Impact Of Thoracic Curve Correction On Trunk Balance In Idiopathic Scoliosis

【Background】Scoliosis is a disease refers to the spinal abnormal curve caused by various reasons.Among all patients, people who have adolescent idiopathic scoliosis is the most commonones, accounting for80%of all patients with scoliosis. Along with the maturity of the bone,when patients are older than20, some of these curves may be futher developed and a morerigid coronal and sagittal imbalance could be found with them, which would result infunction decline of heart and lung and limitation inn daily activity. Part of some patientswould have nerve compression symptoms or even lifelong disability, which brought greatlosses and heavy burden to the society.Since90’s of last century, We had employed Harrington rod fixation in scoliosiscorrection domestically, but only get30%rate correction. With the development of spinalthree-dimensional orthopedic theory, instrumentation and operation technology are alsogetting increasing progress. With the development of new instrumentation and treatmenttheory, there were many pioneers like Dwyer、Luque and Cotrel-Dubousset et al. Thesepeople has improved the conception of treatment of scoliosis. The application of posteriorthoracic pedicle screws in thoracic column is another great progress in the treatment ofscoliosis. Compared to previous single plane fixation devices, the pedicle screws can proviemore powerful pullout and pressure force, correction rate of coronal sagittal and axial plane. Itcan also decrease the complication rate like curve progression, crankshaft phenomenon,internal fixation loosening and pseudarthrosis. Although the application of pedicle screw caneffectively improve the coronal plane correction, research also shows that it would causehypokyphosis of the thoracic spine. Posterior spinal osteotomy technique is another milestonein the treatment of scoliosis. The application of posterior pedicle screw combined with spinalosteotomy has been able to solve the problems of rigid scoliosis. They are SPO、PSO、VCR、VCD et al. At the same time Segmental pedicle screw also increase the economic burden onpatients, Which would make their application more limited. We have analyzedthree-dimensional structure of adolescent lumbar idiopathic scoliosis. As well, we havefollowed up a number of idiopathic scoliosis with Ponte osteotomy. 【Objective】1、To compare the clinical and kyphosis outcomes between Ponte osteotomy accompanyingposterior pedicle screw and APSP in adult idiopathic thoracic scoliosis.2、Factors influencing vertebral rotation of the compensatory lumbar curvature in Lenke1Aadolescent idiopathic scoliosis are explored.【Method】1、From October2008to February2012， cases were picked out from adult idiopathicscoliosis whose problems were located in the thoracic column. Operation were performedby the same group from orthopedics department in our hospital. APSP group consist of24patients and Ponte osteotomy group consist of36patients. Parameters like coronal,sagittal Cobb angle, CVSL, SVA are compared pre and post operation. Health-relatedquality fo life were assessed by Chinese version of SRS-22questionnaire at finalfollow-up. After the patients were divided into2group according to thoracic kyphosis,The decrease quantity of string height of metal rod were compared between APSP groupand Ponte osteotomy group.2、AIS patients from February2004to February2011who finally adopted operation in ourhospital were included retrospectively. All patients were divided into Lenke1A-L andLenke1A-R two groups. Relations of Lumbar curve rotation and coronal, sagittalparameters were analysised between two groups.【Results】1、Correction of Ponte osteotomy group for main thoracic curve in coronal main was higherthan that in APSP group in adult idiopathic scoliosis. In group, a significant difference ofstring height decreasing were observed in APSP group but not in Ponte group. There wereno more significant differences of other radiographic and clinical outcome between twogroups.2、In Lenke1A-L, There was no statistic difference between two groups. The post2yeartotal LVR significantly correlated with the coronary lumbar Cobb angle correction and thethoracic Cobb angle correction,. In Lenke1A-R, lumbar rotation was not significantlycorrelated with the coronary lumbar Cobb angle correction, which was more vulnerable tothe effect of thoracic Cobb angel correction. 【Conclusions】1、Ponte osteotomy can provide more thoroughly correction and on restoring sagittalcontouring rod than ASAP group. We assume that as the rear column of the spine had beenresected, rod deformation was reduced after implantation. Ponte osteotomy can be appliedto the stiffer scoliosis and does not increase postoperative complications.2、In Lenke1-L group, coronal lumbar curve spontaneous correction had a negativecorrelation with the total LVR. And Increased total LVR makes lumbar curve spontaneouscorrection more difficult. When selective fusion was adopted, lumbar rotation should bean important factor to consider thoroughly. We did not find a meaningful impact betweenlumbar spinal rotation deformity and coronal balance in Lenke1A-R AIS. We presumethat when selective fusion was adopted in Lenke1A-R AIS, thoracic correction should bean important factor to consider thoroughly.