Showing papers on "Cobb angle published in 2004"

The Effect of Opening Wedge Thoracostomy on Thoracic Insufficiency Syndrome Associated with Fused Ribs and Congenital Scoliosis

Abstract: Background: Thoracic insufficiency syndrome is the inability of the thorax to support normal respiration or lung growth and is seen in patients who have severe congenital scoliosis with fused ribs. Traditional spinal surgery does not directly address this syndrome. Methods: Twenty-seven patients with congenital scoliosis associated with fused ribs of the concave hemithorax had an opening wedge thoracostomy with primary longitudinal lengthening with use of a chest-wall distractor known as a vertical, expandable prosthetic titanium rib. Repeat lengthenings of the prosthesis were performed at intervals of four to six months. Radiographs were analyzed with respect to correction of the spinal deformity, as indicated by a change in the Cobb angle, and lateral deviation of the spine, as indicated by the interpedicular line ratio. Spinal growth was assessed by measuring the change in the length of the spine. Correction of the thoracic deformity and thoracic growth were assessed on the basis of the increase in the height of the concave hemithorax compared with the height of the convex hemithorax (the space available for the lung), the increase in the thoracic spinal height, and the increase in the thoracic depth and width. The thoracic deformity in the transverse plane was measured with computed tomography, and the scans were analyzed for spinal rotation, thoracic rotation, and the posterior hemithoracic symmetry ratio. Clinically, the patients were assessed on the basis of the relative heights of the shoulders and of head and thorax compensation. Pulmonary status was evaluated on the basis of the respiratory rate, capillary blood gas levels, and pulmonary function studies. Results: The mean age at the time of the surgery was 3.2 years (range, 0.6 to 12.5 years), and the mean duration of follow-up was 5.7 years. All patients had progressive congenital scoliosis, with a mean increase of 15°/yr before the operation. The scoliosis decreased from a mean of 74° preoperatively to a mean of 49° at the time of the last follow-up. Both the mean interpedicular line ratio and the space available for the lung ratio improved significantly. The height of the thoracic spine increased by a mean of 0.71 cm/yr. At the time of the last follow-up, the mean percentage of the predicted normal vital capacity was 58% for patients younger than two years of age at the time of the surgery, 44% for those older than two years of age (p < 0.001), and 36% for those older than two years of age who had had prior spine surgery. In a group of patients who had sequential testing, all increases in the volume of vital capacity were significant (p < 0.0001), but the changes in the percentages of the predicted normal vital capacity were not. There was a total of fifty-two complications in twenty-two patients, with the most common being asymptomatic proximal migration of the device through the ribs in seven patients. Conclusions: Opening wedge thoracostomy with use of a chest-wall distractor directly treats segmental hypoplasia of the hemithorax resulting from fused ribs associated with congenital scoliosis. The operation addresses thoracic insufficiency syndrome by lengthening and expanding the constricted hemithorax and allowing growth of the thoracic spine and the rib cage. The procedure corrects most components of chest-wall deformity and indirectly corrects congenital scoliosis, without the need for spine fusion. The technique requires special training and should be performed by a multispecialty team. Level of Evidence: Therapeutic study, Level IV (case series [no, or historical, control group]). See Instructions to Authors for a complete description of levels of evidence.

Effects of a cervical disc prosthesis on segmental and cervical spine alignment.

Abstract: Object Cervical arthroplasty offers the promise of maintaining motion of the functional spinal unit (FSU) after anterior cervical discectomy The impact of cervical arthroplasty on sagittal alignment of the FSU needs to be addressed, together with its effect on overall sagittal balance of the cervical spine Methods The authors prospectively reviewed radiographic and clinical outcomes in 14 patients who received the Bryan Cervical Disc prosthesis (Medtronic Sofamor Danek, Memphis, TN), for whom early (� 6 months) and late (6–24 months) follow-up data were available Static and dynamic radiographs were measured by hand and computer to determine the angles formed by the endplates of the natural disc preoperatively, those formed by the shells of the implanted prosthesis, the angle of the FSU, and the C2–7 Cobb angle The range of motion (ROM) was also determined radiographically, whereas clinical outcomes were assessed using the Neck Disability Index (NDI), and Short Form–36 (SF-36) questionnaires The ROM was preserved following surgery, with a mean preoperative sagittal rotation angle of 896˚, which was not significantly different from the late postoperative value of 825˚ When compared with the preoperative disc space angle, the shell endplate angle in the neutral position became kyphotic in the early and late postoperative periods (mean change � 38˚ in the late follow-up period; p = 00035) The FSU angles also became significantly more kyphotic postoperatively, with a mean change of � 6˚ (p = 00006) The Cobb angles varied widely preoperatively and did not change significantly after surgery There was no statistical correlation between the NDI and SF-36 outcomes and cervical kyphosis Conclusions Cervical arthroplasty preserves motion of the FSU Both the endplate angle of the treated disc space and the angle of the FSU became kyphotic after insertion of the Bryan prosthesis The overall sagittal balance of the cervical spine, however, was preserved

Kyphoplasty: report of eighty-two thoracolumbar osteoporotic vertebral fractures.

Abstract: Objectives: Document initial outcomes of balloon kyphoplasty. Design: Retrospective analysis of the first 52 patients with 82 painful vertebral body compression fractures secondary to osteoporosis treated at our institution. Setting: Operation on subacute painful fractures with office follow-up. Patients/Participants: First 82 fractures in 52 patients treated. All patients had failed nonoperative treatment and had magnetic resonance imaging scans documenting edematous changes of the vertebral body. Forty-nine out of 52 patients presented for follow-up at an average of 37 weeks. Intervention: Minimally invasive balloon reduction via bilateral transpedicular or extrapedicular approaches followed by polymethyl methacrylate fixation. Main Outcome Measures: Vertebral body height, Cobb angle, visual analogue pain scale, Roland-Morris Disability Survey, and complication rate. Results: Mean length of follow-up was 9 months (37 weeks, range 4-99 weeks); improved height 4.6 and 3.9 mm in the anterior and medial columns, respectively (P > 0.05); Cobb angle increased 14% (P < 0.05), visual analogue pain scale score improved 7 points (P < 0.05); Roland-Morris Disability Survey improved 11 points (P < 0.05); no adverse medical or procedural complications; 9.8% cement leakage rate. Conclusion: Balloon kyphoplasty safely improves vertebral body height and patient quality of life.

Kyphosis does not equal vertebral fractures: the Rancho Bernardo study.

Abstract: OBJECTIVES: Kyphosis is considered a clinical sign of osteoporotic vertebral fractures. We examined the association of radiographically defined kyphosis with vertebral fractures to determine if this belief was true. METHODS: A total of 1407 ambulatory white adults, aged 50-96 years, from the middle-class community of Rancho Bernardo, California, USA, attended a 1992-96 research clinic visit. Bone mineral density (BMD) was measured at the hip and spine, and lateral thoracolumbar spine radiographs were obtained. The degree of kyphosis was determined using the modified Cobb method. RESULTS: A total of 114 of 553 men (20.6%) and 188 of 854 women (22.0%) had one or more thoracic vertebral fractures. Degenerative disc disease was observed in 45.4% of men and 56.7% of women. The mean age-adjusted Cobb angle was significantly higher (p or = 55.5 degrees ), only 36.2% of men and 36.9% of women had prevalent thoracic vertebral fractures; and osteoporosis using WHO BMD criteria was present at the total hip in 9.7% of men and 32.7% of women. CONCLUSION: The majority of men and women with exaggerated kyphosis (the upper quartile of the Cobb angle) had no evidence of thoracic vertebral fractures or osteoporosis. Degenerative disc disease, not vertebral fractures, was the most common finding associated with radiographically defined angle of kyphosis in men and women. Thus kyphosis per se should not be considered diagnostic of osteoporosis. Nevertheless, patients with exaggerated kyphosis should be evaluated for underlying osteoporotic fracture.

Implant removal for late-developing infection after instrumented posterior spinal fusion for scoliosis: reinstrumentation reduces loss of correction. A retrospective analysis of 45 cases

Abstract: A retrospective follow-up study of patients who, having undergone instrumented posterior spinal fusion for scoliosis, experienced late infection and then underwent either implant removal alone or implant removal and instrumented refusion. We conducted this study to determine whether it is possible to avoid loss of correction by a single-stage implant removal and reinstrumentation procedure. There have been a few reports of late-appearing infections after spinal instrumentation. Implant bulk, metallurgic reactions, and contamination with low-virulence microorganisms have been suggested as possible etiologic factors. The clinical symptoms include pain, swelling, redness, and spontaneous drainage of fluid. Complete instrumentation removal and systemic antibiotics is usually curative. We retrospectively reviewed 45 patients who underwent instrumented posterior spinal fusion for scoliosis and experienced development of late infections and, after a mean of 3 years after the initial procedure, either underwent implant removal alone [n=35, instrumentation removal (HR) group] or additionally underwent reinstrumentation and fusion [n=10, reinstrumentation and fusion (RI&F) group]. Three patients were reinstrumented 1.5 years after instrumentation removal, and seven underwent a one-stage rod removal and reinstrumentation/refusion procedure. Allergic predisposition, protracted postoperative fever, and pseudarthrosis appear to increase the risk of late-developing infection after posterior spinal fusion. All wounds in both groups healed uneventfully. Preoperative radiographic Cobb measurements showed no statistically significant between-group differences. At follow-up, however, outcome was clearly better in the RI&F group: Loss of correction was significantly smaller in reinstrumented patients. Thus, the thoracic Cobb angle was 28±16° (range 0–55°) in the RI&F group versus 42±15° (21–80°) in the HR group, and the lumbar Cobb angle was 22±11° (10–36°) in the RI&F group versus 29±12° (13–54°) in the HR group. The results of our study demonstrate that wound healing is usually uneventful after instrumentation removal for late infection, also when patients undergo instrumented refusion in a one-stage procedure. Reinstrumentation appears to achieve permanent correction of scoliosis.

Safety and efficacy of Isola instrumentation and arthrodesis for adolescent idiopathic scoliosis: two- to 12-year follow-up.

Abstract: STUDY DESIGN Retrospective case series including patient outcome assessment. OBJECTIVE To study the safety and efficacy of Isola instrumentation in comparison with similar series. SUMMARY OF BACKGROUND DATA Both the technique and technology used in the surgical treatment of adolescent idiopathic scoliosis continue to evolve, the common theme since the 1980s being provision of instrumentation stable and strong enough to eliminate the need for postoperative immobilization. The purpose of this study is to determine the safety and efficacy of a system deliberately integrating hook, wire, and screw anchors to deliver torsional and countertorsional corrective loads. METHODS A total of 185 consecutive patients, index patient included, were treated by posterior instrumentation and arthrodesis from January 1989 through December 2000. Safety was studied by complications, and reoperation type and occurrence. Effectiveness was studied by deformity correction and health-related quality of life questionnaire response. Variables affecting effectiveness were sought. A total of 179 patients (97%) had outcome assessment at an average of 6 years postoperative, and 176 had radiographic evaluation at an average of 5 years postoperative. RESULTS There were no deaths, spinal cord or nerve root problems, or acute posterior wound infections. Proven pseudarthrosis occurred in 4 patients (2.2%) and delayed deep wound infection in 2 patients (1.1%). The implant-related reoperation rate was 8% and was necessary more often in the first quarter of the series (17% vs. 4.6%, P = 0.0062). The largest Cobb angle averaged 62 degrees preoperative and 23 degrees at latest follow-up, 63% correction. The largest angle of trunk inclination averaged 16.7 degrees before surgery and 9.9 degrees at latest follow-up, a 39% correction (P < 0.0001). Eighty-eight percent of patients were satisfied or very satisfied with the outcome. The principal problems identified were the need for a stronger transverse connector, stable end-instrumented vertebrae foundations, and convex thoracic anchorage. CONCLUSIONS Isola instrumentation seems to be at least as safe and effective as other instrumentations being used for the surgical treatment of adolescent idiopathic scoliosis.

Cotrel-Dubousset (CD) or Universal Spine System (USS) instrumentation in adolescent idiopathic scoliosis (AIS): comparison of midterm clinical, functional, and radiologic outcomes.

Abstract: Study design A retrospective comparison of the clinical, radiologic, and functional results of Cotrell-Dubousset (CD) and Universal Spine System (USS) instrumentation for adolescent idiopathic scoliosis (AIS). Objectives To establish whether there are any differences in outcome between the 2 instrumentation systems. Summary of background data CD is the first complex posterior double rod instrumentation system to provide multiple hook fixation. USS instrumentation permits the use of rod translation instead of rod rotation, the option to secure pedicle hooks with fixation screws, and the option to use transpedicular screws in the lower thoracic and lumbar spine. Midterm and long-term results of USS instrumentation are lacking. Methods Fifty-seven (mean age, 28 years at follow up) patients treated with CD instrumentation and 55 (mean age, 23 years at follow up) patients treated with USS instrumentation for AIS participated in the study. The average follow-up rate was 80% and time 13.0 years for the CD group, and 95% and 7.8 years for the USS group. Radiographs were obtained before surgery, at 2-year follow up, and at final follow up. Additionally, a physical examination was performed by 2 independent observers, and the Scoliosis Research Society (SRS) questionnaire was completed; spinal mobility and nondynamometric trunk strength were measured at the final follow-up visit. RESULTS.: The mean Cobb angle of the instrumented thoracic curve was before surgery 55 degrees (range, 36-83 degrees for the CD and 52 degrees (range, 35-85 degrees) for the USS group. The mean number of instrumented vertebrae was 9.9 (range, 7-12) in the CD and 9.8 (range, 6-12) in the USS group. At final follow up, the mean angles were 32 degrees (range, 13-63 degrees) for the CD group and 29 degrees (range, 9-63 degrees) for the USS group (not significant). No significant difference was observed in thoracic kyphosis or lumbar lordosis between the study groups at final follow up. In the SRS questionnaire, the total score averaged 97 for the CD and 101 for the USS groups, respectively. In the questionnaire, 6 (11%) patients in the CD group, but none in the USS group, reported having low back pain often or very often at rest. No correlation was found between the Cobb angle of the thoracic or lumbar curves at follow up and the total score or back pain indexes of this questionnaire. Nondynamometric trunk strength measurements corresponded with age- and sex-adjusted reference values, on average, but patients in the CD group performed significantly better in the squatting test (P = 0.021) and patients in the USS group performed better in trunk side bending (P = 0.004). Complications were recorded in 15 (26%) patients in the CD and in 13 (24%) patients in the USS group (not significant). Conclusions The midterm radiologic and functional outcomes were quite similar in both groups as were the SRS scores. The patients performed, on average, as well as did the reference population in nondynamometric trunk strength measurements. Intraoperative and late complications were similar in both groups.

Results of thoracoscopic instrumented fusion versus conventional posterior instrumented fusion in adolescent idiopathic scoliosis undergoing selective thoracic fusion.

Abstract: Study design Retrospective review of 31 consecutive female patients with adolescent idiopathic scoliosis undergoing selective thoracic fusion. Objective To compare safety and efficacy of two techniques in treating adolescent idiopathic scoliosis undergoing selective thoracic fusion. Summary of background data There is paucity in the literature comparing posterior versus thoracoscopic instrumented fusion in scoliosis. Methods Nineteen patients (group 1) underwent posterior instrumented fusion. Twelve patients (group 2) had thoracoscopic anterior instrumented fusion. All patients had a minimum of 25 months of follow-up observation. Results Both groups were similar in terms of age at menarche and surgery. Preoperative Cobb angles in the coronal (erect and bending) and sagittal planes did not differ between the two groups. Group 1 patients had higher estimated blood loss (P = 0.006). Operative time (P Conclusions The efficacy of thoracoscopic surgery was similar to standard posterior procedures. Advantages included lower intraoperative blood loss. The longer operative time and intensive care unit stay were attributed to the steep learning curve of this technique.

Biomechanical simulations of the spine deformation process in adolescent idiopathic scoliosis from different pathogenesis hypotheses

Abstract: It is generally recognized that progressive adolescent idiopathic scoliosis (AIS) evolves within a self-sustaining biomechanical process involving asymmetrical growth modulation of vertebrae due to altered spinal load distribution A biomechanical finite element model of normal thoracic and lumbar spine integrating vertebral growth was used to simulate the progression of spinal deformities over 24 months Five pathogenesis hypotheses of AIS were represented, using an initial geometrical eccentricity (gravity line imbalance of 3 mm or 2 degrees rotation) at the thoracic apex to trigger the self-sustaining deformation process For each simulation, regional (thoracic Cobb angle, kyphosis) and local scoliotic descriptors (axial rotation and wedging of the thoracic apical vertebra) were evaluated at each growth cycle The simulated AIS pathogeneses resulted in the development of different scoliotic deformities Imbalance of 3 mm in the frontal plane, combined or not with the sagittal plane, resulted in the closest representation of typical scoliotic deformities, with the thoracic Cobb angle progressing up to 39 degrees (26 degrees when a sagittal offset was added) The apical vertebral rotation increased by 7 degrees towards the convexity of the curve, while the apical wedging increased to 85 degrees (73 degrees with the sagittal eccentricity) and this deformity evolved towards the vertebral frontal plane A sole eccentricity in the sagittal plane generated a non-significant frontal plane deformity Simulations involving an initial rotational shift (2 degrees ) in the transverse plane globally produced relatively small and non-typical scoliotic deformations Overall, the thoracic segment predominantly was sensitive to imbalances in the frontal plane, although unidirectional geometrical eccentricities in different planes produced three-dimensional deformities at the regional and vertebral levels, and their deformities did not cumulate when combined These results support the hypothesis of a prime lesion involving the precarious balance in the frontal plane, which could concomitantly be associated with a hypokyphotic component They also suggest that coupling mechanisms are involved in the deformation process

Weight-bearing radiographs in thoracolumbar fractures: do they influence management?

Abstract: Study design Prospective observational study. Objective Our objective was to compare supine and erect (weight-bearing) radiographs in patients with thoracolumbar fractures without a neurologic deficit and to determine whether the erect radiographs alter the deformity and the management plan. Summary of background data Nonoperative treatment for thoracolumbar fracture without a neurologic deficit is safe and effective. There are some guidelines in the literature that provide objective standards to identify the patients that are suitable for nonoperative treatment. These guidelines are based on measurements on supine radiographs. The role of weight-bearing radiographs in influencing the management plan of these injuries has not been explored. Methods Fractures between T11 and L2 in 28 patients were considered suitable for nonoperative treatment initially. Radiographic measurements included anterior and posterior vertebral body heights, interpedicular distance, and the Cobb angle on the supine and erect radiographs. A change in the treatment from the initial nonoperative management plan, based on the radiographic findings, was recorded. Results Mean supine Cobb angle of 11 degrees increased to 18 degrees on weight-bearing films. The mean anterior vertebral compression increased from 34% to 46%. No change was noted between the posterior vertebral heights and the interpedicular distance. Seven of the 28 patients were subjected to surgical stabilization based on these findings. Conclusion Performing erect radiographs in patients with thoracolumbar fractures without a neurologic deficit provides additional information and did alter the management plan in a significant proportion (25%) of our patients.

The assessment of intraobserver and interobserver error in the measurement of noncongenital scoliosis in children ≤ 10 years of age

Abstract: STUDY DESIGN: Retrospective review of scoliosis radiographs. OBJECTIVES: To determine measurement variability in children < or = 10 years of age with noncongenital scoliosis. SUMMARY OF BACKGROUND DATA: Measurement variability in congenital and adolescent idiopathic scoliosis has been studied. There is no study of measurement variability in young children with noncongenital scoliosis. METHODS: A retrospective review of children < or = 10 years of age followed for noncongenital scoliosis was performed. End vertebrae were identified on radiographs, and the curves were measured (Cobb method) twice by each of six observers. The same soft lead pencil and goniometer was used. Intraobserver and interobserver variability for continuous data was determined. RESULTS: There were 64 children. The diagnosis was infantile/juvenile idiopathic scoliosis in 42, neuromuscular scoliosis in 7, scoliosis associated with mesenchymal disorders or other syndromes in 12, and unknown in 3 children. The curve was thoracic in 54, thoracolumbar in 8, and lumbar in 2. There were 19 left and 45 right curves. The average age was 6.6 +/- 2.6 years. There were a total of 768 Cobb angle measurements with an average Cobb angle of 38 +/- 22 degrees (range, 10 degrees -115 degrees ). Intraobserver variability was +/- 6 degrees; interobserver variability was +/- 7 degrees. CONCLUSION: In children < or =10 years of age with noncongenital scoliosis, intraobserver measurement variability in Cobb angle measurement is +/- 6 degrees and interobserver variability is +/-7 degrees. To be certain that there is a significant difference between Cobb angle measurements in children with noncongenital scoliosis and < or = 10 years of age there must be a change of at least +/-7 degrees.

Traction radiography performed under general anesthetic: a new technique for assessing idiopathic scoliosis curves.

Abstract: STUDY DESIGN A prospective review of 24 patients with late-onset idiopathic scoliosis. OBJECTIVES.: To compare curve flexibility measured using supine bending radiography and traction radiography; to examine the correlation of each technique with postoperative correction; and to determine the influence of each technique on the decision to perform concomitant anterior release surgery with posterior instrumentation. SUMMARY OF BACKGROUND DATA Assessment of curve flexibility is important in decision making before surgical correction of scoliosis. Supine bending radiographs are presently the gold standard technique by which flexibility is assessed, but their reliability has been questioned. No literature has shown a conclusively superior role for traction radiography in assessing idiopathic scoliosis curves. METHODS Each patient had erect anteroposterior radiographs and supine bending radiographs. On the day of surgery, traction radiography was performed under general anesthetic. The correction obtained in the Cobb angle between the bending and traction radiographs was compared. The influence of the traction radiography on the decision for anterior release surgery and its correlation with postoperative result was examined. RESULTS Traction radiography demonstrated significantly greater curve flexibility than supine bending radiographs (P < 0.001). Eleven of 13 patients planned for anterior release surgery and posterior instrumentation avoided anterior release after review of the traction radiography. No significant difference was demonstrated between the traction radiography and postoperative correction (P = 0.13). CONCLUSION Traction radiography is superior to supine bending radiography in assessing curve mobility before surgery. This method benefits patients by allowing them to avoid anterior release surgery and helps predict postoperative correction.

Convex growth arrest in the treatment of congenital spinal deformities, revisited.

Abstract: The authors studied 32 patients to delineate the reliability of well-defined but frequently extended indications to define the ideal patient who will benefit from convex growth arrest. Mean age at the time of convex growth arrest was 29 (range 6-72) months, and average follow-up was 40 (24-120) months. Mean Cobb angle was 55 degrees (31-105 degrees) before surgery and 50 degrees (13-107 degrees) at final follow-up. Thirteen patients (41%) had a true epiphysiodesis effect, while 15 (47%) had fusion and 4 (12%) had progression. The age at surgery, magnitude, length and location of the curve, presence of intraspinal anomaly, and presence of sagittal plane or rib deformity were investigated in terms of the outcome, but none of these parameters was found to have an effect on the outcome. In conclusion, convex growth arrest is a safe and effective method in the management of the young patients with congenital spinal deformities. It can be performed for the balanced and cosmetically acceptable deformities of patients younger than 5 years of age regardless of the type, length, magnitude, and location of the curve, the existence of associated rib fusion, or the presence of sagittal plane abnormality.

The relation between electromyography and growth velocity of the spine in the evaluation of curve progression in idiopathic scoliosis.

Abstract: Study Design. A prospective study in which patients with idiopathic scoliosis were examined longitudinally by radiographic and electromyographic measurements according to a protocol. Objectives. To measure the growth velocity of the spine and the electromyographic ratio of the paraspinal muscles to determine their relation to progression of the scoliotic curve. Summary of Background Data. Several factors have been reported to be involved in the progression of idiopathic scoliosis. Possible factors may be growth disturbances and muscular abnormality. Methods. Thirty patients with idiopathic scoliosis were examined over periods of 4 to 5 months. The periods were scored for progression, defined as an increase in Cobb angle of >10degrees. Spinal growth velocity was measured as the length difference of the scoliotic spine between two consecutive radiographs. The electromyographic activity on both sides of the spine expressed as an electromyographic ratio was measured during relaxed upright standing using bipolar surface electrodes. Predictability of progression was evaluated with regression analysis and receiver operating characteristic analysis. Results. There was an independent association between both spinal growth velocity and electromyographic ratio and progression of the scoliotic curve. An equal sensitivity and specificity of spinal growth velocity for progression of 79.1% was observed at a growth velocity cutoff point of 11 mm/year. Similarly, a cutoff point of 1.25 for the electromyographic ratio could be determined with a predictive value for progression of 68.9%. In the presented nomogram, a spinal growth velocity >15 mm/year combined with an electromyographic ratio >2 gave an 89% probability of progression of the scoliotic deformity. Growth velocities Conclusions. The combined measurement of spinal growth velocity and electromyographic ratio has significant predictive potential and may be valuable in the evaluation and treatment of idiopathic scoliosis.

Is there a need for anterior release for 70–90° thoracic curves in adolescent scoliosis?

Abstract: Large and stiff thoracic scoliotic curves in the adolescent represent a classic indication of anterior release followed by posterior instrumentation. However, third-generation segmental spinal instrumentations have shown increased correction of thoracic curves. Indication for an anterior release may therefore not be required even in large and stiff thoracic curves. The objective of the study was, therefore, to analyze retrospectively the results of third-generation segmental posterior instrumentation in large and stiff thoracic curves and to compare our results with the current literature of anterior release followed by posterior instrumentation. An independent observer, who had not participated in any of the case, reviewed our electronic database of adolescent scoliosis surgery (Scolisoft) with the following query: thoracic curves, Cobb angle between 70° and 90° and posterior surgery only. He was able to identify 19 patients whose thoracic curves were measured between 70° and 90°. Out of these, four had convex-side bending Cobb angle values of less than 45° and were not included in the study, as they were judged too flexible. Fifteen patients (aged 11–18 years, mean 13.6 years) with thoracic scoliosis were left for the study (average Cobb angles 78.5° with a flexibility index of 32.5% (range, 19–42%). The mean follow-up period was 32 months (range 18–64 months). Classic parameters of deformity correction were analysed. The average operative time was 314 min and the mean total blood loss was 1,875 ml. Average level of instrumented vertebrae was 12 (Range, 10–14). Postoperatively, the thoracic Cobb angle was measured at 34.8° (range, 25–45°), which represents a correction rate of 54% (range, 40.0–67.1%) and remained unchanged at the last follow-up (35°). Patients with thoracic hypokyphosis improved from an average 11° to 18°. There were three complications (one excessive bleeding, one early infection and one late infection). One case showed an add-on phenomenon at the last follow-up. Coronal balance was improved from 1.8 cm (Range 0–4cm) down to 0.75 cm (range 0–2.5 cm). Shoulder balance was improved from 1.3 cm (range 0–4cm) down to 0.75 (0–2.5 cm). All patients reported satisfactory results except the patient with an adding-on phenomena. In the literature, most of the results of anterior thoracoscopic release and posterior surgery give a percentage of Cobb angle correction similar or inferior to our series for an average initial Cobb angle of less magnitude. Therefore, with adequate posterior release, and the use of third-generation segmental instrumentation there is no need for anterior release even for curves in the 70–90° range.

Factors determining the final outcome of treatment of idiopathic scoliosis with the Boston brace: a longitudinal study

Abstract: This study tries to determine factors influencing the final outcome of treatment of idiopathic scoliosis with the Boston brace and to compare the results with the natural history. One hundred and fifty-one patients, 130 girls and 21 boys, treated between 1982 and 1991, were reviewed. A series of continuous and categorical variables were measured, allowing for the construction of a multiple regression equation. Continuous variables were age at discovery of the curve, time of interval between discovery and treatment and age at the beginning of treatment. Furthermore age of menarche, duration of treatment, duration of weaning and age and time of follow-up were noted. Continuous numerical variables were the Cobb angle, the apical vertebral rotation, and the Risser stage. Categorical variables consisted of the results of a questionnaire and the King's classification of the curve. Good results are achieved in older children, with low Cobb angles and advanced maturity, who are, however, the very ones not expected to progress, as also indicated in studies on natural history. Brace treatment seems not to alter the natural history in general, and especially not in the older child; this is the case from age 12 years and Risser stage 2 onwards. In the younger child, a brace is probably still indicated, because it has been proved that a scoliosis is more prone to progress and that a possible positive result can still not be ruled out, as long as randomized control trials are not conducted.

Progression of scoliosis after spinal fusion in Duchenne’s muscular dystrophy

Abstract: A consecutive series of 85 patients with Duchenne's muscular dystrophy who underwent spinal fusion over a period of 16 years was followed up with regard to the progression of the scoliosis and pelvic obliquity. Of 74 patients with adequate radiographic follow-up, 55 were instrumented with the Luque single-unit rod system and 19 with the Isola pedicle screw system; seven were instrumented to L3/4, 42 to L5, 15 to S1 and 10 to the pelvis with intrailiac rods. The mean period of follow-up was 49 months (SD 22) before and 47 months (SD 24) after operation. There was one peri-operative death and three cases of failure of hardware. The mean improvement in the Cobb angle was 26 degrees and in pelvic obliquity, 9.2 degrees. Fusion to L3/4 achieved a poorer correction of both curves while intrapelvic rods, achieved and maintained the best correction of pelvic obliquity. Fusion to S1 did not provide any benefit over more proximal fusion excluding the sacrum, with regard to correction and maintenance of both angles. The Isola system appeared to provide and maintain a slightly better correction of the Cobb angle.

Biomechanical modelling of growth modulation following rib shortening or lengthening in adolescent idiopathic scoliosis.

Abstract: A biomechanical model was developed to evaluate the long-term correction resulting from rib shortening or lengthening in adolescent idiopathic scoliosis (AIS). A finite element model of the trunk, personalised to the geometry of a scoliotic patient, was used to simulate rib surgery. Stress relaxation of ligaments following surgery was integrated into the model, as well as longitudinal growth of vertebral bodies and ribs and its modulation due to mechanical stresses. Simulations were performed in an iterative fashion over 24 months. A concave side rib shortening, inducing load patterns on the vertebral end-plates that could act against the scoliosis progression, was tested. A fractional factorial experimental design of 16 runs documented the effects of six modelling parameters. Wedging of the apical vertebra in the frontal plane decreased from 5.2° initially to a mean value of 3.8° after 24 months. The wedging decrease in the thoracic apical region was reflected by changes in the spine curvature, with a Cobb angle decrease from 46° to 44° immediately after the surgery and to a mean of 41° after 24 months. However, both rib hump and vertebral axial rotation increased, on average, by 4° at the curve apex. The most significant parameters were the growth sensitivity to stress in ribs and vertebrae and the rate of stress relaxation of intercostal ligaments. The results confirmed the potential of long-term correction of spinal curvature resulting from the rib shortening on the concavity. This modelling approach could be used for further design of less invasive surgery, taking into account residual growth, for scoliosis correction.

Kyphectomy in myelomeningocele with a modified Dunn-McCarthy technique followed by an anterior inlayed strut graft

Abstract: Rigid congenital kyphosis in myelomeningocele is associated with an important morbidity with skin breakdown, recurrent infection, and decreased function. Kyphectomy is the classic treatment to restore spinal alignment; however, surgery is associated with an important morbidity and long-term correction is uncertain. The authors retrospectively reviewed 9 patients with a mean age of 8.8 years who underwent a two stage surgical procedure: first a posterior kyphectomy with a modified Dunn-McCarthy fixation consisting of lumbar pedicle screws and long S-shape rods buttressing the anterior sacrum. Then a second stage done several weeks later consisting of a thoraco-abdominal approach to the spine with an inlay strut graft classically from T10-S1. The mean follow-up was 34 months (range 1-5 years). The kyphosis was corrected from a mean of 110 degrees of Cobb angle (range 70-130 degrees) to 15 degrees after surgery (45-0 degrees). There was no instrumentation failure, no loss of correction and no pseudarthrosis. Complications consisted of one intra-operative cardiac arrest fortunately reversible, a wound necrosis, one deep venous thrombosis and one late aseptic bursitis on the posterior hardware. Congenital kyphosis in myelomeningocele can be treated successfully with an initial posterior approach correction and instrumentation followed by an anterior approach allowing for anterior inlay impacted structural graft. The authors believe that this technique improves biomechanical and biological fusion mass anteriorly and will prevent late instrumentation failure and loss of correction.

Prospektive Untersuchung zur Korsettbehandlung bei idiopathischen Skoliosen

Abstract: AIM To prospectively evaluate the results of brace treatment in idiopathic scoliosis and to define risk factors of treatment failure. METHOD Fifty-two patients with a Cobb angle of between 25 and 40 degrees were included in the study. Prior to initiation of brace treatment with the Cheneau-Toulouse-Muenster orthesis, skeletal age and flexibility of the curve (bending films) were evaluated. The average follow-up after weaning of the brace was 42 months (36-78 months). RESULTS An average initial Cobb angle of 31 degrees was corrected to 18 degrees (43 %) under brace treatment with a flexibility to 6 degrees Cobb angle on bending films. Three years after weaning there was an overall increase of the Cobb angle to 37 degrees on average. The apical vertebral rotation was corrected from 16 degrees to 11 degrees (31 %) and increased to 20 degrees during follow-up. Thoracic kyphosis changed from 24 degrees to 18 degrees during treatment. At the latest follow-up kyphosis had returned to the pre-treatment angle again. Twenty-two patients had a curve progression during or after brace treatment of more than 5 degrees. In 14 patients surgical correction and fusion have been indicated. There was a positive correlation between flexibility and Cobb angle correction during brace treatment and a negative correlation between Cobb angle correction during brace treatment and curve progression (p < 0.05). CONCLUSIONS Curve progression was prevented in 58 %. Prognostic risk factors are a young age at initiation of brace treatment, a thoracic curve, unsatisfactory curve correction in the brace and a male gender.

The effect of intraoperative traction during posterior spinal instrumentation and fusion for adolescent idiopathic scoliosis.

Abstract: Study Design. A retrospective study comparing patients having traction and a control group not having traction during posterior spinal instrumentation and fusion (PSIF) for adolescent idiopathic scoliosis (AIS). Objective. To evaluate the effect of intraoperative traction on surgical correction of AIS. Summary of Background Data. When the Cotrel-Dubousset instrumentation system was introduced, the use of intraoperative traction was advocated. However, there is no specific report documenting the effect of intraoperative traction on the correction of AIS. Methods. The medical and radiologic records of 140 AIS patients treated by PSIF were reviewed. Forty of these patients had intraoperative traction using a head halter associated with lower extremity skin traction. The radiologic outcome was compared between the two groups intraoperatively (before instrumentation with the first rod) and after surgery using Student t tests (level of significance = 0.05). Results. The intraoperative and postoperative corrections of the coronal primary Cobb angle were similar for both groups, although the patients in the traction group had smaller preoperative Cobb angles and more flexible curves and were instrumented with more screws. The postoperative thoracic kyphosis was significantly increased in both groups. The lumbar lordosis at the 1-year follow-up was maintained in the control group, but it was significantly decreased in the traction group. Conclusion. The authors do not recommend the routine use of intraoperative traction using a head halter combined with skin traction for all AIS patients undergoing PSIF. However, it could be helpful in selected cases, such as in patients having pelvic obliquity and requiring instrumentation of the pelvis.

Scoliosis in Cystic Fibrosis : Is It Idiopathic?

Abstract: Study design This is a retrospective study of all the patients registered with the Yorkshire Regional Cystic Fibrosis unit from 1982 to 1997. Of the 316 patients, there were 184 adults (age 17 years and above) and 132 children (age 0-6 years). Objectives This study was aimed at determining the prevalence of scoliosis in people with cystic fibrosis and describes the characteristics and progression of scoliosis in these patients and highlights predictive factors, which account for high prevalence of scoliosis in this condition. Summary of the background data Two previous North American studies (1978 and 1982) have indicated a high prevalence of scoliosis in patients with cystic fibrosis. Methods The patients were divided into 3 groups based on their chronologic age as on January 1998. Chest, abdomen, and whole spine radiographs were studied for the presence of any spinal deformity, and measurements were made using the Oxford Cobbmeter (Oxford Metrics). The extent, apex, and the side of the curves were described. The disease-specific scores, ie, Chrispin-Norman score (score for radiologic severity of lung disease) and Shwachman score (score for general condition), were noted from the patient follow-up database maintained by the Regional Cystic Fibrosis Unit. Multiple linear regression analysis was used to study the correlation between Cobb angle and the previously mentioned scores. Results In the 4- to 16-year age group, the prevalence of scoliosis was 15.6%, which is 20 times the prevalence in 15,793 school children with a similar age and sex distribution from the same geographic area. The majority of curves were single-thoracic, apical around T6-T8 with no side predilection. In the adult population (above 16 years), the prevalence was 9.8%, which is higher than that of the general population. These curves were thoracic, apical around T7-T8, and approximately two thirds of them were right-sided. Infantile curves are described for the first time in our study; these tend to be nonprogressive, right-sided, upper thoracic curves. Conclusion Our study shows a high prevalence of scoliosis in people with cystic fibrosis. These are benign short midthoracic curves, apical between T6-T8 with no side predilection.

The course of sagittal plane abnormality in the patients with congenital scoliosis managed with convex growth arrest.

Abstract: Summary of background data Patient age; localization, length, and magnitude of the curve; and sagittal plane alignment are reported to be the major determinants in the selection of patients for convex growth arrest. Although the existence of sagittal plane abnormality (kyphosis or lordosis) is accepted as a contraindication for convex growth arrest, this issue has not been discussed in detail. Objectives The purposes of this study are to investigate the effect of sagittal plane abnormality on the control of coronal plane deformity and to evaluate the course of sagittal plane abnormality of the patients with congenital scoliosis who were satisfactorily managed with convex growth arrest. Study design Retrospective analysis. Methods Inclusion criteria are: 1) a diagnosis of congenital scoliosis in a patient younger than 6 years of age, 2) treatment with convex growth arrest, 3) follow up for more than 2 years, 4) stabilized or improved coronal plane deformity, and 5) abnormal sagittal plane alignment within the scoliotic segment before surgery. The patients were evaluated with anteroposterior and lateral radiographs, and segmental measurements were compared according to the normal of their corresponding age. Results A total of 38 patients with congenital scoliosis treated with convex growth arrest were reviewed. Among 13 patients with segmental sagittal plane deformity, 2 were excluded because of insufficient control of the scoliosis. Eleven patients (8 girls, 3 boys) with a mean age of 35 months (range 6-72 months) and mean follow-up of 40 months (range 24-76 months) fulfilled these criteria. The coronal plane deformities were 58 degrees (range 36 degrees-105 degrees) before surgery and 52 degrees (13 degrees-107 degrees) at the final follow-up. While six of the curves improved, the remaining ones stabilized. Sagittal segmental alignments within the scoliotic segments were hyperkyphotic in 9 patients and hypokyphotic in 1 and lordotic in 1. At the end of the follow-up, sagittal Cobb angle of the abnormal segments remained stable in 7 patients and deteriorated in 4. None of the 4 patients required any reconstructive spine procedure for kyphosis during follow-up. Conclusion Sagittal segmental abnormality does not have a negative effect on the control of scoliosis in the majority of the patients (11 of 13). If the coronal curve stabilizes or improves, then sagittal segmental abnormality could also be stabilized (in 7 of 11 patients).

Kyphosis of the thoracic and thoracolumbar spine in the pediatric patient: normal sagittal parameters and scope of the problem.

Abstract: As measured by the Cobb angle, normal sagittal kyphosis is 20 degrees to 40 degrees, which encompasses most of the angulated consecutive vertebrae in the thoracic region of the spine. With pathologic kyphosis, however, the segmental analysis of different regions of the thoracic spine plays an important role. Methods of determining sagittal measurements as well as the causes of kyphosis of the thoracic and thoracolumbar spine, including Scheuermann's disease, spinal cord injury, laminectomy, neurofibromatosis, genetic origins, Marfan syndrome, and tuberculosis, are also important in determining treatment.

Selective thoracic fusion in adolescent idiopathic scoliosis

Abstract: OBJECTIVE: To define the criteria of selective thoracic fusion in adolescent idiopathic scoliosis patients. METHODS: By reviewing the roentgenograms of adolescent idiopathic scoliosis patients undergoing selective thoracic fusion, the curve type, Cobb angle, apical rotation and translation, trunk shift, and thoracolumbar kyphosis were measured and analyzed. RESULTS: There were 12 King type II patients (PUMC type: IIb1 9, IIc3 3). The coronal Cobb angle of thoracic curve before and after surgery were 54.0 degrees and 19.0 degrees respectively, and the average correction rate was 62.7%. The coronal Cobb angle of lumbar curve before and after surgery were 34.6 degrees and 12.5 degrees respectively, and the average spontaneous correction rate was 64.7%. At the final follow-up, the coronal Cobb angle of thoracic and lumbar curve was 18.8 degrees and 15.9 degrees respectively. There was no significant change in the coronal Cobb angle, apical vertebral translation and rotation compared with that after surgery. 1 patient had 12 degrees of thoracolumbar kyphosis after surgery, no progression was noted at the final follow-up. There was no trunk decompensation or deterioration of the lumbar curve. In this group, 3.5 levels were saved compared with fusing both the thoracic and lumbar curves. CONCLUSION: Selective thoracic fusion can be safely and effectively performed in patients with a moderate and flexible lumbar curves, which can save more mobile segments to maintain a good coronal and sagittal balance.

Radiographic and functional outcome after surgical management of severe scoliosis in skeletally immature patients with muscular dystrophy.

Abstract: OBJECTIVE: Most patients with muscular dystrophy (MD) develop progressive scoliosis after losing ambulatory status, but some cases develop severe scoliosis at a skeletally immature age before losing ambulatory status. Only a few studies have been conducted in skeletally immature patients with severe scoliosis. The purpose of this study was to assess the functional and cosmetic outcome in skeletally immature patients with severe scoliosis. METHODS: Preoperative, immediate postoperative, and final follow-up radiographs were analyzed in 10 consecutive skeletally immature patients with respect to the Cobb angle degree and the pelvic obliquity angle correction, how long the correction was maintained, and the development of the crankshaft phenomenon. In the functional assessment, the ability to sit balanced, according to the Mulcahy method, and the ability to use hands, according to the Rhyu method, were evaluated. Furthermore, the degree of subjective satisfaction was evaluated in these patients. RESULTS: The average age of the patients was 10.4 years, and the average follow-up period was 33 months with minimum 2 years' follow-up. All 10 patients survived and were available at the follow-up. The mean Cobb and pelvic obliquity angles were 80 degrees and 17 degrees at the time of the surgery, 31 degrees and 3.7 degrees immediately after the surgery, and 35 degrees and 4.7 degrees at the time of the final follow-up, respectively. The initial mean Cobb angle correction averaged 61%, with 78% of pelvic obliquity corrected. These corrections were maintained over time in most cases. At the time of the surgery, the mean volume of blood loss was 1111 mL, with an average operation time of 411 minutes. There were no major complications. At the time of the last follow-up, no patient showed development of the crankshaft phenomenon. The average score for the ability to sit balanced improved from 4.4 to 6.6 according to the Mulcahy evaluation method. The scores for hand use were 2.2-2.7. However, the forced vital capacity of the lungs decreased from a preoperative 48% to 46.1%. CONCLUSIONS: These results indicate that even in very young MD patients with severe scoliosis, acceptable curve correction can be achieved and maintained with surgery. The improved pelvic obliquity and scoliosis angle stabilized the spine, freeing the upper extremities and allowing productive activities characteristic of childhood.

The effect of a modified boston brace with antirotatory blades on the progression of curves in idiopathic scoliosis. aetiologic implications

Abstract: The effect of a modified Boston Brace with antirotatory blades upon the fate of idiopathic scoliotic (IS) curves, mainly right thoracic with a compensatory left lumbar, is studied. This report refers to curves within the generally accepted range of Cobb angle (20° – 40°) appropriate for conservative treatment. Method and Material: Out of 166 children suffering IS with Cobb angle >10°, 67 (61 girls, and 6 boys), having a mean follow up 2,3 years (4 months to 7 years), were studied. A brace of Boston type with antirotatory blades was applied in 36 scoliotic children. The curve type was: 18 thoracic (T) right (rt) + Lumbar (L) left (lt) in children with a mean age 13,1 years, 3 T lt + L rt in children with a mean age 16,3 years, 7 T rt in children with a mean age 13 years and 8 thoracolumbar (TL) rt curves in children with a mean age 12,1 years. Full documentation during the FU had 23 out of the 36 children with 14 T rt + L lt, 1 T lt + L rt (15 in total – double curve group), 4 T rt (thoracic group) and 4 TL curves (thora-columbar group). Traditionally deterioration (increase) or improvement (decrease) of a curve is considered a change of 5i Cobb compared with the initial reading. Results: In the 15 double curve group children the mean FU was 28 months. In this group 5 curves were improved, 6 remained stable and 4 were increased. For the 4 thora-columbar curves with a mean FU 8 months, 3 remained stable and 1 improved. For the 4 thoracic curves with a mean FU 9 months, 2 were stable and 2 improved. During the final FU of the above 23 scoliotic children, when the assessment of Cobb angle was made with children out of the brace, 8 curves were improvement, 11 remained stable and 4 deteriorated (one patient out of 4 (4,3%) was operated upon). All the deteriorated curves were double (T rt + L lt). When the assessment of Cobb angle was made with children in the brace, 10 curves were improved, 12 remained stable and 1 deteriorated Discussion: The brace treatment affected more the double curves while single curves remained unaffected. Rotation remained unchanged in all curve types except in the lumbar component of double (right thoracic-left lumbar) curves. A composite spiral trunk rotator muscle has been proposed, (consisted of the ipsilateral scapular elevator and rhomboid, the anterior serrated, external oblique and contralateral internal oblique abdominal muscle, (Benninghoff 1985, Wemyss-Holden 1990), which is considered that have an effect on the trunk rotation during gait. Asymmetry of one or more constituent muscles creates scoliosis. These findings are consistent with the view that neuromuscular factors are responsible for the initiation of idiopathic scoliosis. The antirotatory blades of the brace are acting upon the above described composite spiral trunk rotator muscle blocking the deterioration of the scoliotic curve or improving the double curves thus supporting the above aetiologic view. In conclusion the conservative treatment using this brace is beneficially affecting the natural history of the IS in children 12–15 years of age.