. Methods. From 1989 through 1995, 102 consecutive patients (84 females, 18 males) underwent surgery with increasing emphasis on torsional correction. One hundred patients (98%), with an average age of 14.3 years (range, 10.5–20.8 years), were observed for an average of 40 months (range, 24–81 months). The upper instrumented vertebra evolved to be the centered vertebra. The lower instrumented vertebra was chosen based on its ability to become horizontal on contralateral bend radiographs and was termed the caudal foundation vertebra. Because these techniques evolved over the first 3 years of the study period, a split analysis was performed to evaluate improvements in correction and correction maintenance over the course of the study. Results. The average Cobb angle was 59° before surgery, 18° after surgery (69% correction), and 22° (63% correction) at latest follow-up. A comparison of the first half of the series with the second half showed no significant demographic differences. Curve correction was significantly improved for King–Moe IIB (thoracolumbar–lumbar curve only), King–Moe III, and King–Moe V curve types in the second half of the series. In the last 4 years, curve correction at latest follow-up for King–Moe IIB curves was 61% for the thoracic curve and 65% for the thoracolumbar–lumbar curve. King–Moe III curves had a 68% correction, and King–Moe V curves had a 50% high thoracic and a 72% thoracic curve correction. Thoracolumbar, lumbar, and King–Moe I curves averaged 81% correction of the thoracolumbar–lumbar curve. The angle of thoracic curve inclination improvement at 1 year was maintained at latest follow-up. Conclusions. This method of selecting instrumentation levels while using torsional correction techniques is safe and reliable. The results were improved with the evolution of these techniques and appear to provide improved correction and correction maintenance compared with that of historical controls. [Key Words:idiopathic scoliosis, Isola instrumentation]

MRI evaluation of multifidus muscles in adolescent idiopathic scoliosis.

Abstract: Background. The role of the multifidus muscles in the initiation and progression of curve in adolescent idiopathic scoliosis is not fully understood and controversy exists as to the side of the abnormality. Objective. To evaluate on MRI the multifidus muscles at the apex of the major curve in adolescent idiopathic scoliosis to ascertain if the multifidus muscles on the convex or concave side are abnormal and the relationship to curve severity. Materials and methods. Forty-six patients with adolescent idiopathic scoliosis, separated into two groups, were studied using a 1.5-T MR scanner with the synergy spine coil, employing a modified STIR (short tau inversion recovery) axial sequence obtained at the apex of the major scoliotic curve. Results. No hyperintense signal change was demonstrated in the convex side multifidus muscles in any patient. In group I, 16 of 18 patients with severe or rapidly progressive curve showed increase in signal intensity in the multifidus muscle on the concave side of the apex of the curve. In group II, of the 15 patients with mild curve (Cobb angle 10–30 °), 4 had increased signal intensity in the multifidus muscle on the concave side; of the 13 with more severe curve (Cobb angle greater than 30 °), 10 had increase in multifidus signal intensity on the concave side. Conclusions. The concave-side multifidus muscle at the apex of a scoliotic curve was morphologically abnormal. A significant association between abnormal signal change and curve severity was also established.

Treatment of idiopathic scoliosis with side-shift therapy: an initial comparison with a brace treatment historical cohort

Abstract: A group of 44 patients with idiopathic scoliosis (mean age 13.6 years) with an initial Cobb angle between 20° and 32° received side-shift therapy (mean treatment duration 2.2 years). A group of 120 brace patients (mean age 13.6 years) with an initial Cobb angle in the same range (mean brace treatment 3.0 years) was the historical reference group. Failure was defined as an increase of Cobb angle greater than 5° within 4 months or a Cobb angle greater than 35° or a total increase of Cobb angle greater than 10°. The chance of success was not significantly different between the side-shift and the brace groups, whether tested for efficiency (66% vs 68%) or efficacy (85% vs 90%). The difference in the mean progression of the Cobb angle for the respective groups is small (for efficiency: 3° vs –2°, for efficacy: 2° vs –1°). Side-shift therapy appears to be a promising additional treatment for idiopathic scoliosis in adolescents with an inital Cobb angle between 20° and 32°.

Long-Term Results in Patients Treated with Posterior Instrumentation and Fusion for Degenerative Scoliosis of the Lumbar Spine

Abstract: The authors report a homogeneously investigated and surgically treated series of 4 0 patients with degenerative scoliosis of the lumbar spine. The series included 22 females and 18 males with a mean age of 62.8 years. The clinical presentation, the diagnostic work-up, the indication for surgery, the surgical techniques and results are reported. Final evaluation was possible in 30 patients at a mean period of observation of 59.5 months. Following a very precise diagnostic and therapeutic protocol excellent, good and satisfactory surgical results were obtained in 13 (43.3%), 16 (53.3%) and 1 (3.3%) patients, respectively. While scoliosis was converted from a mean preoperative Cobb angle of 18.7° to 7.6° mean pre-operative lumbar lordosis was slightly augmented from 37° to 41.5°. The results suggest that maintainance or correction of lumbar lordosis is more important than the conversion of the scoliotic deformity which is probably treated sufficiently by partial correction and stabilization.

Adolescent idiopathic thoracic scoliosis: apical correction with specialized pedicle hooks

Abstract: Forty-one patients with thoracic adolescent idiopathic scoliosis (AIS) treated with only a posterior spine fusion using specialized pedicle hooks (SPH) (hooks augmented with 3.2-mm screws) at the apex of the curve were reviewed in order to assess the effectiveness of this correction method. Inclusion in the study group required a minimum of 2 years’ follow-up and the same strategy of correction where the apical vertebrae (3 or 4 vertebrae on the concave side) were instrumented with SPH. The mean preoperative Cobb angle was corrected from 55° (42°–80°) to 18° (67%) postoperatively and to 23° (58%) at the last follow-up (28–50 months) for a flexibility index of 46%. Apical vertebral translation was corrected to 70% at the last follow-up. Thoracic kyphosis remained unchanged, from 23° to 26°, and the lumbar lordosis went from –53° to –59°. The lumbar curve was corrected from 38° to 18°. Coronal balance improved from 10 to 1 mm; shoulder balance was improved from 15 to 5 mm. The rib hump was improved from an average of 30 mm preoperatively to 15 mm postoperatively, but only to 25 mm at the last follow-up (17% of correction). One case of a spastic bladder was observed postoperatively, which resolved completely after 8 months. Three patients had to have their instrumentation removed because of pain. There was no complication related to the use of the SPH. The authors conclude that apical correction with SPH allows effective scoliosis correction without spinal distraction and does not require supra- or infralaminar hook in the spinal canal.

Surgical correction of lumbar scoliosis: a comparison of different techniques. Results.

Abstract: Vertebral rotation is at the basis of structural scoliosis. Its measurement gives the possibility to evaluate the surgical correction. Three groups of five lumbar scolioses (means angle 45°) were treated with rotation of the convex rod (group 1), bending in situ (group 2) and bending associated with rotation of the convex screws (group 3). Cobb angle improvement was the same with the three techniques. The Vertebral Rotational Angle (VRA) and the most suitable Intervertebral Rotational Angle (IRA) were used for this study. IRA (difference of rotation between two consecutive vertebrae) stays the same whatever the reference axis and VRA depends on conditions of measurement. IRA is improved of 15% in group 1, 35% in group 2 and 54% in group 3.In situ bending associated with the rotation of the convex screws is a good method for correcting the torsion of the scoliotic lumbar spine.

Perioperative radiographic reconstruction of the scoliotic vertebral column

Abstract: We have developed a new per-operative three dimensional (3D) reconstruction technique to evaluate the 3D correction of a scoliotic spine induced by surgery using Cotrel-Dubousset instrumentation. A small object with 15 embedded markers was used to calibrate the radiographic system. During surgery, the calibration object was sterilized and fixed to the patient just before the acquisition of two pairs of posterior-anterior and sagittal radiographs; one pair before the rotation maneuver of the rod and one pair after the maneuver. The markers were digitized on each radiograph and their relative 3D positions were measured to establish the relation between the 3D positions of the anatomical structures and their 2D positions on the radiographs. This relation was used to calculate the 3D position of six anatomical landmarks per vertebra (the centers of the superior and inferior vertebral body endplates and the proximal and distal bodies of both pedicles) from the identification of these landmarks on each radiograph. We made a 3D representation of the thoracic and lumbar spine of three patients with idiopathic scoliosis undergoing corrective surgery by the posterior approach. Clinical indices (Cobb angle, axial rotation and the plane of maximum curvature) computed from the 3D reconstruction of the spine obtained before and after the rotation maneuver of the rod were compared to evaluate the 3D correction performed during the surgery. The new proposed approach allows the surgeon to evaluate the per-operative shape of the spine. This approach is simpler, faster and less risky for the patient than the previous method which employed an electromagnetic digitizer to measure the 3D coordinates of anatomical landmarks located on the posterior part of the spine. Furthermore, the 3D representation of the spine visualized from different points of view gives the surgeon an accurate evaluation of the 3D correction during the surgical procedure.

Flexible and semi-early vertebral instrumentation in surgical treatment of Duchenne muscular dystrophy scolioses

Abstract: 1) Purpose of the study The purpose of this work is to demonstrate the advantage of early surgical intervention for those suffering from Duchenne muscular dystrophy scoliosis 2) Material: This review relates to 37 patients suffering from Duchenne muscular dystrophy There are detailed results in connection with the first 24, curves offering the longest follow-up period, each a minimum of at least three years The study on complications relates to the first 37 cases 3) Methods: Surgery on all patients involved the insertion of flexible vertebral instrumentation This instrumentation comprises a pedicular screwing system in the lumbar-sacral area and transversal attachments with steel threads at the thoracic level Bone bank arthrodesis was performed only at lumbo-sacral level, in order to maintain flexibility in the thoracic part of the assembly and to maintain growth 4) Results: Throughout the series no further intervention was necessary for technical reasons Four superficial sepses were treatable locally along with an antibiotherapy without removal of material Regretfully there was one stem rupture two years after operation, caused by a road traffic accident There was no death during the longest follow-up period In the frontal plane, the pre-operative Cobb angle was 19° It was brought to 52° at the post-operative stage, and at the latest measurement was 950, ie a loss of angular correction of 4,3° In the sagittal plane, there are physiological curvatures Pelvic balancing is correct and results have held over time Pre-operative vital capacity was 62 %, since then it has reduced by 36 % per year 5) Discussion: These results and a review of the literature encourage us to operate early on these patients in order to avoid anaesthetic, peri- and postoperative complications Likewise, operating early, and therefore giving support to minor curves, reduces mechanical constraints during the first postoperative years Changes in vital capacity as recounted in literature show contradictory results These do not allow conclusions to be drawn as to whether it stabilises It seems partly to lessen its deceleration The absence of thoracic arthrodesis enables growth of about 5 cm where patients are operated on at about the age of 12 years 6) Conclusion: Stabilisation of the myopath's spine enables the child to remain in an upright sitting position The assembly's thoracic suppleness enables us to increase the range of movement in the upper limbs It seems appropriate to operate on such patients when they cease walking, around the age of 12 Likewise, while neither respiratoty function nor life expectancy is improved, we note that most patients, and those around them, are very satisfied by the comfort brought about by the intervention

Correlation study between spinal curvatures and vertebral and disk deformities in idiopathic scoliosis

Abstract: Idiopathic scoliosis involves complex tridimensional (3D) deformations of the spine associated with intrinsic alterations (wedging) of vertebral bodies (VB) and intervertebral disks (ID). This study intends to evaluate analytically in vivo 2D and 3D scoliotic descriptors, based on clinical data from 40 thoracic curves of scoliotic adolescents, and to establish relationships between the regional curve deformations and the local VB and ID deformities. A multiplanar radiographic technique provided 3D positioning of vertebral landmarks. Cobb angle in the postero-anterior (PA) view, in the plane of maximum deformity (CobbP.Max) and the angular orientation of the plane of maximum deformity were used as regional descriptors. Vertebral body endplates were modeled as 3D oriented ellipses. Axial rotation, global PA and local frontal wedgings (inclinations of projected ellipses in the global and vertebral frontal planes), 3D maximum wedging (real inclination of adjacent ellipses) as well as the angular orientation of 3D wedging were calculated to characterize local deformations at the thoracic apex. Mean values for CobbPA, CobbP.Max and the angular orientation of the maximum deformity (with respect to the sagittal plane) reached 44 degrees, 48 degrees and 67 degrees respectively. On average, vertebral axial rotation, global PA, local frontal and 3D wedging angles were respectively 15 degrees, 8.3 degrees, 8.2 degrees and 9.7 degrees. Analyses indicated statistical correlation between: a) Cobb angles and vertebral wedging; b) the orientations of the maximum deformity and of 3D vertebral wedging; c) the axial rotation and CobbPA; d) the axial rotation and the angular orientation of 3D vertebral wedging. At the thoracic level, statistical analyses indicated that vertebral wedging and axial rotation increase with curve progression. Scoliosis severity, as measured by Cobb angles, evolves simultaneously to a coronalization of the plane of maximum deformity, revealing an hypokyphotic phenomenon, and to a real vertebral wedging shifting towards the frontal plane of the vertebra. These 3D in vivo analyses allowed interpretation of spatial relationships between regional and local scoliotic deformities. Compared to 2D in vivo or 3D in vitro analyses alone, this 3D in vivo study provides a more complete assessment of spinal curve progression to fully interpret the real 3D curvature and intrinsic deformations as well as their evolution processes.

Non-radiographic analysis of the pediatric spine in adolescent idiopathic scoliosis

Abstract: Radiation exposure in girls with adolescent idiopathic scoliosis has been reported to increase their risk of reproductive pathology. A novel non-radiographic technique to quantify scoliosis, statically and dynamically, has been developed for use in conjunction with radiographic methods. Using a three-dimensional motion analysis system, a spine and rib cage model is used to quantify clinical measurements such as Cobb angle, lateral deviation of the spine, kyphosis and lordosis, pelvic tilt and trunk rotation.