Postoperative Disc Wedging In Adolescent Idiopathic Scoliosis Of Lenke5/6Type:a Comparison Of Anterior And Posterior Approaches

Objective:To evaluate the difference of anterior and posterior surgical correction of adolescent idiopathic scoliosis of Lenke5/6type upon disc wedging below the lowest instrumented vertebra.Material and methods:A retrospective study was conducted with medical records and long cassette radiographs of adolescent idiopathic scoliosis Lenke5/6patients who underwent either anterior (group A) or posterior (group B) surgical correction from2009to2011in our hospital. Main cobb angle, disc wedging below the lowest instrumented vertebra and other parameters were analyzed.Results:29patients were enrolled in this research, including17cases in group A and12cases in group B. The mean main cobb angles of group A and B were38.48±11.19±and50.34±17.36°, which were significantly (p<0.01) corrected to8.59±7.11°and15.67±11.85°. The mean disc angle below the lowest instrumented vertebra in group A before surgery was3.17±4.54°, which was significantly smaller (p<0.01) than that of in group B8.04±4.20°.After surgery, the disc angles in group A and B were-7.34±3.33°and-2.05±4.09°. They were significantly different (p<0.01). The absolute disc angle values in group A before and after surgery were4.11±3.66°and7.34±3.33°, which were deteriorated (p<0.05). The absolute disc angle values in group B before and after surgery were8.04±4.20°and3.45±2.89°, which were improved (p<0.01).Conclusion:For adolescent idiopathic scoliosis of Lenke5/6type, posterior surgical approach using pedicle screws might provide a better condition upon disc wedging below the lowest instrumented vertebra comparing to anterior approach.