Mean Preoperative Cobb Angle Research Articles

Is Spine Deformity Surgery in Patients With Spastic Cerebral Palsy Truly Beneficial?

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

Treatment of degenerative lumbar scoliosis with selective segmental transforaminal lumbar interbody fusion and posterior spinal fusion.

Objective To investigate the treatment outcome of degenerative lumbar scoliosis (DIS) with selective segmental transforaminal lumbar interbody fusion (TLIF) and posterior spinal fusion. Methods Forty-six patients with DIS treated by selective segmental TLIF and posterior spinal fusion were studied ret-rospectively. There were 14 males and 32 females, with a mean age of 66.4 years (range, 41-78). Posterior spinal fusion was performed 7 segments in 5 cases, 5 in 4, 4 in 4, 3 in 12, 2 in 16, and 1 in 5 cases. The in-dications for TLIF of motion segment included: rigid kyphosis in the lumbar spine, significant vertebral trans-lation in any orientation, segmental instability, and significant upper endplate obliquities of L3 or L4 All pa-tients were followed with a mean duration of 3.6 years postoperatively. The imaging evaluation included Cobb angle of scoliosis, lumbar lordosis angle and segmental lordosis angle. The low-back and lower-extremity clinical symptoms were evaluated with JOA score. Results The mean preoperative Cobb angle of 31.7°±14.4° was significantly corrected to 10.2°±6.5°at the final follow-up (t=15.26, P< 0.05), and the correction rate was 67.8%. The mean preoperative lumbar lordosis angle of 27.5°±12.6° was also significantly corrected to 39.3°±9.7°(t=12.17, P< 0.05), and the correction rate was 44.4%. The mean preoperative segmental lordo-sis angle of 6.5°±5.1° in TLIF segment was increased to 11.6°±5.9°. The segmental deformity and vertebral translation were corrected significantly. The mean preoperative JOA score of 14.1±4.2 was significantly in-creased to 22.2±4.8 (t=11.45, P< 0.01). Besides, there was a significant positive correlation between the fi-nal increment of JOA score and the increment in lumbar lordosis angle (r=0.61,P=0.02). Conclusion Se-lective segmental TLIF is helpful in correcting lumbar lordosis, segmental deformity and translation, and thus obtaining better outcome of posterior spinal fusion for the treatment of DLS. Key words: Spinal fusion; Scoliosis; Lumbar vertebrae

The role of bracing, casting, and vertical expandable prosthetic titanium rib for the treatment of infantile idiopathic scoliosis: a single-institution experience with 31 consecutive patients

There are few data on treatment results for patients with idiopathic infantile scoliosis (IIS). Thus, the authors have performed a retrospective review of their experience with treating these patients, particularly as newer technologies, such as the vertical expandable prosthetic titanium rib (VEPTR), emerge. This retrospective study was conducted to evaluate the methods of treatment used to manage IIS at a single institution. The authors reviewed 31 consecutive patients with a primary diagnosis of IIS. Patients were screened to ensure that there were no confounding congenital anomalies or comorbidities that may have contributed to the spinal deformity. The average age at the time of initial treatment was 25 months. Treatment modalities included bracing, serial body casting, and VEPTR. Pretreatment, posttreatment, and most recent Cobb angles were compared to assess the overall curve correction, and patient charts were reviewed for the occurrence of complications. Of the 31 patients, 17 were treated with a brace, 9 of whom had curve progression and went on to other forms of treatment. Of the 8 who did respond, there was an overall improvement of 51.2%. The 10 patients who received body casts, who had a mean preoperative Cobb angle of 50.4 degrees, demonstrated an average correction of 59.0%, with only a few skin irritations reported. The 10 patients treated with VEPTR devices demonstrated a mean preoperative Cobb angle of 90.0 degrees, and an average correction of 33.8% was attained. Three of the VEPTR-treated patients (33%) experienced minor problems. The authors' results suggest that body casting has utility for appropriately selected patients; that is, those with smaller, flexible spinal curves. Bracing had limited utility, with high levels of progression and the need for secondary treatments. The VEPTR device appears to be a viable alternative for large-magnitude curves.

The Usefulness of VEPTR in the Older Child With Complex Spine and Chest Deformity

The vertical expandable prosthetic titanium rib (VEPTR) was originally designed to treat chest and spine deformities in young children. However, older children with complex spinal deformities may also benefit from placement of a VEPTR when vertebral column resections are deemed too risky neurologically. We report: (1) the changes in Cobb angle, T1 angle, and head tilt; and (2) the occurrence of complications in children older than 10 years of age treated with VEPTR. From a database of 214 patients treated in a Food and Drug Administration Investigational Device Exemption study of VEPTR, we identified 10 patients with assorted diagnoses who underwent surgery after age 10 and had a minimum of 24-month followup (mean, 39.6 months; range, 24-75 months). No patient sustained neurologic injury. Patients underwent an average of five lengthenings. The mean preoperative Cobb angle was 64.7 degrees and improved to 48.4 degrees. Head shift improved an average of 3.8 cm. Two device-related complications occurred (both in the same patient). Four patients have since undergone definitive spinal fusion. For a select group of patients 10 years of age or older, the VEPTR offers a reasonable alternative to potentially risky vertebral column resections for correcting deformities in selected patients. Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Lumbar Degenerative Scoliosis: Outcomes of Combined Anterior and Posterior Pelvis Surgery With Minimum 2-year Follow-up

Combined anterior and posterior surgery is useful for fixed deformity of the lumbar spine. The specific indications for and clinical outcome parameters after combined surgery for patients with degenerative lumbar scoliosis have not been well defined. We retrospectively reviewed 14 consecutive patients with degenerative lumbar scoliosis treated with combined anterior and posterior arthrodesis with instrumentation to the pelvis. Mean patient age was 65 years (range, 49-88 years) and mean clinical follow-up was 44 months (range, 30-78 months). Mean preoperative sagittal imbalance was 4.6 cm (range, 1.5-15.5 cm), which was maintained to 2.5 cm (range, 0.5-8 cm) at last follow-up. Mean preoperative Cobb angle of the major curve was 46 degrees (range, 20 degrees-67 degrees), which improved to 6 degrees (range, 2 degrees-30 degrees) at last follow-up. The highest total postoperative scores were reported in patients with maximal correction of their curves at last follow-up. Correlation analysis of clinical outcome domains demonstrated that patient satisfaction with surgical management correlated strongly with domains of pain (r=0.86; P=.008) and weakly with domains of function (r=0.3; P=.02). Patients with degenerative lumbar scoliosis may be effectively treated with combined anterior and posterior surgery with instrumentation to the pelvis. Our results at a minimum of 2-year follow-up indicate that overall clinical outcomes are best in cases with maximal curve correction, and overall patient satisfaction with surgery is correlated with relief from pain.

Correction of Apical Axial Rotation With Pedicular Screws in Neuromuscular Scoliosis

A retrospective study to measure the postoperative apical axial derotation with posterior pedicle screw fixation in neuromuscular scoliosis. To determine whether the posterior only approach using pedicle screw fixation is able to accomplish apical axial derotation in neuromuscular scoliosis and if there is any difference according to severity of curve or type of disease. Literature search does not reveal anything about the rectification of apical axial rotation in neuromuscular scoliosis with the pedicle screw fixation. Between January 2005 and December 2006, 24 patients (9 females and 15 males, average age 19 y) with neuromuscular scoliosis (6 cerebral palsy, 9 Duchenne muscular dystrophy, 5 spinal muscular atrophy, and 4 others) underwent posterior pedicle screw construct with correction and fusion for the treatment of progressive, symptomatic spinal deformities. Preoperative, immediate postoperative, and final follow-up radiographs were analyzed according to Cobb's angle and pelvic obliquity, whereas apical axial rotation was measured on preoperative and postoperative computerized tomography scan using Aaro-Dahlborn method from mid-sagittal plane. Twelve (9 females and 3 males) adolescent idiopathic scoliosis patients, who underwent similar operation, comprised our control group for the comparison of results. All the patients exhibited improved sitting balance after surgery. The mean preoperative Cobb's angle, pelvic obliquity, and apical rotation were 74, 14, and 42 degrees, whereas postoperative were 32, 6, and 33 degrees, respectively, showing significant correction in all 3 parameters. Comparison of results based on severity of curve did not reveal any statistically significant difference (P=0.255) in correction of apical axial rotation among group I, group II, and group III. A similar apical rotational correction was recorded in different disease groups (P=0.295). Comparing the results between neuromuscular and idiopathic scoliosis groups, we could not find any statistically significant difference. Our results indicate that apical axial derotation can be well achieved with posterior only pedicle screw fixation in patients with neuromuscular scoliosis without any need for an anterior release procedure.

Staged surgical treatment for severe and rigid scoliosis

BackgroundA retrospective study of staged surgery for severe rigid scoliosis. The purpose of this study was to evaluate the result of staged surgery in treatment of severe rigid scoliosis and to discuss the indications.MethodsFrom 1998 to 2006, 21 cases of severe rigid scoliosis with coronal Cobb angle more than 80° were treated by staged surgeries including anterior release and halo-pelvic traction as first stage surgery and posterior instrumentation and spinal fusion as second stage. Pedicle subtraction osteotomy(PSO) was added in second stage according to spine rigidity. Among the 21 patients, 8 were male and 13 female with an average age of 15.3 years (rang from 4 to 23 years). The mean pre-operative Cobb angle was 110.5° (80°-145°) with a mean spine flexibility of 13%. Radiological parameters at different operative time points were analyzed (mean time of follow-up: 51 months).ResultsExternal appearance of all patients improved significantly. The average correction rate was 65.2% (ranging from 39.8% to 79.5%) with mean correction loss of 2.23° at the end of follow-up. No decompensation of trunk has been found. Mean distance between the midline of C7 and midsacral line was 1.19 cm ± 0.51. Two patients had neurological complications: one patient had motor deficit and recovered incompletely.ConclusionStaged operation and halo-pelvic traction offer a safe and effective way in treatment of severe rigid scoliosis. Patients whose Cobb angle was more than 80° and the flexibility of the spine was less than 20% should be treated in this way, and those whose flexibility of the spine was less than 10% and the Cobb angle remained more than 70° after 1st stage anterior release and halo-pelvic traction should undergo pedicle subtraction osteotomy (PSO) in the second surgery.

Comparison of Apical Axial Derotation between Adolescent Idiopathic and Neuromuscular Scoliosis with Pedicle Screw Instrumentation

Study DesignA retrospective study.PurposeTo compare outcomes of apical derotation with pedicle screws in idiopathic and neuromuscular scoliosis (NMS).Overview of LiteratureNo information about apical derotation in NMS with pedicle screws is available.MethodsWe performed deformity correcting surgery using pedicle screw constructs on 12 adolescent idiopathic scoliosis (AIS) patients (mean age 14.1 years) and 16 NMS patients (mean age 16.5 years). Preoperative, postoperative, and final follow-up radiographs were analyzed for Cobb's angle and pelvic obliquity, while apical rotation was measured on CT scans using the Aaro-Dahlborn method.ResultsFor AIS, the mean preoperative Cobb's angle, pelvic obliquity, and apical rotation values were 57.3°, 2.8°, and 20.4°, respectively, and postoperatively they were 16.8°, 1.1° and 14.7°, respectively, showing significant correction. For NMS, the mean preoperative Cobb's angle, pelvic obliquity, and apical rotation values were 75.6°, 13.7°, and 42.9°, respectively, and postoperatively they were 27.1°, 5.8°, and 34.1°, respectively, also showing significant correction. There were no significant differences between AIS and NMS patients Cobb's angle p=0.306, pelvic obliquity p=0.887 and apical derotation p=0.113°. There were no differences in curve severity in the three groups (AIS, NMS >80°and NMS <80°); or the correction of apical rotation (p=0.25), although less correction was achieved in the Cobb's angle in the >80 NMS group (p=0.04).ConclusionsApical axial derotation can be achieved with posterior only pedicle screw fixation in NMS without anterior release, with comparable results in idiopathic scoliosis.

Thoracic Pedicle Screw Insertion in Scoliosis Using Posteroanterior C-arm Rotation Method

Previous researches have emphasized the importance and difficulties in accurate thoracic pedicle screw insertion in scoliosis patients. However, there has been no report on accuracy of the insertion using posteroanterior C-arm fluoroscopy rotated to allow en face visualization of the pedicle in humans. This study aimed to evaluate the accuracy of the thoracic pedicle screw insertion technique using a C-arm fluoroscopy rotation method for the treatment of scoliosis. Between October 1997 and September 2005, 33 scoliosis patients who underwent surgical treatment with a total of 410 screws were analyzed. Eleven were male, 22 female and the mean age was 13.4 years. The mean preoperative Cobb angle was 59.7 degrees. Screws were inserted using the C-arm rotation method; screw positions were evaluated with postoperative computed tomography scans. The mean preoperative Cobb angle of 59.7 degrees was corrected to 18.9 degrees (range, 3 to 45 degrees) in the coronal plane (mean correction rate 68%). Postoperative computed tomography scans demonstrated 48 screws penetrated the medial (9 screws) or lateral (39 screws) pedicle cortex with a mean distance of 3.1 and 3.6 mm, respectively. No screws penetrated the inferior or superior cortex in the sagittal plane. Thoracic pedicle screw insertion in scoliosis patients using the posteroanterior C-arm rotation method allows en face visualization of both pedicles by rotating the C-arm to compensate for the rotational deformity, making it a practical, simple and safe method.

Correction of Neuromuscular Scoliosis in Patients With Preexisting Respiratory Failure

A prospective observational study in scoliosis patients who were on noninvasive night ventilation for respiratory failure. To report the results of spinal deformity correction in a group of patients with progressive scoliosis and rare forms of muscular dystrophy/myopathy with respiratory failure who were on nocturnal ventilatory support at the time of surgery. This is the first study on the results of deformity correction in a series of patients on ventilatory support. Eight patients (6 males, 2 females) presented with progressive scoliosis and respiratory failure. The mean age at surgery was 12 years (range, 8-15 years). The mean follow-up was 48 months (range, 12-80 months). Outcome measures include lung function (spirometry), overnight pulse oximetry, Cobb angles, duration of stay in Intensive care (ICU), and the total hospital stay. The mean stay in the ICU was 2.7 days (range, 2-5 days). The mean hospital stay was 14.2 days (range, 10-21 days). The mean preoperative Cobb angle was 70.2 degrees (55 degrees -85 degrees ). This changed to 32 degrees (16 degrees -65 degrees ) after surgery (P = 0.0002). The mean vital capacity at the time of surgery was 20% (range, 13%-28%). The mean vital capacity of patients at last follow-up was 18% (range, 10%-31%). The desaturation noted on the preventilation overnight oximetry was reversed by nocturnal ventilation. All patients recovered well following surgery with no major cardiac or pulmonary complications. Patients with preexisting respiratory failure on nocturnal noninvasive ventilation can be safely operated for deformity correction. This can help to significantly improve their quality of life.

CHALLENGING DEGENERATIVE LUMBAR SCOLIOSIS WITH SEGMENTAL CORRECTIVE FUSION SURGERY

Changes in the curvature have not been reported in degenerative lumbar scoliosis (DLS) when the correction surgery was performed. The purpose of our study was to clarify the influence of the correction surgery of DLS. Twenty-one patients underwent corrective lumbar reconstruction surgery (1998–2003) only at the neurologically affected levels. The spinal curvature was retrospectively evaluated in these 21 patients with DLS using Cobb's methods. The mean preoperative Cobb's angle was 17.7° while the mean postoperative Cobb's angle was 6.1° (p &lt; 0.0001) at 1 month after the surgery and 9.0° at the final follow-up. The correction rate was 65.2% at 1 month after the surgery and 50.2% at the final follow-up. Cobb's angle increased by 2.9°/43.4 months (mean, 0.80°/year) in these procedure. The surgical goals of DLS are the relief of neurological disorders and the cessation of the deterioration of spinal alignment. Strategies for DLS may include complete decompression, or correction of the spinal alignment in elderly patients with poor bone quality. Decompression and correction in the PLIF procedure only at neurologically affected levels may be one of the surgical procedures to challenge DLS.

Is there a role for selective anterior instrumentation in neuromuscular scoliosis?

Our objective was to report on the clinical and radiological outcome from a cohort of patients with neuromuscular scoliosis who underwent selective anterior single rod instrumentation for correction of thoraco-lumbar and lumbar scoliosis. Traditionally combined anterior release with long posterior instrumentation has been advocated for the treatment of neuromuscular scoliosis. Neuromuscular curves tend to be long and may have significant pelvic obliquity. However, certain neuromuscular curves with minimal pelvic obliquity may lend themselves to selective anterior correction thereby saving motion segments and allow continued ambulation for those patients. Nine patients with neuromuscular scoliosis underwent selective anterior instrumentation between 1994 and 2000. The mean follow up was 2 years and 9 months (range 24-55 months). The clinical outcome (including parent and caregiver satisfaction), radiological outcome (Cobb angle, apical vertebral translation, pelvic obliquity, truncal shift, thoracic kyphosis, lumbar lordosis, sagittal vertical axis) and complications are reported. Subjective outcome was excellent in six patients and good in three. All nine patients retained their ability to walk. There were no neurological or vascular complications. Supplementary posterior surgery was required in two patients. The mean pre-operative Cobb angle of 52 degrees (range 44-60) improved to 20 degrees (range 10-28) at 3 months, achieving Cobb angle correction of 61% and was 19 degrees (range 7-28) at final follow-up. The mean pre-operative compensatory curve of 31 degrees (range 20-42) spontaneously corrected to 18 degrees (range 14-24) at 3 months and was maintained at 18 degrees (range 10-26) at final follow up. The mean pre-operative pelvic obliquity of 7 degrees (range 0-14) corrected to 4 degrees (range 0-8) at 3 months and was 3 degrees (range 0-8) at final follow up. Selective anterior instrumentation and fusion in carefully selected patients with neuromuscular scoliosis (short flexible curves, minimal pelvic obliquity, pre-operative walkers, slow or non-progressive pathology) appears to have satisfactory clinical and radiological outcome at least in the short-term.

Surgical correction of spinal deformities after solid organ transplantation in childhood.

A review of the current literature reveals no systematic analyses of the results of surgical correction of spinal deformity after pediatric organ transplantation. We therefore evaluated clinical and radiographic outcomes of spinal deformity correction after solid organ transplantation in childhood and adolescence. All 211 cases of heart, liver, and kidney transplantations performed in children in our country were reviewed. Six patients had undergone surgical correction of spinal deformity at a mean age 14.6 (range 12-17) years. Clinical data of the patients were evaluated. Radiographs of the whole spine were taken preoperatively, immediately after, at 2-year, and final follow-up visits. The Scoliosis Research Society (SRS) questionnaire was completed and a physical examination was performed at the final follow-up visit. The mean follow-up after spinal surgery was 4.9 years (range 2-7.6 years). Four patients developed scoliosis after organ transplantation without any evidence of scoliosis prior to organ transplantation. One patient with congenital scoliosis was operated on after kidney transplantation. One boy had osteoporosis and severe local kyphosis due to vertebral compression fractures. Four patients underwent anterior and posterior surgery, two posterior only. The mean preoperative Cobb angle of the thoracic curve was 54 degrees (range 42-69 degrees) in the patients with scoliosis. The postoperative values were 30 degrees (26-38 degrees) immediately after instrumentation and 39 degrees (34-42 degrees) at the final follow-up visit. The patient with vertebral compression fractures and progressive kyphosis had 70 degrees curve before surgery, 23 degrees immediately after the operation, and 60 degrees at the final check up. The mean total score on the SRS questionnaire was 95.5 (range 90-101). There is a relatively high incidence (2.8%) of spinal deformities needing operative treatment after solid organ transplantation. Possible etiologies for spinal deformities are growth disturbance and muscle weakness due to the basic disease. The other important factors are related to immunosuppressive medication, especially glucocorticoids needed after transplantation. Primary correction of these deformities was satisfactory, but during follow-up, a certain amount of recurrence of the curves was evident. Poor bone quality may explain some of the loss of correction.

Correction of Adolescent Idiopathic Scoliosis Using Thoracic Pedicle Screw Fixation Versus Hook Constructs

This retrospective study was undertaken to determine the effectiveness and cost of thoracic pedicle screws versus laminar and pedicle hooks in patients undergoing surgical correction of adolescent idiopathic scoliosis (AIS). Immediate preoperative and 6-week postoperative radiographs were examined in 25 consecutive cases of children with AIS who were divided into two groups, those with thoracic pedicle screw constructs and those with thoracic hook constructs. Endpoints collected included radiographic measures, complications, surgical time, implant cost, and quality-of-life measures. Ten children underwent spinal fusion using thoracic pedicle screw fixation and 15 underwent thoracic constructs composed of hooks. Similar sex and age distribution were noted in both groups, and among the 20 girls and 5 boys the average age was 14.5. The mean preoperative Cobb angle was 53.5 degrees for the screw group and 52.5 degrees for the hook group. Correction averaged 70.2% for the screw group and 68.1% for the hook group. There were no significant differences between the two patient groups in terms of percentage of or absolute curve change after surgery. The apical vertebral translation, end vertebral tilt angle, and coronal balance did not differ significantly between the two patient groups. Comparison of operative time and quality of life revealed no significant differences. Screw constructs were significantly more expensive than hook constructs. The correction obtained from thoracic pedicle screw fixation is comparable to traditional hook constructs in AIS. Surgery using either construct effectively corrects AIS.

Thoracic scoliosis fusion in adolescent and adult idiopathic scoliosis using posterior translational corrective techniques (Isola): is maximum correction of the thoracic curve detrimental to the unfused lumbar curve?

Background context Postoperative coronal decompensation in selective thoracic fusion was reported with derotation maneuvers when using the Cotrel-Dubousset (CD) system. Isola instrumentation is a multiple anchor system that corrects spine deformity with segmental vertebral translation to a predetermined contoured longitudinal member. Purpose To evaluate the efficacy of translational corrective techniques using Isola instrumentation in thoracic fusion for adolescent and adult idiopathic scoliosis patients. Study design/setting This is a retrospective review of adolescent and adult patients with idiopathic scoliosis who underwent posterior thoracic fusion using translational corrective techniques with Isola instrumentation. Patient sample Twenty-two patients (14 adolescents with idiopathic scoliosis, 8 adults with scoliosis) who underwent posterior thoracic fusion using translational corrective techniques were evaluated. Outcome measures The charts, radiographs and self-assessment questionnaire were reviewed. Methods Comparative analysis was done between patients who had Lenke Type A curves (Group 1) and Lenke Type B or C curves (Group 2) for both adolescent and adult scoliosis groups. Results The mean follow-up was 54 months (range, 33 to 80 months). The mean preoperative Cobb angle of thoracic and lumbar curves in all 22 patients was 48 degrees (range, 34 to 64 degrees) and 31 degrees (range, 20 to 46 degrees), respectively. Postoperative measurements were 16 degrees (range, 0 to 28 degrees) for thoracic and 13 degrees (range, 2 to 25 degrees) for lumbar (67% thoracic and 60% lumbar correction) in Group 1, and 19 degrees (range, 1 to 33 degrees) for thoracic and 12 degrees (1 to 21 degrees) for lumbar at latest follow-up (61% thoracic and 61% lumbar correction) in Group 2. There was no difference in the final correction of the lumbar curves between Groups 1 (64%) and 2 (58%), although the Cobb angle in Group 2 was larger. Radiographic coronal decompensation occurred in only one patient in Group 2, who remained asymptomatic and required no further treatment. Clinical outcome assessment showed 100% satisfaction (n = 15), 92% relief of symptoms (n = 13) and 92% improvement of activities in both groups. Conclusions Fusion of the major thoracic curve using translational corrective technique (Isola) in patients with idiopathic scoliosis is an effective procedure that achieves high patient satisfaction while providing excellent correction of both the thoracic and lumbar curves. Unlike rotational corrective techniques (CD), clinical decompensation requiring further treatment did not occur in any patient treated with this method.

Pulmonary function and scoliosis in children with spinal muscular atrophy types II and III.

The objectives were to evaluate the clinical course of spinal muscular atrophy (SMA) types II and III patients necessitating scoliosis surgery at the National University Hospital, Singapore. A retrospective review of SMA types II and III patients, born over a 10-year period between 1983 and 1992, was conducted. There were eight patients: four with SMA type II and four with SMA type III. The mean age at scoliosis surgery was 9 years 7 months (range 7 years 6 months-12 years 4 months). The mean preoperative Cobb angle was 65.4 degrees (range 43-90 degrees ) and the mean postoperative Cobb angle was 22.6 degrees (range 12-45 degrees ), with a mean correction of 64.8% (range 47.7-77.8%). The decline in percentage predicted forced vital capacity (FVC) was 7.7% (95% CI: 12.4% to 3.0%) per year preoperatively and this was reduced to 3.8% (95% CI: 5.8% to 1.9%) per year postoperatively. The mean length of preoperative and postoperative lung function follow-up was 6.3 months (range 0.03-31 months) and 44 months (range 0-110 months), respectively. This study suggests that pulmonary function in SMA types II and III continues to decline after scoliosis surgery, though the rate of decline is less marked. Overall, the combined results from this study and all other previously published studies are conflicting in regard to the effect of scoliosis surgery on pulmonary function in SMA types II and III, though half of the studies (3 of 6) did demonstrate a continued decline in lung function postoperatively. This decline in pulmonary function despite spinal stabilization is likely secondary to the progressive neuromuscular weakness of the disease.

Surgical treatment of scoliosis in spinal muscular atrophy

To describe the early and late postoperative data from SMA patients with surgical procedure. Clinical data and radiographic imaging from 14 SMA patients with surgical treatment of scoliosis were reviewed, and all were reassessed clinically with new spinal radiographs and a questionnaire. The mean follow-up were 22 months. The mean preoperative Cobb angle was 78.4 . All patients presented pelvic obliquity (mean 25.5 ) and 11 had cifosis. The mean age at time of surgery was 12 years and 3 months. All patients were treated with posterior spinal fusion with Luque-Galveston instrumentation in 12 and Cotrel-Dubousset instrumentation in 2. The average curve correction at the immediate postoperative was 64.3% for scoliosis and 36.4% for cifosis, with the pelvic obliquity correction of the 70.9%. The complications were liquoric fistula and infection earlier in one case, and lately wire looseness of T1 in 2 patients. It was detected mean lost of the correction at the final assessment of the 0.26 of the scoliosis and the 1.28 of the pelvic obliquity. Relatives and the patients related good improvement regarding to esthetic aspects, posture balance, body care, as well as respiratory problems. The spinal fusion for scoliosis in SMA patients has a satisfactory impact for esthetic, quality of life and respiratory function, with minimal lost of corrected deformities and few complications.

No relationship exists between the correction of the thoracic and the lumbar curves after selective thoracic fusion for adolescent idiopathic scoliosis King type II.

In this study we focus on idiopathic scoliosis with a primary thoracic curve and a secondary lumbar curve. We were interested in how the lumbar curve corrects following selective thoracic fusion and whether one can explain or predict the behaviour of the lumbar curve. In the literature it is said that, if the lower level of fusion is properly selected, the lumbar curve spontaneously corrects to balance the thoracic curve after selective thoracic fusion. Most authors have assumed a mechanism whereby improvement of the lumbar curve occurs through counterbalancing the surgical correction of the thoracic curve. The correction of the lumbar curve is said to echo the correction obtained for the thoracic curve. Because of these hypotheses, we postulate there should be a correlation between the correction of the lumbar and the thoracic curves of a scoliosis. To validate this hypothesis, we performed a retrospective study on 27 patients with King type II adolescent idiopathic scoliosis treated by selective thoracic fusion. The mean preoperative Cobb angles were 54 degrees for the thoracic curve and 34 degrees for the lumbar curve. Postoperatively they were 31 degrees and 22 degrees respectively. Using Pearson correlation analysis, we found no significant correlation between the relative corrections of the individual thoracic and lumbar curves. Moreover, there was a decrease in the correlation between the thoracic and lumbar curve after operation (preoperative R=0.787, postoperative R=0.364). These results show that the correction of the lumbar curve is not a reflection of the thoracic correction. The exact mechanism by which the lumbar spine corrects remains to be elucidated.

Anterior thoracoscopic surgery followed by posterior instrumentation and fusion in spinal deformity.

Many authors believe thoracoscopic surgery is associated with a lower level of morbidity compared to thoracotomy, for anterior release or growth arrest in spinal deformity. Others believe that anterior release achieved thoracoscopically is not as effective as that achieved with the open procedure. We evaluated the clinical results, radiological correction and morbidity following anterior thoracoscopic surgery followed by posterior instrumentation and fusion, to see whether there is any evidence for either of these beliefs. Twenty-nine patients undergoing thoracoscopic anterior release or growth arrest followed by posterior fusion and instrumentation were evaluated from a clinical and radiological viewpoint. The mean follow-up was 2 years (range 1-4 years). The average age was 16 years (range 5-26 years). The following diagnoses were present: idiopathic scoliosis (n = 17), neuromuscular scoliosis (n = 2), congenital scoliosis (n = 1), thoracic hyperkyphosis (n = 9). All patients were satisfied with cosmesis following surgery. Twenty scoliosis patients had a mean preoperative Cobb angle of 65.1 degrees (range 42 degrees-94 degrees) for the major curve, with an average flexibility of 34.5% (42.7 degrees). Post operative correction to 31.5 degrees (50.9%) and 34.4 degrees (47.1%) at maximal follow-up was noted. For nine patients with thoracic hyperkyphosis, the Cobb angle averaged 81 degrees (range 65 degrees-96 degrees), with hyperextension films showing an average correction to 65 degrees. Postoperative correction to an average of 58.6 degrees was maintained at 59.5 degrees at maximal follow-up. The average number of released levels was 5.1 (range 3-7) and the average duration of the thoracoscopic procedure was 188 min (range 120-280 min). There was a decrease in this length of time as the series progressed. No neurologic or vascular complications occurred. Postoperative complications included four recurrent pneumothoraces, one surgical emphysema, and one respiratory infection. Thoracoscopic anterior surgery appears a safe and effective technique for the treatment of paediatric and adolescent spinal deformity. A randomised controlled trial, comparing open with thoracoscopic methods, is required.

The results of anterior fusion and Cotrel-Dubousset-Hopf instrumentation in idiopathic scoliosis.

Anterior instrumentation for the correction of scoliotic curves has recently been gaining in popularity. The problems of high mortality and morbidity that were associated with the employment of anterior instrumentation in the first years it was used have now been overcome. Efforts are now being concentrated on increasing the correction rates in the frontal plane and decreasing the kyphotic effect in the sagittal plane. The anterior Cotrel-Dubousset-Hopf (CDH) system is a recently developed instrumentation that has been claimed to decrease the kyphotic effect through the use of double rods. This study aimed to investigate the impact of the anterior CDH system on idiopathic scoliotic curves in frontal and sagittal planes. To this end, 26 idiopathic scoliosis patients treated with the CDH system were followed for a mean period of 32.8 +/- 5.3 months. In the frontal plane, Cobb angles of major and secondary curves were measured, and postoperative and final correction rates determined. In the sagittal plane, sagittal contours of both the instrumented region and the thoracic and lumbar regions were measured, and their preoperative, postoperative and final control values were determined. In addition to clinical examination, lateral trunk shift (LT), shift of head (SH) and shift of stable vertebra (SS) were measured in vertebral units (VU), on the preoperative and postoperative radiographs in order to evaluate the effect of the system on trunk balance. It was established that in patients with single flexible thoracolumbar and lumbar curves and those with rigid thoracic curves, the correction rates obtained in the frontal plane were respectively 79.4 +/- 14.8%, 68.0 +/- 9.4% and 61.5 +/- 8.0%, with statistical significance. Their final corrections at the last control were 76.3 +/- 17.4%, 56.9 +/- 9.1% and 52.3 +/- 8.3%, respectively. Although the corrections in the lumbar rigid curves were relatively low, they were still statistically significant. Taking all the patients together, the mean preoperative Cobb angle of the major curves of 67.2 degrees +/- 20.2 degrees improved to a mean of 28.6 degrees +/- 21.0 degrees, which was a statistically significant difference (P < 0.05), giving a mean correction rate of 61.2 +/- 20.3%. The mean correction loss of major curves in the frontal plane in all patients was 6.0 degrees +/- 3.8 degrees and the mean final correction rate was 52.6 +/- 23.2%. In the sagittal plane, there was a favorable kyphotic effect on the thoracic region of patients with hypokyphosis and lordosis pattern, whilst in patients with kyphotic pattern, this effect was minimal. In patients with a single flexible lumbar curve, kyphotic effect was not observed except in two patients. In these two patients, it was thought that excessive compression force may have been used. As to the pa tients with rigid lumbar curve. there was a slight decrease in lumbar lordosis. No postoperative complaints were made about imbalance. and the mean overall correction in LT values was 60.1 +/- 21.7%. While preoperatively, the SH and SS values of all patients were over 0.5 VU, postoperatively, 12 patients (46.2%) were completely balanced (SH = 0 VU, SS = 0 VU) and 8 patients (30.8%) were balanced (0 VU < SH and SS < 0.5 VU). The remaining six patients, whose balance values were corrected with statistical significance but were still over 0.5 VU, were found to be the ones with rigid lumbar curves. Implant failure and systemic complications were not noted in the follow-up period. In view of these findings, it was determined that CDH instrumentation achieves significant correction rates in the frontal and sagittal planes, particularly in single flexible lumbar, thoracolumbar and thoracic rigid curves. It was found that the kyphotic effect was minimized with a double rod system. Significant clinical and radiological corrections were achieved in balance values, without any imbalance and decompensation problems.