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  1. 1. Abstracts from: The 1st International Congress on Early Onset Scoliosis and Growing Spine November 2-3, 2007 Madrid, Spain Chairman: Behrooz A. Akbarnia, M.D. Free Papers Paper #1 The Effect of Early Anterior Fusion on Spinal Canal Size: An Immature Porcine Model Muharrem Yazici, M.D., Guney Yilmaz, M.D., Murat Pekmezci, M.D., Kenan Daglioglu, M.D., FC Oner, M.D. Introduction Neurocentral cartilage (NCC) is located at the posterior 2/3 of vertebrae and responsible for the growth of the pedicles and posterior vertebral body. The aim of this study is to evaluate the effect of anterior spinal instrumentation and fusion on the development of vertebral body in porcine model. Materials & Methods Twelve 8 week-old domestic pigs had CT scans preoperatively and underwent anterior circumferential discectomy of the L3-L4 and L4-L5 discs. Anterior spinal instrumentation was performed between L3 and L5 (L4 skipped). After 6 months their vertebrae were evaluated with CT scan for the presence of anterior fusion and vertebral canal size. The area of vertebral segments adjacent to proximal and distal instrumented segments was used as control level area (AC), average area of L3 and L5 was used as area change in instrumented levels (AI), and area of L4 was used as area change at arthrodesis level (AA). The percent increases in the canal area and total canal area were compared. Results All subjects had documented anterior fusion. There was no difference in the canal diameters of three groups preoperatively(AA: 0.70cm2, AI: 0.70cm2, AC: 0.68cm2; p≥0.05). At the end of 6 months average canal diameter was significantly lower than control group in the arthrodesis and instrumentation groups (AA: 1.20cm2, AI:1.24cm2 , AC:1.41cm2; p≤0.001). The average canal diameters of the arthrodesis and instrumentation groups were similar (AA: 1.20 cm2, AI: 1.24 cm2; p≥0.05). The average percent increase in the canal area was significantly lower than the control levels in the arthrodesis and the instrumented segments (AA: 72.6%, AI: 77.1%, AC: 110.1%; p≤0.001). The percent increase in the canal area between the arthodesis and instrumented segment was similar (AA: 72.6%, AI: 77.1%; p≥0.05). Conclusion This study demonstrated that anterior spinal arthrodesis or instrumentation in the immature spine may result in iatrogenic spinal stenosis.
  2. 2. Paper #2 Growing Rod Instrumentation and Vertebral Body Growth: A Radiological Investigation in Immature Pigs Guney Yilmaz, M.D., Muharrem Yazici, M.D., Gokhan Demirkiran, M.D., Kenan Daglioglu, M.D., Cenk Ozkan, M.D. Introduction Distraction forces applied on growth plate of appendicular skeleton stimulate longitudinal growth. However the effect of distraction forces on axial skeletal growth has not been fully investigated yet. The aim of this study is to evaluate the vertebral body growth under distraction forces in immature pigs treated with growing rod technique. Materials & Methods Eight 8-week-old domestic pigs were used in this experimental model to simulate growing rod instrumentation technique. Cranially T12-L1 and caudally L4-L5 vertebrae were instrumented by pedicle screws bilaterally, while L2 and L3 were skipped. Distraction between pedicle screws was applied at index surgery. The rods were then lengthened twice in a month interval. All subjects were evaluated with lateral spinal X- ray preoperatively, postoperatively and at the final follow-up. The vertebral body heights of distracted segments (HD= L2 and L3) and control segments (HC= T9, T10 and T11) were measured. Average vertebral body heights and the percent increase in the vertebral body heights were compared among control segments (n=11) and distracted segments (n=8). Results Four subjects were lost during the immediate postoperative period. The preoperative vertebral body height was similar in two groups (HC:10.97mm, HD:11.27mm, p≥0.05). At the final follow-up, the average vertebral body height in distraction group was significantly higher than the control group (HC:16.92mm HD:18.56mm, p≤0.05). The percent increase in vertebral body height was higher in distracted segments but there was no statistically significant difference between the two groups (HC:54.1%, HD:64.4%, p≥0.05). Postoperative average vertebral body height in distraction group was significantly longer than preoperative measurements (HDpreop: 10.55mm, HDpostop: 17.49mm, p≤0.05). Conclusion The vertebral growth continues during growing rod instrumentation. Distraction forces might stimulate also apophyseal growth of axial skeleton.
  3. 3. Paper #3 Results of Three Classes of Surgical Treatment for Congenital Scoliosis due to Hemivertebrae: A Multicenter Retrospective Review Michael O'Brien, M.D., Peter Newton, M.D., Randy Betz, M.D., Harry Shufflebarger, M.D., Angel Macagno, M.D., Baron Lonner, M.D., Lynn Letko, M.D., Jurgen Harms, M.D., Alvin Crawford, M.D., Suken Shah, M.D., Paul Sponseller, M.D., Michelle Marks, PT MA Summary 42 patients with hemivertebrae (HV) and congenital scoliosis were compared based on one of three surgical treatments. HV resections with posterior instrumentation results in reduced surgical time, shorter fusions, less blood loss, and improved % correction but slightly higher rates of instrumentation and neurologic complications. Introduction We compare the outcomes of 3 surgical treatments for congenital deformities due to a focal hemivertbra (HV). Methods A retrospective multi-center database was compiled from 8 centers to evaluate patients treated surgically for congenital spinal deformity due to 1 or 2 level HV. The surgical treatment were: Group 1, fusion without correction (hemi-epiphysiodesis or in-situ fusion), Group 2, correction without HV resection (with or without anterior or posterior release) and posterior instrumentation, and Group 3, correction with HV resection (anterior and/or posterior) and posterior instrumentation. Results Forty-two patients, with two-year follow-up, were treated between 1991 and 2004. The congenital anomalies were: fully segmented, non incarcerated HV (n=32, 76.2%), incarcerated HV (n=1, 2.4%), and semi-segmented HV (n=9, 21.4%). The distribution of surgical treatments were: Group 1: n=10(24%), Group 2: n=9 (21%), Group 3: n=23 (55%). Pre-operative curve sizes were statistically different: Group 1, 37° and Group 3, 34° were significantly smaller than Group 2, 55° (p=0.04 and p<0.01, respectively). The mean age of the patients was 8 years (range 1-18). The complication rate was 25%: Group 1, 20%, Group 2, 11%, Group 3, 35%. The % coronal correction at 2 years post- op was better for Group 3 (74%) compared to Group 1 (30%) and Group 2 (45%) (both p<0.01). A sub-analysis of Group 3 revealed shorter fusions in those treated with posterior only resection compared to the anterior/posterior techniques (p=0.05). Conclusion HV resection gave the best % correction 2 years post-op. It had a slightly higher complication rate than the other two techniques. HV resection in younger patients results in better correction with fewer levels fused than either of the other two techniques.
  4. 4. Paper #4 A Retrospective Cohort Study of Pulmonary Function, Radiographic Measures and Quality of Life in Children with Congenital Scoliosis: An Evaluation of Patient Outcomes after Early Spinal Fusion. Michael Vitale, M.D., MPH, Hiroko Matsumoto, M.A., Jaime A. Gomez, M.D., Michael R. Bye, M.D., Joshua E. Hyman, M.D., Whitney A. Booker, B.S., David P. Roye, Jr., M.D. Introduction This study evaluates the pulmonary function and quality of life (QOL) of children after a posterior spinal fusion for progressive congenital scoliosis and compares them to those of healthy children. The relationships between radiographic measures, pulmonary function, and QOL will also be examined. Methods Twenty-one patients 12.6 +/- 3.4 years old with diagnosis of congenital scoliosis who were treated with posterior spinal fusion were evaluated using radiographs, pulmonary function testing (PFT) and QOL surveys using Child Health Questionnaire Parent Form (CHQ). Some of the patients were treated with growing rods before the fusion and they were, on average, 6.9 years post definitive spinal fusion. Average age at initial surgery was 4.9 (1-10) years. Results Forced vital capacity (FVC) (p<0.001), forced expiratory volume in one second (FEV1) (p<0.0001), total lung capacity (p=0.001), and vital capacity (p<0.001) were significantly lower than those in healthy children. The CHQ scores in our study patients were significantly lower than healthy children in physical function (p=0.001), general health (p=0.001), and physical summary (p<0.001) and significantly higher in emotional impact on parental time (p=0.036). Patients with larger thoracic curves had lower FVC (r = -.532, p= 0.075) and FEV1 (r = -.590, p=0.04). Patients with larger kyphotic angles had lower self esteem (r = -.560, p=0.008). Patients with larger thoracic curves have lower scores on family activities (r = -679, p = .011) and those with larger thoracolumbar curves have lower scores on physical domains (r = -.701, p = .008). Patients who had lower FEV1 (r = .526. p=.021) and FVC (r = .545, p=.016) had lower global behavior and family activities scores. Conclusion Compared with healthy children, patients with congenital scoliosis, treated with posterior spinal fusion at an early age, have significantly worse pulmonary function and quality of life scores when assessed at average 7 years following initial surgery. These data will add to growing literature which supports alternatives to early spinal fusion, such as fusion- less surgery, growing rods and the Vertical Expandable Prosthetic Titanium Rib (VEPTR) device.
  5. 5. Paper #5 How Does VEPTR Affect Pulmonary Function? Hemal Mehta, M.S., Brian D. Snyder, M.D., Ph.D, Andrew C. Jackson, Ph.D, Stephen R. Baldassarri, B.S., Melissa J. Hayward, M.D., Michael J. Giuffrida, M.D., Vahid Entezari, M.D., Jay M. Wilson, M.D. Summary Thoracostomy in conjunction with VEPTR implantation partly reversed the constricted hemithorax created in young rabbits thereby partially improving lung growth and alveolar Introduction Campbell demonstrated that thoracostomy in conjunction with VEPTR implantation to expand the constricted hemithorax of children with acquired or congenital anomalies of the thorax and spine improves respiratory function and controls spine deformity. The mechanisms for the success of this treatment are unknown. Hypothesis Thoracostomy in conjunction with VEPTR implantation reverses impaired respiration by increasing the volume of the constricted hemithorax to allow partial resumption of lung growth. Methods A constricted left hemithorax was induced in seven 5-week old New Zealand rabbits by asymmetrically tethering ribs 4-8. Thoracic and spinal deformities developed in the Disease group (n=3). Thoracostomy and VEPTR implantation were performed at 10- weeks in the VEPTR group (n=4). Two rabbits served as Normal Control. At serial time points during growth, FRC and respiratory compliance were measured using whole body plethysmography. Lung volume, spine and chest wall deformity were measured using CT. Right, left and total lung volumes were calculated from sequential transaxial CT images of the thorax. Histological analysis was performed on the dissected lungs. Measures of respiratory function, spine and thoracic deformity were compared using ANOVA and Fisher’s least significant difference. Results The constricted hemithorax created in the Disease group was partly reversed in the VEPTR group. This allowed slight improvement in left lung volumes. However, due to the small number of rabbits, this result was not significant. A compensatory increase in right lung volumes resulted in normalization of total lung volume among the Disease and VEPTR groups. Alveolar morphology was significantly improved in the VEPTR group. Conclusions Preliminary results indicate that VEPTR implantation partly reversed the constricted hemithorax created by tethering ribs in a growing rabbit model. There was slight improvement in the growth of the affected lung and partial normalization of alveolar morphology histologically.
  6. 6. Paper #6 The Treatment of Secondary Thoracic Insufficiency Syndrome of Myelominingocele by a Hybrid VEPTR "Eiffel Tower" Construct with S-Hook Iliac Crest Pedestal Fixation Robert M. Campbell, M.D., M. Smith, M.D., W. Allen, M.D., JW Simmons, M.D., S. Inscore, M.D., B. Cofer, M.D., J. Doski, M.D., C. Grohman, M.D. Secondary thoracic insufficiency syndrome in myelomeningocele is associated with lumbar kyphosis, lordosis, or pelvic obliquity. Fusion or kyphectomy may correct angular deformity, but at the cost of growth of the spine with a high rate of complications. A modification of the VEPTR construct for congenital scoliosis has promise for treatment of this disorder. Methods 0 pts. Avg f/u 5.75 yrs ( 2-11.5 yrs ) Unilat hybrids 8 pts., bilat 2 pts. Results Six had a marionette sign preop, none at follow-up. Ratio of diaphragm depth/abdominal height (nl <1) improved from 2.17 preop to 1.56 at f/u. Lumbar kyphosis improved from 43˚ to 26˚. T/L spine ht increased 5.8mm/yr. Pelvic obliquity improved from 34˚ to 11˚. Coronal moment arm of iliac crest s-hook fixation was 2.4 times longer than a theoretical pedicle screw at the same level. Asymptomatic hook migration through avg 39 mm “safe zone” of iliac crest was 24 mm (6.3 mm/yr, or 16% “safe zone”/yr ) Unilateral hooks migrated at 8.4mm/yr , bilateral at 7.4 mm/yr . No slow migrations required reseating. One s-hook incorrectly placed in the SI joint did require acute reseating.. Scoliosis improved from 73˚ to 46˚ . Average f/u VC (n = 7) was 39% normal. Average implant EBL 84 cc. Complications: 3 s-hook fractures, 2 rib cradle migrations, 1 skin slough, 4 wound infections. There were no spinal infections. One patient died of respiratory failure unrelated to surgery. Conclusions VEPTR expansion thoracoplasty with a hybrid VEPTR “Eiffel Tower” construct with s- hook iliac crest pedestal fixation can span the lumbar spine laterally with effective lateral torso/pelvis distraction elevating the diaphragm away from the pelvis with correct of spine deformity and pelvic obliquity without affecting growth potential of the spine. Significance S-Hook iliac crest pedestal fixation VEPTR modification is a powerful means to correct pelvic obliquity because of inherent biomechanical advantage of an extended lateral moment arm compared to central spinal fixation, and spine infection appears be avoided because the central skin scarring in myelomeningocele is not violated.
  7. 7. Paper #7 VEPTR in Non - Ambulatory Myelodysplasia Patients John M. Flynn, M.D., Norman Ramirez, M.D., Randal Betz, M.D., John Smith, M.D., Robert Campbell, M.D. Non-ambulatory children with spina bifida are most likely to develop scoliosis. The dysplastic anatomy of the chest wall in a paralytic child secondarily affects other organ systems. Thoracic insufficiency may go unnoticed due to the child's limited physical activities is and is due to increased sagittal plane deformity as the diaphragm invades the pulmonary cavity. The purpose of this report is to evaluate the patients with spina bifida and spinal deformity treated with the Vertical Expandable Prosthetic Titanium Rib (VEPTR) and included in the FDA Request for Approval of Humanitarian Device Exemption for the Vertical Expandable Prosthetic Titanium Rib. The FDA report includes 247 patients with surgeries performed by members of the Chest Wall Deformity Study Group. Twenty patients were myelodysplastic none ambulatory. Data from remaining 16 patients with adequate follow up was extracted from the FDA report and analyzed. The average age at the first surgery was 5 years; average follow up was 47.3 months. In nine patients the Cobb angle was decreased an average of 14.4°; in five patients increased 12.6°. Thoracic spinal height was increased in twelve patients an average of 3.2 cm. and lost in two patients 0.8 cm. Twelve patients improved and two patients deteriorated ventilatory function. Implant lengthening was done on the average of every sixth months and device exchange every 30 months. Complications in five patients were due to the severity of the decreased pulmonary capacity. Implant failure and skin breakdown occurred in six patients. The rate of complications reported in this group of patients lies within the range reported for spinal fusion using standard approaches. The number of surgical procedures increases due to the need for expanding the implants as the child grows. The advantages of the VEPTR are: surgical incisions are away from the midline avoiding the midline scarred tissue and allowing growth of the spinal column with improved space available for the lung.
  8. 8. Paper #8 Measurement of Forces Generated During Distraction of Growing Rods Marco Teli, M.D., Giuseppe Grava, M.D., Alessio Lovi, M.D., Marco Brayda-Bruno, M.D. Study design Consecutive series of measurements. Objective To measure the forces applied during distraction of growing-rods. Summary of Background Data Growing-rods have been used for decades to treat deformities of the immature spine, with variable success. These rods are periodically lengthened by repeated surgeries, and failure of growing instrumentation is often reported. Methods Distraction forces were measured in 10 pre-puberty patients (mean age, 8 years; range, 6 to 11) undergoing the first distraction of growing-rods, 6 months after implantation for idiopathic scoliosis treatment. For each measurement, output from the transducer of a dedicated pair of distraction calipers was recorded at zero load status and at every 1 mm distraction, up to a maximum of 12 mm. Results 10 measurements were obtained showing a mean peak force of 485N at 12 mm distraction. In one case a single peak force reached 552N at 6 mm distraction. Conclusions At 500N no failure of instrumentation was recorded. This led to satisfactory elongation of the rods. The above limit is therefore to be regarded as the uppermost level of force to be applied during surgical distraction of growing rods.
  9. 9. Paper #9 Single Growing Rods (Review of 21 cases). Changing the Foundations: Does it Affect the Results? Hazem Elsebaie, FRCS, M.D. Study Design A retrospective case review of children treated with submuscular single growing rod technique with proximal double claw and distal double level pedicle screws construct done by the author. Objectives Evaluation of a newer version of single growing rod technique inserted sub muscularly. Changing the foundations in the single rod may change the results. Background Data Single growing rod techniques used to include proximally a single claw and many other constructs that have evolved over years, these reports were used commonly to be compared with the double rods. To the authors’ knowledge there were no reports on sub muscular single rod using consistently these foundations which are assumed to be and more powerful in correction. Methods From 2002 to 2007, 21 patients average age 6 years ( 4 -9) underwent single growing rod procedures using pediatric Isola instrumentation and tandem connectors, 8 had annulotomy. They underwent an average of 4 lengthening ( 1- 9). Diagnoses included infantile and juvenile idiopathic scoliosis (13), congenital (3), neurofibromatosis (3), syndromic (1) and post hydrocephalus (1). Analysis included age at initial surgery, number and frequency of lengthening, changes in scoliosis Cobb angle, length of T1-S1 and complications. Results The mean scoliosis improved from 85° (range, 45° -123°) to 31° (range, 11°-61°) after initial surgery and was 36° (range, 13°-75°) at the last follow-up. T1-S1 length increased on average of 1.32 cm per year. During the treatment period, complications occurred in 7 of the 21 patients, and they had a total of 11 complications all were implant related including 4 proximal claw pull out, 5 rod breakage, one loose set screw of the tandem and one pedicle screw distal migration, there were no infections, skin complications nor neurological complications. Conclusion The sub muscular single growing rod technique with proximal double claw and distal double pedicle screws seems to offer a valid alternative to the double rod techniques with comparable degrees of correction and less incidence of skin complications and infections especially in thin children with minimal subcutaneous fat.
  10. 10. Paper #10 Safety and Efficacy of Growing Rod Technique for Pediatric Congenital Spinal Deformities Hazem Elsebaie, FRCS, M.D., Muharrem Yazici, M.D., George H. Thompson, M.D., John B. Emans, M.D., David S. Marks, FRCS, David L. Skaggs, M.D., Alvin H. Crawford, M.D., Lawrence I. Karlin, M.D., Richard E. McCarthy, M.D., Connie Poe- Kochert, NP, Patricia Kostial, RN, BSN, Tina Chen, BS, Behrooz A. Akbarnia, M.D. Study Design A retrospective analysis of patients with congenital spinal deformities treated with single or dual growing rods that had a minimum of 2 years follow-up. Objectives To determine the safety and efficacy of this technique. Summary of Background Data Growing rod technique has been used as a modern alternative treatment for young children with spinal deformities. There is no comprehensive study focused mainly on the use of growing rod technique in congenital spine deformities. Methods A total of 19 patients with the average age of 6 years and 10 months (3 to 10) with progressive congenital spinal deformities that underwent growing rod procedures with a minimum of 2 years follow up. The congenital anomalies included failure of segmentation in 5, failure of formation in 4, mixed 5 and unclassified or not recorded in 5. The average of affected vertebrae per patient was 5.2 (2-9). The average follow up period was 3 years 9 months (2 to 6). Results The mean scoliosis cobb angle improved from 65.3 (40-90) pre-initial to 44.9 (13-79) post initial (31.2% correction) and 47.2 (18-78) at the last follow-up or post-final fusion. T1-S1 length increased from 263.8mm (192-322) after initial surgery and to 310.5mm (261-352) at last follow-up or post-final fusion with an average T1-S1 length increase 12mm per year. The space available for lungs (SAL) ratio increased from 0.81 preoperatively to 0.94 post latest follow up. Five patients reached final fusion. During the treatment period, complications occurred in 8 of the 19 patients (42%), and there were a total of 15 complications out of 100 procedures (15%): 2 pulmonary, 2 infections and 11 implant-related. There were no neurological complications in any of the patients during the treatment period. Conclusion The growing rod technique is a safe and effective treatment for congenital spinal deformities. There is less correction obtained at initial surgery compared with previous reports for the same technique in other etiologies. However, there was minimal loss of correction over the treatment period. The spinal growth and the SAL improved. The rate of complication is acceptable. Paper #11 Pelvic Fixation of Growing Rods
  11. 11. Paul D. Sponseller, M.D., Behrooz A. Akbarnia, M.D., George H. Thompson, M.D., Richard E. McCarthy, M.D., John B. Emans, M.D., Marc A. Asher, M.D., Muharrem Yazici, M.D., David L. Skaggs, M.D., Connie Poe-Kochert, RN, CNP, Pat Kostial, RN, BSN, Tina Chen, BS Previous studies have not evaluated growing systems in which the distal anchor is the pelvis. This project analyzed the outcomes and complications of this population. 22 patients were studied from 6 centers. Indications included severe pelvic obliquity, distal deformity, or lack of satisfactory alternative anchor sites. All had a minimum of two years treatment with growing rods fixed to the pelvis. Diagnoses included myelomeningocele (4), cerebral palsy (3), congenital (2), arthrogryposis (1) SMA (1), miscellaneous/syndromic (11). Mean age at surgery was 6.1 ± 3.1 years. Mean preoperative curve was 86 ± 22°. Mean coronal imbalance was 9.7 ± 8.2 cm. Mean follow-up was 50 months. Iliac screws or rods were used in 17, sacral hooks used in five. Proximal fixation was with hooks in 12 patients and screws in 10. Dual rods were used in 18 patients; single rod in 4. Use of a distal crosslink improved construct stability. Patients underwent a mean of 2.9 ± 1.8 lengthenings. Mean curve improved to 47± 19° at final follow-up. Coronal imbalance improved to 4.4 cm postoperatively. Mean increase in T1- S1 length was 7.3 ± 2.9 cm during distraction. Seven patients have undergone final fusion at a mean of 10.8 ± 1.4 years. Complications: 6 patients developed deep wound infections; 5 patients had distal fixation complications, but all were salvaged. There were 3 rod breakages; this rate did not differ statistically from the rate for dual growing rods as a whole. Pelvic fixation may be used successfully as a distal foundation for growing rods. Both screws and hooks provide satisfactory distal fixation. Pelvic fixation is a useful adjunct to growing rods for many children who develop severe syndromic or neuromuscular spinal deformity at an early age.
  12. 12. Paper #12 Iatrogenic Thoracic Outlet Syndrome as a Complication of VEPTR Steven Mardjetko, M.D., Ahmad Nassr, M.D., Benjamin Crane, M.D., Kim Hammerberg, M.D. Introduction An innovative treatment for Thoracic Insufficiency Syndrome (TIS) involves a vertical expansion of the chest wall through a horizontal chest wall osteotomy and a distraction device (VEPTR). However, 10% of these patients demonstrate upper extremity neurovascualr dysfunstion following expansion. This study identifies potential etiologies for compression of the brahial plexus following the VEPTR procedure, and suggests strategies to reduce the incidence of this complication. Materials and Methods A cadaveric study with a simulated VEPTR procedure was performed. A thoracotomy and sequential rib distraction was performed while manometric measurements were taken in three anatomic regions of the thoracic outlet. Also, a barium-impregnated putty was placd along the brachial plexus, and evaluated after expansion using fluoroscopy. A midclavicular osteotomy was then performed and this process was repeated. Results Using the manometric technique described, a 20% increase in pressure was seen in the mid-clavicular region of the thoracic outlet after thoracic expansion. Reapproximation of the scapula on the chest wasll further increased the pressure within the thoracic outlet. constriction of the mid-clavicular region of the thoracic outlet between the first rib and clavicle was appatent using the putty technique. Mid-clavicular osteotomy alleviated this region of compression. A second region of compression was noted in the infraclavicular region of the thoracic outlet. This was secondary to a lateral displacement of the second and third ribs during the expansion thoracoplasty. This constriction was worsened by anatomic reapproximation of the scapula to the chest wall. Discussion Surgeons should avoid any attempt to pull the scapula distal or medial to its anatomic position. The utilization of mid-clavicular osteotomy to alleviate thoracic outlet narrowing after VEPTR procedure may be considered if compression is thought to be in the mid-cavicular zone. For compression in the infra-clavicular region, lateral second/third rib osteotomy or resection may be another strategy.
  13. 13. Paper #13 The Development of Spinal Deformities Following Open Heart Surgery Jose Herrera-Soto, M.D., Kelly L. Vander Have, M.D. Patients with congenital heart disease (CHD) are at an increased risk of developing scoliosis. The purpose was to determine the prevalence of spinal anomalies in patients with CHD post open heart surgery. Methods 221 patients post open heart surgery for CHD without congenital anomalies were evaluated. There were 132 males and 89 females with a mean follow-up of 13 years. Results 59 patients presented scoliosis (27%), with similar incidence of scoliosis between groups. 18 presented moderate to severe scoliosis. 39% with moderate to severe scoliosis presented with hyperkyphosis (>40 deg). All patients with severe scoliosis underwent spinal fusion, 9 female and 4 male. Forty patients (18%) presented with hyperkyphosis. Only 1/40 with hyperkyphosis had a thoracotomy (2.6% of thoracotomy patients). The remaining 39 patients underwent a sternotomy or combined procedure. There was no difference in those with cyanosis or not and the development of scoliosis or kyphosis. No difference between those with and without scoliosis and the age at the first procedure was found. Patients with multiple procedures were not at increased risk of deformity. There is an increased incidence of scoliosis in CHD patients. Sternotomy may affect coronal alignment as thoracotomies. But, it was shown to affect sagittal alignment. It is important for continued monitoring of spinal deformities as 80% of our severe curves developed before the age of 9.
  14. 14. Paper #14 Health Related Quality of Life in Children with Thoracic Insufficiency Syndrome Michael Vitale, M.D., David P. Roye, Jr., M.D., Hiroko Matsumoto, MA, Jaime A. Gomez, M.D., Randal R. Betz, M.D., John B Emans, M.D., David L. Skaggs, M.D., John T. Smith, M.D., Kit Song, M.D., Robert M Campbell, Jr., M.D. Purpose The purpose of this study was to compare quality of life (QOL) of children with TIS and impact on their parents prior to and after the implantation of the VEPTR. We also compared the QOL of children with TIS and the parental impact prior to implantation of the VEPTR with previously published QOL of healthy children. Methods As part of the original multi-center evaluation of the VEPTR, Child Health Questionnaire CHQ was collected preoperatively on 45 patients who were subsequently treated with expansion thoracoplasty using the VEPTR. The average age was 8.2 +/-2.6 and parent form of the CHQ was filled by the primary caretaker. Patients were divided into three diagnostic categories: Rib Fusion (RF) N=15, Hypoplastic Thorax Syndromes (HT) N=17 and Progressive Spinal Deformity (PS) N=13. Results There were significant differences between the study patients and healthy children in physical domains. Compared with parents of healthy children, parents of children with TIS experienced more limitations on their time and emotional lives due to their children's health problems. In addition they had poor expectations for their children's health. There were no significant differences in CHQ scores in these children before and after the surgery except for a significant decrease in Self Esteem score among patients with HT. None of the domains in the CHQ had moderate or large degree of responsiveness across all three diagnostic categories. Discussion The children with TIS had lower physical domain scores and higher caregiver burden scores than healthy children. However, the scores in psychosocial domains were similar to those in healthy children. Since responsiveness of the CHQ was small, it can be concluded that our study demonstrates the lack of ability in the questionnaire to reflect clinically important minimal changes in response to the VEPTR instrumentation in this population. Therefore, a Disease Specific Instrument (DSI) may be needed in order to detect the minimal changes in this population. Current efforts are on their way to better understand the clinical features that have the most profound effects on the life of these children and to develop a DSI for this population.
  15. 15. Paper #15 Surgical Complications in Early Onset Scoliosis Jonathan H. Phillips, M.D., D. Raymond Knapp, Jr., M.D., Jose Herrera-Soto, M.D. Between March 2002 and July 2005 a total of 44 surgical procedures were performed in 20 young scoliosis patients involving the use of unfused instrumentation. Average age was 8 years-1 month, range 2 + 3 to 12 + 7. Total number of procedures was 44, average 2.2. and only one patient has gone on to definitive fusion at this point. This indicates the early stage of development of this program at our center. All patients received either ISOLA growing rod instrumentation or VEPTR. There was a 100% complication rate in the VEPTR patients and 64% in the growing rods. 20% of total complications occurred in patients who moved to our area from out of state and were established complications, sometimes after multiple surgeries done elsewhere. Our local complication rate was 45% which is nearly identical to published literature (Akbarnia, BA, et al 2005). There was an alarmingly high rate of deep infection which occurred early in the VEPTR group and late after many lengthenings in the growing rod group. Of 9 infections, implants were salvaged in only 2 cases. The others all need to be removed and definitive treatment of the scoliosis is still pending. There was 1 perioperative death in the group. There was one transient intraoperative neurological deficit with no permanent loss postoperatively. A large variety of very rare syndromes comprised much of this group. As in other reports, implant cut out and breakage constituted the majority of non infectious complications. These patients represent a high risk group but seem to have a complication rate in excess of other high risk patients. For example, our group reported an 8% infection rate in definitive fusion for neuromuscular scoliosis recently (Phillips et al 2005). Our infection rate for this early onset group was five times greater. It is assumed that the multiple surgeries for rod lengthening lie at the heart of this high complication rate and strategies to avoid repeated open procedures may reduce the rate of infection at least. The fact that 20% of complications were inherited from other centers in the USA underlies the need for a central data bank of this small group of patients to truly delineate outcomes in Early Onset Scoliosis surgery.
  16. 16. Paper #16 Long-term Results of Congenital Scoliosis Treatment Martin Repko, Martin Krbec, Jan Burda, Jan Pesek, Richard Chaloupka, Vladimir Tichy Aim The aim of our study is to evaluate clinical and X-ray long-term results of congenital scoliosis treatment. Material The total number of 442 patients with congenital scoliosis treated in our department in the period from 1976 to 2006 was retrospectively evaluated. There were 175 (40%) patients treated by conservative manner, 64 (14%) pts. were treated by single bone fusion, 141 (32%) pts. were treated by correction with instrumentation using the posterior approach and 62 (14%) pts. were treated by combined anterior/posterior surgical approach. An average follow up was 16 years and 3 month. Results 1. conservative treatment - the magnitude of the curves was at time of detection on average 44,1° according to Cobb angle and 39,8 at time of last control. 2. single bone fusion by posterior surgical approach - an average time of surgery was 6,6 years, follow up was 14,2 years. The magnitude of the curves was at time of detection on average 44,1°, 44,2 preoperatively, 34,4 postoperatively and 38,4 at time of last control. There were no neurological complication. 3. posterior surgical approach with instrumentation - the time of surgery was 8,6 years, follow up was 12,6 years. The magnitude of the curves was at time of detection on average 61,1°, 66,8 preoperatively, 40,9 postoperatively and 46,0 at time of last control. There were 1,7% of neurological complications. 4. combined anterior/posterior surgical approach with hemivertebrectomy and instrumentation - the time of surgery was 11,2 years, follow up was 17,9 years. The magnitude of the curves was at time of detection on average 52,2°, 64,9 preoperatively, 38,3 postoperatively and 39,0 at time of last control. There were 1,2% of neurological complications. Discussion and Conclusions Early detection, good timing and choosing of adequate surgical treatment type are the main factors of quality treatment results. All methods of surgical treatment led to the improvement in magnitude of the scoliotic curve. The best method seems combined anterior/posterior surgical approach with hemivertebrectomy and instrumentation stabilization.
  17. 17. Paper #17 VEPTR in Patients with a Previous Spinal Fusion Peter Sturm, M.D., John M. Flynn, M.D., Randal R. Betz, M.D., John T. Smith, M.D., John B. Emans, M.D., Sohrab Gollogly, Robert M. Campbell, M.D., Melissa P. Smart, BS, R.N. Introduction Spinal fusion had been the mainstay of treatment for children with complex congenital scoliosis. This treatment had an unintended deleterious effect on spinal growth and pulmonary development. The use of the VEPTR in these patients has been shown to control curve progression while allowing for trunk growth and further lung maturation. This study looks at the use of a VEPTR in patients who had undergone a spinal fusion. Methods Seventeen patients who had previous spinal fusions, and then subsequently underwent the insertion of a VEPTR between September 1996 and February 2003, were identified among patients entered prospectively into a database for an FDA IDE study. Pre and postoperative Cobb angle, thoracic height and complications were recorded. Eight to twelve month follow up data was available for 12 patients and 36 month follow up in 7. Results The indication for VEPTR in these patients was a progressive curve despite previous fusion, and persistent thoracic insufficiency. Average age at VEPTR insertion was 6 years and 7 months. Average preoperative Cobb angle was 59° (range 10 - 95°). Average postoperative curve measured 49° (range 5 - 80°). In the subgroup with one year follow up the average preoperative Cobb angle was 58.3°, postop 41.6°, follow up 48.7°. The average change in trunk height was 0.74 cm at index surgery. 7 patients had complications. This included 3 patients with loss of fixation alone, 1 patient with a postoperative infection, 2 patients with both an infection and loss of fixation, and 1 patient with postoperative Horner’s syndrome. Conclusion The use of a VEPTR has been shown to be beneficial in children with thoracic insufficiency due to various etiologies. In patients who have already had a spinal fusion the goals of VEPTR implantation are to improve truck deformity, expand the chest, and modulate the spinal deformity when possible. The amount of correction of both the Cobb angle and thoracic height is less than in chlidren who have not undergone a prior spinal procedure. In addition, the complication rate is higher. It should be viewed as a salvage procedure in this group of patients.
  18. 18. Paper #18 Short Anterior Instrumented Fusion of Lateral Hemivertebra Enrique Garrido, MRCS, EBOT, F. Tome, SK Tucker, TR Morley, HNM Noordeen Study Design Retrospective study with clinical and radiological evaluation of 29 patients with congenital scoliosis who underwent 31 short segment anterior instrumented fusions of lateral hemivertebrae. Objective To evaluate the safety and efficacy of early surgical anterior instrumented fusion with partial preservation of the body of the HV in the treatment of progressive congenital scoliosis in children below the age of 6. Summary of Background Data A variety of treatments have been described in the literature for the treatment of HV. We report the results of a novel technique. Materials and Methods Between 1996 and 2005, 29 consecutive patients with 31 lateral HV and progressive scoliosis underwent short segment anterior instrumented fusion with partial preservation of the body of HV. Additional posterior Moe fusion was performed on 29 HV. Mean age at surgery was 2.9 years. Mean follow-up period was 6.2 years. Results Preoperative segmental Cobb angle averaging 39, was corrected to 15 after surgery, being 16° at the last follow up (56,4% of improvement). Compensatory cranial and caudal curves corrected by 50% and did not change significantly on follow up. The angle of segmental kyphosis averaged 14 before surgery, 13 after surgery, and 14° at follow up. Coronal and sagital balance improved postoperatively and gradually during follow up to normal values. 10 patients had a thoracic kyphosis and two patients a lumbar lordosis below average for their age. There were 2 posterior wound infections requiring surgical debridment, one intraoperative fracture of the vertebral body during screw insertion and in one case there was loss of correction due to implant failure. All went on to stable bony union. There were no neurologic complications and no additional operations. Conclusions Early diagnosis and early and aggressive surgical treatment are mandatory for a successful treatment of congenital scoliosis and to prevent the development of secondary compensatory deformities. Anterior instrumentation is a safe and effective technique capable of transmitting a high amount of convex compression allowing short segment fusion which is of great importance in the growing spine
  19. 19. Paper #19 Prior Instrumentation and Fusion Method at the Anchor Sites Tomoaki Kitagawa, M.D., Hiroshi Taneichi, Daisaku Takeuchi, Takashi Namikawa, Satoshi Inami, Tetsuro Kiya, Yutaka Nakamura, Takahiro Iida, Yutaka Nohara Background Growing rods system is usually used for early onset scoliosis that have small and fragile posterior elements due to not only its young age but also congenital or genetic factors, which make it difficult to apply strong corrective force at the time of initial surgery and/or necessitate post-operative immobilization using cast or orthosis. Method To prevent this problem, we have developed a staged operation to apply growing rods. At the initial surgery, only the proximal and distal anchor sites are exposed and the patients undergo one- or two-level instrumentation and fusion at the both sites. Instrumentation includes either hooks, pedicle screws, or their combination. Fusion procedure includes decortication of the lamina and facet joint, and local bone grafting. The second surgery will be planned after the fusion mass becomes mature and solid, usually about three months after initial surgery. The anchor sites will be exposed again and previous screws and hooks will be replaced with thicker ones if necessary. Four cases of this method were investigated retrospectively. The age at the surgery ranged from three to eight years old. The primary diagnosis includes Turner syndrome, neurofibromatosis, Ehlers-Danlos syndrome, and scoliosis associated with CHARGE syndrome. Results Mean pre-operative Cobb angle of the major curve is 112°, ranging from 48 to 143°. Mean post-operative Cobb angle after correction surgery using growing rods was 46°, ranging from 27 to 63°. Mean operation time was 202 minutes at the first surgery and 173 minutes at the second surgery. The laminae were covered with solid fusion mass and pedicle walls were thickened and expanded at the second surgery, so stronger anchors could be obtained. Then growing rods were applied and strong corrective force could be applied to achieve enough initial correction. Patients were allowed to walk within three days after surgery without use of cast or orthosis. Correction loss did not happened until next rods lengthening surgery. Conclusion Prior instrumentation and fusion method for growing rods is effective for strong initial correction and can avoid failure of the posterior element of the spine.
  20. 20. Paper #20 Evaluation of Vertebral Anomalies and Vertebral Osteotomy Noriaki Kawakami, M.D., Taichi Tsuji, Kazuyoshi Miyasaka, Tetsuya Ohara, Yasunori Tatara, Kei Ando, Ayato Nohara Posterior hemivertebrectomy has been reported as effective, safe, and less invasive for the surgical treatment of hemivertebrae; although it is technically demanding. However, the combined anterior and posterior operation is still useful and may be selected for some types of congenital vertebral anomaly. Purpose The purpose of this study was to assess the type of congenital vertebral anomaly and the operative strategy using vertebral osteotomy and to determine which types of vertebral anomaly should be treated through an the combined anterior and posterior approach. Materials and Method Sixty patients who underwent vertebral osteotomy for congenital vertebral anomaly were evaluated retrospectively. They consisted of 31 males and 29 females and the average age at the time of operation was 13 years. One patient underwent two separate operations for discrete, distinct anomalies. Of 61 operations in total, 36 used the posterior approach and 25 used the combined anterior and posterior approach. Of 25 combined anterior and posterior operations, 7 were two-staged. The overall postoperative follow-up time was 55 months (17-156). Results The types of congenital vertebral anomaly were evaluated using 3DCT and were classified into 16 cases of solitary simple, 24 of multiple simple, 16 of multiple complex, and 4 of segmentation failure. The reasons for selection of the combined anterior and posterior operation included the release and/or osteotomy of multiple levels in 11 cases, leaning curve in 7, and additional anterior bone graft for a big gap in the osteotomy site in 6 cases. In 36 patients in whom the posterior approach was utilized, 29 (80%) were included in solitary simple or multiple simple, which indicated anterior and posterior unison type anomalies. Scoliosis was corrected from 43.2° to 16.1° using the posterior approach only, and from 72.6° to 33.1° with the combined anterior and posterior operation, indicating statistically significant differences for both preoperative and postoperative curve magnitudes. Conclusion More severe curves and multiple congenital vertebral anomaly may be factors that necessitate the combined anterior and posterior operation.
  21. 21. Paper #21 PRSS in Management of Adolescent and Juvenile Scoliosis Qibin Ye Objective To study on the therapeutic mechanism of an innovated instrumentation-Plate-Rod System for scoliosis (PRSS) and its effectiveness for the surgical management of adolescent and juvenile scoliosis Method To avoid the necessity of repeated operative instrumentation lengthening, a new device- PRSS was developed in our department. Since October 1998, a total of 183 scoliotic children were treated using PRSS. Among them, 66 cases adolescent and 23 cases juvenile scoliosis were evaluated prospectively. The mean age at the time of surgery was 12.15 years in adolescent group and 7.98 years in juvenile group. The experimental study on type X collagen which reflect cartilage degeneration was studied in PRSS- instrumented animal spine to express the therapeutic biomechanism . Results The preoperative scoliotic curve was 66.58° and post-operative curve was 22.70° (68.86% ) in adolescent group and in juvenile group, the scoliotic curve was improved from 80.7° to 30.5° (62.2%). An average of 11.13mm spinal lengthening of the instrumented segments was achieved in adolescent group and 13.38mm in juvenile group. In 10 cases, the implant was removed after bone maturing was reached. The spine keep good maintained of correction and essential normal flexibility. When PRSS is placed in place, compressive stress was found to exert on the convex side, while tensile stress on the concave side of the curvature, and more type X collagen to be expressed on convex side than concave side, it suggest that compressive stress leads to increase earlier cartilage degeneration of end plate in convex side, so as to retard the growth of the end plate of this side, resulting in maximum spinal realignment. Conclusion The PRSS, which dispenses with spinal fusion and allows extension along with the children growth, is able to provide and maintain desirable correction of scoliosis in one stage operation and it is helpful to prevent Crankshaft phenomenon, essential normal spinal flexibility can be obtained after treatment. This new device is an effective instrumentation for correcting scoliosis, especially in growing children.
  22. 22. Paper #22 Spinal Hemiepiphysiodesis Correlates with Structural Changes Eric Wall, M.D., Donita I. Bylski-Austrow, Ph.D, David L. Glos, BSE, Edgar T. Ballard, M.D., Andrea Montgomery, BS, Alvin H. Crawford, M.D. Introduction Some stapling methods have been shown to alter spine alignment in preclinical models. In long bones, staples have been shown to alter growth plate structure particularly in the hypertrophic zone. In the spine, however, stresses transmitted to the physes are likely affected by the intervertebral disc. The purpose of this study was to determine if structural changes to the vertebral growth plate accompanied increased spine curvatures in a porcine model of spinal hemiepiphysiodesis. The hypotheses were that the height of the hypertrophic zone and size of hypertrophic cells were lower at the stapled levels and side compared to both an unoperated level and the contralateral side. Methods Anatomically-based spine staples were implanted endoscopically into the left side of 6 mid-thoracic vertebrae of five skeletally immature domestic pigs. Each staple was centered over an intervertebral disc and two growth plates, with placement aided by a guide-wire. After 8 weeks, spines were harvested. Mid-coronal sections were prepared for histologic analysis. Hypertrophic zone height, height and width of hypertrophic cells, and disc height were measured at discrete sampling locations across the plane at stapled and unstapled levels. Results Zone height, cell height, and cell width were lowest on the stapled side of the stapled level, with significant differences in the overall statistical model (p≤0.02). Disc heights were reduced at the stapled levels across the coronal plane. Conclusions A staple-like implant and particular endoscopic insertion procedures were associated with gradually decreased growth plate height and cell size, as well as decreased disc height. Clinical Relevance This is the first report of spinal hemiepiphysiodesis using clinically relevant procedures that has been shown to affect the growth plate asymmetrically. The results indicate that some devices may be capable of slowing progression of a developing scoliotic curve by differential growth inhibition.
  23. 23. E-Posters E-Poster #1 Efficacy of Growing Rods in Infantile Marfans Scoliosis Paul D. Sponseller, M.D., George H. Thompson, M.D., Behrooz A. Akbarnia, M.D., Marc A. Asher, M.D., John B. Emans, M.D., Tina Chen, BS, Connie Poe-Kochert, RN, CNP This is a retrospective analysis of nine patients with Marfan Syndrome and scoliosis (developing before age 3) treated with growing rod techniques with a minimum of 2 years follow-up. Radiographic and chart reviews included the following parameters: age, lordosis, kyphosis, complications, coronal balance, T1-S1 length, and initial curve angle. Three patients had single and 6 had dual growing rods. Age at initial surgery was 4.5 years (2-9). Mean scoliosis curve was 80° (54-105) and thoracolumbar kyphosis was 56° (27-85) preoperatively. Patients on Coumadin were lengthened yearly or throughout longer intervals of time. The mean follow up was 65 months. Four of 9 patients have undergone final fusion. The common construct was T2/4 to L4 in 4 patients and or to the pelvis in 4. Curve correction was 54% (41% with single rods, 61% with dual rods). Mean coronal imbalance improved from 56 to 18mm and sagittal imbalance from 31 to 21mm. Increase in T1-S1 length over the treatment period was 10.2cm for the whole group and 13.3cm for those who underwent final fusion. Complications included two rod breakages and two intra-operative dural leaks. There was one anchor dislodgement, however no postoperative dural leaks. None of the patients developed clinically significant junctional kyphosis. One patient died of unrelated causes three months postoperatively. Growing rod techniques can prevent large infantile curves from becoming severe in patients with Marfan Syndrome. Dual rods were more corrective compared to single rods. Significant spinal length can be obtained to minimize trunk disproportion.
  24. 24. E-Poster # 2 The VEPTR "Parasol" Expansion Thoracoplasty for Treatment of Transverse Volume Depletion Deformity of the Convex Hemithorax Rib Hump in Early Onset Scoliosis Robert M. Campbell, M.D., JT Woody Smith, JW Simmons, S. Inscore, BR Cofer, JJ Doski, C. Grohman Cobb angle correction and improved SAL is common with VEPTR treatment, but windswept deformity narrows the room for the lung contained within the rib hump. The structural basis of rib hump is usually not acute angulation of the rib, but a spine rotation- driven deviation of the ribs. Each rib “bucket handle” folds downward, closing shut the convex hemi-thorax, resembling the closure of a parasol. To reverse the mechanism of this deformity, a VEPTR expansion thoracoplasty was developed, termed the “parasol” procedure. Multiple levels of intercostal muscle are lysed to mobilize the depressed chest wall. Rib segments are elevated upward and outward, then stabilized in the “open parasol” position. Methods 10 pts. Avg f/u of 6 yrs from initial concave surgery and 4 yrs from convex parasol procedure. 7 pts 70 mm radius VEPTR, 4 pts hybrid/rib-rib VEPTR Results Cobb angle pre-op 79°, pre-convex proc 51°, 49° at f/u. SAL 1.5 pre-op, 0.92 at f/u. Concave/convex hemithorax width ratio was 2.79 pre-concave implant, 3.07 pre-convex implant, and 2.17 f/u. CT lung volumes (n = 6): pre-implant convex/concave l.v. ratio was 0.87, 0.91 at f/u. Avg. vital capacity at f/u was 37.8% predicted (n=9). Pt complications: (4) spinal hook migration, (3) superior migration rib cradles, (1) fractured hybrid, (1) titanium sling migration, (3) infection, (3) skin slough, (2) pneumonia. Conclusion Expansion of the rib hump in early onset scoliosis by the VEPTR “parasol” procedure increases the lateral width of the hemithorax on radiograph. Some improvement in the convex/concave lung volume ratio is seen. Scoliosis is not increased by the convex distraction. The complication rate is frequent, but treatable. Significance The loss of transverse volume in the convex hemithorax due to rib hump of the pt with EOS contributes to TIS. The VEPTR “parasol” expansion thoracoplasty directly addresses the anatomic deformity of rib hump, probably partially reversing the convex volume depletion problem. If done early in life, this may help encourage convex lung growth. For any growing pt with rib hump, especially if vital capacity is low, the “parasol” procedure should be considered instead of a traditional orthopaedic thoracoplasty.
  25. 25. E-Poster #3 Anterior Instrumented Correction of Congenital Scoliosis Hazem Elsebaie, M.D., Yasser Elmaelligy, FRCS, M.D., Wael Koptan, M.D., Mootaz Salaheldine, MSc, Hilali Noordeen, FRCS Orth Study Design Retrospective analysis. Objectives To determine the safety and efficacy of this technique in the management of progressive congenital spinal deformities due to failure of formation analyzing: correction of spinal deformity, fusion rate and incidence of complications. Summary of Background Data Several modalities have been reported for the treatment of young children with congenital spinal deformities including the recent reports on hemivertebrectomy with instrumentation. There has always been concerns regarding epidural bleeding, neurological complications, pedicle screws placement, implant faillure and prominence of posterior constructs in this very young age group. Anterior release, decancellation of the hemivertebra without opening the spinal canal and anterior instrumentation offers a new alternative which can avoid these concerns. Methods A total of 11 patients with progressive congenital spinal deformities due to failure of formation who had single stage anterior instrumented fusion, decancellation of the hemivertebra and posterior non instrumented fusion followed for a minimum of 2 years were analyzed. All patients had single hemivertebra. The average age of the patients was 2 years 7 months (1y 9m to 3y 10 m). And the average follow up period was 3 years 1 months (2ys to 4ys 5m). Results The mean scoliosis angle improved from 48° (34-58) preoperative to 17 (11-25) at the final follow up, a mean correction rate of 64.5% , the angle of kyphosis was 20° before surgery and 11° at the final follow up a mean correction of 45%, all the patients having radiological fusion. The average operative time was 120 mins (98-180 min). There was one superficial infection. Conclusion Anterior instrumentation with decancellation of the hemivertebra a offers a safe and effective alternative to hemivertebrectomy with less risks and less operative time and blood loss with an equal amount of correction, making the need of the more aggressive hemivertebrectomy questionable in this very young age group. Significance With anterior instrumentation decancellation of the hemivertebra is safer and simpler than hemivertebrectomy with same effectiveness in the very young children.
  26. 26. E-Poster #4 Spinal Open-Wedge Osteotomy Dezso J. Jeszenszky, M.D., Tamas Fulop Fekete, Martin Sutter, Friederike Lattig, Andreas Eggspuhler, Frank S. Kleinstuck Introduction Correction of congenital scoliosis is usually achieved by in situ fusion or by shortening of the spine. Intraoperative distraction may cause neurological damage and is therefore usually avoided or is performed indirectly by slowly distracting the ribcage. A surgical method to correct spinal deformity by osteotomy and distraction in congenital scoliosis has not been reported before. Methods 3 patients treated for mixed congenital scoliosis were studied. The surgical procedure involved concave side exposure of the bar to the anterior aspect using a posterior approach. The surgeon performed a near circumferential osteotomy around the dural sack and then opened up the osteotomized segment to correct the curve. The correction was augmented through distraction under continuous intraoperative spinal cord monitoring. Stabilization was performed without fusion and on one side only, with pedicle screws, rods and rib hooks. The Cobb angles of scoliosis were measured pre- and postoperatively. Results Age at surgery was 4.0 (2.4 – 5.25) years. Follow-up time was 1.52 (0.5 – 2.92) years. The avg scoliotic curve was 60.7° (50 – 69) pre-implant, 29.3° (18 – 40) post-implant, yielding a correction of 31.4° (51.8%). The pre- and postoperative compensatory curves were 34° (31-56) and 17° (12-23), respectively. Multimodal monitoring of the spinal cord during surgery revealed potential damage of the spinal cord in two cases immediately following the correction. Therefore the final correction was delayed for one week in both cases. No postop neurological complication was detected. Conclusion Spinal open-wedge osteotomy is an effective surgical technique for correction of congenital scoliosis. Surgery is performed only at the congenitally affected region of the spine. Goal of surgery is to achieve the greatest correction possible, at this site. All other healthy regions (secondary curves, convex side) of the spine are left intact. The surgery should be performed as early as possible, so all the intact spinal regions can grow normally. The use of intraoperative spinal cord monitoring is essential.
  27. 27. E-Poster #5 The Influence of Fixation Rigidity on Intervertebral Joints Charles-H Rivard, M.D., Christine Coillard, M.D., Gary L. Lowery, M.D., Souad Rhalmi, M.Sc., Marco Berard, M.D. Objectives The study was to determine whether allowing intervertebral micromotion compared to the effect of the rigidity of immobilization on the biological changes in the intervertebral joints.. The OrthobiomTM was developed and used as instrumentation in comparison with a rigid system and a control group. Methods Twenty growing Yucatan minipigs were divided into 4 groups. Six were fixed with a rigid system. Eleven were fixed with a mobile unconstrained implant (OrthobiomTM) that allowed intervertebral micromotion. Three minipigs were used as control. They were euthanized and underwent the same necropsy. X-ray follow-ups were taken to provide information about the fixation of the mobile and rigid system. In addition, a CT scan was performed on a control, rigid and mobile minipigs. Results In the rigid group, despite the growth, the length of the instrumented segment remained unchanged. Initial scoliosis of 31° was maintained at 27° (p= 0.37, paired t test). In the mobile fixation group, the length of the instrumented segment grew from 25.3 cm to 30 cm (p=0.0004, paired t-test). The scoliotic curve of 19° was maintained at 17° (p=0.21, paired t-test). CT scans of a minipig instrumented with the rigid system showed spontaneous fusion within the instrumented section. The CT scans of the minipig with the mobile fixation performed after the removal of the implant showed the posterior joints to be well maintained with the preservation of the joints space, and a clearly visible radiolucent line. The discs viability was maintained with the mobile fixation and degenerated with the rigid one. Conclusions Intersegmental micromotion using flexible unconstrained internal system could preserve the viability of the intervertebral joints incorporated within the instrumented section while maintaining reasonably stable fixation in young pigs during growth. This new approach may be a valuable option to fusions, though it needs to be proven effective in humans.
  28. 28. E-Poster #6 Nutritional Improvement Following VEPTR Surgery in Children with Thoracic Insufficiency Syndrome David L. Skaggs, M.D., Josh Albrektson, Tishya Wren, Robert M. Campbell, M.D. Introduction Young children with thoracic insufficiency syndrome (TIS) secondary to spinal and/or thoracic deformity are often characterized by a failure to thrive. Nutritional depletion occurs in part as the work of breathing approaches the nutritional gain of eating. Methods A total of 79 patients at 7 different institutions underwent placement of VEPTR devices for treatment or prevention of TIS. All patients underwent weight measurements pre-op and post-op. Patients had a mean age at surgery of 44 months (+/- 33) with an average follow up of 45 months (+/-16, minimum f/u 24 months). All weights were converted to normative percentiles based on the patient’s age. Results There was a significant increase in the mean percentile of patients’ weights relative to normative values (p=0.002). Of the 79 patients, 62 (78%) were <5 percentile in weight pre-operatively. Of these most nutrionally depleted patients 35% (22/62) showed a measureable increase in percentile weight following VEPTR surgery. Of patients not showing an improvement, a change in percentile weight may have occurred, but would not be recognized due to the basement effect of normative percentiles. Of the 17 patients who were >5 percentile weight pre-operatively, 76% (13/17) showed measurable improvement in weight percentiles. Conclusion Children with TIS undergoing VEPTR surgery have very poor nutritional status, with 78% of patients being <5 percentile in weight. This study documents an improvement in the nutritional status of children with TIS following VEPTR surgery, which is a critically important outcome measure in this population. Children who have better nutrition pre- operatively (>5 percentile weight) demonstrate larger gains following VEPTR surgery than those < 5 percentile.
  29. 29. E-Poster #7 Outcomes in the Early Treatment of Progressive Infantile Scoliosis Ascani Elio, Ramieri Alessandro, M.D. Infantile scoliosis, idiopathic, congenital or neurophatic, show common characteristics for gravity and rapid worsening. Their treatment is still controversial, with different choices among the spinal surgeons. We present the long-term results (mean F.U. 13 yrs; range 16-30) of a retrospective series of 43 progressive infantile scoliosis with different etiology, treated from 1975 to1990. Conservative treatment consisted in brace or cast immobilization. Halo-traction was also applied. Initial surgical approach was achieved by anterior hemiepiphysiodes and posterior hemiarthrodesis (n=4), posterior epiphysiodesis (n=7), hemivertebra excision with or w/o instrumentation (n=12), Ascani-Zielke subcutaneous rod (n=12), early posterior fusion with pediatric instrumentation (n=8). Trying to define the best procedure in the management of severe spinal deformity in young children, our results with conservative treatment were unsatisfactory due to curve progression. Posterior-anterior hemiepiphysiodes achieved an acceptable stabilization of the congenital curves before the final fusion (n=4), while no significant difference between hemivertebra resection techniques was detected. Posterior epiphysiodes was more effective for kyphoscoliosis. Ascani-Zielke rods generally obtained correction, showing nevertheless mechanical (n=4) or general complications (n=3). Early instrumented fusion obtained the improvement and stabilization of the deformity, except for a case of initial crankshaft, re-operated by an anterior arthrodesis. Our experience in the early treatment of infantile scoliosis recommends a surgical approach. Hemiepiphysiodes, circumferential procedures or growing rod techniques may be safe and effective if correctly applied. Nevertheless, also definitive instrumented spinal fusion at a young age can be judged as valid unique solution for these complex deformities.
  30. 30. E-Poster #8 Surgery Before Age 3 in Patients with Congenital and Syndromic Scoliosis Followed Until the End of Growth Charles D'Amato, M.D. Purpose Patients with progressive congenital and syndromic scoliosis have in the past been treated with spinal fusion at an early age to prevent progression. The effects of spinal surgery on pulmonary development and function are still under investigation. Recent reports have shown diminished pulmonary function in patients who have undergone fusion of the thoracic spine at an early age occasionally leading to pulmonary hypertension, cor pulmonale and, eventually, death. The aim of this retrospective study is to investigate how early spinal arthrodesis (before age 3 years) affects the pulmonary function and the growth of the thorax in patients followed to skeletal maturity. Material and Methods Six patients with congenital scoliosis and three with early onset scoliosis were surgically treated before age 3. The average age at initial surgery was 20 months (range: 12 to 39 months). Six patients were treated with a posterior spinal fusion and three had anterior and posterior surgery. Instrumentation was used in only one patient. Six was the average number of thoracic segments fused (range: 2 to 12). Final standing height (STH) and trunk height (TRh) were measured in all patients. Using standard radiographs thoracic spine height (Th), lumbar spine height (Lh), pelvic width (PW) and chest width (CW) were measured in all patientsª. Vital Capacity (VC), Forced Expiratory Volume in 1 sec. (FEV1), Max. Mid Exp. Flow rate (FEV25-75), Residual Volume (RV) and Total Lung Capacity (TL) were available for four patients. The average follow up was over 14 years. Results STH, TRh, Th were significantly reduced in all patients but one who had fusion of only two thoracic vertebrae. Lh was normal. The observed thoracic dimensionsª were significantly reduced compared to the expected ones in all patients but one who had only two thoracic spine levels fused. Average VC was 1.98 L and 67% of predicted values (range: 1.27-2.96), average FEV1 was 1.69 L and 62% of predicted values (range: 1.04- 2.42), average FEV25-75 was 1.73 L/min. and 56% of predicted values (range: 1.04- 2.23), average TL was 0.85 L and 69% of predicted values (range: 0.73-0.97). Conclusion Patients undergoing thoracic fusion for spinal deformity scoliosis before age three have significantly reduced TRh, Th and chest dimensions. Early thoracic spine surgery inhibits the growth and function of the thorax. The number of thoracic vertebrae fused seems to be related to the severity of the pulmonary impairment. ªEmans JB and coll. Prediction of thoracic dimensions and spine length based on individual pelvic dimensions in children and adolescents. Spine 2005;30(24):2824-2829
  31. 31. E-Poster #9 Unilateral Unsegmented Bars, Do They Grow with Distraction? Hazem Elsebaie, M.D., David L. Skaggs, M.D., Behrooz A. Akbarnia, M.D. Study Design Retrospective analysis of 3 patients with congenital unilateral thoracic unsegmented bar treated with distraction implants with a minimum of 2 years follow-up. Objectives To determine the ability of unilateral bars to grow, quantify this growth and the amount of local coronal angle correction of the unilateral bar by concave side distraction. Summary of Background Data Unilateral bars are identified as having absolutely no growth potential, it has always been assumed that the concave sides of the congenital curve do not grow. A recent study by Campbell and Hell-Vocke showed that unilateral bars placed under tension by a rib prosthesis showed an increase in length of the bar. This finding has been questioned and not repeated to Methods Three patients with progressive congenital spinal deformities due to unilateral thoracic bar treated by distraction implants were analyzed. Results First patient, a 7y 8 m old girl treated with single concave growing rod followed for 2+6 years and had 5 distractions. The cobb angle (measured at both ends of the bar) improved from 48 post initial surgery to 38 at the latest follow up (correction of 20.8%), the bar increased 5mm in length an increase of 16.6% of the original length of the bar The second patient, a 9y 1m old girl treated with single concave growing rod followed for 2 years and had 5 distractions. The Cobb angle improved from 40.5 post initial to 29 at the latest follow up (correction of 28.5%), the bar increased 4mm in length an increase of (12.5% of the bar) The third patient, a 2y 3m old girl treated with VEPTR followed for 5 y 1m and had 7 distractions. The cobb angle remained almost unchanged and the bar increased 6mm in length an increase of (28.5 % of the bar) Conclusion The unilateral bars seem to grow under concave vertebral distraction; their growth is much slower than the normal vertebrae under the same circumstances (around 25%) The coronal Cobb angle of the unsegmented bar was also improved significantly in patients treated with concave growing rod.
  32. 32. E-Poster #10 Continued Spinal Growth in Early Onset (Juvenille) Idiopathic Scoliosis Lynn Letko, M.D., Rubens Jensen, M.D. Introduction The treatment of early onset (juvenile) idiopathic scoliosis remains a challenge for spinal deformity surgeons. The goal of treatment is to control an often rapidly progressing deformity while continuing to allow for an increase in spinal growth. We present a technique of single rod pedicle screw instrumentation without fusion as a treatment alternative to allow for continued spinal growth until time of definitive fusion. Operative Technique The spine is prepared unilaterally using a scissor or scalpel staying above the periosteum. The pedicle screws are placed in the area to be instrumented but not fused. A rod is then placed and the correction is undertaken. The incision is closed. No brace treatment is required. The patient is followed closely. Pre-operatively, it is discussed with the parents that the patient will require multiple lengthenings and/or exchange to larger diameter screw and rods with growth prior to a definitive fusion. Case Study 4 year 7 mo. old patient with EOIS . At the time of the first surgery (4.05) , 106 cm tall. The right thoracic curve measured 37° T6 toT11 ( bending correction to 14°). The left lumbar curve measured 35° T12 to L3 (bending correction to 17°).The patient underwent right dorsal instrumentation T11 to L3 with correction of the thoracic curve to 15° and the lumbar curve to 15°. The correction was maintained until the rod broke in December 2006. The patient was re-instrumented to T8 in 6.07. At the time of revision surgery, the patient measured 124.5 cm . The curves measured 20° T5 to T11 and 23° T12 to L3 pre-operatively The curves measured 20° and 15° respectively post-operatively with 30° thoracic kyphosis and 40° lumbar lordosis. Conclusions Unilateral pedicle screw instrumentation without fusion allows for excellent correction of the spinal deformity and allows for continued spinal growth. Normal thoracic kyphosis and lumbar lordosis may be maintained. The patient is allowed full activity including sports. Close follow-up is required as the instrumentation will need to be lengthened or exchanged prior to definitive spinal fusion.
  33. 33. E-Poster #11 Assessment of Construct Variability Among Experienced Vertical Expandable Prosthetic Titanium Rib (VEPTR) Users Michale Vitale, M.D., Jaime Gomez, M.D., Hiroko Matsumoto, MS, Randal Betz, M.D., Robert Campbell, M.D., John Emans, M.D., Jack Flynn, M.D., John Flynn, M.D., Norman Ramirez, M.D., Brian Snyder, M.D., Sturm Peter, M.D., Kit Song, M.D. John Smith, Jeffrey Shilt, M.D., David Roye, M.D. Background Several reports have demonstrated remarkable variability in construct patterns for adolescent idiopathic scoliosis and adult deformity correction. To this date, the treatment for patients with early onset scoliosis has no algorithm. New treatment options are available such as the vertical expandable prosthetic titanium rib (VEPTR). It is important to identify variability and trends in treatment to guide surgical decisions. Methods As part of the discussion of indications and choice of implant, 13 surgeons were given 12 cases with diagnosis of progressive congenital scoliosis and thoracic insufficiency syndrome, with standard spine radiographs. The reviewers were asked to choose type of treatment, type of construct, construct location and whether or not a thoracotomy should be performed. Results In 8 of the 12 cases all surgeons chose to perform surgical treatments. For each of the remaining 4 cases only one surgeon decided to treat conservatively with casting/bracing (n=3) or observation (n=1) while the others chose surgical treatments. When the reviewers chose surgery, 76.3% (range 40-100%) matched using the VEPTR. Of these VEPTR users 61.2% (range 0-100%) coincided on using it bilaterally. Agreement on the use of growing rods and fusions was 19.5% (range 0-60%) and 4.2% (range 0-25%) respectively. Among all cases agreement on whether instrumentation should extend to the pelvis or not was 70.8% (50-100%). In 5 of 12 cases all surgeons agreed not to perform a thoracotomy. In 3 of the remaining 7 cases a thoracotomy was chosen by only one surgeon, in another 2 cases only two surgeons did not agree with the rest of the group. In the remaining 2 cases about half of the physicians agreed to perform a thoracotomy. Conclusion The study found wide variability in choice of construct type, number of constructs and level of instrumentation, however there was a trend in this experienced group of surgeons to a common solution. This was illustrated by the data on thoracotomy where there was less variability and by the agreement that chest wall instrumentation is indicated frequently.
  34. 34. E-Poster #12 The Development of Thoracic Hypokyphosis/ Lordosis After Dorsal Hemivertebrae Lynn Letko, M.D., Rubens Jensen, M.D. Since 1997, our standard treatment of complex congenital thoracic scoliosis is dorsal hemivertebra resection with or without bar or rib synostosis resection and pedicle screw instrumentation. We report 3 cases which developed thoracic hypokyphosis/ lordosis after this procedure with improvement in the sagittal profile after rod removal. Methods Retrospective review of 3 patients (3 M) with complex thoracic congenital scoliosis deformity who underwent dorsal hemivertebrae with or without bar resection with pedicle screw instrumentation between December 1997 and February 2003. Mean age at index surgery was 27 mos (range 19 to 33 mos ). Mean follow-up 74 mos (range 45 to116 mos). Mean number of vertebrae resected was 3 (range 3 to 4). Mean number of segments instrumented was 8 (range 8 to 9) all between T2 and L1. Results Mean scoliosis pre-op 82° (range 70 to 102°). Mean thoracic kyphosis pre-op 37° (range 22 to 60°). Mean scoliosis post-op 6° (range 0 to13°). Mean thoracic kyphosis post-op 27° (range 20 to 30°). Development of thoracic hypokyphosis/lordosis surgically treated with rod removal a mean of 56 mos after index procedure (range 37 to 92 mos) . Mean kyphosis prior to rod removal was 5° (range minus 5 to10°). Mean kyphosis after rod removal was 13° (range 0 to 20°) Mean kyphosis at last follow- up or before rod reinsertion was 21° (range 10 to 32°). Rod reinsertion was indicated in 2 cases of increasing scoliosis. Conclusions Dorsal hemivertabra resection and pedicle screw instrumentation is provides excellent scoliosis correction in cases of complex thoracic congenital deformity. The posterior pedicle screw instrumentation may act as a tether resulting in the development of hypokyphosis /lordosis as the anterior column continues to grow especially in cases of multilevel instrumentation. Rod removal has allowed for improvement of the thoracic sagittal profile (plastic deformation versus growth). Rod reinsertion with the rods bent to match the improved sagittal profile may be necessary in cases of scoliosis progression
  35. 35. E-Poster #13 Growing Rod for Syndromic Scoliosis Koki Uno, Norihide Sha, Takuya Kimura, Hiroshi Miyamoto, Yoshiyuki Inui, Kou Tadokoro, Naoatsu Megumi Twenty-five syndromic scoliosis treated with growing rods were retrospectively evaluated. There were 9 boys and 16 girls and the average age at first operation was 6.7, ranged 1.5 to12 years old and average follow-up was 3.5 years. Pathology included neuromusucular disease in 4, neurofibromatosis in 3, congenital in 3, bone metabolic disorder in 6, congenital malformation syndromes with mental retardation in 7, thoracic cage defect in 2. Three were 21 ambulators and 4 non-ambulators. Seven patients were mentally retarded. The average magnitude of the curve was 95° and 55° after operation and 60° at final follow-up. Proximal foundation was between T1 to T4 and lowest foundation were between L1 to sacrum. One hundred and thirty operations were performed including initial surgery. The average interval between operations for rod lengthening was 7 months ranging from 5 months to 12 months. Rod lengthening was performed periodically, based on curve progression of 10° for earlier cases. For recent cases, lengthening was performed every 6 months routinely. There were 29 complications. Hook dislodgement in 13, deep infection in 3, superficial infection in 2, rod breakage in 4, others in 2. Of the 29 complications, 18 complications out of 50 surgery occurred in boys and 11 out 80 occurred in girls. Fourteen complications occurred in early 5 cases. Four patients were performed final fusion due to skeletal maturity or due to failure of controlling the deformity. One of them suddenly died 2 years after final fusion . Whether patients have mental retardation or not, and were ambulator or not did not influence the result. Growing rod for syndromic scoliosis can be performed with favorable results at this moment comparimg to those of growing rod for juvenile idiopathic scoliosis.
  36. 36. E-Poster #14 Cell Signaling Pathways Growth of in Mouse Vertebral GP Chitra Dahia, Eric Mahoney, Atiq Durrani, Christopher Wylie Introduction The objective of this study was to delineate signaling pathways present in postnatal lumbar vertebral growth plate (LVGP), and their expression pattern during growth and aging. Material and Methods Eight micrometer cryosections in the coronal plane were collected from decalcified lumbar vertebrae of 1-12 weeks old male FVB mice. Histology was analyzed by H&E. Immunolocalization of components of the TGFbeta1&2, BMP2,4&7, IHH & FGF2 pathways was carried out using confocal microscopy. Results Membrane localization of IHH & its receptor PTC was observed in proliferative zone chondrocytes until 2-weeks of age. Between 2 and 12 weeks of age, active TGF1&2 signaling determined by downstream intermediate (p)Smad2/3 was present at the junction of the proliferative and early hypertrophic zones which disappeared at 9 weeks. Active BMP2, 4&7 signaling determined by their downstream intermediate (p)Smad1/5/8 was found only in the hypertrophic zone chondrocytes at all ages.. FGF2 ligand and activated receptor were found only in the hypertrophic zone chondrocytes of the LVGP of 2-week old mice and decreased with age. Conclusion Our data suggest that IHH signaling is responsible for maintenance of the PZ while TGF beta signaling is involved in the transitioning of the cells from PZ to HZ. TGF beta signaling diminishes with age. Absence of TGF beta signaling marks the end of proliferative zone and closure of vertebral growth plate despite the presence of IHH.
  37. 37. E-Poster #15 Three Dimensional Analysis of a New Porcine Model for Scoliosis Virginie Lafage, Ph.D., Frank Schwab, M.D., Ashish Patel, M.D., Jean-Pierre Farcy, M.D. Introduction Spinal fusion remains the mainstay for surgical treatment of severe/progressive adolescent idiopathic scoliosis. However, there is marked interest in non-fusion techniques that may spare mobility of the spine and induce correction through growth modulation. Development of non-fusion techniques requires an animal model with all the attributes of a scoliotic curve: global deformity but also true vertebral dysplasia and axial rotation Methods This study included 7 Yorkshire pigs. Scoliosis was surgically initiated through a left pedicle based spinal tether and a left-sided ribcage tethering. Animals were euthanized once they reached severe deformity (≥50° Cobb) or stopped progressing (mean, 12 weeks following procedure). Spines were harvested and CT-scans obtained. Axial CT slices were analyzed to compute vertebral and inter-vertebral height (convex vs. concave) of the apical functional unit as well as the axial rotation of apical/end vertebrae. Results Mean Cobb angle was 52° (SD 13°). Apical mean axial rotation was 18° (SD 9°) toward the concavity of the curve. Highly significant correlation was found between apical axial rotation and Cobb angle (r=0.959; p≤0.001). Mean axial rotation of vertebrae outside the tether was 1.5° (SD 5°). In terms of vertebral and intervertebral heights of the apical functional unit, no significant differences between anterior and posterior height were found. However, the convex side was always taller than the concave side: 3.7mm (vertebral), 1.2mm (Disc), differences p≤0.005. Discussion & Conclusion While several authors have reported animal studies related to spinal deformity, none have conducted a true 3-D analysis to quantify the dysplasia induced by growth modulation. To our knowledge, this is the first animal scoliosis model reporting a detailed 3-D analysis of the deformity. Findings in the porcine scoliosis model are promising and further analysis is in progress to quantify the vertebral deformity (pedicle, body, spinous process). A greater understanding of scoliotic deformity will emerge as will a more rigorous analysis of corrective techniques related to growth modulation (ex. fusionless)
  38. 38. E-Poster #16 A Porcine Model for Progressive Scoliotic Deformity Frank Schwab, M.D., Virginie Lafage, Ph.D., Ashish Patel, M.D., Jean-Pierre Farcy, M.D. Introduction Optimal development of non-fusion techniques requires a large animal scoliosis model. Several authors have reported creation of spinal deformity in animals but few of these relate to large animals. Braun et al. demonstrated scoliosis in a goat model. However there were a number of drawbacks: cyclical breeding, a flattened ribcage, and very severe deformities. The goal of this study was to develop a reliable porcine scoliosis model, with moderate deformity, amenable to non-fusion device implantation. Materials and Methods This IACUC approved study included 14 Yorkshire pigs; 6 of them were part of a pilot study to establish surgical technique. Scoliosis was induced in 8 animals through a left midline ligamentous tethering of the spine, fixated superiorly and inferiorly with pedicle screws, and left-sided ribcage tethering. Progressive deformity was documented with bi- weekly x-rays. Frontal and sagittal curves were measured through the Cobb method, axial rotation was estimated by spinous process deviation (with 0 = midline, -50% = concave lateral border). Animals were observed until severe deformity (≥50°), and then sacrificed. Results Failure of progression was noted in 2 animals due to tether rupture. The 6 animals with documented progression were observed during 12 weeks. The mean coronal Cobb angle was 28° immediately post-op and 55° at final follow up. The mean lordosis increased from 9° post op to 23° at final follow up. Apical axial rotation with the posterior vertebral elements into the concavity of the coronal deformity increased from -1.35% post op to -19.76% at last follow up Conclusions The study establishes a porcine scoliosis model. With placement of a unilateral ligamentous tether technique to the spine, combined with concave ribcage ligament tethering, during the rapid growth stage of Yorkshire pigs; a three dimensional spinal deformity can be achieved. The speed of scoliotic deformity leaves significant remaining growth to assess growth modulating therapies for correction. This work forms the basis for a number of investigative efforts at developing new fusionless therapies for patients suffering from Adolescent Scoliosis.
  39. 39. E-Poster #17 VEPTR a Two Year Follow Up Cornelius Wimmer, Peter Wallnoeffer Since 2004 the treatment with VEPTR is established in Europe. From 2005 to 2007 20 patients were treated with VEPTR. Diagnosis were congenital, neuropathic, and idiopathic scoliosis. Material and Method. There were 3 congenital, 9 neuropathic, and 8 idiopathic scoliosis. The average age of the 15 female and 5 male patients were 7,5 range from 3 to 13 years. Correction of the primary curve and after lengthening were measured according to Cobb angle before, after and at the follow up. Complications were noted, a patient satisfaction score and lung function were measured. 5 of the 20 patients had had previous surgery. Results The primary curve measured 65° range from 45 to 130 and improved to 32° range from 25 to 75 at index operation. No complications during surgery were noted. The time at operation was 125 min. range from 65 to 185. In 15 cases a rib to lumbar spine hyprid was used, and in 5 cases a combination from rib to rib and rib to lumbar spine were used. The blood loos during surgery was in mean 125 ml range from 65 to 180. One patient showed a wound healing, another patient had had a pneumonia, which resolved with adequate therapy. All patient were braced after surgery. The average stay in the hospital was 18 days range from 14 to 31. 15 out of 20 patients had 1 to 3 lengthening procedures. The average correction of the lengthening procedures was 15° 19,8%. In 5 of the patients the second curve must be instrumented. All patients and parents were satisfied with this procedure and would do this procedure again. Conclusion The first results of the VEPTR instrumentation are encouraging. Remarkable is the low complication rate and the high patient satisfaction.
  40. 40. E-Poster #18 A Cadaver Spine Study of the Effect of Positional Changes on the Accuracy of Manual and Digital Radiographic Measurement of Spinal Landmarks Robert M. Campbell, M.D., A. Reis, A. Gajjar, L. Cooper It has been assumed that a six foot tube to x-ray plate distance minimizes beam divergence and magnification error for radiographs of the spine, and that digital radiographic measurements are more accurate for measurement than manual, but no study to our knowledge has validated these assumptions. This was studied in a cadaver spine model using 6 foot tube to plate distance with varied distances from posterior spine to plate to simulate obesity, kyphosis, or lordosis. Radiographs were taken at standard tube/plate distance, performed at 2.5cm, 4.5cm, 6.5cm and 8.5cm distances of spine to the plate, measured manually by micrometer and digitally. For spinal lengths there was an avg. 4.3% magnification error rate for manual measurements, and 5.7% for the digitally measured radiographs (p<0.001). The avg. magnification error was 2.7% for the 2.5cm distance radiographs and 7.0% for the 8.5cm group (p<0.001). For the interpedicular distances there was an avg. 3.3% magnification error rate for manual micrometer measurement compared to 4.2% for the digitally measured radiographs (p=0.002). The avg. magnification error was 1.6% for the 2.5cm distance radiographs and 5.6% for the 8.5cm group (p<0.001). Conclusion Manual measurement of radiographic spinal lengths by micrometer is more accurate than digital measurement, but there is still a magnification error of 4.3%. Increasing the distance between spine and plate increases the magnification error. Interpedicular distance measurements also have the same problem with magnification error. Significance Investigators should be aware that measurement of the spine on radiographs, even at 6 ft tube to plate distances, has significant error rates and conclusions about significant growth in length must be interpreted cautiously. While the manual method seems superior, both it and the digital method measure only the virtual image of the spine, not the true dimensions. Increasing the distance of the spine from the plate, either due to obesity, spine kyphosis, or lordosis, probably increases the measurement error. When high spine measurement accuracy is needed, perhaps CT scan analysis would be preferable to radiographic measurement.
  41. 41. E-Poster #19 Posterior Surgery of Scoliosis by Hybrid Instrumentation Costanzo Giuseppe, Ramieri Alessandro, M.D., Barci Vincenzo, M.D. The effects of a dynamic fixation are due to an increase of the back stability, reduction of disk stresses and the chance of restore the sagittal profile. In scoliotic deformities, the use of shape memory staples in anterior procedures seems promising as also the association of rigid fixation and “dampers” in the junctional areas. The aim of the present study was to assess the effectiveness of hybrid constructs in surgical treatment scoliosis of different etiology. We studied a series of 13 scoliosis of different etiology, both of the growing age and of the adult, treated with mixed back fixation, that is composed by classical rigid segmental instrumentation and by “shape memory” elastic interlaminar instrumentation (in compression at the convex side) in nickel-titanium, implanted cephalad or caudad to rigid instrumentation, at the apex of compensation curves (in some cases reducible), with the aim to preserve transition areas. In 11 patients elastic fixation without arthrodesis facilitated curve stabilization. In 2 patients curve progression less than 10° has been shown. We did not find either instrumentation mobilization or intolerance. At 2 years follow-up, no adjacent level degeneration was found. The advantages offered by rigid segmental fixation in scoliosis treatment are well recognized, in relation both to the entity of the obtainable correction and to stability, either primary or in a long term basis. Similarly, adjacent level syndrome may occur above or below the area of arthrodesis. There are interesting recent multicentric studies about dynamic or hybrid systems in the treatment of degenerative conditions of the lumbar spine. Applying the principles of “dynamic” vertebral fixation, it is possible to perform hybrid instrumentations by positioning interlaminar “shape memory” staples, in order to preserve transitional areas. Equally, these staples can be implanted on to “cover” compensation curves (often mild and/or reducible in bending) at the convex side, which facilitate compression reduction.
  42. 42. E-Poster #20 Short-term Results of Dual Growing Rod Technique Yutaka Nakamura, Takahiro Iida, Akihisa Atou, Kanta Tajima, Junya Katayanagi, Satoru Ozeki, Yutaka Nohara Introduction Severe spinal deformity in young children often progresses rapidly. Recently we started the dual growing rod technique that was instrumentation with limited arthrodesis only for cranial and caudal anchor points. We report the short term results of six cases that treated in this method. Material and Methods Between December 2002 and Jun 2006, dual growing rod technique was performed in six patients. The posterior correction was performed with pediatric ISOLA system. Hooks were used in the two cranial vertebra and pedicle screws were used in the caudal two vertebra. Then limited bone graft was performed only for a cranial and caudal anchor part. Rod extension was scheduled once in a half year. Hard brace was applied until bone union was provided. Results The mean Cobb angle was 107° before surgery and 49° after initial correction. We performed twenty times of rod extension to maintain spinal growth. There was one complication with instrument breakage. Case 1: Nine-year-old girl (Sotos syndrome) had severe and rapidly progressive scoliosis. Preoperative Cobb angle was 84° in Th4-11. Growing rod was performed from Th4 to 11 with. Cobb angle decreased to 36° after surgery (correction rate; 57.1%). Six months after the first surgery, the rod extension was performed and spinal deformity was maintained to 46°. Case 2: A three-year-old male (Ehlers-Danlos syndrome) had severe thoracic scoliosis of 143° in Th2-L1. Dual growing rod technique from Th2 to L4 was performed. Postoperative curvature decreased to 82° with correction rate of 42.7%. However, instrumentation failure occurred after surgery. Discussion The dual growing rod technique had good initial correction rate and ability to keep growth spread. In addition, short hard brace periods reduce the mental and physical stress of the patients. We consider this technique is good choice as time saving procedure until final posterior correction and fusion. However, especially in younger patients with bone fragility, additional technique or device is necessary.
  43. 43. E-Poster #21 Controversies in Jarcho- Levin Syndrome Norman Ramirez, John M. Flynn, M.D., Alberto S. Cornier, M.D., Ph.D., Simon Carlo, M.D., Nigel Price, M.D., Frams Pino, M.D. Jarcho-Levin syndrome is an eponym that has been used to describe a variety of clinical phenotypes with short trunk dwarfism associated with rib and vertebral anomalies. Recently molecular, clinical and radiological data has allowed to further characterize between Spondylothoracic and Spondylocostal dysplasia. Introduction This review article will focus on characterizing the differences between Spondylothoracic and Spondylocostal dysplasia and provide a valuable tool for clinical diagnosis and management. Methods This is a literature review of all Jarcho-Levin studies. Results Spondylothoracic Dysplasia (STD) is a rare pleiotropic genetic disorder with autosomal recessive inheritance. Typical radiological findings include segmentation and formation defects throughout cervical, thoracic and lumbar spine, such as hemi-vertebrae, block vertebrae, and unsegmented bars, with fusion of all the ribs at the costo-vertebral junction (Crab like or fan like configuration) The majority of STD cases previously described in the literature had a poor prognosis due to respiratory complications such as pneumonia, congestive heart failure and pulmonary hypertension( mortality rate 42%) . The gene responsible for this disorder is in the MESP2 gene Spondylocostal Dysostosis (SCD) constitutes a heterogeneous group of patients with autosomal recessive and dominant inheritance. They have axial skeletal malformations, including multiple vertebral segmentation and formation defects and unilateral rib anomalies. These malformations are typically more prominent in one hemithorax and frequently leading to a progressive scoliosis of the thoracic spine due to the tethering effect secondary to the rib anomalies. The majority of cases reported in the medical literature have a good prognosis, due in part to the asymmetry of the thoracic anomalies resulting in a less restrictive thorax. The molecular mutations responsible for the majority of cases of SCD rely on the Dll3 gene on chromosome 19q13. Conclusion Jarcho-Levin eponym consists of two distinct pathological conditions. It is essential that this be recognized since the natural history and management of the spinal deformity is completely different.
  44. 44. E-Poster #22 Spinal Fusion with Cotrel-Dubousset Instrumentation for Neuropathic Scoliosis Marco Teli, M.D., Giuseppe Grave, M.D., Alessior Lovi, M.D., Marco Brayda-Bruno, M.D. Study Design Retrospective. Objective To report on the treatment of patients with cerebral palsy and neuropathic scoliosis with third-generation instrumented spinal fusion by Cotrel-Dubousset instrumentation. Summary of Background Data Evidence is needed to evaluate the increasing use of third-generation instrumented spinal fusion in similar patients. Methods Patients with cerebral palsy and spinal deformity treated consecutively by 1 surgeon with Cotrel-Dubousset instrumentation and minimum 2-year follow-up were reviewed. An outcome questionnaire was administered at final follow-up. Results A total of 60 patients were included. Mean age was 15 years at surgery. Mean follow-up was 79 months. There were 26 anteroposterior and 34 posterior-only procedures. Correction of coronal deformity and pelvic obliquity averaged 60% and 40%, respectively. Major complications affected 13.5% of patients (implant loosening, deep infection, and pseudarthrosis). Outcome questionnaires showed marked improvements in the areas of satisfaction, function, and quality of life after surgery. Conclusions Segmental, third-generation instrumented spinal fusion provides lasting correction of spinal deformity and improved quality of life in patients with cerebral palsy and neuropathic scoliosis, with a lower pseudarthrosis rate compared to reports on second- generation instrumented spinal fusion.
  45. 45. E-Poster #23 Effect of Removal of NP Cells on the AF of Mouse IVD Chitra Dahia, Eric Mahoney, Atiq Durrani, Christopher Wylie Introduction The study was designed to analyze the effect of removal of NP cells on the AF in mouse lumbar intervertebral discs (IVD). Methods The nucleus pulposus cells were surgically aspirated from L2-3 and L3-4 discs of 2-week old male mice using a 27-gauge syringe. L4-5 disc in the same mouse was sham-operated as control. The effects on the IVD were assayed 2-8 weeks after the surgery. Eight micrometer cryosections were collected in the coronal plane and histological analysis was carried out using H&E staining. Cell death was determined by active caspase-3 staining. Results 5-weeks following removal of the NP there was significant collapse of the IVD, compared to the sham-operated controls. By 7-weeks, fibrocartilage cells derived from the AF were invading the disc space, which became completely filled by 8 weeks. Growth of the disc was reduced in both cranio-caudal and transverse diameters by 30%, compared to control discs. At 2 weeks following removal of NP, there was no cell apoptosis in the AF as determined by active caspase-3 staining. By 8 weeks following the removal of NP, significant cell apoptosis is seen in the AF. Conclusion Removal of NP cells leads to invasion of the disc space by fibrous tissue which is very similar to that observed in the human degenerated discs. There appears to be a window of time in which the cells of the AF are alive despite removal of NP cells. A potential exists for intervention during this time to prevent the AF from degeneration.