A comparison of anterior and posterior instrumentation for restoring and retaining sagittal balance in patients with idiopathic adolescent scoliosis.

STUDY DESIGN: Retrospective, comparative study.

OBJECTIVE: To compare the effects of anterior rod-screw instrumentation and posterior pedicle screw instrumentation on sagittal balance in patients with Lenke type 5 adolescent idiopathic scoliosis (AIS).

SUMMARY OF BACKGROUND DATA: Lenke type 5 AIS is treated by anterior or posterior spinal fusion surgery. Most studies comparing anterior and posterior fusion surgery have focused on assessing improvement in coronal balance. Studies comparing the effects of anterior and posterior surgery on sagittal balance are lacking.

METHODS: The records of 49 patients diagnosed with Lenke type 5 AIS were examined. A total of 21 patients underwent anterior surgery between 2000 and 2003, while 26 underwent posterior surgery between 2004 and 2006. Preoperative, postoperative, and follow-up thoracic kyphosis (T5-T12 and T2-T12), lumbar lordosis, thoracolumbar junction kyphosis, and spinal vertical axis measurements were made by examining radiographs. Quality of life was assessed using the Scoliosis Research Society-22 questionnaire. All patients were followed up for at least 2 years.

RESULTS: There were no significant between group differences in coronal alignment, thoracic kyphosis, or T11-L2 alignment after surgery. Sagittal alignment improvement was significantly more pronounced in the anterior surgery group compared with the posterior surgery group. The fusion segment was also significantly shorter in the anterior surgery compared with the posterior surgery group. Quality of life scores were significantly higher in the anterior surgery group compared with the posterior surgery group.

CONCLUSION: Anterior solid rod-screw instrumentation results in shorter fusion segments, and better sagittal alignment and quality of life than posterior pedicle screw instrumentation in patients with Lenke type 5 AIS.