Usefulness of Simple Rod Rotation to Correct Curve of Adolescent Idiopathic Scoliosis

OBJECTIVE: To correct apical vertebral rotation for adolescent idiopathic scoliosis (AIS), direct vertebral derotation (DVD) or simple rod rotation (SRR) might be considered. The aim of the present study is to introduce the surgical experiences of AIS by a Korean neurosurgeon and to evaluate the effectiveness of SRR for apical vertebral rotation. METHODS: A total of 9 patients (1 male and 8 females) underwent scoliosis surgery by a neurosurgeon of our hospital. The Lenke classifications of the patients were 1 of 1B, 2 of 1C, 1 of 2A, 1 of 2C, 3 of 5C and 1 of 6C. Surgery was done by manner of simple rod rotation on the concave side and in situ coronal bending. Coronal Cobb's angles, vertebral rotation angles and SRS-22 were measured on a plain standing X-ray and CT before and after surgery. RESULTS: The mean follow up period was 25.7 months (range : 5-52). The mean number of screw positioning level was nine (6-12). The mean age was 16.4 years (range : 13-25) at surgery. The mean Risser grade was 3.7+/-0.9. The apical vertebral rotation measured from the CT scans was 25.8+/-8.5degrees vs. 9.3+/-6.7degrees (p<0.001) and the Coronal Cobb's angle was 53.7+/-10.4degrees vs. 15.4+/-6.5degrees (p<0.001) preoperatively and postoperative, respectively. The SRS-22 improved from 71.9 preoperatively to 90.3 postoperatively. There were no complications related with the operations. CONCLUSION: SRR with pedicle screw instrumentation could be corrected successfully by axial rotation without complications. SRR might serve as a good option to correct AIS deformed curves of AIS.

Determination of Distal Fusion Level with Segmental Pedicle Screw Fixation in Single Thoracic Idiopathic Scoliosis / 대한척추외과학회지

STUDY DESIGN: Retrospective study. OBJECTIVES: To determine the exact distal fusion level in the treatment of single thoracic idiopathic scoliosis (King III and IV) with segmental pedicle screw fixation and rod rotation. SUMMARY OF LITERATURE REVIEW: Pedicle screw fixation effectively shortens the distal fusion extent by improved 3-D deformity correction. However, the selection of distal fusion extent remains controversial in single thoracic idiopathic scoliosis. MATERIAL AND METHODS: Forty-two single thoracic adolescent idiopathic scoliosis patients subject to segmental pedicle screw fixation and rod rotation with minimum follow-up of 2 years (2-6 years) were analyzed. The patients were grouped according to the distal fusion level with reference to the standing neutral vertebra (NV) for comparison of deformity correction, radiological and clinical spinal balance using standing radiographs. Distal fusion down to NV +1 was in 9 patients, NV in 5, NV-1 in 9, NV-2 in 12 and NV-3 in 7 patients respectively. RESULTS: Preoperative 50+/-11 degrees of thoracic deformity was corrected to 13+/-5 degrees showing 74% of curve correction. Preoperative 23+/-7 degrees of lumbar deformity was corrected to 2+/-8 degrees showing 93% of curve correction. Postoperative adding on deformity was obtained in 14 patients. Significant difference was found not by King classification but by distal fusion level: significantly higher chance of unsatisfactory results from not going to the NV-1 (p=0.001). CONCLUSIONS: In correction of single thoracic idiopathic scoliosis with segmental pedicle screw fixation, the curve should be fused to NV-1 saving one or more motion segments when compared to the fusion to the stable vertebra.